CN1729611A - Switching power supply circuit - Google Patents

Abstract

The present invention provides a wide-range-capable switching power supply circuit having a power-factor improvement function, wherein the number of converter parts has been reduced for the number of steps of rising order of secondary DC output voltages, thereby realizing cost-down, small-size and light-weight of circuit, and low power loss. A plurality of switching converters (101,102) are of a complex resonance type obtained by combining a partial resonance voltage circuit with a current resonance type prepared by half-bridge coupling method. A rectifier circuit is so configured as to serve, in accordance with a switching control, as a voltage doubler rectifier circuit when the AC voltage is smaller than 150 volts and as a full-wave rectifier circuit when the AC voltage is greater than 150 volts. The power-factor improvement is realized by using power-factor improvement transformers (VFT) to feed the output voltages of the converters back to the rectified current path, and further by using a rectifying diode to intermittently flow the rectified current, thereby enlarging the conduction angle of the AC input current. The control of the rising order of the secondary DC output voltages is performed by turning on and off, in accordance with an input of a predetermined rising signal, a DC switch circuit (6) inserted in the rectified current path.

Description

Switching power circuit

Technical field

The plasma display panel device that the present invention relates to switching power circuit and comprise described switching power circuit, wherein, described switching power circuit comprises the circuit that is used to improve power factor.

Background technology

In recent years, can bear the bigger high-frequency current and the switch element of voltage, therefore, industrial power be carried out rectification forms switching mode with the most of power circuits that obtain desired dc voltage power circuit owing to developed.

Switching power circuit reduces transformer and other device size by using high switching frequency, and is used as high power DC-DC converter, and is used as the power supply of various electronic equipments.

By the way, usually, if industrial power is carried out rectification, so, because the wave distortion of the electric current of the smoothing circuit of flowing through, the problem that therefore has the power factor of indication power utilization efficient to suffer a loss.

Further, need countermeasure to suppress the harmonic wave that is produced by the distorted waveform electric current.

Thereby, a kind of method that comprises so-called active filter is proposed, wherein, the code converter of rising progressively of PWM control type is set in the rectification circuit system, so that power factor is near 1 (for example with reference to Japanese patent laid-open Hei 6-327246 (Figure 11)).

The circuit diagram of Fig. 8 illustrates the basic configuration of above-mentioned this kind active filter.

With reference to Fig. 8, bridge rectifier Di is connected to industrial AC power supplies AC.Output capacitor Cout be parallel to bridge rectifier Di just/negative line.The rectification output of bridge rectifier Di offers output capacitor Cout, thereby, obtain dc voltage Vout, as the voltage at output capacitor Cout two ends.Provide dc voltage Vout to load 10, as input voltage, described load 10 for example is the DC-DC converter in the next stage.

For the configuration that is used to improve power factor, as shown in Figure 8, inductor L, high speed recovery type diode D, resistor R i, switch element Q and multiplier 11 are set.

Inductor L and diode D series connection is inserted between the positive electricity end of the cathode output end of bridge rectifier Di and output capacitor Cout.

Resistor R i is inserted between the negative pole end of the cathode output end (primary side ground connection) of bridge rectifier Di and output capacitor Cout.

Further, in the case,, use MOS-FET selectively, and as shown in Figure 8, switch element Q is inserted between inductor L and the diode D between the node and primary side ground connection for switch element Q.

Current detecting line LI and waveform incoming line Lw are connected to multiplier 11 as feed forward circuit, and voltage detecting line LV is connected to multiplier 11 as feedback circuit.

Multiplier 11 detects from the level of the rectified current of current detecting line LI input, and wherein, described rectified current flows to the cathode output end of bridge rectifier Di.

Further, multiplier 11 detects from the commutating voltage waveform at bridge rectifier Di cathode output end of waveform incoming line Lw input.This waveforms detection with industrial AC power supplies AC (ac input voltage) is the true corresponding of absolute value.

Further, multiplier 11 detections are from the variation difference of the dc voltage Vout of the output capacitor Cout of voltage detecting line LV input.In other words, multiplier 11 detects the variation difference of the DC input voltage that will be input to load 10.

Then, the drive signal that is used for driving switch element Q from multiplier 11 outputs.

The rectified current that flows to the cathode output end of bridge rectifier Di is input to multiplier 11 from current detecting line LI.Multiplier 11 detects from the rectified current level of current detecting line LI input.Further, multiplier 11 detections are from the variation difference of the dc voltage Vout (DC input voltage) of the output capacitor Cout of voltage detecting line LV input.And then multiplier 11 detects from the commutating voltage waveform at bridge rectifier Di cathode output end of waveform incoming line Lw input.

This waveforms detection with industrial AC power supplies AC (ac input voltage) is the true corresponding of absolute value.

At first, multiplier 11 makes the rectified current level that detects from current detecting line LI in a manner described take advantage of with the difference in change out-phase of the DC input voltage that detects from voltage detecting line LV.Then, multiplier 11 produces its waveform and the identical current instruction value of ac input voltage VAC waveform from multiplication result with the ac input voltage that detects from waveform incoming line Lw.

And then, multiplier 11 mutual more above-mentioned current instruction values and actual AC input current level (input based on current detecting line LI detects), and, according to described difference pwm signal is carried out PWM control, produce drive signal based on pwm signal.With drive signal switch element Q is carried out switch drive.As a result, control AC input current has the waveform identical with ac input voltage, and, improve power factor so that it is almost near 1.Further, in the case, because therefore the current instruction value that control multiplier 11 produces, also suppresses the variation of DC input voltage (Vout) so that its amplitude changes according to the variation difference of DC input voltage (Vout).

Fig. 9 (a) illustrates input voltage vin and the input current Iin that is input to active filter circuit shown in Figure 8.Input voltage vin is corresponding with the voltage waveform of exporting as the rectification of bridge rectifier Di, and input current Iin is corresponding with the current waveform of exporting as the rectification of bridge rectifier Di.Here, although the waveform of input current Iin has rectifier output voltage (voltage Vin) angle of flow that waveform is identical with bridge rectifier Di, this expression also has and the identical angle of flow of electric current I in waveform from the waveform that industrial AC power supplies AC flows to the AC input current of bridge rectifier Di.In other words, obtain power factor near 1.

Fig. 9 (b) illustrates and is input to output capacitor Cout and from the variation of energy (power) Pchg of its output.When input voltage vin when being high, output capacitor Cout accumulation energy, but when input voltage vin when low, output capacitor Cout emitted energy keeps flowing of output voltage thus.

Fig. 9 (c) illustrates the waveform of the charge/discharge current Ichg of output capacitor Cout.Have the phase place identical from charge/discharge current Ichg and find out that charge/discharge current Ichg is according to accumulation/firing operation of the energy Pchg of output capacitor Cout and mobile electric current with the waveform of I/O energy Pchg Fig. 9 (b).

Different with input voltage vin, charge/discharge current Ichg has the essentially identical waveform of second harmonic with AC line voltage (industrial AC power supplies AC).Shown in Fig. 9 (d), by energy the flowing to and flow out of output capacitor Cout, based on the second harmonic component of AC line voltage and produce ripple voltage Vdc.Ripple voltage Vdc have with Fig. 9 (c) shown in charge/discharge current Ichg differ 90 ° phase difference so that preserve invalid energy.Consider the high-frequency ripple electric current of the ripple current of handling second harmonic and booster converter switch and determine the rated value of output capacitor Cout, wherein, the booster converter switch is used for ripple current is modulated.

Figure 10 illustrates the profile instance of active filter, and wherein, active filter comprises Fig. 8 circuit arrangement as basic configuration, and further comprises the basic control circuit system.Should point out, represent with identical reference symbol with Fig. 8 components identical, and the descriptions thereof are omitted at this.

Between the positive terminal of the cathode output end of bridge rectifier Di and output capacitor Cout, switch pre-regulator 17 is set.Switch pre-regulator 17 is the parts that formed by switch element Q, inductor L, diode D etc. among Fig. 8.

Further, the control circuit system that comprises multiplier 11 further comprises voltage error signal amplifier 12, divider 13 and squarer 14.

Voltage error signal amplifier 12 is cut apart the dc voltage Vout of output capacitor Cout by voltage grading resistor Rvo-Rvd, and the voltage of cutting apart is input to the non--not gate input of operational amplifier 15.Reference voltage V ref is input to the not gate input of operational amplifier 15.The amplification coefficient that operational amplifier 15 utilizes feedback resistor Rv1 and capacitor Cv1 to determine, and amplify its level and the corresponding voltage of error between dc voltage Vout and the reference voltage V ref is cut apart in institute, and, export the voltage that obtains to divider 13, as error output voltage V vea.

Further, so-called feed-forward voltage Vff is input to squarer 14.Feed-forward voltage Vff is by input voltage vin being averaged the output (average input voltage) that obtains with average circuit 16 (Rf11, Rf12, Rf13, Cf11, Cf12).14 couples of feed-forward voltage Vff of squarer ask square, and the value that obtains to divider 13 outputs.

The error output voltage V vea of divider 13 usefulness voltage error signal amplifiers 12 is divided by the square value from the average input voltage of squarer 14 output, and to the signal of multiplier 11 outputs as result of division.

In brief, the system by squarer 14, divider 13 and multiplier 11 forms voltage circuit.Then, from the error output voltage V vea of voltage error signal amplifier 12 output the stage before multiply by rectification input signal Ivac by multiplier 11, divided by average input voltage (Vff) square.By this circuit, voltage circuit gain remains unchanged, be average input voltage (Vff) square, without any variation.Feed-forward voltage Vff has the function of the open loop correction that forward is presented in voltage circuit.

To of divider 13 outputs of multiplier 11 input dividers 13 by obtaining except that error output voltage V vea, and, by the rectification output (Iac) of resistor R vac to the cathode output end (rectification output line) of multiplier 11 input bridge rectifier Di.At this, rectification output is not expressed as voltage but is expressed as electric current (Iac).Multiplier 11 multiplies each other described input, produces and output current programming signal (multiplier output signal) Imo.This is corresponding with above current instruction value in conjunction with Fig. 8 description.The control output voltage Vout by the mean amplitude of tide that changes current programmed signal.Particularly, produce pwm signal according to the variation of the mean amplitude of tide of current programmed signal, and, utilize based on the drive signal of pwm signal and carry out switch drive, with the level of control output voltage Vout.

Correspondingly, current programmed signal has the mean amplitude of tide waveform that is used to control input voltage and output voltage.Should point out that active filter is control output voltage Vout not only, and the control input voltage vin.Then, owing to we can say that the current circuit in the feed forward circuit programmes with rectified line voltage, therefore, the input of the converter in the next stage (load) is become the resistive input.

Figure 11 illustrates the profile instance of power circuit, and wherein, the current resonance code converter is connected to the active filter with configuration shown in Figure 10, as next stage.Power circuit shown in Figure 11 prepares to be used for the ac input voltage of VAC=85V-288V.In brief, power circuit is the ready on a large scale type of what is called (global specifications) that preparation is used for the ac input voltage of AC 100V system and AC 200V system industry AC power supplies.Further, the power circuit bearing power preparing to be used for is 600W or bigger.Further, the configuration of current-resonance type converter using independent drive half-bridge coupled system.

Power circuit shown in Figure 11 is arranged in the display device such as television receiver and monitor apparatus, and wherein, that described display device comprises is popular in recent years, and the plasma display panel popularized.In other words, power circuit shown in Figure 11 provides working power to the internal circuit of display device (plasma display panel device), and wherein, described display device comprises aforesaid plasma display panel.

In the case, two common mode choke coil CMC, CMC and three cross-over connection capacitor CL are connected to industrial AC power supplies AC circuit with connectivity scenario shown in Figure 11, to be formed for the circuit noise filter of common-mode noise.

Further, in the case, the main switch SW that is inserted in the industrial AC power supplies AC circuit is shown, wherein, main switch SW is used for the activation power supply.

The electrode input end of two bridge rectifier Di1 and Di2 and negative input jointly be connected to respectively industrial AC power supplies AC just/the negative pole circuit.Further, the cathode output end of bridge rectifier Di1 and Di2 is connected to each other, and the cathode output end of bridge rectifier Di1 and Di2 (earth terminal) is connected to each other.In brief, in the case, for industrial AC power supplies AC provides the two-stage bridge rectifier.

Further, connect by mode shown in Figure 11 by a choking-winding LN and three filtering capacitors (film capacitor) CN, CN, CN and the general mode noise filter 4 that forms is connected between the cathode output end and cathode output end (primary side ground connection) of bridge rectifier Di1 and Di2.

Next stage at general mode noise filter 4 is provided with active filter circuit 8.

Active filter circuit 8 is based on above configuration in conjunction with Figure 10 description.Particularly, active filter circuit 8 comprises the code converter of rising progressively of PWM control type, and this converter is switching from carrying out between the rectification output of bridge rectifier Di1 and Di2 input.For example, form the above-mentioned code converter of rising progressively comprise switch element and control circuit system, wherein, control circuit system is according to the PWM control system and driving switch element.

Further, in order to handle for example bearing power Po=600W identical or bigger heavy duty condition, adopt the countermeasure of setting and a plurality of switch elements in parallel etc. with situation of the present invention.When load is heavy duty, be under 100V or the littler condition especially at ac input voltage VAC, the very high electric current switch element of flowing through.Therefore, a plurality of switch elements are in parallel in a manner described, thereby inhibition flows to the peak level of the switching current of each switching device.Thereby the reliability of active filter circuit 8 is enhanced.

At this moment, control circuit system comprises multiplier, divider, error voltage amplifier, pwm control circuit, is used for the drive circuit of output drive signal etc., and for example form single IC chip, wherein, described drive signal is used for the described switch element of switch drive.In IC, comprise and corresponding circuit block such as multiplier 11 shown in Figure 10, error voltage amplifier 12, divider 13, squarer 14 as control circuit system.And, feedback circuitry and feed forward circuit system are connected to IC chip as control circuit system by the above modes of describing in conjunction with Fig. 8 and 10, and, control and driving switch element by PWM based on the output of Circuits System feedback as the IC chip of control circuit system.

In active filter circuit 8, carry out the switch drive of switch element with above-mentioned configuration according to the drive signal of controlling based on PWM, thereby the angle of flow of rectification output current is basic identical with the above angle of flow that combines the rectifier output voltage waveforms that Fig. 8 and 10 describes.The angle of flow of the AC input current that the basic identical expression of the angle of flow of the angle of flow of rectification output current and rectifier output voltage waveform flows into from industrial AC power supplies AC and the angle of flow of ac input voltage VAC waveform are basic identical, the result, and the power controlling factor is near 1.In brief, realize the raising of power factor.In actual conditions, when bearing power Po=600W, obtain the characteristic of power factor PF ≈ 0.995.

Further, active filter circuit 8 shown in Figure 11 is also operated to such an extent that make the mean value (corresponding with the Vout among Figure 10) of rectification smooth voltage Ei be the fixed voltage in ac input voltage VAC=85V-288V scope.In brief, with the excursion of ac input voltage VAC=85V-264V irrespectively, provide the DC that is stabilized in 375V input voltage to the current resonance code converter of next stage.

The scope of ac input voltage VAC=85V-288V covers the AC 100V system and the AC 200V system of industrial AC power supplies continuously.Correspondingly, with industrial AC power supplies AC whether be 100V system or 200V system independence ground, the stable DC input voltage (Ei) of same level is provided to the switch converters of next stage.In brief, power circuit shown in Figure 11 also forms and prepares to be used for large-scale power circuit by being provided with source filter.

In the case, one group of three smmothing capacitor CiA, CiB and CiC are connected in series to active filter circuit 8 in next stage.

This group smmothing capacitor [CiA//CiB//CiC] is corresponding with the output capacitor Cout in Fig. 8 and 10.Correspondingly, in the case, the rectification smooth voltage Ei that obtains is the voltage at smmothing capacitor group [CiA//CiB//CiC] two ends of parallel connection.Rectification smooth voltage Ei offers the converter part 201,202 and 203 of next stage as the DC input voltage.Then, as mentioned above, in the case, the voltage (rectification smooth voltage Ei) at smmothing capacitor [CiA//CiB//CiC] two ends is stabilized in 375V.

Further, in power circuit shown in Figure 11, in order to handle above-mentioned heavy duty condition, a plurality of combination resonant converters are set, wherein, described combination resonant converter uses the DC input voltage of rectification smooth voltage Ei as operating voltage.The combination resonant converter refers to have the switch converters of following configuration at this: except the resonant circuit that makes the work of mode of resonance switch converters, also increase another resonant circuit in primary side or primary side, thereby a plurality of resonant circuits are work in combination in a switch converters.In Figure 11, the first converter part 201, the second converter part 202 and 203 3 combinations of the 3rd converter part resonant converter are set.Here, each combination resonant converter is formed by the primary side part voltage resonant circuit that is increased on the following current resonance code converter.

For example, the first converter part 201 comprises two switch element Q1 shown in Figure 11 and Q2, as its assembly.In the case, switch element Q1 is connected with the half-bridge connected mode with Q2, thereby switch element Q1 is as the high-end switch element, and switch element Q2 is as the low-end switch element, and switch element Q1 and Q2 are parallel to rectification smooth voltage Ei (DC input voltage).In brief, the first converter part 201 has the configuration of half-bridge coupled mode current resonance code converter.

Current resonance code converter in the case is the independent drive type, and corresponding, MOS-FET is used for switch element Q1 and Q2.Clamping diode DD1 and DD2 are parallel to switch element Q1 and Q2 respectively, thereby, form switching circuit.Clamping diode DD1 and DD2 form the path of reverse current flows when off switch element Q1 and Q2 respectively.

Control IC 2 comprises the oscillating circuit that is used for independent drive mode drive current resonant converter, control circuit, protective circuit etc.Control IC 2 is that portion has the analog IC (integrated circuit) of bipolar transistor within it.

Control IC 2 is to be input to the dc voltage work of power input Vcc.In the case, the rectification smooth voltage Ei through resistor R s input is input to power input Vcc.Further, grounding electrode E is directly connected to primary side ground connection.

Control IC 2 comprises two drive signal output VGH and VGL, as the terminal that is used for to switch element output drive signal (gate voltage).

Export the drive signal that is used for switch drive high-end switch element from drive signal output VGH, be used for another drive signal of switch drive low-end switch element from drive signal output VGL output.

In the case, drive signal output VGH is connected to the grid of high-end switch element Q1.Simultaneously, drive signal output VGL is connected to the grid of low-end switch element Q2.

As a result, be applied to the grid of switch element Q1 from the high-side driver signal of drive signal output VGH output, and, be applied to the grid of switch element Q2 from the low side drive signal of drive signal output VGL output.

Control IC 2 oscillating circuit internally produces the oscillator signal of required frequency.Then, the oscillator signal that control IC 2 utilizes oscillating circuit to produce, and produce high-side driver signal and another low side drive signal.Here, high-side driver signal and low side drive signal produce by the correlation with 180 ° of phase differences.Then, from drive signal output VGH output high-side driver signal, and, from drive signal output VGL output low side drive signal.

Because high-side driver signal and low side drive signal are applied to respectively on switch element Q1 and the Q2, therefore, in drive signal had the cycle of H level, the gate voltage of switch element Q1 or Q2 became and is equal to or higher than gate threshold, and switch element Q1 or Q2 place on-state.On the other hand, in drive signal had another cycle of L level, gate voltage became and is equal to or less than gate threshold, and switch element Q1 or Q2 place off-state.Thereby,, come described switch element Q1 of switch drive and Q2 with required switching frequency in the moment that switch element Q1 and Q2 replace on/off.

To the initiating signal Vt1 of the activated end Vt of control IC 2 input from microcomputer (not shown among Figure 11) output, wherein, described microcomputer is arranged in the equipment that comprises power circuit shown in Figure 11.

When initiating signal is imported, activate control IC 2, begin its operation.In brief, control IC 2 begins from drive signal output VGH and drive signal output VGL output drive signal.Correspondingly, the operation time started of first converter 201 is by determining the input time of the initiating signal Vt1 of control IC 2.

Be provided for the output of the switch of switch element Q1 and Q2 is sent to from primary side the insulation converter transformer PIT-1 of primary side.

The elementary winding N1 of insulation converter transformer PIT-1 is connected to the node (switch output point) of switch element Q1 and Q2 by primary side series resonance capacitor C1 in its end, and be connected to primary side ground connection in its other end.Here, the primary side series resonant circuit is formed by the electric capacity of primary side series resonance capacitor C1 and the leakage inductance (L1) of elementary winding N1.When the switch output of switch element Q1 and Q2 was provided to the primary side series resonant circuit, the primary side series resonant circuit was carried out resonant operation, thereby the switching circuit that is formed by current-resonance type switch element Q1 and Q2 is operated.

Partial resonance capacitor Cp is connected in parallel between drain electrode-source electrode of switch element Q2.The current detecting line LI of the electric capacity of partial resonance capacitor Cp and elementary winding N1 forms antiresonant circuit (part voltage resonant circuit) jointly.Then, obtain only when switch element Q1 and Q2 connection, just to take place the part voltage resonance operation of voltage resonance.

In this way, power circuit shown in Figure 11 has the form of combination resonant converter, and wherein, the resonant circuit that constitutes mode of resonance primary side switch converter combines with another resonant circuit.

On the primary side of insulation converter transformer PIT-1, twine two secondary winding N2a and N2b independently of each other, as secondary winding.

In the case, as shown in figure 11, secondary winding N2a has centre cap disposed thereon, wherein, centre cap is connected to primary side ground connection, and the full-wave rectifying circuit that is formed by rectifier diode Do1 and Do2 and smmothing capacitor Co1 is connected to secondary winding N2a.As a result, obtain primary side DC output voltage Eo1, Eo1 is the voltage at smmothing capacitor Co1 two ends.Primary side DC output voltage Eo1 offers unshowned load-side and is shunted, and, import as the detection voltage that is used for control circuit 1.

Voltage from the level of the primary side DC output voltage Eo1 of input to the control input end of control IC 2 Vc or electric current that control circuit 1 provides its level to regulate according to.For example, the frequency that control IC 2 is regulated oscillator signal according to the control output that is input to control input end Vc is to regulate the frequency of the drive signal that will export from drive signal output VGH and VGL.As a result, the switching frequency of control switch element Q1 and Q2 changeably, and because by-pass cock frequency in this way, therefore, the level of primary side DC output voltage Eo1 is controlled as fixing.In other words, execution is according to the stabilisation of switching frequency control method.

Further, in the case, circuit forms to such an extent that make primary side DC output voltage Eo1 shunting, to form primary side DC output voltage Eo and Eo2.

The Circuits System that is used to produce primary side DC output voltage Eo forms the formula converter that falls progressively, wherein, the control circuit 7 that connects switch element Q7, rectifier diode Dcn1, the choking-winding L1 that is used to remove high-frequency noise, the smmothing capacitor Co that forms by MOS-FET by mode shown in Figure 11 and be used to carry out PWM (pulse-width modulation) control.

Switch element Q7 switches primary side DC output voltage Eo1 by control circuit 7 switch drive, to obtain to exchange output.Carry out rectification and level and smooth by the half-wave rectifying circuit that choking-winding L1, rectifier diode Dcn1 and smmothing capacitor Co form to exchanging output, to produce primary side DC output voltage Eo, wherein, Eo is the voltage at smmothing capacitor Co two ends.

Here, control circuit 7 is carried out PWM control according to the level of primary side DC output voltage Eo.As a result, the switching manipulation of control switch element Q7, thus switching frequency is fixed according to the level of primary side DC output voltage Eo, and the connection cycle in a switch periods changes.Thereby the level of control primary side DC output voltage Eo is controlled as fixing.In other words, realize that primary side DC output voltage Eo's is stable.

And, the Circuits System that is used to produce primary side DC output voltage Eo2 forms the formula converter that falls progressively, wherein, to be connected switch element Q8, rectifier diode Dcn2, choking-winding L2, smmothing capacitor Co2 and the control circuit 7 that forms by MOS-FET with the similar connectivity scenario of the above-mentioned Circuits System that is used to produce primary side DC output voltage Eo1.

Correspondingly, equally in the case, obtain the primary side DC output voltage Eo2 by the PWM control stabilization of control circuit 7, Eo2 is the voltage at smmothing capacitor Co2 two ends.

At this moment, for secondary winding N2b, form the full-wave rectifying circuit that forms by bridge rectifier DBR and smmothing capacitor Co3, and, rectification by full-wave rectifying circuit smoothly obtains primary side DC output voltage Eo3, and Eo3 is the voltage at smmothing capacitor Co3 two ends.

The second converter part 202 has the configuration of combination resonant converter, wherein, by with the elementary winding N1 that is connected the switch element Q3 that connects with the half-bridge connected mode and Q4, clamping diode DD3 and DD4, partial resonance capacitor Cp, control IC 2, insulation converter transformer PIT-2 with the similar connectivity scenario of the above-mentioned first converter part 201 etc. and combination current resonant converter and primary side part voltage resonant circuit.

Further, the primary side of the second converter part 202 is connected to primary side ground connection at the centre cap of secondary winding N2, and, for secondary winding N2, form the full-wave rectifying circuit that comprises rectifier diode Do1 and Do2, smmothing capacitor Co4 and Co5 and be used for removing the resistor R 1 of denoising in mode shown in Figure 11.Thereby, producing primary side DC output voltage Eo4, Eo4 is the voltage at smmothing capacitor Co5 two ends.

Further, in the second converter part 202, owing to the switching frequency that control circuit 7 is carried out the primary side converter based on the level of the primary side rectification smooth voltage that obtains at smmothing capacitor Co4 two ends is controlled, therefore, realize that primary side DC output voltage Eo4's is stable.

Further, in the second converter part 202, be input to the activated end Vt of control IC 2 from the activation signal Vt3 of microcomputer output.

And, the 3rd converter part 203 has the configuration of combination resonant converter, wherein, by combination current resonant converter and primary side part voltage resonant circuit to be connected the switch element Q5 that connects with the half-bridge connected mode and Q6, clamping diode DD5 and DD6, partial resonance capacitor Cp, control IC 2, insulation converter transformer PIT-3 (elementary winding N1 and secondary winding N2), rectifier diode Do1 and Do2, smmothing capacitor Co6 and Co7 and resistor R 2 etc. with the similar connectivity scenario of the second converter part 202.

Further, be input to the activated end Vt of the control IC 2 of the 3rd converter part 203 from the activation signal Vt2 of microcomputer output.

In above-mentioned configuration, obtain 6 primary side DC output voltage Eo, Eo1-Eo5 from primary side.Primary side DC output voltage for example has application as follows and load standard.

Eo: logic power, 5V/6A-2A

Eo1: analog IC driving power, 12V/0.4A

Eo2: digital IC driving power, 3.3V/1.5A

Eo3: voice output power supply, 26V/1.3A-0.1A

Eo4: data power supply, 70V/2.5A-0.35A

Eo5: keep power supply, 200V/1.75A-0.1A

Further, the maximum load power that should prepare of single inverter part is:

The first converter part 201:75W

The second converter part 202:175W and

The 3rd converter part 203:350W

600W altogether.

Further, according to the maximum load power that above-mentioned converter part should be prepared, select the magnetic core of insulation converter transformer in the following manner:

PIT-1：EER-35

PIT-2：EER-40

PIT-3：EER-42

At this moment, the fall progressively choking-winding L11 of formula converter and L12 adopts the EE-25 ferrite core.

The power circuit that is arranged in the plasma display panel device is correspondingly exported a plurality of primary side DC output voltage Eo, Eo1-Eo5 with different loads condition shown in Figure 11 respectively.Further, especially in plasma display panel device, for ease of circuit arrangement, when activating power during with beginning DC input voltage (rectification smooth voltage Ei (375V)), primary side DC output voltage must be with predetermined order starting.

More specifically, at first start, then, start successively as the primary side DC output voltage Eo5 that keeps power supply with as the primary side DC output voltage Eo4 of data power supply as the primary side DC output voltage Eo of logic power.

Thereby in order to obtain this start up sequence of above-mentioned primary side DC output voltage, microcomputer is to the starting end Vt of the control IC 2 of converter part (201,202 and 203) output starting voltage Vt1, Vt2 and Vt3.Shown in the time diagram of Figure 12 by the control operation of the start up sequence of the primary side DC output voltage of starting voltage Vt1, Vt2 and Vt3.

Here, power circuit shown in Figure 11 has so-called main power source configuration, and, not shown stand-by power supply in Figure 11.Because microcomputer provides stand-by power supply, therefore, even main power source is not in state of activation, microcomputer can also be operated.

Then, if main switch SW switches to on-state so that activate circuit shown in Figure 11 from off-state, wherein, circuit shown in Figure 11 is a main power source, so, just provides industrial AC power supplies AC to this circuit, and obtains rectification smooth voltage Ei.Then, if Microcomputer Detecting is elevated to specified level (for example 375V) to rectification smooth voltage Ei, so, microcomputer just switches to the H level to initiating signal Vt1 from the L level at moment t1, and the initiating signal Vt1 of output H level.Thereby the control IC 2 that is transfused to the first converter part 201 of initiating signal Vt1 begins the switch drive operation at time t1.Then, as the response to this, the primary side DC output voltage Eo that obtains on the primary side of the first converter part 201 begins to raise from 0 level at time t1, and is elevated to specified level (5V) on the time point in certain hour cycle in the past.Subsequently, primary side DC output voltage Eo is by the constant voltage control operation of the formula converter that falls progressively and keep the stable state of 12V.

Should point out, confirm in description: all the other primary side DC output voltage Eo1, the Eo2 and the Eo3 that are produced by the first identical converter part 201 raise with the essentially identical moment of primary side DC output voltage Eo.

Then, activation signal Vt2 is set at: raise since time t1 as mentioned above until being elevated to specified level and keeping time t2 after stable at primary side DC output voltage Eo, activation signal Vt2 switches to the H level from the L level, and is output as the H level signal.

Thereby, activate the control IC of the 3rd converter part 203 at time t2.As the response to this, primary side DC output voltage Eo5 began to raise from 0 level in the time more late than time t2, and on the time point in certain hour cycle, primary side DC output voltage Eo5 is fixed as specified level (200V) in the past.

Further, the time t3 after primary side DC output voltage Eo5 places the stable state of specified level as mentioned above, microcomputer switches to the H level to activation signal Vt3 from the L level.As response to this, activate the control IC of the second converter part 202 at time t3, and, primary side DC output voltage Eo4 raises, thereby Eo4 begins after time t3 to raise from 0 level, and is fixed as specified level (70V) on the time point in certain hour cycle in the past.

In this way, the rising time of power circuit shown in Figure 11 control primary side DC output voltage, thereby, can obtain the suitable activation manipulation of power circuit.

Describe and can find out from the front, the power circuit shown in Figure 11 of correlation technique forms to have shown in Fig. 8 and 10 usually the active filter of known configurations as basic configuration.Further, under the situation of circuit shown in Figure 11, three combination resonant converters in parallel in the next stage of active filter.And then, in the combination resonant converter of the first converter part 201, be provided for obtaining the formula converter that falls progressively of primary side DC output voltage Eo and Eo2.

Adopt aforesaid configuration to realize the raising of power factor.Further, power circuit shown in Figure 11 is prepared to be used on a large scale so-called in the following manner, and it can be operated as industrial AC power supplies with AC 100V system and AC 200V system.Further, in conjunction with the formula converter that falls progressively of Circuits System of carrying out constant voltage control with method of controlling switch and the requirement that on primary side, is provided with, to realize the stable of primary side DC output voltage.

Yet the power circuit with configuration shown in Figure 11 has following problem.

((integrated value of η DC → DC) provides the DC-DC power conversion efficiency of η AC → DC) and next stage current resonance code converter (first, second and the 3rd converter part 201,202 and 203) power conversion efficiency of power circuit shown in Figure 11 by the AC-DC power conversion efficiency.

Here, first, second and the 3rd converter part 201,202 and 203 DC-DC power conversion efficiency (η DC → DC) be approximately 95%.

At this moment, when ac input voltage VAC=100V, (η AC → DC) is 93% to the AC-DC power conversion efficiency of active filter, and when ac input voltage VAC=230V, and (η AC → DC) is 95% to the AC-DC power conversion efficiency of active filter.

Correspondingly, when ac input voltage VAC=100V, the combined power conversion efficiency is:

93％×95％＝88.3％

And when ac input voltage VAC=230V, the combined power conversion efficiency is:

95％×95％＝90.2％

Correspondingly, when ac input voltage VAC=100V, the AC input power is 679.5W, and when ac input voltage VAC=230V, the AC input power is 665.2W.

In brief, the situation during with ac input voltage VAC=230V (AC 100V system) is compared, and when ac input voltage VAC=100V (AC 200V system), the conversion efficiency of active filter circuit side descends, and gross efficiency descends.

Further, must design circuit shown in Figure 11, (η AC → DC) for example remains the 94%-97% in ac input voltage VAC=100V-230V scope so that the AC-DC power conversion efficiency of active filter, thereby it is lower than the above-mentioned power conversion efficiency characteristic under bearing power Po=600W or bigger condition that this efficient can not become.

Further, though in active filter 8, carry out the switching manipulation of the formula converter of rising progressively,, because switching manipulation is depended on dv/di and di/dt and is the hard switching operation that therefore, the noise level of generation is very high.

Further, because three combination resonant converters and two formula converters that fall progressively are set in the next stage of active filter, therefore, their switching noise is higher, to such an extent as to can not ignore.Particularly because the formula converter that falls progressively is carried out the hard switching operation, therefore, the switching noise amount of generation is very big.On the contrary, although the combination resonant converter is carried out soft switching manipulation and the generation switching noise amount littler than hard-switching converter, owing to comprise three combination resonant converters in arranging, so the overall noise amount is very big too.From this consideration, need relatively effectively noise reduction measure.

Then, consider that from the necessity of describing power circuit shown in Figure 11 at first comprises two bridge rectifier Di1 and Di2 in the rectification circuit system that is used for industrial AC power supplies AC rectification.

Further, a plurality of power filter choking-windings must be set in active filter circuit 8.And then, for the semiconductor element that is used for switch, must a plurality of switch elements in parallel (transistor, diode etc.) and increase drive circuit, thereby, driving switch element suitably.Further, also must on semiconductor element, connect large-sized heating panel.

And then, in circuit shown in Figure 11,, form the circuit noise filter that comprises two common mode choke coils and three cross-over connection capacitors for the circuit of industrial AC power supplies AC.In brief, need two-stage or multistage circuit noise filter.

Further, the rectification outlet line is provided with by choking-winding LN and three general mode noise filters 4 that filtering capacitor CN forms.And then, in active filter circuit 8, also must be provided for the RC buffer circuit of switch element.Particularly under the situation of Figure 11 circuit in order to prepare to be used for heavy duty, the resistor that forms the RC buffer is the cement resistor device, and has large scale.

In this way, in side circuit, need be based on the noise reduction measure of very large amount parts, this causes increasing cost, and increases the erection space of power supply circuit board.

And then, in circuit shown in Figure 11, consider that three kinds of switch converters exist with hybrid mode.Particularly, they be in the active filter circuit 8 the formula of rising progressively converter, form the combination resonant converter of first to the 3rd converter part 201-203 and be increased to the formula converter that falls progressively on the first converter part 201.

In the case, though the switching frequency of the formula of the rising progressively converter in the active filter circuit 8 is 50KHz, the switching frequency of the combination resonant converter of first to the 3rd converter part 201-203 is in the scope of 70KHz-150KHz.Further, the formula converter that falls progressively of the first converter part 201 for example has the switching frequency of 100KHz.

Under the mutually different in this way situation of the switching frequency of switch converters, such problem is arranged: the ground potential of primary side and primary side interferes with each other, and it is unstable that the processing ease of power circuit becomes.

Further, power circuit shown in Figure 11 is configured to comprise that each is three converter parts 201,202 and 203 of combination resonant converter.This is for the following fact: as describing ground in conjunction with Figure 12, in the case, must control primary side DC rise of output voltage constantly in the three phases of time t1, t2 and t3.

In brief, the output initiating signal is as the signal that is used to activate control IC 2 (activation control signal).Correspondingly, in order to implement the starting sequence with time t1 shown in Figure 12, t2 and the corresponding primary side DC output voltage of t3, correspondingly need three control IC that activate according to starting voltage Vt1, Vt2 and Vt3.Thereby, with three control IC 2 three combination resonant converters are set correspondingly, and, the primary side DC output voltages that will produce by three combination resonant converters distributed according to the order of required starting sequence.

Yet, for the configuration of starting primary side DC output voltage in the above described manner successively, need with initiating signal quantity control corresponding IC quantity, and correspondingly, need with the corresponding converter partial amt of initiating signal quantity.In brief, this means:, also need to increase the quantity of converter part for the progression of the starting sequence of response primary side DC output voltage increases.

This causes following shortcoming: increase if attempt to handle the progression of the starting sequence of primary side DC output voltage, so, the quantity of converter part just only increases for this reason, as a result, the converter component count partly with beginnings such as control IC, insulation converter transformer PIT, switch elements increases above essential quantity.This kind increase of converter partial amt is not preferred, because it causes the size of power supply circuit board and weight to increase.Further, when converter partly increases, the also corresponding increase of the switching loss of primary side switch element, this also is disadvantageous for power conversion efficiency.

Summary of the invention

Thereby, according to the present invention, consider above-mentioned theme, switching power circuit disposes in the following manner.

Particularly, switching power circuit of the present invention receives the industrial AC power supplies of input, to produce the rectification smooth voltage, and, switching power circuit of the present invention comprises rectification smooth and a plurality of switch converters part, wherein, the rectification smooth can be operated according to the level of the industrial AC power supplies of import, be used between isobaric rectification operation and voltage multiplying rectifier operation, carrying out and switch, wherein, isobaric rectification operation is used to produce the rectification smooth voltage that its level equals industrial AC power supplies, the voltage multiplying rectifier operation is used to produce the rectification smooth voltage that its level equals twice industry AC power supplies, and a plurality of switch converters partly are used to receive and operate the rectification smooth voltage as the DC input voltage.

Each of a plurality of switch converters part all comprises and is used to receive the DC input voltage with the switch sections of carrying out switching manipulation and the switch drive part that is used for the switch drive switch element, wherein, described switch sections is formed by the high-end switch element and the low-end switch element that connect with the half-bridge type of attachment.

Each of a plurality of switch converters parts all further comprises by twining the insulation converter transformer that at least one elementary winding and secondary winding form, wherein, the switch output that provides the switching manipulation by switch sections to obtain to described elementary winding, encourage alternating voltage in described secondary winding, described alternating voltage is as the switch output that obtains in the elementary winding.

Each of a plurality of switch converters parts all further comprises: the primary side series resonant circuit, described primary side series resonant circuit is formed by the leakage inductance component of the elementary winding of insulation converter transformer and the electric capacity that is connected in series to the primary side series resonance capacitor of elementary winding at least, is used to carry out the operation of current-resonance type switch sections; And primary side part voltage resonant circuit, described primary side part voltage resonant circuit is formed by the leakage inductance component of the elementary winding of the electric capacity of the part voltage resonance capacitor that is parallel to one of two switch elements and the converter transformer that insulate, wherein, each all forms the half-bridge connection described switch element, and only each moment that switches on and off according to each switch element obtains the voltage resonance operation of primary side part voltage resonant circuit.

Each of a plurality of switch converters parts comprises further that all the DC output voltage produces part, described DC output voltage produces the primary side AC voltage that partly is used to receive by the secondary winding acquisition of insulation converter transformer, and the rectification operation of the execution primary side AC voltage that receives, to produce a plurality of primary side DC output voltages.

Each of a plurality of switch converters parts all further comprises frequency-control-type fixed voltage control section, described frequency-control-type fixed voltage control section is according to required one level of a plurality of primary side DC output voltages and the control switch drive part, change the switching frequency of switch sections, a required primary side DC output voltage is carried out fixed voltage control.

Each of a plurality of switch converters part all further comprises: be the inductance control type fixed voltage control section of each setting of required a plurality of primary side DC output voltages, wherein, except a required primary side DC output voltage, required a plurality of primary side DC output voltage is required it is fixed voltage, the target of the fixed voltage control that a required primary side DC output voltage is described frequency-control-type fixed voltage control section, described inductance control type fixed voltage control section is configured to: the controlled winding as the control transformer of saturable reactor form is inserted into the primary side rectified current path that is used for producing primary side DC output voltage, described control transformer has control winding and winding controlled winding thereon, and, the Control current level that will offer the control winding changes according to the primary side DC output-voltage levels of importing, to change the inductance of controlled winding, thus primary side DC output voltage is carried out fixed voltage control.

Each of a plurality of switch converters parts all further comprises the switch sections that is used to operate, described switch sections is the moment after the scheduled time in the past after predetermined primary side DC output voltage raises, and the primary side rectified current path that is used to produce another predetermined primary side DC output voltage is switched to on-state from off-state

Each of a plurality of switch converters parts all further comprises the power factor raising circuit that is used to improve power factor.Power factor improves circuit and comprises that power factor improves transformer and is inserted into rectifier cell in the desired location of rectified current path, wherein, described power factor improves transformer and is inserted into power factor in the primary side series resonant circuit and improves elementary winding and be inserted into power factor in the rectified current path and improve secondary winding and form by twining series connection, described rectified current path forms the rectification smooth, improve elementary winding by power factor, based on improving the driving voltage that encourages in the secondary winding and carry out switching manipulation, to interrupt rectified current in power factor.

Switching power circuit of the present invention with above-mentioned configuration comprises a plurality of switch converters parts that receive and operate rectification smooth voltage (DC input voltage), so that prepare to be used for the heavy duty condition.

Each switch converters partly has following configuration: the part voltage resonant circuit combines with half-bridge connecting-type current resonance code converter.

At this moment, improve for power factor, rely on following configuration and improve power factor: improve the switched voltage output of transformer to rectified current path feedback combination resonant converter by power factor with loose coupling, and, interrupt rectified current by rectifier diode, enlarge the angle of flow of AC input current thus, improve to realize power factor.

Then, in order to allow switching power circuit to be used on a large scale, according to industrial AC power supplies level, the rectification operation of carrying out the rectification smooth between isobaric rectification operation and voltage multiplying rectifier operation is switched, wherein, described rectification smooth is used to produce rectification smooth voltage (DC input voltage).

Thereby, for example,,, so, just needn't be provided for stablizing the active filter of DC input voltage to switch converters for use on a large scale if attempt power circuit is configured to for example comprise that power factor improves circuit.

Further, switch sections primary side rectified current path when off-state switches to on-state, this operation is the operation that the primary side DC output voltage that primary side rectified current path produces is elevated to specified level from the zero level state.The moment execution of the scheduled time in the past makes primary side rectified current path switch to the operation of on-state from off-state after the predetermined rising in a plurality of primary side DC output voltages.In other words, might in control starting constantly, start a plurality of primary side dc voltages successively.

From then on find out that the present invention adopts following configuration: the switching power circuit on a large scale that comprises power factor raising function does not include source filter.Thereby switching power circuit has following effect: compare with the alternative situations of for example attempting to improve by active filter power factor, the power conversion efficiency of switching power circuit of the present invention improves.

Further, switching power circuit of the present invention does not need to be used to dispose a large amount of element of source filter.Further, carry out soft switching manipulation and significantly reduce switching noise because the current resonance code converter of configuration power circuit and power factor improve circuit, therefore, also unnecessary enhancing noise filter.

Thereby when comparing with correlation technique, number of components obviously reduces, thereby, can expect that the size/weight of power circuit reduces.And, reduce cost equally.

Though switching power circuit according to the present invention is used in particular for the heavy duty condition, owing to be used for the more substantial parts of heavy duty active filter requirement, therefore, reduce size and weight and reduce the effect of circuit cost very effective.

And then, because therefore the cancellation active filter, eliminates in the interference between the ground potential on primary side and the primary side quiet earth electromotive force, and enhancing reliability.

Further, in order to be embodied as the start up sequence of a plurality of primary side DC output voltage regulations, correlation technique is configured to activate with initiating signal the control IC (switch drive part) of single switch converter part.Thereby the progression that correlation technique requires to be provided with the primary side DC output voltage that will start is the corresponding many switch converters parts of initiating signal (activation control signal) quantity.

On the contrary, according to the present invention, switching power circuit comprises switch sections, makes to start a plurality of primary side dc voltages successively in control starting constantly.Thereby, many switch converters parts that unnecessary setting equates with the progression of the primary side DC output voltage that will start, and, in case of necessity, compare with correlation technique, can reduce the quantity of switch converters part.And, can expect that the quantity of element reduces by doing like this, and cause size and weight to reduce and reduce cost, and, owing to reduce the quantity of switch converters part, can expect that switching loss reduces.

Description of drawings

Fig. 1 is the block diagram that illustrates as the profile instance of the plasma display panel device of the embodiment of the invention;

Fig. 2 is the circuit diagram that illustrates as the profile instance of the switching power circuit of first embodiment of the invention;

Fig. 3 (a) and 3 (b) illustrate driving constantly the oscillogram of the control IC of described embodiment to switch element;

Fig. 4 is the cutaway view that the structure example of loosely coupled transformer is shown;

The time diagram that Fig. 5 (a) and 5 (b) control for the starting that primary side DC output voltage among first embodiment is shown;

Fig. 6 is the circuit diagram that illustrates as the profile instance of the switching power circuit of second embodiment of the invention;

The time diagram that Fig. 7 (a) and 7 (b) control for the starting that primary side DC output voltage among second embodiment is shown;

Fig. 8 is the circuit diagram that the basic circuit configuration of correlation technique active filter is shown;

Fig. 9 (a)-9 (d) is the oscillogram that the operation of active filter shown in Figure 11 is shown;

Figure 10 is the circuit diagram of configuration that the control circuit system of active filter is shown;

Figure 11 is the circuit diagram of profile instance that the power circuit that includes source filter of correlation technique is shown; And

The time diagram that Figure 12 (a) and 12 (b) control for the starting that primary side DC output voltage in the power circuit shown in Figure 11 is shown.

Embodiment

Fig. 1 illustrates and disposes as the internal configurations example of the plasma display panel device of the switching power circuit of the embodiment of the invention and the relation between power unit and the functional circuit part.

From the viewpoint of relation between power unit and the functional circuit part, can think to form by switching power circuit 11, plasma display panel part 12 and television receiving function part 13 as plasma display panel device embodiment illustrated in fig. 1 10.

As can be seen from Figure 1, switching power circuit 11 receives the industrial AC power supplies AC of input, carry out switching manipulation by following mode, according to predetermined loading condition output dc voltage Eo, Eo1, Eo2, Eo3, Eo4 and Eo5, as the working power that is used for plasma display panel part 12 and television receiving function part 13.

By the way, switching power circuit 11 is corresponding in conjunction with Fig. 2 and the 6 present embodiment switching power circuits of describing with the back, and, obtain DC supply voltage Eo, Eo1, Eo2, Eo3, Eo4 and Eo5, as the primary side DC output voltage on the present embodiment switching power circuit primary side.Correspondingly, block configuration shown in Figure 1 is the common configurations of aftermentioned first and second embodiment.

Plasma display panel part 12 is the parts that comprise as the display unit and the displayed image of plasma display system.

For the displaying principle of plasma display system, for example, confining gas in the space that between two glass substrates of arranging with relativeness, forms, and gas applied voltage to cause vacuum discharge.As a result, in the space between glass substrate, gas is ionized and is plasma state, and the emission ultraviolet ray.Here, if form fluorescent material layer in the space between glass substrate, so, when ultraviolet irradiation is to fluorescent material layer, just launch the visible light of predetermined color from fluorescent material layer.If form to such an extent that make each display unit that for example forms obtain above-mentioned Discharge illuminating phenomenon with three kinds of color R, G and the corresponding fluorescent material of B, just can realize COLOUR IMAGE VISUALIZATION OF HE with matrix form.

Further, for driving a kind of method that above-mentioned this kind plasma display panel device shows, know subfield method.

Subfield method is a kind of driving method, wherein, and to the light period of each subdomain control display unit, with the gray scale (brightness) that shows each display unit.Further, show in this way that when carrying out line scanning, the data wire of these display units is driven luminous at every turn in order to drive display unit, and, apply in the cycle at each subdomain and to keep pulse.So, when control forms the gray scale of display unit R, the G of a pixel and B, not only carry out the gray balance of whole screen, and carry out the color rendering of each pixel.In brief, can show chromatic image.

Internal structure example for plasma display panel part 12, comprise display panel part, the data drive circuit of arranging display unit on it and be used to apply the pulse driving circuit of keeping of keeping pulse, wherein, described data drive circuit by subfield method according to the pictorial data that is used to carry out demonstration and driving data lines.Further, plasma display panel part 12 comprises the control section that is used to control its operation control.Control section is carried out the various controls relevant with the visual display operation of plasma display panel part 12.For example, control section determines to use any subdomain pattern according to the pictorial data of input, and based on the subdomain pattern of determining and the control data drive circuit is operated with the driving of keeping pulse driving circuit.Further, for the enhancing and the power consumption of the picture quality of realizing displayed image in mode well-known in the art reduces, execution is called the brilliance control of PLE (peak brightness enhancing) control, and simultaneously, control section is also carried out the arithmetical operation that is used for processes such as PLE control and handled.

In the case, plasma display panel device 10 also comprises as the function that is used to receive and show the television receiver of television broadcasting.In brief, plasma display panel device 10 function that has from received broadcast electric wave select target channel and the vision signal/audio signal of this channel is carried out demodulation.Television receiving function part 13 is the functional circuit parts that are used for described function.

Thereby, television receiving function part 13 comprise the tuner (front end) that is used for receiving and selects the predetermined kind broadcasting wave type of earthwave or satellite broadcasting (for example for), tuner receive and select signal to vision signal/audio signal carry out demodulation decoder, or the like.

Television receiving function part 13 is carried out the resulting vision signal of demodulation process and is converted to video signal data, and is input to plasma display panel part 12.As a result, plasma display panel part 12 is carried out the image demonstration of television broadcasting.At this moment, demodulated audio signal is input to the audio signal output Circuits System that is arranged in the identical television receiving function part 13, thereby, it for example from output such as loud speaker as sound.

In the case, obtain 6 DC supply voltage Eo, Eo1, Eo2, Eo3, Eo4 and Eo5 from switching power circuit 11 in the above described manner, simultaneously, utilize described dc voltage, as the supply voltage of preparing to be used for following loading condition.

At first, from 6 DC supply voltage Eo, Eo1, Eo2, Eo3, Eo4 and Eo5, provide DC supply voltage Eo, Eo4 and Eo5 to plasma display panel part 12.

Because DC output voltage Eo is known as logic power, therefore, it provides to the power supply as the IC of the control circuit of plasma display panel part 12 grades.

At this moment, DC supply voltage Eo4 is called the data power supply, and provides the power supply to data line drive circuit, and wherein, described data line drive circuit is used for driving data lines.

DC supply voltage Eo5 is called and keeps power supply, and as allowing the above-mentioned power supply of keeping pulse of output.In brief, DC supply voltage Eo5 provides to the power supply of keeping pulse driving circuit.

Remaining DC supply voltage Eo1, Eo2 and Eo3 offer television receiving function part 13.DC supply voltage Eo1 is called the analog IC driving power, and as the power supply that is used for IC (integrated circuit), described IC for example comprises tuner etc.In recent years, the signal that television receiver tends to for example institute be received and selects is carried out demodulation process, and carry out various video/audio signals by Digital Signal Processing and handle, and television receiver comprises the IC of the digital signal processor that is used to carry out Digital Signal Processing etc.Television receiving function part 13 also comprises the digital IC that has just described, and DC supply voltage Eo2 provides the power supply to digital IC.In other words, DC supply voltage Eo2 is as digital IC driving power.

DC supply voltage Eo3 is called the audio frequency out-put supply, and provides the power supply to the audio output circuit system, and wherein, this system is used for output audio signal.

Fig. 2 illustrates the profile instance of the switching power circuit of first embodiment of the invention, and this switching power circuit is the switching power circuit that can be applicable to switching power circuit 11 shown in Figure 1.Power circuit shown in Figure 2 adopts and can be used for bearing power Po=600W or configuration bigger and that can operate in the AC of industrial AC power supplies 100V system and AC 200V system, thereby this power circuit is applicable on a large scale.

Particularly, have so-called global specifications, thereby it can be worked in the zone of the AC of industrial power 100V system in as the zone of Japan and the U.S. and AC 200V system such as Europe according to the plasma display panel device 10 of present embodiment.Further, the power standard of whole plasma display panel device is generally 600W or bigger.

In power circuit shown in Figure 2, for industrial AC power supplies AC is provided with by a common mode choke coil CMC and two line filters that cross-over connection capacitor CL forms.In other words, in the case, a circuit noise filter that is used to remove common-mode noise only is set.

Further, choking-winding LN, LN in series be inserted into respectively circuit noise filter next stage industrial AC power supplies AC just/the negative pole circuit in.At the filtering capacitor CN//CN that is connected two parallel connections between electrode input end/negative input of choking-winding LN, LN and bridge rectifier Di between the node.

General mode noise filter 4 is formed by choking-winding LN, LN and filtering capacitor CN//CN, and is suppressed at the general mode noise that produces in the rectified current path of industrial AC power supplies.General mode noise filter 4 forms the part that power factor improves circuit 3.

The power circuit of present embodiment has following configuration: form to such an extent that comprise that the power factor raising circuit 3 of rectification circuit system is connected to industrial AC power supplies AC.As shown in FIG., power factor raising circuit 3 comprises bridge rectifier Di, smmothing capacitor Ci1, Ci1, Ci2, Ci2, filtering capacitor CN//CN and loosely coupled transformer (power factor raising transformer) VFT-1 and VFT-2.With the first converter part 101 loosely coupled transformer VFT-1 is set correspondingly, and, with the second converter part 102 loosely coupled transformer VFT-2 is set correspondingly.

The electrode input end of bridge rectifier Di is connected to the anodal circuit of industrial AC power supplies AC by the negative pole connecting circuit of the secondary winding YN12 of loosely coupled transformer VFT-1 and VFT-2.At this moment, the negative input of bridge rectifier Di is connected to the negative pole circuit of industrial AC power supplies AC.

The cathode output end of bridge rectifier Di is connected to the side of the positive electrode of the smoothing circuit that is formed by smmothing capacitor Ci1, Ci1, Ci2, Ci2.Further, the cathode output end of bridge rectifier Di is connected to primary side ground connection.

In the case, the smoothing circuit that is formed by smmothing capacitor Ci1, Ci1, Ci2, Ci2 forms in the following manner.Particularly, be connected in parallel two series circuits of smmothing capacitor Ci1-Ci2.

The positive terminal that is in the smmothing capacitor Ci1//Ci1 of relation in parallel is connected to the cathode output end of bridge rectifier Di.Node between the positive terminal of the negative pole end of smmothing capacitor Ci1//Ci1 and smmothing capacitor Ci2//Ci2 is connected to the negative input of bridge rectifier Di by relay switch S.Relay switch S connects/closes according to the driving condition that is connected to the relay R L of rectification circuit handover module 5.

Rectification circuit handover module 5 is set to drive relay R L, so that between AC 100V system and AC 200V system, switch operation by the rectification circuit system of above-mentioned formation.For this reason, by diode D10 and capacitor C10 industrial AC power supplies AC is carried out the dc voltage that halfwave rectifier obtains and be input to test side T14, as detecting voltage.Show variation from the dc voltage level of test side T14 input according to the level of industrial AC power supplies AC (ac input voltage VAC).In brief, rectification circuit handover module 5 detects the level of rectification smooth voltage Ei, detects the level of industrial AC power supplies AC.

Relay R L is connected between relay drive end T12 and the T13.Should point out that relay R L is according to the conducting state of relay R L self and the on/off of control relay switch S.Should point out that at this when relay R L was in conducting state, relay switch S connected, when relay R L was in nonconducting state, relay switch S disconnected.

At this moment, terminal T15 is used to make the ground connection of rectification circuit handover module 5 to primary side ground connection.

The handover operation of rectification circuit system with above-mentioned configuration is as follows.

Rectification circuit handover module 5 relatively is input to the level and predetermined reference voltage of the ac input voltage VAC of test side T14.When ac input voltage VAC is VAC=150V or when bigger, the voltage level that is input to test side T14 is equal to or greater than reference voltage, and when ac input voltage VAC was lower than 150V, the voltage level that is input to test side T14 was lower than reference voltage.In other words, reference voltage has the corresponding level with ac input voltage VAC=150V.

Then, rectification circuit handover module 5 drives relay R L in the following manner: when the level of the dc voltage of importing was lower than reference voltage, relay R L connected, and when the level of the dc voltage of importing was equal to or greater than reference voltage, relay R L disconnected.

For example suppose at this: correspondingly import and ac input voltage VAC=150V or bigger corresponding level with AC 200V system.

In the case, owing to the voltage level that is input to test side T14 is higher than reference voltage, therefore, rectification circuit handover module 5 disconnects relay R L.As the response to this, relay switch S1 also disconnects (opening).

When relay switch S1 is in off-state, operate as follows: ac input voltage VAC be just/negative two cycles in, with bridge rectifier Di ac input voltage VAC is carried out rectification, rectified current is injected in each parallel circuits of organizing two groups of smmothing capacitors [Ci1-Ci2] // [Ci1-Ci2] that all connects.This is the rectification operation that comprises the common full-wave rectifying circuit of bridge rectifier.As a result, obtain to equal the rectification smooth voltage Ei of ac input voltage VAC, as the voltage at the smoothing circuit two ends that form by smmothing capacitor [Ci1-Ci2] // [Ci1-Ci2].

On the contrary, suppose: correspondingly produce its level with AC 100V system and voltage is lower than the corresponding rectification smooth voltage of ac input voltage VAC=150V Ei.

In the case, owing to be input to voltage level lower and rectification circuit handover module 5 driving relay R L connections than reference voltage of test side T14, therefore, control relay switch S 1 is connected (closure).

When relay switch S1 is in on-state, in ac input voltage VAC is positive cycle, form following rectified current path, along this path, the rectification of bridge rectifier Di output only is used for the parallel circuits of smmothing capacitor Ci1//Ci1 is charged.On the other hand, ac input voltage VAC for another negative cycle in, form another rectification path, along this path, the rectification of bridge rectifier Di output only is used for the parallel circuits of smmothing capacitor Ci2//Ci2 is charged.

Owing to carry out rectification operation in this way, therefore, produce the level that equates with ac input voltage VAC, as the voltage at the antiresonant circuit two ends of smmothing capacitor Ci1//Ci1 and Ci2//Ci2.Correspondingly, obtain to equal the level of twice ac input voltage VAC, as the voltage at the parallel circuits two ends of smmothing capacitor Ci1//Ci1 and Ci2//Ci2.In other words, form so-called voltage doubling rectifing circuit.

In this way, when industrial AC power supplies AC is AC 100V system, circuit shown in Figure 2 is carried out the voltage multiplying rectifier operation, equal the rectification smooth voltage Ei of twice ac input voltage VAC with generation, but, when industrial AC power supplies AC was AC 200V system, circuit shown in Figure 2 was for example carried out isobaric rectification operation by full-wave rectifying circuit, equaled the rectification smooth voltage Ei of ac input voltage VAC with generation.In other words, with industrial AC power supplies AC be AC100V system or AC 200V system independence ground, obtain the rectification smooth voltage Ei of same level, and this can be used on a large scale circuit shown in Figure 2.To the switch converters input rectifying smooth voltage Ei of next stage, as the DC input voltage.

Should point out, switch, so, just might for example utilize the parallel circuits of smmothing capacitor Ci1-Ci2 if only attempt between voltage multiplying rectifier operation and full-wave rectification operation, to carry out.

In this embodiment, two of smmothing capacitor Ci1-Ci2 reasons that parallel circuits is connected in parallel are this embodiment power circuit prepares to be used for bearing power Po=600W or bigger fully loaded transportation condition.Along with loading condition becomes heavier, the electric current that flows in the capacitor that is used to form smoothing circuit in the rectification circuit system increases.Thereby under the situation of smmothing capacitor equally in parallel, the rectified current that flows to smmothing capacitor is branched in embodiment therewith.In brief, suppress to flow to the current level of a smmothing capacitor, and, the burden on each smmothing capacitor reduced.

Should point out, form comprise above-mentioned rectification circuit system the present embodiment power factor power factor that improves circuit 3 improve to operate in and describe below.

Circuit shown in Figure 2 comprises two switch converters, promptly, the first converter part 101 shown in Figure 2 and the second converter part 102, described two switch converters receive the above-mentioned DC input voltage (rectification smooth voltage Ei) of input, and this voltage is the voltage at smoothing circuit (smmothing capacitor [Ci1-Ci2] // [Ci1-Ci2]) two ends.The first converter part 101 and the second converter part 102 are parallel-connected to DC input voltage (rectification smooth voltage Ei) mutually.

Further, the first converter part 101 and the second converter part 102 have combination mode of resonance Capacitor Allocation respectively, wherein, except independent drive semi-bridge type current resonance code converter, described combination mode of resonance capacitor also comprises primary side part voltage resonant circuit.Further, the first converter part 101 and the second converter part 102 also are configured to them and comprise loosely coupled transformer VFT-1 and VFT-2, and the power factor that described transformer forms the Voltage Feedback type improves circuit 3, improve to realize power factor.

At this, the configuration of the first converter part 101 is described.

The first converter part 101 has the basic configuration of above-mentioned current resonance code converter.Further, as shown in Figure 2, each all is that two switch element Q1 (high-end) of MOS-FET form are connected by half-bridge shown in Figure 2 with Q2 (low side) and are connected to each other.Adopt the switch element Q1 of half-bridge connection and the circuit of Q2 to be parallel to rectification smooth voltage Ei.

Further, damper diode DD1 and DD2 are connected in parallel between drain electrode-source electrode of switch element Q1 and Q2 with direction shown in Figure 2.

Partial resonance capacitor Cp is connected in parallel between drain electrode-source electrode of switch element Q2.The electric capacity of partial resonance capacitor Cp and the leakage inductance L2 of elementary winding N1 form antiresonant circuit (part voltage resonant circuit) together.Then, obtain only when switch element Q1 and Q2 connection, just to take place the part voltage resonance operation of voltage resonance.

Control IC 2 comprises with the oscillating circuit of independent drive mode drive current resonant converter and control circuit, protective circuit etc., and forms the general-purpose simulation IC (integrated circuit) comprising bipolar transistor.Control IC 2 is carried out work with the dc voltage that is input to power input Vcc.In the case, rectification smooth voltage Ei is input to power input Vcc by resistor R s.

Further, control IC 2 is grounding to primary side ground connection by earth terminal E.

Further, control IC 2 comprises two drive signal output VGH and VGL, and described drive signal output VGH and VGL are the terminals that is used for to switch element output drive signal (signal).

Export the drive signal that is used for switch drive high-end switch element from drive signal output VGH, and, another drive signal that is used for switch drive low-end switch element exported from drive signal output VGL.

In the case, be applied to the grid of high-end switch element Q1 from the drive signal of drive signal output VGH output.Simultaneously, be applied to the grid of low-end switch element Q2 from the drive signal of drive signal output VGL output.

Further, although not shown in Figure 2, boostrap circuit is set as the outer setting circuit that is used for control IC 2.From the high-side driver signal of drive signal output VGH output is the level that is offset by boostrap circuit, thereby this signal has the suitably level of driving switch element Q1.

In control IC 2, the oscillator signal of required frequency is produced by the oscillating circuit in the control IC 2.Should point out the frequency that oscillating circuit is regulated oscillator signal according to the level of the control output that is input to aftermentioned terminal Vc from control circuit 1.

Thereby the oscillator signal that control IC 2 utilizes oscillating circuit to produce produces high-side driver signal and another low side drive signal.From drive signal output VGH output high-side driver signal, and, from drive signal output VGL output low side drive signal.

According to above description, the high-side driver signal of exporting from drive signal output VGH is applied to switch element Q1.As a result, obtain the grid-source voltage VGH1 of switch element Q1 with the waveform that is suitable for the high-side driver signal.

In brief, shown in Fig. 3 (a), in a switch periods, obtain to produce the cycle of positive polarity square wave pulse and another cycle that produces 0V.

Then, utilize grid-source voltage VGH1 shown in Fig. 3 (a), in a switch periods, obtain the moment of positive polarity square wave pulse, at first switch element Q1 is placed on-state.Particularly, for switch element Q1 is placed on-state, must apply the suitable level voltage that is equal to or greater than threshold voltage of the grid ( 5V).Owing to be set at 10V as the grid-source voltage VGH1 of above-mentioned positive pulse, therefore, with the cycle that applies positive pulse correspondingly, obtain the state that switch element Q1 connects.Then, when grid-source voltage VGH1 became 0V and is lower than threshold voltage of the grid, switch element Q1 switched to off-state.Switch element Q1 is by carrying out switching manipulation in this above-mentioned moment on/off.

On the other hand, the low side drive signal from drive signal output VGL output is applied to switch element Q2.For responding this drive signal, obtain to have the grid-source voltage VGL1 of the switch element Q2 of waveform shown in Fig. 3 (b).

Particularly, grid-source voltage VGL1 has the identical waveform of grid-source voltage VGH1 with switch element Q1 shown in Fig. 3 (a), and still, for timing, grid-source voltage VGL1 and grid-source voltage VGH1 have 180 ° phase difference.From this, switch element Q2 replaces the moment of on/off by switch drive at switch element Q1.

According to (a) of Fig. 3 and (b), after cut-off switch element Q1 the cycle till connecting switch element Q2 with cut-off switch element Q2 after between another cycle till the connection switch element Q1 formation cycle td.

Cycle td is the dead time that switch element Q1 and Q2 disconnect.Formation is in order to obtain charging and the discharge operation of partial resonance capacitor Cp really in the short period between the time of switch element Q1 and Q2 on/off as the cycle td of dead time, and described charging and discharge operation are the operations of part voltage resonance.The time span of cycle td for example can be set by control IC 2 one sides.Control IC 2 is regulated the duty factor of the pulse duration relevant with the drive signal of exporting from drive signal output VGH and VGL, thereby, can form the cycle td of setting-up time length.

Insulation converter transformer PIT-1 is to the switch output of primary side transmit button element Q1 and Q2, and elementary winding N1 and secondary winding with predetermined number of turn.

In the case, the elementary winding N1 of insulating transformer PIT-1 is connected to the node (switch output point) between the drain electrode of the source electrode of switch element Q1 and switch element Q2 around connecting of N11 by primary side DC resonant capacitor C1 and loosely coupled transformer VFT-1 elementary at the one end.Elementary winding N1 is connected to primary side ground connection at its other end.

Further, by the electric capacity of primary side DC resonant capacitor C1 with comprise that the leakage inductance L1 of the insulation converter transformer PIT-1 of elementary winding N1 forms the primary side series resonant circuit.Because the primary side series resonant circuit is connected to the switch output point in a manner described, therefore, the output of the switch of switch element Q1 and Q2 is sent to the primary side series resonant circuit.The primary side series resonant circuit is carried out resonant operation for the switch output that response sends.Thereby the operation of primary side switch converter becomes the operation of current-resonance type.

According to above description, obtain the current-resonance type operation of primary side series resonant circuit (L1-C1) and the partial resonance operation of part voltage resonance (Cp//L1) by primary side switch converter shown in Figure 2.

In other words, the first converter part 101 shown in Figure 2 adopts the configuration of combination resonant converter, and wherein, described combination resonant converter comprises the resonant circuit that is used to form mode of resonance primary side switch converter that combines with another resonant circuit.

Although the omission description taken together with the accompanying drawings, insulation converter transformer PIT-1 is configured to for example comprise EE type magnetic core, and wherein, EE type magnetic core is to form by the E type magnetic core of being made by Ferrite Material is made up.Further, the distribution receiving unit of insulation converter transformer PIT-1 is divided into the winding receiving unit that is used for primary side and primary side, and elementary winding N1 and secondary winding are wrapped on the center magnetic post of EE type magnetic core.

In the case, in insulation converter transformer PIT, twine three windings that comprise secondary winding N2, N2A and N2B independently of each other.

At first, produce primary side DC output voltage Eo, Eo1 and Eo2 from secondary winding N2.Be used for having following configuration from the Circuits System of primary side DC output voltage Eo, Eo1 and Eo2 generation primary side DC output voltage Eo.

Particularly, the tap output that forms on secondary winding N2 is grounding to primary side ground connection, and, on the secondary winding N2 position of the predetermined number of turn in center that is confirmed as tap output, drawing the end opposite tap one by one.Then, rectifier diode Do1 and Do2 are connected to the end opposite tap by the controlled winding NR1 of orthogonal control transformer PRT-1 and the series connection of NR2 respectively, and, further connect smmothing capacitor Co, to form full-wave rectifying circuit.Obtain primary side DC output voltage Eo from full-wave rectifying circuit, as the voltage at smmothing capacitor Co two ends.

Here, primary side DC output voltage Eo is branched, and is input to and is used for stable control circuit 7.

Orthogonal control transformer PRT-1 is configured to: control winding Nc and controlled winding NR1 and NR2 are wrapped on the magnetic core, thereby, for example, the winding direction of controlled winding NR1 and NR2 and the quadrature of controlling winding Nc.The orthogonal control transformer PRT-1 of Xing Chenging becomes saturable reactor in this way.

In the case, control circuit 7 its level of output are according to the DC electric current of the level respective change of primary side DC output voltage Eo, as Control current.In the orthogonal control transformer PRT-1 as saturable reactor, the inductance of controlled winding NR1 and NR2 is respective change along with the variation of Control current level.Because controlled winding NR1 and NR2 series connection are inserted into the rectification circuit system that is used for primary side DC output voltage Eo, therefore, if the inductance of controlled winding NR1 and NR2 changes, the rectified current flow that flows into smmothing capacitor Co so just changes, thereby the level of primary side DC output voltage Eo changes.In this way, carry out constant voltage control by the level of controlling primary side DC output voltage Eo changeably

At this moment, by the rectifier diode Do3 of controlled winding NR-orthogonal control transformer PRT-2 being connected in series to circuit and the connection smmothing capacitor Co1 that draws from the end of secondary winding N2 shown in Figure 2, and be formed for the rectification circuit system of primary side DC output voltage Eo1, as half-wave rectifying circuit.

And the rectification circuit system that is used for primary side DC output voltage Eo1 comprises orthogonal control transformer PRT-2 and control circuit 7, is constant voltage so that control primary side DC output voltage Eo1 by described mode.

In addition, by the rectifier diode Do4 of controlled winding NR-orthogonal control transformer PRT-3 being connected in series to circuit and the connection smmothing capacitor Co2 that draws from the end of secondary winding N2, and be formed for the rectification circuit system of primary side DC output voltage Eo2, as half-wave rectifying circuit.

And the rectification circuit system that is used for primary side DC output voltage Eo2 comprises orthogonal control transformer PRT-3 and control circuit 7, so that control primary side DC output voltage Eo2 is a constant voltage.

Further, from being the full-wave rectifying circuit acquisition primary side DC output voltage Eo3 that primary side winding N2A forms.Form full-wave rectifying circuit by rectifier diode Do5 and Do6 and smmothing capacitor Co3, simultaneously, the centre cap of primary side winding N2A is connected to zero potential.

In full-wave rectifying circuit, as shown in Figure 2, in series insert controlled winding NR1 and the NR2 of orthogonal control transformer PRT-4, and control circuit 7 is exported its level and primary side DC output voltage Eo3 corresponding control current to the control winding Nc of orthogonal control transformer PRT-4.In brief, control primary side DC output voltage Eo3 is a constant voltage.

Further, from being the full-wave rectifying circuit acquisition primary side DC output voltage Eo4 that primary side winding N2B forms.Form full-wave rectifying circuit by rectifier diode Do7 and Do8 and smmothing capacitor Co5, simultaneously, the centre cap of primary side winding N2B is connected to primary side ground connection, thereby, at first obtain dc voltage E4.Further, the transistor Q5 of DC switching circuit 6 in series is inserted between dc voltage E4 circuit and the smmothing capacitor Co6.Obtain primary side DC output voltage Eo4, wherein, Eo4 is the voltage at smmothing capacitor Co6 two ends.

Carry out the stable of primary side DC output voltage Eo4 by the switching frequency control method.In brief, primary side DC output voltage Eo4 is branched, and is input in the control circuit 1 as detecting voltage.The control input end Vc output voltage or the electric current of the control IC 2 of control circuit 1 in the first converter part 101, as control output, its level is regulated according to the level of primary side DC output voltage Eo4.For example, the frequency that control IC 2 is regulated oscillator signal according to the control output that is input to terminal Vc is to regulate from the frequency of the drive signal of drive signal output VGH and VGL output.Thereby, the switching frequency of adjustable ground control switch element Q1 and Q2.As a result, carry out constant voltage control, thereby, but the level of fixed secondary side DC output voltage Eo4.

DC switching circuit (switching device) 6 is set, and to control the starting moment of primary side DC output voltage Eo4 according to the initiating signal Vt3 from microcomputer output, wherein, described microcomputer is arranged in the equipment that comprises power circuit shown in Figure 2.

Form DC switching circuit 6 by connect MOS-FET transistor Q5, bipolar transistor Q6, Zener diode DZ and resistor R 1, R2, R3 and R4 by mode shown in Figure 2.Particularly, the drain electrode of transistor Q5 is connected to the positive terminal of smmothing capacitor Co5, and the source electrode of transistor Q5 is connected to the positive terminal of smmothing capacitor Co6.The grid of transistor Q5 is connected to the collector electrode of transistor Q6 by resistor R 2.Further, the parallel circuits that between the gate-to-drain of transistor Q5, connects resistor R 1//Zener diode DZ.Here, the anode of Zener diode DZ is connected to the gate electrode side of transistor Q5, and the negative electrode of Zener diode DZ is connected to the drain side of transistor Q5.

Initiating signal Vt3 is input to the base stage of transistor Q6 as the on signal by resistor R 4.At this moment, resistor R 3 is inserted between the base-emitter of bipolar transistor Q6.The emitter of bipolar transistor Q6 is connected to primary side ground connection.

As described below, initiating signal Vt3 is the signal that switches between between L level and the H level.When initiating signal Vt3 had L level (0 level), bipolar transistor Q6 kept off-state.At this moment, because voltage does not satisfy threshold value between the gate-to-source of transistor Q5, therefore, transistor Q5 also shows as off-state.Thereby the positive terminal of smmothing capacitor Co5 is not connected mutually with the positive terminal of smmothing capacitor Co6, therefore, does not carry out the charging of rectified current to smmothing capacitor Co6.Thereby even obtain dc voltage E4 between the end opposite of smmothing capacitor Co5, primary side DC output voltage Eo4 also remains 0 level, and wherein, Eo4 is the voltage at smmothing capacitor Co6 two ends.

On the contrary, if initiating signal Vt3 is increased to the H level before obtaining predetermined positive level, transistor Q6 just switches to on-state, and electrical potential difference occurs between the end opposite of resistor R 2.As a result, the anode of Zener diode DZ is connected to primary side ground connection by collector electrode-emitter, thereby Zener diode DZ becomes conducting because of dc voltage E4.Because therefore Zener diode DZ conducting applies the gate voltage that its level satisfies threshold value on the grid of transistor Q5, and transistor Q5 connects.As a result, the positive terminal of the positive terminal of smmothing capacitor Co5 and smmothing capacitor Co6 is connected to each other, thereby Co6 charges into rectified current to smmothing capacitor, and discharges from smmothing capacitor Co6.Correspondingly, produce primary side DC output voltage Eo4.

The second converter part 102 comprises: with the switch element Q3 and the Q4 of half-bridge type of attachment connection; Clamping diode DD3 and DD4; Partial resonance capacitor Cp; Control IC 2; Insulation converter transformer PIT-2 (elementary winding N1 and secondary winding N2); Primary side DC resonant capacitor C1; And loosely coupled transformer VFT-2, they are all to be connected with similar mode in the first converter part 101.Thereby the primary side switch converter forms the combination resonant converter, and wherein, described combination resonant converter comprises that the independent drive half-bridge connects the current resonance code converter and the part voltage resonant circuit of pattern.

Further, on the primary side of the second converter part 202, the centre cap that is provided with for the secondary winding N2 of insulation converter transformer PIT-2 is grounding to primary side ground connection, and, rectifier diode Do9 and Do10, remove make an uproar resistor R 5 and smmothing capacitor Co7 and be connected in mode shown in Figure 2, to form full-wave rectifying circuit with Co8.Thereby the rectification operation by full-wave rectifying circuit obtains primary side DC output voltage Eo5, as the voltage at smmothing capacitor Co two ends.

The fact that comprises control circuit 1 from the second converter part 202 can recognize, carries out the fixed voltage control of primary side DC output voltage Eo5 by the switching frequency control method of the switching frequency that is used to control the primary side switch converter.

Now, describe the configuration of the power factor be used to improve power circuit shown in Figure 2, wherein, described power circuit is configured in a manner described.

Circuit shown in Figure 2 comprises the power factor raising circuit 3 that is used to improve power factor.Power factor improves circuit 3 and is configured to: the switched voltage output of primary side converter feeds back to the rectification circuit system, and wherein, this system carries out rectification and level and smooth to industrial AC power supplies AC.In the case, circuit shown in Figure 2 comprises loosely coupled transformer VFT-1 and VFT-2, as the device that is used for the feedback switch output voltage.

The structure example of loosely coupled transformer VFT-1 shown in Figure 4 and VFT-2.

As shown in Figure 4, loosely coupled transformer VFT comprises EE type magnetic core, and wherein, EE type magnetic core comprises E type magnetic core CR1 and the CR2 that is made by Ferrite Material, and E type magnetic core CR1 and CR2 make up in magnetic post mode relative to each other.

Loosely coupled transformer VFT further comprises the bobbin B that is for example made by resin material, and bobbin B forms dividually, thereby primary side winding part and primary side winding part are independent mutually.Elementary winding N11 is wrapped on the winding part of bobbin B, and simultaneously, secondary winding N12 is wrapped on another winding part.When the bobbin B that twines elementary winding and secondary winding on it in this way was connected to EE type magnetic core (CR1, CR2), primary side winding and primary side winding were wrapped on the center magnetic post of EE type magnetic core in the mutually different winding zone.Obtain the structure of whole loosely coupled transformer VFT in this way.

In the case, in the bonding part of center magnetic post, form clearance G with required gap length.By clearance G, coupling coefficient is set at and for example obtains k=0.75 or littler loose coupling state.

Power factor improves the power factor raising of circuit 3 and operates as follows.

At first, in order more easily to understand description, the power factor of only describing the first converter part 101 improves operation.

Among the loosely coupled transformer VFT-1 in being arranged on the first converter part 101, the output of the switch of the primary side switch converter of the first converter part 101 is sent to elementary winding N11.As response, in the secondary winding N12 of loosely coupled transformer VFT-1, encourage alternating voltage to this.

Here, in the electrode line of industrial AC power supplies AC, the secondary winding N12 of loosely coupled transformer VFT-1 is inserted between the positive input terminal of choking-winding LN and bridge rectifier Di.In brief, the secondary winding N12 of loosely coupled transformer VFT-1 is inserted in the rectified current path.According to loosely coupled transformer VFT-1, obtain operation to the switched voltage output of rectified current path feedback primary side switch converter.

Owing to the voltage of exporting to rectified current path feedback switch in a manner described, therefore, when rectified current flows to the high speed recovery type rectifier diode (Da-Dd) that forms bridge rectifier Di, drive rectifier diode, carry out switching manipulation by the alternating voltage that in the secondary winding N12 of loosely coupled transformer VFT-1, encourages.Thereby the rectified current of the rectifier diode of flowing through switches on and off, and therefore, rectified current has AC wave shape.In brief, at overlapped high-frequency component on as the rectified current of the AC input current IAC of power supply.

High fdrequency component in the above-mentioned rectified current flows at first in the following manner, and here, industrial AC power supplies AC is the 200V type, and forms full-wave rectifying circuit.

In ac input voltage VAC was positive cycle, high fdrequency component flowed along following rectified current path through the electrode line of industrial AC power supplies AC from filtering capacitor CN: the negative line of rectifier diode Da → smmothing capacitor [Ci1//Ci1] of secondary winding N12 → bridge rectifier Di-[Ci2//Ci2] → primary side ground connection → rectifier diode Dd → industrial AC power supplies AC.

Further, in ac input voltage VAC was the cycle of bearing, high fdrequency component flowed along following rectified current path through the negative line of industrial AC power supplies AC from filtering capacitor CN: rectifier diode Dc → smmothing capacitor [Ci1//Ci1]-[Ci2//Ci2] → primary side ground connection → rectifier diode Db → secondary winding N12.

On the other hand, high fdrequency component flows in the following manner, and here, industrial AC power supplies AC is the 100V type, and forms voltage doubling rectifing circuit.

In ac input voltage VAC was positive cycle, high fdrequency component flowed along following rectified current path through the electrode line of industrial AC power supplies AC from filtering capacitor CN: the negative line of rectifier diode Da → smmothing capacitor [Ci1//Ci1] → industrial AC power supplies AC of secondary winding N12 → bridge rectifier Di.

Further, in ac input voltage VAC was the cycle of bearing, high fdrequency component flowed along following rectified current path through the negative line of industrial AC power supplies AC from filtering capacitor CN: the electrode line of smmothing capacitor [Ci2//Ci2] → primary side ground connection → rectifier diode Db → secondary winding N12 → industrial AC power supplies AC.

Can recognize from above-mentioned rectified current path, ac input voltage VAC be just/negative two cycles in, rectified current one of the high speed recovery type rectifier diode (Da-Dd) of flowing through.In brief, can recognize that rectified current switches on and off, thereby, by the high speed recovery type rectifier diode rectified current is carried out switch.Then because rectified current switches on and off in this way, therefore, in the lower cycle, the charging current of injecting smmothing capacitor Ci also flows at the level of rectifier output voltage level ratio rectification smooth voltage Ei.

As a result, because the average waveform of AC input current near the waveform of ac input voltage, therefore, enlarges the angle of flow of AC input current IAC.Because the angle of flow of AC input current IAC enlarges in this way, therefore, realize the raising of power factor.

Then, power factor shown in Figure 2 improves the loosely coupled transformer VFT-2 that circuit 3 in fact also comprises the second converter part 102.

Here, the secondary winding N12 of loosely coupled transformer VFT-2 is parallel to the secondary winding N12 of loosely coupled transformer VFT-1 in the first converter part 101.Correspondingly, in above-mentioned rectified current path, in fact the flow through parallel circuits of secondary winding N12//N12 of loosely coupled transformer VFT-1 and VFT-2 of rectified current.Thereby the parallel circuits of secondary winding N12//N12 is included in the rectified current path.

This means that power factor improves circuit 3 and is configured to: the first converter part 101 and both switched voltage outputs of the second converter part 102 feed back to the rectified current path by loosely coupled transformer VFT-1 and VFT-2.

In brief, present embodiment has following configuration: voltage feeds back to the first converter part 101 by loosely coupled transformer VFT-1, and simultaneously, voltage feeds back to the second converter part 102 by loosely coupled transformer VFT-2, improves to realize power factor.Should point out, select the elementary winding N11 of each loosely coupled transformer VFT-1 and VFT-2 and the inductance value of secondary winding N12, so that obtain for example power factor of PF ≈ 0.8.

Further, according to the configuration of power circuit shown in Figure 2, the first converter part 101 produces five primary side DC output voltages of primary side DC output voltage Eo and Eo1-Eo4, and the second converter part 102 produces primary side DC output voltage Eo5.

Particularly, equally in the present embodiment, the correlation technique situation of describing with the above Figure 11 of combination similarly obtains:

Eo: logic power, 5V/6A-2A

Eo1: analog IC driving power, 12V/0.4A

Eo2: digital IC driving power, 3.3V/1.5A

Eo3: voice output power supply, 26V/1.3A-0.1A

Eo4: data power supply, 70V/2.5A-0.35A

Eo5: keep power supply, 200V/1.75A-0.1A.

Yet, in the present embodiment, partly provide 6 loads (primary side DC output voltage) from the first converter part 101 and 102 two converters of the second converter part.Correspondingly, the maximum load power that the converter part should be available is:

The first converter part 101:250W

The second converter part 102:350W,

Thereby, need 600W altogether.

Then, producing primary side DC output voltage Eo and Eo1-Eo5 in a manner described and offering under the configuration of load, when power supply activated in a manner described, primary side DC output voltage is essential to raise by predetermined order.Particularly, require the primary side DC output voltage Eo of starting as logic power, and then successively starting as the primary side DC output voltage Eo5 that keeps power supply with as the primary side DC output voltage Eo4 of data power supply.

In power circuit shown in Figure 2, this that carry out above-mentioned primary side DC output voltage in the following manner starts successively.

At first, the control of starting successively for primary side DC output voltage, can be from the unshowned microcomputer of Fig. 2 output initiating signal Vt1, Vt2 and Vt3, wherein, initiating signal Vt1, Vt2 and Vt3 are the signal (activation control signal) that is used to control the activation of described control IC at first.

Should point out that at this, microcomputer is arranged in the equipment that comprises power circuit shown in Figure 2.Further, power circuit shown in Figure 2 is a main power source, and, when main power source cuts out, the microcomputer unshowned stand-by power supply work of Fig. 2.Correspondingly, though the main power source inoperation, because therefore microcomputer stand-by power supply work, also might export initiating signal Vt1, Vt2 and Vt3.

Should point out, for plasma display panel device shown in Figure 1 10, only illustrate, and omit microcomputer and stand-by power supply based on configuration as relation between switching power circuit 11, plasma display panel part 12 and the television receiving function part 13 of main power source.

Initiating signal Vt1 is input to the starting end Vt of the control IC 2 of the first converter part 101.Initiating signal Vt2 is input to the starting end Vt of the second converter part 102.Input initiating signal Vt3, as the on signal of the transistor Q6 that is used to control the DC switching circuit, wherein, the DC switching circuit is arranged in the rectification circuit of the primary side DC output voltage Eo4 on the primary side of the above-mentioned first converter part 101.

Here, as (a) among Fig. 5, (d) with (f), initiating signal Vt1, Vt2 and Vt3 switch to the H level from the L level respectively successively in the moment of time t1, t2 and t3 respectively.Further, before all initiating signal Vt1, Vt2 and Vt3 had the time t1 of L level, the first converter part 101 and the second converter part 102 were in the state that they are not activated.

For example, be elevated to specified level if connect main power source and microcomputer identification rectification smooth voltage Ei, so, microcomputer just switches to the H level to initiating signal Vt1 from the L level at the predetermined instant of time t1 regulation, and the initiating signal Vt1 of output H level, shown in Fig. 5 (a).

Thereby,, activate the control IC 2 of the first converter part 101 at time t1.In other words, the first converter part 101 begins to activate.As the response to activating, the primary side DC output voltage that obtains on the primary side of the first converter part 101 raises.In brief, although primary side DC output voltage Eo had 0 level before time t1 shown in Fig. 5 (b), after time t1, primary side DC output voltage Eo raises in the following manner: Eo raises along with the increase of the charge volume of smmothing capacitor Co.Then, after reaching specified level, keep primary side DC output voltage Eo to be fixed and be controlled at the state of specified level.

Yet, should point out, although dc voltage Eo4 raises at time t1 shown in Fig. 5 (c),, primary side DC output voltage Eo4 with shown in Fig. 5 (g) does not similarly raise.This be because: in the moment of time t1, the transistor Q5 in the DC switching circuit 6 is in off-state, wherein, DC switching circuit 6 Be Controlled on/off.As mentioned above, DC switching circuit 6 is by following operation: when the initiating signal Vt3 as the on signal had the L level, oxide-semiconductor control transistors Q5 was controlled as off-state.When transistor Q5 was in off-state, rectified current did not inject smmothing capacitor Co6, and, do not produce primary side DC output voltage Eo4.

Then, the time t2 of initiating signal Vt2 shown in Fig. 5 (d) after initiating signal Vt1 changes into the time t1 of H level switches to the H level, and output is as the H level signal.Should point out, for example, the moment of time t2 is set at more late than the moment that guarantees the operation of beginning circuit part, wherein, circuit part uses primary side DC output voltage Eo as power supply, this is because primary side DC output voltage Eo is elevated to specified level fully, for example switches to the initiating signal Vt1 of H level at time t1 with response.

Then, Vt switches to the H level for the response initiating signal, activates the control IC 2 of the second converter part 102.Thereby primary side DC output voltage Eo5 raises in mode shown in Fig. 5 (e) since time t2.

Then, shown in Fig. 5 (f), being elevated to specified level fully at acquisition primary side DC output voltage Eo5 is the moment t3 of the state of fixed voltage also, and last initiating signal Vt3 switches to the H level.

In the case, Vt3 switches to the H level for the response initiating signal, and the transistor Q5 of DC switching circuit 6 switches to on-state.Switch for responding this, dc voltage E4 charges to smmothing capacitor Co6 by drain electrode-source electrode of transistor Q5, so primary side DC output voltage Eo4 raises shown in Fig. 5 (g).

In this way, the rising order of primary side DC output voltage when present embodiment is controlled at the power supply activation, thus this order is the suitable order identical with Figure 11 situation.

Should point out that as a reference, the shape and size of magnetic core that are arranged on the transformer in the power circuit shown in Figure 2 are as follows.

PIT-1：EER-40

PIT-2：EER-42

VFT-1，VFT-2：EE-28

PRT: ferrite core (15mm * 15mm * 20mm)

Further, the relevant result of experiment that power circuit shown in Figure 2 is carried out is described.

Under the condition of bearing power Po=600W and ac input voltage VAC=100V, comprehensive power conversion efficiency η AC → DC=92.5%, and this shows the characteristic raising 3.2% from correlation technique power circuit shown in Figure 11.

Further, under the condition of bearing power Po=600W and ac input voltage VAC=200V, comprehensive power conversion efficiency η AC → DC=94.0%, and, obtain to improve 2.3% result from the characteristic of power circuit shown in Figure 11.

At this moment, for power factor characteristic, under the condition of bearing power Po=600W and ac input voltage VAC=100V, obtain power factor PF=0.83.Then, when ac input voltage VAC=100V, in the scope of bearing power Po=600W-25W, obtain PF＞0.75.

Further, under the condition of bearing power Po=600W and ac input voltage VAC=230V, obtain power factor PF=0.78.Further, when ac input voltage VAC=230V, in the scope of bearing power Po=600W-300W, obtain the power factor higher than setting, and, successfully satisfy the harmonic distortion adjusted value of IEC (International Electrotechnical Commission).

When mutual present embodiment power circuit more shown in Figure 2 and configuration in a manner described and related art circuit shown in Figure 1, the result is as follows.

At first, in circuit shown in Figure 2,, therefore omit active filter owing to be configured to comprise that the power factor according to the Voltage Feedback type improves circuit 3.Active filter constitutes converter, and, can recognize from description that active filter is in fact by comprising that a plurality of switch elements and a large amount of parts that are used for the IC of driving switch element form in conjunction with Figure 11.

On the contrary, the power factor that is arranged in the power circuit shown in Figure 2 improves circuit 3 increase loosely coupled transformer VFT-1 and VFT-2 on the rectified current path, and loosely coupled transformer VFT-1 and VFT-2 are the element that comprises above-mentioned small size EE-28 type magnetic core.Correspondingly, compare with active filter, power factor improves the parts that circuit 3 comprises suitable small number, and the plate erection space of element reduces.

Thereby, compare with circuit shown in Figure 11, can produce power circuit shown in Figure 2 with much lower cost, comprise that as being used to power factor improves the large-scale power circuit of function.And, can realize effectively that the size of circuit board and weight reduce.

Further, can recognize, in power circuit shown in Figure 2, omit the active filter and the code converter that falls progressively, and the converter of hard switching operation be carried out in cancellation.Here, because present embodiment is configured to comprise orthogonal control transformer PRT and control circuit 7, thereby, by being provided, the Control current such as the DC electric current realizes that primary side DC output voltage Eo, Eo1, Eo2's etc. is stable, therefore, might omit the code converter that falls progressively.

Then, only relate to soft switching manipulation owing to form the operation of the first converter part 101, the second converter part 102 and the power factor raising circuit 3 of power circuit shown in Figure 2, therefore, when comparing, obviously reduce the switching noise level with active filter shown in Figure 11.

Further, though the quantity of combination resonant converter part is 3 in power circuit shown in Figure 11, the quantity of combination resonant converter part is reduced to 2 in power circuit shown in Figure 2, comprises the first and second converter parts 101 and 102.And, reducing in this way to make up under the situation of resonant converter quantity partly, promote the size and the weight of foregoing circuit to reduce.Further, because switching manipulation is soft switching manipulation, therefore, although to begin most be smallest number to switching noise, if the quantity of combination resonant converter part reduces, switching noise descends with regard to as much ground.And, realize advantage in this respect.

Thereby, in circuit shown in Figure 2, if this circuit comprise by a common mode choke coil CMC and two one-level line filters that cross-over connection capacitor CL forms, just be enough to remove power supply and disturb setting.

In addition, by reducing the element quantity of noise filter in this way, just promote the size and the weight that reduce the cost of power circuit and reduce circuit board.

Further, by the AC-DC power conversion efficiency (η AC/DC) of active filter in the previous stage and subsequently in the level DC-DC power conversion efficiency (η DC/DC) of current resonance code converter determine the gross power conversion efficiency of power circuit shown in Figure 11.On the contrary, because power circuit shown in Figure 2 does not comprise the active filter of previous stage, therefore, the comprehensive power conversion efficiency is considered to the AC-DC power conversion efficiency (aggregate values of η AC → DC) of current resonance code converter.And then know: when with present embodiment in the same when Voltage Feedback type power factor being set improving circuit, the power conversion efficiency of described circuit is substantially equal to not comprise that power factor improves the power conversion efficiency of the combination resonant converter of circuit.

Thereby when comparing with above-mentioned power circuit shown in Figure 11, power circuit shown in Figure 2 is significantly improved aspect power conversion efficiency.

Further, power circuit shown in Figure 11 is configured to: active filter circuit 8, three 201,202 and 203 and two of converter parts fall progressively code converter with mutually different switching frequency work.

On the contrary, in the present embodiment, have only two first and second converter parts 101 and 102 to carry out switching manipulation independently of each other with mutually different switching frequency.The first and second converter parts 101 and 102 switching frequency change along with the level of for example primary side DC output voltage Eo4 in the 70KHz-150KHz scope and Eo5, fix to realize voltage.

In this way, when reducing to carry out the quantity of converter of switching manipulation with different switching frequency, because the interference between the ground potential of primary side and primary side reduces equally, therefore, the operation of power circuit is further stable.

By the way, three converter parts 201,202 and 203 are set in circuit shown in Figure 11 as the reasons that make up resonant converter is: as above described in conjunction with Figure 12, in the case, the primary side DC rise of output voltage time must be controlled in the three phases of time t1, t2 and t3.

Particularly, if attempt to start and initiating signal Vt1, Vt2 and the corresponding primary side DC output voltage of Vt3 in time t1, t2 and t3 output, so, adopted following structure before this, this structure comprises three combination resonant converters and controls the activation of the control IC 2 of each combination resonant converter with initiating signal Vt1, Vt2 and Vt3.

On the contrary, in circuit shown in Figure 2, DC switching circuit 6 is set, thereby with the on/off state of initiating signal Vt3 control DC switching circuit 6, with the rising of control primary side DC output voltage Eo4.Thereby the quantity of the control IC that the rising of control primary side DC output voltage is required reduces one.In other words, might reduce by a converter part.

When reducing the converter part, also can expect the parts that reduce same quantity.Further, the switching loss of the switch element of formation primary side switch converter reduces too.

Fig. 6 illustrates the profile instance as the switching power circuit of second embodiment.Should point out, in Fig. 6, represent with identical reference symbol with components identical among Fig. 2, and the descriptions thereof are omitted at this.

In power circuit shown in Figure 6, at first, the internal configurations that is arranged on the DC switching circuit (switch sections) 6 on the first converter part 101 is different with the situation of Fig. 2.Particularly, DC switching circuit 6 comprises time constant capacitor C3.In the case, power factor improves circuit 3 and is for example formed by electrolytic capacitor, and, be connected to the base stage of bipolar transistor Q6 at its positive terminal, be connected to primary side ground connection at its negative pole end.

Further, in the case,, import the primary side DC output voltage Eo5 of the second converter part 102, to replace initiating signal Vt3 as the on signal that is input to DC switching circuit 6.

In above-mentioned this configuration, to after for example beginning to import the positive polarity on signal of predetermined level, acting on scheduled delay according to the time constant of resistor R 4 and time constant capacitor C3 until the moment that transistor Q6 is in on-state fully.Thereby, also to the delay of the effect of the time cycle before transistor Q5 is in on-state fully after beginning to import the on signal according to the time constant of resistor R 4 and time constant capacitor C3.

Further, same on the primary side of the second converter part 102 in circuit shown in Figure 6, DC switching circuit 6A is set to replace the resistor R 5 of making an uproar of removing shown in Figure 2.And DC switching circuit 6A (switch sections) is by forming with transistor Q7, bipolar transistor Q8, Zener diode DZ, resistor R 8, R9, R10 and the time constant capacitor C8 that is connected with the similar substantially mode of DC switching circuit 6 situations.Correspondingly, in addition, by DC switching circuit 6A, to the delay of the effect of the time cycle before transistor Q7 is in on-state fully after beginning to import the on/off signal according to the time constant of resistor R 8 and time constant capacitor C8.Then, import the primary side DC output voltage Eo that the first converter part, 101 1 sides produce to DC switching circuit 6A, as the on signal.

Further, in this power circuit, have only initiating signal Vt1 to export, and be input to the starting end Vt of the control IC 2 of the first converter part 101 from microcomputer.

The control operation of starting primary side DC output voltage in the circuit shown in Figure 6 is successively described in conjunction with the time diagram of Fig. 7.

In addition, in the case, when microcomputer identification main power source was connected, at the predetermined instant of time t1 shown in Fig. 7 (a), microcomputer switched to the H level to initiating signal Vt1 from the L level, and the initiating signal Vt1 of output H level.For response initiating signal Vt1, activate the first converter part 101 at time t1, and shown in Fig. 7 (b), primary side DC output voltage Eo rises.

Further, with time t1 correspondingly, the primary side DC output voltage that obtains on the primary side of the first converter part 101 rises.Yet still in the case, shown in Fig. 7 (h), primary side DC output voltage Eo4 does not rise at time t1.Shown in Fig. 7 (c), for responding the activation of the first converter part 101, the primary side DC output voltage Eo4 of previous stage rises at time t1.

The time t1 that initiating signal Vt1 switches to the H level is corresponding substantially with the time that main power source is connected.The activated end of the second converter part 102 shown in Figure 6 is opened, and does not have the initiating signal input.In the case, control IC 2 begins operation, and is activated according to the activation voltage from power input Vcc input.

Therefore, the second converter part 102 is activated, thereby it is beginning switching manipulation with the essentially identical moment of time t1.Then be the activation of the response second converter part 102, shown in Fig. 7 (d), dc voltage E5 roughly rises at time t1, and wherein, dc voltage E5 is arranged on the voltage at the smmothing capacitor Co7 two ends on the primary side of the second converter part 102.Yet, be in off-state owing to carve the transistor Q7 of DC switching circuit 6A at this moment, therefore, shown in Fig. 7 (f), primary side DC output voltage Eo5 does not rise, and wherein, Eo5 is the voltage at smmothing capacitor Co8 two ends.

Here, at the time t1A after time t1 process certain time interval, primary side DC output voltage Eo places the state that reaches specified level.As the response to this, input primary side DC output voltage Eo is as the on signal.In the DC switching circuit 6A of the second converter part 102, press the mode shown in Fig. 7 (e), for example, at this moment between moment of t1A, the base voltage of transistor Q8 slowly rises.Determine the rising oblique angle of base voltage by the time constant of resistor R 8 and time constant capacitor C8.

Then, if the base voltage of transistor Q8 for example reaches predetermined level at time t2, so, transistor Q8 just places on-state fully.Then, at this moment, obtain the state that transistor Q7 connects fully, and, provide the dc voltage E5 shown in Fig. 7 (d) by transistor Q7 to smmothing capacitor Co8, wherein, dc voltage E5 is the voltage at smmothing capacitor Co7 two ends.Thereby in mode shown in Fig. 7 (f), primary side DC output voltage Eo5 rises since time t2, and wherein, Eo5 is the voltage at smmothing capacitor Co8 two ends.

Then, import the primary side DC output voltage Eo5 that rises at time t2 in a manner described to the DC switching circuit 6 of the first converter part, 101 1 sides, as the on signal.

As the response to this, utilize DC switching circuit 6 to obtain following operation: in the time cycle of being determined by the time constant of resistor R 4 and time constant capacitor C3 shown in Fig. 7 (g), the base voltage of bipolar transistor Q6 rises.

Then, if before bipolar transistor Q6 is in on-state fully, for example at time t3, the base voltage of bipolar transistor Q6 reaches predetermined level, so, just obtains the state that transistor Q5 also connects fully.As a result, provide dc voltage E4 shown in Fig. 7 (c) by transistor Q5 to smmothing capacitor Co6.Thereby in mode shown in Fig. 7 (h), primary side DC output voltage Eo4 rises since time t3, and wherein, Eo4 is the voltage at smmothing capacitor Co6 two ends.

In this way, in power circuit shown in Figure 6, obtain the primary side DC rise of output voltage time similar equally to circuit shown in Figure 11.

Then, utilize the power circuit of this second embodiment, based on the reason similar to the power circuit of first embodiment, obtain following effect: as improving power conversion efficiency, reduce circuit size and weight, and by reducing to have interference between the ground connection of power circuit that power factor improves function enhanced stability.

Further, can expect and reduce number of components and reduce switching loss by reducing the converter part.

Here, if the configuration of switch converters of the present invention is used as basic configuration, the quantity of converter part just can be reduced to one.If relate to the configuration of second embodiment shown in Figure 6, this just recognizes easily.Particularly, in configuration shown in Figure 6, after starting the first converter part 101 with initiating signal Vt1, primary side DC output voltage Eo5 and Eo are input to each DC switching circuit 6 and 6A of comprising time constant circuit, thereby, start primary side DC output voltage according to regulation order shown in Figure 7.In the case, because initiating signal is not input to the starting end Vt of the control IC 2 of the second converter part 102, therefore, might adopt following configuration, wherein, omit the second converter part 102, and, have only first primary side DC output voltage Eo and the Eo1-Eo6 that converter part 101 produces and output is necessary.This realizes technically easily.

Yet in the present embodiment, switching power circuit comprises two converter parts as shown in figs. 1 and 6, and, consider following reason, do not include only the configuration of a converter part.

Particularly, introduce power circuit of the present invention shown in Fig. 1 and 6, as the switching power circuit 11 of plasma display panel device 10 shown in Figure 1.As everyone knows, in the configuration aspects as display unit, for example compare with CRT (cathode ray tube), plasma display panel device 10 can form quite little size, and very little at the thickness of depth direction.For example at the aspects such as installation of plasma display panel device, the fact that plasma display panel device 10 is so thin is a significant advantage.In brief, consider preferably to form plasma display panel device with the thickness that reduces as far as possible.

From situation about just having described, the size and dimension that also requires to be included in the power supply circuit board in the plasma display panel device does not hinder reducing of plasma display panel device thickness.In order to realize this purpose,, require it highly to make lowlyer for the size and dimension of power supply circuit board.Yet because insulation converter transformer PIT has sizable height in the parts that form power circuit, therefore, the height of power supply circuit board depends on the height of insulation converter transformer PIT.

As mentioned above, in the power circuit of first embodiment shown in Figure 1, the magnetic core of EER-40 and EER-42 (bobbin) is respectively applied for above-mentioned insulation converter transformer PIT-1 and PIT-2.Utilize the magnetic core of these sizes, when they were used for perpendicular attitude, height was in the scope from about 41mm to 46mm, but when they were used for horizontal attitude, height was in another scope from about 30mm to 35mm.Correspondingly, also size is corresponding therewith for the height of power supply circuit board.

Should point out, same power circuit for second embodiment shown in Figure 6, because insulation converter transformer PIT-1 and PIT-2 use the magnetic core (bobbin) of similar size and dimension, therefore, the height of power supply circuit board and described above basic identical.

Under present condition, the following layout of use internal part, structure etc., wherein, the height of above-mentioned power supply circuit board does not hinder realizes the thin plasma display panel device that disposes.

Yet if the quantity of converter part is reduced to one and satisfy the total load condition (bearing power 600W) identical with power circuit shown in Fig. 1 and 6 simultaneously, so, the quantity of used insulation converter transformer PIT just also is reduced to one.Thereby the power transmission from the primary side to the primary side only depends on single insulation converter transformer PIT according to above-mentioned 600W loading condition.

Thereby, when comparing with the power circuit of Fig. 1 or 6 illustrated embodiments, essential magnetic core (bobbin) size that increases insulation converter transformer PIT.In other words, if attempt to reduce the quantity of converter part when loading condition keeps equating, just necessary as much ground increases magnetic core (bobbin) size of insulation converter transformer PIT.Be reduced to one and use simultaneously under the situation of configuration shown in Fig. 1 and 6 as basic configuration in the quantity of converter part, in fact minimumly must select EER-49.

It highly is approximately 50mm when EER-49 is used for perpendicular attitude, and, when EER-49 is used for horizontal attitude, its height even be approximately 37mm.If EER-49 compares with EER-40 or EER-42, just cause size centimetre being that unit ground increases.This following situation occurs: plasma display panel device not so that gauge reduce institute's required amount and form.

Thereby in the present embodiment, the quantity of converter part is not reduced to one, but is set at 2.In other words, present embodiment is configured to: only delete a converter part from the correlation technique configuration (Figure 11) that comprises three converter parts, thereby present embodiment comprises two converter parts.Thereby, realize the advantage that reduces number of components and reduce the wastage and do not disturb plasma display panel device thickness to reduce by cancellation converter part.

In brief, we can say that the converter quantity of present embodiment power circuit should decide according to the effect that reduces the converter part and the balance of power supply circuit board required size and shape.

Further, the present invention is not limited to the configuration of above-mentioned power circuit.

For example,, can adopt any element except that MOS-FET, as long as it can be used for the independent drive scheme such as IGBT (igbt) for switch element.Further, the constant of above-mentioned element can change according to physical condition etc.

Further, according to the present invention, power circuit can be configured to comprise the current resonance code converter of autoexcitation half-bridge connecting-type.In the case, for example, switch element can be selected bipolar transistor.

And then, for example, also can suitably change the circuit arrangement that is used on the primary side of insulation variable flow and variable pressure PIT, producing primary side DC output voltage.

Further, configuration that power factor improves circuit 3 is not limited to is announced among the above embodiment, so long as can use, and any circuit arrangement according to various Voltage Feedback system that just can adopt that the assignee of the present invention proposes.

Further, describe and can recognize from the front, in based on power circuit of the present invention, the two-stage that the progression of switch converters need not be confined to for example announce in an embodiment.Progression should decide according to reducing the effect that the converter partial amt obtains and the balance of power supply circuit board required size and shape, and, for example wait suitably to change according to the quantity of the bearing power that will realize, required primary side DC output voltage.Further, because the concrete quantity of the restriction primary side DC output voltage that will partly produce by converter.In addition, according to the present invention, if adopt the configuration that DC switching circuit 6 and 6A (switch sections) are set, so, have the identical load condition and compare with disposing with the alternative situations of the power circuit of identical primary side DC output voltage quantity based on correlation technique, just might reduce the quantity of switch converters part, this requires to obtain the primary side DC output voltage of equal number.

And then switching power circuit of the present invention can be included in the miscellaneous equipment except that plasma display panel device.Particularly, switching power circuit can be included in the following various device, described various device requires to produce a plurality of DC output voltages (primary side DC output voltage) according to the different loads condition of quite big quantity, and in addition also requires to start the DC output voltage successively at predetermined instant.

Claims (7)

1. switching power circuit, described switching power circuit comprise be used for to ac input voltage carry out rectification rectifying part, be used to make flatten sliding smooth and be used to receive and operate first converter part and the second converter part of commutating voltage from described rectifying part from the smooth voltage of described smooth, wherein, described smooth voltage is the DC input voltage, when partly being activated, described first and second converters are activated in the mutually different moment, wherein

Each of a plurality of switch converters parts all comprises:

Be used to receive the DC input voltage to carry out the switch sections of switching manipulation, described switch sections is formed by the high-end switch element and the low-end switch element that connect with the half-bridge type of attachment;

The switch drive part that is used for the described switch element of switch drive;

By twining the insulation converter transformer that at least one elementary winding and secondary winding form, wherein, the switch output that provides the switching manipulation by described switch sections to obtain to described elementary winding, in described secondary winding, encourage alternating voltage, wherein, alternating voltage is as the switch output that obtains in the described elementary winding;

The primary side series resonant circuit, described primary side series resonant circuit is formed by the leakage inductance component of the described elementary winding of described insulation converter transformer and the electric capacity that is connected in series to the primary side series resonance capacitor of described elementary winding at least, is used to carry out the operation of described current-resonance type switch sections;

Primary side part voltage resonant circuit, described primary side part voltage resonant circuit is formed by the leakage inductance component of the described elementary winding of the electric capacity of the part voltage resonance capacitor that is parallel to one of two switch elements and described insulation converter transformer, wherein, each all forms the half-bridge connection described switch element, and only each moment that switches on and off according to each described switch element obtains the voltage resonance operation of described primary side part voltage resonant circuit;

The DC output voltage produces part, described DC output voltage produces the primary side AC voltage that partly is used to receive by the described secondary winding acquisition of described insulation converter transformer, and the rectification operation of the execution primary side AC voltage that receives, to produce a plurality of primary side DC output voltages;

Frequency-control-type fixed voltage control section, described frequency-control-type fixed voltage control section is controlled described switch drive part according to required one level of a plurality of primary side DC output voltages, change the switching frequency of described switch sections, a required primary side DC output voltage is carried out fixed voltage control;

Inductance control type fixed voltage control section for each setting of required a plurality of primary side DC output voltages, wherein, except a required primary side DC output voltage, required a plurality of primary side DC output voltage is required it is fixed voltage, the target of the fixed voltage control that a required primary side DC output voltage is described frequency-control-type fixed voltage control section, described inductance control type fixed voltage control section is configured to: the controlled winding as the control transformer of saturable reactor form is inserted into the primary side rectified current path that is used for producing primary side DC output voltage, described control transformer has control winding and winding described controlled winding thereon, and, the Control current level that will offer described control winding changes according to the primary side DC output-voltage levels of importing, to change the inductance of controlled winding, thus primary side DC output voltage is carried out fixed voltage control; And

Power factor improves circuit, described power factor improves circuit and comprises that power factor improves transformer and is inserted into rectifier cell in the desired location of described rectified current path, wherein, described power factor improves transformer and is inserted into power factor in the described primary side series resonant circuit and improves elementary winding and be inserted into power factor in the rectified current path and improve secondary winding and form by twining series connection, described rectified current path forms described rectification smooth, improve elementary winding by described power factor, based on improving the driving voltage that encourages in the secondary winding and carry out switching manipulation in described power factor, to interrupt rectified current, be used to improve power factor;

Described first switch converters partly comprises first switch sections, the moment after predetermined primary side DC output voltage raises after the scheduled time in the past, described first switch sections is operated, so that the primary side rectified current path that is used to produce another predetermined primary side DC output voltage is switched to on-state from off-state.

2. switching power circuit as claimed in claim 1, wherein, described first switch sections switches to on-state to primary side rectified current path from off-state for response at the activation control signal through the input of the moment after the scheduled time.

3. switching power circuit as claimed in claim 1, wherein,

Described rectifying part is the diode that connects in bridge-type connects, and has: two commutating voltage outputs that are provided the terminal of ac input voltage, the reference potential end that is connected to reference potential and output commutating voltage;

Described smooth is two smmothing capacitors of connecting by node between them between described commutating voltage output and the described reference potential end; And

Described switching power circuit further comprises and is arranged on the second switch part that is used to carry out switching between one of two terminals that are provided ac input voltage and the described node, thereby, when ac input voltage is lower than reference voltage, the operation of execution voltage multiplying rectifier, in this operation, described second switch partly places on-state to produce the rectification smooth voltage that its level equals twice ac input voltage level, but, when ac input voltage is higher than reference voltage, carry out isobaric rectification operation, in this operation, described second switch partly places off-state, to produce another rectification smooth voltage that its level equates with the ac input voltage level.

4. first switching power circuit and another switching power circuit, their boths comprise be used for to ac input voltage carry out rectification rectifying part, be used to make flatten sliding smooth and be used to receive and operate a plurality of converter parts of commutating voltage from described rectifying part from the smooth voltage of described smooth, wherein, described smooth voltage is the DC input voltage, one of described a plurality of converter parts were activated in the pre-determined moment, wherein

Each of a plurality of switch converters parts all comprises:

Be used to receive the DC input voltage to carry out the switch sections of switching manipulation, described switch sections is formed by the high-end switch element and the low-end switch element that connect with the half-bridge type of attachment;

The switch drive part that is used for the described switch element of switch drive;

By twining the insulation converter transformer that at least one elementary winding and secondary winding form, wherein, the switch output that provides the switching manipulation by described switch sections to obtain to described elementary winding, in described secondary winding, encourage alternating voltage, wherein, alternating voltage is as the switch output that obtains in the described elementary winding;

The primary side series resonant circuit, described primary side series resonant circuit is formed by the leakage inductance component of the described elementary winding of described insulation converter transformer and the electric capacity that is connected in series to the primary side series resonance capacitor of described elementary winding at least, is used to carry out the operation of described current-resonance type switch sections;

Primary side part voltage resonant circuit, described primary side part voltage resonant circuit is formed by the leakage inductance component of the described elementary winding of the electric capacity of the part voltage resonance capacitor that is parallel to one of two switch elements and described insulation converter transformer, wherein, each all forms the half-bridge connection described switch element, and only each moment that switches on and off according to each described switch element obtains the voltage resonance operation of described primary side part voltage resonant circuit;

The DC output voltage produces part, described DC output voltage produces the primary side AC voltage that partly is used to receive by the described secondary winding acquisition of described insulation converter transformer, and the rectification operation of the execution primary side AC voltage that receives, to produce a plurality of primary side DC output voltages;

Frequency-control-type fixed voltage control section, described frequency-control-type fixed voltage control section is controlled described switch drive part according to required one level of a plurality of primary side DC output voltages, change the switching frequency of described switch sections, a required primary side DC output voltage is carried out fixed voltage control;

Inductance control type fixed voltage control section for each setting of required a plurality of primary side DC output voltages, wherein, except a required primary side DC output voltage, required a plurality of primary side DC output voltage is required it is fixed voltage, the target of the fixed voltage control that a required primary side DC output voltage is described frequency-control-type fixed voltage control section, described inductance control type fixed voltage control section is configured to: the controlled winding as the control transformer of saturable reactor form is inserted into the primary side rectified current path that is used for producing primary side DC output voltage, described control transformer has control winding and winding described controlled winding thereon, and, the Control current level that will offer described control winding changes according to the primary side DC output-voltage levels of importing, to change the inductance of controlled winding, thus primary side DC output voltage is carried out fixed voltage control; And

First switch sections, described first switch sections is the moment after the scheduled time in the past after predetermined primary side DC output voltage raises, and the primary side rectified current path that is used to produce another predetermined primary side DC output voltage is switched to on-state from off-state; And

Be used to improve the power factor raising circuit of power factor;

Described power factor improves circuit and comprises that power factor improves transformer and is inserted into rectifier cell in the desired location of rectified current path, wherein, described power factor improves transformer and is inserted into power factor in the described primary side series resonant circuit and improves elementary winding and be inserted into power factor in the rectified current path and improve secondary winding and form by twining series connection, described rectified current path forms described rectification smooth, improve elementary winding by described power factor, based on improving the driving voltage that encourages in the secondary winding and carry out switching manipulation, to interrupt rectified current in described power factor.

5. switching power circuit as claimed in claim 1, wherein

Be arranged on described first switch sections in described first switch converters part and be arranged in other switch converters part described first switch sections each all

Reception is by predetermined one in a plurality of primary side DC output voltages of the described DC output voltage generation part generation of described first switch converters part, and, after reception primary side DC output voltage raises, after postponing the time that obtains by time constant circuit, primary side rectified current path is switched to on-state from off-state.

6. switching power circuit as claimed in claim 1, wherein

Described rectifying part is the diode that connects in bridge-type connects, and has: two commutating voltage outputs that are provided the terminal of ac input voltage, the reference potential end that is connected to reference potential and output commutating voltage;

Described smooth is two smmothing capacitors of connecting by node between them between described commutating voltage output and the described reference potential end; And

Described switching power circuit further comprises and is arranged on the second switch part that is used to carry out switching between one of two terminals that are provided ac input voltage and the described node, thereby, when ac input voltage is lower than reference voltage, the operation of execution voltage multiplying rectifier, in this operation, described second switch partly places on-state to produce the rectification smooth voltage that its level equals twice ac input voltage level, but, when ac input voltage is higher than reference voltage, carry out isobaric rectification operation, in this operation, described second switch partly places off-state, to produce another rectification smooth voltage that its level equates with the ac input voltage level.

7. a plasma display panel device comprises as claim 1 or 4 described switching power circuits, provides primary side DC output voltage to described plasma display panel device, as driving power.

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