JPH08186982A - Dc power supply - Google Patents

Abstract

PURPOSE: To rectify an AC voltage and remove harmonics of a current flowing into an AC power supply terminal in a DC power supply for smoothing the voltage with a capacitor and also improve power factor. CONSTITUTION: An QC voltage is rectified with a first rectifying circuit to charge a smoothing capacitor C1. An AC voltage is rectified with a second rectifying circuit. A voltage boosting bias circuit 10 is connected between the second rectifying circuit and the smoothing capacitor C1. A pulse current for charging the capacitor C1 and a bias power source voltage passing through a bias circuit flow are to the AC power supply terminal. Thereby, harmonics in the input current is reduced and the power factor is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a DC power supply device suitable as a power supply for office automation equipment and the like, and more specifically, it can obtain a relatively long power failure guarantee period and improve the input power factor. DC power supply device

[0002]

2. Description of the Related Art A power supply device for an electronic device connected to a commercial AC power supply comprises a rectifier, a smoothing capacitor and a switching regulator circuit. The smoothing capacitor in this type of power supply device functions not only as a smoothing function but also as a power supply for guaranteeing a power failure.

[0003]

When the capacity of the smoothing capacitor is increased, the power failure guarantee time becomes longer, but the power factor on the input side of the rectifier deteriorates. That is, in this case, the ripple of the voltage of the smoothing capacitor becomes small, the current of the capacitor flows only near the peak value of the sine wave AC voltage, the harmonic component of the input current increases, and the power factor deteriorates. This kind of problem can be solved to some extent by reducing the capacity of the smoothing capacitor, but the power failure guarantee time is shortened.

Therefore, an object of the present invention is to provide a DC power supply device which can obtain a relatively long power failure guarantee time and can improve the input power factor.

[0005]

SUMMARY OF THE INVENTION To achieve the above object, the present invention is directed to an AC power supply terminal and includes first and second
A rectification circuit having a rectification output terminal and a common terminal of
One end of the smoothing capacitor is connected to the first rectification output terminal and the other end is connected to the common terminal, and the smoothing capacitor is connected between the second rectification output terminal and the one end of the smoothing capacitor. And a DC power supply configured to supply power from the smoothing capacitor to a load, the boosting DC bias power supply and an impedance included in the bias power supply and / or connected in series to the bias power supply. It is related to the device. As described in claim 2, instead of providing two rectified output terminals, a bias power source can be connected in parallel with the diode. Further, as shown in claim 3, the diode of claim 2 can be omitted. In addition, claim 4
As shown in, the output transformer of the switching power supply circuit can be used to obtain the voltage for the bias power supply. Further, as described in claim 5, means for controlling the bias voltage can be provided. Further, as described in claim 6, the bias voltage can be obtained based on the voltage of the output smoothing choke coil. Further, as described in claim 7, first and second bias power supplies can be provided. Further, a voltage doubler circuit can be formed as described in claim 8.

[0006]

According to the invention of each claim, in addition to the charging current of the capacitor, a current flowing through the bias power supply flows. Since the above two combined currents flow through the AC power supply terminal, the current has less harmonic components than the conventional case where only the capacitor charging current is used, and the power factor is also improved. When the bias power supply is configured by also using the output transformer or the choke coil of the output stage as described in claim 4 or 6, the bias voltage can be easily obtained. By controlling the output voltage as described in claim 5, it is possible to prevent an excessive voltage from being applied to the load. Moreover, the peak of the input AC current becomes small. According to claim 7, since two bias power supplies are provided, the voltage of each bias power supply can be lowered. According to claim 8, a high voltage can be easily obtained.

[0007]

[First Embodiment] Next, a first embodiment of the present invention will be described with reference to FIGS. In the DC power supply device shown in FIG. 1, for example, a rectification having a first rectification output line 3, a second rectification output line 4, and a common line (ground line) 5 at 50 Hz sine wave commercial AC power supply terminals 1 and 2. The circuit 6 is connected. This rectifier circuit 6 is
It comprises a bridge circuit of the fourth diodes D1 to D4 and fifth and sixth diodes D5 and D6 added thereto. The anodes of the fifth and sixth diodes D5 and D6 for obtaining the second rectified output are connected to the AC power supply terminals 1 and 2. Therefore, the fifth and sixth diodes D5,
D6 also serves as the third and fourth diodes D3 and D4 to form a bridge rectifier circuit. The first rectified output line 3 serving as the first rectified output terminal is connected to the cathodes of the first and second diodes D1 and D2, and the second rectified output line 4 serving as the second rectified output terminal is the fifth. And the sixth
Is connected to the cathodes of the diodes D5 and D6 of the common line 5 and the common line 5 serving as a common terminal has the third and fourth diodes D5.
3, connected to the anode of D4.

The smoothing capacitor C1 is connected between the first rectified output line 3 and the common line 5. One end of this smoothing capacitor C1 is connected to the DC output terminal 7, and the other end is connected to the ground terminal 8. A load 9 is connected between the pair of terminals 7 and 8. A bias circuit 10 is connected between the second rectified output line 4 and one end of the capacitor C1. This bias circuit 10
DC bias power supply B for supplying a DC voltage lower than the maximum charging voltage of the capacitor C1 and this bias power supply B
An impedance Z consisting of an inductance and / or a resistance connected in series with the.

As is clear from FIG. 2 which shows the waveforms of the respective parts of FIG. 1, when the AC voltage Vac shown in FIG. 2A is applied to the AC power supply terminals 1 and 2, the capacitor C1 from the first rectified output line 3 is applied. As shown in FIG. 2D, the pulsed current I
a flows. In addition, from the second rectified output line 4, FIG.
A sinusoidal current Ib flows as shown in FIG. This current Ib flows for a longer time than the pulsed current Ia.
The current Iac at the AC power supply terminals 1 and 2 is the current Ia of the first rectified output line 3 and the current Iac of the second rectified output line 4.
Since it is the sum of b and b, the waveform shown in FIG. The waveform of this current Iac is not a sine wave, but the harmonic component is smaller than that of the case of only the charging current Ia of the capacitor C1 shown in FIG. 2D because of the addition of the current Ib of the second rectified output line 4. , The input power factor also improves.

The operation of the circuit shown in FIG. 1 will be described in more detail. As is apparent from FIG. 2, which shows the voltages at the various parts of FIG.
For example, during the positive half-wave period of the sine wave, the voltage (hereinafter referred to as input voltage) Va between the anodes of the diodes D1 and D5 and the ground line 5 is the voltage V of the capacitor C1.
The input current Iac is shown only in the period t1 to t4 which is higher than c.
It flows as shown in (E). t1 to t2 period and t3 to
In the period t4, the input voltage Va is lower than the capacitor voltage Vc, but the voltage Va + V10 = Vb (hereinafter referred to as the bias addition voltage) obtained by adding the bias voltage V10 to the input voltage Va.
Is higher than the capacitor voltage Vc. Therefore, t1 to t2
During the period and t3 to t4, the current Ib shown in FIG. 2C can be passed through the capacitor C1 and the load 9 through the bias circuit 10. Since the bias addition voltage Vb is higher than the capacitor voltage Vc during the period t2 to t3, the bias current Ib flows. Since this bias current Ib flows through the impedance Z composed of an inductance and a resistance, it does not have a steep waveform and has a low level. When the sine wave input voltage Va becomes higher than the capacitor voltage Vc in the period of t2 to t3, the current Ia flowing from the first rectified output line 3 to the capacitor C1 is changed as shown in FIG.
It occurs as shown in (D). Therefore, the capacitor C1
Even if the battery has a relatively large capacity, the desired state of charge can be obtained.

By providing the bias circuit 10 in this DC power supply device, the current Iac can be made to flow for a relatively long period during the half-sine wave period, and the input power factor is determined by the waveform of FIG. 2 (D). Instead, it is determined by the waveform shown in FIG. 2 (E), which has the effect of increasing the power factor. Further, even if the capacity of the capacitor C1 is increased and the power failure guarantee period is lengthened, the power factor is reduced little.

[0012]

[Second Embodiment] Next, a DC power supply device according to a second embodiment will be described with reference to FIG. However, in FIG. 3 and the drawings showing other embodiments to be described later, substantially the same parts as those in FIG. 2 and the drawings showing the other embodiments are denoted by the same reference numerals and the description thereof will be omitted. In FIG. 3, a switching regulator circuit 9a is provided as the load 9 of FIG. The switching regulator circuit 9a is the transformer 1
1 has a primary winding 12 and a series circuit of a switch Q1 composed of a field effect transistor. This series circuit has a line 7a corresponding to the output terminal 7 and the ground terminal 8 of FIG.
It is connected between 8a. Secondary winding 1 of transformer 11
A rectifying / smoothing circuit including a diode 14 and a capacitor 15 is connected to 3. A load 18 is connected to the output terminals 16 and 17 of this rectifying / smoothing circuit. The control circuit 19 connected to the control terminal (gate) of the switch Q1 controls the frequency of the AC voltage of the AC power supply terminals 1 and 2 (for example, 50H).
A PWM pulse for controlling ON / OFF of the switch Q1 is generated at a frequency sufficiently higher than z) (for example, 20 kHz). Since this control circuit 19 is connected to the output terminal 16, it forms a PWM pulse for keeping the output voltage constant by a known method.

The bias circuit 10a of FIG. 3 having the same function as the bias circuit 10 of FIG. 1 comprises a bias power supply capacitor 20, a winding 21 for charging the bias power supply capacitor 20, a diode 22 and a reactor Lx. The bias power supply capacitor 20 is connected between the second rectified output line 4 and one end of the smoothing capacitor C1, that is, the DC output line 7a. The bias power supply winding 21 is electromagnetically coupled to the primary and secondary windings 12 and 13 of the transformer 11. The primary winding 12 and the secondary winding 13 of the transformer 11 are related so as to generate a voltage in a direction for keeping the diode 14 off during the ON period of the switch Q1. The bias power supply winding (tertiary winding) 21 has a polarity such that a voltage for turning on the diode 22 is obtained during the off period of the switch Q1. Therefore, the capacitor 20 is charged by the voltage of the tertiary winding 21 during the ON period of the switch Q1. The diode 22 is connected between the upper end of the capacitor 20 and the upper end of the winding 21 so as not to interfere with the power supply from the smoothing capacitor C1 to the switching regulator 9a. Further, the capacitor 20 has an internal impedance Z, that is, an internal resistance R.

In the DC power supply device of FIG. 3, the bias circuit 10a has substantially the same function as the bias circuit 10 including the bias power supply B and the impedance Z of FIG. Have. Further, the bias circuit 10a is a switching regulator circuit 9a.
Since the transformer 11 is also used, the cost of the bias circuit 10a can be reduced.

[0015]

[Third Embodiment] The DC power supply apparatus of the third embodiment shown in FIG. 4 is the same as that of FIG. 1 except that the diodes D5 and D6 are omitted from the circuit of FIG. 1 and a diode D7 is connected to the bias circuit 10 instead. Is configured the same as. That is, the parallel circuit of the bias circuit 10 and the diode D7 is connected between one output terminal of the rectifying circuit 6a and the capacitor C1. The operation of the circuit of FIG. 4 is the same as that of FIG. 1, and the waveform of each part is as shown in FIG. That is, t1 to t2 period and t3 to t4
During the period, the current Ib flows only through the bias circuit 10, and during the period from t2 to t3, the input voltage Va becomes higher than the capacitor voltage Vc, so that the diode D7 enters the forward bias state, that is, the on state, and the current passing therethrough. Ia also flows. As a result, the same function and effect as those in FIG. 1 can be obtained by the DC power supply device in FIG.

[0016]

[Fourth Embodiment] The DC power supply device of FIG.
3 is replaced with the same switching regulator circuit 9a as in FIG. 3, and the bias circuit 10 is replaced with the same bias circuit 10a as in FIG. Therefore, the DC power supply device of FIG. 5 has the same effects as those of FIGS. 4 and 3.

[0017]

[Fifth Embodiment] The DC power supply device of FIG. 6 has the same structure as that of FIG. 4 except that the diode D7 is omitted from the circuit of FIG. In FIG. 6, an impedance Z composed of an inductance and a resistance is provided between the rectifier circuit 6a and the capacitor C1.
Can be regarded as a choke input type filter circuit. It is necessary to increase the inductance of the choke coil in order to improve the continuity of current in the choke input type filter. On the other hand, in the circuit of FIG. 6, since the DC bias power source B is connected in series to the impedance Z, the bias voltage V10 is added to the input voltage Va even in the region where the sine wave input voltage Va is low. The period in which the voltage Vb becomes higher than the capacitor voltage Vc becomes longer, and the power factor improvement is achieved by the same principle as in FIG. The impedance Z may be a variable impedance so that the impedance value (resistance value) becomes low when the applied voltage is high, and a large charging current can be made to flow in the capacitor C1 near the peak value of the sine wave.

[0018]

[Sixth Embodiment] The DC power supply device shown in FIG.
Is replaced with the switching regulator circuit 9a of FIG. 3, and the bias power source B of FIG. 6 is replaced with the bias circuit 10a of FIG.
The configuration is the same as that of FIG. 6 except that it is replaced with. Therefore, the DC power supply device of FIG. 7 has the same effect as that of FIG. 6, and also has the effect of circuit simplification as in FIG.

[0019]

[Seventh Embodiment] In the DC power supply device according to the seventh embodiment of FIG. 8, the cathode side of the diodes D3 and D4 is connected to the common line 5.
The anode side of the diodes D1 and D2 is the first rectified output line 3, the anode side of the diodes D5 and D6 is the second rectified output line 4, and the capacitor 20 is the second rectified output line 4 and the lower end of the switch Q1. It is connected between and. Further, in FIG. 8, the charging power source of the capacitor 20 is the winding 21 electromagnetically coupled to the smoothing reactor (choke coil) L0 on the secondary side, which is the reactor Lx.
Is connected to the capacitor 20 via a diode 22. Bias capacitor 2 even if formed as shown in FIG.
The function of 0 is the same as that of FIG. 3, and the same effect as that of FIG. 3 can be obtained. The switching regulator circuit 9a of FIG. 8 is configured as a forward type converter so that the diode 14 on the secondary side is turned on during the ON period of the switch Q1. Therefore, the polarities of the secondary and tertiary windings 13 and 21 are opposite to those in FIG. Further, a reactor L0 and a diode D0 for forming a smoothing circuit are added to the secondary side. The reactor L0 is connected in series between the diode 14 and the output terminal 16, and the diode D0 is connected in parallel to the capacitor 15 via the reactor L0. In the circuit of FIG. 8, the voltage for charging the capacitor 20 during the ON period of the switch Q1 is the winding 2
1 is obtained.

[0020]

[Eighth Embodiment] The direct-current power supply device according to the eighth embodiment of FIG. 9 is configured so that a voltage doubler rectifier circuit can be selectively formed. That is, in FIG. 9, two capacitors C1a and C1b are provided in place of the one capacitor C1 in FIG. 1, and a series circuit of these is connected between the lines 3 and 5. Also, AC power supply terminal 2 and two capacitors C1
A changeover switch S is provided between the connection point of a and C1b. When the switch S is on, a voltage doubler circuit is formed. In FIG. 9, two bias circuits 10a and 10b are provided, and the first bias circuit 10a is a diode D5.
, D6 and the output terminal 7, and the second bias circuit 10b is connected between the output terminal 8 and the diodes D7 and D8. The diodes D7 and D8 form a bridge type rectifying circuit together with the diodes D5 and D6. In FIG. 9, the first and second bias circuits 10a and 10b are composed of bias power supplies B1 and B2 and impedances Z1 and Z2.

In the circuit of FIG. 9, when the switch S is off,
It operates substantially the same as the circuit of FIG. When the switch S is turned on, the voltages of the capacitors C1a and C1b are doubled when the switch S is turned off by the operation of the well-known voltage doubler rectifier circuit. At this time, the voltages of the first and second bias power supplies B1 and B2 are also doubled. As a result, the currents Ia and Ib flow as in the case where the switch S is turned off, and the waveform and power factor of the input current Iac are improved.

[0022]

[Ninth Embodiment] A DC power supply device according to a ninth embodiment shown in FIG. 10 is such that the bias circuit 10a shown in FIG. 3 is a variable bias circuit 10c and the switching regulator circuit 9a is shown in FIG.
Similarly to the above, the configuration is the same as that of FIG. 3 except that the forward type is used. That is, a series circuit of the transistor 24 and the diode 25 is connected in parallel to the capacitor 20 and the diode 22 in order to adjust the voltage of the capacitor 20. The base of the transistor 24 is connected to the control circuit 26, and the transistor 24 is intermittently controlled in response to a control signal from the control circuit 26 to bypass the charging current of the capacitor 20 and increase the output voltage of the rectifier circuit 6 to increase the output voltage of the capacitor 20. The voltage is reduced. As a result, the maximum value of the current Ib of the second rectified output line 4 is limited, and the state becomes equivalent to that the current Ib of FIG. 2C is reduced, and the maximum value of the AC input current Iac is also reduced. The resistance of the transistor 24 may be changed to control the charging of the capacitor 20. Since the main part of the circuit of FIG. 10 is the same as that of FIG. 3, the same effect as that of FIG. 3 can be obtained.

[0023]

[Tenth Embodiment] A direct-current power supply device according to a tenth embodiment shown in FIG. 11 is obtained by modifying only the internal structure of a switching regulator circuit 9a as a load and the internal structure of a bias circuit 10a shown in FIG. It is configured in the same manner as 3. In FIG. 11, the switching regulator circuit 9a as a load is configured by using a half bridge type inverter. That is, the series circuit of the first and second switches Q1 and Q2 and the first and second switches are provided between the DC output line 7a from which the output voltage Vc is obtained and the ground line 8a.
Is connected to the series circuit of the capacitors 31 and 32, and the primary winding 12 of the transformer 11 is connected between the connection midpoints thereof. The secondary winding 13 of the transformer 11 has a center tap and is connected to the smoothing capacitor 15 via two diodes 14a and 14b. A control circuit 19 connected to the control terminals of the first and second switches Q1 and Q2.
The reference character a generates a control signal for alternately turning on / off the first and second switches Q1 and Q2 at a frequency sufficiently higher than the AC power supply voltage Vac.

The bias circuit 10d shown in FIG. 11 has a tertiary winding 21 having a center tap and diodes 22a, 22 for rectifying the voltage induced therein and charging the capacitor 20.
b and. The capacitor 20 that functions as a bias power supply is connected between the second rectified output line 4 and the DC output line 7a.

Since the voltage Vc applied to the half-bridge type switching regulator 9a in FIG. 11 is substantially the same as that in FIG. 3, the same effect as that in FIG. 3 can be obtained.

[0026]

[Eleventh Embodiment] The direct-current power supply device of the eleventh embodiment of FIG. 12 omits the capacitor 31 of FIG. 11 and connects the series circuit of the primary winding 12 and the capacitor 32 in parallel with the second switch Q2. It includes a well-known modified half bridge connected. In FIG. 12, the reactors Lx1 and Lx2 are connected in series to the diodes 22a and 22b. 12
In principle, the circuit is the same as that in FIG. 3, so that the same effect can be obtained.

[0027]

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible. (1) The bias circuit 10a shown in FIGS. 3, 5, and 7 is replaced with the bias circuit 10a 'shown in FIGS. 8, 10, 11, and 12.
It can be replaced with 10c, 10d, and 10e. (2) Bias circuit 10 of FIGS. 8, 11, and 12
The a ', 10d, and 10e can be replaced with the bias circuit 10a shown in FIG. (3) FIG. 3, FIG. 5, FIG. 7, FIG. 8, FIG. 9, FIG.
1, the bias circuits 10a, 10a ', 10b of FIG.
10c, 10d, and 10e are replaced by any one of the bias circuits 10f to 10n and 10p to 10u shown in FIGS.
Can be replaced with one. 13 to 24, substantially the same parts as those in FIGS. 3, 5, 7, 8, 10, 11, and 12 are designated by the same reference numerals. 13 to 24, Lx, Lx1, and Lx2 are smoothing reactors, and Cx is a voltage doubler capacitor. Reactor Lx, Lx1, Lx2 connection position is winding 2
1 or the diode 22a or the diode 22b, or the capacitor 20 can be connected to any position in series. 20 to 24 show modified examples in which capacitors corresponding to the capacitors 20, 20a and 20b in FIGS. 13 to 19 are not provided. In this case winding 21
Is the bias voltage. (4) The leakage inductance of the winding 21 can be increased to eliminate the reactors Lx, Lx1, and Lx2. (5) The transistor 24 of FIG. 10 can be connected between the winding 21 and the capacitor 20. Further, the charging voltage of the capacitor 20 can be controlled in various types of bias circuits other than the bias circuit 10a. (6) FIG. 1, FIG. 3, FIG. 4, FIG. 5, FIG. 6, FIG.
0, FIG. 11 and FIG. 12, bias circuits 10a, 1
0c, 10d, 10e are connected to the diode D in the same manner as in FIG.
1, can be connected to the anode side of D2. (7) The rectifying / smoothing circuit connected to the secondary winding 13 of the transformer 11 shown in FIGS. 3, 5, 7, 11, and 12 has a circuit configuration having a reactor L0 as shown in FIGS. 8 and 10. You can (8) The voltage for charging the capacitor 20 is applied to the winding 2
Instead of being obtained from 1, it can be obtained from the primary winding 12 of the transformer 11. (9) In the switching regulator 9a of FIG. 3, in order to reduce the breakdown voltage of the transistor Q1, the winding 12
Another transistor can be connected in series to the upper side of the transistor and turned on / off simultaneously with the lower transistor Q1. (10) In the circuit of FIG. 12, the series circuit of the primary winding 12 and the capacitor 32 can be connected in parallel to the upper transistor Q1. (11) FIG. 3, FIG. 5, FIG. 8, FIG. 10, FIG.
In, the capacitor 20 has a relatively large internal impedance, but in place of or in addition to this internal impedance, the capacitor 20 or the bias circuits 10a, 10a ', 10c, 10d, 10e are preferably connected in series. A separate impedance element consisting of a resistance and / or an inductance can be connected. (12) In the circuits of FIGS. 3, 8, and 10 to 12, the diodes D3 and D4 may not be shared by the two rectifier circuits, and another diode may be provided to form the bridge circuit with the diodes D5 and D6. it can. (13) A high frequency filter can be connected to the input power supply terminals 1 and 2. (14) The load 9 may be a full bridge type inverter circuit. (15) The power supply of the control circuit 19 is the bias circuit 10a,
It can be taken from 10a ', 10c, 10d, 10e.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a DC power supply device of a first embodiment.

FIG. 2 is a circuit diagram showing a state of each part of FIG.

FIG. 3 is a circuit diagram showing a DC power supply device of a second embodiment.

FIG. 4 is a circuit diagram showing a DC power supply device according to a third embodiment.

FIG. 5 is a circuit diagram showing a DC power supply device of a fourth embodiment.

FIG. 6 is a circuit diagram showing a DC power supply device of a fifth embodiment.

FIG. 7 is a circuit diagram showing a DC power supply device according to a sixth embodiment.

FIG. 8 is a circuit diagram showing a DC power supply device of a seventh embodiment.

FIG. 9 is a circuit diagram showing a DC power supply device of an eighth embodiment.

FIG. 10 is a circuit diagram showing a DC power supply device of a ninth embodiment.

11 is a waveform chart showing a state of each part of FIG.

FIG. 12 is a circuit diagram showing a DC power supply device of a tenth embodiment.

FIG. 13 is a circuit diagram showing a modified bias circuit.

FIG. 14 is a circuit diagram showing another bias circuit.

FIG. 15 is a circuit diagram showing still another bias circuit.

FIG. 16 is a circuit diagram showing still another bias circuit.

FIG. 17 is a circuit diagram showing still another bias circuit.

FIG. 18 is a circuit diagram showing still another bias power supply.

FIG. 19 is a circuit diagram showing still another bias power supply.

FIG. 20 is a circuit diagram showing still another bias power supply.

FIG. 21 is a circuit diagram showing still another bias power supply.

FIG. 22 is a circuit diagram showing still another bias power supply.

FIG. 23 is a circuit diagram showing still another bias power supply.

FIG. 24 is a circuit diagram showing still another bias power supply.

FIG. 25 is a circuit diagram showing still another bias power supply.

FIG. 26 is a circuit diagram showing still another bias power supply.

FIG. 27 is a circuit diagram showing still another bias power supply.

[Explanation of symbols]

 6 Rectifier circuit 10 Bias circuit C1 capacitor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H02M 3/335 F

Claims (8)

[Claims] 1. A rectifier circuit connected to an AC power supply terminal and having first and second rectified output terminals and a common terminal; and one end of which is connected to the first rectified output terminal, the common A smoothing capacitor having the other end connected to the terminal; a boosting DC bias power supply connected between the second rectification output terminal and the one end of the smoothing capacitor; And / or an impedance connected in series to the bias power source, and configured to supply power from the smoothing capacitor to a load. 2. A rectifier circuit connected to an AC power supply terminal, a smoothing capacitor connected between one output terminal and the other output terminal of the rectifier circuit via a diode, and one of the rectifier circuits. A step-up DC bias power source connected between the output terminal of the bias power source and the one terminal of the smoothing capacitor and connected in parallel to the diode, and / or included in the bias power source and / or the bias power source. A DC power supply device comprising an impedance connected in series and connected in parallel to the diode, and configured to supply electric power from the smoothing capacitor to a load. 3. A rectifier circuit connected to an AC power supply terminal, a smoothing capacitor connected between one output terminal and the other output terminal of the rectifier circuit, and one output terminal of the rectifier circuit. A step-up DC bias power supply connected to one end of the smoothing capacitor; and an impedance included in the bias power supply and / or connected in series to the bias power supply. A DC power supply configured to supply power to a load. 4. The load is connected in parallel to the smoothing capacitor and outputs at least one switching element for interrupting the voltage of the smoothing capacitor and the voltage interrupted by the switching element. The output power transformer is included in the switching power supply circuit, and the bias power supply rectifies a voltage obtained based on the output transformer to generate a bias voltage. 3. The DC power supply device according to 3. 5. The bias power source has means for controlling a bias voltage, according to claim 1 or 2.
Alternatively, the DC power supply device according to 3 or 4. 6. The switching power supply circuit has a rectifying / smoothing circuit connected to an output winding of the output transformer, the rectifying / smoothing circuit has a choke coil, and the bias power supply has the choke coil. The DC power supply device according to claim 1, 2 or 3 or 5, wherein a DC power supply voltage is obtained by including a bias power supply winding electromagnetically coupled to the diode and a diode that rectifies the voltage of the bias power supply winding. . 7. A first and a second rectifying circuit connected to a pair of AC power supply terminals, and a smoothing connected between one rectifying output terminal and the other rectifying output terminal of the first rectifying circuit. Capacitor, a first DC bias power supply connected between one rectification output terminal of the second rectification circuit and one end of the smoothing capacitor, and a first DC bias power supply included in the first DC bias power supply. / Or a second impedance connected between the first impedance connected in series to the first DC bias power supply and the other rectification output terminal of the second rectification circuit and the other end of the smoothing capacitor And a second impedance included in the second DC bias power supply and / or connected in series to the second DC bias power supply, the power from the smoothing capacitor to the load. Supply DC power supply unit configured to so that. 8. The capacitor comprises a series circuit of first and second capacitors, and one of the pair of AC power supply terminals and a connection midpoint of the first and second capacitors for obtaining a doubled voltage. 5. The DC power supply device according to claim 4, further comprising means for connecting the fixedly or selectively.