KR102592229B1 - Power Supply for LED Lamp - Google Patents

Abstract

An embodiment of the present invention relates to a power supply apparatus of an LED lamp, capable of allowing a current to be linearly controlled in order for an LED lamp used for traffic lights to have a high power factor or a low harmonic factor with respect to AC input power, and preventing traffic lights from malfunctioning due to Z1 impedance on a load switch unit (LSU) installed within a traffic light controller. The power supply apparatus of an LED lamp capable of allowing a current flowing in an LED lamp to be linearly controlled, includes: a power supply part supplying a power voltage; a rectification part rectifying the power voltage supplied from the power supply part; a traffic light emitting part receiving the rectified power voltage to emit light through a plurality of light emission diodes; a current source allowing the current flowing in the traffic light emitting part to flow nearly constantly regardless of the voltage applied to the traffic light emitting part; and a discharge circuit part discharging a temporary voltage caused by Z1 impedance when the power is off in order to prevent traffic lights from malfunctioning due to Z1 impedance on a load switch unit (LSU) installed within a traffic light controller.

Description

Power supply for LED lamp {Power Supply for LED Lamp}

The present invention relates to a power supply device for an LED lamp. More specifically, the current is linearly controlled to make an LED lamp used in an AC power source, such as a traffic signal, have a high power factor or a low harmonic factor with respect to the AC input power. It relates to a power supply device for LED lamps that prevents malfunction of traffic lights due to impedance on the LSU (Load Switch Unit) board installed in the traffic signal controller.

With the development of semiconductor technology, the production of light emitting diodes (LEDs) has diversified, and LEDs, which consume only 1/10 the power required to obtain the same illuminance compared to regular light bulbs, are being applied to vehicle and traffic light lights. It's a trend.

However, a separate power supply is required to drive traffic lights using LEDs. In other words, traffic lights using conventional light bulbs used 220 volt alternating current power, so a separate power device was not needed, but light emitting diodes use direct current power, so the 220 volt commercial power is rectified into direct current, and the rectified direct current voltage is used. In order to convert the voltage into a direct current voltage of the size required for lighting, a switching mode power supply (SMPS) is needed.

Figure 1 is a configuration diagram showing a conventional SMPS circuit for driving an LED lamp.

The conventional SMPS circuit 100 for driving an LED includes an overcurrent and overvoltage protection unit 110 consisting of a fuse, a varistor, and a line filter to protect the SMPS from overcurrent and overvoltage of the input AC power, and an overcurrent and overvoltage protection unit 110 to convert the AC voltage into a DC voltage. A rectifier 120 consisting of a bridge diode, a power supply unit 130 that converts and outputs the current voltage input through the rectifier 120 according to the switching operation of a transistor to be supplied to a signal light (load) using an LED, and the duty cycle of the transistor. A control signal generator 140 generates a control signal from a photo diode to control the ratio, and receives the control signal output from the control signal generator 140 through a photo transistor and outputs it to the secondary side of the power supply unit 130. A control unit 150 for adjusting the magnitude of the voltage, a power factor adjustment unit 160 connected to the primary side of the power supply unit 130 to adjust the power factor of the power supply unit 130, a rectifier unit 120, and a power supply unit 130. ) A pulsating current voltage prevention unit 170 for blocking the pulsating voltage, and a plurality of resistors connected in series between the control signal generating unit 140 and the load end are connected in parallel to form a control signal generating unit 140. It has a configuration including a reference voltage generator 180 including a negative temperature coefficient thermistor connected in parallel with a first resistor connected between the portion that draws the reference voltage output to and the output ground line.

The varistor in the overcurrent and overvoltage prevention unit 110 suppresses the surge voltage that can be input from the AC power terminal by connecting it to the ground to prevent it from affecting the SMPS, and uses a line filter of the reactance component. ) suppresses the overcurrent component, and the rectifier 120 rectifies the alternating current voltage input through the overcurrent and overvoltage prevention unit 110 into a direct current voltage.

The current passing through the diode (D5) is suppressed from rapid rise by the inductor (L2) and is charged to the capacitor (C3) through the primary side (T1, T2) of the power supply unit 130. The diode (D5) is connected to the controller ( When the MOSFET in U1) is turned off, the capacitor C1 is prevented from being reversely charged due to an increase in the transformer voltage of the power supply unit 130. Additionally, the diode (D6) also prevents current from flowing back to the inductor (L2) when the MOSFET in the controller (U1) is turned off. On the other hand, when the MOSFET in the controller (U1) is turned on, the charging voltage of the capacitor (C3) flows through the primary side (T1 and T2) of the power supply unit 130 and is induced to the secondary side (T4).

Here, the inductor L2 in the power factor adjustment unit 160 is associated with the capacitor C1 to improve the power factor. The inductance of the reactor L2 is increased and the capacitance of the capacitor C1 is decreased. The capacitor C2 in the power factor adjustment unit 160 is used as a snubber, and a non-polar coupling capacitor is used as the capacitor C3, which is required due to the nature of the traffic light when a polarized capacitor is used. This prevents frequent breakdowns due to insulation breakdown caused by repeated on and off.

The transient diode (TD1) of the pulsating current voltage prevention unit 170 is a pulsating current that blocks the voltage applied to both ends of the capacitor (C5) connected in parallel with the primary side (T3) of the power supply unit 130 in the line filter when it exceeds a certain level. It is a diode for voltage prevention, and the resistance (R1) of the pulsating voltage prevention unit 170 initially has a time constant (R1*C5) and is used only to charge the capacitor (C5), and after the capacitor (C5) is charged, This is an unused starting resistor.

The controller U1 in the control unit 150 is a pulse width modulation chip, and the width of the voltage pulse changes depending on the change in the turn-on time of the photo transistor U2.

In this way, lighting LED lamps used in traffic lights to have a high power factor of more than 90% or a low harmonic distortion (THD: Total Hamornic Distortion) of less than 40% with respect to AC input power requires 15W. Very difficult at loads below that. In addition, it is technically difficult to maintain the illuminance at a certain level even with ±20% fluctuation in power and temperature changes.

Therefore, in general, the SMPS method as above is adopted and the power factor adjustment unit 160 is used in the front end. As shown in FIG. 1, not only is the circuit itself complicated, but the scale of the device is large due to the use of inductors, electrolytic capacitors, etc. You lose.

In addition, there is a problem that the lifespan of the electrolytic condenser is only about 2 to 3 years, so it is not suitable for LED lamps that must maintain a lifespan of more than 10 years. In addition, due to the problem of electromagnetic interference (EMI) generated during switching, a noise filter such as the pulsating voltage prevention unit 170 is added, causing a problem in that the device circuit becomes more complicated.

In addition, there was a problem in which traffic lights sometimes malfunctioned due to the Z1 impedance value on the LSU (Load Switch Unit) board installed in many old traffic signal controllers installed throughout the country.

Registered Patent No. 10-1740892 (May 23, 2017)

The present invention is intended to solve the above-described conventional problems, and its purpose is to linearly control the current in order to make the LED lamp used in traffic lights have a high power factor or a low harmonic factor with respect to the AC input power. , provides a power supply device for LED lamps that prevents malfunction of traffic lights due to Z1 impedance on the LSU (Load Switch Unit) board installed in the traffic signal controller.

In order to achieve the above-described object, a power supply device for an LED lamp according to various aspects of the present invention is a power supply device for an LED lamp that linearly controls the current flowing in the LED lamp, including a power supply unit for supplying a power voltage; a rectifier that rectifies the power voltage supplied from the power supply unit; a traffic light emitting unit that receives the rectified power voltage and emits light through a plurality of light emitting diodes; A current source that ensures that the current flowing through the traffic light emitting unit flows almost constantly regardless of the voltage applied to the traffic light emitting unit; and a discharge circuit unit that discharges the applied voltage due to the Z1 impedance when the power is turned off to prevent malfunction of the traffic light due to the Z1 impedance on the LSU (Load Switch Unit) board installed in the traffic signal controller.

The current source may include a transistor-type current source, a MOSFET-type current source, an amplifier-type current source, a comparator-type current source, etc.

According to various aspects of the present invention, the LED lamp is linearly controlled to have a high power factor and a low harmonic ratio.

In addition, even if the same LED current flows as before, the energization time is further increased, so that the illuminance of the LED lamp can be maintained for a longer period of time and the lifespan of the LED lamp can be further extended.

In addition, it has the effect of preventing malfunction of traffic lights due to Z1 impedance on the LSU (Load Switch Unit) board installed in the traffic signal controller.

1 is a configuration diagram showing a conventional SMPS circuit for driving an LED lamp;
Figure 2 is a circuit diagram showing a power supply device for an LED lamp according to a first embodiment of the present invention;
Figure 3 is a diagram showing the waveform of current according to voltage;
4 is a circuit diagram showing a power supply device for an LED lamp according to a second embodiment of the present invention;
5 is a circuit diagram showing a power supply device for an LED lamp according to a third embodiment of the present invention;
Figure 6 is a circuit diagram showing a power supply device for an LED lamp according to a fourth embodiment of the present invention;
7 is a circuit diagram showing a power supply device for an LED lamp according to a fifth embodiment of the present invention;
Figure 8 is a diagram showing the operation of the field effect transistors (Q1, Q2) and the waveform of the LED current according to the power supply voltage;
9 is a diagram showing the relationship between voltage, current, and conduction angle;
Figure 10 is a configuration diagram applying the relationship of Figure 9 to a circuit.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In adding reference numerals to components in each drawing, the same components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when describing an embodiment of the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

Figure 2 is a circuit diagram showing the power supply device 200 of an LED lamp according to the first embodiment of the present invention. As shown in the figure, a power supply unit 210 that supplies AC voltage; A rectifier 220 that rectifies the AC voltage supplied from the power supply 210; A traffic light emitting unit 230 that receives a rectified voltage and emits light through a plurality of light emitting diodes (LEDs); A current source 240 that allows the current flowing through the traffic light emitting unit 230 to flow almost constantly regardless of the voltage applied to the traffic light emitting unit 230; and a discharge circuit unit 250 for selectively discharging the rectified voltage.

The signal light emitting unit 230 of the power supply device 200 is composed of a plurality of LEDs.

LEDs have electrical characteristics in which current increases rapidly when a voltage above a certain level is applied. Accordingly, a large amount of current flows through the traffic light emitting unit 230 consisting of a plurality of LEDs, but a constant current (ILED) flows through the current source 240 connected to the traffic light emitting unit 230.

Meanwhile, the energization time of the traffic light emitting unit 230 is only approximately 1/3 of the power supply time from the rectifier 220. As such, since the current of the LED cannot be continuously maintained, the performance of the LED cannot be fully utilized, resulting in lower brightness. As a result, the number of expensive LEDs had to be increased to obtain the desired illuminance.

However, in the embodiment of the present invention, the current source 240 is connected to the traffic light emitting unit 230 as shown in FIG. 2, so that the current flowing through the traffic light emitting unit 230 is as shown in FIG. 3. A square wave current flows only in the part corresponding to the center of the full-wave rectified sinusoidal voltage. Therefore, the power factor can be output at 95% or more, and the harmonic factor can be down to 30% or less.

The discharge circuit unit 250 of the power supply device 200 is provided between the output end of the rectifier unit 220 and the input end of the signal light emitting unit 230.

The discharge circuit unit 250 includes a resistor R40 for limiting current, a diode D40 for detecting the voltage of the rectifier 220, a discharge resistor R43 for switching transistor Q40, a capacitor C40 for smoothing the sensing voltage, and inversion (driving) of switching transistor Q41. switching transistor Q40, driving resistors R41 and R42 of switching transistor Q41, smoothing capacitor C41 of switching transistor Q41, load resistor R44 for discharging, switching transistor Q41 for discharging, and discharging for forming a discharge loop and changing the level. It may include diode D41.

One end of R40 is connected to the output terminal of the rectifier 220 and the other end is connected to one end of D40. The base of Q40 is connected to the other end of D40, the collector is connected to the output terminal of the rectifier 220 through R41, and the emitter is connected to ground. One end of R43 is connected between the bases of D40 and Q40, and the other end is connected to ground. One end of C40 is connected between the bases of D40 and Q40, and the other end is connected to ground. The base of Q41 is connected to the common connection point of the collector of Q40 and R41 and R42, the collector is connected to the output terminal of the rectifier 220 through R44, and the emitter is connected to the terminal through D41. One end of C41 is connected to the base of Q41 and the other end is connected to ground.

In the discharge circuit unit 250, when AC input power (220Vac reference voltage) is normally applied, Q40 is conducted through D40 and Q41 is turned off. Meanwhile, when the input power is cut off, if the voltage falls below a certain level, it is cut off by D40, turning Q40 off and Q41 turning on, forming a discharge circuit with a load resistance in R44 to turn the input power down. This operation discharges the power or applied voltage charged in the condenser when the single-phase power is cut off, thereby preventing malfunction of the traffic light due to the Z1 impedance on the LSU (Load Switch Unit) board installed in the traffic signal controller.

Figure 4 is a circuit diagram showing the power supply device 400 of the LED lamp according to the second embodiment of the present invention, illustrating the case of using a TR type current source as the current source.

Referring to FIG. 4, the power supply device 400 of the LED lamp is electrically connected to the power supply unit 210, the rectifier unit 220, and the traffic light emitting unit 230, and the connection point of the rectifier 220 and the traffic light emitting unit 230 A series structure of a resistor (R1) and a Zener diode (Dz) is connected between (a) and ground, and the anode of the Zener diode (Dz) is grounded.

A first NPN-type transistor (TR1) and a resistor (R4) are connected in series between the signal light emitting unit 230 and the ground, so that one end of the resistor (R4) is grounded, and the resistor (R1) and the Zener diode (Dz) are connected in series. The collector of the second NPN-type transistor (TR2) is connected between the connection point (B) and the first NPN-type transistor (TR1) through a resistor (R2), and the base terminal of the first NPN-type transistor (TR1) and the second NPN-type transistor (TR1) are connected. The base terminals of the transistor TR2 are connected to each other, and the connection point of the two base terminals is connected to the collector of the second NPN type transistor TR2. The emitter of the second NPN-type transistor TR2 is grounded through the resistor R3.

Zener diode (Dz) is a constant voltage diode manufactured to exhibit operating characteristics in the breakdown region of the PN junction. By changing the doping level of the PN semiconductor, it is manufactured for each voltage to have a breakdown range of 2 to 200 [V]. Unlike avalanche breakdown, Zener breakdown causes the depletion layer to become very narrow when the diode is heavily doped. When the intensity of the electric field applied to the depletion layer reaches about 300,000 [V/cm], the valence band electrons move to the conduction band. It refers to a form of surrender that has been lifted sufficiently to become a state of challenge. From the characteristics of the Zener diode (Dz), the reverse current can be ignored until the breakdown voltage Vz is reached.

4, looking at the operation of the power supply device 400 of the LED lamp, when the power supply voltage is applied from the power supply unit 210 to the resistor R1 and the control diode Dz via the rectifier unit 220, the resistance R1 And the current flows through the resistor (R2).

The current (I1) flowing through the resistor (R2) can be expressed as Equation 1, and a part of this current is applied to the base terminals of the first NPN-type transistor (TR1) and the second NPN-type transistor (TR2), The first NPN-type transistor (TR1) and the second NPN-type transistor (TR2) are turned on, and accordingly, the second NPN-type transistor (TR2) sends a current from the collector to the ground through the resistor (R3) via the emitter. flows.

[Equation 1]

In addition, the first NPN-type transistor TR1 also allows current to flow from the collector to the ground through the resistor R4 via the emitter. Accordingly, the LED current as shown in Equation 2 also flows in the traffic light emitting unit 230, causing a plurality of LEDs to emit light.

[Equation 2]

In addition, the power supply device 400 of the LED lamp according to the second embodiment of the present invention has a discharge circuit 250 connected between the output terminal of the rectifier 220 and the connection point A to selectively discharge the rectified voltage. there is.

The discharge circuit unit 250 of the power supply device 400 is provided between the output terminal of the rectifier unit 220 and the input terminal of the signal light emitting unit 230.

The discharge circuit unit 250 includes a resistor R40 for limiting current, a diode D40 for detecting the voltage of the rectifier 220, a discharge resistor R43 for switching transistor Q40, a capacitor C40 for smoothing the sensing voltage, and inversion (driving) of switching transistor Q41. switching transistor Q40, driving resistors R41 and R42 of switching transistor Q41, smoothing capacitor C41 of switching transistor Q41, load resistor R44 for discharging, switching transistor Q41 for discharging, and discharging for forming a discharge loop and changing the level. It may include diode D41.

One end of R40 is connected to the output terminal of the rectifier 220 and the other end is connected to one end of D40. The base of Q40 is connected to the other end of D40, the collector is connected to the output terminal of the rectifier 220 through R41, and the emitter is connected to ground. One end of R43 is connected between the bases of D40 and Q40, and the other end is connected to ground. One end of C40 is connected between the bases of D40 and Q40, and the other end is connected to ground. The base of Q41 is connected to the common connection point of the collector of Q40 and R41 and R42, the collector is connected to the output terminal of the rectifier 220 through R44, and the emitter is connected to the terminal through D41. One end of C41 is connected to the base of Q41 and the other end is connected to ground.

In the discharge circuit unit 250, when AC input power (220Vac reference voltage) is normally applied, Q40 is conducted through D40 and Q41 is turned off. Meanwhile, when the input power is cut off, if the voltage falls below a certain level, it is cut off by D40, turning Q40 off and Q41 turning on, forming a discharge circuit with a load resistance in R44 to turn the input power down. This operation discharges the power or applied voltage charged in the condenser when the single-phase power is cut off, thereby preventing malfunction of the traffic light due to the Z1 impedance on the LSU (Load Switch Unit) board installed in the traffic signal controller.

Figure 5 is a circuit diagram showing the power supply device 500 of an LED lamp according to a third embodiment of the present invention, illustrating a case where a MOSFET type current source is used as the current source.

Referring to FIG. 5, the power supply device 500 of the LED lamp is electrically connected to the power supply unit 210, the rectifier unit 220, and the traffic light emitting unit 230, and the connection point of the rectifier 220 and the traffic light emitting unit 230 A resistor (R1) and a Zener diode (Dz) are connected in series between (a) and ground, and the anode of the Zener diode (Dz) is grounded.

A first MOSFET (FET1) and a resistor (R4) are connected in series between the signal light emitting unit 230 and the ground, and one terminal of the resistor (R4) is connected to the ground. A second MOSFET (FET2) is connected between the connection point (b) of the resistor (R1) and the Zener diode (Dz) and the first MOSFET (FET1) through the resistor (R2), and the gate terminal of the first MOSFET (FET1) is connected to the first MOSFET (FET1). The gate terminals of the two MOSFETs (FET2) are connected to each other, and the connection point of the two gate terminals is connected to the drain of the second MOSFET (FET2). The source of the second MOSFET (FET2) is grounded through the resistor (R3).

Here, the field effect transistor is a device that controls the output current with an input voltage, and the first MOSFET (FET1) and the second MOSFET (FET2) are metal-oxide semiconductor field effect transistors (MOSFET). -Effect Transistor) or can be replaced with another semiconductor amplification element. A field-effect transistor (FET) is a transistor whose input gate is insulated with a thin silicon oxide film and has a fairly high input impedance.

5, looking at the operation of the power supply device 500 of the LED lamp, the power voltage supplied from the power supply unit 210 is rectified by the rectifier unit 220 and applied to the series structure of the resistor R1 and the Zener diode Dz. do. At this time, a Zener voltage (VZ) is generated at both ends of the Zener diode (Dz), and the voltage at both ends is applied to the resistor (R1) connected in series to the Zener diode (Dz). Here, even if the power supply voltage changes, the Zener voltage (VZ) maintains a constant voltage.

In addition, a voltage across both ends is generated by the resistor R2 connected to the connection point (B) of the resistor R1 and the Zener diode Dz, and the voltage across both ends generated by the resistor R2 is connected to the first MOSFET (FET1) and the second MOSFET (FET1). 2 It is applied to the gate terminal of MOSFET (FET2). Accordingly, the first MOSFET (FET1) and the second MOSFET (FET2) are turned on so that current flows from the drain terminal to the source terminal in both the first MOSFET (FET1) and the second MOSFET (FET2). That is, a current (I1) as shown in Equation 3 flows from the drain terminal of the second MOSFET (FET2) to ground through the resistor (R3) via the source terminal, and the first MOSFET (FET1) flows from the drain terminal to the source terminal. As it flows to ground through the resistor R4, the current (ILED) flows from the signal light emitting unit 230 to the first MOSFET (FET1), causing a plurality of LEDs to emit light.

[Equation 3]

In Equation 3, Vz represents the Zener voltage and Vth represents the operation start voltage of the second MOSFET (FET2).

In addition, the power supply device 500 of the LED lamp according to the third embodiment of the present invention has a discharge circuit 250 connected between the output terminal of the rectifier 220 and connection point A to selectively discharge the rectified voltage. there is.

The discharge circuit unit 250 of the power supply device 500 is provided between the output terminal of the rectifier unit 220 and the input terminal of the signal light emitting unit 230.

The discharge circuit unit 250 includes a resistor R40 for limiting current, a diode D40 for detecting the voltage of the rectifier 220, a discharge resistor R43 for switching transistor Q40, a capacitor C40 for smoothing the sensing voltage, and inversion (driving) of switching transistor Q41. switching transistor Q40, driving resistors R41 and R42 of switching transistor Q41, smoothing capacitor C41 of switching transistor Q41, load resistor R44 for discharging, switching transistor Q41 for discharging, and discharging for forming a discharge loop and changing the level. It may include diode D41.

One end of R40 is connected to the output terminal of the rectifier 220 and the other end is connected to one end of D40. The base of Q40 is connected to the other end of D40, the collector is connected to the output terminal of the rectifier 220 through R41, and the emitter is connected to ground. One end of R43 is connected between the bases of D40 and Q40, and the other end is connected to ground. One end of C40 is connected between the bases of D40 and Q40, and the other end is connected to ground. The base of Q41 is connected to the common connection point of the collector of Q40 and R41 and R42, the collector is connected to the output terminal of the rectifier 220 through R44, and the emitter is connected to the terminal through D41. One end of C41 is connected to the base of Q41 and the other end is connected to ground.

In the discharge circuit unit 250, when AC input power (220Vac reference voltage) is normally applied, Q40 is conducted through D40 and Q41 is turned off. Meanwhile, when the input power is cut off, if the voltage falls below a certain level, it is cut off by D40, turning Q40 off and Q41 turning on, forming a discharge circuit with a load resistance in R44 to turn the input power down. This operation discharges the power or applied voltage charged in the condenser when the single-phase power is cut off, thereby preventing malfunction of the traffic light due to the Z1 impedance on the LSU (Load Switch Unit) board installed in the traffic signal controller.

Figure 6 is a circuit diagram showing the power supply device 600 of an LED lamp according to a fourth embodiment of the present invention.

The power supply device 600 for an LED lamp according to the fourth embodiment of the present invention shows a case where an OP-AMP type current source is used as a current source.

In the power supply device 600 of the LED lamp shown in FIG. 6, the power supply unit 210, the rectifier unit 220, and the traffic light emitting unit 230 are electrically connected, and the connection point of the rectifier unit 220 and the traffic light emitting unit 230 is ( A series structure of a resistor (R1) and a Zener diode (Dz) is connected between a) and ground, and the anode of the Zener diode (Dz) is grounded.

A field effect transistor (Q1) and a resistor (Rs) are connected in series between the signal light emitting unit 230 and the ground, and one terminal of the resistor (Rs) is connected to the ground. A resistor (R2), an amplifier (AMP), and a resistor (R6) are connected in series between (b), which is the connection point of the resistor (R1) and the Zener diode (Dz), and the field effect transistor (Q1).

In addition, a resistor (R3) is connected between the resistor (R2) and the connection point (c) of the amplifier (AMP) and ground, and a feedback resistor (R4) is connected between the output terminal and the (-) input terminal of the amplifier (AMP). It is connected, and a resistor (R5) is connected between the connection point (D) of the field effect transistor (Q1) and the resistor (Rs) and the (-) input terminal of the amplifier (AMP).

The amplifier (AMP) is an operational amplifier and has two differential inputs (+, -) and one output terminal. An amplifier (AMP) basically amplifies and outputs the difference in voltage between two input terminals. If the voltage on the (+) input side of the differential input is high, the output will be (+), and if the voltage on the (-) input side is high, the output will be (-). It becomes. However, if this is done, the degree of amplification will be close to infinity, so if there is a differential input voltage, the output will be at the maximum value of (+) or (-), making it impossible to operate as a practically usable amplifier. Therefore, by applying a negative feedback that causes the output to be fed back to the (-) input side through the resistor (R4), it acts to cancel out the voltage difference between the differential inputs.

In Figure 6, looking at the operation of the power supply device 600 of the LED lamp, the power voltage supplied from the power supply unit 210 is rectified by the rectifier unit 220 and applied to the series structure of the resistor R1 and the Zener diode Dz. do. At this time, a Zener voltage (VZ) is generated at both ends of the Zener diode (Dz), and the voltage at both ends is applied to the resistor (R1) connected in series to the Zener diode (Dz). Here, the Zener voltage (VZ) maintains a constant voltage even if the power supply voltage changes.

In addition, the voltage (V1) is generated by the resistor (R2) connected to the connection point (B) of the resistor (R1) and the Zener diode (Dz), and the voltage (V1) generated by the resistor (R2) is expressed in Equation 4 and It appears together and is applied to the (+) input terminal of the amplifier (AMP).

[Equation 4]

The voltage (V1) generated by the resistor (R2) is applied to the (+) input terminal of the amplifier (AMP), and the output of the output terminal of the amplifier (AMP) is applied to the gate terminal of the field effect transistor (Q1), and some It is negatively fed back to the (-) input terminal of the amplifier (AMP) through the resistor (R4). Therefore, the voltage V1 and the voltage Vf at the connection point (D) are controlled to have similar values.

The output of the amplifier (AMP) is applied to the gate terminal of the field effect transistor (Q1), and the field effect transistor (Q1) is operated, thereby passing from the source terminal of the field effect transistor (Q1) to the signal light emitting unit (230). ) current flows. At this time, the LED current (ILED) flowing into the traffic light emitting unit 230 is obtained as shown in Equation 5.

[Equation 5]

As the LED current (ILED) flows from the traffic light emitting unit 230 to the amplifier (AMP), a plurality of LEDs emit light in the traffic light emitting unit 230.

In addition, the power supply device 600 of the LED lamp according to the fourth embodiment of the present invention has a discharge circuit 250 connected between the output terminal of the rectifier 220 and connection point A to selectively discharge the rectified voltage. there is.

The discharge circuit unit 250 of the power supply device 600 is provided between the output terminal of the rectifier unit 220 and the input terminal of the signal light emitting unit 230.

The discharge circuit unit 250 includes a resistor R40 for limiting current, a diode D40 for detecting the voltage of the rectifier 220, a discharge resistor R43 for switching transistor Q40, a capacitor C40 for smoothing the sensing voltage, and inversion (driving) of switching transistor Q41. switching transistor Q40, driving resistors R41 and R42 of switching transistor Q41, smoothing capacitor C41 of switching transistor Q41, load resistor R44 for discharging, switching transistor Q41 for discharging, and discharging for forming a discharge loop and changing the level. It may include diode D41.

One end of R40 is connected to the output terminal of the rectifier 220 and the other end is connected to one end of D40. The base of Q40 is connected to the other end of D40, the collector is connected to the output terminal of the rectifier 220 through R41, and the emitter is connected to ground. One end of R43 is connected between the bases of D40 and Q40, and the other end is connected to ground. One end of C40 is connected between the bases of D40 and Q40, and the other end is connected to ground. The base of Q41 is connected to the common connection point of the collector of Q40 and R41 and R42, the collector is connected to the output terminal of the rectifier 220 through R44, and the emitter is connected to the terminal through D41. One end of C41 is connected to the base of Q41 and the other end is connected to ground.

In the discharge circuit unit 250, when AC input power (220Vac reference voltage) is normally applied, Q40 is conducted through D40 and Q41 is turned off. Meanwhile, when the input power is cut off, if the voltage falls below a certain level, it is cut off by D40, turning Q40 off and Q41 turning on, forming a discharge circuit with a load resistance in R44 to turn the input power down. This operation discharges the power or applied voltage charged in the condenser when the single-phase power is cut off, thereby preventing malfunction of the traffic light due to the Z1 impedance on the LSU (Load Switch Unit) board installed in the traffic signal controller.

Figure 7 is a circuit diagram showing the power supply device 700 of an LED lamp according to the fifth embodiment of the present invention.

The power supply device 700 for an LED lamp according to the fifth embodiment of the present invention shows a case where a comparator (CMP) type current source is used as the current source.

In the power supply device 700 of the LED lamp shown in FIG. 7, the power supply unit 210, the rectifier unit 220, and the traffic light emitting unit 230 are electrically connected as shown in FIG. 6, and the rectifier unit 220 and the traffic light emitting unit 230 are electrically connected to each other. ) has an amplifier (AMP) connected between them.

A second field effect transistor (Q2) is connected between the other output terminal of the signal light emitting unit 230 and the ground resistance (Rs), and the gate terminal of the field effect transistor (Q2) is connected to the amplifier (AMP) through the resistor (R12). connected to the output.

A series connection of a resistor (R7) and a resistor (R8) is connected between the connection point (A) of the rectifier 220 and the signal light emitting unit 230 and the ground, and the connection point (a) of the resistor (R7) and the resistor (R8) is connected to the inverting terminal (-) of the comparator (CMP).

In addition, a series connection of a resistor (RI) and a Zener diode (Dz) is connected between the connection point (A) and the ground, the anode of the Zener diode (Dz) is grounded, and the connection point of the resistor (RI) and the Zener diode (Dz) is connected in series. A series connection of resistor (R9) and resistor (R10) is connected between (b) and ground. The connection point (c) of resistor (R9) and resistor (R10) is connected to the non-inverting terminal (+) of the comparator (CMP). The output of the comparator (CMP) is connected to the gate terminal of the second field effect transistor (Q2) through the resistor (R11).

7, looking at the operation of the power supply device 700 of the LED lamp, the power voltage supplied from the power supply unit 210 is rectified by the rectifier 220 and is connected to the series structure of the resistor R7 and R8. In addition, it is applied to the series structure of the resistor (R1) and the Zener diode (Dz). At this time, a voltage V2 is generated in the series connection of the resistor R7 and R8, and a Zener voltage VZ is generated at both ends of the Zener diode Dz.

The voltage Va generated in the resistor R8 is applied to the inverting terminal (-) of the comparator (CMP), and the divider voltage Vc of the Zener voltage (VZ) is applied to the non-inverting terminal (+) of the comparator (CMP). At this time, when the voltage Va applied to the inverting terminal (-) of the comparator (CMP) is greater than the voltage Vc applied to the non-inverting terminal (+), the comparator (CMP) outputs a high level signal and is higher than the voltage Va. When the voltage Vc is larger, the comparator (CMP) outputs a low level signal. When a high level signal is output from the comparator (CMP), both the first field effect transistor (Q1) and the second field effect transistor (Q2) are turned on, and a low level signal is output from the comparator (CMP). In this case, the second field effect transistor (Q2) does not operate and only the first field effect transistor (Q1) operates.

In addition, the power supply device 700 of the LED lamp according to the fifth embodiment of the present invention has a discharge circuit 250 connected between the output terminal of the rectifier 220 and the connection point A to selectively discharge the rectified voltage. there is.

The discharge circuit unit 250 of the power supply device 600 is provided between the output terminal of the rectifier unit 220 and the input terminal of the signal light emitting unit 230.

The discharge circuit unit 250 includes a resistor R40 for limiting current, a diode D40 for detecting the voltage of the rectifier 220, a discharge resistor R43 for switching transistor Q40, a capacitor C40 for smoothing the sensing voltage, and inversion (driving) of switching transistor Q41. switching transistor Q40, driving resistors R41 and R42 of switching transistor Q41, smoothing capacitor C41 of switching transistor Q41, load resistor R44 for discharging, switching transistor Q41 for discharging, and discharging for forming a discharge loop and changing the level. It may include diode D41.

One end of R40 is connected to the output terminal of the rectifier 220 and the other end is connected to one end of D40. The base of Q40 is connected to the other end of D40, the collector is connected to the output terminal of the rectifier 220 through R41, and the emitter is connected to ground. One end of R43 is connected between the bases of D40 and Q40, and the other end is connected to ground. One end of C40 is connected between the bases of D40 and Q40, and the other end is connected to ground. The base of Q41 is connected to the common connection point of the collector of Q40 and R41 and R42, the collector is connected to the output terminal of the rectifier 220 through R44, and the emitter is connected to the terminal through D41. One end of C41 is connected to the base of Q41 and the other end is connected to ground.

In the discharge circuit unit 250, when AC input power (220Vac reference voltage) is normally applied, Q40 is conducted through D40 and Q41 is turned off. Meanwhile, when the input power is cut off, if the voltage falls below a certain level, it is cut off by D40, turning Q40 off and Q41 turning on, forming a discharge circuit with a load resistance in R44 to turn the input power down. This operation discharges the power or applied voltage charged in the condenser when the single-phase power is cut off, thereby preventing malfunction of the traffic light due to the Z1 impedance on the LSU (Load Switch Unit) board installed in the traffic signal controller.

Figure 8 is a diagram showing the operation of the field effect transistors (Q1 and Q2) and the waveform of the LED current according to the power supply voltage.

As shown in FIG. 8, when the voltage V2 is 220 V, the divided voltage Va of the voltage V2 is applied to the non-inverting terminal (-) of the comparator (CMP), and the output of the comparator (CMP) outputs a low level signal. Therefore, the second field effect transistor (Q2) does not operate and only the first field effect transistor (Q1) operates, so that the LED current with a conduction angle of 90° flows through the first field effect transistor (Q1).

In Figure 8, when the voltage V2 is 150 V, the comparator (CMP) outputs a high level signal, so that not only the first field effect transistor (Q1) but also the second field effect transistor (Q2) is turned on. . Therefore, as the second field effect transistor (Q2) operates, an LED current with a conduction angle of 120° flows, which is larger than when only the first field effect transistor (Q1) operates.

In other words, the LED current flows for a longer time when the second field effect transistor (Q2) is all conductive than when only the first field effect transistor (Q1) is conductive, so that the illuminance of the traffic light emitting unit 230 can be maintained for a long time. will be.

Meanwhile, in order to widen the conduction angle to compensate for the change in luminance of the traffic light emitting unit 230 at low voltage, a two-stage MOSFET was used. However, if this configuration is somewhat complicated, the MOSFET (Q1) is configured as a single stage, As shown in FIG. 9, at low voltage (eg, 176 V), the current size can be increased instead of reducing the conduction angle, and at high voltage (220 V or more), the current size can be decreased.

FIG. 10 is a configuration diagram applied to a circuit so that the relationship between voltage, current, and conduction angle appears as shown in FIG. 9.

As shown in Figure 10, a series structure of the resistor (R100) and the capacitor (C100) is connected between the voltage V1 applied to the connection point (A) and the ground, and the connection point (E) of the resistor (R100) and the capacitor (C100) is It is connected to the inverting terminal (-) of the amplifier (AMP) through a resistor (R101).

The gate terminal of the MOSFET (Q1) is connected to the output terminal of the amplifier (AMP) through a resistor (R6), and a ground resistance (Rs) is connected to the drain terminal of the MOSFET (Q1).

The connection point (d) between the MOSFET (Q1) and the ground resistance (Rs) is connected to the connection point (c) between the resistor (R101) and the inverting terminal (-) of the amplifier (AMP) through the resistor (R5).

According to embodiments of the present invention, it is possible to realize a power supply device for an LED lamp in which the current is linearly controlled so that the LED lamp used in the traffic light has a high power factor or a low harmonic factor with respect to the AC input power. there is.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but are for illustrative purposes, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be construed as being included in the scope of rights of the present invention.

100: SMPS circuit for LED driving
110: Overcurrent and overvoltage protection unit
120: rectifier
130: power supply unit
140: Control signal generator
150: control unit
160: Power factor adjustment unit
170: Pulse voltage prevention unit
180: Reference voltage generator
200, 400, 500, 600, 700: Power unit
210: power unit
220: rectifier
230: Traffic light emitting unit
240: current source
250: Discharge circuit unit
TR1, TR2: NPN type transistor
AMP: Amplifier
ZD: Zener diode
R1 ~ R11, Rs: Resistance
FET1, FET2, Q1, Q2: MOSFET
CMP: Comparator
Q40, Q41 ; seuching transistor

Claims (13)

A power supply unit 210 that supplies power voltage;
A rectifier 220 that rectifies the power supply voltage supplied from the power supply unit;
A traffic light emitting unit 230 that receives the rectified power supply voltage and emits light through a plurality of light emitting diodes (LEDs);
A transistor (TR) type current source that allows the current flowing through the traffic light emitting part to flow almost constantly regardless of the voltage applied to the traffic light emitting part; and
It includes a discharge circuit unit 250 for selectively discharging the rectified voltage,
The transistor-type current source is electrically connected to the power supply unit 210, the rectifier unit 220, and the traffic light emitting unit 230, and the connection point (a) of the rectifier unit 220 and the traffic light emitting unit 230 is grounded. A series structure of a resistor (R1) and a Zener diode (Dz) is connected between them, and the anode of the Zener diode (Dz) is grounded,
A first NPN-type transistor (TR1) and a resistor (R4) are connected in series between the signal light emitting unit 230 and the ground, so that one end of the resistor (R4) is grounded, and the resistor (R1) and the Zener diode are connected in series. The collector of the second NPN-type transistor TR2 is connected between the connection point (B) of (Dz) and the first NPN-type transistor TR1 through a resistor R2, and the collector of the first NPN-type transistor TR1 is connected. The base terminal and the base terminal of the second NPN type transistor TR2 are connected to each other, the connection point of the two base terminals is connected to the collector of the second NPN type transistor TR2, and the connection point of the second NPN type transistor TR2 is connected to the base terminal of the second NPN transistor TR2. The emitter is grounded through resistor (R3),
The discharge circuit unit 250 is connected between the output terminal of the rectifier unit 220 and the connection point (A), and discharges the resistor R40 for limiting the current, the diode D40 for detecting the voltage of the rectifier unit 220, and the switching transistor Q40. Resistor R43, capacitor C40 for smoothing the sensing voltage, switching transistor Q40 for inverting (driving) switching transistor Q41, resistors R41 and R42 for driving switching transistor Q41, capacitor C41 for smoothing switching transistor Q41, load resistor R44 for discharge, It includes a dedicated switching transistor Q41 and a discharge diode D41 to form a discharge loop and change the level,
When the power supply voltage is applied to the resistor (R1) and the Zener diode (DZ), a current flows through the resistor (R1) and the resistor (R2), and the current (I1) flowing through the resistor (R2) is the first By being applied to the base terminals of the NPN-type transistor (TR1) and the second NPN-type transistor (TR2), the first NPN-type transistor (TR1) and the second NPN-type transistor (TR2) are turned on, and accordingly The second NPN-type transistor (TR2) allows current to flow from the collector to the ground via the emitter and the resistor (R3), and the first NPN-type transistor (TR1) also flows from the collector to the emitter via the resistor ( As current flows to ground through R4), LED current flows in the traffic light emitting unit 230, causing a plurality of LEDs in the traffic light emitting unit 230 to emit light. . delete According to paragraph 1,
One end of R40 is connected to the output terminal of the rectifier 220 and the other end is connected to one end of D40; The base of Q40 is connected to the other end of D40, the collector is connected to the output terminal of the rectifier 220 through R41, and the emitter is connected to ground; One end of R43 is connected between the bases of D40 and Q40, and the other end is connected to ground; One end of C40 is connected between the bases of D40 and Q40, and the other end is connected to ground; The base of Q41 is connected to the common connection point of the collector of Q40 and R41 and R42, the collector is connected to the output terminal of the rectifier 220 through R44, and the emitter is connected to the terminal through D41; A power supply device for an LED lamp, characterized in that one end of C41 is connected to the base of Q41 and the other end is connected to ground. A power supply unit 210 that supplies power voltage;
A rectifier 220 that rectifies the power supply voltage supplied from the power supply unit;
A traffic light emitting unit 230 that receives the rectified power supply voltage and emits light through a plurality of light emitting diodes (LEDs);
A metal oxide semiconductor field effect transistor (MOSFET) type current source that allows the current flowing through the traffic light emitting part to flow almost constantly regardless of the voltage applied to the traffic light emitting part; and
It includes a discharge circuit unit 250 for selectively discharging the rectified voltage,
The current source is electrically connected to the power supply unit 210, the rectifier unit 220, and the traffic light emitting unit 230, and is connected between the connection point (a) of the rectifier unit 220 and the traffic light emitting unit 230 and ground. A series structure of a resistor (R1) and a Zener diode (Dz) is connected, and the anode of the Zener diode (Dz) is grounded,
A first MOSFET (FET1) and a resistor (R4) are connected in series between the signal light emitting unit 230 and the ground, one terminal of the resistor (R4) is connected to the ground, and the resistor (R1) and the A second MOSFET (FET2) is connected between the connection point (B) of the Zener diode (Dz) and the first MOSFET (FET1) through a resistor (R2), and the gate terminal of the first MOSFET (FET1) and the second MOSFET The gate terminals of (FET2) are connected to each other, the connection point of the two gate terminals is connected to the drain of the second MOSFET (FET2), and the source of the second MOSFET (FET2) is grounded through the resistor (R3),
The discharge circuit unit 250 is connected between the output terminal of the rectifier unit 220 and the connection point (A), and discharges the resistor R40 for limiting the current, the diode D40 for detecting the voltage of the rectifier unit 220, and the switching transistor Q40. Resistor R43, capacitor C40 for smoothing the sensing voltage, switching transistor Q40 for inverting (driving) switching transistor Q41, resistors R41 and R42 for driving switching transistor Q41, capacitor C41 for smoothing switching transistor Q41, load resistor R44 for discharge, A power supply device for an LED lamp, comprising a dedicated switching transistor Q41 and a discharge diode D41 for forming a discharge loop and changing the level. According to paragraph 4,
When the power voltage is rectified by the rectifier 220 and applied to the series structure of the resistor R1 and the Zener diode Dz, a Zener voltage VZ is generated at both ends of the Zener diode Dz,
A voltage is also generated by the resistor (R2) connected to the connection point (B) of the resistor (R1) and the Zener diode (Dz), and the voltage generated by the resistor (R2) is connected to the first MOSFET (FET1). and is applied to the gate terminal of the second MOSFET (FET2) to turn on the first MOSFET (FET1) and the second MOSFET (FET2),
A current (I1) flows from the drain terminal of the second MOSFET (FET2) through the source terminal to the ground through the resistor (R3), and the first MOSFET (FET1) flows from the drain terminal to the source terminal. By flowing to ground through the resistor (R4), the LED current (ILED) flows from the signal light emitting unit 230 to the first MOSFET (FET1), causing a plurality of LEDs to emit light. Device. According to paragraph 4,
One end of R40 is connected to the output terminal of the rectifier 220 and the other end is connected to one end of D40; The base of Q40 is connected to the other end of D40, the collector is connected to the output terminal of the rectifier 220 through R41, and the emitter is connected to ground; One end of R43 is connected between the bases of D40 and Q40, and the other end is connected to ground; One end of C40 is connected between the bases of D40 and Q40, and the other end is connected to ground; The base of Q41 is connected to the common connection point of the collector of Q40 and R41 and R42, the collector is connected to the output terminal of the rectifier 220 through R44, and the emitter is connected to the terminal through D41; A power supply device for an LED lamp, characterized in that one end of C41 is connected to the base of Q41 and the other end is connected to ground. A power supply unit 210 that supplies power voltage;
A rectifier 220 that rectifies the power supply voltage supplied from the power supply unit;
A traffic light emitting unit 230 that receives the rectified power supply voltage and emits light through a plurality of light emitting diodes (LEDs);
An amplifier (OP-AMP) type current source that allows the current flowing through the traffic light emitting part to flow almost constantly regardless of the voltage applied to the traffic light emitting part; and
It includes a discharge circuit unit 250 for selectively discharging the rectified voltage,
The current source is electrically connected to the power supply unit 210, the rectifier unit 220, and the traffic light emitting unit 230, and is connected between the connection point (a) of the rectifier unit 220 and the traffic light emitting unit 230 and ground. A series structure of a resistor (R1) and a Zener diode (Dz) is connected, and the anode of the Zener diode (Dz) is grounded,
A field effect transistor (Q1) and a resistor (Rs) are connected in series between the traffic light emitting unit 230 and the ground, one terminal of the resistor (Rs) is connected to the ground, and the resistor (R1) and the A resistor (R2), an amplifier (AMP), and a resistor (R6) are connected in series between the connection point (B) of the Zener diode (Dz) and the field effect transistor (Q1).
A resistor (R3) is connected between the resistor (R2) and the connection point (C) of the amplifier (AMP) and ground, and a feedback resistor (R4) is connected between the output terminal and the (-) input terminal of the amplifier (AMP). is connected, and a resistor (R5) is connected between the connection point (D) of the field effect transistor (Q1) and the resistor (Rs) and the (-) input terminal of the amplifier (AMP),
The discharge circuit unit 250 is connected between the output terminal of the rectifier unit 220 and the connection point (A), and discharges the resistor R40 for limiting the current, the diode D40 for detecting the voltage of the rectifier unit 220, and the switching transistor Q40. Resistor R43, capacitor C40 for smoothing the sensing voltage, switching transistor Q40 for inverting (driving) switching transistor Q41, resistors R41 and R42 for driving switching transistor Q41, capacitor C41 for smoothing switching transistor Q41, load resistor R44 for discharge, A power supply device for an LED lamp, comprising a dedicated switching transistor Q41 and a discharge diode D41 for forming a discharge loop and changing the level. In clause 7,
When the power voltage is rectified by the rectifier 220 and applied to the series structure of the resistor R1 and the Zener diode Dz, a Zener voltage VZ is generated at both ends of the Zener diode Dz, A voltage (V1) is generated by the resistor (R2) connected to the connection point (B) of the resistor (R1) and the Zener diode (Dz),
The voltage V1 is applied to the (+) input terminal of the amplifier (AMP), and the output of the output terminal of the amplifier (AMP) is applied to the gate terminal of the field effect transistor (Q1), and some of the amplifier (AMP) )'s (-) input terminal is negatively fed back through the resistor (R4),
The output of the amplifier (AMP) is applied to the gate terminal of the field effect transistor (Q1), and the field effect transistor (Q1) is operated, thereby passing from the source terminal of the field effect transistor (Q1) to the drain terminal. As the current flows into the traffic light emitting unit 230, and the LED current (ILED) flows from the traffic light emitting unit 230 to the amplifier (AMP), a plurality of LEDs emit light from the traffic light emitting unit 230. A power supply device for an LED lamp, characterized in that. In clause 7,
One end of R40 is connected to the output terminal of the rectifier 220 and the other end is connected to one end of D40; The base of Q40 is connected to the other end of D40, the collector is connected to the output terminal of the rectifier 220 through R41, and the emitter is connected to ground; One end of R43 is connected between the bases of D40 and Q40, and the other end is connected to ground; One end of C40 is connected between the bases of D40 and Q40, and the other end is connected to ground; The base of Q41 is connected to the common connection point of the collector of Q40 and R41 and R42, the collector is connected to the output terminal of the rectifier 220 through R44, and the emitter is connected to the terminal through D41; A power supply device for an LED lamp, characterized in that one end of C41 is connected to the base of Q41 and the other end is connected to ground. A power supply device for an LED lamp that linearly controls the current flowing in the LED lamp,
A power supply unit 210 that supplies power voltage;
a rectifier 220 that rectifies the power voltage supplied from the power supply 210;
A traffic light emitting unit 230 that receives the rectified power supply voltage and emits light through a plurality of light emitting diodes (LEDs); and
It includes a discharge circuit unit 250 for selectively discharging the rectified voltage,
The power unit 210, the rectifier 220, and the traffic light emitting unit 230 are electrically connected, and a resistance R1 is formed between the connection point (a) of the rectifier 220 and the traffic light emitting unit 230 and ground. ) and a series structure of a Zener diode (Dz) are connected, and the anode of the Zener diode (Dz) is grounded,
A first field effect transistor (Q1) and a ground resistance (Rs) are connected in series between the signal light emitting unit 230 and the ground, one terminal of the ground resistance (Rs) is connected to the ground, and the resistance ( A resistor (R2), an amplifier (AMP), and a resistor (R6) are connected in series between R1) and (b), which is the connection point of the Zener diode (Dz), and the first field effect transistor (Q1),
A resistor (R3) is connected between the resistor (R2) and the connection point (C) of the amplifier (AMP) and ground, and a feedback resistor (R4) is connected between the output terminal and the (-) input terminal of the amplifier (AMP). is connected, and a resistor (R5) is connected between the connection point (D) of the first field effect transistor (Q1) and the ground resistance (Rs) and the (-) input terminal of the amplifier (AMP),
A second field effect transistor (Q2) is connected between the other output terminal of the traffic light emitting unit 230 and the ground resistance (Rs), and the gate terminal of the second field effect transistor (Q2) is connected through the resistor (R12). Connected to the output of the amplifier (AMP),
A series structure of a resistor (R7) and a resistor (R8) is connected between the connection point (A) of the rectifier 220 and the signal light emitting unit 230 and the ground, and the resistor (R7) and the resistor (R8) are connected in series. The connection point (a) is connected to the inverting terminal (-) of the comparator (CMP), and a series structure of a resistor (RI) and a Zener diode (Dz) is connected between the connection point (A) and ground, and the Zener diode (Dz) is connected to the inverting terminal (-) of the comparator (CMP). ) is grounded, and a series structure of a resistor (R9) and a resistor (R10) is connected between the connection point (b) of the resistor (RI) and the Zener diode (Dz) and the ground, and the resistor (R9) ) and the connection point (c) of the resistor (R10) is connected to the non-inverting terminal (+) of the comparator (CMP), and the output of the comparator (CMP) is transmitted through the resistor (R11) to the second field effect transistor. It is connected to the gate terminal of (Q2),
The discharge circuit unit 250 is connected between the output terminal of the rectifier unit 220 and the connection point A, and discharges the resistor R40 for limiting the current, the diode D40 for detecting the voltage of the rectifier unit 220, and the switching transistor Q40. Resistor R43, capacitor C40 for smoothing the sensing voltage, switching transistor Q40 for inverting (driving) switching transistor Q41, resistors R41 and R42 for driving switching transistor Q41, capacitor C41 for smoothing switching transistor Q41, load resistor R44 for discharge, A power supply device for an LED lamp, comprising a dedicated switching transistor Q41 and a discharge diode D41 for forming a discharge loop and changing the level. According to clause 10,
The power voltage supplied from the power unit 210 is rectified by the rectifier 220 and is connected to the series structure of the resistor R7 and the resistor R8, and the resistor R1 and the Zener diode Dz is applied to the series structure, and at this time, a voltage V2 is generated in the series structure of the resistor R7 and the resistor R8, and a Zener voltage VZ is generated at both ends of the Zener diode Dz,
The voltage Va generated in the resistor R8 as the divided voltage of the voltage V2 is applied to the inverting terminal (-) of the comparator (CMP), and the divided voltage Vc of the Zener voltage (VZ) is applied to the inverting terminal (-) of the comparator (CMP). It is applied to the non-inverting terminal (+), and in this case, when the voltage Va applied to the inverting terminal (-) of the comparator (CMP) is greater than the voltage Vc applied to the non-inverting terminal (+), the comparator (CMP) ) outputs a high level signal, and when the voltage Vc is greater than the voltage Va, the comparator (CMP) outputs a low level signal,
When a high level signal is output from the comparator (CMP), both the first field effect transistor (Q1) and the second field effect transistor (Q2) are turned on, and a low level signal is output from the comparator (CMP). When a signal of is output, the second field effect transistor (Q2) does not operate and only the first field effect transistor (Q1) operates. According to clause 11,
When the voltage V2 is 220V, the output of the comparator (CMP) outputs a low level signal, so that the second field effect transistor (Q2) does not operate and only the first field effect transistor (Q1) operates. And the LED current with a conduction angle of 90° flows through the first field effect transistor (Q1),
When the voltage V2 is 150 V, the comparator (CMP) outputs a high level signal, so that not only the first field effect transistor (Q1) but also the second field effect transistor (Q2) is turned on. , As the second field effect transistor (Q2) operates, the conduction angle is 120°, which is characterized in that the LED current flows with a conduction angle larger than when only the first field effect transistor (Q1) operates. Power supply of LED lamps. According to clause 10,
One end of R40 is connected to the output terminal of the rectifier 220 and the other end is connected to one end of D40; The base of Q40 is connected to the other end of D40, the collector is connected to the output terminal of the rectifier 220 through R41, and the emitter is connected to ground; One end of R43 is connected between the bases of D40 and Q40, and the other end is connected to ground; One end of C40 is connected between the bases of D40 and Q40, and the other end is connected to ground; The base of Q41 is connected to the common connection point of the collector of Q40 and R41 and R42, the collector is connected to the output terminal of the rectifier 220 through R44, and the emitter is connected to the terminal through D41; A power supply device for an LED lamp, characterized in that one end of C41 is connected to the base of Q41 and the other end is connected to ground.