JP2013030390A - Power supply device and lighting apparatus having power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device that can control lighting-off while restraining power consumption.SOLUTION: A power supply device 300 has: a transformer TR having a primary coil T1 and secondary coils T2, T4; a MOS-FETQ1 connected to the primary coil T1 and controlled by a lighting control circuit IC; a control power supply generation circuit 340 connected to the secondary coil T4 and generating a control power source Vcc2; an output voltage regulation circuit 380 for decreasing an impedance on an output side of the secondary coil T2 when the control voltage Vcc2 is less than a predetermined voltage, and increasing the impedance when it is not less than the predetermined voltage; and a light control signal conversion circuit 390 for stopping the MOS-FETQ1 when a dimmer 2000 outputs lighting-off signals. Therefore, power consumption can be restrained when a light source 140 is lit on, and lighting-off can be controlled even when the lighting-off signals are inputted from the dimmer 2000 connected to the power supply device 300.

Description

  The present invention relates to a power supply device that turns off a light source.

  A connection terminal for connecting a light source, a power supply unit for supplying a light emission current whose current value is set in advance to cause the light source to emit light to the light source via the connection terminal, and a light source connected to the connection terminal If the light source is determined to be connected by the resistance and determination unit that determines whether or not the light source is connected, the power source unit outputs a light emission current between the connection terminals, and the light source is not connected. When the determination is made, there is a power supply device including a control unit that prohibits the output of the light emission current between the connection terminals by the power supply unit. (For example, refer to Patent Document 1).

JP 2007-234414 A (refer to paragraphs “0031” to “0039” and FIGS. 1 to 3).

  However, in order to determine whether or not a light source is connected to the power supply device, the output voltage of the power supply device is set so that a weak current can flow through the light source connected to the power supply device. There is a problem that it cannot be done.

  Therefore, in order to turn off the light source, it is conceivable to stop switching of the switching element. However, when switching of the switching element is stopped, an output voltage cannot be obtained on the secondary winding side of the transformer. In order to operate each control circuit, a control power source must be generated using a circuit on the primary winding side of the transformer.

  However, since the voltage of the commercial power source input to the circuit on the primary winding side of the transformer has a large difference from the voltage of the control power source, if the control power source is generated using a resistor or the like, the power loss increases. There is.

  In addition, there may be a case where a control power supply is generated by providing a switching regulator circuit or the like on the primary winding side of the transformer. However, there is a problem that the circuit configuration constituting the power supply device becomes complicated and the lighting device is enlarged. is there.

  The power supply device of the present invention is a power supply device for supplying direct current power to a light source, an insulating transformer having a primary winding and a secondary winding, and a first switching element connected in series to the primary winding. And a capacitor connected to the secondary winding, a dimming signal conversion circuit that receives an external signal from the outside and outputs an oscillation stop signal when the external signal is a turn-off signal indicating turn-off, and A second switching element connected to a capacitor, and when the extinction signal is input to the dimming signal conversion circuit, the second switching element is turned on to generate a secondary generated in the secondary winding. The capacitor is charged to a voltage in a first charging time, and when the extinction signal is not input to the dimming signal conversion circuit, the second switching element is turned off and generated in the secondary winding 2 Next voltage Based on the output voltage regulation circuit and the switching of the first switching element as a second charging time longer than the first charging time, the charging time for charging the capacitor, and based on the oscillation stop signal, A lighting control circuit that stops switching of the first switching element; a control power supply circuit that generates a control power supply when the first switching element is oscillating and supplies the control power supply to the dimming signal conversion circuit; Have.

  According to the present invention, since the control power supply is generated based on the output voltage of the secondary winding of the transformer, the power consumption can be suppressed when the light source is turned on, and the dimmer connected to the power supply device Even when a turn-off signal is input from, turn-off control can be performed.

FIG. 3 is a perspective view showing the lighting apparatus in the first embodiment. It is a disassembled perspective view of the lighting fixture of FIG. FIG. 3 is a circuit diagram showing details of the power supply circuit of FIG. 2. It is a characteristic view which shows the electrical property of LED connected to the power supply circuit of FIG. FIG. 3 is a timing chart showing the operation of the power supply circuit of FIG. 2. FIG. 6 is a circuit diagram showing details of a power supply circuit in a second embodiment.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing a lighting fixture of the present embodiment, and FIG. 2 is a cross-sectional view showing a cross section of the lighting fixture of FIG.

  The luminaire 1000 includes a lamp unit 100, a power supply device 300 that is physically and electrically connected via an electric wire 200 drawn from the lamp unit 100, and a power supply case 400 that houses the power supply apparatus 300. Have

  The lamp unit 100 includes a lamp body 110, a mounting spring 120 attached to the lamp body 110, a radiating fin 130 attached to the lamp body 110, and a radiating fin 130, and is stored in the lamp body 110. And a light source 140.

  Although the illustration of the outer shape of the light source 140 is omitted, the light source 140 includes 48 light-emitting diodes 141 (hereinafter also referred to as LEDs 141) connected in series and a printed circuit board 142 on which the 48 LEDs 141 are mounted. .

  The power supply apparatus 300 supplies power to the light source 140 via the electric wire 200 to turn on or off the light source 140. Details of the power supply apparatus 300 will be described later.

  The power supply case 400 includes a base case 410 that supports the power supply device 300, and a cover case 420 that covers the power supply device 300 and is attached to the base case 410.

Next, the circuit configuration of the power supply apparatus 300 will be described.
FIG. 3 is a circuit diagram showing a circuit configuration of the power supply device of FIG.

  The power supply device 300 receives the smoothing voltage generated by the rectifying / smoothing circuit 310 that converts the input AC voltage AC into a DC voltage to generate a smoothing voltage, and the constant voltage to the connected LED 141. A switching power supply circuit 320 for supplying power, a first control power generation circuit 330 connected to the switching power supply circuit 320, a second control power generation circuit 340 also connected to the switching power supply circuit 320, and a first control power generation An oscillation stop circuit 350 connected to the circuit 330 and the second control power supply generation circuit 340, a feedback circuit 360 connected to the switching power supply circuit 320, an on-time control circuit 370 connected to the feedback circuit 360, and a switching power supply Output voltage regulation circuit 380 connected to circuit 320, and oscillation stop circuit Having a converter PWM signal conversion circuit 390 which is connected to 50 and a feedback circuit 360, the.

  The rectifying / smoothing circuit 310 includes a diode bridge DB that converts the AC voltage AC into a pulsating DC voltage (rectified voltage), and a capacitor C1 that smoothes the rectified voltage rectified by the diode bridge DB and generates a smoothed voltage. Have.

  The switching power supply circuit 320 is connected to the lighting control circuit IC, a transformer TR that insulates the primary side and the secondary side, two diodes D10 and D20 connected to the transformer TR, and a cathode terminal of the diode D10. Electrolytic capacitor C10, detection resistor R10 connected to the negative electrode side of electrolytic capacitor C10, starting resistor R1 for starting up lighting control circuit IC, and switching element Q1 connected to transformer TR and switched by lighting control circuit IC (Hereinafter also referred to as MOS-FET Q1), and a resistor R2 and a diode D1 connected in series connected between the transformer TR and the lighting control circuit IC.

  The lighting control circuit IC includes a switching output terminal P1 connected to the MOS-FET Q1, a zero cross detection terminal P2 for detecting 0 volt (zero cross), and a control power supply terminal P3 (hereinafter referred to as the first control generation circuit 330). , Vcc terminal P3), connected to the oscillation stop circuit 350, and connected to an overvoltage detection terminal P4 (hereinafter also referred to as OVP terminal P4 or protection terminal P4) for detecting an overvoltage, and an on-time control circuit 370. And an on-time detection terminal P5.

  The transformer TR has one end connected to the high potential side of the rectifying and smoothing circuit 310 and the other end connected to the drain terminal of the MOS-FET Q1, and a winding wound in the same direction as the primary winding T1. A first secondary winding T2 having one end connected to the anode terminal of the diode D10, and a second secondary winding having one end connected to the resistor R2 and wound in the same direction as the primary winding T1. T3 and the primary winding T1 are wound in opposite directions, and have a third secondary winding T4 whose one end is connected to the anode terminal of the diode D20.

  The electrolytic capacitor C10 is connected to the high potential side of the first secondary winding T2 via the diode D10.

  The detection resistor R10 has one end connected to the low potential side of the electrolytic capacitor C10 and detects a current flowing through the LED 141 connected to the other end side and the high potential side of the electrolytic capacitor C10.

  The starting resistor R1 has one end connected to the high potential side of the capacitor C1 and the other end connected to the first control power generation circuit 330.

  The drain terminal of the MOS-FET Q1 is connected to the primary winding T1, and the gate terminal is connected to the switching output terminal P1 of the lighting control circuit IC.

  The first control power generation circuit 330 includes, via a resistor R2, a diode D2 whose anode terminal is connected to one end of the second secondary winding T3, a resistor R3 connected to the cathode terminal of the diode D2, An electrolytic capacitor C2 having a positive electrode connected to the resistor R3 and a Zener diode DZ1 connected in parallel to the electrolytic capacitor C2 are provided.

  The second control power generation circuit 340 includes an electrolytic capacitor C20 having a positive electrode connected to the cathode of the diode D20, a resistor R20 connected to the positive electrode of the electrolytic capacitor C20, and a transistor Q20 having a collector terminal connected to the resistor R20. And a resistor R21 connected in parallel to the collector terminal-base terminal of the transistor Q20 and a Zener diode DZ20 whose cathode terminal is connected to the base terminal of the transistor Q20. The second control power supply generation circuit 340 is a so-called constant voltage power supply circuit, and a second control power supply Vcc2 (hereinafter also referred to as a second control voltage Vcc2) is output from the emitter terminal of the transistor Q20.

  The oscillation stop circuit 350 includes a photocoupler PC1 whose collector terminal is connected to the positive electrode of the electrolytic capacitor C2 of the first control power generation circuit 330, resistors R4 and R5 connected in series connected to the photocoupler PC1, and resistors A capacitor C3 connected in parallel to R5, a resistor R22 connected between the emitter terminal of the transistor Q20 of the second control power generation circuit 340 and the photocoupler PC2, and a collector terminal connected to the photocoupler PC1, And a transistor Q21 having an emitter terminal connected to a reference voltage terminal GND2 (hereinafter also referred to as a secondary circuit ground terminal GND2) on the secondary side.

  The midpoint of the resistors R4 and R5 of the oscillation stop circuit 350 is connected to the OVP terminal P4 of the lighting control circuit IC.

  The photocoupler PC1 includes a photodiode PC1-1 that emits light when a current flows, and a phototransistor PC1-2 that operates according to light emitted from the photodiode PC1-1.

  Photodiode PC1-1 has an anode terminal connected to resistor R22 and a cathode terminal connected to the collector terminal of transistor Q21.

  The phototransistor PC1-2 has a collector terminal connected to the first control power generation circuit 330 and an emitter terminal connected to the resistor R4.

  The feedback circuit 360 is operated by the resistor R25 connected to the detection resistor R10, the second control power supply Vcc2, and the operational amplifier OP1 whose negative input terminal is connected to the resistor R25, the output terminal of the operational amplifier OP1, and the on-time control circuit. A first reference value connected to the positive input terminal of the operational amplifier OP1; a resistor R23 connected between the resistor 370; a capacitor C21 and a resistor R24 connected in series to the negative input terminal-output terminal of the operational amplifier OP1; A setting unit Vs1.

  The on-time control circuit 370 includes a resistor R6 connected to the on-time detection terminal P5 of the lighting control circuit IC and a photocoupler PC2 connected to the resistor R6 and the feedback circuit 360.

  The photocoupler PC2 includes a photodiode PC2-1 that emits light when a current flows, and a phototransistor PC2-2 that operates in accordance with light emitted from the photodiode PC2-1.

  The anode terminal of the photodiode PC2-1 is connected to the second control power generation circuit 340 (second control power supply Vcc2), and the cathode terminal is connected to the resistor R23 of the feedback circuit 360.

  The phototransistor PC2-2 has a collector terminal connected to the resistor R6, and an emitter terminal connected to a primary side reference voltage terminal GND1 (hereinafter also referred to as a primary side circuit ground terminal GND1).

  The output voltage regulating circuit 380 includes resistors R30 and R40 connected to the high potential side of the electrolytic capacitor C10, a drain terminal connected to the resistor R30, a source terminal connected to the secondary circuit ground terminal GND2, and a gate terminal The MOS-FET Q30 connected to the resistor R40, the resistor R41 connected between the gate terminal and the source terminal of the MOS-FET Q30, the drain terminal is connected to the gate terminal of the MOS-FET Q30, and the source terminal is MOS- The MOS-FET Q31 connected to the source terminal of the FET Q30, the resistor R43 connected between the gate terminal and the source terminal of the MOS-FET Q31, the second control power generation circuit 340, and the gate terminal of the MOS-FET Q31 And a resistor R42 connected to the.

  The PWM signal conversion circuit 390 is connected to a dimmer 2000 that is an external device via a signal line.

  The PWM signal conversion circuit 390 is a dimming signal output from the dimmer 2000 (for example, a pulse width modulation signal (hereinafter also referred to as a PWM signal) having a variable on-duty ratio) or an extinction signal (for example, a HIGH signal (constant). The voltage signal)) is received, and the reference voltage V1 of the first reference voltage setting device Vs1 is varied according to the on-duty ratio of the dimming signal.

  When the PWM signal conversion circuit 390 receives a turn-off signal from the dimmer 2000, the PWM signal conversion circuit 390 turns on the transistor Q21 of the oscillation stop circuit 350.

  Next, an operation in which the power supply device 300 turns on the LED 141 will be described.

  When the AC voltage AC is supplied, the power supply device 300 is charged with the electrolytic capacitor C2 via the starting resistor R1, and when the voltage charged in the electrolytic capacitor C2 exceeds the starting voltage of the lighting control circuit IC, the lighting control is performed. The circuit IC is activated. The lighting control circuit IC starts switching control of the MOS-FET Q1, and a current flows through the primary winding T1.

  At this time, a current flows through the first to third secondary windings T2 to T4 of the transformer TR, and secondary voltages are generated respectively. Therefore, the capacitor C10 connected to the first secondary winding T2 is charged, the first control power supply Vcc1 is generated by the first control power generation circuit 330 connected to the second secondary winding T3, and the first The second control power source Vcc2 is generated by the second control power source generation circuit 340 connected to the third secondary winding T4.

  The PWM signal conversion circuit 390 and the operational amplifier OP1 are activated by being supplied with the second control power supply Vcc2.

  At this time, if a dimming signal (PWM signal) for turning on the LED 141 is input from an external device (the dimmer 2000) connected to the PWM signal conversion circuit 390, the reference voltage V1 is determined according to the dimming signal. Adjust the voltage level. Note that when the dimming signal is input to the PWM signal conversion circuit 390, the transistor Q21 is in an OFF state.

  The secondary voltage output from the first secondary winding T2 is rectified by the diode D10 and smoothed by the electrolytic capacitor C10. The smoothed voltage smoothed by the electrolytic capacitor C10 is applied to the detection resistor R10 via the connected LED 141.

  Since the voltage applied to the detection resistor R10 is a voltage corresponding to the current flowing through the connected LED 141, the voltage applied to the detection resistor R10 is input as a detection voltage to the operational amplifier OP1 via the resistor R25. Is done. When the input detection voltage is higher than the reference voltage V1, the operational amplifier OP1 decreases the output voltage and increases the current flowing through the photodiode PC2-1. When the detection voltage is lower than the reference voltage V1, the operational amplifier OP1 outputs the output voltage. The current flowing through the photodiode PC2-1 is decreased.

  The photodiode PC2-1 of the photocoupler PC2 operates according to the current flowing through the phototransistor PC2-2. The on-time detection terminal P5 of the lighting control circuit IC is operated so as to output a constant predetermined current, and the voltage output from the on-time detection terminal P5 is changed by the operation of the phototransistor PC2-2. In accordance with the voltage output from the on-time detection terminal P5, the lighting control circuit IC determines an on-duty time during which the MOS-FET Q1 is turned on.

  The voltage output from the second secondary winding T3 is input to the zero cross detection terminal of the lighting control circuit IC through the resistor R2 and the diode D1. The lighting control circuit IC determines an off-duty time during which the lighting control circuit IC turns off the MOS-FET Q1 based on a voltage (a timing when it becomes 0 volts) input to the zero-cross detection terminal P2.

  Since the off-duty time of the MOS-FET Q1 is often substantially constant, the on-duty time of the MOS-FET Q1 is often controlled to control the LED current flowing through the LED 141.

  As described above, the power supply device 300 controls the current flowing through the connected LED 141 so that the LED 141 has an arbitrary brightness in accordance with the dimming signal from the dimmer 2000.

Here, the relationship between the forward voltage and forward current of the LED 141 will be described.
FIG. 4 is an electrical characteristic diagram showing the relationship between the forward voltage and the forward current of the LED of FIG.

  When the forward voltage Vf applied to 48 LEDs 141 connected in series is gradually increased from 0V, the forward current If does not flow through the LED 141 up to 120V, that is, the LED 141 is not lit.

  Further, when the forward voltage Vf applied to the LED 141 is increased, the forward current If becomes 18.2 mA at 126 V, and the LED 141 starts to light from this point. When the forward voltage Vf is further increased, the forward current If starts to flow through the LED 141 abruptly. The minimum voltage value at which the forward current If starts to flow through the LED 141 is referred to as a minimum lighting voltage Vf (low).

  Note that each element of the LED 141 has a specific upper limit value of the forward voltage Vf and forward current If, and if the upper limit value of the forward voltage Vf and forward current If is exceeded, the lifetime of the element of the LED 141 is exceeded. May suddenly become shorter or in the worst case, it may break down.

Next, an operation in which the power supply apparatus 300 turns off the LED 141 will be described.
FIG. 5 is a timing chart showing voltage waveforms of each circuit when the power supply device performs an operation of turning off the LED. 5A is a voltage waveform indicating the output voltage of the second control power supply generation circuit, FIG. 5B is a voltage waveform indicating the voltage of the gate terminal of the MOS-FET Q30, and FIG. -Voltage waveform indicating the voltage of the gate terminal of the FET Q1, FIG. 5D is a voltage waveform indicating the voltage of the gate terminal of the MOS-FET Q21, and FIG. 5E is an overvoltage terminal of the lighting control circuit 0IC. The input voltage waveform, FIG. 5 (f), is a voltage waveform indicating the voltage applied to the LED 141.

  First, when the power supply device 300 lights the LED 141 (FIG. 5, time t0 to time t1), the second control power generation circuit 340 outputs the second control voltage Vcc2, and the OVP of the lighting control circuit IC. A voltage lower than the oscillation start voltage Fst (oscillation start signal) is applied to the terminal P4, and no voltage is applied to the gate terminal of the MOS-FET Q31 and the transistor Q21, and the MOS-FET Q31. The transistor Q21 is off.

  At this time, a switching signal (rectangular voltage signal consisting of 0 V and voltage V1on) is input to the gate terminal of the MOS-FET Q1, and a forward voltage Vf exceeding the minimum lighting voltage Vf (low) is applied to the LED 141. As a result, a current flows through the LED 141 and is lit.

  Next, when the turn-off signal output from the dimmer 2000 is input to the PWM signal conversion circuit 390 (time t1), the PWM signal conversion circuit 390 turns on the transistor Q21, and the second control voltage Vcc2 causes the resistor R22 to be turned on. Current flows through the photodiode PC1-1 of the photocoupler PC1, thereby turning on the phototransistor PC1-2.

  When the phototransistor PC1-2 is turned on, the voltage of the second secondary winding T3 flows in a loop of resistor R2, diode D2, resistor R3, phototransistor PC1-2, resistor R4, resistor R5, and capacitor C3. The capacitor C3 is gradually charged (time t1 to time t2). When the voltage charged in the capacitor C3 is applied to the OVP terminal P4 of the lighting control circuit IC and the applied voltage is the oscillation stop voltage Foff, the lighting control circuit IC stops switching of the MOS-FET Q1 (time). t2).

  When the switching of the MOS-FET Q1 is stopped, no current flows through the primary winding T1 of the transformer TR. Therefore, no secondary voltage is generated in the first to third secondary windings T2 to T3.

  Therefore, since the second control power supply generation circuit 340 cannot generate the second control power supply Vcc2, the charge charged in the electrolytic capacitor C20 is gradually discharged, and the electrolytic capacitor C20 (second control power supply Vcc2) is discharged. The voltage decreases (time t2 to time t4).

  At this time, the electric charge charged in the electrolytic capacitor C10 is discharged at the same time, and the voltage drops, and falls below the lighting minimum voltage Vf (low) that is the lowest voltage at which the LED 141 lights (point A shown in FIG. 5 (f)). Then, the LED 141 is turned off.

  Further, when the electric charge of the electrolytic capacitor C20 is discharged and the voltage is lowered, the gate voltage of the MOS-FET Q31 divided by the resistors R42 and R43 is lowered, and the ON state of the MOS-FET Q31 cannot be maintained.

  When the MOS-FET Q31 is turned off, a divided voltage obtained by dividing the voltage of the capacitor C10 by the resistors R40 and R41 is applied to the gate terminal of the MOS-FET Q30, and the MOS-FET Q30 is turned on (time t4).

  Therefore, rapid discharge of the electric charge charged in the electrolytic capacitor C10 is started (time t4 to time t5).

  When the electric charge of the electrolytic capacitor C20 is further discharged, the current flowing through the photodiode PC1-1 through the resistor R22 decreases.

  Therefore, the phototransistor PC1-2 is gradually turned off, and the voltage applied to the OVP terminal P4 of the lighting control circuit IC is decreased (time t5 to time t6).

  When the voltage applied to the OVP terminal P4 reaches the oscillation start voltage Fst, the lighting control circuit IC starts switching of the MOS-FET Q1 (time t6).

  When the switching of the MOS-FET Q1 is started, current starts to flow through the primary winding T1, current also flows through the first to third secondary windings T2 to T4, and the first secondary winding T2 is 2 Since the next voltage is generated, the electrolytic capacitor C10 starts to be charged, and at the same time, the second control power supply generation circuit 340 starts to generate the second control power supply Vcc2 (time t6 to time t7).

  At this time, the control power supply Vcc2 is input to the output voltage regulating circuit 380, but the voltage value of the control power supply Vcc2 gradually increases without rapidly increasing. Therefore, since the divided voltage divided by the resistors R50 and R51 immediately after the MOS-FET Q1 starts switching does not reach the gate voltage of the MOS-FET Q31, the MOS-FET Q31 maintains the OFF state. doing.

  When the MOS-FET Q31 is maintained in the OFF state, the voltage of the electrolytic capacitor C10 is divided by the resistors R40 and R41, and the MOS-FET Q30 is kept on, so that the resistor R30, MOS is connected in parallel with the electrolytic capacitor C10. -The drain terminal-source terminal of the FET Q31 is electrically connected.

  That is, since the impedance on the output side of the first secondary winding T2 is lowered by the resistor R30 and the MOS-FET Q31, the charging for charging the electrolytic capacitor C10 by the secondary voltage output by the first secondary winding T2 is performed. The time is longer than that in the state in which the MOS-FET Q31 is OFF, and the voltage rise of the electrolytic capacitor C10 becomes gradual.

  Subsequently, when the extinction signal is output from the dimmer 2000 to the PWM signal conversion circuit 390, the PWM signal conversion circuit 390 turns on the transistor Q21, so that the resistor R22 → the photodiode PC1- A current flows through 1 to turn on the phototransistor PC1-2.

  Therefore, a current flows from the first control power supply Vcc1 to the collector-emitter of the phototransistor PC1-2 → the resistor R4 → the resistor R5 and the capacitor C3, and charging of the capacitor C3 is started.

  When the capacitor C3 is charged, the voltage of the capacitor C3 reaches the oscillation stop voltage Foff again, so that the lighting control circuit IC stops switching of the MOS-FET Q1 (time t7 to time t8).

  That is, before the voltage charged in the electrolytic capacitor C10 reaches the lighting minimum voltage Vf (low), the electric charge of the electrolytic capacitor C10 is discharged again, and no current flows through the LED 141.

  Thereafter, the power supply apparatus 300 repeats the operation from time t6 to time t8, and maintains the LED 141 in the extinguished state (time t8 to time t10).

  In this embodiment, the power supply apparatus 300 uses the voltage of the electrolytic capacitor C10 that is charged by repeating the operation from time t6 to time t8 (hereinafter, the voltage of the electrolytic capacitor C10 when the LED 141 is turned off) as the turn-off voltage Vlo. It is desirable to set 30V to 80V. The extinguishing voltage Vlo is set according to the specifications of the light source 140 connected to the power supply device 300 (the number of LEDs 141 constituting the light source 140 or the forward voltage Vf of the LEDs 141).

  In this way, the lighting control circuit IC is repeatedly restarted, but the voltage charged in the electrolytic capacitor C10 is maintained at a voltage lower than the forward voltage Vf of the LED 141 by the output voltage regulating circuit 380, so Does not flow, and the state where the LED 141 is not lit can be maintained.

  Further, since the voltage can be continuously applied to the OVP terminal P4 of the lighting control circuit IC until the electric charge charged in the capacitor C3 connected in parallel to the resistor R5 is discharged, the electrolytic capacitor is provided by the starting resistor R1. Even if C2 reaches the starting voltage of the lighting control circuit IC, the lighting control circuit IC does not immediately switch the MOS-FET Q1. Therefore, since the interval period until the lighting control circuit IC starts switching the MOS-FET Q1 again can be lengthened, energy saving can be achieved.

  In addition, when the MOS-FET Q1 is switching, the first control power supply Vcc1 and the second control power supply Vcc2 are generated based on the output power of the second and third secondary windings T3 and T4. Therefore, for example, there is less loss than a method of generating a low control power voltage from a high voltage on the primary side by resistance voltage division or the like, and the overall power consumption of the power supply apparatus 300 can be suppressed.

  In addition, although the lighting fixture 1000 of this Embodiment demonstrated the case where the light source 140 was incorporated in the lighting fixture 1000, you may make it make the light source 140 removable from the lighting fixture 1000. FIG.

  In the present embodiment, the case where the rectifying / smoothing circuit 310 is a capacitor input type rectifying circuit including the diode bridge DB and the capacitor C1 has been described. I do not care.

Embodiment 2. FIG.
The present embodiment is a modification of the first embodiment.
In the first embodiment, the method of maintaining the light-off state of the LED 141 by repeatedly stopping and restarting the operation of the lighting control circuit IC has been described. However, in this embodiment, the operation of the lighting control circuit IC is stopped. A method for maintaining the LED 141 in the off state will be described.
In the present embodiment, the same components as those in the first embodiment are denoted by the same reference numerals and the description thereof will be omitted, and configurations and operations different from those in the first embodiment will be described in detail.

  The luminaire 1000a includes a lamp unit 100, a power supply device 300a that is physically and electrically connected via an electric wire 200 drawn from the lamp unit 100, and a power supply case 400 that houses the power supply device 300a. Have

  The power supply device 300a receives the smoothing voltage generated by the rectifying / smoothing circuit 310 that converts the input AC voltage AC into a DC voltage to generate a smoothing voltage, and the constant voltage to the connected LED 141. A switching power supply circuit 320 for supplying power, a first control power generation circuit 330 connected to the switching power supply circuit 320, a second control power generation circuit 340 also connected to the switching power supply circuit 320, and a first control power generation An oscillation stop circuit 350 connected to the circuit 330 and the second control power supply generation circuit 350, a feedback circuit 360 connected to the switching power supply circuit 320, an on-time control circuit 370a connected to the feedback circuit 360, a switching power supply The output voltage detection circuit 380a connected to the circuit 320 and the output Having an output voltage decision circuit 380b connected to the voltage detection circuit 380a and the on-time control circuit 370a, a PWM signal conversion circuit 390 which is connected to the oscillation stop circuit 350 and a feedback circuit 360, a.

  The on-time control circuit 370a includes resistors R6 and R7 connected to the on-time detection terminal P5 of the lighting control circuit IC, a photocoupler PC2 connected to the resistor R6 and the feedback circuit 360, a resistor R7, and an output voltage determination circuit. It consists of photocoupler PC3 connected to 380b.

  The photocoupler PC3 includes a photodiode PC3-1 that emits light when a current flows, and a phototransistor PC3-2 that operates in accordance with light emitted from the photodiode PC3-1.

  The photodiode PC3-1 has an anode terminal connected to the second control power generation circuit 340 (second control power supply Vcc2) and a cathode terminal connected to the output voltage determination circuit 380b.

  The phototransistor PC3-2 has a collector terminal connected to the resistor R7 and an emitter terminal connected to the primary side reference voltage terminal GND1.

  The output voltage detection circuit 380a includes two resistors R50 and R51 connected in series.

  The output voltage determination circuit 380b is connected to the resistor R52 connected to the middle point of the resistors R50 and R51, the operational amplifier OP2 whose negative input terminal is connected to the resistor R52, and the negative input terminal and output terminal of the operational amplifier OP2. A resistor R53 and a capacitor C51 connected in series, a resistor R54 connected to the output terminal of the operational amplifier OP2, and a second reference voltage setting device Vs2 connected to the positive input terminal of the operational amplifier OP2.

  When the PWM signal conversion circuit 390 outputs a lighting state signal (LOW signal), the reference voltage setting unit Vs2 switches the reference voltage V2 to the first reference value V21, and the PWM signal conversion circuit 390 turns off the light state signal (HIGH signal). ) Is output, the reference voltage V2 is switched to the second reference value V22. The first reference value V21 is set to a value (voltage value) higher than the second reference value V22.

  Next, the operation of the power supply apparatus 300a will be described. Note that the operation of the power supply device 300a to turn on the LED 141 is the same as in the first embodiment, and a description thereof will be omitted.

  First, when a turn-off signal (HIGH signal) is input from the dimmer 2000 to the PWM signal conversion circuit 390, the transistor Q21 is turned on and the reference voltage V2 of the operational amplifier OP2 is changed from the first reference value V21 to the second reference value. Change to V22.

  When the transistor Q21 is turned on, the current from the second control power supply Vcc2 flows through the resistor R22 to the photodiode PC2-1 of the photocoupler PC2, thereby turning on the phototransistor PC2-2. When the phototransistor PC2-2 is turned on, a current flows from the first control power supply Vcc1 to the resistors R4 and R5 via the phototransistor PC2-2. At this time, a voltage is generated in the resistor R5, a voltage is applied to the OVP terminal P4 of the lighting control circuit IC, and the lighting control circuit IC stops switching of the MOS-FET Q1.

  Therefore, no current flows through the primary winding T1 of the transformer TR, and no current flows through the first to third secondary windings T2 to T4.

  Next, when the electrolytic capacitor C2 is charged via the starting resistor R1, and the voltage charged in the electrolytic capacitor C2 exceeds the starting voltage of the lighting control circuit IC, the lighting control circuit IC operates again (switching of the MOS-FET Q1). ).

  When the lighting control circuit IC starts operation and switches the MOS-FET Q1, a current flows through the primary winding T1, a current flows through the first to third secondary windings T2 to T4, and outputs a secondary voltage respectively. To do.

  Therefore, the electrolytic capacitor C10 connected to the first secondary winding T2 starts to be charged, and the voltage of the electrolytic capacitor C10 is monitored by the voltage detection circuit 380a, and is a voltage proportional to the voltage of the electrolytic capacitor C10. A detection signal is output to the operational amplifier OP2.

  The operational amplifier OP2 compares this voltage detection signal with the reference voltage V2 (second reference value V22) and outputs the result. That is, when the voltage detection voltage is higher than the reference voltage V2, the operational amplifier OP2 decreases the output voltage and increases the current flowing through the photodiode PC3-1. When the detection voltage is lower than the reference voltage V2, the operational amplifier OP2 outputs the output voltage. The current flowing through the photodiode PC3-1 is decreased.

  The photodiode PC3-1 of the photocoupler PC3 operates according to the current flowing through the phototransistor PC3-2. The on-time detection terminal of the lighting control circuit IC operates so as to output a constant predetermined current, and the voltage output from the on-time detection terminal P5 is varied by the operation of the phototransistor PC3-2. In accordance with the voltage output from the on-time detection terminal P5, the lighting control circuit IC determines an on-duty time during which the MOS-FET Q1 is turned on.

At this time, since no current flows through the LED 141, no voltage is generated in the detection resistor R10.
Therefore, since the detection voltage input to the negative terminal of the operational amplifier OP1 does not reach the reference voltage V1, the operational amplifier OP1 increases the output voltage to reduce the current flowing through the photodiode PC1, and the collector terminal of the phototransistor PC1-2. -The current flowing through the emitter terminal is very small.

  Accordingly, although a small amount of current flows through the resistor R6, the current flowing through the resistor R7 is much larger, so the voltage at the on-time detection terminal P5 is greatly influenced by the current flowing through the resistor R7.

  That is, when the LED 141 is turned off, the output voltage determination circuit 380b controls the photocoupler PC3, whereby the on-duty for the lighting control circuit IC to switch the MOS-FET Q1 is determined.

  Thus, by changing the on-duty of the MOS-FET Q1, the period during which current flows through the primary winding T1 is shortened, and the voltage generated in the first secondary winding T2 is kept low.

  Therefore, the voltage charged in the electrolytic capacitor C10 is maintained at a voltage lower than the forward voltage Vf of the LED 141, and the LED 141 can maintain the extinguished state.

  Thus, by using the output voltage detection circuit 380a and the output voltage determination circuit 380b, the voltage of the electrolytic capacitor C10 is set to a voltage lower than the forward voltage Vf (lighting minimum voltage Vf (low)) of the LED 141, and the LED 141 is thereby made Can be turned off.

  Further, since the reference voltage V2 of the output voltage determination circuit 380b (second reference voltage setter Vs2) is switched to the first reference value V21 and the second reference value V22, the first reference value V21 is switched to the power supply device 300a. It can also be set to a voltage value for protecting the constituent circuit components or the connected LED 141.

  For example, the power supply device 300a for turning on the LED 141 often has a constant current circuit configuration. Therefore, when the LED 141 is not connected to the power supply device 300a or the number of LEDs 141 connected in series increases, the output voltage output from the power supply device 300a increases.

  When the output voltage of the power supply device 300a rises abnormally, the circuit components constituting the power supply device 300a are stressed, or if the LED 141 is connected when the output voltage is high, the LED 141 is overvoltaged and destroyed. There are times when it falls.

  However, if the first reference value V21 of the reference voltage V2 is set to a voltage for protecting the circuit component constituting the power supply device 300a or the LED 141 connected thereto, the circuit component constituting the power supply device 300a or the LED 141 connected thereto. Can be protected.

  Thus, since the reference voltage V2 is switched between the first reference value V21 and the second reference value V22, the circuit component constituting the power supply device 300a or the connection is provided while the LED 141 is turned off. The function of protecting the LED 141 can be configured by a common circuit. Therefore, the circuit configuration of the power supply device 300a is simplified, and the number of circuit components can be reduced.

  Further, since the third secondary winding T4 is wound in the direction opposite to the primary winding T1 (forward type), the voltage generated in the third secondary winding T4 is applied to the primary winding T1. Depends on the voltage. Therefore, even if the duty of the MOS-FET Q1 is changed in order to keep the voltage generated in the first secondary winding T2 low, the voltage generated in the third secondary winding T4 is affected. Absent.

  Therefore, since the second control power generation circuit 340 can continue to generate the control power Vcc2, the lighting control circuit IC, the on-time control circuit 370a, the output voltage determination circuit 380b, and the PWM signal conversion circuit 390 are continuously operated. Thus, the LED 141 can be maintained in an extinguished state.

  DESCRIPTION OF SYMBOLS 100 Lamp body unit, 110 Lamp body, 120 Mounting spring, 130 Radiation fin, 140 Light source, 141 LED, 142 Printed circuit board, 200 Electric wire, 300, 300a Power supply device, 310 Rectification smoothing circuit, 320 Switching power supply circuit, 330 1st control Power generation circuit, 340 Second control power generation circuit, 350 Oscillation stop circuit, 360 feedback circuit, 370, 370a On-time control circuit, 380 Output voltage regulation circuit, 380a Output voltage detection circuit, 380b Output voltage determination circuit, 390 PWM signal Conversion circuit, GND1 primary side reference voltage terminal (primary side circuit ground terminal), GND2 secondary side reference voltage terminal (secondary side circuit ground terminal), Vs1 first reference voltage setter, V1 reference voltage, Vs2 Second reference voltage setter, V2 reference voltage, 40 0 power supply case, 410 base case, 420 cover case, 1000, 1000a lighting fixture, 2000 dimmer, AC AC voltage, DB diode bridge, IC lighting control circuit, TR transformer, D10, D20 diode, R1 start resistance, R10 detection Resistor, Q1 switching element (MOS-FET), P1 switching output terminal, P2 zero cross detection terminal, P3 control power supply terminal (Vcc terminal), P4 overvoltage detection terminal (OVP terminal, protection terminal), P5 on-time detection terminal, T1 Primary winding, T2 first secondary winding, T3 second secondary winding, T4 third secondary winding, C1, C2, C10, C20 electrolytic capacitor, C21, C51 capacitor, D1, D2 Diode, DZ1, DZ20 Zener diode, Q20 Q21 transistor, Vcc2 second control power supply (second control voltage Vcc2), PC1 to PC3 photocoupler, PC1-1 to PC3-1 photodiode, PC1-2 to PC3-3 phototransistor, Vs1 first reference value setting unit , GND1 primary side reference voltage terminal (primary side circuit ground terminal), GND2 secondary side reference voltage terminal (secondary side circuit ground terminal), Q30, Q31 MOS-FET, R2 to R7, R20 to R25, R30, R40 to R43, R50 to R54 resistors, OP1, OP2 operational amplifier, Vs2 second reference voltage setter, V2 reference voltage, V21 first reference value, V22 second reference value.

Claims (3)

In a power supply device that supplies DC power to a light source,
An insulated transformer having a primary winding and a secondary winding;
A first switching element connected in series to the primary winding;
A capacitor connected to the secondary winding;
A dimming signal conversion circuit that receives an external signal from the outside and outputs an oscillation stop signal when the external signal is an extinction signal indicating extinction;
A second switching element connected to the capacitor, and when the extinction signal is input to the dimming signal conversion circuit, the second switching element is turned on to generate 2 in the secondary winding. The capacitor is charged to the next voltage in the first charging time, and when the extinction signal is not input to the dimming signal conversion circuit, the second switching element is turned off and generated in the secondary winding. An output voltage regulating circuit having a charging time for charging the capacitor to a secondary voltage as a second charging time longer than the first charging time;
A lighting control circuit that controls switching of the first switching element and stops switching of the first switching element based on the oscillation stop signal;
A control power supply circuit for generating a control power supply when the first switching element is oscillating, and supplying the control power supply to the dimming signal conversion circuit;
A power supply device comprising: In a power supply device that supplies DC power to a light source,
An insulated transformer having a primary winding and a secondary winding;
A first switching element connected in series to the primary winding;
A capacitor connected to the secondary winding;
A lighting control circuit for controlling the switching of the first switching element;
A dimming signal conversion circuit that receives an external signal from the outside and outputs an oscillation stop signal when the external signal is an extinction signal indicating extinction;
An output voltage detection circuit connected to the capacitor and detecting a voltage charged in the capacitor, and outputting a voltage detection signal based on the detected voltage;
When the oscillation stop signal is input, the voltage detection signal detected by the output voltage detection circuit is compared with a reference voltage, and the voltage charged in the capacitor is lower than the minimum voltage for lighting the light source. An output voltage determination circuit that controls an on-duty ratio and / or a switching frequency of the first switching element via the lighting control circuit,
A control power supply circuit for generating a control power supply when the first switching element is oscillating, and supplying the control power supply to the dimming signal conversion circuit;
A power supply device comprising: The power supply device according to claim 1 or 2,
A light source connected to the power supply;
The lighting fixture characterized by having.

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