JP5079043B2 - Power supply device, discharge lamp lighting device including the power supply device, and lighting fixture including the discharge lamp lighting device - Google Patents

Description

  The present invention relates to a power supply device, a discharge lamp lighting device including the power supply device, and a lighting fixture including the discharge lamp lighting device.

  As a conventional discharge lamp lighting device, when the discharge lamp voltage detected by the discharge lamp voltage detection circuit or the discharge lamp current detected by the discharge lamp current detection circuit is out of a predetermined range, the discharge lamp is turned off, Some have a control circuit that makes the on-duty of the switching element of the boost converter smaller than the on-duty when the discharge lamp voltage or the discharge lamp current is within a predetermined range. The voltage output from the boost converter is discharged by the DC voltage detection circuit by turning on and off the switching element of the boost converter due to the reduced on-duty, and the voltage is generated in the secondary winding of the boost converter inductance. The voltage is ensured (see, for example, Patent Document 1).

Japanese Patent No. 4211022 (page 4, FIG. 1)

  When the AC power supply is adapted to a wide range of voltages, the voltage width to be boosted becomes smaller when the AC power supply voltage is higher than when the effective value of the AC power supply voltage is low. For this reason, even when the on-duty of the switching element of the boost converter is smaller than the on-duty when the discharge lamp voltage or the discharge lamp current is within a predetermined range at no load when the discharge lamp is not lit, the AC power supply In places where the instantaneous value of voltage is high, the output voltage of the boost converter reaches a predetermined target value in a short period of time, and the switching element of the boost converter is intermittently operated. For this reason, there is a problem in that a predetermined control voltage is not generated from the secondary winding provided along with the inductance of the boost converter.

  The present invention has been made to solve the above-described problems. Even when the AC power supply is adapted to a wide range of voltages, a stable voltage is obtained from the secondary winding of the boost converter inductance when there is no load. It is an object to obtain a power supply device that can be generated, a discharge lamp lighting device including the power supply device, and a lighting fixture including the discharge lamp lighting device.

A power supply device according to the present invention includes a rectifier circuit that rectifies an AC power supply voltage, a switching element, a boost chopper circuit that boosts an output voltage of the rectifier circuit based on an operation of the switching element, and an output voltage of the boost chopper circuit A voltage detection means for detecting a voltage, a control voltage generation winding provided in the inductance of the boost chopper circuit, a control voltage generation circuit for generating a predetermined control voltage from the voltage generated in the winding, and at least a voltage detection Control means for controlling the switching element so that the output voltage of the boost chopper circuit detected by the means becomes a preset target voltage, and the control means is an effective value or average of the AC power supply voltage when there is no load. As the value or maximum value increases, a target voltage that is larger than the target voltage is set, and the output voltage of the boost chopper circuit is set to the target voltage. Controlling the switching element so that the pressure.

According to the power supply device of the present invention, when there is no load, the target voltage having a value larger than the target voltage is set as the effective value or average value or maximum value of the AC power supply voltage increases, and the output voltage of the boost chopper circuit is It becomes equal to the target voltage so that he is trying to control the switching element. Thereby, even when the voltage of the AC power supply is low, the boosted voltage width can be set to an optimum value, and the switching element of the boost chopper circuit can be continuously turned on / off. For this reason, it is possible to generate a stable voltage from the control voltage generating winding provided along with the inductance of the boost chopper circuit .

1 is a circuit diagram showing a configuration of a discharge lamp lighting device according to Embodiment 1. FIG. 4 is a flowchart showing an operation of a control circuit in the discharge lamp lighting device according to the first embodiment. 6 is a flowchart illustrating an operation of a control circuit in the discharge lamp lighting device according to the second embodiment. 10 is a flowchart showing an operation of a control circuit in the discharge lamp lighting device according to the third embodiment. It is a figure which shows the structure of the lighting fixture which concerns on Embodiment 4. FIG.

Hereinafter, embodiments of a discharge lamp lighting device and a lighting fixture including a power supply device of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
1 is a circuit diagram showing a configuration of a discharge lamp lighting device according to Embodiment 1. FIG.
As shown in the figure, the discharge lamp lighting device according to the first embodiment is connected to the commercial AC power supply 1 on the input side, and the secondary winding of the step-up transformer 20 and the high-pressure discharge lamp 21 described later on the output side. Are connected in series.

  The discharge lamp lighting device includes a rectifier circuit 2 that rectifies AC power from a commercial AC power supply 1 into DC power, a voltage detection circuit 3 that is connected between output terminals of the rectifier circuit 2, and an output terminal of the rectifier circuit 2. The step-up chopper circuit 4 connected, the voltage detection circuit 9 connected between the output terminals of the step-up chopper circuit 4, the step-down chopper circuit 10 connected to the output terminal of the step-up chopper circuit 4, and the output of the step-down chopper circuit 10 A voltage detection circuit 23 connected between the terminals, an inverter circuit connected to the output terminal of the step-down chopper circuit 10, a starting circuit 22 for applying a high-pressure pulse to the high-pressure discharge lamp 21 of the load circuit, and the step-down chopper circuit 10 A current detection circuit 24 made of a resistor inserted between the inverter circuit, a control circuit 25, and a control voltage generation circuit 26 is provided.

  The voltage detection circuit 3 on the output side of the rectifier circuit 2 is configured by a resistance voltage dividing circuit, and detects the output voltage of the rectifier circuit 2. The step-up chopper circuit 4 includes an inductance 5 and a switching element 6 connected in series between output terminals of the rectifier circuit 2, a diode 7 connected in a forward direction to a connection point between the inductance 5 and the switching element 6, and the switching element 6. And an electrolytic capacitor 8 connected in parallel via a diode 7. The inductance 5 is composed of a primary winding 5a and a secondary winding 5b that are magnetically coupled to each other. The voltage detection circuit 9 on the output side of the step-up chopper circuit 4 is constituted by a resistance voltage dividing circuit as described above, and detects the output voltage of the step-up chopper circuit 4.

  The step-down chopper circuit 10 includes a switching element 11 connected to a connection point of the diode 7 and the electrolytic capacitor 8 of the step-up chopper circuit 4, and a forward diode 13 connected in parallel to the electrolytic capacitor 8 via the switching element 11. , An inductance 12 connected to a connection point between the switching element 11 and the diode 13, and a capacitor 14 connected in parallel to the diode 13 via the inductance 12. The voltage detection circuit 23 on the output side of the step-down chopper circuit 10 is configured by a resistance voltage dividing circuit, and detects the output voltage of the step-down chopper circuit 10 (corresponding to the voltage of the high-pressure discharge lamp 21).

  The aforementioned inverter circuit includes a series circuit of the first switching element 15 and the second switching element 16, and a series circuit of the third switching element 17 and the fourth switching element 18 between the output terminals of the step-down chopper circuit 10. And a full bridge type inverter connected in parallel. The load circuit described above is inserted between the connection point of the first switching element 15 and the second switching element 16 and the connection point of the third switching element 17 and the fourth switching element 18 of the inverter circuit. Yes. A capacitor 19 is connected in parallel to the load circuit.

  The starting circuit 22 is connected to the primary winding magnetically coupled to the secondary winding of the step-up transformer 20, generates a high-pressure pulse when the high-pressure discharge lamp 21 is started, and is applied to the high-pressure discharge lamp 21 to light up. Let The current detection circuit 24 detects the output current of the step-down chopper circuit 10 (corresponding to the current of the high-pressure discharge lamp 21). The high-pressure discharge lamp 21 of the load circuit corresponds to the discharge lamp in the present invention, and for example, an HID lamp (high-pressure mercury lamp), a high-pressure sodium lamp, a metal halide lamp, or the like is used.

  The control circuit 25 is configured by an arithmetic device such as a microcomputer or a DSP (Digital Signal Processor), for example, the switching element 6 of the step-up chopper circuit 4, the switching element 11 of the step-down chopper circuit 10, the switching elements 15, 16 of the inverter circuit, 17 and 18 are controlled. The control circuit 25 is connected to the voltage detection circuits 3, 9, 23 and the current detection circuit 24 described above and a control voltage generation circuit 26 that generates a control voltage.

  The control voltage generation circuit 26 includes a diode 27 connected in the forward direction to one end of the secondary winding 5b of the inductance 5 provided in the boost chopper circuit 4, an electrolytic capacitor 28 connected to the diode 27, A constant voltage IC 29 having an input terminal connected to a connection point between the diode 27 and the electrolytic capacitor 28, a resistor 30 connected to the output terminal of the rectifier circuit 2, a Zener diode 31 connected to the resistor 30, a resistor 30 and It is composed of a diode 32 inserted in the forward direction between the connection point of the Zener diode 31 and the output terminal of the constant voltage IC 29, and an electrolytic capacitor 33 connected in parallel to the Zener diode 31 via the diode 32. A connection point between the diode 32 of the control voltage generation circuit 26, the electrolytic capacitor 33, and the output terminal of the constant voltage IC 29 is connected to the power supply terminal of the control circuit 25.

  Next, the operation of the discharge lamp lighting device configured as described above will be described with reference to FIG. When the commercial AC power supply 1 is turned on to the rectifier circuit 2, the full-wave rectified voltage is applied to the resistor 30 of the control voltage generation circuit 26, and a current flows through the resistor 30. The electrolytic capacitor 33 is charged with the direct current voltage. Then, a control voltage is applied to the control circuit 25 by the charging energy charged in the electrolytic capacitor 33.

  When the control voltage is applied, the control circuit 25 starts the operation of the boost chopper circuit 4 and boosts the voltage that has been full-wave rectified by the rectifier circuit 2. The boosted DC voltage is converted into AC by the inverter circuit via the step-down chopper circuit 10 and applied to the high-pressure discharge lamp 21. At this time, the control circuit 25 drives the starting circuit 22 to generate a high-pressure pulse for starting the high-pressure discharge lamp 21 and applies it to the high-pressure discharge lamp 21 to light it.

  When the high-pressure discharge lamp 21 is turned on, the control circuit 25 detects the output voltage of the step-down chopper circuit 10 detected by the voltage detection circuit 23 (corresponding to the voltage of the high-pressure discharge lamp 21), and from this voltage, the control circuit 25 A target current value of the high pressure discharge lamp 21 is calculated so that the power becomes a predetermined power. The control circuit 25 switches the switching element of the step-down chopper circuit 10 so that the calculated target current value matches the output current of the step-down chopper circuit 10 detected by the current detection circuit 24 (corresponding to the current of the high-pressure discharge lamp 21). 11 on-duty is controlled.

  The control circuit 25 reads the output voltage of the step-up chopper circuit 4 detected by the voltage detection circuit 9, and the input is set to a high power factor so that the output voltage matches a preset target voltage value. Thus, the on-duty of the switching element 6 of the boost chopper circuit 4 is controlled.

  When the switching element 6 of the step-up chopper circuit 4 is turned on, a current flows through the inductance 5 and energy is accumulated in the primary winding 5a of the inductance 5. When the switching element 6 is turned off, the energy stored in the primary winding 5 a of the inductance 5 is charged to the electrolytic capacitor 8 through the diode 7.

  At this time, since the transformer is constituted by the primary winding 5a and the secondary winding 5b of the inductance 5, a voltage is generated in the secondary winding 5b when a current flows through the primary winding 5a. This voltage is smoothed by the diode 27 and the electrolytic capacitor 28 of the control voltage generation circuit 26 and becomes a predetermined control voltage by the constant voltage IC 29. The control voltage generated by the constant voltage IC 29 is set to be slightly higher than the control voltage generated by the resistor 30 and the Zener diode 31. This is to prevent current from flowing through the resistor 30 when a control voltage is supplied from the constant voltage IC 29. That is, when the boost chopper circuit 4 at the time of power-on is not operating, the output voltage of the rectifier circuit 3 is supplied through the resistor 30 of the control voltage generation circuit 26, but the boost chopper circuit 4 starts operating. Sometimes, a voltage is supplied from the secondary winding 5 b of the inductance 5 of the boost chopper circuit 4.

  However, since no current flows from the step-up chopper circuit 4 when the high-pressure discharge lamp 21 is not lit, the switching element 6 of the step-up chopper circuit 4 stops when the output voltage of the step-up chopper circuit 4 reaches a predetermined voltage. To do. Thereafter, when the output voltage of the step-up chopper circuit 4 is gradually discharged by the voltage dividing resistor of the voltage detection circuit 9 and falls to a predetermined voltage, the switching element 6 of the step-up chopper circuit 4 starts to operate again. In this case, since no current flows to the high pressure discharge lamp 21, the output voltage of the boost chopper circuit 4 immediately reaches a predetermined voltage, and the switching element 6 of the boost chopper circuit 4 stops again. Thus, since the switching element 6 of the step-up chopper circuit 4 does not operate continuously when there is no load when the high-pressure discharge lamp 21 is not lit, the control voltage is applied from the secondary winding 5b of the inductance 5 of the step-up chopper circuit 4. The voltage necessary to generate the power is not supplied.

  In addition, when the voltage (effective value) of the commercial AC power supply 1 is high, the voltage width to be boosted is smaller than when the voltage is low, so that the boost chopper is particularly at a place where the voltage (instantaneous value) of the commercial AC power supply 1 is high. The switching element 6 of the circuit 4 is intermittently operated, and it becomes more difficult to supply a voltage necessary for generating the control voltage from the secondary winding 5b of the inductance 5 of the boost chopper circuit 4.

  Even when such an AC power supply is adapted to a wide range of voltages, a voltage necessary for generating a control voltage is obtained from the secondary winding 5b of the inductance 5 of the step-up chopper circuit 4 when there is no load when the discharge lamp is not lit. An example for this is described below.

FIG. 2 is a flowchart showing the operation of the control circuit in the discharge lamp lighting device of the first embodiment.
The control circuit 25 detects the output voltage (corresponding to the voltage of the high-pressure discharge lamp 21) of the step-down chopper circuit 10 detected by the voltage detection circuit 23 (S101), and then the step-down chopper circuit detected by the current detection circuit 24 10 output currents (corresponding to the current of the high-pressure discharge lamp 21) are detected (S102).

  Thereafter, the control circuit 25 determines whether or not the detected output voltage is lower than a preset voltage threshold value (S103), and the high-pressure discharge lamp 21 is not lit when the output voltage is equal to or higher than the voltage threshold value. And the process proceeds to S106. Further, when the output voltage is lower than the voltage threshold, the control circuit 25 determines whether or not the detected output current is higher than a preset current threshold (S104). The control circuit 25 determines that the high-pressure discharge lamp 21 is not lit when the output current is equal to or less than the current threshold value, and proceeds to S106, but proceeds to S105 when the output current is higher than the current threshold value.

  In other words, the control circuit 25 determines that the high-pressure discharge lamp 21 is lit when the detected output voltage is lower than the voltage threshold and the detected output current is higher than the current threshold, and the boost chopper circuit 4 is set to a predetermined value (S105). Then, the control circuit 25 generates a boost chopper circuit so that the output voltage of the boost chopper circuit 4 detected by the voltage detection circuit 9 matches the above target voltage value, and the input has a high power factor. 4 is controlled (normal control), and the process returns to step S101.

  Further, as described above, the control circuit 25 determines that the high-pressure discharge lamp 21 is not lit when the detected output voltage is equal to or higher than the voltage threshold value or when the detected output current is equal to or lower than the current threshold value. Then, the target voltage value of the boost chopper circuit 4 is set to a value larger than a predetermined value when the high pressure discharge lamp 21 is lit (S106), and the process returns to step S101.

  As described above, according to the first embodiment, when there is no load when the high pressure discharge lamp 21 is not lit, the target voltage value of the boost chopper circuit 4 is larger than a predetermined value when the high pressure discharge lamp 21 is lit. It is set to. Thereby, even when the voltage (effective value) of the commercial AC power supply 1 is high, the voltage width to be boosted becomes large, and the switching element 6 of the boost chopper circuit 4 can be continuously turned on / off. For this reason, it is possible to generate a stable voltage from the secondary winding 5b for generating a control voltage that is provided in the inductance 5 of the boost chopper circuit 4.

Embodiment 2.
In the first embodiment, regardless of the voltage (effective value) of the commercial AC power supply 1, the high voltage discharge lamp 21 is lit with the target voltage value of the boost chopper circuit 4 when no load is applied when the high pressure discharge lamp 21 is not lit. In the second embodiment, the target voltage of the boost chopper circuit 4 is set according to the voltage (effective value, average value, or maximum value) of the commercial AC power supply 1. A value is set.
The configuration of the discharge lamp lighting device in the present embodiment is the same as that of the first embodiment (FIG. 1) described above.

FIG. 3 is a flowchart showing the operation of the control circuit in the discharge lamp lighting device of the second embodiment.
As described above, the control circuit 25 detects the output voltage of the step-down chopper circuit 10 detected by the voltage detection circuit 23 (S201), and then outputs the output current of the step-down chopper circuit 10 detected by the current detection circuit 24. Detect (S202).

  Thereafter, the control circuit 25 determines whether or not the detected output voltage is lower than a preset voltage threshold (S203), and the high-pressure discharge lamp 21 is not lit when the output voltage is equal to or higher than the voltage threshold. And the process proceeds to S206. Further, when the output voltage is lower than the voltage threshold, the control circuit 25 determines whether or not the detected output current is higher than a preset current threshold (S204). The control circuit 25 determines that the high-pressure discharge lamp 21 is not lit when the output current is less than or equal to the current threshold value, and proceeds to S206, but proceeds to S205 when the output current is higher than the current threshold value.

  The control circuit 25 determines that the high-pressure discharge lamp 21 is lit when the detected output voltage is lower than the voltage threshold value and the detected output current is higher than the current threshold value, and the boost chopper circuit 4 The target voltage is set to a predetermined value (S205), and the control circuit 25 inputs so that the output voltage of the boost chopper circuit 4 detected by the voltage detection circuit 9 matches the above-mentioned target voltage value. Is controlled (normal control) for the ON period of the switching element 6 of the step-up chopper circuit 4 so that the power factor becomes high, and the process returns to step S201.

  Further, when the detected output voltage is equal to or higher than the voltage threshold value or when the detected output current is equal to or lower than the current threshold value, the control circuit 25 determines that the high pressure discharge lamp 21 is not lit, and step S206. Migrate to At this time, the control circuit 25 detects the half cycle of the commercial AC power supply 1 from the output voltage of the rectifier circuit 2 detected by the voltage detection circuit 3 (S206). Then, the control circuit 25 sets the target voltage value of the boost chopper circuit 4 according to the detected output voltage of the rectifier circuit 2 (S207), and proceeds to step S201. In this case, the target voltage value is set larger as the detected effective value, average value, or maximum value of the rectifier circuit 2 increases.

  As described above, according to the second embodiment, the target voltage value of the step-up chopper circuit 4 is set according to the effective value, the average value, or the maximum value of the rectifier circuit 2 when the high pressure discharge lamp 21 is not lit. I am trying to set it. Thereby, even when the voltage (effective value) of the commercial AC power supply 1 is low, the boosted voltage width can be set to an optimum value, and the switching element 6 of the boost chopper circuit 4 can be continuously turned on / off. For this reason, it is possible to generate a stable voltage from the secondary winding 5b for generating a control voltage that is provided in the inductance 5 of the boost chopper circuit 4.

Embodiment 3.
In the first and second embodiments, the target voltage value of the step-up chopper circuit 4 is changed at no load when the high-pressure discharge lamp 21 is not lit, but in the third embodiment, the discharge lamp is lit. When there is no load, the ON period of the switching element 6 of the step-up chopper circuit 4 is limited.
The configuration of the discharge lamp lighting device in the present embodiment is the same as that of the first embodiment (FIG. 1) described above.

FIG. 4 is a flowchart showing the operation of the control circuit in the discharge lamp lighting device of the third embodiment.
As in the first embodiment, the control circuit 25 detects the output voltage of the step-down chopper circuit 10 detected by the voltage detection circuit 23 (S301), and then detects the output voltage of the step-down chopper circuit 10 detected by the current detection circuit 24. The output current is detected (S302).

  Thereafter, the control circuit 25 determines whether or not the detected output voltage is lower than a preset voltage threshold value (S303), and the high-pressure discharge lamp 21 is not lit when the output voltage is equal to or higher than the voltage threshold value. And the process proceeds to S306. Further, when the output voltage is lower than the voltage threshold, the control circuit 25 determines whether or not the detected output current is higher than a preset current threshold (S304). The control circuit 25 determines that the high-pressure discharge lamp 21 is not lit when the output current is less than or equal to the current threshold value, and proceeds to S306, but proceeds to S305 when the output current is higher than the current threshold value.

  The control circuit 25 determines that the high-pressure discharge lamp 21 is lit when the detected output voltage is lower than the voltage threshold value and the detected output current is higher than the current threshold value, and the boost chopper circuit 4 The target voltage is set to a predetermined value (S305). Then, the control circuit 25 generates a boost chopper circuit so that the output voltage of the boost chopper circuit 4 detected by the voltage detection circuit 9 matches the above target voltage value, and the input has a high power factor. 4 is controlled (normal control) and the process returns to step S301.

  The control circuit 25 determines that the high-pressure discharge lamp 21 is not lit when the detected output voltage is equal to or higher than the voltage threshold value or when the detected output current is equal to or lower than the current threshold value. In this case, the control circuit 25 detects the output voltage of the rectifier circuit 2 detected by the voltage detection circuit 3 (S306), and limits the ON period of the switching element 6 of the boost chopper circuit 4 according to the detected output voltage. (S307), the process returns to step S301. In this case, as the detected instantaneous value of the rectifier circuit 2 increases, the ON period of the switching element 6 is made shorter than the ON period when the high-pressure discharge lamp 21 is lit (normal control).

  As described above, according to the third embodiment, when there is no load when the high-pressure discharge lamp 21 is not lit, the on-period of the switching element 6 of the boost chopper circuit 4 is increased as the instantaneous value of the rectifier circuit 2 increases. It is set to be shorter than the control. As a result, even when the voltage (instantaneous value) of the commercial AC power supply 1 is high, the voltage width to be boosted is reduced, and the switching element 6 of the boost chopper circuit 4 can be continuously turned on / off. For this reason, it is possible to generate a stable voltage from the secondary winding 5b for generating a control voltage that is provided in the inductance 5 of the boost chopper circuit 4.

  In addition, the control circuit 25 can be made to perform the process which combined the process demonstrated in Embodiment 1, 2 and the process demonstrated in Embodiment 3 arbitrarily.

Embodiment 4 FIG.
FIG. 5 is a diagram showing a configuration of a lighting apparatus according to Embodiment 4.
The lighting fixture 300 shown in the figure includes the discharge lamp lighting device 100 according to any of the first to third embodiments described above, the high-pressure discharge lamp 21 of the load circuit attached to the discharge lamp lighting device 100, and a reflector. 200.

  With such a configuration, in the lighting fixture 300 according to the present embodiment, the control circuit 25 included in the discharge lamp lighting device 100 in the lighting fixture 300 is configured as described above when there is no load when the high-pressure discharge lamp 21 is not turned on. The process in any one of forms 1 to 3 is performed.

  As described above, according to the fourth embodiment, since the discharge lamp lighting device 100 according to any one of the first to third embodiments is provided in the lighting fixture 300, the high-pressure discharge lamp 21 is not lit. At this time, it is possible to generate a stable voltage from the secondary winding 5b for generating the control voltage provided in the inductance 5 of the boost chopper circuit 4.

  In the first to third embodiments, the step-down chopper circuit 10 is used, but a configuration in which this is removed may be used. Moreover, although the example in which the inverter circuit is configured as a full bridge type is shown, it may be configured as a half bridge type. Further, the configurations of the load circuit, the starting circuit 22 and the control voltage generating circuit 26 are not limited to this.

  As an application example of the present invention, in each of the above-described embodiments, the discharge lamp lighting device that mainly turns on the high-pressure discharge lamp 21 has been described. However, the present invention is not limited to this, and other types of discharge lamps are turned on. You may apply to a discharge lamp lighting device. In addition, any device provided with a step-up chopper circuit such as a motor drive device, an LED power source, and an induction heating cooker can be applied.

DESCRIPTION OF SYMBOLS 1 Commercial AC power supply, 2 Rectifier circuit, 3 Voltage detection circuit, 4 Boost chopper circuit, 5 Inductance, 6 Switching element, 7 Diode, 8 Electrolytic capacitor, 9 Voltage detection circuit, 10 Buck chopper circuit, 11 Switching element, 12 Inductance, 13 diode, 14 capacitor, 15 first switching element, 16 second switching element, 17 third switching element, 18 fourth switching element,
19 capacitors, 20 step-up transformers, 21 high-pressure discharge lamps, 22 starting circuits, 23 voltage detection circuits, 24 current detection circuits, 25 control circuits, 26 control voltage generation circuits, 27 diodes, 28 electrolytic capacitors, 29 constant voltage ICs, 30 resistances , 31 Zener diode, 32 diode, 33 electrolytic capacitor, 100 discharge lamp lighting device, 200 reflector, 300 lighting fixture.

Claims (4)

A rectifier circuit for rectifying the AC power supply voltage;
A step-up chopper circuit having a switching element and boosting the output voltage of the rectifier circuit based on the operation of the switching element;
Voltage detection means for detecting an output voltage of the boost chopper circuit;
A winding for generating a control voltage provided along with the inductance of the step-up chopper circuit;
A control voltage generation circuit for generating a predetermined control voltage from the voltage generated in the winding;
And at least control means for controlling the switching element so that the output voltage of the boost chopper circuit detected by the voltage detection means becomes a preset target voltage,
The control means sets a target voltage having a value larger than the target voltage as the effective value or average value or maximum value of the AC power supply voltage increases when there is no load, and the output voltage of the boost chopper circuit is the target voltage. A power supply device that controls the switching element to be A rectifier circuit for rectifying the AC power supply voltage;
A step-up chopper circuit having a switching element and boosting the output voltage of the rectifier circuit based on the operation of the switching element;
Voltage detection means for detecting an output voltage of the boost chopper circuit;
A winding for generating a control voltage provided along with the inductance of the step-up chopper circuit;
A control voltage generation circuit for generating a predetermined control voltage from the voltage generated in the winding;
And at least control means for controlling the switching element so that the output voltage of the boost chopper circuit detected by the voltage detection means becomes a preset target voltage,
When there is no load, the control means shortens the ON period of the switching element shorter than the ON period of the normal control when the load is connected, and increases the output voltage of the boost chopper circuit as the instantaneous value of the AC power supply voltage increases. A power supply device characterized by that. A discharge lamp lighting device comprising the power supply device according to claim 1 . A lighting fixture comprising the discharge lamp lighting device according to claim 3 .

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