JPH06113556A - Power supply, discharge lamp lighting unit, and illuminator - Google Patents

Abstract

PURPOSE:To provide a power supply, a discharge lamp lighting unit, and an illuminator wherein reduction can be realized in cost and size. CONSTITUTION:A capacitor 8 is discharged through ON/OFF operation of an inverter circuit 12 to induce a voltage in a constant current inductor 6. Consequently, a voltage is induced in an inductor 5 and then it is full-wave rectified through a rectifying circuit 3 thus feeding the inverter circuit 12 with an input voltage wherein a high frequency voltage is superposed on a pulsating voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device for converting a rectified and smoothed voltage obtained by full-wave rectifying an AC voltage into a high frequency voltage,
The present invention relates to a discharge lamp lighting device using this power supply device and a lighting fixture using this discharge lamp lighting device.

[0002]

2. Description of the Related Art Generally, a lighting device is required to light a discharge lamp.

FIG. 5 is a circuit diagram showing an example of a conventional discharge lamp lighting device using a high frequency voltage. This discharge lamp lighting device has a commercial power source (for example, frequency; 50 Hz, voltage 1).
00V) 101, a high frequency noise reduction circuit 102, a rectification circuit 103, an inductor 104, a switching transistor 105, a control circuit 106, a step-up chopper circuit 108 having a smoothing capacitor 107, an inverter circuit 109, and a transformer 110. And a discharge lamp 111.

In this discharge lamp lighting device, the commercial power supply 101 is rectified by a rectifier circuit 1 via a high frequency noise reduction circuit 102.
03 full-wave rectification, the switching circuit 105 is alternately turned on and off under the control of the full-wave rectified pulsating voltage by the control circuit 106, and the power stored in the power storage inductor 104 at the time of ON is turned off. It is supplied to the smoothing capacitor 107.

The inverter circuit 109 converts the smoothed DC voltage input from the smoothing capacitor 107 of the step-up chopper circuit 108 into a high frequency voltage, and the transformer 11
0 generates a high frequency voltage on the primary winding 110a side and generates a boosted high frequency voltage on the secondary winding 110b side,
The discharge lamp 111 is turned on.

[0006]

In the discharge lamp lighting device having the step-up type chopper circuit described above, a high power factor and a low distortion of the input current can be achieved, but on the other hand, the switching transistor 105, the control circuit 106, and the step-up device. Since the die chopper circuit 108 and the like are required, there are problems that the cost becomes high and the entire discharge lamp lighting device becomes large.

The present invention has been made for the purpose of solving the above-mentioned problems, and it is possible to achieve a high power factor and a low distortion of an input current with a simple structure to achieve cost reduction and size reduction. It is intended to provide a lighting device and a lighting fixture.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a rectifier circuit for full-wave rectifying a commercial voltage applied from an AC power supply, and an output terminal of the rectifier circuit. A first inductor, a backflow prevention diode, and a smoothing capacitor that are provided in series with each other, and a second magnetically coupled to the first inductor between the output terminals of the smoothing capacitor. A load device having a switching element that is turned on and off at a high frequency provided via an inductor, and a voltage induced in the second inductor in accordance with the turning on and off of the switching element of the load device is applied to the first device. Of the inductor, the pulsating current voltage is multiplied by a high frequency voltage to charge the smoothing capacitor, and the input current is made to have a constant distortion.

Further, in the present invention according to claim 2, a rectifier circuit for full-wave rectifying a commercial voltage applied from an AC power source,
A first inductor, a diode for preventing backflow, and a smoothing capacitor, which are provided in series between the output terminals of the rectifier circuit, and the first inductor magnetically connected between the output terminals of the smoothing capacitor. An inverter circuit having a switching element which is turned on and off at a high frequency and which is provided via a second inductor coupled to the discharge lamp, and supplies the high frequency voltage obtained by the inverter circuit to a discharge lamp for lighting. In the discharge lamp lighting device, a voltage induced in the second inductor is induced in the first inductor according to ON / OFF of a switching element of the inverter circuit, and the pulsating current voltage is multiplied by a high frequency voltage. The smoothing capacitor is charged to reduce the distortion of the input current.

According to the present invention of claim 3, there are provided a discharge lamp, a discharge lamp lighting device according to claim 2 for lighting the discharge lamp, and a lighting fixture main body to which the discharge lamp and the discharge lamp lighting device are attached. It is characterized by having.

[0011]

According to the present invention, the waveform of the high-frequency voltage induced in the first inductor according to ON / OFF of the switching element is added to the waveform of the full-wave rectified pulsating current voltage. Since the smoothing capacitor is charged by the voltage multiplied by the pulsating current voltage, the input current flows from the AC power source when the instantaneous value of the combined waveform is lower than the rectified voltage. Therefore, the distortion of the input current is reduced.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on the illustrated embodiments.

FIG. 1 is a circuit configuration diagram showing a discharge lamp lighting device provided with a power supply device according to the present invention. As shown in this figure, this discharge lamp lighting device includes, for example, a commercial power source (for example, frequency: 50 Hz, voltage: 100 V) 1 as an AC power source,
The high frequency noise reduction circuit 2, the rectification circuit 3, and the capacitor 4 at both ends of the rectification circuit 3 are provided, and the high frequency noise component of the commercial voltage supplied from the commercial power supply 1 is reduced to perform full wave rectification of the commercial voltage. .

An inductor (first inductor) 5 and a constant current inductor (second inductor) 6 which are magnetically coupled to one of the outputs of the rectifier circuit 3, for example, the positive output.
And a diode 7 for preventing backflow is connected between the inductor 5 and the constant current inductor 6. A smoothing capacitor 8 is connected in series with the constant current inductor 5 on the output side of the diode 7.

An inverter circuit (parallel bush-pull inverter) 12 having switching transistors 9 and 10 and a capacitor 11 is connected via a constant current inductor 6, and the inverter circuit 12 is discharged via an output transformer 13. The electric light 14 is connected. A control circuit 15 for controlling ON / OFF operations is connected to the switching transistors 9 and 10.

The discharge lamp lighting device according to this embodiment is configured as described above, and the commercial voltage is the high frequency noise reduction circuit 2
→ Rectifier circuit 3 → Inductor 5 → Diode 7 → Input to the inverter circuit 12 through the constant current inductor 6, and one end of the capacitor 4 → Inductor 5 → Diode 7 → Capacitor 8 → The other end of the capacitor 4 flows in the route 8 is charged.

At this time, by the high-speed (for example, 50 kHz) ON / OFF operation of the switching transistors 9 and 10 of the inverter circuit 12 under the control of the control circuit 15, the charge supplied from the rectifying circuit 3 or discharged from the capacitor 8 causes A voltage induced by a high frequency current flowing in the constant current inductor 6 is induced in the inductor 5,
As shown in FIG. 2, the high frequency voltage generated by the constant current inductor 6 is multiplied by the pulsating current voltage from the inductor 5 to charge the capacitor 8, and the smoothed DC current is supplied to the inverter circuit 12 and input. Reduces the current distortion.

The inverter circuit 12 generates a high frequency AC voltage when the voltage smoothed by the smoothing capacitor 8 is input. The input voltage input to the inverter circuit 12 is the DC voltage smoothed by the capacitor 8 as described above. Therefore, the discharge lamp 14 is continuously turned on without repeating extinction and re-ignition for each cycle of the output voltage of the rectifier circuit 3. The primary winding 13a of the output transformer 13 is generated by the high-frequency AC voltage generated in the inverter circuit 12.
Since a high frequency voltage is generated in the discharge coil 14, a boosted high frequency voltage is generated in the secondary winding 13b and the discharge lamp 14 is turned on.

FIG. 3 is a circuit diagram showing a discharge lamp lighting device according to another embodiment of the present invention. In the present embodiment, a series inverter is used for the inverter circuit 12, and the discharge lamp 14 is connected via the capacitors 16 and 17, and other configurations and operations are the same as those in the above-mentioned embodiment.

FIG. 4 is a schematic sectional view showing an illuminating device using the above-mentioned discharge lamp lighting device. As shown in this figure, in this lighting device, a discharge lamp lighting device 30 having the configuration shown in FIG. 1 is housed in a lighting fixture body 20, and two discharge lamps 14 are attached to the surface of the lighting fixture body 20. Has been.

[0021]

As described above in detail with reference to the embodiments, according to the present invention as set forth in claims 1, 2 and 3, the high frequency wave induced in the first inductor according to ON / OFF of the switching element. Since the smoothing capacitor is charged with the voltage obtained by multiplying the waveform of the voltage by the pulsating voltage, the input current flows from the AC power supply when the instantaneous value of the combined waveform is lower than the rectified voltage. Therefore, it is possible to achieve a high power factor and a low distortion of the input current with a simple configuration, thereby achieving cost reduction and size reduction.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram showing a discharge lamp lighting device using a power supply device according to an embodiment of the present invention.

FIG. 2 is a waveform diagram showing a waveform of an input voltage to the inverter circuit in the present embodiment.

FIG. 3 is a circuit configuration diagram showing a discharge lamp lighting device according to another embodiment of the present invention.

FIG. 4 is a schematic sectional view showing an illuminating device using the discharge lamp lighting device according to the present invention.

FIG. 5 is a circuit configuration diagram showing an example of a conventional discharge lamp lighting device.

[Explanation of symbols]

 1 Commercial power supply 2 High frequency noise reduction circuit 3 Rectifier circuit 4, 8, 11 Capacitor 5 Inductor 6 Constant current inductor 7 Diode 9, 10 Switching transistor 12 Inverter circuit 14 Discharge lamp

Claims (3)

[Claims] 1. A rectifying circuit for full-wave rectifying a commercial voltage applied from an AC power source, a first inductor provided in series between output terminals of the rectifying circuit, a diode for preventing backflow and a smoothing circuit. And a load device having a switching element which is provided between the output terminals of the smoothing capacitor via a second inductor magnetically coupled to the first inductor and which is turned on and off at high frequency. A voltage induced in the second inductor according to ON / OFF of a switching element of the load device is induced in the first inductor, and the pulsating current voltage is multiplied by a high frequency voltage to smooth the smoothing capacitor. The power supply device is characterized by charging the battery and reducing the distortion of the input current. 2. A rectifier circuit for full-wave rectifying a commercial voltage applied from an AC power source, a first inductor provided in series between output terminals of the rectifier circuit, a diode for preventing backflow and a smoothing circuit. And an inverter circuit having a switching element which is provided between the output terminals of the smoothing capacitor via a second inductor magnetically coupled to the first inductor and which is turned on and off at high frequency. A discharge lamp lighting device for supplying the high-frequency voltage obtained by the inverter circuit to a discharge lamp and lighting the discharge lamp, wherein a voltage induced in the second inductor according to ON / OFF of a switching element of the inverter circuit. The first
A discharge lamp lighting device, characterized in that the smoothing capacitor is charged by multiplying the pulsating current voltage by a high frequency voltage, and the input current is reduced in distortion. 3. A lighting fixture comprising: a discharge lamp; a discharge lamp lighting device according to claim 2 for lighting the discharge lamp; and a lighting fixture body to which the discharge lamp and the discharge lamp lighting device are attached. .