JP2002300784A - Power supply device, discharge lamp lighting device and laminaire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device which prevents the device from enlarging. SOLUTION: When a fluorescent lamp FL is short-circuited and brought in an abnormal mode, current of the secondary winding of an inverter transformer Tr1 is increased and the current of the primary winding is also increased. Oscillating current of an oscillation circuit 13 increases when the current of the primary winding is increased, and the output voltage of the oscillation circuit 13 becomes higher when the fluorescent lamp FL is short-circuited as compared with when the fluorescent lamp FL is lit on. As compared with voltage of a parallel resonance circuit 16 when the fluorescent lamp FL lit on, the voltage of the parallel resonance circuit when short-circuited is raised, and the voltage of an inductor L2 is also raised. Detecting rise of the voltage of the inductor L2 by a detection winding L3, on-off of switching of a transistor Q1 in an inverter circuit 15 is controlled by a control circuit 17 when the voltage is a predetermined value or more, the outputting stops. Bad effect on the transistor Q1 by overcurrent is prevented by making the output voltage of the oscillation circuit 13 lower and by making resonance voltage of the parallel resonance circuit 16 lower.

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, a discharge lamp lighting device, and a lighting device for preventing a high voltage from being generated when a discharge lamp is short-circuited.

[0002]

2. Description of the Related Art Conventionally, as a discharge lamp lighting device of this type, for example, a structure described in Japanese Patent Application Laid-Open No. Hei 5-212774 is known. In the discharge lamp lighting device described in Japanese Patent Application Laid-Open No. 5-217774, a full-wave rectifier circuit is connected to a commercial AC power supply, and a first capacitor and a second capacitor are connected to output terminals of the full-wave rectifier circuit. ing. Also,
An oscillation circuit having a charging capacitor and an inductor is connected to the second capacitor, and an inverter circuit is connected to the oscillation circuit. In the inverter circuit, a resonance circuit and a switching element of the capacitor and the inductor are connected in series. The fluorescent lamp is connected to the inductor of the resonance circuit.

[0003] By the high-frequency switching operation of the switching element, resonance occurs in the resonance circuit, a resonance voltage is generated, and the fluorescent lamp is lit at high frequency.

[0004]

However, in the discharge lamp lighting device described in JP-A-5-212774, when the fluorescent lamp is short-circuited, a large current flows through the inductor of the resonance circuit and a large current flows through the inductor of the oscillation circuit. Since current flows and the voltage of the oscillating circuit rises and a large stress is applied to the switching elements of the inverter circuit, the withstand voltage of each element must be increased, which causes a problem that the elements become large and the device becomes large. I have.

[0005] The present invention has been made in view of the above problems, and has as its object to provide a power supply device, a discharge lamp lighting device, and a lighting device that prevent the device from being enlarged.

[0006]

According to a first aspect of the present invention, there is provided a power supply device including an oscillation circuit having an inductor and a charging capacitor for generating a high frequency, and reducing a harmonic by superimposing a high frequency on alternating current from an alternating current power supply. Means for reducing harmonics;
Inverter means for generating a high-frequency voltage based on the output from the high-frequency reducing means; voltage detecting means for detecting the voltage of the inductor of the oscillating circuit; output of the inverter means when the voltage detected by the voltage detecting means exceeds a predetermined value. Control means for reducing at least the voltage of the inductor of the oscillating circuit is detected by the voltage detection means, for example, when the output side of the inverter means is short-circuited and the voltage of the inductor rises, the control means is controlled by the voltage detection means. If the detected voltage is equal to or higher than a predetermined value, at least the output of the inverter means is reduced, so that the voltage applied to each element can be reduced, so that stress on the elements is reduced, and it is not necessary to increase the withstand voltage of the device. Therefore, the size of the device is reduced.

According to a second aspect of the present invention, there is provided a power supply device including a vibration circuit having an inductor and a charging capacitor for generating a high frequency, and a harmonic reduction means for reducing a harmonic by superimposing a high frequency on an AC from an AC power supply. A resonance circuit having a resonance capacitor and a resonance inductor, an inverter means having a switching element connected to the resonance circuit, and generating a high-frequency voltage by a switching operation of the switching element; and a voltage detection means detecting a voltage of the resonance inductor. Control means for reducing at least the output of the inverter means when the voltage detected by the voltage detection means exceeds a predetermined value, wherein the voltage of the resonant inductor is detected by the voltage detection means, for example, the output of the inverter means; When the voltage on the resonant inductor rises due to short-circuit on the side, the control means detects the voltage If the voltage detected by the stage is equal to or higher than a predetermined value, the voltage applied to each element can be reduced by at least lowering the output of the inverter means, thereby reducing the stress on the elements and increasing the breakdown voltage of the device. Is eliminated, and the device is downsized.

According to a third aspect of the present invention, there is provided the power supply device according to the first or second aspect, wherein the harmonic reduction means includes a rectification means for rectifying an AC from an AC power supply; A first capacitor connected to the first capacitor; a diode connected in series with one end of the first capacitor in a forward polarity; and a second capacitor connected in parallel to the first capacitor via the diode. The oscillating circuit is connected in parallel to a second capacitor that charges the charging capacitor with a voltage lower than the maximum instantaneous voltage value of the output of the rectifier. The inverter has a function of charging the output level of the rectifier. The input current is supplied from the first capacitor and the second capacitor when the charge level is equal to or higher than the charge level of the charging capacitor, and the output level of the rectifier means the charge level of the charging capacitor. When lower supplies an input current from the vibration circuit, a resonant circuit is resonant operation by the switching operation of the switching element to reduce the harmonics, the high-frequency output crest factor is improved.

According to a fourth aspect of the present invention, in the power supply unit of the first or second aspect, the harmonic reduction means includes a first capacitor connected to an AC power source; and the first capacitor connected to the first capacitor. Rectifying means; and a second capacitor connected to the rectifying means, wherein the oscillating circuit is arranged in parallel with the second capacitor for charging the charging capacitor with a voltage lower than the maximum instantaneous voltage value of the output of the rectifying means. The inverter means supplies an input current from the first capacitor and the second capacitor when the output level of the rectifying means is equal to or higher than the charging level of the charging capacitor. When the charge level of the capacitor is lower, the input current is supplied from the oscillation circuit,
The resonance operation of the resonance circuit is performed by the switching operation of the switching element to reduce harmonics, and a high frequency output with an improved crest factor is provided.

According to a fifth aspect of the present invention, there is provided the power supply unit according to the first or second aspect, wherein the harmonic reduction means includes a rectification means for rectifying an AC from an AC power supply; A first capacitor connected to the first capacitor; a diode connected to the first capacitor; a second capacitor connected in parallel to the diode;
The oscillating circuit is connected in parallel to the first capacitor via a second capacitor and a diode for charging the charging capacitor with a voltage lower than the maximum instantaneous voltage value of the output of the rectifier. Supplies the input current from the first capacitor and the second capacitor when the output level of the rectifier is equal to or higher than the charge level of the charging capacitor, and supplies the input current from the oscillation circuit when the output level of the rectifier is lower than the charge level of the charging capacitor. An input current is supplied, and a resonance circuit is resonated by a switching operation of a switching element to reduce harmonics and output a high frequency with an improved crest factor.

According to a sixth aspect of the present invention, there is provided a discharge lamp lighting device including the power supply device according to any one of the first to fifth aspects for lighting a discharge lamp.

According to a seventh aspect of the present invention, there is provided an illuminating device comprising: a fixture main body to which a discharge lamp is mounted; and a discharge lamp lighting device according to the sixth aspect, which has the function of the discharge lamp lighting device according to the sixth aspect. .

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a lighting device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing the appearance of the lighting device. The lighting device 1 has a fixture main body 2, and a reflection surface 3 is formed on the lower surface of the fixture main body 2. Lamp sockets 4 and 4 are attached to both ends of the reflecting surface 3 in the longitudinal direction, and a fluorescent lamp FL as a discharge lamp is mounted between the lamp sockets 4 and 4, and the fluorescent lamp FL is inserted into the fixture body 2. The lighting device 5 is housed.

FIG. 1 is a circuit diagram showing a discharge lamp lighting device. As shown in FIG. 1, the discharge lamp lighting device 5 superimposes a high frequency on an AC from the commercial AC power source e on a commercial AC power source e. And a harmonic reduction circuit 11 as a harmonic reduction means for reducing harmonics. The harmonic reduction circuit 11 is connected to an input terminal of a full-wave rectification circuit 12 as rectification means of a diode bridge. A first capacitor C1 having a large capacity is connected to an output terminal of the wave rectifier circuit 12, and the first capacitor C1 has a diode D1 having a forward polarity and a first capacitor C1.
The second capacitor, whose capacity is smaller than that of the capacitor C1
The series circuit of C2 is connected.

An oscillating circuit is connected to the second capacitor C2.
13 is connected, this oscillation circuit 13 is a charging capacitor for charging with a voltage value lower than the maximum instantaneous voltage of the full-wave rectifier circuit 12.
C3, multiple, eg two, inductors connected in series
The series circuit of L1 and diode D2 is connected and inductor
A diode D3 is connected between L1 and the diode D2.

Further, an inverter circuit 15 as inverter means is connected to the vibration circuit 13. The inverter circuit 15 includes a parallel resonance circuit 16 including a series circuit of a primary winding Tr1a and a inductor L2 of a complete coupling type leakage flux type inverter transformer Tr1 as a resonance inductor and a resonance capacitor C4, and a transistor Q1 serving as a switching element. Collector and emitter are connected.

A control circuit 17 is connected to the base of the transistor Q1. The control circuit 17 has a detection winding L3 as voltage detection means magnetically connected to an inductor L2.
Is connected.

Further, filaments FL1 and FL2 of a fluorescent lamp FL as a discharge lamp are connected to the secondary winding Tr1b of the inverter transformer Tr1.
A starting capacitor C6 is connected to L2.

The load circuit 18 is composed of a fluorescent lamp FL or the like.

Next, the operation of the above embodiment will be described.

First, when the inverter circuit 15 oscillates by the switching operation of the transistor Q1 as a switching element by the control circuit 17, the inverter transformer Tr1
A high-frequency voltage is generated by the resonance between the primary winding Tr1a and the charging capacitor C3, and a high-frequency voltage is also induced in the secondary winding Tr1b.

When the transistor Q1 is turned on, a current flows through the primary winding Tr1a of the inverter transformer Tr1, and a current flows through the charging capacitor C3, the inductor L1, and the diode D3, thereby charging the charging capacitor C3. Then, a DC voltage lower than the peak value of the pulsating voltage from the full-wave rectifier circuit 12 can be stored in the charging capacitor C3.

Here, a description will be given of a section in which the pulsating voltage of the full-wave rectifier circuit 12 is higher than the charging voltage of the charging capacitor C3 and a section in which the pulsating voltage is lower than the charging voltage of the charging capacitor C3.

First, when the transistor Q1 of the inverter circuit 15 is turned on at an arbitrary time in a section where the pulsating voltage of the full-wave rectifier circuit 12 is higher than the charging voltage of the charging capacitor C3, the primary winding Tr1a of the inverter transformer Tr1 is turned on. Most of the current is supplied from the first capacitor C1, and part of the current is supplied from the second capacitor C2. The combined capacity of the first capacitor C1 and the second capacitor C2 is a capacity sufficient to provide the energy required by the inverter circuit 15. In accordance with the current supply from the first capacitor C1 and the second capacitor C2, energy flows from the commercial AC power supply e side as an input current. Then, an operation is performed so as to accompany the switching operation of the transistor Q1 in accordance with the change in the pulsating voltage, and the small and equal amplitude of the high frequency of the inverter operation of the inverter circuit 15 is changed to the full-wave rectification along the AC voltage sine wave value. The voltage of the circuit 12 is superimposed on all high sections.

That is, in the section where the voltage value of the full-wave rectifier circuit 12 is high, the first capacitor C1 and the second capacitor C2
Is a value that satisfies the energy given by the supplied pulsating voltage with respect to the energy required by the inverter circuit 15.

For this reason, both the first capacitor C1 and the second capacitor C2 have a small ripple component, a small amount of heat generation, and can improve the operation reliability.

Then, in a section where the voltage value of the full-wave rectifier circuit 12 is high, the charging capacitor C3 is charged when the transistor Q1 is turned on. In a section where the voltage value of the full-wave rectifier circuit 12 is high, the discharge is not performed from the charging capacitor C3 to the inverter circuit 15 side.

Next, in a section where the voltage value of the full-wave rectifier circuit 12 is low, when the pulsating sine wave voltage of the full-wave rectifier circuit 12 starts to decrease with respect to the charging voltage of the charging capacitor C3, the transistor Q1 is turned on. When turned on, the current to the primary winding Tr1a of the inverter transformer Tr1 is first supplied from the second capacitor C2. Since the capacity of the second capacitor C2 is insufficient to provide the energy required by the inverter circuit 15, the current of the second capacitor C2 increases as the current flowing through the primary winding Tr1a increases after the transistor Q1 is turned on. The voltage drops. Then, the voltage of the second capacitor C2 becomes the first
The first capacitor C1 supplies the energy to the inverter circuit 15 that is insufficient in the second capacitor C2 from the time when the voltage of the capacitor C1 drops to the voltage of the capacitor C1.

The power is supplied until the transistor Q1 is turned off. However, the decrease in the voltage of the second capacitor C2 after the start of the energy supply from the first capacitor C1 is reduced. The first capacitor C1 is connected to the inverter circuit.
Energy supply to 15 causes an amount of energy corresponding to this to flow as input current from the commercial AC power supply e side.

On the other hand, the release of energy of the charging voltage of the charging capacitor C3 is delayed due to the transient impedance of the inductor L1, and the energy is released immediately before the transistor Q1 is turned off. When the transistor Q1 is turned off, the charging voltage of the charging capacitor C3 is changed to the inductor voltage.
It provides a voltage supply to the series circuit of L1, diode D2 and second capacitor C2. Here, since the inductor L1 and the second capacitor C2 are set so as to obtain an oscillating resonance, the charging of the second capacitor C2 is performed in a sine wave shape. This charging is increased in the inverter circuit 15 to a voltage at which the energy supply does not become insufficient when the transistor Q1 is turned on next time. When the transistor Q1 is turned off, resonance occurs in the resonance capacitor C4 and the primary winding Tr1a of the inverter transformer Tr1. And
This resonance current is applied to the primary winding Tr1 of the inverter transformer Tr1.
The current flows through the path of a and the second capacitor C2, and the second capacitor C2 is charged to generate an oscillating voltage. At this time, the voltage across the second capacitor C2 is almost equal to the DC voltage in both the highest instantaneous voltage portion and the lowest instantaneous voltage portion of the commercial AC power supply e.

Then, as the voltage of the first capacitor C1 decreases with respect to the charging voltage of the charging capacitor C3, the voltage of the second capacitor C2 decreases.
Of the capacitor C2 increases. Further, although the input current decreases, the current flows continuously.

As described above, since the input current from the commercial AC power supply e continuously flows, it is possible to prevent a harmonic component from intervening in the input current.

Further, by increasing the fluctuation of the voltage value of the second capacitor C2, the crest factor of the lamp current waveform of the fluorescent lamp FL is improved, and the crest factor is improved.

When the fluorescent lamp FL is short-circuited and enters an abnormal mode, for example, the current of the secondary winding Tr1b of the inverter transformer Tr1 increases, and the current of the primary winding Tr1a also increases. As the current of the primary winding Tr1a of the inverter transformer Tr1 increases, the oscillating current of the oscillating circuit 13 increases, and the output voltage Va of the oscillating circuit 13 becomes smaller than that of the fluorescent lamp FL shown in FIG. Is higher when the fluorescent lamp FL is short-circuited. Therefore, the fluorescent lamp shown in FIG.
As compared with the voltage Vb of the parallel resonance circuit 16 when the FL is lit, FIG.
The voltage Vb of the parallel resonance circuit when the fluorescent lamp FL is short-circuited
Rises, and the voltage of the inductor L2 also rises.

Therefore, the rise in the voltage of the inductor L2 is detected by the detection winding L3, and when the voltage detected by the detection winding L3 is equal to or more than a predetermined value, the control circuit 17
Control the on / off of the switching of the transistor Q1 to at least lower, for example, stop, the output of the inverter circuit 15 to reduce the output voltage of the oscillation circuit 13 and reduce the resonance voltage of the parallel resonance circuit 16; In addition to preventing the current from adversely affecting the transistor Q1, the withstand voltage of the transistor Q1, the resonance capacitor C4, the diode D1, the diode D2, and the diode D3 is reduced, and the size of the element is reduced.

Next, another embodiment will be described with reference to FIG.

FIG. 7 shows a discharge lamp lighting device according to another embodiment. In the embodiment shown in FIG. 7, the diode D1 is removed from the embodiment shown in FIG. A full-wave rectifier circuit 12 is connected between the capacitors C2.

As described above, by eliminating the diode D1, the circuit configuration can be simplified while the basic operation is substantially the same.

Another embodiment will be described with reference to FIG.

FIG. 8 shows a discharge lamp lighting device according to another embodiment. In the embodiment shown in FIG. 8, the second capacitor C2 is connected in parallel to the diode D1 in the embodiment shown in FIG. Connected.

Even in such a configuration, the basic operation is as shown in FIG.
This is the same as the embodiment shown in FIG.

Further, another embodiment will be described with reference to FIG.

FIG. 9 shows a discharge lamp lighting device according to another embodiment. The embodiment shown in FIG. 9 is different from the embodiment shown in FIG. Using the inverter transformer Tr1, remove the inductor L2 and the detection winding L3 of the inductor L2,
A detection winding L4 as voltage detection means is magnetically coupled to the inductor L1.

The operation is basically the same as that of the embodiment shown in FIG. 1. However, for example, when the fluorescent lamp FL is short-circuited and becomes an abnormal mode, the secondary winding Tr1b of the inverter transformer Tr1 is turned off. The current increases, and the current of the primary winding Tr1a also increases. As the current of the primary winding Tr1a of the inverter transformer Tr1 increases, the oscillating current of the oscillating circuit 13 increases, and the voltage of the inductor L1 of the oscillating circuit 13 is higher when the fluorescent lamp FL is short-circuited than when the fluorescent lamp FL is lit. Is higher.

Therefore, the rise in the voltage of the inductor L1 is detected by the detection winding L4, and when the voltage detected by the detection winding L4 is equal to or higher than a predetermined value, the control circuit 17 controls the inverter circuit 15
Control the on / off of the switching of the transistor Q1 to at least lower, for example, stop, the output of the inverter circuit 15 to reduce the output voltage of the oscillation circuit 13 and reduce the resonance voltage of the parallel resonance circuit 16; In addition to preventing the current from adversely affecting the transistor Q1, the withstand voltage of the transistor Q1, the resonance capacitor C4, the diode D1, the diode D2, and the diode D3 is reduced, and the size of the element is reduced.

Another embodiment will be described with reference to FIG.

FIG. 10 shows a discharge lamp lighting device according to another embodiment. In the embodiment shown in FIG. 10, the diode D1 is removed from the embodiment shown in FIG. Full-wave rectifier circuit 12 between capacitor C2
Are connected.

As described above, by eliminating the diode D1, the circuit configuration can be simplified while the basic operation is substantially the same.

Another embodiment will be described with reference to FIG.

FIG. 11 shows a discharge lamp lighting device according to another embodiment. The embodiment shown in FIG. 11 is different from the embodiment shown in FIG. 9 in that a second capacitor C2 is connected in parallel to a diode D1. Connected.

Even in such a configuration, the basic operation is as shown in FIG.
This is the same as the embodiment shown in FIG.

[0053]

According to the power supply device of the first aspect, the voltage of the inductor of the oscillation circuit is detected by the voltage detecting means. For example, when the output side of the inverter means is short-circuited and the voltage of the inductor rises, the control means sets the voltage of the inductor. When the voltage detected by the detection means is equal to or higher than a predetermined value, at least the output of the inverter means is reduced, so that the voltage applied to each element can be reduced, so that stress on the elements is reduced and the withstand voltage of the device is increased. This eliminates the need and allows the device to be downsized.

According to the power supply device of the second aspect, the voltage of the resonance inductor is detected by the voltage detection means. For example, when the output side of the inverter means is short-circuited and the voltage of the resonance inductor rises, the control means is controlled by the voltage detection means. By reducing the output of the inverter means at least when the detected voltage is equal to or higher than a predetermined value, the voltage applied to each element can be reduced, so that stress on the elements is reduced,
It is not necessary to increase the pressure resistance of the device, and the device can be downsized.

According to the power supply device of the third aspect, in addition to the power supply device of the first or second aspect, when the output level of the rectifying means is equal to or higher than the charge level of the charging capacitor, the inverter means may include the first capacitor and the second capacitor. The input current is supplied from the capacitor 2 and when the output level of the rectifier is lower than the charge level of the charging capacitor, the input current is supplied from the oscillating circuit. Reduce
High frequency output with improved crest factor.

According to the power supply device of the fourth aspect, in addition to the power supply device of the first or second aspect, when the output level of the rectifier is equal to or higher than the charge level of the charging capacitor, the first capacitor and the inverter are connected to each other. The input current is supplied from the capacitor 2 and when the output level of the rectifier is lower than the charge level of the charging capacitor, the input current is supplied from the oscillating circuit. Reduce
High frequency output with improved crest factor.

According to the power supply device of the fifth aspect, in addition to the power supply device of the first or second aspect, when the output level of the rectifying means is equal to or higher than the charging level of the charging capacitor, the inverter circuit may include the first capacitor and the first capacitor. The input current is supplied from the capacitor 2 and when the output level of the rectifier is lower than the charge level of the charging capacitor, the input current is supplied from the oscillating circuit. Reduce
High frequency output with improved crest factor.

According to the discharge lamp lighting device of the sixth aspect,
Since the power supply device according to any one of claims 1 to 5 for lighting a discharge lamp is provided, each effect can be obtained.

According to the illuminating device of the seventh aspect, since the fixture body to which the discharge lamp is attached and the discharge lamp lighting device of the sixth aspect are provided, the effect of the lighting device of the sixth aspect is exhibited. be able to.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of a discharge lamp lighting device of the present invention.

FIG. 2 is a perspective view showing an appearance of the lighting device.

FIG. 3 is a waveform diagram showing an output voltage of the vibration circuit when the fluorescent lamp is turned on.

FIG. 4 is a waveform diagram showing an output voltage of the vibration circuit when the fluorescent lamp is short-circuited.

FIG. 5 is a waveform chart showing a voltage of an inductor L2 when the fluorescent lamp is turned on.

FIG. 6 is a waveform chart showing a voltage of an inductor L2 when the fluorescent lamp is short-circuited.

FIG. 7 is a circuit diagram showing a discharge lamp lighting device according to another embodiment of the present invention.

FIG. 8 is a circuit diagram showing a discharge lamp lighting device according to another embodiment of the present invention.

FIG. 9 is a circuit diagram showing a discharge lamp lighting device according to still another embodiment of the present invention.

FIG. 10 is a circuit diagram showing a discharge lamp lighting device according to still another embodiment of the present invention.

FIG. 11 is a circuit diagram showing a discharge lamp lighting device according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Illumination device 2 Appliance body 5 Discharge lamp lighting device 11 Harmonic reduction circuit as harmonic reduction means 12 Full-wave rectification circuit as rectification means 13 Vibration circuit 15 Inverter circuit as inverter means 16 Parallel resonance circuit 17 Control means C1 No. 1 capacitor C2 Second capacitor C3 Charging capacitor C4 Resonant capacitor D1 Diode e Commercial AC power supply FL Fluorescent lamp as discharge lamp L1 Inductor L3, L4 Detection winding as voltage detecting means Q1 Transistor Tr1 as switching element Resonant inductor Inverter transformer as

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K072 AA02 BA03 BB05 CA16 DB03 DD04 EA06 EA07 EB05 GA01 GB04 GC03 GC04 HB03 HB05 5H007 AA08 BB03 CB07 CB09 CC01 DC05

Claims (7)

[Claims] 1. An oscillator comprising an inductor and a charging capacitor for generating a high frequency, comprising a vibration circuit for superimposing a high frequency on an alternating current from an AC power supply to reduce a harmonic, and a harmonic reducing means; Inverter means for generating a high-frequency voltage from the output; voltage detecting means for detecting the voltage of the inductor of the oscillating circuit; control means for at least reducing the output of the inverter means when the voltage detected by the voltage detecting means is equal to or higher than a predetermined value. And a power supply device comprising: 2. A harmonic reducing means comprising: an oscillation circuit having an inductor and a charging capacitor for generating a high frequency, wherein the harmonic is reduced by superimposing the high frequency on an alternating current from an AC power supply; A resonance circuit having a switching element connected to the resonance circuit and generating a high-frequency voltage by a switching operation of the switching element; a voltage detection means for detecting a voltage of the resonance inductor; Control means for reducing at least the output of the inverter means when the applied voltage exceeds a predetermined value. 3. A rectifier for rectifying an alternating current from an AC power supply; a first capacitor connected in parallel to an output terminal of the rectifier;
A diode connected in series with one polarity to one end of the first capacitor; and a second capacitor connected in parallel to the first capacitor via the diode. 2. A capacitor connected in parallel to a second capacitor charged with a voltage lower than the maximum instantaneous voltage value of the output of the rectifier.
Or the power supply according to 2. 4. The harmonic reduction means comprises: a first capacitor connected to an AC power supply; a rectifier connected to the first capacitor; and a second capacitor connected to the rectifier. The oscillation circuit is connected in parallel to a second capacitor that charges the charging capacitor with a voltage lower than the maximum instantaneous voltage value of the output of the rectifier.
Or the power supply according to 2. 5. A rectifier for rectifying an alternating current from an AC power supply; a first capacitor connected in parallel to an output terminal of the rectifier;
A diode connected to the first capacitor; and a second capacitor connected in parallel to the diode. The oscillation circuit charges the charging capacitor with a voltage lower than the maximum instantaneous voltage value of the output of the rectifier. 3. The power supply device according to claim 1, wherein the power supply device is connected in parallel to the first capacitor via a second capacitor and a diode. 6. A discharge lamp lighting device comprising the power supply device according to claim 1 for lighting a discharge lamp. 7. An illumination device comprising: a fixture main body to which a discharge lamp is attached; and the discharge lamp lighting device according to claim 6.