JP2002101667A - Power supply device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power supply device small in input current distortion and high in power factor. SOLUTION: The power source device has first and second power supply circuits E1, E2 generating mutually different high and low direct current voltages connected to the rear stage of a rectifier DB1 rectifying the alternating current respectively, a drive circuit 9 outputting a drive signal based on the output of an oscillator making the second power source circuit E2 a power source, and a power converter circuit 7 making the power source of the first power source circuit E1 driving a switching element by the drive signal of the drive circuit 9 and outputting high frequency power. Direct current voltage from the first power supply circuit E1 apart from it is applied as energy supplement together with the output voltage of the rectifier DB1 on the input terminal of the second power supply circuit E2.

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 used for an electrodeless discharge lamp lighting device which emits light by applying a high-frequency electromagnetic field to the electrodeless discharge lamp.

[0002]

2. Description of the Related Art Conventionally, as a power supply device which supplies an electric power to an electrodeless discharge lamp as a load, there is, for example, one having a circuit configuration as shown in FIG. The conventional power supply device shown in FIG. 5 has a transparent or inner wall coated with a phosphor.
An electrodeless discharge lamp 1 in which a discharge gas (for example, mercury and a rare gas) such as an inert gas or a metal vapor is sealed in a spherical glass bulb, and arranged close to each other along the spherical outer periphery of the electrodeless discharge lamp 1. Induction coil 2 and a high-frequency power supply 3 connected to the induction coil 2 and supplying high-frequency power to the induction coil 2
And a matching circuit 4 that matches both the induction coil 2 and the high-frequency power supply 3 to eliminate reflection and efficiently supply high-frequency power to the electrodeless discharge lamp 1.

Then, a high frequency current of several hundred kHz to several hundred MHz is supplied from the high frequency power supply 3 to the induction coil 2 to generate a high frequency magnetic field in the induction coil 2 and supply high frequency power to the electrodeless discharge lamp 1. A high-frequency plasma current is generated in the electrodeless discharge lamp 1 to generate ultraviolet light or visible light. The high-frequency power supply 3 includes a drive circuit 9 that outputs a drive signal, and a power conversion circuit (hereinafter referred to as a main amplifier) 7 that outputs high-frequency power based on the drive signal from the drive circuit 9. , An oscillation circuit 5 using a crystal oscillator X, and a preamplifier 6 for amplifying the oscillation output of the oscillation circuit 5. The oscillation circuit 5, the preamplifier 6, and the main amplifier 7
Operate by receiving power supply from a single DC power supply E.

The main amplifier 7 includes two field effect transistors (hereinafter, referred to as switching elements) Q
1 and Q2 are connected in series, and a so-called class D amplifier circuit having an inductor L2 and a capacitor C2 is provided. A secondary winding n21 of a transformer T1 is provided between control terminals of the switching elements Q1 and Q2. n22 are respectively connected. Further, a resonance circuit is configured by the inductor L2 and the capacitor C2. Transformer T1 1
The output voltage of the preamplifier 6 is applied to the next winding n1,
Switching elements Q1 and Q2 are driven via secondary windings n21 and n22 of transformer T1.

In the conventional power supply device shown in FIG. 5, the oscillation circuit 5, the preamplifier 6, and the main amplifier 7 are all configured to operate by receiving power supply from a single DC power supply E. In addition, the circuit efficiency is likely to decrease, and it is difficult to control the dimming of the electrodeless discharge lamp 1 by varying the DC voltage, and there are insufficient points in reducing the variation in the output voltage of the main amplifier 7. .

Therefore, in the prior art, a power supply device as shown in FIG.
0887). 6, the components corresponding to those shown in FIG. 5 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the conventional power supply device shown in FIG. 6, an output voltage obtained by rectifying an AC power supply AC by a rectifier DB1 via a filter circuit 20 is supplied to a first DC power supply E1, and a second DC power supply is provided via a diode D1. The power is also input to the power supply E2 at the same time. Then, the first DC power supply E1 is used as a drive power supply for the main amplifier 7, and the second DC power supply
Is used as a drive power supply for the drive circuit 9.

In order to control the output voltage of the second DC power supply E2, a detection circuit 10 for detecting the voltage between both ends of the induction coil 2 is provided, and the detection output of the detection circuit 10 is applied to the second DC power supply E2. The power is input to the second control circuit 82 of the power supply E2.

Here, the first DC power supply E1 comprises a so-called step-up chopper circuit as a stabilized DC power supply. This step-up chopper circuit includes an inductor L11, a switching element Q11, a diode D11, and a smoothing capacitor C1.
1 and a first control circuit 81. Then, the first control circuit 81 detects the voltage across the smoothing capacitor C11 and controls the switching element Q11.

Therefore, in the first DC power supply E1, the output voltage obtained by rectifying the AC power supply AC by the rectifier DB1 is boosted to a high voltage by switching the switching element Q11 under the control of the first control circuit 81. At the same time, the input current distortion is improved.

The second DC power supply E2 comprises a so-called step-down chopper circuit as a stabilized DC power supply. This step-down chopper circuit smoothes the output voltage of the rectifier DB1 and a capacitor C13 serving as a noise filter. , Switching element Q12, inductor L1
2, a diode D12, a smoothing capacitor C12, and a second control circuit 82. The second control circuit 82 detects the voltage between both ends of the smoothing capacitor C12 and controls the switching element Q12 by inputting the signal of the detection circuit 10.

Accordingly, in the second DC power supply E2, the output voltage obtained by rectifying the AC power supply AC by the rectifier DB1 is reduced to a low voltage by switching the switching element Q12 under the control of the second control circuit 82. ing.

Further, on the AC input side of the rectifier DB1,
A filter circuit 20 is inserted. This filter 20
As shown in FIG. 7, the first DC power supply E1
And averaging the triangular waveform current Id flowing through each input terminal of the second DC power source E2 to obtain a sine waveform current Ie, thereby bringing the input current Iin from the AC power source AC closer to a sine wave, reducing waveform distortion, The power factor has been improved.

Here, the power supply device shown in FIG. 6 uses a first DC power supply E1 as a drive power supply for the main amplifier 7, and uses a second DC power supply E2 as a drive power supply for the drive circuit 9. The DC power supplies E1 and E2 are used separately for each of the circuits 7 and 9. For this reason, a decrease in circuit efficiency can be prevented as compared with the power supply device shown in FIG.
It has various advantages, such as easy dimming control of the electrodeless discharge lamp 1 as a load, obtaining a sufficient voltage at start-up, and reducing variations in the output voltage of the main amplifier 7.

[0014]

In the conventional power supply device shown in FIG. 6, the second DC power supply E2 includes:
A capacitor C13 is provided to smooth the output voltage of the rectifier DB1 and also function as a noise filter. If the capacitance of the capacitor C13 is relatively large, the entire waveform of the input current Iin of the AC power supply AC is distorted. As a result, the power factor decreases.

Conversely, when the capacitance of the capacitor C13 is reduced, the value of the input voltage decreases near the valley where the voltage in the full-wave rectified voltage of the output of the rectifier DB1 approaches zero, and the input energy decreases. Will run out of
There is a problem that the current supplied from the AC power supply AC temporarily increases, and the input current Iin has a waveform as shown in FIG. 8 and distortion occurs.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a power supply having a small input current distortion of an AC power supply and a high power factor.

[0017]

In order to achieve the above-mentioned object, the present invention employs the following constitution. That is, the invention according to claim 1 includes a rectifier for rectifying an alternating current, first and second power supply circuits respectively connected to a succeeding stage of the rectifier to generate different high and low DC voltages, and the second power supply. A drive circuit that outputs a drive signal based on an output of an oscillator using a circuit as a power supply, a power conversion circuit that outputs a high-frequency power by driving a switching element by the drive signal of the drive circuit using the first power supply circuit as a power supply, In the power supply device having the above configuration, a DC voltage for replenishing energy other than the output voltage of the rectifier is applied to an input terminal of the second power supply circuit.

According to a second aspect of the present invention, in the configuration of the first aspect, the DC voltage for replenishing the energy is a DC voltage from the first power supply circuit.

According to a third aspect of the present invention, in the configuration of the first aspect, the DC voltage for replenishing the energy is a DC voltage from the second power supply circuit.

According to a fourth aspect of the present invention, in the configuration of the first aspect, the first power supply circuit includes an inductor element, and the DC voltage for replenishing energy is induced in the inductor element. DC voltage.

According to a fifth aspect of the present invention, in the configuration of the first aspect, the DC voltage for replenishing energy is a DC voltage from another DC power supply arranged outside.

According to a sixth aspect of the present invention, in the configuration of the first to sixth aspects, the drive circuit has a preamplifier that amplifies the oscillation output of the oscillator and outputs a drive signal.

According to a seventh aspect of the present invention, in the configuration according to any one of the first to sixth aspects, the first and second power supply circuits include a step-up chopper circuit, a step-up / step-down chopper circuit, and a step-down chopper circuit. Either.

According to an eighth aspect of the present invention, in the configuration of the seventh aspect, the first power supply circuit is a step-up / step-down chopper circuit or a step-up / step-down chopper circuit, and the second power supply circuit is a step-down chopper circuit. is there.

According to a ninth aspect of the present invention, in the configuration according to any one of the first to eighth aspects, the power conversion means comprises:
A class D or class E amplifier circuit.

The invention according to claim 10 is the invention according to claims 1 to 9
In the configuration according to any one of the above, an electrodeless discharge lamp is connected downstream of the power conversion unit.

According to an eleventh aspect of the present invention, there is provided a rectifier for rectifying an alternating current, first and second power supply circuits respectively connected to a succeeding stage of the rectifier to generate different high and low DC voltages, and A drive circuit that outputs a drive signal based on an output of an oscillator using a power supply circuit as a power supply;
A power conversion circuit that drives a switching element by a drive signal of the drive circuit and outputs high-frequency power using the power supply circuit of the power supply circuit as a power supply. A different DC voltage for energy replenishment is applied together with the output voltage, and the first power supply circuit is a step-up chopper circuit or a step-up / step-down chopper circuit, and the second power supply The circuit is a step-down chopper circuit, and the power conversion means is a class D or class E amplifier circuit.

[0028]

[First Embodiment] FIG. 1 is a circuit diagram of a power supply device according to a first embodiment. Components corresponding to those of the prior art shown in FIG. 6 are denoted by the same reference numerals. Attach. Note that a detailed description of portions having the same configuration and the same operation and effect as those of the related art will be omitted.

In the power supply device according to the first embodiment,
As in the prior art, a high-frequency power supply 3 for supplying high-frequency power to the electrodeless discharge lamp 1 via the induction coil 2 using the electrodeless discharge lamp 1 as a load, and first and second power supplies for supplying power to the high-frequency power supply 3 The DC power supplies E1 and E2, the rectifier DB1, the filter circuit 20, and the detection circuit 10 are mainly configured. The high-frequency power supply 3 is common in that a drive circuit 9 including an oscillator (not shown) and a preamplifier and a main amplifier 7 as a power conversion circuit are provided.

The power supply device according to the first embodiment is characterized in that the first DC power supply E1 is constituted by a so-called step-up / step-down chopper circuit as a stabilized DC power supply, and the output voltage of the first DC power supply E1 is Is the second through the diode D2.
Is applied to the input terminal of the DC power source E2. The second DC power supply E2 is composed of a step-down chopper circuit having the same configuration as the conventional case shown in FIG.

The step-up / step-down chopper circuit as the first DC power supply E1 includes switching elements Q21 and Q22, an inductor L21, diodes D21 and D22, a capacitor C21, a drive transformer T2, a control circuit 81, and a smoothing capacitor C11. . The operation of such a step-up / step-down chopper circuit is described in, for example, JP-A-5-13.
No. 0771, which is well known, detailed description is omitted here.

In the DC power supply of the first embodiment, since the output voltage of the first DC power supply E1 is applied to the input terminal of the second DC power supply E2 via the diode D2, the full-wave output of the rectifier DB1 When the value of the input voltage tends to decrease near the valley in the rectified waveform, the shortage of the input voltage is supplemented by the output voltage of the first DC power supply E1. For this reason, the situation where the input energy is insufficient in the second DC power supply E2 does not occur.

Therefore, the function of accumulating the voltage of the capacitor C13 at the input terminal of the second DC power supply E2 can be reduced, that is, the capacity of the capacitor C13 can be set relatively small, and the cost and the size of parts can be reduced. Can be achieved. Moreover, the input current Iin of the AC power supply AC as shown in FIG.
Is not distorted, so that a high power factor can be obtained.

The first and second DC power supplies E1, E2
Are composed of non-insulated chopper circuits that do not use a transformer, so that the circuit efficiency is higher than that of an isolated DC stabilized power supply circuit that uses a transformer.

In the first embodiment, the first DC power supply E1 is constituted by a step-up / step-down chopper circuit. However, a step-up chopper circuit may be used. Also,
The main amplifier 7 is a class D amplifier circuit, but may be a so-called class E amplifier circuit. As in the case of the class D, the class E amplifier circuit can realize high efficiency even when the load operates at a very high frequency like the electrodeless discharge lamp 1.

Further, in the case of a light source having a very long life such as the electrodeless discharge lamp 1, it is desired that the lighting device also has a long life. As in the first embodiment, by increasing the efficiency of the first and second DC power supplies E1 and E2 and the main amplifier 7, heat generation inside the device can be suppressed and the life of components can be prolonged. The above request can be fully satisfied.

[Second Embodiment] FIG. 2 is a circuit configuration diagram of a power supply device according to a second embodiment. Components corresponding to those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals. Note that a detailed description of a portion having the same configuration and the same operation and effect as Embodiment 1 will be omitted.

The power supply device according to the second embodiment is characterized in that a secondary winding L22 is provided for an inductor L21 in a step-up / step-down chopper as a first DC power supply E1, and a voltage generated in the secondary winding L22. Is applied to the input terminal of the second DC power supply E2 via the diode D2.

In the case of the second embodiment, the secondary winding L provided for the inductor L21 of the first DC power source E1
An AC voltage is generated in the switch 22 by the switching operation of the switching elements Q21 and Q22. The AC voltage is rectified by the diode D2 and then applied to the second DC power supply E2.

Therefore, in the case of the second embodiment, the degree of smoothing of the voltage applied to the second DC power supply E2 from the first DC power supply E1 via the diode D2 is somewhat inferior to that of the first embodiment. Basically, the same effects as in the first embodiment can be obtained.

[Third Embodiment] FIG. 3 is a circuit diagram of a power supply device according to a third embodiment. Components corresponding to those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals. Note that a detailed description of a portion having the same configuration and the same operation and effect as Embodiment 1 will be omitted.

The power supply device according to the third embodiment is characterized in that the output voltage of the second DC power supply E2 is applied to the input terminal of the second DC power supply E2 via the diode D2. It is.

In the case of the third embodiment, when the value of the input voltage tends to decrease near the trough in the full-wave rectified waveform of the output of the rectifier DB1, the shortage of the input voltage is equal to the second voltage.
Is supplemented by the output voltage fed back from the DC power supply E2 via the diode D2. For this reason, since the situation where the input energy is insufficient in the second DC power supply E2 does not occur, the same effect as in the first embodiment can be obtained.

[Fourth Embodiment] FIG. 4 is a circuit diagram of a power supply device according to a fourth embodiment. Components corresponding to those of the first embodiment shown in FIG. 1 are denoted by the same reference numerals. Note that a detailed description of a portion having the same configuration and the same operation and effect as Embodiment 1 will be omitted.

A feature of the power supply device according to the fourth embodiment is that a DC voltage from another third DC power supply E3 disposed outside the device is supplied to the input of the second DC power supply E2 via a diode D2. That is, it was applied to the edge.

In the fourth embodiment, the rectifier DB1
When the value of the input voltage tends to decrease near the valley in the full-wave rectified waveform of the output of the above, the shortage of the voltage is caused by the output voltage supplied from another third DC power supply E3 via the diode D2. Be replenished. For this reason, since the situation where the input energy is insufficient in the second DC power supply E2 does not occur, the same effect as in the first embodiment can be obtained.

[0047]

According to the present invention, since the output voltage of the first DC power supply is applied to the input terminal of the second DC power supply, the output voltage of the rectifier can be applied near the valley in the full-wave rectified waveform. Since the input energy does not become insufficient and the entire waveform of the input current of the AC power supply does not become distorted, the power factor becomes high. Furthermore, the capacity of the capacitor at the input end of the second DC power supply can be made relatively small, and the cost and size of the components can be reduced.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a power supply device according to a first embodiment of the present invention.

FIG. 2 is a circuit configuration diagram of a power supply device according to Embodiment 2 of the present invention.

FIG. 3 is a circuit configuration diagram of a power supply device according to Embodiment 3 of the present invention.

FIG. 4 is a circuit configuration diagram of a power supply device according to a fourth embodiment of the present invention.

FIG. 5 is a circuit configuration diagram showing an example of a conventional power supply device.

FIG. 6 is a circuit configuration diagram of another conventional power supply device.

FIG. 7 is a waveform chart for explaining an operation of the filter circuit with respect to an input current from an AC power supply.

FIG. 8 is a waveform diagram of a current supplied from an AC power supply AC.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrodeless discharge lamp 2 induction coil 3 high frequency power supply 4 matching circuit 5 oscillation circuit 7 power conversion circuit (main amplifier) 9 drive circuit 10 detection circuit E1 first DC power supply E2 second DC power supply DB1 rectifier 20 filter circuit L2 inductor Secondary winding

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shingo Masumoto 1048 Oaza Kadoma, Kadoma-shi, Osaka F-term in Matsushita Electric Works, Ltd.

Claims (11)

[Claims] 1. A rectifier for rectifying an alternating current, first and second power supply circuits respectively connected to a subsequent stage of the rectifier to generate different high and low DC voltages, and an oscillator using the second power supply circuit as a power supply A power supply device comprising: a drive circuit that outputs a drive signal based on the output of the first power supply circuit; and a power conversion circuit that uses the first power supply circuit as a power supply and drives a switching element by the drive signal of the drive circuit to output high-frequency power. A power supply device wherein an input terminal of the second power supply circuit is supplied with an output voltage of the rectifier and a DC voltage for replenishing energy other than the output voltage of the rectifier. 2. The power supply device according to claim 1, wherein the DC voltage for replenishing energy is a DC voltage from the first power supply circuit. 3. The power supply device according to claim 1, wherein the DC voltage for replenishing energy is a DC voltage from the second power supply circuit. 4. The first power supply circuit includes an inductor element, and the DC voltage for replenishing energy is:
The power supply according to claim 1, wherein the power supply is a DC voltage induced in the inductor element. 5. The power supply device according to claim 1, wherein the DC voltage for replenishing energy is a DC voltage from another DC power supply arranged outside. 6. The power supply device according to claim 1, wherein the drive circuit includes a preamplifier that amplifies an oscillation output of the oscillator and outputs a drive signal. 7. The power supply device according to claim 1, wherein said first and second power supply circuits are one of a step-up chopper circuit, a step-up / step-down chopper circuit, and a step-down chopper circuit. 8. The power supply device according to claim 7, wherein the first power supply circuit is a step-up / step-down chopper circuit or a step-up / step-down chopper circuit, and the second power supply circuit is a step-down chopper circuit. 9. The power supply device according to claim 1, wherein said power conversion means is a class D or class E amplifier circuit. 10. The power supply device according to claim 1, wherein an electrodeless discharge lamp is connected downstream of said power conversion means. 11. A rectifier for rectifying an alternating current, first and second power supply circuits respectively connected to a succeeding stage of the rectifier to generate different high and low DC voltages, and an oscillator using the second power supply circuit as a power supply. A power supply device comprising: a drive circuit that outputs a drive signal based on the output of the first power supply circuit; and a power conversion circuit that uses the first power supply circuit as a power supply and drives a switching element by the drive signal of the drive circuit to output high-frequency power. The input terminal of the second power supply circuit is supplied with a DC voltage for replenishing energy other than the output voltage of the rectifier together with the output voltage of the rectifier, and the first power supply circuit includes: A step-up chopper circuit or a step-up / step-down chopper circuit, the second power supply circuit is a step-down chopper circuit, and the power conversion means is a class D or class E amplifier circuit. Switching control in accordance with and.