JPH10228992A - Discharge lamp lighting device and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device, in which no excessive rush current flows when power is supplied and which has a high power factor and decreased harmonic distortion, and a lighting system using the same. SOLUTION: A voltage doubler rectifier means 2 including a first capacitor C1 and a second capacitor C2 of small capacitance is connected between ac terminals 1a, 1b, and a first inductor L1 is connected between the rectifier means and the first capacitor C1. An inverter 3, having a third capacitor C3 of large capacitance, which is charged at the dc output of the rectifier means and at a high frequency, and having a pair of switching means 3b1, 3b2 connected in series, is connected, and when one of the switching means is on, some of the components of the inverter 3 constitute a chopper, and further a feedback circuit is connected between the load circuit of the inverter 3 and each ac terminal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp lighting device which operates at a high frequency.

[0002]

2. Description of the Related Art Lighting a discharge lamp such as a fluorescent lamp at a high frequency can improve luminous efficiency, reduce flicker in brightness, enable immediate lighting,
Since the lighting device can be reduced in size and weight, it has been frequently used recently.

However, the initial high-frequency lighting circuit method has a problem that the power factor is low and harmonic distortion occurs in the low-frequency AC power supply, and various improvements for overcoming this problem have been proposed. As one of the methods, there is a discharge lamp lighting device described in JP-A-6-231887.

FIG. 10 is a circuit diagram showing the above prior art.

In the figure, 101a and 101b are AC input terminals, 102 is booster means, 103 is rectifier means, 1
04 is a DC-AC converter, 105 is a load circuit, 10
6 is a feedback circuit.

[0006] The AC input terminals 101a and 101b are connected to a low-frequency AC power supply.

The booster means 102 comprises a capacitor 102a connected between AC input terminals and an inductor 102b connected between the rectifier 103.

The rectifying means 103 includes a pair of rectifiers 103a.
And a pair of capacitors 103b constitute a voltage doubler rectifier circuit.

The DC-AC converter 104 includes a series circuit of a pair of switching means 104a1 and 104a2 connected between the DC output terminals of the rectifying means 103, and a feedback transformer 104b for controlling the switching means 104a1 and 104a2 in accordance with a load current. And as main components.

The load circuit 105 includes a discharge lamp 105a
, Inductor 105b, capacitors 105c, 10
5d and a positive temperature coefficient resistor 105e.

The feedback circuit 106 has an AC input terminal 101a.
And a series circuit of a pair of capacitors 106a and 106b connected between the rectifier 103 and one DC output terminal of the rectifier 103.

Then, the DC-AC converter is operated with the DC voltage obtained by rectifying the low-frequency AC by double voltage by the rectifier 103, so that the switching means 104a1 and 104a2 are operated.
Work loss of the discharge lamp 105a
During the lighting of, the pair of capacitors is charged via the booster means 102, so that when the amplitude of the low-frequency AC voltage is close to its maximum value, the potential becomes such that no peak-like current is drawn from the main power supply. Rate is higher.

[0013]

However, in the above-mentioned prior art, since an electrolytic capacitor having a large capacity is used as the capacitor of the rectifier 103, an excessive rush current flows when the power is turned on. When the inrush current flows, there is a problem that the contacts of switches and relays for opening and closing the power supply are easily welded.

FIG. 11 is a waveform diagram of the low-frequency AC power supply voltage and current when the power is turned on in the prior art shown in FIG.

[0015] In the figure, the time t ₀ when the power is turned on, V _in
Shows a power supply voltage applied to the discharge lamp lighting device, I _in the input current, respectively. The flow conditions are excessive rush current i _p in the power-on t ₀ will be appreciated from FIG. 11.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a discharge lamp lighting device in which an excessive rush current does not flow when the power is turned on, a high power factor and reduced harmonic distortion, and a lighting device using the same. .

[0017]

According to a first aspect of the present invention, there is provided a discharge lamp lighting apparatus comprising: an AC terminal connected to a low-frequency AC power supply; a first capacitor connected between the AC terminals; And a voltage doubler rectifier including a pair of second capacitors having a relatively small capacity and rectifying the low frequency alternating current input from the AC terminal by voltage doubler; a second voltage rectifier connected in series between the first capacitor and the voltage doubler rectifier. A third capacitor having a relatively large capacity to which a DC output of the voltage doubler rectifier is applied; and a DC input terminal, a switching means, and a high frequency output terminal connected to the DC output terminal of the voltage doubler rectifier. And a feedback circuit connected between the AC terminal and the load circuit.

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.

The low frequency AC power supply is typically at 50 or 60 Hz, but is not limited to these frequencies.

Since the second capacitor smoothes the DC output of the voltage doubler rectifier before the inverter operation, a capacitor having a capacity commensurate with the smoothing is used. For example, an electrolytic capacitor is suitable.

The third capacitor is charged by the DC output of the voltage doubler rectifier and smoothes the DC output. After the operation of the inverter, the high frequency output fed back to the low frequency AC power supply is rectified by the voltage doubler rectifier. It is charged by the high frequency direct current and performs a smoothing action.

The inverter generates a high frequency between the high frequency output terminals of the load circuit based on the switching of the direct current by the switching means. The inverter only needs to include the above-described components, and may use any suitable circuit type. Can be used.

The load circuit includes a high frequency output terminal. A discharge lamp is connected between the output terminals. The load circuit can have other circuit configurations as needed. For example, a second inductor can be connected in series with the high-frequency output terminal. Further, a capacitor for preheating the filament can be connected between the non-power supply terminals of the discharge lamp. Further, one end of the load circuit can be connected to a portion where a high-frequency voltage of the inverter appears through a DC cut capacitor in series.

In the present invention, the high frequency is 20 KHz.
As described above, the frequency is preferably 20 to 200 KHz.

The feedback circuit functions to draw a high-frequency current from the AC power supply to the inverter by returning the high frequency generated in the inverter to the AC terminal, thereby increasing the potential of the AC terminal by the high frequency.

Thus, in the present invention, when the power is turned on, a charging circuit for the third capacitor having a large capacity is formed in series with the second capacitor having a relatively small capacity of the rectifying means. The charging current is kept small.

When the low-frequency AC power supply is turned on, the voltage doubler rectifier generates a rectified DC having a voltage value twice as high as the low-frequency AC voltage, and the inverter starts operation using this voltage as an input to generate a high frequency. .

This inverter operates as follows. The resonance frequency differs between the peak or low peak of the low-frequency AC voltage and the rising and falling peaks or valleys due to the operation and non-operation of the feedback circuit. By approaching the point, the output voltage is increased to increase the load current, that is, the lamp current, and conversely, at the peak, the output voltage is decreased to decrease the lamp current.

Therefore, the ripple of the high-frequency current is suppressed, and the crest factor represented by the ratio of the peak value to the effective value of the lamp current falls within the allowable values of the IEC standard and the electrical equipment standard. Becomes possible.

Further, since the DC input voltage of the inverter can be increased by the voltage doubler rectifying means, the current flowing through the switching means of the inverter can be reduced by the increased voltage, so that the switching conduction loss can be reduced.

Further, since the first inductor is interposed in series in the conduction loop of the input current viewed from the low-frequency AC power supply, harmonics of the input current can be reduced.

The discharge lamp lighting device according to the second aspect of the present invention comprises:
An AC terminal connected to the low-frequency AC power supply; a first capacitor connected between the AC terminals; a low-frequency input from the AC terminal including a pair of rectifying means and a pair of second capacitors having a relatively small capacity. Voltage doubler rectifying means for voltage double rectifying AC; first inductor connected in series between the first capacitor and voltage doubler rectifying means; relatively large capacity to which a DC output of the voltage doubler rectifying means is applied. A third capacitor; a DC input terminal connected to the DC output terminal of the voltage doubler rectifier, a series circuit of a pair of switching means connected between the DC input terminals, and a pair of diodes connected in anti-parallel to each switching means. And an inverter having a load circuit including a high-frequency output terminal and a third inductor in series; a feedback circuit connected between the AC terminal and the load circuit; When one of the switching means is turned on after the operation of (1), a chopper including a load circuit including a high-frequency output terminal, a diode connected in antiparallel to the one switching means, the other switching means and a third capacitor; It is characterized by having.

According to the present invention, as compared with the first aspect of the present invention, there is provided a pair of switching means in which an inverter is connected in series, and a part of the inverter constitutes a chopper when one of the switching means is turned on. A configuration is defined in which the operating voltage of the inverter can be made higher than the DC output of the voltage doubler rectifier.

The inverter forms a half-bridge type inverter.

According to a third aspect of the present invention, there is provided a discharge lamp lighting device,
A first capacitor connected between the low-frequency AC power supplies; a voltage doubler rectifier including a pair of rectifiers and a pair of capacitors having a relatively small capacity to double rectify the low-frequency AC voltage; A first inductor connected in series between the voltage doubler rectifiers; a second capacitor having a relatively large capacity connected to be charged by the DC output voltage of the voltage doubler rectifier; A series circuit of a pair of switching means connected between the DC output terminals; a pair of diodes connected in anti-parallel to each switching means; a connection point of the pair of switching means and a position where a high-frequency voltage appears due to switching of the switching means. A load circuit serially including a second inductor and a pair of high-frequency output terminals connected between the AC terminal and the load circuit; It is characterized in that it comprises a; connected a feedback circuit.

The present invention, when compared to the preceding claims,
It differs mainly in that the connection form of the circuit element is specified.

According to a fourth aspect of the present invention, there is provided a discharge lamp lighting device,
The discharge lamp lighting device according to claim 2 or 3,
The feedback circuit is characterized in that it is connected between one AC terminal and a high-frequency output terminal of the load circuit opposite to the second inductor side.

The present invention specifies an example of connection of a feedback circuit.

According to a fifth aspect of the present invention, there is provided a discharge lamp lighting device,
The discharge lamp lighting device according to claim 2 or 3,
The feedback circuit is connected between the AC terminal and a connection point between the high-frequency output terminal of the load circuit and the second inductor.

The present invention specifies another example of the connection of the feedback circuit.

According to a sixth aspect of the invention, there is provided a discharge lamp lighting device,
The discharge lamp lighting device according to claim 2 or 3,
The feedback circuit is characterized in that one of the AC terminals is connected to a high-frequency output terminal of the load circuit opposite to the high-frequency output terminal on the second inductor side.

The present invention specifies still another example of the connection of the feedback circuit.

According to a seventh aspect of the present invention, in the discharge lamp lighting device according to any one of the first to third aspects, the feedback circuit includes one AC terminal via one end of the load circuit and the rectifier of the voltage doubler. And is connected between them.

The present invention specifies still another example of the connection of the feedback circuit. In the present invention, a diode for preventing current from flowing into each of the input terminals of the inverter can be inserted in series in the forward direction in order to more reliably perform high-frequency feedback.

The discharge lamp lighting device according to the invention of claim 8 is:
8. The discharge lamp lighting device according to claim 1, further comprising: voltage detecting means for detecting peaks and valleys of the low-frequency AC voltage; and controlling the operating frequency of the inverter to be low in response to the detection of the peaks. And control means for controlling the operating frequency to be high according to the detection of the valley.

According to the present invention, the operating frequency of the inverter is forcibly changed by the control unit in accordance with the peaks and valleys of the low-frequency AC voltage regardless of whether the operating frequency changes in the inverter. Can reliably reduce the ripple of the lamp current corresponding to the low-frequency AC voltage.

According to a ninth aspect of the present invention, there is provided a discharge lamp lighting device,
The discharge lamp lighting device according to any one of claims 1 to 8, further comprising a discharge lamp connected between the high-frequency output terminals.

The present invention includes a discharge lamp as a part of the structure.

According to a tenth aspect of the present invention, there is provided a lighting device comprising: a lighting device main body; and the discharge lamp according to the ninth aspect, which is supported by the lighting device main body.

The lighting device is applicable to any device utilizing the light emission of a discharge lamp, such as a lighting fixture, a display device, a signal lamp device, and a bulb-type fluorescent lamp.

[0051]

Embodiments of the present invention will be described below with reference to the drawings.

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

First, the circuit configuration will be described.

In the figure, 1a and 1b are a pair of AC terminals, C1 is a first capacitor, 2 is a voltage doubler rectifier, L
1 is a first inductor, C3 is a third capacitor, 3 is an inverter, 4 is a feedback circuit, and 5 is a low-frequency AC power supply.

The pair of AC terminals 1 a and 1 b are connected to a low-frequency AC power supply 5.

The first capacitor C1 has an AC terminal 1a,
1b.

The voltage doubler rectifier 2 includes a pair of rectifiers 2.
a and 2b and a pair of second capacitors C21 and C22 having a relatively small capacity. A pair of rectifying means 2
a and 2b are connected in series, and the connection point is connected to one AC terminal 1a. A pair of second capacitors C2
1, C22 are connected in series, and the connection point is connected to the AC terminal 1b via the first inductor L1 in series. Therefore, the two connection points constitute an AC input terminal of the voltage doubler rectifier 2. Further, a pair of rectifying means 2
a, 2b and a pair of second capacitors C2
1, the series circuit of C22 is connected in parallel with each other, and the connection point constitutes a DC output terminal.

The first inductor L1 is connected between the first capacitor C1 and the voltage doubler rectifier 2.

The third capacitor C3 uses an electrolytic capacitor having a relatively large capacity, and is connected between the DC output terminals of the voltage doubler rectifier 2.

The inverter 3 includes input terminals 3a1, 3a2, switching means 3b1, 3b2, and a high-frequency output terminal 3c connected between the DC output terminals of the voltage doubler rectifier 3.
At least a load circuit 3c including 1 and 3c2 is provided.

The switching means 3 b 1 and 3 b 2 are connected in series and connected between the DC output terminals of the voltage doubler rectification means 2. Diodes 3f1, 3f2 are connected in anti-parallel with the respective switching means 3b1, 3b2.

The high frequency output terminals 3c1, 3c of the load circuit 3c
A discharge lamp 3d, for example, a fluorescent lamp is connected between c2. A fourth capacitor C4 for preheating the filament is connected between the non-power-supply-side terminals of the discharge lamp 3d. A second inductor L2 is inserted in series in the load circuit 3c. One end of the load circuit 3c is connected to the negative side of the DC output terminal of the voltage doubler rectifier 2 via a fifth DC cut capacitor C5.

The feedback circuit 4 comprises a sixth capacitor C6, and is connected between the AC terminal 1a and one end of the load circuit 3c.

Next, the operation will be described.

Inrush current When the low-frequency AC power supply 5 is turned on, the following three charging circuits are formed, and a capacitor charging current flows. That is,
The first charging circuit includes an AC terminal 1a, a rectifier 2a, a third
Circuit of the capacitor C3, the second capacitor C22, the first inductor L1, and the AC terminal 1b. The second charging circuit includes an AC terminal 1a, a rectifier 2a, a second capacitor C21, a first inductor L1, and an AC terminal 1a.
This is the circuit of FIG. The third charging circuit is a circuit including the AC terminal 1a, the sixth capacitor C6, the fifth capacitor C5, the second capacitor C22, the first inductor L1, and the AC terminal 1b.

Thus, the first charging circuit includes the third capacitor C3 having a large capacity.
Since the second capacitor C22 having a small capacity is connected in series with the capacitor 3, the charging current is low and the time width is narrow. The second charging circuit includes a second capacitor C21 having a small capacitance.
Therefore, the charging current is low and the time width is narrow. Third
Of the fifth and sixth capacitors C5, C6
Since both capacitors have small capacities, the charging current does not matter even if the second capacitor C22 is further connected in series.

FIG. 2 is a waveform diagram showing voltage and current waveforms when the low-frequency AC power supply is turned on in FIG.

In the figure, the time t _{0 on the} horizontal axis indicates when the low-frequency AC power is turned on. V _in is the input voltage, I _in is the input current,
i _p represents the inrush current. By comparing with FIG. 11, it can be clearly understood that the inrush current is very low and the time width is narrow.

Operation of Inverter and Chopper When the low frequency AC power supply 5 is turned on and the inverter 3 operates, when one of the switching means 3b2 is turned on, some components of the inverter 3 constitute a step-up chopper.

FIG. 3 is a circuit diagram of the chopper in FIG.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals. That is, the switching means 3b2 is connected to the power supply via the second inductor L2, and a series circuit of the diode 3f1 and the third capacitor C3 is connected in parallel with the switching means 3b2 to form a boost chopper.

When the switching means 3b2 is turned on, the low-frequency AC power supply 5, the sixth capacitor C6, the discharge lamp 3d, the second inductor L2, the switching means 3b2, the second capacitor C22, and the first inductor L
1 and the low-frequency AC power supply 5
The electromagnetic energy is stored in the inductor L2 of. When the switching means 3b2 is turned off, the second inductor L
2 is stored in the diode 3f1
, The third capacitor C3 is charged.

At this time, the terminal voltage of the capacitor C3 is
The voltage is boosted in proportion to the on-duty of the switching means 3b2. The terminal voltage of the capacitor C3 is boosted to almost twice the peak value of the low-frequency AC voltage. Therefore, the inverter 3 generates a high frequency based on the boosted voltage.
During this time, the low-frequency AC power supply 5 supplies the second capacitor C2
1. No charging is performed on C22.

The high frequency generated by the inverter 3 is fed back to the AC terminal 1a through the feedback circuit 4, and
a, the high frequency and the low frequency voltage have the same polarity, that is, the switching means 3b2
When the power supply is on, the low-frequency AC power supply 5
, A high-frequency current flows through the load circuit 3c. This is a state where a high-frequency current is called from the low-frequency power supply 5. Therefore, in the present embodiment, the power factor is improved.

By the way, near the rising portion and the falling portion of the low-frequency AC voltage, that is, in the valley, since the current from the low-frequency AC power supply 5 is small, the voltage across the sixth capacitor C6 is small, The capacity of the capacitor C6 can be ignored. Therefore, the fifth capacitor C5
, A relatively large-capacity series circuit of C1 and C22 is connected in parallel. The resonance frequency at this time is given by the following equation.

In the vicinity of the peak value of the low-frequency AC voltage, that is, at the peak, f _V = 1 / 2π {L2 · C4} ^1/2 , contrary to the above, the fifth capacitor C5 is connected to the first capacitor C1. And a series circuit of the second capacitor C22 is connected in parallel. Assuming that the resonance frequency of the second capacitor C22 is higher than the sixth capacitor C6 at this time, the following equation is used.

F _M = 1 / 2π ｛L2 · (C5 + C6) ·
C4 / (C5 + C6 + C4)｝ ^1/2 The capacitance relationship of each capacitor is as follows.

C1, C21, C22 >>C6> C4, C5 As described above, the resonance frequency changes between the valley and the peak of the low-frequency AC voltage. Since also changes in the resonant frequency likewise valleys and crests upon on the other switching unit 3b1, the resonance frequency in the valleys and f _V, the resonance frequency at the peak portion as f _M, f _V <F _M , the capacitances of the fifth capacitor C5 and the sixth capacitor C6 are set to C5 <C.
If it is set to 6, when operating at the same frequency under the slow phase operation, the valleys are close to the resonance point and the hills are far from the resonance point. Therefore, the lamp current increases because the output voltage increases at the trough, and the lamp current decreases because the output voltage decreases at the peak.

FIG. 4 is a waveform diagram showing the voltage and current waveforms of each part in FIG.

[0080] In view shows (a) the current I _in the discharge lamp lighting device to the applied voltage V _in, and flows from the low-frequency AC power source 5. (B) conceptually shows a high-frequency current flowing through the discharge lamp 3d.

Regarding Harmonics As a result of the high frequency being fed back to the low-frequency AC power supply 5 via the feedback circuit, current flows from the low-frequency power supply 5 with a phase-lag and a waveform close to a sine wave, so that generation of harmonics is small. . Furthermore, since the first inductor L1 is inserted in series in the input current loop, harmonics are cut off, so that harmonic distortion is reduced.

FIG. 5 is a circuit diagram showing a second embodiment of the discharge lamp lighting device according to the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the connection position of the feedback circuit 4 is changed. That is, the other end of the feedback circuit 4 is connected to a connection point between the discharge lamp 3d and the second inductor L2.

FIG. 6 is a circuit diagram showing a discharge lamp lighting device according to a third embodiment of the present invention.

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the connection position of the feedback circuit 4 is changed, and the other end of the feedback circuit 4 is connected to the other end of the load circuit 3c.

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

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

In this embodiment, the connection position of the feedback circuit 4 is changed. One end of the feedback circuit 4 is connected to the DC output terminal 3a1 of the voltage doubler rectifier 2, and a diode is connected in series with both input terminals of the inverter 3. 6a and 6b are connected in the forward direction to prevent the current from flowing around.

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

In the figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 7 denotes a DC power supply, 8 denotes a driving device, 9 denotes voltage detecting means, and 10 denotes control means.

The DC power supply 7 comprises the first capacitor C1, the first inductor L1, and the voltage doubler rectifier 2 in FIG.

The driving device 8 includes the inverter 3 and the third
, And a feedback circuit 4.

The voltage detecting means 9 detects peaks and valleys of the low-frequency AC voltage.

The control means 10 controls the operating frequency of the inverter 3. When the voltage detecting means 9 detects a peak, the control means 10 lowers the operating frequency. When a valley is detected, the operating frequency is controlled to be high.

Thus, the present invention is suitable for the case where even if the operating frequency changes in accordance with the peaks and valleys of the low-frequency AC voltage inside the inverter 3, the degree cannot be satisfied. That is, according to the present invention, the operating frequency can be reliably changed to a desired range. Therefore, the crest factor can be reduced by reducing the ripple of the lamp current.

FIG. 9 is a perspective view showing a lighting apparatus which is an embodiment of the lighting apparatus of the present invention.

In the figure, reference numeral 11 denotes a lighting device main body, and 12 denotes a discharge lamp.

The lighting device main body 11 has a discharge lamp lighting device built therein.

The discharge lamp 12 is supported by the lighting device main body 11.

[0102]

According to the first to ninth aspects of the present invention, it is possible to provide a discharge lamp lighting device in which an excessive rush current does not flow when the power is turned on, a power factor is high, and harmonic distortion is reduced. it can.

According to the second and third aspects of the present invention, in addition, since some components of the inverter constitute a chopper, the low-frequency AC voltage can be boosted and then converted into a high-frequency by the inverter. A discharge lamp lighting device in which conduction loss of the switching means is further reduced can be provided.

According to the fourth to seventh aspects of the present invention, it is possible to provide a discharge lamp lighting device in which the connection positions of the feedback circuits are respectively changed.

According to the eighth aspect of the present invention, in addition, peaks and valleys of the low-frequency AC voltage are detected, and the operating frequency of the inverter is controlled to be low at the peaks and high at the valleys accordingly. Thus, the crest factor can be improved by reliably reducing the ripple of the lamp current.

According to the ninth aspect of the present invention, it is possible to provide a discharge lamp lighting device including a discharge lamp as a component.

According to the tenth aspect, it is possible to provide a lighting device having the effects of the first to ninth aspects.

[Brief description of the drawings]

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

FIG. 2 is a waveform diagram showing voltage and current waveforms when a low-frequency AC power supply is turned on in FIG.

FIG. 3 is a circuit diagram of the chopper in FIG. 1;

FIG. 4 is a waveform chart showing voltage and current waveforms of respective parts in FIG.

FIG. 5 is a circuit diagram showing a discharge lamp lighting device according to a second embodiment of the present invention.

FIG. 6 is a circuit diagram showing a discharge lamp lighting device according to a third embodiment of the present invention.

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

FIG. 8 is a circuit block diagram showing a fifth embodiment of the discharge lamp lighting device of the present invention.

FIG. 9 is a perspective view showing a lighting device which is an embodiment of the lighting device of the present invention.

FIG. 10 is a circuit diagram showing the above-described conventional technique.

11 is a waveform diagram of a low-frequency AC power supply voltage and current at the time of power-on in the prior art shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Low frequency AC power supply 1a ... AC terminal 1b ... AC terminal 2 ... Voltage doubling rectifier 3 ... Inverter 3a1 ... DC input terminal 3a2 ... DC input terminal 3b1 ... Switching means 3b2 ... Switching means 3c ... Load circuit 3c1 ... High frequency output terminal 3c2 high frequency output terminal 3d discharge lamp 4 feedback circuit C1 first capacitor C2 second capacitor C3 third capacitor L1 first inductor

Claims (10)

[Claims] 1. An AC terminal connected to a low-frequency AC power supply;
A first capacitor connected between the AC terminals; and a voltage doubler rectifier including a pair of rectifiers and a pair of second capacitors having a relatively small capacity to double rectify low-frequency AC input from the AC terminals. A first inductor connected in series between the first capacitor and the voltage doubler rectifier; a third capacitor having a relatively large capacity to which a DC output of the voltage doubler rectifier is applied; An inverter provided with a load circuit including a DC input terminal connected to an output terminal, switching means, and a high-frequency output terminal; and a feedback circuit connected between the AC terminal and the load circuit. Discharge lamp lighting device. 2. An AC terminal connected to a low-frequency AC power supply;
A first capacitor connected between the AC terminals; and a voltage doubler rectifier including a pair of rectifiers and a pair of second capacitors having a relatively small capacity to double rectify low-frequency AC input from the AC terminals. A first inductor connected in series between the first capacitor and the voltage doubler rectifier; a third capacitor having a relatively large capacity to which a DC output of the voltage doubler rectifier is applied; A DC input terminal connected to the output terminal, a series circuit of a pair of switching means connected between the DC input terminals, a pair of diodes connected in anti-parallel to each switching means, a high-frequency output terminal, and a third inductor in series. An inverter having a load circuit including: a feedback circuit connected between an AC terminal and the load circuit; one of the switching means is turned on after the operation of the inverter A chopper comprising a load circuit including a high-frequency output terminal, a diode and a third capacitor connected in anti-parallel to one switching means and the other switching means; and a connection between the AC terminal and the load circuit. And a feedback circuit provided. And a first capacitor connected between the low-frequency AC power supplies; and a pair of rectifiers and a pair of second capacitors having a relatively small capacity. Means; a first inductor connected in series between the low frequency AC power supply and the voltage doubler rectification means; and a third relatively large capacity connected to be charged by the DC output voltage of the voltage doubler rectification means. A capacitor; a series circuit of a pair of switching means connected between the DC output terminals of the voltage doubler rectifier; a pair of diodes connected in anti-parallel to each switching means; and a connection point of the pair of switching means and a switching means. A load circuit including, in series, a second inductor and a pair of high-frequency output terminals connected to a position where a high-frequency voltage appears by switching; And connected with a feedback circuit between the load circuit; discharge lamp lighting apparatus, characterized in that it comprises a. 4. The feedback circuit according to claim 2, wherein the feedback circuit is connected between one of the AC terminals and a high-frequency output terminal of the load circuit opposite to the second inductor. Discharge lamp lighting device. 5. The discharge lamp lighting device according to claim 2, wherein the feedback circuit is connected between the AC terminal and a connection point between the high-frequency output terminal of the load circuit and the second inductor. . 6. The feedback circuit according to claim 2, wherein one of the AC terminals is connected to a high-frequency output terminal of the load circuit opposite to the high-frequency output terminal of the second inductor.
Or the discharge lamp lighting device according to 3. 7. The feedback circuit according to claim 1, wherein the feedback circuit is connected between one end of the load circuit and one of the AC terminals via the rectifying means of the voltage doubler rectifying means. The discharge lamp lighting device as described in the above. 8. Voltage detecting means for detecting peaks and valleys of a low-frequency AC voltage; controlling the operating frequency of the inverter to be low according to the detection of the peaks and increasing the operating frequency according to the detection of the valleys. The discharge lamp lighting device according to any one of claims 1 to 7, further comprising control means for controlling. 9. The discharge lamp lighting device according to claim 1, further comprising a discharge lamp connected between the high-frequency output terminals. 10. A lighting device, comprising: a lighting device main body; and the discharge lamp according to claim 9 supported by the lighting device main body.