JPH07274535A - Power system, discharge lamp lighting device, and lighting system - Google Patents

Abstract

PURPOSE:To provide a lighting system of a simple structure with small distor tion. CONSTITUTION:In a steady state, a first and a second switching device SW1, SW2 are alternately turned on and off. When the second switching device SW2 is turned on, a primary winding Tr1 of a leakage transformer Tr is charged with electric charge of a capacitor for smoothing C2. Then, when the second switching device SW2 is turned off, current flows through the route of the primary winding Tr1 of the leakage transformer Tr, a diode D2, a capacitor C3, a diode D1, and the primary winding Tr1 of the leakage transformer Tr. When the first switching device SW1 is turned on, the capacitor for smoothing C2 charges the primary winding Tr1 of the leakage transformer Tr and the current which flows in the primary winding Tr1 becomes the one which improves a power factor. When the first switching device SW1 is turned off, current flows through the route of the primary winding Tr1 of the leakage transformer, the capacitor for smoothing C2, a diode D3, and the primary winding Tr1 of the leakage transformer Tr. By this method, noise decreases and distortion becomes small.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-distortion power supply device having a small inrush current, a discharge lamp lighting device, and a lighting device.

[0002]

2. Description of the Related Art Conventionally, there is a lighting device in which an inverter circuit is cascaded in a polarity reversal type chopper circuit and a discharge lamp is connected to the inverter circuit.

In this lighting device, the polarity reversal type chopper circuit reduces the input current, and the low distortion input current is converted into a high frequency by an inverter circuit to turn on the discharge lamp.

[0004]

However, in order to reduce the distortion, a polarity inversion type chopper circuit is used, and the current is converted into a high frequency by the inverter circuit. Therefore, two circuits are used for the high frequency current and the low distortion. Has to be used and has a problem that the configuration becomes complicated.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a power supply device, a discharge lamp lighting device, and a lighting device which have a simple structure and reduce distortion.

[0006]

A power supply apparatus according to claim 1 is a rectifying means for rectifying a voltage of an AC power supply, a smoothing capacitive element connected between output terminals of the rectifying means, and a smoothing capacitor. Series circuit composed of a rectifying element that is switched by the rectifying element and rectifies it, an impedance element connected between the output terminals of the rectifying means, a series circuit consisting of a first switching element and a second switching element, and the smoothing circuit. Capacitive element, an inductive element to which a load connected between the connection points of the first switching element and the second switching element is connected, and a ripple capacitance that resonates with the inductive element and generates ripple. And a conductive element.

According to a second aspect of the present invention, in the power source apparatus according to the first aspect, the ON width of the second switching element is controlled to control the electric power to the load.

In the discharge lamp lighting device according to the third aspect, the load of the power supply device according to the first and second aspects is the discharge lamp.

According to a fourth aspect of the present invention, there is provided the discharge lamp lighting device according to the third aspect including a fixture main body.

[0010]

According to the power supply device of the present invention, the smoothing capacitive element and the rectifying element that is switched and rectified by the smoothing capacitive element are connected to the rectifying means for rectifying the voltage of the AC power source, and the induction is performed. The high-frequency ripple can be superimposed on the output of the rectifying means, the off period of the rectifying means can be maintained, the distortion can be reduced, and the first switching Since the element and the second switching element are alternately operated, the inductive element is connected to the connection point of the first switching element and the second switching element, and the load is connected to the inductive element, the configuration is simple. AC can be obtained from the inductive element.

According to a second aspect of the present invention, in the power source apparatus according to the first aspect, the charge amount to the smoothing capacitor can be changed by controlling the ON width of the second switching element, and the load can be easily applied. Power can be controlled.

In the discharge lamp lighting device according to the third aspect, since the load of the power supply device according to the first and second aspects is the discharge lamp, the distortion can be reduced with a simple structure.

In the lighting device according to the fourth aspect, since the discharge lamp lighting device according to the third aspect includes the fixture body, the distortion can be reduced with a simple structure.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the illumination device of the present invention will be described below with reference to the drawings.

In FIG. 2, reference numeral 11 designates a main body of the instrument, and lamp sockets 12 are attached to both ends of the main body 11 of the instrument. The discharge lamp lighting circuit 13 is housed therein.

In the discharge lamp lighting circuit 13, as shown in FIG. 1, a commercial AC power source E is connected to a filter circuit 21 composed of a coil L1 and a capacitor C1, and the filter circuit 21 is composed of a diode bridge or the like. The input terminal of a full-wave rectifier 22 as a rectifying means is connected.

The output terminal of this full-wave rectifier 22 is
A series circuit of a diode D1 as a rectifying element and a smoothing capacitor C2 as a smoothing capacitive element, a capacitor C3 as an impedance element, a series circuit of a first switching element SW1 and a second switching element SW2, A ripple capacitor C4 as a small-capacity ripple capacitive element is connected. The first switching element SW1 and the second switching element SW2 are respectively connected to a freewheeling diode D2 and a diode D3.
Are connected in parallel.

Further, between the diode D1 and the smoothing capacitor C2 and the connection point of the first switching element SW1 and the second switching element SW2, a primary winding Tr1 of the leakage transformer Tr as an inductive element is provided. It is connected.

The secondary winding of the leakage transformer Tr
A fluorescent lamp FL is connected to both ends of Tr2, and a starting capacitor C6 is connected in parallel to the fluorescent lamp FL.

Next, the operation of the above embodiment will be described with reference to FIGS.

First, the voltage of the commercial AC power source E is noise-removed by the filter circuit 21, full-wave rectified by the full-wave rectifier 22, and smoothed by the smoothing circuit 23.

In the steady state, the first and second switching elements SW1 and SW2 are alternately turned on and off.
First, the case where the voltage of the full-wave rectifier 22 is higher than the voltage of the smoothing capacitor C2 shown in FIG. 3V will be described.

When the second switching element SW2 is turned on, as shown in period A of FIG. 5, the smoothing capacitor C2,
A current flows through the path of the primary winding Tr1, the second switching element SW2, and the smoothing capacitor C2 of the leakage transformer Tr, and the leakage transformer is charged by the charge of the smoothing capacitor C2.
The primary winding Tr1 of Tr is charged and the second switching element
A current I _SW2 based on _SW2 flows.

When the second switching element SW2 is turned off, as shown in period B of FIG. 5, the primary winding Tr1 of the leakage transformer Tr, the diode D2, the capacitor C3,
Primary winding Tr of diode D1 and leakage transformer Tr
The current flows in the path of 1, and the current I _D1 based on the diode _D1
And the current I _{SW 1} based on the first switching element _{SW 1}
Becomes

The primary winding Tr of the leakage transformer Tr
When the current of 1 is inverted and the first switching element SW1 is turned on, as shown in the period C of FIG. 5, the full-wave rectifier 22,
A current flows through the path of the capacitor C3, the first switching element SW1, the primary winding Tr1 of the leakage transformer Tr, and the smoothing capacitor C2, and the primary winding Tr1 of the leakage transformer Tr.
Are charged and become a current I _SW1 for improving the power factor based on the first switching element SW 1.

When the first switching element SW1 is turned off, as shown in the period D of FIG. 5, the primary winding Tr1 of the leakage transformer Tr, the smoothing capacitor C2, the diode D3 and the primary winding Tr1 of the leakage transformer Tr. A current flows through the path of and becomes a current I _D3 based on the diode D3.

That is, when the voltage full-wave rectified by the full-wave rectifier 22 is low, the high-frequency ripple voltage from the ripple capacitor C4 is superposed and becomes a substantially constant voltage. That is, since the capacitance of the ripple capacitor C4 is relatively small, the discharge ends immediately even if the current from the full-wave rectifier 22 decreases, and the ripple current is rectified by the full-wave rectifier 22 by repeating discharge and charge. It is superimposed on the voltage.

Next, the case where the voltage of the full-wave rectifier 22 is lower than the voltage of the smoothing capacitor C2 shown in FIG. 3VI will be described.

When the second switching element SW2 is turned on, as shown in the period A of FIG. 6, the smoothing capacitor C2,
A current flows through the path of the primary winding Tr1, the second switching element SW2, and the smoothing capacitor C2 of the leakage transformer Tr, and the leakage transformer is charged by the charge of the smoothing capacitor C2.
The primary winding Tr1 of Tr is charged and the second switching element
A current I _SW2 based on _SW2 flows.

Then, the second switching element SW2 is turned off, and the voltage of the smoothing capacitor C2 changes to the ripple capacitor.
When it is lower than the voltage of C4, as shown in period B of FIG.
Primary winding Tr1 of leakage transformer Tr, diode D2,
Capacitor C3, diode D1 and leakage transformer
Current flows through the route of the primary winding Tr1 of tr, the current I _SW1 based on a current I _D1 and the first switching element SW1 based on a diode D1.

The primary winding Tr of the leakage transformer Tr
When the current of 1 is inverted and the first switching element SW1 is turned on, as shown in the period C of FIG. 5, the full-wave rectifier 22,
A current flows through the path of the capacitor C3, the first switching element SW1, the primary winding Tr1 of the leakage transformer Tr, and the smoothing capacitor C2, and the primary winding Tr1 of the leakage transformer Tr.
Is charged, and after a predetermined time has passed, the first switching element
The current I _SW1 improves the power factor based on _SW1 .

When the first switching element SW1 is turned off, the primary winding Tr1 of the leakage transformer Tr, the smoothing capacitor C2, the diode D3 and the primary winding Tr1 of the leakage transformer Tr are turned on as shown in the period D of FIG. A current flows through the path of and becomes a current I _D3 based on the diode D3.

That is, similarly, when the full-wave rectified voltage by the full-wave rectifier 22 is low, the high-frequency ripple voltage from the ripple capacitor C4 is superposed and becomes a substantially constant voltage. That is, the ripple capacitor C4
Since the capacity of is relatively small, discharge ends immediately even if the current from the full-wave rectifier 22 drops, and the ripple current is superimposed on the voltage rectified by the full-wave rectifier 22 by repeating discharge and charge. is there.

Then, these operations are repeated.

Further, as shown in FIG. 4, the ripple component is removed, the power factor is improved, the distortion of the input current is also reduced, and the AC current generated in the secondary winding Tr2 of the leakage transformer Tr is used for the fluorescent lamp. Turn on FL to reduce noise and prevent flicker.

In the embodiment shown in FIG. 1, the ripple capacitor C4 may not be connected, and the capacitor C1 may be made to have a small capacity to resonate with the primary winding Tr1 of the leakage transformer Tr to generate ripple.

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

The embodiment shown in FIG. 7 is different from the embodiment shown in FIG. 1 in that a resonance capacitor C7 is connected in parallel to the second switching element SW2.

When the first switching element SW1 and the second switching element SW2 are alternately turned on and off, a period in which neither the first switching element SW1 nor the second switching element SW2 is turned on is provided, During this period, the capacitor C7 and the primary winding of the leakage transformer Tr
Resonance with Tr1 improves switching and the ripple capacitor C4 allows full-wave rectifier 22
Smooth the rising on the positive electrode side.

Another embodiment will be described with reference to FIG.

The embodiment shown in FIG. 8 is different from the embodiment shown in FIG. 1 in that the leakage transformer Tr is replaced by an inductor.
L2 is provided and a choke coil is placed between both ends of this inductor L2.
The fluorescent lamp FL is connected via L3.

As described above, the fluorescent lamp FL can be used without being electrically insulated.

[0043]

According to the power supply device of the present invention, the smoothing capacitive element and the rectifying element are connected to the rectifying means, and the ripple capacitive element that resonates with the inductive element to generate ripple is connected. As a result, high-frequency ripple can be superimposed on the output of the rectifying means, and the off period of the rectifying means can be maintained.
A low distortion can be achieved, the first switching element and the second switching element are alternately operated, and an inductive element is connected to a connection point of the first switching element and the second switching element to form an inductive element. Since the load is connected, alternating current can be obtained from the inductive element with a simple configuration.

According to a second aspect of the present invention, in the power source apparatus according to the first aspect, the amount of charge to the smoothing capacitor can be changed by controlling the ON width of the second switching element, and the load can be easily applied. Power can be controlled.

In the discharge lamp lighting device according to the third aspect, since the load of the power supply device according to the first and second aspects is the discharge lamp, the distortion can be reduced with a simple structure.

In the lighting device according to the fourth aspect, since the discharge lamp lighting device according to the third aspect is provided with the instrument main body, the distortion can be reduced with a simple structure.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing the same illumination device.

FIG. 3 is a waveform diagram showing a relationship between an input voltage waveform and an input current waveform.

FIG. 4 is a waveform diagram showing a relationship between an input voltage waveform and a lamp current of the above.

FIG. 5 is a waveform diagram showing voltage and current waveforms in FIG. 3V shown in FIG.

FIG. 6 is a waveform diagram showing voltage and current waveforms in FIG. 3IV above.

FIG. 7 is a circuit diagram showing a discharge lamp lighting device of another embodiment of the same as above.

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

[Explanation of symbols]

 11 Instrument main body 22 Full-wave rectifier as rectifying means C2 Smoothing capacitor as smoothing capacitive element C3 Capacitor as impedance element C4 Ripple capacitor as ripple capacitive element D1 Diode as rectifying element E Commercial AC power supply FL Fluorescent lamp as load and discharge lamp SW1 First switching element SW2 Second switching element Tr Leakage transformer as inductive element

Claims (4)

[Claims] 1. A rectifying means for rectifying a voltage of an AC power supply, a smoothing capacitive element connected between output terminals of the rectifying means, and a rectifying element for switching and rectifying by the smoothing capacitive element. A series circuit, a series circuit including an impedance element, a first switching element and a second switching element connected between the output terminals of the rectifying means, the smoothing capacitive element, and the first switching element and A power supply device comprising: an inductive element to which a load connected between connection points of the second switching element is connected; and a ripple capacitive element that resonates with the inductive element to generate ripple. . 2. The power supply device according to claim 1, wherein the power supply to the load is controlled by controlling the ON width of the second switching element. 3. A discharge lamp lighting device, wherein the load of the power supply device according to claim 1 is a discharge lamp. 4. A lighting device comprising the discharge lamp lighting device according to claim 3 and a fixture main body.