JP2000116147A - Power supply device, discharge lamp lighting device and lighting device - Google Patents

Abstract

(57) [Problem] To provide a discharge lamp lighting device capable of easily performing feedback control. SOLUTION: A control circuit 51 turns on and off first and second field-effect transistors Q1 and Q2 alternately to induce a high-frequency alternating current in an autotransformer Tr1 to generate an autotransformer Tr1 and a ripple capacitor C2. To generate a high-frequency voltage, and this ripple current is superimposed on the output of the full-wave rectifier 42 to boost the voltage from the full-wave rectifier 42. When the current is inverted, the voltage of the full-wave rectifier 42 decreases, the voltage after rectification becomes equal to the voltage before rectification, and the power factor improving current flows. The lamp voltage detection circuits 48, 49 detect the lamp voltages of the fluorescent lamps FL1, FL2, and the control circuit 51 controls the gate voltages to the first and second field effect transistors Q1, Q2 according to the lamp voltages.
Soft start of the fluorescent lamps FL1 and FL2, control of starting and lighting, and output of an appropriate voltage or stop of operation when the fluorescent lamps FL1 and FL2 are at a point or end of life.

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, a discharge lamp lighting device, and a lighting device with a small rush current.

[0002]

2. Description of the Related Art Conventionally, as a discharge lamp lighting device of this type, for example, a configuration described in Japanese Patent Application Laid-Open No. 7-274536 is known.

In the discharge lamp lighting device described in Japanese Patent Application Laid-Open No. 7-274536, a diode bridge is connected to a commercial AC power supply via a filter circuit, and a polarity inversion type chopper circuit is connected to the diode bridge. In the inverting chopper circuit, a first switching element and an inductor are connected to a diode bridge, a first capacitor and a diode having relatively large capacitance are connected to the inductor, and a diode bridge is connected to the inductor in parallel with the diode. A second switching element that flows a current in the opposite direction is connected, a second capacitor that resonates with a regenerative current in cooperation with an inductor is connected to a diode bridge, and a fluorescent lamp serving as a load is connected to the inductor. I have.

Then, a second switching element causes a current in a direction opposite to a current from the diode bridge to flow through the inductor to a polarity inversion type chopper circuit having a first switching element, an inductor, a first capacitor, and a diode. The second capacitor superimposes a regenerative current on the diode bridge with a small capacity that resonates with the inductor, and currents of different polarities alternately flow through the inductor, so it also has the function of an inverter, reducing distortion with a simple configuration. I can do it.

[0005]

However, in the configuration disclosed in Japanese Patent Laid-Open No. Hei 7-274536, since the potential of the second switching element and the potential of the load are different, the potential of the load cannot be detected as it is. Even at the end of life, the lamp voltage cannot be directly detected, and a detection circuit for feedback control for coping with the end of life of the fluorescent lamp becomes complicated.

[0006] Further, since the second switching element is also connected via the first capacitor, an insulating element such as a photocoupler is required for control.

Further, the fluorescent lamp is not connected to a stable potential, and the potential is not stable because the potential is floating, so that there is a problem that noise from the fluorescent lamp as a load is easily generated.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has as its object to provide a power supply device, a discharge lamp lighting device, and a lighting device which can stabilize a load potential and facilitate feedback control and the like.

[0009]

According to a first aspect of the present invention, there is provided a power supply apparatus comprising: a rectifier for rectifying a voltage of an AC power supply; and a first switching element and a load connected in series to the rectifier. Chopper circuit having a relatively large-capacity first capacitive element and a rectifying element connected in parallel to the inductive element; and a chopper circuit in parallel with the rectifying element on the negative side of the rectifying means. A second switching element which is connected and allows a current in a direction opposite to the rectifying means to flow to the inductive element; and a second capacitive element which resonates with a regenerative current in cooperation with the inductive element. When a chopper circuit having one switching element, an inductive element, a first capacitive element, and a rectifying element is provided with a second switching element for flowing a current in a direction opposite to a current from the rectifier to the inductive element. And a second capacitive element that resonates with the inductive element and superimposes the regenerative current on the rectifier with a small capacitance that resonates, so that currents of different polarities alternately flow through the inductive element, so that the function as an inverter is also achieved With this configuration, the distortion can be reduced with a simple configuration, and the control of the second switching element can be facilitated by making the potential of the second switching element and the potential of the load the same. For example, since the potential of the load can be detected with a simple configuration without using an insulating means or the like, feedback from the load can be easily performed.

According to a second aspect of the present invention, there is provided a power supply device comprising: a rectifier for rectifying a voltage of an AC power supply; a first switching element connected in series to the rectifier and an inductive element connected to a load; A chopper circuit having a relatively large first capacitive element and a rectifying element connected in parallel to the inductive element; and a rectifying element connected in parallel to the rectifying element on the negative side of the rectifying means. A second switching element that causes a current in the opposite direction to flow to the inductive element; a transformer that operates the first switching element and the second switching element in association with each other; and resonates with the regenerative current in cooperation with the inductive element. A chopper circuit having a first switching element, an inductive element, a first capacitive element and a rectifying element, and a rectifying means in the inductive element. With the al current providing a second switching element to flow in the opposite direction of the current, second superimposing a regenerative current to the rectifying means a small volume resonates with the inductive element
Since currents of different polarities alternately flow through the inductive element, the inductive element also has a function as an inverter, can achieve a low distortion with a simple configuration, and has a second switching element. By making the potential and the load potential the same, the control of the second switching element can be facilitated, and the potential of the load can be detected with a simple configuration without using, for example, insulating means. Can be easily performed, and the first switching element and the second switching element are operated in association with each other by the transformer, so that the control of the first switching element and the second switching element is facilitated.

According to a third aspect of the present invention, in the power supply device of the first or second aspect, the load has one end connected to a negative electrode side of the rectifying means, and one end of the load is the same as the negative electrode of the rectifying means. It becomes a potential and suppresses noise from the load.

According to a fourth aspect of the present invention, there is provided the power supply device according to any one of the first to third aspects, further comprising a protection circuit for protecting the first switching element when a current flowing through the first switching element increases. Thus, the first switching element is protected from an inrush current flowing through the first switching element with a simple configuration without performing, for example, software processing.

According to a fifth aspect of the present invention, there is provided the power supply device according to any one of the first to fourth aspects, further comprising control means for reducing the ON width of the first switching element when the voltage of the AC power supply increases. In addition, since the current can be made almost symmetrical, the inductive one is prevented from being demagnetized.

According to a sixth aspect of the present invention, the load of the power supply according to any one of the first to fifth aspects has a discharge lamp.

According to a seventh aspect of the present invention, in the discharge lamp lighting device, the load of the power supply device according to any one of the first to fifth aspects includes a plurality of discharge lamps having different power consumptions, and the inductive element has a plurality of different power consumptions. It supplies power corresponding to each of the discharge lamps, and also supports discharge lamps with different power consumption.

An illuminating device according to an eighth aspect of the present invention includes a discharge lamp lighting device according to the sixth or seventh aspect and a fixture main body on which a discharge lamp lit by the discharge lamp lighting device is mounted. Has the effect of

[0017]

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

FIG. 1 is a circuit diagram showing a discharge lamp lighting device, and FIG.
FIG. 3 is an exploded perspective view showing the lighting device, FIG. 3 is a sectional view showing the lighting device, and FIG. 4 is a sectional view showing the lighting device with the shade and the holder body removed.

As shown in FIGS. 2 to 4, a recessed hooking ceiling 2 is installed on an instrument mounting surface 1 such as a ceiling, and an adapter 3 is electrically and mechanically connected to a lower surface of the hooking ceiling 2. This adapter 3
On both sides, a pair of locking claws 4 are urged by a built-in spring so as to always protrude, and a release button 5 is provided on the lower surface so as to protrude. By pressing the release button 5 into the adapter 3, The pair of locking claws 4 are configured to retreat inward. The adapter 3 is provided with a connector 7 via a connection cord 6.

Reference numeral 11 denotes a tool body. The tool body 11 is formed in a disc shape, and an opening 12 having a shape through which the adapter 3 can be inserted is formed in a center portion.
Elastic member 13 located between instrument body 11 and instrument mounting surface 1
Is attached. Further, the opening 12 of the instrument body 11
Is engaged with the locking claw 4 of the adapter 3.

Further, on the lower surface of the instrument body 11, a reflecting surface portion 14 for reflecting downward is formed.
The reflector 15 is attached, the reflector 15 is formed in an annular shape, a concave groove-shaped holder attachment portion 16 is formed along the radial direction, and a reflection surface portion 17 that reflects toward the outer peripheral direction is provided around the reflector 15. Is formed.

Further, a connector 21 is provided on the holder mounting portion 16, and the connector 21 is a discharge lamp lighting device shown in FIG.
It protrudes from a substrate 23 on which the 22 is mounted.

Also, at the symmetrical position of the peripheral portion of the instrument body 11,
A locking body 25 for detachably locking the light-transmitting shade 24 to the appliance main body 11 is attached, and a lever 26 is integrally formed with the locking body 25, and by pulling the lever 26, Sade 24 can be removed.

Further, FL1 and FL2 are fluorescent lamps as annular discharge lamps, and these fluorescent lamps FL1 and FL2 are:
For example, it is a so-called T5 having a tube diameter of about 16 mm at 34 W and 27 W.

Reference numeral 31 denotes a lamp holder. The lamp holder 31 is fitted into the holder mounting portion 16 to form a fluorescent lamp.
A pair of lamp sockets 32, 32 for connecting FL1, FL2 and lamp holders 33, 33 for holding fluorescent lamps FL1, FL2.
Is attached.

Further, a conical reflective cover 34 is mounted on the lamp holder body 31 at the center of the fixture body 11, and a concave reflective surface 35 that reflects toward the outer periphery is provided on the lower surface of the reflective cover 34. Is formed.

In the discharge lamp lighting circuit 22, as shown in FIG. 1, a filter circuit 41 having, for example, an inductor and a capacitor (not shown) is connected to a commercial AC power supply e. The input terminal of a full-wave rectifier 42 as a rectifying means is connected.

The output terminal of the full-wave rectifier 42 includes:
A first field-effect transistor Q1 as a first switching element, a current detection resistor R1 of a protection circuit 43 for protecting the first field-effect transistor Q1, and a shunt winding of an autotransformer Tr1 as an inductive element. Line Tr1a is connected in series.

Further, in parallel with the shunt winding Tr1a of the autotransformer Tr1, a smoothing capacitor C1 as a smoothing first capacitive element having a relatively large smoothing capacity and a parasitic diode are rectified. A second field-effect transistor Q2 as a second switching element having a function as an element, and a protection circuit for protecting the second field-effect transistor Q2
A series circuit of 44 resistors R2 for current detection is connected.

A ripple capacitor C2 as a second capacitive element having a relatively small capacity is connected between the output terminals of the full-wave rectifier 42.

The gate of the second field effect transistor Q2 is grounded via the resistor R3 and the primary winding Tr2a of the transformer Tr2, and the secondary winding Tr2b of the transformer Tr2 is connected to the resistor R4
Is connected between the gate of the first field-effect transistor Q1 and the resistor R1 via the first field-effect transistor Q1.
The second field-effect transistor Q2 is turned on and off alternately. In addition, the first field-effect transistor Q1, the autotransformer Tr1, and the smoothing capacitor
The polarity inversion type chopper circuit 46 is configured by C1.

The protection circuit 43 includes a resistor for preventing malfunction.
A series circuit of a resistor R5 and a capacitor C4 is connected in parallel to R1, a resistor R6 is connected in parallel to a capacitor C4, and a connection point of the resistor R5 and the resistor R6 is connected to a base of a transistor Q3. The collector of Q3 is connected to the gate of the first field-effect transistor Q1 and is connected across the secondary winding Tr2b.

Similarly, in the protection circuit 44, a series circuit of a resistor R7 and a capacitor C5 is connected in parallel with the resistor R2 to prevent malfunction, and a resistor R8 is connected in parallel with the capacitor C5. Connect the transistor Q4 to the connection point of the resistor R8.
The collector of the transistor Q4 is connected to the gate of the second field-effect transistor Q2, and is connected between the primary winding 2a and the capacitor C3.

A load 47 is connected to the autotransformer Tr1.

That is, the shunt winding Tr1a of the autotransformer Tr1
A 34W fluorescent lamp FL1 is connected between the two terminals of the series winding Tr1b through a DC cut capacitor C6 and a primary winding Tr3a of a filament transformer Tr3 also serving as a choke.
One end of the filaments FL1a and FL1b is connected, and the filament FL1a is connected to a preheating winding Tr3b of a filament transformer Tr3.
The preheating winding Tr3c of the filament transformer Tr3 is connected to the filament FL1b. The ratio of the shunt winding Tr1a to the shunt winding Tr1a and the series winding Tr1b is:
1: 1.5 is set.

A DC cut capacitor C7 and a primary winding Tr4a of a filament transformer Tr4 also serving as a choke are provided between the shunt winding Tr1a and the series tap of the series winding Tr1b of the autotransformer Tr1. 27W fluorescent lamp FL2
One end of the filament FL2a, FL2b is connected, and the filament FL2a is connected to the preheating winding Tr4b of the filament transformer Tr4.
The preheating winding Tr4c of the filament transformer Tr4 is connected to the filament FL2b. The ratio between the shunt winding Tr1a and the intermediate taps of the shunt winding Tr1a and the series winding Tr1b is set to 1: 1.4.

Further, the filament FL of the fluorescent lamp FL1
A lamp voltage detecting circuit 48 is connected between one ends of the lamps 1a and FL1b as a lamp voltage detecting means for detecting a lamp voltage, for example, at the end of the life or the like. The lamp voltage detecting circuit 48 is a capacitor between the filaments FL1a and FL1b. A series circuit of C11 and capacitor C12 is connected, diode D1 is connected in parallel to capacitor C12, and diode D2 is connected to the connection point of capacitor C11 and capacitor C12.
Is connected.

Similarly, a lamp voltage detecting circuit 49 is connected between one end of the filaments FL2a and FL2b of the fluorescent lamp FL2 as a lamp voltage detecting means for detecting a lamp voltage, for example, at the end of life. The lamp voltage detection circuit 49 includes a capacitor C1 between the filaments FL2a and FL2b.
3 and a capacitor C14 are connected in series, and a diode D3 is connected in parallel to this capacitor C14.
A diode D4 is connected to a connection point between the capacitors C13 and C14.

Further, a control circuit 51 as a control means is connected between the AC input terminals of the full-wave rectifier 42. The control circuit 51 includes a parallel connection of a resistor R11 and a resistor R12 between the AC input terminals of the full-wave rectifier 42. The circuit and the resistor R13 are connected, and the resistor R1
3 is connected in parallel with capacitor C15, and capacitor C16 and capacitor are connected in parallel with capacitor C15.
A series circuit of C17 is connected, a resistor R14 is connected in parallel with the capacitor C17, a connection point of the capacitors C16 and C17 is connected to a connection point of the capacitor C1 and the second field-effect transistor Q2, and an operational amplifier is connected. Connected to 52 non-inverting input terminals. The reference voltage source E1 is connected to the inverting input terminal of the operational amplifier 52,
A resistor R15 is connected between the inverting input terminal and the output terminal of the operational amplifier 52.
The output terminal of the operational amplifier 52 is connected to an oscillator 53 as a drive circuit. Diodes D2 and D3 are connected to the oscillator 53, and the outputs of the lamp voltage detection circuits 48 and 49 are input to the oscillator 53. Also, the oscillator 53 makes the L level variable with the H level being constant for a fixed time, that is, the primary winding Tr2a of the transformer Tr2 operates with a constant on-width and an off-width variable, and when the voltage is high, the frequency is changed to the primary winding Tr2a. The frequency is controlled by adding the on time and off time of the line Tr2a, and the buffer 54 and the capacitor for DC cut
Via C18, the resistor R3 and the primary winding Tr of the transformer Tr2
It is connected to the connection point 2a.

Next, the operation of the above embodiment will be described with reference to the simplified circuit diagrams shown in FIGS.
This will be described with reference to the waveform diagram shown in FIG.

First, noise of the voltage of the commercial AC power supply e is removed by the filter circuit 41 and full-wave rectification is performed by the full-wave rectifier 42.

Then, the PWM signal output of the oscillator 53 is cut off by the capacitor C18 through the buffer 54, and the second field effect transistor Q2 is turned on and off alternately, thereby turning on and off the second transistor Q2. Accompanying transformer Tr2
As shown in FIG. 11, a voltage opposite to the gate voltage of the second field-effect transistor Q2 is applied to the secondary winding Tr2a, and the first voltage is applied in a state opposite to that of the second field-effect transistor Q2.
Is turned on and off, and the first field-effect transistor Q1 and the second field-effect transistor Q2 are turned on and off alternately.

First, as shown in FIG. 5, when the first field-effect transistor Q1 is turned on, the full-wave rectifier 42, the first field-effect transistor Q1, the resistor R1, the autotransformer Tr1, and the full-wave rectifier 42 A current flows through the path, the autotransformer Tr1 is charged, and enters the state I shown in FIG. 10. When the voltage of the ripple capacitor C2 is equal to or less than the voltage of the commercial AC power supply e, a current flows to the full-wave rectifier 42. . Further, when the first field-effect transistor Q1 is turned on and an inrush current flows through the first field-effect transistor Q1, the voltage of the resistor R1 of the protection circuit 43 rises, and the capacitor C4 is charged to charge the capacitor C4. Supply current to the base. At this time, as the voltage of the resistor R1 becomes higher, the base current of the transistor Q3 is increased, the gate voltage of the first field effect transistor Q1 is further reduced, and the current flowing through the first field effect transistor Q1 is less than a certain value. As a result, the first field effect transistor Q1 is prevented from being destroyed without performing soft processing or the like. That is, an overcurrent flows through the resistor R3, and the voltage of the resistor R3 increases, turning on the transistor Q3. As a result, the gate voltage of the first field effect transistor Q1 as shown in FIG. 12 is not applied, and the gate voltage decreases. . Then, as the gate voltage of the first field-effect transistor Q1 decreases,
This prevents the drain current from lowering and flowing over a set value. Here, the set value of the drain current is I
Assuming that DM is the base and emitter voltage of the transistor Q3 is VBEQ3, IDM = (/ R1) {R4 / (R3 + R4)}. In general, VBEQ3 is about 0.6. The protection circuit 43 is set so as not to operate in the steady state shown in FIG.

Then, as shown in FIG. 6, when the first field-effect transistor Q1 is turned off, the autotransformer Tr1, the smoothing capacitor C1, the resistor R2, the second field-effect transistor
A current flows through the path of the parasitic diode Q2D of Q2 and the autotransformer Tr1, and the smoothing capacitor C1 is charged by the energy stored in the autotransformer Tr1, resulting in the state II shown in FIG.

Next, as shown in FIG. 7, when the second field effect transistor Q2 is turned on, the current direction is reversed to become AC as shown in FIG. 6, and the smoothing capacitor C1, autotransformer Tr1, Current flows through the path of the second field-effect transistor Q2, the resistor R2, and the smoothing capacitor C1, and the autotransformer
A current is supplied to Tr1 to charge the autotransformer Tr1, and the state changes to the state III shown in FIG. Further, when the second field-effect transistor Q2 is turned on and an inrush current flows through the second field-effect transistor Q2, the voltage of the resistor R2 of the protection circuit 44 rises and charges the capacitor C5, thereby turning on the transistor Q4. Supply current to the base. At this time, as the voltage of the resistor R2 becomes higher, the base current of the transistor Q4 is increased, the gate voltage of the second field effect transistor Q2 is further reduced, and the current flowing through the second field effect transistor Q2 is reduced below a certain value. As a result, the second field effect transistor Q2 is prevented from being destroyed without performing soft processing. Also in this case, the protection circuit 44 operates similarly to the protection circuit 43. The protection circuit 44 is set so as not to operate in the steady state shown in FIG.

Then, as shown in FIG. 8, when the second field effect transistor Q2 is turned off, the autotransformer Tr1, the first
A current flows through the path of the parasitic diode Q1D of the field-effect transistor Q1, the ripple capacitor C2, and the autotransformer Tr1, and resonates in the autotransformer Tr1 and the ripple capacitor C2 to generate a high-frequency voltage. Is superimposed on the output of the full-wave rectifier 42, and the voltage from the full-wave rectifier 42 is boosted, and the state becomes IV shown in FIG.

Further, as shown in FIG. 9, the current is inverted to be an alternating current, and the inversion lowers the voltage of the full-wave rectifier 42 to make the voltage after the rectification equal to the voltage before the rectification, thereby reducing the distortion. Then, the power factor improving current flows and the state becomes V shown in FIG.

Then, the voltage is increased to a different voltage by the autotransformer Tr1, and a voltage higher than that of the fluorescent lamp FL2 is applied to the fluorescent lamp FL1 to start and light it.

The lamp voltage detecting circuits 48 and 49 detect the lamp voltages of the fluorescent lamps FL1 and FL2, respectively, and perform frequency control for controlling the off time of the oscillator 53 according to the lamp voltages of the fluorescent lamps FL1 and FL2. Control the gate voltage to the second field effect transistor Q2 with the
Soft start of FL1 and FL2, control of starting and lighting, and output or stop operation of an appropriate voltage when the fluorescent lamps FL1 and FL2 are out of order or end of life.

Further, since the lamp voltage detection circuits 48 and 49 have one ends connected to the negative side, which is the stable potential side of the full-wave rectifier circuit 42, the lamp voltage detection circuits 48 and 49 can be easily used without using an insulating material such as a photocoupler. Can be detected.

By connecting the second field effect transistor Q2 to the negative electrode of the full-wave rectifier 42, the fluorescent lamp
Since it has the same potential as FL1 and FL2, the fluorescent lamps FL1 and FL2 and the control circuit can be used without using a circuit to adjust the voltage.
51 has the same potential, and the lamp voltage detection circuit 4 has a simple configuration.
Feedback control can be performed based on 8, 49.

The fluorescent lamps FL1 and FL2 are connected to full-wave rectifiers.
42, the fluorescent lamps FL1, FL
2 can reduce noise.

Further, the voltage inputted to the full-wave rectifier 42 is detected, and the operational amplifier 52 operates so as to keep the voltage of the capacitor C1 constant. That is, when the voltage value inputted to the full-wave rectifier 42 becomes higher. The voltage input to the non-inverting input terminal of the operational amplifier 52 increases, and the oscillator 53 is controlled to
The voltage applied to the gate of the field-effect transistor Q2 is reduced, the gate voltage of the first transistor Q1 is controlled by the transformer Tr2, and the current flowing through the first field-effect transistor Q1 is set to be substantially equal in potential to the chopper circuit. The output of 46 is kept constant, and the bias of the autotransformer Tr1 is prevented. That is, as shown in FIG. 14, as a comparative example, the first field-effect transistor Q1
When the gate voltage of the second field-effect transistor Q2 is kept constant, the autotransformer Tr1 and the like may be demagnetized. However, as shown in FIG. 13, the current flowing through the first field-effect transistor Q1 is By becoming almost positive and negative,
Prevents the autotransformer Tr1 etc. from becoming magnetized.

The fluorescent lamp is not limited to the combination of 34 W and 27 W, but may be, for example, a combination of 34 W and 20 W. In this case, 20 W is connected to the shunt winding Tr 1 a and the series winding.
What is necessary is just to connect to the connection point with Tr1b.

[0055]

According to the power supply device of the first aspect, the first
A chopper circuit having a switching element, an inductive element, a first capacitive element, and a rectifying element is provided with a second switching element for flowing a current in a direction opposite to a current from the rectifying means to the inductive element. A second capacitive element that superimposes a regenerative current on the rectifier with a small capacity that resonates with the inductive element, so that currents of different polarities alternately flow through the inductive element, so that it also has a function as an inverter, Distortion can be reduced with a simple configuration, and by making the potential of the second switching element and the potential of the load the same, the control of the second switching element can be facilitated. Since the potential of the load can be detected with a simple configuration without using any means, feedback from the load can be easily performed.

According to the power supply device of the second aspect, the chopper circuit having the first switching element, the inductive element, the first capacitive element, and the rectifying element receives the current from the rectifying means in the inductive element. A second switching element for flowing a current in the opposite direction is provided, and a second capacitive element for superimposing the regenerative current on the rectifier with a small capacity that resonates with the inductive element is provided. Since the current flows alternately, it also has a function as an inverter, can achieve low distortion with a simple configuration, and has the same potential as the potential of the second switching element and the potential of the load.
Control of the switching element can be facilitated, and the potential of the load can be detected with a simple configuration without using, for example, insulating means. Therefore, feedback from the load can be easily performed, and the first switching element and Since the second switching element is operated in association with the transformer, the control of the first switching element and the second switching element can be easily performed.

According to the power supply device of the third aspect, in addition to the power supply device of the first or second aspect, since one end of the load is connected to the negative electrode of the rectifier, one end of the load is connected to the negative electrode of the rectifier. The potential becomes the same, and noise from the load can be suppressed.

According to the power supply device of the fourth aspect, in addition to the power supply device of the first to third aspects, a protection circuit for protecting the first switching element when the current flowing through the first switching element increases. Since the first switching element is provided, the first switching element can be protected from an inrush current flowing through the first switching element with a simple configuration without performing, for example, software processing.

According to a fifth aspect of the present invention, there is provided the power supply device according to any one of the first to fourth aspects, further comprising control means for reducing the ON width of the first switching element when the voltage of the AC power supply increases. Since the current can be made almost symmetrical in the positive and negative directions, the inductive one is prevented from being demagnetized.

According to the discharge lamp lighting device of the sixth aspect,
Since the load of the power supply device according to any one of the first to fifth aspects has a discharge lamp, it is possible to cope with the discharge lamp with each effect.

According to the discharge lamp lighting device of the seventh aspect,
The load of the power supply device according to any one of claims 1 to 5 includes a plurality of discharge lamps having different power consumptions, and the inductive element supplies a corresponding power to the plurality of discharge lamps having different power consumptions. It can also handle discharge lamps with different power consumption.

According to the illuminating device of the eighth aspect, since the fixture main body equipped with the discharge lamp lit by the discharge lamp lighting device of the sixth or seventh aspect is provided, each effect can be obtained. .

[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 an exploded perspective view showing an appearance of the lighting device.

FIG. 3 is a cross-sectional view showing the lighting device.

FIG. 4 is a cross-sectional view showing a state where a shade of the lighting device is removed.

FIG. 5 is a circuit diagram showing one operation in which a part of the discharge lamp lighting device is simplified.

6 is a circuit diagram showing a part of the discharge lamp lighting device in the same manner as in FIG. 5 and showing the next operation. FIG.

FIG. 7 is a circuit diagram showing a part of the discharge lamp lighting device in the same manner as in FIG.

FIG. 8 is a circuit diagram showing a part of the discharge lamp lighting device in the same manner as that of FIG.

FIG. 9 is a circuit diagram showing a part of the discharge lamp lighting device in the same manner as FIG.

FIG. 10 is a waveform chart showing an operation of the discharge lamp lighting device.

FIG. 11 is a waveform chart showing an output of the oscillator.

FIG. 12 is a waveform chart showing a state of the first field-effect transistor Q1 in the overcurrent state;

FIG. 13 is a waveform chart showing an operation of the discharge lamp lighting device.

FIG. 14 is a waveform chart showing the operation of the discharge lamp lighting device of the comparative example.

[Explanation of symbols]

11 Instrument body 42 Full-wave rectifier as rectifying means 43 Protection circuit 46 Polarity inverting type chopper circuit 47 Load circuit 51 Control circuit as control means C1 Smoothing capacitor as first capacitive element C2 As second capacitive element Ripple capacitor e Commercial AC power supply FL1, FL2 Fluorescent lamp as discharge lamp Tr1 Autotransformer Tr2 as inductive element Transformer Q1 First field effect transistor Q2 as first switching element Q2 As second switching element Second field effect transistor

Claims (8)

[Claims] Rectifying means for rectifying a voltage of an AC power supply;
A first switching element connected in series to the rectifier and an inductive element to which a load is connected; a first capacitive element having a relatively large capacity connected in parallel to the inductive element; A chopper circuit having a rectifying element; a second side connected in parallel with the rectifying element on the negative side of the rectifying means and flowing a current in a direction opposite to the rectifying element to the inductive element.
And a second capacitive element that resonates with a regenerative current in cooperation with the inductive element. 2. A rectifier for rectifying a voltage of an AC power supply;
A first switching element connected in series to the rectifier and an inductive element to which a load is connected; a first capacitive element having a relatively large capacity connected in parallel to the inductive element; A chopper circuit having a rectifying element; a second side connected in parallel with the rectifying element on the negative side of the rectifying means and flowing a current in a direction opposite to the rectifying element to the inductive element.
A switching element that operates in association with the first switching element and the second switching element; and a second capacitive element that resonates with a regenerative current in cooperation with the inductive element. A power supply device characterized by the above-mentioned. 3. The power supply device according to claim 1, wherein one end of the load is connected to a negative electrode of the rectifier. 4. The power supply device according to claim 1, further comprising a protection circuit that protects the first switching element when a current flowing through the first switching element increases. 5. The power supply device according to claim 1, further comprising control means for reducing the ON width of the first switching element when the voltage of the AC power supply rises. 6. The discharge lamp lighting device according to claim 1, wherein the load of the power supply device includes a discharge lamp. 7. The load of the power supply device according to claim 1, comprising a plurality of discharge lamps having different power consumption, and the inductive element corresponding to each of the plurality of discharge lamps having different power consumption. A discharge lamp lighting device characterized by supplying electric power. 8. A lighting device comprising: the discharge lamp lighting device according to claim 6; and a fixture main body to which a discharge lamp to be lighted by the discharge lamp lighting device is mounted.