JP3402389B2 - Power supply device, discharge lamp lighting device and lighting device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device, a discharge lamp lighting device and a lighting device having an inverter circuit for converting a DC voltage into a high frequency voltage by using a switching device.

[0002]

2. Description of the Related Art Conventionally, various types of power supply devices of this type have been known. Further, recently, for the purpose of suppressing the distortion of the input current while increasing the input power factor, there has been proposed a power supply device including a combination of a step-up chopper and an inverter. As such a power supply device, for example, one having a configuration as shown in FIG. 7 is known. In the circuit shown in the figure, an inverter 4 is connected via a smoothing capacitor C to a chopper circuit 1 having an inductor L1, a switching device S and a diode D1 connected to a power source (not shown). Then, the inductor L1 is provided with the secondary winding L2,
The secondary winding L2 has a capacitor C1, a capacitor C3,
A first auxiliary DC power supply device is configured by connecting the diode D2, the diode D4, and the resistor R2. The chopper control circuit 2 and the inverter control circuit 3 are connected to the first auxiliary DC power supply device, and the inverter control circuit 3 is also connected to the power supply via the starting resistor R1.

On the other hand, the inverter circuit 4 has two half-bridge type switching elements Q1 and Q2, and one switching element Q2 of these switching elements Q1 and Q2 includes a capacitor C4 and a diode D5. A snubber circuit is provided. Power is supplied to the chopper control circuit 2 from the middle of the capacitor C4 and the diode D5 of the snubber circuit via the diode D6 and the capacitor C5. That is, the diode D6 and the capacitor C
Reference numeral 5 constitutes a second auxiliary DC power supply device.

When the power is turned on, the inverter control circuit 3 is activated via the activation resistor R1, and the operation of the inverter circuit 4 causes the snubber circuit and the diode D to be activated.
6, the power is supplied via the capacitor C5 (second auxiliary DC power supply device), the chopper control circuit 2 operates,
The chopper circuit 1 is activated. After that, the chopper control circuit 2 and the inverter control circuit 3 are operated by the output of the secondary winding L2 of the inductor L1 in the chopper circuit 1,
The chopper control circuit 2 and the inverter control circuit 3 are driven.

However, in the case of the conventional example shown in the figure, when the current consumption of the control circuit increases, the snubber circuit is constructed,
At the same time, the capacity of the capacitor C4 which becomes the power source impedance must be increased. However, when the capacitance of the capacitor C4 is increased, the electric charge accumulated in the capacitor C4 when the switching element Q2 of the inverter circuit 4 is off increases, and when the switching element Q2 is on, the current waveform of the switching element Q2 is shown in FIG. As shown in, a steep overcurrent component is generated, which may cause abnormalities in the switching operation.

Further, in the configuration of FIG. 7, since power is supplied from the power source to the inverter control circuit via the starting resistor R1, the output loss due to the starting resistor R1 is large. There is. In order to increase the rise time of the power supply device shown in FIG. 7, it is necessary to reduce the resistance value of the starting resistor R1. In this case, the power loss is further increased.

[0007]

As described above, in the conventional case shown in FIG. 7, when the power source impedance of the control circuit is increased, there is a possibility that the switching operation of the switching element of the inverter circuit may become abnormal. It was There is also a problem that power loss is relatively large.

Therefore, the present invention solves the above-mentioned inconvenience, and can supply the necessary electric power to the control circuit without inducing abnormalities in the switching operation of the switching element of the inverter circuit, and can also reduce the power loss. It is an object of the present invention to provide a power supply device, a discharge lamp lighting device, and a lighting device capable of reducing the above.

[0009]

In order to achieve the above object, the invention according to claim 1 provides a pair of switching devices which are provided in series between output terminals of a DC power supply device and which are alternately turned on and off, A capacitor, a resistor, and a first rectifying element are included in series, the capacitor is on the positive electrode side of the DC power supply device, and the conducting direction of the first rectifying element is opposite to the conducting direction of the switching device. A snubber circuit connected in parallel to one side of the device,
It has a capacitor for smoothing the output of the second rectifier element and the rectifier element, the one of the switching devices
When turned on, the charge of the snubber circuit capacitor
, The one switching device, the first rectifying element
And an auxiliary power supply device to which electric power is supplied by discharging through the resistor .

According to a second aspect of the present invention, there is provided a chopper circuit having an inductor device, a first switching device and an oscillation control device for the first switching device, and a second chopper circuit.
Self-exciting type having a switching device, a starting circuit for starting the second switching device, and a snubber circuit provided in parallel with the second switching device, and feeding back a part of its output to oscillate. Inverter circuit, an output control device capable of controlling the output of the inverter circuit, a load energized by the output of the inverter circuit, and the second switching of the inverter circuit. Device turned on
In this case, the charge of the snubber circuit capacitor is
A second switching device, the first rectifying element and a front
A first auxiliary power supply device having a relatively small capacity for extracting power from the snubber circuit to supply power to at least the oscillation control device by discharging via the resistor, and extracting power from the inductor device for oscillation control. And a second auxiliary power supply device having a relatively large capacity for supplying power to the device and the output control device.

A discharge lamp lighting device according to a third aspect of the present invention is characterized in that a discharge lamp lighting means for lighting the discharge lamp is connected to the power supply device according to the first or second aspect.

Furthermore, the lighting device of the present invention is characterized in that the discharge lamp lighting device is built in the fixture body to light the discharge lamp.

[0013]

According to the first aspect of the invention, since the series circuit constituting the snubber circuit has the resistor interposed therein, it is possible to suppress a steep overcurrent component when the capacitor is discharged. The capacity can be increased, and thus the power source impedance of the auxiliary DC power supply device can be reduced.

According to the second aspect of the present invention, neither the oscillation control device of the chopper circuit nor the output control device of the inverter circuit requires the starting resistor as shown in FIG. When the power is turned on, the second switching device of the inverter circuit is started by the starting circuit, and then self-oscillated by its own output. As a result, a voltage is generated in the snubber circuit, and the first auxiliary power supply device supplies power to the oscillation control device of the chopper circuit according to this voltage. When the oscillation control device of the chopper circuit operates, the chopper circuit starts to generate a predetermined output, and a predetermined voltage is also generated in the inductor. From this point onward, the oscillation control device and the oscillation control device Supply power to the output controller.

The invention according to claim 3 is the above 1 or 2
The discharge lamp is turned on by the power supply device according to the invention.

According to a fourth aspect of the invention, there is provided a lighting fixture in which the discharge lamp is lighted by the discharge lamp lighting device according to the third aspect of the invention.

[0017]

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

In FIG. 2, reference numeral 11 denotes a main body of the appliance, a reflective surface is formed on the lower surface of the main body 11 of the appliance, and lamp sockets 12, 12 are attached to both ends of the reflective surface. Is connected to a discharge lamp FL. Moreover, the circuit shown in FIG. 1 is built in the instrument main body 11.

As shown in FIG. 1, a full-wave rectifier 21 is connected to a commercial AC power source E, and a full-wave rectifier 21 is connected to a step-up chopper circuit 22 for improving power factor and preventing harmonics. The boost chopper circuit 22 includes an inductor L1.
1. A field effect transistor as a switching device Q11 and a diode D11.

The output terminal of the boost chopper circuit 22 is connected to an inverter circuit 23 for high frequency conversion via a smoothing capacitor C11.

The inverter circuit 23 is mainly composed of transistors as switching devices Q12 and Q13 provided in a half-bridge type, and a current transformer of a saturable type is provided between the base and the emitter of the switching device Q12. The control winding Tr1b of Tr1 is connected, the control winding Tr1c of the current transformer Tr1 is connected between the base and the emitter of the switching device Q13, and the full-wave rectifier is connected between the emitter of the switching device Q12 and the collector of the switching device Q13. The input winding Tr1a of the current transformer Tr1 is connected between the negative electrode of 21 and the negative electrode.

Further, the inverter circuit 23 has a DC cut capacitor C12 and a choke coil L12.
The filaments of the discharge lamp FL are connected to each other via a capacitor, and a starting capacitor C13 is connected between the non-power source side terminals of these filaments.

An output winding L13 is magnetically coupled to the inductor L11 of the step-up chopper circuit 22, one end of the output winding L13 is connected to the negative electrode of the full-wave rectifier 21, and the other end is a diode D12 and a capacitor. It is connected to the negative electrode via C14. An oscillation control device 24 that controls the switching device Q11 of the boost chopper circuit 22 is connected to the connection point of the diode D12 and the capacitor C14.

On the other hand, the switching device Q13 includes a capacitor C15, a current limiting resistor R12 and a first rectifying element D.
A snubber circuit consisting of a diode as 15 is connected as shown. This snubber circuit capacitor C15
A diode serving as a second rectifying element D13 is connected to the middle point between the resistor R12 and the resistor R12, and a capacitor C17 that smoothes the output of the second rectifying element D13 is provided. The second rectifying element D13 and the capacitor C
Reference numeral 17 forms an auxiliary power supply device. The output of the auxiliary DC power supply device is supplied to the output control circuit 25 which controls the output of the inverter 23. In the present embodiment, the output control device 25 controls the current transformer Tr1 and changes the saturation time of the current transformer Tr1 and the switching frequencies of the switching devices Q12 and Q13 to change the output.

Further, the output of this auxiliary DC power supply device is
It is adapted to be supplied to the oscillation control device 24 of the chopper via the resistor R11 and the diode D15.

Although not shown in FIG. 1, a starting resistor as shown in FIG. 7 or a known inverter 23 starting circuit is appropriately provided.

Next, the operation of the embodiment of the circuit shown in FIG. 1 will be described. First, the voltage of the commercial AC power source E is full-wave rectified by the full-wave rectifier 21, and the boost chopper circuit 22
Since the switching device Q11 is not operating, the boosting operation is not performed, and the starting resistor or the well-known inverter 2 is used.
The inverter 23 operates first by the 3 starter circuit. When the inverter 23 operates, the auxiliary DC power supply device is charged via the capacitor C15 of the snubber circuit, supplies power to the output control device 25, and simultaneously oscillates the control device 2.
Power is also supplied to 4. As a result, the oscillation control device 24
Activates the boost chopper circuit 22. Then, when the step-up chopper circuit 22 starts to operate, the output winding L13 provided in the inductor L11 of the step-up chopper circuit 22.
The output supplies power to the oscillation control device 24.

After that, the booster chopper circuit 22 improves the power factor and suppresses the higher harmonics to boost the power, and the inverter 23 converts the booster to a high frequency to turn on the discharge lamp FL at a high frequency.

Here, the operation of the snubber circuit and the auxiliary DC power supply device constituting the power supplies of the output control device 25 and the oscillation control device 24 will be described. As shown in FIG. 3, the switching devices Q12 and Q13 of the inverter 23 are alternately arranged. When switching is performed and the switching device Q12 is turned on and the switching device Q13 is turned off as shown in FIG. 7A, the capacitor C15 and the capacitor C17 are charged via the second rectifying element D13.
Electric power is supplied to each control device 25, 24. Further, as shown in FIG. 7B, when the switching device Q12 of the inverter 23 is turned off and the switching device Q13 is turned on, the electric charge of the capacitor C15 is changed to the switching device Q13.
13, the first rectifier D15 and the current limiting resistor R12 are discharged in a closed loop, so that the current limiting resistor R12 suppresses the generation of a steep overcurrent component when the capacitor C15 discharges.

Therefore, the capacitance of the capacitor C15 can be increased without causing abnormal operation of the switching element of the inverter, and the power source impedance of the auxiliary DC power supply device can be lowered.

Further, as shown in FIG. 1, the inverter 2
If 3 is always operated first, the voltage of the boost chopper circuit 22 will not increase more than necessary due to a light load,
There is an advantage that reliability is improved.

In the present embodiment, the power of the auxiliary DC power supply device is mainly supplied to the output control device of the inverter, but in addition to this, the power is mainly supplied to the oscillation control device of the chopper, and both are mainly supplied. Or may be supplied to other things. Further, in the present invention, the combination with the chopper is not essential.

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

In the circuit shown in the figure, in the circuit shown in FIG. 1, the output winding of the inductor L11 is eliminated, and the oscillation control device 24 is operated by the output of the auxiliary DC power supply device even after the step-up chopper 22 is started. It is a thing.

Therefore, in the case of the circuit shown in FIG.
Since the inverter 23 always operates first, the voltage of the boost chopper 22 does not increase more than necessary due to a light load, and there is an advantage that the reliability is improved.

Another embodiment will be described with reference to FIG. The same or corresponding parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. The inverter 30 in this embodiment is of a self-excited type that mainly oscillates by feeding back a part of its output, and has a current transformer Tr1 as in the case of FIG. It also has a starting circuit 31. This starting circuit 3
Reference numeral 1 is composed of a time constant circuit CR, a trigger element T, etc., and is known per se. Since the current of the starting circuit 31 may be smaller than that of the starting resistor of FIG. 7, the power loss by the starting circuit 31 is small. Further, as in the case of FIG. 1 or 6, a snubber circuit is provided in parallel with the transistor as the second switching device Q13, and the first auxiliary power supply device 32 for extracting electric power from this snubber circuit is provided. The first auxiliary power supply device 32 supplies electric power to the oscillation control device 24 of the chopper 22. The first auxiliary power supply device 32 constitutes a power supply device having a relatively small capacity in relation to a second auxiliary power supply device 33 described later.

The inductor L11 of the chopper 22 is provided with an output winding L13 as in the case of FIG. 1, and the output of this output winding L13 is rectified and smoothed to produce a second auxiliary power supply 33.
Are configured. Then, the second auxiliary power supply device 33
Has a capacity relatively larger than that of the first auxiliary power supply device 32, and supplies power to the oscillation control device 24 and the output control device 25. In this embodiment, the first auxiliary power supply device 32 and the second auxiliary power supply device 33 share the smoothing capacitor C18.

The operation of this embodiment will be described with reference to FIG. By turning on the power source E at t1 (FIG. 6 (a)), the switching device Q13 of the inverter 30 is started by the starting circuit 31, and then self-oscillated by its own output (FIG. 6 (c)). . As a result, a voltage is generated in the snubber circuit, and the voltage of the first auxiliary power supply device 32 (voltage of C18)
Reaches the operating voltage Vc of the oscillation control device 24 of the chopper 22 (Fig. 6 (d)), the oscillation control device 24 operates and the chopper 22 starts to generate a predetermined output (Fig. 6 (d)).
(b)) Since a predetermined voltage is generated in the inductor L11, thereafter, power is mainly supplied from the second auxiliary power supply device 33 to the oscillation control device 24 and the output control device 25. Further, as a result, the output control device 25 is also supplied with the operable voltage.

As described above, according to the first aspect of the invention, since the snubber circuit for supplying power to the auxiliary DC power supply device has the resistor interposed therein, the steepness when the capacitor discharges Since such an overcurrent component can be suppressed, the capacitance of the capacitor can be increased, and thus the power source impedance of the auxiliary DC power supply device can be reduced.

According to the second aspect of the invention, it is possible to eliminate the need for the start-up resistor and therefore reduce the power loss.

The invention according to claim 3 is the above 1 or 2
By lighting the discharge lamp with the power supply device of the described invention, it is possible to provide a discharge lamp lighting device that achieves the above effects.

The invention according to claim 4 can provide a lighting fixture in which a discharge lamp is lit by the discharge lamp lighting device according to the invention described in claim 3.

[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 outer appearance of the above lighting device.

FIG. 3 is an explanatory diagram showing a circuit operation in the embodiment.

FIG. 4 is a circuit diagram showing another embodiment of the discharge lamp lighting device of the present invention.

FIG. 5 is a circuit diagram showing still another embodiment of the discharge lamp lighting device of the present invention.

FIG. 6 is a diagram for explaining the operation of the embodiment shown in FIG.

FIG. 7 is a circuit diagram showing a conventional discharge lamp lighting device.

8 is a waveform diagram of the circuit shown in FIG.

[Explanation of symbols]

22 ... Step-up chopper, 23 ... Inverter, 24 ... Oscillation control device, 25 ... Output control device, 31 ... Starting circuit, 32 ... First auxiliary DC power supply device, 33 ... Second auxiliary DC power supply device, FL ... Discharge lamp , C15 ... Capacitor, D15 ... Diode, R11 ... Resistor.

Continuation of front page (56) Reference JP-A-4-337294 (JP, A) JP-A-2-179267 (JP, A) JP-A-5-56658 (JP, A) JP-A-5-56662 (JP , A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02M 7/48 H02M 7/538 H05B 41/00 H05B 41/24 H05B 41/282

Claims (4)

(57) [Claims] 1. A pair of switching devices which are provided in series between output terminals of a DC power supply device and which are alternately turned on and off; and a capacitor, a resistor and a first rectifying element, which are connected in series,
A snubber circuit connected in parallel to one of the switching devices, with the capacitor on the positive electrode side of the DC power supply device and the conduction direction of the first rectifying element being opposite to the conduction direction of the switching device; it has a capacitor for smoothing the output of the rectifying element and the rectifier element, the one of the switching devices
When turned on, the charge of the snubber circuit capacitor
, The one switching device, the first rectifying element
And an auxiliary power supply device to which electric power is supplied by discharging through the resistor . 2. A chopper circuit having an inductor device, a first switching device and an oscillation control device for the first switching device; a second switching device, a starting circuit for starting the second switching device, and the first switching device. A self-exciting inverter circuit which has a snubber circuit provided in parallel with two switching devices and which oscillates by feeding back a part of its output; and the output of this inverter circuit can be controlled. An output control device; a load energized by the output of the inverter circuit; and a second switching device of the inverter circuit
If it is turned on, the charge of the snubber circuit capacitor
, The second switching device, the first rectifying element
And a relatively small-capacity first auxiliary power supply device that extracts electric power from the snubber circuit by discharging through the resistor and supplies electric power to at least the oscillation control device; And a second auxiliary power supply device having a relatively large capacity for extracting electric power and supplying the electric power to the oscillation control device and the output control device. 3. A discharge lamp lighting device comprising a discharge lamp lighting means for lighting a discharge lamp connected to the power supply device according to claim 1. 4. A lighting device, characterized in that the discharge lamp lighting device according to claim 3 is built in a fixture body to light the discharge lamp.