JPH07147776A - Power unit, discharge lamp lighting device, and illuminator - Google Patents

Abstract

PURPOSE:To reduce the switching loss and improve the waveform of an input current by controlling a switching device with the specified frequency to perform zero-voltage switching, and also, changing its on-duty so as to adjust the output of a high frequency generating circuit. CONSTITUTION:For an inverter circuit 23, an input winding Tr11 as the resonance inductor of an inverter transformer Tr11 and a switching element Q11 are connected in series, and a capacitor C14 for resonance is connected in parallel to the switching element Q11. And controller 24 controls a main switching element Q11 with the specified frequency so that it may perform substantially zero-voltage switching operation, while changing the on duty. Hereby, even when a user has changed the inverter circuit 23, the switching loss can be reduced.

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 in which harmonics of an input current are reduced.

[0002]

2. Description of the Related Art Conventionally, several circuit systems have been proposed as a power supply device or a discharge lamp lighting device of this type. FIG. 8 shows one of them, and this discharge lamp lighting device has a full-wave rectifier 1 connected to a commercial AC power source E and a capacitor C1 connected between output terminals of the full-wave rectifier 1. Diode D1 in parallel with capacitor C1
And a series circuit of the capacitor C2 is connected.

A smoothing circuit 2 for filling valleys in the voltage waveform is connected to the capacitor C2. The smoothing circuit 2 includes a series circuit of a capacitor C3, an inductor L1 and a diode D2, and an inductor L1 and a diode D2. It is constituted by a diode D3 connected to the connection extension of the.

Further, the smoothing circuit 2 is connected with a one-stone inverter circuit 3. In this inverter circuit 3, an input winding Tr1a of an inverter transformer Tr1 and a transistor Q1 are connected in series, and a resonance capacitor C4 is connected to the input winding Tr1a.

The output winding Tr1b of the inverter transformer Tr1 has a filament FLa of the fluorescent lamp FL,
FLb is connected to these filaments FLa, FLb
A capacitor C5 for starting and preheating is connected to.

Then, the voltage of the commercial AC power source E is full-wave rectified by the full-wave rectifier 1 to obtain capacitors C1 and C2.
Further, the smoothing circuit 2 smoothes it, and the inverter circuit 3 converts it into a high-frequency alternating current to turn on the fluorescent lamp FL.

Further, in order to improve the crest factor, that is, the peak value / effective value of the lamp current of the fluorescent lamp FL, the capacity of the capacitor C2 is made small so that the input winding T
The capacitor C2 is boosted during the regeneration of r1a.

[0008]

However, in the above-mentioned conventional technique, when the capacitance of the capacitor C2 is reduced, the regenerative current of the input winding Tr1a becomes difficult to flow, and a part of the regenerative current flows into the resonant capacitor C4. As a result, it becomes difficult for the transistor Q1 to perform zero voltage switching, which causes a problem that switching loss occurs.

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 that reduce switching loss and improve the input current waveform. .

[0010]

A power supply device according to claim 1 is
A rectifying unit that rectifies an AC power supply voltage, a first power storage unit that is provided at an output end of the rectification unit, and a switching device that switches an input DC voltage. A high-frequency generation circuit that is provided on the output side and generates a voltage with a frequency higher than that of the AC power supply,
The second energy storage means arranged to store electricity during the ON period of the switching device, and the electric energy stored in the second energy storage means during the OFF period of the switching device during the period in which the output voltage of the rectifying means decreases. A booster circuit that supplies the first power storage means, an output circuit that outputs the electrical energy of the first power storage means to the high frequency generation circuit during a period in which the output voltage of the rectification means is lower than the voltage of the second power storage means, The switching device controls the switching device at a predetermined frequency at which substantially zero voltage switching is performed, and also includes a control device that can change the on-duty and adjust the output of the high frequency generation circuit. .

According to another aspect of the power supply device of the present invention, the rectifying means for rectifying the AC power supply voltage, the first storage means provided at the output end of the rectifying means, and the output side of the rectifying means and the first storage means. One stone that has a main switching element that is provided and switches the input DC voltage, and resonates the inductor connected in series with this main switching element and the capacitor connected in parallel with the main switching element to generate a high-frequency voltage. Type inverter circuit, an auxiliary switching element connected in series to the inductor, and a second switching element arranged to store electricity during the ON period of the main switching element.
And a booster circuit for supplying the electric energy stored in the second power storage means to the first power storage means during the off period of the main switching element in the period in which the output voltage of the rectification means is reduced, and the output of the rectification means. An output circuit for outputting the electric energy of the first power storage unit to the inverter circuit during a period in which the voltage is lower than the voltage of the second power storage unit.

According to a third aspect of the present invention, in the second aspect, the auxiliary switching element is closed only when a resonance current flows from the inductor to the capacitor. A discharge lamp lighting device according to a fourth aspect includes the power supply device according to any one of the first to third aspects and a discharge lamp that is energized by a high frequency output of the power supply device. An illumination device according to a fifth aspect includes the discharge lamp lighting device according to the fourth aspect, and an illumination device main body provided with the discharge lamp lighting device.

[0013]

According to the invention of claim 1, in a section where the voltage of the rectifying means is higher than the voltage of the first storage means, the input current is mainly supplied from the rectifying means to the high frequency generating circuit, and the high frequency generating circuit operates to generate the high frequency. Generate output. Further, in the section where the voltage of the rectifying means is lower than the voltage of the first power storage means, the second power storage means, which has been charged when the switching device of the high-frequency generation circuit is on, receives the first electric energy via the booster circuit. 1 is supplied to the power storage means
The power storage means serves as a power source to supply an input current to the high frequency generation circuit. Thus, even when the voltage of the rectifying means is low, the current is supplied from the power supply side to the high-frequency generation circuit without interruption, so that the current flowing from the AC power supply has a continuous waveform and the harmonics are significantly reduced. . Further, since the control means controls the switching device at a predetermined frequency at which the switching device performs substantially zero voltage switching, the switching loss can be reduced even when the output of the high frequency generation circuit is changed.

According to the second and third aspects of the present invention, since the auxiliary switching element is further provided, the resonance voltage applied to the main switching element can be reduced, and the switching loss of the main switching element can be further reduced.

The invention of claim 4 is a discharge lamp lighting device, but it has the same operation as the invention of claims 1 to 3, and while the discharge lamp is lit well, it does not generate harmonics to the power supply.

The invention of claim 5 is an illuminating device, but has the same operation as the invention of claims 1 to 4.

[0017]

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. 1, 11 is a main body of the luminaire, a reflecting surface is formed on the lower surface of the main body of the luminaire, and lamp sockets 12, 12 are attached to both ends of the reflecting surface.
A fluorescent lamp FL as a discharge lamp is connected between the lamp sockets 12, 12. Further, the discharge lamp lighting circuit shown in FIG. 2 is arranged in the lighting fixture main body 11.

That is, as shown in FIG. 2, a full-wave rectifying circuit 21 which is a rectifying means is connected to the commercial AC power source E, and a capacitor C11 is connected to the output terminal of the full-wave rectifying circuit 21. In parallel with C11, a series circuit of a diode D11 as a rectifying element and a capacitor C12 forming the first storage means is connected.
Further, the booster circuit 22 is connected in parallel with the capacitor C12 forming the first power storage means. The booster circuit 22 includes a capacitor C1 which constitutes a second storage means.
3, an inductor L11 and a diode D12 are connected in series, and a diode D13 is provided at the midpoint of connection between the inductor L11 and the diode D12.
Are connected.

Further, between the output terminals of the full-wave rectification circuit 21,
An inverter circuit 23, which is a high frequency generation circuit, is connected. This inverter circuit is an inverter transformer Tr
An input winding Tr11a as a resonance inductor of 11 and a switching device (main switching element) Q11 composed of, for example, a field effect transistor are connected in series, and a resonance capacitor C14 is connected in parallel to the main switching element Q11. ing. The main switching element Q11 is controlled by the controller 24, which controls the main switching element Q11 to perform substantially zero voltage switching operation, for example, 45.
The on-duty is changed and controlled at a predetermined operating frequency of KHz.

The filament F of the fluorescent lamp FL is connected to the output winding Tr11b of the inverter transformer Tr11.
La, FLb are connected, and these filaments FLa, FLa,
A starting capacitor C15 is connected between FLb.

Next, the operation of the above embodiment will be described.

When the commercial AC power supply is turned on and the charging voltage of the capacitor C13 is lower than the output voltage of the rectifier circuit 21, that is, the terminal voltage of the capacitor C11, when the high frequency inverter circuit 23 performs the oscillating operation, the oscillation is turned on. The high frequency inverter circuit 23 mainly includes a capacitor C.
An input current is supplied from 11, and the AC power supply E supplies energy to the capacitor C11. At the same time, the capacitor C13 is charged and stores a DC voltage lower than the peak value of the pulsating voltage from the rectifier circuit 21. Capacitor C
When the voltage of 11 becomes lower than the voltage of the capacitor C13,
When the oscillation is turned on, the high frequency inverter circuit 23 is first supplied with an input current from the capacitor C12,
When the voltage of 12 becomes equal to the voltage of the capacitor C11,
This time, the input current is supplied from the capacitor C11. The input current from the capacitor C13 to the high frequency inverter circuit 23 is delayed due to the inductance of the inductor L11 and is performed immediately before the oscillation of the high frequency inverter circuit 23 is turned off. When the oscillation is turned off, the capacitor C13
Serves as a voltage supply source for the inductor L11 and the capacitor C12. Then, the capacitor C12 is charged by the boosting action accompanied by the resonant vibration.

When the input current is supplied to the inverter circuit 23 as described above, a high frequency alternating current is induced in the output winding Tr11b of the inverter transformer Tr11 and the fluorescent lamp F
L is lit at high frequency.

When the fluorescent lamp FL is dimmed, the controller 24 controls the main switching element Q11 to perform substantially zero voltage switching operation, for example, 4
The on-duty is changed while maintaining a predetermined operating frequency of 5 KHz. That is, when reducing the output of the fluorescent lamp FL, the on-duty is reduced to reduce the output of the inverter circuit 23.

As described above, even when the voltage of the rectifying means is low, the current is supplied from the power supply side to the inverter circuit without interruption, so that the current flowing from the AC power supply has a continuous waveform and the harmonics are significantly large. Is reduced to. Also,
Since the control device controls the switching element at a predetermined frequency at which the switching element performs substantially zero voltage switching, the switching loss can be reduced even when the output of the inverter circuit is changed.

Next, a discharge lamp lighting device of another embodiment is shown in FIG.
Will be explained.

The discharge lamp lighting device shown in the same figure is different from the discharge lamp lighting device shown in FIG. 1 in that a freewheeling diode D15 is connected in parallel to the main switching element Q11 and the input winding Tr11a and the main switching element are connected. Q
An auxiliary switching element Q12 is connected between 11 and 11. Further, a freewheeling diode D16 is connected in parallel to the auxiliary switching element Q12.
Regarding the free wheeling diodes D15 and D16, when a field effect transistor is applied to the corresponding main switching element Q11 or auxiliary switching element Q12, the parasitic diode component of the transistor may be used. It is not necessary to connect D16 in parallel.

When the main switching element Q11 is closed, the auxiliary switching element Q12 is closed at the same time, and the auxiliary switching element Q12 is kept closed even after the main switching element Q11 is turned on. If the auxiliary switching element Q12 is configured to open when the current flows from the line Tr11a to the resonance capacitor C14, it is possible to prevent the current from flowing from the input winding Tr11a to the resonance capacitor C14. That is, when the current flowing from the resonance capacitor C14 to the input winding Tr11a is reversed, the auxiliary switching element Q12 is turned off, and the current from the input winding Tr11a to the resonance capacitor C14 is turned off,
It is possible to prevent the resonance capacitor C14 from being charged,
Therefore, the voltage across the main switching element can be reduced, and the switching loss can be further improved.
Further, since the current flowing through the fluorescent lamp FL has a positive / negative asymmetrical waveform, there is an advantage that striation and an acoustic resonance phenomenon can be improved. Further, another embodiment of the discharge lamp lighting device will be described with reference to FIG.

In this discharge lamp lighting device, the field effect transistor Q21 is used as the main switching element and the thyristor Q22 is used as the auxiliary switching element.

The control device also has a high frequency oscillator 31, which is connected to the primary winding Tr12a of the transformer Tr12 via a capacitor C21.
One end of the primary winding Tr12a is connected to the gate of the field effect transistor Q21 via the resistor R11, and the other end is connected to the source.

Further, the secondary winding Tr of the transformer Tr12
12b is a capacitor C22, a resistor R12 and a resistor R1.
3 is connected between the gate and cathode of the thyristor Q22.

Then, the high frequency generator 31 oscillates at a high frequency to drive the field effect transistor Q21. Further, as shown in FIG. 5, when the voltage shown in FIG. 5A is applied between the gate and the source of the field effect transistor Q21, the voltage shown in FIG. 5A is applied between the drain and the source. , The current shown in FIG. This voltage is detected by the primary winding Tr12a of the transformer Tr12, a voltage is induced in the secondary winding Tr12b, a voltage is applied to the gate of the thyristor Q22, and the thyristor Q22 is turned on.
Then, as shown in FIG. 7C, the resonance capacitor C1
4, a resonance current flows, and the input winding Tr11a has a current as shown in FIG. Since the field effect transistor Q21 does not have a self-holding function,
A voltage as shown in FIG. 5A is shown corresponding to the voltage shown in FIG. 5E. However, since the thyristor Q22 has a self-holding function, after the field effect transistor Q21 is turned off, the input winding Tr11a is connected to the resonance capacitor. The on state is maintained until the current flowing toward C14 becomes equal to or lower than the holding current.

A discharge lamp lighting device of another embodiment is shown in FIG.
Will be described with reference to.

In the discharge lamp lighting device shown in FIG. 1, a freewheeling diode D15 is connected in parallel to the main switching element Q11, and in parallel with the main switching element Q11, in series with the resonance capacitor C14. , The auxiliary switching element Q12 is connected. Further, a freewheeling diode D16 is connected in parallel to the auxiliary switching element Q12. In addition,
Similar to the above-mentioned embodiment, the free wheeling diodes D15, D16
With regard to the above, when a field effect transistor is applied to the corresponding main switching element Q11 or auxiliary switching element Q12, the parasitic diode component of the transistor may be utilized, and the freewheeling diodes D15 and D1
It is not necessary to connect 6 in parallel.

Then, as shown in FIG. 7, after the main switching element Q11 is closed in a pulse manner as shown in FIG. 7A, the auxiliary switching element Q12 is pulsed as shown in FIG. , The auxiliary switching element Q12 is opened, and after a while, the main switching element Q12 is closed.
Turn on 11 again. That is, the auxiliary switching element Q12 may be turned on only during the period when the resonance current flows from the input winding Tr11a to the resonance capacitor C14. Therefore, from the input winding Tr11a to the resonance capacitor C1.
When the current flowing in 4 is reversed, the auxiliary switching element Q12 is turned off and the input winding

From the line Tr11a to the resonance capacitor C14
Since the auxiliary switching element Q12 turns off the current flowing to the resonance capacitor C14 and the input winding Tr11.
It is possible to further improve the switching loss of the main switching element without breaking the resonance waveform due to a. Further, since the current flowing through the fluorescent lamp FL has a positive / negative asymmetrical waveform, there is an advantage that striation and an acoustic resonance phenomenon can be improved.

The present invention has the following effects because it has the structure and operation described in detail above.

According to the first aspect of the present invention, even when the voltage of the rectifying means is low, the current is supplied from the power supply side to the high-frequency generation circuit without interruption, so that the current flowing from the AC power supply has a continuous waveform, and the harmonic The waves are greatly reduced.
Further, since the control means controls the switching device at a predetermined frequency at which the switching device performs substantially zero voltage switching, the switching loss can be reduced even when the output of the high frequency generation circuit is changed.

In the inventions of claims 2 and 3, since the auxiliary switching element is further provided, the resonance voltage applied to the main switching element can be reduced, and the switching loss of the main switching element can be further reduced.

The invention of claim 4 is a discharge lamp lighting device, but it has the same effect as the invention of claims 1 to 3, and while the discharge lamp is satisfactorily lit, it does not generate harmonics to the power supply.

The invention of claim 5 is an illuminating device, but has the same effect as the invention of claims 1 to 4.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of an embodiment of a lighting device of the present invention.

FIG. 2 is a circuit diagram showing an embodiment of a discharge lamp lighting device of the present invention.

FIG. 3 is a circuit diagram showing another embodiment of the discharge lamp lighting device of the present invention.

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

FIG. 5 is a waveform diagram showing the operation of the discharge lamp lighting device. (A) Drain and source voltage of field effect transistor Q21 (b) Drain current of field effect transistor Q21 (c) Output current of resonance capacitor C14 (d) Output current of input winding Tr11a (e) Field effect transistor Q21 Gate, source voltage

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

FIG. 7 is a waveform diagram showing the operation of the discharge lamp lighting device. (A) Switching operation of main switching element Q11 (b) Switching operation of auxiliary switching element Q12

FIG. 8 is a circuit diagram showing a conventional discharge lamp lighting device.

[Explanation of symbols]

 11 Lighting Equipment Main Body 21 Rectifier Means 22 Booster Circuit 23 High Frequency Generation Circuit (Inverter Circuit) 24 Control Device C12 First Electric Storage Means C13 Second Electric Storage Means C14 Resonance Capacitor FL Fluorescent Lamp Q11 Main Switching Element Q12 Auxiliary Switching Element Tr11a Resonance Inductor

Claims (5)

[Claims] 1. A rectifying means for rectifying an AC power supply voltage; a first storage means provided at an output end of the rectifying means; and a switching device for switching an input DC voltage. A high-frequency generation circuit that is provided on the output side of the first power storage unit and that generates a voltage of a frequency higher than that of the AC power supply; a second power storage unit that is arranged to store power during the ON period of the switching device; A booster circuit for supplying the electric energy stored in the second power storage means to the first power storage means during the off period of the switching device in the period in which the output voltage of the means has decreased; and the output voltage of the rectification means being the second power storage means. An output circuit for outputting the electric energy of the first power storage means to the high-frequency generation circuit during a period when the voltage is lower than the voltage; Controls the switching device in the wave number, the control unit and by changing the on-duty allowing adjust the output of the high frequency generation circuit; power supply device characterized by comprising a. 2. Rectification means for rectifying an AC power supply voltage; first storage means provided at an output end of the rectification means; and rectification means and an output side of the first storage means for input. A one-stone inverter circuit that has a main switching element for switching a DC voltage, and resonates an inductor connected in series with the main switching element and a capacitor connected in parallel with the main switching element to generate a high frequency voltage; An auxiliary switching element connected in series with the inductor; a second power storage means arranged to store power during the ON period of the main switching element; a main switching element during a period in which the output voltage of the rectifying means has dropped A booster circuit that supplies the electric energy stored in the second power storage means to the first power storage means during the off period of An output circuit that outputs the electric energy of the first power storage unit to the inverter circuit during a period when the voltage of the second power storage unit is lower than the voltage of the second power storage unit; 3. The power supply device according to claim 2, wherein the auxiliary switching element is closed only when a resonance current flows from the inductor to the capacitor. 4. A discharge lamp lighting device comprising: the power supply device according to claim 1; and a discharge lamp that is energized by a high frequency output of the power supply device. 5. A lighting device comprising: the discharge lamp lighting device according to claim 4; and a lighting device main body provided with the discharge lamp lighting device.