JP3486879B2 - 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 that improves the input power factor from an AC power supply and reduces the distortion of the input current.
The present invention relates to a discharge lamp lighting device and a lighting device.

[0002]

2. Description of the Related Art The applicant of the present application has previously proposed the following technical means as an apparatus of this type in Japanese Patent Application No. 6-178925. Hereinafter, the discharge lamp lighting device among the technical means will be described with reference to FIG. 7.

First, the structure will be described. Commercial AC power supply 21
A filter circuit including a choke coil 212 and a capacitor 213 is connected to 1, and a rectifying device 214 is connected to the filter circuit. The rectifying device 214 is
For example, it is formed from a diode having a high-speed switching property. A first switching device 215 and a second switching device 216 are connected in series between the output terminals of the rectifying device 214. These switching devices 215 and 216 are composed of, for example, field effect transistors, and each of the parasitic diodes is used as a diode for conducting a reverse current.

The first switching device 215 is also used.
The primary winding 217-1 of the leakage type insulation transformer as the inductor 217 and the first capacitor 218 are connected so as to have a parallel relationship with the. The first capacitor 218 has a smoothing effect on the output frequency of the rectifying device 214.

Secondary winding 217-of the inductor 217
A fluorescent lamp 219 is connected to 2. A condenser 220 for preheating the filament is connected between the filaments of the fluorescent lamp 219. The leakage inductance of the inductor 217 also acts as a current limiting impedance of the fluorescent lamp 219.

Also, the second switching device 216
For, a second capacitor 221 is connected in parallel via an inductor 217. The capacitance of the second capacitor 221 is extremely smaller than the capacitance of the first capacitor 218, and is selected as a value that resonates at the switching frequency of the switching devices 215 and 216 together with the inductance of the inductor 217.

In the figure, reference numeral 222 is a control device for controlling ON / OFF of the switching devices 215 and 216.
The control device 222 includes switching devices 215, 21.
6 is turned on and off at a frequency higher than the output frequency of the rectifier 214 which is substantially constant. In addition, the AC power source 211
The ON period of the second switching device 216 can be changed according to the magnitude of the peak value of the output voltage (output voltage of the rectifying device 214) of FIG.

That is, the ON period is made small when the peak value of the output voltage of the rectifying device 214 is large, and the ON period is made large when the peak value is small. Therefore, the ON period of the first switching device 215 changes to the opposite relationship. Specifically, a detection unit 222-1 that detects the output voltage of the rectifier 214 and an oscillation unit 222-2 that changes the ON period according to the detection voltage of the detection unit 222-1 are provided. The oscillation means 222
-2 is provided with a PWM (pulse width adjustment) control function and a switching device driving function, for example.

As the device having the PWM control function, for example, an IC can be used and the IC can be mainly configured. As for the switching device drive function,
It can be composed of a buffer and a transmission means such as a transformer or a photocoupler. It is also possible to provide an external control signal input section 222-3 to the oscillating means 222-2 and control the ON period of the switching devices 215 and 216 by an external control signal.

Next, the operation of the discharge lamp lighting device shown in FIG. 7 will be described with reference to FIGS. 9 to 12. In addition,
FIG. 9 is an equivalent circuit diagram in which only the main parts necessary for the explanation are simplified and shown, and the same parts as those in FIG. 7 are designated by the same reference numerals.
10 and 11 show the voltage and current waveforms of the respective parts, where V is the voltage and I is the current in each figure, and the respective symbols match those of FIG. 7 (however, FIG.
11A, VGS5 indicates the gate-source voltage of the first switching device 215, and VGS6 of FIG. 11C indicates the gate-source voltage of the second switching device 216.
Indicates the source-to-source voltage. ). The horizontal axis (time axis) of FIGS. 10 and 11 corresponds to the cycle of each switching frequency. FIG. 12 shows the voltage and current waveforms of each part,
The horizontal axis corresponds to the cycle of the output frequency of the rectifier.

First, the AC power supply voltage (non-smoothed DC voltage)
The period during which the peak value is large will be described with reference to FIGS. 9 and 10. During this period, the control device 222
Controls the second switching device 216 in accordance with the detected voltage so that the ON period thereof becomes relatively small.

During the period (a) ((a) of FIG. 9, (a) of FIG. 10, and so on), the first capacitor 21
8, first switching device 215 and inductor 2
Seventeen closed circuits are formed. Therefore, the electric charge accumulated in the first capacitor 218 discharges the closed circuit,
As shown in FIGS. 10B and 10C, the currents I215 and I
216 flows.

In the period (b), the first switching device 215 is turned off and the second switching device 216 is turned on.
Turns on its parasitic diode. As a result, the inductor 217 and the second capacitor 221 exhibit series resonance, and the resonance current I21 as shown in FIGS.
6, I221 flows. As a result, the voltages V221 and V217 of the second capacitor 221 and the inductor 217 are increased.
A resonant voltage appears at. Also, the second capacitor 2
A resonance voltage also appears in the voltage V214 across the rectifier 214, which is equal to the sum of the voltage of 21 and the first capacitor 218. The peak value of the resonance voltage depends on the energy stored in the inductor 217, that is, the current value (I215) flowing through the first switching device 215 at the end of the period (a) and the voltage across the second capacitor 221 (V221). It is determined.

During the period (c), the second switching device 216 is turned on, the polarity of the resonance current is inverted, and the resonance current flows in the opposite direction (FIGS. 10 (d) and 10 (d)). The peak value of the resonance voltage in the periods (b) and (c) is larger than the non-smoothed DC voltage because the resistance component of the resonance circuit is small. That is, the pressure is increased.

In the period (d), the resonance voltage decreases (attenuates) and the voltage across the second capacitor 221 and the first capacitor 218 also tries to decrease. Therefore, the rectifying device 214 causes the first capacitor 218, Inductor 2
Currents I214, I218 and I216 flow through 17 and the second switching device 216 (FIG. 10).
(F), (H), (D)).

In the period (e), the second switching device 216 is turned off and the first switching device 215 is turned on.
Is turned on, and the stored energy of the inductor 217 causes the current I21 to flow through the parasitic diode of the first switching device 215 and the first capacitor 218.
5, I218 flows (FIG. 10 (b), (h)). Then, the state returns to the state of the period (a).

Next, a period in which the peak value of the non-smoothed DC voltage is small will be described with reference to FIG. During this period,
The control device 222 controls the second switching device 216 so that the ON period is relatively long according to the detected voltage. The circuit operation in this case is basically the same as in the case of FIG. 9, but the voltage and current waveforms of the respective parts are as shown in FIG.

The point to be noted in FIG. 11 is that the peak value of the resonance voltage is as shown in FIGS.
It is larger than zero. This is because during the period when the peak value of the unsmoothed DC voltage is small, the voltage charged in the second capacitor 221 becomes small according to this peak value (see (i) in FIGS. 10 and 11). Second for this
Current flowing into the capacitor 221 of the circuit, that is, the period (b)
This is because the initial resonance current value at is large.

Therefore, during the period when the peak value of the non-smoothed DC voltage is low, the voltage can be further boosted and the valley portion of the non-smoothed DC voltage can be raised. As described above, in the case of FIG. 7, the ON periods of the switching devices 215 and 216 are controlled in the relationship of FIG. 8, so that the ON period of the first switching device 215 is reduced during the period when the peak value is small. It is relatively small. As a result, the current is passed through the first switching device 215 when the current value is relatively small. This acts to reduce the initial resonance current value in the period (b), and thus the resonance voltage increases due to the charging voltage of the second capacitor 221, as described above, but the voltage is extremely boosted and rises. There is no excessive increase in the voltage value of the part.

Due to such an action, the inductor 217
A high-frequency AC voltage is induced in the secondary winding 217-2 to light the fluorescent lamp 219 at a high frequency. Then, the input current I214 from the AC power supply 211 is as shown in FIG. This is because, as described above, the current from the rectifying device 214 in the period (d) flows over almost the entire period of the unsmoothed DC voltage of the rectifying device 214. Therefore, this current increases the input power factor and contributes to low distortion of the input current. The high frequency component of the input current I214 can be absorbed by the filter circuit. Further, the voltage V214 between the output terminals of the rectifier 214 is shown in FIG.
As shown in (b). Further, the current of the fluorescent lamp 219 is as shown in FIG. 12C, and as a result of being smoothed by the first capacitor, its envelope becomes a ripple in which the unsmoothed DC voltage is reduced. In FIG. 12B, the white part of the sine wave shows the unsmoothed DC voltage of the rectifier 214, and the part superimposed on the sine wave shows the voltage boosted by resonance. This output voltage V2
In order to make 14 smoother, the ON period control of the switching devices 215 and 216 may be changed to a greater extent than that shown in FIG.

[0021]

As described above, the technical means shown in FIG. 7 is extremely effective. The present invention is a further improvement of this prior application, in which a rectified current is surely flowed through a rectifier circuit with a relatively simple structure, so that a high power factor can be maintained without a pause section of the input current, and a power supply unit. An object of the present invention is to provide a lighting device and a lighting device.

In addition, it is an object of the present invention to surely achieve the low distortion of the input current.

[0023]

The invention according to claim 1 is
A rectifying device that rectifies an AC voltage and outputs an unsmoothed DC voltage; first and first rectifying devices that are connected in series with each other and alternately turn on and off to switch the output of the rectifying device at a frequency higher than the output frequency of the rectifying device A second switching device, which is provided in parallel with the first switching device, and which is provided during the ON period of the second switching device.
Is charged by the output of the rectifying device via the switching device, smoothes the output frequency of the rectifying device, and charges the charge during the ON period of the first switching device via the first switching device. A first capacitor that is discharged by an electric current; an inductor that is inserted between the midpoint of the first and second switching devices and the first capacitor, and that conducts a charging / discharging current of the first capacitor. A second capacitor that resonates with the inductor according to ON / OFF of the first and second switching devices; and an ON period of the second switching device according to a detection signal of an output current of the rectifying device. A control device; and an output circuit that obtains a high frequency output based on the resonance of the inductor and the second capacitor.

In the present invention, for example, a field effect transistor can be used as the switching device. In this case, the parasitic diode built in the field effect transistor due to its structure can be used for reverse current flow. Also, like a bipolar transistor, a switch element without a built-in parasitic diode between the collector and emitter may be the main constituent. In this case, the conduction direction is reversed and the diode is connected in parallel between the collector and emitter. To do. However, when a diode is connected between the emitter and the base due to the structure of the base circuit of the transistor, this diode may be used for reverse current flow.

In the present invention, when the pair of switching devices are alternately turned on and off, it means that there is a period in which both are substantially off while one is turned on and the other is turned off. , You don't have to. The switching frequency of the pair of switching devices is higher than the output frequency of the rectifying device, preferably several kHz or higher, and more preferably 20 kHz or higher, which is higher than the audible frequency.

Further, in the present invention, "in series" or "in parallel" means to include both cases where other electric parts are interposed and cases where other electric parts are not interposed.

Furthermore, the second capacitor forming the resonance circuit together with the inductor may be provided anywhere as long as the resonance circuit can be formed. For example, it can be provided in parallel with the series circuit of the second switching device and the inductor. Moreover, you may connect between the output terminals of a rectifier.
Furthermore, part or all of the second capacitor may be provided between one output end of the rectifying device and the pair of switching devices.

In the present invention, the inductor is the second
Any capacitor that can resonate with the capacitor can be used, such as a choke coil or a transformer.

(The above also applies to the following inventions.) The invention according to claim 2 is a rectifying device connected to an AC power supply; and a rectifying device connected in series between output terminals of the rectifying device. First and second switching devices that alternately turn on and off at a frequency higher than the output frequency of the first switching device; and a series of a relatively large-capacity first capacitor and an inductor that are provided in parallel with the first switching device. A circuit; a second capacitor having a relatively small capacity, which is provided in a relationship forming a resonance circuit with the inductor in response to ON / OFF of the first and second switching devices;
According to the detection signal of the output current of the rectifying device, the second
The control device controls an ON period of the switching device; and an output circuit that obtains a high frequency output based on the resonance of the inductor and the second capacitor.

The first capacitor of the present invention also performs a smoothing action on the output frequency of the rectifier.
In addition, that the second capacitor is provided so as to form a resonance circuit with the inductor means that the second capacitor may be provided anywhere as long as the resonance circuit can be formed, as in the first aspect of the invention.

The invention according to claim 3 is the invention according to claim 1 or 2.
In the power supply device described above, the control device has a current detection means for detecting an output current of the rectifying device, and controls the ON period of the second switching device according to a detection signal of the current detection means.

The current detecting means can be formed by using, for example, a current transformer, a photo coupler, a resistor or the like.

The invention according to claim 4 is the invention according to claims 1 to 3.
In the power supply device according to any one of the above, the control device controls to turn off the second switching device when the integrated value of the output current of the rectifying device reaches a predetermined value.

According to the present invention, it is possible to manage the current value when the second switching device is off in response to the fact that the integrated value of the output current of the rectifying device has reached a predetermined value. Further, in the present invention, as the means for detecting that the integrated value has reached the predetermined value, for example, current detecting means and integrating means for integrating the output of this means can be used. It can also be realized by using a saturable current transformer and turning off the second switching device when the saturable current transformer is saturated.

According to a fifth aspect of the present invention, in the power supply device according to the fourth aspect, the predetermined value is given according to the instantaneous value of the input voltage.

The predetermined value is a value corresponding to the instantaneous value of the input voltage, for example, a value obtained by dividing the rectified voltage in the rectifier, and the output current integral value of the rectifier is compared with the predetermined value. By controlling the ON period of the second switching device, the input voltage waveform and the input current waveform can be matched.

The invention according to claim 6 is the same as claims 1 to 5.
And a discharge lamp that is energized by the output of the power supply device.

According to a seventh aspect of the present invention, there is provided a lighting device main body;
The discharge lamp lighting device according to claim 6;

[0039]

In the power supply device according to the first and second aspects, the first capacitor is charged by the output of the rectifying device and holds the smoothed DC voltage having a value smaller than the peak value of the non-smoothed DC voltage. Further, the resonance circuit of the second capacitor and the inductor generates a resonance voltage in response to the switching of the first and second switching devices. This resonance voltage acts so as to form a period in which the load voltage as viewed from the rectifying device becomes lower than the unsmoothed DC voltage over substantially the entire period of one cycle of the unsmoothed DC voltage. As a result, the input current from the AC power supply is secured (the charging current flows through the first capacitor) even during the period when the peak value of the unsmoothed DC voltage is low, and the input power factor is increased and the input current is reduced in distortion. Reduces harmonics of the input current. Further, the control means detects the output current of the rectifying device, and controls the ON period of the second switching device according to the detection signal.

According to another aspect of the power supply device of the present invention, the current detecting means detects the output current of the rectifying device and controls the ON period of the second switching device according to the detection signal.

According to a fourth aspect of the present invention, in the control device, the control device controls to turn off the second switching device when the integrated value of the output current of the rectifying device reaches a predetermined value.

According to a fifth aspect of the power supply device of the present invention, in the control device, a value corresponding to the instantaneous value of the input voltage, for example, a value obtained by dividing the rectified voltage in the rectifying device is set as a predetermined value, and the output current of the rectifying device is set. By controlling the on period of the second switching device by comparing the integrated value with the predetermined value, the input voltage waveform and the input current waveform can be matched.

In the discharge lamp lighting device according to the sixth aspect, since the discharge lamp is used as the load of the power supply device according to any one of the first to fifth aspects, in addition to the function of these power supply devices, the pulsation of the output is reduced. The luminous efficiency is improved and the light ripple is reduced.

In the lighting device according to the seventh aspect, since the discharge lamp lighting device according to the sixth aspect is provided in the main body of the fixture, the luminous efficiency is improved and the light ripple is reduced.

[0045]

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

FIG. 1 is an electric circuit of the main part of the power supply device according to the first embodiment of the present invention.

In FIG. 1, reference numeral 1 is, for example, a commercial frequency AC power supply. In the power supply device, a filter circuit 5 including a common mode choke coil 2, a choke coil 3 and a capacitor 4 is connected to the AC power supply 1, and a full wave rectifier as a rectifying device 6 is connected to the filter circuit 5. ing. The rectifying device 6 is formed of, for example, a high-speed switching diode. A first switching device 7 and a second switching device 8 are connected in series between the output terminals of the rectifying device 6.

The first switching device 7 includes a primary winding 9-of a leakage type insulation transformer as an inductor 9.
A series circuit of smoothing capacitors having a relatively large capacity as the first and first capacitors 10 is connected in parallel. The first capacitor 10 has a smoothing effect on the output frequency of the rectifier 6.

In this embodiment, output circuits are formed at both ends of the inductor 9. That is, the secondary winding 9-2 of the inductor 9 is used as an output circuit. This secondary winding 9
-2 is connected to, for example, a discharge lamp 19 (see FIG. 5) as a load, for example, a fluorescent lamp. A condenser 20 for preheating the filament is connected between the filaments of the discharge lamp 19 (see FIG. 5). In this embodiment, the leakage inductance of the inductor 9 also acts as the current limiting impedance of the discharge lamp 19.

On the other hand, a resonance capacitor having a relatively small capacity as the second capacitor 11 is connected in parallel to the second switching device 8 via the primary winding 9-1 of the inductor 9. There is. This second capacitor 1
The capacitance of 1 is extremely smaller than the capacitance of the first capacitor 10, and resonates with the inductance of the inductor 9 and the switching frequencies of the switching devices 7 and 8.

In the figure, reference numeral 18 is a control device for controlling ON / OFF of the switching devices 7 and 8. The control device 18 alternately turns on and off the pair of switching devices 7 and 8 at a substantially constant frequency, and controls the on period of the switching device 8 according to the output current of the rectifying device.

[0052] In this embodiment, the control device 18 includes a detection circuit 13 for detecting an output current of the rectifier device 6, on the controlled the pair of switching devices 7 and 8 in a drive circuit (not shown), off controls The detection circuit 1
Inputs an output signal from the 3, and a flip-flop 12 to signal the generation output for controlling the ON period of the switching device 8.

The detection circuit 13 is arranged on the minus output side of the rectifying device 6, and the current detecting means 15 for detecting the output current of the rectifying device 6 and the current detecting means 15 are provided.
Circuit 17 for delaying and outputting the detection signal of
The variable reference power supply 14 and a comparator 16 for comparing a predetermined value of the variable reference power supply 14 with the output from the delay circuit 17 constitute a main part.

That is, in the present embodiment, the switching device 7 is turned off and the switching device 8 is turned on to form a closed circuit of the rectifying device 6 to the first capacitor 10 to the inductor 9 to the switching device 8 to the rectifying device 6. The current detecting means 15 detects the current flowing into the rectifying device 6 when a current (hereinafter referred to as a power factor correction current) flows in the circuit.

[0055] The flip-flop 12, turns on the switching device 7, 8 (not shown) is controlled by the driver circuit of the pair as described above are alternately performs the OFF control,
Further, it receives an output signal from the comparator 16 in the detection circuit 13 and outputs a signal for turning off the switching device 8.

Next, the operation of this embodiment will be described with reference to FIG.

FIG. 2 is a diagram showing a switching current flowing through the switching device 8 in the power supply device of this embodiment.

The power supply device of this embodiment is basically the same in operation as the conventional example shown in FIG. 7, but the flip-flop 12 driven by the drive circuit (not shown)
The switching device 7 and the switching device 8 are alternately turned on and off. Then, the switching device 7
Is turned off, the switching device 8 is turned on, and the rectifying device 6 to
A closed circuit including the first capacitor 10 to the inductor 9 to the switching device 8 to the rectifying device 6 is formed, and when the power factor improving current flows through the circuit, the current detecting unit 15 detects the current flowing into the rectifying device 6. To detect.

The power factor improving current detected by the current detecting means 15 is delayed by the delay circuit 17 for a predetermined period, converted into the voltage, and input to the comparator 16. The comparator 16 outputs the voltage to the variable reference power source 14
And outputs a predetermined signal to the R terminal of the flip-flop 12 when the reference voltage is reached. Receiving this signal, the flip-flop 12 outputs a signal to turn off the switching device 8. At this time, the switching current of the switching device 8 is turned on for a predetermined period and then turned off as shown in FIG. That is, in the figure, the rectifying device 6 outputs a current during the period shown by the diagonal lines. The shaded period can be varied by arbitrarily setting the delay time of the delay circuit 17 and the reference voltage of the variable reference power supply 14.

According to this embodiment, since the ON time of the switching device 8 is determined by the flow of the power factor correction current, the input current can be surely supplied. Further, by controlling the width of the power factor correction current, the output can be controlled easily and surely. Further, since the rectifier circuit current that surely forms the input current can be supplied in each cycle, the input current distortion can be reduced even if the input / output conditions change.

FIG. 3 is an electric circuit diagram showing a main part of the power supply device according to the second embodiment of the present invention. In order to avoid duplication of explanation, the same components as those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The second embodiment has the same structure as that of the first embodiment except that the connecting positions of the first capacitor and the second capacitor are different from those of the first embodiment. . That is, in this embodiment, the ON period of the switching device 7 is controlled based on the output current of the rectifying device 6 detected by the detection circuit 13. In addition,
Since the control is the same as that of the first embodiment, detailed description thereof will be omitted here.

According to the second embodiment, the same effect as that of the first embodiment can be obtained.

FIG. 4 is an electric circuit diagram showing the main part of the power supply device according to the third embodiment of the present invention. In order to avoid duplication of explanation, the same components as those of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The third embodiment is different from the first embodiment in the means for detecting the output current of the rectifier 6.
In the third embodiment, the detection circuit 23 is replaced by the rectifier 6 instead of the detection circuit 13 in the first and second embodiments.
Is connected to the negative output side of.

This detection circuit 23 is the same as the current detection means 1 described above.
5, a current detecting means 25 that fulfills the same role as 5, a integrating circuit 27 that integrates and outputs the power factor correction current detected by the current detecting means 25, and a portion connected in parallel to the output terminal of the rectifying device 6. A series circuit composed of piezoresistors 24-1, 24-2 and a comparator 26 for comparing a predetermined voltage divided by the voltage-dividing resistors 24-1, 24-2 with the output from the integrating circuit 25. Parts are made up.

Next, the operation of this embodiment will be described.

The power supply device of the present embodiment is basically the same in operation as the first embodiment, but the switching device 7 and the switching device 8 are alternately switched by the flip-flop 12 driven by the drive circuit (not shown). Controlled on and off. Then, the switching device 7 is turned off and the switching device 8 is turned on to form a closed circuit of the rectifying device 6 to the first capacitor 10 to the inductor 9 to the switching device 8 to the rectifying device 6, and to improve the power factor in the circuit. When a current flows, the current flowing into the rectifying device 6 is detected by the current detecting means 25.

The power factor improving current detected by the current detecting means 25 is integrated by the integrating circuit 27, and then,
The voltage is converted and input to the comparator 26. The comparator 16 compares the voltage with the divided voltage, and when the divided voltage is reached, outputs a predetermined signal to the R terminal of the flip-flop 12. In response to this signal, the flip-flop 12
A signal is output to turn off the switching device 8.
The timing for turning off the switching device 8 is
It can be arbitrarily set by changing the voltage dividing resistance.

According to this embodiment, in addition to the effect of the first embodiment, the power factor correction current detected by the detection circuit 23 is integrated for each high frequency cycle, and the value corresponding to the input voltage, that is, the rectifying device 6 is used. By interrupting the switching current of the switching device 8 at the time when the output voltage of the output voltage is equal to the divided voltage value, the input voltage waveform and the input current waveform can be made to coincide with each other, and the input distortion can be further reduced. .

FIG. 5 is an electric circuit diagram showing an embodiment of the discharge lamp lighting device of the present invention.

In this embodiment, a discharge lamp 19 as a load, such as a fluorescent lamp, is connected to the output circuit of the power supply circuit of the first embodiment. A condenser 20 for preheating the filament is connected between the filaments of the discharge lamp 19. In this embodiment, the leakage inductance of the inductor 9 also acts as the current limiting impedance of the discharge lamp 19.

FIG. 6 is a perspective view showing an embodiment of the illuminating device of the present invention.

In the figure, reference numeral 201 is a lighting device body,
The discharge lamp 19 is mounted on the main body 201. Further, for example, the discharge lamp lighting device shown in FIG. 5 is arranged in the main body 201. The discharge lamp lighting device may be provided outside the body 201 instead of being provided inside the body 201. Further, although the lighting device of this embodiment is of a type directly attached to the ceiling, it may be a device other than this.

The present invention is not limited to the above embodiment. For example, the low-speed rectifier may be used instead of the high-speed rectifier, and the high-speed diode may be connected to the output side of the low-speed rectifier. It is also possible to combine the above-mentioned respective embodiments as appropriate.

[0076]

According to the power supply device of the present invention, the input current from the AC power supply is surely secured for each cycle (the charging current flows to the first capacitor) to increase the input power factor and input power. The current is distorted to reduce the harmonics of the input current.

Since the power supply device according to the present invention controls so that the second switching device is turned off when the integrated value of the output current of the rectifying device reaches a predetermined value, the on period of the second switching device is controlled. Can be determined, and the input current can be reliably flowed. Further, output control can be performed by controlling the ON period.

According to another aspect of the power supply device of the present invention, the input voltage waveform and the input current waveform are matched by controlling the ON period of the second switching device according to the value corresponding to the instantaneous value of the input voltage. To be

In the discharge lamp lighting device of the sixth aspect, since the discharge lamp is used as the load of the power supply device, the pulsation of the output is further reduced, the luminous efficiency is improved, and the optical ripple is reduced.

In the lighting device according to the seventh aspect, since the discharge lamp lighting device according to the sixth aspect is provided in the main body of the fixture, the luminous efficiency is improved, the pulsation of the lamp current is reduced, and the light ripple is reduced.

[Brief description of drawings]

FIG. 1 is an electric circuit diagram showing a power supply device according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a switching current flowing through a second switching device in the power supply device of the first embodiment.

FIG. 3 is an electric circuit diagram showing a power supply device according to a second embodiment of the present invention.

FIG. 4 is an electric circuit diagram showing a power supply device according to a third embodiment of the present invention.

FIG. 5 is an electric circuit diagram showing an embodiment of the discharge lamp lighting device of the present invention.

FIG. 6 is a perspective view showing an embodiment of a lighting device of the present invention.

FIG. 7 is a circuit diagram showing a prior art of the present invention.

FIG. 8 is a diagram showing a change state of the ON period of the first switching device.

FIG. 9 is an equivalent circuit diagram similarly showing only a main part in a simplified manner.

FIG. 10 is a view showing the voltage and current waveforms of the respective portions in a period in which the output voltage of the rectifier is relatively high, corresponding to the switching frequency.

FIG. 11 is a diagram showing voltage and current waveforms of respective portions in a period in which the output voltage of the rectifier is relatively small, corresponding to the switching frequency.

FIG. 12 is a diagram showing an input current, a voltage across the output terminals, and a load current waveform of the rectifier corresponding to the output frequency of the rectifier.

[Explanation of symbols]

1 ... AC current 6 ………… Rectifier 7 ... First switching device 8 ... Second switching device 9 ... Inductor 10 ... the first capacitor 11 ... Second capacitor 12 ... Flip-flop 13 ... Detection circuit 14: Variable reference power source 15 ... Current detection means 16: Comparator 17 ... Delay circuit 18 ... Control device 19 ... Discharge lamp 201 ... Lighting device main body

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Takahashi 4-3-1, Higashi-Shinagawa, Shinagawa-ku, Tokyo Inside Toshiba Lighting & Technology Co., Ltd. (56) Reference JP-A-61-218096 (JP, A) JP 61-218095 (JP, A) JP-A-6-283286 (JP, A) JP-A-3-3675 (JP, A) JP-A-2-223989 (JP, A) (58) Fields investigated (Int .Cl. ⁷ , DB name) H02M 7/48 H02M 7/5387 H05B 41/24

Claims (7)

(57) [Claims] 1. A rectifying device for rectifying an AC voltage to output a non-smoothed DC voltage; switching the output of the rectifying device at a frequency higher than the output frequency of the rectifying device by connecting in series with each other and alternately turning on and off. A first switching device and a second switching device that are provided in parallel with the first switching device, and output of the rectifying device via the second switching device during an ON period of the second switching device. A first capacitor that is charged by the capacitor and has a smoothing function with respect to the output frequency of the rectifying device, and that discharges the charged electric charge through the first switching device during the ON period of the first switching device; 1 and 2
An inductor that is interposed between a midpoint of the switching device and the first capacitor, and that allows a charging / discharging current of the first capacitor to flow therethrough; according to ON / OFF of the first and second switching devices. A second capacitor that resonates with the inductor; a control device that controls the ON period of the second switching device in accordance with a detection signal of the output current of the rectifier; and a resonance of the inductor and the second capacitor. An output circuit for obtaining a high frequency output based on the power supply; 2. A rectifying device connected to an AC power supply; first and second rectifying devices connected in series between output terminals of the rectifying device and alternately turned on and off at a frequency higher than the output frequency of the rectifying device. A switching device; a series circuit of a relatively large-capacity first capacitor and an inductor provided in parallel with the first switching device; and a switching device for turning on and off the first and second switching devices. A second capacitor having a relatively small capacity, which is provided in a relationship forming a resonance circuit with the inductor; control for controlling an on-period of the second switching device according to a detection signal of an output current of the rectifying device A power supply device comprising: a device; and an output circuit that obtains a high frequency output based on resonance of the inductor and the second capacitor. 3. The control device has a current detecting means for detecting an output current of the rectifying device, and controls an ON period of the second switching device according to a detection signal of the current detecting means. The power supply device according to claim 1, wherein the power supply device is a power supply device. 4. The control device controls to turn off the second switching device when the integrated value of the output current of the rectifying device reaches a predetermined value.
4. The power supply device according to any one of 3 to 3. 5. The power supply device according to claim 4, wherein the predetermined value is given according to an instantaneous value of the input voltage. 6. A discharge lamp lighting device, comprising: the power supply device according to claim 1; and a discharge lamp that is energized by an output of the power supply device. 7. A lighting device comprising: a lighting device main body; and the discharge lamp lighting device according to claim 6.