JPH08275536A - Power supply, electric-discharge lamp lighting device and lighting fixture - Google Patents

Abstract

PURPOSE: To enhance the input power factor, to decrease the distortion of the input current and to make the output variable by controlling the switching means on the side of the high voltage and the side of the low voltage, which are detected by current detecting means, by the control means, which is connected to the low voltage side of a rectifier means. CONSTITUTION: The input terminal of a rectifier circuit 12 as a rectifier means is connected to a commercial AC power supply E. A field-effect transistor Q1 as a switching means on the high-voltage side, a field-effect transistor Q2 as a switching means on the low voltage side and a resistor R as a current detecting means are connected between the output terminals of the rectifier circuit 12 in series. A control means 13, which is connected to the low voltage side of the rectifier circuit 12, controls the field-effect transistor Q1 on the high voltage side and the field-effect transistor Q2 on the low voltage side based on the current detected by the resistor R1. Thus, the input power factor is improved, the distortion of the input current can be decreased and the output can be made variable.

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 which improve the input power factor from an AC power supply and reduce the distortion of the input current.

[0002]

2. Description of the Related Art Heretofore, as a discharge lamp lighting device of this type, a structure disclosed in, for example, Japanese Patent Application Laid-Open No. 5-174986 has been known.

In the configuration disclosed in Japanese Patent Laid-Open No. 5-174986, a small-capacity capacitor is connected to the output side of a full-wave rectifier connected to a commercial AC power source via a resonance resonance coil and a resonance capacitor. A half-bridge type inverter circuit in which a switching element is connected in series is connected to the output side of this smoothing capacitor.

During the ON period of the high-voltage side switching element, the inverter circuit is initially supplied with a small-capacity capacitor. Since this capacitor has a small capacity, the voltage will soon drop, and after the capacitor is discharged, commercial power is supplied. Allow current to flow from the AC power supply.

Further, in the off period of the high-voltage side switching element, the inflow current is cut off to generate a resonance voltage resonated by the resonance coil and the resonance capacitor, and the resonance current is supplied to the capacitor.

Then, the input current is caused to flow even during a period when the input voltage from the commercial AC power source is low, so that the distortion of the high input power factor and the input current is reduced.

[0007]

However, the configuration described in Japanese Patent Laid-Open No. 5-174986 has a problem that a smoothed output cannot be obtained.

The present invention has been made in view of the above problems. A high input power factor and a low distortion of an input current can be achieved while a high frequency output having a smoothed envelope can be obtained. An object of the present invention is to provide a power supply device, a discharge lamp lighting device, and a lighting device that can adjust and change the output with a configuration.

[0009]

According to a first aspect of the present invention, there is provided a power supply device comprising: rectifying means for rectifying an output voltage of an AC power source to output a non-smoothed direct current voltage; The switching means on the high voltage side and the switching means on the low voltage side for switching the output of the rectifying means at a higher frequency than the output of the rectifying means; the switching means on the high voltage side being provided in parallel with the switching means on the low voltage side. During the period, it is charged by the output of the rectifying means via the switching means on the high voltage side, smoothes the output frequency of the rectifying means, and charges the charge on the low voltage side during the ON period of the switching means on the low voltage side. A first capacitor discharged through; a middle point between the low-voltage side switching means and the high-voltage side switching means, and the first capacitor. On the low voltage side switching means and high-voltage side switching means; inductor and flowing through the charging and discharging current of the first capacitor inserted between the
A second capacitor that resonates with the inductor when turned off; an output circuit that extracts a high-frequency output based on the resonance of the inductor and the second capacitor; a current detection unit that detects a current flowing through a switching unit on the low voltage side; a rectification unit And a control means connected to the low voltage side of the control means for controlling the high voltage side switching means and the low voltage side switching means based on the current detected by the current detecting means.

According to a second aspect of the present invention, there is provided a power supply device which comprises: rectifying means for rectifying an output voltage of an alternating current power source to output a non-smoothed direct current voltage; High-voltage side switching means and low-voltage side switching means for switching at a frequency higher than the output of the rectifying means; high-voltage side switching means provided in parallel with the low-voltage side switching means, and in the ON period of the high-voltage side switching means A first charge which is charged by the output of the rectifying means through the means, performs a smoothing action on the output frequency of the rectifying means, and discharges the charged electric charge through the low-voltage side switching means during the ON period of the low-voltage side switching means. A capacitor between the low voltage side switching means and the high voltage side switching means and the first capacitor. An inductor for passing a charging / discharging current of the first capacitor; a second capacitor that resonates with the inductor according to ON / OFF of the low-voltage side switching means and the high-voltage side switching means; and the inductor and the second capacitor An output circuit for extracting a high frequency output based on resonance; a voltage detecting means for detecting a voltage applied to a switching means on the low voltage side; a high voltage connected to the low voltage side of the rectifying means, and a high voltage based on a current detected by the current detecting means Side switching means and control means for controlling the low voltage side switching means;

According to a third aspect of the present invention, in the power source apparatus according to the first or second aspect, the control means includes a transformer for transmitting a signal to the switching means on the high voltage side and the switching means on the low voltage side. .

A discharge lamp lighting device according to a fourth aspect comprises the power supply device according to any one of the first to third aspects, and a discharge lamp that is energized by the power supply device.

A discharge lamp lighting device according to a fifth aspect of the present invention is the discharge lamp lighting device according to the fourth aspect, wherein the power supply device lowers the output during preheating and starting of the discharge lamp and increases the output during lighting. .

An illumination device according to a sixth aspect comprises an illumination device main body; and the discharge lamp lighting device according to the fourth or fifth aspect.

[0015]

According to the power supply device of the present invention, the first capacitor smoothes the unsmoothed DC voltage of the rectifying means, and the resonance voltage generated by the resonance circuit of the second capacitor and the inductor causes the first capacitor to The voltage is tried to be lower than the unsmoothed DC voltage rectified by the rectifying means during one cycle of switching of the pair of switching means, and the input current is secured and input even while the peak value of the rectified unsmoothed DC voltage is low. In addition to increasing the input current, the input current is distorted to reduce the harmonics of the input current, and the control means connected to the low voltage side of the rectifying means is based on the current detecting means for detecting the current of the switching means on the low voltage side. To control
The potential difference from the current detecting means is small and the voltage separating means etc. are not necessary, and the output voltage is controlled with a simple configuration.

According to another aspect of the power supply device of the present invention, the first capacitor smoothes the unsmoothed DC voltage of the rectifying means, and the resonance voltage generated by the resonance circuit of the second capacitor and the inductor causes the first capacitor The voltage is tried to be lower than the unsmoothed DC voltage rectified by the rectifying means during one cycle of switching of the pair of switching means, and the input current is secured and input even while the peak value of the rectified unsmoothed DC voltage is low. In addition to increasing the input current, the input current is reduced in distortion to reduce the harmonics of the input current, and the control means connected to the low voltage side of the rectifying means is based on the voltage detecting means for detecting the voltage of the switching means on the low voltage side. Since the control is performed, the potential difference from the voltage detecting means is small, and the voltage separating means or the like is unnecessary, and the output voltage is controlled with a simple configuration.

The power supply device according to a third aspect of the present invention is a power supply device according to the first or second aspect, and is provided with a transformer for transmitting a signal to the switching means on the high voltage side and the switching means on the low voltage side. At the same time, the high-voltage side switching means and the low-voltage side switching means do not turn on at the same time and short-circuit.

The discharge lamp lighting device according to a fourth aspect of the invention has respective effects because the discharge lamp is energized and lit by the power supply device according to any one of the first to third aspects.

The discharge lamp lighting device according to a fifth aspect of the present invention is the discharge lamp lighting device according to the fourth aspect, wherein the power supply device lowers the output during preheating and starting of the discharge lamp and increases the output during lighting. .

An illumination device according to a sixth aspect of the invention has the respective effects because the discharge lamp lighting device according to the fourth or fifth aspect is provided in the illumination device main body.

[0021]

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.

FIG. 2 is a perspective view showing the appearance of the lighting device.
As shown in FIG. 2, sockets 2 are provided at both ends of the lighting device body 1, and between the sockets 2 and 2,
A discharge lamp FL is attached and started and lit by a discharge lamp lighting device 11 provided inside.

FIG. 1 is a circuit diagram of a discharge lamp lighting device 11 built in the lighting device body 1.
A commercial AC power source E is connected to an input terminal of a rectifying circuit 12 as rectifying means. Between the output terminals of the rectifying circuit 12, a high-voltage side field effect transistor Q1 as high-voltage side switching means and a low-voltage side. A low-voltage side field effect transistor Q2 as a switching means and a resistance as a current detection means are connected in series.The high-voltage side field-effect transistor Q1 and the low-voltage side field-effect transistor Q2 each have a parasitic diode. are doing. In addition, normally, between the commercial AC power supply E and the rectifier circuit 12,
A filter (not shown) that cuts high frequencies is provided.

Further, a series circuit of a smoothing first capacitor C1 having a relatively large capacitance and a resonance second capacitor C2 having a relatively small capacitance is connected between the output terminals of the rectifier circuit 12. .

Between the connection point of the high-voltage side field effect transistor Q1 and the low-voltage side field effect transistor Q2 and the connection point of the second capacitor C2 and the first capacitor C1, an inductor such as The series circuit of the primary winding Tr1a of the output transformer Tr1 of the leakage transformer is connected.

Further, the high-voltage side field effect transistor Q1
A diode D2 is connected between the gate and source of the resistor via a parallel circuit of a resistor R2 and a diode D1, and a capacitor C3 and a first winding Tr2a of the drive transformer Tr2 are connected in parallel to the diode D2. .

Further, a parallel circuit of a resistor R3 and a diode D3, a capacitor C3 and a second of the drive transformer Tr2 are provided between the gate and the source of the low-voltage side field effect transistor Q2.
The series circuit of winding Tr2b is connected. The first winding Tr2a and the second winding Tr2b are respectively connected to the gate of the high-voltage side field effect transistor Q1 and the gate of the low-voltage side field effect transistor Q2 in opposite polarities.

Further, a series circuit of a resistor R4 and a capacitor C5 is connected between the output terminals of the rectifier circuit 12, and a connection point of the resistor R4 and the capacitor C5 is used for controlling, for example, a model number MC34261 manufactured by Motorola Co. An IC 13 is connected, the control IC 13 is connected to a resistor R1 via a resistor R5 and a capacitor C6 which form a time constant circuit, and a delay circuit 14 is further connected. In addition, control IC
13 is commercially available for control, for example, when the boost chopper is used as an active filter. Further, when the voltage generated in the resistor R1 reaches a predetermined value, that is, when the current of the low-voltage side field effect transistor Q2 reaches a predetermined value, the low-voltage side field effect transistor Q2 is shut off and driven by its inverted signal. High-voltage side field effect transistor Q1
Turn on. After the time determined by the delay circuit 14, the control I
The output of C13 is inverted, and the high-voltage side field effect transistor Q1
Turns off, the low-voltage side field effect transistor Q2 turns on,
After that, it operates repeatedly.

On the other hand, one ends of filaments FL1 and FL2, which are hot cathodes of a fluorescent lamp FL as a discharge lamp, are connected to the secondary winding Tr1b of the output transformer Tr1, and the other ends of these filaments FL1 and FL2 are resonated. Capacitors for
C7 is connected.

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

First, in the control IC 13, the low voltage side field effect transistor Q2 is turned on by the second winding Tr2b and the high voltage side field effect transistor Q1 is turned on by the first winding Tr2a.
When the switch is turned off, the first capacitor C1 is discharged, and the first capacitor C1, the primary winding Tr1a, the drain and source of the low-voltage side field effect transistor Q2, and the closed circuit of the first capacitor C1 Flows.

Next, when the low voltage side field effect transistor Q2 is turned off by the control IC 13, the primary winding Tr1a, the parasitic diode of the high voltage side field effect transistor Q1 and the second
A series resonance occurs in the closed circuit of the capacitor C2 and a resonance current flows. Note that the magnitude of the resonance current at this time is such that when the high-voltage side field effect transistor Q1 is turned off, the first capacitor C1, the primary winding Tr1a, the low-voltage side field effect transistor Q2, and the first capacitor C1. Depends on the value of the current flowing through.

Further, the high-voltage side field effect transistor Q1
In order to prevent the field effect transistor Q2 on the low voltage side and the field effect transistor Q2 on the low voltage side from simultaneously turning on and short-circuiting, the field effect transistor Q1 on the high voltage side is turned on with a time delay, and when the resonance current reverses, the primary winding Tr1a, the second winding A current flows in the closed circuit of the capacitor C2, the high-voltage side field effect transistor Q1 and the primary winding Tr1a.

Then, the resonance voltage is lowered and the voltage across the second capacitor C2 and the first capacitor C1 is changed to the rectifier circuit.
When it becomes lower than the unsmoothed voltage of 12, the rectifier circuit 12, the rectifier circuit 12, the high-voltage side field effect transistor Q1, the primary winding Tr
A current flows in the closed circuit of 1a, the first capacitor C1 and the rectifier circuit 12.

When the high-voltage side field effect transistor Q1 is turned off, the energy stored in the primary winding Tr1a is discharged,
A current flows in the closed circuit of the primary winding Tr1, the first capacitor C1, the diode D2 and the primary winding Tr1a.

Then, the low voltage side field effect transistor Q2 is turned on again by the second output winding CT3, and the above operation is repeated.

Further, in a period in which the peak value of the unsmoothed DC voltage rectified by the rectifier circuit 12 is large, the ON period of the high-voltage side field effect transistor Q1 is controlled to be relatively small, and a period in which the peak value is small is controlled. Then, the ON period of the high-voltage side field effect transistor Q1 may be controlled to be relatively long. In the vicinity of the zero-cross where the peak value of the current rectified by the rectifier circuit 12 is the lowest, the voltage across the second capacitor C2 also drops accordingly. Then, the current flowing into the second capacitor C2 during this period, that is, the resonance current increases. Therefore, in the portion where the non-smooth rectified waveform from the rectifier circuit 12 becomes small, the boosting may be increased to smooth the output.

Under this resonance condition, the primary winding
Since only Tr1a can be inserted between the field effect transistor Q1 and the field effect transistor Q2 and between the capacitor C1 to reduce the resistance component, the resonant voltage based on these resonant currents is generated over almost the entire period of the pulsating voltage. Becomes a voltage higher than the pulsating voltage of the rectifier circuit 12. This allows
High input power factor and low distortion of input current can be achieved.

Further, the interruption timing of the low-voltage side field effect transistor Q2 is detected by the resistor R1 to set the interruption timing. For example, the peak value of the current flowing through the resistor R1 is detected, and when this peak value reaches a predetermined value, the low-voltage side field effect transistor Q2 is turned off. The peak value of the current flowing through the resistor R1 affects the magnitude of the resonance voltage as described above. Therefore, the resonance voltage, that is, the high frequency output voltage can be controlled by controlling the on-width of the low-voltage side field effect transistor Q2 according to this peak value.
It should be noted that it is possible to obtain substantially the same result even if the integrated value is detected in addition to the peak value.

The control IC 13 is connected to the negative side of the rectifier circuit 12, and the resistor R1 detected by the control IC 13 is also connected to the rectifier circuit 12.
Since it is connected between the low-voltage side field effect transistor Q2 located on the negative electrode side and the rectifier circuit 12, the potential difference between the two is small, so that the low-voltage side field effect transistor Q2 of Since the current can be detected, the circuit can be downsized.

Further, the first winding Tr2a and the second winding Tr2b of the drive transformer Tr2 are connected to opposite polarities, and the first winding Tr2a and the second winding Tr2b alternately cause the electric field on the high voltage side. Since the effect transistor Q1 and the low-voltage side field-effect transistor Q2 are turned on and off, there is a delay due to the input capacitance of the resistor R3 and the high-voltage side field-effect transistor Q1 and the low-voltage side field-effect transistor Q2. Since the turn-on of the field effect transistor Q1 and the low-voltage side field effect transistor Q2 is delayed, it is possible to prevent the high-voltage side field effect transistor Q1 and the low-voltage side field effect transistor Q2 from turning on at the same time.

Next, another embodiment will be described.

In another embodiment, as shown by the broken line in FIG. 1, the drain of the field effect transistor Q2 on the low voltage side,
A voltage detection circuit 15 as a voltage detection means is provided between the sources, and the control IC 13 is controlled based on the voltage detected by the voltage detection circuit 15.

In this case, the first capacitor C1
And the voltage of the second capacitor C2 is controlled to be constant. That is, the low-voltage side field effect transistor Q2
Is applied with the voltage of the first capacitor C1 and the second capacitor C2.

[0045]

According to the power supply device of the first aspect, the distortion of the input current is reduced to reduce the harmonics of the input current, and the control means connected to the low voltage side of the rectifying means is the switching means of the low voltage side. Since the control is performed based on the current detecting means for detecting the current, the potential difference is small and the voltage separating means is unnecessary, and the output voltage can be controlled with a simple configuration.

According to the power supply device of the second aspect, the distortion of the input current is reduced to reduce the harmonics of the input current, and the control means connected to the low voltage side of the rectifying means is the switching means of the low voltage side. Since the control is performed based on the voltage detecting means for detecting the voltage, the potential difference from the voltage detecting means is small and the voltage separating means or the like is unnecessary, and the output voltage can be controlled with a simple configuration.

According to the power supply device of the third aspect, in addition to the power supply device of the first or second aspect, a transformer for transmitting a signal to the switching means on the high voltage side and the switching means on the low voltage side is provided. It is possible to prevent the switching means and the switching means on the low voltage side from being simultaneously turned on and short-circuited.

According to the discharge lamp lighting device of the fourth aspect,
Since the discharge lamp is energized and turned on by the power supply device according to any one of claims 1 to 3, the respective effects are exhibited.

According to the discharge lamp lighting device of the fifth aspect,
In addition to the discharge lamp lighting device according to claim 4, the power supply device lowers the output at the time of preheating and starting the discharge lamp, increases the output at the time of lighting, reduces the stress on the discharge lamp, and ensures the lighting. Aim for longer life.

According to the lighting device of the sixth aspect, since the lighting device main body is provided with the discharge lamp lighting device of the fourth or fifth aspect, each effect is exhibited.

[Brief description of drawings]

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

FIG. 2 is a perspective view showing the outer appearance of the above lighting device.

[Explanation of symbols]

1 Lighting device main body 11 Discharge lamp lighting device 12 Rectifying circuit as rectifying means 13 Control IC as control means 15 Voltage detecting circuit as voltage detecting means C1 First capacitor C2 Second capacitor Q1 As switching means on high voltage side High-voltage side field-effect transistor Q2 Low-voltage side field-effect transistor R1 as a low-side switching means Resistor Tr1 current detection means Output transformer as an inductor Tr2 Drive transformer

Front page continuation (72) Inventor Yuji Takahashi 4-3-1, Higashishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Lighting & Technology Corporation

Claims (6)

[Claims] 1. Rectifying means for rectifying an output voltage of an AC power source to output a non-smoothed DC voltage; a rectifying means connected in series with each other to alternately turn on and off to make the output of the rectifying means higher than the output of the rectifying means. A switching means on the high-voltage side and a switching means on the low-voltage side, which are switched in parallel with the switching means on the low-voltage side. A first capacitor which is charged by the output, performs a smoothing action on the output frequency of the rectifying means, and discharges the charged electric charge through the low voltage side switching means during the ON period of the low voltage side switching means; The first capacitor is charged and discharged by being interposed between an intermediate point of the switching means and the switching means on the high voltage side and the first capacitor. An inductor for passing a current; a second coil that resonates together with the inductor depending on whether the low-voltage side switching means and the high-voltage side switching means are on or off
Capacitor; an output circuit for extracting a high frequency output based on the resonance of the inductor and the second capacitor; a current detecting means for detecting a current flowing through the switching means on the low voltage side; and a current detecting means connected to the low voltage side of the rectifying means for detecting the current. Control means for controlling the switching means on the high voltage side and the switching means on the low voltage side based on the current detected by the means;
A power supply device comprising: 2. Rectifying means for rectifying an output voltage of an AC power source to output a non-smoothed DC voltage; a rectifying means connected in series with each other to alternately turn on and off to make the output of the rectifying means higher than the output of the rectifying means. A switching means on the high-voltage side and a switching means on the low-voltage side, which are switched in parallel with the switching means on the low-voltage side. A first capacitor which is charged by the output, performs a smoothing action on the output frequency of the rectifying means, and discharges the charged electric charge through the low voltage side switching means during the ON period of the low voltage side switching means; The first capacitor is charged and discharged by being interposed between an intermediate point of the switching means and the switching means on the high voltage side and the first capacitor. An inductor for passing a current; a second coil that resonates together with the inductor depending on whether the low-voltage side switching means and the high-voltage side switching means are on or off
Capacitor; an output circuit for extracting a high frequency output based on the resonance of the inductor and the second capacitor; a voltage detecting means for detecting a voltage applied to the switching means on the low voltage side; and a voltage detecting means connected to the low voltage side of the rectifying means. And a control means for controlling the switching means on the high voltage side and the switching means on the low voltage side based on the current detected by the current detecting means. 3. The power supply device according to claim 1, wherein the control means includes a transformer that transmits a signal to the high voltage side switching means and the low voltage side switching means. 4. A discharge lamp lighting device, comprising: the power supply device according to any one of claims 1 to 3; and a discharge lamp that is energized by the power supply device. 5. The discharge lamp lighting device according to claim 4, wherein the power supply device lowers the output during preheating and starting of the discharge lamp and increases the output during lighting. 6. A lighting device comprising: a lighting device main body; and the discharge lamp lighting device according to claim 4 or 5.