JPH07272873A - Power source device, discharge lamp lighting device, and lighting system - Google Patents

Abstract

PURPOSE:To surely preheat a filament to apply start voltage and to prolong the life of a discharge lamp by performing a reset wherein the capacitor of a soft starting timer circuit, performing the preheating of the filament of the discharge lamp, is surely discharged when a power source is turned on. CONSTITUTION:The terminal voltage of a capacitor C1 is increased at the time of the oscillation start of an inverter 5, and is supplied to the base of the transistor Q5 of a reset circuit 10. When the transistor Q5 is turned on (continued) to earth the capacitor C2 of a timer circuit 8 and if there is an residual electric charge, a reset is performed to discharge the residual electric charge. Starting the oscillation action of the inverter 5 causes the terminal voltage of the capacitor C1 becomes 0V concurrently to turn the transistor Q5 of a reset circuit Q7 off. Preheating the filament of a discharge lamp 7 is surely performed by the reset for discharging the residual electric charge of the capacitor C2 of the timer circuit 8 due to the a short break of an A.C. power source 2 and the like, and then high start voltage is applied.

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 perform soft start by applying a high voltage to a filament of a discharge lamp and then applying a high voltage.

[0002]

2. Description of the Related Art Conventionally, in a discharge lamp lighting device, an alternating current (A
C) A DC voltage obtained by rectifying and smoothing the AC voltage from the power source is applied to the inverter. Then, the high frequency output generated by the inverter is supplied to the discharge lamp to light it.

In such a discharge lamp lighting device, for example, 1 s to 1.5 s is applied to the filament when the discharge lamp is started.
A soft start is performed by applying a low voltage during this time to preheat and then applying a high voltage after this preheating to start and illuminate. The filament preheating time setting for this soft start is
An example is known in which a timer circuit that uses the charge / discharge time based on the time constant of a series circuit of a capacitor and a resistor is used.

In such a timer circuit, a DC voltage obtained by rectifying and smoothing an AC voltage is applied to a capacitor and a resistor of the timer circuit. Therefore, AC
When the power switch of the power source is turned off, the electric charge of the capacitor of the timer circuit is discharged, and when the power switch of the AC power source is turned on (turned on) next time, the soft start using the charge / discharge time of the capacitor and the resistor operates.

As described above, in the conventional discharge lamp lighting device,
When the C power supply is turned off, the timer circuit for soft start is reset.

[0006]

However, in the above-described conventional discharge lamp lighting device, when the power switch is turned on / off at high speed or when the AC power is interrupted instantaneously, the charge of the capacitor of the timer circuit is changed. May not fully discharge. In this way, when the electric charge remains in the capacitor of the timer circuit, that is, when the timer circuit is not reset, the soft start does not operate. Therefore, a high voltage for starting lighting is applied without filament heating of the discharge lamp being performed, and the discharge lamp is deteriorated and its life is shortened.

The present invention solves the above-mentioned drawbacks in the prior art, and the residual electric charge of the capacitor of the timer circuit for performing the soft start in which the starting voltage is applied after preheating the filament of the discharge lamp, To provide a power supply device, a discharge lamp lighting device, and a lighting device that can perform a quick and reliable discharge reset at the time of turning on the power supply, reliably apply a starting voltage after preheating, and extend the life of the discharge lamp. To aim.

[0008]

In order to achieve the above object, the present invention according to claim 1 is a power source having an inverter for performing a soft start for applying a high voltage to a filament of a discharge lamp and then applying a high voltage to start the lamp. In the device, an oscillation starting means for sending a signal for starting the oscillation of the inverter, a soft start setting means provided with a capacitor for setting a soft start, and a soft start setting means for each start of supplying the signal from the oscillation starting means. And a charge discharging unit for discharging and resetting the electric charge of the capacitor.

According to another aspect of the power supply device of the present invention, a series-connected resistor and capacitor for charging and discharging the DC voltage applied to the inverter are used as the oscillation starting means.

According to a third aspect of the present invention, there is provided a power supply device comprising, as soft start setting means, a direct current converting means for converting the high frequency voltage applied to the discharge lamp into direct current, and a series connection for charging and discharging the direct current voltage from the direct current converting means. It is configured to use a resistor and a capacitor.

According to a fourth aspect of the present invention, as the soft start setting means, a resistor and a capacitor connected in series for charging and discharging the DC voltage applied to the inverter are used.

According to another aspect of the power supply device of the present invention, as the charge discharging means, a transistor circuit is used which conducts each time the supply of the signal from the oscillation starting means is started to discharge the charge stored in the capacitor of the soft start setting means. .

A discharge lamp lighting device according to a sixth aspect of the present invention includes the power supply device according to the first, second, third, fourth or fifth aspect, and a discharge lamp that is turned on by an output from an inverter of the power supply device.

An illumination device according to a seventh aspect comprises a discharge lamp lighting device according to the sixth aspect, and a light control means for reflecting or transmitting the light emitted from the discharge lamp and radiating the light outward.

[0015]

In the power supply device, the discharge lamp lighting device, and the lighting device according to claims 1 to 7 of this structure, the charge of the capacitor of the timer circuit, which is the soft start setting means for setting the soft start each time the oscillation of the inverter is started, is performed. It has discharged and resets the timer circuit. Therefore, for example, resetting is performed to surely discharge the residual electric charge of the capacitor of the timer circuit caused by high-speed on / off of the power switch or instantaneous interruption of the AC power supply when the power is turned on. This reset ensures the application of a high voltage starting voltage after preheating.

[0016]

Embodiments of the power supply device, discharge lamp lighting device and lighting device of the present invention will be described in detail with reference to the drawings. FIG. 1 is a circuit diagram showing the configuration of an embodiment of the discharge lamp lighting device of the present invention. In FIG. 1, in this example, an AC (AC) power source 2 to which a power switch SW is connected, a bridge rectifier Da, and a smoothing electrolytic capacitor Ca are provided.
A DC circuit 3 for converting the voltage to DC (DC) and a DC voltage from the DC circuit 3 are applied to generate a frequency of 13.
A self-excited inverter 5 that outputs a high frequency of 56 MHz,
Between the DC voltage output terminal of the DC circuit 3 and the ground, a resistor R for starting the oscillation of the inverter 5 as described below.
1 and the capacitor C1 are connected in series.

Further, in this example, a soft start is performed in which a high-frequency output from the inverter 5 is turned on, and a high-voltage starting voltage is applied after the discharge lamp 7 in which the starting capacitor C4 is connected in parallel and the filament of the discharge lamp 7 are preheated. Timer circuit 8 for resetting, reset circuit 10 for resetting timer circuit 8 when power is turned on, and discharge lamp 7
A detection circuit 12 that outputs a direct-current voltage based on the high-frequency voltage applied to it and an output control circuit 14 that controls the high-frequency output from the inverter 5 based on the detection voltage from the detection circuit 12 are provided.

The inverter 5 is a half-bridge self-exciting inverter using two transistors. The transistor Q1 to which the DC voltage from the DC circuit 3 is applied to the collector and the emitter of the transistor Q1 are connected to the collector. Further, a transistor Q2 whose emitter is grounded is provided, and the coil CT1 of the saturable current transformer is connected to a connection point between the emitter of the transistor Q1 and the collector of the transistor Q2. Protective diodes Da and Db are connected between the collectors and emitters of the transistors Q1 and Q2, respectively.

Resistors Ra and Rb are respectively connected to the bases of the transistors Q1 and Q2, drive coils CT2 and CT3 of the saturable current transformer are connected, and a coil CT1 of the saturable current transformer is further connected.
A capacitor C3 and an inductor L1 are connected in series on the high frequency output side of the. The discharge lamp 7 is connected to the high frequency output side of the inductor L1. Furthermore, the resistor R1
A diode is provided between the series connection point of the capacitor C1 and the capacitor C1 and the connection point of the emitter of the transistor Q1 and the collector of the transistor Q2, and between the series connection point of the resistor R1 and the capacitor C1 and the base of the transistor Q2. The trigger diode TD is connected.

The timer circuit 8 includes a resistor R2 and a capacitor C
It is composed of two series circuits. The reset circuit 10 is provided with a transistor Q5 to which the detection voltage from the detection circuit 12 is applied to the base through a resistor Rc. A capacitor C9 for stabilizing operation is provided between the base of the transistor Q5 and the ground, and
Reference numeral 5 turns on (conducts) based on the detected voltage, short-circuits the capacitor C2 of the timer circuit 8, and discharges the residual charge when there is residual charge.

The detection circuit 12 is provided with capacitors C5 and C6 for dividing the high frequency output applied to the discharge lamp 7, and the peaks (envelopes) of the divided high frequency output here are divided by the diodes De and Df and the capacitor C8. The doubled voltage rectified detection voltage is supplied to the timer circuit 8 and the output control circuit 14.

The induced voltage of the coil CT4 of the saturable current transformer is supplied to the output control circuit 14 through the bridge rectifier Dg and the capacitor C12, and the resistor R is connected to the emitter.
A transistor Q3 with 20 is provided. The DC voltage from the DC circuit 3 is set as a bias voltage at the base of the transistor Q3 by the resistor R3, the diode Di and the resistor R4. Further, the output control circuit 14 is connected to the base of the transistor Q3 and its collector, and the detection voltage from the detection circuit 12 is used as a base for the resistor R.
And a transistor Q4 set through R22. Further, the Zener diode ZD3 connected to the connection point between the resistor R2 and the capacitor C2 of the timer circuit 8 is connected to the base and the resistor R23.
Is connected between the base and the ground, and the collector is connected to the base of the transistor Q4 through the resistor R24.

Next, the operation of this embodiment will be described. FIG. 2 is a diagram showing a voltage waveform of each part in this operation. In FIG. 2, when the power switch SW is turned on, the AC voltage is rectified and smoothed by the DC circuit 3 as shown in FIG. 2A, and this DC voltage is rectified by the resistor R1 as shown in FIG. 2B. Through which the capacitor C1 is charged.
When the voltage across the capacitor C1 exceeds the breakover voltage of the trigger diode TD as shown in FIG. 2B, the trigger diode TD becomes conductive (turns on) and the transistor Q2 turns on.

Next, using the capacitor C3 as a power source, a current flows through the coil CT1 of the saturable current transformer. That is, the capacitor C3 and the coil CT of the saturable current transformer
Current flows through the path of 1, the transistor Q2, and the starting capacitor C4. This current saturates the coil CT1 of the saturable current transformer to turn off the transistor Q2 as shown in FIG. 2C, and at the same time turn on the transistor Q1 as shown in FIG. Starts, and outputs a high frequency output from the output terminals of the transistors Q1 and Q2. In this case, the charge of the capacitor C1 is the diode D1.
Is discharged to 0 V (zero volt). In this state, the transistor Q3 of the output control circuit 14 is off, the natural frequency of the coil L1 and the capacitor C4, and the oscillation of the inverter 5 at both ends of the discharge lamp 7. The low high frequency output voltage shown in Fig. 2 (e), which is determined by the frequency, is applied, that is, the discharge lamp 7 is in a preheated state.

The high frequency output applied to the discharge lamp 7 is divided by the capacitors C5 and C6 of the detection circuit 12,
The divided high frequency voltage is doubled and rectified by the diode. That is, this peak voltage is supplied to the timer circuit 8 and the output control circuit 14 as a detection voltage.

The preheating time of the discharge lamp 7 is the charge / discharge time of the time constant of the resistor R2 and the capacitor C2 of the timer circuit 8,
It is determined by the set voltage of the Zener diode ZD3. That is, the preheating time of the discharge lamp 7 is until the voltage across the capacitor C2 of the timer circuit 8 reaches the set voltage of the Zener diode ZD3. This discharge lamp 7
During the preheating time of, the constant current circuit of the transistor Q4 and the Zener diode ZD2 controls the base current of the transistor Q3. That is, the coil CT4 of the saturable current transformer of the transistor Q3 and the drive coils CT2, CT
By the operation of the inverter 5 and the detection circuit 12 to which 3 is coupled, the closed loop control for making the high frequency voltage constant across the discharge lamp 7 is performed.

When the voltage of the capacitor C2 of the timer circuit 8 rises and the Zener diode ZD3 turns on, the transistor Q6 of the output control circuit 14 turns on and the base voltage of the transistor Q4 drops. In this case, the saturable current transformer coil CT4 of the transistor Q3 and the inverter 5 in which the drive coils CT2 and CT3 are coupled are controlled so that the base voltage of the transistor Q4 is kept constant. With this control, the output voltage rises, and a high-frequency high-frequency output is applied across the discharge lamp 7. That is, the starting voltage is applied to turn on the light. When the power switch SW is turned off after the discharge lamp 7 is lit in this way, the operation of all circuits from the DC circuit 3 to the detection circuit 12 is stopped and the discharge lamp 7 is turned off.

Next, the operation when the power switch SW is turned off after the discharge lamp 7 is turned on will be described.
When the power switch SW is turned on after a sufficient time has passed since the power switch SW was turned off, there is no residual charge in the capacitor C2 of the timer circuit 8 and the capacitor C2 is sufficiently discharged. Therefore, the discharge lamp 7 is lit by operating as described above.

Here, when the power switch SW is turned on / off in a short time, or when the AC power source 2 is momentarily cut off,
When the DC voltage is turned on / off in a short time t as shown in FIG. 2A, the electric charge of the capacitor C2 of the timer circuit 8 is not sufficiently discharged, and when the power switch SW is turned on,
As shown in (f), there is residual charge in the capacitor C2,
Since the soft start operation is performed based on this residual charge, the preheating time of the discharge lamp 7 is shortened. Alternatively, when the charge of the capacitor C2 of the timer circuit 8 is not discharged at all, a high-voltage starting voltage is applied without preheating the filament of the discharge lamp 7.
Here, when the power switch SW is turned on, resetting is performed to discharge the electric charge of the capacitor C2 of the timer circuit 8. The residual charge of the capacitor C2 shown in FIG. 2 (f) turns on (conducts) the transistor Q5 as shown in FIG. 2 (g).
Is discharged. As a result, the same operation as described above is performed when there is no residual charge in the capacitor C2. That is, after the filament of the discharge lamp 7 is preheated, a high-frequency high-frequency output is applied to the discharge lamp 7 to start it.

In this case, first, when the oscillation is started, as shown in FIG.
When the voltage across the capacitor C1 shown in (b) rises,
The voltage is supplied to the base of the transistor Q5 of the reset circuit 7, and the transistor Q5 is turned on (conducting).
When the transistor Q5 is turned on, the capacitor C2 of the timer circuit 8 is grounded and its charge becomes 0V. When the inverter 5 starts the oscillating operation, the voltage across the capacitor C1 becomes 0V, and at the same time, the transistor Q5 of the reset circuit 10 is turned off. After that, the above-described preheating operation and the operation of lighting the discharge lamp 7 by applying the high-frequency high-frequency output as the starting voltage are performed.

FIG. 3 is a circuit diagram showing the structure of the main part of another embodiment. In FIG. 3, this example shows a timer circuit 20 including a series circuit of a resistor R10 and a capacitor C10.
Is provided between the DC output end of the DC circuit E and the ground. Furthermore, the capacitor C10 of this timer circuit 20
A reset circuit 21 is provided for discharging the electric charges of the capacitor C1 based on the voltage across the capacitor C1. Reset circuit 2
In No. 1, the collector is connected to the series connection point of the resistor R10 and the capacitor C10, the base is grounded by the resistor R12, and the base is connected to the series connection point of the resistor R4 and the capacitor C1 by the resistor R11. And a transistor Q8.

Further, a resistor R10 and a capacitor C10
Resistor R1 for outputting an output level setting signal for setting the voltage of the series connection point of the discharge lamp 7, that is, the preheating time of the discharge lamp 7.
And a transistor Q9 provided with R3, R14 and R15. The output level setting signal from the transistor Q9 is supplied to a control circuit (not shown) to control the high frequency output from the inverter 5. Other operations are basically the same as the configuration shown in FIG.

Next, an illuminating device using the discharge lamp lighting device shown in FIGS. 1 to 3 will be described. FIG. 4 is a circuit diagram showing a configuration when the discharge lamp lighting device shown in FIGS. 1 to 3 is used as a lighting device. In FIG. 4, this illuminating device is provided with a reflecting plate 40 near the discharge lamp 7 having the configuration shown in FIGS. 1 to 3. Also, the discharge lamp 7
A transparent member 41 for guiding the light emission L of the discharge lamp 7 in a predetermined direction is provided on the front surface of the. The reflector 40,
Only one of the transparent members 41 may be provided. Other configurations are the same as those in FIG. The operation in this case is also similar to the configuration shown in FIG.

Although the discharge lamp lighting device shown in FIGS. 1 to 3 and the lighting device shown in FIG. 4 are each equipped with the discharge lamp 7, they may be used as a power supply device not equipped with the discharge lamp 7. good. In this case, as shown in FIG. 4, at the output end of the inverter 5 and the ground end of the detection circuit 12,
Connection terminals T1 and T2 are provided respectively, and the discharge lamp 7 is connected to the connection terminals T1 and T2 after shipment of this device. At the same time, the reflection plate 40 and the transmission member 41 are mounted and used.

[0035]

As is apparent from the above description, the power supply device, the discharge lamp lighting device and the lighting device according to claims 1 to 7 are the soft start setting means for setting the soft start each time the inverter starts oscillating. Since the residual charge of the capacitor of the timer circuit is discharged and resetting,
The residual charge of the timer circuit capacitor generated by the high-speed on / off of the power switch or the momentary interruption of the AC power source is surely discharged and reset, and this reset enables the application of the starting voltage after preheating. This has the effect of extending the life of the discharge lamp.

[Brief description of drawings]

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

FIG. 2 is a diagram showing voltage waveforms of respective parts in the operation of the configuration shown in FIG.

FIG. 3 is a circuit diagram showing a main part configuration of another embodiment.

FIG. 4 is a circuit diagram showing a configuration when the discharge lamp lighting device of the embodiment is used as a lighting device.

[Explanation of symbols]

 3 DC circuit 5 Inverter 7 Discharge lamp 8 Timer circuit 10 Reset circuit 12 Detection circuit 14 Output control circuit C1 Capacitor Q1, Q2 Transistor R1 Resistor

Claims (7)

[Claims] 1. A power supply device comprising an inverter for performing soft start by applying a high voltage after preheating a filament of a discharge lamp and performing start lighting, oscillation starting means for sending a signal for starting oscillation of the inverter, A soft start setting unit including a capacitor for setting a soft start; and a charge discharging unit configured to discharge and reset the charge of the capacitor of the soft start setting unit every time the supply of a signal from the oscillation starting unit is started. Power supply. 2. The power supply device according to claim 1, wherein a resistor and a capacitor connected in series for charging and discharging a DC voltage applied to the inverter are used as the oscillation starting means. 3. As the soft start setting means, a direct current converting means for converting the high frequency voltage applied to the discharge lamp into direct current, and a series-connected resistor and capacitor for charging and discharging the direct current voltage from the direct current converting means are used. The power supply device according to claim 1, wherein: 4. A resistor and a capacitor connected in series for charging and discharging the DC voltage applied to the inverter are used as the soft start setting means.
The power supply described. 5. The transistor according to claim 1, wherein the charge discharging means is a transistor circuit that is turned on each time the supply of a signal from the oscillation starting means is started to discharge the charge stored in the capacitor of the soft start setting means. Power supply. 6. A discharge lamp lighting device, comprising: the power supply device according to claim 1, 2, 3, 4 or 5, and a discharge lamp that is turned on by an output from an inverter of the power supply device. 7. A lighting device comprising: the discharge lamp lighting device according to claim 6; and a light control means for reflecting or transmitting the light emission of the discharge lamp to radiate the light outward.