JPS6332238B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a discharge lamp lighting device having a voltage-responsive starter, and its purpose is to enable stable dimming down to low illuminance and to be suitable for use when the ambient temperature is low. To provide a discharge lamp lighting device which can stably light the lamp even when the lamp is lit and can start the lamp reliably.

As shown in FIG. 1, a conventional discharge lamp lighting device connects a discharge lamp 1, a dimmer 2 and a ballast 3 in series, and connects it to an AC power source 4. A voltage-responsive starter (hereinafter simply referred to as starter) 6, such as a glow starter, was connected to both ends of the side not connected to the power source 4. In this case, when the discharge lamp 1 is dimmed to a low illuminance, the re-ignition voltage of the discharge lamp 1 rises and the starter 6 restarts, causing the discharge lamp 1 to repeatedly blink and If it is not possible to dim the discharge lamp 1 while maintaining stable lighting down to low illuminance for restarting, and the ambient temperature drops, the lamp voltage will increase due to the characteristics of the discharge lamp, and the starter 6 will restart. It had the disadvantage that it would operate and blink repeatedly. Therefore, as shown in FIG. 2, the terminals A to D of the secondary winding of the filament preheating transformer 7 are
It has been proposed to reduce the voltage across the starter 6 by connecting the terminals a to d of the starter 6 so that the same symbols match. Note that 8 is a power switch. In this case, when the power switch 8 is closed to start the discharge lamp 1, the filaments 5a and 5b are preheated by the filament preheating transformer 7 at the same time as the AC power source 4 is turned on, and a voltage is generated across the starter 6. is reduced by the voltage drop due to filament preheating, which has the disadvantage that the voltage across the starter 6 does not reach its operation start voltage and the starter does not start.

The present invention has been made in view of this point, and will be explained in detail below with reference to Examples.

FIG. 3 shows an embodiment of the present invention, in which an AC power supply 4 is connected to a discharge lamp 1 through a dimmer 2 and a ballast 3.
In the discharge lamp lighting device, a voltage responsive starter 6 is connected between one end of both filaments 5a and 5b, and a voltage responsive starter 6 is connected between the other ends of both filaments 5a and 5b. A correction power supply consisting of a filament preheating transformer 7 connected in series so as to reduce the above-mentioned correction power supply output, and a switch means consisting of a switch 9 for controlling whether or not to generate the correction power supply output are provided. The filament preheating transformer 7 is the same as the conventional example shown in FIG.

Now, when the discharge lamp 1 is turned on, if you operate the dimmer 2 to dim the light to a low luminance, when the dimming level decreases and the lamp voltage increases, close the switch 9 and operate the filament preheating transformer 7. Preheat filaments 5a and 5b. At this time, the voltage V _bd generated between terminals b and d becomes V _bd =V _ac -2v. Here, V _ac is the voltage between terminals a and c, and v is the voltage of the secondary winding of the filament preheating transformer 7. Therefore, despite the increase in the lamp voltage of the discharge lamp 1, the voltage across the starter 6 is reduced due to the connection of the filament preheating transformer 7.
The voltage drops by 2v, preventing the starter 6 from operating again.

Next, FIG. 4 shows another embodiment of the present invention, in which the primary winding of a transformer 10 constituting a correction power supply connected in series with a starter 6 is connected between filaments 5a and 5b via a switch 9. If the switch 9 is closed when the lamp voltage increases while the discharge lamp 1 is lit, a voltage V _be is generated in the secondary winding of the transformer 10 in accordance with the voltage V _bd between terminals b and d, and the starter 6 The voltage across V _ed becomes V _ed = V _bd − V _be , and can be reduced by V _be . Therefore, the voltage across the starter 6 can be suppressed below the operation start voltage, and stable lighting can be maintained.

Next, in FIG. 5, switch 9 in FIG. 4 is used as contact 12 of relay 11, and relay 11 is replaced by time limit circuit
This circuit is operated by the time limit circuit 1.
3 is a relay 11 that is turned on until the time t elapses after the power switch 8 is turned on and the discharge lamp 1 completes starting.
The contact point 12 of the discharge lamp 1 is opened, and not only can the discharge lamp 1 be started reliably, but also stably lit after starting.

Next, FIG. 6 shows the switch 9 of the embodiment shown in FIG.
The thyristor 14 is replaced with the thyristor 14, and the trigger is triggered by a timer and ignition circuit 15. 16 is a current detection circuit.

Now, the time t from turning on the power switch 8 to starting the discharge lamp 1 is a time limit as in the case of Fig. 5.
Since the thyristor 14 is not triggered by the timer circuit in the ignition circuit 15 and remains non-conducting, no voltage is generated in the secondary winding of the filament preheating transformer 7, and no voltage is generated across the starter 6. A voltage necessary for starting operation is generated, and starting of the discharge lamp 1 is completed after time t. After the time t has passed, the time limit is reached and the ignition circuit 1
The ignition circuit in 5 starts operating and thyristor 1
4 becomes conductive, operating the filament preheating transformer 7 and reducing the voltage across the starter 6.

When the discharge lamp 1 is fully lit or dimmed to high illuminance, the voltage across the starter 6 is kept below the operation start voltage of the starter 6.
A small filament preheating current is required to reduce the voltage across the filament. Therefore, when the load current is large by the current detection circuit 16, that is, when the lighting is fully lit or the brightness is dimmed, the firing angle of the ignition circuit is delayed to reduce the filament preheating current. When the illuminance is low, that is, when the illuminance is dimmed to a low level, the firing angle of the firing circuit is accelerated to reduce power loss in the filament preheating circuit.

As described above, the present invention is a discharge lamp in which an AC power source is connected between one end of both filaments of a discharge lamp via a dimmer and a ballast, and a voltage responsive starter is connected between the other ends of both filaments. The electric light lighting device is provided with a correction power supply connected in series to the voltage responsive starter so as to reduce the voltage across the starter, and a switch means for controlling whether or not to generate the correction power supply output. Since the voltage applied to both ends of the voltage-responsive starter can be adjusted by controlling the generation of the correction power source using a means, stable dimming is possible down to low illuminance, and even when the ambient temperature is low. It also has the effect of providing stable lighting and reliable starting.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an example of a conventional discharge lamp lighting device, FIG. 2 is a circuit diagram of another example of the same, FIG. 3 is a circuit diagram of an embodiment of the present invention, and FIGS. 4 to 6 are circuit diagrams of other embodiments of the same as above. DESCRIPTION OF SYMBOLS 1... Discharge lamp, 2... Dimmer, 6... Voltage responsive starter, 7... Filament preheating transformer, 10... Transformer, 13... Time limit circuit, 15... Time limit, ignition circuit, 16... Current detection circuit.

Claims (1)

[Claims] 1. A discharge lamp comprising an AC power source connected between one end of both filaments of the discharge lamp via a dimmer and a ballast, and a voltage responsive starter connected between the other ends of both filaments. The lighting device is characterized in that the voltage responsive starter is provided with a correction power supply connected in series so as to reduce the voltage across the starter, and a switch means for controlling whether or not to generate the correction power supply output. Electric light lighting device. 2. The discharge lamp lighting according to claim 1, characterized in that the switch means is controlled by a time limit circuit that starts the time limit when AC power is turned on, and the correction power source is inserted after the discharge lamp starts. Device.