JPS5936878Y2 - discharge lamp lighting device - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a discharge lamp lighting device.

In a discharge lamp lighting device, the discharge lamp is normally lit using a commercial AC power supply and a ballast, and when the commercial AC power supply is cut off, the discharge lamp is lit at high frequency using a pre-prepared battery, high frequency inverter, and oscillation transformer. The device with the number 5 is known as an emergency light or guide light lighting device.

In such a lighting device, a ballast and an oscillation transformer are connected across the discharge lamp, so that when high-frequency lighting is performed, high-frequency current does not flow into the ballast or other circuits used for lighting using commercial AC power. To achieve this, a triac (for example, a bidirectional control rectifier) is connected between the ballast and the discharge lamp, and it is turned on when lit by a commercial AC power supply, and the gate current is turned on when lit at high frequency. A configuration is being considered in which the water is turned off without being flushed.

By the way, in such a configuration, if a heating circuit is attached to the filament of the discharge lamp when it is lit by a commercial AC power source, at least two triacs are required.

In addition, the same number of gate signal generation circuits as the triacs must be prepared for gating the triacs.

This idea requires only one semiconductor switch, such as a triac, to prevent high-frequency current from flowing to the commercial AC power supply as well as the ballast and other circuits required for lighting using the same power supply during high-frequency lighting. The purpose is to

An embodiment of this invention will be described below with reference to the drawings.

1 is a power supply terminal connected to a commercial AC power supply, 2 is, for example, an autotransformer type ballast, 3 is a discharge lamp, 4A and 4B are heating coils for heating the filament of the discharge lamp 3, and 5 is a DC power supply, for example. battery, 6 is a high frequency inverter that converts the voltage of battery 5 to high frequency, T is an oscillation transformer, 8
is a ballast capacitor, 9 is a filament capacitor,
Reference numeral 10 denotes a contact that is turned on when the commercial AC power source is cut off, and is, for example, a contact of a relay that is excited by the commercial AC power source.

According to this idea, the primary coil 12 of a separate transformer 11 having a winding ratio of 1:1 is connected to one of the heating coils 4A and 4B, for example, the heating coil 4A, and the secondary coil 13 is released. Connect it to one filament of electric light 3.

Further, a triac 14 is connected between the primary coil 12 and the secondary coil 13.

Reference numeral 15 denotes a gate signal generation circuit that generates a gate signal for the triac, which receives the voltage of a commercial AC power source as an input, generates a gate signal in a countercurrent to this, and supplies the gate signal to the triac.

In the above configuration, when lighting the discharge lamp 3 using a commercial AC power source, the gate signal generating circuit 1
5 is driven, the triac 14 is turned on, whereby the output voltage of the ballast 2 is applied to the discharge lamp 3, and the discharge lamp 3 is lit.

In this case, since the ballast capacitor 8 exhibits a high impedance with respect to the output current from the ballast 2, no commercial alternating current flows through the oscillation transformer T.

On the other hand, a voltage is also induced in each of the heating coils 4A and 4B, and the induced voltage of the heating coil 4B is directly applied to one filament of the discharge lamp 3 to heat that filament, but the voltage of the other heating coil 4A is When the induced voltage is applied to the primary coil 12 of the separate transformer 11, the secondary voltage induced in the secondary coil 13 is applied to the other filament, thereby heating that filament.

When lighting the discharge lamp 3 at high frequency, the contact 10 is turned on, and the output voltage of the high frequency inverter 6 is outputted as a secondary voltage of the oscillation transformer I and applied to the discharge lamp 3.

As a result, the discharge lamp 3 is lit at high frequency.

In this case, the triac 14 is connected to the OFF state because its gate current does not flow due to disconnection of the commercial AC power supply, so that no high frequency current flows through the ballast 2vc.

In this case, if the heating coil 4A is directly connected to the filament of the discharge lamp 3 without using the separate transformer 11, it is necessary to connect a triac to both ends of the heating coil 4A. If one of the triacs is omitted, a high frequency current will flow into the ballast 2.

This is as explained at the beginning.

However, if you use a separate transformer 11 as shown in the figure, you only need to connect one triac 14.
Even when lighting with a commercial AC power source, the output voltage of the ballast 2 can be applied to the discharge lamp 3 and each filament can be heated, and when lighting at high frequency, one end of the heating coil 4A can be turned off by turning off the triac 14. The other end is also cut off by the separate transformer 11.

By doing the above, it becomes possible to prevent the high frequency current from flowing back to the commercial AC power supply side.

In the illustrated example, only one filament is heated by the high-frequency current via the filament capacitor 9 during high-frequency lighting.

Although the configuration shown in FIG. 1 is a lighting device using a constantly heated rabbit start, this invention can also be applied to a lighting device using a glow start.

FIG. 2 shows the configuration for this purpose.

According to this configuration, the primary coil 12 of the separate transformer 11 is connected in series to the glow switch 16 and one filament of the discharge lamp 3, and this series circuit is connected between the output terminals of the ballast 2.

In this configuration, if the lights are powered by commercial AC power,
The discharge lamp 2 is lit by applying the output voltage of the ballast 2 to the discharge lamp 3 via the triac 14, as in the case of FIG. 1, but heating of each filament is done when the glow switch 16 is turned on. One of the filaments is heated via the primary coil of the separate transformer 11 and the glow switch 16, and at this time, a voltage is induced in the secondary coil 13 of the separate transformer 11. The voltage will heat the other filament.

High frequency lighting is exactly the same as in FIG.

Even in this circuit configuration, if the separate transformer 11
If the glow switch 16 is not used and the discharge lamp 3 is connected in parallel, high-frequency current will flow through the glow switch 16 during high-frequency lighting, so an attempt is made to cut it off. In order to do this, triac 1
4, it is necessary to connect another triac in series with the glow switch 16.

However, by maintaining the separate transformer 11 as shown in the figure, it becomes possible to prevent high frequency current from flowing into the commercial AC power supply and the circuit for lighting using the same power supply, just by using one triac.

As detailed above, according to this invention, even when heating the filament of a discharge lamp, it is possible to prevent high-frequency current from flowing into a commercial AC power source during high-frequency lighting by using just one semiconductor switch. be effective.

[Brief explanation of the drawing]

11 is a circuit diagram showing an embodiment of this invention, and FIG. 2 is a circuit diagram showing another embodiment of this invention. 1... Commercial AC power supply terminal, 2... Ballast, 3... Discharge lamp, 5... Battery, 6...
...High frequency inverter, I...Oscillation transformer, 11...Separate transformer, 12...
...Primary coil, 13...-Secondary coil, 1
4...Semiconductor switch (TRIAC).

Claims (1)

[Scope of utility model registration request] In a discharge lamp lighting device that lights a discharge lamp by selecting a commercial AC power source and a high frequency power source, the discharge lamp is connected between both ends of an oscillation transformer of the high frequency power source and is turned on when lit by the commercial AC power source. , is connected between the output terminals of the ballast connected to the commercial AC power source via a semiconductor switch that is turned off when the lamp is lit by the high frequency power source, and a secondary voltage is applied to one filament of the discharge lamp. 1 of the separate transformer that applies power for heating
A discharge lamp lighting device comprising the semiconductor switch connected between a secondary coil and a secondary coil.