JPS5873998A - Device for firing via high frequency discharge lamp - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a high-frequency lighting device for a discharge lamp, and is directed to a configuration in which a high-frequency oscillator is connected to the discharge lamp via a leakage type transformer, and which enables sufficient preheating of the discharge lamp. This is an attempt to downsize leakage type transformers.

An example of a circuit of a typical conventional discharge lamp high frequency lighting device is shown in FIG. That is, a high frequency oscillator 2 that converts a commercial power source 1 into a high frequency signal is connected to a discharge lamp 4 via a leakage type transformer 3. The leakage type transformer 3 includes a first main winding 6 and a feedback winding 6 on the primary side, and the high frequency oscillator 2 constitutes a self-excited oscillator. Further, on the secondary side, a lighting winding 7 and one end of a preheating auxiliary winding 8 wound in an opposite phase to the lighting winding 7 are connected to the lighting winding 7, and these filaments 9, 9, etc. A preheating auxiliary winding 8 and a starting means are connected between the ends.

It is connected via 1o. The starting means 10 is configured to be controlled by a timer circuit section 11, and utilizes opening/closing contacts of an electromagnetic relay (not shown) provided within the timer circuit section 11. In this circuit example, when preheating the discharge lamp 4, the starting means 10 is closed by the timer circuit section 11, and the filament 9.9' is preheated by the differential voltage between the lighting winding 7 and the preheating auxiliary winding 8. . This preheating is performed for about 1 second, after which the starting means 10 is opened by the timer circuit section 11. Then, the high voltage of the lighting winding 7 is applied between the filaments 9 and 9' of the discharge lamp 4, so that the discharge lamp 4 is lit. By the way, in this circuit example, by using the beam cage type transformer 3, this transformer itself exhibits a current limiting effect, so there is no need to insert a separate current limiting device (coil or capacitor) in series with the discharge lamp 4.
Although it is easy to miniaturize the device, there is a limit to miniaturization because it is necessary to equip the leakage type transformer 3 with the preheating auxiliary winding 8. Furthermore, when a glow switch is used as the starting means 1o, since there is a considerable time delay in the operation of the bimetal in the glow switch, the lighting winding 7 of the discharge lamp 4 is activated before the glow switch is closed. There is a drawback that the voltage is applied and the discharge lamp 4 cold starts, resulting in a short life span.

When the switching contacts of an electromagnetic relay are used as the starting means 10 and controlled by the timer circuit section 11, such a drawback does not occur because the high-frequency oscillator 2 operates when the commercial power supply 1 is applied, and the lighting winding 7 receives a high voltage. This is because the timer circuit section 11 can close the starting means 1o before the appearance of the start means 1o. Furthermore, in this circuit example, once the timer circuit section 11 has opened the starting means 10, it is difficult to close it again (although this can be done by repeating the operation from the beginning), so that the discharge lamp 4 can be turned on at low temperatures. There is a drawback that it is easy to make it impossible to turn on the light. On the other hand, when a glow switch is used as the starting means 10, there is no such drawback, and although it takes time for the discharge lamp 4 to light up, the glow switch can be used any number of times, resulting in a shortened lifespan of the discharge lamp 4 due to cold starts. There is.

The present invention aims to fundamentally eliminate the drawbacks of the conventional circuits described above. 1. Miniaturization of the leakage type traceless, sufficient preheating of the discharge lamp, and cold start when a glow switch is used as the starting means. The present invention is hereinafter explained based on an example of an implementation circuit.

An example of a circuit for implementing the present invention is shown in FIG.
Components common to those in the figures are given the same numbers. The difference is that an intermediate terminal 12 is provided in the lighting winding 7 of the leakage type transformer 3', and each filament of the discharge lamp 4 is
A switching means 13 is provided which can selectively connect one end of the filament 9 to a part of the lighting winding 7, and a starting means 1o is provided between the other ends of each filament 9 and 9' of the discharge lamp 4. It was connected. The switching means 13 is a timer circuit 11
It is appropriate to perform the starting operation in synchronization with the means 16. Similarly to the starting means 1o, the electromagnetic starting means 1o (not shown) and the switching means 13 are operated in conjunction with each other using manual switches. Alternatively, semiconductor switching means may be used, or alternatively,
A glow switch may be used as the starting means 10.

The operation according to the above circuit configuration is such that when starting the discharge lamp 4, the timer circuit section 11 closes the starting means 1o, connects the switching means 13 to the intermediate terminal 12 of the lighting winding 7, and connects the switching means 13 to the intermediate terminal 12 of the lighting winding 7. Filament of discharge lamp 4) 9.9
' is connected to a part of the lighting winding 7 for preheating. Next, the setting time of the timer circuit section 11 (about 1 second)
After lapse of time, the starting means 1o is opened, and the switching means 13 is connected to the end of the lighting winding 7, so that one end of the filament 9 and 9' of the discharge lamp 4 is connected via the switching means 13 to the lighting winding. The high voltage of all the lighting windings 7 is applied between the filaments 9 and 9' of the discharge lamp 4, so that the discharge lamp 4 is lit.

uses a part of the lighting winding 7, but if a leakage type transformer 3' is used, a large preheating current can be passed through the filaments 9, 9t.

For example, when a 14W type discharge lamp 4 is used, all of the lighting winding 7, that is, when the switching means 13 is connected to the end of the lighting winding 7 (solid line state), all of the lighting winding 7 is connected to the end of the lighting winding 7. When the number of windings is 280, only a preheating current of 300mm can be obtained, but the switching means 13 is connected to the intermediate terminal 1 of the lighting winding 7.
2 (state of 9-dotted line), a preheating current of 410 mm could be obtained even though only 11,200 turns of the lighting winding 7 were used. Note that the oscillation frequency of the high frequency oscillator 2 is approximately 30 K)Iz.

This is based on the same principle as the conventional example shown in FIG. However, this conventional example has the disadvantage of increasing the size of the cage type transformer 3 due to the need for an extra preheating auxiliary winding 8, whereas the present invention has the advantage of being able to be made smaller. .

In addition, when a glow switch is used as the starting means 1o,
Although it may be difficult to synchronize with the switching means 13, the switching means 13 may be set to switch from the dotted line state to the solid line state at the timing when the glow switch is once closed and then opened. If the discharge lamp 4 does not turn on once at low temperatures, the glow switch is automatically operated again, so that it can be turned on. In the case of this glow switch, the timer circuit 11 is set so that the switching means 13 switches to the dotted line state before a high voltage is applied to both ends of the discharge lamp 4, that is, the glow switch. Since no high voltage is applied to the electric lamp 4, a cold start of the discharge lamp 4 can be prevented, and the life of the discharge lamp 4 can be extended. + In other words, the actual measurement shows that the lighting winding °.

The open circuit voltage of all 7 is e o o Vp-p, and the discharge lamp 4 cold starts, but if a part of the lighting winding 7 is used (the switching means 13 is in the dotted line state), the open circuit voltage of the present invention The high frequency oscillator 2, which is a component, may be separately excited type,
The timer circuit section 11 is not necessarily required yet. This is the case where the switching means 13 and the starting means 1° = user switch.

As described above, the present invention provides a discharge lamp high-frequency lighting device in which a high-frequency oscillator is connected to a discharge lamp via a leakage type transformer, in which an intermediate terminal is provided in the lighting winding of the leakage type transformer to connect each filament of the discharge lamp. A switching means is provided that can selectively connect one end to all or a part of the lighting winding, and the other end of each filament of the discharge lamp is connected via a starting means to preheat the discharge lamp. At times, the starting means is closed, and one end of each filament of the discharge lamp is connected to a part of the lighting winding via the switching means, and when the discharge lamp is lit, the starting means is opened. and a discharge lamp 10, characterized in that one end of each filament of the discharge lamp is connected to all of the lighting windings via the switching means. When preheating the discharge lamp, a sufficient preheating current can be obtained by using part of the lighting winding of the 17-cage type transformer, so there is no need to wind the preheating auxiliary winding around the leakage type transformer as in the past. However, this transformer has the excellent feature of being able to be miniaturized, which is useful in terms of miniaturization required for this type of high-frequency lighting device, and it also becomes possible to use a glow switch as the starting means.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of one embodiment of the present invention, and FIG. 2 is a typical conventional circuit diagram. 2... High frequency oscillator, 3'... Leakage type transformer, 4... Discharge lamp, 7...
・Lighting winding, 9.9′...Filament, 1o
...Starting means, 11 ... Timer circuit section, 12 ... Intermediate terminal, 13 ... Switching means.

Claims (4)

[Claims] (1) A high frequency oscillator is connected to the discharge lamp via a leakage type transformer, an intermediate terminal is provided in the lighting winding of the leakage type transformer, and the entire lighting winding is connected between one end of each filament of the discharge lamp. Alternatively, a switching means that can be selectively connected to a part is provided, and the other ends of each filament of the discharge lamp are connected via a starting means, and when the discharge lamp is preheated, the starting means is closed. , one end of each filament of the discharge lamp is connected to a part of the lighting winding via the switching means, the starting means is opened when the discharge lamp is lit, and the starting means is connected via the switching means to a part of the lighting winding. 1. A high-frequency discharge lamp lighting device, characterized in that one end of each filament of the discharge lamp is connected to all of the lighting windings. (2) A high-frequency discharge lamp lighting device according to claim 1, which uses a glow switch as a starting means. (3) The high-frequency discharge lamp lighting device according to claim 1, wherein the starting means and the switching means are controlled by a timer circuit section. (4) A high-frequency discharge lamp lighting device according to claim 2, wherein the switching means is controlled by a timer circuit.