JPH10208959A - Discharge lamp stabilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a discharge lamp stabilizer which prevents itself from going into an abnormal state such as smoking due to the abnormal heat of a coil. SOLUTION: The stabilizer 3 comprises a body 10 having a coil 9 composed of a base winding separate coil 9a and top winding separate coil 9c insulated from and wound round the coil 91, and a temp. fuse 11 for detecting the temp. of the coil 9 to thermally protect the body 10. The fuse 11 is disposed between the base and top coils 9a, 9c, thereby directly receiving the abnormally generated heat of the coil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge lamp ballast used for a high-pressure discharge lamp or the like having two arc tubes electrically connected in parallel, provided with a proximity conductor for starting assistance.

[0002]

2. Description of the Related Art FIG. 3 is an electric circuit diagram showing the configuration of a lighting circuit for a high-pressure discharge lamp. In FIG. 3, reference numeral 1 denotes an AC power supply, 2 denotes a noise filter comprising a capacitor 2a and a resistor 2b parallel thereto. 3 is a discharge lamp stabilizer and 4 is a high pressure discharge lamp.

The high-pressure discharge lamp 4 includes a first arc tube 5 having a proximity conductor 5a for assisting start, a second arc tube 6 also having a proximity conductor 6a for assisting start, and a bimetal type, for example. A starter 7 is provided with a starter 7a and a resistor 7b connected in series. The first and second arc tubes 5 and 6 are electrically connected in parallel, and the adjacent conductors 5a and 6a are provided so as to have polarities different from each other. The light emitting tubes 5, 6 and the starter 7a are accommodated in an outer tube (not shown) of the high-pressure discharge lamp 4.

The discharge lamp ballast 3 disposed between the noise filter 2 and the high-pressure discharge lamp 4 has an impedance so that both arc tubes 5 and 6 of the high-pressure discharge lamp 4 are lit at a ratio of about half each. A component obtained by dividing the component into two approximately equally is used. As shown in FIGS. 2A and 2B, the discharge lamp ballast 3 detects the temperature of the coil 9 in a ballast body 10 having an iron core 8 and a coil 9 combined with the iron core 8 via a coil bobbin. And a thermal fuse 11 for thermally protecting the ballast body 10.

The coil 9 includes a lower winding separate coil portion 9a and an upper winding separate coil portion 9c wound around an outer periphery thereof via an electrical insulating layer 9b such as an insulating tape in order to achieve the lighting ratio described above. Have. Note that FIG.
12A and 12B show a flange of the coil bobbin.

In the prior art, the thermal fuse 11 is attached to the outer periphery of the upper coil 9c by an electrically insulating adhesive tape 13. The upper winding separate coil section 9c is connected to one terminal 1a of the AC power supply 1 via the thermal fuse 11, and the lower winding separate coil section 9a is connected to the other terminal 1b of the AC power supply 1.
It is connected to the.

In such a lighting circuit for the high-pressure discharge lamp 4, even after the high-pressure discharge lamp 4 is lit according to the light emission of one of the arc tubes 5, 6, the separate coil portions 9a, 9c of the discharge lamp ballast 3 In both cases, the AC power supply 1 is continuously supplied, so that both the separate coil portions 9a and 9c generate heat. Such heat generation is detected by the thermal fuse 11.

Therefore, when the coil 9 generates abnormal heat due to a rare short-circuit or interlayer short-circuit, the temperature is sensed by the thermal fuse 11, and the power supply is cut off by blowing the coil 9 to protect the ballast body 10.

[0009]

However, in the prior art, since the thermal fuse 11 is provided on the outer periphery of the upper winding separate coil portion 9c as described above, the lower winding separate coil portion 9a may have a rare short circuit or an interlayer short circuit. In the case of abnormal heat generation, the heat capacity of the upper winding separate coil portion 9c interposed between the coil portion 9a and the thermal fuse 11 delays the sensing of abnormal heat generation of the lower winding separate coil portion 9a. Thereby, the lower winding separate coil part 9a
There is a possibility that abnormal heat generation may occur, and smoke may be generated from the abnormal heat generation.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a discharge lamp ballast capable of preventing an abnormal state such as smoke emission of a ballast body when a coil generates abnormal heat. is there.

[0011]

According to the present invention, a thermal protector for detecting the temperature of the coil and thermally protecting the ballast body is mounted on a ballast body having an iron core and a coil combined therewith. In addition, it is assumed that the coil is a discharge lamp ballast including a lower winding separate coil section and an upper winding separate coil section wound around the lower winding separate coil section insulated.

In order to solve the above-mentioned problem, the invention of claim 1 is characterized in that the thermal protector is provided between the lower winding separate coil portion and the upper winding separate coil portion. .

According to the first aspect of the present invention, since the thermal protector attached to the coil is provided between the lower winding coil section and the upper winding coil section, which of the two separate coil sections generates abnormal heat. Even in this case, it is possible to directly receive the heat of the one of the separate coil units that has generated abnormal heat without sensing the heat via one of the separate coil units, thereby preventing a delay in the heat detection.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 and FIG.
A first embodiment of the present invention will be described with reference to FIG. The lighting circuit in which the discharge lamp ballast according to this embodiment is used is the same as the lighting circuit of the high-pressure discharge lamp 4 shown in FIG. 3, and the description of the lighting circuit is omitted here to avoid duplication. .

The discharge lamp ballast 3, which divides the impedance component into two approximately equally so that both the arc tubes 5, 6 of the high-pressure discharge lamp 4 are lit at a ratio of about half, is shown in FIGS. 1A and 1B. As shown, a ballast body 10 having an iron core 8 and a coil 9 combined therewith via a coil bobbin,
A thermal protector for detecting the temperature of the coil 9 and thermally protecting the ballast body 10, for example, a temperature fuse 11 is attached. In FIGS. 1A and 1B, reference numeral 12 denotes a flange of the coil bobbin. In order to set the lighting ratio as described above, the coil 9
Has a lower winding separate coil portion 9a and an upper winding separate coil portion 9c wound around the outer periphery thereof via an electric insulating layer 9b such as an insulating tape.

The thermal fuse 11 is sandwiched between the lower coil and upper coil separate coil portions 9a and 9c, for example, contacts one surface of the electrical insulating layer 9b and has an inner peripheral surface of the upper coil separate coil portion 9c. It is installed on the other side.

The thermal fuse 11 has a fuse body having lead legs (not shown) made of two wires covered with an electrically insulating tube. And the thermal fuse 11
The tips of the two lead legs, one ends of which protrude from the tube, are pressed into a slit-like groove (not shown) formed so as to cut into the flange 12 from the peripheral edge thereof, so as to be placed on the electric insulating layer 9b. The upper winding separate coil portion 9c is held under such a state.

In the discharge lamp ballast 3 of the high-pressure discharge lamp 4 having such a configuration, the temperature fuse 11 sandwiched between the separate coil portions 9a and 9c sets the temperature of the upper winding separated coil portion 9c to the lower winding separated coil portion 9c. The temperature of the lower winding separate coil portion 9a can be directly sensed without being disturbed by the coil portion 9a, and the temperature of the upper winding separate coil portion 9c can be directly detected without being disturbed by the upper winding separate coil portion 9c. Can be sensed.

Therefore, when one of the lower coil or upper coil separate coil portions 9a, 9c abnormally generates heat due to a rare short circuit or an interlayer short circuit, the thermal responsiveness of the thermal fuse 11 is good, and the heat sensing is delayed. Therefore, the power supply can be turned off by quickly operating the thermal fuse 11 in response to the abnormal heat generation.

When abnormal heat generation occurs in the coil 9 as described above, the heat detection is not delayed in the thermal fuse 11, and the thermal fuse 11 can function properly to perform a protection operation. In addition, smoke from the ballast body 10 can be prevented.

In order to provide the same protection function, the temperature fuse 11 is connected to both the separate coil portions 9a, 9a.
c, between one end face thereof and one flange 1
2 may be provided so as to be sandwiched between them.
1 easily gets in the way. On the other hand, in the arrangement arranged as in this embodiment, the lower winding separate coil portion 9a does not hinder the winding operation, and the upper winding separate coil portion 9c also includes the thermal fuse 11 together. The winding operation of the coil 9 can be easily performed because the winding operation is sufficient. Moreover, by winding the upper winding separate coil portion 9c, the degree of adhesion of the thermal fuse 11 to both the separate coil portions 9a and 9c is increased, which is excellent in that quicker temperature sensing can be realized.

The present invention is not limited to the first embodiment. For example, the thermal protector 11 such as a thermal fuse is provided between the separate coil portions 9a and 9c, on the side of the lower winding separate coil portion 9a, that is, by contacting the thermal protector 11 with the outer periphery of the lower winding separate coil portion 9a by the electric insulating layer 9b. May be attached. In addition, in this case, since the thermal protector 11 can be held by the electric insulating layer 9b, it is possible to save the processing of forming the groove for holding the protector on the flange 12 and the time of holding the thermal protector 11 in the groove. .

In the present invention, the thermal protector 11 may be either a return type such as a bimetal or a non-return type such as a thermal fuse. Is excellent in that if the coil 9 generates abnormal heat, the coil temperature can be prevented from rising repeatedly.

[0024]

The present invention is embodied in the form described above and has the following effects.

According to the invention described in claim 1, a thermal protector for preventing an abnormal rise in temperature of the coil is provided between the lower winding separate coil portion and the upper winding separate coil portion, thereby causing abnormal heat generation. Since the thermal protector directly receives the heat of the separate coil part, the delay of the heat detection of the abnormal heat does not occur. Can be prevented beforehand.

[Brief description of the drawings]

FIG. 1A is a front view showing a configuration of a discharge lamp ballast according to a first embodiment of the present invention, with a part cut away. FIG. 2B is a side view showing the configuration of the discharge lamp ballast according to the first embodiment, with a part cut away.

FIG. 2A is a front view showing a configuration of a conventional discharge lamp ballast with a part cut away. (B) is a side view which shows the structure of the discharge lamp ballast which concerns on a prior art example by cutting out a part.

FIG. 3 is an electric circuit diagram showing a configuration of a lighting circuit of the high-pressure discharge lamp.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 3 ... Discharge lamp stabilizer, 8 ... Iron core, 9 ... Coil, 9a ... Upper winding separate coil part, 9b ... Electric insulating layer, 9c ... Lower winding separate coil part, 10 ... Ballast body, 11 ... Thermal fuse (thermal protector) ).

Claims (1)

[Claims] 1. A thermal protector for detecting the temperature of the coil and thermally protecting the ballast body is mounted on a ballast body having an iron core and a coil combined with the iron core, and the coil is wound by a lower winding. In a discharge lamp ballast comprising a separate coil portion and an upper wound separate coil portion wound around the outer periphery of the lower wound separated coil portion, the thermal protector is provided with the lower wound separated coil portion and the upper wound separated coil portion. A discharge lamp ballast characterized by being installed between the discharge lamp ballast.