JPH0595021U - Coil bobbin device for high voltage pulse transformer - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a coil bobbin for a high voltage pulse transformer which has excellent magnetic coupling by sharing the bobbin of the primary winding and the secondary winding, and also has good insulation performance. A primary winding 4 is wound around a groove 2 formed near an intermediate portion on the outer circumference of a bobbin 1, and the primary winding 4 is formed in a groove 3 adjacent to the groove 2 and slightly shallower.
The secondary winding 5 is wound over substantially the entire area of the bobbin 1 in the longitudinal direction so that the winding pitch is substantially the same.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a coil bobbin device for a high voltage pulse transformer used as a starting device used for starting and restarting a high pressure discharge lamp such as a mercury lamp or a metal halide lamp.

[0002]

[Prior Art]

 Generally, high-voltage discharge lamps such as mercury lamps and metal halide lamps require a high starting voltage, and a high-voltage pulse generated by a starting device (referred to as an igniter) is applied to both ends of the lamp to start it. Is. Although it depends on the type of lamp, in order to instantly restart the high-pressure discharge lamp, a very high voltage of several tens of kv is generally required, and the circuit shown in Fig. 7 is used. .. 8 shows the igniter circuit in the circuit of FIG.

The operation state will be described with reference to the circuit diagrams of FIGS. A no-load secondary voltage of the ballast X is generated between the secondary side terminals x and y of the ballast X, and this voltage is boosted by the step-up transformer Trf in the circuit of the igniter Ig. On the secondary side of the ballast X, a high voltage as shown by the broken line in FIG. The secondary side of the ballast X, capacitor C _2, the primary winding n ₁ and discharge gears-up Gap of the high-voltage pulse transformer PT is connected, the capacitor C ₂ as shown in FIG. 9 (A) The voltage at both ends gradually rises. Then, when this voltage reaches the discharge start voltage Vgap (for example, about several kv) of the discharge gap Gap, the electric charge accumulated in the capacitor C ₂ becomes the primary winding n ₁ of the high voltage pulse transformer PT and the discharge gap Gap. Discharges rapidly through.

At that time, a high voltage pulse voltage (for example, about several tens of kv) is generated in the secondary winding n ₂ of the high voltage pulse transformer PT according to the winding ratio. Then, this high-voltage pulse voltage is applied to both ends of the lamp L via the capacitor C ₁ to start the lamp L. The operation at the time of restart is also the same, and a high-voltage pulse of about several tens of kv is generated, but it can be restarted immediately even after the light is turned off. In addition, when the lamp L is started and lit, the secondary side terminal voltage of the ballast X becomes substantially a lamp voltage, which is reduced to about 1/2 or less of that at no load. Therefore, the secondary side of the step-up transformer Trf of the igniter Ig. The voltage does not rise up to the discharge start voltage Vgap of the discharge gap Gap, and the generation of the high voltage pulse voltage stops in the discharge gap Gap.

FIG. 3 shows an example of a structure of a conventional high-voltage pulse transformer. For winding a cylindrical primary winding b on a core a made of a material such as a cylindrical ferrite, similarly. A primary bobbin c and a secondary bobbin e for winding the secondary winding d are externally configured. In such a high voltage pulse transformer, a high voltage pulse of about several tens of kv is generated in the secondary winding d, so the withstand voltage between the primary winding b and the secondary winding d or the creepage between the secondary winding d. In order to ensure a withstand voltage function, the high-voltage pulse transformer is housed in a case f and filled with an epoxy resin g. As shown in FIGS. 4A and 4B, a groove h for winding a winding is formed on the primary bobbin c or the secondary bobbin e, and the winding work is performed for this groove h. Not only can this be done simply, but the distance between the windings is kept constant.

[0006]

[Problems to be solved by the device]

 As described above, in the conventional high-voltage pulse transformer, the epoxy resin is filled to ensure the withstand voltage, but this filling is incomplete, and the resin does not flow sufficiently between the primary bobbin c and the secondary bobbin e. When a space is formed between them, when a high-voltage pulse voltage is generated, the electric field concentrates in that space, causing an electrical breakdown, which prevents the prescribed pulse voltage from being generated. In the worst case, there is a risk of destroying or burning the high voltage pulse transformer.

Further, in order to reduce the size of the high voltage pulse transformer, the gap between the primary bobbin c and the secondary bobbin e is made as small as possible. If the resin is to be filled in, the filling time will take longer, and the filling temperature will need to be raised, leading to poor filling workability. In order to facilitate the filling operation, there is a method of providing a protrusion i on the inside of the secondary bobbin e 1 to increase the gap between the primary bobbin c and the secondary bobbin e as shown in FIG. Since the shape is increased only in the part i and the relative distance between the primary winding b and the secondary winding d is increased, the magnetic coupling is deteriorated and the pulse voltage generated in the secondary winding d There is a drawback that the value decreases. Furthermore, since the primary bobbin c 2 and the secondary bobbin e are provided, the overall structure of the high-voltage pulse transformer becomes large, and after the primary winding b is wound around the primary bobbin c, the primary bobbin c Since it has to be inserted into the secondary bobbin e having the secondary winding d, it is difficult to process the winding start and end of the primary winding b.

Further, as shown in FIG. 6, there is a structure in which the primary winding b and the secondary winding d are wound together on one bobbin j. There is also a problem that the magnetic coupling between the windings d deteriorates and the peak value of the pulse voltage generated in the secondary winding d decreases. In consideration of the above conventional problems, the present invention uses a common bobbin for the primary winding and the secondary winding to achieve excellent magnetic coupling and high voltage pulse with good insulation performance. It is intended to provide a coil bobbin for a transformer.

[0009]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention winds a primary winding in a groove formed near the middle part of the outer circumference of a bobbin, and has a depth different from that of the groove and is adjacent to the groove. A secondary winding is wound in the groove formed in the longitudinal direction of the bobbin.

[0010]

[Action]

 The operation of this device will be described. The bobbin is shared and the primary winding and the secondary winding are wound around two grooves with different depths provided on the outer circumference of the bobbin to maintain the magnetic coupling and insulation performance of the two in good condition. Of.

[0011]

【Example】

 An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows a first embodiment of this idea, in which a primary winding 4 is wound around a groove 2 formed in the vicinity of an intermediate portion of the outer circumference of a bobbin 1, and the groove 2 is slightly shallower adjacent to the groove 2. In the formed groove 3, the secondary winding 5 is wound over substantially the entire area of the bobbin 1 in the longitudinal direction so that the winding pitch is substantially the same as the winding pitch of the primary winding 4. With this configuration, one bobbin 1 can be shared and the primary winding 4 and the secondary winding 5 can be wound, good magnetic coupling can be achieved, and sufficient insulation performance between the two can be achieved. Can be secured.

FIG. 2 shows a second embodiment of the present invention. The difference from the first embodiment is that both the primary winding 4 and the secondary winding 5 are wound over substantially the entire area of the bobbin 1 in the longitudinal direction. It has a structure. In such a structure, if the number of turns of the primary winding 4 and the secondary winding 5 is the same as that of the first embodiment, for example, there is an advantage that the length of the bobbin 1 in the longitudinal direction can be remarkably shortened. Further, since the primary winding 4 can be wound substantially over the entire area of the secondary winding 5, the magnetic coupling is further improved as compared with the case of the first embodiment, and a higher high-voltage pulse can be generated. The starting performance of the lamp can be improved.

Although the groove 3 is formed to be slightly shallower than the groove 2 in both the first and second embodiments, the groove 2 may be formed to be slightly shallower than the groove 3. Further, it goes without saying that if the high-voltage pulse transformer is housed in the case and the inside is filled with, for example, an epoxy resin, the insulation performance is improved and the size can be greatly reduced.

[0014]

[Effect of the device]

 The present invention is configured as described above, and has the advantages that the bobbin of the primary winding and the secondary winding is shared and the magnetic coupling is excellent and the insulation performance is good.

[Brief description of drawings]

FIG. 1 is a front view of a bobbin showing a first embodiment of the present invention.

FIG. 2 is a front view of a bobbin showing a second embodiment of the present invention.

FIG. 3 is a sectional front view of a conventional high voltage pulse transformer.

4A is a front view of a bobbin used in a conventional high voltage pulse transformer, and FIG. 4B is a side view of the same.

FIG. 5 is a side view showing another example of the bobbin used in the conventional high voltage pulse transformer.

FIG. 6 is a front view showing another example of a conventional high-voltage pulse transformer.

FIG. 7 is a circuit diagram of a high pressure discharge lamp lighting circuit.

FIG. 8 is an igniter circuit diagram inside a high pressure discharge lamp lighting circuit.

FIG. 9 is a voltage waveform diagram of a high pressure discharge lamp lighting circuit.

[Explanation of symbols]

 1 bobbin 2,3 groove 4 primary winding 5 secondary winding

Claims (1)

[Scope of utility model registration request] 1. A primary winding is wound around a groove formed in the vicinity of an intermediate portion on the outer periphery of a bobbin, and the groove is formed adjacent to the groove and has a depth different from that of the groove. ,
A coil bobbin device for a high voltage pulse transformer, which is formed by winding a secondary winding in the longitudinal direction of the bobbin.