JPH0532982Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The invention can be used to supply high voltage, focus voltage, etc. to a small cathode ray tube used, for example, in an electronic viewfinder of a camera-integrated videotape recorder. The present invention relates to a flyback transformer suitable for use.

[Summary of the idea]

The present invention has a first notch part that exposes the core of the flyback transformer body and a second notch part that leads the high voltage lead wire to the outside on one surface of the insulating case that covers the flyback transformer body. By providing the lead wires continuously and sandwiching the lead wires between the second notch and the core, the workability of assembly is improved.

[Conventional technology]

For example, conventional flyback transformers used for supplying high voltage, focus voltage, etc. to small cathode ray tubes used in electronic viewfinders of camera-integrated videotape recorders have been
Something like the one shown in the figure has been proposed.

In the figure, 70 is the main body of the flyback transformer, 71 is a ferrite core, 72 is a bobbin, 73 is a coil, 74 is a rectifier consisting of a rectifier diode and a smoothing capacitor, 75 is a terminal pin, and 76 is a rectifier. This is a high voltage lead wire that is connected to the section 74 and leads out high voltage HV to the outside. Note that the terminal pin 75 is used for supplying the primary side voltage, outputting the focus voltage, and the like.

In addition, such a flyback transformer body 7
0 is sequentially housed in an insulating case 77 and a shield case 78 made of an insulating material such as plastic. Through holes 79 and 80 are formed in these insulating case 77 and shield case 78 for passing high voltage lead wire 76 therethrough.

[The problem that the idea attempts to solve]

According to the conventional flyback transformer as shown in the example in FIG.
0 in the insulation case 77 and the shield case 78, the lead wire 76 must be inserted into the insulation case 7.
7 and a through hole 79 formed in the shield case 78
80 was required, resulting in poor assembly workability.

Incidentally, such a flyback transformer is described in Japanese Utility Model Application Publication No. 109415/1983.

The present invention takes these points into consideration and aims to improve the workability of assembling a flyback transformer.

[Means to solve the problem]

The present invention is a flyback transformer in which a flyback transformer main body 1 is housed in an insulating case 2, and a first notch 21a that exposes a core 11 of the flyback transformer main body 1 on one surface of the insulating case 2. and flyback transformer body 1
A second notch 21b for leading out the high voltage lead wire 14 for extracting higher voltage is continuously provided, and the lead wire 14 is held between the second notch 21b and the core 11. It is something.

[Effect]

In the above structure, the high voltage lead wire 14 is held between the second notch 21b and the core 11, so when assembling the flyback transformer, it is not necessary to pass the lead wire through the through hole as in the conventional case. No other work is required, and assembly can be easily performed.

〔Example〕

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

FIG. 1 is a perspective view of the flyback transformer of this example, FIG. 2 is a front view thereof, and FIG. 3 is a sectional view thereof. FIG. 4 is an exploded perspective view thereof.
As shown in FIG. 4, this example is comprised of a flyback transformer main body 1, an insulating case 2, a shield case 3, a grounding fitting 4, and a lid 5.

In the flyback transformer main body 1, 11 is a ferrite core, 12 is a bobbin, 13 is a coil,
D1 and C1 are diodes and smoothing capacitors for high voltage rectification, and D2 and D3 are diodes for low voltage rectification. And 14 is a diode D1
This is a high voltage lead wire connected to the connection point of the capacitor C1 and for leading out the high voltage HV obtained at this connection point. Moreover, T1 to T8 are 1
This is a terminal pin used for secondary power supply, focus voltage output, etc., and is planted on the bobbin 12.

Here, the bobbin 12 is made of an insulating material such as plastic, and the low voltage side and the high voltage side are integrally formed as shown in FIG.
1 to T8 are formed in a T-shape with a square cross section, and one end of a long piece portion _TL extending in the vertical direction is connected to the bobbin 12.
The wire is press-fitted into a hole (not shown) formed on the bobbin 12, so that the wire is fixed on the bobbin 12.
As shown in FIG. 4, the ends of the coil 13 are soldered to the short pieces T _S extending horizontally.
As shown in _FIG . 6, the terminal pins T1 to T8 are pressed into the bobbin 1.
2 so that it cannot easily slip out through the hole formed therein.

Further, the portion of the flange portion 12a of the bobbin 12 that is in contact with the high voltage lead wire 14 is made into a stepped portion to form a thin wall portion 12b, as shown in FIG. The high voltage lead wire 14 is led out along this thin portion 12b. Further, in this case, the height of the high voltage lead wire 14 is made to match the height of the ferrite core 11, for example, by adjusting the thickness of the thin portion 12b.

Further, the grounding fitting 4 is formed in a U-shape, and when the flyback transformer is assembled as shown in FIGS. is attached to the ferrite core 11, and its state is maintained by the springiness of the grounding fitting 4.

The insulating case 2 is made of an insulating material such as plastic and has a box shape with five sides. One surface 21 of the insulating case 2 includes a rectangular cutout 21a through which the ferrite core 11 of the flyback transformer body 1 described above is exposed, and a semicircular cutout for leading the high voltage lead wire 14 to the outside. 21b is formed continuously.

Further, the shield case 3 is configured in a box shape with a metal plate and five sides similar to the insulating case 2 so that it can cover the above-mentioned insulating case 2. A notch 31a is formed on one surface 31 corresponding to one surface 21 of the insulating case 2, corresponding to the notches 21a and 21b. Furthermore, a connecting piece 31b is integrally formed on one surface 31 side of the shield case 3. This connecting piece 31b is connected to the first
When the flyback transformer is assembled as shown in FIGS. 3 to 3, it is bent along the tapered portion 21c formed on the one surface 21 side of the insulating case 2, and the tip of this connecting piece 31b is bent as described above. The ferrite core 11 is soldered to the ground fitting 4 attached to the ferrite core 11, so that the ferrite core 11 and the shield case 3 are integrally grounded.

Furthermore, claw portions 32a, 32b, and 32c are formed on the open surface side of this shield case 3. The claws 32a and 32b are used when the flyback transformer is assembled as shown in FIGS. 1 to 3.
It is bent inward so that the lid body 5 is fixed. Further, the claw portion 32c is used for positioning the flyback transformer when attaching it to the board.

Further, the lid body 5 is formed into a flat plate shape using an insulating material such as plastic. This lid body 5 is fitted into the open surface side of the insulating case 2 described above, so that the uneven shape of its outer periphery and the uneven shape of the open surface side end of the insulating case 2 have an opposite relationship. . In addition, through holes 51 are formed in the lid body 5 to correspond to the terminal pins T1 to T8, through which the terminal pins T1 to T8 of the flyback transformer main body 1 pass through and exit. Furthermore, recesses 52a and 52b are formed in the lid body 5, corresponding to the claws 32a and 32b of the shield case 3, into which the claws 32a and 32b fit when bent.

Flyback transformer body 1, insulation case 2,
The shield case 3, the grounding fitting 4, and the lid 5 are constructed as described above, and a flyback transformer is assembled, for example, in the following steps.

First, the insulating case 2 is housed inside the shield case 3. Next, the flyback transformer main body 1 with the grounding fitting 4 attached to the ferrite core 11 is housed in the insulating case 2. in this case,
The high voltage lead wire 14 is connected to the notch 2 of the insulating case 2.
1b from the open side. At this time, the high voltage lead wire 14 is held between the notch 21b of the insulating case 2 and the ferrite core 11, and is stably held. At this point, the connecting piece 31b of the shield case 3 is bent along the tapered portion 21c of the insulating case 2, and its tip end is soldered to the ground fitting 4 attached to the ferrite core 11. Next, the terminal pin T1 of the flyback transformer body 1
- Fit the lid 5 to the end of the open surface of the insulating case 2 so that T8 comes out from the through hole 51. and,
The claws 32a and 32b of the shield case 3 are bent inward to fix the lid 5.

In this way, a flyback transformer as shown in FIGS. 1 to 3 is assembled.

FIG. 8 shows a connection diagram of a high voltage circuit using the flyback transformer of this example. In FIG. 8, parts corresponding to those in FIGS. 1 to 7 are designated by the same reference numerals.

In the figure, 100 indicates a flyback transformer as a whole, and a ferrite core 11 and a shield case 3 are grounded via a terminal pin T6. Further, DC voltage +B is supplied to terminal pin T4, and output transistor is supplied to terminal pin T7.
A Tr and a resonance capacitor C are connected, and a damper diode D is connected to the terminal pin T8. Further, a smoothing capacitor C2 is connected to the terminal pin T1, and a focus voltage is output from this terminal pin T1. Further, a smoothing capacitor C3 is connected to the terminal pin T5, and a video circuit system voltage is output from this terminal pin T5. Further, a heater voltage is output between terminal pins T2 and T3.

In this case, the number of turns of the coil 13 is, for example, 3 turns between terminal pins T2 and T3, 70 turns between terminal pins T4 and T7, 7 turns between terminal pins T7 and T8, and 7 turns between terminal pins T8 and diodes D2, D.
600 turns between the points P where the anodes of No. 3 are connected,
When 2400 turns are made between point P and the point where the anode of diode D1 is connected, and a voltage of +5V is supplied as DC voltage +B to terminal pin T4,
+2500V as high voltage HV, +500V as focus voltage, -50V as video circuit voltage,
An effective value of 0.5V is output as the voltage for the heater.

In the flyback transformer of this example configured as described above, one surface of the insulating case 2 has a rectangular cutout 2 through which the ferrite core 11 is exposed.
A semicircular notch 21b for leading out the flyback transformer body 1 and the high voltage lead wire 14 to the outside is continuously formed.
When storing the high-voltage lead wire 14 in the notch 21b from the open side, the high-voltage lead wire 14 is held between the notch 21b and the ferrite core 11.
Maintained stably. Therefore, unlike conventional flyback transformers, work such as passing lead wires through through holes is not necessary, and assembly can be easily performed.

Further, in this example, the flyback transformer main body 1 is arranged between the insulating case 2 and the shield case 3 in a state in which the ferrite core 11 is exposed through the notches 21a and 31a provided on the surfaces 21 and 31 of the insulating case 2 and the shield case 3. 3, it can be made thinner in the horizontal direction than conventional flyback transformers. In this case, the ferrite core 11 is connected to the shield case 3 via the grounding fitting 4, and is grounded during use as shown in the connection diagram in FIG. ,
The ferrite core 11 takes the place of the shield case 3, and high frequency signals will not leak outside through the notch 31a of the shield case 3.

Further, in this example, the flange 12a of the bobbin 12
As shown in FIG. 7, a thin wall portion 12b is formed at the part where the high voltage lead wire 14 contacts, so that the same effect as if the diameter of the high voltage lead wire 14 were reduced by the thinner portion is obtained. will occur,
It can be formed thinner in the vertical direction than conventional flyback transformers. Further, since the high voltage lead wire 14 is led out along this thin portion 12b, the high voltage lead wire 14 can be reliably guided to a predetermined position. Further, when the thickness of the thin wall portion 12b is adjusted so that the height of the high voltage lead wire 14 matches the height of the ferrite core 11, the flyback transformer main body 1 is attached to the insulating case 2.
It can be stored stably without rattling inside.

In addition, in this example, since T-shaped terminal pins T1 to T8 are used, they can be attached to the bobbin 12 from the top, and the bobbin 12 can be made into an integrated low-voltage side and high-voltage side. In addition, the coil 13 and the like are connected by soldering to the horizontally extending short pieces T _S of the terminal pins T1 to T8. It can be made thinner in the vertical direction by not connecting the coil 13 or the like to the long piece T _L extending in the vertical direction. Further, since heat escapes during soldering is large, there is no fear that the bobbin 12 will be deformed during soldering and the terminal pins T1 to T8 will be displaced. Therefore, there is no need to adjust the position of the terminal pin, which may cause the coil 13 to break, and work efficiency is improved.

In the above embodiment, the grounding fitting 4 is attached to the ferrite core 11 of the flyback transformer main body 1, and the connecting piece 31b of the shield case 3
Although the end portion of the connecting piece 31b is soldered to the earthing metal fitting 4, the connecting piece 31b may be directly connected to the ferrite core 11 without using the earthing metal fitting 4.

[Effect of idea]

According to the present invention described above, a rectangular notch through which the core is exposed and a semicircular notch through which the high voltage lead wire is guided to the outside are continuously formed on one surface of the insulating case. Therefore, when storing the flyback transformer main body in the insulating case, the high voltage lead wire should be inserted into the notch from the open side, thereby ensuring that the high voltage lead wire is held between the notch and the core. is maintained stably. Therefore, according to the present invention, unlike conventional flyback transformers, work such as passing the high voltage lead wire through the through hole of the insulating case is no longer necessary.
Easy to assemble.

[Brief explanation of the drawing]

Figures 1 to 3 are configuration diagrams showing an embodiment of the present invention, Figures 4 to 8 are explanatory diagrams, and Figure 9
The figure is a configuration diagram of a conventional example. 1 is a flyback transformer main body, 2 is an insulating case, 3 is a shield case, 4 is a grounding metal fitting, 5 is a lid body, 11... ferrite core, 21a and 21
b is a notch.

Claims (1)

[Scope of Claim for Utility Model Registration] A flyback transformer in which a flyback transformer main body is housed in an insulating case, a first notch exposing a core of the flyback transformer main body on one surface of the insulating case; A second notch is continuously provided for leading a high voltage lead wire for taking out high voltage from the transformer body to the outside, and the lead wire is connected to the second notch.
A flyback transformer characterized by being sandwiched between the notch portion of the core and the core.