JPS6018904A - Flyback transformer with variable resistor - Google Patents

Abstract

PURPOSE:To facilitate the connection of the secondary coil of a transformer with a variable resistor and case sealing work by pressing a seal made of conductive rubber into a through hole on the side of the transformer and mounting the variable resistor on the outside of a case so as to cover the seal. CONSTITUTION:A flyback transformer 20 with a variable resistor is composed of a flyback transformer 21, a variable resistor 22, and a transformer case 30. Each of primary and secondary coils 23 and 24 is wound on the transformer 21 surrounded by the case 30. A resistor case 31 is provided on the side of the case 30 on which the resistor 22 is mounted, in which a case 32 made of an insulator is arranged. A film resistive layer is formed on the base 32. The case 31 is connected by a resistor case connecting frame 43 provided on the side of the case 30. On the side of the case 30 surrounded by the connecting frame 43 is formed a through hole 44, into which a seal as an input terminal 46 made of conductive rubber is provided. The seal is connected with an output terminal 45 to facilitate sealing work.

Description

Detailed Description of the Invention The present invention comprises a secondary coil and a secondary coil, both coils are sealed with resin within a transformer case, and an output terminal of the secondary coil provided within the transformer case is connected to the secondary coil. This invention relates to a flyback transformer with a variable resistor connected to a variable resistor attached to the outside of one side of the transformer case.

Conventionally, there is a flyback transformer with a variable resistor as shown in FIG. This flybank transformer 1 with a variable resistor has a primary coil 2 and a secondary coil 3.
Equipped with These 2.3 coils are wound around the coil bobbins 4 and 5, fitted together, and then sealed in a transformer case 6 made of insulating resin.

Note that these coils 2 and 3 are inserted into the bobbin 4 and are magnetically coupled to each other. Secondary coil 3
The coil bobbin 5 is provided with an output terminal 7 protruding from its outer circumferential surface, and is connected to a lead wire at an intermediate portion of the secondary coil 3. An opening 8 for attaching a variable resistor is formed in one side of the transformer case 6. The variable resistor 1o is
It has a resistor case 11 made of insulating resin and having an open mounting surface side to the transformer case 6. An alumina substrate 12 is placed inside this resistor case 11 . A film resistor 13 forming a variable resistance section and a fixed resistance section is formed on the inner surface of this alumina substrate 12, and a film resistor 13 attached to the end face of the rotor 14 forms the film resistor forming the variable resistance section. It is made to slide into contact with. The rotor 14 is rotated using a knob 16 that projects outside of the resistor case 11. The variable resistor 10 is a transformer case 6.
It is attached so as to cover the opening 8 of. Variable resistor 10
A lead wire 17 connected to the terminal electrode of the film resistor 13 is led out from the outer surface of the alumina substrate 12 , and this lead wire 17 is connected to the output terminal 7 . 18 is a pin terminal to which the end of the primary coil 2 etc. implanted in the base of the bobbin 4 is connected, and 19 is an insulating resin filled in the cavity in the case 6.

This flyback transformer 1 with a variable resistor is assembled in the following steps. That is, the primary and secondary coils 2,
3 is wound around each bobbin 4, 5, and the terminal portion (not shown) of the primary coil 2 is connected to a predetermined pin terminal 18, and the output lead wire (not shown) of the secondary coil is connected to the output terminal 7, etc., and then are fitted together, and the lead wire 17 of the variable resistor 10 is soldered to the output terminal 7. After that, they are assembled into the transformer case 6. In order to prevent the resin 19 from leaking from the gap between the transformer case 6 and the variable resistor 10 during resin injection to be performed later, an adhesive or the like is used to seal the gap when the variable resistor is attached to the transformer case 6. Apply sealant to the required locations. Finally, the insulating resin 19 is injected into the transformer case 6 and hardened, and the core is inserted into the bobbin 4.

However, the soldering of the lead wire 17 of the variable resistor 10 and the output terminal 7 of the secondary coil is a work, and the assembly of the primary and secondary coils 2 and 3 and the transformer case of the variable resistor 10 is a work. The process of applying the sealant is time-consuming and difficult to automate using a machine.

In view of the above, the present invention has been made so that the connection between the secondary coil and the variable resistor and the sealing of the through hole formed in the transformer case for the connection can be easily mechanized, and can be performed by a simple and easy operation. The purpose is to

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 2 is a circuit diagram of a flybank transformer with a variable resistor according to an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view thereof. This flyback transformer with variable resistor 20
For example, as shown in FIG. 2, a fly bank transformer 21 is connected to a variable resistor 22 (not shown) for adjusting the focus voltage and screen voltage of a CRT. The transformer 21 includes a primary coil 23 and three diodes 24 to 2.
The secondary coil 27 has a secondary coil 27 interposed therebetween.

Both coils 23 and 27 are wound around bobbins 28 and 29, respectively, and are inserted into the transformer case 30 in a mutually fitted state. Among the bobbins 28 and 29, at least the bobbin 29 on which the secondary coil 27 is wound is a split bobbin having a plurality of flanges.

The variable resistor 22 includes a box-shaped resistor case 31 with an open side. A substrate 32 made of an insulator such as alumina is placed inside the case 31. Two arc-shaped film resistors 33 and 34 forming a variable resistance section are formed on the inner surface of this substrate 32. These resistors 33.
34 are connected in series through a film resistor forming a fixed resistance part, and film resistors forming a fixed resistance part are also formed at opposite ends of the resistors 33 and 34. Sliding contacts 37, 38 supported by rotors 35, 36 are brought into contact with the film resistor 3'334 forming the section.

Each rotor 35, 36 is rotatably supported by the resistor case 31, and each rotor 39, 40 extends outside the case 31.
By rotating the focus voltage output terminal 41
and a screen voltage output terminal 42 (not shown in FIG. 3) so that the output voltage can be adjusted.

By the way, on one side of the transformer case 30, a quadrilateral resistor case connection frame 43 is provided which is open on the outer side to accommodate a variable resistor. This connecting frame 43
The resistor case 31 is fitted and fixed inside. A through hole 44 is provided in a portion of the transformer case 30 surrounded by the connecting frame 43.

A needle-shaped output terminal 45 is implanted into the bobbin 29 of the secondary coil 27 housed in the transformer case 30 and protrudes from the circumferential surface of the flange toward the through hole 44 . This output terminal 4
5 is connected to a lead wire at the intermediate portion of the secondary coil 27.

In addition, a sealing plug 46 made of conductive rubber is provided in the through hole 44.
is fitted in a sealed manner. Sealing plug 4 fitted into through hole 44
6, the output terminal 45 is inserted. Also, resistor 2
The case 31 is attached to the connecting frame 4 on the outer surface of the board 32 of No. 2.
A needle-shaped input terminal 47 is provided which pierces the sealing plug 46 when attached to the terminal 3. 48 is an insulating resin filled in the transformer case 31. In addition, resistor case 3
The means for fixing the resistor case 31 to the transformer case 30 is not limited to the one using such a quadrilateral connecting frame 43, but also the means for fixing the resistor case 31 to the transformer case 30, for example, by sandwiching the resistor case 31 between a pair of support pieces protruding from the circumference of the case 30. It may also be a means of inserting it into the case 30 or a means of fixing it to the circumferential surface of the case 30 with an adhesive. Furthermore, the needle-like shape of the output terminal 45 and the input terminal 47 does not necessarily mean that the tips of the terminals are sharp, provided that the terminals are thin as a whole. Furthermore, the connection of the input terminal of the resistor 22 is not limited to the lead wire from the middle part of the secondary coil 27 as in the above embodiment, but may be a lead wire from the end of the winding of the secondary coil 27.

As explained above, the present invention has the following advantages: By forming the output terminal of the secondary coil and the input terminal of the variable resistor into needle shapes,
When installing a variable resistor on the outer circumference of the transformer case by fitting a sealing plug made of conductive rubber into the through hole on the side of the transformer case into which the primary coil and secondary coil are inserted, and covering this sealing plug. The output terminal and input terminal are inserted into the sealing plug, and the output terminal of the secondary coil and the input terminal of the variable resistor are connected through the sealing plug, and conventional soldering is not required. is removed, making assembly work extremely simple and easy. In addition, since the assembly work consists of simply fitting two parts together, it can be easily automated by mechanical work. Furthermore, since the through hole is tightly closed with a sealing plug made of conductive rubber, resin leakage is less likely to occur when resin is injected, and changes in the characteristics of the variable resistor due to resin leakage can be eliminated, and the resin seal can be used as a variable resistor. This can be done before assembling the transformer, and there is no need to discard the variable resistor due to a defective transformer. In addition, since a sealant such as an adhesive for preventing resin leakage is not required, the method can be implemented at a lower cost. Furthermore, since the variable resistor is attached to the outer circumferential surface of the transformer case, the insulating substrate on which the film resistor of the variable resistor is mounted does not touch the resin inside the transformer case, so there is no need for a buffer on the variable resistor side. Effects such as no need to fill with soft resin as a material can be obtained.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a conventional example, FIG. 2 is a circuit diagram of an embodiment of the present invention, and FIG. 3 is a longitudinal sectional view thereof. 22... Variable resistor, 23... Primary coil, 24... 2
Next coil, 30...Transformer case, 44...Through hole, 4
5... Output terminal, 46 - Input terminal. Applicant Murata Manufacturing Co., Ltd. Agent Kazuhide Okada Patent Attorney Figure 1 Figure 3 24 28 23

Claims (1)

[Claims] (1) The primary coil and secondary coil, which are magnetically coupled to each other through the core, are sealed in resin in a transformer case, and a variable resistor is attached to the transformer case.
In a flyback transformer with a variable resistor in which the output terminal of the next coil and the input terminal of the variable resistor are connected to each other, a through hole is formed in one side of the transformer case, and a conductive rubber is inserted into the through hole. A variable resistor is attached to the outer peripheral surface of the transformer case so as to cover the sealing plug, and the output terminal of the secondary winding and the input terminal of the variable resistor are connected in a needle-like manner. A fly bank transformer with a variable resistor is characterized in that the transformer is formed and pierced through a sealing plug made of conductive rubber.