JPH0722505U - Variable resistor for high voltage - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the occurrence of dielectric breakdown and discharge between the adjacent terminals and the insulation-coated high-voltage conductor. A second terminal T20 includes an insertion terminal portion a connected to the second electrode, a flat plate portion b extending in contact with the back surface of the circuit board, and a core wire connecting terminal portion c extending from the flat plate portion b. Have and. The flat plate portion b has such a length that the terminal portion c for connecting the core wire does not come into contact with the first insulation-coated high-voltage conductor 4. Then, the width W2 of the portion b2 located between the insertion terminal portion a and the portion b1 of the flat plate portion b to which the core wire connecting terminal portion c is connected,
Width W1 of the part b1 where the terminal part c for connecting the core wire is connected
Smaller than. The terminal portion c is arranged so that the core wire 5a of the second insulation-coated high-voltage conductor 5 inserted into the hole h of the terminal portion c extends in a direction parallel to the direction in which the first insulation-coated high-voltage conductor 4 extends.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a high voltage variable resistor used for obtaining a high voltage output such as a focus voltage and a screen voltage of a television receiver.

[0002]

[Prior art]

 FIG. 2 shows the back surface of a known high-voltage variable resistor for supplying the focus voltage and the screen voltage, and FIG. 3 shows the resistance circuit pattern viewed from the back surface side of the circuit board. This type of high voltage variable resistor uses an insulating case 1 with one end open. In this insulating case 1, a ceramic high-voltage circuit board 2 having a resistance circuit pattern shown in FIG. 3 is arranged. On the surface of the substrate 2, there are provided a first variable resistor R1 for focusing, a second variable resistor R2 for a screen and electrodes E1 to E4. The electrode E1 is a focusing electrode, and the electrode E2 is a screen electrode. The first electrode E1 for focus and the second electrode E2 for screen are arranged in a straight line along one edge 2a of the circuit board 2. Although not shown, a slider having a contact that slides on the resistors R1 and R2 is operably housed between the base plate 2 and the case 1.

Terminals T1 to T4 electrically connected to the electrodes E1 to E4 are fixed to the back surface of the circuit board 2. Each of the terminals T1 to T3 has an L-shaped cross section, and has a connecting portion formed by punching in a portion that comes into contact with the back surface of the base plate 2, and this connecting portion is a through hole formed in the base plate 2. It is fixed by soldering to the corresponding electrode provided on the front surface side of the substrate after being inserted into. The terminal T2 for the screen is laterally fixed in order to extend an insulation-coated high-voltage conductor 4 described later along the edge 2a of the substrate 2. An insulating resin is cast to form an insulating layer 3 in the space surrounded by the opening of the insulating case 1 and the circuit board 2. The terminals of the terminals T1 to T4 are separated from the insulating layer 3 by the insulating layer 3. Exposed. The terminal portions of the terminals T1 and T2 are formed with through holes h into which the core wires of the insulation-coated high-voltage conductors 4 and 5, which will be described later, are inserted.

As shown in FIG. 4, an insulation-coated high-voltage conductor 4 for focusing and an insulation-coated high-voltage conductor 5 for a screen pass through guide holes 1 a and 1 b provided at the end of the insulating case 1 to connect the resistors. It is routed to the back side. The high-voltage conductor 4 has a core wire soldered to the terminal portion of the terminal T1 and extends along the edge 2a of the substrate 2 toward the terminal T2 side. The high-voltage conducting wire 5 is connected to the terminal T2 by soldering with the core wire 5a inserted in a through hole h provided in the terminal portion of the terminal T2 fixed horizontally.

[0005]

[Problems to be solved by the device]

 Conventionally, the terminals having the same L-shape are used as the terminals T1 to T3, and the terminal T2 is simply placed sideways to allow passage of the high-voltage conductor 4. Therefore, when the core wire 5a of the high-voltage conductor 5 is inserted into the hole h of the terminal portion of the terminal T2, the tip of the core wire 5a faces the high-voltage conductor 4 side, and the solder portion 6 approaches the high-voltage conductor 4. This type of variable resistor is often fixed to a flyback transformer via a resin layer made of an insulating resin such as epoxy resin. FIG. 5 shows a state in which the high-voltage conductor 4 is pressed by the thermal expansion or thermal contraction of the insulating layer 7 and is in contact with the solder portion 6 when fixed to the flyback transformer via the insulating layer 7. As shown in FIG. 5, when the solder portion 6 and the outer coating portion 4b of the high voltage conductor 4 are in contact with each other, when the potential difference between the solder portion 6 and the core wire 4a of the high voltage conductor 4 becomes large, Dielectric breakdown and discharge may occur. When the focus voltage is 10 kV and the screen voltage is 1 kV, a potential difference of 9 kV is generated. If air bubbles are present in the outer coating 4b of the high-voltage conducting wire 4, sufficient dielectric breakdown occurs even at such a voltage.

An object of the present invention is to provide a high voltage variable resistor that solves the above problems.

[0007]

[Means for Solving the Problems]

 A high-voltage variable resistor to be improved by the present invention is an insulating case having one end opened, a first variable resistor and a second variable resistor which are disposed in the insulating case and are provided on the surface thereof. Circuit board for high voltage provided with the electrode and the second electrode, a slider provided with a contactor sliding on the variable resistor, and the first electrode fixed to the back surface side of the circuit board. And the first terminal and the second terminal electrically connected to the second electrode, and the opening of the insulating case and the circuit so as to expose the terminal portions of the first terminal and the second terminal. An insulating layer in which an insulating resin is cast in a space surrounded by the substrate, a first insulation-coated high-voltage conductor and a second insulation-coated high-voltage conductor connected to the first terminal and the second terminal It has and. The first electrode and the second electrode are arranged along one edge of the circuit board. The first insulation-coated high-voltage conductor is arranged so as to extend toward the second terminal side to which the second insulation-coated high-voltage conductor is connected and to extend along the edge of the circuit board. The high-voltage conducting wire is soldered to the terminal portion of the second terminal with the core wire inserted in the hole provided in the terminal portion.

According to the present invention, the insertion terminal portion in which the second terminal is connected to the second electrode, the flat plate portion extending in contact with the back surface of the circuit board, and the core wire connecting terminal portion extending from the flat plate portion are provided. I have it. The flat plate portion has a length such that the terminal portion for connecting the core wire does not come into contact with the first insulation-coated high-voltage conductor. In addition, the flat plate part has a shape in which the width dimension between the insertion terminal part and the part where the core wire connecting terminal part is connected is smaller than the width size of the part where the core wire connecting terminal part is connected. is doing. The core wire connecting terminal portion is provided so that the core wire of the second insulation-coated high-voltage conductor inserted into the hole extends in a direction parallel to the direction in which the first insulation-coated high-voltage conductor extends.

[0009]

[Action]

 If the second terminal has the above-described shape, the solder portion between the terminal portion of the second terminal and the core wire of the second insulation-coated high-voltage conductor is located at a position away from the first insulation-coated high-voltage conductor. Even if the insulating resin is disposed and used for attachment, there is no possibility that the first insulation-coated high-voltage conducting wire and the solder portion come into contact with each other, and the problem of dielectric breakdown and discharge can be solved.

[0010]

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

FIG. 1A shows a main part of an embodiment in which the present invention is applied to a high voltage variable resistor attached to a flyback transformer. In FIG. 1A, the same members as those of the conventional resistor shown in FIGS. 2 to 4 are denoted by the same reference numerals as those used in FIGS. 2 to 4. In this embodiment, a terminal having a shape as shown in FIG. 1B is used as the second terminal T20 to which the high voltage conductor 5 for the screen is connected.

The terminal T20 includes an insertion terminal portion a that is inserted into a through hole provided in the board and is soldered to an electrode provided on the front surface of the board, and a flat plate portion b that contacts the back surface of the board. It comprises a terminal portion c extending from the flat plate portion b at a substantially right angle. The length of the flat plate portion b is determined such that the terminal portion c does not come into contact with the high voltage conductor 4, and the terminal portion c is provided at a position where the core wire 5a of the high voltage conductor 5 can be inserted without bending. The flat plate portion b is composed of a portion b1 to which the terminal portion c for connecting the core wire is connected, and a portion b2 located between the portion b1 and the insertion terminal portion a. As shown in the figure, the width dimension W2 (dimension in the direction orthogonal to the longitudinal direction) of the portion b2 of the flat plate portion b is smaller than the width dimension W1 of the portion b1 to which the terminal portion c is connected. . With such a shape, even when a large force is applied to the terminal portion c when the insulating resin forming the insulating layer 7 (FIG. 5) on the flyback transformer side is cured, the force is applied to the flat plate portion b. It is possible to prevent an excessive force from being absorbed by the portion b2 having a small width and being applied to the terminal insertion portion a to be soldered and connected to the second electrode. Therefore, even if the length of the flat plate portion b becomes long, it is possible to prevent the connection failure from occurring in the soldering portion between the second electrode and the terminal insertion portion a of the second terminal T20.

According to the present embodiment, as shown in FIG. 1A, when the core wire 5a of the high-voltage conductor 5 is inserted into the hole h of the terminal portion c and soldered, the core wire 5a becomes the high-voltage conductor wire. Since it extends in the direction parallel to the wire 4, there is no risk that the solder portion 6 will come into contact with the high-voltage conductor 4.

[0014]

According to the present invention, the half section of the terminal portion of the second terminal and the core wire of the second insulation-coated high-voltage conductor is arranged at a position apart from the first insulation-coated high-voltage conductor. Therefore, there is no possibility that the first insulation-coated high-voltage conductor and the solder portion will come into contact with each other, it is possible to prevent the occurrence of dielectric breakdown and discharge, and it is possible to greatly improve the reliability of the product. Further, it is possible to prevent a connection failure from occurring in the connection portion between the second electrode and the second terminal.

[Brief description of drawings]

FIG. 1A is a diagram showing a main part of an embodiment of the present invention,
(B) is a perspective view of the terminal used in (A).

FIG. 2 is a back view of a conventional high voltage variable resistor.

FIG. 3 is a diagram showing a substrate provided with a resistance circuit pattern when the circuit substrate used in the resistor of FIG. 2 is viewed from the back surface.

FIG. 4 is a view showing a mounting state of a high voltage conductor of a conventional resistor.

FIG. 5 is a cross-sectional view showing a mounting state of a high voltage winding when a conventional resistor is mounted on a flyback transformer.

[Explanation of symbols]

 1 Insulation case 2 High-voltage circuit board 3 Insulation layer 4 First insulation-coated high-voltage conductor 5 Second insulation-coated high-voltage conductor 5a Core wire 6 Solder part T1 First terminal T2, T20 Second terminal a Insertion terminal part b Flat plate part c Terminal part h hole

Claims (1)

[Scope of utility model registration request] 1. An insulating case (1) having one end open, a first variable resistor and a second variable resistor, a first electrode and a second electrode which are arranged in the insulating case and are on the surface. A high-voltage circuit board (2), a slider having a contactor that slides on the variable resistor, and a first electrode and a second electrode fixed to the back surface of the circuit board. A first terminal and a second terminal electrically connected to the electrode, and an opening of the insulating case and the circuit board so as to expose the terminal portions of the first terminal and the second terminal. An insulating layer (7) in which an insulating resin is cast in the enclosed space, a first insulation-coated high-voltage conductor (4) connected to the first terminal and the second terminal, and a second insulation Coated high voltage conductor (5)
The first electrode (E1) and the second electrode (E2) are arranged along one edge of the circuit board, and the first insulation-coated high-voltage conductor (4) is The second insulation-coated high-voltage conductor (5) is arranged so as to extend toward the second terminal side to which the second insulation-coated high-voltage conductor (5) is connected and along the edge of the circuit board. Is a variable resistor for high voltage, which is soldered to the terminal portion of the second terminal with the core wire (5a) inserted in the hole (h) provided in the terminal portion, wherein the second terminal (T20) is an insertion terminal portion (a) connected to the second electrode (E2), a flat plate portion (b) extending in contact with the back surface of the circuit board, and a core wire connection extending from the flat plate portion. And a terminal portion (c) for connecting the core wire to the flat plate portion (b). Has a length that does not come into contact with the insulation-coated high-voltage conductor (4), and the flat plate portion (b) is a portion where the insertion terminal portion (a) and the core wire connecting terminal portion (c) are connected ( The width dimension (W2) of the portion (b2) between the portion (b1) and the terminal portion (c) for connecting the core wires is the width dimension (W1) of the portion (b1).
), And the core wire connection terminal portion (c) has a core wire (5) of the second insulation-coated high-voltage conductor (5) inserted into the hole (h).
A variable resistor for high voltage, wherein a) is provided so as to extend in a direction parallel to a direction in which the first insulation-coated high-voltage conductor (4) extends.