JPH0729603Y2 - Variable resistor for high voltage - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention is used, for example, as a current control volume for adjusting the horizontal balance of an electron beam of a color television, and a high voltage of several thousand to tens of thousands of volts is applied. High voltage variable resistor.

[Conventional technology]

FIG. 3 is a plan view showing the internal structure of a conventional high voltage variable resistor. In the figure, a substantially horseshoe-shaped resistor 2 made of carbon or the like is formed on the surface of a ceramic substrate 1. A silver electrode 3 is provided at one end of the resistor 2 and a silver electrode 4 is provided at the other end thereof. Are formed respectively. A terminal 5 for live electricity is soldered to the end of the silver electrode 3 not covered with the resistor 2, and a ground terminal is provided at the end of the silver electrode 4 not covered with the resistor 2. 7 is solder 8
These terminals 5 and 7 are attached to the ceramic substrate 1
Protruding on both sides of. Slider holder 9 with knob 9a protruding
Is rotatable with respect to the ceramic substrate 1, and a sliding contact 10a on the lower side of the slider 10 fixed to the slider receiver 9 is provided.
Slide on the resistor 2, and the sliding contact 10b on the upper side of the slider 10 is always elastically contacted with a metal lead plate (not shown), and this lead plate is connected to the ground terminal 7. ing. Therefore, the slider 10 is kept at the same potential as the ground terminal 7.

The ceramic board 1 and the slider receiver 9 described above are housed inside a casing (not shown), and the live terminal 5 and the ground terminal 7 are provided.
A high voltage of, for example, 4000 V is applied between and. When adjusting the resistance value, the knob 9a that is projected to the outside of the casing is rotated to change the contact position between the sliding contact 10a and the resistor 2, so that the current control can be performed. ing.

[Problems to be solved by the device]

By the way, in this type of high voltage variable resistor, the resistor 2 is 100 MΩ.
The sliding contact 10a is often used in the vicinity of the silver electrode 3 because of its high resistance. However, if an abnormal voltage is applied in a state where the sliding contact 10a and the sliding electrode 10a are close to each other, as shown in FIG. , Arc discharge A occurs from the tip of the base electrode portion 3a of the silver electrode 3 covered by the resistor 2 toward the slider 10, and the base electrode portion 3a and the resistor 2 are burned by the arc heat to set resistance. There was a problem that the value changed.

Therefore, it is an object of the present invention to solve the above-mentioned problems of the prior art and to provide a highly reliable high-voltage variable resistor in which the variation of the set resistance value caused by arc discharge is prevented.

[Means for Solving the Problems]

To achieve the above object, the present invention provides a resistor substrate having a first electrode and a second electrode formed at both ends of a strip-shaped resistor, and soldering the first electrode to the resistor substrate. A first terminal protruding from the resistance board; a second terminal soldered to the second electrode and protruding from the resistance board;
A slider that slides on the resistor and is electrically connected to the second terminal, and a slider receiver that is fixed to the resistor and is rotatable are provided. In the high-voltage variable resistor to which a high voltage is applied between the second terminal and the first terminal, the one end of the resistor is connected to the first electrode through a low resistance region having a resistance smaller than that of the resistor. The slider is connected and the slider is positioned on the resistor except the low resistance region.

[Action]

With the above configuration, the slider is always located in the high resistance region, and the low resistance region that connects the high resistance region and the first electrode functions as a protective resistance even when an abnormal voltage is applied. The high voltage is attenuated to make arc discharge less likely to occur, and the presence of the low resistance region increases the distance between the first electrode and the slider, so that the solder that has adhered to the first electrode slides on. The arc discharge can be preferentially caused between the children or between the first terminal and the second terminal, and the possibility of arc discharge occurring between the first electrode and the slider is extremely small.

〔Example〕

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

1 and 2 show a high-voltage variable resistor according to an embodiment of the present invention. FIG. 1 is an explanatory view of a main part, FIG. 2 is a plan view of a resistance substrate, and FIG. The same reference numerals are given to the parts corresponding to those in FIG.

In the high-voltage variable resistor shown in FIGS. 1 and 2, the end portion of the substantially horseshoe-shaped resistor 2 on the silver electrode 3 side is a low resistance region 2a of about 50 kΩ, and the end portion of this low resistance region 2a is silver. The silver electrode 3 is characterized in that it is in contact with the electrode 3, and the silver electrode 3 to which the live-electricity terminal 5 is soldered 6 has almost no base electrode portion. Therefore, the silver is almost the length of the low resistance region 2a. Electrode 3 and high resistance area 2b
Is separated from. Since the resistance in the low resistance area 2a is significantly smaller than that in the high resistance area 2b of about 100 MΩ, the slider 10
The sliding contact 10a is always kept in contact with the high resistance region 2b, and the sliding contact 10a is located on the high resistance region 2b in the vicinity of the low resistance region 2a in the normal usage pattern.

Therefore, when the sliding contact 10a is positioned on the high resistance area 2b near the low resistance area 2a as shown in FIG. 1, an abnormal voltage is applied between the live terminal 5 and the ground terminal 7. Even if it does, the low resistance region 2a functions as a protective resistance, so that the high voltage is attenuated and arc discharge is less likely to occur. Further, since the silver electrode 3 and the high resistance region 2b are separated from each other by the length of the low resistance region 2a, the distance between the silver electrode 3 and the slider 10 is large even in a normal use mode, and therefore arc discharge is caused. 1 may occur between the solder 6 and the slider 10 or between the solder 6 and 8 as shown in FIG. 1, or between the live terminal 5 and the ground terminal 7 on the back side of the ceramic substrate 1. By preferentially causing arc discharge at these points, arc discharge between the silver electrode 3 and the slider 10 can be avoided. Therefore, the risk that the silver electrode 3 and the resistor 2 are burned by the arc heat is reduced, and the set resistance value can be kept stable.

Other than that, the configuration and operation of parts not particularly described are the same as those of the conventional product shown in FIG.

In the above embodiment, the high voltage variable resistor in which the slider 10 is electrically connected to the ground terminal 7 has been described. However, the high voltage variable resistor in which the slider 10 is electrically connected to the live terminal 5 is described. In the case of a vessel, it is necessary to avoid arc discharge between the silver electrode 4 and the slider 10. Therefore, in such a case, the end of the resistor 2 on the side of the silver electrode 4 may be a low resistance region, and the end of this low resistance region may be brought into contact with the silver voltage 4.

[Effect of device]

As described above, the present invention provides protection between the electrode to which a high voltage is applied between the slider and the high resistance region of the resistor in which the sliding contact of the slider is located. Since a low resistance region as resistance is formed, even when an abnormal voltage is applied,
The high voltage is attenuated by the low resistance region and arc discharge is unlikely to occur.Also, even if arc discharge occurs, it is at a place other than between the electrode and the slider, which is widely separated, and the electrode or resistor does not arc heat. There is less risk of burnout due to
It is possible to provide a highly-reliable high-voltage variable resistor in which the set resistance value is stabilized.

[Brief description of drawings]

1 and 2 show a high-voltage variable resistor according to an embodiment of the present invention. FIG. 1 is an explanatory view of essential parts, FIG. 2 is a plan view of a resistance substrate, and FIG. FIG. 4 is a plan view showing the internal structure of a variable resistor for high voltage according to an example, and FIG. 1 ... Ceramic substrate, 2 ... Resistor, 2a ... Low resistance region, 2b ... High resistance region, 3 ... Silver electrode, 5 ... Live power terminal, 6 ... Solder, 7 ... Ground terminal , 10 …… Sliding contact.

Claims (1)

[Scope of utility model registration request] 1. A first electrode and a second electrode on both ends of a strip-shaped resistor.
And a first terminal that is soldered to the first electrode and protrudes from the resistance substrate, and a second substrate that is soldered to the second electrode and protrudes from the resistance substrate. A second terminal; a slider that slides on the resistor and is electrically connected to the second terminal; and a slider receiver that fixes the slider and is rotatable. In a high-voltage variable resistor in which a high voltage is applied between a first terminal and the second terminal, one end of the resistor is connected through a low resistance region whose resistance is smaller than that of the resistor. A variable resistor for high voltage, characterized in that the slider is connected to the first electrode and the slider is positioned on the resistor excluding the low resistance region.