DC potentiometer

Abstract

A DC potentiometer with four stepping discs for DC voltage measurement, each of its stepping discs is composed of a measuring disc and a replacement disc with the same structure as the measuring disc, and it measures on the first step disc There is a resistor welded between the contacts of the disc and the replacement disc, and there is no resistance on the other step discs, which makes the internal lead resistance of the potentiometer, the contact resistance of the switch and its variation, and the influence of the thermoelectric potential on the potentiometer can be ignored.

Description

technical field [0001] The invention relates to an instrument for measuring DC voltage. Background technique [0002] At present, for a DC potentiometer with four stepping discs, the connection between the four stepping discs is generally switched by switches in the middle disc, which will cause the deterioration of the contact resistance and limit the resolution. In order to overcome this problem, large brushes are generally used to increase the contact area, and silver-copper composite materials are used; application number 200810120441. method, its four stepping discs are composed of measuring discs and substituting discs, excluding auxiliary discs, each measuring disc and substituting discs have resistance, and the measuring discs and substituting discs on its four stepping discs are Changing the disc constitutes a bridge circuit in the circuit. Its biggest problem is that the error is not independent. Once the indication value of a certain point of the measuring disc i...

AI Technical Summary

Problems solved by technology

[0002] At present, for a DC potentiometer with four stepping discs, the connection between the four stepping discs is generally switched by a switch in the middle disc, which will cause the deterioration of the contact resistance and limit the resolution.

In order to overcome this problem, large brushes are generally used to increase the contact area, and silver-copper composite materials are used; application number 200810120441. method, its four stepping discs are composed of measuring discs and substituting discs, excluding auxiliary discs, each measuring disc and substituting discs have resistance, and the measuring discs and substituting discs on its four stepping discs are Changing the disc constitutes a bridge circuit in the circuit. Its biggest problem is that the error is not independent. Once the indication value of a certain point of the measuring disc is out of tolerance, it is impossible to determine which resistance is caused by the out-of-tolerance, which brings inconvenience to identification and maintenance.

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