Voltage measuring instrument without variation

Abstract

A voltage measurer with no variation is prepared as forming the first stepping disc by one measurement disc and two auxiliary discs, forming the second stepping disc by measurement disc with 9x9 omega ring resistance net and two 1 omega resistance as well as auxiliary disc with 10x0.5 omega resistances, forming the third stepping disc by 10x1 omega measurement disc and 10x1 omega replacement disc, connecting various contacts of the fourth stepping disc to relevant contacts on measurement disc of the third stepping disc, connecting all said measurement discs by wire without using any switch and connecting certain resistances in circuit.

Description

technical field [0001] The invention relates to an instrument for measuring DC voltage. Background technique [0002] At present, for a potentiometer with four measuring discs, the connection between the four measuring discs is generally switched by a switch in the middle disc, which will cause a change in contact resistance and limit the resolution. In order to overcome this problem, large electric brushes are generally used to increase the contact area, and silver-copper composite materials are used; application number 200510062365.8 discloses a new method for solving the deterioration of switch contact resistance by a potentiometer with four measuring discs. The first and second stepping discs are composed of a measuring disc and a replacement disc. The resistance values ​​on the measuring disc and the substituting disc are the same. Every time a resistance is added to the measuring disc, the substituting disc will reduce the same resistance. 3. The fourth stepping disc ...

AI Technical Summary

Problems solved by technology

The four measuring discs are connected between the two measuring terminals, so that the brush on the stepping disc switch is excluded from the measuring circuit, and there is no switching between the resistances on the four measuring discs, so there is no variation; Since the potentiometer step disc switch rotates at an angle of 15° for each step, 24 contacts can be distributed on each layer. There are resistances on each layer, and the inner layer’s resistance is out of tolerance, which will cause inconvenience to maintenance. The fourth stepping plate has half layers of measuring plate, replacement plate and auxiliary plate. The stepping plate switch also needs two layers inside and outside, and the inner layer also has resistance. Maintenance is also inconvenient

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