Two-range DC potentiometer

Abstract

A two-range DC potential difference meter for DC voltage measurement includes a first stepping panel composed of a measuring panel of 21x10 ohm and two bracket panels without resistance, a second stepping panel comprising a measuring panel formed of ring resistance meshwork and a bracket panel formed by a 10x0.5 ohm resistance, a third stepping panel comprising of a measuring panel of 10x1 ohm and a substitution panel. Each contact of the forth stepping panel is connected with the corresponding contact of the measuring panel of the third stepping panel, using the resistance of the measuring panel of the third stepping panel together, and a resistance of 100 ohm are used to shunt current for range conversion at x0.1 range with the minimum resolution reaching 0.1 muV, the measuring panels are connected by conductors without on-off switch, which is capable of ignoring variation and potential effect when measuring by potential difference meter.

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 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, a large electric brush is generally used to increase the contact area, and a silver-copper composite material is used; the application number 200510062266. Its first and second stepping discs are composed of a measuring disc and a substituting 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 reduces the same resistance. The third and fourth stepping discs are composed of measuring disc, substituting disc and auxiliary disc. Since the third stepping disc is not set at 10 o...

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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