Voltage measuring device with 1muV resolution

Abstract

The invention relates to a voltage measurer with the resolution as 1muV, wherein a first step disc is composed of a measuring disc, and two auxiliary discs without resistances, a second step disc uses a 9X9omega annular resistance networks and two 1omega resistance to form a measuring disc and uses 10 0. 5omega resistances to form an auxiliary disc, a third step disc is composed of a 10X1omega measuring disc and a replace disc, each contactor of a fourth step disc is connected with relative contactors on the measuring disc of the third step disc, in the X0. 1 range, the invention uses the 100omega resistance to divert current to switch ranges, while the minimum resolution can reach 0. 1muV, the measuring discs are connected via wires without switched by switch, therefore avoids the effects of variable difference and thermoelectric force.

Description

technical field [0001] The invention relates to a device 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, 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'clock, ...

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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