Two measuring ranges portable potentiometer

Abstract

A two-range portable potentiometer with three measuring discs for DC voltage measurement. Its first stepping disc consists of a 21×10Ω measuring disc and auxiliary discs I' and I" without resistance. The second step plate is composed of 10×10Ω ring resistance network to form the measuring plate, and the auxiliary plate is composed of 10 0.5Ω resistors. The third plate is a double sliding line plate. Switching, so that there is no variation and thermoelectric potential influence in the measurement of the potentiometer, the resolution reaches 1μV, and the replacement of the first and second stepping disks is omitted.

Description

technical field [0001] The invention relates to an instrument for measuring DC voltage. Background technique [0002] At present, for the potentiometer with three measuring discs, in the connection between the three measuring discs, the intermediate disc is generally switched by a switch, which will cause a change in 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; Patent No. ZL200520101772.0 has announced a new method for solving the variation of switch contact resistance with a potentiometer with three measuring discs. The first and second stepping discs are composed of a measuring disc, a substituting disc and an auxiliary 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. , since t...

AI Technical Summary

Problems solved by technology

After the two measuring discs are connected, they are connected with the sliding wire disc between the two measuring terminals, so that the brush on the switch of the stepping disc is excluded from the measuring circuit, and there is no switching between the resistances on the three measuring discs, and There will be no deterioration; since the first and second stepping discs have replacement discs, the number of layers of the first and second stepping disc switches is increased, thereby increasing the volume of the instrument and making the switch and instrument structure become complicated

Images