Four-range voltage measuring device adopting current splitting branch

Abstract

A four-range voltage measuring instrument with shunt branch includes a first stepping panel composed of a measuring panel and two bracket panels without resistance, a second stepping panel comprisingameasuring panel formed of a ring connected by nine resistance of 90 ohm and two 10 ohm resistance, a bracket panel formed by a ten resistances of 5 ohm, a third stepping panel comprising of a measuri ng panel of 10x10 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, and the measuring panels are connected by conductors without on-off switch, which is capable of ignoring variation and thermal potential effect when measuring by voltage measuring instrument. The voltage measuringinstrument with the maximum measuring voltage of 2.31V and the minimum resolution of 0.1 muV is provided with four ranges of x10, x1, x0.1, x0.01.

Description

Technical field [0001] The invention relates to a device for measuring direct current voltage. Background technique [0002] At present, for potentiometers with four measuring discs, the middle disc generally adopts a switch for the connection between the four measuring discs, which causes the deterioration of the contact resistance and limits 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 200510062369.6 discloses a new method for solving the deterioration of switch contact resistance with a potentiometer with four measuring plates. The first and second stepping disks are each composed of a measuring disk and a substitution disk. The resistance value on the measuring disk and the substitution disk is the same. Each time a resistance is added to the measuring disk, the substitution disk reduces the same resistance. 3. The fourth stepping d...

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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