RU1835104C - Method of and apparatus for determination of electrical resistance of materials - Google Patents

Abstract

Usage: electric cars. SUMMARY OF THE INVENTION: a common terminal is made in the form of a plane around the perimeter equal to the perimeter of the composite brush. The common terminal material is copper. The common terminal is provided with grooves or holes of a predominantly longitudinal shape, located across the conductive layers of the composite brush, and the hole for the conductive lead-out of the cable is equipped with a hood made of the same material as the common terminal through which the cable and the common The cord terminal is tapped, for example, by dipping into a bath of solder and then soldering the conductive layers of the composite brush to the common terminal. 2 sec and 2 zpp-fs, 3 ill.

Description

The invention relates to electrical engineering, and more particularly to methods and devices for measuring the resistance of brush materials of electrical machines.

The purpose of the invention is to increase labor productivity during measurements, increase accuracy and provide automation of measurements.

Fig. 1 shows a diagram of measuring the electrical resistance of materials; figure 2 - current contacts; in Fig.Z - potential knives.

The method for determining the electrical resistance of materials consists in placing potential knives on the surface of the sample to which a potentiometer is connected, for example, a micro or millivoltmeter or a galvanometer. Current contacts are also installed on the sample to be measured, through which electric current is passed and it is also measured, and the electrical resistance or electrical resistivity is determined

calculation of the received measurements. And to increase the accuracy of measurements, the surface of the measured sample under current contacts is coated with conductive grease.

For example, the determination of resistance, including electrical resistivity of carbon products including brush material for electric machines, is carried out by installing current contacts on a bar, the dimensions of which can determine its cross section to a sufficient degree of accuracy, current knives are installed, having previously been lubricated contact surface with conductive grease. Then, potential blades connected to the measuring device are installed on one straight line connecting the opposite current contacts, and between the current contacts. The voltage and current drops are measured and the resistance of the bar is calculated, and dividing by the cross section gives the results of the resistivity.

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Claims (4)

The device for determining the electrical resistance of materials contains a measured sample 1 onto which current contacts 2 are made, made in the form of a panicle or in the form of knives. Potential knives 3 are installed between current contacts 2 on the same surface of the measured sample 1. Current contacts 2 are included in the power supply circuit 4, connected in series with a current meter, for example, ammeter 5, current regulator 6, made in the form of an active rheostat resistances, for example, and switch 7. Potential knives 3 are connected to a milli-microvoltmeter or galvanometer 8 or the like. measuring device. The current contacts 2 are made in the form of knives with sharp rims, or in the form of a brush contact 9 made of several conductive spring wires connected to a bundle in the form of a panicle or in the form of several such panicles located around the circumference of the disk, and are rigidly fixed from one end. In order to improve and reduce the transition resistance between the current contacts 2 and the measured sample 1, a conductive lubricant 10 is deposited on the surface of the sample 1. Potential knives 3 are made in the form of conductive disks with sharp rims. Sample 1 of the material is made in the form of a plate or bar with a height substantially equal to the radial size of the brush. Current 2 and potential knives 3 are installed on one straight line on one surface of sample 1, Turn on the switch 7 and measure the current and voltage using devices 5 and 8 and calculate the resistance or resistivity of the material. SUMMARY OF THE INVENTION 1. A method for determining the electrical resistance of materials, comprising c, in the installation on the surface of the measured material of potential knives with a measuring device and current contacts with a second measuring device and a current source, an electric current is passed through the material, the readings of the devices are recorded and the electrical resistance or electrical resistivity of the material is calculated, characterized in that, in order to increase of labor productivity during measurements, current contacts are installed on the same surface of the material on which potential knives are mounted, and current E contacts and potential knives are installed on one straight line. 2. A method according to claim 1, characterized in that, in order to increase the accuracy of measurement, the surface of the measured material under current contacts is coated with a conductive grease. 3. A device for determining the electrical resistance of materials comprising potential knives with a measuring device and current contacts with a second measuring device and an e / H electric current source, characterized in that. In order to reduce the transition resistance between the current contacts and the material and increase the accuracy of the measurement, the current contacts are made in the form of panicles from conductive spring wires. 4. Device pop.Z, characterized in that, in order to ensure automation of the measurement process, the current contacts are made in the form of disks, the rims of which are made in the form of brooms located around the circumference, and potential knives are made in the form of disks with sharp rims. Figure 1