SU1488902A1 - Method for determining fluctuations of transient resistance of sliding contacts - Google Patents

Description

The invention relates to electrical engineering and can be used when conducting acceptance tests and scientific research of electrical contacts. The purpose of the invention is to improve the definition of accuracy. The measured 1 and measuring 2 contact pairs pass current through the test, measure the voltage between the test and measuring 3 contact pairs. The dependence is given, allowing to calculate the sought resistance with regard to the exclusion of measurement errors.

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The invention relates to electrical engineering and can be used when conducting acceptance tests and in scientific research characteristics of electrical contacts.

The aim of the invention is to improve the accuracy.

FIG. 1 is a diagram for measuring fluctuations of the transition resistance of the sliding contacts; on

FIG. 2 is a plan of the current lead.

In the considered circuit, contact pairs 1–3 are used. A load 4 is connected to the last. An ammeter 5 is connected to the first one, and a voltmeter 6 with its own internal resistance is connected to the last two. In the dynamic mode, the current flows through the contact pairs 1 and 2 and the ammeter 5. The voltage is measured by a voltmeter 6 between the contact pairs 1 and 3.

The instantaneous value of the transition resistance on the contact pair 1 is calculated by the formula

where C (b) is the instantaneous value of the voltage between the contact pairs 1 and 3, measured by a voltmeter 6;

I - the current flowing through

contact pairs 1 and 2, measured by ammeter 5;

p is the electrical resistivity of the material of the moving contact;

L is the length of the moving part of the contact 1 under study;

1 - the length of the movable section

the part of the investigated contact 1 from the point of contact of the brush to the point of soldering the common circuit;

5 - the cross-sectional area of the movable part of the studied contact pair 1.

For a flat current lead (Fig. 2), point A is the point of contact of the brush with an annular moving contact 1.

Claims (1)

Claim The method for determining fluctuations of the contact resistance of the sliding contacts, according to which current is passed through the test and measuring contact pairs, measures voltage fluctuations, determines the contact resistance of the sliding contacts, characterized in that, in order to improve the accuracy, a second measuring contact pair is introduced electrically with the test and first measuring contact pairs, measurements of voltage fluctuations are performed between the test and additional contacts GOVERNMENTAL pairs, and the contact resistance of sliding contacts is calculated by the formula _{25 E (s) =} f). E I-D, where and (b) - the instantaneous value of the voltage drop between the studied and additional 30 (second) measuring contact pairs; I is the current flowing through the test and first measuring contact pairs; p is the electrical resistivity of the material of the movable nastya of the contact pair under study; L is the length of the movable part of the follower contact pair; 1 - the length of the section parts of the contact pair from the point of contact of the brush to the point of connection . _e all contact pairs; ι “ 8 - cross-sectional area of the movable part of the studied contact pair. 1488902 —NE & 1