SU1310735A1 - Device for measuring d.c. - Google Patents

Abstract

The invention relates to electrical measuring equipment and can be used in systems for measuring, regulating and stabilizing direct current. The goal is to improve the measurement accuracy and reduce power loss by typing the temperature gradient and reducing the inhomogeneity of the external magnetic field. It is achieved by the fact that, in the device for measuring direct current, the magnetic modulation transducer 1 is placed coaxially in the internal cavity 2 of the tubular conductor (TE) 3 on the branch formed by sections 4, 5 of the TP and the conductive rod 6 attached to them. TP 3 on the outer side has a thermal insulation coating 7 and crimped sections 8, 9 at both ends. 3 il.

Description

The invention relates to electrical measuring equipment and can be used in systems for measuring, regulating and stabilizing direct current.

The purpose of the invention is to improve the accuracy of measurement and reduction of power losses by equalizing the temperature gradient and reducing the inhomogeneity of the external magnetic field.

FIG. 1 shows the proposed device; in fig. 2 and 3 are diagrams explaining the manufacturing process of the device.

A device for measuring direct current (Fig. 1) consists of a magnetomodulation transducer 1 installed coaxially in the internal cavity 2 of a segment of a conductive tube

3 on the branch formed by the plots

4 and 5 of the conductive tube and the conductive rod 6 attached to them. The conductive pipe 3 on the outside has a thermal insulation coating 7 and crimped sections 8 and 9 at both ends.

The device works as follows.

The total current 1 ", flowed along the parallel branches of the divider, is divided by the measured current shunt current Tsch, Then

wearing

l

eem

+ I

a otchz / l

to about. is the division factor of the current in the branches of the device. Then 1 KnI

In

-.

from / to, from where

 + ism From the last expression follows

that the measurement accuracy of the total current If depends on the stability of the division factor of the current Ka.

Enforcing a current divider from a material with a low resistivity, such as copper, reduces the power dissipation on the current divider, but copper has a relatively high temperature coefficient of resistance. To eliminate the effect of temperature on the K l division factor, the measuring branch

the divider formed by sections 4 and 5 of the copper pipe and copper rod 6 is placed in the internal cavity 2 of the copper pipe 3, on which, in turn, a layer of thermal insulation coating 7 is applied outside. The pressed sections 8 and 9 of the pipe 3 are contact pads at switching on the measured total current In.

To manufacture a device for measuring direct current, cut a section of pipe 3 (FIG. 2) from a conductive material, separate two sections 4 and 5 on it by two longitudinal and one transverse sections, bend the formed sections 4 and 5 inside pipe 3 (FIG. 3), put the magnetically modulating transducer 1 on the conductive rod 6, solder the second section 5 to the conductive rod 6, then crimp the pipe 3 from the ends 8 and 9 and apply a thermal insulation coating on top.

Claims (1)

Invention Formula A device for measuring direct current, containing paired parallel shunt and measuring circuits, the last of which is equipped with a contactless magnetic modulation transducer, characterized in that 35 to increase the accuracy of measurement and reduction of power losses by equalizing the temperature gradient and reducing the inhomogeneity of the external magnetic field, the magneto-modulation converter 40 is aligned. but in the internal cavity it is insulated from the outside and crimped at both ends of the tubular conductor on the branch formed by the section 45 of the tubular conductor and a galvanic conductive rod connected to it, the tubular conductor and the conductive rod being made of a material with low resistivity, such as copper. 4 5