SU1322193A1 - Device for measuring the earthing resistance - Google Patents

Abstract

A device for measuring the grounding resistance comprises a pulse generator 1, a current electrode 2, integrators 3 and 7, shunt 4, switch 6, measuring device 8, potential electrode 9, comparator 10. The invention improves the noise immunity of the device to impulse noise. 1 il. (L to S o; 0 CO

Description

that

The comparator 10 controlling the key 5 to 6 in the input circuit of the voltage integrator 7 on the grounding device normalizes the charge

3

V3dt q

11322193 2

The invention relates to electro- where: v is the voltage across the current shunt; measuring equipment, namely to. R is the resistance of the current shun-to devices for ensuring electrical safety, and is intended to measure the resistance of the earthing devices of electrical installations.

The purpose of the invention is to increase the noise immunity of the device to the pulse-integrator integration time 7. Noise interference. The resistance value in this device The drawing shows the device circuit is determined by the formula of the device.

The device contains a pulse generator 1, the first output of which is connected to the current electrode 2, the second output of the pulse generator 1 is connected to the first input of the integrator 3 and the output of the shunt 4, the second output of which is connected to the second input of the integrator 3, the terminals 5 and the first output key 6, the second 20 output of which is connected to the first input of the integrator 7, the output of which is connected to the measuring device 8, the second input of the integrator 7 is connected to the potential electrode 9, the output of the integrator 3 is connected to the input of the comparator 10, you the stroke of which is connected to the control input of the key 6.

The device works in a way

When a current pulse is applied by the generator 1 to the measuring circuit, the key 6 is closed. As a result, the voltage on the grounding device 5 is simultaneously integrated with the integrator of the 5 pulse generator waters connected to step 7, and the integrator 3 helps the first output of the shunt and nepBt iM input voltage at current shunt 4, integ-. The shaft of which determines the charge, is; coming from the pulse generator 1. With

thirty

where q is the charge passed from generator 1 and pulse for time t, which is set in advance with the help of comparator 10,

The scale of the measuring device 8. at a constant value of the integral obtained in the integrator 3, can immediately display the resistance value of the earth conductor 5,

Claims (1)

Invention Formula A device for measuring the grounding resistance, which contains a pulse generator, current and potential electrodes, a measuring device, characterized in that, in order to increase the noise immunity, two integrators, a comparator, a key and a shunt, and one of the first integrator, whose output is connected to the input, are entered into it. the comparator, and its output is connected to the control input reaching the integrated voltage of a given level, the comparator 10 generates a signal to turn off the key 6 in the input circuit of the integrator 7, The integrator 3, integrating the voltage on the current shunt 4, determines the charge that has passed through the circuit: the grounding device is the current 40 key, the second shunt output is connected to the tested earthing switch, the second input of the first integrator and the key input. electrode, value of which is  -2 MU Editor M, Blanar 5 OUT of which is connected to the first input of the second integrator, the second input — of which is connected to the potential electrode, and the output of the second integrator is connected to the input of the measuring instrument, the second output of the pulse generator is connected to the current one 50 electrode. Compiled by B, Smirnov Tehred I.Popovich Proofreader C, Cherni Order 2859/41 Circulation 730 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab ,, d.4 / 5 . Production and printing company, Uzhgorod, Projecto st., 4, that The comparator 10 controlling the key 5 to 6 in the input circuit of the voltage integrator 7 on the grounding device normalizes the charge where V is the voltage across the current shunt; . R - resistance current shun- "  integrator integration time 7. Resistance in this device 3 V3dt q e is determined water pulse generator connected to the first output shunt and nepBt iM input where q is the charge passed from generator 1 and pulse for time t, which is set in advance with the help of comparator 10, The scale of the measuring device 8. At a constant value of the integral, which is acquired in the integrator 3, it can immediately display the resistance value of the earth conductor 5, Invention Formula A device for measuring the grounding resistance, containing a pulse generator, current and potential electrodes, a measuring device, characterized in that, in order to increase the noise immunity, two integrators, a comparator, a key and a shunt are connected to it, and one pulse of the 5 pulse water is connected to the first output of the shunt and the nepBt iM input the first integrator, the output of which is connected to the input of the comparator, and its output is connected to the control input 40 key, the second shunt output is connected to the tested earthing switch, the second input of the first integrator and the key input. 5 OUT of which is connected to the first input of the second integrator, the second input — of which is connected to the potential electrode, and the output of the second integrator is connected to the input of the measuring instrument, the second output of the pulse generator is connected to the current one