SU1034017A1 - Device for checking electric circuit input impedance - Google Patents

Abstract

A device for monitoring the input resistance of an electrical circuit containing a key, a voltage sensor connected by a first input to the first input terminal of the device and the first output of the first conductivity. the second input - with the first input of the current sensor and with the second input terminal of the device, a dividing unit connected by an output through a comparator to the input of the actuator, characterized in that, in order to improve the accuracy of control, the second conductive, first and second pulse selectors and a multivibrator connected by an output to a key input connected by a first output to a second output of the first conductivity and a first output of a second conductivity, the second output to the second output of a second conductivity and a dual input Occupancy AC coupled through a first selector output-§ cos momentum to the first input .bloka fission. SP connected by the second input through the second; a swarm selector pulses with the output of the strain sensor. 00 4: min

Description

The invention relates to measuring equipment and can be used to automatically control the input resistance of electric circuits with sources of electrical driving forces without disrupting their normal operating condition, for example, for diagnostic monitoring of electrical insulation resistance and electrical networks. A device for measuring the insulation resistance relative to the earth is known, which contains a source of operational current, a current sensor, a voltage sensor, a dividing unit (logometer) ClJ This device has a low control accuracy, since it does not allow continuous monitoring of the input resistance without disturbing the normal working condition of the electric circuit, since it is necessary to disconnect it for the period of measurements. When the circuit is turned on under operating voltage, the control error of this device reaches several, ten percent. The closest to the assumption {is a device for automatic control of the resistance of an electrical circuit containing a key, a voltage sensor connected; the first input to the first input of the device and the first output of the first conductivity, the second input to the first input of the current sensor and the second input of the device , a dividing unit, connected by a comparator to the input of the actuator 2. The state of the input resistance 2 in the known device is estimated by reading the ammeter and the voltmeter when the (y 0) and the included conductivity according to the formula y4 and u-Od Where} Q is the input voltage at Od 0; and - input voltage at 4U Uo -. A disadvantage of the known device is the low control accuracy. The greater error of control is due to the presence of time between the readings of the ammeter and voltmeter readings at Ud O and ud 0, they have a finite quenching time, it also takes time to turn on the switch manually. During this total time during the operation of electrical installations connected to the circuit, may change significantly, i.e. The device fundamentally hinders the opportunity. .Oshiki measurement in several tens or even hundreds of percent. The purpose of the invention is to improve the accuracy of control. The delivered target is achieved by the fact that the device for the input resistance of an electrical circuit containing a key, a voltage sensor connected with the first input to the first input terminal of the device and the first output of the first conductivity, the second input to the first input of the sensor, and the second input terminal devices, a dividing unit connected by an output through a switch to the input of an executive body, a second conductivity, the first and second pulse selectors, and a multivibrator connected by an output to the key input ,, connected n The first is the first input with the second output of the first conductivity and the first output of the second conductivity, the second output with the second output of the second conductivity, and the second input of the current sensor connected by the output through the first pulse selector to the first input of the dividing unit connected to the second input. through the second pulse selector with voltage sensor input. The drawing shows a block diagram of the proposed device. The device contains first and second input terminals 1 and 2, voltage sensor 3, current sensor 4, second and first conductance 5 and 6, key 7, multivibrator 8, first pulse selector 9, dividing unit 10, second pulse selector 11, comparator 12j Executive body 13, the Device operates as follows. The multivibrator 8 automatically switches the key 7 (electronic) on and off, which periodically shunts and desunts the second conductivity 5. At the same time, under the action of the electromotive force of the controlled circuit, a pulsed current / 1J flows through the main current of the load. The pulse current is emitted by the current sensor 4 and the pulse collector 9. The pulse voltage drop .4U at the input resistance between the input terminals 1 and 2 is detected by the voltage sensor 3 and the pulse selector 11, In the dividing unit 10, the operation A lt is performed, where kd is the total transmission coefficient of the current and voltage sensors of the unit division. In comparator 12, an analog signal proportional to Z compares with the setpoint Zy and when Z 2d is used

3. 10340174

body 13 automatically CHF, but it is assumed that the control carried out over from Iruet about the nonconformity is input continuously

resistance of the nominal value

"is determined by the accuracy class of the sensor. The proposed device allows 5 selectors, an additive error

to control the input copro-comparator and does not exceed in% accuracy with high accuracy, since Thus, the introduction of a multivibrion with a small pulse duration of the irator 8, conductivity 5 and the selection of a large frequency of their follow-up of the pulses 9 and 11 allows the contour time between moments of auto- scrolling input resistance

The readout of 41 and non-continuously and the accuracy of counter cuts is reduced, i.e. mo-rol.

current and voltage, inaccuracy

Claims (1)

DEVICE FOR MONITORING INPUT RESISTANCE OF ELECTRIC CIRCUIT, containing a key, a voltage sensor connected to the first input terminal of the device and the first output of the first conductivity, the second input to the first input of the current sensor and the second input terminal of the device, the division unit connected to the output through a comparator with an input of an executive organ, characterized in that, in order to increase the accuracy of control, the second conductivity, the first and second pulse selectors and a multivibrator connected to with the key input connected to the first output with the second output of the first conductivity and the first output of the second conductivity, the second output to the second output of the second conductivity and the second input of the current sensor connected by the output through the first pulse selector to the first input of the division unit connected by the second input through the second pulse selector with voltage sensor output. „“ SU .. „1034017