SU1396072A1 - Device for contactless measurement of amplitude of pulsed signals - Google Patents

Abstract

The invention relates to a measurement technique and makes it possible to increase the reliability of measurements. The device contains an electromagnetic transducer 1, an electronic integrator, including a DC amplifier 3, electronic switches 4 and 5, a comparator 6, a source 7. of a stabilized voltage. The introduction of the signal preprocessing unit 2, the differentiator 8, the ZI-NE element, and the resistors 13 and 14 eliminates the disturbance of a given functional relationship between the input and output signals when changing measuring ranges. 1 il. (L 00 O) o

Description

The invention relates to the measuring technique and can be used to measure pulse currents using electromagnetic transducers.

The purpose of the invention is to increase the reliability of measurements.

The drawing shows a functional diagram of a device for contactless measurement of the amplitude of pulse signals.

; A device for contactless I measurement of the amplitude of a pulsed signal-: catch contains an electromagnetic transducer; distributor 1, preprocessing unit 2, electron integrator, switching amplifier 3

direct current, two electronic keys 4 and 5, comparator 6, source 7

voltage stabilized, differential; Fenzator 8, z Lei ZI-HE 9, besides the electronic integrator contains an input resistor 10 and a feedback capacitor 1 1 (C1), a capacitor 12 (C2) and resistors 13 and 14. The first input of the comparator 6 under:, keys to the output of the amplifier 3 direct current, the second - to the source 7

: stabilized voltage, first

: the output of the capacitor 11 (C1) is connected to the first output of the capacitor 12 (C2), the second output of which is connected to the input of the first electronic switch 4, and the input of the second electronic switch 5 is connected to the output of the DC amplifier 3, the output of the electromagnetic converter 1 is connected through the unit 2 preprocessing the signal to the resistor 10 (R1) of the electronic integrator, the output of the amplifier 3 DC. Connected to the input of the differentiator 8, the outputs of the electronic switches 4 and .5 are combined. And connected to the first pins of the resistors 13, 14 (R2 and R3 ) second the output of the resistor 13 (R2) is connected to the first output of the capacitor 11 (C1), the second output of the resistor 14 (R3) is connected to the output of the DC amplifier 3, the first input of the ZI-NE element 9 is connected to the output of the differentiator 8, the second input is the input external blanking, the third is connected to the output of the comparator 6, and the output of the ZI element is NOT connected to the control inputs of the electronic switches 4 and 5,

Improving the reliability of measurements when changing measurement ranges is carried out as follows.

The work of an electronic integrator is described by phasing.

& Yy

 - RP B. dt,

where R C 1

RC

integrator input resistance (R1);

capacitance feedback capacitor electronic integrator (C1);

electronic integrator sensitivity. It can be seen from the above expression that a change in the capacitance of the feedback capacitor of an electronic integrator leads to a change in sensitivity and, as a result, to a change in the measurement limit.

For the case when the measured high current I (t) varies along the end - well

de

-I (t) 1. e,

- initial talk-,

-time i

-constant charge time of capacitor C1 (Г RC), the voltage produced by the electromagnetic converter is:

(t) M-4 / T and dt °

Uax (t)

where M is the inductance of the electromagnetic converter 1. The voltage at the output of the electronic integrator formed by the input resistor-10 (R1), the amplifier 3 DC current by the capacitor C. C1 + C2, has the form:

s j

 bx-dt - -J-, (1th

At the point in time when the voltage at the output of the electronic integrator Uftbix reaches the threshold of operation of the comparator 6 set with high accuracy, the output signal U | comparator 6 is fed to the third, the input element ZI-NOT 9. If at the same time the rate of change of voltage. the output of the electronic integrator is greater than the specified one, then the first input of the ZI-NOT 9 element receives the signal of the differentiator 811, (while removing the external blanking signal from the second input of the ZI-NO 9 element leads to disconnecting the capacitor 11 (C2) and turning on the resistor 14 ( R3) in series with resistor 13 (R2) and, consequently, to changes in the sensitivity of the electronic integrator.

Compared with the known technical solutions, the proposed device makes it possible to increase the reliability of measurements of pulsed signals in a non-stationary time process by eliminating the violation of a given functional relationship between the input and output signals when changing measurement ranges.

Claims (1)

Invention Formula A device for contactless measurement of the amplitude of pulse signals containing an electromagnetic converter, an electronic integrator with a capacitor in the feedback circuit and a resistor, a second capacitor, two electronic switches, a comparator and a stabilized voltage source, the first input of the comparator being connected to the input of the electronic integrator, the second to the source of a hundred 0 five 0 five 0 unpowered voltage, the first output of the first capacitor is connected to the first output of the second capacitor, the second output of which is connected to the input of the first electronic key, and the input of the second electronic key is connected to the output of the electronic integrator, so that , in order to use the accuracy of the measurements, a preprocessing unit, a differentiator, a ZI-NO element and two resistors are inserted into it, and the output of the electromagnetic converter is connected via a preprocessing unit to the electronic integrator, the output of which is connected to the input of the differentiator, the outputs of the electronic switches are combined and connected to the first terminals of the second and third resistors, the second terminal of the second resistor is connected to the first terminal of the first capacitor, the second terminal of the third resistor is connected to the output of the electronic integrator, the first input of the element ZI is NOT connected to the output of the differentiator, the second input is the input of external blanking, the third is connected to the output of the comparator, and the output of the element ZI is NOT connected to the control m inputs of the electronic switches.