SU1196779A1 - Capacitance meter for compensation pickups of mechanical values - Google Patents

Abstract

I. CAPACITY METER FOR COMPENSATIONAL SENSORS OF MECHANICAL VALUES, containing a rectangular voltage generator, a double T-shaped non-linear quadrupole, consisting of two capacitors, each of which is connected to a resistor and a diode, and a measuring device, characterized in that increasing the conversion slope and simplifying the meter, the rectangular voltage generator is connected to two resistors and connected to the same poles of the diodes of the double T-shaped non-linear quadrupole huge capacity capacitors and inputs measuring device provided on the differential amplifier posto- direct current, whose output is the output of the meter. 2. The meter according to claim 1, which is based on the fact that the duration of the pulses of the rectangular voltage generator refers to (time delay circuits formed by capacitors and resistors of a double T-shaped non-linear four-terminal network as 1.54: 1.

Description

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The invention relates to the field of capacitance measurement and can be used when measuring small deviations of the capacitance from the nominal value in capacitive indicators of the mismatch of compensation sensors of mechanical quantities.

Purpose. of 6bret, eni — increase the steepness of the transformation and simplify the gauge.

FIG. I shows a diagram of a capacitance meter for mechanical sensors of mechanical quantities; on pkg. 2 -, the form of electrical voltage on the stationary electrode of one of the compared capacitors.

The device contains two fixed electrodes .1 and 2 and a grounded electrode 3, which form the compared capacitors of the differential capacitive sensor error indicator of mechanical quantities, a generator 4 of a rectangular voltage, two resistors 5 and 6 connected between the output of the generator 4 and the fixed electrodes 1,2 and diodes 7,8, to the same poles of which are connected storage capacitors 9 and 10 and the inputs of the differential amplifier 11 of direct current (UFD)

A capacitance meter for compensation sensors for mechanical quantities works as follows.

Upon receipt of a rectangular voltage from generator 4 to the circuits formed by resistors

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5 and 6, and capacitors with electrodes 1 .- 3, on stationary electrodes 1 and 2, an alternating voltage arises, the shape of which is formed by segments of exponentials (Fig. 2).

Through the peak detectors formed by diodes 7 and 8 and capacitors 9 and 10, the inputs UT II receive a voltage U (Fig. 2), the value of which is determined by the expression

 °° Py7x + G

where E is the amplitude of the output voltage of the rectangular-shaped generator voltage 4;

R

-Resistance of resistor;

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-pulse duration. With increasing pulsation capacity

voltage decreases, i.e. the voltage U increases. Since when the moving electrode 3 moves, the capacitances change in different directions, the voltage on the inputs of the DCF 11 undergoes the corresponding changes, and a difference signal appears at the output of the DCF.

Ratio the pulse width of the rectangular voltage generator to the time constant of the circuits formed by capacitors and double T-shaped non-linear, quadrupole resistors chosen to be 1.54 to increase the slope of the transform.

Claims (2)

1. CAPACITY METER FOR COMPENSATION MECHANICAL SENSORS, comprising a square-wave generator, a double T-shaped nonlinear four-terminal network consisting of two capacitors, each of which is connected to a resistor and a diode, and a measuring four___ ff Out _ = / 0 a device, characterized in that, in order to increase the steepness of the conversion and simplify the meter, the square-wave generator is connected to two resistors, and storage capacitors and inputs of a measuring device made on a differential DC amplifier are connected to the same poles of the diodes of the double T-shaped non-linear four-terminal, the output of which is the output of the meter. 2. The meter in π. 1, the fact that the pulse duration of the square-wave generator refers to the time constant of the circuits formed by the capacitors and resistors of a double T-shaped nonlinear four-terminal, as 1.54: 1.