SU1182285A1 - Magnetoelectric dynamometer - Google Patents

Abstract

MAGNETOELECTRIC DYNAMOMETER, containing a sensing element on an elastic suspension, a magnetoelectric power compensator with a moving coil, on which the windings of negative stiffness and power compensation j a capacitive displacement transducer included in the balancing circuit consisting of a plug-in plug-in unit, a set-in unit, a pattern, a pattern, a pattern, and a body, and a body, can be set. synchronized pulse generator, and a current stabilizer, characterized in that, in order to increase the upper limit of measurement and exclude Cheney Tolerances compensator power from instability of the magnetic induction, it introduced a second modulator, a control input coupled to an output of the pulse generator, wherein the coil negative stiffness through the second modulator connected to a current stabilizer.

Description

The invention relates to information-measuring technology and can be widely used for accurate measurements of the forces, mass, density, and weight of various bodies in a wide range.

The purpose of the invention is to increase the upper limit of measurement and to eliminate the error of the power compensator from the instability of the magnetic induction.

The drawing shows the design of the dynamometer (a) and its structural diagram (b),

The device consists of a power compensation coil 1, a coil with two negative-stiffness windings 2, an elastic suspension 3, a magnetic system 4, a magnetic circuit 5, a rigidly connected plate 6 and a fixed plate 7 of a capacitive sensor, a stable current source 8, the first 9 and second to modulators pulse generator 11, amplifier 12 and phase-sensitive voltmeter 13.

The measured force Fy acts on the sensitive element of the dynamometer - a moving part containing a power compensation coil 1 with two windings of negative rigidity 2 rto edge on the common frame. The underside part is fixed with the base by means of an elastic suspension 3. The power compensation coil 1 is located in the working a magnetic gap with a permanent magnet 4 and a magnetic core 5. A plate b of a capacitive displacement sensor, the fixed electrode 7 of which is fixed to the magnetic core 5, is rigidly connected to the movable part. The negative stiffness terminals are connected to a stable current source 8 through the modulator 10. The modulators 9 and 10 in the current circuit of the power compensation coil are controlled synchronously from the generator 11. The voltage difference in both half-periods of modulation To / 2 is amplified by amplifier 12 and higher ml phase sensitive voltmeter .13.

The dynamometer works as follows.

The generator 11 generates symmetric rectangular modulation pulses of duration T.

During the half-period of modulation, modulators 9 and 10, for example, are open, and are closed during the second half-period. Then, in the first Half-Period, only the measured force FX acts on the sensitive element of the dynamometer, and the rigidity of the elastic suspension is determined only by the mechanical rigidity C. Under the action of the force, the elastic suspension 3 is deformed and the moving part moves by FX value X. The displacement Xj is converted by the capacitive sensor 7 into an electrical signal li (supplied to the input of the differential link. In the second half-period, the modulators 9 and 10 are closed and the sensing element is affected by the force where F, Vd1ao1c is the force of the feedback circuit of the magnetoelectric power compensator with coil length LQ coil 1, located in the gap with induction BO. The resulting stiffness of the elastic part Cg-uC, where

In

L j g value negate4, С

Bo

Noise stiffness created by catuig 2 with a length of coils LC, current o with a gradient of magnetic induction grad B (about the width of the gap).

Under the action of effort GH-P. the movable part is moved to the distance

F, -FK

g. Moving Xs trans.

is produced by a capacitive sensor into an electrical signal 0, which is subtracted with the signal O, and the difference & U U | - and 2 is amplified by amplifier 12, rectified by a voltmeter 13 and the current enters the coil 1 of the power compensator, creating a force FK reducing the difference of the signals uU Uj-1/2 By small values in the autocompensation tracking system. With a sufficiently large value of the transformation coefficient of the system, A and O can be considered with sufficient accuracy, and the transformation equation of the system will be written as

x-cTl -McTile

L oSfl

e

From the expression of the measured force we see that it is in | Yu times more compensating effort. On the other hand, stiffness is negative. It is surplus to magnetic induction in the gap, and from 11822854

the measured force is also proportional to, in the dynamometer is

but the magnitude of the magnetic induction Bj, and, as we can see, the measured force does not depend on the magnetic induction. So

the main source of error of the power compensator, due to the instability of the magnetic induction.

Claims (1)

A MAGNETO-ELECTRIC DYNAMOMETER containing a sensitive element on an elastic Suspension, a magnetoelectric power compensator with a moving coil, on which windings of negative stiffness and power compensation are located, a capacitive displacement sensor included in the balancing circuit, consisting of a modulator, an amplifier connected to a phase-sensitive oscillator , and a current stabilizer, characterized in that, in order to increase the upper limit of measurement and exclusion ogreshnosti power compensator instability of the magnetic induction · introduced into it a second modulator, a control input coupled to an output of the pulse generator §, when this coil L · negative stiffness through the second modulator connected to a current stabilizer. | S 00 SI> 1 182285