SU1529127A1 - Overload meter - Google Patents

Abstract

The invention relates to a measurement technique and can be used to measure mechanical quantities. The aim of the invention is to improve the accuracy and noise immunity. The goal is achieved by the fact that varicap 4 and series-connected auto-oscillator and amplitude limiter 6, the output of which is connected to recorder 7, are entered into the meter, and varicap 4 in series with the second inductance coil 3 is connected to the input of the auto-oscillator, inductor 3 is inductively connected to the first inductance 2 connected to the piezoelectric transducer 1, while the inductors are made in the form of coaxial coils, the diameters of which are selected in the range of 1.2-1.5. When exposed to overload, the piezoelectric transducer 1 generates a signal acting on the varicap 4, changing its capacitance. This leads to a change in the frequency of the oscillator 5, which is recorded. 2 Il.

Description

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The invention relates to a measurement technique and can be used to measure mechanical quantities, in particular vibration and shock accelerations, force and pressure pulsations. The aim of the invention is to improve accuracy and noise immunity.

FIG. I shows the electrical circuit of the proposed device; in fig. 2 - p position of the coils.

The overload meter contains a piezoelectric transducer 1, which, together with the first inductance coil 2, forms an additional oscillatory circuit fixed on the moving body, and a second inductance coil 3, which together with the element with controlled capacitance varicap 4 forms the main oscillatory circuit fixed fixedly and included in the measuring circuit consisting of a series-connected auto-generator 5, an amplitude limiter 6 and a recording device 7.

The proposed device works as follows.

When the power is turned on, a sinusoidal voltage appears at the output of the autogenerator 5 with a frequency determined by the parameters of the system of coupled circuits, namely, the partial frequencies of the additional and main circuits and the coupling coefficient of the circuits.

Thus, the frequency of the oscillator is determined by the parameters of elements 1-4, namely, their capacitances and

Editor T. Parfenova

Compiled by A. Severin

Tehred A. Krachvuk Proofreader S.Shekmar

Order 7635/40

Circulation 789

VNIIPI State Committee for Inventions and Discoveries at the State Committee on Science and Technology of the USSR 113035, Moscow, Zh-35, Raushsk nab. 4/5

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inductance and parasitic capacitance mounting.

The overload is sensed by the piezoelectric transducer I, on which an additional charge occurs, which in the form of a voltage change through coils 2 and 3 affects the varicap 4, changing its capacity.

A change in the capacitance of varicap 4 leads to a change in the frequency of the oscillator 5. The frequency and its changes are recorded by the recording device 7. To ensure the invariance of the result to the instability of the signal amplitude, an amplitude limiter 6 is installed in front of the recording device.

Claims (1)

Invention Formula An overload meter containing a piezoelectric transducer connected to the first inductance inductively connected to the second inductance and a recorder characterized in that, in order to improve the accuracy and noise immunity, a varicap and a series-connected autogenerator and amplitude limiter are introduced in it, the output of which connected to the recorder, and the varicap in series with the second inductance coil is connected to the input of the oscillator, while the coils inductances are made in the form of coaxial coils, the ratio of the diameters of which are selected in the range of 1.2-1.5. Figg Subscription