Interval variable capacitor type non-contact angle displacement sensor

Abstract

A non-contact angular displacement sensor with gap-variable capacitor is composed of a mechanical transmission unit and a circuit for measuring the dcapacitance of angle transforming capacitor. Said circuit consists of frequency-variable pulse generator, shaping emitter follower, and control-gate unit. The input and GND of circuit are respectively connected to the upper and lower electrodes of the capacitor in said mechanical transmission unit. When an angular displacement is input, the gap between electrodes of capacitor is linearly changed. Its advantages are simple structure and high sensitivity.

Description

technical field [0001] The invention relates to a sensor, in particular to a variable pitch capacitive non-contact angular displacement sensor used for detecting indication signals. Background technique [0002] The original old type rudder position indicator can also be called "contact potentiometer type rudder angle displacement sensor". The principle is: when the cross-sectional area and resistivity of the resistance conductor are constant, its resistance value is proportional to the length of the resistance conductor. A movable mechanical spring brush is added to this resistor. By adjusting the position of the brush on the resistor, the output resistance changes with the change of the spring brush. This is the potentiometer. The working principle of the old rudder angle displacement sensor: add a standard voltage to both ends of the potentiometer, through the change of the rotation angle of the rudder position shaft, the position of the movable s...

AI Technical Summary

Problems solved by technology

[0003] (1) In the case of high-intensity impact force, it is easy to damage, deform and break the movable spring brush of the potentiometer-type angular displacement sensor, resulting in damage to the sensor

[0004] (2) Since the work of the thermal machine can form a strong vibration environment, this strong vibration can be transmitted to the contact point of the resistor film of the potentiometer through the spring brush of the potentiometer type angular displacement sensor, and the strong vibration of the spring brush Friction can easily cause groove marks on the resistive film, resulting in failure, damage, signal drift, and instability of the operating point of the potentiometer-type angular displacement sensor.

Stored in an environment with a certain humidity, these two different metal materials are prone to chemical reactions of the original battery at the contact point, resulting in rust spots, which hinder the electrical path of the contact point and affect the performance of the sensor.

[0006] (4) The contact point between the spring brush and the resistance film performs signal energy conversion in high-frequency mechanical friction. The life of civilian products is about 20,000 times, and the life of military products is about 100,000 times. In high-speed control systems , this kind of consumption is easy to achieve, so that the potentiometer enters the period of soft fault, making the circuit unstable and unreliable

Images