Capacitor voltage conversion circuit

Abstract

The present invention provides a capacitor voltage conversion circuit. The capacitor voltage conversion circuit comprises CPU unit, a square-wave excitation signal generation circuit, a detected capacitor (C), a synchronous digital detecting circuit, a time-sharing integrating circuit and a low-pass RC filter circuit. The CPU unit is configured to generate synchronous excitation signals and logiccontrol signals; the square-wave excitation signal generation circuit is configured to take the synchronous excitation signals as triggering signals to convert a reference level as square-wave excitation signal output configured to be applied to the detected capacitor (C) to excite the detected capacitor (C); the synchronous digital detecting circuit is connected with a returning end of the detected capacitor (C) to take the synchronous excitation signals as triggering signals to detect returning signals of the detected capacitor (C) to integration half-wave signals; and the time-sharing integrating circuit is configured to take the synchronous excitation signals as triggering signals to perform time sharing integration of the integration half-wave signals to output a direct current level.The capacitor voltage conversion circuit solves the technical problems that the capacitor voltage conversion circuit is complex in structure, limited in application range, large in error and low in detection sensitivity.

Description

technical field [0001] The invention relates to the technical field of capacitance measurement. In particular, it relates to a capacitive voltage conversion circuit. Background technique [0002] At present, capacitive sensors are widely used because of their simple structure, good dynamic response, high sensitivity, and ability to work in harsh environments. The basic principle of the capacitive sensor is to reflect the change of the measured physical quantity by measuring the transformation of capacitance. The capacitance of a capacitive sensor is usually small, and its measurement method is mainly to convert the capacitance into a corresponding voltage, and then digitally convert the voltage signal through analog-to-digital conversion before collecting and analyzing it. Among the current capacitance-to-voltage conversion methods: LRC bridge measurement method has a complex structure and requires many hardware resources, so the cost is high, and the measurement result is...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the capacitance-to-voltage conversion method in the prior art, there are technical problems such as complex structure, limited application range, large error and low detection sensitivity, especially when measuring small capacitance value capacitance

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