Circuit device for detecting capacitance and/or capacitance change of capacitive device and regulating apparatus

A circuit device for detecting capacitance and/or capacitance change of a capacitive device and a regulating apparatus are disclosed. The circuit device comprises a monostable trigger capable of control through a control signal and composed of at least two input ends and an output end; a converting device connected with the output end of the monostable trigger and configured and arranged for converting an output signal generated on the output end into signal voltage which has a changing curve proportional to the duration of the output signal; and an evaluation unit connected with the converting device to evaluate the signal voltage and as a result generate at least a detection value which shows the capacitance and/or capacitance change of the capacitive device. The converting device comprises an integrator having an operational amplifier, and the integrator is configured and connected between the output end of the monostable trigger and the evaluation unit so that the output signal of the monostable trigger is applied onto an amplifier input end of the operational amplifier and the signal voltage changing linearly with time is generated.