电容电感检测仪工作原理
Working principle of capacitance and inductance detector
变压器输出 20V或 2V测试电压，通过测试线连接到电容组的两个汇流排上。汇流排电压，又经过测试线引入到仪器内部的电压检测电路上。经过 A/D转换器变为数字信号后，通过隔离器件，将信号送到 CPU。待测电容 Cx的电流，经过钳型 CT取样和程控放大后，通过 A/D转换器变为数字信号，送到 CPU。 CPU将收到的数字信号进行处理，并取得电压 U和电容电流 Ic ，然后按：Cx=Ic/ωU计算电容量，ω=2πf,f为频率。
The transformer outputs 20V or 2V test voltage, and is connected to the two bus busbar of the capacitor group through the test line. The bus voltage is introduced into the voltage detection circuit of the instrument through the test line. After the A/D converter is converted into a digital signal, the signal is sent to CPU through the isolation device. The current of the capacitor Cx to be measured is sampled by clamp CT and amplified by program control. It is converted into digital signal by A/D converter and sent to CPU. The CPU processes the digital signals received and obtains the voltage U and the capacitive current Ic, then calculates the capacitance by: Cx = Ic / _U, _ = 2pif, F as the frequency.