An Inductance-Capacitance Measurement Method Based On Auto-Balancing Bridge

Abstract

Modern measurement modules are extremely demanding on the hardware and must accurately capture the relevant parameters of capacitance and inductance. The inductance and its quality factor, capacitance and its loss angle tangent value are very important parameters, but also the current testing difficulties. To efficiently and accurately measure the inductance and its quality factor, capacitance and its loss angle tangent, this paper developed a capacitance-inductance testing method based on automatic balanced bridge circuit. Firstly, based on the DSP development board, test capacitance and inductance by switching dip switches; Then, the use of self-excited oscillation method to generate a fixed frequency sinusoidal signal, through the amplifier to increase the amplitude of its signal, and the use of adder to the signal to provide a certain bias to meet the amplitude requirements; Finally, based on the automatic balanced bridge method, through the full-wave rectification plus filter will be converted into the average of the signal to be tested, and then use the amplifier circuit to control the average value of the signal to be tested, and then use the amplifier circuit to control the average value. Then use the amplifier circuit to control the average value within the AD sampling range, and use the micro-controller to collect the test amplitude, phase and other related parameters. The test results show the effectiveness of the proposed method.