2018 Electronic Competition Question A-Current Signal Detection Device (Qingdao University of Technology)

This system uses the ARM Cortex-M3 microcontroller as the core of circuit control and data processing, and designs and implements a current signal detection device using non-contact sensing. A power amplifier circuit was designed using the power amplifier chip LM1875T, which achieved distortion-free amplification of the signal generated by the arbitrary wave signal generator. An enameled wire was used to wind a coil on a manganese core magnetic ring, and a current sensor was made to obtain the loop current signal, and the loop current signal was obtained through The voltage follower and AGC automatic gain controller are then input into the microcontroller to detect the amplitude and frequency of the loop current signal. With the help of the complex logic control capability of the microcontroller, automatic switching of the measurement range and real-time display of signal parameters are achieved. After rigorous theoretical analysis, calculation and repeated testing, the performance of this design is stable and reliable, able to achieve various index requirements stipulated in the question, and the measurement accuracy fully meets the requirements of the question, and it is a good realization of non-contact measurement of current signal parameters. .