The Design of Low-Frequency Digital Phase Difference Measurement Instrument
Abstract: The design that low-frequency digital phase difference measurement system combines FPGA with SCM which constitutes the main measuring and controlling system of this entire design. FPGA is used to collect the time differences respectively corresponding to the frequency and phase difference of the measured sine signals with the same frequency .Ahead of that ,the measured sine signals of the same frequency should be changed to the forms of square waves by the plastic circuit module.At the same time, SCM is used to accept the data signals collected by FPGA , and then according to these data signals ,calculates the frequency and phase difference of the measured sine signals with the same frequency. And also on the meanwhile, SCM can switch the function buttons to show frequency and phase difference by the 8 Common Anode Seven-Segment LEDs which have the functions of digital display. This system can resist the outside interferences and has the advantages of reliability and high- precision measurement .If this design is further improved in stabilization and reliability , it can be used in the real industrial system .