Zero crossing forecast of synthesize test circuit

In order to accurately control the standing arc circuit's turn in time on synthesize test so as to assure tests with success, in this paper a phase shifting method based on digital filtering technology is presented, as a result, short circuit current's zero crossing can be forecasted according to users' need, and the breaking capability of circuit breakers on the second the third halfwave of corrent examined. In this paper the complex programmable logic device (CPLD) technology is used for designing the measuring circuit and digital processing system. The simulation results show that the method presented in this paper has tae good performance with high precision and low cost to improve the control level of synthesize test circuit.