Intelligent SCR AC-AC Low Frequency Power Supply System

Based on the technique of the frequency inverter, the design expounds the application of AC-AC low frequency power supply system; the constitution, the functions and design principle of main circuits and the unit circuits are introduced. The microprocessor is used to realize digital control as flip plus of the SCR. The IC chip SA866AE of MITEL company is utilized as the low frequency signal generator of the system. Furthermore in the zero-current detection circuit, use the photocoupler GaAlAs IRED and photo IC to detect zero-current, furthest shorten the commutating "died region" , prevent the current from distorting . The two problems of old low frequency power supply system are soluted.