4、控制,从而实现电风扇无级调速,满足人们对风扇转速的要求。这样电路的优点在于体积小,成本低,电路简单,易于设计制造。关键词:晶闸管;交流调压;保护电路;谐波分析AbstractThetwo thyristorinverseparallel afterthe series inACcircuits, bycontrollingthe thyristor cancontrol ACoutput. This circuitdoesnotchange thefrequencyofthealternatingcurrent, c