Patent ID: 8248020

Claim:
A starting circuit for a single-phase AC motor, comprising a rectifying and voltage-stabilizing circuit; a control circuit comprising a zero-cross detecting circuit and a counter; and a bidirectional thyristor; wherein said bidirectional thyristor is serially connected to a starting winding and a starting capacitor; said bidirectional thyristor, said starting winding and said starting capacitor are connected a utility power AC input; an input end of said rectifying and voltage-stabilizing circuit is connected to said utility power AC input; an output end of said rectifying and voltage-stabilizing circuit operates to supply power to said control circuit; an input end of said zero-cross detecting circuit is connected to said utility power AC input; an output end of said zero-cross detecting circuit is connected to an input end of said counter; said zero-cross detecting circuit operates to detect zero crossing points of said utility power AC input, and to input said zero crossing points to said counter; and said counter operates to trigger a signal whereby controlling said bidirectional thyristor as the total number of said zero crossing points reaches a predetermined value.