STARTING DEVICE FOR SINGLE-PHASE INDUCTION MOTOR

摘要

When a starting current runs through an auxiliary winding (S), a main PTC (12) and an auxiliary PTC (14) undergo self-heating for an increased electric resistance. When the auxiliary PTC (14) is heated to 140°C, a snap-action bimetal (18) is turned off to stop a current flow to the main PTC (12) and completes the starting of a single-phase induction motor (70). With the bimetal (18) off, a feeble current runs through the auxiliary PTC (14) side only to keep the bimetal (18) off by heat generated by the current.