| 摘要 |
PROBLEM TO BE SOLVED: To provide a synchronous motor that can reliably shift from start operation to synchronous operation, is reliable, and is compact. SOLUTION: A microcomputer 22 performs switching control within a range where a rectification current that alternately flows to the armature coil of a starting operation circuit 14 is inverted, and suppresses input at the inverted side for a non-inverted side for starting operation, turns off first to fourth transistors 16-19 when the speed of a permanent magnet rotor being detected by a photosensor 12 reaches a speed close to a synchronous speed for a power supply frequency being detected by a power supply frequency detection part 24 and turns on triac SW 1 and SW 2 for switching to a synchronous operation circuit 21 and for shifting to a synchronous operation. |
