| 摘要 |
PURPOSE:To efficiently start a commutatorless DC motor by restarting the motor by timer means in a short time when the starting is failed and performing a protecting operation when the starting are failed continuously for a predetermined times. CONSTITUTION:The output of a counterelectromotive force detector 6 is input to a drive circuit 7 to drive semiconductor switching elements S1-S6 of a semiconductor commutator 2. This drive circuit 7 has operating means 7a, second timer means 7b, frequency detecting means 7c, modulo-N counting means 7d and first timer means 7e. When the commutator 2 fails to start, it is restarted in a short time, and when the failures of the starting continue for N times, it is handled similarly to a protecting operation. |
