| 摘要 |
PURPOSE: To provide a variable speed controller for a single-phase AC induction motor that has its auxiliary coil, which is in series with a capacitor, continuously excited while a controllable switch is in series with the main coil of the motor. CONSTITUTION: A switch 34 is always open, when no current flows to a main coil 24. When this switch 34 is opened, the counter electromotive force of the main coil 24 is detected 36 for measuring the speed of a motor 10. This counter electromotive force is compared 44 with a necessary speed signal, and this comparison is used to control the closed circuit of the switch. The motor 10 is held at a necessary constant speed, even if load varies. |
