| 摘要 |
A speed control switching circuit for a synchronous motor having windings to which identical switching circuits are coupled. Each switching circuit includes two transistors which are turned on and off alternately to drive current first in one direction through its winding and then in the other direction through its winding. When a transistor is turned off, the current through the winding decreases, and this current drop is sensed, and, at a predetermined dropoff point, the other transistor is turned on. |
