| 摘要 |
Two diode bridges (P1,P2) are in series with a two position switch contact (K) and motor winding (L). The bridge d.c. output is from a MOS transistor (T) which can be used to block the passage of a.c. current to the corresponding winding. A timing circuit (TMP) is triggered application of an a.c. voltage to the bridge. The timing circuit controls conduction of transistor as soon as the a.c. voltage is applied and stops conduction a predetermined time after a.c. voltage application. The electro-mechanical controller for a motor (M) with at least two windings (L1,L2) fed from an a.c. source. A switch (K), which changes the operating sense of the motor, is connected on the one hand to each of the two windings and on the other hand to directly feed one or the other of the windings. The timing circuit includes a resistance and capacitor. A short circuiting photo-coupler device is designed to discharge the capacitor. The device is controlled by the passage of current in the other bridge (P2) so that activation of the bridge (P1) used for operating the motor in one direction triggers reinitializing of the second bridge (P2) for driving the motor in the other direction and vice versa. |
