| 摘要 |
The starting circuit, for a speed-controlled small brushless d.c. motor, allows the motor start-up characteristics to be set independently of the speed regulation circuitry. The speed control is accomplished by comparing an e.m.f. derived from the motor windings with a reference value. The derive e.m.f. is smoothed by an RC circuit before passing to the setting and control circuits. The setting circuit output is then fed over a second RC smoothing circuit back to its own input or to the input of the control circuit. The capacitor in the second smoothing circuit is charged to a given voltage level by a charging circuit while the motor is stationary. |
