摘要 |
<p>Apparatus (10) for controlling the supply of power from a power source (12) to a motor (14, 14"). The apparatus (10) has a controllable switch (20, 20") for coupling power to the (14, 14") responsive to a pulse train, a circuit (20, 22") for converting the voltage applied to the motor (14, 14") to a logic signal, a line contactor (26) for connecting and disconnecting the power source (12) to and from the motor (14, 14"), and a microprocessor (60) for generating the pulse train and controlling the line contactor (26) to disconnect and connect the power source (12) from and to the motor (14, 14") in response to the presence and absence of the logic signal, respectively. By sensing short circuits and discontinuing the supply of power in response to the short circuit, a runaway motor speed condition can be avoided, and by using a microprocessor, the present invention is highly reliable, fast, durable, and cost-effective. </p> |