摘要 |
<p>A travel DC motor (12) and a loading DC motor (18) are connected to a common battery power source (10). The motor (12) is supplied with current through a transistor chopper (28) whose on/off operation is controlled, and the motor (18) is supplied with current through a thyristor chopper (32). The transistor chopper (28) and the thyristor chopper (32) are repeatedly turned on and off in response to pulse signals P1, P2, P3 generated by chopper control circuits (30), (47). When the thyristor chopper (32) is on, the chopper control circuit (30) keeps the transistor chopper (28) off in response to an inhibition signal Va.</p> |