| 摘要 |
<p>999,989. Control of D.C. motors. ROTAX Ltd. Aug. 14, 1963 [Aug. 24, 1962], No. 32564/62. Heading H2J. [Also in Division H3] A motor control circuit comprises four cross coupled transistors or other switching devices arranged substantially as shown to have one stable state with transistors 6 and 9 conducting whereby the motor 5 is energized with D.C. or rectified A.C. from lines 1 and 2 and another stable state in which transistors 7 and 8 are conducting so that the motor is energized in the other direction. A further transistor 35 is connected across the motor in series with a contact 37 which is closed only when a shaft driven by the motor is in a desired rest position. This transistor is biased by resistor 36 to conduct only when the circuit is in the second stable state so that when the circuit is in this state and the shaft is in the desired rest position the motor is short-circuited through the transistor and the contact. The circuit is switched between its stable states by pulses applied at 26 or directly to the base electrodes of transistors 6 and 7.</p> |
