| 摘要 |
The armature (4) of the series-wound motor (5) which is operated using alternating current is short-circuited in a pulsed manner above a rotation-speed range which can be set. For this purpose, a phase-gating semiconductor (9), which is controlled as a function of the armature voltage, is connected in parallel with the armature (4). The triggering circuit for the phase-gating semiconductor (9) has a multiple, adjustable RC combination (17, 22). Such an arrangement prevents an unacceptable increase in rotation speed when the motor is running on low load. <IMAGE> |
