| 摘要 |
<p>PURPOSE:To suppress the abrupt variation of an armature current of a motor, when the voltage of a DC power source is rapidly varied, by energizing a special series field coil which is connected in series with the armature. CONSTITUTION:An interpole coil 3, a series field coil 4 and a special series field coil 8 are connected in series with the armature 2 of a motor. A pulse generator 12 fires semiconductor elements 9, 10 in the normal operation time to shortcircuit the coil 8. When the voltage of a DC power source 1 is, on the other hand, abruptly varied, a signal voltage corresponding to the abrupt variation of the armature current is generated from the secondary coil 11b of a transformer 11, a deenergization signal is outputted from the generator 12, thereby deenergizing the elements 9, 10. Thus, the armature current flows through the coil 8. Accordingly, the rise of the counter electromotive force of the armature is accelerated. In this manner, the variation of the peak armature current which abruptly changes transiently can be suppressed.</p> |
