| 摘要 |
<p>The commutatorless dc motor requires no extra rotor for precise position indication. This is achieved by locating a number of position detectors around the circumference of the rotor that only respond to flux generated by the motor in a given direction, and by locating positioning magnetic poles opposite the detectors and poles to give this unidirectional flux response in the detectors. Each position detector consists of a magnetic amplifier and a permanent magnet. The arrangement prevents two or more excitation windings being excited simultaneously, and also prevents none of the windings carrying current when the motor is switched on.</p> |
