摘要 |
<p>A permanent magnet brushless 3-phase motor comprises windings R, Y, B, each divided into a plurality of sections 1-5 and switch means S1-S12 for selectively connecting the section of the respective winding e.g. R in series and/or parallel with all other sections of that winding R. Control means are provided for actuating the switch means S1-S12 to connect the winding sections 1-5 in different configurations whilst the motor is running to alter the speed/torque characteristics of the motor.</p> |