| 摘要 |
1,017,589. Construction and control of A.C. motors. BORG-WARNER CORPORATION. Oct. 22, 1962 [Nov. 14, 1961], No. 39918/62. Headings H2A and H2J. A polyphase electric motor and control system comprises a motor having a pair of oppositely wound coils for each phase which are sequentially connected to a D.C. supply by switching transistors, e.g. silicon controlled rectifiers, located in a static control unit and operated by a programme unit. A pulse generator 10 supplies fixed or variable frequency pulses to programme unit 11 which supplies triggering voltages, in sequence, to gate electrodes 20g, 21g of transistor switches 20, 21 which are connected in the series circuit including the D.C. supply 23, 29 and oppositely wound coils 25, 26 forming one phase of the motor. Similar transistor switches are used in the supply to the other phase windings of the motor and are controlled by programme unit 11 to produce a rotating magnetic field in the motor. A capacitor 22 is connected between each pair of phase windings to ensure that only one winding of a pair is conducting at any instant and feedback connection 15 ensures that supply is made to only one pair of coils at any instant. Discharge diodes 27, 28 in parallel with the phase windings are used to prevent high voltage switching transients from damaging rectifiers 20, 21. |
