| 摘要 |
1,230,424. Control of A.C. motors. A. HONSBERG. 12 Sept., 1968 [15 Sept., 1967], No. 43475/68. Heading H2J. A polyphase electric motor M has A.C. semiconductors a, b, c between its windings A, B, C and the neutral point St. The motor is switched on and off by the presence and absence of a control signal applied at 16 and through resistors 10. It is stated that with this arrangement danger of short-circuiting or "phase cutout" is avoided due to the damping effect of the windings. In alternative embodiments the motor has extra windings for reversal and/or pole changing with a control circuit for each set of semi-conductors. For reversal the winding B is not duplicated but is switched on for both directions by the control signals for the forward or reverse windings which are applied to the semi-conductor for B via diodes. |
