公开(公告)号：DE3069643D1

公开(公告)日：1984-12-20

申请号：DE3069643

申请日：1980-11-28

Applicant: IBM

Inventor： DAVY JOHN COLIN ,  FENTON BRIAN PETER ,  RAMAGE JOHN GILBERT

IPC: H02P1/30 ,  H02P1/42

Abstract: A single phase induction motor control system employs power line assisted starting and runs at higher than power line frequency from an electronically generated inverter supply. This inverter supply is employed to provide an out of phase mains frequency signal to the run winding during starting in order to create the rotating magnetic field needed to start the motor. After the motor has started, the power line supply is disconnected from the start winding and the inverter supply frequency is increased gradually to a final value corresponding to the desired operating speed. In this system no phase shifting capacitors are needed to provide the out of phase starting voltage and the run winding is optimized for running conditions.

公开(公告)号：DE3472867D1

公开(公告)日：1988-08-25

申请号：DE3472867

申请日：1984-02-29

Applicant: IBM

Inventor： COMMANDER ROBERT DUNCAN ,  FENTON BRIAN PETER ,  RAMAGE JOHN GILBERT

IPC: H02M7/537 ,  H02M7/5387 ,  H03K17/691 ,  H02M1/08 ,  H02M3/335 ,  H02P1/18 ,  H02P6/02

Abstract: The power switching circuit employs a solid state device (14) responding to a drive signal at its output to switch power repetitively to a load at a low frequency. The device is driven across an isolating transformer interface (60). The drive signals are HF pulse signals which are modulated withthe LF switching information. The modulations are detected in the secondary winding (62) of the transformer. Power for the detector is derived by a diode bridge (120-123) rectifying the HF signals induced in the transformer secondary output. The current through the device is sensed and chopped to keep it within safety limits.