05744921 is referenced by 87 patents and cites 126 patents.

A control system (100) for a five-phase brushless DC motor (102) including a stator having five windings and a rotor (116) mounted for rotation relative to the windings (114). The windings (114) are adapted to be electronically commutated in response to the rotary position of the rotor (116). The control system (100) includes a sensing circuit (106) to sense the rotary position of the rotor (116) using an optical or magnetic sensor or the back electromotive force voltages in the windings (114). Electronic switches (112) control the flow of current through the windings (114) in response to control signals generated by a control circuit (110) in response to the rotary position of the rotor (116). The control circuit (110) includes start-up logic to start the motor (102). If the rotor (116) is rotating in a wrong direction upon start-up, the control circuit (110) energizes preselected windings (114) and waits for the movement of the rotor (116) to come substantially to a stop and then energizes the windings (114) in a start-up sequence to cause the rotor (116) to rotate in a correct direction. Once the rotor (116) is rotating in the correct direction, the control circuit (110) electronically commutates the windings (114) in response to the rotary position of the rotor (116).

Title
Control circuit for five-phase brushless DC motor
Application Number
8/643160
Publication Number
5744921
Application Date
May 2, 1996
Publication Date
April 28, 1998
Inventor
John E Makaran
London
CA
Assignee
Siemens Electric
CA
IPC
H02K 23/00
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