04692674 is referenced by 25 patents and cites 39 patents.

A control system for a brushless DC motor responsive to digital control signals is disclosed. The motor includes a multiphase wound stator and a permanent magnet rotor. The rotor is arranged so that each phase winding, when energized from a DC source, will drive the rotor through a predetermined angular position or step. A commutation signal generator responsive to the shaft position provides a commutation signal for each winding. A programmable control signal generator such as a computer or microprocessor produces individual digital control signals for each phase winding. The control signals and commutation signals associated with each winding are applied to an AND gate for that phase winding. Each gate controls a switch connected in series with the associated phase winding and the DC source so that each phase winding is energized only when the commutation signal and the control signal associated with that phase winding are present. The motor shaft may be advanced one step at a time to a desired position by applying a predetermined number of control signals in the proper sequence to the AND gates and the torque generated by the motor may be regulated by applying a separate control signal to each AND gate which is pulse width modulated to control the total time that each switch connects its associated winding to the DC source during each commutation period.

Title
Brushless DC motor control system responsive to control signals generated by a computer or the like
Application Number
6/727838
Publication Number
4692674
Application Date
April 26, 1985
Publication Date
September 8, 1987
Inventor
Donald E Schmitt
San Jose
CA, US
Douglas T Packard
La Canada
CA, US
Agent
Thomas H Jones
John R Manning
Paul F McCaul
Assignee
The United States of America represented by the Administrator of the National Aeronautics and Space Administration
DC, US
IPC
H02P 6/02
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