04250435 is referenced by 100 patents and cites 18 patents.

A speed control system for an electrically commutated motor which is readily adaptable to digital velocity control input and which provides highly efficient and accurate control in a relatively inexpensive manner. Desired motor rotational velocity is commanded by an input clock rate, which may be variable, rather than by a voltage or current signal. A sensor is provided for determining actual rotor position, and actual rotor position is periodically compared with instantaneous desired motor position as indicated by the time of occurance of one of the input clock signals or pulses. Depending upon the results of this periodic comparison, a dynamically established active current limit is modified. Specifically, if motor rotor actual position leads desired position, the current limit is reduced. If, on the other hand, actual motor position is lagging, the current limit is increased. If the rotor is at the correct position, or within a predetermined deadband, the current limit is unchanged. This control action occurs simultaneously with conventional winding commutation taking place under the control of a, commutation sequencer periodically advanced in conventional fashion as the rotor reaches each of a plurality of predetermined positions.

Title
Clock rate control of electronically commutated motor rotational velocity
Application Number
6/109579
Publication Number
4250435
Application Date
January 4, 1980
Publication Date
February 10, 1981
Inventor
Richard C Weischedel
Camillus
NY, US
Robert P Alley
Manlius
NY, US
Agent
Radford M Reams
Assignee
General Electric Company
KY, US
IPC
H02P 6/02
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