05869946 is referenced by 66 patents and cites 5 patents.

Methods and apparatuses are provided for use in driving a multiple-phase brushless motor. The methods and apparatuses include generating a slewed phase control signal for each phase of the motor. The slewed phase control signals are substantially proportional to a speed control signal during non-transitioning periods, and are slewed from one state to the next state over time during transitioning periods. The transitioning periods being associated with a commutation point. The slewed phase control signals are used to generate pulse width modulated (PWM) driving signals, for each phase of the motor. Thus, the shape of the resulting PWM driving signal will include additional PWM pulses during the transitioning period that provide for a trapezoidal shaping of the current supplied to each of the phase coils in the motor. The result is that torque ripple is reduced because the overall current applied to the motor and the torque resulting therefrom will tend to be more constant during commutation.

Title
PWM control of motor driver
Application Number
8/814932
Publication Number
5869946
Application Date
February 27, 1997
Publication Date
February 9, 1999
Inventor
Francesco Carobolante
Scotts Valley
CA, US
Agent
Lisa K Jorgenson
Theodore E Galanthay
Steve D Beyer
Assignee
STMicroelectronics
TX, US
IPC
H02P 5/17
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