Controller for computer control of brushless dc motors
Abstract
A motor speed and torque controller for brushless d.c. motors provides an unusually smooth torque control arrangement. The controller provides a means for controlling a current waveform in each winding of a brushless dc motor by synchronization of an excitation pulse train from a programmable oscillator. Sensing of torque for synchronization is provided by a light beam chopper mounted on the motor rotor shaft. Speed and duty cycle are independently controlled by controlling the frequency and pulse width output of the programmable oscillator. A means is also provided so that current transitions from one motor winding to another is effected without abrupt changes in output torque.
- Publication:
-
National Aeronautics and Space Administration Report
- Pub Date:
- February 1981
- Bibcode:
- 1981nasa.reptQ....H
- Keywords:
-
- Automobile Engines;
- Controllers;
- Direct Current;
- Electric Motors;
- Gates (Circuits);
- Numerical Control;
- Comparators;
- Decoders;
- Electric Choppers;
- Oscillators;
- Patents;
- Rotating Shafts;
- Synchronism;
- Torque;
- Electronics and Electrical Engineering