摘要 |
The rotor of a brushless DC motor is monitored continuously, and successive positions thereof are encoded in the form of digital counts. The count is continuously converted to analog form, and is compared with an analog reference signal, to determine the position error, and hence the speed error, or the motor relative to the desired constant speed reference. The error differential is suitably converted back to digital form to provide the motor power/drive amplifiers with sufficient electrical drive for the degree of correction which must be made. The digital position count from the counter is also coupled to a memory, which maintains in storage representations of position, and torque characteristics of the motor. Hence, based on these stored quantities and upon the actual motor parameters as exemplified by the present position, the memory issues control signals, that is timing and directional commands for correction of the motor speed.
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