Dither (motor control)
The disadvantage of driving the motor at a frequency above
human hearing is that there is a loss of drive (torque) from the
motor at low speeds. A solution for this loss was found. If the
motor pulses are not exactly on time, much of the lost torque
is regained.
Think of a teen-age garage band. They might be able to play a
hit song, but they can’t all stay on the beat. Assume that the
drummer is spot-on with his beat, but sometimes the singer is
ahead of him and some times behind. Various decoder manu-
facturers call this variation around the “correct” time “dither”
or “torque compensation”.
Yes, it is possible to have dither and BEMF in the same decoder.
The current offerings from TCS and others do so.
9
9: Motor voltage pulses at 75% power going forward.
