| 摘要 |
A digital motor control system utilizes at least two variable pulse generators to produce two streams of pulse width modulated pulses to control the motor speed and direction of rotation of a motor. An input control signal may be compared with two reference signals, such as two waveforms which are inverted with respect to each other, to produce two streams of pulse width modulated signals. A logic circuit combines the two streams of pulses. In one embodiment, depending on the input control signal level, where the two streams do not overlap, reverse motor control signals are produced and where the two streams overlap, forward motor control signals are produced. As the pulse widths of the pulse width modulated pulses change, the motor may receive continuous power in one direction, slow down, stop, and then increase speed in the opposite direction until it receives continuous power in the other direction. The variable pulse generators may be of various types including one-shot multivibrators and comparators. In one embodiment, two sets of N-channel and P-channel power switches may be utilized to drive the motor.
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