| 摘要 |
A motor control chip (62) for asserting the control signals used to regulate the energization of the windings of a DC motor. The motor control chip includes a tachometer (94) that receives pulsed signals that vary with the rotation of the motor rotor and that produces a pulse width modulated tachometer signal as a function of the motor speed. A pulse width modulator (90) receives the tachometer signal and an analog signal representative of the user-selected motor speed. Based on the received input signals, the pulse width modulator produces a variable speed control signal. A forward/reverse oscillator (92) receives user-set signals indicating if the motor should be run in the forward or reverse directions or in an oscillatory pattern. Based on the received signals, the forward/reverse oscillator asserts a forward/reverse signal having an appropriate signal state or cycle. A motor decoder (98) receives the signals produced by the pulse width oscillator and the forward/reverse oscillator. The motor decoder then asserts the control signals that regulate when power switches selectively tie the motor windings to either a power source or ground.
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