| 摘要 |
PURPOSE:To improve the responsiveness of a speed control system and also to improve the processing efficiency by inputting the detected value of a current which flows through an electric motor to a variable frequency oscillator, and using its output as the oscillation source for a counter which generates a pulse width signal. CONSTITUTION:When the output signal CQUT1 of a current detector 14 rises, the signal CQUT1 is inputted to an oscillator 10, whose oscillation frequency (signal QSC3) therefore increases. The oscillator 10 serves as the oscillation source for the counter 11, so it operates to reduce the current by decreasing the pulse width data of the counter when the signal QSC3 rises. Namely, the pulse width of current detection is increased and decreased directly by the counter. A control logical device 16 is therefore dedicated to only speed detection, so the responsiveness of the speed control system is improved extremely and the processing efficiency is also improved. |
