| 摘要 |
PURPOSE:To highly accurately control a motor speed without affect of temperature and voltage changes by converting the operating amount of operating means to digital signal and digitally processing it to generate a motor speed control signal. CONSTITUTION:When a pedal is pressed in the state that a DC motor DM is stopped, photo switches 12, 13 are operated to apply one by one pulse signals each having predetermined phase difference to a D-type flip-flop 31. The signal obtained at output terminals 1Q, 3Q are fed back to input terminals 2D, 4D produce pulse signals having delayed clock pulses in one period for the output terminals 1Q, 3Q, respectively. The output signals are applied to the select terminals S0, S1 of a multiplexer 32 to thus obtain predetermined outputs at the terminals 1Y, 2Y, respectively. The output signal of the multiplexer 32 is inverted by inverters 33, 34, and the inverted outputs are applied to the input terminals UP, DN of the counter 35. The output from the counter is applied to the motor control circuit 42 to control the rotating speed of the DC motor DM. |
