| 摘要 |
PURPOSE:To attain a safe car speed control even if a power supply is interrupted momentarily, by inserting a discharge means between a terminal of a capacitor of an integration circuit and a line being a higher voltage than a line that at the terminal when the power supply voltage is normal. CONSTITUTION:When a power supply voltage VB from a battery is 0(V), (interrupted), a potential VP at a point P drops to 0(V), a diode Dc is biased forward and charges in a capacitor Cc at the anode of the diode Dc are discharged. Thus, the voltage Vc is rapidly decreased and a potential Vv of a car speed voltage signal is decreased. When the voltage VB is restored to a prescribed voltage, voltages Vcc and Vr rise and when the Vr rises to a prescribed voltage Vr1, an FETQd turns off. A potential difference¦Vv1-Vr1¦just before the turning off is stored in a capacitor Cd, and since the charge in the capacitor Cc s once discharged, the voltage Vv rises comparatively slowly in response to the voltage Vcc and the car speed, and a car speed slower than the preset car speed is stored in the capacitor Cd. |
