| 摘要 |
PURPOSE:To prevent abnormal rise of the number of revolution of an engine by installing a release prohibitting circuit which prohibits release of overdive when the car speed becomes high and continues said prohibition unitil the car-speed lowers to a prescribed value. CONSTITUTION:The differential voltage between a set-speed voltage 3 and a car- speed voltage 1 is output from a subtraction circuit 2. An autodrive control- circuit 4 controls the opening of a throttle etc. and controls traveling at a set speed. As the output of a flip-flop 15 is ''0'', when a car travels at a high speed, an overdrive cutting solenoid 9 is not excited, and release of overdrive is prohibited. As the reset output of the flip-flop 15 becomes ''1'' when the car-speed reduces below a prescribed value, the overdrive cutting solenoid 9 is excited and switching from the fourth-speed to the third-speed is performed, when a flip- flop 7 is set. Thus, abnormal high-speed revolution can be prevented. |
