| 摘要 |
PURPOSE:To prevent the malfunction and runaway of a car height adjusting apparatus having a digital control means, according to a method wherein a power source is turned off with a delay time after an ignition switch is turned off, and car height control is stopped after the output voltage of a constant voltage generating means decreases. CONSTITUTION:When Ig and Sw are turned off, a transistor T2 is driven only through R4, and then VIN of a micro computer 30 becomes low. Therefore, the destruction timer in the micro computer 30 is operated, VOUT being turned off after a predetermined times, T1 and T2 being turned off, electric supply to a constant voltage Vcc being stopped. The voltage Vcc is monitored through R8 by means of a comparator CMP, the signal at the RES terminal of the micro computer 30 being decreased to low level through R7 when the voltage Vcc is lower than the Zener voltage Vz of Z1. According to the above constitution, the micro computer 30 is certainly turned off after the transistors T1 and T2 are turned off, so that malfunction and runaway can be prevented. |
