Vacuum pump control esp. for vehicle door locking systems - has transistorised switch to avoid battery discharge

摘要

The vehicle door locking system vacuum pump (1) is supplied with current via a switch (6) which is dependent on the pressure prevailing in the storage tank (2). A monitoring unit (8) interrupts the pump motor supply current after a predetermined number of working cycles to prevent battery discharge when the vehicle is parked. The monitoring unit circuit interrupts the pump motor feed corresponding to the air leak rate from the depression system. a transistorised switch is used to interrupt the pump motor feed by using the increasing pump motor tension at a predetermined threshold. The working cycle is repeated by either charging capacitors or a binary counter.