Safety interlock circuit for vehicle windscreen wiper motor control - switches off motor when e.g. hatch-back door opened and does not immediately restart motor after closing rear door

摘要

The circuit switches the windscreen wiper drive motor off when a part of the vehicle, e.g. the rear door, is moved from a rest position. When the door is returned to its rest position, the motor is at first not re-activated, and is switched on after a set time period, or when a switch is operated by a user. The interlocked drive circuit for screen wiper motor (M) consists of on/off control switch SBS, hatch-back door switch SHS, interlock logic (2), drive circuit (3). In operation, an R-S flip flop (4) is set by the switch (SBS) ON and the switch (SHS) in the door closed position. The wiper motor is energised. As SHS opens, SQ is reset and power to the wiper motor is switched off. ADVANTAGE - Avoids injury to user.