car lights warning device

lektor july/august 1983 45 car lights warning device L.1 Anyone who has ever forgotten to switch the car lights off, after having driven in poor weather con- ditions, and returned later in the day to find the car battery flat will appreciate this circuit. The circuit sounds a buzzer when you turn off the engine and have forgotten to switch off the head lights. When required, the circuit can be reset with push button Si. This may be necessary, for instance, when you have your headlights on, get stuck in a traffic jam and turn theengineofftokeepthecarbon monoxide level down. When you turn the ignition key and start the engine, the dynamo or alternator runs, relays are operating, the electric fan comes on, the auto- matic radio aerial extends ... All these produce large voltage spikes on the car"s electrical system and any electronic circuit must be protected against these. The circuit is connected to contact breaker S3 and the lighting switch S2. At first sight the use of the contac...