car light reminder

There are many different designs for alarm circuits which remind the motor-ist to switch off his lights before leaving the car. The advantage of the circuit presented here is that no extra com-ponents have to be connected in series with the existing wiring, so that it will not effect the operation of the car electrical system. Furthermore the cir-cuit is extremely simple, consisting solely of a DC buzzer, a double-pole double-throw switch, and a handful of diodes (depending upon the num-ber of functions to be monitored).