We found this circuit in a 1968 Electronics World. It fires a buzzer if the ignition key is turned on and the headlight is off. The circuit uses an included oscillator buzzer like the Sonalert.
Just touch the sensor and the L1 lamp will light. The circuit has no lock, which means that the...
The presented circuit is suggested by Texas Instruments (www.ti.com) in its Application Report...
The circuit presented was obtained in a technical documentation from National Instruments. The...