This simple circuit uses a car ignition coil. The circuit appeared in the 1983 Radio Electronics Annual Edition. The circuit supports equivalent transistors.
The circuit is from 1968, but we can use a modern one like the 741. The symmetrical power supply...
The circuit presented uses Linear Technology Operationals, having been found in a 1993 manual. The...
Found in American documentation from the 90s, this circuit triggers a buzzer with a Sonalert-type...