Found in a 90s Popular Electronics, this circuit uses a simple 9 V source. The power can be used from the circuit with which it works.
This circuit was obtained from an 80's Electronic Engineering. The circuit detects ice formation...
This circuit is from the Motorola Linear Databook published in 1990. The circuit for 1 kHz can be...
In the fist circuit the alarm triggers on when any sensor is CUT. In the second circuit the alarm...