This 5 V circuit was found in December 1978 Radio Electronics magazine. The power transistor must be mounted on a good heat sink.
This circuit is from Motorola's Linear Interface ICs from 1993. The MC1723 is the equivalent of...
T This circuit produces an audible signal when someone touches the sensor, or even approaches. The...
We found this circuit in a 1968 Electronics World. The transistors are from the era and...