This circuit triggers by choosing the higher of two voltages. The circuit is from a 1964 Electronic Design. The transistors are of the time and can be replaced by current equivalents.
The simple touch of the fingers on a sensor causes this circuit to drive a motor that goes into...
Motorola's MC1456 integrated circuit used in this application is not very common today. The...
This circuit of an old publication produces the insect-like noise that drives them away. The...