We found this circuit in a Popular Electronics from the 90s. It operates at a frequency of 15 kHz. Components can be difficult to obtain, such as the integrated circuit.
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...