We found this interesting circuit in a 1969 American documentation. It shows a solution with transistors for limiting surges in an alternating current power line.
In the figure we show our first circuit that consists of a simple touch switch capable of driving a...
This circuit was found in an 80's Electronic Engineering. The power supply must be symmetrical. The...
This metal detector was found in a French magazine Radio Plans from 1977. The phone can be a...