Found in a 1967 General Electric SCR manual, this circuit can be used to protect a load by switching in case of excess current. R1 determines the trigger current.
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...