Using the name of varactor this circuit was found in the Radio Electronics magazine of July 1982. Varicaps of any type can be used and the components selected according to the component.
With the coded activation of the relays, it is possible to control which of the 16 outputs...
The integrated circuit used in this application is not very common. Transistors and resistors...
This simple circuit makes use of neon lamps to indicate the voltage of a power grid. The lamps are...