We found this circuit in a Popular Electronics of the 90s. The circuit can be easily mounted today, as the components are common. The SCR can be the TIC106.
We find this circuit in a 1980s documentation. The circuit uses uncommon components today which can...
We found this circuit in a 1977 Radio Shack documentation. The circuit should be powered, for...
With the circuit shown in the figure it is possible to digitally control the gain of an...