This is a low-gain amplifier to operate as a booster. We found it in an American documentation from 1947. The circuit uses a coupling transformer at the input.
The RCA integrated circuit used in this control is uncommon today. The circuit is from an...
We found this circuit in a Popular Electronics of the 90s. The circuit uses a touch sensor formed by...
We found this circuit in a European schematic from the 90s. The used integrated circuit can still...