Found in a magazine 73 for radio amateurs of the 90s, this circuit converts a continuous voltage and another continuous voltage, but with insulation between the circuits.
This is a commercial radio circuit from the 1960s. The circuit was found in a Japanese publication from...
The integrated circuit used in this 80's differential amplifier is a quadruple version of the 741...
This touch or proximity sensor circuit was found in a Popular Electronics from 1992. In the...