Suggested by Siliconix in documentation from the 90s, this circuit can present gains of digitally selected by the input going from 1 to 1000. The circuit can be adapted to work as a shield.
We found this circuit in a publication of 1991. The audio amplifier is an operational that admits...
Found in an 80's Hands On Electronics, this circuit turns on a light when it gets dark and goes...
This circuit regulates the output voltage of a 78xx according to the light incident on the sensor....