Found in an American publication from 1969, this circuit can be adapted to be used as a shield. Operational amplifiers can be of modern equivalent types.
This circuit was found in an English publication from 1989. The integrated circuit is an...
This circuit was obtained from a 1964 magazine and has some interesting features such as the input...
Using a general-purpose transistor this AC amplifier was found in the November 1993 issue of...