This operational amplifier circuit with variable gain was obtained in an 80's Electronic Engineering. The circuit applies to other operational amplifiers.
This circuit is from a PopularElectronics of June 1992. The magazine no longer exists, but the...
This circuit was obtained from a 1967 General Electric manual. The circuit makes use of absolutely...
Found in a 1988s Radio Electronics, this circuit uses transistors of general use to increase the...