Obtained from an Electronic Engineering of the 90s, these circuits can be applied to almost any operational amplifier. Signal shapes are given next to the diagram.
This circuit was found in Radio Electronics magazine from February 1962. The sensor is an LDR, and the...
This circuit carries small batteries of Nicad that can be connected in series in number of up to...
This circuit was found in a 1967 US documentation. It shows how to build a gain control by digital...