Found in a 1964 Electronic Design, this circuit makes use of FETs of the time. These transistors can be replaced by modern general-purpose types. The input resistance is 30 M.
We found this common application of the 741 operational amplifier in a 1977 documentation. The...
This circuit, found in an old 1967 publication, cuts the current from a source when the current...
This LED bar graph circuit was found in the October 1980 issue of Radio Electronics magazine. The...