We found this circuit in the Radio Electronics magazine of May 1977. The circuit has the frequency given by the components according to the formula next to the diagram.
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...