The setting of this power supply is only 0.1%. We found it in a 1969 US documentation. Transistors may be current equivalents. Note the use of symmetrical power supply.
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...