This circuit with the LM741 operational amplifier can be applied to other operational amplifiers. We found it in the September 1989 Radio Electronics magazine.
This dual-LED circuit indicates three signal levels. It was found in the January 1996 issue of...
With this circuit of a Popular Electronics from the 90's it is possible to test a diode with the...
Found in an Electronics World of 1966, this circuit makes use of FETs of the time. Modern...