The operational amplifier used in this circuit is uncommon nowadays. We obtained this circuit from documentation from the 1980s, but it can be adapted to use more modern equivalents.
This circuit with signal acceptance filter was found in the June 1993 Electronics Now magazine. Other...
We found this 555 integrated-circuit tester in an old Electronics Hobbyst from 1977. The circuit is...
Found in a1969’s neon lamp documentation, this circuit uses a high voltage transistor. The output...