The circuit shown was found in the 1994 National Semiconductor's Linear Application Handbook. The op amp admits equivalents and the power supply must be symmetrical.
We found this circuit in the 1982 SGS integrated circuit manual. The integrated circuit is not...
This circuit tests the grounding of a three-pin outlet. We found it in a Popular Electronics from the 80s....
This video game that we published at the same time the full article in the magazine Eletrônica was also found...