This circuit was found in a 90s American publication. The same configuration appears in several places on this site, obtained from different sources. The lamps can be replaced by LEDs.
The PA222 integrated circuit used in this project from an American 1967 documentation is not...
This circuit with an optical path sensor was found in a 1995 documentation. The circuit fires...
This circuit was found in an 80's Electronic Design. It amplifies TTL fast signals for a coaxial...