This circuit works like a solid-state contactor. We find it in General Electric documentation from 1965. SCRs can be modern equivalents according to the controlled load.
The integrated circuit used is equivalent to the 555 and the transistor can be the BC558. R1 and...
We found this circuit in issue 10 of the Italian magazine Selezione Rádio of 1982. The circuit...
This circuit is from 1997 documentation, a time when the parallel port was the most common means of...