General Electric suggests this circuit in a 1980s documentation. The operational of the time is FET-type input. Modern equivalents may be used.
This circuit was found in an old publication from 1989 but can still be assembled today with BD135...
We found this circuit in a 1987 documentation. Its purpose is to turn on a garage light using the...
In the figure we have a simple logic level indicator for TTL circuits or powered by 5 V....