Found in American documentation from the 1990s, this circuit can generate signals of up to a few tens of megahertz. The transistor must be suitable for high frequencies.
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....