This power supply was obtained from an Electronic Design from the 90's. The circuit applies to other 3-terminal regulators. The maximum output current is 200 mA.
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....