In the figure we have a 9V source using a 5V 7805 regulator. The circuit is from an American documentation from the 90s. The circuit has a 12V input. The maximum current is 1 A.
This protection circuit for standing waves was found in a manual of high frequency circuits and...
We found this circuit in a Popular Electronics of the 80s. Used integrated circuits are uncommon...
This experimental circuit with Nixie tube was found in the Radio Electronics magazine of March...