This circuit was found on an old EDN and can be used as a shield. Optical couplers are from the era and modern equivalents can be used.
This is the conventional configuration of an astable multivibrator with operational, found in a...
This 1969 Electronics World power supply has 5 V to power digital circuits and a 170 V output for...
The Texas TL783 integrated circuit is a three-terminal high voltage regulator with a wide range of...