Found in a 90s EDN, this circuit is indicated for power control through a 4-20 mA line. The circuit makes use of optical couplers of the time.
This circuit is from 1997 documentation, a time when the parallel port was the most common means of...
Datasheet of We found this circuit in the 1982 SGS Linear Integrated Circuits manual. A | table...
This sophisticated logic probe for 5 to 12 V circuits (CMOS and TTL) was found in a 1980s...