Optical isolator (CB9165E)

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.

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Hand Dryer (CB18786E)
With this circuit it is possible to use a common hair dryer as a hand dryer. The circuit is timed...
Power supply for LM12 amplifier (CB26149E)
This power supply was found in the same 1990 special issue of Radio Electronics Experimenter...
Three-phase power factor controller (CB7156E)
Suggested by an Electronic Engineering, this circuit uses components of the time. Modern...