This circuit is from Motorola's Linear Interface ICs of 1993. The integrated circuit is not common and the Triac is chosen according to the power of the controlled load.
Suggested by General Electric in 1965 documentation this circuit is intended for the 120 Vac...
This very high impedance circuit was found in documentation from the 1990s. The configuration can...
Found in the 1969 neon lamp documentation, using neon lamps this circuit provides 18 V regulated...