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 optically coupled circuit was found in the February 1968 Radio Electronics magazine. The...
We found this circuit in the April 1978 issue of Radio Electronics magazine. The power supply must...
This circuit supports several sets of coils and can oscillate from 1 to 44 MHz. The transistor is an old...