This circuit is for traditional old-style telephone lines found in an American 1980s documentation. Components are common and the optical coupler can be replaced with an equivalent.
We found this oscillator that can supply up to 3 A of output in the 1982 SGS linear integrated circuit...
This circuit is from the 1992 Radio Electronics Handbook. The components used are from the period,...
The load current can be adjusted up to about 1 A. The transistor can be TIP32 or TIP42. The...