This shield circuit can be used in several applications that involve a feedback signal. The circuit is from American documentation from the 80s and the transistors are according to the loads driven.
This amplifier was found in a Japanese publication in 1972. Transistors are uncommon today, and...
The current of this source is 200 mA at the most, and the output depends on the zener that may...
Found in Mallory documentation from 1968 this circuit uses an integrated circuit from that time. The...