This circuit is from American documentation from the 70s. The circuit makes use of the operating system of the time, but it can be implemented with more modern equivalents.
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...