This physical line servo control uses components that are not currently common. The circuit is from an 80's documentation and is powered by a voltage according to the servo.
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...