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.
The author has many books he had written in Eglish (See the Biography) published by famous...
This circuit is from an old publication of the 70's. It can be implemented with modern transistors like the...
This configuration often addressed on this site is from a 2000 documentation. The circuit can be...