After building and programming a scaled down version of a project, I decided to begin work on scaling up. My first step was to purchase strong(er) servo motors. I figured (perhaps incorrectly) that my best bet was to obtain some used industrial servos. I then came across a couple honeywell synchronous motor servos. One of them came with an instruction manual that was printed in 1969 and has apparently been stored quite poorly. They both are identical and require a 120v 60Hz (typical Mains values) "Line Phase". This is as far as I get without some confusion. They require a control "PH."of 120v. Although I do not know what PH stands for in this instance, I do believe that a change in frequency on the control line results in a change in angle of the servo. So up until here I am still hanging on, but now comes my question. what hardware would I need/could I use to control this servo with an arduino? My guess involves some kind of amplifier. I have experience with 3-lead servos, this is my first encounter with a 4-lead and help on the internet is sparse. If this is covered in another thread than I apologize, and would appreciate a point in the right direction.
They sound like they may be SelSyn/Syncho "servos"; from what little I know about them, they had two parts - a transmitter and a receiver, turning the shaft on the transmitter rotated the shaft by the same amount on the receiver. They were mainly used for "virtual shafts" to connect a fire control computer to deck guns on a battleship. See:
