How does this servo motor work? - Page 1
Forum section: electronics / beginners

author: sbennett1298
author_rank: Contributor
timestamp: June 23, 2017, 12:49:18 pm
content: I found this in a second hand store for cheap and I want to know how to use it. It says:Kearfott Inertial Servo motor TYPE R1310-2B 400HZIt has 6 wires. The diagram on it shows three windings. One winding is labeled PHASE I and is depicted vertically.The other two windings are depicted horizontally and are labeled PHASE II.I don't know if the orientation of the windings in the diagram means anything.Any ideas? I know what a servo motor is but this diagram has me confused.-Steve

author: Yansi
author_rank: Super Contributor
timestamp: June 23, 2017, 01:08:37 pm
content: https://en.wikipedia.org/wiki/SynchroThats what it probably is.

author: sbennett1298
author_rank: Contributor
timestamp: June 23, 2017, 01:30:42 pm
content: Page 16 of this document calls it an "inertially-damped servo motor"https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19670009306.pdfI have some syncros and they only have 5 wires. Two for the excitation voltage and three for the output.-Steve

author: metrologist
author_rank: Super Contributor
timestamp: June 23, 2017, 05:55:12 pm
content: maybe a two phase stepper?

author: Yansi
author_rank: Super Contributor
timestamp: June 23, 2017, 05:56:25 pm
content: If only two phases are labeled, it as well might be a synchronous reluctance motor. Just have two windings with the center taps pulled out. (you can verify the connections with a DMM)A photo might help a lot, if you wish

author: sbennett1298
author_rank: Contributor
timestamp: June 23, 2017, 06:23:30 pm
content: I Googled "two phase servo" and found that there is a motor by that name but still do not know how to tell if this is one or how to drive it.The two phase servo rotates at the difference between two frequencies.If that is what it is I could put 400hz on one winding and 450HZ on the other but then what is the third winding for?The diagram on it does not show any center taps.I will post a photo soon.

author: sbennett1298
author_rank: Contributor
timestamp: June 24, 2017, 12:24:42 pm
content: Here are photos of the motor.https://www.flickr.com/photos/71127000@N08/albums/72157683123847621

author: sbennett1298
author_rank: Contributor
timestamp: June 24, 2017, 12:40:10 pm
content: I just noticed something. Phase I is marked 115V but no voltage is given for the two Phase II windings.Maybe Phase II is a sin cos resolver? Maybe this thing is a syncro transmitter.

author: Yansi
author_rank: Super Contributor
timestamp: June 24, 2017, 02:48:32 pm
content: Yes, three windings (six wires) can also lead to a sin-cos resolver. Grab the meter and measure the configuration of the wires. Should have three separate windings, two with the same DCR, one slightly different (the excitation coil).

author: sbennett1298
author_rank: Contributor
timestamp: June 24, 2017, 03:31:52 pm
content: I will do some tests when I have time. Until then I'm wondering. If it IS a sin cos resolver why does it have the word MOTOR printed on it?A resolver is not considered a type of motor is it?

author: Yansi
author_rank: Super Contributor
timestamp: June 25, 2017, 08:33:53 am
content: Resolver will never work as a motor, thats for sure.But still, this is a guesswork. I don't know why the OP just cannot do any measurement and take it apart and photograph the internals?