Gene Heskett wrote: > > The other possibility is that its a resolver, where one set of wires would be > power, probably 5 volts, The next set, possibly the green one is an index at > 0 output, and the other 3 would divide the full rotation in 1/2 turn, 1/4 > turn, and 1/8 turn. But that on the face of it, would need about 4 or 5 more > divisions to achieve sufficient accuracy. But one could make an educated > guess as to that particular signal from a resolver by using the std nema > color code sequence. The Bad Boys etc phrase comes to mind. :) If its all > externally powered, then 5 sets of wires would let the resolution be divided > further to 1/16th and 1/32nd of a turn, which with decent ballistics would > allow thread cutting. As for an index, the MSB's 0-1 transition would > suffice if that's the case.
That's not a resolver. Sounds like you are describing a parallel absolute encoder. Such things exist but are rare. A resolver is a rotary transformer, similar to the old synchros and selsyns that were used in the 40's and 50's. See http://en.wikipedia.org/wiki/Resolver_%28electrical%29 for more details. There is no electronics or optics in a resolver, only copper windings and iron laminations. It does not use a DC power supply voltage. One winding is excited by an AC sine wave (typically a few volts at 2500 or 5000Hz), and the magnitude and/or phase of the signals on two other windings are decoded to get the position. The nice thing about resolvers is that they are very rugged - with no electronics in the resolver itself, they can handle high temperatures, coolant, and other abuse that would kill an optical encoder in short order. The bad thing about resolvers is that the circuitry to generate the sine wave reference and interpret the resulting signals is usually complex and expensive. Usually if you are retrofitting a machine with resolvers the best approach is to remove them and replace them with encoders. Regards, John Kasunich ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
