On Thursday 12 July 2012 22:28:46 Jon Elson did opine: > Todd Zuercher wrote: > > Is there a Way to tell if a motor is trapezoidal wound? > > In theory, if you spun it at a constant rate and observed the waveform > on an oscilloscope, it would be non-sinusoidal. But, I've never been > able to tell the difference. With a big enough flywheel to assure a pretty constant angular velocity in the presence of the motors natural cogging tendency, I still don't think the diffs would be all that visible on the scope. My common sense says that the cogging would probably tend to make it look more sinusoidal than it is. Fed to an audio distortion analyzer, either would be pretty hard put to be under 5%. Or, more than likely, to get noticeably higher than 20%. But just for S&G, I'd like to try it anyway. I have access to one analyzer that has a noise floor of about .0012% so I think we could believe what it tells me.
> > Besides trying it both ways and seeing which works best. > > I did try spinning the motor and looking at what the back EMF was with > > a scope, and what I saw on the screen looked like a smooth sine wave > > to me. But maybe that isn't a valid test. It should be if its actually delivering a usable current as a generator. I tend to not trust things 100% if the only load is the high impedance load of the analyzer when its input terminators, if present, are disabled. > Right, it seems logical to me that should be definitive, but... > > Jon > > ------------------------------------------------------------------------ > ------ Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. > Discussions will include endpoint security, mobile security and the > latest in malware threats. > http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) My web page: <http://coyoteden.dyndns-free.com:85/gene> is up! Disc space -- the final frontier! ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
