Quote:
Originally Posted by sikeston34m
Thank you Patrick. I've pondered some of these variables, back when I was experimenting with rewinding outrunner motors. John Rob and I were playing around with some ideas at the time.
I wonder why the thinner laminations work so much better at conducting magnetism? I'm sure it has alot to do with, the core of the lamination isn't what does the work since the magnetism follows surface area. The greater number of laminations in the same amount of space equals more surface area, thus conducting more magnetism overall.
I was glad to see that you chose a comparable kv rating for no load current. Kv does directly affect no load current, correct?
Resistive losses change from one motor wind to the next. I'm sure this is why a 1 or 2 turn motor has less overall resistence.
I know this isn't practical, but for the sake of efficiency, wouldn't a motor wound with silver wire work better than copper?
Overall resistence is also based on how good of a conductor, the wind wire is.
Guys, I have a feeling what Patrick posted here is "in a nutshell". I'm sure there's ALOT more to "the big picture".
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As Brian said earlier, the thinner laminations allow fewer eddy currents to form that are perpendicular to the magnetic field, and resist the field.
This is the same reason why high electrical resistance is a good thing -- the eddy currents that do form will be lower in power if the resistance of the steel is high.
Silver is a better conductor than copper, but costs so much that it's not practical. And it's only a little bit (I think about 20% or so) better than copper.
And it's not just the cost of the metal -- it's the processing too. There are very few manufacturers that are setup to process silver into electrical wire, and there are a few applications which demand it (some space applications.) So they command a HUGE premium. After processing, silver wire is around $2500 a pound. That would make a 1515 cost somewhere in the $600.00-$800.00 (just an estimate!!!) range.
