Star connected you will have 15 x 1.7 = 25.5v ac. The dc mean will be x 1.4 or about 36v. This doesn't seem so bad.
No using thicker iron will make no difference your error is to have no flux return path for the magnets. You would need a high grade laminated iron backing or a spinning flux return disc to get most benefit.
The resistance is high but until you decide on the volts and speed you want you can't do much about choosing wire size.
Your short circuit currents are virtually meaningless, dont waste time worrying about them.
Flux
"No using thicker iron will make no difference your error is to have no flux return path for the magnets. You would need a high grade laminated iron backing or a spinning flux return disc to get most benefit."
Wait, I thought my pile of steel sheets provided a flux return path for the magnets? The magnets are sitting on a bunch of thin steel sheets, 18" in diameter. The steel ring is just as wide as the magnets (2") and 1/4" thick. Doesn't that work, or am I fooling myself? I've heard that if a paperclip sticks to the back, it isn't thick enough. Paperclips and lots of other things stick to the back of my steel magnet backing.
I've got an steel backing on the magnets. Are we talking about an iron backing behind the coils as well? And laminated? I think I can visualize how that would help. I'm also guessing that iron is better than steel for this purpose.
I'm looking for as much power as possible (aren't we all?), 12+ volts at around or below 60 rpm. I've got a savonius with 3.5 square meters of surface area. I'm willing to use gearing, but I'd like to avoid that.
I see you calculated that I could get 36 volts dc, star connected. Am I right in assuming that if delta wired I'd get 21 volts dc, and more current? I'm just trying to get the formulas right.
I promise I'll have pictures soon! I very much appreciate your help.Robert Firth[ Parent ]
Yes delta will get you down to 21V at the same speed.
Flux[ Parent ]
One last thing - the laminate on the iron - is that any insulating material? Does the laminate work well, or is spinning the disk a better option? It seems to me that keeping that disk stationary makes the design simpler, if I didn't have to worry about eddy currents. I just don't understand how laminating the iron prevents eddy currents. I see you call it a "high grade laminated iron backing", and high grade usually means expensive.
Thank you for your time. I was disappointed before, but now I'm excited. This is going to work.Robert Firth[ Parent ]
