Blade program

[Smithson]

Hello   I have two questions that I can't find the answer to.

1.    How do you figure the resistance of the alternator on the Blade programs..  Previously someone commented that on a three phase alternator it would be the same as two of the legs in series.   That's assuming it is star wound.  And if it was Delta wound it would be 1/3rd of the star.  

But what about these 10 phase machines or even an off the wall experimental machine?

I have a 12 phase stator, with 6 of those full wave rectifiers, much like the plans that Hugh has.   I made it with 70 turns of 16awg wire per coil.  The suggestion was made that since it was not made with 15awg wire it would heat up with the extra resistance.  Hence I used only 70 turns of 16 awg wire verses the number of turns in the windmill plans.  90 of 15awg I think..  And when the coils were laid in the mold there was so much extra room I just added two more coils.

The simple solution would have been to go buy 15awg, but I used what I had on hand.

Also could the machine have been built with 90 turns of 16awg wire and 12 coils.  Wouldn't that have cut down the resistance with the added coils.

I searched this web site and read the help file at Windstuffnow but can not find where this issue is addressed.    

2.    And a second question if the drop is figured on the trailing edge as the distance from the top of the board  why  are the wedges for added blade angle put at the front of the blade and not at the back of the blade?

Thank you        Smithson

[Flux]

I don't know what blade program you have, but I can't see where alternator resistance comes into a blade calculation.

From your description I assume you have made an alternator with 12 poles and 12 coils, if so that is single phase and was not a good move. Had you used the smaller wire with the same as or a few turns less than the specified it wouldn't have made a really drastic difference. The resistance would have been higher and the permissible output less but the low speed performance would have been similar and you would never have hit stall.

You are into unknown territory with single phase, one thing is certain it will vibrate. Its efficiency will be lower and I doubt if it will track the blade speed well.

As far as I can tell from your description the resistance will be 1/12 of the resistance of 1 coil if that helps.

Had you kept to 10 coils that would have been 5 phase not 10. The resistance would again been that of 2 coils in series but you would halve that answer as you have 2 sections of winding in parallel.

I hope that you haven't joined all the starts together and connected the rectifier to the finishes or you will get nothing.

Flux

[picmacmillan]

hi smithson...its too late now but just some afterthought...i would have suggested you use two strands of #16 if thats all you had, it would emmulate a lot thicker wire......maybe even three strands....can you make your stator smaller to just accomodate what hugh had done?...or what ever idea you were working from...the farther you wonder off, the more trouble you will have...i did the same as you when i started and i had to make a couple stators before i was happy....might just be a learning curve....it will play on your mind all the time..."now if i would have used #15 would it be better"?...you will sort it out, but the good thing is your trying and trying always leads to success.....pickster