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Author Topic: 8" dual rotor + 61" blades.  (Read 908 times)

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Jerry

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8" dual rotor + 61" blades.
« on: April 12, 2006, 10:35:14 PM »
When I first built this alt a while back I tested it with my 49" blades. It did very well at 24 volts but stalled baddly at 12 volts.


Today I tryed it againg at 12 volts but with my blade extensions. This took the blade to 61".


At 49" and 24 volts I pushed the littel alt to 1296 watts and it stayed stone cold.


Today with the 12 volt battery load and with the 61" blades it got quite hot.


Here are the wind test #s.


 10 mph 63.5 watts.


 15 mph 130 watts.


 20 mph 196.5 watts.


 25 mph 331.25 watts.


 30 mph 432 watts.


 35 mph 630 watts.


It did more power at 24 volts with a smaller blade and no heat.


However I'm thinking of flying at 12 volts. The tower cables will be longer (more resistance) and I can shut it down in higher winds.


Heres a couple picture. I'm also trying out the nesel(sp). Seems to work well?













It has been sugjested my #s are most likely scewed by the wind excelerating over the cab of the truck? That may be? However these 2 tests were made the same way so at least the diferances are real.


Its all fun.


                             JK TAS Jerry

« Last Edit: April 12, 2006, 10:35:14 PM by (unknown) »
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willib

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Re: 8" dual rotor + 61" blades.
« Reply #1 on: April 12, 2006, 05:12:19 PM »
Jerry i think the stalling badly at 12 Volts tells  something important.

If it can produce power at 24V , i would say go for it , at 24..

because there will be a LOT LESS  power lost in the stator , by charging at 24V.

just my humble opinion.
« Last Edit: April 12, 2006, 05:12:19 PM by willib »
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Carpe Ventum (Seize the Wind)

oztules

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Re: 8" dual rotor + 61" blades.
« Reply #2 on: April 12, 2006, 09:51:34 PM »
Jerry well done


You have proven beyond doubt for me that Flux's "matching the load" discussion is correct in asserting that higher cutin is the way to go for better stator efficiency. The complication of the boost will be worth the effort.


1kw+ with minimul stator heating, or  600w+ and risk thermal malfunction...


Thanks Jerry..............oztules

« Last Edit: April 12, 2006, 09:51:34 PM by oztules »
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Flinders Island Australia

Jerry

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Re: 8" dual rotor + 61" blades.
« Reply #3 on: April 12, 2006, 10:20:01 PM »
Your right Oztules.


I went back out to see why the alt wasn't spinning as easy as it was earlyer. It now has a littel scratch rub in one small spot. It was stuck there. I think the heat warped or move a coil or somthing. I'll pull it apart tommorow to see whats rubbing?


I couldn't see any burnt coils.


                           JK TAS Jerry

« Last Edit: April 12, 2006, 10:20:01 PM by Jerry »
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