got some wire and magnets

[Treehouse]

I was just given about 3 pounds of #22 magnet wire and 14 ceramic magnets(can get more) 1"x2"x3/8" and would like to build a wind genny out of it but dont know many turns and coils to make. I would like to charge some 12V batts with it. Can anyone give me so pointers?

Thanks Treehouse.  

[picmacmillan]

hi treehouse...the wire is very thin...the good news is it's free....if it were me, i would use multiple strands for my coils to increase the current.....if you don't then there will be a huge amount of resistance because of the length of wire needed per coil...if this is your first genny it is a good place to start, but i also would recommend getting some neodynium magnets to further your cause....even some small neo's would do better than the ceramic ones...good luck on your project, i look forward to seeing your pictures....pickster

[pyrocasto]

When it's free though, you dont worry about neos and bigger wire.

If you can get ahold of some more(or even bigger) wire, you can double or triple them up like Pic said.

[DBGenerator]

"If it's FREE, it's for ME!!"

Actually I found that since ceramic magnets are not as strong as NEO magnets, so thicker wire may not work.  Make some test coils and see what works.  Trapazoid coils work best, but sometimes take up more space.  The middle of the coil should be about the size of the diameter of the magnet.

[Treehouse]

any idea of how many winding? I'v wound 1 coil on a 1" by 2"  3/8-thick former, 100 turns, single wire. Set it up on an 8"disk with 12 of the magnets single rotor, and sping it by hand i'm only getting about .3V and the coil is about 1.5ohms so is there a way to figure out with what I have here a way to make it put out 50watts or so? or am I dreaming?

[farmerfrank]

Is it true that trapezoid coils are more efficient that square coils? Any idea how much better they are? Thanks in advance

farmerfrank

[DBGenerator]

The spacing sounds about right.  An eight inch disk with 1" wide magnets should give you a little more than and inch of spacing between the magnets at the edges.  About 1" in the middle would work best, but that should work anyhow.  .3Volts with 1.5 ohms might be all your going to get, but I think you could get a little bit more.  More widings, means more resistance, more resistance means more voltage up to the point where the magnet can not over come the resistance of the coil.  

How close are the coils to the magnets?  Should be less than 1/8".  I would suggest either more windings on the coil, but it might get to a point where it levels out.  Thinner wire with more windings might get more voltage, but less current, but might be more efficient with the ceramic magnets.  (And you hate to not use that free wire!!)

I hope that helps.

 

[electrondady1]

treehouse check the ohms on your meter when you touch the leads together. i spent months struggling with coil/mag design before i realized there was a .2-.3 ohms residual resistance . it doesn't sound like much but when your turning different coils insearch of reduced resistance it makes your experiments pointless , also make shure the speed you rotate the magdisks is as consistant as possible . slight varyations in rpm can really through you off.

[Jerry]

Hi Treehouse.

Not to long ago I built my first dual rotor alt. I used 24 Lowes ceramic magnets. These measure 1-7/8" X 7/8" X 3/8". Very simular to yours. 12 magnets per rotor. I used 10" saw blades stacked 3 deep per rotor with teeth removed. This made the discs 8.75" dia. I wound 9 coils of 24 ga. wire 300 turn each. I used a fullwave bridge diode per coil then perelelled all the diode dc outputs.

Here are the wind test #s I got. This was with a 49" tip to tip 3 blade with "Jerry Blades".

5 mph 12 watts, 10 mph 30 watts, 15 mph 60 watts, 20 mph 120 watts, 25 mph 145 watts, 30 mph 246 watts and 35 mph 281.25 watts.

I think since your magnets are slightly larger and also your wire you will have simular or a littel higher power than mine.

The story is on one of my diary postings but be warned there are many pix and it takes a long time to load.

See it at http://www.feldlines.com/story/2005/1/30/4118/94606  I hope thats it If not it was Jerrys first dual rotor diary.

                JK TAS Jerry

[Jerry]

Well sorry the link dosn't work. This was the first time I tryed to link a story so I think it will be my last. I don't get along with putters. Thet are not my freind.

                       JK TAS Jerry

[stop4stuff]

here's your page Jerry

http://www.fieldlines.com/story/2005/1/30/4118/94606

[Jerry]

Thanx stop4stuff. Silly me I left the i out of feildlines and then blaimed the puter?

                          JK TAS Jerry