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Yet another Coil question??
By Moosie, Section Mechanical Posted on Thu Apr 27, 2006 at 12:01:46 AM MST
Yes, it's me again....Moosie

All through the forum, I see windings of 170, 40, 35 turns each. The number of windings seems to be critical.
In my studies, and testing, and trying to come up with a design that's easy and practical, I'm going with 30 gauge wire, that'll be on plastic spools for the coils.
The spools have a one inch inside diameter, stand 1.5 inches tall, and an outside diameter of 2".
I have enough 30 gauge magnet wire to load these spoils up to the brim.
Would that be foolish as in a waste of wire, or foolish as in killing output of my gen?
More copper/more power, or more copper/power chopper?

Yet another Coil question?? | 13 comments (13 topical)

Re: Yet another Coil question?? (3.00 / 0) (#1)
by Moosie on Wed Apr 26, 2006 at 06:05:27 PM MST

I should mention, I'm using 1" x .375 round neos........

Re: Yet another Coil question?? (3.00 / 0) (#2)
by electrondady1 on Wed Apr 26, 2006 at 09:09:15 PM MST

moosie, i may be way out of line here but i checked your files and posts i can't see were you ever did any sort of test coil . as in , how many turns gives you what voltage at what rpm? you just decided to do 40 turn coils? and then built the whole stator?

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#4)
by electrondady1 on Wed Apr 26, 2006 at 10:00:39 PM MST

oh, i see the problem . your drinking folgers coffee . if you switch to maxwell house your geni should work well.lol moosie, your coils should only be about the same thickness as one of your mags use 3 coils for every four mags . if your trying to charge a battery you need fourteen volts dc. thats about ten volts ac from each phase.with 9 coils over 12 mags, that means every coil must make about 3.3 volts. thats were the test coil come in . here's the thing, it's easy to get volts just put on more turns. but you also want maximum amps. for that you need thicker wire. or multiple strands of thin wire . this is were it all gets tricky. you have to come up with some idea as to what rpm you want the geni to start to produce this charging voltage (cut in speed).that depends on the dia. and profile of your prop. i'm into vertical axis stuff and i can't help you with that . i just think you've been jumping the gun a bit.chill out and use the google search good luck!

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#6)
by Moosie on Thu Apr 27, 2006 at 09:53:55 AM MST

Actually, 40 turns was all I could fit with my rotor size. So I stuck with that, and built the stator. It flopped.

Thanks to everyone's help, Wilbur in particular, It was determined that my magnets needed to be spread out.

With what I have invested in my proto-type, I think at this point I'm stuck with 8 poles per rotor and 6 coils. I realize I'm not going to produce as much as I want, but if I can get enough output to charge a 12 volt lawn tractor battery, I'd be happy......

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#3)
by veewee77 on Wed Apr 26, 2006 at 09:20:32 PM MST

More copper = more power if it is the right "more". More turns of thinner wire will produce more voltage and lower amps but "power" will remain the same and less turns of thicker wire, which will produce lower voltage but more amps but "power" will remain the same.

So when talking about "power" (watts) there are many things to consider.

It will depend on the voltage of your system. For a 12V system, less turns of thicker wire and for a 48V system, more turns of thinner wire. But watts is watts.

Volts at 10Amps = 120Watts
Volts at 5Amps = 120Watts
Volts at 2.5Amps = 120Watts
Volts at 1Amp = 120Watts.

You'd need much thicker wire and less turns to get the 12Volts because it is 10Amps.
You'd need much thinner wire and more turns to get the 48Volts and 2.5Amps.
But both of these are 120Watt systems.

Think about this. . .

A hair dryer draws 1200Watts for one of those big ones.

Look at the size of the power cord in that thing. You'd be lucky if it were bigger than a 14G wire.

120Volts at 1200Watts is 10Amps. The 14G wire will carry that pretty good.

But let's look at it with a 12Volt system. . .

12Volts at 1200Watts = 100Amps!!!! Think that little cord on the hair dryer would carry 100AMPS??? Still 1200Watts, no matter how you slice it, though! You'd have to have 4G or larger wire running to the hair dryer! You could use the cord for a stand and not have to hold the hair dryer! Of course we know that the hair dryer wouldn't work on the 12Volts so this is completely hypothetical, but the concept and relation ship between volts, amps and watts remains the same. . .

Hope this helps you to understand a bit more. . .

Doug

Re: Yet another Coil question?? (3.00 / 0) (#5)
by Flux on Thu Apr 27, 2006 at 12:35:22 AM MST

"Would that be foolish as in a waste of wire, or foolish as in killing output of my gen?"

Sorry it would be both. You say correctly that turns are critical, so are lots of other things. You seem to have no idea of the basic concepts of these generators.

You would do far better just to copy something that someone has done and that works.

When you have mastered the ideas involved then you can start doing your own variations.

It's nice to learn by experimenting but if you want to end up with something that works then you have to stick to reasonable variations of a proven idea.

For 3/8 thick magnets your coils are miles too thick, you seem to have plucked the number of turns and wire size out of the air. Unless you understand the basics of magnetic circuits and emf equations you will not arrive at a number of turns without doing a test coil.

Flux

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#7)
by Flux on Thu Apr 27, 2006 at 10:39:13 AM MST

I have checked back through earlier posts and it seems that at one time you were near to doing something sensible with 12 magnets and nine coils.

I am not sure what changed but I suspect you tried to put 12 magnets on a tiny disc and run out of space.

You can make something perfectly usable with 8 magnets and 6 coils but you will be short of space on the inside diameter of the stator.

If you tell me what size discs you have and how small the hole in the stator can be to work with your hub I will try again to design something for you, but you don't help much by changing everything and coming back with totally silly ideas for coils wound with fuse wire on bobbins miles too thick.

From other comments you have made I am not even sure how you have connected your present attempt.

If you can describe exactly what you did on the one that flopped it would help me to help you.
Flux

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#8)
by Moosie on Thu Apr 27, 2006 at 02:46:44 PM MST

Thanks Flux.....you're very helpful!

And, you're very correct.....12 magnets on my 7" rotor was too much. (Using 1" x 3/8" round Neos). So much so that I couldn't get enough windings in my coils to produce much of anything. (Hence the flopped stators in my mind)

The Magnets are centered on a 5.3" diameter. The neoprene coil mount I machined out will accomodate 6 coils. They too are on 5.3" centers.

The inside diameter of the stator is 3", I can get 6 - 2" diameter coils in it.

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#9)
by Flux on Fri Apr 28, 2006 at 12:55:32 AM MST

Keep your coils no more than 1/2" thick.

Try 100 turns per coil and you will likely be able to get #16 wire in. If you have other wire sizes let me know and I will try to work out a way of using it.

It you make a test coil you should get about 4v ac at a bit over 250 rpm with both magnet rotors.

Connect it star and you should cut in at 12v at a speed of 250 to 280 rpm depending on your grade of magnets.

It should suit a 5ft prop with tsr of 6 and do about 150W.

You could have made a better machine with the 12 magnets on those discs but I will not say any more about that.

Sorry this was a bit rushed, I am out for the day but if you have any questions of wire size or similar I will answer later.
Flux

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#10)
by Moosie on Fri Apr 28, 2006 at 07:12:23 AM MST

Actually, I just got in 2lbs. of 30 gauge wire....I was thinking 2 in hand as I wind the coils.

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#11)
by Moosie on Fri Apr 28, 2006 at 07:54:41 AM MST

Here's what I worked on last night. I disassembled the proto, and printed out a stencil to use to re-position my magnets. My son helped by cutting out the stencil for me.

Afterwards, I noticed alot of surface rust already happening, so I thought I'd go ahead and slap some latex on now.....(couldn't hurt)....

Here's the stator case, or coil case, or whatever you want to call it, milled out of neoprine. I'll be able to change out coils, test different sizes, try different wire configurations......the bolts are stainless, and I will have to figure out how to countersink the ones inside the rotor diameter.

And here's the point I got to last night.

<img<br> src="http://www.otherpower.com/images/scimages/5667/000_0550.JPG" width=80%>
I got a digital pedometer that I'm going to use to rig up a coil winder. That's what I plan on messing with tonight.....

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#12)
by Flux on Fri Apr 28, 2006 at 03:07:22 PM MST

#30 is a bit far off the mark. You will need about 24 in hand if you wind the 100 turn coils.

If you wind each coil with about 230 turns of perhaps 10 in hand you could connect each coil to its own bridge rectifier. ( search for jerry rig )

At least you can experiment with your stator support to try various coils.
Flux

[ Parent ]

Re: Yet another Coil question?? (3.00 / 0) (#13)
by Moosie on Tue Jun 06, 2006 at 05:22:17 PM MST

In lieu of your last comment, I have enough 18 gauge to wind 6 coils at 125 turns.

Would it be useless to add more magnets at this point? I want to stick with the neoprine stator, which limits me to the 6 coils.

Would going to 12 magnets per rotor be useless since the poles will be hitting all six coils simultanously? I know, I know, stupid question for most of you, I just want to be clear....

[ Parent ]

Yet another Coil question?? | 13 comments (13 topical)

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