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Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333
Posted: 05:58am 07 Jul 2010
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Hi Mac,
The term 2 in hand is an American expression as far as i can tell, as the correct term is bifilar.
Maybe it would be best for someone like yourself to put together a Basic Terms list from what you have learnt, as many of us take it for granted of these things, and tend to get to technical when explaining them.
I am guessing that the turns ratio you need would be around 50 or less, but this is only a figure i pulled out of my underpants and not based on any true facts.
Oz is the man here for a better guess at this, but think he wants you to work it out so you learn.
Pete.
Sometimes it just works
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329
Posted: 06:11am 07 Jul 2010
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Pete,
Yup! My guess is he's a retired professor or something like that. One thing's for sure, I'm learning a lot !
I'm still going to test the little coil tomorrow. I was secretly extrapolating the same thing in my head, that however much wire I have wound on the little round one, ten or twenty shorter strands of the same total length would fill up approximately the same space, but gather more current (like the water pipe example). So, that's next on my "to-do" list.
Like I said earlier, when all the smoke clears, I'm going to cull out all the "good" information and do a complete build tutorial so anyone comin' up behind won't fall into the same holes. Thanks for your input.
The bewitching hour approaches . . . . . Zzzzzz.
. . . . . MacNothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686
Posted: 08:21am 07 Jul 2010
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OK, my wild guesses are like this.
With 200 turns, I suspect you will get your 1.8vac@ 130 rpm.
This will mean I reckon, about 70 turns of 7 in hand of .255mm wire (AWG #30), for a coil about 5mm thick, and a 8mm air gap, and N50 magnets.... a bit of a squeeze perhaps with the winding window .... if your lucky, you may get the coil resistance down to less than an ohm (maybe??) for perhaps 120 grams of wire?????
Power out at 10m/s (22mph approx) will be maxed at 120W or 10A, for 50% losses at this power.
Of course this could all be drivel too. I havent tried a small unit like this.
Nope ... no professors here... just the village idiot at large.
.........oztules
Edit:
This will show that guessing at what Mac builds will prove me completely and utterly inept..... and very optimistic with the 7 in hand. Coil hole about 10mm and outer 25.. ish.
Mac, thats about 10 feet of wire per coil X 7 pieces.... or 7pieces of wire 10 feet long should do each coil.
Edited by oztules 2010-07-08Village idiot...or... just another hack out of his depth
GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127
Posted: 02:31pm 07 Jul 2010
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The volume of the magnets, will be reasonable guide to the maximum power output for a particular rpm.
I have 24, 2"x1/2" magnets and have measured approx 2kW. Oztules has the same magnet volume and has measured I think over 4kW. This is approx 36cu inches of magnet.
Mac, has I think approx 1/2" thick x 1/2" rounds, so 24 of these have a volume of around 2.5 cu inches.
Allowing for some flux leakage etc, gives around somewhere 50W-150W peak.
The wire resistance and the rpm, coupled with magnet geometry will still determine what percentage can be obtained.
Gordon.
become more energy aware
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329
Posted: 04:14pm 07 Jul 2010
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[Quote=Oztules]Mac, thats about 10 feet of wire per coil X 7 pieces....
See, there ya go again with that smart stuff. I was thinking along the same lines, but what I was going to do was unwind the little coil after I test it and then fold the entire length in half several times until I got what appeared to be a wire bundle, which would still fit through the little hole I drilled in the end plate of my little winder tool and go from there.
I think the big difference here, aside from experience (remember I'm the one who built air pumps and used off-the-shelf generators until just recently) is the majority of the Backshed crew senior members can actually build stuff between their ears that works. I have to have a hands-on working model to make any progress.
Like I said before, when the smoke clears, I'm going to compile a thorough show-and-tell building tutorial to make it way easier for the next fellow.
I saw on someone's Web site where they had a hamster-powered axial-flux electric generator. Heck, from the way things look now, what I'm building won't even compete with that silly thing as far as actually generating any useable power.
Still, like 'the little engine that could', I'm driven by that still, small voice whispering, "I think I can, I think I can." I'll let you know what I cook up.
. . . . . Mac
Nothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333
Posted: 04:35pm 07 Jul 2010
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Kinda glad you are not a cook as it would be mash for dinner often
Also glad you dont have a hampster, as the poor little bugger would have legs like baseball bats trying to overcome the cogging of your previous attempts.
I could hear him saying ...i think i can, i think i can, be buggered if i can..
The main thing is you are having fun
Pete.Sometimes it just works
oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686
Posted: 10:23pm 07 Jul 2010
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It's just a guess, and came from a region not so different to Petes guess. (unmentionables)
Will be interested to see what the real world figures are.
........oztulesVillage idiot...or... just another hack out of his depth
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329
Posted: 05:15am 08 Jul 2010
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Initial Coil Test
I chucked the two magnet wheels in the lathe and spun it up to 600 rpm for starters. Placing the single coil in the spot it would normally run produced absolutely NO reading on the volt meter.
Now before anyone jumps to a conclusion, I have to tell you my volt meter is for testing 220 volt circuits just so MacGyver doesn't light himself up like a Christmas tree when changing out electric water heaters in homes. My meter has only a 200-volt and a 700-volt setting.
Me thinks it may be time to invest in a new VOM, ya think? I didn't have the balls to hold the bare wires in my teeth or anything gutsy like that, so we'll all just have to wait until i can come up with a real multi-meter. Maybe tomorrow morning; dark here now.
. . . . . MacNothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686
Posted: 07:56am 08 Jul 2010
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I would have expected about 14vac or more.... (200 turns, 600 rpm), now I'm worried at what you have got there.....
You did use the AC setting?
.........oztulesVillage idiot...or... just another hack out of his depth
GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127
Posted: 09:11am 08 Jul 2010
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I think the ccts described here would be the AC type.
US has an AC grid as well to my knowledge.
There must be a simple explanation for the lack of an output. 600rpm, is really hooting.
I did most of my own testing at about 60rpm, spinning by hand, with single turns first, and then test coils.
I amsure Mac will find what is wrong.
Gordon.
become more energy aware
GreenD88 Senior Member Joined: 19/05/2009 Location: United StatesPosts: 104
Posted: 10:05am 08 Jul 2010
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I noticed he said He only was testing a single coil so he shouldn't be getting that much voltage out of it. I made one similar to the one he's making now and only could get .5v at around 1000 rpm, with 100 turns, for a single coil. My magnets were only 1/8" x 1" though. So I would say his meter isn't sensitive enough for the low voltage AC. Edited by GreenD88 2010-07-09Licensed Master Plumber / EPA 608 Universal License / 410a Safety Certified / Medical Gas Brazer/Installer
oztules Guru Joined: 26/07/2007 Location: AustraliaPosts: 1686
Posted: 12:00pm 08 Jul 2010
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Can I be that far out????
......oztulesVillage idiot...or... just another hack out of his depth
niall1 Senior Member Joined: 20/11/2008 Location: IrelandPosts: 331
Posted: 12:38pm 08 Jul 2010
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ignore this...
i posted but was looking at the 1 inch mags and thought the coils looked to small in diameter ... Edited by niall1 2010-07-09niall
GWatPE Senior Member Joined: 01/09/2006 Location: AustraliaPosts: 2127
Posted: 12:55pm 08 Jul 2010
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Hi oztules, the magnet volume and the number of turns, and the 600rpm test should have given at least 10VAC, so your calcs are not that far from mine.
If the gap is too wide, then it is possible the flux is pretty well all leaking back to the end plate, and little is actually getting across the gap.. Small magnets need special geometry to work well.
I suspect a meter problem, as a .1/4" magnet gap should be OK. With the coils size and the magnets size and alternating magnetic fields, it should work.
Mac will have the answers. I don't intend to replicate these findings, as I still have some new 2" mags to find a place for on my own mills.
Gordon.
Edited by GWatPE 2010-07-09become more energy aware
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329
Posted: 05:34am 09 Jul 2010
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[Quote=GWatPE]Mac will have the answers.
First off, I bought a new analog VOM; I like analog better. Next, I proceeded to test the resistance of the little coil and found out I had not scrapped enough of the enamel off the ends of the wires. Think that may have anything to do with the "no readings"? Duh!
I sand-paper-stripped the enamel off the ends of the 30-ga. wire and found the little coil has 0.5 ohms resistance.
Next, I set the lathe to 480 rpm and tested the little coil. The gap is 3/8" and not 1/4", which I'm sure has something to do with the net results. When I do the next coil (multi-wire winding) I'll make it thinner, but this one is right at 1/4", hence the 3/8" air gap.
Anyway at 480 rpm and a gap of 3/8" the coil puts out 2.3 volts a.c. I figure adding just a couple more coils like this one to the mix should give me enough for an all-electric house, eh?
Just kidding.
That's all for now. I'll work on getting the wheels closer together as well as manufacturing a multi-wire coil. I haven't had enough good weather to stretch out the wire on the existing coil to see how long it is. We've been having rain (in July??) lately. As soon as I figure out how many feet is on one coil, I'll divide that amount by whatever gives me about 10 feet (per Oz) and we'll try that.
Hey, look at the bright side. Even if I had tested this with my teeth, there wasn't enough there to sizzle a fruit fly!
. . . . . Mac
Nothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
Perry Senior Member Joined: 19/11/2009 Location: Posts: 190
Posted: 09:56pm 09 Jul 2010
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I find it is easier to burn the insulation off the ends with a propane torch. Just a few seconds will do. After that quick cleanup with san paper will be much easier.
Perry
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329
Posted: 12:54am 10 Jul 2010
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Perry
Thanks; I thought of that too. The trouble here is it's 30-gauge copper wire and any heat from my torch would vaporize it for sure. I was just being to nice to it the first go-round, that's all.
I've learned my lesson. Next time, I'll continuity-check it before I make that same mistake twice!
. . . . . MacNothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
Here there! I am a newbe to wind power stuff but reading this post has answered a lot of questions I have about a little six inch prof-of-concept desk top mag-lev alternator I am building. More on that in another post
My 2 cents on enamel removal is to use a cigar lighter to burn off the enamel, a quick wipe with a clean soft cloth and a quick sanding with something like sand paper or an emery board. Gets them done fast! "As for me, all I know is that I know nothing." - Socrates
Downwind Guru Joined: 09/09/2009 Location: AustraliaPosts: 2333
Posted: 03:26am 10 Jul 2010
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While we are all in the stripping mood my tip is burn the ends with a cigarette lighter or match or candle, then use a broken (or full) hacksaw blade and draw the wire end through 1 tooth gap.
It is the quickest easyiest way i know and beats the hell out of sandpaper
A couple of scrapes through with a little rotation between scrapes and job done.
After you have rewired the 10th stator you tend to find the better ways of doing things .
Sandpaper sucks!!!!
Pete.Sometimes it just works
MacGyver Guru Joined: 12/05/2009 Location: United StatesPosts: 1329
Posted: 03:29am 10 Jul 2010
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Pete
Hmmmmm . . . . . Saturday, mid-day. I see the crew down under is at the ready!
If it's any comfort, I used "open-mesh" and it worked like a champ. Remember, these little wires are almost hair-thin!
. . . . . MacEdited by MacGyver 2010-07-11Nothing difficult is ever easy!
Perhaps better stated in the words of Morgan Freeman,
"Where there is no struggle, there is no progress!"
Copeville, Texas
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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