Author Topic: Magnets (Read 2891 times)

trumpets3u · « **on:** February 22, 2009, 01:59:39 PM »

Would I have to change any thing if I went with a grade N42 up from a grade N40?

This would be for a 10 turbine. would I have to change the windings? I now have the Homebrew wind power book.

Thanks Brian

halfcrazy · « **Reply #1 on:** February 22, 2009, 07:04:14 AM »

Where are you finding the magnets? where you planning on the 2 inch discs? those will give you a substantial power boost but do require a different wire size and winding count.

wdyasq · « **Reply #2 on:** February 22, 2009, 07:17:58 AM »

My car is blue. What air pressure do I need to run in my tires? I had a dog but she died.

Hope this helps in your decision,

Ron

trumpets3u · « **Reply #3 on:** February 22, 2009, 07:35:31 AM »

http://www.magnet4less.com/shopping_cart.php?sort=2a

These are 2x1x1/2

trumpets3u · « **Reply #4 on:** February 22, 2009, 07:37:39 AM »

For us who are tiring to learn here you are not helping.

Please be nice. Flame wars and rude comments are NOT tolerated here, and the offending comments will be deleted immediately. Keep in mind that sarcastic and cynical comments that you might make in person (with a smile on your face!) often appear to be very rude on a discussion board.

halfcrazy · « **Reply #5 on:** February 22, 2009, 07:42:29 AM »

well that does certainly seem like a good deal i wonder if we are missing something that makes them that much less expensive then dans? I would look hard at using the 2 inch discs if you haven't wound the stator yet. I know it is slightly more money but with greater outcome especially if you ever decide to run the turbine threw a controller like i am here.

As for the original question i cant imagine needing to change anything for the little bit stronger these magnets are supposed to be. what battery voltage are you going with?

trumpets3u · « **Reply #6 on:** February 22, 2009, 07:54:50 AM »

I have not started yet. I would go with 48 volts. I was planning on going with the same controller as you are.

Thanks Brian

halfcrazy · « **Reply #7 on:** February 22, 2009, 08:06:28 AM »

Then i would go with the 2 inch discs that website had them as well. I will be doing two new magnet rotors in the real near future with the discs i think it will boost the output a fair amount.

On a good note i should be getting the Midnite solar Clipper this week to go with the Classic this will give us full control of the turbine then we can get some good test results. Robin will have it live on the internet soon APRS World is building the data logging equipment so everyone can keep an eye on it.

With the 1 by 2 by 1/2 mags i can routinely get 2kw comfy out of it i am hoping with the 2 inch discs to squeeze 2.5-3kw comfortably. i have seen 3kw out of mine when we recorded 56mph wind but it was spinning faster then most would probably want. once we get the clipper we will also have a RPM meter it is built into the clipper.

wdyasq · « **Reply #8 on:** February 22, 2009, 08:06:32 AM »

Those who truly want to learn properly describe a problem. They can be ignorant.

The stupid waste others time and seldom learn.

Ignorance can be cured. Stupid is forever.

The choice is the individual's.

Ron

halfcrazy · « **Reply #9 on:** February 22, 2009, 08:21:40 AM »

This is and has been a tough board. most newcomers aren't really welcomed here. I understand that answering the same question on a regular basis is no fun.

My recommendation Brian is grow thick skin you will need it on this sight. But the sight is full of a lot of good info. I have personally left for long periods after having enough of the crap but my work with the classic brings me back here again for now.

PS what was stupid about Brian's question? seemed simple enough will the stronger magnets have any negative effects or require different windings?

trumpets3u · « **Reply #10 on:** February 22, 2009, 08:23:04 AM »

Thanks for the update on the controller. And thanks for pointing out the magnet up grade I hadn't got that far in the book.

Brian

halfcrazy · « **Reply #11 on:** February 22, 2009, 08:26:41 AM »

yeah they spend a little time on it in the book. But a ways back Dan had a thread about the stronger magnets. I believe he said Twice the power. But if the cost isnt to prohibitive i would go that route.

trumpets3u · « **Reply #12 on:** February 22, 2009, 08:30:36 AM »

I'm on other forums, music ones that I know alot about. There are many like this guy, I like to take the high road. The only way to learn is to ask, as I like to say there is no dumb question just dumb answers. If you don't like the question don't answer.

Thanks halfcrazy for you help I'll be up sometime if the snow will ever stop.

Brian

halfcrazy · « **Reply #13 on:** February 22, 2009, 08:48:45 AM »

yeah where did tonight's storm come from? 12-16 inches here.

wdyasq · « **Reply #14 on:** February 22, 2009, 09:12:10 AM »

"Would I have to change any thing if I went with a grade N42 up from a grade N40?

This would be for a 10 turbine. would I have to change the windings? I now have the Homebrew wind power book."

Try this - I am building a version of (turbine type and size here). It is a (number of magnets and coils might help as well as 'dual rotor'; single rotor ... no rotor). Rather then using the (size magnet and grade here) I plan on using (new size here). The book recommends X turns for Y volts. Will the number of turns need to be changed?

The fact we still don't (Those of us who do not have 'the book') have much of an idea what Brian is building could guess what he needs to do ... after all it is not MY time or MY money he will be wasting.

I know of none here who are clairvoyant. Little hints of what the heck is doing doing help a lot to those who might help.

Ron

vawtman · « **Reply #15 on:** February 22, 2009, 09:43:13 AM »

Hi Brian

I would think the difference is negligable between the two.If anything you could slightly adjust the gap.Don't loose any sleep over it.

Mark

tecker · « **Reply #16 on:** February 22, 2009, 02:32:56 PM »

Thw winter has been long an cold .Hang in there

hvirtane · « **Reply #17 on:** February 22, 2009, 03:17:32 PM »

Would I have to change any thing if I went with a grade N42 up from a grade N40?

I think that the difference is so small that you don't need to worry about that. If not sure, you could try making a test coil to see what voltage you will get.

I think that the difference with hand made blades is always bigger than the difference because of slightly different grade magnets, if your magnets are otherwise just the same as with the plans.

- hv

cdog · « **Reply #18 on:** February 22, 2009, 03:29:42 PM »

1/2crazy, is the clipper an addition to the classic, or another separate unit altogether?

Sounds like a very interesting way to handle the mill, just hope it doesnt cost a fortune for the controller(s)?

Cdog.

halfcrazy · « **Reply #19 on:** February 22, 2009, 04:28:01 PM »

the clipper is in addition to the classic the classic will control the clipper and we will be able to limit the turbine based on volts, rpm's or amps or all 3. the clipper will come with its own rectifiers and stop switch etc.

the cost i am not sure of yet but here is a copy of a statement boB made a while back

">>Any idea of how much these will cost?

Probably more than 380$ Less than 920$... Lots less...

(I know. I know... define "lots"! ) I let the bean counters decide that kind of stuff.

I hate counting beans ! Actually, I don't like eating beans a whole lot, I mean some.

boB"

The pair will be a bargain in my eyes when you can comfortably get 2.5-3 times the power out of a smaller turbine. Plus the clipper will be able to work stand alone and i think will open the door for safe easy grid tying these machines. of course the machine would have to be wound for a higher voltage depending on what inverter you used but then you could program the clipper to make sure the turbine never gave the inverter to much voltage.

cdog · « **Reply #20 on:** February 23, 2009, 06:36:12 AM »

Thanks a bunch, please keep us updated on the results !!!

Cdog.

trumpets3u · « **Reply #21 on:** February 23, 2009, 09:53:41 AM »

We got 20-24 inches here and with the wind blowing up to 6 feet deep on our 2000' drive way.

Brian

halfcrazy · « **Reply #22 on:** February 23, 2009, 12:22:02 PM »

yep we got 16-20 inches easy oh did i mention i hate my snowblower

Ungrounded Lightning Rod · « **Reply #23 on:** February 24, 2009, 03:14:01 PM »

I don't see that any more description was necessary to answer the basic question:

Q: Going from N40 to N42 with the same magnet geometry, what's the effect on an alternator and do I have to make an adjustment elsewhere to compensate?

A: They are stronger by a factor of (x), which is enough that you might want to take advantage of the extra strength (which produces a corresponding increase in voltage), winding about 1/x turns of wire of a correspondingly increased wire cross section (adjusting the gauge and/or in-hand count, getting the closest you can fit to a factor of X) to instead maintain the same voltage and increase the current by a factor of your cross-section increase. Alternatively, you can throw away the extra strength by widening the gap and leaving the coils as they are, giving you a larger tuning range. Later, if it turns out that your winds are lower than you planned for, you can reduce the gap to bring back some of the extra field strength and use it to obtain a lower cutin speed.

Why do you need to know the mill's size, color scheme, furling scheme, blade count, phase count, pole count, turns count, wire size, blade profile, or which way it rotates to give an answer of the above form?

halfcrazy · « **Reply #24 on:** February 24, 2009, 03:44:04 PM »

Thank you for the response ungrounded. the sight Brian is looking at has a lot of n50 magnets to so one could use them and probably get a substantial increase if he wound accordingly?

imsmooth · « **Reply #25 on:** February 24, 2009, 07:48:16 PM »

On magnet4less at http://www.magnet4less.com/product_info.php?cPath=1_11&products_id=160 they are about $12.50 a piece x 24 N50.

I got N48 at http://www.magnet4sale.com for $11 a piece x 24 (g=14200 vs their 14700)

imsmooth · « **Reply #26 on:** February 24, 2009, 07:51:25 PM »

I'm building a rotor with 2" x 1/2" N48 discs. What wire gauge and turn count did you use, and what rpm did you hit an open voltage of 50v and 100v? Also, how does the rpm counter on the inverter work? Does it clock the frequency of one of the phases or do you have to input a reed switch open/close signal?

imsmooth · « **Reply #27 on:** February 24, 2009, 07:59:12 PM »

I don't know how ambitious you are with electronics, but the linear shunt controller I put together worked beautifully, limiting the rotor rpm by setting the threshold voltage. Once hit, excess current was sent to a dump load. The turbine never went faster, even with 50-60mph winds.

You can see the schematic at http://www.mindchallenger.com/wind/wgpage16.html

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Author Topic: Magnets (Read 2891 times)