Wind Generator with Hard Drive Magnets

[mrkooo]

I'm from Peru, South America, I've read and learned a lot from this forum. I decided to build my first wind generator. No problems with the blades, they are 1m each (2m diameter rotor), I try them without load and work fine, very happy when I saw running so fast. But with the alternator, is anoother story, is very hard to get the magnets here in Peru, so I used HD magnets, I broke them in 2 pieces in order to have one pole. The problem is that nopw I have very little magntes. My winds are #21 wire and 160 turns, I expect to obtain al least 12V to charge a battery.

Any suggestions or comments to get the most power from this configuration?.

Blades without alternator, just a test, I can´t see the blades when running.

Double rotor with 16 poles

My wind former

12 winds, #21 wire, 160 turns

Thanks for everyone

Francisco

[ZooT]

I know very little about gennies, but just looking I'll have to say that the air gap between the rotors is "way" too wide.

I don't know if you'll be able to get the air gap narrow enough unless you either get thinner nuts or cut/file the nuts thinner on the threaded rods...

From what I've read at O.P. and other sites the smaller the diameter of the wire in the windings the higher the voltage (due to being able to fit more turns in a given area) created with a decrease in amperage and wattage.

If I'm wrong here, somebody please correct me.....like I said, I know VERY little about this stuff

[Jon Miller]

Now the only thing i needed here is a picture of your complet windings in there casting.  The problem sounds like you might have wired the coils up the wrong way and so all the emergy is going into producing heat and not electricity.  Pleas posed a pic of the coils in the cast (or however you have set them up).  

.

[electrondady1]

perhaps another layer of magnet pieces could be added to each disk to increase the power.

[henjulfox]

If I read you right I believe you have a fundamental problem with your magnets. You say you broke them in half to get 1 pole. When you break a magnet into half, or any number of pieces, you get smaller magnets with 2 poles each. I believe the problem with using hard drive magnets is that the poles run the length of the magnet when what you need is magnets that have poles on the face.

I believe there are a few posts here of folks using hard drive magnets.

Except for the magnets it looks like a beautiful set up. I'll bet our hosts would be happy to sell and ship you some magnets.

Good luck,

-Henry

[hiker]

use thicker wire[#16or17]--75-85 turns should work out..make the hole in the coils about the same size as mags[a hair smaller is okay]..make the stator 1/4" thick,and you should get the max from your mags and coils..

heres a shot of my old 1/4" thick stator..single phase..coils inlaid in wood.

and a little box fan alt.powered by harddrive mags--single phase..[easy 10amps]

[electrondady1]

 just just had the lab. double check my findings.( oh yea!)there are two poles per face one at each end .he's got it right.but isn't it standard to have the stator thickness about the same as one mag?

[mrkooo]

The problem with HD magntes is that the have 2 poles per face NS and in the opposite face SN, but when you break it in 2 pieces you get a magnet with one pole per face and the oposite pole in the other face. Thats what I have with my broken HD magnets and I can probe it when they atract or repel with the same or diferentes poles.

I drawed a 1:1 scale design for my stator, this weekend I will work on it.

[hiker]

nothing wrong with breakin the mags in half--his had both poles same side up--

when broke in half you end up with north on one side and south on other..

been there.............

[henjulfox]

Thank-you! I didn't realize they were magnetized that way. I'm sitting here playing with a HD and neo and you are certainly right.

-Henry

[electrondady1]

have you done a test on a single coil yet?

[Ungrounded Lightning Rod]

Instead of breaking the magnets in half, why not just lay them out along the circumference of your rotors?

Space them maybe a fifth of their length apart as you go around the circumference (1 unit gap, 2 units north pole, 1 unit effective gap in the middle of the magnet, two units south pole).  You'll have more poles for a given radius - which is GOOD.  Rasies your frequency and the voltage (because the effective risetime of the field is shorter), lowers your cutin speed.  The polarity of the magnets comes out right for a dual-rotor if you position them so the bodies of the magnets are opposite each other.

Expand your radius and use still more magnets for more power, or to let you use more and thinner coils so the gap can be reduced and the field strength increased.

[hiker]

nice coils--but i still would go with thicker wire and less turns...

the way you have it set up now you will get high volts --but very low amps[if any].

rewind your coils with less turns if your going to use the same size of wire and you will get a few amps[amps is what its all about] and go with a 1/4" stator thicknes..

just my thoughts..again...............

what phase are you going for?-- single or more....

[hiker]

nice blades

[Jon Miller]

Probably best to do a single test on one of the coils and find out what you get.  to be honest (and I made this mistake) you should build the PMA and then design blades to power it, not the other way round like you (and I) have done as this limits the power as if the blades are to big they spin to slow and if there to small they won't have enough torque to turn in lower wind speeds.

Basically do a single coil test and see what you get then come back to this post or another one and tell use what you get.  From this we can help more.

.

[mrkooo]

I made a test with one coil, but I think I did'nt make it right because held the coil with one hand and spind the rotor with the other then I watch the meter and read 0.8V but I had to use a big air gap to avoid touch the magnets with the coil, remember I was holding it with my hand and it isn`t very firm.

So I spect more V with a thinner air gap, hope so. I know that maybe I not going to reach 12V but I want to try it in the time a get a bigger magnets and make a new Genny

Thanks Francisco

[electrondady1]

hello mr. kooo,

 yesterday i went to some computor stores and got 7 old harddrives. now i have neo magnets . i have been experimenting for about 1 year with ceramic magnets to understand the process of generation. i found out the hard way to test the coils with the same clearance and speed as will be used in the finished genni. you can do testing with one mag. rotor , cover it with a disk of paper or cardboard that is the same thickness as your intended clearance.what ever power you get with one disk will be double with two.

[mrkooo]

Good idea electrondady, I will try it that way. Tomorrow I will cast the estator with resin. That will let me have almost finished all the windgenerartor. I can't wait for it.

Thank for your advice

Francisco

[electrondady1]

 check out danb's post for monday . he uses some glue and fiberglass to make shure the coils don't move around when does the stator.

good luck!

[mrkooo]

Finally I cast the stator, I forgot to use wax, had problems to get it off the mold, but it'ok.

Now is installed with the rotors, when I spin it with my hands I have 7.2 per phase. I thinking to wired it in star configuration, how much volts you think I will get with 3 rectified phases. Its ok to connect it in star or delta with this volts per phas. I want to char a 12V battery. One phase has 4ohms.

[ghurd]

I am surprised with the 7.2V.  Good work!

Have you considered rectifying each phase seperately?  

Like 3 single phase generators in one stator.

I have a feeling with 4 ohms per phase, and 7.2V at low RPMs, it could work out much better.

I also have a feeling the blades might be too long. Shorter blades of the same design will run faster.

Only 16 (Only 16!) more hard drives will give enough magnets to increase the output, stacking them 3 thick on both rotors.  Or 8 hard drives and place all the additionial magnets on the same rotor.  The air gap to magnet ratio will be better.

G-

[mrkooo]

What is the differences between connecting it in star than seerately each phase. What advantages and disadvantages.

I think that maybe more V if after rectifying the 3 DC I connect it in series than if I connect it in star. And what about the amps?

Thanks

Francisco

[electrondady1]

 hello and congratulations mr.koo.

i have had good luck. in another town, i got 8 more harddrives from the computor stores there .

 some harddrives contain only one magnet which is double thickness. i intend to use these magnets as the default thickness.others will need to be dubble to match.

gurd, i asked this question in hikers post. what about a coil for each pole (single phase) but three layers thick,= three phase?

[mrkooo]

elctrondady, how you are planing to make the alternator, breaking the magntes in two pieces or with the 2 poles per face.

[electrondady1]

  its more work, but if i cut them up i will have more control over the size and shape of the coil. i like long coils

[electrondady1]

one thing i noticed, there seems to be a lot of different thicknesses ,  

[ghurd]

I had a couple projects with too high resistance, too many coil turns, and too low cut in speed.

They worked better rectified seperatly, like 3 seperate single phase generators in 1 stator.  Normaly it is not the best idea.

G-

[ghurd]

The 3 layer thick stator. Look around here for overlapping coils, or a 12/36 arrangement, and look at windstuffnow Ed's 18/27 "Alt from scratch".  Better suited for a single-rotor, or maybe with real thick magnets, due to too much material at the top and bottom of the coils.

Also have a look at Ed's old post '3 phase vs. 3 phases' it might be called.

I have a single rotor 6/9 or 8/12 about half done. High hopes. Too busy to get more done for a while.

Just finished last years taxes(!) last night. 2 extensions, No kidding.

G-

[electrondady1]

the last two i built were disapointing as well, but they were both experiments so i won't let that stop me .  i learned alot !

[finnsawyer]

When he mentions rectifying each phase separately I think he means running each phase through a diode (rectifier) to a capacitor to set up the output voltage for that winding.  The three outputs are then stacked or added to form the output voltage to the battery.  This should get you the maximum voltage possible for a given alternator rpm.  We recently went through a discussion of the merits of such an approach.  Check my recent comments to track it down and find a schematic for the circuit.  Just keep in mind that there are no single answers in electronic design.  You have to tailor the design to fit your needs.

[electrondady1]

hello fin, how you doing? i think i follow gurds method. instead of going star or delta  he's turning the output of each phase into dc and then combining them , i'll try to find the post you describe. am i right in thinking the dc can be combined in paralel or series?

[mrkooo]

By the moment I had connected it in star and rectifing with 3 bridges diodes. I going ti test it and then change to rectifying each phase separetly and then connect it in parallel in order to get more amps. All depents in the cut in speed to decide which configuration.

Electrindady if you built a genny with HD magnets I would like to see your results. Will be great if you could find a way to get the most power of them. You know HD are the only easy source of magnets for me.

Thanks

Francisco

[electrondady1]

mr. koo i have 22 hd mags but they are 3 different thicknesses not enough of each to do a rotor.   the mags are strong.it seems a waiste to let them go to the garbage. two stores will save them for me . when i get a lot i will decide on a design.