Generator - this should work right?

[ImaBiggles]

If I take a 12 arm stator, wrap ABABAB. . . Attach it to a gear set, and eventually to a small windmill - I will get ac power off the two leads correct? The lower the KV of the motor, the higher the voltage right? This is for a science project for my son.

[TMorita]

A brushed motor is easier.

Or you can use a brushless motor and three full-wave bridge rectifiers, I think.

Toshi

[ImaBiggles]

A brushed motor is easier.

Or you can use a brushless motor and three full-wave bridge rectifiers, I think.

Toshi

Since its going to be outside, I didnt what to hassle with the brushes getting wet and stuff.

[jj1]

IIRC someone suggested to wind AaAaAa... with only 1 wire for windmill use.
Havent tried that though.

link below might give some ideas..

www.otherpower.com

-JJ

[new flyer]

yes if you only have 1 wire on a brushless motor and the can is atatched to the windmil it will work fine.
i built one last year out of a gobrushless motor. it is not powerful but it works and can light a few leds. i sugest getting a computer fan from walmart and find a way to attatch the blades to the can they work very well for catching wind.

[ImaBiggles]

cool, yeah didnt even think about the one wire. My plan is to use verticle windmill blades - eight of them. Verticle blades have the advantage that anyway the wind blows, spins the mill. Each blade will be about 34" long. Rough calcs show that with a 4 mile per hour wind and the appropriate gearing, I should be able to turn the rotor on the motor at 800-1000 RPM. It will charge a 12volt gell cell, which will in turn power some landscape lights. The key appears to be to minimize friction losses, but that shouldnt be an issue with a couple of good bearings at the speed the mill will rotate at. To keep it honest, my son has to build the mill blades and support.

[jj1]

Winding with 1 wire should give highest voltage. (lowest amps). Seems that in windmills gearing might add starting problems if generator gogging is high. Would suggest to ditch gears and do the gearing in the windings..lots of thin wire. Kv about 20. Please keep us updated how it runs.

-JJ

[BeavrdamElectric]

I've read a little bit about windmills, and cogging can be a problem, both (mainly) starting and causing vibration at certain speeds.

Good Luck!

[GlennS]

Biggles,
I ended up doing something similar for a school project for my kids. For the generator I used an old 3.5 inch floppy drive stator and a bunch of magnets on the rotor. The stator is screwed down to a bit of chipboard and the rotor spins on top if it supported by a couple of bearings.
It uses a vertical axis turbine (savonious rotor) made from aluminium flashing bent up. Generates about 5 volts or so in a light wind. See photos (its a bit dirty now....). With a couple of high intensity leds on it, it makes a lot of light from up the back yard.
Cheers,
Glenn.

[ImaBiggles]

Biggles,
I ended up doing something similar for a school project for my kids. For the generator I used an old 3.5 inch floppy drive stator and a bunch of magnets on the rotor. The stator is screwed down to a bit of chipboard and the rotor spins on top if it supported by a couple of bearings.
It uses a vertical axis turbine (savonious rotor) made from aluminium flashing bent up. Generates about 5 volts or so in a light wind. See photos (its a bit dirty now....). With a couple of high intensity leds on it, it makes a lot of light from up the back yard.
Cheers,
Glenn.
And that was with an AaAa . . wind?

[GlennS]

And that was with an AaAa . . wind?
I think so. It is single phase, so I think they are all in series with each adjacent phase reverse. I can have a look and photograph if you like, it was made a couple of years ago and have forgotten the details now.
The floppy disk drive had a large stator on a pcb, it was about 2.5-3inches in diameter.

[ImaBiggles]

I think so. It is single phase, so I think they are all in series with each adjacent phase reverse. I can have a look and photograph if you like, it was made a couple of years ago and have forgotten the details now.
The floppy disk drive had a large stator on a pcb, it was about 2.5-3inches in diameter.
No reason to photo it, Ill give try AaAa... and if that is unsatisfactory, try something else. Thanks for your input.

[osmium_192]

The BEST generator is the reader drive motor (steppers) for 5 1/4" floppys. That if you use the right diodes can generate a whole heap of power. I was finger spinning the 5mm shaft and it fried 2 high intensity leds instantaneously. I havent used it as a windmill but it drives about 10 high brightness LEDs in parallel (uses more current instead of voltage thus loading the motor to obtain power) when turning the shaft by hand with a supercapacitor in parallel to maintain a more consistent brightness.

The high load means that direct drive on windmill blades can get alot of power. I get about 5 volts unloaded at about 1000 rpm and spinning it at the fastest i can with my fingers i get about 20+ volts (of course unloaded so preactically 0A but means its got a really low KV so it can mean that a gearbox is unnecessary)

It has 5 wires, one common and 4 winding outputs. The wires used in the winds are REALLY thin so its prob not good for high currents but if you use a high voltage (say 12V) then it works well.

Owen

[ScubaSteve]

hey ima keep us posted on how this goes - very interesting:)

[ImaBiggles]

hey ima keep us posted on how this goes - very interesting:)

Will do. Having a hard time finding prefab pullies or gears for this beast, but when it is finished, I will let ya know - after all it is one of your motors in there!

[ScubaSteve]

Update? ;)

[BeavrdamElectric]

Anything new?

Since it's been windy, I was messing with this little Savonius rotor I made out of a couple vitamin bottles. I used a floppy drive motor for the bottom bearing and a hard drive bearing at the top. The shaft is a bamboo skewer. I left the magnet ring and windings stock but the wind has quit now (of course) so I don't know what it will produce. I don't expect much from this size of course, maybe make some LEDs blink.

I was thinking about the AaAa... winding, wouldn't that need as many magnets as teeth? That would produce very strong cogging, I would think it would be used mostly with coreless setups. If cogging is a problem, maybe a LRK wind would be the way to go. Mine is far from perfect but it does spin pretty freely. Cogging is light but the offset didn't come out quite 90 deg so it takes a bit of wind to get it to start. Gearing up the generator would make it more sensitive to cogging.

Good Luck!

[jskrebs]

www.picoturbine.com

[BeavrdamElectric]

jskrebs: I found this on Google, same thing:
http://www.donandcarla.com/WindProjects_PicoTurbine.shtml

I think using the upper and lower pieces to match the rotor's shape instead of round would make it a bit easier. The site you linked to provides a PDF with instructions and templates, cool!

Here's another I found interesting:
http://www.angelfire.com/ak5/energy21/microsavonius.htm

I made another (single) rotor similar to the one with flat blades in the center, but it didn't like to start until I added some tabs perpendicular to the flat ends. Now it blows back and forth a bit but then takes off. I haven't mounted that one yet.

And another site:
http://mb-soft.com/public/wind.html

The guy here says a shroud will increase the efficiency of the S-rotor to that of a normal windmill, but it takes away the omni-directional advantage and complicates it.

Good Luck!

[birdofplay]

Osmium is right re Steppers. I have a CNC ann the mfgr said to NOT hand turn them
while connected to the controllers. Even though the Dual Dahrlington chips
have some back emf protection they didnt want uses to "Test" the feature !
Also do not move the carriages by hand .
Fun experiment:
Take a stepper and spin the shaft with the leads all seperated from each other
then connect them all and try it - grrrrrrnt ! Very powerfull ! ie hard to spin

Then again you will back to the hard Starting due to Cogging issue.

Regardless Keep us in the loop :-)

[jj1]

Hi,

Found a small 220V AC fan motor that i intend to try as a small generator.
Stator is only 4 pole so this may not be a good one, but as only needed to machine groove to rotor and glue magnets in, like to see what comes out..

Any ideas of the magnet setup?

-JJ

[Trikster]

Wow, this is a cool thread. Any working models yet? I have a few stators and bells out of some old VCR's. One looks really promising... It is about 2.5 in inner diameter. I also have one from a 3.5 ZIP drive. Large stator, but only about 1/4 in thick. It has a really nice bearing in it, so I wonder how it would do.

If I wanted something to put out your standard 13.8v and some fair amount of amps, what do you all think would be required? Can you run these in series to increase volts?

[BeavrdamElectric]

Hi,

Found a small 220V AC fan motor that i intend to try as a small generator.
Stator is only 4 pole so this may not be a good one, but as only needed to machine groove to rotor and glue magnets in, like to see what comes out..

Any ideas of the magnet setup?

-JJ

Nice setup!! I'm no expert but I'd think you'd want to run 6 magnets. 4 or 8 might create cogging problems, 2 might or might not generate enough voltage, depending on the coils and RPM.

@Trickster:
Nothing actually working here yet, but I do have a nice tacky whirligig for my back porch (not the one pictured above - worse). Every spring when it's windy (& gas goes up) I get in sailboat/windmill mode. Then the wind stops before I get anything finished. I built a small (6' :eek: ) sailboat that I just need to finish the rigging on - 2 years ago. One thing the whirligig has shown me though - those bearings out of Ditto drives won't stand up to weather. I haven't looked at the floppy motor in the first one but it's tight now too.

Voltage and power depend on the wind speed, the size and type of your windmill, gearing, windings, and probably a few other things. You might be able to find some equations and get pretty close to your goal. There are wind power forums out there that you could learn way more than I know from. As far as connecting multiple windmills, the rectified output could be connected in series or parallel. I considered putting a row of small ones along the ridge of my roof.

Here's a neat windmill design:
http://www.greenwindmill.com/

Good Luck!

[Trikster]

What is AaAa winding? I know only a little bit about winding motors, but that is one term I haven't heard before.

If you were using one of these windmills to charge up a battery, will the varying voltage cause any problems for the battery its charging? (If at some moment, the windmill is putting out 4v to a 12v battery...)

[jj1]

@Beaverdam
thanks for suggestion, makes sence.
---

@Trikster
AaAa winding is used in one phase winding generator where its more easy to get enough voltage from slow turning direct drive generator.

Generator is 'isolated' from the battery with rectifier diodes. Those convert AC to DC and prevents current flowing 'backwards' from battery to the generator.
---

interesting induction motor -> generator link:
http://www.saunalahti.fi/elepal/moottori/gener_e.html

-JJ

[BeavrdamElectric]

What is AaAa winding? I know only a little bit about winding motors, but that is one term I haven't heard before.

If you were using one of these windmills to charge up a battery, will the varying voltage cause any problems for the battery its charging? (If at some moment, the windmill is putting out 4v to a 12v battery...)

AaAa means the generator is wound with only one phase, the coils alternate clockwise and counterclockwise.

There is some speed that you need to reach before you produce useful voltage, referred to as "cut -in speed". Below that the windmill isn't doing any work.

Good Luck!

[jj1]

Tested the fanmotor with 6 magnets glued on the rotor. Magnet coverage below 50%. It has good but not owerly hard gogging, but the kv (~110) is still too high for my purposes. Current test shorted was dissapointingly low.. only 10mA at 700 rpm.
The connection seems to be AaAa for the 4 statorpoles..

-JJ

[jj1]

Slow progress on the cd rom generator field.

Tested AaAa.. wind with 12 magnets and the results were poor.
At closer look it showed that 12 magnets werent in synk with the winds and generated power was partly cancelled by opposite magnet polarity on same wind polarity...

So Dont try AaAa.. wind with 12 mags and 9 statorpoles.

-----

Moved on a slightly bigger generator dismantling an automotive alternator.
It has originally AaAa..wind on 12 poles (both stator and rotor) and massive cogging.
Planned to keep the AaAa.. wind, with turns increased from 10 to 70, but thinking of changing the magnet setup to something less cogging but as high pole nr as possible.

Any ideas for good magnet setup? 14?16?

-JJ

[feathermerchant]

RE Cogging - Ever turned an Astro 05? No cogging
Hacker - No cogging.
The Astro has a helical armature and magnets. I think this is why. I have not seen a Hacker apart.
I think it is possible to build a no-cogger.

[austin RC]

I am making an airplane

[Trikster]

I am making an airplane
Well, gosh... That is pertinent to the topic.

[jj1]

Hello,

update on the generator project started over a year ago...

Found a better wreck to convert, this has 36 statorpoles, original winds seems to be overlapping every 3 poles to match the 12 pole rotor.

Planned to make a new rotor from 90mm T6 block and 20mm rod,
replace windings, and use as many magnets possible.

Goal is to have a very low Kv generator/motor.

Got a question about cogging:
Which of the folloving configurations coggs less:

48 magnets NSNSNS... and ABCABCABC... wind OR
40 magnets NSNSNS... and AaABbBCcC...

???

Below few pics from new rotor

-JJ

[herbertkabi]

Wind generator, wound by concentrated windings or overlapped - must to be done by low-cogging scheme. When used just ABC scheme then your turbine will be not self-starting. Concentrated wound stator / low cogging sheme you can find everywhere - when someone likes to try overlapped/low cogging - I can help. Overlapped wound stator needs less turns.
Regards,
Herbert

[birdofplay]

Would it NOT be easier to simply take an existing motor and
connect it up with some rectifier diodes ?

All this speculation seems silly when 6 diodes would get the ball rolling here.

Wouldnt what one could expect OUT of a motor being run as a generator in this manner
be similar to the motors specs when used as a motor.

Guess I'll have to go dig out some doides, eh ?

[jj1]

Wind generator, wound by concentrated windings or overlapped - must to be done by low-cogging scheme. When used just ABC scheme then your turbine will be not self-starting. Concentrated wound stator / low cogging sheme you can find everywhere - when someone likes to try overlapped/low cogging - I can help. Overlapped wound stator needs less turns.
Regards,
Herbert

Thanks for tips, Herbert.
Wouldnt mind rewinding with overlapping scheme if that would be the key to minimise cogging. Please tell more..stator is not yet rewound.
BTW tried to find magnet scheme for concentrated windings.. no luck yet.
Care to point out some links for study?

Actually the starting is not the biggest problem, noise is, as generator is going to be water powered and the other use involves a bicycle..

Magnets for the project are still shipping...

-JJ

Birdofplay,

alternator has 6 diodes already, but the problem is that neither the alternator or existing motors produce enough voltage at 400rpm. Kv~5 (five) seems to about right for my purposes.

[herbertkabi]

What magnets you planned to use? Car-alternator stator has very thick lamination plates, but OK - you can try. The bast magnets has Mr.George
Motor Magnet M5020 Arc segments for motor - OD-3.5 inches, ID-3 inches, 1 inch wide. 18 pcs to make a circle. Set includes 18 magnets N40 Nickel Up to 2 for $70 each From 3 to 9 for $60 each Over 9 for $45 each (check up - will these fit to your stator)
http://www.engconcepts.net/List_Of_Motor_Magnets.asp,
You will need use 16 pole for 36 slot low cogging motor/generator. I will add the picture a little bid later. I have to draw it, but right now Im busy with my own works. Be patient ;-)
Use the time for planning a new housing - I will be very disappointed when see your generator inside this old original one. If you want to use old - then two face sides.
Regards,
Herbert


Thanks for tips, Herbert.
Wouldnt mind rewinding with overlapping scheme if that would be the key to minimise cogging. Please tell more..stator is not yet rewound.
BTW tried to find magnet scheme for concentrated windings.. no luck yet.
Care to point out some links for study?

Actually the starting is not the biggest problem, noise is, as generator is going to be water powered and the other use involves a bicycle..

Magnets for the project are still shipping...

-JJ

[jj1]

Thanks Herbert,

Those magnets almoust fit just as they are, the stator is 88,5-88,8mm id dia.
Od 3,5" = 88,9mm so just a tiny bit of material is needed to remove from stator.
Hmm. 70$ :eek:

Planned to use 20x4x2mm n45 magnets from supermagnete.de.
Ordered 50pcs of them already so making a groups of 3 magnets could sum up to 16 poles..

Origininal winding were 5T Delta 1,5mm wire..

-JJ

[herbertkabi]

These magnets Mr.George has especially for motor-generators where used stator from common car-alternator. $70 ... I have ordered somewhat 10 sets of :-(
OK - now winding scheme:
It is better to wind windings separately and then put each winding side by side in to slot. When all placed then need to place another sides of windings - then you will get very close like on the picture.
First you need to decide wire dianeter and to try lot of time - you need to get the right dimension of pre-wound windings (tried as much as possible turns as mych as possible diameter). My English is DIY but I hope you understand:
On the Phase 1 (green windings alwais on my drawings) you see red and blue buttons -> WINDING DIRECTION (CW/CCW)
Total scheme is similar to 18 tooth stator 16 pole:
AaABbBCcCAaABbBCcC - just cleverly overlapped ;-)
Look at 18/8 ---> ABaCAcBCbABaCAcBCb ---> this is more similar but only half of your motor/generator ;-)
If you do not understant promptly - then try to think 3D
*Pre-wound windings * side by side in to right slot * then to fill another sides = will get exact like on the picture.
But first you try...try..try. You do not make too small pre-wound coils - keep some reserves - you need it for curves - anyway it will look very profissional and nice.
If you are extreme smart - then you can make all from one wire per phase. But no problems to make total separately - you can connect all wires later very nicely. (i do like - I am not too smart ;-)

You can use thinner wire -> then you have 4 (four) groups - these groups you can connect series or parallel - or 2s2p.
Remember: Group itself aAa (as well as bBb and cCc) need to be connectes SERIES !!!!
Number of poles acts only to frequency - not to output voltage - > rotating speed and diameter - these do act. Frequency must to be at least 50hz (lower will ripple). For example when 400 rpm - then you will get 53,3hz.
I have built this kind of generator, used Toyota alternator and Mr.Georges magnets - great. I wound it used relatively thin wire and did bring by groups to the connection panel where it is easy to reconnect series, parallel or 2s2p per phase. I do not remember exact data but it was good enough like is speaking the end-user up till today.
Of course you can use another magnets (two or three per pole) but please do not try with too thin ones - no way! Magnets need to be thick enogh if you are building the generator.
The same scheme is exelent for 36 tooth motors as well (18 tooth crocos I have wound like that 18/8 , h-40mm, 2 turns - extreme good!).

Regards,
Herbert

PS:

/Planned to use 20x4x2mm n45 magnets/ - Oh dear! - do not spend the time and money, even 4mm thick magents are too weak. At least 6 mm thick you need. When to use 2mm thick magnets then you need to find much more skinny stator, some slim one. If not - then you will need fury rpm to get few volts from this at modest load. Grade of Neodym acts per cent - thickness makes all the rest.



Thanks Herbert,

Those magnets almoust fit just as they are, the stator is 88,5-88,8mm id dia.
Od 3,5" = 88,9mm so just a tiny bit of material is needed to remove from stator.
Hmm. 70$ :eek:

Planned to use 20x4x2mm n45 magnets from supermagnete.de.
Ordered 50pcs of them already so making a groups of 3 magnets could sum up to 16 poles..

Origininal winding were 5T Delta 1,5mm wire..

-JJ

[jj1]

:) :) :)
Many thanks Herbert for such expert advice.
Believe or not but i think i understand the winding schema. :confused: ;)
Those excellent 3D images made it, otherwise would have had to bore you (and others) with endless questions.

Looks like i cannot put more updates on the project as it might differ somewhat of the good advice given.. :o ;)

For gererator use im aiming only to 50-100W of power, so lets see what comes out. Airgap is going to be small; ~0,5mm.

Although the 2mm magnets are probably underpowered, ill allready ordered them and its an easy task to glue them on and test. (then maybe soak the rotor in asetone and use lathe to remove the already glued back iron and install better magnets..etc. but i was prepared to try different magnet configurations empirically anyway so ..well..)

I have enough of 1mm wire, i think ill try that first and connect all phases in star for max voltage.-- in the unlikely case voltage is too high ill have lots of options to reduce ..hmm 1mm dia wire has still the volume of half the original 1,5mm so it might be bit on the thick side..we'll see..


One pic to show progress..unwound dirty stator...

Thanks again :D

-JJ

ps. Dont bother DIY english, its not my native language either.

[herbertkabi]

If you need only 50W...100W of power then you can really use some slimmer stator.But remember - with tiny magnets you need fury rpm. I have built many small and lightweight 3-ph generators ca 80mm outer diameter, ca 20mm of height (total sizes) , ca 160 ... 210 g of weight, at 50w up to 300w ... but needs at 3000 rpm up to 9000 rpm. There I use - yes - 2mm thick magnets. OK when twice longer magnets/stator (mentioned my gen has h-10mm) then twice less rpm will be need but even 1500 is too much for windmill ;-) Then you need 40mm lenght of magnet/stator when D is between 80...90mm.
If you will use 2mm magnets for this car alternator stator - you will spend all to fighting with losses- not much useful energy you will detect. This thick laminated robust iron is for higher power.
The best low losses small power, not very high rpm generator you can build when use Pontius stators - the largest one was 110mm 48 tooth, medium was 83mm 36 tooth, and then 60mm 24 tooth. Pontius used 0,12mm sheet - losses will very low. This 48 tooth one, used 48/40 scheme could be extreme cood - lot of possibilities to group series/parallel ...
At that you will have a great motor for several experiments.
Have a nice time,
Regards,
Herbert





For gererator use im aiming only to 50-100W of power, so lets see what comes out. Airgap is going to be small; ~0,5mm.


-JJ

ps. Dont bother DIY english, its not my native language either.

[jj1]

Ok, some progress again. First thanks again Herbert for valuable help. :)

Rotor is ready, and tested with a quick test wind of thin wire and only 5 turns/pole.
With 420rpm i see 4,4V(DC) rectified 3-phase and 4,6A(AC) between shorted 2-phases.

Looks like ill need about 25-30 turns/pole to get usefull voltage for battery charging...

Airgap came due to a measurement error too big.. about 0,8mm. :(
Maybe one sheet more back iron is coming behind magnets if nessessary..
(Will there be any significant improvement by closing the airgap to something tighter?)

Accidently found a helpful trick to glue same polarity magnets next to each other.
As anyone who has tried knows that they like to jump all the other places but not where it should.
The trick is to use the remaining magnet stack over the first or middle magnet,
and somehow it changes the flux so that then it is easy to glue more same polarity magnets next to each other.
See picture where 3 same polarity magnets are stacked.
The one with a black dot is glued on and it stays put by the help of stacked magnets.

-JJ

Ps. Ordered the 70$ set of magnets from George... :rolleyes:

[herbertkabi]

Principle minimum thickness of backing iron -> 1/2 of thickness of magnets .
Georges $70 curved was right choice. Builded correct and powerful rotor you have many possibilities for future. When this car alternator stator will be depleted for your ideas - you can find many anothers where better properties (even machined yourself a new stator using large (5 inch, mix 26 or 45 Micrometals) toroid core). Do not forget adeguate backing iron for new rotor. Please note - dangerous !!! - rotor insrertion in to stator must to be done very carefully , better to use some remedies,
these magnets are V E R Y powerful.

Good luck,
Herbert

Ok, some progress again. First thanks again Herbert for valuable help. :)

Rotor is ready, and tested with a quick test wind of thin wire and only 5 turns/pole.
With 420rpm i see 4,4V(DC) rectified 3-phase and 4,6A(AC) between shorted 2-phases.

Looks like ill need about 25-30 turns/pole to get usefull voltage for battery charging...

Airgap came due to a measurement error too big.. about 0,8mm. :(
Maybe one sheet more back iron is coming behind magnets if nessessary..
(Will there be any significant improvement by closing the airgap to something tighter?)

-JJ

Ps. Ordered the 70$ set of magnets from George... :rolleyes:

[jj1]

Some update on generator project..

Got the set of monster magnets, these really need some careful handling,
these 1" x 1/4" pieces of rare earth are hard to separate from each other. :eek:
Smashed one to pieces while being careless for split sec... :o

Turned new rotor, it was now much easier just to replicate most of the previous work/measurements.
Magnet installation was lot easier than the previous NNNSSSNNN...
despite the huge forces of these bits.

Thanks for warning, Herbert, installing rotor to stator was a frightening experience.

Ok, test run (5tY) showed promisingly 9,6VDC(3ph) open and 10,6A shorted @420rpm,
but cogging forces also at least doubled with the new rotor :(
Also there is some align problems with the stator to housing..but..
If it were too easy there would not be much fun succeeding either :rolleyes:

At the moment i have no suitable wire enough to make the final winds..
5 turns produces that 9,6V but to charge 12V battery i think the open
voltage must be at least 30V so 15-20 turns star connected could be next test.

more later :rolleyes:

-JJ

[fly_boy99]

Very nice JJ1.

I can tell you from experience that mating the stator with the bell on these
large magnets can take a finger off. I was once working near my car once getting the original magnetring out and one of the new magnets flew out
of my hand and stuck to the top of my car about a foot away!!!

B

[ImaBiggles]

Holy crap, this thread is still active? I ended up using a GBx single thats wound with a million (ok 40, but seemed like a million) turn of 32 or 36. I figured that would get the Kv low so I didnt have to gear it. Three phase with a rectifier, caps and regulator. Charges a pack of old NiCads that runs some LEDs. Very unimpressive when you look at that 1000 watt monster jj is building (show off ;) )

[jj1]

Update on project,
Visited a local motor repair shop and got a near empty reel of 0,63 wire for 10$..
some 2 pounds of copper still there :)

Winded up the stator 30T x36. These separate winds will be connected like Herbert kindly advised few posts back.
Wasnt too difficult, only the last two winds need to be sewed in, due to little error in placing..
Little over 300g copperwire used on winds (~100m)

It should give 26V open voltage with star termination and rotor#1@420rpm,
and 33V with delta termination and rotor#2, that has those hefty magnets.. shall see :)

Few pics from winding..

-JJ

[jj1]

Few more...

-JJ

[jj1]

Finally generator is ready - and working :D

Not too much power in the star configuration now in test, but enough to my purposes i hope.
Nice thing is that generator kicks in at reasonable low RPM.
Specially with rotor2 (~100rpm)

Need to do field tests next and it will take some time from now on...

Heres some data just to be archived somewhere..

Rotor 1: (Kv=15, star termination)

RPM Uo UL I torq Uo/loaded(Nm) efficiency% Power(W)
125 8,3 - - - /-
210 14 14,0 0,0 0,15 / -
420 28 14,0 3,0 0,20/2,0 47 42
420 28 12,4 3,2 0,20/2,3 44 40
420 28 15,9 2,4 0,20/1,9 51 38
620 42 13,2 5,5 0,26/3,5 36 73
620 42 30,0 2,0 0,26/1,6 64 60
1k 69 16,5 8,2 0,30/4,4 32 135
1k 69 18,0 8,0 0,30/4,2 36 144
1k 69 34,0 5,5 0,30/3,5 57 187
1k 69 49,0 2,7 0,30/1,8 78 132
1k 69 52,0 2,2 0,30/1,5 80 114


Could take only few measurements on Rotor 2 as my lathes belt started slipping :eek:
Termination will be changed later to delta with rotor 2

Rotor 2: (Kv=7, star)

RPM Uo I@14V
125 18 0,7
210 30 3,5
420 59 slipping belt



Rotor 2: DELTA (Kv=12)

RPM Uo UL I torq Uo/loaded(Nm) efficiency% Power(W)

210 17 13,2 1,8 0,80/2,8 45 24
420 34 27,4 3,5 1,10/4,2 58 96
620 49 33,0 8,5 1,20/8,0 60 280



Rotor 1: delta (Kv=25)

RPM Uo UL I torq Uo/loaded(Nm) efficiency% Power(W)

420 16 11,6 2,1 0,20/1,1 57 24
620 24 12,7 6,0 0,26/2,6 50 76
1k 40 13,2 12,2 0,30/4,2 41 161
1k 40 31,0 3,0 0,30/1,4 63 93
2k - 50,0 8,0 - /3,2 66 400


-JJ


(efficiency% = 100((I*UL) / (Nm/0,9*RPM*0,1047))

Edited more data to the table. Efficiency got alot better if generator is allowed to work at higher voltage. (2 or 3 12V batteries in series.)
Also torq arm was 90cm not 1m ;)
last edit: 400W test

[jj1]

Finally have been able to test the generator in the attended application.
Picture says it all :eek: :eek:

Well, it works, unless generator/prop/boat combination is not yet fully optimised.

Generator starts working at 3 knots, at 4 knots i get same power as average PV-solarpanel and at 6 knots, 65 Watt charging power. :)
After 6 knots the prop surfaced :( so the max potential is not yet seen
as boat can reach 7-8 knots at good winds.
-

Still further thinking if generator output could be boosted up with a cheap DC-DC step down converter.
Although converter robs 10% of the efficiency,
could get it twice back by reducing prop torque allowing more rews (875rpm unloaded at 6 knots)
and moving generator work point to more effective area. (50%->+70%)
Windings could be easily altered (from 4s delta to 2s2p star) to bit higher Kv but that will make the cut in speed also higher.

Can anyone say if using the converter is somehow impossible?
Converter could (in theory) give some flexibility and make the most of the generator output that varies alot in different speeds.

Thanks for reading
Any comments? everything welcome :D

-JJ

[PaulVi]

are you using some sort of down rigger to keep the prop lower in the water..

use a setup like they use for salmon fishing off the coast..

as to the fluxuating power redisign to get max eficiancy at a lower RPM so that nominalcruse speeds of 5 to 6 knots keeps the prop spinning in the sweat zone for RPM..

Great idea you have cooking here.. also if you put a load (discharged battery) on the motor output it may settle in at a VDC and AMP range

[olmod]

We used a paravane to keep lures down deep :)

[jj1]

are you using some sort of down rigger to keep the prop lower in the water..

use a setup like they use for salmon fishing off the coast..

as to the fluxuating power redisign to get max eficiancy at a lower RPM so that nominalcruse speeds of 5 to 6 knots keeps the prop spinning in the sweat zone for RPM..

Great idea you have cooking here.. also if you put a load (discharged battery) on the motor output it may settle in at a VDC and AMP range


No downriggers yet tested, the prop is aluminium and the rope is actually 6mm cable wire so they sink quite well.

Still some sort of downrigger is a good idea to prevent prop surfacing.
That would need to have some sort of bearing in the connection as the rope is continuesly spinning.

Yes, battery (usually discharged, due fridge etc) is always connected to the output of the generator.

Thanks for input.

-JJ

[ImaBiggles]

Finally have been able to test the generator in the attended application.
Picture says it all :eek: :eek:

Well, it works, unless generator/prop/boat combination is not yet fully optimised.

Generator starts working at 3 knots, at 4 knots i get same power as average PV-solarpanel and at 6 knots, 65 Watt charging power. :)
After 6 knots the prop surfaced :( so the max potential is not yet seen
as boat can reach 7-8 knots at good winds.
-

Still further thinking if generator output could be boosted up with a cheap DC-DC step down converter.
Although converter robs 10% of the efficiency,
could get it twice back by reducing prop torque allowing more rews (875rpm unloaded at 6 knots)
and moving generator work point to more effective area. (50%->+70%)
Windings could be easily altered (from 4s delta to 2s2p star) to bit higher Kv but that will make the cut in speed also higher.

Can anyone say if using the converter is somehow impossible?
Converter could (in theory) give some flexibility and make the most of the generator output that varies alot in different speeds.

Thanks for reading
Any comments? everything welcome :D

-JJ

THis is on a real boat right? I wonder if you would be better served to use a windmill (like a vertical blade design so it doesnt have to pivot - eg. darrieus or savonius design types) than a prop. The prop and drive system can be causing lots of drag. Also, you dont have to worry about snagging/mucking it up, and it would charge all the time. Anyway, wicked cool! Couldnt you just use a diode/capacitor to increase voltage and drop current for charging? The loss would be less than a linear regulator I think. Anyway, for ideas - cross link this post to the DIY electronics section.

One thing about your flexible shaft - Ive never met a flexible shaft that didnt torque itself apart. The flex cable is in a hollow solid shaft or not?

EDIT: I just looked at your post again and saw you are looking for buck/boast type of regulator, not a convertor. Look at the anyvolt circuit from dimension (http://www.dimensionengineering.com/AnyVolt.htm) I believe you can parralel them for increase watts. You can talk to deminsion about your specific application - at the very least, it will provide you with more info.

[jj1]

THis is on a real boat right? I wonder if you would be better served to use a windmill (like a vertical blade design so it doesnt have to pivot - eg. darrieus or savonius design types) than a prop. The prop and drive system can be causing lots of drag. Also, you dont have to worry about snagging/mucking it up, and it would charge all the time. Anyway, wicked cool! Couldnt you just use a diode/capacitor to increase voltage and drop current for charging? The loss would be less than a linear regulator I think. Anyway, for ideas - cross link this post to the DIY electronics section.

One thing about your flexible shaft - Ive never met a flexible shaft that didnt torque itself apart. The flex cable is in a hollow solid shaft or not?

EDIT: I just looked at your post again and saw you are looking for buck/boast type of regulator, not a convertor. Look at the anyvolt circuit from dimension (http://www.dimensionengineering.com/AnyVolt.htm) I believe you can parralel them for increase watts. You can talk to deminsion about your specific application - at the very least, it will provide you with more info.

Yep, its a real boat :)
windmill is also taken into consideration, thanks for pointing it out.
Idea for this tow drag propeller came once to me when i noticed that windmills wont work well downwind.
To try something unknown i came up with Tow-generator that works always when boat is moving.

When the boat is in anchor the generator can be fitted with blades and converted to windmill.
Or can use another unit converted from another scrap automotive alternator. Then the whole system is hoisted between beam and mast.
See another pic. Ampair has a commercial product like this, which i sadly discovered after reinventing wheel :o

http://www.ampair.com/ampair/waterpower.asp
http://www.absak.com/pdf/AQ4-6spec.pdf

Prop and drive causes lot of drag, but it slows boat amasingly little,
measured speed drop of only 0,1 knot from 4 when generator was turned on. Boat weigh 10k lbs (5 tonnes)

Its true that there is some job rigging it up, but so far it has been very interesting.
The rope can be dangerously springy when its lifted out water.. boat is better stopped before, otherwise rope could be all messed up.

The flexible shaft is steel cable capable of withstanding very high tension.

Thanks alot from anyvolt link, this is something to be more looked up.
Looking for a high efficiency switch-mode step down regulator that can charge 12V batteries,
from a wide input voltage range, 20-80volts.

thanks again for good input.

-JJ

[ImaBiggles]

very cool project. What size/pitch screw are you spinning? Did you figure out the KV of the motor yet? What is the voltage you are seeing off of one of the phases? Hope you dont mind the questions. I can see that the shaft can be a significant issue bringing it in with the boat in motion. I wonder if getting some seamless stainless tubing would be practical. How far back are you towing the screw?

[jj1]

very cool project. What size/pitch screw are you spinning? Did you figure out the KV of the motor yet? What is the voltage you are seeing off of one of the phases? Hope you dont mind the questions. I can see that the shaft can be a significant issue bringing it in with the boat in motion. I wonder if getting some seamless stainless tubing would be practical. How far back are you towing the screw?

Prop is from 10hp mercury outboard, pitch is 6" dia about 8".

Kv is about 25 now, highest tested sofar. Kv is mentioned in the tables in post top of the page. (post #48)
Havent measured 1 phase voltage but in those same tables above you can see rectified 3ph DCvoltage in different rpms.
Uo is 3ph VDC without load and UL is voltage when spinning generator is connected and loading a 12 or 24 or 36V battery.
Rotor 1 is the one with 20x5x2 magnets and rotor 2 is the one with the 1"x 1/4" curved ones.

With the current delta termination, 40VDC is seen at 1000rpm.

Have pondered also the shaft issue.
Non flexible shaft could probably be better to take out from water in motion and it maybe could be shorter also.

At present the tow line is 10m (30ft).

keep the questions coming, glad to answer :)

BTW, found a suitable DC-DC converter that would probably work as a electric gearbox.
Wide input voltage range and good efficiency. only problem is the additional 99$...

http://zahninc.com/spec48-12-160.html




-JJ

[darkmask]

Here's a good site for improvisation... just search for wind generator, or wind turbine, they also have a cheap method for building an easy cnc machine/router.

check it out, www.instructables.com, lot of other cool stuff there as well as rc stuff.

[Fourdan]

Hi JJ1

You have the possibility to change Kv rpm/V or Kt (reciprocal or V/rpm)
1) by connecting coils of the same phase
All parallel, all serie or mixed parallel/serie
2) by Star or Delta to get 3 wires from 6

It is not elegant to use a DC-DC converter (not so cheap)
You could also use a linear voltage regulator (or current limiter) with a LM317 + big pass NPN transistors + some heat sinks

Louis

[jj1]

Here's a good site for improvisation... just search for wind generator, or wind turbine, they also have a cheap method for building an easy cnc machine/router.

check it out, www.instructables.com, lot of other cool stuff there as well as rc stuff.

Nice site, thanks.

-JJ

[jj1]

Hi JJ1

You have the possibility to change Kv rpm/V or Kt (reciprocal or V/rpm)
1) by connecting coils of the same phase
All parallel, all perie or mixed parallel/serie
2) by Star or Delta to get 3 wires from 6

It is not elegant to use a DC-DC converter (not so cheap)
You could also use a linear voltage regulator (or current limiter) with a LM317 + big pass NPN transistors + some heat sinks

Louis

Hi Louis,

yes ive played with the different coil connections and sofar ive settled
to use delta connection in the water turbine use and star connection
in wind turbine with the blade set tested sofar.

Parallel star could be tested but there is lot of hassle reterminating
almost all coils, and although peak power will increase,
cut in speed will also rise and overall performance will drop.

Last modification to the generator is a star/delta switch that can be
used to get the most of it in different weather conditions.
This switch will possibly be automatic in the future.

Im still thinking of the electrical gearbox, that will eat high voltage/low amps
and put out low voltage and boosted amps.
Although this powersupply is additional cost, it would allow generator to work in much better efficiency areas
and still have low enough cut in speeds, allowing generator to produce more overall energy.

Got actually quite nice readings in practical tests, "Tow-water-turbine" produces 6A at 6 knots and 9,5A at 7,5knots.
Enough to keep batteries charged and beer cool in long cruises :)
Finally this old 12x8 Master airscrew found some good use :D
10meter rope works nicely between underwater prop and generator.
Rope is much more safe to use than steel cable.

When used as a wind turbine generator is better to be star terminated unless in rough
conditions above 8-10m/s winds where delta termination starts to produce more amps due to better efficiency.
Both terminations produce about 6-8Amps in those speeds.
Rotor speed is close to 1000rpm@10m/s, but is silent enough.

Slightly smaller and faster blades are next on the list :rolleyes:

Attached some pics from last summer tests.

-JJ

[jj1]

Some data from the wind turbine.

Well,not too efficient at 12V ,(power coefficient only 10-20) but its working.
Project continues with new blades, switching regulators.. etc tests..

-JJ

ps. tested the 2s2p connection with both rotors and it was ok with the more powerful rotor 2, but in practical use it would need much larger turbine blades.

540W, however, measured using 24Volt system and 1000rpm.
So there is potential; its just hard to get it out...

[herbertkabi]

Simple switch mode regulator I made:
works great 14.8V->40V input, adjust. 0...13.8V out, up to 5A. When needs for more current then two or more parallel units. About paralleling I did read abot, not tested - Im not strong about electronics at all. I have no idea why some recommend to use shunt reg. instead switch mode. I like switching regulators.
Regards,
Herbert

[herbertkabi]

Also Star/Delta controller I found several years ago, never tested by me but great idea.
Greetings,
Herbert

[jj1]

Simple switch mode regulator I made:
works great 14.8V->40V input, adjust. 0...13.8V out, up to 5A. When needs for more current then two or more parallel units. About paralleling I did read abot, not tested - Im not strong about electronics at all. I have no idea why some recommend to use shunt reg. instead switch mode. I like switching regulators.
Regards,
Herbert

That looks very well made. Nice work.
Have you tested it with windmills or other generator?

Some time ago ordered some samples from National and tested similar, (pic)
but i wasnt too happy with the efficiency and had some trouble with the coil involved in this circuit.
Also my connection started working reliably with 20V upwards input (coil?).
The high freq involved gave some headache with the groundplanes.. Should have made a proper board like yours.. :o
Newer tested it with the windmill, ive made this circuit in purpose to boost up solarpanel efficiency.
Now ive ordered a solar panel booster that claims to have over 90% efficiency and works up to 45V / 7A input and 13A output.
It really boosts SolarPV current but well see if its suitable for wind/watermill use...
http://www.napssystems.com/products/consumer/charge_controllers.html

Shunt regulators are nono in these applicatios where every bit of energy counts.

thanks for comments
-JJ

[herbertkabi]

I made it for my special generator - current up to 10A (even up to 20A), Stator 70x10mm - rpm 3000....9000, netto weight of generator 180g - it is not a windmill ;-)
After several tests and tryings I found out that inductor is the most important part - finally I used this relative large one you see on the photo, two coils (there used ca 0.8mm wire (as well as gen uses)) are connected series, total 52uH.
When smaller size inductors then results was far not good. Printed board made relative large because heat - it will not overheat.
Herbert

[Eaglebird]

I was curious as to how you made those windmill blades :eek:

[jj1]

I was curious as to how you made those windmill blades :eek:

I took a series of photos of the different stages of blades been made,
but unfortunately me (or kids) have erased them from camera...

Anyway, those were first made by gluing 2 pieces of apache wood to each other,
then copying rough lines using a factory made blade for the 3D measurements.
Gluing/stacking wood was necessary to get the blade root thicker and wider.

Rough lines were cut with bandsaw,
curvature was started with chainsaw where lots of wood needed to be removed and finished with belt sander.
It took only 1 evening to make all three.
Later those were fiberglassed and that took some more time...

Some good advice on blade making can be found
http://www.scoraigwind.com/

2,3 meter (90") example:
http://www.scoraigwind.com/selfblade/index.htm

some pics:
http://www.scoraigwind.com/liselotte/index.htm


-JJ

[Eaglebird]

I took a series of photos of the different stages of blades been made,
but unfortunately me (or kids) have erased them from camera...

Anyway, those were first made by gluing 2 pieces of apache wood to each other,
then copying rough lines using a factory made blade for the 3D measurements.
Gluing/stacking wood was necessary to get the blade root thicker and wider.

Rough lines were cut with bandsaw,
curvature was started with chainsaw where lots of wood needed to be removed and finished with belt sander.
It took only 1 evening to make all three.
Later those were fiberglassed and that took some more time...

Some good advice on blade making can be found
http://www.scoraigwind.com/

2,3 meter (90") example:
http://www.scoraigwind.com/selfblade/index.htm

some pics:
http://www.scoraigwind.com/liselotte/index.htm


-JJ

Ah, I was curious how you got them so nice. :D

[jj1]

Ah, I was curious how you got them so nice. :D

Thanks, :)

BTW finally got that switching regulator in hand and tested.
In the nutshell, it works by raising the overall efficiency of the practical rpm range.
Averaged efficiency rise 15% despite of the added losses of the electronics.

But this test was made with lathe.. im expecting the real world wind test to be even better
as the lathe applies torque differently than wind turbine prop blades..
more later..

-JJ

[jj1]

Update, real world tests with the smart controller..

In a short summary it works like an automatic "star-delta" switch for the results.


In the graph the wind turbine is run in same wind speeds (horisontal)
and output power difference is clearly seen.

-JJ

[vitervi]

No se si me vais a entender.

Muchas gracias pòr todo la pena es que en españa no haya este tipo de informacion y en español, hare un esfuerzo para saber que deciis ya que de ingles no se.

Gracias

[jj1]

I took a series of photos of the different stages of blades been made,
but unfortunately me (or kids) have erased them from camera...

Anyway, those were first made by gluing 2 pieces of apache wood to each other,
then copying rough lines using a factory made blade for the 3D measurements.
Gluing/stacking wood was necessary to get the blade root thicker and wider.

Rough lines were cut with bandsaw,
curvature was started with chainsaw where lots of wood needed to be removed and finished with belt sander.
It took only 1 evening to make all three.
Later those were fiberglassed and that took some more time...



Hi,
found the lost pics for the blade carving.

-JJ

[herbertkabi]

Hi,
found the lost pics for the blade carving.

-JJ

hi man,
This is huge lot of work - :eek: - respect!
I have the same shapes from plastic,
one 3-blade 1.6m diameter and two 3-blade 1.8m.

Yesterday I thought about - perhaps to try 6-blade 1.8m
What do you think - advantages and disadvantages

cheers,
Herbert

[jj1]

hi man,
This is huge lot of work - :eek: - respect!
I have the same shapes from plastic,
one 3-blade 1.6m diameter and two 3-blade 1.8m.

Yesterday I thought about - perhaps to try 6-blade 1.8m
What do you think - advantages and disadvantages

cheers,
Herbert

Thanks Herbert,

3-blade is said to be the best average system for allround wind conditions, using more blades could be better if the site is not that windy.
In high winds less blades is better. 6 blade turbine will start up easier in lower winds but wont give more power in a stronger breeze.

-JJ

[herbertkabi]

Yeah - lower and higher winds :rolleyes:
Today morning:
07:00 - 3 m/sec - sunny +2 C :o
08:00 - 8 m/sec - SNOWING! +1 C :(
09:00 -15 m/sec peak - snow +3 C ... all is under snow :eek:
10:00 - 3 m/sec - very nice SUNNY! +6 C ... no snow at all :p

Seems only variable pitch will help :cool:

Cheers,
Herbert

[unattainium]

A good motor to use as an alternator for a windmill is a motor pulled from from a Fisher and Paykel washing machine. From memory you can get 500-1000 wattts from one.

[jj1]

yes, have read of them. Unfortunately those are not popular in Europe..
Here's a site with lots info of them:
http://www.thebackshed.com/Windmill/assemblyA.asp

Anyway, the Korean manufacturer LG makes direct drive washing machines that have similar motor.
Those are probably still too new/rare to be easily found from scrappies etc..

-JJ