Controlling the machine

[Yyrkoon]

Hello all,

I was curious if anyone here has any hands on with controlled stall, and/or various forms of braking.

My ideas are this:

1. Design, or purchase a set of blades that will stall the machine to keep RPM's at or below a determined RPM no matter the wind speed. The Idea here of course is to keep the machine from over speeding. I know of furling, but I am looking for an effective alternative. A friend has an AirX system, and I believe this system uses something like this to enter into "regulated mode" (as per the user manual). I also do not know if there is anything else other than the blades that "help" stall, so any information on this would be appreciated.
   
2. While later(no time frame yet) we may be making our own hydrogen generator(s), I would like the machine to shut down automatically when the batteries are fully charged. I do not like the idea of resistive load dumping, and I would much rather the machine were shut off than taking more wear and tear when it did not need to. I have read a little about Hysteresis braking, but really do not know much about it(other than again, my friends AirX system uses it). My ideas here were to MAYBE, use a dump load controller to send a signal to a circuit that could short the generator. Comments ? Ideas ?
   
3. Regulation. I kind of touched on this in another thread but was curious if anyone had any ideas on how to keep a machine operating at its peak efficiency. MPPT's, transformers, and PWM controlled MOSFETs were mentioned. What are the ramifications of allowing the machine to charge only a percentage of its potential output at a given time ? This last question here would be tied to #2 above. Example: let the machine charge put everything it can into the batteries until say 12.8v, and after this only allow a percentage of the power the machine can give flow into the batteries. Will this cause the machine to slightly speed up?
   
   

Everything I have asked, or mentioned here has to do with my wanting to keep a mill as reliable as possible. If anyone would like to comment on related reliability subjects that I have not mentioned here, PLEASE, feel free

 

[dbcollen]

If your goal is to make your mill as reliable as possible, then adding all of the unnecessary complexity you discussed is counterproductive. you need to keep the mill as simple as possible. Also resistive heating for a dump load can be very usefull, I use mine to preheat a 50 gallon water tank. At the end of most days the water is around 150F, and the on demand heater doesn't even come on. The wear and tear from running the mill full time and diverting excess power is going to be minimal.

As Tom would say "I think you are overthinking the plumbing."

Dustin

[ghurd]

Number 1.  

I half-heartedly tried it.  It worked a little bit.  Higher winds overpowered the stall-based-idea machine.

The short fat PVC-style blades would overpower the PMA with torque if the winds became high.

The blades 'fluttered' ("regulated mode" (as per the user manual). ?) enough to stall, but the crappy bucket blades couldn't take repeated flexing.

I had other PVC blades do it fairly well, by accident.  When the wind hit a certain speed the blades stalled.  If the wind picked up much higher, the blades bent back and the tips went negative.  They didn't work very well at lower wind speeds.  It was loud in "regulated mode".  The PVC couldn't have taken the flexing very long.

Number 2.

Confused.  Wouldn't another hydrogen generator be considered a dump load?

Shutting down a windmill by shorting is violent.  More wind means more violent.

A few people are/were using my kit to do it.

'Alibro' is the first that comes to mind...

http://www.fieldlines.com/story/2008/2/10/223830/948

Number 3.

To me, it seems you are confusing 2 ideas as a single idea.

One is getting everything the machine can make.

The other is getting rid of the extra.

The flow to the battery is not a problem.

It keeps the windmill under control.

The 'extra power' is mostly surface charge, IMHO.

PWM is damn fast, and it sounds like you are thinking damn slow.

"Will this cause the machine to slightly speed up?"

If it isn't done properly, the speed will blow it up.

Again, maybe it just sounds like it to me, but it sounds like you want to copy the Air-X brochure sales pitch.

What some people believe are sales points, others believe are shortcomings and design flaws.

G-

[Flux]

"Design, or purchase a set of blades that will stall the machine to keep RPM's at or below a determined RPM no matter the wind speed."

That is what the original Air 303 did and it didn't do it very well. They let the blades flutter to destroy the aerodynamic efficiency, the noise was unbelievable and it could only work on a tiny machine.

It is also the basis of pitch controlled machines and when done properly it is an excellent solution but needs good engineering and will never be cheap and is not really a do it yourself approach (I get the impression that won't bother you as I think I see the final aim). The old Wincharger air brake also accomplished this but it was not the blades themselves that did the control in that case.

Unless you do clever things with the blades then stall is not dictated by the blades, it is dictated by the load. Constant speed induction grid fed alternators often work in stall. There are electronic loaded machines ( AIR X and some others that achieve this). Unless the machine is gynormous or you get a warranty that wind will never exceed a certain speed you may even then get it out of control and loose it. If the electronics fails again it will get away. Unless you can have  FOOLPROOF means of stopping it if you loose control then it will self destruct ( unless it is tiny like an Air X, then it may revert to blade flutter)

The Air X brakes by shorting the windings above a certain wind speed, in low winds it just brakes enough to keep the noise down and as the wind picks up it brakes more and more to keep some sort of speed limit. When batteries are charged it stays shorted and doesn't spin ( it satisfies your next criteria in that it stops and you don't need to dump power).

If you want performance at the expense of reliability then mppt loading will give excellent results ( my experience is that reliability can be ok but I don't live in a lightening zone and the things are not handled by people with no knowledge of wind power).

Starting with a big enough alternator you can run mppt up to a certain wind, or until batteries are charged, then pull it off peak power and it will effectively run stalled with drastically less power out. I don't have the winds high enough to find the limit for my latest one and the alternator was only built big enough to be efficient in the working range I wanted, but I believe it will at least hold in stall mode up to 50 mph and within the rating of the alternator. The peak power for this one ( comes down from over 1kW to about 150W). I can't guarantee that it wouldn't get away in 70+ miles an hour.

In it's present form it couldn't be run unfurled except for tests because there is no other foolproof back up to stop it. It can be shorted to stop it when batteries are charged but although many consider this adequate I never rely entirely on any electrical loading scheme as there is the possibility that it could loose load.

So what you want can be achieved. I see the best solution as blade pitch control with mppt loading but it is not the cheapest option ( in fact the reverse).

I am not entirely sure where you are heading but if this is for an individual machine then I think Dustin's advice is about as good as you are going to get. Commercially I see some of your idea coming fairly soon and some are already with us. I still believe that there may be some rude awakenings with these new electronic control schemes unless they use some form of emergency back up other than electrical loading. I only play as a hobby, I don't have to compete in a commercial market.

All I can say that this is light years away form what most people do, they actually operate nearly all the time in stall mode, purely for convenience and simplicity.

I largely agree with some of your aims but not from the point of view of reliability. As I see it MPPT has everything going for it, stopping when charged may be good in some cases but the dumped heat can be very useful. Exceptionally well engineered blade pitch control looks to be the best for reliability but in the hands of the average person it is a route to disaster.

Flux

[Yyrkoon]

First things first.

Please explain to me how 'sales pitch', and 'shortcomings/flaws' translates into a machine that has flown fine for the last 3 years while other machines died prematurely in the same exact area? The proof is in the pudding as they say. Do I personally care if Southwest windpower makes money ? No.

As for the rest of your comments - they do not make sense to me. Telling me you half heartedly tested something using PVC blades  ... please. Ok, when you say that shorting a machine is a violent way to stop it. Great. Except I can show you a few commercial systems(as in the manual) where this is their recommended way of stopping a machine. The rest you either took what I had written out of context, plain just did not read what I wrote, OR, you could be narrow minded.

DO I think my suggestions which led to questions are perfect ?  Of course not, that is why the questions where there. However, it would be nice to receive an answer that had something to actually do with the question, and then leaving out the sarcasm, and dripping disdain would make the posting guidelines happy.

If in the future you care to be taken serious, and to not be thought of as a child, you may want to reconsider how you respond to peoples questions.

[Yyrkoon]

Flux, thanks again for a well thought out reply. TO be perfectly honest, I am still just exploring ideas before I actually do anything. I have no plans on going 'commercial', but I am trying to flesh out some ideas of things I have seen in commercial designs. It sounds like no matter what you do, whether furling, Hysteresis braking, etc, each method of keeping a machine in check has its flaws.

I suppose what you said before that furling would be the best/simplest way of keeping a machine from over speeding, but what about huge gusts ? The long heavy gusts here honestly has me more worried than anything else (namely because they tend to kill mills pretty fast).

For what it is worth, the Air 403/303 did use 'wing flutter' but according to the manual, the AirX does not. Instead they say it uses Hysteresis braking . . . something that makes no sense to me because the definition of Hysteresis that I know of has to do with rapid cooling/heating of an object until it become brittle . . .shrug

[fungus]

"Great. Except I can show you a few commercial systems(as in the manual) where this is their recommended way of stopping a machine."

Stopping a machine by stopping it can work fine under manual control, as you can wait for a lull in the wind to throw the switch to shut it down, if you try in too high of a wind the alternator might not stop it and possibly burn out the machine, and also in higher wind speeds the speed change is much more abrupt, putting stress on the structure.

But with a controller, as I think you're suggesting (?), then it would short the wind turbine when the batteries are full, without any regard for what the windspeed is, and the batteries will often be full when windspeeds are high or a large amount of power going in, and it would do this repeatedly, putting high stresses on the structure.

About the Air-x, it can work ok in high wind areas, but many people still find it noisy, in low wind areas it can take a lot of wind to get it started and produce not much power ..

[TomW]

Yyrkoon;

A couple comments:

If you live your life believing in what sales drones pitch and what manuals state, I can only hope you get out into the real world before you expire.

Perfection is achieved not when no more can be added but when no more can be taken away and achieve the desired results.

Being a DIY board you will likely see lots of "half heartedly tested" ideas. ridiculing someone for sharing it means you ridicule most of the doers here. We don't get paid, we are not under contract to help anyone.

Say thank you, take the free information and go make it better. Or not.

I am so tired of this attitude from new users who seem to think they are entitled to million dollar answers served fast, friendly and free. oh, yeah.

Luckily there is a cure for cranial Rectosis but it can only be treated by trained medical professionals.

Tom

[Flux]

"I suppose what you said before that furling would be the best/simplest way of keeping a machine from over speeding, but what about huge gusts ? The long heavy gusts here honestly has me more worried than anything else (namely because they tend to kill mills pretty fast). "

Unless you have a very strange site you are worrying unnecessarily . Huge gusts should be catered for by a well designed furling system ( some short quick gusts catch them out but do no damage). If furling machines can survive on Scoraig they will survive most places. Don't get wrong opinions because some half baked commercial machine gets fried in your location, a lot of fairly expensive commercial machines are Crap.

The 303 did limit by blade flutter but the noise was unbelievable and in real windy areas the blades only lasted a few weeks. SWWP were forced to come up with something better. They are largely aiming for the marine market where furling schemes have trouble when not absolutely vertical ( they are also looking for a cheap solution).

The Air X brakes by shorting the winding at a certain rpm, the thing stops and then accelerates again to that speed then stops again. It protects the thing but once you are above braking speed the mean power falls and in high winds the nominal power drops drastically below that of the old 303/403 and it falls well below some competitors machines that claim only a fraction of the rating. Paul Gipe has data on this if you are interested.

The sudden and continuous braking is possible with tiny machines ( that thing is just a pup). The application of this technique to larger machines would be difficult and it would not be a one off type design, you would have to prove much of the reliability problems add modify until you got something to survive.

There are lots of good reliable commercial machines but they tend to be costly, there are a load of half baked cheaper schemes, many of which are not on the market long and some are successful in low wind areas but come to grief in demanding sites. Most of the commercial design is aimed at being cost competitive (understandable for a commercial venture).

For some reason some manufacturers that have bee at this for years just seem to miss some basic concepts and commercial furling schemes ( when fitted) are not always very clever.

Flux

[Yyrkoon]

TomW let me explain a couple of things to you !

Just in case it did not sink in the first time I said it. I DO NOT care about Southwest windpower, what their manual says, or any of that garbage. All I care about is their machine survived where many other machines have failed. There is a reason for that, and what exactly it is I do not know exactly. I bet the over speed protection has a lot to do with that.

I am sorry, what exactly am I supposed to be thanking this person for again ? A post full of sarcasm, and then he all by called me an idiot, and you want ME to thank him ? I really think you need to get a grip on reality Tom, and seriously my response was SERIOUSLY toned down after several re-writs. Also I saw at least two violations of the posting guidelines.

I am not a kid,I am an adult, like most of the posters here I am sure. Keep this in mind, because I expect to be treated as such.

[dbcollen]

Yyrkoon;

Ghurd is a well respected member of this board and has been very helpful to many people. He did not insult you or "call you an Idiot". What you took as an insult must have been "PWM is damn fast, and it sounds like you are thinking damn slow." what he meant was pwm is a high frequency load, hysteresis is a very slow on-off. he was not saying your thinking process was slow, but with your defensive nature after getting your questions answered, I tend to believe the latter,

Dustin

[Flux]

I wondered about the rant as well. As these replies end up in strange places I wasn't sure that it was directed at Ghurd but I did suspect so.

Like Dustin I don't think this was warranted but I am British and we have a slightly different sense of humour sometimes. I certainly didn't see anything to get upset about.

As your reply to me was not controversial I ignored the other bit and replied as I intended.

Ghurd has been around a long time and tries to help everyone, if you took it the wrong way then I can assure you it was not intended that way.

Flux

[Yyrkoon]

Ok, then. I owe Gurd an apology. Gurd, I am very sorry for taking your post out of context, and treating you as though your response was hostile, when it was not.

I do not know everything no, and I do not feel that my posts come across as me thinking i know it all. Fact is, next to several/many of you I know nothing.

Gurd, again I am sorry for misinterpreting your post as hostile, and I apologize for my behavior.  

[Yyrkoon]

TomW, I feel I owe you an apology as well, and I treated you badly. I am sorry.

However, I would like it made clear, I care nothing about Southwest Windpower, or their systems, except that in our area here they are the only systems that seem to survive for any length of time. I am just trying to figure out why, so when I build my own system that my money spent does not turn into a huge mistake.

[TomW]

Yyrkoon;

No worries.

Tom

[Yyrkoon]

My friend with the AirX likes it because it did not die after 3 months like his previous system did(3 Mallard 400's I believe he said). The Mallards also according to him put out 2400W most of the time, but again died after 3 months. The AirX system on the other hand does not put out 800W each in moderate winds, but it can apparently in this area live much longer. This is just fact, well, what I think I know as fact as told to me by a friend who has no reason to lie, or exaggerate. I did notice that his machine does make an audible noise while charging, but it was nothing I could not live with personally. Mounted on a house may be altogether a different story.

As for my comments about shorting the system when the required charge needed is met. Well yes, and no. You bring up a valid point, there would need to be a smart controller, not just a simple dumb controller. As another has already mentioned however, you add complexity, and other points of failure into the mix. Also, this sounds as though the larger the machine , the more stress yo uput on it. I had already suspected that machines take stress from being shut down like this(going by what I have read on these forums), and found it odd that the small system my friend has uses something similar(and still flys). Going by what Flux mentioned above, smaller machines in reasonable winds can be shut down like this, where as larger machines may not be able to handle the stress. Torque ? Momentum ? I still do not know why.

[Yyrkoon]

What would be a good source of information concerning furling ? I suspect you may say these forums, and in anticipation I will do my best to search. Outside of these forums ? Hugh P's book(s) ?

[ghurd]

Sorry it read that way.

I don't recall anyone but me trying DIY controlled stall (without variable pitch), so I shared my results.

I meant what Fungus said about serious mechanical stress if done at in slow cycles,

And there could be a problem with heat in the coils or electronics if done at high speeds, like how many of the 1KW Chinese machines being sold in the UK and AU fail or how the 403(?) had a habit of burning out coils.

Also what Flux said about blade flutter and short lived blades, how my blades wouldn't have held up either, and how it is loud.

I have reports the Air-X will still go into very loud blade flutter, and one of the reports comes from a Aussie who also has a burned up Chinese mill.

As others said, and I also believe, the ideas would make for a less reliable machine.

G-

[Yyrkoon]

Thanks for your post Gurd.

Yeah, my buddy suggested variable pitch about a week ago, but I pretty much wrote that off(for now) as my understanding of it, is that its very complex. Lots of the things involved with a well designed machine seem to be that way(for me). That is in my nature though, I can not just take plans for a machine, and put it together(this part is easy for me). Being a tinkerer at heart, I have to know how it works, change things around, and do something custom towards my liking.

Maybe I will just buy Hugh P's book with the 'alternate' 4' plans, and tinker with my own controller after that. By then hopefully I should have a better understanding of how, where, and why furling is highly recommended. I do tend to over think things, but in this case I see that as a good thing, not bad.

[TheCasualTraveler]

     I'm a little hesitant to get in on this one for fear of showing my ignorance but I have been pondering the same thing you mention in number 1. to design blades to control the machine instead of furling.

     I am thinking along the lines of more blades and an oversized generator (alternator). Now I Know...

     I know that 3 blades are the optimum for balance, speed, noise and simplicity and that using many blades is good for operations requiring more torque like water pumping, but it seems to me that for some purposes there could be a compromise. Just as there are many different wind situations there must be some degree's between 3 blades and many blades that might better suite an application.

     For example, a site with low winds, 8 to 12 mph where you want to generate a modest (50 to 150 watts) but fairly reliable amount of power, it would seem to me that using 5 or 6 blades would,

1. - Help low wind start up
   
2. - provide more torque to a over sized generator built to run into stall
   
3. - be slower to reach high rpm's in occasional higher gusts.
   
   

     I further know that I would miss the power in the higher winds, but if those winds are rare or inconsistent, what of it?

     Any way, that is what I am messing with. I've built a number of different blades sets but only one small inefficient alternator. I need to build a decent alternator to test them but from what I've seen so far using 6 blades I never had any problems with 30 to 40 mph winds.

[Flux]

Quite a few comments and questions scattered throughout this lot.

I will try to answer some of them here rather than reply to posts all over the place.

The person who simplified furling and made it understandable to the masses is Hugh piggott. If you have enough basic knowledge and read his books carefully you may just about get to understand most of it. If you follow his plans you will be ok but if you want to tinker and modify then I am afraid you may come unstuck unless you really have a full grasp of what is going on.

The Dan's of this site have continued the work and adapted the idea to a variety of sizes of mill and again if you follow their designs exactly you will be ok. If you change ideas or applications you may again come unstuck. Even small changes in simple things like connecting cables can raise the furling speed to the point where the alternator can't cope. Changes of loading from battery to other things require a drastic rethink.

Small is beautiful with wind turbines, things under 5ft diameter rarely fail mechanically even in a major storm. If you want to take the chance there are tricks to make the alternator survive and there are many commercial small machines that will survive. Some furl and some don't( some offer both versions, furling for high wind areas, but the low wind version usually survives as well but with very high tower loading).

Beyond 6ft you will need some proper form of control or you will need to design the blades to become dreadfully inefficient in high winds. ( low speed high solidity wind pump type blades, they work but very inefficiently and with extremely high tower loading).

You can stall limit as long as the alternator is big enough and you don't loose load and that will work with any blades. In the event of loosing load you stand a better chance of survival with more blades and lower tsr but when you are not in "survival mode" the lower speed requires a much larger and more costly alternator to hold it in stall.

I can't imagine why anyone would try to build a non furling machine larger than 4ft unless they have the ability to do a pitch control hub. It's simple, effective adds little to the cost and if done properly prevents disaster. Even in low wind areas most places see the occasional storm and you are asking a lot for a reasonable sized non furling machine to survive even the tower loading let alone survive burn out and blade failure. The very nature of the wind and it's cube law makes this a serious challenge.

I don't want to comment much on commercial machines, I do this for a hobby and I couldn't afford them so I have little interest. There are good ones that perform well and are reliable, they are incredibly expensive. There ones that perform badly but survive and they often come a bit cheaper. There are a large number of things about that are a disgrace to the wind power industry and the one beginning with M ( can't remember what it was and don't want to go back a page to find out)may fit into this category. I don't consider the Air X a good machine but if the other is worse then no comment needed. Your friend is no doubt honest in his comments but I think he based it on a rogue machine.

Flux

[spinningmagnets]

Yyrkoon, Concerning the use of blade shape to control over-speeding, I'm certain Flux is correct "... (they are also looking for a cheap solution)..."

I suppose the Air-X engineers did some research, and their blades perform as well as is possible with that type. If they wear out to soon for your taste, perhaps you could use one as a mold pattern, and make composite spares (if, of course, you can be satisfied living with their modest faults)

I haven't built a wind-gen yet, but its my understanding that most spinning products are balanced "well enough" to work under the average expected conditions, but an unloaded prop in high winds will ocasionally reach a point where it experiences catastrophic failure, so it is wise to keep some type of (dump) load on the gen, for that moment when the battery suddenly trips the controller as "full".

I'm under the impression that furling prevents the generator from overheating (was that the cause your friends Mallard-400's dying?)

Personally, when its time for me to build, I will exactly copy a proven design. However, if you like to experiment, perhaps you might consider one of the several "furl-up/furl back" designs. I imagine after its built, it might be more adjustable to new modifications that you try.

Its my understanding that the benefit of variable pitch is not that it saves you the cost of a furling mechanism, clearly its more complex and expensive. I believe it will harvest more power from the available wind (its possible I may end up living where I'm only allowed one wind machine).

A coarse pitch may provide an earlier start-up, and a slight pitch might moderate the RPM's so that the machine continues to harvest power when other (much more affordable) machines have furled away. At least thats my hope. Best of luck with whatever you try.

http://www.fieldlines.com/story/2008/9/4/5447/22366

http://www.fieldlines.com/story/2008/2/18/41831/3205

http://www.fieldlines.com/story/2004/5/21/62956/3358

http://www.fieldlines.com/story/2006/9/25/143144/890

Variable Pitch hub discussions (pics)

"They (the press) accused us of suppressing freedom of expression. This was a lie, so we couldn't let them publish it"

-Minister of information Nelba Blandon, Nicaragua, 1984

[Yyrkoon]

As has been already said, Mallards are basically a half baked Idea from someone who only cares to make money from the idea, or possibly is under the delusion that his equipment because of being so small with 6 blades on the hub; that it is immune to dying. Basically, the machine are just car alternators mounted to steel mounting kits that mounts to 2" schedule 40 I believe. The idea is not a terrible one, and is inexpensive, but if mtbf is so low . . . they also use no furling, and having another neighbor who has two D600's, and watching them. they whip through the wind while seeking it a lot of the time. I am pretty sure the D600's are also dead as they have been left unattended for the last 6 + months spinning wild. There are other dead machines around, and a couple of water pumping mills even !

Again, I feel that the idea was not a terrible one, but the thought process was not thought through completely. I have thought about buying one of their mounting kits since they are semi-local to me, and just mounting an unmodified car alternator on it just to see what it could do. With so many neighbors flying machines 'close' to me however, I know what ever I put up will do decent for what it is(as long as it survives), so knowing if I have enough winds really is not in question.

The attraction is this: You can buy a new modified alternator from another source for ~$229, mounting brackets from Mikes shop for ~$75, and blades from yet another source(which may/may not work well with this) for ~$40, or ~$80 for blades, and a hub. A total cost for $350-$400 is not too bad for a machine that can output 500-800W in moderate to semi high winds. Of course then you need to worry about cabling, and a tower, which in our area these machines do ok on a 20' tower, and placement concerning cabling for connection to your battery bank is up to you, the owner.

Now in case it sounds as though as I am hyping these systems - I really am not. I would not buy one of these as a kit because of their demonstrated reliability, for which I only need to step out side to see several dead systems of this type. I do not know why exactly each and every system has died around here, but if I were to guess I would have to say that either over speeding  killed them, or the elements killed them since they are not sealed. Maybe both. Maybe other factors I have not considered yet. Either way I would not spend $500 to find out.

[ghurd]

A quick note on one of the common $229 blue auto-style PMAs.  I know a guy who is having a very hard time getting 60W out of a few versions and even resorted to Jerry-Rigging one without much success.

No way it gets close to the amps into a battery where the chart levels off, more like it peaks at a bit over 1/2 at 1200RPM in a lathe.

Maybe he will chime in?

A 1HP Leeson PM motor makes more power for less money (ebay), in a more heavy duty package.

Unmodified car alts are 99% useless for wind.

G-

[scorman]

controlled stall blade design by Martin Hepperle:

http://www.mh-aerotools.de/airfoils/windmill.htm

article on patented multiblade design by William Allison:

http://s145.photobucket.com/albums/r203/scorman1/Wind/Allison%20article/

the above design was verified by Allan O'Shea (one of the original founders and first president of the AWEA)in a 20 ft licensed working model that flew for 6 months back in '80

Stew Corman from sunny Endicott

[Fused]

Hello all,

Ive been in the background reading and learning for over a year. One of the first things I read was that a car alt would not make a good generator.

Well, I bought the parts to assemble one of those "blue" units. What I bought was a low wind stator and the rotor fitted with neo mags. At 400 rpm I seen 1.02 amps into 12.0 vdc. At 1200 rpm I had 8.24 amps into 12.0 vdc.

With the help of a man named Glen (Guru) I wired the stator Jerry-Rigged then tested.

My findings were that at 400 rpm I had 1.07 amps into 12.1 v dc and at 1200 rpm It was showing 9.06 amps to battery.

Ive since swapped the stator with a 19 ga wired stator and built a set of freelite blades for it. I tested it with new stator and now it puts 1.41 amps into 2-12v marine batterys and 8.99 amps at 1200 rpm.

I don't know if my tests will be helpful, but these are actual hands on tests. No, they don't follow any graphs I looked at when I thought this was such a great idea.

Proof is in the pudding, and mine flopped.

Much thanks to Glen for my many, many questions.

[ghurd]

Again, I am sorry.

The 'you are thinking dang slow' part could easily be taken as hostile.

I never claimed to be eloquent.

G-

[Yyrkoon]

Do not sweat it Gurd, I was not exactly friendly myself(but my behavior was intentional, yours was not). The important part to me is realizing that I was wrong, apologizing, and having said apology excepted. No hard feelings on my end, though I still feel like a butthead  . . . heh.  

[Yyrkoon]

Sounds like the modified alts I was speaking of above. I did not realize they were this bad however. 1200 RPM is barely above idle of a car motor, so maybe if geared/pullied . . . or maybe not. I really do not know.

Just another reason to buy plans for a known working system, build it myself, and then toy around with things after that.

I am actually leaning heavily towards buying Hugh P's june 2005 plan book, and build the 4' model just for the experience. Another part of me is wanting to build a high voltage alt . . . 110vac or higher. Talk me out of it Flux (or anyone for that matter)! heh

[Flux]

When you talk about 110v ac I hope you aren't thinking you can run things directly from a wind turbine. The power from wind is wild it is not suitable for driving many things directly. The voltage and frequency is constantly changing. Normally it is tamed with batteries or fed into the grid to give a steady source of power.

Pumps and heating can be run directly but even then you need a bit if control equipment if you want other than a dismal performance.

Flux

[Yyrkoon]

DO I come off as being that dense ? Of course I am not going to try and run appliances off the machine. I did however think it might have been interesting to come off the alt directly into an old switching power supply from a PC. Most likely would have to filter the output to 60hz (somehow)first.

[Yyrkoon]

I had thought about like 6 blades on an over sized alternator too, but my understanding is that the machine would suffer in low winds.

Furling really does not seem all that bad, especially when you just follow the specs for a pre-designed system like I think I am going to do now.

Vertical however would be harder, but not impossible(for furling), and I would imagine that electronics would have to come into play. Well, I do not exactly know of the term 'furling' would apply, but the end result would be similar(just done differently).

[Flux]

I am not used to people quoting 110v ac for a wind turbine unless it is an induction grid tie.

With wind there is only one voltage at any given speed. You will only see your 110ac at one wind speed unless you use some form of commercial alternator with a voltage regulator.

Switching regulators rectify to dc inside and most will not be bothered about frequency. They may be more bothered about voltage range. Commanda and others in the southern hemisphere have done some work on this and the idea is feasible but not that simple. These things are single phase unless you do something to them and you will need to track it to the load

High voltage transmission is easier but dealing with it at the end spoils the fun somewhat.

If reliability is your main concern then this may not be a great idea.

Flux