I live in Finland. I build a home wind turbine and I need some help from this forum.
I shall use an auto alternator/generator for to get the 12v – 14v that I need. An alternator has to spin (move around) very fast. For this I need a right angle gearbox speed changer. With a ratio of 1:10 – 1:20. Like in the picture that I attaché here.
Can be used one (very cheap :) ).
Where can I find it here in Finland.
Thanks for your help.
Ron
Hi Ron,
Car alternators are of course available at/via any auto parts store in your location. There are several chains but just to mention a couple, Motonet and AD-varaosat come to mind.
Those of course sell new units and they have their price. If you don't need a new unit then there are places like Autovahinkokeskus (AVK) (https://www.avk.fi/) that tear down crashed cars and resell the usable parts. If you search for "laturi" you will find a huge amount of used alternators that may serve your purpose. You didn't mention your location, but AVK is located in Espoo and Pirkkala near Tampere, if those work for you.
Then of course there are the normal scrapyards many of which dissect old cars. But those you will have to find yourself.
P.S. You do know that a car alternator is regulated by varying the stator coil current? That means you will need an auxiliary power supply and regulator to maintain the output voltage within limits. Also, it means that the generator will eat power at all times unless you build a control system to turn the alternator on only when the shaft is turning faster than a set minimum.
Usually (often?) homebuilt windmills employ a low speed (no gearbox) permanent magnet unregulated generator that consumes no power. I have detailed design info if you are interested. It is somewhat more effort because one has to be built but it is not precision engineering so easily doable. You just need a trailer wheel hub, a bunch of real strong permanent magnets, some magnet wire and casting epoxy. And a bit of time & patience :)
Hello
It is better to use low speed angle gear they are more common, so easier to find.
Then I would use belts to step up speed, easy and cheap.
If you are worrying efficiency of belts you could use step up gearbox.
Thanks, I'm Israeli, Here already 15 y, work life.
not refugy) now in penssion. Never Never Never got negstive feelings from Finish people. Only positive.
Tonight I'll bring here the draw of the wind mill.
Hi, good evening
Again I'm late :).
I see now that the discussion goes like a chain and I can't relate directly (like answer) to a certain response.
Jussik – I put here a picture of a step up gearbox. is this what you mean? This one is of ratio 1X3.
Kremmen (also Jussik and others). I live in a village close to Kauhava (that is near Seinäjoki ).
I put here a picture of how I view my wind turbine. It is a Vertical axis wind turbine (VAWT).
I planed a complicate and not reliable gear system based on bicycles wheels. I am afraid that if something goes wrong there – the whole tower will fly away. This is why I look for other possibilities.
My idea came after I saw the attached video that is based on a rotor of (how funny) snow shovels.
On Minute 3:39 he shows a certain Generator Motor (that is instead of the alternator). What is this Generator Motor?
https://www.youtube.com/watch?v=g0tiiA52ec8
And yes – I will love to get the detailed design info about the low speed permanent magnet unregulated generator. (I think that I saw on youtube something about it.
I still think of a Horizontal-axis wind turbines (HAWT) that is more efficient in using the wind but the rotor bother – how to make or get one. I want a rotor of about 3m in diameter (1.5 m in radius).
Opinions?
One thing is for sure – Not to use the energy that blows here freely is a waste of money that goes to the electric company.
You will be wasting a lot of energy using gearbox and car alternator. My hometown is Alavus (some 50km from seinäjoki) but nowadays I live in Kokkola (west coast). I remember that the winds are not as strong inland as here in the coast, but I might remember wrongly.
There is a lot of effort to build a wind turbine so I'd take Kremmens advises seriously or it might be that you build something with great effort but in the end you might not be satisfied with the outcome.
I've also considered to build some sort of wind turbine myself and I like the fact that you have chosen a design invented by a Finn (http://en.wikipedia.org/wiki/Savonius_wind_turbine)
When you answer a previous post, you will see a list of earlier posts and in the right margin a link "Lisää lainaus" == "insert quote". This will insert the post at cursor in your reply so you can comment it.
Kauhava & Seinäjoki are familiar places - my wife comes from not too far away (Kurikka).
The less gearing your turbine has, the more efficient it will be. Step-up gears are very unadvantageous in that the friction is multiplied by the gear ratio instead of divided by it as happens in a reduction gear. For that reason you need to pay every attention to getting a maximally low loss transmission for up-gearing. The ideal case would be to avoid gearing in the first place.
The shovel mill looks interesting but it has the same weakness as the square-rigged sailboats (think Pirates of the Caribbean): The shovel is a square sail that can never exceed the wind velocity as the wind pushes directly against it. A modern sailboat with a Bermuda style rig (triangular sails) acts as a wing instead and can easily move faster than the wind when it cuts diagonally across the airstream. A propeller type turbine blade works the same way.
A working wind turbine can be made using either type of "airfoil". But the choice impacts also the choice of the generator. For a low rpm turbine (shovels) you will want to use a naturally low rpm generator instead of up-gearing a fast generator. for a higher rpm turbine a different generator design is appropriate.
The thing with car alternators is that they have been designed to run at several 1000 rpm which is hard to get from a windmill. For that reason a different kind of generator design will perform better and easier. One such design is the permanent magnet pancake design to which i referred earlier. That one could be a good candidate for a vertical shaft windmill since the generator can be placed on the lower end of the shaft out of the airstream and thus it can be made large radius. As you may recall the voltage induced in a conductor moving in a magnetic field is directly proportional to the speed of movement. Making the generator radius larger increases the relative speed between the conductors and magnets.
I will dig up the design documentation for the generator and come back to it. The general idea is that you will build 3 pancakes, 2 of which consist of a circle of permanent magnets and the 3rd is a disk of wire coils rotating between the magnet disks**. All of the pancakes need to be constructed solidly so that they can take the mechanical stresses of generation. For this reason everything is usually set in epoxy and bolted solidly together. A popular way is to use a trailer wheel hub as the support for the rotating coil assembly but that is not strictly necessary. To minimise the air gaps and thus maximize efficiency, tight tolerances are needed, leading to the use of ball bearings in the shaft suspension. It sounds complicated but actually it is not so hard to do. You just need some time, patience and a reasonable set of DIY tools.
More later.
**P.S. Actually it should be the other way around :) it is easier to make the coil stand still and rotate the magnets.
Just a try using the "lainaus" that is at the upper right corner of a post.
Also - is there a way to get automatic notification to my email about actions in the topic?
It is a nice day so I go to do some works outside.
I'll Come back later.
Lainaus käyttäjältä: Kremmen - 09.06.15 - klo:11:07
The shovel mill looks interesting but it has the same weakness as the square-rigged sailboats (think Pirates of the Caribbean)
But it works fine, I saw it on tv! ;D
Lainaus käyttäjältä: Ron - 09.06.15 - klo:15:50
....
Also - is there a way to get automatic notification to my email about actions in the topic?
.....
Click the "MUISTUTUS" button at the upper right corner of the
page.
Lainaus käyttäjältä: pave - 09.06.15 - klo:18:43
But it works fine, I saw it on tv! ;D
Yes, of course it will work if the shovels are smartly positioned. :) It just needs a different kind of generator than a high rpm propeller design because the shovels will rurn slower.
So it is only a weakness if you plan to use a high rpm generator which would then need an up-gear to get to the right speed. And that would introduce losses.
P.S. Ron: I seem to have misplaced my DIY wind turbine book, it was not where i thought it would be. But i will find it and come back.
Ron, check this: https://www.dropbox.com/s/peer1rp6nq88yzp/Building%20Your%20Own%20Wind%20Turbine.pdf?dl=0 (https://www.dropbox.com/s/peer1rp6nq88yzp/Building%20Your%20Own%20Wind%20Turbine.pdf?dl=0)
You might wanna check out washing machine motors like samsung and few other brands with a similar design. These are brushless 3 phase dc motors. For increased efficiency and power you can also change ferrite magnets to neodymium. Without a doubt these would be much better choice for direct drive and lower speeds. These can even be rewound if you wanna squeeze the last drops of efficiency out of them. :)
Here is a pic of samsungs motor.
(http://product-images.highwire.com/4668329/maytag-neptune-samsung-front-load-washer-drum-motor-pn-04ca444-001.jpg)
Most valuable document. No way to express my thanks.
Thanks - I sure will give it a very serious attention.
Kremmen - what do you think of Cartti's idea of using a washing machine motor?
It is a motor and as such taking electricity power IN. How do I get from it Electricity power OUT?
Thanks Cartti, but as a motor it takes electricity power in. How do I get from it electricity power OUT?
Lainaus käyttäjältä: Ron - 10.06.15 - klo:19:21
Kremmen - what do you think of Cartti's idea of using a washing machine motor?
It is a motor and as such taking electricity power IN. How do I get from it Electricity power OUT?
Basically every motor is also a generator. you push electricity in and you get torque and rpm out. You put those in and out come voltage and current.
The motor Cartti linked would probably work nicely. It has a permanent magnet excitation so will not consume parasitic power. Just turn the shaft and you will see a voltage at the stator connections. All motors have certain characteristic constants such as rpm per volt or conversely volts per rpm if used as a generator. Withing reasonable limits you need to find a motor that produces voltages that you can use. The washing machine motor could be direct drive, i.e. it is connected directly to the drum with 1:1 "gear ratio". That means it will turn roughly somer 1600 rpm at 230 VAC (or whatever the spin cycle rpm is for the particular washing machine). If you turn the shaft at the same 1600 rpm, you will get more or less the same 230VAC out of the "generator".
To expand my previous post a bit:
An electric machine is a converter that changes voltage and current to rotation and torque, or the other way around.
If you consider an ideal DC motor, then its speed of rotation is directly proportional to the armature voltage. Likewise its shaft torque is directly proportional to the armature current.
Since it is an ideal machine (that does not exist in real life) there are no losses anywhere. The motor will turn without consuming current, and any current through the armature will not cause a voltage loss. That being the case the ideal machine is a perfect converter between electrical and mechanical power. It is important to note that the conversion can happen in either direction - the machine won't care.
Example: An ideal DC machine is used as a motor. Let's assume its motor constant Kv is 10 rpm/volt to make calculations easy. That means that for every volt of armature voltage the shaft will turn an additional 10 rpm more.
So say we supply 100V of armature voltage; what happens? The armature and shaft accelerate until the back EMF of the motor is equal to the supply voltage. The back EMF (ElectroMotor Force or in some texts ElectroMotive Force) is the voltage produced by the machine when it turns. When the supply voltage exactly equals the back EMF the shaft speed has achieved final speed and accelerates no more. Now the motor is in balance and will continue turning until further notice.
Next we close a clutch connected to the motor shaft and start turning a load. Assume the load is something like a propeller so that the faster it turns the more torque the motor must provide. Now you can visualize that the load causes the motor speed to go down and the back EMF no longer matches the supply voltage. Since the armature resistance of an ideal machine is exactly zero, a basically infinite current will start to circulate in the armature winding. This current will induce a torque in the machine shaft and that torque will accelerate the shaft until the back EMF again matches the supply voltage. When the machine is again in balance, an armature current will circulate such that it exactly produces the torque needed to turn the shaft at the speed where back EMF matches supply voltage. This current depends on another machine constant, the torque constant Kt giving Nm / ampere.
The important point is that in an ideal machine the supply voltage and that only, determines the shaft speed. Similarly, the armature current and that only, determines the shaft torque. Also, the ideal machine is a perfect converter so that power in always equals power out. Thus the electric power in watts (==volts * amps) is always equal to the mechanical power in watts (==torque * angular speed, expressed in newtonmeters * radians/second).
In a practical machine there are all kinds of losses that cause the voltage and current to interfere but those can be compensated or ignored.
Now, you can turn all of the above around and use the machine to convert shaft speed to voltage and shaft torque to current. Of course to get current you need an electrical load just as you need a mechanical load to create torque. In a wind generator the load is usually controlled by a Power Point Controller that monitors the shaft speed (due to wind) and based on a model of the windmill tries to maximize the extracted power by causing the generator to see a heavier or lighter load. If this process is optimized, the controller is called a Maximum Power Point Tracking Controller or MPPT. (Caution: lots of the cheap Chinese MPPT controllers are not. They just advertise MPPT but don't actually implement a working MPPT algorithm. It is not trivial to do.)
suoraveto pesukoneen moottorista saa ihan hyvän generaattorin itse kokeilimme muutama vuosi sitten moista ja vieläkin pyörii ja tuottaa sähköä.
Suoraveto koneen moottorin testausta sorvilla
https://www.youtube.com/watch?v=3SpI7v6Mtxg
Käämit piti vaan kytkeä toisin siitä löytyy netistä suoraan kytkentä miten ne kannattaa että kierroksia ei tartte olla niin paljoa.
This link has some info about washing machine motors as generators like TeacDance's version. Also other potentially useful info.