Cheap chinese horizontal wind turbine, an in depth exploration.

brandnewb

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load: 4 x 12v5w in series
caps in cuircuit: x 2
rpm +-320
Vdc: 21
Adc: 0.22
THe light bulbs did light up but not so brightly.
1637246159294.png
My god tinkering takes a lot of time, especially when one does not know what they are doing.
Had my second arc today. This time I lost no lifespan as I actually saw it coming/expected it.
 

brandnewb

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Byw guys, I'll gladly go the extra distance and expose the makeup of this alternator. Or possibly first do some more experiments if you guys might find that interesting data.
I am not sure but for now I believe we can't expect it to do something useful at safe speeds anyway can we? I might as well disassemble it.

Also I will be creating a new thread about my winding my own alternator after I have read that kindle cook book but I am dyslectic on a whole other level so that will take me a few seconds.. ehh weeks to get through.
 

brandnewb

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I still very much believe, not having read that kindle yet so I might be way off, that for an alternator to do something usefull at low rpm one needs to increase the diameter by alot. Have much more poles and much more coild groups. theneven at slow speeds the outer part of the rotatory is spinning quite fast already.

Ok sure it will possibly present new problems that even with a mild storm one can fry chicken on the turbine. But that is a problem I'll solve somewhere down the road
 

brandnewb

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I will have to refrain from helping out in any more testing
Under my own responsibility I highly am in demand of any type of advice including yours. Let this be a warning to all viewers that electrics are dangerous under any circumstance. And playing with it is at ones own risk even though following tips and tricks of others. We are on our own in terms of responsibility is my stance on this.
But sure we can double up on safety aspects. For example like I did now. I make sure to insulate all and everything. This could be like a standards warning in the forum software ;)
 

brandnewb

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I have asked for a move of this thread to a more serious, less newb friendly sub topic. Everyone there should know things can get out of hand.

 

Hedges

I See Electromagnetic Fields!
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load: 4 x 12v5w in series
caps in cuircuit: x 2
rpm +-320
Vdc: 21
Adc: 0.22
THe light bulbs did light up but not so brightly.

4.62W, similar to before (5.66W).
95.5 ohms for 4 in series (23.9 ohms each) vs. 37.2 ohms for one.
Because filament didn't get so hot, it was lower resistance.

21V vs. 14.5V, 50% higher, and power was slightly less.

320 RPM isn't terribly fast.
Examine slope of blade (vs. circumference where measured) and estimate wind speed.
You're going to have to spin much faster to get higher voltage and current at that voltage.

AC motors are typically 3600 RPM at 60 Hz, half that if they have twice as many poles.
Yours probably has many more poles.
Up to about 1000 Hz, silicon rectifiers work OK (400 Hz is common for airborne applications to save weight of magnetic cores.) Above 1000 Hz, the rectifiers don't turn off fast enough and conduct for a while in reverse direction.
 

Hedges

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A capacitor after the rectifier will store energy after turbine stops.
By placing a resistor in parallel, it will discharge after time. With an LED in series, it will light up when voltage is present. Resistor value might be selected for 10 mA through LED. Lower resistance higher wattage in parallel if that is too slow to discharge.

A resistor sized for 1W at operating voltage would drain 10J on the order of 10 seconds (exponential decay, so takes longer.)
It will also dissipate 1W the entire time it is powered by generator. If you pick a resistor rated for intended wattage, it will get hot enough to burn your finger (maybe 100 to 150 degrees C). If you connected eight 1/8W resistors in series with total value selected for about 1/4W dissipation it should only have 35 degrees rise to about 55 or 65 degrees, still rather hot to the touch.
 

brandnewb

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A capacitor after the rectifier will store energy after turbine stops.
I am not sure I understand. Did you mean to say it stores energy while the alternator generates but keeps releasing power until empty?
If that is not what you means I have to go back to the drawing board again as then I still am missing a lot of finer concepts.
Anyway, maxmimum respect for your input
 

Hedges

I See Electromagnetic Fields!
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I am not sure I understand. Did you mean to say it stores energy while the alternator generates but keeps releasing power until empty?
If that is not what you means I have to go back to the drawing board again as then I still am missing a lot of finer concepts.
Anyway, maxmimum respect for your input

Yes.

While generator is turning (fast enough to have higher peak AC voltage than voltage in capacitor), current will flow from generator through diodes into capacitor.

When generator stops, charge will remain in capacitor until it has drained, either due to self-discharge, reverse leakage of diodes, or a load you connect. The 10 Meg ohm input of a volt meter will drain it slowly. It is common to connect a resistor to drain capacitors, probably required in most products which store hazardous energy. Old CRT television sets are particularly known for being a shock hazard even when unplugged. Instructions for PV inverters typically say to disconnect PV and wait some 5 or 15 minutes before opening.

Some capacitors, if held charged for a long time, will drive charge into the dielectric. You can drain them to zero volts, but after a while voltage reappears as charge leaks back from inside dielectric to plates. Large capacitors can recharge themselves to lethal energy levels. For storage they are discharged and a strap left connected.

So that's why I say to do the math J = 1/2 C V^2; if above 1 joule, take additional precautions.

Some capacitors in research facilities would be a megajoule. I've read that 1 kilojoule can blow body parts off. That would equal the energy from a large handgun bullet. (takes more energy to remove something by vaporization of water than by cutting action.)
 

boondox

Chief Engineer, RedNeckTech Industries
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I still very much believe, not having read that kindle yet so I might be way off, that for an alternator to do something usefull at low rpm one needs to increase the diameter by alot. Have much more poles and much more coild groups. theneven at slow speeds the outer part of the rotatory is spinning quite fast already.

Ok sure it will possibly present new problems that even with a mild storm one can fry chicken on the turbine. But that is a problem I'll solve somewhere down the road
I can't remember if I posted this already, but if you really want to learn about wind power, go here:


Much information and some very good threads on building an alt that will do what it is designed to do.
 

brandnewb

Going for serious. starting as newb
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I can't remember if I posted this already, but if you really want to learn about wind power, go here:


Much information and some very good threads on building an alt that will do what it is designed to do.
Yes I am still waiting to be accepted by a moderator for more than a few weeks now.
I did not see a contact option yet, but I will admit that I did not real scan the site for one
 

boondox

Chief Engineer, RedNeckTech Industries
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Yes I am still waiting to be accepted by a moderator for more than a few weeks now.
I did not see a contact option yet, but I will admit that I did not real scan the site for one
Shoot me a PM with your user name for the site and I'll post and see if I can get the attention of a mod. But you can still search through threads.
 

brandnewb

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Yes, I got around to it again. No electricity needed this time ;)
So the values for the winding resistance (can be found at OP are in kOhm not Ohm) does that change anything?

Anyway without further ado... drummrolls
1637686510114.png
1637686537135.png
What we have here is a 36 coil 12 pole alternator.
The coil strands have a 0.4mm diameter.
The poles are so called sector magnets (image below) of which I do not have any data yet.
I will be looking for some tools to measure their power in tesla units
There is soooo much that can and should be improved that I can hardly wait to continue making my own alternator. It's gonna be.. wait for it.. legendary!!! (Barney Stinson's famous quote)
I'll also get more details on the coil total length and the turns they contain.
1637686986303.png
also apparently the misalignment of the poles to the coils is intentionally it seems. It is to reduce clogging if I understood correctly.

Are there still people interested in my findings? I mean I'd rather be tinkering than typing ;) But of course if it is for an audience than that makes it worth while.
 

Hedges

I See Electromagnetic Fields!
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Let us know how you measure magnetic field strength.
We need to do that inside a 3/8" hole. Want to evaluate effectiveness of a de-gauss function.
The probes I've found on-line so far are too large.

I previously got a chip & demo board from DigiKey, was checking out relays with it.
 

brandnewb

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On second though I am considering abandoning this alternator design as it is not making use of both magnetic poles of each magnet. 50% of potential power is wasted and doing nothing while glued to that metal. I might be wrong though and then all bets are on again of course.
Also if I stick to this design and want to double the amount of poles I'd end up with a rotor 2ce the diameter.
Currently that is 80mm and would become 160mm.

I still want to find out what the magnetic strength is though of these magnets. I mean I need to be able to test any future magnet anyway.

So unless anyone has a specific request for additional stats, tests or what have you then I am going to mark this thread as solved sooner or later.
@Hedges I will keep you updated regarding the teslameter if I ever get my hands on one.

I assume this forum is not really the place to start a thread regarding my custom alternator design process is it?
 

Hedges

I See Electromagnetic Fields!
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Instead of "Beginners Corner", the "Wind" section of the forum would be good:


Just post a link back here when you start a new thread.

I would hope that rotor has a magnetic material in it stitching each magnet together.
Besides having a weaker field in the gap if it doesn't do that, might also put stronger moving magnetic field in rest of case, causing circulating currents and loss.

Colleague today had a Gauss meter with probe on a skinny PCB. It was reading 100's of Gauss down to 0.1 Gauss for one of our electromagnetic gizmos. Not sure if it has a milli/micro-Gauss range.

Pull-test of a form-fitting metal piece could be a non-calibrated way. Maybe "calibrate" by holding a flat end of same metal to a reference magnet of known value.

This may have been the sensor I tried a few years ago:

 

brandnewb

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The story continues here
Please pitch in if you have suggestions and or answers to questions I might have
 
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