16 pole gen finished and working

[Jason Wilkinson]

Hi to all, just finished a 16 pole/12 coil genny 32 1x2x.5 mag 12 coils/70 turns,current goes into the 12v batt at about110 to 120 rpm, moderate winds, got up this morning to find the inverter alarm on (overvoltage shutdown), i disc the turbine from the batt pack and connect it to a used automobile batt. when i checked the voltage of the batt pack it read 15.5v  at around 11am i read it again and it was 12.36v.  Question.... should the voltage drop so low so soon without a load ?

 Another thing i've found out is that when the turbine is connected to the used 12v car batt the rpm drops to under 100rpm with about 3 to 4 amps into the batt,(seems like a good dump load ) and remain there for hours never increasing in rpm or amps

 I have another large tractor batt 12 v with a dead cell i cut out the dead cell and now have a 10 v batt , when connected to the turbine it bubbles like a ,kettle, is there any harm in doing this ?

 Jason

[Flux]

You give very little information but I seem to remember you using an 8ft prop. If so you have a classic example of stall. You have a lot of magnet there and with 70 turns it will be too slow for 8ft. Try it at 24v ( or 22v with the sick tractor battery) and see if it comes to life.

The car battery may only be half charged and would drop to 12.36v off load when the surface charge is removed. Longer charging may bring it back up to about 12.6 or more off load.

The sick tractor battery with dead cell that gasses violently at 4A must be well sulphated. Let it boil for a few days, it may improve, it's likely about useless so a bit of experimenting will not hurt.

Flux

[Jason Wilkinson]

It looks like i've jumped in at the deep side of the pool (an old Barbadian saying) like building a turbine, getting it to stay on a tower,spin and produce some voltage is far easier than understanding terms like "stall" and how much watts it should make when operated at its max.I thought it would get easier as i progress but i'm getting more confused   Thanks anyway for responding

    Jason

[Jason Wilkinson]

I've just disconnected the batt from the turbine and it sped up going all the way to the 70 v mark and and climbing  when i reconnected the batt there was a frightening  spark and the amp meter shot up over 10 amps  before returning to 4 amps the batt are connected in series to make 24 v.   To me this turbine is making power, maybe i'm not using it wisely

     Jason

[Flux]

I have had a quick look at your figures and I suspect your cut in is below the 110 rpm that you quote. If you can find enough batteries it would be interesting to try 36v and even 48v to find out where it matches best. You would then have a far better idea where you are aiming for.

You have already doubled the power from 4A at 12v to 4A at 24v. I am sure you are still stalled.

Flux

[ghurd]

I have been in intermittent contact with Jason.

I do not intend to overstep the boundaries.

If I do, maybe I'll have to fly down to Barbados for a week (or a month), in January and say I am sorry in person.  Wouldn't that be too bad for me?

Some missing information I have...

At the same wind.

Approx 4 to 5 amps into the 12v battery pack.

If it goes to 24 v batt it is about 6 to 8 amps.

I am sure people would like to know what gauge wire was used in the stator.

And how many wires exit the stator.

G-

[Jason Wilkinson]

The stator is 15.5 ins  12 coils 70 turns of  #14awg single stran (and yes ghurd the trip to Barbados would be good lots of sea and sand,and bring along Flux Danb and the whole board) i had a small turbine up (10 in diam disc 16 1x1/4 round mags 12 coils #16awg 36 turns  41 in blades  that gave me about 4 to 5 amps into the same batt pack  4 x 100 ah connected in parallel  36vdc and climbing open circuit. I made the bigger turbine same method hoping to get more amps with a slightly larger blade. i have a larger blade 5ft diag which i will try when i can get this one down. But does not a bigger blade turn more slower ? i have quite a bit of pictures but they all get mixed up with the ones that were posted already

   Jason

 

[Jason Wilkinson]

sorry i missed it 3 wires out the stator which weigh 20 lbs and each rotor is 9 1/4 lbs whole assembly including tail weight 55 to 60 lbs

[Flux]

Yes the bigger blade does turn slower and that will match the very low cut in speed better.

With a 10ft prop you will have more power to get the thing out of stall. Even so I think you will need to run at 24v especially with the single strand of #14 wire.

When you do break out of stall I think you will be surprised what you can get out of it. You seem to be in a good wind area. If you get those winds regularly I would not aim for the lowest possible cut in speed. If you start producing at 8 mph you will likely do better than aiming for a few mA in lower winds.

Flux

[Flux]

Yes that rules out Jerry connecting it so you are stuck with 24v minimum.

Flux

[Jason Wilkinson]

To wind another stator (i'll have to hide from the wife to do this and be ending up with 3 spare ones) the cost of the wire is far less than a 24 volt inverter. In the coming weeks   D V  i'll wind with 2 in hand #14 36 turns

 ps how can i submit pictures with the post

  Jason

[ghurd]

I hope he wants a face to face apology...

Given the output, etc, would anyone have a guess at a decent new stator for 12V?

Also the 12V amps such a stator could make with the same blades and rotors?

I had it figured at around 800W, however I am not good at this stuff, not even a little.

[jmk]

 Hugh's 12' calls for 50 turns of 13 gage. He may be better off with a twelve foot rotor or open up the gap? He should see 100 amps 12 volts. With a ten foot rotor it is probably stalled and not getting out of stall like Flux said.

[snowcrow]

Hi Jason, 2 in hand #14 36 turns is fine for 3 coils per phase, but you have 4 coils per phase.

36. turns x 3 coils = 108 turns per phase.
    
108. turns / 4 coils = 27 turns per coil.
     
     

Blessings, Snow Crow

[Jason Wilkinson]

Thanks Snowcrow   so it looks like 27 turns of 2 strands of #14 awg magnetic wire

 Jason

[Flux]

I would be inclined to suspect that 27 turns will be ok for 10ft.

Before winding a new stator I would try running the existing one into higher voltages until you then find the correct load speed.

From Ghurd's figures you are way better at 24v, I would also try 36 as I think it may do better. If it does then try 48 and if that is worse you have gone too far.

Then say it worked best at 36v you would use 1/3 of the existing turns. That way you have your result without more trial and possibly error.

Flux