2 in hand coils

[Pebbles]

Hi Guys
Looking at 10 ft coil winding, older builds use 65 turns of 14 to 17 awg and the newer plans have 36 turns (2 in hand) of 14. Aside frome higher current carrying capabilities, what are the benefits of this advancement? Is there an effect on cut-in, power out ?
Thx for any explanation
Pebbles

[Flux]

There has been quite a lot of development over the years and there is a lot of information about. I haven't kept up with all the changes and Dan is probably your best source of answers to your question and he probably will respond when he is available again.

I think the main thing to remember is that over the years magnets have changed as better grades came available and also there has been a shift to stronger round magnets in place of the rectangular blocks.

My advice is to stick with the recommendations for each project as it was produced. All worked well enough but the later machine with bigger magnets may have better survival chances in high wind areas if you are not too careful with the furling.

Please don't go taking bits of the various projects and mixing them up, that is a recipe for disaster. there is a great difference between 36 and 75 turns, so much so that they are not interchangeable. Make sure you use the correct winding for the voltage you want to work at ( there are several options so don't confuse them) then choose the winding for the magnets you intend to use. If you can afford the extra I would use the later round magnets as it is probably the best developed version but the rectangular magnets will make a good machine, just be absolutely sure you use the winding suited to your magnet choice.

All the correctly matched options will cut in in similar wind speeds but you may have more overload capability with the later design. The peak power out will not be very different but you will have to be more careful not to overload the earlier machine.

Flux

[Pebbles]

Hi Flux,
Thx for the reply and recommendations, however, as all the mentioned wiring configurations come from 10 ft models using 1" X 2 " rectangular neo mags and using 12 " rotor plates, I find myself still in the dark as why "Our latest 10 foot wind turbine" "Active Project " uses 2 in hand X 36 Turns, "Tim's 10 foot wind turbine" also an active project , uses 34 turns two in hand with rectangular 1" X 2 " mags and the older ones use 65 or so single winding , all configurations are using 14 awg and some others I have seen are single winding up to 72 turns and awg down to 16 and 17 awg.
These machines all have the same magnets and rotor sizes , however for some reason they started winding the stators 2 in hand with half the number of turns.

[Flux]

OK now we have eliminated the round magnets I see where you are struggling.

The current designs are fairly clear in that windings are specified for the various voltages , the designs are star connected and for 12v the turns are in the 35 range, plus or minus a few turns depending on the wind site and choice of magnet.

Some of the older designs are not so well documented and it took me a while to unscramble things. For star connection the 65 turns would be a 24v machine but when I read through it I found they were using a delta connection for 12v. It was also suggested that it would be ok for 24v star connected.

I personally would stick with winding 2 in hand at 35 turns rather than using a single 65 turn and connecting delta but both options will work.

The only reason I could see to choose the 65 turn option if if you wanted to upgrade at some later stage to 24v. by bringing out all 6 ends you would have the option of working at 12 or 24v, although if wound specifically for 24v it may be better with a few more turns in a low wind area to keep in line with common practice. I suspect that in reality the 65t at 24v would be fine and if you did go to 70 t you may end up opening the air gap in the end.

I hope this clears up your confusion, i am sure Dan would have sorted this quicker if he was not in Dakar.

Flux

[Pebbles]

k Thx again Flux

Pebbles

[DanB]

Hi Guys
Looking at 10 ft coil winding, older builds use 65 turns of 14 to 17 awg and the newer plans have 36 turns (2 in hand) of 14. Aside frome higher current carrying capabilities, what are the benefits of this advancement? Is there an effect on cut-in, power out ?
Thx for any explanation
Pebbles

I'm afraid all of the plans we have out there now are 'older'.
But I think you are confusing voltages here.  65 Turns of AWG 14 wire should be decent for a 24 volt wind turbine (although I think we called for 70 turns).  You can fit a bit more copper in there if you wind with two strands of AWG 16 in hand, and 65 turns.  That works well for a 24 volt turbine if you use the rectangular 1" x 2" x 1/2" magnets.

36 turns fit if you use two strands of 14, although lately I've been winding those 12 Volt stators with 33 turns two strands of AWG 13 wire, or 4 strands of 16 ~ they need to be tightly wound though to get the thicker wire to fit. 

The thicker wire helps a little bit to reduce resistance and heat in the stator ~ however no matter how you build, be sure if furls such that it does not produce more than about 700 Watts sustained output.  We called to offset the alternator from the yaw bearing about 5" in the book - lately I have been going with more like 6".

[Pebbles]

Thx Dan , appreciate the info
Pebbles

[Wisdom Bear]

What does 2 in hand mean?

[ChrisOlson]

What does 2 in hand mean?

Each coil is wound with two strands of wire in parallel.  It's a method used to increase ampacity of the winding without resorting to using large wire, which is hard to wind.
--
Chris