Alternating Coils or not....

[ejl7007]

Hi,  I have a question about coils.  It seems a bit confusing. I have read many articles about how to construct your own mill, though when it comes to creating a stator I am a little bit confused.  For Instance, When one is placing his perfectly wound coils onto the stator I am told that the coils should all "face-up" or be placed in the same direction as they are wound.  i.e. in-out-in-out-in-out e.t.c. Now I came accross an article on how to make your own turbine at http://www.otherpower.com/wood103.pdf  which shows diagrams and states quite clearly that the coils should also alternate just like the mags, i.e. clockwise-counterclock wise-clockwise.....e.t.c. What gives?

I appreciate any help.

Cheers

[madkane]

what you are seeing  it the alternator is a single phase  machine

and  you can wind c/w and then c/c/w but all you have to do is reverse the ins and outs on every other coil

 if not the the  bad coil works against you and you loss the volts its trying to make

[Flux]

This can be confusing. Just consider one phase, it doesn't matter how many phases it has.

If there is a coil under each magnet ( the magnets have alternate polarity NSNS etc.)then the emf induced in each coil as you go round will be of alternate polarity. To keep things additive if the coils are all placed the same way then you need to reverse the leads to alternate coils start finish finish start start and so on. You can get the same effect if you reverse alternate coils and join start to finish all the way round.

If as in some windings alternate coils are missed out then you have coils under like poles. in that case there is no need to reverse any coil and the things connect start to finish all the way round.

If you take the common 12 magnet 9 coil arrangement even more coils are missed out per phase and that one works out with no coils needing reversing in any phase.

Unless you fully understand what you are doing then choose plans that work and stick to the plans, don't get ideas from more than one design and start hybrids that is asking for trouble.

Flux

[TheCasualTraveler]

I never did understand this and I also saw conflicting methods.

     Here's what I did to wire 3 coils together to make 1 phase. I put my meter on the first coil and gave the alt a spin, measuring the voltage. Then I connected the next coil and measured the voltage. If the voltage was double I figured I had it right. If the voltage went down, I reversed the coil and tested again, and on to the next coil. So that when all 3 were connected I had 3 times the voltage of one coil. Incidentally I place all coils the same way and left all the leads exposed when I poured my stator.

Can you go wrong doing it this way?

[madkane]

 i see where flux is coming from  you can wire 3phase all with c/w windings but on one of the phases  it will have to  have a reverse conection to it

 as 1 be coming on to  and 1 going of pos peak  and the last on the other phase be on the neg peak at time

 i ahve same probs some times but its all about marking cables and planning it out so it is done quicker and less hassle

[Flux]

This seems to be another confusing area. I can see where you are coming from and if you take the winding in sequence on many supposed 3 phase windings you need to reverse the B phase. What is really happening is that you have chosen a 120 degree mechanical sequence which happens to be a six phase electrical distribution of 60 deg.

This works fine and is done in many motors but if you skip alternate coil groups and take the 3 phases at 120 electrical degrees then there is no need for a reversal.

Again the 12 magnet 9 coil arrangement has so many coils missing that the mechanical sequence is also the same as the electrical sequence and choosing the coils 120 degrees apart works out with starring the starts or finishes with no reversal.

These things are different for different types of winding so you need to look at every case differently. You may have to treat a motor conversion very differently from a 12 pole 9 coil single layer machine.

Flux

[ejl7007]

Thank you Flux

[ejl7007]

Thank you Andy

[ejl7007]

Thank you