A.C. electrical systems

Jon Dalton /

On a moped with no battery, just 2 coils under the flywheel, what would happen if you had one of the coils reverse wound? it occured to me that when i unwound one of my coils, the one that goes to the points, i might have wound it back the wrong way. This would result in opposit current flow, since current flow is the cross product of derivative of magnetic flux and the directional vector length of the wire, therefore if you reverse one of those directions, the other ones reverse too. It's my guess that since the coils are opposite each other, the way they are supposed to work is they are in phase with each other, so when one magnet passes by one, the other magnet is passing by the other at the same time. They both have a common ground, so they have to be in series not parallel. IF one of them is reversed, would that not cause opposing current flow that reduces voltage? or could it cause the two coils to act in series, increasing voltage? if so, that would explain why my light coil is putting out way more than 6 volts (around 12) and blowing the bulbs, and why my points are sparking. I can't think of any other way to explain an increase in voltage since the induced voltage depends on the speed, strength of flywheel magnets, and number of turns of coil wire, and none of these could possibly go up with time and usage, definitely not twice as high. But, if you have 2 coils the same voltage in series, it would do exaclty that, double the voltage. I don't want to rewind that coil again until i find out if it could possibly be reversed, it's a lot of work to wind and unwind. for now, i'm off to find a few more condensers and some 12 volt bulbs.

Re: A.C. electrical systems

gimmejimmie /

Did he say something about that flux capacitor modular thingy in that car from "Back To the Future" in that post somewhere?

It's Friday and I've been drinkin.

Jon, ask your professor.:{)

Re: A.C. electrical systems

Ron Brown /


Did you just tell Fred that your coil was original equipment and forget to mention that you had re-wound your Iginition power coil under the flywheel, and did you casually ignore my reference to this being a problem in my last post and did you forget to mention this at all in any of your posts asking for help??????

I give up!

Jimmie is right, talk to your proffessor, he is probably Phd. impared and you two can communicate just fine.


Re: A.C. electrical systems

Chris Robertson /


You're a little beyond me with the inductor theory at this point. If the problem has to do with the cross product of the coil winding direction (i.e. clockwise vs. anti-clockwise windings) couldn't you just reverse the connection leads without changing the coil's orientation inside the magneto?

I honestly don't know if it matters, but I would love to hear if you find out it does! This might come up and bite me some day.

Good luck.


Re: A.C. electrical systems

Jon Dalton /

the coil worked fine voltage-wise, tested it, so it only occured to me it could be a problem when i realized it could be putting out voltage the wrong way.

Re: A.C. electrical systems

Jon Dalton /

good idea - if I can get at the end of the wire that's grounded, i could just solder another wire to there and hook the other end to the points, and then ground the other end. it's a bit of work, but a lot less than rewinding. I didn't think of that. However, I"m on a reliability record, 2+ days with no breakdown, and it's been running like a beauty too.

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