Coil turns vs resistance and voltage output

[spestis]

I have a dirt bike stator and I’m trying to understand the correlation between coil turns, wire size, resistance, output voltage and amps.

These readings were taken from the coils alone. They were not connected to the voltage regulator or CDI box. Both voltage readings were taken at the same RPM.

Bike head light coil = 172 ohms ~12 VAC

Bike ignition coil = 60 ohms ~ 40 VAC

I know that the more turns a coil has the higher the voltage output. If the head light coil has more resistance I would think it has more wire turns. But how is it that the head light creates less voltage. Does the wire size make a difference?

 

[Clyde38]

Yes, wire size does make a difference. Smaller diameter wire is higher in resistance than larger diameter wire of the same length and material. See below:

http://www.powerstream.com/Wire_Size.htm

 

[spestis]

I would think they would use larger diameter wire on the head light coil to help with the large current draw. And the ignition coil does not require a lot of current just high voltage. It would seem that the ignition coil with smaller wire and more turns should have a higher resistance, correct?

 

[Clyde38]

I think that the dirtrider.net forum that you are working with will be able to help you more than this forum.

It would seem that the ignition coil with smaller wire and more turns should have a higher resistance, correct?

Yes, that is correct. If you have two coils that are the same physical dimensions and one is wound with more turns of a smaller gauge wire the resistance will be higher. If your two coils have the same magnet and air gap the coil with the higher number of turns will have a higher voltage at the same speed.