I have stumbled across a Sachse electronic ignition system for my GTS. I note that Sachse suggest 3 ohm single output coils (bike is kick start only) for this application but else where around here I notice that 5 ohm is the weapon of choice. Little confused as I see that heat build up is said to be the issue with the 3 ohm units but I thought heat was the by-product of greater resistance?
I was going to run without ballast resistors as she is kick only.
Any thoughts?
3 or 5 ohm coils
Re: 3 or 5 ohm coils
http://www.ohmslawcalculator.com/ohms-law-calculator
You can see plugging in 14V & 3 or 5 ohms, that with the lower resistance you get higher current (amps) / power (watts) values than with higher resistance. That must be absorbed, or a large part of it anyway, buy the coil itself and it is - mostly in the form of heat. Not a problem if the coil can live with that, but apparently Dyna coils tend toward more frequent failures at the higher current / power loadings.
You can see plugging in 14V & 3 or 5 ohms, that with the lower resistance you get higher current (amps) / power (watts) values than with higher resistance. That must be absorbed, or a large part of it anyway, buy the coil itself and it is - mostly in the form of heat. Not a problem if the coil can live with that, but apparently Dyna coils tend toward more frequent failures at the higher current / power loadings.