AC or DC!!!???

[Derekh1234]

Hey guys,
I just got a 1982 185s and im now working on getting the lights installed. The trike is rather beat up, so i decided to measure the current coming from the wires for the head light and tail light. The voltage varied from 3 volts to 17 volts AC depending on motor RPM. Is AC current normal?
My understanding is genrators are supposed to put out DC
What is the puopose of the "pick up coil"? Is this supposed to make it DC?
I do not have the DC power kit.
I have other ATV's and they all put out DC

Thanks
Derek

[Macs]

well iam not sure if it should be putting out ac or not. ac stands for alternating current and get put out by alternaters and other type of generating devices such as in power plants. dc stands for direct current and comes from batteries and other forms of stored electricity. a car has a current converter to change the voltage from ac to dc. now your 3 wheeler should have a type of generating device so should be dc. there should not be any ac current at all. but i am not sure on your three wheeler it is possible to have an alternating current producing. i hope that helps or i probly really confused you.

[Derekh1234]

yea i know how electricity works and what ac and dc stand for. my question still has not been answered tho
thanks
derek

[ATCnut]

The light power should be DC, sounds like the rectifier is shot.

The pick up coil is used by the ignition, it is completly seperate from the lighting coil

[Dirtcrasher]

a Diode converts AC to pulsating DC. An specific arrangement of Diodes or a full wave rectifier creates true DC. You didn't ask but I told you anyway.

[TimSr]

Yep, its generated as AC, and changed to DC via rectifier (diodes), which is sometimes a separate unit, and sometimes its built into the regulater. Rectified AC which is poorly filtered and regulated (as is typical for analog automotive applications) or pulsating DC still changes in amplitude, just never drops below 0 and changes plarity will measure as an AC average voltage on a digital voltmeter. Ignore the AC reading and go by the DC reading. If you measure AC but no DC, or high runaway spikes when you rev, its usually a regulator problem, as stand alone rectifiers usually open rather than short.

The pickup coil generates an electrical pulse when the magnets pass over it, which after being stepped up makes your spark. A separate (usually much larger) coil is used for lighting.

[Derekh1234]

ok thanks a bunch!! my dad said something about the rectifier being bad, so i guess his guess was on the rite track. Do any of you guys have any idea where i could pick up a random part like the rectifier?
Thanks
Derek

[Derekh1234]

thanks for all your help. Finally got it fixed!