This has to do with my Sportster project. The problem is, I'm pretty much an idiot when it comes to this stuff. Don't know what I'm doing.

The ignition is handled separately by the magneto, which is entirely isolated from any of this.

What I need is to generate power for the headlight/taillight/stoplight and the speedometer.

My original plan was to do this:


And that's not working.

Did some basic multimeter testing last night. What I discovered is that I'm getting good AC voltage coming out of the stator. (22VAC or so at idle, 35VAC or so when I rev the throttle). So I think the stator is doing what it should.

But I'm getting essentially zero DC Volts out of the voltage regulator. (It reads like 0.2V or so).

That said, I do get a strong flicker on the speedometer backlights when I'm kicking it, so something is happening. Or at least it was. I disconnected the speedo for now in case I was in the process of burning it out.

I assume the voltage regulator is designed to ground through it's body as it's bolted to the frame.

Is this basic design any good?
Is it possible that my trouble is caused by the heavy layer of powedercoat preventing a good ground contact on the voltage regulator?
Should I fasten a ground wire to the regulator to ensure a solid connection?
Is it possible that I burned up my voltage regulator by running it without a good ground?

I've been reading stuff about guys running capacitors ("battery eliminators") when setting these things up, but those all seem to be older, generator bikes. Not the newer, alternator stuff.

Does it make sense to add a capacitor to this system to smooth things out?
If I do run a capacitor, do I want to run it in series ("Plan B") with the rest of the system, or in parallel ("Plan C")?



Any thoughts/comments/advice would be most helpful and welcome!

 

Yeah, I suggest you buy that gizmo that someone that figured out how to do that sells.

For experimentation purposes, put a 12V battery across your existing circuit, measure the voltage, start the bike, measure the voltage.

 

When you did your multi-meter testing, were there any other electrical users in your circuit? If not, I suspect the regulator is burning all electrical power to ground which causes your voltage to collapse to almost nothing.

*edit*
Ninjaad
But indeed, like Hess mentioned, put a user in your circuit and a battery would be an excellent candidate. Basically, a battery is a big *** capacitor

 

Plan C would be the way to wire the cap, but why don't you just replace your VR?

 

And yes, you need a good ground connection (if it has one). My VR doesn't even have a ground lead so I'm guessing it's chassis grounded through the metal bracket.

Try firming up the ground on the VR first, then retest voltage output from it.

 

I would put the battery where all the lights and other stuff is. Then uses a mini fuse block with different circuts for stuff like the head and tail lights and have the positive lead for that come riggt off the battery hot terminal as well. Its just a stripped down chop right?

 

Oh, and Plan B won't work at all.

 

I remember when a bad ground for the voltage regulator would actually drive the DC voltage up to as far as 18v. The fact that that your only reading .2 volts would definitely indicate a bad regulator... Sounds like the rectifier is shot. Your rotor and stator sound right at both idle and 2000 rpm plus... 35vac is perfect....

 

The charging system is basically an alternator...alternators need battery voltage to "excite" them to get them to charge...there are ways to get the alternator to "self excite" but they don't work well under 2500 rpm...so even if you get this to work...not going to have much headlight at idle...the easiest way out is to hide a small battery somewhere.

 

I think it's the other way around... The battery is needed to store the voltage that is supplied by the ac alternator via the convertor of the voltage regulator. The system runs off the battery not the ac alternator.... If that was the case the only thing we need the battery for is the starter....