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Lighting and Electrical Things that go ZOT! Ignition components, batteries, lighting and accessories

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  #1  
Old 06-07-2013, 03:55 PM
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Default Lighting from our magneto white wire

I think I've invented a way to run lights from our china girl magneto white wire with no loss of performance, or dependability, and still have a very bright light.

Actually I designed this devise for my moped so I could use a Cree LED light bulb, but it should work fine on a china girl with any kind of LED rated for 6 vdc. The magneto white wire on our beloved china girls puts out something like 6 vac. That's what I've been told. I haven't actually got around to checking it yet, because I read on the forum years ago that it's useless to use the white wire for lighting because it robs to much performance to be worth it.

Mopeds also run their lights on ac volts, so I had to invent some kind of rectifier to use a Cree bulb. After a little trial and error I now have a good working and dependable rectifier. About the only difference between my moped's magneto, and a china girl magneto is, my moped puts out regulated 12vac, but our china girl's put out unregulated 6 vac. I don't think that will have a great effect on what we're trying to do, which is have lighting without using batteries all the time. The voltage being unregulated won't make much difference, because most LEDs tolerate a somewhat wide range of voltage, and since our magnetos are so weak I don't think we need to worry too much about blowing up our bulbs from too much voltage.

This rectifier can be duplicated for about $5.

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Old 06-07-2013, 03:56 PM
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Default Re: Lighting from our magneto white wire

I'll start working on putting one of these on Stunner soon, and let everyone know how it works out.
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Old 06-07-2013, 04:35 PM
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Default Re: Lighting from our magneto white wire

I forgot to mention what the advantage to this is. The advantage is that, by rectifying the voltage to dcv we can run high output, low wattage LED bulbs off our puny china girl magnetos without fear of hurting the windings, or losing any performance.
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Old 06-07-2013, 04:43 PM
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Default Re: Lighting from our magneto white wire

Nice, and hopefully with the capacitor there won't be any "flicker" they normally get. Let us know how it works out.
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Old 06-07-2013, 04:45 PM
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Default Re: Lighting from our magneto white wire

Why is there a jellyfish attached at the bottom?
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Old 06-07-2013, 04:52 PM
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Default Re: Lighting from our magneto white wire

Quote:
Originally Posted by killercanuck View Post
Nice, and hopefully with the capacitor there won't be any "flicker" they normally get. Let us know how it works out.
My moped headlight had very pronounced flicker at idle when running on acv with an incandescing bulb.

Now with this devise installed, after the motor is warmed up there's no difference in brightness from idle to full speed. I don't know if that will be the case or not on a china girl, because I don't really have any idea what the voltage is at idle.

That's not really that important to me though as long as I can have a bright headlight, and taillight when I'm riding.
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Old 06-07-2013, 05:58 PM
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Default Re: Lighting from our magneto white wire

This is how the devise looks. The white wires go to the ac.

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Old 06-08-2013, 11:47 PM
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Default Re: Lighting from our magneto white wire

You hook 'er up yet, BikNut?

Here's an iPhone charger circuit I've been meaning to test (assumes 10VAC)
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Old 06-09-2013, 12:48 AM
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Default Re: Lighting from our magneto white wire

I had a conversation tonight with the guy that designed my rectifier for my moped, and he said the same devise should work fine on a china girl. It will just depend on getting the right voltage LED bulb.
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Old 06-11-2013, 06:31 PM
ivan H ivan H is offline
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Hi Bikenut, I've been using a similar system to that shown in ur schematic 4 a long while now & it works fine. I made the recyifier using 4 x 40V/1A Schottky diodes as they have a lower voltage drop acrossthem than standard diodes, & used a 6V, 4.5A/h SLA battery in place of the capacitor, so it is charging whenever the motor is running. As u said, the mag doesnt output enough to nescessitate a regulator. As I do only limited night riding I used a small automotive driving light fitted with a 6V 26watt halogen bulb which gives ample light for long enough periods for my needs. I have done 20 minute to 1/2 hour rides with no problem, but I think the system u propose with a high efficiency Cree LED would give continuous quality lighting off the white wire. Add the battery & ur lights wouldnt even dim when at idle. Kiosk, to use a regulator, as u have noted, the regulator requires an input of a few volts more than the intended output. Use a voltage doubler type rectifier made up of 2 x 4700uf/35V electrolytics in series & two doides & it will give u the required voltage. Cheers

Last edited by ivan H; 06-11-2013 at 06:40 PM. Reason: Added text
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