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Converting AC for DC lighting while using Motogadget M-Unit

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I'm building a 2014 KTM 300 XCW street tracker and ran across a charging / lighting issue. I'd like to use a Hella headlight that uses DC power with an H3 55w bulb. This is currently wired off the DC output of the stator which as you may have guessed is where my charging issue comes from. 

 

I've read the DC output of the stator in this bike is 30W (sound right?). So with the headlight on the battery gets drained. 

I'm using a Motogadget M-Unit controller for all the signal inputs and outputs. 

The wiring currently looks like this:2CECA50D-0AF7-4CAF-BD32-9ACF55289168.jpeg.4f7551149ade7b3f3f54f307cf706ef3.jpeg

 

These are my theoried solutions. Let me know which aren't possible:

1. Wire Yellow AC wire to rectifier and send DC output to stock regulator via White input:

04370477-494E-4629-AD70-B5ACF31E950B.jpeg.f9bcf4f48e6d1b310644292b02e60fda.jpeg

 

2. Replace stock regulator with regulator/rectifier. Can you send DC into a R/R just to regulate it?

 

 

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Everything coming from stator ,    ac voltage ......  rectifier changes it to dc......regulator controls voltage output ....there is a converter that will up the voltage ...   chect the motorcycle headlight bulbs on EBAY .......

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15 hours ago, Mucci said:

I'm building a 2014 KTM 300 XCW street tracker and ran across a charging / lighting issue. I'd like to use a Hella headlight that uses DC power with an H3 55w bulb. This is currently wired off the DC output of the stator which as you may have guessed is where my charging issue comes from. 

 

I've read the DC output of the stator in this bike is 30W (sound right?). So with the headlight on the battery gets drained. 

I'm using a Motogadget M-Unit controller for all the signal inputs and outputs. 

The wiring currently looks like this:2CECA50D-0AF7-4CAF-BD32-9ACF55289168.jpeg.4f7551149ade7b3f3f54f307cf706ef3.jpeg

 

These are my theoried solutions. Let me know which aren't possible:

1. Wire Yellow AC wire to rectifier and send DC output to stock regulator via White input:

04370477-494E-4629-AD70-B5ACF31E950B.jpeg.f9bcf4f48e6d1b310644292b02e60fda.jpeg

 

2. Replace stock regulator with regulator/rectifier. Can you send DC into a R/R just to regulate it?

 

 

If the headlight is an incandescent type, it doesn't care if it gets ac or DC. It may be easier to use the controller to switch relays, and run ac...

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16 minutes ago, RichBaker said:

If the headlight is an incandescent type, it doesn't care if it gets ac or DC. It may be easier to use the controller to switch relays, and run ac...

Oh really? Does a Halogen bulb qualify as incandescent?

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4 minutes ago, Mucci said:

Oh really? Does a Halogen bulb qualify as incandescent?

Yep...

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23 hours ago, RichBaker said:

Yep...

This. You will get a much better result running that bulb off AC power, conversion to DC loses some of your output power plus the AC output has more to begin with.  Only light that requires DC is LED and HID. 

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Ok, sounds like having the controller switch a relay for the headlight is a good way to go then. Thanks guys

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1 minute ago, Mucci said:

Ok, sounds like having the controller switch a relay for the headlight is a good way to go then. Thanks guys

Why a controller and a relay? Just run straight to the light with the AC reg inline, it'll turn on when you start the bike and won't affect your battery at all. 

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13 minutes ago, XR650RSMOKEDU said:

Why a controller and a relay? Just run straight to the light with the AC reg inline, it'll turn on when you start the bike and won't affect your battery at all. 

I was thinking so that you could use the light without the bike running then just remembered it's not connected to the battery...

Hmm, this is a street bike now so I guess I'll have to gauge how important that is. Worst case scenario the bike breaks down on the road at night and you become invisible. I guess I can still run the tail off battery though. 

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1 hour ago, Mucci said:

I was thinking so that you could use the light without the bike running then just remembered it's not connected to the battery...

Hmm, this is a street bike now so I guess I'll have to gauge how important that is. Worst case scenario the bike breaks down on the road at night and you become invisible. I guess I can still run the tail off battery though. 

Standard taillight bulb is an 1157 and only draws 5 watts or so, you can definitely run that off a switched DC power source, I'd switch to an LED tail light if you have the budget, they're around $65 from Baja Designs. I really like this setup on mine.

 

IMG_7957.JPG

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In Ca. for street,you have to run lites off battery by law so if you stall lites stay on & you might be visible & possibly not get ran over[good luck], one of the few common sense laws that we have.....

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