Lighting from our magneto white wire

I think ur right about the white wire Tom, if trying to run the light system directly off it. It will power a normal bicycle lamp but that is not good enough for these by far. If u use it to charge a battery tho, then run a decent incandecent lamp off the battery, things r much better, so long as ur night riding time is less than the battery's duration. I use a bridge rectifier (IIRC, I also used blocking diodes between the rectifier & battery) all made up with Schotky diodes, to charge a 6 volt, 4.5 A/h SLA battery & run a 26 watt 6 volt halogen lamp off it. It doesnt give motor cycle type light, but it gives ample for the small amounr of night riding I do. The good thing about this is I dont have to charge the battery so long as I do daytime riding, it charges constantly when the motor is running & the white wire simply doesnt put out enough current to cook a battery without a regulator. BTW KCVale, $75 for the light & battery, not even close to that much. The whole system didnt cost $30. The 4.5A/h SLA 6V battery cost $17 off the shelf at the local electronics outlet so buying online would be even less. The lamp shell is a small automotive driving light from an auto wreckers that I put the 6V 26W bulb in, & 6 diodes, so nowhere near $75. Problems with it dragging down the magneto, nil. My homemade CDI copes with it very well. I know that the white wire wont run the light or cope with a very run down battery. Like I said, I do limited night riding but I know that any night of the week I can switch on that 26 watt halogen light for half an hour to ride home & it wont drain the battery. In the morning I can start it without a problem & no performance loss while riding. To me thats worth the money it cost to set it up. I know its limitations & dont try to exceed them. Obviously using the light til the battery is low will cause magneto issues, but a 1/2 hour ride home using it & being able to see well enough definitely doesnt. Cheers.trlrl.
 
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I'm hoping not to have to resort to using a battery. Battery's suitable for bicycles are expensive, and have relatively short lives. My moped doesn't have a battery, so I don't see why a motor bicycle should need one.

Based on my very limited testing so far, I'm pretty sure the white wire can easily support up to 1 amp. Even if that's as good as it gets it should be more than enough.

I don't think you guys are up to speed on Cree technology. It's changing faster than cell phones. This picture is of a same identical 20w Cree bulb that I'm using in my moped right now. This bulb draws 0.2 amps, and puts out about 600 lumens. The claim was 800 but I think they're lying.

Dig it, this is what a 20w Cree that draws 0.2 amps looks like.



I have two 50w Cree bulbs on order now. I expect it to draw around 0.8 amp or less.
 
biknut said:
I'm hoping not to have to resort to using a battery. Battery's suitable for bicycles are expensive, and have relatively short lives. My moped doesn't have a battery, so I don't see why a motor bicycle should need one.
I have two 50w Cree bulbs on order now. I expect it to draw around 0.8 amp or less.
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Night Light all comes down to what you can see in front of you and have time to react to at your given speed.

Main roads with street lights are usually pretty comfortable to ride on but I know first hand on many occasions riding the canal banks in dead dark with a crap light and so scared about 10MPH is all I would run as as a little to one side put me in a fence, and little the other way in the canal.
 
Turns out after testing, my rectifier is completely operational. Also the faulty magneto coil was able to be repaired. I'm pretty sure that coil was going bad on it's own. It's failure was in the common place where a lot of people have reported a bad solder joint. Where the coil wire is soldered to the frame.

My working theory right now is my Cree bulb failed, because the magneto coil was intermittently shorting out, and producing rapidly varying voltage, which made the micro processor in the bulb go nuts. Inside the bulb is a micro processor, a transformer, and 2 very rapid switching relays. All my top scientists agree that what probably happened is the micro processor more than likely became confused, and switched both relays on at the same time, which blew the micro processor.
 
KCvale said:
Night Light all comes down to what you can see in front of you and have time to react to at your given speed.

Main roads with street lights are usually pretty comfortable to ride on but I know first hand on many occasions riding the canal banks in dead dark with a crap light and so scared about 10MPH is all I would run as as a little to one side put me in a fence, and little the other way in the canal.
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I realize that off roading in the dark requires 10 bijillion lumens to see where you're going, but that's not what I'm trying to accomplish. All my riding is in concrete jungle. What I would like to do is be able to push about 800 to 1000 lumens out of a 25 to 50 watt Cree using only the white wire with no battery, and be able to sustain that kind of brightness indefinitely as long as the engine is running.

Keep in mind a Cree bulb rated at 50 watt doesn't really use 50 watts of power, only a tiny fraction of that. It's just that the bulb puts out the equivalent of 50 watts of light
 
Hi biknut, just checking in to see how u r progressing with the lighting. Hopefully u've had some success. My understanding is that the white wire output around 0.3A, tho that is only my understanding & could well be wrong. 6 volts @ 0.3A equates to about 1.8 watts of useable power. Whether or not its dragging down the magneto's stator output at this consumption I dont know. Cheers
 
Im watching this because Im trying to learn this stuff Id like to set up something like nut but I might set it up with a 6v deepcycle batt if one is made because sometimes I like to go for long night rides
 
biknut said:
What I would like to do is be able to push about 800 to 1000 lumens out of a 25 to 50 watt Cree using only the white wire with no battery, and be able to sustain that kind of brightness indefinitely as long as the engine is running.
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Best of luck with that as you'll never pull 25W from that white magento wire at idle and maybe not even WOT, and it's varying AC not the steady DC voltage and varying current to determine brightness.
 
KCvale said:
Best of luck with that as you'll never pull 25W from that white magento wire at idle and maybe not even WOT, and it's varying AC not the steady DC voltage and varying current to determine brightness.
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You don't need 25w. Right now I have a "50w" Cree on my moped that draws a little less than 7w. If 7w is too much a "25w" Cree bulb only draws 5w.

The problem is we're going to need a voltage regulator to keep the voltage constant at idle. A 5v regulator needs 7v to operate, and all I see at higher speed is 6v.

Another even bigger problem I'm having is low motivation right now, because my moped now has a 50w cree that's bright as heck, and I'm all hyped up about buying an electric bike.
 
Lately I'm thinking the better (easier) thing to do is buy a 3 cell 4.5v factory made Cree bicycle headlight, and modify it to run off the white wire. That might work with just my rectifier not needing to worry about a regulator since the design voltage will be a lot closer to what the white wire puts out.
 
I did something very similar about 2 years ago and it works fine. I was powering 3X 18LED mini-flashlights, only difference is I put rechargeable batteries inside the flashlights so there was some power reserve. It worked great, I was planning on moving over to a high output LED, meanwhile I got an old (free) scooter running and started riding it at night instead and never got around to it. I never had any problems starting the motor or any negative effects on performance at all from using power from the white wire (once rectified and filtered). When I added the rechargeable batteries I had to add blocking diodes to prevent the rapid draining of the batteries when I hit the kill switch....

You can also just use 4 diodes to make the bridge rectifier instead of using the bulky bridge rectifier package, the diodes will take up much less space folded around the capacitor. I put rechargeable batteries inside two flashlights and the rectifier/filter circuit inside the third flashlight. I never had a problem with the diodes failing without the heat dissipation of the bridge rectifier package....
 
Hi, if u make the bridge up urself, use Schotky diodes instead of regular diodes as they get a lower voltage drop across them. Its not a great difference but when dealing with the small voltage output from the white wire, minimising loss is a good idea. As biknut said earlier, regulator's require a few volts higher input than the output voltage. Another thing with regulator's, non switching types are always bleeding some voltage to ground which u also want to avoid, so if u want a regulator try finding a switching type. I also used blocking diodes (again, Schotky types) between my rectifier & battery. All up I used 6 x 40V/1A Schotky diodes. I didnt use an electrolytic filter cap, just straight to the 6V, 4.5A/h SLA battery via the 2 blocking diodes. I personally think its the best way to make use of the white wire. Cheers
 
ivan H said:
Hi, if u make the bridge up urself, use Schotky diodes instead of regular diodes as they get a lower voltage drop across them. Its not a great difference but when dealing with the small voltage output from the white wire, minimising loss is a good idea. As biknut said earlier, regulator's require a few volts higher input than the output voltage. Another thing with regulator's, non switching types are always bleeding some voltage to ground which u also want to avoid, so if u want a regulator try finding a switching type. I also used blocking diodes (again, Schotky types) between my rectifier & battery. All up I used 6 x 40V/1A Schotky diodes. I didnt use an electrolytic filter cap, just straight to the 6V, 4.5A/h SLA battery via the 2 blocking diodes. I personally think its the best way to make use of the white wire. Cheers
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ivan, do you think a small battery of this type would eliminate the need for a voltage regulator? I didn't really want a battery, but that might be a lot easier.
 
Good point about the schotky diodes. I used normal ones because they were cheaper, but yeah, where every volt counts like this, they would be better.
 
Hi Biknut, yes, that is right, so long as u dont use too small a battery where the charge current could exceed the battery's charge current limit, but generally the white wire's output current is si low as to only be trickle charging. With something like mine, at 6V 4.5A/h, which is only a small battery (physically about 3"x 2 1/4" x 1 1/2"), there is absolutely no chance of ever cooking it & ripple current isnt a concern. If I was using a smaller battery or rechargeable pac I would maybe throw in an electrolytic to take care of that (ripple current).
Mine has a 26 watt halogen running off the battery, which is WAY more than the white wire can supply, so really, next time I do some night riding I should hook a multimeter in there b4 the rectifier set to read AC mA & throw it in my pocket & use the min/max hold feature so that we can get an accurate figure of exactly how much current our white wire can supply.
Oh, the Schottky (I spelled it wrong b4) diodes that I used are 1N5819 types, & cost the same as an 1N4007. They are a 1A diode but only rated for about 40V. I used 4 for the bridge (of course) & 2 as blocking diodes. Hope this all helps. Cheers
zpt
 
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I am personally interested in the results of this (old) post. I have plenty of knowledge and equipment to make a full on light that will work with the white wire...I just am wondering if it is worth it.
 
ratman150 said:
I am personally interested in the results of this (old) post. I have plenty of knowledge and equipment to make a full on light that will work with the white wire...I just am wondering if it is worth it.
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The bottom line is simple, do you want full engine power to the back wheel or willing to sacrifice some to generate power too?

Have you ever seen a simple home gas powered generator in operation?
It will idle just dandy with no load (no light on) but as soon as you draw power (turn your lights on) the engine has to rev up to make the power.

That is because there is a LOT of engine drag to create the magnetic field that the generator/magnetos convert to electricity, kind of like turning your air conditioner on in your car, a gas sucking performance drag.

On a 2-stroke 'white wire' light system your idle will drop to stall like sitting at a light or stop sign with the light on or keep the engine revved.

You can adjust the idle up, but then when the light is off your idle revs like crazy.

If you have some crazy power 2-stroke and the ability to tap the 'white wire' to a trickle charge to a battery so it charged when you ride without light to handle your great lighting needs at night best I can tell you from my experience is forget the white wire as 'free power', it's not.

So much that Skyhawk changed their magneto for a fatter coil wrapping for the blue and removed the white wire winds and connection completly.
Nice new mag by the way ;-}

Just check Amazon for 1200 Lumen lights and you will find a bunch of bicycle bike light kits that will blow you away. for $20-$35 delivered with mount, battery pack and charger.

http://www.amazon.com/s/ref=nb_sb_s...0 lumen bike light&sprefix=1200+,sporting,263

Personally I like the 3-mode lights.

High and low power intense solid beam for night, and the intense strobe for daytime because nothing says 'PAY ATTENTION TO ME' in daylight than a flashing light and no BS here, I have seen 4 people in cars that would have pulled out or across my path 4 times now if I didn't have my daytime strobe, so much so that I keep a 'shop light' here to put on test ride bikes to go with the helmet for my test riders.

Just some first hand experience, take it or leave it ;-}
 
Couldn't agree more. I've said this before and I'll repeat it again. Having a light is not enough. First, you need to be seen. But you also need to be able to see. Taping a flashlight to your handlebars, or clamping it, will not give you ample light to ride safely at night. I want to know what's out in front of me. You should too.
Strobes are good and so are flashing red rear lights but a headlight needs to show you the way.
The white wire will never provide you with enough light, or enough power to charge an adequate battery. Cap it or remove it and look for alternatives for you electrical energy needs.

Tom
 
So, I've read this thread a hundred times by now. I guess I don't understand the rectifier. For a lot of miles and two seasons I've been running my brake and running lights off of the white wire through a single diode that I had extra from a tractor magneto project. It too only used one diode to charge the battery. I run it to my 6v battery. My battery has a switch to take it out of the system if needed. All my led lights can run without the battery as well. I have no problems charging the battery, Usually running above 7v, in fact I need to hookup my headlight to it to get more drain to prevent overcharging on long high speed trips, but i haven't had any issues yet. I've never noticed any lack of spark in any condition. I guess I just don't see what the fear of the white wire is, and why it has to be so complicated when its not.
Edit for clarity: when my battery is not in the circuit, they do strobe at idle a bit.


I added a diagram, as you can see my lights are happy with this arrangement. I'll lookup what diodes I bought, but they were 5 for $1 on the bay some years ago. I used them on a briggs twin tractor circa 91? all of my lights are led.

Also It would be smart to add a fuse.
 
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turnofftheradio said:
I guess I don't understand the rectifier.
I've been running my brake and stop lights off of the white wire through a single diode to charge the battery.
I run it to my 6v battery. My battery has a switch to take it out of the system if needed. All my led lights can run without the battery as well.
I guess I just don't see what the fear of the white wire is, and why it has to be so complicated when its not.
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A single diode simply clips off the negative ~7V part of the magnetos AC single so you are only drawing half the potential thus only half the power loss for generating power from the engine.

A full wave 4 diode rectifier turns that negative pulse to positive so you get both sides of it, all AC power supplies and even those little brink chargers you use for nay low voltage use this.

In short a pulsed trickle charge to you battery so not a constant drain and why you don't feel it so much.

Our DON'T USE THE WHITE WIRE stance is simple.
It takes power to use and store power.
You can do it with your little 2-stroke gas/oil mix engine at the expense of riding power and gas mileage, or use your home AC and charger and store a weeks worth of power in a little Lithium Ion battery for less than a penny and let your engine put all it's power to your wheel 100% of the time.
 
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