The Blue,the Black and the Ugly (White)

[arceeguy]

Of course you are "pretty" sure,but are you absolutely 100% foolproof sure,because you actually checked......

You crack me up. Where do you think the output of the ignition coil is finding it way back to "ground"?

 

[duivendyk]

I have never said that the HT system has no ground connection,I speculated that a floating system on a bicycle could be safer without getting into this any further.You say that the common was connected to the motor casing,which seems reasonable allright,although not essential.It could might been connected to the frame some place else as per instructions.I trust measurements more than opinions.BTW,I have an electrostatic generator that produces copious sparks to my finger tips without the benefit of any ground return,tingles a bit,that's all.
Some readers are of the opinion that since the power output of the White wire is limited (at least for a lightbulb) a battery system has the same limitation .That is only true if the lights are on all the time. An efficient charger setup would permit energy storage and provide a stable dc output suitable for running LED's when needed.The battery can also be charged from the 120V.LED's can't be run on ac and may flicker on rectified ac unless big storage cap is used and require a fairly constant supply voltage,otherwise they are liable to burn up at high speed.

 

[Torques]

I apologize if this is getting off topic but I realize there are subscribers on this thread that have lots of electrical experience. I have a bicycle headlight that was powered by to aa cells. I have replaced the bulbs with the kpr 112's. I want to hook up the white wire to run these bulbs through the headlight. The headlight has an on/off switch and also a low beam position and a high beam position. My question is this: the little battery holder has two wires coming off of it. One goes to the back of the bulb and the other goes to the on/off switch. How can I hook up ONE wire from the white wire (engine) but going to two wires? Thanks in advance for anyone's help.

 

[Torques]

I could be wrong but shouldn't I connect the red wire (going to back of bulb) to the white wire (coming off bicycle motor magneto) and the black wire to ground somewhere (on the frame?

 

[duivendyk]

Connect the White wire to the side of the holder that has the on/off switch connected to it and put a 1Amp fuse in that wire close to the engine if possible, to play it safe (you don't want a short to ground on the white wire that can fry the generator coil).The other wire has to be connected to the black wire at the engine or the CDI.You could in principle also use a frame ground close to the light box instead.I prefer running ground connections to a common ground (the black wire at the engine.)

 

[Torques]

Is this diagram ok with you duivendyk?

 

[Torques]

Ok, I just changed everything, exactly as per the diagram above except I kept the kill switch grounded to the engine mounting bolt. The motor runs fine except I can quite figure out the headlight selections now. There two bulbs in the headlamp, an on/off switch and the three position beam selector. In the center position, the bulb in the center seems to be working ok, not sure how bright it is but will find out when I ride next time at night. When I move the three position select off center to the left (of center, the other bulb lights that's angled down, I guess for close up beam but the motor quits. When I move the selector to the right of center, nothing happens. I checked all wire connections are ok. I am using the krp 112 bulbs (6 volts, 2 of them). Maybe someone else on here is familar with those kind of light setups. Here is a picture of one. Maybe the bulb ratings aren't correct?

 

[duivendyk]

The kill switch is hooked up correctly and should function OK.No sign on diagram of what you did with white wire,did you hook it up per my instructions?.It looks to me that you have one bulb for "high",the center position,one for "low ,the left position,and the right one is the "off" position.If these bulbs are identical it doesn't make sense that the engine would quit.Are bulbs identical ?.Is it possible that in the left pos. both bulbs are connected?.That would kill the engine.Have you used this light before and are sure it's OK.Further tests:Take out the low beam bulb, run engine and put switch in center position,high beam light should be on and engine should keep running.Repeat with other bulb, should do the same. Now switch to left position.Does engine keep running? if not, there is a short to ground at the switch or at the bulb.If engine runs and high beam bulb remains "on", the switch turns both bulbs "on" in the left position! That's why engine quits, too much of a load
Next test: move bulb from high beam position to low beam position.Switch to center position bulb should not light.Switch to left pos. and try again, bulb should light and engine should keep running.This pretty much checks things out.