White wire lighting system

[Stan4d]

No. It will not kill the motor.

Hook the anode end of the diode to the white wire. Try shorting the cathode end (striped end) to ground. The motor keeps running. In order to kill the motor, you will have to short the white wire to ground before the diode. If you have a bad diode or the diode is hooked up backwards, the motor will die when the diode is shorted to ground. A correctly installed diode prevents you from interrupting the half of the wave form used by the CDI. You can safely use the other half of the rectified wave form to trickle charge a battery. Hook the cathode end (striped end) to the 6v battery (+).

Because a diode does not block current in both directions. It is like a one way valve. It allows current to flow from the coil into the battery. And it prevents current flowing from the battery into the coil.

Something is not adding up.....are you turning the diode around between these two statements? If it will not allow current to go to ground then how will it allow current to go to the battery.

Thank you for the rudimentary lesson. Apply it to your previous post.

 

[ibdennyak]

Stan4d....sounds like you don't understand AC power. The voltage goes from 0 to plus six volts and back to 0 and then minus 6 volts (or there abouts) and back to 0 yadda yadda yadda. The diode removes the 0 to minus 6 volts half of the wave and applies it to the battery. That part of the wave isn't used for the CDI. The CDI only uses the 0 to plus 6 volts part to begin with (probably another diode in the CDI). That way the battery won't affect the ignition portion of the system.

Oh carp.....now I confused myself. :-/

 

[Stan4d]

Stan4d....sounds like you don't understand AC power. The voltage goes from 0 to plus six volts and back to 0 and then minus 6 volts (or there abouts) and back to 0 yadda yadda yadda. The diode removes the 0 to minus 6 volts half of the wave and applies it to the battery. That part of the wave isn't used for the CDI. The CDI only uses the 0 to plus 6 volts part to begin with (probably another diode in the CDI). That way the battery won't affect the ignition portion of the system.

Oh carp.....now I confused myself. :-/

Exactly the reason I asked about a schematic......If I could visualize it I could understand better than talk of waving a diode around and attaching it to different parts of the bike. I am wondering if diode is the correct term......sound like a rectifier to me.

 

[ibdennyak]

Exactly....now you got it. A rectifier has several diodes connected in parallel. Half will have the stripe on one side, and the other half in the other direction. The plus half of the wave is filtered on one side and the minus on the other. The outputs are connected together giving DC.....kinda sorta. It will have an AC ripple on top of the DC value which can have filters to bleed off the ripple. You've just created a DC power supply...or battery charger.

I'm on a borrowed computer because mine has a nasty virus that Augi is going to try to fix for me....soon as I can get it to him, otherwise I could draw up a schematic for you. Maybe google bridge rectifier and it will show you how it works. Anyway, what we are describing on the thread is half of a rectifier using the minus half of the wave. The output on the white wire is going to be a very dirty DC (lots of ripple), but batteries are fairly forgiving. Now I got a headache.

 

[Ypedal]

Aha !!... so that's what the white wire does lol.. ( just built my first HT bike !!! and nothing in the instructions to tell me what it did !! )

motor RPM must also play a role in the output from the white wire, more rpm = higher voltage ?

Has anyone measured it at idle and at max rpm ?

 

[blckwlfny1]

A negative ground 1/2 wave rectifier has no affect on the "juice" to run properly. You can trickle charge a 6v battery, not 12v. It is the other half of the AC wave form that is needed by the CDI.

Sounds good to me!
Any suggestions on wher I can get a 6 volt negative ground. 1/2 wave rectifier?

 

[Stan4d]

You know, if you took a new maglite with the 3W LED bulb (3 cell) you could cut it down to about 4 inches long, seal up the back & power it from the white wire or a hub generator, or even a good scrubber generator.

I have a regulator circuit I found, and which has also been posted here, to recharge a 4-cell nicad battery pack. The regulator circuit could probably be housed inside the the shortened flashlight housing.

A 3W mag-light is awfully bright, and you can focus the beam for higher speed, or widen it out when you need to, just by turning the head.

Also - dr_clabo: Your diagram is a bit off. The two diodes on the right side are reverse polarity - they are pointing the wrong way. All diodes in a bridge rectifier must be 'pointing' towards positive. (ref the altered schematic, below) If it gets wired as is, the right side diodes will short out the white wire.

The idea is OK, with a few clarifications, and one reservation. First, you should use schotsky diodes - they are a low forward voltage drop, about half that of a standard silicon diode, and will thus reduce the .6 volt loss to .3 volt loss. Second - the lights/aux circuitry MUST be isolated from the frame ground, or you must isolate the engine from ground (a much tougher approach.) If a light is grounded by its mounting bracket to ground, it will bypass two of the diodes, and probably act to kill the motor, just like the kill switch.

Finally, the reservation - This approach, while it will work, will lead to reduced battery life. There's just no way to avoid overcharging the battery. (The way that the IC based battery chargers avoid this problem is by monitoring battery temperature with a thermistor. When the battery temperature starts rising faster than ambient temperature, then the battery is fully charged, and then they stop charging.)

Exactly....now you got it. A rectifier has several diodes connected in parallel. Half will have the stripe on one side, and the other half in the other direction. The plus half of the wave is filtered on one side and the minus on the other. The outputs are connected together giving DC.....kinda sorta. It will have an AC ripple on top of the DC value which can have filters to bleed off the ripple. You've just created a DC power supply...or battery charger.

I'm on a borrowed computer because mine has a nasty virus that Augi is going to try to fix for me....soon as I can get it to him, otherwise I could draw up a schematic for you. Maybe google bridge rectifier and it will show you how it works. Anyway, what we are describing on the thread is half of a rectifier using the minus half of the wave. The output on the white wire is going to be a very dirty DC (lots of ripple), but batteries are fairly forgiving. Now I got a headache.

Thanks Denny. But I had found what I was looking for after my post and moved the related posts to this thread. Lou has already posted the schematic (Correctly).

 

[Sgt. Howard]

Currently I have a 6 volt tank battery flashlight bulb and reflector (ace hardware, $5) running hot off the white on my HT... no switch- no effect on the motor and minimal effect on darkness. Does anybody use carbide? If so, how effective is that?

 

[Kevin McLendon]

I bought 2 - 12v 8ah 1280 batteries and just always leave one on a charger, just swap out when one gets weak. Powers a great motorcycle headlight, tail light, brake light and blinkers. I plan to change to a motorcycle lead acid when I install a radio with GPS