So in other words, it's probably best to leave the stock guy alone and work on shoehorning coils for a separate 12v circuit in there, right?
White wire, headlight, elctrical stuff
- Thread starter Creative Engineering
- Start date
It really depends on how hard it is to get to the common ground points for the windings, Jason.
It's not feasible to isolate the ignition winding. Number 1, it has to fire the plug, which is grounded. It would be nice to isolate that but since the CDI is potted, we can't go in to add a separate ground for the input.
If we isolate the ground for the lights, all the lights would have to be insulated. That's fine for purpose built lights, but eliminates the standard one wire connection bicycle lights.
I can't remember all the transformer theory I learned in the 60's. I don't know how much effect the mod I'm thinking of will affect the existing windings.
I've checked the ends of the mag pickup. There is plenty of flux available for another winding. I'm gonna take a ] shaped iron bar to connect the ends of the legs. The short legs of the ] should move the long side back far enough to wind a few hundred turns of wire on it.
Then remove the pickup, remove the varnish from the ends of the legs and stick it to the pickup with a drop of superglue on each leg for testing. If it works then pull it back out to glue it properly.
If that works (voltage and current wise) we're still left with interaction with the ignition windings if we ground one side.
A one-to one isolation transformer may or may not solve the interaction.
I'm going to order another magneto. I don't know if I'll be able to keep all the smoke in mine.
Where are all the Double Eagles on this forum?
Ted
It's not feasible to isolate the ignition winding. Number 1, it has to fire the plug, which is grounded. It would be nice to isolate that but since the CDI is potted, we can't go in to add a separate ground for the input.
If we isolate the ground for the lights, all the lights would have to be insulated. That's fine for purpose built lights, but eliminates the standard one wire connection bicycle lights.
I can't remember all the transformer theory I learned in the 60's. I don't know how much effect the mod I'm thinking of will affect the existing windings.
I've checked the ends of the mag pickup. There is plenty of flux available for another winding. I'm gonna take a ] shaped iron bar to connect the ends of the legs. The short legs of the ] should move the long side back far enough to wind a few hundred turns of wire on it.
Then remove the pickup, remove the varnish from the ends of the legs and stick it to the pickup with a drop of superglue on each leg for testing. If it works then pull it back out to glue it properly.
If that works (voltage and current wise) we're still left with interaction with the ignition windings if we ground one side.
A one-to one isolation transformer may or may not solve the interaction.
I'm going to order another magneto. I don't know if I'll be able to keep all the smoke in mine.
Where are all the Double Eagles on this forum?
Ted
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Seems to me that the simplest way to go would be to have the 12v power coils completely isolated from the ignition. That leaves you with the least chance of causing a bad interaction. 1 wire bicycle lights, what are those, lol. The point is to run some REAL lights.
If you can run a power wire, you can run a ground right along with it.
If you can run a power wire, you can run a ground right along with it.
Ted: can you determine the output votage of the secondary coil, the blue wire, or make an educated guess?
I had deducted 72V just based on the number of windings and using the other coil as a reference based on 300 turns @ 6V. If it's working as a true automotive type coil, (coil in coil), the voltage will be much higher.
Jim
I had deducted 72V just based on the number of windings and using the other coil as a reference based on 300 turns @ 6V. If it's working as a true automotive type coil, (coil in coil), the voltage will be much higher.
Jim
Yes, time for some experiments...smoke test...wheee!
Seriously, we should try a few things just based on theory and see if the whole thing is doable within a reasonable cost envelope.
There must be enough room in the mag area to add another coil that would power a lamp larger than a typical bike light. As Jason was saying, I also want a "real" headlight. They don't draw that much...maybe 5-7 Amps?
If you or Jason need any hard parts machined to carry out your ideas let me know...I'll be glad to do it.
I've got the rest of December off, (meaning I don't anticipate any work comming in). So I will be looking at new bike products.
Jim
It doesn't work like an ignition coil. The ignition coil depends on a voltage on the primary (low number of turns in this case) building a flux and then when the voltage is suddenly removed the collapsing flux through the windings of the secondary (high number of turns) inducing a very high voltage.
The coils on the pickup have relatively slow rising and falling voltages. Slow compared to a points coil; fast compared to 110VAC.
Our ignition coil, I think, is in the CDI. The output transformer in the CDI steps up our ~72V to 20,000 or so volts. It has a much more favorable step-up ratio to deal with.
I think right now our best bet is to leave the white wire alone and try adding an auxiliary coil. Then we can play with injecting a voltage in the white wire to stroke the CDI. I'd be surprised if we could go very high without smoking it.
I couldn't get to town today so the scope is still just looking at me like it wants to go outside for a walk.
Ted
O.K. I'm not totally losing it...I was just thinking for a moment that the magnetic pulse from the stator was creating the same type effect as a typical automotive type coil. Impossible: as both coils are being energized by the stator simultaneously.It doesn't work like an ignition coil. The ignition coil depends on a voltage on the primary (low number of turns in this case) building a flux and then when the voltage is suddenly removed the collapsing flux through the windings of the secondary (high number of turns) inducing a very high voltage.
The coils on the pickup have relatively slow rising and falling voltages. Slow compared to a points coil; fast compared to 110VAC.
Our ignition coil, I think, is in the CDI. The output transformer in the CDI steps up our ~72V to 20,000 or so volts. It has a much more favorable step-up ratio to deal with.
I think right now our best bet is to leave the white wire alone and try adding an auxiliary coil. Then we can play with injecting a voltage in the white wire to stroke the CDI. I'd be surprised if we could go very high without smoking it.
I couldn't get to town today so the scope is still just looking at me like it wants to go outside for a walk.
Ted
Jim
I would like to know "exactly" how this set-up works. I've never seen this configuration on an engine before...Coil in Coil, (in the mag),...It may have been nothing more than a space, cost savings, design that is meaningless in any other respect.
I know I've read other posts that describe this engine as "4-cycling" or firing every other time...I prefer to call it a miss-fire...but I wonder if this, (ignition), set-up has a built in rev-limiter; whether intentional or not that is causing upper RPM missfiring? It may be built into the CDI.
Jim
I know I've read other posts that describe this engine as "4-cycling" or firing every other time...I prefer to call it a miss-fire...but I wonder if this, (ignition), set-up has a built in rev-limiter; whether intentional or not that is causing upper RPM missfiring? It may be built into the CDI.
Jim
We'll sure give it a try...as you know for the most part anything "can" be done it's just a matter of cost. I'm hoping the outcome will be an inexpensive replacement coil assembly that can simply be bolted on for added elctrical power.
l.e.d.'s are not power hogs, so you should be fine! I really don't know how much current you can tap from the White wire before there is a problem with the ignition. Apparently it's not much!
Jim
I made billet headlight and tail light for my winter build so I am banking on you guys getting this white wire thing figured out. I am hoping I can use them for more than just looks.
Keep up the good work.
John
Thats correct on the anything can be done. My first Machine shop instructor(about 40 years ago) always said "The impossible just takes a little longer"
John
Norman is using very low wattage 6v bulbs. You can pull a couple watts off the white wire before you start running into issues.
I have a feeling that this coil configuration was mainly for space and not necessarily for any special properties with the ignition. We ought to be able to get 12w or so out of that white wire coil with no issues, but I think because of the coil configuration, we can't.
Seeing as a typical automotive fog light is around 55w, we'd probably want to be able to pull 65-75w after all is said and done. In other words, 5-7 amps. A coil using 20-22ga wire should do the trick. I doubt you'd be able to fit enough turns of 20ga in one place though...may have to use multiple smaller coils. A stronger rotor would definitely help though, and would require less turns. May create too much voltage in the ignition coil though.
I wish I could do more work on this than just speculation and design right now. Unfortunately I'm 2 weeks away from even being able to order the rest of the parts I need to get my bike back together.
I'd like to know just what voltage our CDI puts out. Just going by the weight, there's not much to it. It's super light compared to a real coil.
Are you thinking of an early Briggs or Kohler coil, or an automotive coil? Those have a heavy core and are oil filled to dissipate heat. The auto coils are designed to fire 8 times more often that this one.
Another thing that allows the use of a light coil is the shortness of the firing pulse to the primary of the output coil. The total average current is much less. The heavy coils have 12V saturation on them unless they're firing.
OT: Issues other than this have arisen. I have to go to Lake Sam Rayburn, pick up paperwork for a vehicle, come back home, register it and take paperwork back to the lake. A day or two at the least.
Another thing. I have ins. with the lizard on my '93 Jimmy. To add full coverage on another 2001 vehicle will bump my payments to $960/6 mo. With just liability for the El Do and the Jimmy it will bump it $141. What to do?
Progressive wants $1409.00. So much for the TV adds. I've wondered about ins. that comes in a box. Now I know.
Ted
Another thing that allows the use of a light coil is the shortness of the firing pulse to the primary of the output coil. The total average current is much less. The heavy coils have 12V saturation on them unless they're firing.
OT: Issues other than this have arisen. I have to go to Lake Sam Rayburn, pick up paperwork for a vehicle, come back home, register it and take paperwork back to the lake. A day or two at the least.
Another thing. I have ins. with the lizard on my '93 Jimmy. To add full coverage on another 2001 vehicle will bump my payments to $960/6 mo.
With just liability for the El Do and the Jimmy it will bump it $141. What to do? Progressive wants $1409.00.
So much for the TV adds. I've wondered about ins. that comes in a box. Now I know.Ted
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I guess I am thinking of an automotive type of coil. But, if you even look at a coil from a 50cc scooter, it is more significant than ours. The coil alone is bigger than our cdi/coil combo.
33cc/43cc/49cc Ignition Coil.
As for insurance...I pay around $960/6 for just one car. Luckily it should go down next month.
33cc/43cc/49cc Ignition Coil.
As for insurance...I pay around $960/6 for just one car. Luckily it should go down next month.