Roll Your Own CDI

[Ratchetbirds]

I had that happen once before also. No messages for 3 weeks.

For Sinistar: I don't have any extra tested units and do not plan to sell any. I DO have lots of extra components, all tested now. I could sell you the components for a very reasonable price if you want to try to make a CDI yourself. It was one of the easiest projects I have ever done. I have the caps, resistors, diodes, and SCR's. I do not know electronics very well, but the drawings and photo's here made it a simple job. Soldering electronic components on the other hand does take a little practice....but just a little. Check youtube for videos on that.

 

[Sinistar]

thank you for your replys I'm studying this stuff as much as I can in free time from life. I found a old stereo at work and the thing has 1.0uf cap or resistors I think they look round and they are orange but have 2.0uf on them and there are two of them. heres a good question for anyone that knows is there any youtube of a cdi being described anybody know of or have the link to post.


CHEERS

 

[MonkeySeller808]

I made my Cdi and it works great! I left the heat sink exposed out of my box for cooling and I can tell you.... Dont touch it when your engine is running lol. You will feel it shocking you a little.
Thank you

 

[rohmell]

That's great!
Can you post some pics?
What kind of ignition coil did you use?
I am sure that others would like to see your CDI build.

 

[Ratchetbirds]

Heya Rohmell, My CDI is deffinately not hot enough for 12 degree F weather <LOL>. Poor thing would not pop this morning no matter what. Got home from work at 24 degrees and started right up, so I know for sure it is the cold. Brought her inside for the night and can ride tomorrow no matter the temp or if it snows tonight. She started last friday at 18 degrees but wasn't super happy about it. I am having so much fun <G>. Just some cold weather info on the CDI for everyone to be aware of.

 

[Sinistar]

Yes pictures pictures people. I'm going tomm to pickup my components for this SIMPLE CDI um I'm using a rising field coil from a 85 TOYOTA and the wire also it gave a 3.0 ohm on the low ohm scale If i remember correctly I mounted it also in a way towards the front and have to take a picture to show it off because I'm also using the top side kinda for the CDI box mount plate. I have a camera borrowed of course but the batteries take a long time to charge and I have to be wise with my shooting them.
I did test to see if the CDI I made from spare parts would work but no luck and I was even using a new B6HS but I didn't use the right caps (tey may have been resistors I think).

Important question I need to know. Has anyone that uses a external coil and had it exposed to the elements(i.e. not covered at all + - wires, and plug wire exposed but plugged up) and had it gotten wet? Did you have problems since it got wet?

These coils usually are under a hood of a car and don't get directly wet but are exposed to temps and maybe some condensation during their lifespan.

Thank you.

Pictures soon.

 

[Ratchetbirds]

It can handle the moisture, I am sure. My pit bike coil works fine in the rain and snow. It's the CDI box and magneto box you really need to keep the moisture from. Those are the killers. Car coils work great in all weather as long as no water gets into the high tension lead output ( where the plug wire plugs into the coil at). Be sure to use the rubber cap over the wire that comes out of the coil. Easy peasy. You could even mount it upside down if you are really worried about it. Also very glad to see you making this CDI. Join our exclusive club and roll your own <G>.

 

[Ratchetbirds]

I made my Cdi and it works great! I left the heat sink exposed out of my box for cooling and I can tell you.... Dont touch it when your engine is running lol. You will feel it shocking you a little.
Thank you

Been there, hated it. I didn't realize the heat sink was going to be electrically hot at all. Caught that inner thigh and instantly got my attention. Provided lotsa humor for the wife, just what she needs. Hehehe.

 

[rohmell]

The SCR is most likely the culprit, causing problems in cold weather.

Semiconductor devices are most ofter specified for use in 'commercial' applications, and the temperature range for this is 0 - 70 degrees C ( 32 - 158 degrees F).

12 degrees F is of course outside this range, and the SCR's operation is not guaranteed at these temperatures. The problem lies in the gate triggering voltage and hold currents, timing, leakage currents, etc.

The diodes would most likely still be operational.
.
A part rated for 'industrial' use is rated for use between -40 - 85 degrees C (-40 - 185 degrees F) Yes, -40 is the same, C or F.

So, if you REALLY want to ride in those extreme temperatures, replace your semiconductor devices with ones that have an 'industrial' temperature rating.

A can of 'freeze spray' can help determine if the SCR is acting up at low temperatures.

If you have no freeze spray, hold a can of 'dust off" compressed air upside down when spraying.

 

[Sinistar]

Thanks Rohmell I didn't know that stuff about the industrial ratings. I got all my components except the caps. Theres another place in town I called today that has one cap at the warehouse it's a 2.0 uf 440v he said I'm going to pick it up tomm. I'm gonna try and take some more important photos tonight If the batteries hold up to get them taken and I am eager to post them. Especially a photo of a flyback board that I want you to see and tell me what it could maybe be.

What's the differance in a Isolated and a non-isolated tabbed SCR? Mine is isolated I think I will check that.

Thank you all so much,

 

[Sinistar]

heres my first unsuccessful attempt @ a working CDI. I think that I might have cooked the SCR on removal from the old board. I havent given up yet still getting components together.

 

[Sinistar]

heres my components is this cap ok to use?

I found these interesting circuits. any Ideas as to if they can be used or modified some to work? or just what they are

I have much more spare stuff but those above looked very interesting.

 

[Ratchetbirds]

Heya Rohmell, check this out.

I just opened my winter sealed CDI to change the SCR to an industrial rated and look at my 82 ohm resistor. There was no moisture anywhere at all in the CDI or the mag case. Would you recommend a higher wattage resistor? At most I have about 5 hours on this CDI.



.

 

[rohmell]

Yes, it looks like a higher wattage resistor is needed in this design.

Once the warmer weather comes back around to New York, I will be back to working on the Chinese CDI clone, which seems to be much simpler, and doesn't seem to have these kinds of problems.

 

[Sinistar]

I'm So excited I got my bike running again. I had a bad magneto was wound back in 2009. My new one is 2011. and my CDI was to blame also. I'm getting the fine tuning to get the ride feel better. I'm also going to try this circuit building business tinkering.

Any ideas as to what the flyback circuit i posted could be I can take more.

Cheers,

Will post my ride n pics this evening possibly.

 

[Ratchetbirds]

I'm So excited I got my bike running again. I had a bad magneto was wound back in 2009. My new one is 2011. and my CDI was to blame also. I'm getting the fine tuning to get the ride feel better. I'm also going to try this circuit building business tinkering.


This is all great news. Good for you for taking the time to try. Your successes are ours as well, so keep us informed and always remember pictures.

 

[rohmell]

CDI UPDATE:
Warm weather is here again in NY, and it's time to revisit the ROLL YOUR OWN CDI thread.
Currently consulting with a(n) R&D firm to re-engineer the Chinese CDI module, and discussions are to have it on a PCB, mounted in a box, no potting material is to be used, so that all components can be easily seen and identified, and can be repaired by the end-user if needed.
We might be winding our own custom ignition coil, too.

 

[ivan H]

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Hi Rohmell & Rachetbirds, hows it going. On the last page of the thread "modified cdi & cr80 coil" is a scematic of the cdi I have been using that i derived from various posts by Jaguar & others about his cdi. It is hand written on a diary page, I asked Headtramau to post. Thanks Headtrauma. Maybe one of you guys could help & post it in a more easily read format for the punters, please. Thanks. Cheers

 

[rohmell]

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Hi Rohmell & Rachetbirds, hows it going. On the last page of the thread "modified cdi & cr80 coil" is a scematic of the cdi I have been using that i derived from various posts by Jaguar & others about his cdi. It is hand written on a diary page, I asked Headtramau to post. Thanks Headtrauma. Maybe one of you guys could help & post it in a more easily read format for the punters, please. Thanks. Cheers

Here is the original schematic, cleaned up the lines a little bit:


Here it is redrawn:

 

[ivan H]

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Thanks heaps Rohmell, thats great. I wish u all the best with the cdi/coil u are developing. Cheers