Roll Your Own CDI

Are You Going to Roll Your Own CDI?

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moosinatrix said:
ill go back and read your post, im still trying to wrap my head around all of this.

so the 2 i linked are they not gonna work for this application???
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Since I haven't used either of those SCR's I can't testify, but the specs seem to be appropriate. If you are ordering them, I suggest order a few different SCR's to try, cause their cheap enough.... I would also second the idea of using larger wattage resistors, mainly because the cost is insignificant as would be the difference in size, so there are no negatives there.....
 
kk TY for the input, once i get one made i want to make a second one and add a timing curve if you guys wouldnt mind helping me with that
 
hi i know im kinda late on this one but im relley intrested in making a cdi with 3 to 5 timing curves or even more if i can i can get my hands on parts and tools but not so good at the math and designing and setup of it with out a if someone could take the time to draw it and or help me draw it it would be very appreciated as my stock one just blew
 
i got the rohmell cdi working!!! Turnes out i had a few bad solders touching, and i neverput the capacitors into the circuit lol. But i got 6 miles on her when the chain tensioner broke, the nylon wheel fell off. I found a nice tensioner sprocket off a tricycle that uses similar setup. Matching pitch problem solved. But i got 17 mi. In amd i blew a resistor, was pretty high rpm. The engine seemed to hesitate throughout range, and limit out too early. This could be something to do with 18.5mm carb that i havent played with yet. But...bigger resistors a must for sure i didnt realize the were quarter watt when i bought em
 
Was it the 82omh resistor that blew? That's the one that has given problems to some members. I got my resistors from ebay, only 2$ shipped for five.
 
moosinatrix said:
i cantfind the 1/2w resistors at radio shack, and i double up my 1/4 watt without effecting resistance??
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Two same value resistors in parallel will double the power they can handle, however the resistance will be cut in half. So you would need to double the resistance if you want to parallel them, or you could put two parallel pairs of the same resistor in series to get back to the original resistance (using 4 of the original value resistors)
That said, you should check out Mouser.com, you can order any resistor you want in any wattage from them for like a nickle appiece...
 
rich4240 said:
hi i know im kinda late on this one but im relley intrested in making a cdi with 3 to 5 timing curves or even more if i can i can get my hands on parts and tools but not so good at the math and designing and setup of it with out a if someone could take the time to draw it and or help me draw it it would be very appreciated as my stock one just blew
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any help plese
 
A friend of mine stopped off at Fry electronics in Downers Grove Il. today with a shopping list he put together. I checked before hand to make sure the components were in stock and the prices. He called to inform me they wanted $6.99 for the SCR that was listed as $1.79 on the website. Needless to say, shopping cancelled!

Darren M.
 
rich4240 said:
any help plese
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Rich theres a schematic and partslist for the jaguar CDI which has 4 presets floating around the thread somewhere


ok my box died again, this time its not the resistor. i started up the bike, and it didnt want to idle so, you know, i play with the throttle a lil bit and then try to putt down the road and as soon as i get going and drop clutch it dies. and now i have no spark.

I replaced the resister thats giving me problems, and its still not working, tried another coil, still no go.

one of my diodes broke last night while i was rebuild the board and putting it in box, so i figure well a diode only protect from reverse currents, so i guess putting this other black diode thats bigger in wont hurt.... did i make an oopsy??

any thoughts/ ideas???
 
moosinatrix said:
Rich theres a schematic and partslist for the jaguar CDI which has 4 presets floating around the thread somewhere


ok my box died again, this time its not the resistor. i started up the bike, and it didnt want to idle so, you know, i play with the throttle a lil bit and then try to putt down the road and as soon as i get going and drop clutch it dies. and now i have no spark.

I replaced the resister thats giving me problems, and its still not working, tried another coil, still no go.

one of my diodes broke last night while i was rebuild the board and putting it in box, so i figure well a diode only protect from reverse currents, so i guess putting this other black diode thats bigger in wont hurt.... did i make an oopsy??

any thoughts/ ideas???
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When say it broke, how did it break and what type of diode did you put in to replace it? Did you make sure you put it in the right direction?

Down in my signature there is a link to Jag clone schematic and parts list.
 
dracothered said:
When say it broke, how did it break and what type of diode did you put in to replace it? Did you make sure you put it in the right direction?

Down in my signature there is a link to Jag clone schematic and parts list.
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IDK it just stopped making spark. yes the diode is the correct direction, and im not sure of the spec of it, i pulled it out of a computer power supply. but it is larger in size then the n4004s that i was using.
 
moosinatrix said:
IDK it just stopped making spark. yes the diode is the correct direction, and im not sure of the spec of it, i pulled it out of a computer power supply. but it is larger in size then the n4004s that i was using.
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All parts like diode can be damaged by to much heat when you put the solder iron to it. Also even if it is bigger in size it doesn't mean it is a good replacement. You are best off getting a known good part as a replacement or you could end up chasing ghosts and not get it working.
 
Diodes and resistors literally cost like a nickle, buy a dozen or two of each component and it's still only a couple bucks.... So why salvage parts? Specially when you don't know how to identify the parts and understand if they are compatible.... Try Mouser.com for parts, they have everything....
 
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hey guys im building a couple this time i got some different SCR's .

Part number: C106DG(click for link to where i bought it)

they are to-225 case, im not sure which pins are which on this SCR . i looked on mouser where i purchased, but it doesnt say ori cant find it can anyone please help
 
moosinatrix said:
hey guys im building a couple this time i got some different SCR's .

Part number: C106DG(click for link to where i bought it)

they are to-225 case, im not sure which pins are which on this SCR . i looked on mouser where i purchased, but it doesnt say ori cant find it can anyone please help
Click to expand...

The datasheet linked on that page for the device will give you the info you need... here's a direct link.
http://www.onsemi.com/pub_link/Collateral/C106-D.PDF

See "Marking Diagram and Pin Assignment" Illustration.
 
Hey Everyone. Been reading the forums heaps, but hadn't gotten around to making an account to post anything before now.

I'm interested in making one of these, My HT motor has done a whole 300kms and I've already killed the stock CDI :-||
I've ordered another one from ebay, but am intrigued by the idea of making my own.

I've read heaps in this thread and am pretty sure I have the Idea of what to do to make the basic one, just want to make sure all the parts I've located are right

SCR:
10 Pcs T0-220 Package Phase Control SCR Triacs 600V 4A

Capacitor:
10Pcs DIP Metallized Polypropylene Film Capacitors 1uF

Diode:
25PCS 1N4007 1A 1000V Rectifier Diode DO-41 Tape

Resistors:
1/2w Watt 18 ohm 18ohm Metal Film Resistor 0.5 W +/-1% 20pcs
1/2w Watt 82 ohm 82ohm Metal Film Resistor 0.5 W +/-1% 20pcs

Also Some PCBs to put it all on

Lastly I've found the following ignition coil:
Ignition Coil Honda NSR75 NSR575 Motorcycle 2004 NEW
 
You also may want to check out the thread for the CDI (Modified CDI) down below in my signature. It is a copy and improved CDI that you can buy from a vendor online.
 
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