Roll Your Own CDI
- Thread starter rohmell
- Start date
Don't worry, you will have plenty of time to build your unit, and sell the extras that you make.
Rohmell, how much clearance do you have from the bottom of your spark plug porcelan to your top tube on the frame? do you have a 45degree head? I have a stick coil i can ship to you for testing.
Flybytaco, thanks for the offer, but I do have various coils that I am using for CDI testing.
I'm thinking maybe those coils are designed for a lesser duty cycle since they fire every other revolution divided by the number of cylinders in the engine being used, so for example in a 2 cycle, 3000 RPM, firing every revolution= 3000 pulses per minute, 50 pulses per second
In a V6 at 3000 RPM, would be 3000/2= 1500/6=250 pulses per minute, 4.16 pulses per second.
In other designs that fire on the exhaust stoke as well as the compression stroke, you would have 3000/6=500 pulses per minute, 8.3 pulses per second.
I wouldn't want to blow up a coil on yuh.
I'm thinking maybe those coils are designed for a lesser duty cycle since they fire every other revolution divided by the number of cylinders in the engine being used, so for example in a 2 cycle, 3000 RPM, firing every revolution= 3000 pulses per minute, 50 pulses per second
In a V6 at 3000 RPM, would be 3000/2= 1500/6=250 pulses per minute, 4.16 pulses per second.
In other designs that fire on the exhaust stoke as well as the compression stroke, you would have 3000/6=500 pulses per minute, 8.3 pulses per second.
I wouldn't want to blow up a coil on yuh.
I'm having trouble laying out the components on a board. I guess I'll be using a universal PC Board from RS. I've never done this before, so I'm very excited for this project. Could someone please show me how it should look on both sides? I'll be assembling the basic CDI from the first design, then going from there. I'm using the suggested components and (2) of the big capacitors. I saw how they connect off the board, but I'd just like a nice neat way to connect them on a board. Thanks guys.
I'm in AusHere's a nice CDI PCB:
Unfortunately, seems to be only available in OZ.
where were they available at ?
Would this work as well?Parts are not to scale, but more or less like this:
Attachments
yes it would
however i'm wondering what diodes and semi conductor is in the picture there as i would build one this weekend
I would also love the schematics to the binary one he has a couple of pages back
Capacitor Discharge Ignition Kit for Motor Bikes | Buy Online | Volt ElectronicsI'm in Aus
Capacitor Discharge Ignition | ITSPOT.COM.AU Computer Components
Capacitor Discharge | TECH4U.COM.AU Online Computer Store
BUY Capacitor Discharge Ignition Kit for Motor Bikes | MegaBuy Computer Parts
Any diodes and SCRs that you have lying around that are at least 400 PIV.yes it would
however i'm wondering what diodes and semi conductor is in the picture there as i would build one this weekend
I would also love the schematics to the binary one he has a couple of pages back
Simple CDI schematic and PCB layout in early stages(open with FREE CAD software from
ExpressPCB - Free PCB layout software - Low cost circuit boards - Top quality PCB manufacturing
View attachment Simple CDI.zip
ExpressPCB - Free PCB layout software - Low cost circuit boards - Top quality PCB manufacturing
View attachment Simple CDI.zip
Patent of a CDI circuit similar to the 'Roll Your Own CDI':
CAPACITIVE DISCHARGE IGNITION SYSTEM
And another here:
CAPACITIVE DISCHARGE IGNITION SYSTEM
CAPACITIVE DISCHARGE IGNITION SYSTEM
And another here:
CAPACITIVE DISCHARGE IGNITION SYSTEM
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Hi rohmell-I can billed this from the pic 'paint by #s' but I don't know if
this is an advancing and then retarding cdi? or a stagnant timing cdi?
I'm good with nut and bolts but this is beyond me I'm looking for (15-20) btdc @ 1000rpm (0) out tdc @ 4500 rpm.+ or - I can tune around that
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