Roll Your Own CDI
- Thread starter rohmell
- Start date
impression
New Member
Answer:
AWESOME
i think i need to sleep so i can get up early and ride the bike down to the store lol to get all the gear.
oh a question with the retard portion of the circuit.... does it automatically "kick in" when you idle at traffic lights ? or is there a switch or something we need to add in ?
sorry about the questions electronics is my poor side when it comes to my engineering ( 2nd year student )
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rohmell
Active Member
There will be no retard or advance at idle, because the magneto output voltage is low and the cap will not charge enough to significantly alter the timing, it is almost as if the capacitor is not in the circuit.. As you rev higher and higher, the voltage being applied to the capacitor is higher, so the SCR will fire sooner, advancing the timing, so the function is automatic.
The value is not set in stone, some experimentation with the value may be required, due to variances in the magneto, magnet gauss, etc.
The value is not set in stone, some experimentation with the value may be required, due to variances in the magneto, magnet gauss, etc.
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Cagiva4ever
New Member
hi !
i contacted him about a month ago by using a "mail box" on his Homepage. been writing couple emails to him since that about cdi's and Schematics.
You could use the mentioned mailing system/format on his Homepage to reach him.
bye
m
Guestion to "Rohmel"
-Can you show how to (with a Schematic) apply the rocker on/off Switches into a RC network ?
-once you showed the Adjustable cdi of yours that had 16 different settings to choose from, and the pcb layout had those rocker Switches on it.
(hopefully this made sense as i dont know how to explain it in english)
-am i wrong or are those "Grayhill" components juts a simple on/off rocker switches ?
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rohmell
Active Member
That circuit is still in the testing stages.
Yes, the 'Grayhill' is a simple on/off switch in rocker style.
impression
New Member
damn bastards want $35 to $50 for an ignition coil 
i can get the circuit done today but don't want to pay that much for a coil
i can get the circuit done today but don't want to pay that much for a coil
impression
New Member
well i got all the parts and blew a hole in the exhaust on the ride back lol.
but we'll tend to that later... Now CDI time
but we'll tend to that later... Now CDI time
GearNut
Active Member
damn bastards want $35 to $50 for an ignition coil
i can get the circuit done today but don't want to pay that much for a coil
Try an automobile or motorcycle junk yard.
impression
New Member
that was the price from those places
brand new they are more like $100+ we get ripped for everything here in Aus.
I'm just setting up the circuit now.
oh and on the way home from the electronic store the exhaust blow a piece of itself out.. right where the welds were to hold the rear bracket on
ah well. time to make a new one i guess.
update:
CDI is done
( non retard version) the damn guy @ the electronic store didn't give me a 47ohm resistor
gave me the wrong packsee pics
next step > find myself an ignition coil and test this unit out. If it works i make one with retard as well as better caps I non polarized ones. what type do you guys reccomend ?
Attachments
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impression
New Member
rohmell
Active Member
that was the price from those places
brand new they are more like $100+ we get ripped for everything here in Aus.
I'm just setting up the circuit now.
oh and on the way home from the electronic store the exhaust blow a piece of itself out.. right where the welds were to hold the rear bracket on
ah well. time to make a new one i guess.
update:
CDI is done
( non retard version) the damn guy @ the electronic store didn't give me a 47ohm resistor
see pics
next step > find myself an ignition coil and test this unit out. If it works i make one with retard as well as better caps I non polarized ones. what type do you guys reccomend ?
The capacitors that are shown in the photo are no good for use in this application. They should be rated at least 400 volts and be a non-electrolytic type of capacitor.
impression
New Member
thankyou
I'll be purchasing some of the other ones you linked earler instead and making another one.
skrew37
Member
Mine isn't working. Maybe I'm hooking it up wrong. I hooked blue to blue (red from my cdi) and black to black, then green to the LT on the coil. I grounded the other terminal from the coil and nothing. I bypassed the killswitch just to see if it works, and nothing. Hmm... I'll try again tonight.
rohmell
Active Member
Can you post pics of both sides of your PCB, so that I can look and see how it looks?
skrew37
Member
Yes, but unfortunately I'm at work until 5pm. Tonight, I'll post some pics of the other side. I have no idea why I didn't think to do that initially. I'm hoping it just wasn't a strong connection between the hook-up wires (I just sort of twisted them together) and not bad soldering of the components.
impression
New Member
I bought
10 x 1.0 uF / 630 V. METALLISED POLY AXIAL CAPACITORS | eBay
so i'll have enough to make 5
the rest of the gear is easy for me to find
Will be making mine within the next week when i get the ignition coil and these capacitors in the mailbox.
edit:
would the attached image be correct Rohmell ?
1. not sure about the polarity of the ignition coil... whether it's correct or should be the other way around...
2. the switch i was thinking of putting in for 1 of the discharge caps is so you can go between 1uF and 2uF because bike like mine might find it easier to start with just 1uF and then switch to 2uF when started.
3. also, does the 2.2uF capacitor in the retard section of the schematic... Does it have to be polarized ? and what voltage would you reccomend ?
10 x 1.0 uF / 630 V. METALLISED POLY AXIAL CAPACITORS | eBay
so i'll have enough to make 5
the rest of the gear is easy for me to find
Will be making mine within the next week when i get the ignition coil and these capacitors in the mailbox.
edit:
would the attached image be correct Rohmell ?
1. not sure about the polarity of the ignition coil... whether it's correct or should be the other way around...
2. the switch i was thinking of putting in for 1 of the discharge caps is so you can go between 1uF and 2uF because bike like mine might find it easier to start with just 1uF and then switch to 2uF when started.
3. also, does the 2.2uF capacitor in the retard section of the schematic... Does it have to be polarized ? and what voltage would you reccomend ?
Attachments
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