Sure wish I had this when I was a mechanic's instructor. This is one of the most concise, well conceived and presented little video "vignettes" on this subject I have ever seen. WELL DONE SIR! Thank YOU!
Ha, brilliant! My mechanic just said my boat needed a trigger today, so when I found your video, it explained EXACTLY the info I wanted to understand. Kudos to you sir!!!!
Excellent description. Just what I was looking for. It's difficult for me to comprehend how my new CDI distributor on my 1974 Ford 302 V-8 manages to "trigger" with the components I see withing the distributor cap. Not that it makes an difference, but mine is a marine application. Thank you very much for the description.
I normally watch your radio videos. My 1984 Honda "Big Red" stopped running. What a pleasant surprise to find YOUR video covering this! Great job as always. The Big Red is running now, by the way. Thanks again my friend!
Great explanation ! I envy your ability to simplify this to the point where anyone could understand... even after watching your video, I couldn't explain it so clearly. I get so caught up on details... I'd go off on a rant about timing advance curves, 2 cycle vs 4 cycle, coil fed vs battery fed ... and I'd walk frustrated and with the other person more confused than when I started.
an excellent explanation. thank you. I had no idead what vehicle ignition was until yesterday, but watching this video, I can totally comprehend what vehicle ignition is and how CDI works.
I would like to add a note here, because it seems some people having trouble understanding it. Not all cdi's have this excitor coil, some old cdi's have that. Most of them nowdays have an inverter build in. These kinds of cdi's gets their power directly from the battery.
I have been teaching electronics at a local university, and will recommend my students to watch this video even though we don't go into power electronics. This is an excellent video describing the basics of a CDI system. There is supposed to be a signal conditioning circuit in the pulse rotator path that terminates at the SCR gate; its main function is to clean/filter the spikes from the triggering mechanism. All in all your explanation is very clear, and concise. Thanks for uploading the video.
Rich, Great information. This helps to understand various components. Now it also helps to see how the function in a radio or any other device. 73, Mike
Highly invaluable video, I saved a lot of time and money making my own CDI circuit from basically exactly this schematic for a 125cc dirt bike. 100ohm resistor, 1n4007 diodes, 1uf 250v cap and a BT169D thyristor.
Hi good work frank this project, I need to make this CDI of my dirt bike he is a suzuki rm 125 92 you know its work on my motorcycle? send me a e-mail please i realy need this project help me please, sende from: ph_monteiro2005@hotmail.com
HI All American Five today I opened an original dirt bike CDI, I can see to have a 250v orange capacitor, I am from Brazil, but I did not think to buy this cdi here and when I thought it was very expensive 450 500 $ How Do I understand enough of electronics to make my own cdi
Thanks Daniel, I've been busy working on a 50,000 Watt transmitter. Both three-phase circuit breakers failed. The station was off the air since Wednesday afternoon, got the parts in today and she's back on the air. Glad the video was helpful. Rick
I have been trying to learn and diagnose a small engine with no spark. these type videos are great ! Im almost amazed at the effort people put into these videos and the value that we all can get out of them. Im no engine or electronics expert but i know enough to fix some things and other times royally ruin things. I might be totally wrong but it doesn't make sense to me that the ignition's primary coil is grounded directly. I figured it would get the solid ground thru the gate(SCR/transistor or whatever it is)
Thanks Rick for uploading this video,, little bit of insight for others. Pulse coil is the one which would trigger when piston comes to top dead center in motor bikes. IN four stroke engine, u have intake(getting GA), compression(compress the GAS), spark(spark the compressed gas) and exhaust as four events, u want to spark the engine at the top of compression stroke, pulse coil will provide pulse exactly at that stage.. In Cars Transistor is used to pulse the coil ground and power is steady
Hi my friend, good video, I like to know if all kinds of pick up coils generate low voltage to excite the CDI? My engine is an RM 125 and 92, but it did not generate something voltage i think have a problem from my pick up coil, what do you think ?
Thanks for the demo was wondering how I could reverse engineer this and I think I can now. I have a bank of coils discharging into a network of caps. I then want to discharge these caps while effectively swapping the coils onto another bank of caps so I can charge these while discharging the other bank then swapping back to the other bank and then the whole sequence repeats. Just one query shouldnt the primary coils emf collapse as the cap discharges then induce into the secondary coil and across the spark gap?
Excellent! I will use your video for reference when I get to this subject on motorcycle electrical systems. This is the quality of tutorial I remember from Airframe and Powerplant mechanics school years ago. (Mostly great quality WWII training films). JB
You prolly dont give a shit but does anybody know a method to get back into an instagram account..? I somehow lost the account password. I appreciate any tricks you can offer me.
@Kase Jayden thanks so much for your reply. I got to the site through google and I'm in the hacking process now. Seems to take quite some time so I will reply here later when my account password hopefully is recovered.
GREAT description of how a CDI works, easy to understand. I need to build a CDI for a motorcycle engine that uses two trigger coils. One at 10 BDTC and another at 35 BTDC. I assume I'd duplicate the SCR to the trigger circuit. But how would it "switch" to the 35 BTDC trigger as the engine speeds up? I need the advance to occur before 2,500 rpm.
Hi again. I have a link to a cdi I think I can use. I was going to mirror the circuit to get two trigger inputs and two outputs. The original mercury circuit does exactly that but uses two unidentifiable transistors to dump the charge instead of an scr. Do you think it can be done with this circuit? Many thanks in advance for looking
I put a CDI system in a Ford 4 cylinder Cortina many years ago and straight away noticed more power and better idling , except one night i noticed that the engine was idling roughly when I opened the hood it looked like a Xmas tree, sparks leaking from all over the spark plug leads .The higher induced voltages must of been to much for the leads , the simple solution then was to buy HV insulating sleeve and install the leads inside.
If the trigger is given to the SCR not only while starting the bike, does it mean that CDI is required even for running the bike smoothly? My motorcycle under cold conditions burps out for about 5-10 minutes past starting and switches off while the throttle is not revved (I set the idling to its best form but this still happens). Because of this fuel efficiency has severely been plummeted, do you think there might be a problem in the CDI. (I kind of related this to the CDI because my bike tremendously burps out through the silencer whenever i start).
Silicon Control Rectifier SCR Basic DC Circuit th-cam.com/video/ImyTwZGZ-Ls/w-d-xo.html Silicon Control Rectifier SCR Basic AC Circuit th-cam.com/video/45H4J_S52Y4/w-d-xo.html
Interesting. I was trying to figure out an Amazon review for a small engine accessory coil to provide 12 volts for gas engine bicycle lighting. This reviewer said that just adding the aftermarket coil (approx 180 degrees from the ignition charge coil) kept his engine from running more than 3,000 rpm. We used to do this exact trick with old Ducati and other euro "scrambler" dirt bikes that only had one magneto coil so we could get some lighting, and it was never a problem. Of course, those were the days of separate spark coils with contact breaker points (and incandescent lights that didn't care about the non-rectified AC pulse from the lighting coil), but still, I'm having a hard time understanding how adding another coil would possibly have any affect on the CDI system. The aftermarket coil is grounded to the engine and has one power lead coming from the other end of the coil, so both the ignition coil and the aftermarket lighting coil share the engine block as a ground - but that shouldn't be an issue... should it? Strange, eh?
Capacitors, DC and AC Current th-cam.com/video/NInt1Ss3vQ4/w-d-xo.html AC Alternating Current, for the Beginner th-cam.com/video/xVbqMFkyuXI/w-d-xo.html Transformer Basic Parts & Function th-cam.com/video/q3YhbugYjJY/w-d-xo.html
Could you run it from 6 or 12v dc battery? Or is AC (no current cycle through diode) necessary to enable the SCR to shut off after it has been triggered?
Sure wish I had this when I was a mechanic's instructor. This is one of the most concise, well conceived and presented little video "vignettes" on this subject I have ever seen. WELL DONE SIR! Thank YOU!
Thanks Jim Dixon
Excellent video, thank you for taking the time to do this. I now completely understand how this system works. My 50 HP merc outboard uses this system.
thank you very much for such a clear concise description of how the scr based cdi works.
Glad you made this. Learning all the components and their contributions is hard enough but seeing any changes in a real time model, greatly helps
I'm glad you found this video useful.
Thank you, and your welcome.
This is the best explanation i have seen so far. Thanks
...and even his voice is so pleasant, a calm voice that is good to be heard!
Such an awesome job! I am very visual learner and I’ll be watching this repeatedly. Thank you!!!
I'm glad this video is helping. THANKS!
Ha, brilliant! My mechanic just said my boat needed a trigger today, so when I found your video, it explained EXACTLY the info I wanted to understand. Kudos to you sir!!!!
Thanks
Thank You for this demonstration, everything was clear and understandable! Great job!
Thank you!
Excellent description. Just what I was looking for. It's difficult for me to comprehend how my new CDI distributor on my 1974 Ford 302 V-8 manages to "trigger" with the components I see withing the distributor cap. Not that it makes an difference, but mine is a marine application. Thank you very much for the description.
I normally watch your radio videos. My 1984 Honda "Big Red" stopped running. What a pleasant surprise to find YOUR video covering this! Great job as always. The Big Red is running now, by the way. Thanks again my friend!
Thanks. I'm glad this video helped.
Great explanation ! I envy your ability to simplify this to the point where anyone could understand... even after watching your video, I couldn't explain it so clearly. I get so caught up on details... I'd go off on a rant about timing advance curves, 2 cycle vs 4 cycle, coil fed vs battery fed ... and I'd walk frustrated and with the other person more confused than when I started.
Thanks for your comment.
Thank you for your explanation.
an excellent explanation. thank you. I had no idead what vehicle ignition was until yesterday, but watching this video, I can totally comprehend what vehicle ignition is and how CDI works.
THANKS
Good video, excellent visualization. Thank you
Thanks
I would like to add a note here, because it seems some people having trouble understanding it. Not all cdi's have this excitor coil, some old cdi's have that. Most of them nowdays have an inverter build in. These kinds of cdi's gets their power directly from the battery.
Wow, what a gift this video is to me. Great explanation, thank you!
Thanks and your welcome.
Very nice of you. The best compliment. " I got it ".Thank you.
This is how my Honda Rebel 250 ignition system works.
Thank you for the visual explanation!
Thanks and your welcome.
I have been teaching electronics at a local university, and will recommend my students to watch this video even though we don't go into power electronics. This is an excellent video describing the basics of a CDI system. There is supposed to be a signal conditioning circuit in the pulse rotator path that terminates at the SCR gate; its main function is to clean/filter the spikes from the triggering mechanism. All in all your explanation is very clear, and concise. Thanks for uploading the video.
Thank you. I'm glad you find this video worthwhile watching and useful, and hope your students will also.
Rich, Great information. This helps to understand various components. Now it also helps to see how the function in a radio or any other device.
73,
Mike
You have a great way of explaning things, thank-you.
Thanks you, and your welcome.
Very very good video and good description, thank you so much
Highly invaluable video, I saved a lot of time and money making my own CDI circuit from basically exactly this schematic for a 125cc dirt bike. 100ohm resistor, 1n4007 diodes, 1uf 250v cap and a BT169D thyristor.
Hi good work frank this project, I need to make this CDI of my dirt bike he is a suzuki rm 125 92 you know its work on my motorcycle? send me a e-mail please i realy need this project help me please, sende from: ph_monteiro2005@hotmail.com
Usually the capacitor is the part that fails first.
HI All American Five today I opened an original dirt bike CDI, I can see to have a 250v orange capacitor, I am from Brazil, but I did not think to buy this cdi here and when I thought it was very expensive 450 500 $ How Do I understand enough of electronics to make my own cdi
I'm glad the video helped
Do you believe this circuit meets my dirt bike? because shee reaches 11 000 rpm two stroke power monocylinder
Thanks Daniel, I've been busy working on a 50,000 Watt transmitter. Both three-phase circuit breakers failed. The station was off the air since Wednesday afternoon, got the parts in today and she's back on the air.
Glad the video was helpful.
Rick
Great video on operation........Thanks for the explanation!
I have been trying to learn and diagnose a small engine with no spark. these type videos are great !
Im almost amazed at the effort people put into these videos and the value that we all can get out of them.
Im no engine or electronics expert but i know enough to fix some things and other times royally ruin things.
I might be totally wrong but it doesn't make sense to me that the ignition's primary coil is grounded directly. I figured it would get the solid ground thru the gate(SCR/transistor or whatever it is)
Yes even 8 years later. fantastic!!
How to use eliminate,
And ,did you know how to create a klin spark ignition for ceramic factory
Thank you, with the video simulator above, I came to understand how the CDI works.
Thanks
The Best Video on TH-cam !
THANK YOU!
Thanks for clarifying how it works. This helps me a lot
Glad it helped. Thanks, and your welcome.
Great video!! I am going share this with my son.
Thanks Rick for uploading this video,, little bit of insight for others. Pulse coil is the one which would trigger when piston comes to top dead center in motor bikes. IN four stroke engine, u have intake(getting GA), compression(compress the GAS), spark(spark the compressed gas) and exhaust as four events, u want to spark the engine at the top of compression stroke, pulse coil will provide pulse exactly at that stage.. In Cars Transistor is used to pulse the coil ground and power is steady
Great video and explanation! Thank You!
Crystal clear explanation. Thank you very much!
Thank you, and your welcome.
Very nice illustration. THANKS!
Thanks, and your welcome.
FANTASTIC explanation.
Thanks
appreciate it....great demonstration....keep up the good work :-)
Thanks
Hi my friend, good video, I like to know if all kinds of pick up coils generate low voltage to excite the CDI? My engine is an RM 125 and 92, but it did not generate something voltage i think have a problem from my pick up coil, what do you think ?
Nice circuit animation....thanks Rick.
Very informative, thanks very much!
Very clear explanation Rick.Thx a lot
simple and straight to the point, thanks
Thank you, and your welcome.
Great job, thanks AllAmericanFiveRadio!
Thanks and your welcome.
Thanks for the demo was wondering how I could reverse engineer this and I think I can now. I have a bank of coils discharging into a network of caps. I then want to discharge these caps while effectively swapping the coils onto another bank of caps so I can charge these while discharging the other bank then swapping back to the other bank and then the whole sequence repeats. Just one query shouldnt the primary coils emf collapse as the cap discharges then induce into the secondary coil and across the spark gap?
excellent video. Thanks for posting and sharing. Cheers
Thanks
Very helpful for my training! Thanks!
Thanks and your welcome.
Very clear explanation , Thanx for the video loved it
Great animation! What role does the kill switch diode play? Would the switch still ground and kill the circuit without the diode?
An excellent video and description.
Thank you, and your welcome.
Thank you! This is very helpful!
Thanks
Good explanation, i've ever seen...
Thank you
Thank you, and your welcome.
What a great explanation ,Thank you.
Thanks, and your welcome.
Excellent explanation, thanks for your time and effort.
Thanks
Great job! did you put all this animation together too?
Yes
Excellent! I will use your video for reference when I get to this subject on motorcycle electrical systems. This is the quality of tutorial I remember from Airframe and Powerplant mechanics school years ago. (Mostly great quality WWII training films). JB
You prolly dont give a shit but does anybody know a method to get back into an instagram account..?
I somehow lost the account password. I appreciate any tricks you can offer me.
@Duncan Jaxson Instablaster ;)
@Kase Jayden thanks so much for your reply. I got to the site through google and I'm in the hacking process now.
Seems to take quite some time so I will reply here later when my account password hopefully is recovered.
VERY NICE. VERY UNDERSTANDABLE. THANK YOU.
GREAT description of how a CDI works, easy to understand. I need to build a CDI for a motorcycle engine that uses two trigger coils. One at 10 BDTC and another at 35 BTDC. I assume I'd duplicate the SCR to the trigger circuit. But how would it "switch" to the 35 BTDC trigger as the engine speeds up? I need the advance to occur before 2,500 rpm.
This explanation is really perfect
Thanks.
Your welcome.
Гарна робота!!!
Thanks and your welcome.
That was a great video.
Thanks and your welcome.
Thank u so much for this video.
Thanks
WOOOOW big thanks!
very useful information
Thank You for explanations!
Thank you, and your welcome.
Hi again. I have a link to a cdi I think I can use. I was going to mirror the circuit to get two trigger inputs and two outputs. The original mercury circuit does exactly that but uses two unidentifiable transistors to dump the charge instead of an scr. Do you think it can be done with this circuit?
Many thanks in advance for looking
I put a CDI system in a Ford 4 cylinder Cortina many years ago and straight away noticed more power and better idling , except one night i noticed that the engine was idling roughly when I opened the hood it looked like a Xmas tree, sparks leaking from all over the spark plug leads .The higher induced voltages must of been to much for the leads , the simple solution then was to buy HV insulating sleeve and install the leads inside.
+190055joe THANKS
Finally a full understanding,,thank you sir.
Thanks and your welcome.
Very nicely explained, cct done in a very simple manner, easily understood.
This gentleman should do more projects ! Good teacher!
Thank you, and your welcome.
THANKS FOR THE CLEAR EXPLANATION
Thanks
If the trigger is given to the SCR not only while starting the bike, does it mean that CDI is required even for running the bike smoothly?
My motorcycle under cold conditions burps out for about 5-10 minutes past starting and switches off while the throttle is not revved (I set the idling to its best form but this still happens). Because of this fuel efficiency has severely been plummeted, do you think there might be a problem in the CDI. (I kind of related this to the CDI because my bike tremendously burps out through the silencer whenever i start).
Great video very clear and to the point with easy to understand illustration thank you sir👍
Thanks
Muy claro, gracias. ( Very clear, thanks)
Thank you, and your welcome.
Hope this video helps.
excellent demo!!
Thanks
Excellent video to understand how CDI functions along with magneto coil and spark plug.
Thanks
Kind Sir thank you so much, super clear and very well explained.
Thank you, hope this video helps.
Thank you for the informative program.
Thank you, and your welcome.
Cool video Interesting to know how it really works animated . Since i work on this stuff everyday for the past 30 years as a Motorcycle / AtV Mechanic
Thanks
Great explanation, thank you. Just for reference SCR stands for Silicon Controlled Rectifier.
Thanks
excelente explicacion amigo
saludos amigo
Thanks
Thanks Tony T.
great video thank you!
Thanks
Great video! So what makes the SCR shut off? Is there some sort of flyback current from the ignition coil that reverse biases the SCR?
Silicon Control Rectifier SCR Basic DC Circuit
th-cam.com/video/ImyTwZGZ-Ls/w-d-xo.html
Silicon Control Rectifier SCR Basic AC Circuit
th-cam.com/video/45H4J_S52Y4/w-d-xo.html
Interesting. I was trying to figure out an Amazon review for a small engine accessory coil to provide 12 volts for gas engine bicycle lighting. This reviewer said that just adding the aftermarket coil (approx 180 degrees from the ignition charge coil) kept his engine from running more than 3,000 rpm. We used to do this exact trick with old Ducati and other euro "scrambler" dirt bikes that only had one magneto coil so we could get some lighting, and it was never a problem. Of course, those were the days of separate spark coils with contact breaker points (and incandescent lights that didn't care about the non-rectified AC pulse from the lighting coil), but still, I'm having a hard time understanding how adding another coil would possibly have any affect on the CDI system. The aftermarket coil is grounded to the engine and has one power lead coming from the other end of the coil, so both the ignition coil and the aftermarket lighting coil share the engine block as a ground - but that shouldn't be an issue... should it?
Strange, eh?
T would need to see the circuit.
Great video, so if I'm right, the exciter coil timing is irrelevant but the trigger timing is critical?
The capacitor needs to be charged before the SCR fires.
GREAT VIDEO
Thanks
the silicone rectifier or SCR is a electric one way gate that's controlled by the pulsar coil.
thanks the best explanation now I understand 👍
Thanks
Great demonstration Rick regards Ian VK2IJ.
Great video thanks
Excellent, especially with the "animation"!
Thanks
Good Video Thanks!
Thanks and your welcome.
its easy to understanding,thanks~
Thanks
Thank's for the tutorial.
Thank you, and your welcome.
Thats a analogic CDI, today we use DIGITAL CDI , always good video very clean diagram!
Send me a diagram of a digital CDI. Thanks.
how many acv will the trigger coil make when trying to start it?????
Thanks, now I understand
Thanks so much for the great explanation sir.
Your welcome
Thanks AntiqueRadioandTV
Thanks Giovanni Brazzoli
Well done!
Thank you, and your welcome.
In the trigger coil, is the magnet on the rotor or in the trigger coil? having trouble understanding how pulse is making ac voltage.
Capacitors, DC and AC Current
th-cam.com/video/NInt1Ss3vQ4/w-d-xo.html
AC Alternating Current, for the Beginner
th-cam.com/video/xVbqMFkyuXI/w-d-xo.html
Transformer Basic Parts & Function
th-cam.com/video/q3YhbugYjJY/w-d-xo.html
Thank you very much for sharin.
Thanks, and your welcome.
excellent. i will need to re-follow , to understand. thank you
Thank you, and your welcome.
Could you run it from 6 or 12v dc battery? Or is AC (no current cycle through diode) necessary to enable the SCR to shut off after it has been triggered?
You may be able to run this on a battery but it would be a large design change.