DIY CDI kit ... 1997 Silicon Chip magazine article from Oz ...

[Early_S_Man]

Anybody from Oz familiar with this kit from Jaycar Electronics???

That has apparently taken on cult status in Germany among racers and bike enthusiasts ... it has a web presence in a couple of versions!

The nice thing about this DIY design is that it can be configured to take points or magnetic reluctor input triggers!

http://www.molla.org/DIY-CDI/SC-DIY-CDI-article-hires.pdf

http://www.not2fast.com/ignition/cap-dis-ignit-cdi.pdf

[Porsche_monkey]

Guinea pig required.

[euro911sc]

Cool. I just opened up my CDI last week to peak inside and see if I could clean it up... it is looking very old! I winder if you could jam this board in an OEM housing so no one would ever know and you would have something you could easily fix and rebuild...

All of this you can buy at Radio shack including the board etching kit. Might give this a try... what the worst that happens... fry a coil?

Best regards,

Michael

[304065]

Way cool Warren!

With the inverter being driven by the pair of MOSFETs at 22KHZ, we won't be able to hear the distinctive 2Khz "whine" of the old Bosch CDI!

I also find it interesting that they recommend the Siemens HKZ101 hall-effect sensor. . . isn't that what's found inside the SC distributor? And Volvo, etc.

Thanks for posting. . . I'm no EE but I sure do learn a lot from reading the circuit descriptions.

[Lorenfb]

Good for a high school shop class, but hardly a good design for a high
reliability automotive application, i.e. given the complexity of design and
high component count. Great to promote if you're trying to unload a lot
of salvage electronic parts.

Compare that (and the MSD design) to the simplicity of the Bosch CDI and its
resulting inherent reliability.

[obrut]

warren

jaycar have a shop on the same street as my office. would you like me to check if they still sell the kit?

[Early_S_Man]

Ryan,

That would be great! This kit is '97 or '98 vintage, unlike the identical-looking, current 'High-Energy Ignition' that is based on a micro-controller PIC chip and features the same case, and has a red lightning bolt decal on the cover.

Funny, thousands and thousands of satisfied customers used a Delta Mark 10B Capacitor Discharge Ignition back in the '60s and '70s, and it was also sold in kit form by Heathkit [CP-1060] and Radio Shack [Archerkit] at the time ... that included me and a few other Pelicans, too! In my case, the Mark 10B ran for almost 18 years without any problems on a Datsun 620 pickup! Still have it, as I removed it before having my totaled truck hauled off - done in by an idiot colege kid while parked out front on the street!

[304065]

Warren, I heard that Chuck Stoddard, when he took delivery of his immaculate black '67S at the factory, actually brought a Delta Mark 10 with him and insisted that it be installed before he took delivery. Perhaps the factory took note of this!

[rick-l]

Hey
I've screwed up using those parts before.

IR managing transients

IR floating well high voltage gate driver tips

datasheet

If I were going to make this reliable I'd put the driver ALOT closer to the MOSFETs. I think I'd consider a ground plane on the other side also.

[rick-l]

Look at the new improved version.

ir2153

It has a shutdown. The original design implements a similar feature (and a bunch of parts) to regulate 300 volts.

It also has "improved latch immunity", very important considering the consequences of having both outputs on.

[Early_S_Man]

Rick,

I believe the IR2155 is no longer readily available, and the IR2153 is, at around $3.40 in low quantities, cheaper now than the IR2155 was 10 years ago!

I was actually trying to get feedback from any users in Oz on the kit ... not suggesting that it was a drop-in replacement for our Bosch (or unfortunate Permatune owners) units ... but it does have some interesting design features worth considering and using, like the high-frequency inverter with a regulated output. I think I would put a few more turns on the secondary winding, use a ferrite toroid for the core, and regulate the output to 375-400 Volts, and a two-sided board with ground plane would be an easy job, too! I have plenty of MTH40N06 and MTW16N40E MOS drivers on hand that are rated a bit higher than the MTP3055 and IRF822 drivers specified. I would arrange the board layout to be able to have all of the point and reluctor input components installed simultaneously, switchable by jumper.

I am thinking the costs are low enough to build in complete redundancy in every stage, including coils, and still have it fit in the same size case, after watching Apollo 13, again, the other night for the umpteenth time!

There is even an Internet users group of amateur bike and auto racers in Germany using this DIY CDI design, perhaps with good reason!

[Lorenfb]

"There is even an Internet users group in Germany for this DIY CDI design"

Maybe as a teaching effort. Inductive discharge presently used by ALL OEMs
is more than adequate for an ignition system for the last 30 years.

"perhaps with good reason"

Like what? A CDI system was appropriate 40-50 years ago when high speed/current
switching semiconductors weren't available as is the case NOW.

Bottom line: A CDI system is a lacking for present applications:
1. Poor reliability, e.g. the energy storage device (capacitor)
and circuit complexity
2. Cost (especially for DIS)
3. Spark burn time

[TimT]

Hey Lorenfb

have you ever had a positive thing to post about?

you do a nice cut and paste, yet never back it up...

Loren if i've learned anything from the 'net, its that I would NEVER use your services...

and thats the impression you project

On edit:

I equate Lorens posts the same as fastpats

[Lorenfb]

"if i've learned anything from the 'net"

You don't, especially from the B.S. posted on most forums by hobbiests of
questionable abilities and knowledge.

Go to the library and do some worthwhile reading!