DIYEFI.org Forum

I was looking on the interwebs for information and schematics for a multiple spark discharge system all I coulkd find was some wiring diagrams for hooking up and MSD Brand ignition, or soem simple schematics from patent papers. I was wondering if anyone around here had anything useful? Or a source?

There was a silicone chip article and you could get kits locally for years. It was pretty decent, however you've got to realise this:

CDI == distributor V8s where there is insufficient time for anything else

And

CDI == two-stroke engines where mixtures with oil are hard to burn through AND you're short on time

Normal inductive ignition with a modern coil and a non-MegaSquirt driver setup can light off 30psi of boost without an issue.

Fred.

Fred you wouldn't happen to know when abouts that issue of silicon chip was? I love that magazine. More than Nuts and Volts even. Wish It was reasonable to get it here in the US, that international shipping is ballocks.

Although for the sake of sharing information I did find this. It's very nice and detailed, although not specifically automotive it does mention it.
http://www.sci-experiments.com/HighVoltagePulser/

Check out overhere.
http://www.transmic.net/en/home.htm
Its mainly for 1 cillinder bikes

Here are also a few links i have gathered.
http://www.electronics.gompy.net/
http://home.comcast.net/~loudgpz/GPZweb ... oints.html
http://chevellestuff.net/tech/hei.htm

Here's another one. Its a break down of the MSD 6AL ignition, a little dated for being on the internet but has good information. Has all the schematics and information if you want to make a copy unit. Just a few pages, certainly worth downloading and sticking in the library before the interweb spders eat it.

http://web.tiscalinet.it/giordy/ECU/msd6a_02.pdf

Fact remains: You probably don't need it.

More facts: The electrical noise from these systems is deadly to your ECU unless you're ultra careful with how you configure the vehicle wiring wise.

What's your application? Or just curious?

I couldn't find the kit or info about the article online, yet. I may have an actual kit, though. Will check next time I'm in my storage.

Fred.

there is a Yahoo group with this theme, hardly active. the silicone chip design was not the best to use. there was something that always burned out.
a friend of mine used it to design his own version, http://m1n1.de/html/cdi.html , worked perfect in my Mini years ago. no problem with noise or something. i could just change some connectors to switch from inductive to CDI and back. the engine seamed to like the CDI.
we didn't follow this as its quite expensive to make and demand is low.

The third reason to ponder CDI is when contemplating the conversion of a vehicle with an under-powered alternator. Some bikes need a well-charged battery to achieve redline, as the stock charging system can't feed the TCI coils and lights at full speed. Add in a high-pressure pump and injectors, and you have an exercise in futility. LED lights help, but the ignition is the hungriest system .


Edit - "LED lights", not LCD lights. Isn't 'LCD lights' a contradiction in terms?!

You're probably right.  Though my counter point is that modern engine power is based on little efficiencies.

I'm well acquainted with EMI and have some experience dealing with it in the automotive perspective as well working with mobile radios and antennas.  I do have a pretty insatiable curiosity but am convinced that CD/MSD has good validity.

As far as an application goes one of the engines I intend to setup is a 230 cc single. DonTZ125's point makes sense for that.

Fred I did find the article from silicon chip. But think I will give a stab at the kit from sci-experiments.com. Having read all the sites everyone else posted I cant believe the detail of information there. Also I really like the versatility of their board. It s amazingly functional, full featured, and still has lots of room for shrinkage, perhaps as a daughterboard, or as a coil per cylinder configuration. At 300 hz pulse rate that can handle a 15,000 rpm redline. But even that can be changed by modifying a couple caps in the circuit.