Alternator image request

[Jordan]

If anyone has access to a Ducati single CDI type stator, I'd love to have a close up photo of it. That is, the Ducati Elettrotecnica one without the potting resin, not the Motoplat brand.
I wouldn't mind buying one, too.

Jordan

[graeme]

Hi Jordan,
CDI as in 1974 Ducati Electronica, red box and red igniter?
Send me your email graeme@rhq.net.au
I have my '74 in bits at present.
Graeme

[ducwiz]

Hi,

do you mean
?
I have such item in my shelf, can take photos to your needs.
You can also find a photo of it in the Haynes workshop manual, http://www.amazon.com/Ducati-Singles-Haynes-Workshop-Manuals/dp/085696445X.

cheers Hans

[Jordan]

Thanks guys.
Hans, if you can get close ups of the stator, especially the ignition charging coil, please do.
Graeme - ditto! More is good. I'll send you an email.
Reason I'm curious is that I notice some details on the Motoplat, and wonder if similar was done on the Ducati Elettrotecnica. Namely, the copper/brass plate over the ign charging coil. I wonder what that is for? Also, the coil is placed as far as possible away from the magnets, which seems deliberate.
This info might help me get a workable CDI without having to buy another one.

Jordan

[ducwiz]

Hi jordan,

you are lucky today, as I am sitting around, waiting for a craftsman I called to repair a broken window glass. I just went into the basement, got the stator on the bench and took some snapshots, http://ducwiz.minus.com/mOqLCAKPA/.

I always wondered about the detail you mentioned, too. My idea: it is basically a short circuit winding, mutually coupled with the charge coil. From my knowledge about electric current transformers I conclude this winding to be a low pass or smoothing filter against voltage spikes, which could damage the electronics inside the CDI transducer box.
I never had an opened Motoplat stator on hand, I always avoided the Motoplat CDI due to many reports of weak sparks or total failures. I only remember that the HV winding is grounded here, in contrast to the DUCATI item, where it is floating. That's why the no. of output wires differs, 4 or 5, respectively.

Edit:
I found an interesting url in my bookmarks, but haven't read this page dealing with the DUCATI CDI in the Moto Morini bikes, due to the craftsman's arrival ...
http://www.motomoriniclub.nl/tech.html#Morini%20ignition%20system


Hans

[Jordan]

Hello Hans,

Thank you for taking the trouble and giving the photos.
It looks like the Elettrotecnica CDI charging coil has the same arrangement as the Motoplat's, with copper "ring" on top. I don't understand enough about power electrics to appreciate how that might work. It reminds me a little of a shaded pole AC motor, with a shorted copper turn.
The Morini page has descriptions and further links that could be useful.

Jordan