450 RT Magneto

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sjd007
Posts: 6
Joined: Tue Mar 25, 2014 12:20 pm
Location: Auckland, New Zealand

Re: 450 RT Magneto

Postby sjd007 » Mon May 05, 2014 9:36 am

I think I'm on the right track now - but let me just check in with the experts!

" is there an easy way to tell if the wires have been redone at the coil end "

____ Yes, with an ohm-meter...
With one meter-lead grounded to motor-casing, and the other test-lead connected to EITHER alt.lead-wire,, your meter should read less than 1-ohm (for a stock-setup) !
However if there happens to be no continuity through to ground,, then you might find an ohm-reading of between 1 & 2 ohms, between the two alt.wire-leads, (if somebody has internally ungrounded & connected the two power-coils together [for bridge-rectification] ).


My alternator resistances are:
White to ground 0.8 ohms
Black to ground 0.4 ohms
White to black 1.2 ohms (they add up! - what a nice way to verify they are both grounded at the stator)

Which looks to me like they are wired as stock - with the finer windings on the ignition coil as white, and I can use the black for lighting.

Onwards... Head shimmed, now engine seal and gasket and stainless bolt replacement :)

Simon

DewCatTea-Bob
Posts: 2897
Joined: Sun Nov 01, 2009 10:53 am
Location: Near SE side of Lake Michigan

Re: 450 RT Magneto

Postby DewCatTea-Bob » Mon May 05, 2014 5:01 pm

[quote="sjd007 ...
" White to ground 0.8 ohms "

____ That's consistent with the higher tension power-coil form the ign.system.



" Black to ground 0.4 ohms "

____ That's consistent with the power-coil meant for the head & tail lighting.



" White to black 1.2 ohms (they add up! "

____ Confirms all your ohm-meter readings & connections were all good !



" what a nice way to verify they are both grounded at the stator)
Which looks to me like they are wired as stock "

____ That indeed means your stator is still left as stock, and your bridge-rectifier would not be of use in the normal fashion. _ However it could still be connected-up (in a non-conventional way) to divert otherwise wasted power, to charge a battery (for powering brake-light & horn).



" with the finer windings on the ignition coil as white, and I can use the black for lighting. "

____ So then are you content to have a stock electrical-system that's just meant for off-road riding only ?



" Head shimmed,"

____ Who did the work ? _ (Hope the closing-clearances weren't set too tight !)



" stainless bolt replacement "

____ For what exactly ?
The cyl.head screws ought rather be of aluminum !


Duke-Cheers,
-Bob
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob

sjd007
Posts: 6
Joined: Tue Mar 25, 2014 12:20 pm
Location: Auckland, New Zealand

Re: 450 RT Magneto

Postby sjd007 » Tue May 06, 2014 12:01 am

Hi Bob

Thanks for the verification I'm on the right track!
Just out of interest, where exactly would my bridge rectifier go? Is it ok to ground two terminals on the rectifier ie

Gnd___Gnd
| |
AC___ DC+

Sort of thing? Using the Ignition feed to recycle wasted power?

It may not be needed though, as I have bought some high power COB (warm white to look authentic) LED chips which draw 700mA each and are quoted at 1200lumens. I'd mount them on a flat bar and one facing upwards for dip, and both running up and down(1.4A) for full beam. On my benchtop supply, they gave a good output even down to 6V with the supplied drivers (which is too bright to stare at so should keep legal people satisfied it is a normal bulb in there). I like the HID look of LED's in modern vehicles, but not for the desmo as I am keen to keep this looking as stock as possible, hence the warm white option.

My stainless bolt kit replaces the engine bolts to, um, look better. Nothing much more than vanity! The current steel ones are a bit rusty and will look a little out of place when I attack the sidecovers with my buffer :) I'm not after mirror shine, but removing years of unwanted patina would be nice (front forks / brake drums etc have come up very nicely with some effort!).

I'll figure out how to post a pic of the parts that are about to become a motorycle...

All the best

Simon

DewCatTea-Bob
Posts: 2897
Joined: Sun Nov 01, 2009 10:53 am
Location: Near SE side of Lake Michigan

450RT Magneto / Electrical-system Options

Postby DewCatTea-Bob » Tue May 06, 2014 1:21 am

[quote= sjd007 ...
" where exactly would my bridge rectifier go? "

____ Well 'electrically',, in the case of being connected-up to a 'grounded' power-coil (meant for the stock magneto-like ign.circuit), the power-coil's single-output/feed should be connected to the bridge-rectifier's AC.input(s).
Then that-way, the positive & negative outputs of the b.rect unit would be-so polarized relative rather to 'ground' (instead-of to each-other, as is normally the case).
That resultingly divides-up the AC.power (into separate neg & pos p.DC-outputs) so that it ALL doesn't have-to get circuited to just the ign.system alone ! _ (And of-course the ET.type ign.system itself, doesn't suffer any loss whatsoever [without the missing/excess-half of the AC],, since the-half of the AC that's rather diverted, would otherwise be completely FUNCTIONLESSLY 'shorted-out' directly to ground [through the ign.points] and totally-WASTED, anyhow!)


Is it ok to ground two terminals on the rectifier ie

Gnd___Gnd
| |
AC___ DC+

Sort of thing?
____ Not sure of exactly what you're suggesting, but if I got-it as you've intended,, then I'd say 'no', since BOTH ground-circuits in question, are of the very-same power-circuit. - (Sort-of the same-thing as running two uninsulated wires together through the same harness-conduit, and-yet expect their assigned circuit-current's flowing electrons to stay loyally confined to their-own respective wires [rather than accept the opportunity to take the shortest-circuit, as electron-flow is rather apt to do].)



" Using the Ignition feed to recycle wasted power? "

____ The amount of AC.power that's WASTED by the ign.system, is certainly quite SIGNIFICANT,, but none of it can really be "recycled" per-se ! _ Instead, HALF of the supplied AC can be rather 'diverted' away from being entirely short-circuited straight-through the ign.points, with the use of just one-pair of diodes ! _ However, a commonly-available bridge-block can be rather handy for performing the AC.halves separating-job though !
After separating the useful-half of the AC for the ign.system, the otherwise regularly wasted-half can then be rather saved & diverted to power another load (of most any sort).
__ I have more related details to tell about this option, if really interested !
So if you still have any more specific/related questions, I'll be glad to specifically address them.



" as I have bought some high power COB (warm white to look authentic) LED chips which draw 700mA each and are quoted at 1200lumens. I'd mount them on a flat bar and one facing upwards for dip, and both running up and down(1.4A) for full beam. "

____ Seems like a great plan ! _ So it would be pretty-nice if you'd start a dedicated thread on the subject and show & tell us all about it !
If your chosen LED-chips are-not already preset to be intended for a 'grounded-system', THEN you could still possibly full-wave rectify a stock/grounded power-coil, and rather run twin-lead wiring.
__ So anyhow,, I gather that since you'd thusly be saving at-least 3.5-amps, that you'd thus-then expect to have plenty of reserve-power leftover to also fully power any brake-light as well. _ Is that not correct ?
But even-so, you still couldn't power-up a worthy/DC horn.



" On my benchtop supply, "

____ But it's likely FULL-wave & cap.filtered, right ?



" they gave a good output even down to 6V with the supplied drivers "

____ That's going to work well enough whenever your RPMs are kept rather low BUT,, with such a rather low load on the lighting power-coil, the voltage-level during high-RPMs may quite possibly build-up high enough to overwhelm the supplied drivers !
__ So-then what's been your expected plan to control your (lighting-coil powered) intended batteryless-system's likely excessive power-level ? _ Have you been considering the inclusion of some kind of voltage-limiting circuit (to protect your intended low-power lighting-system from becoming over-powered during high-RPM) ?
__ There's been good-reason for why Ducati had always made fair attempt to closely 'MATCH' the power-output (of their power-production systems) with the power-consumption (of their expected load-systems), so as to avoid such over miss-balancing.
I-myself am thinking that perhaps the ign.power-coil could possibly handle ALL your-intended (rather low power) power-needs, all on it's own,, and thusly come closer to being balanced.




" I'll figure out how to post a pic of the parts that are about to become a motorycle... "

____ I've copied the following post-wording from another (rather obscure) section of this w.site. _ I hope it helps !
____ And for anyone else who's not clear on exactly how to submit your intended pictures along with you post here (at this w.site), here's the method I suggest (so as to not somehow loose you post-wording in the process)...
__ After you've safely gotten your text posted, (and you're still logged-in at this w.site), note the 'EDIT' button (directly to the Right of your post's Title), included on your post-page (which you wish to add digital-pics to), and click on that edit-button,
then scroll-down towards the bottom of the presented page (which allows for editing), and click on the 'Upload attachment' button...
You will then be presented with a 'Browse' button of which clicking-on will then provide the means to locate any pictures which you already have stored (in some folder) within your PC.
After you've double-clicked on a chosen picture*, you may add a 'File comment' and then click the button: 'Add the file' .
You may repeat that process twice more (for 3 pix per post),
and when you're ready to finally add your pictures to your post, you can then click on the 'Submit' button, which will then present you with your (completed) posting, just as usual.
(* Keep in mind that the first added picture/file will end-up placed in the bottom-position [in the case of more than one picture per post].)



Hopeful-Cheers,
DCT-Bob
Now twice edited !
PLEASE NOTE... If this-post is not-yet signed-off with '-Bob', then I'm still in the process of completing it,, and if not also included with 'DCT' near bottom as well, then I may edit this post's wording at a later time. - Dct.Bob


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