Ducati Elettrotecnica Coil pole identification

[thatnameisal]

Working with what appears to be the original DE 6V coil for my '65 160cc Jr

One pole is marked "1" and the other is marked "15"

Which is the ground and which comes from the points? Does it matter?

Thanks in advance!

[thatnameisal]

[Jordan]

Look up DIN 72552 standard, which is for automotive wiring codes.
1 and 15 are common terminal designations for European made high tension coils.
See also sample wiring diagrams (Google Images) to help figure out how to connect correctly.

[thatnameisal]

Thank you Jordan:

1 ignition coil, distributor, low voltage
15 battery+ from ignition switch

[Ventodue]

I stand to be corrected , but ..

Isn't that a DC coil? And don't Monzas use an AC ignition system?

Just asking ....

Craig

[DewCatTea-Bob]

____ Sorry I haven't felt much like exploring recently listed threads over the last month...

____ For this straight-forward inquiry,, I had assumed had been fully-covered by Jordan, so I hadn't bothered to take a look-see at what's been stated in here until now.


[quote= Ventodue ...
" Isn't that a DC coil? And don't Monzas use an AC ignition system? "

____ ALL ign.coils actually work on 'DC' only, whether it be straight-DC or pulsed-DC ! _ The AC that's allowed to be subjected to the ign.coil in magneto-type ign.systems is simply done for the sake of cheap-convenience and NOT by design !
The supplied AC has an unlimited number of negative & positive DC.power-pulses, of which only part of one single power-pulse (per 4-stroke cycle) is actually used by such an ign.system to produce it's (solitary) ign.spark ! _ While all the rest of the DC.power-pulses (of the AC) are uselessly wasted to ground !
__ Monza-Jr models (along-with all pre-1968 Scrambler & M3 models) employ the 'green-label' ign.coil which is intended for the magneto-type ign.system, while the 250Monza-models employ the 'red-label' ign.coil that's intended for battery-powered type ign.systems !!

____ Anyhow, while it doesn't matter a great deal,, the #1 terminal-post is supposed to be connected to the ign.points, while the #15 terminal-post is the one which is supposed to be fed by the power-source (be it DC or AC), (at-least according to various manual-books).


Dukaddy-DUKEs,
-Bob

[Ventodue]

ALL ign.coils actually work on DC only ...

Thanks Bob.
(As it goes, in between making my original post and you posting your reply, I had kinda worked that out by myself - I couldn't see how a coil could work using AC. But good to have confirmation from someone who actually knows .)

Monza Jr models (along with all pre-1968 Scrambler & M3 models) employ the 'green label' ign.coil which is intended for the magneto-type ign.system, while the 250 Monza models employ the 'red label' ign.coil that's intended for battery-powered type ign.systems.

Thanks. Do you know how they differ?

Anyhow, while it doesn't matter a great deal, the #1 terminal post is supposed to be connected to the ign.points, while the #15 terminal post is the one which is supposed to be fed by the power source (be it DC or AC).

Can you say a bit more on this, please?

Comparing the wiring diagrams for a) bikes with magneto-fired ignition b) bikes with battery-fired ignition, the coils seem to be connected differently. While the battery-fired models follow the 'classic' scheme (such as you describe), the magneto-fired system are shown with one terminal of the coil acting as a common terminal, taking power from the alternator and feeding it to the points. The other terminal on the coil goes to ground. To illustrate, here's the 160 Monza scheme:



I can see that it doesn't make any difference in practice which 'end' of the coil the points are connected to, or the primary winding grounded. But is this actually how these magneto-fired bikes were/are wired, do you know?

TIA

Craig

[DewCatTea-Bob]

[quote= Ventodue ...

Monza Jr models (along with all pre-1968 Scrambler & M3 models) employ the 'green label' ign.coil which is intended for the magneto-type ign.system, while the 250 Monza models employ the 'red label' ign.coil that's intended for battery-powered type ign.systems.

" Do you know how they differ? "

____ Not entirely but, I believe that the green-coil has a less radical turns-ratio.

Anyhow, while it doesn't matter a great deal, the #1 terminal post is supposed to be connected to the ign.points, while the #15 terminal post is the one which is supposed to be fed by the power source (be it DC or AC).

Can you say a bit more on this, please?

Comparing the wiring diagrams for a) bikes with magneto-fired ignition b) bikes with battery-fired ignition, the coils seem to be connected differently. While the battery-fired models follow the 'classic' scheme (such as you describe), the magneto-fired system are shown with one terminal of the coil acting as a common terminal, taking power from the alternator and feeding it to the points. The other terminal on the coil goes to ground.

____ DARN, I sure hate-it when I fail to notice my-own posting short-falls !
Thanks for bringing my oversight to light !
__ I should've better elaborated especially concerning the AC/magneto-type ign.coil circuit-arrangement.
In my quoted post-wording, where I stated "should be connected to the ign.points,", I rather instead should've stated 'main-source of ground' !
(If I had gotten-around to reading my-own post again, I then probably would've noticed that wording-error and edited it to make more proper sense, as I often do.)



" But is this actually how these magneto-fired bikes were/are wired, do you know? "

____ Not-sure what you may actually mean by "this" exactly, but the magneto-type ign.circuit is set-up so that the points ground-out most-all AC.power-pulses until the particular power-pulse that's actually needed can be diverted from ground and left nowhere-else to go other than through the ign.coil (at the moment when the ign.points open).
And with that pointed-out, you ought-to now understand why the mag.type ign.coil-connections seem so odd (as compared to the "classic" ign.circuit).


Dukaddy-DUKEs,
-Bob

[thatnameisal]

Wait a second...do I have this right?

I connected wiring diagram (from Ventodue above) wires #6 & #12 to primary coil lead labeled "1" (in photo above) and
GROUND from wiring diagram (from Ventodue above) to primary coil lead labeled "15" (in photo above)

Correct?

[Ventodue]

Wait a second...do I have this right? I connected wires #6 & #12 to primary coil lead labeled "1" and GROUND to primary coil lead labeled "15"

Wait for Bob to come back on this - I tread very carefully when It comes to subjects like this ...

In the meanwhile, you might be interested by these articles on the effect of having the coil hooked up backwards. It will still work, just - in theory at least - less well. In practice, the author of the second article found it made no difference: but whether that would be true for a little Ducati - non lo so
http://mgaguru.com/mgtech/ignition/ig104.htm
http://www.avmz31.dsl.pipex.com/ht/coil.htm

Craig