Troubleshooting Alternator Wiring

[wcorey]

edit, and the bought item would probably prove to do a better job than an alternator rewound by me.

You don't need to rewind, just some re-arrangement of connections on the stator and the option of robbing a couple coils from another stator and adding them on (with the four coil alt). The current thread is a spinoff/continuation of a past one that makes this one look small and easy to follow.

[LaceyDucati]

Graeme

See also new posting coming soon on machining your own pistons from solid

I'm with you on buying a ready made unit, as I've other things more pressing to do. Maybe that's why I chose to be a mechanical engineer not an electrical one after my first year of my apprenticeship! Making ammeters, transformers etc was all very interesting at the time but once was enough for me! But again we are all different and whatever floats your boat! If you've the time and interest carry on, good luck, I'll pass!

I'll get back in my corner too, only jesting!

Regards Nigel

[ecurbruce]

Bob says;"This is a right-hand winding example.
__ Here is shown a simple way to check-on the resulting polarity of a winding.
Of-course flipping-around the battery will certainly correspondingly also do likewise with the magnetic-polarity of the nail ! _ But ALSO, altering the wind-direction from right-hand to left-hand would also flip the polarity as well, (without any need for flipping-around the battery) !

Bob, I was just doing some RE-reading, and as I re-digest this , I was wondering, can you think of any other way to flip the polarity in this example?

Bruce

[ecurbruce]

Bob says;"____ It seems that you've certainly failed to conceive the concern I've had for why it's really-NOT so very-SIMPLE as merely-just that ! ...
Simply swapping-around the wire-connections to reverse the current-flow so that the coil's polarization is then reversed, does-not properly address ALL the 3-dimentional mag.field effects ! ...
__ Maybe you had read right-past my previous-attempt to convey the star-core polarization concern that I've had, so here's another attempt.
Imagine the (otherwise invisible) mag.fields rotating along-with the current flowing-through the coiled-windings... If ALL-6 of the coil-windings were wound either right-hand (or all left-hand),, then as the mag.rotor spins it's N & S poles, the generated fields of the coils under the influence of the rotor's S.poles would then rotate in the OPPOSITE-direction of the rotating fields under the N.poles, (much-like six meshed gears all rotating together, on the six core-fingers).
Now apparently Ducati determined that rather than that-relationship, it's better to have all-six fields set-up to rotate ALL in the SAME-direction (instead of having half opposed),, so they chose to wind every-other coil-winding oppositely from the neighboring coils (simply to compensate for the fact that every-other mag.pole is a N.pole [or S.pole] ). _ And you must understand that the other-option of simply reversing the interconnecting wire-connections (between the neighboring-coils) so-as to compensate, is-NOT a valid-option/fix,, because THAT would thus-then cause the power of the three small-coils to attempt cancelling that of the large-coils !
__ So why even CARE to address this seemingly non-issue (of virtually-meshed coil-fields), you may next ask ?
Well apparently it's done out of concern for keeping all the N & S fields (which get concentrated within the star-core), all coherently-arranged in rather correlated harmonious concert (instead of any potentially canceling-opposition). _ Cuz otherwise, the beneficial-effect of the core would then be diminished. "



If the proximity effect of eddie currents is strong enough to affect the neighboring induced secondary magnetic field,- what if we compared the output of THAT situation with the output of the two dual-wound coils all by themselves on an otherwise empty stator core. Would this not tell us if the Eddie effect is increasing or decreasing our parallel-series-parallel coils output?

Bill,
I have an empty stator core, if you're interested in testing this idea, you could install only the two rewound spools on it and test. You could test one coil at a time with no interference of any kind, to see if it changes the results... They could be tested side-by side, and also at 90 degree configuration, just the two rewound spools, the rest of the stator core empty, just to see if there is a difference.

If that shows a difference in output, either gain OR loss, then a test where all six coils have a connected circuit, so all eddie currents are interacting, specifically the ones directly on either side of the rewound spools. (You may have already tested this???)

Bruce

[DewCatTea-Bob]

[quote= ecurbruce ...
" I was wondering, can you think of any other way to flip the polarity in this example? "

____ Concerning the electromagnet-nail example,, I'm thinking that you possibly want me to realize or point-out that the coil could be slipped off-from the nail and then flipped-around & reinstalled back onto the nail, thus-then swapping the N & S mag.field positions (from how they WERE before).
__ As your-topic became the-topic,, instead of me then assuming that you were already like-minded/on-track with my-own mindset on what's-what with this-stuff, I should've started-out from the very-beginning fully-explaining that we need to make-sure that we keep in-mind that there are BOTH the primary AND the secondary mag.fields to be concerned with, (and NOT just one or the other) ! _ So that we then wouldn't have had any chance to confuse which-ever of those two that either of us was actually in discussion of.
__ Anyhow, in direct-answer to your question,, other than re-setting the mag.rotor's polarity,
as far as I know, there are no OTHER ways to cause the N & S poles to become swapped-around.




" If the proximity effect of eddie currents is strong enough to affect the neighboring induced secondary magnetic field, "

____ Not-sure exactly what your chosen wording is actually meaning to state, but 3rd.dimensional 'eddy currents' are minimized by the laminated-layers of the core.




" what if we compared the output of THAT situation with the output of the two dual-wound coils all by themselves on an otherwise empty stator core. Would this not tell us if the Eddie effect is increasing or decreasing our parallel-series-parallel coils output? "

____ First I'll mention that I'm sure that the parallel-arrangement of the double-windings plays no significant role in any related manor.
However it seems logical that the series-arrangement between the two neighboring coils, may well work-together in conjunction (if-not exactly concerted-harmony) with their mutual secondary-fields, and the primary-fields (induced into the core by the mag.rotor-poles) as well.
But as Bill has mentioned, it may-not prove to be necessarily advantageously beneficial to connect a coil that's being mostly pushed to a neighboring coil that's being mostly pulled.
__ It's well established that a layered-core helps to concentrate & intensify the magnetic-field around it, so any side-effect that helps (rather than upsets) the intended-cause of the core, has got to be of at-least SOME-amount of further benefit.
__ The concern I've had was whether having the pair of power-coils wound the wrong-way (with respect to each-other), could possibly be killing some of the core's desired effect.
To compare power-outputs, we'd then need two (either small OR large) coils that are wound oppositely from each-other, to then be separately tried-out along-with the tested coil that's kept left installed on the stator-core.



" Bill,
I have an empty stator core,
you could install only the two rewound spools on it and test. You could test one coil at a time with no interference of any kind, to see if it changes the results... "

____ A thought I have about this, is that while the primary-fields which are ALWAYS induced into the star-core (by the mag.rotor) would all still remain in effect,, the secondary-fields are only in existence JUST when the coils are connected to a circuit !
So-thus any other coils left installed on the stator-core, shouldn't produce any interfering mag.fields, so long as THEY aren't connected-up to anything.



" They could be tested side-by side, and also at 90 degree configuration, "

____ You must mean '180' degrees, opposed.


" just the two rewound spools, the rest of the stator core empty, just to see if there is a difference. "

____ I've always wondered about that -(if there would be any benefit if the center stator-core wasn't so busy conducting the mag.flux of more than one-pair of coils) ! ...
In the mid-60's, I was given a collection of 1962-65 cycle-mags and read in one of them a slight-mention of Ducati having developed a new alternator with 50% more power,, and having been fairly familiar with two of their three 4-pole alt.models, I became quite interested to examine their new alt.version (to see exactly how they had managed to get 50% more power) !
But it wasn't until at-least a couple-years later that I was finally going to get my first-chance to actually see in person one of the updated alternators (in a Monza that needed a new con.rod [thought to be due-to having been ran too-long with excessively fuel-diluted sump-oil]).
Not long before pulling the mag.rotor, I had become quite excited with the expectation of discovering either a pair of LARGER power-coils (of the std.4-pole type, with obviously more winding-loops), or-else an added/third std.type power-coil.
But as soon as the flywheel-rotor got pulled-off, my eyes then became rather shocked and my mind-set became blown-away ! _ Cuz not only had I not expected anything of the kind (as the un-simple 6-pole stator), but also, I couldn't comprehend how such a STRANGE stator-arrangement could possibly work (at-all in the established manor which I had been familiar with) !
I really very-much disliked Ducati's new-alt.version ! _ And it wasn't until 1973, that I finally came to somewhat appreciate Ducati's 6-pole type alternators.
__ What I've always since wondered about it,, is whether the power-coils still get full-effect of BOTH mag.rotor-poles, even-though ONE of the alt.rotor's two mag.poles is relatively remotely-located, and-therefore MORE dependent-upon the core to transfer-conduct the full/combined-strength of the mag.fields (towards a power-coil's opposite/inside-end as well).



Hopeful-Cheers,
D-Bob

Note that I've completed my post (which I had left unfinished), with the now-added part done with blue-lettering, as seen on the previous-page.

[wcorey]

Bill,
I have an empty stator core, if you're interested in testing this idea, you could install only the two rewound spools on it and test.

Whatever... If you guys think it's that worthwhile, I'll test it.
Seems like a lot of this sort of thing is splitting hairs for small gains but since something seems amiss with the projected output vs actual, then since we've come this far with it...

So I guess I should hold off on reducing the coil windings then.
When I do it, I think I'll first try only the large coil. Take a couple layers off, try it, then reduce it to the same weight as the small coil and hook them up as series windings with both coils in parallel.

I also did some numbers for the coils in series/series, as expected the voltage goes up appreciably and so does the working impedance.
I'm only including the load values for peak output and one on either side.

3550 rpm, generic bridged rec (full rectification).

Small coil, both windings in series.

2 ohm----2.4a------5.1vdc------12.5w
3 ohm----2.1a----6.5vdc------13.6w
5 ohm----1.6a----8.2vdc------13.1w


Large coil, both windings in series.

5 ohm----1.7a----8.4vdc-----14.3w
7 ohm----1.5a-----10.4vdc----15.6w
9 ohm----1.3a----11.7vdc-----15.2w


Both coils, each with both windings in series, both coils in series.

12 ohm----1.3a----17.5vdc-----26.2w
14 ohm----1.4a-----19.1vdc----26.7w
15 ohm----1.3a----19.8vdc-----25.7w

Same, with the addition of caps

7 ohm----1.8a-----12.9vdc----23.2w
15 ohm----1.4a----21vdc----29.4w

[DewCatTea-Bob]

[quote= wcorey ...
" If you guys think it's that worthwhile, I'll test it. "

____ I-myself am fairly neutral as to whether you bother yourself with such a particular test. _ I think it would be worth doing only if YOU have nothing more important for yourself to spend the time on.



" So I guess I should hold off on reducing the coil windings then. "

____ I'm somewhat relived that you haven't already jumped-ahead with that, as I had forgotten to mention some suggestions I had previously thought-of (which your below wording reminds me of) ...



" I think I'll first try only the large coil. Take a couple layers off, try it, "

____ That's what I was going to recommend,, do before & after testing of just the large-coil (alone by itself, with & without it's outer two layers removed), so we can then discover exactly how much difference winding-length actually makes.
So when you remove the two-layers, please try to measure it's length as it's removed.



" then reduce it to the same weight as the small coil and hook them up as series windings with both coils in parallel. "

____ I hadn't thought of actually doing THAT, but if that's a test which YOU wish to try, it'd be okay I guess.
But rather than make either of the double-windings into one (series connected) winding, and-then arrange the two power-coils in parallel for testing their combined-output in that (likely mismatched) manor,, MY-own thought was that IF the large-coil testing yields any really noteworthy-difference after it's outer two-layers have been removed, that then the parallel/series/parallel-test be retried again (so that we can learn if that discovered-difference STILL shows-up).



" I also did some numbers for the coils in series/series, "

____ I assume that means that you've now tried testing each coil separately, with it's double-windings rather connected-together in 'series' (instead of parallel),, and-then with them both left that-way, also tested with both power-coils also connected-together in series, (for a series/SERIES/series configured test).



" the voltage goes up appreciably and so does the working impedance. "

____ Naturally, of-course... As I believe the only reason for that is because, as the test-load's resistance-value is increased,, the built-up tension is not bled-off as greatly, thusly allowing the voltage a chance to climb-up higher.
__ So it would be of interest to see how this series-test's voltage-result fairs-out when matched-up against the particular test-load value which yielded the highest-voltage result in the PARALLEL-test.



" I'm only including the load values for peak output and one on either side. "

____ That's fairly nice of-course but, it would be more informative if you'd test & list the results that allow the overlapping of both series & parallel testing. _ In other-words, instead of just listing only one 'result' on either side of the optimum/peak-result,, all the overlapping test result-figures (of both series & parallel arrangements) should be listed so that we can then see how the SERIES-arrangement does with the particular test-load which had revealed the parallel-arrangement's BEST test-result, and-also, that of how the PARALLEL-arrangement does with the particular test-load which had revealed the series-arrangement's BEST test-result. _ As those two BEST test-results were spaced-apart by several test-load resistance-values. - (Such as: 3;4;5;6;7;8;9;10;11;12;13;14;15 ohms.)
That way, it can then be more fully realized how the parallel-arrangement is more useful (than the series-arrangement).

Small coil, both windings in series.

2 ohm----2.4a------5.1vdc------12.5w
3 ohm----2.1a----6.5vdc------13.6w
5 ohm----1.6a----8.2vdc------13.1w


Large coil, both windings in series.

5 ohm----1.7a----8.4vdc-----14.3w
7 ohm----1.5a-----10.4vdc----15.6w
9 ohm----1.3a----11.7vdc-----15.2w


Both coils, each with both windings in series, both coils in series.

12 ohm----1.3a----17.5vdc-----26.2w
14 ohm----1.4a-----19.1vdc----26.7w
15 ohm----1.3a----19.8vdc-----25.7w

____ It's interesting (and questionable) that the 3-ohm & 7-ohm optimum test-loads seem to add-together to yield a 14-ohm optimum test load for both power-coils combined in series (instead of just 10-ohms).
This (possible trend) indicates that 'impedance' is-not a linear factor. (?)
So if those uncombined series test-results weren't already undesirable enough, it seems that further-still series-arrangements are somewhat exponentially even WORSE !
While this outcome (from the series-arrangement) really isn't bad for intended load-systems with rather quite light current-demands (like merely just a tail-light), a high current-demand load (like a headlight) could never consume the majority of the produced-power because the power-winding itself would then become THE bottle-neck (and-thus rob the majority of the produced-power) !
__ We really need to compare these test-results with those of the STOCK power-coils.

Same, with the addition of caps

7 ohm----1.8a-----12.9vdc----23.2w
15 ohm----1.4a----21vdc----29.4w

____ Capacitors tend to obscure test circumstances (almost as badly as batteries do).
Something that might be of interest,, is to see just how high the voltage can possibly become, with a cap & NO load (at the near 3500-RPM).
__ I wonder if you again tried-out the same headlight, to compare how bright it could get ?


Enlightened-Cheers,
-Bob

[ecurbruce]

Bob says;"__ So my new proposed power-coil scheme would be to wind TWO separate winding-coils (placed right-next to one-another) on each bobbin, with at-least six layers of #20-gauge wire.
That-way we can then surely be quite CERTAIN to (at-least) attain a 50% increase in power (over that of the stock power-coils), since there will then effectively be TWO independent power-coils per bobbin (with EACH producing at-least 25% [apiece] more power than a stock power-coil) !

I just happen to have a partial spool of #20, I could wind that with.
Are you about ready to send me some spare bobbins to wind on?

I'm wondering if you have any concerns about the inboard coil being farther out of the magnetic field and having some adverse effect?

Have you done the math on that concept- related to length of wire in each coil at six layers, and the expected resistance of each? You're usually pretty close on that stuf...

Bruce

[DewCatTea-Bob]

[quote= ecurbruce ...
" I just happen to have a partial spool of #20, I could wind that with. "

____ Great, can you use all that to check & make-sure that 6-layers is actually doable (with that thickness of wire-gauge) ? _ As you'd then be unwinding that (stock inner-layers) winding and-then attempt to try rewinding that-length on just one end of the bobbin, (probably filling-in only one to four rows of the bobbin's full-width).
__ Be sure to make note of the stock-winding's number of loop-turns, length, turns-direction, etc.



" Are you about ready to send me some spare bobbins to wind on? "

____ Actually, I have TWO stock n-c.type/4power-coil stators I'd like to send you, with hopes that you'll be willing to rewind all-eight power coils,, so that hopefully we then end-up with both a 6-coil stator (for you to keep for your-own project), PLUS a 4-coil version (for possible future use on a n-c.motor).
That way, we can then try-out less un-risky power-winding options (as previously intended).
__ So-then send me your shipping-address, to robhan548@hotmail.com .



" I'm wondering if you have any concerns about the inboard coil being farther out of the magnetic field and having some adverse effect? "

____ While the more inward coil -('inboard-coil') will be more dependent on the core's field (which is likely SLIGHTLY-weaker), I don't see that probable issue having any adverse effect. _ But considerably MORE important is that the inboard & outboard coils will be 'matched' ! - (Matched almost just-like the paired/double-windings, except that we'll have two independently-separated 'coils' acting more-like the stock coils.)



" Have you done the math on that concept- related to length of wire in each coil at six layers, and the expected resistance of each? "

____ No, not yet,, but if you'll let me know how long one 6-layer row actually is, (or how long 2 or 3 or 4 rows is [that's 6-layers deep]), I'll then figure the resulted resistance for the entire intended coil-winding.


Hopeful-Cheers,
-Bob

[ecurbruce]

image.jpg

Bob says;"____ Great, can you use all that to check & make-sure that 6-layers is actually doable (with that thickness of wire-gauge) ? _ As you'd then be unwinding that (stock inner-layers) winding and-then attempt to try rewinding that-length on just one end of the bobbin, (probably filling-in only one to four rows of the bobbin's full-width).
And;
" but if you'll let me know how long one 6-layer row actually is, (or how long 2 or 3 or 4 rows is [that's 6-layers deep], I'll then figure the resulted resistance for the entire intended coil-winding.

Bob, I can see where you're coming from on this line of thinking,-- what I have is a store-bought spool of #20 copper, I guess you were thinking one more Ducati spool?
I'm all out of ducati stator bobbins for the moment, we'll fix that shortly...
I'm pretty sure six layers is doable.

Bob says;"__ Be sure to make note of the stock-winding's number of loop-turns, length, turns-direction, etc. "

Copy that!!!

Bruce