Alternator forensics

[Jordan]

Hi DCT Bob,

Photos as requested, but you'll have to rely on my text descriptions. It'd have to be a movie to prove the wiring configurations - too difficult!

." I really hesitate to stick my toe back into these waters "
____ Even-so Bill, you are certainly not unwelcome to contribute (as you wish) further !

Ans: I second that.


" I don't see a need to change direction of rotation, which would be more work and complication, compared to just swapping over the wire ends if you want to change the current direction. Or am I missing something? "
____ Right-now, I suppose all the various lead-ends of the individual coil-windings could certainly be arranged so that the circuit-connections between them will still allow positive-current to flow in opposite-directions -(that's in respect to the two yellow alt.wire-lead outputs), at the same time,, even-though the winding-turns are wrap-wound in the same direction. _ It would just make the physical-locations of the connection-points (between neighboring power-coils), a little less conveniently located (I think).

Ans: No Bob, there is no inconvenience as to the end connection locations.


" Curiously, I unwound them both in the opposite direction from the first coil's - counter-clockwise this time. "
____ That's as it indeed has to be, so that the stator's neighboring power-coils will have their produced-current flow all in the very-same direction, as the neighboring magnets in the alt.rotor are of opposite polarity.

Ans: But the wire ends could easily be swapped! Coil winding direction is probably arbitrary, unless I'm missing something (quite possible).


__ When I get time later, I'll then explain the whole-story so that most anyone can understand it.

Ans: We understand but don't agree with your theory. Have you considered what I said about the voltage waveforms being in the wrong phase with respect to each other, to be able to be utilised? There is no storage effect we know about, that could lend weight to your idea.

It's an intriguing thought though, and I sort of wish you were right. But looking at it with hard logic - it just don't add up!

Jordan

[Jordan]

this http://minus.com/ltVZiOuvlCVZv is what I just found, stored deeply hidden on my PC, source unknown, sorry. Obviously, someone had analyzed the wdg. scheme and rewound the stator. Does this depict the situation you found?

Hans

That's a nice drawing.
Only 5 "battery charging" coils shown, so must be a CDI type. I wish he'd shown the 6th CDI coil details!
The one I'm pulling apart has 6 coils - from a points model widecase with no special CDI coil.
Curious how the number of turns seems rather approximate?
The wire diameter is stated as 0.8mm. Is that the same with yours? My 6 coil alternator uses 1mm.

Jordan

[DewCatTea-Bob]

" Photos as requested, but you'll have to rely on my text descriptions. It'd have to be a movie to prove the wiring configurations - too difficult!"

____ I have no trouble accepting your word concerning "the wiring configurations".
The reason I was interested in pix of what you've done, was so it could be accurately realized which power-coils, (as they're originally located on the stator-core), you were examining.
__ Anyways, THANKS for all your pix !

_ It would just make the physical-locations of the connection-points (between neighboring power-coils), a little less conveniently located (I think).

" Ans: No Bob, there is no inconvenience as to the end connection locations. "

____By "inconvenience", what I meant is that the resulting locations for the (power-coil interconnecting) connection-points (from one stator-finger to the next), may require longer than the otherwise shortest-possible lengths for the lead-ends of each winding (of each power-coil),, due to the needed required flow of pos.current with both windings wound/turned in the SAME direction, (as opposed to if they were wound in opposite directions ).

____ That's as it indeed has to be, so that the stator's neighboring power-coils will have their produced-current flow all in the very-same direction, as the neighboring magnets in the alt.rotor are of opposite polarity.

" Ans: But the wire ends could easily be swapped! Coil winding direction is probably arbitrary, unless I'm missing something (quite possible). "

____ I can see your point, so it would seem that the only reason may be due to the "convenience" of interconnection between power-coils, (due to physical concerns, [which I've just explained above] ).



" We understand but don't agree with your theory. "

____ Who's "we" ?
__ After you've been convinced, you will then understand that the P/P-effect is not MY-own "theory".
____ Do you already understand how a transformer is able to function ? _ (I'm thinking not, or else you would've gotten a proper grasp of the workings [of the P/P.theory].)
__ That which would be actual-fantasy, would be if the operation (of the theory) did-NOT work ! _ And if that was the case, then transformers wouldn't function as they do, either.
__ How can YOU explain-away the flux-interaction (that must exist, between the two windings), so as to possibly prove/suggest that the P/P.effect CAN'T work ?
I suggest you think about it a while, and wait to post your response on that, until after I've gotten-around to posting why the Pull/Pull-effect MUST have to exist.
(I hope to get to it sometime after I've returned back-home, Saturday.)



" Have you considered what I said about the voltage waveforms being in the wrong phase with respect to each other, to be able to be utilised? "

____ I'm not sure, as I'm not clear as to exactly what you may actually be referring to.
Could you please elaborate on what you mean ?



" There is no storage effect we know about, that could lend weight to your idea. "

____ I can think of no "storage effect" of any kind that could possibly be involved (with anything to do with the Ducati-alternator/dual half-wave rectification setup), concerning the P/P.effect ! _ As I've already previously indicated, there's nothing to do with any kind of "storage", that's involved in any way with the P/P-effect. _ I don't understand how you can even conceive of any such notion,
as the P/P.effect is DIRECTLY concurrent with the (allowed) flow of current that's pushed by the alt.rotor-magnets.
It's all so fairly similar to the workings of a std.transformer, only just a little-bit more complex.
That you think that there would have to be any sort of 'storage-effect', leads me to suspect that you don't even have an understanding of the workings of a simple transformer,, and if you believe that a transformer has some kind of storage-effect, then could you please explain exactly what you mean (by "storage effect") ?
__ UPDATE: - It now occurs to me that perhaps you may've been thinking your related thoughts while assuming that what I've been claiming has changed since it's been revealed that the two stator-windings are not actually wound in opposite-directions. _ And-so if that's the case, then it may-then be helpful for you to read my last (now edited)- post, at the bottom of the previous-page.



" It's an intriguing thought though, and I sort of wish you were right. But looking at it with hard logic - it just don't add up! "

____ But it has to be ESTABLISHED-logic, which indeed DOES ADD UP !
Do you think Ducati simply did all that which they bothered to produce, without any good/logical reason for it ?


Hopeful-Cheers,
DCT-Bob

[DewCatTea-Bob]

__ When I get time later, I'll then explain the whole-story so that most anyone can understand it.

____ Somewhat unfortunately, I've since come to realize that I won't soon get-around to completing such an extended post-work (in a more timely mannor) if I also include the wording required to explain how a simple transformer is able to function. _ So I'm merely going to word my explaintion (of how the Pull/Pull-effect must have to work), as if the reader already has a fairly-good understanding of exactly how a transformer or ign.coil is able to fuction (with the associated electromagnitizm), as they both also similairly function (much like the P/P.effect has to), as well.
__ Now next I intend to use wording with the intent to establish some common terminology, so as to relate the common counter-parts of both those induction-dependent items -(stator & transformer).
____ The Ducati-alternator has two separate stator-windings which are both wound-around all the very-same common alt.stator finger-cores, (much the same-way as the two windings of a simple-transformer are both wound-around a common core).
Now like the Ducati-stator, a simple-tranformer has two separate windings - one winding is called the 'primary' (as that winding-circuit is fed input-current, and-thus may be considered as being 'live', since it provides the dynamic-magnitizm which causes the flux-feild excitement),, while the other-winding is the 'secondary' (which becomes a source for output-current, and may be considered as the 'dead' winding-circuit, [until it has become excited, of-course], since it's the RECIPIENT of the induction-process).
Now while that 'primary' & 'secondary' relationship remains perminent within a transformer,, conversely, the two windings of the Ducati alt.stator have that relationship constantly flipping back & forth, due to the 'dual half-wave' rectification setup...
So-then, (because the two stator-windings are 180-degrees out-of-phase, due to being reverse-circuited - [rather than oppositely-wound] ), when one winding-circuit is allowed (by it's diode) to be "live" -(current-flow wise), THEN -(at that time) the other winding-circuit is thus-then "dead", (since both of their diodes are faced in the same direction).
Now since the two stator-windings are connected-up (respectfully reverse-circuited) so that each of their very-own current-flows are passed in OPPOSITE directions around the common-cores, (UNLIKE in a center-tapped transformer !), that then means that when one winding-circuit goes 'live', it will then induce an identical-polarity current-flow within the 'dead' winding-circuit,, (as there's no way to prevent that [seeingly free] induced-power) !
__ So in a further detailed example of the process, (concerning the case of the n-c.type circuit-arrangement),,
when the alt.rotor-magnets begin to push a positive half-cycle of current-flow through the First winding-circuit, (thus THEN acting as a live/primary-circuit), then that flowing-current first produces an 'expanding' positive-polarity flux-field which must 'induce' an identical-portion of positive-waveform within the other/neighboring (otherwise dead, at the same-moment) Second winding-circuit,
and then-next as the remaining-portion of the 'primary' pos.half-cycle falls-back towards zero, it's then 'collapsing' flux-field next 'pulls' the rest of the 'secondary' pos.half-cycle of induced-power within the Second winding-circuit.
That (detailed) process can-not be denied, as it's pretty-much the very-same as that within a simple transformer ! _ The difference here with the Ducati-stator, is that it's two windings take turns being "live" or "dead" & being 'primary' or 'secondary'.
__ And-so furthermore, when the First winding-circuit is being forced by the alt.rotor to produce a (half-cycle)- pulse of positive-power out-through it's diode-output and the connected load-system, then in like-kind, the Second winding-circuit is then concurrently forced (by the induction-effect from the First-winding) to also produce it's-own (induction-generated) pulse of pos.current through it's-own diode-output.
However the amplitude of the pos.power-output from the Second winding-circuit, (whichever of the two circuits that may happen to be, at any particular moment), is likely less powerful due to the flux-field being less than 100% effecient (depending on the winding-core).
Also, a regulator-circuit only actually has to deal with just the power generated due to merely the action of the alt.rotor, and not ever to be concerned with the additional-power provided by the mutual-induction / P/P.effect, since THAT power-production is more directly related to the current-consumption by the load-system and thus never exists as excess-energy needing to be dealt with, (since it's only created as it's being consumed). _ Now isn't that nifty & cool !?
__ So now, when the First -(acting-primary) winding-circuit is powering the load-system with it's alt.rotor produced half-cycle of positive-power, it then also creates an induced positive half-cycle of 'induction-effect' produced power within the Second -(acting-secondary).
So thus when the First winding-circuit is providing 'alt.rotor' produced pos.power out-through it's-own diode-output, then at that same moment, the Second winding-circuit is then providing 'induction-effect' produced pos.power out-through IT'S-own diode-output (at the SAME time). _ And of-course that relationship (between the two winding-circuits) exchanges places when the second-half of the AC-cycle is made by the alternator, (etc. & so-on).
____ I should probably make-note that the more detailed part of my explanation was using the n-c.type of rectification-circuit, and that the equivalent w-c.system is backwards, in that IT handles negative-power to the frame, (rather than positive-power to the battery).

____ The above is not really presented/worded completely as I've been thinking-over during the past few days, and as my various thoughts on the matter come-back to me, I'll likely then find a way to incorporate my past/earlier wording-thoughts into this post (so as to hopefully get it to more easily be understood and perhaps also be more technically-correct).
It's just what I've come-up with for now, so that my promised post doesn't get even further delayed, (as is usually the case with most of my postings).
__ Also, I hope to get some questions & any counter-points made against that which it seems I'm trying to claim, so that I can then provide edited-wording to better avoid any similar possible misinterpretation.
So for any of you who are smart enough about such things as I've brought-up here-above, if you have not yet been convinced, then please give your reasoning as to why you still don't understand or why you don't agree with the "theory" of the presented process,
and I'll then try to address such concerns, (hopefully when I'm more clear-minded).
In any case, I'm sure I'll be getting-back to this post (with some wording-editing), later.


Fun-Cheers,
-Bob

[Jordan]

Hi Bob,
Thanks very much for taking the trouble to explain your view.
I'm still not clear about one thing. How is it that any current could be induced to flow, when the circuit is "dead"?

samecore2.jpeg

The drawing shows what's confusing me. Can one winding contribute anything to the other, when it's flat-lining at zero volts?

Jordan

[DewCatTea-Bob]

____ Good-Day Jordan,
I'm pleased you've bothered to summit a response-post !


" How is it that any current could be induced to flow, when the circuit is "dead"? "

____ Okay, that's a question I like to get responded-to...
__ I use the word "dead" because it's more 'commonly' used (than an equivalent tech.term), and, (as like that of a 'secondary-winding' within a simple transformer, which is not considered as the 'live' side of the affair), it's meaning in this case is in reference to whichever winding-circuit happens to be kept from flowing current (by it's diode), thus it's then being non-productive (during the moment when it's not producing a positive [half-cycle] pulse of it's very-own [by alt.rotor-action], and-so thus-then it's rather "dead" [for the brief time being] ).
And since that winding-circuit's diode is killing any possibility of negative power-circulation within it's-own circuit (thus leaving it self-dead [until it produces it's very-OWN positive half-cycle] ), that thus-then opens the door for the induction-effect (from the 'live' winding-circuit) to induce pos.power-output out-through it's-own diode. _ So-thus while that winding-circuit happens to be 'dead' on it's own, it could then be considered to BECOME virtually-live, but only due to the INDUCTION-effect, (and not by it's very-own power-production).
So that's why it's thought-of as being "dead" (for the brief-moment that it actually is, all on it's own).
__ In my previous-posting, I had expected my post's wording to allow the reader to realize that either winding-circuit is only "dead" for just a very-tiny fraction of a second, at a point when the circuit is not SELF-producing a positive half-cycle and it's diode is then stopping the negative half-cycle from flowing, thus at THAT moment, the circuit is then "dead",, and-so THEN (at THAT time), it becomes possible to induce pos.power into that currently dead circuit. _ (Indeed, if that circuit wasn't 'dead' at the time, then it wouldn't be possible to 'induce' any power into it [by the induction-effect from the then acting-primary].)


" Can one winding contribute anything to the other, when it's flat-lining at zero volts? "

____ That question (as it's worded) allows me to think that you haven't correctly-followed my intended explanation quite right.
I've since edited my previous-post, so it may now make more/better sense to you, hopefully making for a deeper understanding.
__ Anyhow, actually it's best for the acting 'secondary' to be "dead" -(doing nothing on it's own), when it gets a signal induced into it by the acting "live" 'primary'.
When a winding is flat-lined at zero, it then no-longer has any flux-field to excite any life into it's neighboring winding,, so at the zero crossover-point, neither winding is then -(at that almost non-existent moment in time), producing either type -(alt.rotor or winding-induced), of power-production.
__ Now if I take your question literally-raw, then the answer would of-course have to be 'no', as a winding-itself can-not (directly) contribute to it's neighboring-winding (especially after it's gone-into it's-own dead-mode !).
However, while the "winding" itself can't directly "contribute", it's actually it's created 'flux-field' that is the actual direct-contributor which 'induces' power into it's (otherwise dead) neighboring-winding.
__ So while the 'live' winding-circuit is inducing power into the 'dead' one (at the very-SAME moment), that short-lived process will quickly end & be over-with, and then THAT same winding-circuit will next become the 'dead' one while the OTHER winding-circuit has changed from 'dead' to 'live' and thus-then likewise repays-back the favor (which had just been done for IT,, etc.,etc.),, thus the "Pull/Pull" coined-term, (or perhaps: 'flip-flop mutual-induction').

____ I've added the part of your pic which depicts the half-wave rectified (180-degrees out of phase) outputs of the two alt.stator-windings, (as still represented in black),, and to that I've included the expected added power-outputs due to the mutual induction-effect, (as represented by the added blue & red half-cycle DC.pulses).
__ When the two power-outputs are connected-up to an oscilloscope without any 'load', then only the black pulses of power will be shown,, however with a load included, then as the load is increased, the amplitude of the blue & red pulses will then begin to show-up in increasing amounts, (likely never reaching the same amount of amplitude as that of the black-pulses).
____ Hope this helps,, but if not well enough, then please feel free to ask more clarifying questions.

____ Also, I wonder where MotoMike is ? _ As I sort-of miss his efforts to shake-around much of whatever I claim concerning electronics.
Actually though, I REALLY have been missing his regular contributing-posts which he has always been good for. _ I sure hope he's alright !
You still with us Mike ?


Hopeful-Cheers,
-Bob

[Jordan]

I borrowed a friend's magneto testing machine, a wonderful tool for a motorcycle type flywheel generator. It has a reversible motor, with variable speed control, and a tachometer. It was set up for a Suzuki, but happily the stator mount has exactly the correct dimensions to accept the Ducati's stator. Even the mounting screws are just right, but only 2 instead of 4. Coincidence? I just need to make a shaft with the correct taper. When I get it up and running, some tests should reveal what's really happening in Ducati's eccentric alternator!

Jordan

[Jordan]

I made a new spindle so now I can spin a Ducati rotor on the Crypton Magmaster.
I did a quick check of a Ducati stator output with the oscilloscope. Boy, the AC looks very un-sine like - very "peaky". I don't suppose that matters, but it's surprising to see. Now I'm wondering if I'm doing something silly, to generate such a waveform. An 18VAC transformer I have, plugged into a wall socket, makes a beautiful, classic sine wave.
I'll have to play around with it a bit before I get any sensible data I think.

Jordan

[DewCatTea-Bob]

" I did a quick check of a Ducati stator output with the oscilloscope. Boy, the AC looks very un-sine like - very "peaky".
Now I'm wondering if I'm doing something silly, to generate such a waveform. An 18VAC transformer I have,
makes a beautiful, classic sine wave. "

____ You probably have the oscilloscope's input-sensitivity set to a voltage-scale that's more appropriate for the transformer's 18-volts of power-output, (and it too could become shown as "peaky" if the scope's set sensitivity-scale were to be set too low). _ Where-as if there's no load connected in parallel with the o.scope's input, then the voltage-output from the alt.stator can climb to a much higher voltage (than just 18-volts), and-so thus-then swamp the scope's set view. _ So to bring the alt.stator's voltage-peaks down to what would appear to be a more normal-looking 'sine' type wave,, then either add a load, or decrease your o.scope-unit's input-sensitivity. _ OR, if your particular o.scope-unit has limited range-settings, then perhaps you could instead adjust it's time/frequency range (so as to show fewer Hz -[cycles-per-second] on the scope),, since the alt.stator could (likely) be running AC.cycles well-over 3000-Hz - (at least 50-times greater than that of the transformer connected to house-current !).
Either range-adjustment -(voltage or time) should be able to un-squash the view of the sine-wave waveform presented on the scope-screen.


Hopeful-Cheers,
-Bob

[Jordan]

I'm waiting for delivery of some matched oscilloscope probes, so I can try to get some waveforms to compare.
In the meantime, here's the setup. Note the peaky rectified "sine" wave. After posting a query at an electronics forum, some said that a true sine wave is difficult to achieve, and that power stations try hard to do it. So, all the textbook pictures are just theoretical it seems. Not that it matters much on motorbike alternators I guess.

Jordan