Troubleshooting Alternator Wiring

[DewCatTea-Bob]

[quote= ecurbruce ...
" Bob, I can see where you're coming from on this line of thinking,-- "

____ And to be sure of that, what exactly are YOU thinking in that regard ?



" what I have is a store-bought spool of #20 copper, "

____ OH, I hadn't realized that you ALREADY-had some #20-gauge stock in your-own possession (which wasn't sourced from your spare Ducati-bobbins).
__Then in that case,, instead of bothering-with merely checking with the use of the (too short) stock-length of 20-gauge, you could rather go-ahead & use your new-wire to completely wind BOTH separate coils onto one bobbin.



" I guess you were thinking one more Ducati spool? "

____ Yes, right... When I wrote my post-wording, (for some reason) I was then presuming that you still had one Ducati-bobbin left with just 2-layers (of the stock inner dual-winding) of 20-gauge wire still-left wound on it.



" I'm pretty sure six layers is doable. "

____ Since the stock winding-spool is 4-layers deep, it would be quite nice if each of your coils could be 8-layers high,, cuz THEN, each coil would thusly have the SAME number of loop-turns as the stock power-coil, thus just one completed spool would then be at-least equal to TWO stock power-coils ! _ But I guess we'll have-to settle for merely 6-layers & just the resulting extra-50% increase.



" I'm all out of ducati stator bobbins for the moment, we'll fix that shortly...

Copy that!!! "

____ But first we now apparently have-to wait until you've received my stator-spools.



Hopeful-Cheers,
-Bob

[graeme]

The later 450's (and I assume the 350 and 250?) use these alternators.

I assume they deliver the same wattage as the points widecase scramblers but with only 5 coils ? Is that correct?
If so the 5 windings must be different to the normal 6 coils. Perhaps test what these windings deliver and copy that to 6 coils to get more wattage?
Graeme
(should I go back in the corner?

[DewCatTea-Bob]

[quote= graeme ...
" I assume they deliver the same wattage as the points widecase scramblers but with only 5 coils ? "

____ I wouldn't assume that,, the claimed 70-watts for the 6 power-coil 450-alt.system is likely under-RATED to begin with, so-thus your 450's 5 power-coil alt.system is still good for the 70-watt rating.



" If so the 5 windings must be different to the normal 6 coils. "

____ I don't really know for sure but, I'd bet that they are just the same as all the other 6-pole type power-windings.



" Perhaps test what these windings deliver and copy that to 6 coils to get more wattage?

(should I go back in the corner? "

____ All Ideas are welcome, of-course,, but I'm fairly doubtful that those main-type power-coils deliver any more power than any of the others like them.
However the one coil that's dedicated to powering the ign.system, quite more-likely has differently intended output characteristics (which would be interesting to test !).


Dukaddy-DUKEs,
-Bob

[Harvey]

[quote= graeme ...
" I assume they deliver the same wattage as the points widecase scramblers but with only 5 coils ? "

____ I wouldn't assume that,, the claimed 70-watts for the 6 power-coil 450-alt.system is likely under-RATED to begin with, so-thus your 450's 5 power-coil alt.system is still good for the 70-watt rating.



" If so the 5 windings must be different to the normal 6 coils. "

____ I don't really know for sure but, I'd bet that they are just the same as all the other 6-pole type power-windings.



" Perhaps test what these windings deliver and copy that to 6 coils to get more wattage?

(should I go back in the corner? "

____ All Ideas are welcome, of-course,, but I'm fairly doubtful that those main-type power-coils deliver any more power than any of the others like them.
However the one coil that's dedicated to powering the ign.system, quite more-likely has differently intended output characteristics (which would be interesting to test !).


Dukaddy-DUKEs,
-Bob

The ignition coil on Graeme's later single is for the CDI system, that generates about 350 Volts.

[wcorey]

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

...and-then arrange the two power-coils in parallel for testing their combined-output in that (likely mismatched) manor,,...

Why would there be a mismatch if they both have the same amount of wire?

" 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).

Yes

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

__ 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.

Both coils, each with both windings in series, both coils in series.
3550 rpm, generic bridged rec (full rectification).
3ohm---2a---6.1vdc---12.2w

" 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.

If it ever becomes that important, I'll bother to tabulate all those results but until then...

____ 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. (?)

Difference in wattage between 3 and 5 ohm on small coil; 0.5w
Difference in wattage between 7 and 9 ohm on large coil; 0.4w
Difference in wattage between 12 and 14 ohm on both coils; 0.5w

Considering the small percentage of difference in wattage and that figures were all rounded off to one decimal place, it's well within the mathematical margin of error to assume that it could just as easily have been;
Peak wattage for small coil 4ohm, large coil 8ohm and both 13ohm, leaving only a 1 ohm disparity...

Plus...

Quite often when I test, the output figures at two decimal places back fluctuate somewhat in real time. I watch it for a few seconds and use my best judgement as to where the numbers seem to spend the majority of time and jot it down, then on to the next test. Also I have a number of resistors in series with spade connectors between each to achieve the desired values. There's a 3, then (4) 1's, then (2) 5's and another 3. To save a bit of time I often use whatever combination only requires me to switch one lead, so for example sometimes 3 ohms is one 3w or (3) 1w's. I'm sure there is some variation in the values though I've tested a few combinations against one another and they're pretty close but still another few hundredth's of variability to add in along with everything else.

So it may be wise to not waste your time reading too much into variations of a few percentage points...

____ Capacitors tend to obscure test circumstances (almost as badly as batteries do).

And quite consistently improve output, always makes that headlight brighter. And before you start... I don't care by what means, it's not some trickery. Brighter is brighter, for all intents and purposes here.

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).

53vdc

__ I wonder if you again tried-out the same headlight, to compare how bright it could get ?

In this case, not very bright at 25w so I haven't bothered making a regular habit of it with only the two coils, only when I'm suspicious of something going on that I can't see...

[wcorey]

Test data from Bruce's rewound 'large' coil.
‘Double wound', connected in parallel.
3550 rpm, generic bridged rec (full rectification).

.5ohm----4.4a-----2.1vdc------8w
1 ohm----3.3a----3.7vdc------12.2w
2 ohm----2.6a----5.4vdc------14w
3 ohm----2a------6.4vdc------12.8w


Same tests but one 'layer' of wire (48") removed.

.5ohm----4.2a----2.3vdc-------9.7w
1 ohm----3.5a----3.8vdc------13.3w
2 ohm----2.5a----5.3vdc------13.25w
3 ohm----1.9a----6.1vdc------12w

Seems predictable where the results of removing another layer will go (as well as similarly downsizing the small coil), so I stopped here.


Stock large coil, windings in series, same test parameters as above.

.5ohm----3.9a----2.2vdc-------8.6w
1 ohm----3.2a----3.4vdc------10.9w
2 ohm----2.2a----4.7vdc------10.3w
3 ohm----1.7a----5.2vdc------8.8w

With the windings in parallel, the peak output was about half of series and at somewhere around .3 ohm.

Looks to me like time for a single wound pair with stock gauge and more turns and possibly one with larger gauge and (maybe) more turns.

[DewCatTea-Bob]

____ Sorry I've been away for so long fellas, (I only recently returned home) ! ...
Last Monday when I got out of my house, (which is a RARE occurrence), so as to ship-out the n-c.type 6-pole stators to Bruce,, I then discovered that I was quite very-much out-of-shape and assumed I must've been overly dehydrated (which I wouldn't have noticed had I stayed inactive at home as usual), so thusly I was then made alert to needing to be concerned with my health. _ So come Tuesday-eve (when by-then any dehydration should've been solved), I again unusually-exerted myself (purposely in home) and then discovered that Monday's excursion had probably not revealed a case of severe dehydration after-all,, so I began looking for other clues and later discovered that I was 'passing' lots of blood ! _ So Wednesday I went to the hospital and they discovered that I had lost HALF of my normal amount ! _ So during most of the days I was there, it took 7-units -(about 3-quarts) to bring my body's supply up-to about 3/4ths of normal-capacity by the time the-problem became under control and I finally got released. _ (I'm only now/today beginning to build-up the remaining amount back-up to normal-level.)
__ The only reason for why I'm bothering to include this OFF-topic information, is because if Bruce hadn't inspired me to get-out & ship him the stator-parts when he did,, then there's a fair-chance that by Thursday, DewCatTea-Bob may've posted his LAST-post and past-away in his sleep ! _ As I wouldn't have been pre-alerted to my-issue if I hadn't taken the opportunity to get-out of my home to ship the package by 5pm !

...and-then arrange the two power-coils in parallel for testing their combined-output in that (likely mismatched) manor,,...

Why would there be a mismatch if they both have the same amount of wire?

____ Well of-course in such case as they both have the same LENGTH of wire, then you're right to question my statement,, but,
I figured that if you attempt to figure that by 'weight', then it's likely that you don't happen to have a balance-scale which would notably notice a difference in weight of just 1-inch length of wire. _ As any more than that amount, would be a relative mismatch.

__ 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.

Both coils, each with both windings in series, both coils in series.
3550 rpm, generic bridged rec (full rectification).
3ohm---2a---6.1vdc---12.2w

____ Thanks but,, I had-thought that the optimum-resistance for the parallel-arrangement, was 4-ohms (rather than "3ohm").

____ 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.

If it ever becomes that important, I'll bother to tabulate all those results but until then...

____ You're right Bill, it's not-really important enough for you to be bothered-with.

Difference in wattage between 3 and 5 ohm on small coil; 0.5w
Difference in wattage between 7 and 9 ohm on large coil; 0.4w
Difference in wattage between 12 and 14 ohm on both coils; 0.5w

Considering the small percentage of difference in wattage and that figures were all rounded off to one decimal place, it's well within the mathematical margin of error to assume that it could just as easily have been;
Peak wattage for small coil 4ohm, large coil 8ohm and both 13ohm, leaving only a 1 ohm disparity...

Plus...

Quite often when I test, the output figures at two decimal places back fluctuate somewhat in real time. I watch it for a few seconds and use my best judgement as to where the numbers seem to spend the majority of time and jot it down, then on to the next test. Also I have a number of resistors in series with spade connectors between each to achieve the desired values. There's a 3, then (4) 1's, then (2) 5's and another 3. To save a bit of time I often use whatever combination only requires me to switch one lead, so for example sometimes 3 ohms is one 3w or (3) 1w's. I'm sure there is some variation in the values though I've tested a few combinations against one another and they're pretty close but still another few hundredth's of variability to add in along with everything else.

____ Thanks for this thoughtful answer.
__ While all-that sheds doubt that the impedance-factor seems to be non-linearly increasing as the windings get longer,, what more clearly indicates (and tends to definitely confirm) that the impedance increases at a greater-factor than increased winding-lengths, is that the larger-coil which is only about 50% longer (than the small-coil), still has around 233% as much impedance (which is about 133% MORE, [not just 50% more impedance]) !
So-thus it makes fairly logical-sense that the "3" (of the small-coil) and the "7" (of the large-coil) combine-together for a total of "14" (rather than just 10-ohms of total-impedance).
__ Now since the 3 & 7 (optimum-load values) compared to the 1 & 1.5 (unit-lengths), yields a ratio of 1.55:1,, that same non-linear factor applied to both power-coils in series, means that we could thus-then expect the 3 + 7 to yield an impedance-total of 15.5ohms (instead of the straight-linear 10-total),, which is considerably closer to your "14" than the more expected 10-total. _ Therefore (somewhat logically) relaxing the stretching-stress placed-upon your expected tolerance-range variances (due-to the rounding-off of all your result-figures).
So from having kicked-around these somewhat confirming figures, it now SEEMS that the impedance-factor increases at about a ratio of 1.5:1 as winding-length increases. _ In other-words, for instance,, a power-winding that's doubled in length doesn't merely have just twice the impedance-total, but rather 3-times as much. - For example, if two large-coils were connected in series, their 7 + 7 (individual impedance-values) wouldn't total-up to just 14-ohms, but-RATHER up-to a 21-ohm impedance-total.
__ Now I admit that this deduction is based upon shaky-ground, so we need to check-further for other confirming (or contradictory) figures,, so lets all keep our eyes-open for such ! _ Because most who are following this thread ought-to understand that power-winding impedance is an UNWANTED factor ! - (Cuz it causes the power-winding to become more of a 'bottle-neck' [and thusly reduces power-transfer to the intended-load]!)

And quite consistently improve output, always makes that headlight brighter. And before you start... I don't care by what means, it's not some trickery.

____ A cap can only store any-leftover power that the load had failed to consume from the pulsed-DC, and-then deliver it between the DC.pulses,, thus-then keeping the filament maintained at a hotter-temp, (as cooler filaments consume power-juice at a FASTER rate !). _ So it makes some sense that your caps cause the light to become brighter ! ...
If your chosen cap.capacity were to be too-small, or if you tried powering more than one (such powerful) headlight,, THEN the inclusion of the caps would make NO such beneficial improvement !

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).

53vdc

____ Doing that test regularly, may be of relative importance...
__ Since the preferred method of determining power-coil strength is so difficult to dial-into precisely, we may find that performing this test could likely yield a more-accurate test-result for comparing the relative strength of various power-windings. _ As the very-high (and rather consistent) resistance of the volt-meter will allow rather precise measurement of a power-winding's max.tension, which I'm sure is linearly related to max.power. _ But-however of-course, max.power can only be determined by dialing-in a test-load value that's precisely matched to whatever the actual impedance of the power-coil is,, and Bill has made it fairly apparent that attempting to dial-in test-loads into fractions of an ohm (to find the optimum load-value), is way-far more too-tedious to get accurately tested !
__ So providing that I'm not proven wrong about this max.voltage measurement being straight-forwardly linearly equal to max.power,, then with such test-measuring, it ought-to be rather easy to calculate max.power, rather than actually performing all the tedious/taskful work of attempting to 'measure' whatever it actually is.
____ So as a baseline, we need to discover whatever the 'max.voltage' is of stock power-coils,, and also, that of some power-winding example which Bill was able to precisely dial-in the max.power rating of.
__ Does this reasoning not make fairly good sense to you guys ?


Hopeful-Cheers,
-Bob

[graeme]

I hope you recover Bob, scary how things can creep up as we get older.
Look after yourself

Graeme

[DewCatTea-Bob]

[quote= graeme ...
" scary how things can creep up as we get older.
Look after yourself "

____ I was told that "the-problem" is-not so very uncommon, (even amongst more youthful-sorts),, so most-ANY of us need to-be concerned with looking-after ourselves whenever taking NSAID-type pain-pills (such-as aspirin) for long-term !
__ My Doctor had prescribed 'Celebrex' which is the one brand of NSAID which is supposed to be safe from the harmful common side-effect, but my insurance-company would-not cover that (somewhat more expensive) brand/type. _ So another common NSAID was covered by them instead, (which indeed saved them a few bucks [on the pain-drug]),, but NOW, my ins.co is going to have-to cover a hospital-stay that's going to cost them over 6000-bucks, (which is at-least 100-times more) ! _ Is there any logic to that ? ...
Sort-of makes me wonder if they had had hopes that the rather unsafe drug would've been successful at permanently taking me off-of their register !? _ If so, then they likely won't like Bruce too much now !

____ Of-course THIS post is WAY off-topic, so I'll soon be deleting it and all other posts solely-concerned with merely-just this matter.

Test data from Bruce's rewound 'large' coil.

.5ohm----4.4a-----2.1vdc------8w
1 ohm----3.3a----3.7vdc------12.2w
2 ohm----2.6a----5.4vdc------14w
3 ohm----2a------6.4vdc------12.8w

____ First I thought we had found that the 'optimum' load-value was near 4-ohms -(which I now believe was for both the large & small coils in parallel/SERIES/parallel), then lastly-before: "3ohm",, but-NOW you've found the optimum-load for Bruce's large-coil is at "2 ohm"...
What seems to be amiss ?

Same tests but one 'layer' of wire (48") removed.

.5ohm----4.2a----2.3vdc-------9.7w
1 ohm----3.5a----3.8vdc------13.3w
2 ohm----2.5a----5.3vdc------13.25w
3 ohm----1.9a----6.1vdc------12w

____ First question is,, is the "(48")" of the removed outermost-layer of the 'double-winding', actually 2-lengths of 48-inches (for a total of 96" total-length), OR, have you already added-together that removed double-winding's two-lengths, thus-then meaning that the combined outer-layer was actually just 24-inches long ?
Anyhow,, is your method for measuring weight capable of measuring the weight of the removed winding-layer, down-to fractions of a gram ?
__ Of-course it makes logical-sense that the max.power has fallen-down with the shortened power-winding (being just 9, instead of 10 layers),, but I have no explanation for why the power-drop wasn't all flat across-the-board AND that there was an actual 21% INCREASE at the lowest test-load. _ I can only guess that either perhaps Bruce's concern about the outermost layers being too far-away from the concentrated mag.field, or, perhaps too-far from the core and/or too-close to the stator-plate,, has allowed THAT outer-layer's ratio of power-production vs. impedance to become less productive (than the inner-layers are).



" Seems predictable where the results of removing another layer will go
, so I stopped here. "

____ Considering the measured inconsistencies, I-myself really can't see where it's very predictable at all !
__ We need to compare the weight of the removed-layer to that of the remaining-layers, so-as to get an idea of how much more of the power-winding has to be removed to get the large-coil to be matched with the small-coil.
__ Did you measure the weight of the large-coil before you removed it's outer-layer ?
How does the large-coil's weight now compare to the small-coil's, presently ?

Stock large coil, windings in series, same test parameters as above.

.5ohm----3.9a----2.2vdc-------8.6w
1 ohm----3.2a----3.4vdc------10.9w
2 ohm----2.2a----4.7vdc------10.3w
3 ohm----1.7a----5.2vdc------8.8w

____ Okay-now, I gather that you've reconnected the stock 'dual' power-windings of a large-coil so that they now rather work-together in series-fashion, so that the stock 20-gauge dual-windings are just as-if a single 4-layer power-winding.
__ It would also be useful to know what the NO-load max.voltage is from this stock power-coil, as well !

With the windings in parallel, the peak output was about half of series and at somewhere around .3 ohm.

____ By: "peak output", I assume you mean same as 'max.power'.
Max.power ought-to be close to the same-amount, regardless whether in series or parallel, (providing that the two separate power-windings are 'matched'). _ Unless one of the two windings was somehow left offline, the fact that the max.power was ONLY about half that of the series-arrangement, means that the longer/outer-winding saw the shorter/inner-winding as a 'load' (more-so than a helping-buddy), and-so the parallel-combined power-winding was robbed before it's combined-output could get-to the test-load. _ However, I wouldn't expect the mismatch to account for so much power-loss,, so I rather suspect that one of the two (parallel combined) power-windings was-not fully connected-up with the other (at at-least one of it's end-connections).
__ It would be of some interest to learn what the 'NO-load max.voltage' measurements are, for both the inner & outer windings, (separately).



" Looks to me like time for a single wound pair with stock gauge and more turns and possibly one with larger gauge and (maybe) more turns. "

____ I'd agree that a 6-layer 18-gauge single-winding power-coil would be of fair interest to get tested-out,, but for thinner-gauges, double-windings or 'twined' power-coils are needed to help keep power-winding resistance & impedance minimized !


Hopeful-cheers,
-Bob

[ecurbruce]

Bob,
I echo what Graeme says!
Take care of YOU- get up every day, somehow!
I wish for you a speedy recovery...

I recieved the package from you safe & sound, we'll get started on that in the next day or two.

Bruce