n-c alternator modifications: discussion and testing

[DewCatTea-Bob]

By: wcorey...
" Seems like 'stock parallel' would be best at 6v (shouldn't be a surprise as that's what it's designed to do) "

____ While I agree the stator was likely designed with a 6-volt system in mind, I wish to point-out that the designers couldn't possibly expect their product to be designed specifically for just 6-volts alone. _ Consequently, it may work equally well within a 3-volt or 12-volt system.
(To expand on the plane-of-thought,, even an alternator that's intended for a 12-volt system will have an easier-time providing charging-juice through a 6-volt battery than a 24-volt battery, as it's RPMs rise-up from 0-RPM. _ As naturally so for ALL alternators.)

Preliminary results of Bruce's Latest are a bit underwhelming but not entirely unexpected...

____ Exactly what test are these results concerning ?

" Oh, come on Bob, just what other setup that I'd be doing is there, that could be confused with "Bruce's Latest" at this point in time? "

____ Well Bill, even though that's what I would've expected (eventually some time down the road), at the time when I discovered your results, I thought perhaps I had missed some other newer-postings since new pages were popping-up so often that day, AND, your posted test-outcome figure-results were way-off from that which would've been expected from the hoped-for "grand" / 'straight' series-arrangement !!


" I've decided to use 'Grand series' for now but still don't think it's self-explanatory/descriptive enough. "

____ Right Bill, I agree with your notion. ...
So I believe that Mike's term 'straight series' is really best cuz the intended straight-series winding stays straightly wound in just a forward-only fashion,, whereas the two Ducati-wound windings (put into series by the common/simple way), are 'U-turned' back along-side one another.
(I hope to provide a pic.drawing to depict the exact difference which I'm meaning to indicate/convey.)

__ How about a 10-ohm load test, Bill ?

A ten ohm test of what/which? lol.

" 10 ohm, 21vdc, 44w "

____ It's now been reviewed that the indicated 'impedance' of the latest series-winding arrangement -(whatever it actually might be), is somewhere between 6 & 10 ohms.
(Bruce, take-note that the progression which you had pointed-out for the "series setup" is reversing [somewhere less than 10-ohms].)


"

...then something is certainly wrong !

Could very well be but if the inner/outer order isn't an issue then I don't know what’s off, "

____ I'd guess that the two separate stator-windings are STILL (at least partially) in a non-straight arrangement (of some sort). _ Cuz for ONE thing, I expected to see about 80-watts with the 3-ohm load.


" someone please enlighten me with a concise pictorial layout. As far I can see there are only two ways to do it and each is more or less equal in result. "

____ That sorta-seems like it could be expected, without a more notable alteration. ...
If you can't turn every-other spool 180-around on it's core-finger/lug, then perhaps short jumper-connections need to be done for half the coil-winding lead-ends (so that they'll be able to reach the actual connections where they need to be made).
I don't know for sure if such is really required, but if you've already tried all the easier reconnection possibilities, then my alternate concept is likely valid.
If you look at Mike's (nice!) drawing, it's obvious that half the pig-tails -(coil lead-ends) need to be fairly longer.


" I disconnected/separated all wires on the stator and rang out/mapped out the individual (two wire) winding sets. If you picture each spool with four wires in a row (coming out of holes in the bottom of the spool flange), numbered 1 through 4, the one consistent thing is that the wire pair layout of the first individual winding set is 1-3 and the other 2-4 (with the exception of the two smaller spools where two ‘end’ wires come out of the same hole). I found no obvious way to discern inner from outer winding sets. "

___ That's all quite-understandable, and makes it fairly-clear that the only way to trust that all coil-winding pairs are coherently passing current in the proper-order/direction,, is to fully employ the North/South-field effect method.


" I skipped a few steps and then tried what seemed like the most obvious scheme, connecting 2-3 together on each spool but when powered up produced no magnetic attraction at the pole. "

____ That indicates that the two coil-windings were passing current in OPPOSITE directions, which is just the occurrence which you DON'T want ! _ Meaning that either '2' or '3' needs to be connected to either '1' OR '4' , (and either '1' or '4' is the same coil-winding [thus the wrong pig-tail]).


" Next try was connecting 3-4, which did produce magnetic attraction, then 1-2 which also worked and also kept the same polarity. Using this scheme, starting with positive dc input on the first large coil, the polarities were north on all three smaller spools and south on two of the larger but north on the (first large) one that the output wires normally attach to. "

____ It seems likely then, that the coil-spools sent to you were from a different generation of 6-pole stators.


" The physical layout was easier using 3-4 connected so I soldered all of those together, then 2 on one spool to 1 on the next, with the one odd large spool reversed. When the whole stator was powered up the compass needle alternated concisely from north to south as it was passed by each pole. The magnetic attraction to a metal object to each pole seemed to have consistent force. "

____ Sure seems like all that would've likely achieved that which was desired then !


" I tested it full wave with the usual sequence of loads and posted the somewhat abbreviated results... "

____ Unfortunately, those results indicate that SOMETHING is not as it would be expected to be.
__ You mentioned also doing half-wave tests as well...
Were all their figure-results accordingly exactly half of what you got with your full-wave tests?


Hopeful-Cheers,
-Bob

[MotoMike]

I don't know what is limiting the straight series grand series output. the thought that it is impedance of the stator doesn't seem right to me. other series wound stators produce much more voltage and power than we are dealing with here. many over 200 watts which is clearly a load much less than an ohm. the rewound stators have more wire to get more voltage by having more turns. and if while doing this they decrease the wire size it increases the resistance and overall impedance further. still pondering it.

[DewCatTea-Bob]

" I don't know what is limiting the straight series grand series output. the thought that it is impedance of the stator doesn't seem right to me. "

____ At first it was easy to jump to the conclusion that the "reduction-effect" was still in-play due to the noted wattage-increasing-with-increased-load progression,, however that reverse of normal-progression could possibly simply be due to the load-impedance still remaining lower than that of the stator-winding itself. _ (And THEN of course it's very much more likely that Bill has indeed properly found & provided the fully-correct 'straight-series' winding arrangement.)
So what needs to be done (in order to confirm this possibility), is to try 20 & 50 ohm loads (so as to confirm the 'downward-trend' exposed by the 10-ohm load test),, and do 7-ohm (plus 8 or 9 ohms) tests to then discover the effective working-impedance of the straight-series stator-winding.
__ I had actually expected the peak working-impedance to increase to a point where it may become un-efficiently too high for the intended total load-system,, however I wasn't expecting it to be so raised-up, to as high as nearer to 7-ohms,
(as I had expected around the 4-ohm level).
If Bill does the extra load testing (@ 3450), we can then realize whether the results simply indicate a much raised stator-winding impedance level, or that the 'reduction-effect' (of the unwanted coil-winding arrangement) still remains,
(or maybe both, still ?).


" other series wound stators produce much more voltage and power than we are dealing with here. many over 200 watts which is clearly a load much less than an ohm. "

____ Not "clearly" so Mike, as such high wattage COULD possibly be with a considerably higher load-resistance, (is that not correct ?).

____ My own received tech.training had made it clear to me, that most efficient power-transfer from stator-winding to load, is only at maximum when their 'impedance' is matched !
Do you-yourself not recall of any such relationship, Mike?


Hopeful-Cheers,
-Bob

[MotoMike]

Bob wrote:
Not "clearly" so Mike, as such high wattage COULD possibly be with a considerably higher load-resistance, (is that not correct ?).


Bob, when you say higher load resistance I take that to mean more ohms.


If that is what you mean, I would say no because all the alternator systems I'm thinking of are automotive or motorcycle. So they are all regulated 12 volt systems. If you look at all the loads placed on the system, you can use 12 volts and the wattage to calculate with ohms law what the resistance is. all the loads on the system are parallel and again using ohms law we know that resistance in parallel is less than the least branch except when all the branches are the same in which case it is the resistance of one branch divided by the number of branches. if the wattage was say 150 watts on a 12 volt system, your current would be 12.5 amps and your resistance would be .96 ohms. on some of the modern motorcycles with big electric loads, it is sometimes much more.

yes matched impedance will yield most efficient transfer, but a system seldom has the perfect match and in most cases will produce on either side of the match if not optimally. delicate solid state electronic circuits will balk at the mismatch but our more hardy system composed of wire and magnets should keep on chugging away.

Still thinking about it, and don't want to be pinned down yet, but have an idea working. we have anomalies to consider as Bevel Bob keeps his battery charged and runs his system with the lifted earth and series connected full wave rectification. Then too, I have read of BB's modification several times elsewhere, so it is not uncommon and apparently yields acceptable results within limits.

If you look at what they do to upgrade alternators with a rewind, they put more turns on the existing cores. sometimes the factory did a sloppy job which can be improved on by more careful hand winding. As such using the rule that resistance in series is additive, they are increasing the resistance and impedance of the stator. This to deal with increased wattage demand on their 12 volt systems, which would be an ever decreasing ohmic loads.

Lots of automotive systems have ohmic loads way down at .3 ohms or lower. Most can provide full power to the system even with a discharged battery, so probably down to .1 ohms. certainly well below the impedance of the stator windings.

And for those who did not know and care to, impedance is a way of saying all opposition to current flow. Not just resistance, but also inductive reactance and capacitive reactance which vary with frequency or in our case with engine revs.


I just think something else is going on here. I don't know what yet but knocking it around. It is late, so have not double checked my math.

[wcorey]

By: wcorey...
" Seems like 'stock parallel' would be best at 6v (shouldn't be a surprise as that's what it's designed to do) "

____ While I agree the stator was likely designed with a 6-volt system in mind, I wish to point-out that the designers couldn't possibly expect their product to be designed specifically for just 6-volts alone.
(To expand on the plane-of-thought,, even an alternator that's intended for a 12-volt system will have an easier-time providing charging-juice through a 6-volt battery than a 24-volt battery, as it's RPMs rise-up from 0-RPM. _ As naturally so for ALL alternators.)

Here we go again... (and I don't know why I'm going here, recent history should have taught me otherwise)

Even *I* realize that the output isn't fixed... And the designed range of output is most likely optimized for it's intended application, in this case 6 F'in volts!

_ Consequently, it may work equally well within a 3-volt or 12-volt system.

May..., but here it certainly doesn't seem to... What I'm referring to is only and very simply that (just as you already more or less said) at lower rpm's, this particular alt puts out high enough voltage to charge a 6v battery but not really enough for a 12v.
My very rudimentary conception of alternator design has more coil turns equaling more voltage so it seems somewhat obvious that if you wanted to produce 50k volts you'd add a few more windings to the design than if you wanted 5v (for operation of either within the same general rpm range). You make it sound as though there is little difference...

The more modern ones I have tested that were originally intended to be used in a 12v system do put out sufficient voltage for the task. Are you saying that's some sort of random unplanned coincidence and not a result of intentional design? (That was a rhetorical question, If you feel compelled to answer, 'yes' or 'no' will be sufficient)

" I've decided to use 'Grand series' for now but still don't think it's self-explanatory/descriptive enough. "

So I believe that Mike's term 'straight series' is really best cuz the intended straight-series winding stays straightly wound in just a forward-only fashion,

Then what do you call Bruce's proposed rewind (like JBC's) also with (even straighter) straight series and how will the two be differentiated?

, whereas the two Ducati-wound windings (put into series by the common/simple way), are 'U-turned' back along-side one another.

Do we go back and edit them all to be 'u-turn series'? If not, it will be very confusing to future readers...

____ That sorta-seems like it could be expected, without a more notable alteration. ...
If you can't turn every-other spool 180-around on it's core-finger/lug, then perhaps short jumper-connections need to be done for half the coil-winding lead-ends (so that they'll be able to reach the actual connections where they need to be made).
I don't know for sure if such is really required, but if you've already tried all the easier reconnection possibilities, then my alternate concept is likely valid.
If you look at Mike's (nice!) drawing, it's obvious that half the pig-tails -(coil lead-ends) need to be fairly longer.

The spools can't be turned around without loping off the bottom lip, plus the wires would then have to be re-routed out from behind the coil making them further apart still...
There are only two jumper-ed connections and both are less than an inch, and other connections are soldred closer together than originally. Bear in mind that Mikes drawing is an 'exploded' view and also in a straight line as opposed to circular (not that that changes anything but the output lines). If you want a closer approximation, picture it as in my description with 6 squares, each with four wires in a row horizontally.

" Next try was connecting 3-4, which did produce magnetic attraction, then 1-2 which also worked and also kept the same polarity. Using this scheme, starting with positive dc input on the first large coil, the polarities were north on all three smaller spools and south on two of the larger but north on the (first large) one that the output wires normally attach to. "

____ It seems likely then, that the coil-spools sent to you were from a different generation of 6-pole stators.

The donor coils were from a similar four coil stator and each one has an identical counterpart to a coil on my stator. On my stator, no one coil is quite the same layout to any of the other three.
So, on the stock stator, the two smaller coils would seem to have the same schematic layout but different physical layout. The two larger coils are different both schematically and physically.

__ You mentioned also doing half-wave tests as well...

If I did, it was in error...


Bill

[ecurbruce]

DctBob-check PM

[wcorey]

Apologies for disturbing our little rest but figured this would be worth it...

I found the (my) error in the grand series setup!

I had noticed in this particular round of testing that the meter readings were slightly bouncing around/unstable but it was only by a half decimal point or less (and mostly on vdc) so I unwisely decided to ignore it for the moment. The constant calling into question of the data integrity in general (not pointing fingers, I'm the biggest skeptic of all) has been eating at me so this became the tipping point to start another redo of the test setup. If I had any clue I was going to be at this for this long with such a variety of test parameters I would have done things much differently right from the beginning...

Latest upgrade included getting rid of the majority of alligator clip leads and replacing them with spade terminals and made a hardwired load/resistor array consisting of (all in series) three 1ohm, a 3ohm and a 5ohm with soldered in spades in six locations.
This way loads/connections will be more consistent and I can 'switchboard' the load to get anything (in 1ohm increments) from 1 to 11 ohms.

Anyway, I pulled the stator and took a close look at the new connection scheme under magnification and I found a small rub mark on a wire, turns out I have an intermittent short. One wire between coils was just contacting the rotor rivets (that attach the center hub of the rotor) as they spun by. That explains why I was getting the fluctuating readings but when I'd ring out the stator all looked normal. Part of the problem is some of the stator coil connections are routed in a rather convoluted way because I didn't want to trim the wires shorter and make it more difficult to go back to stock configuration.

I need to complete the setup mods to get a new data set but rigged it up temporarily for one test and saw close to 80w at 3ohm 3450rpm and back to nice steady meter readings. Yay.

So sorry for all the consternation this has caused...

Bill

[DewCatTea-Bob]

Not "clearly" so Mike, as such high wattage COULD possibly be with a considerably higher load-resistance, (is that not correct ?).

" Bob, when you say higher load resistance I take that to mean more ohms. "

____ Well Mike, I guess it's understandable why you (and perhaps others as well) often don't properly understand my wording... Cuz I did-not state: "higher load resistance" ,, rather, I had stated: "higher load-resistance" ! _ Therefore the other possible interpretation of "higher load resistance" (which is 'higher-load resistance'), is not an option !
__ This significant difference is just one of an untold-number of instances where easy misinterpretation is quite likely without the use of 'hyphens' added between words so as to keep the reader on proper track. _ Otherwise without such obvious steering, the reader then has to do the added work of reading the presented sentence with added effort, so as to make 'good-sense' out of it, (or else the whole paragraph's actual-meaning may be lost to the reader).
I've realized this hap-hazard misconception-situation possibility many years ago from written-communication to foreign-countries where my contacts did-not have the exact-same understanding of English-wording (as those of us who live with it). _ So to help them with properly interpreting my English-wording, I began adding strategically placed 'hyphens'. _ Indeed, adding the hyphens between selected words, ought help ALL readers decipher the actual INTENDED meaning of most chosen wording !


" If that is what you mean, I would say no because all the alternator systems I'm thinking of are automotive or motorcycle. So they are all regulated 12 volt systems. If you look at all the loads placed on the system, you can use 12 volts and the wattage to calculate with ohms law what the resistance is. all the loads on the system are parallel and again using ohms law we know that resistance in parallel is less than the least branch except when all the branches are the same in which case it is the resistance of one branch divided by the number of branches. if the wattage was say 150 watts on a 12 volt system, your current would be 12.5 amps and your resistance would be .96 ohms. on some of the modern motorcycles with big electric loads, it is sometimes much more.
yes matched impedance will yield most efficient transfer, but a system seldom has the perfect match and in most cases will produce on either side of the match if not optimally. delicate solid state electronic circuits will balk at the mismatch but our more hardy system composed of wire and magnets should keep on chugging away. "

____ All that is well & good Mike, but it seems you've missed my intended point....
What I had actually meant was, is it not certainly likely that when an alternator is 'rated' for it's MAX.power-output, that it's power is then measured WHILE it's connected load's resistance-value is 'matched' to the impedance of the alternator's power-circuit ?
I'm thinking that that-circumstance must be so, and Bill's extended testing outcome obviously concurs with such a conclusion...
__ With his 6 & 10 ohm test-outcome result-figures, we can see that the working-impedance of the complete straight-series alt.winding is somewhere between 6 & 10 ohms ! _ So I expect that in order to obtain the MAX.power-output figure (of this particular tested setup), we ought try testing with a 7 or 8 ohm load.


" Still thinking about it, and don't want to be pinned down yet, but have an idea working. we have anomalies to consider as Bevel Bob keeps his battery charged and runs his system with the lifted earth and series connected full wave rectification. Then too, I have read of BB's modification several times elsewhere, so it is not uncommon and apparently yields acceptable results within limits. "

____ Right, the std.series-arrangement is not uncommonly done, but it obviously works for 12-volt systems, with low current-drawing loads, so it's not really an anomaly to need to consider.


" If you look at what they do to upgrade alternators with a rewind, they put more turns on the existing cores. sometimes the factory did a sloppy job which can be improved on by more careful hand winding. As such using the rule that resistance in series is additive, they are increasing the resistance and impedance of the stator. This to deal with increased wattage demand on their 12 volt systems, which would be an ever decreasing ohmic loads.
Lots of automotive systems have ohmic loads way down at .3 ohms or lower. Most can provide full power to the system even with a discharged battery, so probably down to .1 ohms. certainly well below the impedance of the stator windings. "

____ Perhaps actual alt.power is determined by another means ?
__ Having the total load-resistance at a lower value than the impedance of the alternator's power-circuit, only results in mismatching which leads to excessive alt.stator heating.


" I just think something else is going on here. I don't know what yet but knocking it around. "

____ Assuming that Bill got everything rewired-up correctly so that both coil-windings on each spool produce the very-same magnetic-polarity, (and also oppositely from one spool to the very next), (as he most likely accomplished),, then what else other than 'impedance-mismatching' could account for all the fairly consistent test-outcome results ?


Concerting-Cheers.
-Bob

[DewCatTea-Bob]

By: wcorey (June 13th)...
" Even *I* realize that the output isn't fixed... And the designed range of output is most likely optimized for it's intended application, in this case 6 F'in volts! "

____ Sorry Bill, I can see how it may seem I'm beating a dead-horse, but I feel the need to continue dispelling the commonly dumbed-down notion that the alternator is a '6-volt' model, (or that any alternator [made to run at variable speeds], is 'designed' to produce a particular voltage).
__ Please realize & keep in mind, that I don't consider my posts to be as PMs ! _ Thus my responses (to your wording which is merely quoted for reference, [as to what inspired my response-post-wording]), are intended mainly for the 'general-reader', and NOT just specifically at you-yourself Bill, (unless I state your name or: "you").

_ Consequently, it may work equally well within a 3-volt or 12-volt system.

" May..., but here it certainly doesn't seem to... What I'm referring to is only and very simply that (just as you already more or less said) at lower rpm's, this particular alt puts out high enough voltage to charge a 6v battery but not really enough for a 12v. "

____ But that was my very point for ANY alternator, regardless of intended-design ! _ If there were such a thing as a 3v.system, then it would just as likely be stated that: 'What I'm referring to is only and very simply that at lower rpm's, this particular alt puts out high enough voltage to charge a 3v battery but not really enough for a 6v.'
__ It seems that my past attempts to pass-on a certain concept has still failed. _ So I'll try once again to convey the concept I've always tried to.
Now before you begin to think that I'm heading-down another road you've already been on and thus think you already know-of well enough, please consider that (it seems) you have yet to fully realize my actual intended particular main-concept. ...
__ Any 'voltage' (alone) of an alternator is basically IRRELEVANT ! ... That's because an alternator doesn't really offer a voltage, (only potential-voltage!),, and what an alternator REALLY produces is merely 'raw power' -(undefinable as either voltage or amperage, [without a connected circuit !]) ! _ And it's the 'power' (not 'voltage') which really matters ! _ Thus if the connected load-circuit has a low-resistance, a low-voltage will 'develop' into existence, (from otherwise mere potential-existence),, and if the connected load-circuit has a higher resistance, then (providing that 'power' is sufficient), a higher voltage will develop.
So two separate variable-speed alternators (equal in 'power' !), one intended for a 6v.system and the other intended for a 12v.system, will BOTH have an easier task providing a charging-flow for a 6v.battery, and a more difficult task for a 12v.battery, (when near barely sufficient revs). _ So the two alt.units could be swapped between their intended load-systems, and nothing would change, as both will perform each-other's job equally well enough. _ Cuz it's the 'power' they can each produce, which really matters,, as the required 'voltage' comes (into existence) out of the raw-power, as whatever amount is dictated by the connected circuit-load, (whether it be for a 6v, or a 12v battery).


" My very rudimentary conception of alternator design has more coil turns equaling more voltage so it seems somewhat obvious that if you wanted to produce 50k volts you'd add a few more windings to the design than if you wanted 5v (for operation of either within the same general rpm range). You make it sound as though there is little difference... "

____ That's a pretty-good paragraph indicating that you have been developing a fairly good grasp of this stuff !
So we're getting close to fully grasping my intended point.
While it's certainly true that more coil-turns would provide more potential, it doesn't necessarily directly equate into more 'voltage', unless a particular circuit allows so. _ (Without a 'circuit', additional coil-turns will only certainly insure more 'power' !)
__ Of course two radically different designed alternators (of same wattage) could be constructed for radically different maximum potential... One unit to be able to produce 0 to 50k-volts (at relatively low amperage) within a certain RPM-range, and the other to produce 0 to 5-volts (at a relatively high amperage) within the same RPM-range.
Such a radical difference as even close to that, would no doubt most certainly require considerably different alternator designs.
However one thing I've been meaning to convey is that in either case of an alternator intended for charging a 6v.battery or a 12v.battery, they both must consequently be able to produce enough power that's capable of providing voltages considerably above that of the battery, in order to produce any charging-current near the lowest RPMs. _ And so required alternators for either 6 or 12 volt systems (of equal wattage-loads), are thus resultantly so nearly much the same, as to be virtually no different.
So when switching from a 6-volt to a 12-volt system (of equal wattage loads), the so-assumed 6v.alternator simply continues building-up it's 'power' (thus also potential-voltage) until the battery begins to accept charging current-flow, (same as an assumed '12v.alternator' has to do). _ I don't think there's any kind of art that's practiced to differentiate alternators so that it's 'voltage' could reach 12-volts any sooner (as revs build), other than to increase the strength of it's 'power'. _ So then if a common-type alternator's total power-output remains the same amount, then it ought not be considered as a 12v.model any more-so than a 6v.model.


" The more modern ones I have tested that were originally intended to be used in a 12v system do put out sufficient voltage for the task."

____ But of course, as that's only because they must produce sufficient 'power' for the intended/connected load-circuit (which no-doubt requires more power!). _ 'Voltage' can't exist without 'power', but power does exist without voltage* (* not to be confused with 'potential' !). _ (Side-note: I've come-up with another way to help explain the difference between 'voltage' & 'potential'... 'Voltage' compares to 'potential' as 'Celsius' (or Fahrenheit) compares to 'temperature'.)


" Are you saying that's some sort of random unplanned coincidence and not a result of intentional design? "

____ No... They were simply designed to make more 'power', not more voltage (alone only),, as the increased voltage is but a mere side-effect of more power, (for a given load-circuit). _ An alternator can't be made with merely increased voltage (without also increasing it's "power' as well).

" I've decided to use 'Grand series' for now but still don't think it's self-explanatory/descriptive enough. "

So I believe that Mike's term 'straight series' is really best cuz the intended straight-series winding stays straightly wound in just a forward-only fashion,

" Then what do you call Bruce's proposed rewind (like JBC's) also with (even straighter) straight series and how will the two be differentiated? "

____ How about 'chained straight-series' (for the former) and 'no-breaks straight-series' (for the latter) ?
(Does anyone know the short-term/name for when a transport-plane flys to the final-destination with no other stops in-between ?)

, whereas the two Ducati-wound windings (put into series by the common/simple way), are 'U-turned' back along-side one another.

" Do we go back and edit them all to be 'u-turn series'? If not, it will be very confusing to future readers... "

____ The "U-turned" was just meant to describe how the current-flow is directed by the two stator-windings when in the common/std.series-arrangement. _ I don't really see the need to go-back and name it with the 'U-turn' designation, as the 'straight-series' designation (for the extra-modified stator-reconnection modification), should differentiate the two types of stator-modifications well enough.

____ That sorta-seems like it could be expected, without a more notable alteration. ...
If you can't turn every-other spool 180-around on it's core-finger/lug, then perhaps short jumper-connections need to be done for half the coil-winding lead-ends (so that they'll be able to reach the actual connections where they need to be made).
I don't know for sure if such is really required, but if you've already tried all the easier reconnection possibilities, then my alternate concept is more likely valid. "
If you look at Mike's (nice!) drawing, it's obvious that half the pig-tails -(coil lead-ends) need to be fairly longer.

" The spools can't be turned around without loping off the bottom lip, plus the wires would then have to be re-routed out from behind the coil making them further apart still... "

____ Sorry, it was just some thoughts thrown-out as assumed possible cures, since I've not seen such stator-models in a very long time, and so just assumed that the spools' two pairs of lead-ends would be nearer their sides rather than ALL on front.



By: wcorey (June-14th)...
" I found the (my) error in the grand series setup!
I need to complete the setup mods to get a new data set but rigged it up temporarily for one test and saw close to 90w at 3ohm 3450rpm and back to nice steady meter readings. "

____ Great !
This means that further ohm-load testing (of the exact circuit-setup you last had), is no-longer of any possible use.
__ (I must admit that I never really liked seeing those alligator-clips used for such high-amperage current-flow.)
____ I'm sort-of hoping that after you get your 'good' test-results for the straight/continuous-series alt.winding, that you'll next be willing to divide-up the single-continuous stator-winding, with 1 or 2 center-tap points. _ With the intention of trying the segments in parallel, so as to lower the alt.power-circuit's overall-impedance.
The reason for wishing to do so, is to more closely 'match' the alternator's working-impedance to a high-draw working-load, thus help keep stator-heat lower.


Hopeful-Cheers,
-Bob

[wcorey]

...thus help keep stator-heat lower.

Sounds like a worthwhile goal to me, particularly since we're pushing things past where they were likely designed to go.

I have the new setup done, as well as my other unrelated duties and am about to do a round of test's, should be posting them up soon.
I figure I'll then try it with still the grand series but only the four original coils... because it's easy to do and may provide an upgrade option for people who don't want the extra hassle of the six coil arrangement.

And here we go... I added yet another 3ohm resistor to the load pak after realizing I had no combination for 7 ohm, so now also have 14ohm. Did pretty much the whole progression (twice) to ensure consistency (yes, overkill). Through all the testing the stator never got more than 15 degrees f above ambient.

Grand series, 6 coil.

1ohm, 3450rpm, 4.9a, 8.1vac, 5vdc, 24.5w
2ohm, 3450rpm, 4.7a, 13vac, 9.6vdc, 45.1w
3ohm, 3450rpm, 4.5a, 17.7vac, 13.7vdc, 61.7w
4ohm, 3450rpm, 4.3a, 21.4vac, 17.1vdc, 73.5w
5ohm, 3450rpm, 4a, 24.8vac, 20.2vdc, 80.8w
6ohm, 3450rpm, 3.8a, 27.9vac, 23vdc, 87.2w
7ohm, 3450rpm, 3.6a, 30.2vac, 25.1vdc, 90.4w
8ohm, 3450rpm, 3.4a, 32.4vac, 27.1vdc, 92.1w
10ohm, 3450rpm, 3a, 36vac, 30.4vdc, 91.2w
11ohm, 3450rpm, 2.9a, 37.3vac, 31.6vdc, 91.6w


1ohm, 6krpm, 5.1a, 8.3vac, 5.2vdc, 26.5w
2ohm, 6krpm, 5a, 13.9vac, 10.3vdc, 51.5w
3ohm, 6krpm, 5a, 19.3vac, 15.1vdc, 75.5w
4ohm, 6krpm, 4.8a, 24vac, 19.4vdc, 93.1w
5ohm, 6krpm, 4.7a, 28.8vac, 23.6vdc, 110.9w
6ohm, 6krpm, 4.6a, 33.1vac, 27.6vdc, 127w
7ohm, 6krpm, 4.4a, 36.8vac, 31vdc, 136.4w
8ohm, 6krpm, 4.3a, 40.5vac, 34.3vdc, 147.5w
10ohm, 6krpm, 4a, 47.1vac, 40.3vdc, 161.2w
11ohm, 6krpm, 3.9a, 50.1vac, 43.1vdc, 168.1w
14ohm, 6krpm, 3.5a, 57.3vac, 49.5vdc, 173.3w




Bill