n-c alternator modifications: discussion and testing

[wcorey]

____ How can just one side be "series" ?

Sorry, it was late... but if you want to get technical, it is four coils wound in series .
When I said "preliminary" and "rough numbers", I meant to convey that these were not to be taken seriously enough to use for in depth analysis, just threw them out to give everyone an idea of what was going on. I planned on deleting it as soon as I got the real numbers up, after my last 'abreviated, non-standard' data post, I didn't want to go there again but looks like I managed to anyway...

__ I wonder just what we actually have here, as it doesn't seem right that one alt.winding by itself would produce almost as much as the (stock like) 'DUAL half-wave' setup.

But it did..

I gather that this test is with full-wave rectification, rather than merely half-wave, right ?

Yes

a test of Mike's drawing 'E' from page 14? On your own time, of course, we're like a bunch of mad scientists late night in the basement (Grandpa Munster)

Ahead of you there, 84w 2ohm 3450rpm, though it's 'preliminary' data so don't abuse it . The mad scientist thing sounds pretty accurate at the moment...

Oh, and some more 'preliminary' data (disclaimer; for temporary comparison purposes only); parallel 2 ohm 77w, series 2ohm 45w.

The real numbers in 'standard format' are hopefully coming soon...

Trying hard not to think about the new single series setup until I get caught up on the 6 coil tests ( and the full wave 4 coil stuff I still need to re-post with pics).


Bill

[DewCatTea-Bob]

By: Bruce...
" Mike, yes, that's what I was getting to in the proposal for a rewire (in that screwed up diagram), thanks for the support. I think it would work well. Now who's going to build and test the theory? "

____ Obviously Bill is on the case for us !
__ Calculating-onward from Bill's earlier half-wave single-winding test (of June,2nd-5:46 on page 21), which had obtained 13.3-watts ... (13.3 x2 x2 = 53.2 x 1.5 = 79.8-watts), so (with the added 50%), that's about 80-watts which should be expected with full-wave rectification of one-complete individual single-winding (of 432 coil-turns).
But Bill has yet to post any results for the full-wave rectification of just the single-continuous 432 coil-turn stator-winding (around an entire six coil-spool, setup). _ And the 80-watt figure probably won't pan-out, since Bill has discovered that the 1-ohm test-load is no longer sufficient in value to review the 50%-expanded stator's max.power-output.


" Yea, MIke sounds right, however, for my case, I already have the 6 coil spools set up, so guess I'll keep it and enjoy some excess. "

____ What's going to need to be decided on Bruce, is if you'll go for the greatest power-output available (from the 432 coil-turn single-winding full-wave rectified setup), or (at the other/lower end), stick with the unique Ducati-type -(dual half-wave rectification, of parallel 216 coil-turn dual-windings) design. ...
With the Ducati-type design, the alternator will enjoy a relaxed duty-cycle ! _ However with your proposed ONE single-winding full-wave rectification setup, I'd expect that stator heating may become a notable issue.
To determine which is BEST for your particular intended load-system, you ought to be doing some testing of your own ! ... You could take a fully powerful 12v.DC-source and connect it up to each of your expected 12v.loads, and add-up all their individual current-consumptions. _ Then with the totaled-draw / max.power-consumption figure, you could then accurately figure-out what your intended load-system's resulting minimum resistance will be. _ And then hopefully Bill may have a ohm-load with a similar value to test-out, for more direct comparison.
Be forewarned that if your total-load resistance-value is less than the impedance-value of the 432 coil-turn winding, then a certain overheating problem could be expected.
Hope you can come-up with some power-draw figures of your various chosen loads, soon Bruce.


Hopeful-Cheers,
-Bob

[DewCatTea-Bob]

By: wcorey...

__ I wonder just what we actually have here, as it doesn't seem right that one alt.winding by itself would produce almost as much as the (stock like) 'DUAL half-wave' setup.

But it did..

I gather that this test is with full-wave rectification, rather than merely half-wave, right ?

Yes

____ Okay then Bill, it's understandable then that the full-wave rectification of just one of the single-windings would produce about the same as half-wave rectifying both.
Just didn't know for sure what type of rectification-setup you had done.


Content-Cheers,
-Bob

[wcorey]

Back to 'standard format'...

Six coil stator mod (two additional coils/bobbins/winding sets added to the two unused cores on the four coil stator), all tests at 3450 RPM.







Mikes E scheme, 2ohm, 6.4a, 17.4vac, 13.1vdc, 84w






Fullwave, series, 1ohm, 4.9a, 7.8vac, 4.8vdc, 24w
Fullwave, series, 2ohm, 4.7a, 13.2vac, 9.6vdc, 45w
Fullwave, series, 3ohm, 4.5a, 17.8vac, 13.7vdc, 62w
Fullwave, series, 5ohm, 4a, 24.7vac, 20.1vdc, 80w





Fullwave, 'the other side' 1ohm, 7.6a, 11.1vac, 7.4vdc, 56w
Fullwave, 'one side' 1ohm, 7.6a, 11vac, 7.4vdc, 56w
Fullwave, 'one side' 2ohm, 6a, 16.3vac, 12.3vdc, 74w
Fullwave, 'one side' 3ohm, 4.9a, 19vac, 14.8vdc, 73w
Fullwave, 'one side' 5ohm, 3.5a, 21.6vac, 17.4vdc, 61w





Dual half wave, 'stock parallel' 1ohm, 7.8a, 26vac, 7.6vdc, 59w
Dual half wave, 'stock parallel' 2ohm, 6.1a, 35vac, 12.6vdc, 77w
Dual half wave, 'stock parallel' 3ohm, 5a, 40vac, 15.2vdc, 76w
Dual half wave, 'stock parallel' 5ohm, 3.6a, 45vac, 17.7vdc, 64w


Same data but without pics, easier to see the ebb and flow of things.

Mikes E scheme, 2ohm, 6.4a, 17.4vac, 13.1vdc, 84w


Fullwave, series, 1ohm, 4.9a, 7.8vac, 4.8vdc, 24w
Fullwave, series, 2ohm, 4.7a, 13.2vac, 9.6vdc, 45w
Fullwave, series, 3ohm, 4.5a, 17.8vac, 13.7vdc, 62w
Fullwave, series, 5ohm, 4a, 24.7vac, 20.1vdc, 80w


Fullwave, 'the other side' 1ohm, 7.6a, 11.1vac, 7.4vdc, 56w

Fullwave, 'one side' 1ohm, 7.6a, 11vac, 7.4vdc, 56w
Fullwave, 'one side' 2ohm, 6a, 16.3vac, 12.3vdc, 74w
Fullwave, 'one side' 3ohm, 4.9a, 19vac, 14.8vdc, 73w
Fullwave, 'one side' 5ohm, 3.5a, 21.6vac, 17.4vdc, 61w


Dual half wave, 'stock parallel' 1ohm, 7.8a, 26vac, 7.6vdc, 59w
Dual half wave, 'stock parallel' 2ohm, 6.1a, 35vac, 12.6vdc, 77w
Dual half wave, 'stock parallel' 3ohm, 5a, 40vac, 15.2vdc, 76w
Dual half wave, 'stock parallel' 5ohm, 3.6a, 45vac, 17.7vdc, 64w



Bill

[wcorey]

Adding the pics to the 4 coil stator 'dual half wave' and full wave tests.



Dual half wave, ‘stock parallel’, 1ohm 3450rpm---------6.6a, 21.6vac, 6.8vdc-------44.9w
Dual half wave, ‘stock parallel’, 3ohm 3450rpm----------3.6a, 28.9vac, 11vdc-----39.6w
Dual half wave, ‘stock parallel’, 5ohm 3450rpm-----------2.4a, 30.4vac, 12vdc,-----28.8w






Full wave, Series, 1ohm 3450rpm-------------------4.9a, 8vac, 5vdc-------------24.5w
Full wave, Series, 3ohm 3450rpm--------------------4.1a, 16.2vac, 12.5vdc-----51.2w
Full wave, Series, 5ohm 3450rpm---------------------3.4a, 21.2vac, 17vdc------57.8w





Full wave, Single winding, 1ohm 3450rpm---------6.3a, 9.7vac, 6.5vdc---------40.9w
Full wave, Single winding, 3ohm 3450rpm----------3.4a, 13.7vac, 10.3vdc------35w
Full wave, Single winding, 5ohm 3450rpm-----------2.3a, 14.7vac, 11.4vdc----26.2w




Bill

[DewCatTea-Bob]

" Adding the pics to the 4 coil stator 'dual half wave' and full wave tests. "

____ Thanks for your latest/final set of test-outcome result-figures for these established circuit-arrangements, Bill !


____ This first presented stock-like rectification circuit-scheme half-wave rectifies the AC-output of each alt.winding separately, and because those two stator-windings are 'wired-up' (not 'oppositely-wound') out-of-phase, the outputs from the single pair of diodes thus take alternating turns providing Positive DC-pulses to the charging-system. _ And due to the fact that the Negative half-cycles (of the full AC-cycles produced by each alt.winding) are all left ignored & unused, the stock rectification-system should therefore be referred to as: 'dual half-wave', (rather than complete "full wave" rectification, despite that the resulting wave-form may appear as normal 'full-wave' on an o.scope).
__ Note that the employed & depicted full-wave rectifier-block is wired-up to make use of ONLY two (of it's four) diodes.....

Dual half wave, ‘stock parallel’, 1ohm 3450rpm----6.6a, 21.6vac, 6.8vdc----44.9w
Dual half wave, ‘stock parallel’, 3ohm 3450rpm----3.6a, 28.9vac, 11.vdc----39.6w
Dual half wave, ‘stock parallel’, 5ohm 3450rpm----2.4a, 30.4vac, 12.vdc,---28.8w



____ This next presented rectification circuit-scheme full-wave rectifies the combined-output of both alt.windings connected together in the common/std.series fashion (which most everyone has naturally reasoned ought provide doubled power-output as well as doubled voltage). _ However, consistent test-results indicate that while the 'voltage' may indeed double, the 'power' obtained cannot be maintained (at higher values) while under increased load.
Therefore anyone who so converted merely to run a 12-volt system, is probably well-off enough,, however, of those who ALSO increased their system's overall running-load,
it's now been made clear that they've made the wrong modification-choice. _ As is clear by the very-low available power-output with the 1-ohm load-resistance.....

Full wave, Series, 1ohm 3450rpm-------------4.9a, 8.vac, 5.vdc-----------24.5w
Full wave, Series, 3ohm 3450rpm-------------4.1a, 16.2vac, 12.5vdc-----51.2w
Full wave, Series, 5ohm 3450rpm-------------3.4a, 21.2vac, 17.vdc-------57.8w



____ This last presented rectification circuit-scheme full-wave rectifies only one alt.winding (at a time), while purposely leaving the other dead.
The purpose of this one-at-a-time test, is to confirm that both alt.windings are equal, and also to help determine what effects might be in play when both stator-windings are in operation, either while in normal parallel-configuration or in non-stock series-arrangement.
__ Note that max.power-output (in this single-winding test), is a full 4-watts lower than Ducati's intended half-wave + half-wave (of each winding) type circuit.....

Full wave, Single winding, 1ohm 3450rpm-----6.3a, 9.7vac, 6.5vdc--------40.9w
Full wave, Single winding, 3ohm 3450rpm-----3.4a, 13.7vac, 10.3vdc-----35w
Full wave, Single winding, 5ohm 3450rpm-----2.3a, 14.7vac, 11.4vdc-----26.2w

[wcorey]

Any last testing requests for the mod'ed six coil stator setup before I pull it apart to prep for the next phase?



Bill

[ecurbruce]

Thanks, Bill for all of the 6 coil tests!

Bruce & Dad.

[MotoMike]

Any last testing requests for the mod'ed six coil stator setup before I pull it apart to prep for the next phase?





Bill

None here Bill. You have done a lot of work that is important. I suspect the next phase as you put it will be more so.

thanks
Mike

[DewCatTea-Bob]

By: wcorey...
" Any last testing requests for the mod'ed six coil stator setup "

____ Yes Bill, how about trying the 'dual full-wave' test ?
That is if you still feel like more (complicated) testing and have the required parts.
This 'Dual full-wave' parallel-type setup is what I've been recommending to single & twin owners since the mid-70's, and it would be nice to get confirmation (of the 4 core-coil version, results), as to how this dual-rectifier arrangement compares to all the other* '6 dual-coil' testing which you've recently done. _ (* In order for this dual rect.block test to be fairly-compared to Mike's single rect.block setup, both sides have to be working at the same time [although they don't have to be meter-measured at the same time!].)
__ Ive added the circuit-scheme below, only difference is 6 instead of the depicted 4 pairs of coils, and 2-ohm loads instead of the stated "1-ohm". _ (If you don't have two 2-ohm loads, then a 3-ohm on one side, will do.)


" before I pull it apart to prep for the next phase? "

____ The "prep for the next phase" I assume is all the reconnections required for all-12 individual coil-windings, so as to create just ONE continuous single-alt.winding (for testing purposes).
__ I believe that while this seems like a worth-while endeavor, the overall-outcome will be undesirable if the final-intended total-load's resistance becomes lower than the impedance-value of the one-single continuous extended alt.stator-winding.
So after that single grand-winding test-trail has been completed, I next propose after that, that a dual stator-winding be tried-out with the same Non-Ducati type coil-winding arrangement. _ So as to end-up with what Mike no doubt would certainly agree with as being a true/standard center-tapped transformer-like arrangement.


Fun-Cheers,
-Bob