Because you have been making a fool out of your self starting with this post 4 days ago when I initially suggested a 20 ohm resistor for a dummy load where you claimed people would burn their bikes up if they built a 20 ohms dummy load.
http://www.thegsresources.com/_forum/showpost.php?p=1392069&postcount=30
Now I have computed (as I said I would) the power and revised the design for a 10 ohms resistor which according to you would have been twice as bad as when I posted the first time.
Now you realize my measurements are OK and your think that the
output of ~60 vice mine @ 90 is due to variation in manufacturer specs because you have no other way to explain the difference.
There is a fundamental reason and
you are NOT getting it. Go chew on that and see how long it takes you to figure it out.
Tic Tic Tic..................
Actually, what I freaked out on was not a 20 ohm load, but an 8 ohm load,
2 and a half times as bad.
Additionally, the type of resistor you
advocated and linked to in that specific post are a different design than the ones you are suggesting in this thread.
The ones you are suggesting now are enclosed in an aluminum housing and appear physically bigger, which would imply greater thermal inertia.
Given that you intend to do a short pulse test that matters a lot as to how much they will heat up.
your initial power calculation was
The stator puts out nominally 70-80 volts at 5KRPM; with 8 ohms resistors that would be about 80/16=5 amps and a nearly full voltage test. P = 5*8=40/.707=28 watts at 5K RPM.
Do you still stand by that ? Cause that's a big part of what I initially objected so much to.
All in all, yes, I still think that building the dummy load you initially suggested is actually pretty dangerous. I still stand behind a warning not to do it.
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As to the revised dummy load as described in the pdf in the first post of this thread.
well, its better, you moved from 8 to 10 ohms, and the resistors themselves seem bigger, so hopefully better able to take a short pulse.
OTOH:
The heatsink you recommend is woefully inadequate.
look at the spec sheet you provided, you need at least 1 sq-ft /resistor.
You are running at 1/12 that, which pretty much derates the power handling to 20 watts: 1/5 of even your calculation.
The warning in the PDF is woefully inadequate: "the dummy load heatsink will become hot to the touch in 2-3 minutes"
No, it should be more like "the dummy load heatsink will become hot enough to damage paint and/or melt through insulation in less than a minute, be sure to place it on a nonflammable surface"
If you had a realistic warning in there I wouldn't be warning people its potentially dangerous.
Tell me, do YOU think it would be safe to rest the dummy load as described in the PDF on your wiring harness and rev it to 5000 for 90 seconds ... because as the PDF stands now that's all ok, and it shouldn't even be "hot to the touch" yet ???
Because you know that's whats eventually going to happen ... someone is going to build one with short leads and rest it on the wiring harness or tank ... and then its going to take them longer to get a good reading than they expect ... and then bad things WILL happen.
I know not to do that, you know not to do that, anyone following this thread knows not to do that ... not everyone using the stator pages will know not to do that ...
So, yeah, I still think the dummy load procedure as described in the PDF in your first post of this thread is dangerous. Put it in the stator pages that way and someone will eventually damage their bike.
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Re: the voltage calculations.
I measured 92 VAC RMS, (equates to 130 VAC 0-peak)
Suzuki's manual states a minimum of 80 VAC RMS (113 VAC 0-peak)
In your voltage calculations you claimed 80 VAC 0-peak (equates to 56 VAC RMS). As an open circuit test this would fail even the lower limits given in the stator papers.
you claimed in post 26 that this
was measured open circuit (during the non-regulating phase with a series R/R; so agreed, open circuit)
That would indicate a faulty stator, so yes: I thought you were mis-measuring it.
In post 4 of this thread you said that the loaded tests will only drop the voltage ~5%. It may be a bigger drop in reality, but for our purposes here, I'll use the number you provided.
That gets a barely passing stator (60 RMS) almost down to 80 0-peak (56 RMS).
which I will guess is where you got your voltage for the calculations.
Applying the same 5% drop under load takes my stator to 87 VAC RMS (123 VAC 0-peak) still well above 80 VAC RMS called for by Suzuki,
and still leaving the power into the revised dummy load at >400% rated.
still way to much.
This is all pretty much what I already agreed to in post 38.
but spelled out in more detail.
what are you looking for
POSPLAYR's calculations are correct for a stator with his characteristics !!!
(but mine are still correct for a stator with my characteristics ... and his dummy load is still extra dangerous with my stator)
is that it ???
So what is the fundamental reason I am still not getting, because I still think I understand it. Show me where I am wrong.
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And then, show me the money ...
show me how the dummy load helps troubleshooting at all.
Wheres the money ...
How does the dummy load discriminate between bad and good stators in a better way than the unloaded tests.
SHOW ME THE MONEY ...
How will loaded tests beat the perfect diagnostic record that Graham quoted.
WHERES THE MONEY ...
ANSWER THE ONE QUESTION I ASK IN ALMOST EVERY POST IN THESE THREADS ... THE ONE QUESTION THAT YOU NEVER ADDRESS ... THE ONE QUESTION THAT YOU NEVER HAVE AN ANSWER TO ...
WHERES THE MONEY ... WHERES THE GOSH DARNED MONEY ... what actual benefit does the loaded test have ...
Give me an actual valid cogent answer to the question you always avoid and I'll be quite happy to drop it.
Thanks I knew I’d get something out of this. Think you could add the ammeter and megger in there too for even more labor charges. 9 stator tests at 2 hours each is $585 because a printed publication said do it this way. Now that is a good equation.
