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Hi Kelly,
Thanks for the link. Some interesting info,
but... What is lacking is any sort of statistical info to indicate that this is
a real problem. I'm not convinced that using a Cherokee as an example system is
all that applicable. And I dont know how old this article is, but gather it is
pretty old given the reference to problems with alternator failures in cars
resulting in nothing more than burning out lights. I'd venture to say that for
virtually any car built since the mid 80s, a runaway alternator output would
result in far more than a few burnt out lights.
Since virtually all cars these days use
internal solid state regulators, if these things were prone to failure, and
since a runway over volt failure on any modern car would likely toast some
pretty expensive electronics, I'd expect a fair number of really expensive
repairs, warranty issues, etc.... My conclusion is that this type of failure is
actually quite rare, but if you can point to relevant statistical data that
says otherwise, I'm all ears.
Some folks are more risk averse than others
and a 1 in a million possibility is enough to justify making a change. But
sooner or later you have to stop engineering for every possible risk no matter
how remote the failure mode and just get on with it.
Meanwhile, the important points I take from
this reference are, dont overload your alternator, ensure that the field is
de-energized while cranking the engine, and keep it cool.
Off topic, another 1.2 hours closer to
completing my Phase 1. This was the first flight that after I landed I didnt
have anything on my list to fix before the next flight. 95 degrees OAT at
takeoff today and the oil temp got to 200 at the top of the climb to 5000' but
backed off to 192 after I leveled. H2O temp never above 180. Starting to gain
some confidence in it. Oh, and I have a DNA muffler on order. Should have it by
next weekend but may put off installing it so I can fly some more.
Mike Wills
RV-4 N144MW
----- Original Message -----
Sent: Sunday, August 30, 2009 1:21
PM
Subject: [FlyRotary] FW: More Charging
Circuit Info
Group,
I am still on the bandwagon about
modifying our flying alternators for an external
regulator as noted in my past posts...........After supplying group
member Tim Holt &
also the group with info how to modify the Mazda alternator I remembered
the link
below which explains in language even the electrically challenged among
us will be
able to understand...............This info may have been already seen by
some of you
but I believe all of us should file it and also copy it to have available
when wiring
our aircraft electrical systems.............IMHO!!..........
--
Kelly Troyer
"Dyke Delta"_13B
ROTARY Engine
"RWS"_RD1C/EC2/EM2
"Mistral"_Backplate/Oil Manifold
--------------
Forwarded Message: --------------
From: "Kelly Troyer"
<keltro@att.net>
To: tntholt23@bellsouth.net (Timothy Holt)
Subject: More Charging Circuit Info
Date: Sun, 30 Aug 2009 20:06:30
+0000
Tim,
For your informaton here is additional justification in my
opinion for going to an external
regulator in our aircraft and having the ability to either automaticly
or manualy cut power
to the field windings in case of a shorted regulator............Note
that solid state regulators
tend to fail "Shorted" about 50% of the time and all current internal
regulators are solid
state.............Link Below..................."Nuff Said"
!!...............IMHO
--
Kelly
Troyer
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