Today's Message Index:
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1. 06:35 AM - Re: Re: Dark and stormy night during CAVU (Ernest Christley)
2. 08:05 AM - Re: Re: Switch Question (Robert L. Nuckolls, III)
3. 07:32 PM - Re: Switch Question (farmrjohn)
Message 1
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| Subject: | Re: Dark and stormy night during CAVU |
I don't have a circuit diagram.=C2-
I used one of the regulators like this:=C2- https://www.amazon.com/Oumurs
-Regulator-Rectifier-1989-1999-74519-88A/dp/B079CJ4DN9/ref=sr_1_18?crid
=3R1Q0AO9RIBJQ&dchild=1&keywords=harley+davidson+regulator&qid=1606
313589&sprefix=harley+davidson+regu%2Caps%2C164&sr=8-18
This is truly a black box device.=C2- There are dozens of sources selling
what looks like the identical item, and I could find exactly zero informat
ion about what is inside any of them.=C2- All the reviews I could find sa
id basically, "It works", and being a Harley part, it seems to be targetted
at people that do not need or care to know more about what is inside. They
all have two wire inputs, and all have one wire output.=C2- I found one
that has a 14.5V set point, which is good for my LiFePO battery that doesn'
t have a BMS other than charge equalization.
I spliced my tach signal wire into one of the leads from the PMA to the reg
ulator.=C2- I had not considered that the regulator might be dumping all
the energy from the PMA to ground.=C2- I assumed it would just switch the
input off completely.=C2- That would leave the generator with some hyste
resis current, but that shouldn't amount to much.=C2- At this point, I'm
of a mind to tear this brand new regulator apart, just to find out what is
in there.=C2- Dang, education is expensive.
On Tuesday, November 24, 2020, 10:30:30 PM EST, dj_theis <djtheis58@gma
il.com> wrote:
> I have to find another method of picking up the rpm. I already have a rel
uctor. Just have to install it. But, a word to the wise. . . don't use the
generator as a tachometer source. This is experimental aviation, and I cons
ider this experiment to be a success. I learned something, and no metal >wa
s bent in the process.
I have a couple of thoughts and some questions related to this post.
first the thoughts.=C2-
Is it possible the tachometer is wired on the wrong side of the regulator /
rectifier?
I have as exhibits, three attached documents.=C2-
1) a similar tachometer circuit as shown in the Remaster electrical manual
(i.e. PM alternator with Westach, tachometer)
2) the Revmaster alternator connections as shown in their illustrious manua
l.
3) the alternator connections as I've redrawn them (after much noodling and
consideration).=C2-
Recognizing that not all RR for PMA are created under the same zodiac.=C2
- And, I'm in the process of verifying the operation of the Revmaster as
I've interpreted and redrawn it.
I can imagine at least one RR design that would shunt the AC coils out when
reaching the setpoint, which would nullify the tach signal.=C2- The desi
gn of the Revmaster (series regulator, in my personal venacular) does not s
hunt the PMA coils but instead,=C2- opens the PM circuit when the battery
voltage reaches a set value (with an SCR that completes the PMA circuit to
battery common).=C2- If the tach is wired on the AC side of the RR, (as
Revmaster shows it) the voltage signal will still drive the tachometer when
the RR reaches setpoint and opens the circuit to the battery (as described
by Bob, with plenty of extra power to spare).
Alternatively, if the tach is on the DC side of the RR, the signal is likel
y to die out, as the RR intermitantly disconnects the PMA from the battery,
as it reaches the target voltage.=C2- Also, ( in the case of the Revmast
er's dual alternar) tif the "other" PMA is selected as the "chosen one" to
supply power to the battery and ships devices, the original (now disconnect
ed) alternator will still be available to run the tach, with the voltage pu
lses it is happily generating at basically an "open circuit" voltage condit
ion.=C2-
In the version (that I've not seen, but only heard of) where the PMA is sho
rt circuited when reaching voltage setpoint, I can imagine that the tach co
nnected to the AC side would fail to sense any voltage as the RR reached se
tpoint.=C2- It would seem that this design (a shunted PMA RR) would be ve
ry hard on the RR as it has to reject the heat of full current and it's nom
inal voltage drop and b) damn unnecessary added heat to the PMA as it gener
ates near full short circuit current across its coils.
Does the original post member have a circuit diagram and alternator we can
evaluate?
Dan Theis
--------
Scratch building Sonex #1362
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=499506#499506
Attachments:
http://forums.matronics.com//files/revmaster_2300_rev13_alternator_ckt_190.
pdf
http://forums.matronics.com//files/revmaster_manual_alternator_connection_4
92.pdf
http://forums.matronics.com//files/remaster_manual_tach_connection_377.pdf
-
S -
WIKI -
-
=C2- =C2- =C2- =C2- =C2- -Matt Dralle, List Admin.
Message 2
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| Subject: | Re: Switch Question |
At 09:47 PM 11/24/2020, you wrote:
>
>My airplane is an Alon Aircoupe that Univair now has the TCSD
>for. It does not have a battery master contactor, and the STC
>available to add one does not include the Alons due to a change in
>the battery box and location. I am working with my A&P/IA on a
>possible field approval, along with a lithium battery
>installation. I was curious about the AN switch and what its
>characteristics are.
I used to have some Cuttler-Hammer data from that
era but I'm unable to access it. But we can be
sure that this switch is not off your grandpa's
yard tractor. It's a beefy device used on many
small aircraft of the era as THE battery master.
Getting a field approval for battery and contactor
upgrade shouldn't be a big deal. It's a rudimentary
but significant performance upgrade.
Bob . . .
Un impeachable logic: George Carlin asked, "If black boxes
survive crashes, why don't they make the whole airplane
out of that stuff?"
Message 3
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| Subject: | Re: Switch Question |
nuckolls.bob(at)aeroelect wrote:
>
>
> Getting a field approval for battery and contactor
> upgrade shouldn't be a big deal. It's a rudimentary
> but significant performance upgrade.
>
>
>
> Bob . . .
>
> Un impeachable logic: George Carlin asked, "If black boxes
> survive crashes, why don't they make the whole airplane
> out of that stuff?"
Totally agree, it's just a matter of finding someone at the local FSDO that has
the same point of view. John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=499529#499529
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