AeroElectric-Archive.digest.vol-gc
September 07, 2006 - September 14, 2006
Bob . . .
________________________________________________________________________________
| From: | "Jim Baker" <jlbaker(at)msbit.net> |
| Subject: | JPI remote mount..... |
X-mailer: Pegasus Mail for Windows (4.41)
Does anyone have any experience with remote mounting a JPI
EDM 700 head separate from the electronics case. Poor "due
diligence" on my part shows that in the Bellanca Viking, pre '75,
there aren't a lot of options as to mounting locations....except
top, dead center where my altimeter now resides (welded in
panel bars and bracing...rats!). I have a three inch location for
the 3 inch display and can make up a couple of AMPMODU IV
dual row connectors to extend from the head to the electronics.
Question is.....how long could I rerasonably expect to make the
ribbon cables without problems. I know this is a loaded question
since one doesn't know the specifics of internal hardware
(suspect a serial interface to the head), so shooting in the
dark...JPI are adamant about not entertaining questions of this
sort. Period.
Jim Baker
580.788.2779
Elmore City, OK
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Re: AOPA battery article |
OBAM stands for Owner Built and Maintained, which the designation that Bob
prefers to call Experimental / Amateur Built aircraft.
Carlos
----- Original Message -----
From: "Cleone Markwell" <cleone(at)rr1.net>
Sent: Thursday, September 07, 2006 4:31 PM
Subject: Re: AeroElectric-List: AOPA battery article
>
> Bob, What does OBAM mean?
>
>
> At 09:29 PM 9/6/2006, you wrote:
>>
>>
>>
>>
>>>---- "Robert L. Nuckolls wrote:
>>> III"
>>> >
>>> >
>>> > >The article is in the AOPA pilot magazine Aug or Sept issue, on
>>> > >aircraft
>>> > >batteries.
>>> > >Bobs name is mentioned right in the introduction of the article and
>>> > >later
>>> > >near the end with a reference to the connection. I have a rotax
>>> 912 with a
>>> > >20Amp generater, was setting up
>>> > >for an RG battery from B&C, but took out the vented battery box
>>> I got with
>>> > >my kit and dusted it off wondering if this article is correct.
>>> >
>>> > I don't subscribe to AOPA Pilot any more so I missed
>>> > the article. It would be interesting/useful to review
>>> > it. If someone could scan it and email it to me, I'd
>>> > appreciate it.
>>> >
>>> > Bob . . .
>>>
>>>Listers,
>>> The relevent article is on page 133 of the September issue
>>>Charlie Kuss
>>
>> Dave sent me a copy. It's an innocuous piece and relatively
>> accurate. If I were to expand beyond where it stopped short
>> would be to explain the value in KNOWING what your endurance
>> loads are and KNOWING if your battery is likely to support
>> this load for whatever endurance YOU decide.
>>
>> There was one rather glaring error on the top of page
>> 138 where it's stated that a 1C rated battery is discharged
>> at 2C, it will deliver energy for 1/2 hour. Twice the
>> load is ALWAYS less than half the previous capacity. By
>> the same token, 0.1C load is always more than 10X the
>> 1C label capacity.
>>
>> Exemplar capacity vs. discharge rates are illustrated
>> in . . .
>>
>>http://www.aeroelectric.com/Pictures/Curves/37AH_Capacity_vs_Load.gif
>>
>> and
>>
>>http://www.aeroelectric.com/Pictures/Curves/17AH_Capcity_vs_Load.gif
>>
>> These graphs from manufacturer's data show that increasing
>> loads increases internal losses and that apparent
>> capacity drops as load increases.
>>
>> Our perpetual parents on the TC side have decided that
>> "30 minutes" is the magic number for endurance and
>> "85% of label capacity" is end of life for the battery.
>> This makes the certification effort easy and makes FBOs
>> task of selling batteries easier. This is an excellent example of
>> standardization that benefits the manufacturers and
>> regulators while limiting the owner's ability to tailor
>> realistic targets to match his/her own mission requirements.
>>
>> Neither one of the 30-minute/85% assertions suggest that
>> the owner/operator of an airplane might possess tools and
>> be willing to acquire skills needed increase personal endurance
>> target to say 1 hour. Or, take the time to monitor a battery
>> with an eye toward meeting the endurance level such that
>> 70% of label capacity is the TRUE end of life for the battery
>> in that particular airplane.
>>
>> Aren't you guys glad you don't have to salute those
>> flags? I still like "duration of fuel aboard" for
>> endurance and "pitch it when e-bus loads cannot be
>> supported for duration of fuel aboard." Of course,
>> on the OBAM side of the house we're free to select
>> and operate to our personal design goals.
>>
>>
>> Bob . . .
>>
>>
>> ---------------------------------------------------------
>> < What is so wonderful about scientific truth...is that >
>> < the authority which determines whether there can be >
>> < debate or not does not reside in some fraternity of >
>> < scientists; nor is it divine. The authority rests >
>> < with experiment. >
>> < --Lawrence M. Krauss >
>> ---------------------------------------------------------
>>
>>
>>
>>
>>
>
>
>
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
| Subject: | Re: AOPA battery article |
Bob,
Would you care to comment with regard to the article's assertion that
generators under 50 amps are adversely affected by the high capacity
RG35 batteries, in particular, as opposed to small alternators? Or
have you heard from the gentleman at Concorde?
I know alternators are a little more self limiting, but it seems like
the larger charging demand from the low resistance of that battery
would have adverse effects on both generators and alternators.
Quoting "Robert L. Nuckolls, III" :
>
>
>
________________________________________________________________________________
| From: | Jerry2DT(at)aol.com |
I don't often post to this fine list but do monitor it daily and have
learned much from Bob and others. The whole debate/interchange/scuffle between
gmcjet and Bob sometimes are fascinating, once in awhile educational and
sometimes just worthy of the delete key. However, at one point a few months ago,
I
had a need for advice which I posted here, and got useful info from Bob and
others. To my surprise however, George emailed me directly and spent lots of
time very graciously leading me by the hand , developing and sending schematics,
explanations, etc. He came across as very caring and helpful.
Just wanted you all to know there is another side to this guy, thas' all...
One amazing thing of note is the similarity in styles of argument and
outcomes between George and Paul Messinger.
My .02 as usual,
Jerry Cochran
________________________________________________________________________________
| Subject: | Re: AOPA battery article |
| From: | Brian Lloyd <brian-av(at)lloyd.com> |
On Wed, 2006-09-06 at 19:29, Robert L. Nuckolls, III wrote:
> These graphs from manufacturer's data show that increasing
> loads increases internal losses and that apparent
> capacity drops as load increases.
Bob:
I am going to pick a nit here. At least twice I have seen you mention
losses in a battery in relationship to the change in battery capacity
with change in discharge rate. The interesting thing is, this
relationship occurs even when losses are not at issue, i.e. in batteries
intended for high-reliability stationary applications where they can
afford to construct massive plate structures where I*R losses are
virtually nonexistent. The relationship is still an exponential one and
was discovered by a gentleman named Peukert, hence it is named Peukert's
law.
The real reason has to do with the rate at which the electrolyte
diffuses into the active area of the plate and how the active portion of
the plate changes with time at different rates of discharge.
Good information about this can be found at
"http://en.wikipedia.org/wiki/Peukert's_Law". The first external link is
to a PDF file with a good discussion (with pictures!) of the actual
chemical behavior of the plate of a battery and why Peukert's exponent
applies.
Yes, this is a small thing and probably not worth worrying about when
building aircraft electrical systems since you will always be
discharging the battery on you e-bus at the same rate every time. But
pedantic people (like me) care about such little things. :-)
Brian Lloyd
________________________________________________________________________________
| Subject: | gmcjetpilot's legacy |
| From: | "John W. Cox" <johnwcox(at)pacificnw.com> |
Maybe for the point of humor you can all assume "gmcjetpilot" is a
former and now furloughed corporate pilot contracted by GMC before or
during the time they made so many foolish decisions. And now he is
bitter due to the cutbacks.
My delete key works great and is a source of confirming the system is
working well. Think of his as a possible Renault pilot with a French
attitude.
John Cox
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Ernest Christley
Sent: Thursday, September 07, 2006 7:12 AM
Subject: AeroElectric-List: gmcjetpilot's legacy
OK. The guy was/is a blowhard, with obviously way to much time on his
hands to be able to write long rambling dissertations with no point;
however....maybe there is a diamond or two amoungst all that
pig....stuff.
Bob wrote:
(1) He refused to acknowledge a modern alternator could experience a
gross OV failure in spite of demonstrations to the contrary. (2) He
brushed aside my oft stated design goals for providing seamless
integration of his favorite product (the IR alternator) into classic
aircraft electrical systems.
It irritated the snot out of me that he would never simply state an
alternative set of design goals. He did expound on the benefits that an
IVR has...temp compensation, slow start, etc. I think those are
desirable, but not if they don't fit in with the rest of the design
goals. Bob has clearly and succinctly stated that the design goal is
that the pilot have complete control of the charging system. It seems
to me that simply modifying one word would open the door for IVR systems
and maintain or increase the current level of safety. Do we really need
'complete' control, or will 'ultimate' control suffice? That is, we
allow the IVR to work it's magic was the IVR designers have seen fit to
have the magic performed, but the pilot has "all rights reserved".
(S)he can hit the kill switch and take it out of the system at any time.
Yes that might break the alternator, but isn't it being taken offline
because it's already broke?
--
,|"|"|, Ernest Christley |
----===<{{(oQo)}}>===---- Dyke Delta Builder |
o| d |o http://ernest.isa-geek.org |
________________________________________________________________________________
| From: | "Bob Lee" <bob(at)flyboybob.com> |
| Subject: | OV Module additional requirement |
OK 'Lectron heads, let me know, did question just got dropped in the midst
of all the George-bantor, or is it too dumb to get an answer?
The questions:
1. can the OVM be modified to allow for three inputs: sense, trip, and
ground? (I don't want to crowbar the same place that I want to measure the
voltage.)
2. Can one OVM detect and react to an OV event fast enough to trip the
correct alternator in a two alternator/OVM installation?
The deatils are in the attached message.
Regards,
Bob Lee
N52BL KR2
Suwanee, GA
91% done only 65% to go!
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Bob
Lee
Sent: Saturday, September 02, 2006 1:37 PM
Subject: AeroElectric-List: OV Module additional requirement
I upgraded my engine from mag to electronic ignition and carb to fuel
injection. This has increased the electrical demand far in excess of the 20
amp alternator that is supplied with my engine. I am using Z13-20 with a 40
amp alternator installed in the mag drive of the engine.
My load analysis shows 59 amps with everything on (including pitot heat).
Therefore I would like to be able to run both alternators together as my
standard operation. Now lets make the assumption that one of the
alternators has an OV event. Using the existing Crowbar OVM revE as a base
line I would like to know if it is possible to remove the wire between pinA
of the Gate S6025L, and add an additional output from the OVM to be the trip
for the alternator field. The existing positive connection of the OVM would
be connected to the alternator B+ as a sense lead.
I have a schematic of this idea at
http://flyboybob.com/images/kr2/n52bl/electric%20and%20instrument/ov001-rev2
-4.jpg
to illistrate my question.
The power distribution has the two alternators each with a separate OVM
comming together at the battery contactor on opposite sides which puts the
battery between B+ power feeds of the two alternators.
That's the background, now the question:
Would an OVMs be able to sence the offending high voltage alternator and
only trip that one alternator off line? Or would the battery not be able to
clamp the OV event long enough to prevent the OVM on the good alternator
from tripping too?
Regards,
Bob Lee
N52BL KR2
Suwanee, GA
91% done only 65% to go!
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
>I don't often post to this fine list but do monitor it daily and have
>learned much from Bob and others. The whole debate/interchange/scuffle
>between gmcjet and Bob sometimes are fascinating, once in awhile
>educational and sometimes just worthy of the delete key. However, at one
>point a few months ago, I had a need for advice which I posted here, and
>got useful info from Bob and others. To my surprise however, George
>emailed me directly and spent lots of time very graciously leading me by
>the hand , developing and sending schematics, explanations, etc. He came
>across as very caring and helpful.
>
>Just wanted you all to know there is another side to this guy, thas' all...
>
>One amazing thing of note is the similarity in styles of argument and
>outcomes between George and Paul Messinger.
Thank you for sharing this Jerry. I appreciate
the existence of some non-negative data in what has
been mostly troubling and tiresome experience . . .
Bob . . .
________________________________________________________________________________
| From: | "Bill Boyd" <sportav8r(at)gmail.com> |
| Subject: | Re: gmcjetpilot's legacy |
I believe his screen name derives from his name, rumored to be G.
McQueen, and I can vouch for his willingness to devote lots of time to
private off-list mentoring and his usefulness as a source for
alternator and regulator part numbers. Not all his posts are caustic,
but too many are.
On 9/7/06, John W. Cox wrote:
>
> Maybe for the point of humor you can all assume "gmcjetpilot" is a
> former and now furloughed corporate pilot contracted by GMC before or
> during the time they made so many foolish decisions. And now he is
> bitter due to the cutbacks.
>
> My delete key works great and is a source of confirming the system is
> working well. Think of his as a possible Renault pilot with a French
> attitude.
>
> John Cox
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Ernest Christley
> Sent: Thursday, September 07, 2006 7:12 AM
> To: AeroElectric-List Digest Server
> Subject: AeroElectric-List: gmcjetpilot's legacy
>
>
>
> OK. The guy was/is a blowhard, with obviously way to much time on his
> hands to be able to write long rambling dissertations with no point;
> however....maybe there is a diamond or two amoungst all that
> pig....stuff.
>
> Bob wrote:
> (1) He refused to acknowledge a modern alternator could experience a
> gross OV failure in spite of demonstrations to the contrary. (2) He
> brushed aside my oft stated design goals for providing seamless
> integration of his favorite product (the IR alternator) into classic
> aircraft electrical systems.
>
> It irritated the snot out of me that he would never simply state an
> alternative set of design goals. He did expound on the benefits that an
> IVR has...temp compensation, slow start, etc. I think those are
> desirable, but not if they don't fit in with the rest of the design
> goals. Bob has clearly and succinctly stated that the design goal is
> that the pilot have complete control of the charging system. It seems
> to me that simply modifying one word would open the door for IVR systems
> and maintain or increase the current level of safety. Do we really need
> 'complete' control, or will 'ultimate' control suffice? That is, we
> allow the IVR to work it's magic was the IVR designers have seen fit to
> have the magic performed, but the pilot has "all rights reserved".
> (S)he can hit the kill switch and take it out of the system at any time.
> Yes that might break the alternator, but isn't it being taken offline
> because it's already broke?
>
>
> --
> ,|"|"|, Ernest Christley |
> ----===<{{(oQo)}}>===---- Dyke Delta Builder |
> o| d |o http://ernest.isa-geek.org |
>
>
________________________________________________________________________________
| From: | "David M." <ainut(at)hiwaay.net> |
| Subject: | Re: AOPA battery article |
Owner Built and Maintained. Invented while searching for a politically
correct term for homebuilt.
David M.
Cleone Markwell wrote:
>
> Bob, What does OBAM mean?
>
>
> At 09:29 PM 9/6/2006, you wrote:
>
>>
>>
>>
<<>>
________________________________________________________________________________
| From: | Dave N6030X <N6030X(at)DaveMorris.com> |
| Subject: | Argumentative people and personal attacks |
People are sometimes unaware of how easy it is to become drawn into
personal attacks by the anonymous nature of the net. Those who have
been around for a long time since the day of BBSes and Compuserve and
such will probably agree they have deleted MANY of their own posts
prior to hitting the Send key. Sometimes it's better to vent to
yourself, and then delete before sending. The emoticons were
invented to try to replace the missing body language and facial
expressions. But calling somebody a name and then following it with
a smiley face doesn't do the trick.
If it's something you would not say to a person's face at an EAA
meeting, why say it on the net where your words will be enshrined
forever and searchable in archives for decades to come? There's no
reason for name-calling. Don't forget, there IS such a thing as
private e-mail if you feel you really need to argue with someone.
But, this IS Bob's "classroom". If you don't agree with Bob after a
few exchanges that will enlighten the group, you can always go off
and do it your way. Just please come back and report to us how well
it worked, so we can all be better informed by your first-hand
experience. Experience trumps theory in my book. Create your own
classroom if you have better ideas.
I, too, have had very civil discussions with George off-list and wish
we could all just stick to emotion-free technical discussions and to
the agreement to occasionally just disagree. I've never deleted
anything George or Paul have said without reading it, but have
searched within their writings for any speck of information that I
might be able to learn from. As long as what someone writes has good
data in it, I'll keep reading it. But attacks get boring.
(This was way too long. I should delete it. Nah, I'm allowed one mistake.)
Dave Morris
N6030X
________________________________________________________________________________
| From: | "Matt Prather" <mprather(at)spro.net> |
I believe that a person's positive activities can't always make up for
their negative ones.. One aw-shucks can wipe out a whole bunch of
attaboys. This is so because it's almost always much easier to poison a
good process than it is to recover one that's already tainted.
Regards,
Matt-
>
>
>
>>I don't often post to this fine list but do monitor it daily and have
>>learned much from Bob and others. The whole debate/interchange/scuffle
>>between gmcjet and Bob sometimes are fascinating, once in awhile
>>educational and sometimes just worthy of the delete key. However, at one
>>point a few months ago, I had a need for advice which I posted here, and
>>got useful info from Bob and others. To my surprise however, George
>>emailed me directly and spent lots of time very graciously leading me by
>>the hand , developing and sending schematics, explanations, etc. He came
>>across as very caring and helpful.
>>
>>Just wanted you all to know there is another side to this guy, thas'
>> all...
>>
>>One amazing thing of note is the similarity in styles of argument and
>>outcomes between George and Paul Messinger.
>
> Thank you for sharing this Jerry. I appreciate
> the existence of some non-negative data in what has
> been mostly troubling and tiresome experience . . .
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | <chaztuna(at)adelphia.net> |
---- "Robert L. Nuckolls wrote:
>
>
> >I don't often post to this fine list but do monitor it daily and have
> >learned much from Bob and others. The whole debate/interchange/scuffle
> >between gmcjet and Bob sometimes are fascinating, once in awhile
> >educational and sometimes just worthy of the delete key. However, at one
> >point a few months ago, I had a need for advice which I posted here, and
> >got useful info from Bob and others. To my surprise however, George
> >emailed me directly and spent lots of time very graciously leading me by
> >the hand , developing and sending schematics, explanations, etc. He came
> >across as very caring and helpful.
> >
> >Just wanted you all to know there is another side to this guy, thas' all...
> >
> >One amazing thing of note is the similarity in styles of argument and
> >outcomes between George and Paul Messinger.
>
> Thank you for sharing this Jerry. I appreciate
> the existence of some non-negative data in what has
> been mostly troubling and tiresome experience . . .
>
> Bob . . .
Bob,
I have found George to be very helpful as well. On subjects electrical and otherwise.
He has made great efforts to educate me to the whys and hows of various
aviation related items. He recently outlined for me why certain brands of aircraft
parts are superior to other brands. All done in a cheerful matter.
Charlie Kuss
________________________________________________________________________________
| Subject: | Re: AOPA battery article |
| From: | "Matt Prather" <mprather(at)spro.net> |
Picking nits here... Maybe it's just me, but I think "politically
correct" has taken on a rather negative connotation.
I believe "OBAM," in some ways, more accurately reflects our aircraft.
Very often (usually), the airplanes we build and operate are direct copies
of other aircraft. They are built for entertainment and transportation.
Little aerodynamic study or scientific endeavor is accomplished (and
that's okay). Experimentation is minimal.
"OBAM," as you say, also may put a better spin on things with the
uninformed public than do other terms that describe what we are doing...
Regards,
Matt-
>
> Owner Built and Maintained. Invented while searching for a politically
> correct term for homebuilt.
>
> David M.
>
>
> Cleone Markwell wrote:
>
>>
>>
>> Bob, What does OBAM mean?
>>
>>
>>
>> At 09:29 PM 9/6/2006, you wrote:
>>
>>>
>>>
>>>
> <<>>
>
>
________________________________________________________________________________
| From: | Sean Stephens <sean(at)stephensville.com> |
chaztuna(at)adelphia.net wrote:
>
> Bob,
> I have found George to be very helpful as well. On subjects electrical and otherwise.
He has made great efforts to educate me to the whys and hows of various
aviation related items. He recently outlined for me why certain brands of
aircraft parts are superior to other brands. All done in a cheerful matter.
> Charlie Kuss
>
I feel like the suckerfish swimming along the bottom of the creek that
spots a piece of cheese on the end of a string, having no idea that
cheese on the end of a string has no business being in a creek.
But I'll bite...
Why are certain brands of aircraft parts superior to other brands? Care
to elaborate?
-Sean
________________________________________________________________________________
| Subject: | Re: Dual radio interference |
| From: | "europa flugzeug fabrik" <n3eu(at)comcast.net> |
sjhdcl(at)kingston.net wrote:
> When I select both radio to listen to and then transmit on one, the transmission
is very garbled for me. ATC reads me loud and clear but I can barely make
out what I'm saying. Happens with both radios.
How close are the 2 freqs on COM 1 and 2 when this phenomenon occurs? I couldnt
duplicate the phenomenon using two VHF handhelds, unless the freqs were really
close together. That's also like the two devices are within inches of each
other, not the case of an airplane antenna installation.
Fred F.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=60253#60253
________________________________________________________________________________
| From: | "Allan Aaron" <aaaron(at)tvp.com.au> |
I don't want to beat this thing to death but I've also had several
off-line email exchanges with George that have been very helpful and
he's been very gracious with his time in helping me out. I'm not
arguing with the will of the group or Bob here, just wanting people to
realise that he's not all that bad .....
Allan
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Single Display EFIS |
Listers
Does anybody have any experience flying with a single display EFIS, with
graphical engine monitor? Can you please share your impressions, mainly by
the fact to have to change from the PFD to the Engine page because of the
single screen.
Since I will have backup analog instruments for airspeed, altitude and
attitude, I'm thinking in saving some money not buying the second EFIS
display unit, hence need to know if anybody already flying thinks it is
perfectly doable.
TIA
Carlos
________________________________________________________________________________
| From: | Deems Davis <deemsdavis(at)cox.net> |
| Subject: | Re: Single Display EFIS |
The Op Tech EFIS screen is designed so that you have 4 engine gauges of
your choice displayed on the same screen as the HSI and the Moving map,
minimizing/eliminating the need to switch screens for the vast majority
of the instances.
Deems Davis # 406
Fuse/Finish/Panel
http://deemsrv10.com/
Carlos Trigo wrote:
>
>
> Listers
>
> Does anybody have any experience flying with a single display EFIS,
> with graphical engine monitor? Can you please share your impressions,
> mainly by the fact to have to change from the PFD to the Engine page
> because of the single screen.
> Since I will have backup analog instruments for airspeed, altitude and
> attitude, I'm thinking in saving some money not buying the second EFIS
> display unit, hence need to know if anybody already flying thinks it
> is perfectly doable.
>
> TIA
> Carlos
>
>
________________________________________________________________________________
| From: | "Darwin N. Barrie" <ktlkrn(at)cox.net> |
| Subject: | gmcjetpilot's legacy |
Many have said they have back line conversations with George McClean and
he has been helpful. However, how do you know if his information is
valid? I reiterate, who is this guy?
If you have followed his threads on the various lists he displays a
knowledge of ALL aspects of aviation, kit building, fiberglass work,
painting, camp stoves. If someone disagrees with him he will belabor the
point to death. He knows everything. I have never seen him post a
question. On Doug's Forums he is often the last one to post on a given
subject. He is a thread killer. He is beligerent, argumentative and
contrary to most opinions that are not parallel to his. This type of
activity is not needed.
This may appear personal and in part it is. If you saw the LONG personal
attack he sent me you'd understand. Notice he doesn't post any real
information but at least has posted he is from the Raliegh NC "area." I
asked him why he doesn't post who he is and he said, "there are stalkers
out there." Sounds pretty paranoid to me.
For those of you who have said he has been helpful, use caution. We
don't know who he is. Does anyone actually know him?
With this list we have a known expert in the field, with Bob Nuckols.
I'm sticking with his advice. My concern is some new and unsuspecting
person following George's advice only to find he is full of sh*t.
Darwin N. Barrie
Chandler AZ
________________________________________________________________________________
| From: | "Alan K. Adamson" <aadamson(at)highrf.com> |
| Subject: | Single Display EFIS |
So does the AFS-3400/3500. Well, actually more than 4, you get all the
essential engine instruments and then a few. Worth a check out if you are
going to go single screen. Do consider the single point of failure
however...
Alan
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Deems
Davis
Sent: Thursday, September 07, 2006 9:23 PM
Subject: Re: AeroElectric-List: Single Display EFIS
-->
The Op Tech EFIS screen is designed so that you have 4 engine gauges of your
choice displayed on the same screen as the HSI and the Moving map,
minimizing/eliminating the need to switch screens for the vast majority of
the instances.
Deems Davis # 406
Fuse/Finish/Panel
http://deemsrv10.com/
Carlos Trigo wrote:
>
>
> Listers
>
> Does anybody have any experience flying with a single display EFIS,
> with graphical engine monitor? Can you please share your impressions,
> mainly by the fact to have to change from the PFD to the Engine page
> because of the single screen.
> Since I will have backup analog instruments for airspeed, altitude and
> attitude, I'm thinking in saving some money not buying the second EFIS
> display unit, hence need to know if anybody already flying thinks it
> is perfectly doable.
>
> TIA
> Carlos
>
>
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: OV Module additional requirement |
Hi Bob Lee
With paralleled alternators you probably can't really have an
overvoltage due to a single failure with such a heavilly loaded system.
If either alternator running full on at 100% output would still not
exceed the system load, then the second alternator would just reduce its
output (although it might well oscillate). I actually observed something
similar today. After a night flight I had inadvertantly left a fuel pump
on that drained one battery. It seemed like an opportunity to experiment
a bit with my Z-14 architecture so I ran the engine. Bad idea I guess as
the 20amp PM alternator now seems to want to run full on. However in the
short term it does not come close to tripping the OVP as long as the
batteries are paralleled. With 20 amps or more load the voltage stays
completely normal.
Back to your situation - even with small loads I would not expect an OVM
to trip only the problem alternator if two alternators are paralleled
and one goes to max output. Two regulators or two OVMs will always have
slightly different control voltages. There is some discussion on the
difficulties of paralleling alternators in the archives. You might want
to consider a larger main alternator unless it is only temporary loads
like landing lights that is bringing you up to 59 amps. Certainly you
can build an OVM with a separate sense wire but I haven't looked at your
proposed method.
Ken
Bob Lee wrote:
>
>OK 'Lectron heads, let me know, did question just got dropped in the midst
>of all the George-bantor, or is it too dumb to get an answer?
>
>The questions:
>
>1. can the OVM be modified to allow for three inputs: sense, trip, and
>ground? (I don't want to crowbar the same place that I want to measure the
>voltage.)
>
>2. Can one OVM detect and react to an OV event fast enough to trip the
>correct alternator in a two alternator/OVM installation?
>
>The deatils are in the attached message.
>
>Regards,
>
>Bob Lee
>N52BL KR2
>Suwanee, GA
>91% done only 65% to go!
>
>
>-----Original Message-----
>From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Bob
>Lee
>Sent: Saturday, September 02, 2006 1:37 PM
>To: Aeroelectric (E-mail)
>Subject: AeroElectric-List: OV Module additional requirement
>
>
>I upgraded my engine from mag to electronic ignition and carb to fuel
>injection. This has increased the electrical demand far in excess of the 20
>amp alternator that is supplied with my engine. I am using Z13-20 with a 40
>amp alternator installed in the mag drive of the engine.
>
>My load analysis shows 59 amps with everything on (including pitot heat).
>Therefore I would like to be able to run both alternators together as my
>standard operation. Now lets make the assumption that one of the
>alternators has an OV event. Using the existing Crowbar OVM revE as a base
>line I would like to know if it is possible to remove the wire between pinA
>of the Gate S6025L, and add an additional output from the OVM to be the trip
>for the alternator field. The existing positive connection of the OVM would
>be connected to the alternator B+ as a sense lead.
>
>I have a schematic of this idea at
>http://flyboybob.com/images/kr2/n52bl/electric%20and%20instrument/ov001-rev2
>-4.jpg
> to illistrate my question.
>
>The power distribution has the two alternators each with a separate OVM
>comming together at the battery contactor on opposite sides which puts the
>battery between B+ power feeds of the two alternators.
>
>That's the background, now the question:
>
>Would an OVMs be able to sence the offending high voltage alternator and
>only trip that one alternator off line? Or would the battery not be able to
>clamp the OV event long enough to prevent the OVM on the good alternator
>from tripping too?
>
>Regards,
>
>Bob Lee
>N52BL KR2
>Suwanee, GA
>91% done only 65% to go!
>
>
________________________________________________________________________________
| From: | "Steve & Denise" <sjhdcl(at)kingston.net> |
| Subject: | Re: Dual radio interference |
Freqs are far apart. 122.5 and 126.7.
Antenna are about 4 ft apart.
Steve
RV7A
> Subject: AeroElectric-List: Re: Dual radio interference
> From: "europa flugzeug fabrik" <n3eu(at)comcast.net>
>
>
>
> sjhdcl(at)kingston.net wrote:
> > When I select both radio to listen to and then transmit on one, the
transmission
> is very garbled for me. ATC reads me loud and clear but I can barely make
> out what I'm saying. Happens with both radios.
>
> How close are the 2 freqs on COM 1 and 2 when this phenomenon occurs? I
couldnt
> duplicate the phenomenon using two VHF handhelds, unless the freqs were
really
> close together. That's also like the two devices are within inches of
each
> other, not the case of an airplane antenna installation.
>
> Fred F.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=60253#60253
>
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: JPI remote mount..... |
In a message dated 9/7/06 12:06:54 PM Eastern Daylight Time,
jlbaker(at)msbit.net writes:
> Does anyone have any experience with remote mounting a JPI
> EDM 700 head separate from the electronics case. Poor "due
> diligence" on my part shows that in the Bellanca Viking, pre '75,
> there aren't a lot of options as to mounting locations....except
> top, dead center where my altimeter now resides (welded in
> panel bars and bracing...rats!). I have a three inch location for
> the 3 inch display and can make up a couple of AMPMODU IV
> dual row connectors to extend from the head to the electronics.
> Question is.....how long could I rerasonably expect to make the
> ribbon cables without problems. I know this is a loaded question
> since one doesn't know the specifics of internal hardware
> (suspect a serial interface to the head), so shooting in the
> dark...JPI are adamant about not entertaining questions of this
> sort. Period.
>
> Jim Baker
> 580.788.2779
> Elmore City, OK
============================
Jim:
Of course JPI won't answer your question, it would totally change their
warranty on the item and if something went wrong you would say "You told me I could
do that."
There is noting in the electronics signal that will restrict additional
length to the JPI. You can probably run 25 feet before a voltage drop would start
causing problems.
But, why not entertain the idea about a remote mounted "BUDD BOX". Probably
off the bottom of the panel or is there room between the seats?
I know the Bellanca Viking uses many different types of construction
throughout. Is there any place above your head - between the seats, where you
can
mount a BUDD BOX? Off a support frame tubing? Or off the floor on a small
stanchion?
How about on top of the glare shield, again in a BUDD BOX?
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
________________________________________________________________________________
| From: | "Peter Braswell" <pbraswell(at)alterthought.com> |
| Subject: | Single Display EFIS |
Carlos,
A bit of food for thought...
I have a BMA EFIS One and I absolutlely love it. I originally was going to
put all the engine instrumentation on the E1 to have a nice minimalistic
panel. For various reasons (chief among them was that I was convinced I was
going to install an auto-conversion -- which I ended up not doing). Anyway,
like you I have a backup AS and ALT and all steam gauges for the engine
instruments. This inadvertantly saved "down time" as my E1 had to go back
to BMA for some service work. Moral of the story: if you put everything on
one "box" it will probably be a non-event in the case of failure in VFR
conditions, but consider having to send your single EFIS unit back for
repair after you are down safe. You'll be grounded if you were relying on
that device for your engine instrumentation. Bottom line: I'd try to
conceive of some way to split the engine instruementation from the nav data
either by two distinctly separate EFIS boxes or a hybrid of EFIS + steam
gauges.
FWIW,
Peter
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Carlos
Trigo
Sent: Thursday, September 07, 2006 7:38 PM
Subject: AeroElectric-List: Single Display EFIS
-->
Listers
Does anybody have any experience flying with a single display EFIS, with
graphical engine monitor? Can you please share your impressions, mainly by
the fact to have to change from the PFD to the Engine page because of the
single screen.
Since I will have backup analog instruments for airspeed, altitude and
attitude, I'm thinking in saving some money not buying the second EFIS
display unit, hence need to know if anybody already flying thinks it is
perfectly doable.
TIA
Carlos
________________________________________________________________________________
| From: | "Mark Sletten" <marknlisa(at)hometel.com> |
Both Paul and GMCJetpilot (which I still find aggravating that he's
unwilling to sign his posts with his name...) are like the neighborhood
delinquents.
Sure, every once in a while they go out of their way to help someone --
they'll mow the widow's lawn, or help the neighbor who's husband is out of
town shovel the drive, but they probably only do it because their Mom's told
them to...
Most of the time, though, they run around pulling chains and depositing
flaming bags of (verbal) dog feces on our neighborhood porches leaving
others to stomp out the flames and clean up the mess. After awhile, the
occasional lawn mowing or drive shoveling doesn't make up for the hassle and
annoyance -- you're just glad when they grow up and move away. Kids will be
kids, but you always know it's temporary...
Just deleting the rants is a great solution -- for me. I've been reading
this list for several years and it's easy for me to spot the good, the bad
and the ugly. But the new guy/gals on the list can't. As the moderator of a
list dedicated to the exchange of simple ideas based on logic and
observation, Bob feels he has moral OBLIGATION to respond to the crap so new
guys aren't lost in the wilderness of circular arguments about... well...
crap, mostly.
I, for one, have seen Bob stomp on enough flaming bags. And I don't see Paul
or GMCJetpilot (sigh!) growing up anytime soon. I'm glad to see Bob able to
devote more of his valuable time to what he does best, investigate, learn
and teach.
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | OV Module additional requirement |
>
>OK 'Lectron heads, let me know, did question just got dropped in the midst
>of all the George-bantor, or is it too dumb to get an answer?
>
>The questions:
>
>1. can the OVM be modified to allow for three inputs: sense, trip, and
>ground? (I don't want to crowbar the same place that I want to measure the
>voltage.)
>
>2. Can one OVM detect and react to an OV event fast enough to trip the
>correct alternator in a two alternator/OVM installation?
>
>The deatils are in the attached message.
Your system narrative seems to describe two alternators
running in parallel to a single battery. You've also
expressed a desire to rate your system's load carrying
ability by a dependence on both alternators running
to drive a single bus.
Running two or more engine driven power sources in parallel
takes special regulators that talk to each other, compare
present loads with respect to capacity of each alternator
and agree on how the loads are divided so that each machine
shares total load in proportion to it's ratings.
On the Hawker 800, we can run both engine generators and
the APU simultaneously and even tho the apu is a much smaller
generator, one can check the running loads and see that
all machines are carrying their "fair" share . . . i.e.
all read close to the same percentage of total load.
I've not studied the details of the generator control units
supplied with this system but I'd be surprised if the built-in
OV detection and shut down systems are not smart enough to
know who is responsible for an OV condition; the generator
over which I have responsibility -OR- some other machine
in the system.
If you use B&C regulators in some combination like that
depicted in Z-12 (Main and Aux alternators driving a common
bus), the regulators are designed to differentiate between
an OV condition caused by "my alternator" or the "other guy's
alternator" and respond accordingly. We call it selective
OV trip.
Without knowing more about the hardware you selected to
deduce whether or not selective trip is possible/practical
for your system.
Let's look at the basics first. Under what conditions do
you anticipate a 59A running load? Have you crafted a load
analysis and filled out a form like:
http://www.aeroelectric.com/PPS/Load_Analysis/Blank_Form.pdf
I'm skeptical that you really need a 59A running capacity
unless you have some form of electric heated windows, etc.
Let's look over your numbers first. If you've a mind to
use Excel as opposed to a paper form, the directory at:
http://www.aeroelectric.com/PPS/Load_Analysis
. . . has several exemplar Load Analysis spread sheets
you are invited to exploit for data and/or modify for
your own use as you wish.
When this is complete, let's revisit you alternator
choices/options and see what it takes to make it all work.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: AOPA battery article |
>
>Bob,
>Would you care to comment with regard to the article's assertion that
>generators under 50 amps are adversely affected by the high capacity
>RG35 batteries, in particular, as opposed to small alternators? Or
>have you heard from the gentleman at Concorde?
>I know alternators are a little more self limiting, but it seems like
>the larger charging demand from the low resistance of that battery
>would have adverse effects on both generators and alternators.
Working on that. Received a clarification from Skip and guess what?
Root cause for the recommendation has nothing to do with "overloading
a generator." I'm editing the thing right now. Might have it done
tomorrow.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
| Subject: | Re: JPI remote mount..... |
I don't know enough about the differences in their internal electronics,
but EI offers a remote head for their UBG16 analyzer. Perhaps you could
sell the JPI and get EI instead.
FLYaDIVE(at)aol.com wrote:
>
> In a message dated 9/7/06 12:06:54 PM Eastern Daylight Time,
> jlbaker(at)msbit.net writes:
>
>> Does anyone have any experience with remote mounting a JPI
>> EDM 700 head separate from the electronics case. Poor "due
>> diligence" on my part shows that in the Bellanca Viking, pre '75,
>> there aren't a lot of options as to mounting locations....except
>> top, dead center where my altimeter now resides (welded in
>> panel bars and bracing...rats!). I have a three inch location for
>> the 3 inch display and can make up a couple of AMPMODU IV
>> dual row connectors to extend from the head to the electronics.
>> Question is.....how long could I rerasonably expect to make the
>> ribbon cables without problems. I know this is a loaded question
>> since one doesn't know the specifics of internal hardware
>> (suspect a serial interface to the head), so shooting in the
>> dark...JPI are adamant about not entertaining questions of this
>> sort. Period.
>>
>> Jim Baker
>> 580.788.2779
>> Elmore City, OK
> ============================
________________________________________________________________________________
| From: | Dave N6030X <N6030X(at)DaveMorris.com> |
| Subject: | OV Module additional requirement |
Is anybody else having trouble getting Excel to open these? It locks
up everytime I try one of them and gives me an error that Excel is
trying to communicate with some other program using OLE.
Dave Morris
At 07:44 AM 9/8/2006, you wrote:
I'm skeptical that you really need a 59A running capacity
> unless you have some form of electric heated windows, etc.
> Let's look over your numbers first. If you've a mind to
> use Excel as opposed to a paper form, the directory at:
>
>http://www.aeroelectric.com/PPS/Load_Analysis
>
> . . . has several exemplar Load Analysis spread sheets
> you are invited to exploit for data and/or modify for
> your own use as you wish.
________________________________________________________________________________
| From: | "Alan K. Adamson" <aadamson(at)highrf.com> |
| Subject: | OV Module additional requirement |
Dave, just checked with excel 2003 and they opened fine...
Alan
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dave
N6030X
Sent: Friday, September 08, 2006 9:34 AM
Subject: RE: AeroElectric-List: OV Module additional requirement
-->
Is anybody else having trouble getting Excel to open these? It locks up
everytime I try one of them and gives me an error that Excel is trying to
communicate with some other program using OLE.
Dave Morris
At 07:44 AM 9/8/2006, you wrote:
I'm skeptical that you really need a 59A running capacity
> unless you have some form of electric heated windows, etc.
> Let's look over your numbers first. If you've a mind to
> use Excel as opposed to a paper form, the directory at:
>
>http://www.aeroelectric.com/PPS/Load_Analysis
>
> . . . has several exemplar Load Analysis spread sheets
> you are invited to exploit for data and/or modify for
> your own use as you wish.
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
| Subject: | Fw: Wasted message size |
----- Original Message -----
From: "Fergus Kyle" <VE3LVO(at)rac.ca>
Sent: Friday, September 08, 2006 10:32 AM
Subject: Wasted message size
| John,
| Could you please discover and use a technique which does not
| involve repeating an entire digest when sending a message. If you check
the digest for today, you will find several hundred lines of text which
have no bearing on the subject at hand. The Matronics QandA message shows
how to avoid this for the comfort of readers.
| Thanks
| Ferg Kyle
| Europa A064 914 Classic
PS: I sent this as a personal request, but since you reject personal
messages, I have included it in the net.
________________________________________________________________________________
| From: | "Dr. Andrew Elliott" <a.s.elliott(at)cox.net> |
| Subject: | 2.0 Farad Capacitor? |
Today I saw an ad for a 2.0 farad capacitor ($40) from an auto audio
company. Anyone know what something like that might be used for? It was
referred to as a "stiffening" capacitor.
Turns out they make these with capacities as high as *50* farad! (Lots
more $$.) Would such devices have any application to an aircraft
system? Yes, I know that even a very large capacitor holds very few
amp-hours compared to even a small battery, but I wondered what other
uses they might have.
Andy Elliott
N481HY/AA-1(TD,160)/KFFZ
That's "One Hot Yankee"
http://members.cox.net/n481hy/
________________________________________________________________________________
| From: | Brian Lloyd <brian-av(at)lloyd.com> |
| Subject: | Re: OV Module additional requirement |
On Sep 8, 2006, at 6:34 AM, Dave N6030X wrote:
>
>
> Is anybody else having trouble getting Excel to open these? It
> locks up everytime I try one of them and gives me an error that
> Excel is trying to communicate with some other program using OLE.
Try grabbing a copy of OpenOffice. (http://www.openoffice.org) I find
it seems to do well with many different file formats. The price is
right. It is good enough that I am moving away from the Microsoft
office suite as a result.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
| Subject: | Re: Wasted message size |
John Esch,
I couldn't find them! But I asked Matt Dralle to tell you how to
avoid the problem and I hope he will do so. A busy guy, he has made the job
of constructing SO easy by supplying these nets that we mustn't convince him
otherwise! Stay tuned............
Cheers
Ferg Kyle
Europa A064 914 Classic
----- Original Message -----
From: "John Esch" <jfesch(at)earthlink.net>
Sent: Friday, September 08, 2006 11:09 AM
Subject: Re: Wasted message size
| Ferg
| I have look around on Matronics and can't find the Q&A section. I see the
FAQ link but I do not have permissions to view it. Any ideas?
|
| John
|
| -----Original Message-----
| >From: Fergus Kyle <VE3LVO(at)rac.ca>
| >Sent: Sep 8, 2006 7:32 AM
| >To: jfesch(at)earthlink.net
| >Subject: Wasted message size
| >
| >John,
| > Could you please discover and use a technique which does not
| >involve repeating an entire digest when sending a message. If you check
the
| >digest for today, you will find several hundred lines of text which have
no
| >bearing on the subject at hand. The Matronics QandA message shows how to
| >avoid this for the comfort of readers.
| >Thanks
| >Ferg Kyle
| >Europa A064 914 Classic
| >
________________________________________________________________________________
| From: | Matt Dralle <dralle(at)matronics.com> |
| Subject: | Re: Wasted message size |
Ferg/John et al,
The FAQ for the List can be found here:
http://www.matronics.com/FAQ/AeroElectric-List.htm
It contains lots and lots of great information about the List features. At the
end is also a section on Usage Guidelines that details what is expected of members
when participating in discussions.
I hope everyone will take a minute to have a look at the List FAQ right now.
Thank you!
Matt Dralle
Matronics Email List Administrator
Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551
925-606-1001 V | 925-606-6281 F | dralle(at)matronics.com Email
http://www.matronics.com/ WWW | Featuring Products For Aircraft
________________________________________________________________________________
| From: | Dave N6030X <N6030X(at)DaveMorris.com> |
| Subject: | Re: OV Module additional requirement |
I've got the latest updated copy of Excel 2002
SP3 but it's trying to do something strange with
these particular files. I don't have this problem with other Excel files.
Dave
At 11:31 AM 9/8/2006, you wrote:
>
>
>On Sep 8, 2006, at 6:34 AM, Dave N6030X wrote:
>
>>
>>
>>Is anybody else having trouble getting Excel to open these? It
>>locks up everytime I try one of them and gives me an error that
>>Excel is trying to communicate with some other program using OLE.
>
>Try grabbing a copy of OpenOffice. (http://www.openoffice.org) I find
>it seems to do well with many different file formats. The price is
>right. It is good enough that I am moving away from the Microsoft
>office suite as a result.
>
>Brian Lloyd 361 Catterline Way
>brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
>+1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
>I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
________________________________________________________________________________
| From: | "Bob Lee" <bob(at)flyboybob.com> |
| Subject: | OV Module additional requirement |
Bob,
Thanks for your reply. I can tell that the path I was trying to go down is
not the one to take (two alternators on one bus). The load analysis shows
15 amps on the battery bus (electronic ignition/fuel injection), 6 amps on
the endurance bus (minimum equipment for safe flight) and 36 amps on the
Main bus.
It is posted at: http://flyboybob.com/web_pages/kr2/index.htm, if you click
the link to "electrical" in the left frame the first thing that comes up is
the load analysis.
I'll go with the 40 amp main alternator and 20 amp back up and just do the
switching manually. It seems that making it automatic will not be as simple
as I had hopped.
Once again, thanks for sharing your experience.
Regards,
Bob Lee
N52BL KR2
Suwanee, GA
91% done only 65% to go!
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Robert
L. Nuckolls, III
Sent: Friday, September 08, 2006 8:44 AM
Subject: RE: AeroElectric-List: OV Module additional requirement
>
>OK 'Lectron heads, let me know, did question just got dropped in the midst
>of all the George-bantor, or is it too dumb to get an answer?
>
>The questions:
>
>1. can the OVM be modified to allow for three inputs: sense, trip, and
>ground? (I don't want to crowbar the same place that I want to measure the
>voltage.)
>
>2. Can one OVM detect and react to an OV event fast enough to trip the
>correct alternator in a two alternator/OVM installation?
>
>The deatils are in the attached message.
Your system narrative seems to describe two alternators
running in parallel to a single battery. You've also
expressed a desire to rate your system's load carrying
ability by a dependence on both alternators running
to drive a single bus.
Running two or more engine driven power sources in parallel
takes special regulators that talk to each other, compare
present loads with respect to capacity of each alternator
and agree on how the loads are divided so that each machine
shares total load in proportion to it's ratings.
On the Hawker 800, we can run both engine generators and
the APU simultaneously and even tho the apu is a much smaller
generator, one can check the running loads and see that
all machines are carrying their "fair" share . . . i.e.
all read close to the same percentage of total load.
I've not studied the details of the generator control units
supplied with this system but I'd be surprised if the built-in
OV detection and shut down systems are not smart enough to
know who is responsible for an OV condition; the generator
over which I have responsibility -OR- some other machine
in the system.
If you use B&C regulators in some combination like that
depicted in Z-12 (Main and Aux alternators driving a common
bus), the regulators are designed to differentiate between
an OV condition caused by "my alternator" or the "other guy's
alternator" and respond accordingly. We call it selective
OV trip.
Without knowing more about the hardware you selected to
deduce whether or not selective trip is possible/practical
for your system.
Let's look at the basics first. Under what conditions do
you anticipate a 59A running load? Have you crafted a load
analysis and filled out a form like:
http://www.aeroelectric.com/PPS/Load_Analysis/Blank_Form.pdf
I'm skeptical that you really need a 59A running capacity
unless you have some form of electric heated windows, etc.
Let's look over your numbers first. If you've a mind to
use Excel as opposed to a paper form, the directory at:
http://www.aeroelectric.com/PPS/Load_Analysis
. . . has several exemplar Load Analysis spread sheets
you are invited to exploit for data and/or modify for
your own use as you wish.
When this is complete, let's revisit you alternator
choices/options and see what it takes to make it all work.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Dual radio interference |
| From: | "europa flugzeug fabrik" <n3eu(at)comcast.net> |
sjhdcl(at)kingston.net wrote:
> Freqs are far apart. 122.5 and 126.7.
4 MHz apart is huge. A fault in a COM to cause that is possible, but not the same
fault on 2 radios within SuperLotto odds.
Is it just on one or both of those frequencies? Possibly also in a specific geographic
area? If so, maybe theres a TV broadcast tower which in combination with
your xmit on the problem freq, is trashy signal being received on the selected
freq of the other COM.
Otherwise, whats common in the symptoms is when BOTH are selected. Per picture
of a 340 audio panel, looks like tactile type switches, not pushbuttons. That
means, if not mechanical relays, then semiconductor switches and a faulty component
somewhere. However, this may be difficult to duplicate on an avionics
bench.
So first I would pull the audio panel, and hot wire the system. It looks like we
just need a Dconnector or two of opposite sex, bringing out 6 wires (mic audio,
mic key, and phone audio each). Then, jury-rigged to your headset and mic
or PTT setup, see if we still have the problem, which I presume occurs also on
the ground. If not, its the audio panel, and not anything installed in the
aircraft.
Fred F.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=60404#60404
________________________________________________________________________________
| Subject: | Re: 2.0 Farad Capacitor? |
| From: | "Chris In Madison" <cowens(at)cnw.com> |
Finally, a question I know the answer to! :-)
In the competitive car audio community (to which I formerly belonged), the amplifiers
in use often require an enormous amount of instantaneous current to meet
the demands of peak musical transients. Generally speaking, batteries (as I
understand them) don't have the response time necessary to deliver that short-burst
current. Capacitors, on the other hand, were designed for this kind of
storage and instantaneous current delivery. So, to pick up the slack where batteries
cannot, large capacitor banks are useful. And trust me, they work :-)
The one thing you don't want to do, though, is accidentally short the terminals
on one of these charged-up capacitors. Ever blown up a perfectly good pair of
wire strippers cutting through hot romex in your house? Same basic effect.
BWAAAP!!! Temporary blindness and a hole in your strippers or screwdriver (or
they're welded to the two terminals).
Best regards,
Chris
--------
Chris Owens
Waunakee, WI
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=60407#60407
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | OV Module additional requirement |
>
>Bob,
>
>Thanks for your reply. I can tell that the path I was trying to go down is
>not the one to take (two alternators on one bus). The load analysis shows
>15 amps on the battery bus (electronic ignition/fuel injection), 6 amps on
>the endurance bus (minimum equipment for safe flight) and 36 amps on the
>Main bus.
>It is posted at: http://flyboybob.com/web_pages/kr2/index.htm, if you click
>the link to "electrical" in the left frame the first thing that comes up is
>the load analysis.
>
>I'll go with the 40 amp main alternator and 20 amp back up and just do the
>switching manually. It seems that making it automatic will not be as simple
>as I had hopped.
>
>Once again, thanks for sharing your experience.
Not sure you need to resort to manual switching. If you wire
per Z-12 with B&C hardware, automatic assumption of loads by
the auxiliary alternator is built in. Both alternators are ON
all the time . . . Aux alternator is set for 13.0 volts while main
alternator is set for 14.2 volts. The aux alternator regulator sees
"too high" bus voltage and relaxes. If main altenrator goes off
line, bus voltage sags and aux alternator comes alive. If loads
on the Aux Alternator exceed rated output of 20A, then the "AUX
ALT LOADED" light flashes. You turn things off until the light
stops flashing.
But your load analysis suggests that Z-13/8 would be all you
need. How much RUNNING current does the pitot heater draw when
submerged in an ice bath? This is the real load-analysis current.
Are the position lights LED? if not, 2.0A for nav lights is
too low.
The dynamo relay would be an E-bus load, not a battery bus load.
Ignition of 8A is REALLY big . . . what engine are you using
and what ignition system?
Landing and taxi lights are generally not combined with pitot
heat. You may adopt an operating protocol that runs pitot heat
in VMC when lights would be off.
Let's tweak this analysis a bit. I'm not convinced that you
need a 40/20 system . . . and 40/8 may well get done what you
need to do.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: 2.0 Farad Capacitor? |
>Today I saw an ad for a 2.0 farad capacitor ($40) from an auto audio
>company. Anyone know what something like that might be used for? It was
>referred to as a "stiffening" capacitor.
>
>Turns out they make these with capacities as high as *50* farad! (Lots
>more $$.) Would such devices have any application to an aircraft
>system? Yes, I know that even a very large capacitor holds very few
>amp-hours compared to even a small battery, but I wondered what other uses
>they might have.
Capacitor technology has mushroomed in the past 20 years.
I recall my dad (Navy electrician aboard wooden mine sweeper
in the Aleutian islands) telling me that a "one farad capacitor
would be the size of this room".
Nowadays, one may purchase a 1 farad capacitor good for
5.5 volts in a 1" x 1/2" case:
http://dkc3.digikey.com/PDF/T063/1184.pdf
The poor individuals who do not particularly value their
ears are fond of the devices you've cited for what they're
told is a quantum jump in performance for their killowatt
mobile sound systems. Further, if "one farad is good, many
farads is better", hence devices like . . .
http://www.sonicelectronix.com/pictures.php?id=7409
. . . are good for separating our young friends from about $150
of their lunch money.
As a practical matter, one might consider buffering
the bus in their airplane with a large capacitor if
they were carrying small, low capacity but high current
batteries needed only for engine cranking. Such batteries
are not yet available . . . but they're coming.
A number of systems propose or even use large capacitors
to replace storage batteries. See:
http://www.tavrima.com/Alternato.PDF#search=%22supercapacitor%20engine%20cranking%22
http://www.tavrima.com/home.html
http://www.maxwell.com/ultracapacitors/support/papers.html
http://www.findarticles.com/p/articles/mi_m0FZX/is_10_67/ai_92586564
I love this business, unlike horse racing and growing
tomatoes, this industry rolls out quantum jump technology
every year or so. It's a great time to be alive.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Alternator Problem - Not in plane |
OK, I give up and need some help and some new blood for this one.
I have gone through 4 alternator:
2 New
1 Rebuilt
1 Junk Yard
I put them on the Pep Boys test bench and run them at test speed and load.
Here is the results:
ALL have shown an out put of 10.5 V and 60 to 80 Amps.
I then had the opportunity to use a home made test bench on two of the
alternators:
1 New
1 Rebuilt
Here are the results:
12.2 V @ 80 Amps
??? I do not recall the voltage but the amperage was 65 Amps
Now, as I'm sure you all know you cannot charge a battery with 12.2 V. You
need 13.8 to 14.2 V
So, what do you think the problem is?
BTW, the alternators are from a 1999 Hyundai Elantra Station Wagon.
I even went to a Hyundai Dealer ... They don't have a clue.
Barry
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
I will ask you too sir to vacate the AeroElectric List.
Ferg Kyle
Europa A064 914 Classic
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Alternator Problem - Not in plane |
FLYaDIVE(at)aol.com wrote:
>
>OK, I give up and need some help and some new blood for this one.
>
>I have gone through 4 alternator:
>2 New
>1 Rebuilt
>1 Junk Yard
>
>I put them on the Pep Boys test bench and run them at test speed and load.
>Here is the results:
>ALL have shown an out put of 10.5 V and 60 to 80 Amps.
>
>I then had the opportunity to use a home made test bench on two of the
>alternators:
>1 New
>1 Rebuilt
>Here are the results:
>12.2 V @ 80 Amps
>??? I do not recall the voltage but the amperage was 65 Amps
>
>Now, as I'm sure you all know you cannot charge a battery with 12.2 V. You
>need 13.8 to 14.2 V
>So, what do you think the problem is?
>BTW, the alternators are from a 1999 Hyundai Elantra Station Wagon.
>
>I even went to a Hyundai Dealer ... They don't have a clue.
>
>Barry
>
Are they really rated to put out 60-80 amps? If not, try loading them at
rated output current.
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Alternator Problem - Not in plane |
In a message dated 9/8/06 8:52:29 PM Eastern Daylight Time,
altoq(at)cebridge.net writes:
> Barry,
>
> Diode (One of three pressed into the case) or diode trio.
>
> Shot in the Dark
> John D.
================================
John:
I don't believe the diode pack would be bad in ALL 4 alternators, especially
2 NEW alternators right off the shelf. I know, I know, weirder things have
happened but the logic says no. And why would I get the 60 to 80 Amps output?
Unfortunately none of these test benches have a 'O' Scope hooked up to them.
Barry
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Alternator Problem - Not in plane |
In a message dated 9/8/06 11:43:19 PM Eastern Daylight Time,
ceengland(at)bellsouth.net writes:
> Are they really rated to put out 60-80 amps? If not, try loading them at
> rated output current.
=============================================
Charlie:
What is that going to do? I already get 60 to 80 Amps out and that is way
more than what the load requires.
Barry
________________________________________________________________________________
| From: | "Bob Lee" <bob(at)flyboybob.com> |
| Subject: | OV Module additional requirement |
Bob Nuckolls wrote: (my reply in << brackets >>
Not sure you need to resort to manual switching. If you wire
per Z-12 with B&C hardware, automatic assumption of loads by
the auxiliary alternator is built in. Both alternators are ON
all the time . . . Aux alternator is set for 13.0 volts while main
alternator is set for 14.2 volts. The aux alternator regulator sees
"too high" bus voltage and relaxes. If main altenrator goes off
line, bus voltage sags and aux alternator comes alive. If loads
on the Aux Alternator exceed rated output of 20A, then the "AUX
ALT LOADED" light flashes. You turn things off until the light
stops flashing.
<< The 20 amp dynamo supplied with the engine has a regulator that seems to
be a type of zenor that meerly clamps the voltage to a limit. There are
only three connections on the regulator: AC(1), [AC(2) and +12], and
ground. I cannot use the B&C hardware here because it is a permanant magnet
unit, therefore Z-13. >>
But your load analysis suggests that Z-13/8 would be all you
need. How much RUNNING current does the pitot heater draw when
submerged in an ice bath? This is the real load-analysis current.
<< Will need to test this because I don't know - see below >>
Are the position lights LED? if not, 2.0A for nav lights is
too low.
<< Yes, LED >>
The dynamo relay would be an E-bus load, not a battery bus load.
<< It ends up on the battery bus because I have used the method suggested
on Z-13/8 that brings the ground to the panel through a circuit-breaker that
gets tripped for an OV event. The positive side of the relay is just
connected to the b+ lead on the battery side of the disconnect relay. >>
Ignition of 8A is REALLY big . . . what engine are you using
and what ignition system?
<< Great Plains Aircraft Supply 2600cc. It is an auto conversion based on
the VW TypeIV engine. The ignition is a Comp-u-Fire electronic ignition.
There are several flying and they measure 8 amps. >>
Landing and taxi lights are generally not combined with pitot
heat. You may adopt an operating protocol that runs pitot heat
in VMC when lights would be off.
<< Certainly this is an option that can work. I was trying to develop a
solution that reduced the number of electrical events that the pilot got
involved in. Let the airplane solve any problem it can and reduce the types
of events that the pilot was responsible for managing is the design goal
here. In reality, I don't intend to need pitot heat by flying in VMC. I
meerly want to have the legal equipment to allow me to regularly file IFR.
I find that flying IFR all the time makes you a better pilot on those
extremely rare ocassions where you end up in less than VFR weather by
mistake. If pitot heat gets turned on though, the charging system needs to
handle it. >>
Let's tweak this analysis a bit. I'm not convinced that you
need a 40/20 system . . . and 40/8 may well get done what you
need to do.
<< The engine is supplied with a 20 amp perminant-magnet dynamo so the 8/20
decision has already been made by the engine supplier. The 40 amp
alternator is from a Honda Gold Wing motorcycle. I selected it because it
is driven off the transmission end of the primary drive (1/2 engine speed).
This makes the rpm range of my engine a very close match to the design rpm
range of this alternator. I have modified it's mounting to allow it to be
placed in the mag drive of my engine. I also modified the alternator to
remove the internal regulator and use an external regulator. The faston
male connector that was the idot light is now the field input. >>
Bob . . .
<< me to! >>
________________________________________________________________________________
| From: | "Gilles Tatry" <gilles.tatry(at)wanadoo.fr> |
| Subject: | Re: Transponder antenna location |
Should the bottom of the front fuselage, 2 ft behind the engine, be a proper
location?
Is it a problem to be so close to the engine, isn't it far better at the
rear?
Thanks,
Gilles
>
>Has anyone tried mounting a transponder antenna on the bottom of the
rear
>fuselage? That location (about 2/3 of the length of the fuselage
back)
>slopes upward on a Rebel but it is the location least blanked by
large
>gear fairings, and metal radiator ducting. Unfortunately the worst
signal
>would likely be forward to where the ground station I'm trying to
reply to
>is likely to be during first contact. I am willing to mount the
>transponder behind me to keep the coax within the 8.8 feet max
specified
>by Garmin.
>
>The other option seems to be on the roof. That is apparently not
>recommended and it would be near skylights and my head which I'm not
>comfortable with. I could get it the minimum recommended 3 feet away
from
>the VHF antenna but the high wing might tend to blank ground stations
to
>the side. I suspect that roof mounting would provide a better signal
to
>other aircraft which is probably more important to me than a signal
to
>ground so I guess I could put the antenna on the roof back near the
>tail. It seems silly to invest in a transponder though unless it is
>likely to perform well with both ATC and also traffic warning devices
on
>other aircraft.
Any place on the bottom would be preferable to top mounted.
The aft fuselage location you cited would be fine.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Alternator Problem - Not in plane |
FLYaDIVE(at)aol.com wrote:
>
>In a message dated 9/8/06 11:43:19 PM Eastern Daylight Time,
>ceengland(at)bellsouth.net writes:
>
>
>
>>Are they really rated to put out 60-80 amps? If not, try loading them at
>> rated output current.
>>
>>
>=============================================
>Charlie:
>
>What is that going to do? I already get 60 to 80 Amps out and that is way
>more than what the load requires.
>
>Barry
>
If they came off small cars, they might not be rated for that much
current & unable to maintain voltage if you demand excess current.
Another thought: are they internally or externally regulated? If
external & you're using a regulator built into the test set, are you
sure the test set regulator is set correctly and are you sure the test
set voltmeter is accurate? Getting the same volt reading for all using
one test set & a different, same volt reading for all on another test
set seems to point at the test sets.
________________________________________________________________________________
| Subject: | Re: Alternator Problem - Not in plane |
FLYaDIVE(at)aol.com wrote:
>
> In a message dated 9/8/06 11:43:19 PM Eastern Daylight Time,
> ceengland(at)bellsouth.net writes:
>
> > Are they really rated to put out 60-80 amps? If not, try loading them at
> > rated output current.
> =============================================
> Charlie:
>
> What is that going to do? I already get 60 to 80 Amps out and that is way
> more than what the load requires.
>
> Barry
>
Hi Barry,
What Charlie is saying is maybe you are overloading the alternator. Put
a smaller load on, no more than the rated output and see what the
voltage is.
Bob W.
--
http://www.bob-white.com
N93BD - Rotary Powered BD-4 (first engine start 1/7/06)
Custom Cables for your rotary installation -
http://www.roblinphoto.com/shop/
________________________________________________________________________________
| From: | Kevin Kinney <kkinney(at)fuse.net> |
| Subject: | Fuel Pump Switch(es) |
I'm planning a left/right fuel system each with an on/off valve and an aux pump
on each incoming line.
I'm thinking of using an on/off/on switch for pumps rather than an on/off switch
for each pump.
Can anyone offer any thoughts on the downside of this?
Regards,
Kevin Kinney
--
Non-parent - I don't see how you can raise children & stay sane.
Parent - You don't. You pick one and go with it.
________________________________________________________________________________
| From: | "Jeffrey W. Skiba" <jskiba(at)icosa.net> |
| Subject: | Switch contact rattings which is best for this app |
Okay,
I Have gone and confused myself, I am looking at ordering some switches for
my OBAM aircraft and can't rember which would be better Higher current
switch
The catalog states two options:
1: Silver Rated 3A @ 125V AC
2: Gold Rated 0.4 VA max @ 28V AC/DC max
My application will be used in a 12-14 Volt system I want the switch with
the higher switch capability which is it?
THANKS in advance
P.s. my guess is option one the silver contacts but for some reason I don't
think that is correct....
--
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
| Subject: | Re: Switch contact rattings which is best for this |
app
It is definitely the first, as you guessed. However, what are you
planning to switch with this? The silver one you list still doesn't
have a very high rating. Perfectly fine for most avionics, but
definitely not so good for landing lights or pitot heat, or other high
current applications.
The gold one listed would be perfect for a low contact control switch
for avionics - a PTT switch or an acknowledge switch for a warning
light, etc.
Dick Tasker
Jeffrey W. Skiba wrote:
>
> Okay,
>
>I Have gone and confused myself, I am looking at ordering some switches for
>my OBAM aircraft and can't rember which would be better Higher current
>switch
>
>The catalog states two options:
>
>1: Silver Rated 3A @ 125V AC
>
>
>2: Gold Rated 0.4 VA max @ 28V AC/DC max
>
>
>My application will be used in a 12-14 Volt system I want the switch with
>the higher switch capability which is it?
>
>THANKS in advance
>
>
>P.s. my guess is option one the silver contacts but for some reason I don't
>think that is correct....
>
>
>
--
Please Note:
No trees were destroyed in the sending of this message. We do concede, however,
that a significant number of electrons may have been temporarily inconvenienced.
--
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | John Deere PM alternator regulator |
I can now say for certain that the AM101406 regulator will not come to
life with a totally dead battery. Since I was at homebase, without
power for a charger, and like to experiment, I attempted to charge the
dead battery by closing the Z-14 cross feed contactor and charging the
dead battery with the good alternator for a few minutes until the PM
alternator came to life. I wouldn't recommend that and in this case it
seems to have caused the regulator to fail full on. I don't really know
why it failed as the rpm was modest (well below the max output
capability of the 20 amp PM alternator) and it is not particularly
uncommon to have dead batteries on the small tractors that these are
original equipment on. Further the regulator is on the cool side of the
firewall.
My best theory is that the totally dead small AGM battery allowed the
output to overvoltage some component in the regulator. I do not have a
battery contactor so I felt that there was no need for a large
electrolytic capacitor on the output since the battery would never be
disconnected. The oem application doesn't have a capacitor. AFAIK
totally dead batteries can be reluctant to take a charge at first so
maybe it wasn't absorbing enough current initially to dampen the output
pulses?? Again I wouldn't have expected that to fail a regulator
designed to work with up to 200vac open circuit voltage from the alternator.
The OVM worked perfectly. It is wired to interupt the line from the
alternator to the regulator. In further experimenting, the little 40 amp
relay does not seem to have suffered noticeably from a few 20 amp
disconnects. I also learned that a single 9ah battery will start the
subaru rather nicely so all in all I have obtained some value for the
cost of my experimentation ;) I guess I also obtained some value from
the OVM modules ;)
As a shot in the dark I am thinking of putting a capacitor on the output
of the regulator. That would leave the capacitor permanently wired
across the battery through the b-lead circuit breaker. I don't think
transorbs there would help. Any other suggestions? The obvious one is to
charge the battery first but that is not always convenient as sooner or
later I will likely run a battery dead again in some out of the way place.
I do not have a charging indicator lamp wired to the regulator but I am
assuming that is irrelevant.
Ken
________________________________________________________________________________
| From: | "Bob McCallum" <robert.mccallum2(at)sympatico.ca> |
| Subject: | Re: Fuel Pump Switch(es) |
Kevin;
One downside is "single point of failure". If the switch fails you loose
both pumps. Also, if one pump fails and blows the fuse you loose both pumps.
Two switches allows two fuses, two circuits, redundancy.
Bob McC
----- Original Message -----
From: "Kevin Kinney" <kkinney(at)fuse.net>
Sent: Saturday, September 09, 2006 11:17 AM
Subject: AeroElectric-List: Fuel Pump Switch(es)
>
> I'm planning a left/right fuel system each with an on/off valve and an aux
pump on each incoming line.
> I'm thinking of using an on/off/on switch for pumps rather than an on/off
switch for each pump.
>
> Can anyone offer any thoughts on the downside of this?
>
> Regards,
> Kevin Kinney
>
> --
> Non-parent - I don't see how you can raise children & stay sane.
> Parent - You don't. You pick one and go with it.
>
>
________________________________________________________________________________
| Subject: | Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Sure!.. if the single point of failure (namely the
switch)...er...fails...You crash!
If you are dependant on those electric pumps (like I am) always wire
them seperatly all the way back to the battery...If you have two
batteries make sure they are isolated and feed one pump from each
battery.
Frank RV7a, IO360 electic pump in each wing root. No mechanical pump,
single Odyssey and dual alternator.
Flying as of yesterday.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Kevin
Kinney
Sent: Saturday, September 09, 2006 8:18 AM
Subject: AeroElectric-List: Fuel Pump Switch(es)
I'm planning a left/right fuel system each with an on/off valve and an
aux pump on each incoming line.
I'm thinking of using an on/off/on switch for pumps rather than an
on/off switch for each pump.
Can anyone offer any thoughts on the downside of this?
Regards,
Kevin Kinney
--
Non-parent - I don't see how you can raise children & stay sane.
Parent - You don't. You pick one and go with it.
________________________________________________________________________________
| From: | Cleone Markwell <cleone(at)rr1.net> |
| Subject: | Re: AOPA battery article |
At 11:24 AM 9/7/2006, you wrote:
>
>
>OBAM stands for Owner Built and Maintained, which the designation
>that Bob prefers to call Experimental / Amateur Built aircraft.
>
>Carlos Thanks Carlos, now I know. Cleone
>
>
>----- Original Message ----- From: "Cleone Markwell" <cleone(at)rr1.net>
>To:
>Sent: Thursday, September 07, 2006 4:31 PM
>Subject: Re: AeroElectric-List: AOPA battery article
>
>
>>
>>Bob, What does OBAM mean?
>>
>>
>>
>>At 09:29 PM 9/6/2006, you wrote:
>>>
>>>
>>>
>>>
>>>>---- "Robert L. Nuckolls wrote:
>>>>III"
>>>> >
>>>> >
>>>> > >The article is in the AOPA pilot magazine Aug or Sept issue,
>>>> on > >aircraft
>>>> > >batteries.
>>>> > >Bobs name is mentioned right in the introduction of the
>>>> article and > >later
>>>> > >near the end with a reference to the connection. I have a rotax
>>>>912 with a
>>>> > >20Amp generater, was setting up
>>>> > >for an RG battery from B&C, but took out the vented battery box
>>>>I got with
>>>> > >my kit and dusted it off wondering if this article is correct.
>>>> >
>>>> > I don't subscribe to AOPA Pilot any more so I missed
>>>> > the article. It would be interesting/useful to review
>>>> > it. If someone could scan it and email it to me, I'd
>>>> > appreciate it.
>>>> >
>>>> > Bob . . .
>>>>
>>>>Listers,
>>>> The relevent article is on page 133 of the September issue
>>>>Charlie Kuss
>>>
>>> Dave sent me a copy. It's an innocuous piece and relatively
>>> accurate. If I were to expand beyond where it stopped short
>>> would be to explain the value in KNOWING what your endurance
>>> loads are and KNOWING if your battery is likely to support
>>> this load for whatever endurance YOU decide.
>>>
>>> There was one rather glaring error on the top of page
>>> 138 where it's stated that a 1C rated battery is discharged
>>> at 2C, it will deliver energy for 1/2 hour. Twice the
>>> load is ALWAYS less than half the previous capacity. By
>>> the same token, 0.1C load is always more than 10X the
>>> 1C label capacity.
>>>
>>> Exemplar capacity vs. discharge rates are illustrated
>>> in . . .
>>>
>>>http://www.aeroelectric.com/Pictures/Curves/37AH_Capacity_vs_Load.gif
>>>
>>> and
>>>
>>>http://www.aeroelectric.com/Pictures/Curves/17AH_Capcity_vs_Load.gif
>>>
>>> These graphs from manufacturer's data show that increasing
>>> loads increases internal losses and that apparent
>>> capacity drops as load increases.
>>>
>>> Our perpetual parents on the TC side have decided that
>>> "30 minutes" is the magic number for endurance and
>>> "85% of label capacity" is end of life for the battery.
>>> This makes the certification effort easy and makes FBOs
>>> task of selling batteries easier. This is an excellent example of
>>> standardization that benefits the manufacturers and
>>> regulators while limiting the owner's ability to tailor
>>> realistic targets to match his/her own mission requirements.
>>>
>>> Neither one of the 30-minute/85% assertions suggest that
>>> the owner/operator of an airplane might possess tools and
>>> be willing to acquire skills needed increase personal endurance
>>> target to say 1 hour. Or, take the time to monitor a battery
>>> with an eye toward meeting the endurance level such that
>>> 70% of label capacity is the TRUE end of life for the battery
>>> in that particular airplane.
>>>
>>> Aren't you guys glad you don't have to salute those
>>> flags? I still like "duration of fuel aboard" for
>>> endurance and "pitch it when e-bus loads cannot be
>>> supported for duration of fuel aboard." Of course,
>>> on the OBAM side of the house we're free to select
>>> and operate to our personal design goals.
>>>
>>>
>>> Bob . . .
>>>
>>>
>>> ---------------------------------------------------------
>>> < What is so wonderful about scientific truth...is that >
>>> < the authority which determines whether there can be >
>>> < debate or not does not reside in some fraternity of >
>>> < scientists; nor is it divine. The authority rests >
>>> < with experiment. >
>>> < --Lawrence M. Krauss >
>>> ---------------------------------------------------------
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>>
>
>
________________________________________________________________________________
| From: | Cleone Markwell <cleone(at)rr1.net> |
| Subject: | Re: AOPA battery article |
At 01:10 PM 9/7/2006, you wrote:
>
>Owner Built and Maintained. Invented while searching for a
>politically correct term for homebuilt.
>
>David M. Thanks David. Cleone
>
>
>Cleone Markwell wrote:
>
>>
>>Bob, What does OBAM mean?
>>
>>
>>
>>At 09:29 PM 9/6/2006, you wrote:
>>
>>>
>>>
><<>>
>
>
________________________________________________________________________________
| From: | "David Carter" <dcarter11(at)sbcglobal.net> |
| Subject: | Re: John Deere PM alternator regulator |
Ken,
For my info what is your last name? I thought at first you would be Ken
Powell who I have shared info with about Deere PM alternators, but the
e-mail address is different.
In any case, could you will in some of the "scenario":
1. The battery was dead, and you charged the battery from a non-PM
alternator after starting the engine.
. . . So, you have two batteries, 1 was dead, 1 was OK enough to start
engine.
. . . You have two alternators (a PM and a "standard" - not a bad idea when
building experience with an unproven application like a Deere on an
airplane)
. . . . . and used the non-PM to attempt to charge the dead battery.
2. Was the PM alternator isolated from the good battery so it or its Deere
voltage regulator lacked some needed "excitation"?
Looks like we need a "functional test" (experiment) to determine
characteristics of a Deere PM alternator and VR to see how it performs in
our application: We should find out "on a bench" that the Deere system
won't work with a dead battery.
Actually, there are two dead battery cases that come to mind:
1. Before flight, battery is dead. Don't fly with dead battery - so this
is a ground maintenance scenario.
2. During flight, battery dies and I want to continue flight with my PM
alternator to some suitable landing spot, either "soon" or "procede to final
destination" (whatever my risk analysis and good judgement and experience
and prior planning for this scenario may indicate is "safe enough")
. . . I plan to have two batteries, so 2. would have to include loss of BOTH
batteries or some portion of the electrical circuit.
Does you experience in this case you are reporting indicate that the PM
alternator system might stop putting out voltage and current if battery
power is lost?
David Carter
----- Original Message -----
From: "Ken" <klehman(at)albedo.net>
Sent: Saturday, September 09, 2006 2:31 PM
Subject: AeroElectric-List: John Deere PM alternator regulator
>
> I can now say for certain that the AM101406 regulator will not come to
> life with a totally dead battery. Since I was at homebase, without power
> for a charger, and like to experiment, I attempted to charge the dead
> battery by closing the Z-14 cross feed contactor and charging the dead
> battery with the good alternator for a few minutes until the PM alternator
> came to life. I wouldn't recommend that and in this case it seems to have
> caused the regulator to fail full on. I don't really know why it failed as
> the rpm was modest (well below the max output capability of the 20 amp PM
> alternator) and it is not particularly uncommon to have dead batteries on
> the small tractors that these are original equipment on. Further the
> regulator is on the cool side of the firewall.
>
> My best theory is that the totally dead small AGM battery allowed the
> output to overvoltage some component in the regulator. I do not have a
> battery contactor so I felt that there was no need for a large
> electrolytic capacitor on the output since the battery would never be
> disconnected. The oem application doesn't have a capacitor. AFAIK totally
> dead batteries can be reluctant to take a charge at first so maybe it
> wasn't absorbing enough current initially to dampen the output pulses??
> Again I wouldn't have expected that to fail a regulator designed to work
> with up to 200vac open circuit voltage from the alternator.
>
> The OVM worked perfectly. It is wired to interupt the line from the
> alternator to the regulator. In further experimenting, the little 40 amp
> relay does not seem to have suffered noticeably from a few 20 amp
> disconnects. I also learned that a single 9ah battery will start the
> subaru rather nicely so all in all I have obtained some value for the cost
> of my experimentation ;) I guess I also obtained some value from the OVM
> modules ;)
>
> As a shot in the dark I am thinking of putting a capacitor on the output
> of the regulator. That would leave the capacitor permanently wired across
> the battery through the b-lead circuit breaker. I don't think transorbs
> there would help. Any other suggestions? The obvious one is to charge the
> battery first but that is not always convenient as sooner or later I will
> likely run a battery dead again in some out of the way place.
>
> I do not have a charging indicator lamp wired to the regulator but I am
> assuming that is irrelevant.
>
> Ken
>
>
>
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Transponder antenna location |
In a message dated 9/9/06 9:37:19 AM Eastern Daylight Time,
gilles.tatry(at)wanadoo.fr writes:
> Should the bottom of the front fuselage, 2 ft behind the engine, be a
proper
> location?
> Is it a problem to be so close to the engine, isn't it far better at the
> rear?
>
> Thanks,
>
> Gilles
=================
Gilles:
Keep it away from the exhaust gases. Keep it away from the breather tube.
Place it as perpendicular to the to the earth surface as possible and where it
sits in the center of at least 1 Sq. Ft of aluminum surface. And as close to
centerline as possible. ON THE BELLY!
Basic rule:
If the base station you are trying to communicate with is on the ground then
the antenna should be ON THE BELLY.
The exception to the rule is COM#2, there the antenna should be ON THE TOP.
The reason for that is, COM#2 is used to communicate while on the GROUND and
the base station antennas are UP above the plane. You don't want to transmit
into the ground.
Examples (ON THE BELLY):
COM#1
XPONDER
ADF
LOC/GS
RNAV
and VOR, yet 99% of VOR antennas are mounted on the rudder. [Not on my RV-6
... On the Belly at the tail]
Examples (ON THE TOP)
COM#2
GPS [Gee, I wonder why?]
ELT [Gee, I wonder why?]
Hope this helps.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Alternator Problem - Not in plane |
In a message dated 9/9/06 10:54:08 AM Eastern Daylight Time,
ceengland(at)bellsouth.net writes:
> If they came off small cars, they might not be rated for that much
> current & unable to maintain voltage if you demand excess current.
>
> Another thought: are they internally or externally regulated? If
> external & you're using a regulator built into the test set, are you
> sure the test set regulator is set correctly and are you sure the test
> set voltmeter is accurate? Getting the same volt reading for all using
> one test set & a different, same volt reading for all on another test
> set seems to point at the test sets.
====================================
Charlie:
The rated amperage of the alternator is 90 Amps.
Normal draw is about 15 Amps.
It is internally regulated.
The test benches are at automotive parts stores and rebuilding shops.
At both locations, on all 4 alternators the output was 10.5 V.
This is a crazy problem. It is not a simple problem. I know there is
someone out there with the knowledge and past experience of this situation. If
is
was simple I would have solved it months ago. NO ONE has been able to identify
the problem. Not even Hyundai or Bosch. And it is their alternator's!
Barry
"Chop'd Liver"
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Fuel Pump Switch(es) |
In a message dated 9/9/06 11:21:44 AM Eastern Daylight Time, kkinney(at)fuse.net
writes:
>
> I'm planning a left/right fuel system each with an on/off valve and an aux
> pump on each incoming line.
> I'm thinking of using an on/off/on switch for pumps rather than an on/off
> switch for each pump.
>
> Can anyone offer any thoughts on the downside of this?
>
> Regards,
> Kevin Kinney
========================
WHY!
Kevin:
There are thousands of planes out there with a ONE PUMP boost system running
off on the one common line going to the engine or from the fuel selector.
What I would do though is put a fuel filter on each tank. And then if you want
to go crazy put in a parallel boost pump. That will give you redundancy and of
course more weight and maintenance.
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
________________________________________________________________________________
| From: | FLYaDIVE(at)aol.com |
| Subject: | Re: Switch contact rattings which is best for this |
app
In a message dated 9/9/06 3:29:38 PM Eastern Daylight Time, jskiba(at)icosa.net
writes:
>
>
> Okay,
>
> I Have gone and confused myself, I am looking at ordering some switches for
> my OBAM aircraft and can't rember which would be better Higher current
> switch
>
> The catalog states two options:
>
> 1: Silver Rated 3A @ 125V AC
>
>
> 2: Gold Rated 0.4 VA max @ 28V AC/DC max
>
>
> My application will be used in a 12-14 Volt system I want the switch with
> the higher switch capability which is it?
>
> THANKS in advance
>
>
> P.s. my guess is option one the silver contacts but for some reason I don't
> think that is correct....
==================================
OK, here is the break down:
Silver is the better conductor - But - Oxidized much more.
Gold is obviously slightly less in conductivity (but, you will never know
that) than Silver - But - for the practical, does not oxidize.
Without getting ridiculous in explaining a switch ... If you Double the
Voltage you Half the current. So a Switch that is rated at 0.4 Amps @ 28 VDC will
be able to handle 0.8Amps @ 14 VDC.
As for your amperage rating of the switch:
1 - Find out what the circuit draw at MAX will be.
2 - Use a switch that is about 50% over rated than the MAX draw.
3 - If a switch is rated in AC DE-RATE the amperage by 36 to 40%
[This is a rule of thumb. It has NEVER FAILED for me. Some pencil pusher
may have worked out a more accurate number but definitely not a better one.]
Barry
"Chop'd Liver"
"Show them the first time, correct them the second time, kick them the third
time."
Yamashiada
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: John Deere PM alternator regulator |
David Carter wrote:
>
>
> Ken,
>
> For my info what is your last name? I thought at first you would be
> Ken Powell who I have shared info with about Deere PM alternators, but
> the e-mail address is different.
> In any case, could you will in some of the "scenario":
>
> 1. The battery was dead, and you charged the battery from a non-PM
> alternator after starting the engine.
> . . . So, you have two batteries, 1 was dead, 1 was OK enough to start
> engine.
> . . . You have two alternators (a PM and a "standard" - not a bad idea
> when building experience with an unproven application like a Deere on
> an airplane)
> . . . . . and used the non-PM to attempt to charge the dead battery.
Yes with a Z-14, you just clost the crossfeed contactor to parallel the
batteries.
>
> 2. Was the PM alternator isolated from the good battery so it or its
> Deere voltage regulator lacked some needed "excitation"?
Yes. For experimentation I put a few short charges into the completely
dead battery and kept trying the pm alternator. The pm alternator would
not come alive until the dead battery was pretty much up to 12 volts.
This does not bother me as in normal use a dead battery would mean the
alternator has already failed and I have low voltage warning. Mostly I'm
mentioning it in regards to the recent thread where with other
architectures some guys are wiring their units to be able to come alive
with no battery voltage present.
>
> Looks like we need a "functional test" (experiment) to determine
> characteristics of a Deere PM alternator and VR to see how it performs
> in our application: We should find out "on a bench" that the Deere
> system won't work with a dead battery.
I believe I have confirmed that. What does bother me is that the VR
failed while I was conducting the above scenario. I would like to
prevent that in the future as sooner or later I will miss a switch and
run the battery dead again. At home base I will charge it first but this
aircraft will fly to a number of remote locations. At least the VR
failed on rather than off. It seemed to run fine paralleled with the
crossfeed closed as long as I had the total system loads above the pm's
20 amp output.
>
> Actually, there are two dead battery cases that come to mind:
> 1. Before flight, battery is dead. Don't fly with dead battery - so
> this is a ground maintenance scenario.
Yes
>
> 2. During flight, battery dies and I want to continue flight with my
> PM alternator to some suitable landing spot, either "soon" or "procede
> to final destination" (whatever my risk analysis and good judgement
> and experience and prior planning for this scenario may indicate is
> "safe enough")
> .
This does not concern me at all. Loss of either of my systems is not a
show stopper for me and I don't believe it is a significant risk in any
event.
> . . I plan to have two batteries, so 2. would have to include loss of
> BOTH batteries or some portion of the electrical circuit.
>
> Does you experience in this case you are reporting indicate that the
> PM alternator system might stop putting out voltage and current if
> battery power is lost?
Don't know. I donlt think one shorted cell would not stop it. I have
seen several flooded batteries open circuit in operation though and I
never even noticed til shutdown and subsequent restart attempt. I am not
confident that would happen with this regulator though because I don't
really know why it failed in this case. I am certain that it failed
before it was heavily loaded and before it had a chance to heat up
significantly. I suspect that it won't tolerate this scenario. Note that
my OVM cut off power into the VR but the VR still failed.
Ken Lehman
(haven't put my last name on a list in years other than in my address
but this list is pretty large now I guess)
>
>
> David Carter
>
> ----- Original Message ----- From: "Ken" <klehman(at)albedo.net>
> To:
> Sent: Saturday, September 09, 2006 2:31 PM
> Subject: AeroElectric-List: John Deere PM alternator regulator
>
>
>>
>> I can now say for certain that the AM101406 regulator will not come
>> to life with a totally dead battery. Since I was at homebase,
>> without power for a charger, and like to experiment, I attempted to
>> charge the dead battery by closing the Z-14 cross feed contactor and
>> charging the dead battery with the good alternator for a few minutes
>> until the PM alternator came to life. I wouldn't recommend that and
>> in this case it seems to have caused the regulator to fail full on. I
>> don't really know why it failed as the rpm was modest (well below the
>> max output capability of the 20 amp PM alternator) and it is not
>> particularly uncommon to have dead batteries on the small tractors
>> that these are original equipment on. Further the regulator is on the
>> cool side of the firewall.
>>
>> My best theory is that the totally dead small AGM battery allowed
>> the output to overvoltage some component in the regulator. I do not
>> have a battery contactor so I felt that there was no need for a large
>> electrolytic capacitor on the output since the battery would never
>> be disconnected. The oem application doesn't have a capacitor. AFAIK
>> totally dead batteries can be reluctant to take a charge at first so
>> maybe it wasn't absorbing enough current initially to dampen the
>> output pulses?? Again I wouldn't have expected that to fail a
>> regulator designed to work with up to 200vac open circuit voltage
>> from the alternator.
>>
>> The OVM worked perfectly. It is wired to interupt the line from the
>> alternator to the regulator. In further experimenting, the little 40
>> amp relay does not seem to have suffered noticeably from a few 20 amp
>> disconnects. I also learned that a single 9ah battery will start the
>> subaru rather nicely so all in all I have obtained some value for the
>> cost of my experimentation ;) I guess I also obtained some value
>> from the OVM modules ;)
>>
>> As a shot in the dark I am thinking of putting a capacitor on the
>> output of the regulator. That would leave the capacitor permanently
>> wired across the battery through the b-lead circuit breaker. I don't
>> think transorbs there would help. Any other suggestions? The obvious
>> one is to charge the battery first but that is not always convenient
>> as sooner or later I will likely run a battery dead again in some out
>> of the way place.
>>
>> I do not have a charging indicator lamp wired to the regulator but I
>> am assuming that is irrelevant.
>>
>> Ken
>>
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
| Subject: | Glowing Warning Lights |
I have 2 of the B&C LR3C-14 regulators hooked up to warning lights on my
panel. The warning lights are LED. They work fine, flashing when the voltage
is low. I finally got my plane out at night an noticed that both warning
lights have a dim glow. My other warning lights are totally dark.
Any ideas?
Mike Easley
Lancair ES
Colorado Springs
________________________________________________________________________________
| From: | Dave N6030X <N6030X(at)DaveMorris.com> |
| Subject: | Re: John Deere PM alternator regulator |
Many in the Corvair group (www.FlyCorvair.com) are using this same
John Deere generator/VR combo. You might take up the question there
and find out what people have witnessed. The guy who's probably
flown more hours with that combo than anybody is Gus Warren down at
William Wynne's hangar in Florida.
Dave Morris
At 07:38 AM 9/10/2006, you wrote:
>
>David Carter wrote:
>
>>
>>
>>Ken,
>>
>>For my info what is your last name? I thought at first you would
>>be Ken Powell who I have shared info with about Deere PM
>>alternators, but the e-mail address is different.
>>In any case, could you will in some of the "scenario":
>>
>>1. The battery was dead, and you charged the battery from a non-PM
>>alternator after starting the engine.
>>. . . So, you have two batteries, 1 was dead, 1 was OK enough to
>>start engine.
>>. . . You have two alternators (a PM and a "standard" - not a bad
>>idea when building experience with an unproven application like a
>>Deere on an airplane)
>>. . . . . and used the non-PM to attempt to charge the dead battery.
________________________________________________________________________________
| From: | "glen matejcek" <aerobubba(at)earthlink.net> |
| Subject: | Fuel Pump Switch(es) |
Hi Kevin-
>I'm planning a left/right fuel system each with an on/off valve and an aux
pump
>on each incoming line.
>I'm thinking of using an on/off/on switch for pumps rather than an on/off
switch
>for each pump.
>Can anyone offer any thoughts on the downside of this?
Yup, there are a few. Other folks have touched on most of them already.
The fusing issue could be handled by either putting the FP fuses downstream
of a SPDT center off switch with a larger fuse at the bus (for a total of
3), or by using a DPDT center off switch and two feeds from 2 fuses at the
bus(ses). The former arrangement would have the single feed wire, the
connectors at each end, the big fuse at the bus, and the switch itself as
'single point of failure' nodes. The latter arrangement would reduce the
single point of failure nodes to just the switch itself, rather than all
the other stuff . The most bullet proof system would indeed involve
separate switches for the individual pumps, which would ideally be fed by
separate busses. On balance, having one fuse, one feed wire, and one
switch controlling two pumps leaves you with no less redundancy than my
single pump system, and actually has a smidge more. Unless, of course,
your pumps are inherently less reliable than mine. I have no info on that,
tho-
Having typed this all out, and considering that the electric fuel pumps are
already a back up for the mechanical pump, I'd personally stick with the
single electric pump solution. Especially if one only had one bus to draw
power from. If you are committed to two pumps, I'd probably be perfectly
happy with the single switch, three fuse arrangement. Two electric fuel
pumps gets into the 'belts and suspenders' zone, and complete independent
power systems seems to get into the 'belt, suspenders, and duct tape' zone.
As ever, this is worth precisely what you've paid for it-
glen matejcek
aerobubba(at)earthlink.net
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
| Subject: | Engine analyzer OFF for engine start? |
I'm installing an EI UBG16. The instructions are very clear that they
believe the unit should be on an avionics switch and turned OFF for
engine start. Which of course raises the question in my mind, why?
Did they shortcut on voltage regulation or spike/noise protection for
the units power supply?
The aircraft in question has a Delco 50 amp generator and a Zeftronics
solid state regulator, which appears to be very good at holding 14.1 v
at all rpms above 1100.
________________________________________________________________________________
| From: | Matt Prather <mprather(at)spro.net> |
| Subject: | Re: Glowing Warning Lights |
Mike,
I seem to remember that the regulator was designed to drive incandescent
lamps instead of LED's. I can't remember why the regulator produces a
bias on the warning circuit.. At any rate, lamps won't produce any
light at low voltage/current bias, but LED's will. I think the fix was
to put a high value resistor (1kohm?) across the leads of the LED. It's
in the archive as I recall.
Regards,
Matt-
MikeEasley(at)aol.com wrote:
> I have 2 of the B&C LR3C-14 regulators hooked up to warning lights on
> my panel. The warning lights are LED. They work fine, flashing when
> the voltage is low. I finally got my plane out at night an noticed
> that both warning lights have a dim glow. My other warning lights are
> totally dark.
>
> Any ideas?
>
> Mike Easley
> Lancair ES
> Colorado Springs
>
>*
>
>
>*
>
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
| Subject: | the George debate |
The banning of someone, even for misdemeanours, is agreed to be a failure of
some sort in the system. But I believe it is also a failure of some
measureable dimension, in that eventually one must decide whether the act
reduces in effectiveness or increases it.
I came to an independent conclusion that the 'failure' is a lesser dimension
than the neglect to ban. It is the net which carries such value after all.
That is why I said "be gone" with regret but with conviction. To Eric may I
say I admire your stance if I cannot agree to its significance in this
instance. It needed to be said. As with Jensen I received a vituperative
personal message that was complete twaddle. I suspect professional help is
wanted here.
In the meantime I am determined to side with Bob N because of his attitude
and his understanding. His was an exemplary presentation at our EAA chapter,
and I will not have him maligned - this is MY net too.
Ferg Kyle
Europa A064 914 Classic
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Transponder antenna location |
>
>
>Should the bottom of the front fuselage, 2 ft behind the engine, be a
>proper location?
>Is it a problem to be so close to the engine, isn't it far better at the rear?
>
>Thanks,
>
>Gilles
I guess I don't know how to quantify "proper". Everything in
the choice of system architectures is a trade off. As an antenna
guy I could demand of my fellow airplane builders that they provide
me with installation conditions aboard the airplane that approach
the idealized antennas I can build and fully test in the lab. By
the same token, gurus of other disciplines could impose similar
constraints that make their installations look good too. The
end result is a product that performs poorly and looks so bizarre
that nobody would want to be seen flying it.
It's not in the spirit of compromise that we work together to
craft a product that performs adequately -AND- attracts customers.
It a goal of "optimized" performance given a relatively inflexible
platform. Once optimization is achieved, then performance needs to
be evaluated for adequacy to the task.
In the case of antennas, adequacy to the task is dependent
on the user's mission requirements. I've seen relatively
mediocre antennas slammed by pilots who routinely needed
to talk to RCO's on the horizon while others who only talked
to other airplanes and controllers in the airport control area
thought it worked "great".
In the case of transponder antennas, the manufacturer will suggest
coax length limits based on perceived reductions in the optimized
performance of his product (usually the receiver side) to "hear"
that very strong interrogation pulse shot out to the aircraft from
the ground based radar afar.
In the instance were considering, moving the antenna say 5' further
aft might reduce receive sensitivity by some factor we can deduce
by use of a coax loss calculator found at:
http://www.timesmicrowave.com/cgi-bin/calculate.pl
Plug in RG-400, 1050 Mhz and and a RUN of 6'. We find
that a typical installation has an attenuation of about 0.9 db.
Now, plug in 11' for an installation further aft and we get
1.7 db or an ADDITIONAL 0.8 db of attenuation.
If one chooses to worry about this, we could go to
one of the super-sexy coaxes like LMR-400 for a 6 foot
loss of 0.3 db and 11 foot loss of 0.5 db . . . still better
than 6' of RG-400.
Now, suppose we went flying and did some testing of our
transponder's ability to be "read" by ground stations
and could switch back and forth between an idealized
installation per the book: "right under the pilot's
seat antenna and 6' of LMR-400" and the "compromised
location and 11' of RG-400".
We're talking about such small changes in the grand
scheme of things as to make differences detectable in anything
less than a precision antenna lab environment. The guy
on the ground and the guy in the air will have zero
probability of telling which is the "worse" antenna
buy observing behavior of the electro-whizzies in front
of them.
Bob . . .
>
>
>
> >
> >Has anyone tried mounting a transponder antenna on the bottom of
> the rear
> >fuselage? That location (about 2/3 of the length of the fuselage back)
> >slopes upward on a Rebel but it is the location least blanked by large
> >gear fairings, and metal radiator ducting. Unfortunately the worst
> signal
> >would likely be forward to where the ground station I'm trying to
> reply to
> >is likely to be during first contact. I am willing to mount the
> >transponder behind me to keep the coax within the 8.8 feet max
> specified
> >by Garmin.
> >
> >The other option seems to be on the roof. That is apparently not
> >recommended and it would be near skylights and my head which I'm not
> >comfortable with. I could get it the minimum recommended 3 feet
> away from
> >the VHF antenna but the high wing might tend to blank ground
> stations to
> >the side. I suspect that roof mounting would provide a better signal to
> >other aircraft which is probably more important to me than a signal to
> >ground so I guess I could put the antenna on the roof back near the
> >tail. It seems silly to invest in a transponder though unless it is
> >likely to perform well with both ATC and also traffic warning
> devices on
> >other aircraft.
>
>
> Any place on the bottom would be preferable to top mounted.
> The aft fuselage location you cited would be fine.
>
> Bob . . .
>
>
> ---------------------------------------------------------
> < What is so wonderful about scientific truth...is that >
> < the authority which determines whether there can be >
> < debate or not does not reside in some fraternity of >
> < scientists; nor is it divine. The authority rests >
> < with experiment. >
> < --Lawrence M. Krauss >
> ---------------------------------------------------------
>
>
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Glowing Warning Lights |
>
>Mike,
>
>I seem to remember that the regulator was designed to drive incandescent
>lamps instead of LED's. I can't remember why the regulator produces a
>bias on the warning circuit.. At any rate, lamps won't produce any light
>at low voltage/current bias, but LED's will. I think the fix was to put a
>high value resistor (1kohm?) across the leads of the LED. It's in the
>archive as I recall.
>
>
>Regards,
>
>Matt-
Out of my archives:
>I believe I have seen that two 220 ohm resistors can be used in
>conjunction with an LED to act as a OV light on the B&C LR3s. Can
>someone help me with how 220 ohm was determined and why two of them?
>Normally, I use a 600 ohm resistor in series with an LED to operate at
>13.8V. (drop 12V at 20ma). What am I missing here?
To replace an incandescent lamp on the LR-3 Alternator Controller
with and LED, one has to account for a built-in leakage current
for the LR-3's lamp driver picked so that the lamp will illuminate
even when ALL power is removed from the LR-3 as long as the warning
lamp has + power.
This allows the LR-3 to be used with incandescent annunciator
panels that get power from a third source and still annunciate
regulator failure if all power is removed from the regulator.
This leakage is too small to cause an incandescent lamp to glow
but it will cause an LED to glow even when it's supposed to be
dark. Hence, the resistor around the lamp to drive up it's minimum
illumination current to something on the order of 7-8 mA.
So taking the 220 ohm resistors as recommended, let's figure
2v across the illuminated lamp which means we have about 9 mA
used up in the parallel resistor. Figure 12.5v for the bus voltage
while flashing which leaves 10.5 volts across the series resistor
and 47 mA total through it. With 8 mA being sucked off by
the parallel resistor, this leaves 39 mA or so for the LED.
A bit more than its "rated" current but by no means overly
stressful.
The 10.5 volt drop on series resistor at 47 mA suggests
that a 490 milliwatt resistor is called for . . . except
that this is used in a flashing light system with about 50%
duty cycle which cuts dissipation in half. So the 1/2
watt callouts on the drawing at
http://www.aeroelectric.com/Pictures/Schematics/LV_Led.jpg
are plenty conservative.
Why 220 ohm resistors? That was a size stocked by
Radio Shack (stock #271-1111) in packages of
5 for about a dollar. Other resistors could have
worked just as well for the parallel value . . . but
then one would have to buy two 5-paks and throw
away 8 resistors. The design offered gets the job
done with one purchase.
Why the "leakage" in the LR-3? We had a design goal
for the LV warning light to illuminate BOTH for
real Low Volts warning -AND- when the LR-3 had lost
power entirely. To achieve the second goal, the LR-3
had to appear "very leaky" in the OFF state, hence the
resistor optimized for incandescent lamps but something
of a nuisance for LEDs when attempting to directly
substitute the LED for incandescent.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Engine analyzer OFF for engine start? |
>
>I'm installing an EI UBG16. The instructions are very clear that they
>believe the unit should be on an avionics switch and turned OFF for engine
>start. Which of course raises the question in my mind, why?
>Did they shortcut on voltage regulation or spike/noise protection for the
>units power supply?
>
>The aircraft in question has a Delco 50 amp generator and a Zeftronics
>solid state regulator, which appears to be very good at holding 14.1 v at
>all rpms above 1100.
I'm saddened that any product offered to general aviation
or any other market is still burdened with such admonitions
in their installation instructions. It's a blatant admission
that they're incapable or unwilling to make their product
live in the real-world environment of DC power systems and/or
simply don't understand the world in which they choose to
live. See:
http://www.aeroelectric.com/articles/Whats_all_this_DO160_Stuff_Anyhow.pdf#search=%22avionics%20master%22
http://www.aeroelectric.com/articles/avmaster.pdf
It's the engineering equivalent of child's play to
craft products totally compatible with DC vehicular
power systems.
One can only guess at the rational behind their inclusion
of such a statement . . . and maybe it's for the same reasons
cited by a number of engineers I've queried over the past
30 years:
"Sir, why do the instructions for your product recommend
powering it from an 'avionics' bus 'protected' by an avionics
master switch?" The replies something like, "Gee, I guess
just 'cause other folks are doing it. I personally don't care."
Call them up and ask . . .
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| Subject: | Re: Fuel Pump Switch(es) |
| From: | Brian Lloyd <brian-av(at)lloyd.com> |
On Sun, 2006-09-10 at 04:41, FLYaDIVE(at)aol.com wrote:
> > I'm planning a left/right fuel system each with an on/off valve and an aux
> > pump on each incoming line.
> > I'm thinking of using an on/off/on switch for pumps rather than an on/off
> > switch for each pump.
> >
> > Can anyone offer any thoughts on the downside of this?
Kevin, I think your approach is just fine. Yes, the switch is a
single-point-of-failure but it shouldn't cause your engine to stop
running as the engine-driven fuel pump should be able to keep the engine
running. To lose the engine you would have to lose the both halves of
the switch, both electric fuel pumps, and the engine driven fuel pump.
> There are thousands of planes out there with a ONE PUMP boost system running
> off on the one common line going to the engine or from the fuel selector.
> What I would do though is put a fuel filter on each tank. And then if you want
> to go crazy put in a parallel boost pump. That will give you redundancy and
of
> course more weight and maintenance.
Barry, I think Kevin's idea of two pumps, each right at the tank, is a
good one. That approach means that your boost pump is never having to
suck against a fuel line thus reducing the chance for vapor lock to
almost zero. (I have experienced a vapor lock in flight on the
engine-driven fuel pump. It gets your attention.) If he is thinking of
running mogas, this might be a very good idea. Most automotive systems
now immerse the fuel pump right in the fuel. This ensures that the pump
has prime and that there is no chance for vapor lock.
Brian Lloyd
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Switch Ratings |
>
>
> >
> > Okay,
> >
> > I Have gone and confused myself, I am looking at ordering some
> switches for
> > my OBAM aircraft and can't rember which would be better Higher current
> > switch
> >
> > The catalog states two options:
> >
> > 1: Silver Rated 3A @ 125V AC
> >
> >
> > 2: Gold Rated 0.4 VA max @ 28V AC/DC max
> >
> >
> > My application will be used in a 12-14 Volt system I want the switch with
> > the higher switch capability which is it?
> >
> > THANKS in advance
> >
> >
> > P.s. my guess is option one the silver contacts but for some reason I
> don't
> > think that is correct....
>==================================
>OK, here is the break down:
>
>Silver is the better conductor - But - Oxidized much more.
>Gold is obviously slightly less in conductivity (but, you will never know
>that) than Silver - But - for the practical, does not oxidize.
>
>Without getting ridiculous in explaining a switch ... If you Double the
>Voltage you Half the current. So a Switch that is rated at 0.4 Amps @ 28
>VDC will
>be able to handle 0.8Amps @ 14 VDC.
>
>As for your amperage rating of the switch:
>1 - Find out what the circuit draw at MAX will be.
>2 - Use a switch that is about 50% over rated than the MAX draw.
>3 - If a switch is rated in AC DE-RATE the amperage by 36 to 40%
>[This is a rule of thumb. It has NEVER FAILED for me. Some pencil pusher
>may have worked out a more accurate number but definitely not a better one.]
Don't make it any more complicated than it needs to be. Check
out the article at:
http://www.aeroelectric.com/articles/swtchrat.pdf
I've never seen a failure of a switch in a TC or OBAM aircraft
that can be attributed to failure to observe ratings. The ratings
assume many thousands of operations that you're NEVER going to
achieve in your airplane. On the other hand, if you keep your airplane
10 years or longer, it's almost a given that you'll have to replace
some switch, some time . . . but not because you 'overloaded' it. See:
http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/Anatomy_of_a_Switch_Failure.html
http://www.aeroelectric.com/Pictures/Switches/miniswitches.jpg
Here's and airplane flown often and had over 5 years service on MINATURE
toggles in the landing light, nav light, and strobe circuits. All of
these switches could be said to be 'overloaded' when the catalog
ratings are treated as limits.
Gold contacts are for very small signal switching, what Microswitch
calls "non-arcing" in . . .
http://www.aeroelectric.com/Mfgr_Data/Switches/tl_series.pdf#search=%22switch%20ratings%22
We often purchase 5A relays with silver-cad contacts plated with
a thin layer of gold. If NEVER subjected to higher currents, the
gold plating allows the relay to function well in very small signal
switching . . . but if ever used in a higher current application,
the gold layer is damaged and it officially reverts to a silver-cad
contact relay.
Someone at Beech decided years ago that it would be a good thing
to do 100% receiving inspection of all incoming super whippy mil spec
relays.
They set up a test bench and dutifully subjected every incoming relay
to 5A switching loads and pronounced them 'fit for duty'. Months later
we were having a rash of field failures in some circuits due to the
fact that inspection blew off the gold on relays used in both
"power" and "signal" switching applications. An EXPENSIVE way
to learn difference.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Switch Ratings |
>
>
> >
> > Okay,
> >
> > I Have gone and confused myself, I am looking at ordering some
> switches for
> > my OBAM aircraft and can't rember which would be better Higher current
> > switch
> >
> > The catalog states two options:
> >
> > 1: Silver Rated 3A @ 125V AC
> >
> >
> > 2: Gold Rated 0.4 VA max @ 28V AC/DC max
> >
> >
> > My application will be used in a 12-14 Volt system I want the switch with
> > the higher switch capability which is it?
> >
> > THANKS in advance
> >
> >
> > P.s. my guess is option one the silver contacts but for some reason I
> don't
> > think that is correct....
>==================================
>OK, here is the break down:
>
>Silver is the better conductor - But - Oxidized much more.
>Gold is obviously slightly less in conductivity (but, you will never know
>that) than Silver - But - for the practical, does not oxidize.
>
>Without getting ridiculous in explaining a switch ... If you Double the
>Voltage you Half the current. So a Switch that is rated at 0.4 Amps @ 28
>VDC will
>be able to handle 0.8Amps @ 14 VDC.
>
>As for your amperage rating of the switch:
>1 - Find out what the circuit draw at MAX will be.
>2 - Use a switch that is about 50% over rated than the MAX draw.
>3 - If a switch is rated in AC DE-RATE the amperage by 36 to 40%
>[This is a rule of thumb. It has NEVER FAILED for me. Some pencil pusher
>may have worked out a more accurate number but definitely not a better one.]
Don't make it any more complicated than it needs to be. Check
out the article at:
http://www.aeroelectric.com/articles/swtchrat.pdf
I've never seen a failure of a switch in a TC or OBAM aircraft
that can be attributed to failure to observe ratings. The ratings
assume many thousands of operations that you're NEVER going to
achieve in your airplane. On the other hand, if you keep your airplane
10 years or longer, it's almost a given that you'll have to replace
some switch, some time . . . but not because you 'overloaded' it. See:
http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/Anatomy_of_a_Switch_Failure.html
http://www.aeroelectric.com/Pictures/Switches/miniswitches.jpg
Here's and airplane flown often and had over 5 years service on MINATURE
toggles in the landing light, nav light, and strobe circuits. All of
these switches could be said to be 'overloaded' when the catalog
ratings are treated as limits.
Gold contacts are for very small signal switching, what Microswitch
calls "non-arcing" in . . .
http://www.aeroelectric.com/Mfgr_Data/Switches/tl_series.pdf#search=%22switch%20ratings%22
We often purchase 5A relays with silver-cad contacts plated with
a thin layer of gold. If NEVER subjected to higher currents, the
gold plating allows the relay to function well in very small signal
switching . . . but if ever used in a higher current application,
the gold layer is damaged and it officially reverts to a silver-cad
contact relay.
Someone at Beech decided years ago that it would be a good thing
to do 100% receiving inspection of all incoming super whippy mil spec
relays.
They set up a test bench and dutifully subjected every incoming relay
to 5A switching loads and pronounced them 'fit for duty'. Months later
we were having a rash of field failures in some circuits due to the
fact that inspection blew off the gold on relays used in both
"power" and "signal" switching applications. An EXPENSIVE way
to learn difference.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Switch Ratings |
>
>
> >
> > Okay,
> >
> > I Have gone and confused myself, I am looking at ordering some
> switches for
> > my OBAM aircraft and can't rember which would be better Higher current
> > switch
> >
> > The catalog states two options:
> >
> > 1: Silver Rated 3A @ 125V AC
> >
> >
> > 2: Gold Rated 0.4 VA max @ 28V AC/DC max
> >
> >
> > My application will be used in a 12-14 Volt system I want the switch with
> > the higher switch capability which is it?
> >
> > THANKS in advance
> >
> >
> > P.s. my guess is option one the silver contacts but for some reason I
> don't
> > think that is correct....
>==================================
>OK, here is the break down:
>
>Silver is the better conductor - But - Oxidized much more.
>Gold is obviously slightly less in conductivity (but, you will never know
>that) than Silver - But - for the practical, does not oxidize.
>
>Without getting ridiculous in explaining a switch ... If you Double the
>Voltage you Half the current. So a Switch that is rated at 0.4 Amps @ 28
>VDC will
>be able to handle 0.8Amps @ 14 VDC.
>
>As for your amperage rating of the switch:
>1 - Find out what the circuit draw at MAX will be.
>2 - Use a switch that is about 50% over rated than the MAX draw.
>3 - If a switch is rated in AC DE-RATE the amperage by 36 to 40%
>[This is a rule of thumb. It has NEVER FAILED for me. Some pencil pusher
>may have worked out a more accurate number but definitely not a better one.]
Don't make it any more complicated than it needs to be. Check
out the article at:
http://www.aeroelectric.com/articles/swtchrat.pdf
I've never seen a failure of a switch in a TC or OBAM aircraft
that can be attributed to failure to observe ratings. The ratings
assume many thousands of operations that you're NEVER going to
achieve in your airplane. On the other hand, if you keep your airplane
10 years or longer, it's almost a given that you'll have to replace
some switch, some time . . . but not because you 'overloaded' it. See:
http://www.aeroelectric.com/articles/Anatomy_of_a_Switch_Failure/Anatomy_of_a_Switch_Failure.html
http://www.aeroelectric.com/Pictures/Switches/miniswitches.jpg
Here's and airplane flown often and had over 5 years service on MINATURE
toggles in the landing light, nav light, and strobe circuits. All of
these switches could be said to be 'overloaded' when the catalog
ratings are treated as limits.
Gold contacts are for very small signal switching, what Microswitch
calls "non-arcing" in . . .
http://www.aeroelectric.com/Mfgr_Data/Switches/tl_series.pdf#search=%22switch%20ratings%22
We often purchase 5A relays with silver-cad contacts plated with
a thin layer of gold. If NEVER subjected to higher currents, the
gold plating allows the relay to function well in very small signal
switching . . . but if ever used in a higher current application,
the gold layer is damaged and it officially reverts to a silver-cad
contact relay.
Someone at Beech decided years ago that it would be a good thing
to do 100% receiving inspection of all incoming super whippy mil spec
relays.
They set up a test bench and dutifully subjected every incoming relay
to 5A switching loads and pronounced them 'fit for duty'. Months later
we were having a rash of field failures in some circuits due to the
fact that inspection blew off the gold on relays used in both
"power" and "signal" switching applications. An EXPENSIVE way
to learn difference.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Switch contact rattings which is best for this |
app
| From: | Brian Lloyd <brian-av(at)lloyd.com> |
On Sun, 2006-09-10 at 04:56, FLYaDIVE(at)aol.com wrote:
> Silver is the better conductor - But - Oxidized much more.
> Gold is obviously slightly less in conductivity (but, you will never know
> that) than Silver - But - for the practical, does not oxidize.
Switches maintain their low on resistance by both mechanical wiping and
by the very tiny arc that occurs on make and break. If you do not pass
any current through a switch, often the mechanical wiping is
insufficient to ensure a low on-resistance. Gold, unlike silver, has the
characteristic that it maintains its low on-resistance regardless of the
current flowing through it. That is why it is used to switch signals
with no appreciable current (like audio signals).
> Without getting ridiculous in explaining a switch ... If you Double the
> Voltage you Half the current. So a Switch that is rated at 0.4 Amps @ 28 VDC
will
> be able to handle 0.8Amps @ 14 VDC.
This is 100% false and incorrect. A switch rated at 0.4A is rated at
0.4A regardless of the voltage. The voltage ratings have to do with
reliably breaking the circuit. This also depends on whether you are
breaking a circuit carrying AC or DC. The amp rating also depends on
whether you are switching a resistive load or a lamp load. The low
resistance of a lamp filament causes a high inrush current so you need a
switch that is designed to carry more current so it isn't damaged by the
inrush current.
Barry, I strongly recommend you go back and reread the Aeroelectric
Connection. Bob does an excellent job of covering these things in there.
In a forum such as this, you really need to be sure of your answer
before you post one.
Brian Lloyd
________________________________________________________________________________
| From: | Dave N6030X <N6030X(at)DaveMorris.com> |
| Subject: | Re: Engine analyzer OFF - Avionics Master |
Bob, it's bizarre to me that the "Avionics Master Switch" is still
touted as a "feature" rather than as a "single point of failure
liability" in most classified ads I've seen recently for
airplanes. Clearly you/we still have a lot of educating to do! :)
Dave Morris
At 12:50 PM 9/10/2006, you wrote:
>
>
> "Sir, why do the instructions for your product recommend
> powering it from an 'avionics' bus 'protected' by an avionics
> master switch?" The replies something like, "Gee, I guess
> just 'cause other folks are doing it. I personally don't care."
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Engine analyzer OFF for engine start? |
Hi Kelly
Just an observation but the GRT engine monitor specifically recommends
powering it up before engine start and confirming zero oil pressure
indication. On my particular installation it resets anyway during start
but I have not investigated whether it is voltage dropout during
cranking or momentary loss of power from my marine key switch which
controls power to it and the starter. It is back up in a second or so
anyway.
Ken L.
Kelly McMullen wrote:
>
>
> I'm installing an EI UBG16. The instructions are very clear that they
> believe the unit should be on an avionics switch and turned OFF for
> engine start. Which of course raises the question in my mind, why?
> Did they shortcut on voltage regulation or spike/noise protection for
> the units power supply?
>
> The aircraft in question has a Delco 50 amp generator and a Zeftronics
> solid state regulator, which appears to be very good at holding 14.1 v
> at all rpms above 1100.
________________________________________________________________________________
| From: | G McNutt <gmcnutt(at)shaw.ca> |
| Subject: | Re: Fuel Pump Switch(es) |
Kevin, aside from the on/off switch debate, an on/off valve on each
tank introduces problems and complexity into emergency procedures for a
fuel delivery interruption. For example if you had a blockage or
inadvertently ran a tank dry you will have to reposition two fuel
valves, presumably on opposite sides of the cockpit.
Also check valves may be required to prevent fuel transfer if both tank
valves were inadvertently left open?
George in Langley BC
Kevin Kinney wrote:
>
> I'm planning a left/right fuel system each with an on/off valve and an aux pump
on each incoming line.
> I'm thinking of using an on/off/on switch for pumps rather than an on/off switch
for each pump.
>
> Can anyone offer any thoughts on the downside of this?
>
> Regards,
> Kevin Kinney
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: "Oversized" RG batteries and small generators |
Received a clarification from Skip Koss at Concorde on the
a topic earlier this week where it was suggested that putting
"too large" and RG battery in an airplane with a small generator
(<35A) was potentially harmful to the generator.
Skip forwarded me a note that he'd sent to AOPA Pilot magazine
that included the following:
-----------------
My reference to small capacity generating systems is not for the protection
of the generator but for the airframe wire and C/B. I have had several reports
from operators of post WWII light airplanes (Ercoupes and Stinsons etc,) of
"After
an engine start, I have to reset the C/B around 5 times before the battery
charge
current is low enough to not pop the breaker"
Typically the RG-35AXC will accept 50 amps at 14 volts for a minute or so after
a start, before the current tapers down to less than 25 amps, so I recommend to
these operators to only use the lower plate count batteries that have a higher
internal resistance, so they won't over tax their wiring etc.
-----------------
So it seems that Skip's recommendations were mis-interpreted. The
circuit breaker tripping phenomenon in these small generator airplanes
is a predecessor to the nuisance-tripping of b-lead breakers in
modern airplanes.
Customer's airplanes were "peddling hard" to recharge the larger,
lower impedance battery which held the generating system at or
slightly above the nameplate rated output. As one customer noted,
he had to reset the breaker several times before it would stay in.
Skip's concerns were (based on tripping of the breaker) mostly
for wiring . . . but we know that as much as 200% overload beyond
the as-installed rating of the wire doesn't place it in imminent
danger.
I wasn't aware that the generator systems would suffer from the
same types of nuisance trips that alternators in most TC aircraft
do. The 60A breaker on a 60A alternator is designed to nuisance
trip. It took some serendipitous installations of modern hardware
in older airplanes to bring the condition forward. It seems the
phenomenon goes back a lot further than the beginning of the
alternator era. It's seldom a problem because most generators
and alternators are normally lightly loaded. A modern, perhaps
larger sized RG battery offers an opportunity to tax the system to
nameplate ratings of the equipment for extended periods of time.
If the system is designed to nuisance-trip, then this scenario
will get breakers pop'n. Interestingly enough, upgrading an older
airplane fitted with a 60A alternator could produce exactly
the same effects; a relatively 'trouble-free' airplane could
suddenly exhibit the symptom by simply changing out a flooded
cell battery for an RG battery.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| Subject: | Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
I have an electric pump in each wing root and NO mechanical pump...I
assumed this system was the same but if it has a mechanical pump then
sure a single switch would be just fine.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Brian
Lloyd
Sent: Sunday, September 10, 2006 10:57 AM
Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
-->
On Sun, 2006-09-10 at 04:41, FLYaDIVE(at)aol.com wrote:
> > I'm planning a left/right fuel system each with an on/off valve and
> > an aux pump on each incoming line.
> > I'm thinking of using an on/off/on switch for pumps rather than an
> > on/off switch for each pump.
> >
> > Can anyone offer any thoughts on the downside of this?
Kevin, I think your approach is just fine. Yes, the switch is a
single-point-of-failure but it shouldn't cause your engine to stop
running as the engine-driven fuel pump should be able to keep the engine
running. To lose the engine you would have to lose the both halves of
the switch, both electric fuel pumps, and the engine driven fuel pump.
> There are thousands of planes out there with a ONE PUMP boost system
> running off on the one common line going to the engine or from the
fuel selector.
> What I would do though is put a fuel filter on each tank. And then if
> you want to go crazy put in a parallel boost pump. That will give you
> redundancy and of course more weight and maintenance.
Barry, I think Kevin's idea of two pumps, each right at the tank, is a
good one. That approach means that your boost pump is never having to
suck against a fuel line thus reducing the chance for vapor lock to
almost zero. (I have experienced a vapor lock in flight on the
engine-driven fuel pump. It gets your attention.) If he is thinking of
running mogas, this might be a very good idea. Most automotive systems
now immerse the fuel pump right in the fuel. This ensures that the pump
has prime and that there is no chance for vapor lock.
Brian Lloyd
________________________________________________________________________________
| Subject: | Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
On my electric only system I simply switch pumps to switch tanks...No
selector valve...Just a non return valve in each line joining to a tee
then up to the standards vans selector that has been plumbed to act as
an on-off valve.
The valve has 4 ports so its simple to configure it this way.
System has now flown a total of 2.8 hours...:)
Frank
7a
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of G
McNutt
Sent: Sunday, September 10, 2006 2:21 PM
Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
Kevin, aside from the on/off switch debate, an on/off valve on each
tank introduces problems and complexity into emergency procedures for a
fuel delivery interruption. For example if you had a blockage or
inadvertently ran a tank dry you will have to reposition two fuel
valves, presumably on opposite sides of the cockpit.
Also check valves may be required to prevent fuel transfer if both tank
valves were inadvertently left open?
George in Langley BC
Kevin Kinney wrote:
________________________________________________________________________________
| From: | Brian Lloyd <brian-av(at)lloyd.com> |
| Subject: | Re: Fuel Pump Switch(es) |
On Sep 10, 2006, at 7:39 PM, Hinde, Frank George (Corvallis) wrote:
> (Corvallis)"
>
> On my electric only system I simply switch pumps to switch tanks...No
> selector valve...Just a non return valve in each line joining to a tee
> then up to the standards vans selector that has been plumbed to act as
> an on-off valve.
My only concern with that would be that a pump failure could render
1/2 your fuel unavailable. Several aircraft have been lost on long
over-water flights when electric transfer pumps have failed thus
rendering necessary fuel unavailable. Something to think about.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| Subject: | Re: Fuel Pump Switch(es) |
Hi all,
>>
>> On my electric only system I simply switch pumps to switch tanks...No
>> selector valve...Just a non return valve in each line joining to a tee
>> then up to the standards vans selector that has been plumbed to act as
>> an on-off valve.
I had to design a fuel circuit for an electrically dependant engine :
in order to achieve true redundancy I had to run each pump from a
separate battery. The main pump runs from the main battery, and is on
whenever the mags are "on". The boost pump runs from the auxiliary
battery, and has a switch. The fuel valve works the normal way. For the
pilot, everything works as in a engine with mechanical pump.
No single electric failure can deprive the engine of its fuel supply.
A schematic of my setup can be seen at
http://contrails.free.fr/engine_pierburg.php
(Scroll down to the bottom of the page)
FWIW
Regards,
Gilles Thesee
Grenoble, France
http://contrails.free.fr
________________________________________________________________________________
| Subject: | Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Absolutely correct Brian,
That is the one downside I came up with too. Basically you have to allow a small
reserve in each tank, For normal flying that means 0.5 hours in each tank...For
out in the badlands that might be a bit more...:)
Frank
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Brian Lloyd
Sent: Monday, September 11, 2006 12:10 AM
Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
-->
On Sep 10, 2006, at 7:39 PM, Hinde, Frank George (Corvallis) wrote:
> (Corvallis)"
>
> On my electric only system I simply switch pumps to switch tanks...No
> selector valve...Just a non return valve in each line joining to a tee
> then up to the standards vans selector that has been plumbed to act as
> an on-off valve.
My only concern with that would be that a pump failure could render
1/2 your fuel unavailable. Several aircraft have been lost on long
over-water flights when electric transfer pumps have failed thus
rendering necessary fuel unavailable. Something to think about.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Dave N6030X <N6030X(at)DaveMorris.com> |
| Subject: | Troll Hypervox intercom pinout |
Does anyone happen to have the pinout diagram for a Troll Avionics
Hypervox intercom?
Thanks,
Dave Morris
1960 Mooney M20A
N6030X at 52F
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Fawcett Pump Data???? |
I spent as much time as I could searching the 'net
for specifications on Fawcett pumps popular with the
OBAM aircraft industry.
Don't have time to search any more today, need to attend
one of those "$1,000 meetings" (ten engineers and
managers sit around table for an hour). If anyone
runs across a source for this data, I'd appreciate
hearing about it.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "glen matejcek" <aerobubba(at)earthlink.net> |
| Subject: | Fuel Pump Switch(es) |
George / Kevin-
George- "... an on/off valve on each
tank introduces problems and complexity..."
Boy, am I glad you wrote that! I completely missed the part about
independent fuel valves. Kevin, besides all the good points George makes,
and as someone pointed out a while back on one of these lists, you will
only find a "BOTH" position on a fuel selector in a high wing single engine
airplane. The low wing planes have left, right, and off. With a high wing
plane, you will sometimes see quite an imbalance develop when drawing fuel
from both tanks simultaneously, even with the head pressure caused by the
tank location. This effect could be much greater in a low wing
installation. If you had the ability to have both tanks plumbed to the
engine at the same time, when one tank emptied you could suck air into the
system. Obviously, this would not be good. I would definitely recommend
against two fuel valves.
Sorry for not catching that sooner-
glen matejcek
aerobubba(at)earthlink.net
________________________________________________________________________________
| From: | "Bill Steer" <steerr(at)bellsouth.net> |
| Subject: | Re: Troll Hypervox intercom pinout |
Yes. I'll send it to you off-line.
Bill
> Does anyone happen to have the pinout diagram for a Troll Avionics
> Hypervox intercom?
________________________________________________________________________________
| Subject: | Fawcett Pump Data???? |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
http://www.facet-purolator.com/mcl/pages/frame_src/appref_frmsrc.html
The solid state cube pumps are the standard for carb'd fuel systems.
They come in various flowrates and pressures both with and without in
built check valves.
I ran these for 400 hours and worked perfectly.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Robert L. Nuckolls, III
Sent: Monday, September 11, 2006 7:36 AM
Subject: AeroElectric-List: Fawcett Pump Data????
-->
I spent as much time as I could searching the 'net for specifications on
Fawcett pumps popular with the OBAM aircraft industry.
Don't have time to search any more today, need to attend one of those
"$1,000 meetings" (ten engineers and managers sit around table for an
hour). If anyone runs across a source for this data, I'd appreciate
hearing about it.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | OldBob Siegfried <oldbob(at)BeechOwners.com> |
| Subject: | Fuel Pump Switch(es) |
Good Morning Frank,
I've been away for a few days and am just catching up
on my E-mail so I have not yet digested this thread.
However, the following statement piques my curiosity.
"Basically you have to allow a small reserve in each
tank, For normal flying that means 0.5 hours
in each tank...For out in the badlands that might be a
bit more...:)"
Would you mean by this statement that you do not want
to run a tank dry or that you feel it is actually
dangerous to do so?
May I ask what sort of an engine is being fed and why
you feel the need for it to never be allowed to run
dry?
Many light aircraft, both certified and experimental,
have multiple fuel tanks. Some Bonanzas have six
separate fuel tanks. If a half hours worth of fuel is
to be considered unusable in each tank, a lot of
payload and range is being lost.
The vast majority of commonly used light plane engines
are driving a solidly connected propellor that will
windmill quite well following a loss of fuel flow. I
understand that some of the experimental airplanes do
have propellors that will declutch or otherwise not
drive the engine if power is lost, but that is not
true of most.
Running a fuel tank dry is a very viable fuel
management operation if it is done correctly.
Any more information or thoughts you would care to
mention?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Stearman N3977A
Downers Grove, IL
LL22
--- "Hinde, Frank George (Corvallis)"
wrote:
> Frank George (Corvallis)"
>
> Absolutely correct Brian,
>
> That is the one downside I came up with too.
> Basically you have to allow a small reserve in each
> tank, For normal flying that means 0.5 hours in each
> tank...For out in the badlands that might be a bit
> more...:)
>
> Frank
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
>
[mailto:owner-aeroelectric-list-server(at)matronics.com]
> On Behalf Of Brian Lloyd
> Sent: Monday, September 11, 2006 12:10 AM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
>
>
> -->
>
>
> On Sep 10, 2006, at 7:39 PM, Hinde, Frank George
> (Corvallis) wrote:
>
> Frank George
> > (Corvallis)"
> >
> > On my electric only system I simply switch pumps
> to switch tanks...No
> > selector valve...Just a non return valve in each
> line joining to a tee
> > then up to the standards vans selector that has
> been plumbed to act as
> > an on-off valve.
>
> My only concern with that would be that a pump
> failure could render
> 1/2 your fuel unavailable. Several aircraft have
> been lost on long
> over-water flights when electric transfer pumps have
> failed thus
> rendering necessary fuel unavailable. Something to
> think about.
>
> Brian Lloyd 361 Catterline
> Way
> brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788
> (fax)
>
> I fly because it releases my mind from the tyranny
> of petty things . . .
> - Antoine de Saint-Exupry
>
>
>
>
>
>
>
>
>
>
>
> browse
> Subscriptions page,
> FAQ,
> http://www.matronics.com/Navigator?AeroElectric-List
>
> Web Forums!
>
>
> Admin.
>
>
>
>
>
________________________________________________________________________________
| Subject: | Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Well that depends.
On a carbed engine it does not matter if you run a tank dry with Both
tanks feeding the engine.
The pump that draws air will simply airlock and cease to pump
anything...It can't pump against the other pump that is pumping fuel.
Secondly...even if the pump did pump air it simply gets flushed out of
the float bowl in the carb.
I have proved this over 400 hours in my last airplane.
In my new FI'd airplane, Getting air to the servo would not be great but
I really doubt the pump will pump any air against the 30 psi made by the
other pump...I haven't tried to prove this yet.
The really neat thing about this install is that you can even lose all
the fuel out of one tank on take off, plug a fuel filter etc, and the
engine will still run normaly.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of glen
matejcek
Sent: Monday, September 11, 2006 7:43 AM
Subject: AeroElectric-List: Fuel Pump Switch(es)
-->
George / Kevin-
George- "... an on/off valve on each
tank introduces problems and complexity..."
Boy, am I glad you wrote that! I completely missed the part about
independent fuel valves. Kevin, besides all the good points George
makes, and as someone pointed out a while back on one of these lists,
you will only find a "BOTH" position on a fuel selector in a high wing
single engine airplane. The low wing planes have left, right, and off.
With a high wing plane, you will sometimes see quite an imbalance
develop when drawing fuel from both tanks simultaneously, even with the
head pressure caused by the tank location. This effect could be much
greater in a low wing installation. If you had the ability to have both
tanks plumbed to the engine at the same time, when one tank emptied you
could suck air into the system. Obviously, this would not be good. I
would definitely recommend against two fuel valves.
Sorry for not catching that sooner-
glen matejcek
aerobubba(at)earthlink.net
________________________________________________________________________________
| From: | Brian Lloyd <brian-av(at)lloyd.com> |
| Subject: | Re: Fuel Pump Switch(es) |
On Sep 11, 2006, at 7:43 AM, glen matejcek wrote:
> airplane. The low wing planes have left, right, and off. With a
> high wing
> plane, you will sometimes see quite an imbalance develop when
> drawing fuel
> from both tanks simultaneously, even with the head pressure caused
> by the
> tank location. This effect could be much greater in a low wing
> installation.
The Nanchang CJ6A and Yak-52 both are low-wing airplanes with a
single on/off fuel selector. The wing tanks gravity feed to a header
tank at the low point in the fuselage. The header tank feeds the carb
through a manual wobble pump, the firewall fuel shut-off, and the
engine-driven fuel pump. All three tanks share a common vent. The
header tank has small flapper valves to prevent fuel from flowing
back out to a tank.
Many complain of uneven fuel feed but I have found that keeping the
ball in the center solves the problem. And even if you do get a
substantial imbalance, getting the ball back into the center causes
the fuel to feed from the more-full tank. It seems to work pretty well.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| Subject: | Re: Fuel Pump Switch(es) |
| From: | "Bill Denton" <bdenton(at)bdenton.com> |
aerobubba(at)earthlink.ne wrote:
> George / Kevin-
>
> George- "... an on/off valve on each
> tank introduces problems and complexity..."
>
> Boy, am I glad you wrote that! I completely missed the part about
> independent fuel valves. Kevin, besides all the good points George makes,
> and as someone pointed out a while back on one of these lists, you will
> only find a "BOTH" position on a fuel selector in a high wing single engine
> airplane. The low wing planes have left, right, and off. With a high wing
> plane, you will sometimes see quite an imbalance develop when drawing fuel
> from both tanks simultaneously, even with the head pressure caused by the
> tank location. This effect could be much greater in a low wing
> installation. If you had the ability to have both tanks plumbed to the
> engine at the same time, when one tank emptied you could suck air into the
> system. Obviously, this would not be good. I would definitely recommend
> against two fuel valves.
>
> Sorry for not catching that sooner-
>
> glen matejcek
> aerobubba(at)earthlink.net
RE: Kevin, besides all the good points George makes,
and as someone pointed out a while back on one of these lists, you will
only find a "BOTH" position on a fuel selector in a high wing single engine
airplane.
JFTR: New Cessna 172's have a Left/Right/Both fuel selector
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=60969#60969
________________________________________________________________________________
| From: | Steve Allison <stevea(at)svpal.org> |
| Subject: | Re: Fawcett Pump Data???? |
Robert L. Nuckolls, III wrote:
> If anyone
> runs across a source for this data, I'd appreciate
> hearing about it.
>
>
> Bob . . .
Facet website:
http://www.facet-purolator.com/Default1.html
________________________________________________________________________________
| Subject: | Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
See below....
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of OldBob Siegfried
Sent: Monday, September 11, 2006 8:26 AM
Subject: RE: AeroElectric-List: Fuel Pump Switch(es)
-->
Good Morning Frank,
I've been away for a few days and am just catching up on my E-mail so I have not
yet digested this thread.
However, the following statement piques my curiosity.
"Basically you have to allow a small reserve in each tank, For normal flying that
means 0.5 hours in each tank...For out in the badlands that might be a bit
more...:)"
Would you mean by this statement that you do not want to run a tank dry or that
you feel it is actually dangerous to do so?
The biggest issue in running a tank dry is that you are now down to a single pump
that can pump fuel...I.e a single point of failure. Certainly on a Carb'd install
there is no issue whatsoever in running a tank dry as far as the engine
is concerned. It will run quite happily...As I posted earlier that airlocked
pump "SHOULD" not pump air against the head of the other pump that is still pumping
fuel...and even if it did the air would be flushed harmlessly through the
float bowl.
On my new FI'd installation The pressure is higher so I seriously doubt any air
would get to the engine but I have not proved this yet...If you did get air there
there might be some spluttering, fixed simply by switching off the empty
tank's pump.
May I ask what sort of an engine is being fed and why you feel the need for it
to never be allowed to run dry?
Engine is an IO360 clone..see above. The roller vane pumps do not like to be run
dry...They rely on the fuel to lubricate them and I am told they will fail if
you run them dry...i don't personally know this for a fact however.
I really need to do the tank dry pumping test...simply because if doing a big slip
in a crosswind with low fuel level you could uncover a tank pick up....AS
I said though, the air pump would have to overcome the pressure made by the opposite
fuel pump...I really don't see that happening.
Many light aircraft, both certified and experimental, have multiple fuel tanks.
Some Bonanzas have six separate fuel tanks. If a half hours worth of fuel is
to be considered unusable in each tank, a lot of payload and range is being lost.
The vast majority of commonly used light plane engines are driving a solidly connected
propellor that will windmill quite well following a loss of fuel flow.
I understand that some of the experimental airplanes do have propellors that
will declutch or otherwise not drive the engine if power is lost, but that is
not true of most.
Running a fuel tank dry is a very viable fuel management operation if it is done
correctly.
Any more information or thoughts you would care to mention?
Sure...No one has asked why I went for 2 electric pumps with no mechanical pump?...Heres
why...Eventually (after engine break in) I want to run Mogas in my Lycoming
clone. Mogas has a higher vapour pressure than avgas and so is less tolerant
of being sucked upon before boiling....If you make the fuel warmer it
will boil with even less provocation (sucking). Now where is the Mechanica fuel
pump?....In front of a HOT firewall sucking a fair distance from the tanks through
pressure drops such as the selector valve and filters. Not normally an
issue because the boost pump is running.
So imagine this scenario...its a 100F day....You rotating on takeoff and your boost
pump quits...Your running mogas, the HOT mechanical pump is now sucking as
hard as it can...Will the fuel boil at the inlet to the pump?....Pretty likely
I think.
In realife one of my jobs is to design pumoing systems for all kinds of liquids...some
high vapour pressure...Thats where my interest came from to put the pumps
at the source of the fuel...Preferably in the tanks but mine are in the wingroots
of the RV.
Happy Skies,
You too....These RV's are FAST...never flown at anything like these kinds of speeds
before...:)
Frank
Old Bob
AKA
Bob Siegfried
Stearman N3977A
Downers Grove, IL
LL22
--- "Hinde, Frank George (Corvallis)"
wrote:
> Frank George (Corvallis)"
>
> Absolutely correct Brian,
>
> That is the one downside I came up with too.
> Basically you have to allow a small reserve in each tank, For normal
> flying that means 0.5 hours in each tank...For out in the badlands
> that might be a bit
> more...:)
>
> Frank
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
>
[mailto:owner-aeroelectric-list-server(at)matronics.com]
> On Behalf Of Brian Lloyd
> Sent: Monday, September 11, 2006 12:10 AM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
>
>
> -->
>
>
> On Sep 10, 2006, at 7:39 PM, Hinde, Frank George
> (Corvallis) wrote:
>
> Frank George
> > (Corvallis)"
> >
> > On my electric only system I simply switch pumps
> to switch tanks...No
> > selector valve...Just a non return valve in each
> line joining to a tee
> > then up to the standards vans selector that has
> been plumbed to act as
> > an on-off valve.
>
> My only concern with that would be that a pump failure could render
> 1/2 your fuel unavailable. Several aircraft have been lost on long
> over-water flights when electric transfer pumps have failed thus
> rendering necessary fuel unavailable. Something to think about.
>
> Brian Lloyd 361 Catterline
> Way
> brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788
> (fax)
>
> I fly because it releases my mind from the tyranny of petty things . .
> .
> - Antoine de Saint-Exupry
>
>
>
>
>
>
>
>
>
>
>
> browse
> Subscriptions page,
> FAQ,
> http://www.matronics.com/Navigator?AeroElectric-List
>
> Web Forums!
>
>
> Admin.
>
>
>
>
>
________________________________________________________________________________
| Subject: | Antenna locations in an RV9 |
| From: | Gerry Filby <gerf(at)gerf.com> |
I'm getting ready to install my antennas in my RV9 - COM bent
whip and a TPDR blade. I'd like to mount them just forward of
the wing spar outboard edges of the cockpit floor. I think I
can just keep the connections under the foward center section
covers.
I get the sense that most people go behind the wing spar - 2
advantages of mounting forward is that i) you don't have to
pass the wires through the center section and ii) it gets a
little more distance between the antenna cables and the wing
strobe head cables.
Any good reason why I shouldn't mount them forward of the
center section ?
__g__
==========================================================
Gerry Filby gerf(at)gerf.com
----------------------------------------------------------
________________________________________________________________________________
| Subject: | Antenna locations in an RV9 |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Closer to engine noise,
Not much room between the floor and underside of cover...Have to allow
enough bend on the cable...Or use a right angled adaptor.
Frank
7a...flying since Friday
I'm getting ready to install my antennas in my RV9 - COM bent whip and a
TPDR blade. I'd like to mount them just forward of the wing spar
outboard edges of the cockpit floor. I think I can just keep the
connections under the foward center section covers.
I get the sense that most people go behind the wing spar - 2 advantages
of mounting forward is that i) you don't have to pass the wires through
the center section and ii) it gets a little more distance between the
antenna cables and the wing strobe head cables.
Any good reason why I shouldn't mount them forward of the center section
?
__g__
==========================================================
Gerry Filby gerf(at)gerf.com
----------------------------------------------------------
________________________________________________________________________________
| Subject: | Antenna locations in an RV9 |
| From: | Gerry Filby <gerf(at)gerf.com> |
Yup, right angle adaptor was where I was going ... engine noise
is a very good point ... thx.
g
>
> (Corvallis)"
>
> Closer to engine noise,
>
> Not much room between the floor and underside of cover...Have to allow
> enough bend on the cable...Or use a right angled adaptor.
>
> Frank
> 7a...flying since Friday
>
>
> I'm getting ready to install my antennas in my RV9 - COM bent whip and a
> TPDR blade. I'd like to mount them just forward of the wing spar
> outboard edges of the cockpit floor. I think I can just keep the
> connections under the foward center section covers.
>
> I get the sense that most people go behind the wing spar - 2 advantages
> of mounting forward is that i) you don't have to pass the wires through
> the center section and ii) it gets a little more distance between the
> antenna cables and the wing strobe head cables.
>
> Any good reason why I shouldn't mount them forward of the center section
> ?
>
> __g__
>
> ==========================================================
> Gerry Filby gerf(at)gerf.com
> ----------------------------------------------------------
>
>
>
>
>
>
>
--
__g__
==========================================================
Gerry Filby gerf(at)gerf.com
----------------------------------------------------------
________________________________________________________________________________
| From: | Richard Dudley <rhdudley1(at)bellsouth.net> |
| Subject: | Re: Antenna locations in an RV9 |
Gerry,
I put my transponder antenna in the center just in front of the spar in
my -6A. Behind the console, there is no need for a right angle adaptor.
My two comm antennas are left and right in front of the landing gear
weldments well outboard of the centerline. There, I used right angle
adaptors. With sound proofing material between the ribs of the floor
about the thickness of the rib height, the adaptors seem adequately
protected. With a carpet over the soundproofing material, the cable lies
between the carpet and soundproofing material. I have about 100 hours on
the aircraft and both transponder and comms work well.
Regards,
Richard Dudley
-6A
Gerry Filby wrote:
>
>
>I'm getting ready to install my antennas in my RV9 - COM bent
>whip and a TPDR blade. I'd like to mount them just forward of
>the wing spar outboard edges of the cockpit floor. I think I
>can just keep the connections under the foward center section
>covers.
>
>I get the sense that most people go behind the wing spar - 2
>advantages of mounting forward is that i) you don't have to
>pass the wires through the center section and ii) it gets a
>little more distance between the antenna cables and the wing
>strobe head cables.
>
>Any good reason why I shouldn't mount them forward of the
>center section ?
>
>__g__
>
>==========================================================
>Gerry Filby gerf(at)gerf.com
>----------------------------------------------------------
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Antenna locations in an RV9 |
| From: | Gerry Filby <gerf(at)gerf.com> |
Interesting, thanks for the comments. Question - with the
transponder in the center are you seeing any affects of
heat/dirt from the engine exhaust pipes ?
g
>
>
>
> Gerry,
>
> I put my transponder antenna in the center just in front of
> the spar in
> my -6A. Behind the console, there is no need for a right angle adaptor.
> My two comm antennas are left and right in front of the landing gear
> weldments well outboard of the centerline. There, I used right angle
> adaptors. With sound proofing material between the ribs of the floor
> about the thickness of the rib height, the adaptors seem adequately
> protected. With a carpet over the soundproofing material, the
> cable lies
> between the carpet and soundproofing material. I have about 100
> hours on
> the aircraft and both transponder and comms work well.
>
> Regards,
>
> Richard Dudley
> -6A
>
> Gerry Filby wrote:
>
> >
> >
> >I'm getting ready to install my antennas in my RV9 - COM bent
> >whip and a TPDR blade. I'd like to mount them just forward of
> >the wing spar outboard edges of the cockpit floor. I think I
> >can just keep the connections under the foward center section
> >covers.
> >
> >I get the sense that most people go behind the wing spar - 2
> >advantages of mounting forward is that i) you don't have to
> >pass the wires through the center section and ii) it gets a
> >little more distance between the antenna cables and the wing
> >strobe head cables.
> >
> >Any good reason why I shouldn't mount them forward of the
> >center section ?
> >
> >__g__
> >
> >==========================================================
> >Gerry Filby gerf(at)gerf.com
> >----------------------------------------------------------
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
>
>
>
>
>
--
__g__
==========================================================
Gerry Filby gerf(at)gerf.com
----------------------------------------------------------
________________________________________________________________________________
| Subject: | Re: Fuel Pump Switch(es) |
| From: | Brian Lloyd <brian-av(at)lloyd.com> |
On Mon, 2006-09-11 at 08:57, Bill Denton wrote:
> RE: Kevin, besides all the good points George makes,
> and as someone pointed out a while back on one of these lists, you will
> only find a "BOTH" position on a fuel selector in a high wing single engine
> airplane.
Well, it is probably not safe to use the words "always", "never", and
"only" when describing systems. As I pointed out earlier, both the
Nanchang CJ6A and Yak-52 are low-wing aircraft that have only an on/off
fuel selector at the firewall. There is no way on either of these
aircraft to select a left or right tank. They are always on "both".
Brian Lloyd
________________________________________________________________________________
| From: | Richard Dudley <rhdudley1(at)bellsouth.net> |
| Subject: | Re: Antenna locations in an RV9 |
Gerry,
The only effect that I see is some oil accumulation from the breather.
I have not yet eliminated the oil on the undercarriage even though the
breather is immediately above the left exhaust pipe. There has been no
noticible effect on transponder function.
RHDudley
Gerry Filby wrote:
>
>
>Interesting, thanks for the comments. Question - with the
>transponder in the center are you seeing any affects of
>heat/dirt from the engine exhaust pipes ?
>
>g
>
>
>
>>
>>
>>Gerry,
>>
>>I put my transponder antenna in the center just in front of
>>the spar in
>>my -6A. Behind the console, there is no need for a right angle adaptor.
>>My two comm antennas are left and right in front of the landing gear
>>weldments well outboard of the centerline. There, I used right angle
>>adaptors. With sound proofing material between the ribs of the floor
>>about the thickness of the rib height, the adaptors seem adequately
>>protected. With a carpet over the soundproofing material, the
>>cable lies
>>between the carpet and soundproofing material. I have about 100
>>hours on
>>the aircraft and both transponder and comms work well.
>>
>>Regards,
>>
>>Richard Dudley
>>-6A
>>
>>Gerry Filby wrote:
>>
>>
>>
>>>
>>>
>>>I'm getting ready to install my antennas in my RV9 - COM bent
>>>whip and a TPDR blade. I'd like to mount them just forward of
>>>the wing spar outboard edges of the cockpit floor. I think I
>>>can just keep the connections under the foward center section
>>>covers.
>>>
>>>I get the sense that most people go behind the wing spar - 2
>>>advantages of mounting forward is that i) you don't have to
>>>pass the wires through the center section and ii) it gets a
>>>little more distance between the antenna cables and the wing
>>>strobe head cables.
>>>
>>>Any good reason why I shouldn't mount them forward of the
>>>center section ?
>>>
>>>__g__
>>>
>>>==========================================================
>>>Gerry Filby gerf(at)gerf.com
>>>----------------------------------------------------------
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
________________________________________________________________________________
| From: | "Marty" <martorious(at)charter.net> |
| Subject: | Fuel Pump Switch(es) |
Bob, I think the reason he wanted to leave a reserve in each tank is in case
the fuel pump in the opposite tank quit and he was therefore denied access
to the fuel in that tank he would have the reserve fuel in the 'good' tank.
Marty
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of OldBob
Siegfried
Sent: Monday, September 11, 2006 10:26 AM
Subject: RE: AeroElectric-List: Fuel Pump Switch(es)
Good Morning Frank,
I've been away for a few days and am just catching up
on my E-mail so I have not yet digested this thread.
However, the following statement piques my curiosity.
"Basically you have to allow a small reserve in each
tank, For normal flying that means 0.5 hours
in each tank...For out in the badlands that might be a
bit more...:)"
Would you mean by this statement that you do not want
to run a tank dry or that you feel it is actually
dangerous to do so?
May I ask what sort of an engine is being fed and why
you feel the need for it to never be allowed to run
dry?
Many light aircraft, both certified and experimental,
have multiple fuel tanks. Some Bonanzas have six
separate fuel tanks. If a half hours worth of fuel is
to be considered unusable in each tank, a lot of
payload and range is being lost.
The vast majority of commonly used light plane engines
are driving a solidly connected propellor that will
windmill quite well following a loss of fuel flow. I
understand that some of the experimental airplanes do
have propellors that will declutch or otherwise not
drive the engine if power is lost, but that is not
true of most.
Running a fuel tank dry is a very viable fuel
management operation if it is done correctly.
Any more information or thoughts you would care to
mention?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Stearman N3977A
Downers Grove, IL
LL22
--- "Hinde, Frank George (Corvallis)"
wrote:
> Frank George (Corvallis)"
>
> Absolutely correct Brian,
>
> That is the one downside I came up with too.
> Basically you have to allow a small reserve in each
> tank, For normal flying that means 0.5 hours in each
> tank...For out in the badlands that might be a bit
> more...:)
>
> Frank
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
>
[mailto:owner-aeroelectric-list-server(at)matronics.com]
> On Behalf Of Brian Lloyd
> Sent: Monday, September 11, 2006 12:10 AM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
>
>
> -->
>
>
> On Sep 10, 2006, at 7:39 PM, Hinde, Frank George
> (Corvallis) wrote:
>
> Frank George
> > (Corvallis)"
> >
> > On my electric only system I simply switch pumps
> to switch tanks...No
> > selector valve...Just a non return valve in each
> line joining to a tee
> > then up to the standards vans selector that has
> been plumbed to act as
> > an on-off valve.
>
> My only concern with that would be that a pump
> failure could render
> 1/2 your fuel unavailable. Several aircraft have
> been lost on long
> over-water flights when electric transfer pumps have
> failed thus
> rendering necessary fuel unavailable. Something to
> think about.
>
> Brian Lloyd 361 Catterline
> Way
> brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788
> (fax)
>
> I fly because it releases my mind from the tyranny
> of petty things . . .
> - Antoine de Saint-Exupry
>
>
>
>
>
>
>
>
>
>
>
> browse
> Subscriptions page,
> FAQ,
> http://www.matronics.com/Navigator?AeroElectric-List
>
> Web Forums!
>
>
> Admin.
>
>
>
>
>
________________________________________________________________________________
| From: | "Peter Braswell" <pbraswell(at)alterthought.com> |
| Subject: | Whelen Strobes Blowing Fuses |
Gang,
I've got a problem with my Whelen strobe system blowing a 10 amp fuse.
I'm using a 10 amp mini-blade fuse which is blowing intermittently. The kit
manufacturer as per the instructions, recommends a 10 amp fuse, but of
course they allude to a 10 amp aircraft style reset-able fuse. I can seem
to get the fuse to blow fairly regularly if I turn the strobes on and off in
quick succession. The fuse will blow less reliably if I turn the strobes on
prior to takeoff and just leave them on.
My questions are these: Would there be any difference in a 10 amp blade fuse
vs. the mechanical breaker style fuse as prescribed by the manufacturer?
And the other question is is there such thing as a slow-blow mini blade
style fuse and could this possibly make a difference? And finally perhaps
there is something more insidious at work here?
TIA,
Peter
_______________________________________
Peter J. Braswell
804.934.0300 Office
804.690.5896 Mobile
_______________________________________
________________________________________________________________________________
| Subject: | Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
You got it...Now did I religiously adhere to that rule when arriving home from
a long flight....well once or twice in 400 hours would have been a bad time to
loose a pump....:)
Tested high cruise power today (full rich) on a single pump and it still makes
almost full (i.e return valve relief) pressure...I'm pretty confident the pumps
are adequately sized.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Marty
Sent: Monday, September 11, 2006 3:16 PM
Subject: RE: AeroElectric-List: Fuel Pump Switch(es)
-->
Bob, I think the reason he wanted to leave a reserve in each tank is in case the
fuel pump in the opposite tank quit and he was therefore denied access to the
fuel in that tank he would have the reserve fuel in the 'good' tank.
Marty
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of OldBob Siegfried
Sent: Monday, September 11, 2006 10:26 AM
Subject: RE: AeroElectric-List: Fuel Pump Switch(es)
Good Morning Frank,
I've been away for a few days and am just catching up on my E-mail so I have not
yet digested this thread.
However, the following statement piques my curiosity.
"Basically you have to allow a small reserve in each tank, For normal flying that
means 0.5 hours in each tank...For out in the badlands that might be a bit
more...:)"
Would you mean by this statement that you do not want to run a tank dry or that
you feel it is actually dangerous to do so?
May I ask what sort of an engine is being fed and why you feel the need for it
to never be allowed to run dry?
Many light aircraft, both certified and experimental, have multiple fuel tanks.
Some Bonanzas have six separate fuel tanks. If a half hours worth of fuel is
to be considered unusable in each tank, a lot of payload and range is being lost.
The vast majority of commonly used light plane engines are driving a solidly connected
propellor that will windmill quite well following a loss of fuel flow.
I understand that some of the experimental airplanes do have propellors that
will declutch or otherwise not drive the engine if power is lost, but that is
not true of most.
Running a fuel tank dry is a very viable fuel management operation if it is done
correctly.
Any more information or thoughts you would care to mention?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Stearman N3977A
Downers Grove, IL
LL22
--- "Hinde, Frank George (Corvallis)"
wrote:
> Frank George (Corvallis)"
>
> Absolutely correct Brian,
>
> That is the one downside I came up with too.
> Basically you have to allow a small reserve in each tank, For normal
> flying that means 0.5 hours in each tank...For out in the badlands
> that might be a bit
> more...:)
>
> Frank
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
>
[mailto:owner-aeroelectric-list-server(at)matronics.com]
> On Behalf Of Brian Lloyd
> Sent: Monday, September 11, 2006 12:10 AM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
>
>
> -->
>
>
> On Sep 10, 2006, at 7:39 PM, Hinde, Frank George
> (Corvallis) wrote:
>
> Frank George
> > (Corvallis)"
> >
> > On my electric only system I simply switch pumps
> to switch tanks...No
> > selector valve...Just a non return valve in each
> line joining to a tee
> > then up to the standards vans selector that has
> been plumbed to act as
> > an on-off valve.
>
> My only concern with that would be that a pump failure could render
> 1/2 your fuel unavailable. Several aircraft have been lost on long
> over-water flights when electric transfer pumps have failed thus
> rendering necessary fuel unavailable. Something to think about.
>
> Brian Lloyd 361 Catterline
> Way
> brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788
> (fax)
>
> I fly because it releases my mind from the tyranny of petty things . .
> .
> - Antoine de Saint-Exupry
>
>
>
>
>
>
>
>
>
>
>
> browse
> Subscriptions page,
> FAQ,
> http://www.matronics.com/Navigator?AeroElectric-List
>
> Web Forums!
>
>
> Admin.
>
>
>
>
>
________________________________________________________________________________
| From: | "glen matejcek" <aerobubba(at)earthlink.net> |
| Subject: | Fuel sys config, was Fuel Pump Switch(es) |
Hello Brian!
As ever, you are absolutely correct. My bad. I know better than to use
absolutes, especially with this crowd1
On the other hand, the systems you've cited feed from the mains to a header
tank at the low point. This arrangement should preclude drawing air from
the empty tank. In my RV, the fuel pick up in the tank is the low point in
the system. It's all uphill from there, and there is no header tank to
buffer the system. To the best of my knowledge, and I cringe as I type the
words, there are no certified, low wing singles that will feed
simultaneously from multiple tanks other than those equipped with headers.
As a point of interest, does anybody out there know of a plane configured
that way?
>On Mon, 2006-09-11 at 08:57, Bill Denton wrote:
>> RE: Kevin, besides all the good points George makes,
>> and as someone pointed out a while back on one of these lists, you will
>> only find a "BOTH" position on a fuel selector in a high wing single
engine
>> airplane.
>
>Well, it is probably not safe to use the words "always", "never", and
>"only" when describing systems. As I pointed out earlier, both the
>Nanchang CJ6A and Yak-52 are low-wing aircraft that have only an on/off
>fuel selector at the firewall. There is no way on either of these
>aircraft to select a left or right tank. They are always on "both".
>
>Brian Lloyd
glen matejcek
aerobubba(at)earthlink.net
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Whelen Strobes Blowing Fuses |
>Gang,
>I've got a problem with my Whelen strobe system blowing a 10 amp fuse.
>
>I'm using a 10 amp mini-blade fuse which is blowing intermittently. The
>kit manufacturer as per the instructions, recommends a 10 amp fuse, but of
>course they allude to a 10 amp aircraft style reset-able fuse. I can seem
>to get the fuse to blow fairly regularly if I turn the strobes on and off
>in quick succession. The fuse will blow less reliably if I turn the
>strobes on prior to takeoff and just leave them on.
>
>My questions are these: Would there be any difference in a 10 amp blade
>fuse vs. the mechanical breaker style fuse as prescribed by the
>manufacturer? And the other question is is there such thing as a slow-blow m
How old is this system? Is this a "new" phenomenon that's
popped up after a period of satisfactory operation or has
it existed from square-one? Have you placed an ammeter in
series with the supply line to measure the system's current
draw? You need an analog meter to get some notion of minimum
and maximum current between firings. Which strobe system is it?
>ini blade style fuse and could this possibly make a difference? And
>finally perhaps there is something more insidious at work here?
Fuses are faster to respond than most breakers. It could
be that your strobes are drawing an average well below
the 10A rating of the fuse but hit it repeatedly with
levels that exceed 10A and degrade the fuse over a period
of time.
The real definitive measurement would be to put a data acquisition
system on it and watch it for a period of time and the compare
that data with a system that performs as expected. Unfortunately,
most folks in your position don't have access to such equipment
and you're stuck with hip-shots hopefully filtered through some sense
of the physics.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Gary Casey <glcasey(at)adelphia.net> |
| Subject: | Re: Fuel Pump Switch(es) |
I might have missed some of the discussion, but the comment below
seems to be directed at the tank valving method - specifically
whether to use two separate fuel valves or one, with the
recommendation to run all the fuel through one valve. I chose to put
two valves on mine for the following reasons:
1. A single valve is a single point of failure - what if the handle
breaks off or the valve sticks? The most likely time for that to
happen is when one port is being closed off before the other opens
(apparently most or all fuel selectors go to "off" between right and
left positions). If it jams in this position all fuel is shut off.
My on-off valves are completely independent and controlled from their
own lever and cable. If one jams either open or shut the other is
unaffected.
2. The fuel can be shut off at the tank, not in the middle of the
cockpit. When both valves are shut off no fuel can enter the
cockpit, which would be reassuring in case of an off-airport landing.
3. It reduces the number of fuel fittings and therefore the number
of potential leak paths, especially in the cockpit.
4. It allows the backup electric pump to be placed at the lowest
point in the fuel system which should provide the best protection
against vapor lock.
5. When switching tanks the new tank can be turned on before the old
tank is shut off, guaranteeing a continuous flow of fuel.
6. A trivial one: If the plane is landed with an unbalanced fuel
load, both valves can be left on, equalizing the fuel load before the
next flight.
The disadvantage is that both valves could be inadvertently turned
on, which on a low-wing plane means that if one tank is run dry in
that condition the engine could draw air. In that case one fuel gage
would read empty and changing the fuel valve positions (shutting off
the empty tank) would correct the condition. Interestingly, my DAR
was skeptical about the arrangement, but was satisfied by the
placement of a placard "continuous operation on both tanks
prohibited." Conversely, my test pilot like the arrangement, saying
that for at least the first half tank the engine could be operated on
both, keeping the fuel load balanced (well, anyone that has had a
Cardinal would not be convinced that would happen). Why do high-wing
planes often have a "both" position? Probably because the fuel is
joined together at the bottom of the plane, several feet below the
tanks. One tank would have to run dry with the other pulling enough
vacuum to overcome maybe 4 feet of head pressure - very unlikely. A
low wing plane has nowhere to connect the tanks together except
essentially even with the bottom of the tanks. When one runs dry air
would immediately enter the engine.
Just my nickel's worth (inflation, you know)
Gary Casey
On Sep 11, 2006, at 11:55 PM, AeroElectric-List Digest Server wrote:
> George- "... an on/off valve on each
> tank introduces problems and complexity..."
>
> Boy, am I glad you wrote that! I completely missed the part about
> independent fuel valves. Kevin, besides all the good points George
> makes,
> and as someone pointed out a while back on one of these lists, you
> will
> only find a "BOTH" position on a fuel selector in a high wing
> single engine
> airplane. The low wing planes have left, right, and off. With a
> high wing
> plane, you will sometimes see quite an imbalance develop when
> drawing fuel
> from both tanks simultaneously, even with the head pressure caused
> by the
> tank location. This effect could be much greater in a low wing
> installation. If you had the ability to have both tanks plumbed to
> the
> engine at the same time, when one tank emptied you could suck air
> into the
> system. Obviously, this would not be good. I would definitely
> recommend
> against two fuel valves.
>
> Sorry for not catching that sooner-
>
> glen matejcek
________________________________________________________________________________
| Subject: | Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Not switching the valve is also one of the advantages of the fuel pumps
in the wingroot method. In this case the lines are simply joined
together in a tee fitting before going to the on /off valve.
In this installation the valve is only turned off in the event of an
emergency, never in normal operation.
True there is pressurised fuel in the lines in the cockpit...Hopefully
in an off field landing one would remember to turn off the pumps.
With dead (roller vane FI pumps) pumps the amount of fuel that could
trickle through under gravity would be very small, certainly less than
the standard arrangement.
Incidently my FAA inspector looked very skeptical for a few minutes. Not
surpring this guy had built like 5 RV's and this was very different.
Thought my "goose was cooked" for a moment but he signed it off once he
understood the system.
Frank
________________________________
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Gary
Casey
Sent: Tuesday, September 12, 2006 7:16 AM
Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
I might have missed some of the discussion, but the comment below seems
to be directed at the tank valving method - specifically whether to use
two separate fuel valves or one, with the recommendation to run all the
fuel through one valve. I chose to put two valves on mine for the
following reasons:
1. A single valve is a single point of failure - what if the handle
breaks off or the valve sticks? The most likely time for that to happen
is when one port is being closed off before the other opens (apparently
most or all fuel selectors go to "off" between right and left
positions). If it jams in this position all fuel is shut off. My
on-off valves are completely independent and controlled from their own
lever and cable. If one jams either open or shut the other is
unaffected.
2. The fuel can be shut off at the tank, not in the middle of the
cockpit. When both valves are shut off no fuel can enter the cockpit,
which would be reassuring in case of an off-airport landing.
3. It reduces the number of fuel fittings and therefore the number of
potential leak paths, especially in the cockpit.
4. It allows the backup electric pump to be placed at the lowest point
in the fuel system which should provide the best protection against
vapor lock.
5. When switching tanks the new tank can be turned on before the old
tank is shut off, guaranteeing a continuous flow of fuel.
6. A trivial one: If the plane is landed with an unbalanced fuel load,
both valves can be left on, equalizing the fuel load before the next
flight.
________________________________________________________________________________
| From: | "Peter Braswell" <pbraswell(at)alterthought.com> |
| Subject: | Whelen Strobes Blowing Fuses |
Bob et. al. -
No, this is a brand new install/system and has been exhibiting this behavior
from almost day 1.
I do have an inline amp meter that I can hook up in an attempt to see what
kind of current draw I'm actually getting. I agree with you guys that this
and looking for obvious "bad" things (bad switch, bad/faulty connections) is
probably the place to start.
And yes, you are right Bob, no fancy-smancy equipment in my toolshed as you
suggested :-)
Thanks!
Peter
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Tuesday, September 12, 2006 8:49 AM
Subject: Re: AeroElectric-List: Whelen Strobes Blowing Fuses
-->
>Gang,
>I've got a problem with my Whelen strobe system blowing a 10 amp fuse.
>
>I'm using a 10 amp mini-blade fuse which is blowing intermittently.
>The kit manufacturer as per the instructions, recommends a 10 amp fuse,
>but of course they allude to a 10 amp aircraft style reset-able fuse.
>I can seem to get the fuse to blow fairly regularly if I turn the
>strobes on and off in quick succession. The fuse will blow less
>reliably if I turn the strobes on prior to takeoff and just leave them on.
>
>My questions are these: Would there be any difference in a 10 amp blade
>fuse vs. the mechanical breaker style fuse as prescribed by the
>manufacturer? And the other question is is there such thing as a
>slow-blow m
How old is this system? Is this a "new" phenomenon that's
popped up after a period of satisfactory operation or has
it existed from square-one? Have you placed an ammeter in
series with the supply line to measure the system's current
draw? You need an analog meter to get some notion of minimum
and maximum current between firings. Which strobe system is it?
>ini blade style fuse and could this possibly make a difference? And
>finally perhaps there is something more insidious at work here?
Fuses are faster to respond than most breakers. It could
be that your strobes are drawing an average well below
the 10A rating of the fuse but hit it repeatedly with
levels that exceed 10A and degrade the fuse over a period
of time.
The real definitive measurement would be to put a data acquisition
system on it and watch it for a period of time and the compare
that data with a system that performs as expected. Unfortunately,
most folks in your position don't have access to such equipment
and you're stuck with hip-shots hopefully filtered through some sense
of the physics.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| Subject: | Whelen Strobes Blowing Fuses |
| From: | "Matt Prather" <mprather(at)spro.net> |
Is the mini blade fuse smaller than the regular ATC fuse (for which b and
c sells holders)?
Many amp meters are limited to 10A. If the trouble you are having is
blowing a 10A fuse, likely the circuit is drawing more than 10A. Be a
little careful here with the meter, though it's also likely fuse
protected.
As Bob has mentioned in the past, an analog meter often has faster
response time than many Digital MultiMeters (DMM). The quicker response
time can help in observing transient behavior in a circuit. It may be
quite a bit ea$ier to get an analog ammeter than it would be to get a more
sophisticated data acquistion system.
Dumb question: Is there anything else wired on the same 10A fuse circuit
(even though maybe it's turned off)?
If a device has much input capacitance (power supply caps), turning the
device on can cause a significant above-steady-state current draw - to
charge the caps. Power cycling the device repeatedly can generate higher
average current.
Regards,
Matt-
>
>
>
> Bob et. al. -
> No, this is a brand new install/system and has been exhibiting this
> behavior
> from almost day 1.
>
> I do have an inline amp meter that I can hook up in an attempt to see what
> kind of current draw I'm actually getting. I agree with you guys that
> this
> and looking for obvious "bad" things (bad switch, bad/faulty connections)
> is
> probably the place to start.
>
> And yes, you are right Bob, no fancy-smancy equipment in my toolshed as
> you
> suggested :-)
>
> Thanks!
> Peter
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert
> L.
> Nuckolls, III
> Sent: Tuesday, September 12, 2006 8:49 AM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Whelen Strobes Blowing Fuses
>
> -->
>
>
>>Gang,
>>I've got a problem with my Whelen strobe system blowing a 10 amp fuse.
>>
>>I'm using a 10 amp mini-blade fuse which is blowing intermittently.
>>The kit manufacturer as per the instructions, recommends a 10 amp fuse,
>>but of course they allude to a 10 amp aircraft style reset-able fuse.
>>I can seem to get the fuse to blow fairly regularly if I turn the
>>strobes on and off in quick succession. The fuse will blow less
>>reliably if I turn the strobes on prior to takeoff and just leave them
>> on.
>>
>>My questions are these: Would there be any difference in a 10 amp blade
>>fuse vs. the mechanical breaker style fuse as prescribed by the
>>manufacturer? And the other question is is there such thing as a
>>slow-blow m
>
> How old is this system? Is this a "new" phenomenon that's
> popped up after a period of satisfactory operation or has
> it existed from square-one? Have you placed an ammeter in
> series with the supply line to measure the system's current
> draw? You need an analog meter to get some notion of minimum
> and maximum current between firings. Which strobe system is it?
>
>>ini blade style fuse and could this possibly make a difference? And
>>finally perhaps there is something more insidious at work here?
>
> Fuses are faster to respond than most breakers. It could
> be that your strobes are drawing an average well below
> the 10A rating of the fuse but hit it repeatedly with
> levels that exceed 10A and degrade the fuse over a period
> of time.
>
> The real definitive measurement would be to put a data acquisition
> system on it and watch it for a period of time and the compare
> that data with a system that performs as expected. Unfortunately,
> most folks in your position don't have access to such equipment
> and you're stuck with hip-shots hopefully filtered through some sense
> of the physics.
>
> Bob . . .
>
>
> ---------------------------------------------------------
> < What is so wonderful about scientific truth...is that >
> < the authority which determines whether there can be >
> < debate or not does not reside in some fraternity of >
> < scientists; nor is it divine. The authority rests >
> < with experiment. >
> < --Lawrence M. Krauss >
> ---------------------------------------------------------
>
>
________________________________________________________________________________
| From: | "Peter Braswell" <pbraswell(at)alterthought.com> |
| Subject: | Whelen Strobes Blowing Fuses |
Matt,
Thank you very much for the input.
I probably need to offer a amendment/correction to my earlier post, prompted
by one of your questions. I perhaps may have mis-named what I'm using. I
AM using a 10a ATC fuse. I purchased an assorted tray of them from Stein
Air. Sorry for the confusion.
Also, I do not have anything else on that circuit. I tried very hard (and
succeeded) to have one device/one fuse.
Peter
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Matt
Prather
Sent: Tuesday, September 12, 2006 11:49 AM
Subject: RE: AeroElectric-List: Whelen Strobes Blowing Fuses
-->
Is the mini blade fuse smaller than the regular ATC fuse (for which b and c
sells holders)?
Many amp meters are limited to 10A. If the trouble you are having is
blowing a 10A fuse, likely the circuit is drawing more than 10A. Be a
little careful here with the meter, though it's also likely fuse protected.
As Bob has mentioned in the past, an analog meter often has faster response
time than many Digital MultiMeters (DMM). The quicker response time can
help in observing transient behavior in a circuit. It may be quite a bit
ea$ier to get an analog ammeter than it would be to get a more sophisticated
data acquistion system.
Dumb question: Is there anything else wired on the same 10A fuse circuit
(even though maybe it's turned off)?
If a device has much input capacitance (power supply caps), turning the
device on can cause a significant above-steady-state current draw - to
charge the caps. Power cycling the device repeatedly can generate higher
average current.
Regards,
Matt-
>
>
>
> Bob et. al. -
> No, this is a brand new install/system and has been exhibiting this
> behavior from almost day 1.
>
> I do have an inline amp meter that I can hook up in an attempt to see
> what kind of current draw I'm actually getting. I agree with you guys
> that this and looking for obvious "bad" things (bad switch, bad/faulty
> connections) is probably the place to start.
>
> And yes, you are right Bob, no fancy-smancy equipment in my toolshed
> as you suggested :-)
>
> Thanks!
> Peter
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Robert L.
> Nuckolls, III
> Sent: Tuesday, September 12, 2006 8:49 AM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Whelen Strobes Blowing Fuses
>
> -->
>
>
>>Gang,
>>I've got a problem with my Whelen strobe system blowing a 10 amp fuse.
>>
>>I'm using a 10 amp mini-blade fuse which is blowing intermittently.
>>The kit manufacturer as per the instructions, recommends a 10 amp
>>fuse, but of course they allude to a 10 amp aircraft style reset-able
fuse.
>>I can seem to get the fuse to blow fairly regularly if I turn the
>>strobes on and off in quick succession. The fuse will blow less
>>reliably if I turn the strobes on prior to takeoff and just leave them
>>on.
>>
>>My questions are these: Would there be any difference in a 10 amp
>>blade fuse vs. the mechanical breaker style fuse as prescribed by the
>>manufacturer? And the other question is is there such thing as a
>>slow-blow m
>
> How old is this system? Is this a "new" phenomenon that's
> popped up after a period of satisfactory operation or has
> it existed from square-one? Have you placed an ammeter in
> series with the supply line to measure the system's current
> draw? You need an analog meter to get some notion of minimum
> and maximum current between firings. Which strobe system is it?
>
>>ini blade style fuse and could this possibly make a difference? And
>>finally perhaps there is something more insidious at work here?
>
> Fuses are faster to respond than most breakers. It could
> be that your strobes are drawing an average well below
> the 10A rating of the fuse but hit it repeatedly with
> levels that exceed 10A and degrade the fuse over a period
> of time.
>
> The real definitive measurement would be to put a data acquisition
> system on it and watch it for a period of time and the compare
> that data with a system that performs as expected. Unfortunately,
> most folks in your position don't have access to such equipment
> and you're stuck with hip-shots hopefully filtered through some sense
> of the physics.
>
> Bob . . .
>
>
> ---------------------------------------------------------
> < What is so wonderful about scientific truth...is that >
> < the authority which determines whether there can be >
> < debate or not does not reside in some fraternity of >
> < scientists; nor is it divine. The authority rests >
> < with experiment. >
> < --Lawrence M. Krauss >
> ---------------------------------------------------------
>
>
________________________________________________________________________________
| From: | "John Burnaby" <jonlaury(at)impulse.net> |
| Subject: | Re: Fuel Pump Switch(es)Fuel Pump Switch(es)Fuel Pump |
Switch(es)
My $.02.
Electrically dependent planes with two pumps need a dedicated switch for
each pump drawing from independent power sources.
FWIW, I am using an EFI on my 6cyl Franklin in a Glasair TD and have
spent a lot of hours thinking about my fuel system. As fuel starvation
seems to be the most common cause of engine stoppage, and that my 58
year old ADD noggin sometimes trys to kill me, I wanted a system that
was as idiot proof as possible. That meant not having to remember to
switch tanks, that all fuel in the system goes to the intake of the
pumps no matter what I do. All I have to remember is to turn on the
pump(s) when I start the engine. I have a fool proof reminder to do
that, when the engine won't start.
Fuel from my split tanks flows through one way umbrella valves to a
common sump,on the bottom of the wing and at the low point of the fuel
system. A header tank is also plumbed to the sump. All recirculated fuel
goes back to the header with an internal overflow well that will dump
the overflow back to the mains. Both pumps, (separate switches, to two
batteries), pointed aft, draw from the common sump. There is no R-L
selector valve, no shut off valve, as the Bosch aerotor pumps, each with
a built in check valve, do not flow fuel without power and the fuel
filter on the FW is higher than the sump . If I don't want fuel to flow
to the engine, I turn off a switch. There is an on-off valve for the
header tank so that I can allow the header to be refilled from
recirculated fuel to use for landings and TO's (more head on the pump
intakes), however if I forget to turn this on, and the tank fills, it
will overflow back to the mains.
As long as their is fuel on board, it will flow to the pump intakes,
mental incapacitation of the pilot notwithstanding.
________________________________________________________________________________
| From: | "james wickert" <jimw_btg(at)earthlink.net> |
| Subject: | Whelen Strobes Blowing Fuses |
Food for thought a full strobe system can draw from 7 A for the Whelen
A413A HDA-CF at 14 Volts to as low as 1.7A with the A409ATS CF at 14 volts.
If you have a 7A operating unit when you turn it on it could I believe when
loading up the capacitors to fire the 4kv trigger coil and provide the 250v
anode to cathode current....I am not sure if it would surge the load to
over 10 Amps?
Jim Wickert
Vision CorvAir #159
> [Original Message]
> From: Peter Braswell <pbraswell(at)alterthought.com>
> To:
> Date: 9/12/2006 11:17:56 AM
> Subject: RE: AeroElectric-List: Whelen Strobes Blowing Fuses
>
>
>
> Matt,
> Thank you very much for the input.
>
> I probably need to offer a amendment/correction to my earlier post,
prompted
> by one of your questions. I perhaps may have mis-named what I'm using. I
> AM using a 10a ATC fuse. I purchased an assorted tray of them from Stein
> Air. Sorry for the confusion.
>
> Also, I do not have anything else on that circuit. I tried very hard (and
> succeeded) to have one device/one fuse.
>
> Peter
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Matt
> Prather
> Sent: Tuesday, September 12, 2006 11:49 AM
> To: aeroelectric-list(at)matronics.com
> Subject: RE: AeroElectric-List: Whelen Strobes Blowing Fuses
>
> -->
>
> Is the mini blade fuse smaller than the regular ATC fuse (for which b and
c
> sells holders)?
>
> Many amp meters are limited to 10A. If the trouble you are having is
> blowing a 10A fuse, likely the circuit is drawing more than 10A. Be a
> little careful here with the meter, though it's also likely fuse
protected.
>
> As Bob has mentioned in the past, an analog meter often has faster
response
> time than many Digital MultiMeters (DMM). The quicker response time can
> help in observing transient behavior in a circuit. It may be quite a bit
> ea$ier to get an analog ammeter than it would be to get a more
sophisticated
> data acquistion system.
>
> Dumb question: Is there anything else wired on the same 10A fuse circuit
> (even though maybe it's turned off)?
>
> If a device has much input capacitance (power supply caps), turning the
> device on can cause a significant above-steady-state current draw - to
> charge the caps. Power cycling the device repeatedly can generate higher
> average current.
>
>
> Regards,
>
> Matt-
>
> >
> >
> >
> > Bob et. al. -
> > No, this is a brand new install/system and has been exhibiting this
> > behavior from almost day 1.
> >
> > I do have an inline amp meter that I can hook up in an attempt to see
> > what kind of current draw I'm actually getting. I agree with you guys
> > that this and looking for obvious "bad" things (bad switch, bad/faulty
> > connections) is probably the place to start.
> >
> > And yes, you are right Bob, no fancy-smancy equipment in my toolshed
> > as you suggested :-)
> >
> > Thanks!
> > Peter
> >
> > -----Original Message-----
> > From: owner-aeroelectric-list-server(at)matronics.com
> > [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> > Robert L.
> > Nuckolls, III
> > Sent: Tuesday, September 12, 2006 8:49 AM
> > To: aeroelectric-list(at)matronics.com
> > Subject: Re: AeroElectric-List: Whelen Strobes Blowing Fuses
> >
> > -->
> >
> >
> >>Gang,
> >>I've got a problem with my Whelen strobe system blowing a 10 amp fuse.
> >>
> >>I'm using a 10 amp mini-blade fuse which is blowing intermittently.
> >>The kit manufacturer as per the instructions, recommends a 10 amp
> >>fuse, but of course they allude to a 10 amp aircraft style reset-able
> fuse.
> >>I can seem to get the fuse to blow fairly regularly if I turn the
> >>strobes on and off in quick succession. The fuse will blow less
> >>reliably if I turn the strobes on prior to takeoff and just leave them
> >>on.
> >>
> >>My questions are these: Would there be any difference in a 10 amp
> >>blade fuse vs. the mechanical breaker style fuse as prescribed by the
> >>manufacturer? And the other question is is there such thing as a
> >>slow-blow m
> >
> > How old is this system? Is this a "new" phenomenon that's
> > popped up after a period of satisfactory operation or has
> > it existed from square-one? Have you placed an ammeter in
> > series with the supply line to measure the system's current
> > draw? You need an analog meter to get some notion of minimum
> > and maximum current between firings. Which strobe system is it?
> >
> >>ini blade style fuse and could this possibly make a difference? And
> >>finally perhaps there is something more insidious at work here?
> >
> > Fuses are faster to respond than most breakers. It could
> > be that your strobes are drawing an average well below
> > the 10A rating of the fuse but hit it repeatedly with
> > levels that exceed 10A and degrade the fuse over a period
> > of time.
> >
> > The real definitive measurement would be to put a data acquisition
> > system on it and watch it for a period of time and the compare
> > that data with a system that performs as expected. Unfortunately,
> > most folks in your position don't have access to such equipment
> > and you're stuck with hip-shots hopefully filtered through some
sense
> > of the physics.
> >
> > Bob . . .
> >
> >
> > ---------------------------------------------------------
> > < What is so wonderful about scientific truth...is that >
> > < the authority which determines whether there can be >
> > < debate or not does not reside in some fraternity of >
> > < scientists; nor is it divine. The authority rests >
> > < with experiment. >
> > < --Lawrence M. Krauss >
> > ---------------------------------------------------------
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
>
________________________________________________________________________________
| Subject: | Re: Alternator Problem - Not in plane |
FLYaDIVE(at)aol.com wrote:
>
> In a message dated 9/9/06 10:54:08 AM Eastern Daylight Time,
> ceengland(at)bellsouth.net writes:
>
> > If they came off small cars, they might not be rated for that much
> > current & unable to maintain voltage if you demand excess current.
> >
> > Another thought: are they internally or externally regulated? If
> > external & you're using a regulator built into the test set, are you
> > sure the test set regulator is set correctly and are you sure the test
> > set voltmeter is accurate? Getting the same volt reading for all using
> > one test set & a different, same volt reading for all on another test
> > set seems to point at the test sets.
> ====================================
> Charlie:
>
> The rated amperage of the alternator is 90 Amps.
> Normal draw is about 15 Amps.
> It is internally regulated.
> The test benches are at automotive parts stores and rebuilding shops.
> At both locations, on all 4 alternators the output was 10.5 V.
>
> This is a crazy problem. It is not a simple problem. I know there is
> someone out there with the knowledge and past experience of this situation.
If is
> was simple I would have solved it months ago. NO ONE has been able to identify
> the problem. Not even Hyundai or Bosch. And it is their alternator's!
>
>
> Barry
> "Chop'd Liver"
>
Hi Barry,
I've been thinking about your alternator problem. I wonder if it could
be as simple as having a bit of series resistance between the
alternator and the voltmeter. At 90 amps, you only need 0.04 to 0.05
ohms to see that kind of voltage drop. Test equipment I've seen at
parts stores have a big clips to connect to the alternator and I could
easily imagine having that much resistance in the connections.
Particularly with 90 amps running through them. The fact that the
voltage varied from 10.5 V to 12.2 V with a different tester is an
indication of that kind of problem. (Or the voltmeters aren't very
accurate.)
If possible, try the test with a voltmeter connected directly to the B
lead and alternator case so that none of the test current is flowing in
the leads to the voltmeter.
Bob W.
--
http://www.bob-white.com
N93BD - Rotary Powered BD-4 (first engine start 1/7/06)
Custom Cables for your rotary installation -
http://www.roblinphoto.com/shop/
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Whelen Strobes Blowing Fuses |
>
>
>
>Matt,
>Thank you very much for the input.
>
>I probably need to offer a amendment/correction to my earlier post, prompted
>by one of your questions. I perhaps may have mis-named what I'm using. I
>AM using a 10a ATC fuse. I purchased an assorted tray of them from Stein
>Air. Sorry for the confusion.
>
>Also, I do not have anything else on that circuit. I tried very hard (and
>succeeded) to have one device/one fuse.
>
>Peter
Okay. Just for grins, put a 15A fuse in and see what happens.
15A is not so much greater as to put the wire in danger. I presume
the strobe is running normally when the fuse is not blown. The
15A fuse experiment will help us put a crude bound on the
incoming current and at least show that it's not a transient
hard fault which will blow the 15A fuse too
Bob . . .
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Re: Fuel Pump Switch(es) |
On 12 Sep 2006, at 10:15, Gary Casey wrote:
> I might have missed some of the discussion, but the comment below
> seems to be directed at the tank valving method - specifically
> whether to use two separate fuel valves or one, with the
> recommendation to run all the fuel through one valve. I chose to
> put two valves on mine for the following reasons:
>
> 1. A single valve is a single point of failure - what if the
> handle breaks off or the valve sticks? The most likely time for
> that to happen is when one port is being closed off before the
> other opens (apparently most or all fuel selectors go to "off"
> between right and left positions). If it jams in this position all
> fuel is shut off. My on-off valves are completely independent and
> controlled from their own lever and cable. If one jams either open
> or shut the other is unaffected.
> 2. The fuel can be shut off at the tank, not in the middle of the
> cockpit. When both valves are shut off no fuel can enter the
> cockpit, which would be reassuring in case of an off-airport landing.
> 3. It reduces the number of fuel fittings and therefore the number
> of potential leak paths, especially in the cockpit.
> 4. It allows the backup electric pump to be placed at the lowest
> point in the fuel system which should provide the best protection
> against vapor lock.
> 5. When switching tanks the new tank can be turned on before the
> old tank is shut off, guaranteeing a continuous flow of fuel.
> 6. A trivial one: If the plane is landed with an unbalanced fuel
> load, both valves can be left on, equalizing the fuel load before
> the next flight.
>
> The disadvantage is that both valves could be inadvertently turned
> on, which on a low-wing plane means that if one tank is run dry in
> that condition the engine could draw air. In that case one fuel
> gage would read empty and changing the fuel valve positions
> (shutting off the empty tank) would correct the condition.
> Interestingly, my DAR was skeptical about the arrangement, but was
> satisfied by the placement of a placard "continuous operation on
> both tanks prohibited." Conversely, my test pilot like the
> arrangement, saying that for at least the first half tank the
> engine could be operated on both, keeping the fuel load balanced
> (well, anyone that has had a Cardinal would not be convinced that
> would happen). Why do high-wing planes often have a "both"
> position? Probably because the fuel is joined together at the
> bottom of the plane, several feet below the tanks. One tank would
> have to run dry with the other pulling enough vacuum to overcome
> maybe 4 feet of head pressure - very unlikely. A low wing plane
> has nowhere to connect the tanks together except essentially even
> with the bottom of the tanks. When one runs dry air would
> immediately enter the engine.
You are worried about fuel valve handles breaking. With your design,
what happens if you have run one tank down low, want to switch to the
other tank, and the valve handle on the tank that is feeding breaks
so you can't close that valve? Won't the engine quit once that tank
is empty and the engine starts sucking air? How is this better than
a valve handle failure with the normal design?
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| From: | "Peter Braswell" <pbraswell(at)alterthought.com> |
| Subject: | Whelen Strobes Blowing Fuses |
Bob,
Easy enough to do! I'll give it a whirl and see what happens. And to
answer your question, yes the strobe work fine when it is working.
Thanks!
Peter
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Tuesday, September 12, 2006 9:11 PM
Subject: RE: AeroElectric-List: Whelen Strobes Blowing Fuses
-->
>
>
>
>Matt,
>Thank you very much for the input.
>
>I probably need to offer a amendment/correction to my earlier post,
>prompted by one of your questions. I perhaps may have mis-named what
>I'm using. I AM using a 10a ATC fuse. I purchased an assorted tray of
>them from Stein Air. Sorry for the confusion.
>
>Also, I do not have anything else on that circuit. I tried very hard
>(and
>succeeded) to have one device/one fuse.
>
>Peter
Okay. Just for grins, put a 15A fuse in and see what happens.
15A is not so much greater as to put the wire in danger. I presume
the strobe is running normally when the fuse is not blown. The
15A fuse experiment will help us put a crude bound on the
incoming current and at least show that it's not a transient
hard fault which will blow the 15A fuse too
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Whelen Strobes Blowing Fuses |
>
>Is the mini blade fuse smaller than the regular ATC fuse (for which b and
>c sells holders)?
Interesting question. If he WAS using the ATM "mini" fuses, would
we expect it to be twitchy compared to it's larger brother. I uploaded
the spec sheets to:
http://www.aeroelectric.com/Mfgr_Data/Fuses_and_Current_Limiters/Bussman/ATC_Specs.pdf
and
http://www.aeroelectric.com/Mfgr_Data/Fuses_and_Current_Limiters/Bussman/ATC_Specs.pdf
I note that the "little guys" spec the same
headroom (ATM-3 ATC-3 fuses both go asymtotic
at 4A). At 10A, the ATM-3 average blow is about 140 mS
and the ATC-3 is 80 mS. I don't know if you were thinking
the same thing I was but in any case, it's interesting
to note that the smaller fuse has a bit more
thermo-dynamic mass than big brother. Who wuda thunk it?
>As Bob has mentioned in the past, an analog meter often has faster
>response time than many Digital MultiMeters (DMM). The quicker response
>time can help in observing transient behavior in a circuit. It may be
>quite a bit ea$ier to get an analog ammeter than it would be to get a more
>sophisticated data acquistion system.
One of the reasons I keep analog meters around is to
watch trends/dynamics of the parameter being observed.
A digital meter is difficult to get a sense of min/max,
duty cycle (stays high longer than low) and frequency.
Digitals may be giving be perfectly accurate data for each
time they take a reading (typically 1 to 4 times per second)
but one cannot deduce the behaviors cited from what appears
to be a dancing set of random numbers.
Many digital meters have a bar graph built in under the
digits but it's hard to beat the black pointer waving
across a white scale to get a sense of "the beat".
Bob . . .
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
| Subject: | Re: Glowing Warning Lights |
After studying the schematic (I'm a little slow with this stuff), it appears
that the resistors can be installed at the regulator, one across terminals 3
and 5, and the other in series from the wire running from terminal 5 to the
LED. I'm assuming some heat will be generated by the resistors and
installing them at the regular would work better for me with cooling.
One other question, why not use a relay? I understand the added complexity
issue, but that would give you a dark LED without sacrificing any brightness
when it's illuminated. Right? Any part number recommendations would be
appreciated.
Mike Easley
Colorado Springs
Lancair ES
________________________________________________________________________________
| From: | Gary Casey <glcasey(at)adelphia.net> |
| Subject: | Re: Fuel Pump Switch(es) |
Yes, there are still a number of failure modes that could create a
problem, even with two independent fuel valves. In the case
mentioned below, the low tank valve breaks and won't shut off. In
that case the (presumably fuller) tank could be turned on, feeding
fuel from both tanks and the plane landed at the earliest
convenience. The fuller tank would probably back-feed into the lower
tank, extending the range compared to just feeding off the lowest
tank, depending on the level of fuel in the fuller tank. In any
event one has to assume there is only the fuel left in the lowest
tank. If the valve for the "new" tank failed to open (broke in the
closed position) the response is simple - land before the low tank
goes empty. Not a perfect condition, but there are still options
available that might not be available with a single valve. If a
single valve broke in the "low" tank position fuel in the fuller tank
is completely unavailable. If it sticks and breaks between tanks
(what I think is a more likely failure) neither tank is available and
the engine quits right away. The normal operating procedure with two
valves is to open the valve for the new tank, confirming that it
actually moved, and then shutting off the valve from the old tank.
Never shut the old one off before turning the new one on. Also, I
know that there have been some postings advocating, or at least
acknowledging, running a tank dry as a routine operating mode. I
suppose if there were more than two tanks this isn't so bad, but with
only two tanks doing that gives up one of the redundancies in the
system - two independent sources of fuel. I personally don't like
the idea of running a tank dry. My own standard is to never run
either tank lower than what is required to get to the nearest
airport. FWIW.
Gary Casey
Lancair ES
On Sep 12, 2006, at 11:55 PM, AeroElectric-List Digest Server wrote:
>
> You are worried about fuel valve handles breaking. With your design,
> what happens if you have run one tank down low, want to switch to the
> other tank, and the valve handle on the tank that is feeding breaks
> so you can't close that valve? Won't the engine quit once that tank
> is empty and the engine starts sucking air? How is this better than
> a valve handle failure with the normal design?
>
> Kevin Horton RV-8 (finishing kit)
> Ottawa, Canada
________________________________________________________________________________
| From: | "gordon or marge" <gcomfo(at)tc3net.com> |
| Subject: | Fuel Pump Switch(es) |
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Gary
Casey
Sent: Tuesday, September 12, 2006 9:16 AM
Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
I might have missed some of the discussion, but the comment below seems
to
be directed at the tank valving method - specifically whether to use two
separate fuel valves or one, with the recommendation to run all the fuel
through one valve. I chose to put two valves on mine for the following
reasons:
1. A single valve is a single point of failure - what if the handle
breaks
off or the valve sticks? The most likely time for that to happen is
when
one port is being closed off before the other opens (apparently most or
all
fuel selectors go to "off" between right and left positions). If it
jams in
this position all fuel is shut off. My on-off valves are completely
independent and controlled from their own lever and cable. If one jams
either open or shut the other is unaffected.
2. The fuel can be shut off at the tank, not in the middle of the
cockpit.
When both valves are shut off no fuel can enter the cockpit, which would
be
reassuring in case of an off-airport landing.
3. It reduces the number of fuel fittings and therefore the number of
potential leak paths, especially in the cockpit.
4. It allows the backup electric pump to be placed at the lowest point
in
the fuel system which should provide the best protection against vapor
lock.
5. When switching tanks the new tank can be turned on before the old
tank
is shut off, guaranteeing a continuous flow of fuel.
6. A trivial one: If the plane is landed with an unbalanced fuel load,
both valves can be left on, equalizing the fuel load before the next
flight.
The disadvantage is that both valves could be inadvertently turned on,
which
on a low-wing plane means that if one tank is run dry in that condition
the
engine could draw air. In that case one fuel gage would read empty and
changing the fuel valve positions (shutting off the empty tank) would
correct the condition. Interestingly, my DAR was skeptical about the
arrangement, but was satisfied by the placement of a placard "continuous
operation on both tanks prohibited." Conversely, my test pilot like the
arrangement, saying that for at least the first half tank the engine
could
be operated on both, keeping the fuel load balanced (well, anyone that
has
had a Cardinal would not be convinced that would happen). Why do
high-wing
planes often have a "both" position? Probably because the fuel is
joined
together at the bottom of the plane, several feet below the tanks. One
tank
would have to run dry with the other pulling enough vacuum to overcome
maybe
4 feet of head pressure - very unlikely. A low wing plane has nowhere
to
connect the tanks together except essentially even with the bottom of
the
tanks. When one runs dry air would immediately enter the engine.
Just my nickel's worth (inflation, you know)
Gary Casey
Gary: With regard to your point 1); Anything is posssible but a Cessna
valve (large single engine) uses a cam to lift check balls from their
seats.
Unlikely to seize. Point 2); good. Point 3); I count the same number
of
fittings. Point 4); Not sure. My -4 pump is not at the low point and
there has been no trouble. My -8 will have a Weldon pump which has good
suction capabilities. Point 5); The plane would have to be level and
such
an act would obscure your knowledge of fuel used from each tank. I
prefer
to know that if, for example, if I've used an hour of fuel from a tank
that
it stays that way. As to operating on both for the initial part of the
flight, my experience with the -4 is that when operating in a "both"
position one tank will deliver fuel to the other and if it becomes full
the
surplus goes overboard. At this point we reallly don't know our fuel
state.
The only airplane I've flown with 2 shutoff valves is a Fairchild 24 and
we
did not fly with both valves open although I never experimented with
both on
so don't really know what implications there might be.
These are good discussions about non trivial matters. A look at the
early
Venture fuel system is enough to give you the willies.
Gordon Comfort
N363GC
________________________________________________________________________________
| From: | "Bill Denton" <bdenton(at)bdenton.com> |
| Subject: | Fuel Pump Switch(es) |
Just an observation...
While you're sitting there with your head down troubleshooting valves and
breaking the handles off and flipping switches until they fall out of the
panel, you may well end up sticking your airplane in the ground.
I know that it is sometimes necessary to have multiple tanks, valves, and
pumps to manage complex fuel systems. But some of what I've been reading on
this thread sounds like it's coming from graduates of the Rube Goldberg
School of Engineering...
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Gary Casey
Sent: Wednesday, September 13, 2006 7:51 AM
Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
Yes, there are still a number of failure modes that could create a problem,
even with two independent fuel valves. In the case mentioned below, the low
tank valve breaks and won't shut off. In that case the (presumably fuller)
tank could be turned on, feeding fuel from both tanks and the plane landed
at the earliest convenience. The fuller tank would probably back-feed into
the lower tank, extending the range compared to just feeding off the lowest
tank, depending on the level of fuel in the fuller tank. In any event one
has to assume there is only the fuel left in the lowest tank. If the valve
for the "new" tank failed to open (broke in the closed position) the
response is simple - land before the low tank goes empty. Not a perfect
condition, but there are still options available that might not be available
with a single valve. If a single valve broke in the "low" tank position
fuel in the fuller tank is completely unavailable. If it sticks and breaks
between tanks (what I think is a more likely failure) neither tank is
available and the engine quits right away. The normal operating procedure
with two valves is to open the valve for the new tank, confirming that it
actually moved, and then shutting off the valve from the old tank. Never
shut the old one off before turning the new one on. Also, I know that there
have been some postings advocating, or at least acknowledging, running a
tank dry as a routine operating mode. I suppose if there were more than two
tanks this isn't so bad, but with only two tanks doing that gives up one of
the redundancies in the system - two independent sources of fuel. I
personally don't like the idea of running a tank dry. My own standard is to
never run either tank lower than what is required to get to the nearest
airport. FWIW.
Gary Casey
Lancair ES
On Sep 12, 2006, at 11:55 PM, AeroElectric-List Digest Server wrote:
You are worried about fuel valve handles breaking. With your design,
what happens if you have run one tank down low, want to switch to the
other tank, and the valve handle on the tank that is feeding breaks
so you can't close that valve? Won't the engine quit once that tank
is empty and the engine starts sucking air? How is this better than
a valve handle failure with the normal design?
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
________________________________________________________________________________
| From: | Dave N6030X <N6030X(at)DaveMorris.com> |
| Subject: | Re: Fuel Pump Switch(es) |
I have a little different point of view that I'd like to just throw out there.
In my experimental Dragonfly, I was gripped for a long time by a
NASA-like desire to have multiple redundant systems everywhere. I'm
a software guy, so I love complicated, microprocessor-controlled
everythingies. But when I started working through the cockpit
workload part of dealing with multiple independent pumps and switches
and bypasses for everything and backup this and that, I realized that
there was a single point of failure that was getting more and more
overloaded with every new complexity: the pilot (me).
Look at the NTSB reports, and you'll see there are many more failures
of the human to throw the switch than of the switch breaking. Fuel
Starvation due to forgetting how much fuel is in the tank, not
knowing how much fuel is in the tank, forgetting to switch tanks,
taking off without adequate fuel, etc. etc. I don't remember seeing
too many "the fuel selector handle broke off between tanks". The
oldest airplanes still flying anywhere (the survivors of all our
human failures) have the simplest systems. Take a look at how they did things.
My advice, which could be worth exactly as much as you're paying for
it is this: build it light, build it high quality, and build it
simple enough that you can intuitively grasp it without schematic
diagrams and lengthy troubleshooting charts while handling an
inflight emergency. If you have requirements such as "don't ever
turn off this tank before turning on that tank", I think you're
starting to set yourself up for failure. Think Gravity Feed from a
header tank wherever possible. Instead of buying two redundant
valves and plumbing, buy one high quality valve and replace it every
2 years just for the helluvit. What's that gonna cost you? A
hundred bucks? How much weight will you save, and how much cockpit workload?
When you're doing your failure mode analysis, include a list of all
of the things the pilot has an opportunity to do wrong. We try to do
this in software development, and it's a useful exercise before you
get carried away anticipating equipment failures that are just never
going to occur. When designing software, we no longer worry about
whether there will be a bit error on the memory board, or whether the
disk drive will crash a track. But we spend a lot of time worrying
about whether the user will forget to enter a value or will enter the
wrong value. If the user (pilot) CAN do anything wrong, he
WILL. Try applying that to your aircraft design and see if you come
up with some interesting scenarios you had not thought of before.
Dave Morris
1960 Mooney M20A
Manual gear retract
3 fuel tanks - single valve
No fuel system failures in 46 years (knock on wood wing)
At 07:51 AM 9/13/2006, you wrote:
>Yes, there are still a number of failure modes that could create a
>problem, even with two independent fuel valves. In the case
>mentioned below, the low tank valve breaks and won't shut off. In
>that case the (presumably fuller) tank could be turned on, feeding
>fuel from both tanks and the plane landed at the earliest
>convenience. The fuller tank would probably back-feed into the
>lower tank, extending the range compared to just feeding off the
>lowest tank, depending on the level of fuel in the fuller tank. In
>any event one has to assume there is only the fuel left in the
>lowest tank. If the valve for the "new" tank failed to open (broke
>in the closed position) the response is simple - land before the low
>tank goes empty. Not a perfect condition, but there are still
>options available that might not be available with a single
>valve. If a single valve broke in the "low" tank position fuel in
>the fuller tank is completely unavailable. If it sticks and breaks
>between tanks (what I think is a more likely failure) neither tank
>is available and the engine quits right away. The normal operating
>procedure with two valves is to open the valve for the new tank,
>confirming that it actually moved, and then shutting off the valve
>from the old tank. Never shut the old one off before turning the
>new one on. Also, I know that there have been some postings
>advocating, or at least acknowledging, running a tank dry as a
>routine operating mode. I suppose if there were more than two tanks
>this isn't so bad, but with only two tanks doing that gives up one
>of the redundancies in the system - two independent sources of
>fuel. I personally don't like the idea of running a tank dry. My
>own standard is to never run either tank lower than what is required
>to get to the nearest airport. FWIW.
>
>Gary Casey
>Lancair ES
>On Sep 12, 2006, at 11:55 PM, AeroElectric-List Digest Server wrote:
>
>
>>
>>You are worried about fuel valve handles breaking. With your design,
>>
>>what happens if you have run one tank down low, want to switch to the
>>
>>other tank, and the valve handle on the tank that is feeding breaks
>>
>>so you can't close that valve? Won't the engine quit once that tank
>>
>>is empty and the engine starts sucking air? How is this better than
>>
>>a valve handle failure with the normal design?
>>
>>
>>Kevin Horton RV-8 (finishing kit)
>>
>>Ottawa, Canada
>
>
________________________________________________________________________________
| Subject: | Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Exactly!
And now back to the one pump in each wingroot solution....left tank
...switch left pump on...Right tank switch right pump on... Both tanks
(TO and landing).. Both switches on. Pretty simple I think.
The other advantages are...
No selector valves to switch.
Highly resistant to Vapour lock...Biggest driver to use auto fuel
SIMPLE
No single point of failure anywhere...OK the fuel line, servo and
battery is (assuming you don't have an isolated twin battery setup)
Plug a fuel filter...Who cares?
Downsides
Uses more electrical power.
Have to design the "what happens if the alternator craps out" failure
mode...I have dual alternaors...8 amp back up is just big enough for a
radio, tansponder and one fuel pump
Extra 3 feet of pressurised fuel line in the cockpit.
Frank
RV7a 4 hours
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dave
N6030X
Sent: Wednesday, September 13, 2006 6:45 AM
Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
-->
I have a little different point of view that I'd like to just throw out
there.
In my experimental Dragonfly, I was gripped for a long time by a
NASA-like desire to have multiple redundant systems everywhere. I'm a
software guy, so I love complicated, microprocessor-controlled
everythingies. But when I started working through the cockpit workload
part of dealing with multiple independent pumps and switches and
bypasses for everything and backup this and that, I realized that there
was a single point of failure that was getting more and more overloaded
with every new complexity: the pilot (me).
Look at the NTSB reports, and you'll see there are many more failures of
the human to throw the switch than of the switch breaking. Fuel
Starvation due to forgetting how much fuel is in the tank, not knowing
how much fuel is in the tank,
________________________________________________________________________________
| Subject: | What I learned today |
| From: | "RV Builder (Michael Sausen)" <rvbuilder(at)sausen.net> |
You want this to be a list of the people, so to speak, so here is my
question. Out of curiosity what is the actual percentage of requests to
ban George over the entire list membership? Is this another case of the
vocal minority winning out over the silent majority?
I for one think George, Paul, and others add value even if it is
veiled in a load of rhetoric and even BS sometimes. Some of the most
brilliant people in history had social issues. When I smell something
funny in a post I always have the option of exercising the delete key.
Honestly I spend more time deleting posts of complaints about other
people than I do of the actual people. Talk about circular arguments.
One of the problems with email has always been the way a person
interprets emotions in the writing. Most of the time people are wrong
in their assumptions so it is better to take emotion out and look for
the actual substance of a post. Less bruised egos and useless replies
that only escalate a situation that probably didn't exist in the first
place.
My $0.02
Michael Sausen
-10 #352 Fuselage
Oh yes, and unlike most of the other posts on this subject.... Do Not
Archive
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Robert L. Nuckolls, III
Sent: Wednesday, September 06, 2006 8:11 AM
Subject: AeroElectric-List: What I learned today
-->
Listers,
Folks have been bugging me about George for some time.
Over a year perhaps. They keep citing this venue as being my list and
suggested that I have full authority to manage it in whatever way I
want.
I never wanted to view this as "my list". It's always been my fondest
wish that the AeroElectric List be a joint venture, a quest for the
best-we-know-how-to-do. On the other hand, I cannot tolerate circular
arguments that perpetually hat-dance around the simple-ideas while
confusing or misleading those who come here for practical advice.
I guess I could treat this more like a university job.
It's not my building but it is my classroom. A good teacher must be open
to consider every idea but with absolute control over classroom decorum
and a bulwark against bad science and individuals who disrupt what
should be a calm, considered sifting of the simple-ideas.
I might liken this effort to that of accident investigator.
The real work begins after the fire trucks, ambulances and distraught
individuals have left. I've had several occasions where folks who
witnessed or were involved in an accident came over to see what I was
doing and conversationally relive the events from their perspective.
This was always distracting and never yielded useful information. I
never asked any of those folks to leave . . .
after all, the space we shared wasn't my personal property.
In retrospect I'm coming to understand that "space"
comes in many forms and just because someone has a fundamental right to
co exist with us in a physical space doesn't give them a right to invade
(and stir up
trouble) in folk's intellectual space. I promise not to allow such
situations to carry on so long again.
We all have better ways to invest our most precious commodity, time.
Thank you all for your understanding and support of the AeroElectric
List mission. I learn from the List every day and I believe it to be a
powerful tool for advancing the state of our art and science in crafting
the best airplanes to have ever flown.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | "Dennis Jones" <djones(at)northboone.net> |
I'm wiring the harness for a Terra TX-760D radio. My question is the
interconnect diagram shows the shield for the mic. audio, mic. key and the
headphone attach to the ground. I plan on using the daisy chain system shown
by Bob, however I'm confused about the shields connecting into the ground
wire itself or do they connect to the shield of the ground wire?
Dennis
________________________________________________________________________________
| From: | "Doug Windhorn" <N1DeltaWhiskey(at)comcast.net> |
| Subject: | Re: What I learned today |
Michael,
I agree with your last paragraph. Of course, one way to handle the
situation is to not post messages when on has an emotional response. Both
of these gentlemen seem to have a difficult time doing that. We should also
recognize that Bob sometimes contributes to these ongoing threads by taking
up the challenges posed by these two individuals (I recognize he feels a
need to do so to keep misinformation or poor quality from getting a hold).
It takes two to have an argument. IMHO, all could benefit from some marshal
arts training to learn how to brush off challenging posts.
For laughs, I checked messages that I have saved that I thought might be
useful down the road sometime. I have counted 3 from George and a dozen or
so from Paul off this list that I thought might fit that category; that is
from more than 400 saves. So for all of their postings, and certainly by
word count, I think almost anyone on this list has a higher percentage of
worthwhile content than do either George or Paul. Also, given the fact that
their postings are often lengthy it takes a lot of time to get through
them - not good value. Not sure that I will miss what might have been
future postings, but not sure they should be banned (wrong word - they have
been told to lay off) either.
My $0.01 worth.
Doug Windhorn
P.S. Now, my pet peeve. My browser opens a message at the top. If one has
important something to say, post it at the top of the message, not the
bottom (I probably have already read the prior messages, that the meaty
content is the resolution of a thread - why should I have to wade through
all the other stuff to get to the conclusion?) Exception: when responding
to several subjects with embedded comments, that is OK, but say you are
doing that at the top.
----- Original Message -----
From: "RV Builder (Michael Sausen)" <rvbuilder(at)sausen.net>
Sent: Wednesday, 13 September, 2006 9:36
Subject: RE: AeroElectric-List: What I learned today
>
>
> You want this to be a list of the people, so to speak, so here is my
> question. Out of curiosity what is the actual percentage of requests to
> ban George over the entire list membership? Is this another case of the
> vocal minority winning out over the silent majority?
>
> I for one think George, Paul, and others add value even if it is
> veiled in a load of rhetoric and even BS sometimes. Some of the most
> brilliant people in history had social issues. When I smell something
> funny in a post I always have the option of exercising the delete key.
> Honestly I spend more time deleting posts of complaints about other
> people than I do of the actual people. Talk about circular arguments.
>
> One of the problems with email has always been the way a person
> interprets emotions in the writing. Most of the time people are wrong
> in their assumptions so it is better to take emotion out and look for
> the actual substance of a post. Less bruised egos and useless replies
> that only escalate a situation that probably didn't exist in the first
> place.
>
> My $0.02
>
> Michael Sausen
> -10 #352 Fuselage
>
> Oh yes, and unlike most of the other posts on this subject.... Do Not
> Archive
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
> Robert L. Nuckolls, III
> Sent: Wednesday, September 06, 2006 8:11 AM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: What I learned today
>
> -->
>
> Listers,
>
> Folks have been bugging me about George for some time.
> Over a year perhaps. They keep citing this venue as being my list and
> suggested that I have full authority to manage it in whatever way I
> want.
>
> I never wanted to view this as "my list". It's always been my fondest
> wish that the AeroElectric List be a joint venture, a quest for the
> best-we-know-how-to-do. On the other hand, I cannot tolerate circular
> arguments that perpetually hat-dance around the simple-ideas while
> confusing or misleading those who come here for practical advice.
>
> I guess I could treat this more like a university job.
> It's not my building but it is my classroom. A good teacher must be open
> to consider every idea but with absolute control over classroom decorum
> and a bulwark against bad science and individuals who disrupt what
> should be a calm, considered sifting of the simple-ideas.
>
> I might liken this effort to that of accident investigator.
> The real work begins after the fire trucks, ambulances and distraught
> individuals have left. I've had several occasions where folks who
> witnessed or were involved in an accident came over to see what I was
> doing and conversationally relive the events from their perspective.
> This was always distracting and never yielded useful information. I
> never asked any of those folks to leave . . .
> after all, the space we shared wasn't my personal property.
>
> In retrospect I'm coming to understand that "space"
> comes in many forms and just because someone has a fundamental right to
> co exist with us in a physical space doesn't give them a right to invade
> (and stir up
> trouble) in folk's intellectual space. I promise not to allow such
> situations to carry on so long again.
> We all have better ways to invest our most precious commodity, time.
>
> Thank you all for your understanding and support of the AeroElectric
> List mission. I learn from the List every day and I believe it to be a
> powerful tool for advancing the state of our art and science in crafting
> the best airplanes to have ever flown.
>
>
> Bob . . .
>
>
> ---------------------------------------------------------
> < What is so wonderful about scientific truth...is that >
> < the authority which determines whether there can be >
> < debate or not does not reside in some fraternity of >
> < scientists; nor is it divine. The authority rests >
> < with experiment. >
> < --Lawrence M. Krauss >
> ---------------------------------------------------------
>
>
>
________________________________________________________________________________
| Subject: | Re: Radio shields |
| From: | Brian Lloyd <brian-av(at)lloyd.com> |
rOn Wed, 2006-09-13 at 10:12, Dennis Jones wrote:
> I?m wiring the harness for a Terra TX-760D radio. My question is the
> interconnect diagram shows the shield for the mic. audio, mic. key and
> the headphone attach to the ground. I plan on using the daisy chain
> system shown by Bob, however I?m confused about the shields connecting
> into the ground wire itself or do they connect to the shield of the
> ground wire?
If the radio itself has separate sheild and ground connections (most
don't) then you would connect the shield and ground to their respective
connections. Most radios just have a ground connection so both the
shield and the ground wire (if they are separate) should connect to the
ground pin(s) at the radio.
Normally I would run separate wire for mic/ptt and headphone. Speaking
specifically of the mic/ptt wiring, you can use the shield of the mic
cable as your mic and ptt ground wiring if you wish. If your mic wiring
has three conductors plus shield, I would probably use one conductor for
ground and then not attach anything to the shield (except at the radio).
If you are using an intercom you will probably have separate mic/ptt
wiring for each mic jack. (Most intercoms provide mic isolation when you
hit the PTT for one mic, the other mics are muted to keep noise from
getting into the transmit audio.)
If you are not using an intercom then you may daisy-chain your mic and
PTT connections. Just continue ground, shield, PTT, and mic hot.
Whatever you choose to do be sure you insulate the mic jacks from the
airframe.
Headphone wiring does not need to be shielded. I would use twisted pair.
You can get away with using airframe ground for the ground side of your
headphone but you are more likely to get some noise pick-up. This may
become objectionable if you are trying to have high-fidelity audio. Best
to insulate the headphone jacks as well.
Brian Lloyd
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Glowing Warning Lights |
>After studying the schematic (I'm a little slow with this stuff), it
>appears that the resistors can be installed at the regulator, one across
>terminals 3 and 5, and the other in series from the wire running from
>terminal 5 to the LED.
Look at it again. The two resistors would go in series between 3 and 5
and the LED fed from the protected end of the fuse and the TAP BETWEEN
the two resistors.
> I'm assuming some heat will be generated by the resistors and
> installing them at the regular would work better for me with cooling.
The RECOMMENDED resistors are at least 1/2 watt and 1 watt is preferred.
Like the selection of 1N540X series diodes over 1N400X series is their
mechanical robustness. The actual power dissipated in the 220 watt series
resistor is about 11(squared)/220 = 550 milliwatts which is divided in
two again due to the approx 50% duty cycle of the flashing lamp.
So heating is an insignificant concern.
>
>One other question, why not use a relay? I understand the added
>complexity issue, but that would give you a dark LED without sacrificing
>any brightness when it's illuminated. Right? Any part number
>recommendations would be appreciated.
LED's are current operated devices, the resistors don't sacrifice
brightness, they prevent darkness by keeping the LED from being
destroyed by using it to directly replace an incandescent lamp
sans resistors. A relay would suffer from the same kinds of issues
as a barefoot LED. Relays can be held closed by a tiny fraction of
the current that it takes to energize it. Further, you would still
need at least one of the two resistors to set the LED's operating
current. Finally, relays are rated amongst the least reliable of
components. It behoves us to limit their use where ever practical.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Radio shields |
>I m wiring the harness for a Terra TX-760D radio. My question is the
>interconnect diagram shows the shield for the mic. audio, mic. key and the
>headphone attach to the ground. I plan on using the daisy chain system
>shown by Bob, however I m confused about the shields connecting into the
>ground wire itself or do they connect to the shield of the ground wire?
Can you scan the wiring from the instruction manual
and send it to me?
It would be useful to see how they've depicted their
suggestions for the installation.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Re: Fuel Pump Switch(es) |
Fuel system problems are a major cause of engine stoppage in
homebuilt aircraft. Any fuel system that deviates from the norm, in
either design or installation details, opens the door to unexpected
problems. You have made a bunch of assumptions on how the system
will perform following various types of failures. It would be wise
to validate those assumptions via actual tests, either on the ground,
or in the air over a nice long runway.
Kevin Horton
On 13 Sep 2006, at 08:51, Gary Casey wrote:
> Yes, there are still a number of failure modes that could create a
> problem, even with two independent fuel valves. In the case
> mentioned below, the low tank valve breaks and won't shut off. In
> that case the (presumably fuller) tank could be turned on, feeding
> fuel from both tanks and the plane landed at the earliest
> convenience. The fuller tank would probably back-feed into the
> lower tank, extending the range compared to just feeding off the
> lowest tank, depending on the level of fuel in the fuller tank. In
> any event one has to assume there is only the fuel left in the
> lowest tank. If the valve for the "new" tank failed to open (broke
> in the closed position) the response is simple - land before the
> low tank goes empty. Not a perfect condition, but there are still
> options available that might not be available with a single valve.
> If a single valve broke in the "low" tank position fuel in the
> fuller tank is completely unavailable. If it sticks and breaks
> between tanks (what I think is a more likely failure) neither tank
> is available and the engine quits right away. The normal operating
> procedure with two valves is to open the valve for the new tank,
> confirming that it actually moved, and then shutting off the valve
> from the old tank. Never shut the old one off before turning the
> new one on. Also, I know that there have been some postings
> advocating, or at least acknowledging, running a tank dry as a
> routine operating mode. I suppose if there were more than two
> tanks this isn't so bad, but with only two tanks doing that gives
> up one of the redundancies in the system - two independent sources
> of fuel. I personally don't like the idea of running a tank dry.
> My own standard is to never run either tank lower than what is
> required to get to the nearest airport. FWIW.
>
> Gary Casey
> Lancair ES
> On Sep 12, 2006, at 11:55 PM, AeroElectric-List Digest Server wrote:
>
>
>>
>> You are worried about fuel valve handles breaking. With your design,
>> what happens if you have run one tank down low, want to switch to the
>> other tank, and the valve handle on the tank that is feeding breaks
>> so you can't close that valve? Won't the engine quit once that tank
>> is empty and the engine starts sucking air? How is this better than
>> a valve handle failure with the normal design?
>>
>> Kevin Horton RV-8 (finishing kit)
>> Ottawa, Canada
>
________________________________________________________________________________
| From: | "Dennis Jones" <djones(at)northboone.net> |
In a transponder what is considered suppression out and remote ground when
used in the wire harness.
Dennis
________________________________________________________________________________
| From: | "Dennis Jones" <djones(at)northboone.net> |
Bob
Here is the drawings for the Terra 760-D in regards to dealing with the
shields and grounds.
Thanks
Dennis
________________________________________________________________________________
| From: | "B Tomm" <fvalarm(at)rapidnet.net> |
| Subject: | Replacement led lights |
Bob,
Do you have a suggestion for a source for reasonably priced LED replacement
bulbs for my non aircraft related project. T3-1/4 and T1-3/4 cases, 14 or
28V.
Bevan
RV7A finish kit
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Wednesday, September 13, 2006 4:08 PM
Subject: Re: AeroElectric-List: Glowing Warning Lights
-->
>After studying the schematic (I'm a little slow with this stuff), it
>appears that the resistors can be installed at the regulator, one
>across terminals 3 and 5, and the other in series from the wire running
>from terminal 5 to the LED.
Look at it again. The two resistors would go in series between 3 and 5
and the LED fed from the protected end of the fuse and the TAP BETWEEN
the two resistors.
> I'm assuming some heat will be generated by the resistors and
> installing them at the regular would work better for me with cooling.
The RECOMMENDED resistors are at least 1/2 watt and 1 watt is preferred.
Like the selection of 1N540X series diodes over 1N400X series is their
mechanical robustness. The actual power dissipated in the 220 watt series
resistor is about 11(squared)/220 = 550 milliwatts which is divided in
two again due to the approx 50% duty cycle of the flashing lamp.
So heating is an insignificant concern.
>
>One other question, why not use a relay? I understand the added
>complexity issue, but that would give you a dark LED without
>sacrificing any brightness when it's illuminated. Right? Any part
>number recommendations would be appreciated.
LED's are current operated devices, the resistors don't sacrifice
brightness, they prevent darkness by keeping the LED from being
destroyed by using it to directly replace an incandescent lamp
sans resistors. A relay would suffer from the same kinds of issues
as a barefoot LED. Relays can be held closed by a tiny fraction of
the current that it takes to energize it. Further, you would still
need at least one of the two resistors to set the LED's operating
current. Finally, relays are rated amongst the least reliable of
components. It behoves us to limit their use where ever practical.
Bob . . .
________________________________________________________________________________
| From: | "William Gill" <wgill10(at)comcast.net> |
Hello Dennis,
What brand of transponder are you dealing with?
Bill
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Dennis Jones
Sent: Wednesday, September 13, 2006 8:03 PM
Subject: AeroElectric-List: Transponders
In a transponder what is considered suppression out and remote ground
when used in the wire harness.
Dennis
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: John Deere PM alternator regulator |
I can add one more interesting tidbit to this thread. Disconnecting the
Battery wire from the failed regulator does NOT stop the overvoltage.
I'm told it does stop the alternator output with a good regulator but it
does not do that on this failed unit.
Sounds similar to the automotive IR alternator where we also can not
guarantee that disconnecting the IGN wire will stop the alternator
output if the VR has already failed and is causing an overvoltage.
Ken
Dave N6030X wrote:
>
>
> Many in the Corvair group (www.FlyCorvair.com) are using this same
> John Deere generator/VR combo. You might take up the question there
> and find out what people have witnessed. The guy who's probably flown
> more hours with that combo than anybody is Gus Warren down at William
> Wynne's hangar in Florida.
>
> Dave Morris
________________________________________________________________________________
| From: | Tony Gibson <umgibso1(at)yahoo.com> |
| Subject: | Re: alternator vs. second battery |
Thanx for the reply Ken, sounds like good advice!
I'll take it!
Tony
From: Ken <klehman(at)albedo.net>
Subject: Re: AeroElectric-List: Debating on an alternator or two
batteries?
Hello Tony
Personally with an electric dependant engine, I'd happily trade 4 lbs
or so of battery for a small permanent magnet alternator and I suspect
the alternator would be the lighter option if you have a few hours of
fuel on board.
Bob just posted some references on battery discharging that you will
want to look at.
For a primary battery with no alternator I'd suggest multiplying your
hours of fuel by 2.5 amps and then picking a battery that can supply
that (from its spec. sheet) and then doubling it. Another battery
characteristic is that the deeper you discharge them, the fewer
discharge - charge cycles they last so planning for a 50% discharge
when
the fuel runs out might be reasonable. That would also allow for other
sub optimal conditions such as temperature.
Ken
Tony Gibson wrote:
> Hi Group, my name's Tony Gibson, I've been a lurker on the list for
> almost a year now and am building a Sonerai 2L - read 550lb slightly
> underpowered two place! :)
>
> I'm trying to take as much weight out of the plane as I can by
keeping
> it simple. There's a lot of reasons I'm considering two batteries
> rather than a battery and an alternator. But saving a bit of weight
> isn't the main reason, the fact that I can move the weight of
battery
> where ever I want in the plane is a big bonus for servicing it
> nevermind balancing, and ....the last thing I will do is put lead
> weight back into it!
>
> I have an ignition system that draws ~1 amp and a single fuel pump
> that draws another amp. I decided against the starter and the only
> other amp draws will be two small Stratomaster instruments drawing
> less than half an amp together. Total draw would be less than 2.5
Amps
>
> With the right warning system to indicate a low primary battery
> I'm wondering if something like a 3 - 5 Ah battery would be large
> enough for a backup? What about the primary?
>
> The downside of course is what would I do on a crosscountry trip?
> Argh! :)
>
> Thanx a lot, appreciate any help and opinions!
> Tony
>
---------------------------------
________________________________________________________________________________
| From: | "Dennis Jones" <djones(at)northboone.net> |
Terra TRT 250D
_____
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of William
Gill
Sent: Wednesday, September 13, 2006 9:20 PM
Subject: RE: AeroElectric-List: Transponders
Hello Dennis,
What brand of transponder are you dealing with?
Bill
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Dennis
Jones
Sent: Wednesday, September 13, 2006 8:03 PM
Subject: AeroElectric-List: Transponders
In a transponder what is considered suppression out and remote ground when
used in the wire harness.
Dennis
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________________________________________________________________________________
| From: | SMITHBKN(at)aol.com |
| Subject: | Magneto Switches and Wiring |
Listers,
I've read Bob's book and searched the archives but still can't seem to find
answers to confirm that my desired approach on magneto and starter wiring
will work (or maybe there is a simpler way).
I have two traditional magnetos for an IO-360. I would like to have a
toggle switch for each mag, and a momentary toggle for the starter (with a toggle
guard for added protection of inadvertent activation).
I don't fully understand the "impulse" aspect of the magneto. Could someone
help explain such and outline the correct wiring for this setup?
Thanks,
Jeff
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Re: Magneto Switches and Wiring |
On 14 Sep 2006, at 06:08, SMITHBKN(at)aol.com wrote:
>
> I don't fully understand the "impulse" aspect of the magneto.
> Could someone help explain such and outline the correct wiring for
> this setup?
>
The impulse function is not electrically controlled. It is
controlled by a mechanical device inside the mag. The mag either has
an impulse coupler, or it doesn't. Typical installations have only
one mag with an impulse coupler. In that case, this is the only mag
that you want to have ON during start. The one with without the
impulse coupler needs to be OFF. That can be accomplished by pilot
switch selections, or the start switch could be wired to disable the
non-impulse mag while the starter is powered.
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| Subject: | Re: Fuel Pump Switch(es) |
| From: | "steveadams" <dr_steve_adams(at)yahoo.com> |
The most common causes of fuel exhaustion when there is fuel on board is pilot
error. Switching to the wrong tank or not fully turning a mechanical switch to
a completely on position. Failure of a properly maintained mechanical fuel valve
is extremely rare. Vapor lock in a well designed system running AV gas is
pretty rare in flight. While having seperate wing root pumps on seperate electrical
systems may seem like complete redundancy, in reality it only assures partial
functionality of the fuel system by giving you 2 independant fuel systems
with less capacity. Say you're tooling along enjoying a flight, and forget to
switch tanks. I know it will never happen to us because we are such conscientious
pilots, but let's just imagine it could happen. Maybe you run one tank dry,
or you realize you forgot and switch tanks with minimum fuel in one tank.
You switch on the other pump and nothing happens. You still have a perfectly good
pump on one side, with redundant power supplies, and no risk of vapor lock,
but that side has no fuel. Your redundancy has disappeared and all your additional
fail safe modifications are useless. Adding header tanks, cross feeds etc
only adds to the complexity and introduces additional failure modes. Keep it
simple, stick to proven designs and methods, and keep it maintained properly.
In my non-engineer opinion, you'll have a more reliable system.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=61544#61544
________________________________________________________________________________
| From: | Brian Lloyd <brian-av(at)lloyd.com> |
| Subject: | Re: Transponders |
On Sep 13, 2006, at 6:03 PM, Dennis Jones wrote:
> In a transponder what is considered suppression out and remote
> ground when used in the wire harness.
The suppression pin there there to effectively mute the reply from
your transponder when the signal comes from your DME.
The DME is at a frequency very near to that of the transponder. When
the DME transmitter sends out a couple hundred watt pulse the
transponder's receiver is overloaded. It may generate a reply. To get
around this problem the DME puts a pulse on the suppression line when
it is getting ready to transmit. This inhibits the transponder from
responding and sending out a bogus reply.
If you have a DME you should connect its suppression output to the
suppression input of the transponder. No DME? No worry.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Gary Casey <glcasey(at)adelphia.net> |
| Subject: | Re: Fuel Pump Switch(es |
> Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
>
> Fuel system problems are a major cause of engine stoppage in
> homebuilt aircraft. Any fuel system that deviates from the norm, in
> either design or installation details, opens the door to unexpected
> problems. You have made a bunch of assumptions on how the system
> will perform following various types of failures. It would be wise
> to validate those assumptions via actual tests, either on the ground,
> or in the air over a nice long runway.
>
> Kevin Horton
Here is the reply below the reference, as suggested by another lister..
Yes, perhaps the biggest disadvantage of using two separate fuel
valves is the one you suggest - it deviates from the "norm." And
changing tanks takes two motions - opening the new valve, followed by
closing the old valve. Since the weakest link in any safety system
is usually the operator, what would happen if he (me) did something
wrong? If you shut off one tank before turning the other on the
engine will quit immediately - instant feedback and obviously
correctable. If you turn one on and forget to turn the other off
nothing will immediately happen, but before the engine will suck air
one tank has to go completely empty and in the case of my
installation there are gages and both audio and visual warnings of
that event. I felt these disadvantages are compensated for by the
advantages of being able to shut the fuel off before it enters the
cockpit, reduction in the number of fittings in the cockpit (someone
correctly pointed out that the total number of fittings might not
change), and completely independent fuel controls. But I don't think
I've made any "assumptions" regarding the operation - the failure
modes and results are fairly straightforward - valve off, no flow -
valve on, flow. Perhaps the only unknown is what happens with low
tanks and both valves open, and that has been discovered by others -
the empty tank can allow air into the system, preventing the use of
the fuel in the other tank. To verify this one would have to fly
with one tank empty and the other almost empty, and I am not willing
to do that. Regarding the number of fittings I recall counting the
possible in-cockpit leaks in the standard ES system at something over
30 with one moving seal and quite a number of those remain "wet" even
though the fuel valve is turned off. My system has a total of 7
potential leak paths in the cockpit and no moving seals, all of which
go "dry" with the fuel valves off. The builder with the "electric"
engine and one electric pump in each wing can probably has even
fewer, except he can't positively shut anything off.
Gary Casey
________________________________________________________________________________
| From: | "Bill Denton" <bdenton(at)bdenton.com> |
It's also used in instances where you have two (or more!) transponders in an
aircraft...
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Brian
Lloyd
Sent: Thursday, September 14, 2006 8:08 AM
Subject: Re: AeroElectric-List: Transponders
On Sep 13, 2006, at 6:03 PM, Dennis Jones wrote:
> In a transponder what is considered suppression out and remote
> ground when used in the wire harness.
The suppression pin there there to effectively mute the reply from
your transponder when the signal comes from your DME.
The DME is at a frequency very near to that of the transponder. When
the DME transmitter sends out a couple hundred watt pulse the
transponder's receiver is overloaded. It may generate a reply. To get
around this problem the DME puts a pulse on the suppression line when
it is getting ready to transmit. This inhibits the transponder from
responding and sending out a bogus reply.
If you have a DME you should connect its suppression output to the
suppression input of the transponder. No DME? No worry.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| Subject: | Re: Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Ahh there in lies your assumption....I agree, with AVGAS VL incidences
are very rare...With Mogas they are alarmingly common and a mechanical
fuel pump North side of a hot firewall is in exactly the "hydraulically
incorrect" place.
Yes true, you have to be aware of how much fuel you leave in one tank,
that's the one limitation of the wing root system, but does any of us
really go below half an hour on a tank...Some folks do suck a tank dry
before switching with a standard system, but of course your asking for
it if you did that with my system.
And note there are no cross feeds or any other so called fail safes, its
just one pump for one tank, no cross feeds nothing. I agree with you,
adding complexity is simply adding failure modes. With a simple wingroot
system just don't go below half an hour on each side before switching
pumps.
Works for me
Frank
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
steveadams
Sent: Thursday, September 14, 2006 5:33 AM
Subject: AeroElectric-List: Re: Fuel Pump Switch(es)
-->
The most common causes of fuel exhaustion when there is fuel on board is
pilot error. Switching to the wrong tank or not fully turning a
mechanical switch to a completely on position. Failure of a properly
maintained mechanical fuel valve is extremely rare. Vapor lock in a well
designed system running AV gas is pretty rare in flight. While having
seperate wing root pumps on seperate electrical systems may seem like
complete redundancy, in reality it only assures partial functionality of
the fuel system by giving you 2 independant fuel systems with less
capacity. Say you're tooling along enjoying a flight, and forget to
switch tanks. I know it will never happen to us because we are such
conscientious pilots, but let's just imagine it could happen. Maybe you
run one tank dry, or you realize you forgot and switch tanks with
minimum fuel in one tank. You switch on the other pump and nothing
happens. You still have a perfectly good pump on one side, with
redundant power supplies,!
and no risk of vapor lock, but that side has no fuel. Your redundancy
has disappeared and all your additional fail safe modifications are
useless. Adding header tanks, cross feeds etc only adds to the
complexity and introduces additional failure modes. Keep it simple,
stick to proven designs and methods, and keep it maintained properly. In
my non-engineer opinion, you'll have a more reliable system.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=61544#61544
________________________________________________________________________________
| From: | "Jeff Moreau" <jmoreau2(at)cox.net> |
Is there a calculator or simple table that I can use to determine the size of wire
to us for each particular device that I am installing in my airplane?
Perhaps a website that has an online calculator?
Any advice would be greatly appreciated.
Thanks
Jeff
--------
Jeff Moreau
RV8A
Virginia Beach, VA
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=61580#61580
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
>
>Is there a calculator or simple table that I can use to determine the size
>of wire to us for each particular device that I am installing in my airplane?
>Perhaps a website that has an online calculator?
>Any advice would be greatly appreciated.
This is discussed and tabulated in:
http://aeroelectric.com/articles/Rev11/Ch8_R12.pdf
Also, check out the other resources you'll find
at:
http://aeroelectric.com/
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
________________________________________________________________________________
| From: | OldBob Siegfried <oldbob(at)BeechOwners.com> |
| Subject: | Re: Fuel Pump Switch(es) |
Good Morning Frank,
You state: "And note there are no cross feeds or any
other so called fail safes, its just one pump for one
tank, no cross feeds nothing. I agree with you, adding
complexity is simply adding failure modes. With a
simple wingroot system just don't go below half an
hour on each side before switching pumps.
Works for me
Frank"
And I am sure it will work just fine for any other
pilot that never makes a mistake!
Unfortunately, I have found that I am not one of those
pilots. I make an awful lot of mistakes and I often
forget to switch tanks when I should.
I believe the point that Steve wanted to make is that
it is the human pilot who has the higher failure mode.
Happy Skies,
Old bob
--- "Hinde, Frank George (Corvallis)"
wrote:
> Frank George (Corvallis)"
>
> Ahh there in lies your assumption....I agree, with
> AVGAS VL incidences
> are very rare...With Mogas they are alarmingly
> common and a mechanical
> fuel pump North side of a hot firewall is in exactly
> the "hydraulically
> incorrect" place.
>
> Yes true, you have to be aware of how much fuel you
> leave in one tank,
> that's the one limitation of the wing root system,
> but does any of us
> really go below half an hour on a tank...Some folks
> do suck a tank dry
> before switching with a standard system, but of
> course your asking for
> it if you did that with my system.
>
> And note there are no cross feeds or any other so
> called fail safes, its
> just one pump for one tank, no cross feeds nothing.
> I agree with you,
> adding complexity is simply adding failure modes.
> With a simple wingroot
> system just don't go below half an hour on each side
> before switching
> pumps.
>
> Works for me
>
> Frank
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
>
[mailto:owner-aeroelectric-list-server(at)matronics.com]
> On Behalf Of
> steveadams
> Sent: Thursday, September 14, 2006 5:33 AM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: Re: Fuel Pump Switch(es)
>
> "steveadams"
> -->
>
> The most common causes of fuel exhaustion when there
> is fuel on board is
> pilot error. Switching to the wrong tank or not
> fully turning a
> mechanical switch to a completely on position.
> Failure of a properly
> maintained mechanical fuel valve is extremely rare.
> Vapor lock in a well
> designed system running AV gas is pretty rare in
> flight. While having
> seperate wing root pumps on seperate electrical
> systems may seem like
> complete redundancy, in reality it only assures
> partial functionality of
> the fuel system by giving you 2 independant fuel
> systems with less
> capacity. Say you're tooling along enjoying a
> flight, and forget to
> switch tanks. I know it will never happen to us
> because we are such
> conscientious pilots, but let's just imagine it
> could happen. Maybe you
> run one tank dry, or you realize you forgot and
> switch tanks with
> minimum fuel in one tank. You switch on the other
> pump and nothing
> happens. You still have a perfectly good pump on one
> side, with
> redundant power supplies,!
> and no risk of vapor lock, but that side has no
> fuel. Your redundancy
> has disappeared and all your additional fail safe
> modifications are
> useless. Adding header tanks, cross feeds etc only
> adds to the
> complexity and introduces additional failure modes.
> Keep it simple,
> stick to proven designs and methods, and keep it
> maintained properly. In
> my non-engineer opinion, you'll have a more reliable
> system.
>
>
>
>
> Read this topic online here:
>
>
http://forums.matronics.com/viewtopic.php?p=61544#61544
>
>
>
>
>
>
>
>
>
>
>
>
>
> browse
> Subscriptions page,
> FAQ,
> http://www.matronics.com/Navigator?AeroElectric-List
>
> Web Forums!
>
>
> Admin.
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: What I learned today |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
The Final Solution:
(Apologies to Rev. Martin Niemoeller)
First they banned the discourteous,
And I didn't speak up because I was a follower.
Then they banned the insubordinate,
And I didn't speak up because I was easily cowed by authority.
Then they came for the passionately contentious,
And I didn't speak up because I was a follower.
Then they came for the independent technological thinkers,
And I didn't speak up because I wasn't an independent thinker.
Then they came for me, And by that time no one was left to speak up.
The REAL issue Bob, is that people who disagree are a thousand times more valuable
than those who merely follow--albeit the discussion could be more civil--and
we seek not to confuse the beginner too much. But you and I are not above being
jerks. None of your foils started their interchanges with you in an intemperate
tone. They react to what they consider your intransigence and arrogance.
And it makes them go bonkers.
When I see that you are prepared to fight seemingly innocuous points like my recent
disagreement that "copper is a very active metal" (chapter 8), I am nonplussed.
You obviosly fight to defend territory. Hell, I just thought I would do
you a favor. Fool me once....
Bob, you are obviously a man of exceptional talents and a lot of people, including
me, and I would guess your difficult list characters, depend on you and respect
you.
But don't look for obedience...some of us just can't do it.
"What the West really has to offer is honesty. Somehow, in the midst of their horrid
history, the best among the Gaijin learned a wonderful lesson. They learned
to distrust themselves, to doubt even what they were taught to believe or
what their egos make them yearn to see. To know that even truth must be scrutinized,
it was a great discovery...."
-- David Brin, "Dr. Pak's Preschool"
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=61584#61584
________________________________________________________________________________
| Subject: | Re: Fuel Pump Switch(es) |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Certainly can't argue that one...I made a mistake myself once...:)
What I think I was trying to get at though was the 'pump failing just as
you have inadvertantly run out of gas from the other tank'...Is a double
failure...I.e it assumes the pilot forgot to switch tanks when he
should...AND....the pump on the tank with fuel in it has just failed.
That is a VERY unlikely situation...I mean lets say there is a 1 in 1000
chance the dumb*ss pilot (me) will suck a tank dry. Assume also there is
a 1 in 1000 chance a pump will fail on any particular flight.
The risk of both failures occurring concurrently is 1000*1000= 1 in 1
million.....Of course these numbers are completely arbitrary but the
point is clear, double failures are so rare that you almost never plan
for them in both aeronautical or industrial systems.
Of course if the risk so high (like 400 people on a DC10) then there
might be 3 independent hydraulic systems...But for GA its never planned
for as far as I can think of.
So your point about will work fine for any other pilot that never makes
a mistake is not true, if you make a mistake you will not drop out of
the sky...So what our hero sucks a tank dry...then simply switch the
other pump on...I very much doubt you would even have to turn off the
"air pump" to get the engine to run quite happily.
To counter the standard airplane system...Suppose you suck a tank
dry...Are we any more certain that the boost pump will re-prime, i.e
suck the air out of the line before it continues to pump fuel? Or the
handle doesn't suddenly snap off?...It is highly likely it will work as
planned (always has done) but I doubt you could prove it is any more
reliable than the wing root pump system.
Anyway, it really comes down to personal preference. I have run this
system for 410 hours and I like it. It is also done for a specific
purpose, i.e to reduce the risk of vapour lock with MOGAS...Otherwise I
would have just gone with a standard system.
I am not so invested in this solution that I am touting it as the only
way to go. It has its pros and cons, its just that for the specific
purpose (Mogas) its about the best (as an engineer who sometimes designs
pumped systems) I can come up with.
But assuming all is lost because the pilot makes a mistake is a false
assumption.
Young Frank....:)
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
OldBob Siegfried
Sent: Thursday, September 14, 2006 8:29 AM
Subject: RE: AeroElectric-List: Re: Fuel Pump Switch(es)
-->
Good Morning Frank,
You state: "And note there are no cross feeds or any other so called
fail safes, its just one pump for one tank, no cross feeds nothing. I
agree with you, adding complexity is simply adding failure modes. With a
simple wingroot system just don't go below half an hour on each side
before switching pumps.
Works for me
Frank"
And I am sure it will work just fine for any other pilot that never
makes a mistake!
Unfortunately, I have found that I am not one of those pilots. I make an
awful lot of mistakes and I often forget to switch tanks when I should.
I believe the point that Steve wanted to make is that it is the human
pilot who has the higher failure mode.
Happy Skies,
Old bob
--- "Hinde, Frank George (Corvallis)"
wrote:
> Frank George (Corvallis)"
>
> Ahh there in lies your assumption....I agree, with AVGAS VL incidences
> are very rare...With Mogas they are alarmingly common and a mechanical
> fuel pump North side of a hot firewall is in exactly the
> "hydraulically incorrect" place.
>
> Yes true, you have to be aware of how much fuel you leave in one tank,
> that's the one limitation of the wing root system, but does any of us
> really go below half an hour on a tank...Some folks do suck a tank dry
> before switching with a standard system, but of course your asking for
> it if you did that with my system.
>
> And note there are no cross feeds or any other so called fail safes,
> its just one pump for one tank, no cross feeds nothing.
> I agree with you,
> adding complexity is simply adding failure modes.
> With a simple wingroot
> system just don't go below half an hour on each side before switching
> pumps.
>
> Works for me
>
> Frank
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
>
[mailto:owner-aeroelectric-list-server(at)matronics.com]
> On Behalf Of
> steveadams
> Sent: Thursday, September 14, 2006 5:33 AM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: Re: Fuel Pump Switch(es)
>
> "steveadams"
> -->
>
> The most common causes of fuel exhaustion when there is fuel on board
> is pilot error. Switching to the wrong tank or not fully turning a
> mechanical switch to a completely on position.
> Failure of a properly
> maintained mechanical fuel valve is extremely rare.
> Vapor lock in a well
> designed system running AV gas is pretty rare in flight. While having
> seperate wing root pumps on seperate electrical systems may seem like
> complete redundancy, in reality it only assures partial functionality
> of the fuel system by giving you 2 independant fuel systems with less
> capacity. Say you're tooling along enjoying a flight, and forget to
> switch tanks. I know it will never happen to us because we are such
> conscientious pilots, but let's just imagine it could happen. Maybe
> you run one tank dry, or you realize you forgot and switch tanks with
> minimum fuel in one tank. You switch on the other pump and nothing
> happens. You still have a perfectly good pump on one side, with
> redundant power supplies,!
> and no risk of vapor lock, but that side has no fuel. Your
> redundancy has disappeared and all your additional fail safe
> modifications are useless. Adding header tanks, cross feeds etc only
> adds to the complexity and introduces additional failure modes.
> Keep it simple,
> stick to proven designs and methods, and keep it maintained properly.
> In my non-engineer opinion, you'll have a more reliable system.
>
>
>
>
> Read this topic online here:
>
>
http://forums.matronics.com/viewtopic.php?p=61544#61544
>
>
>
>
>
>
>
>
>
>
>
>
>
> browse
> Subscriptions page,
> FAQ,
> http://www.matronics.com/Navigator?AeroElectric-List
>
> Web Forums!
>
>
> Admin.
>
>
>
>
>
________________________________________________________________________________
| From: | "John McMahon" <blackoaks(at)gmail.com> |
Jeff Here is another link to a calculating spreadsheet by Jim Wier that
might work for you.
http://www.rst-engr.com/rst/jimsdata/wirecalc.xls
John M.
On 9/14/06, Jeff Moreau wrote:
>
>
> Is there a calculator or simple table that I can use to determine the size
> of wire to us for each particular device that I am installing in my
John McMahon
Lancair Super ES, N9637M
________________________________________________________________________________
| From: | "B Tomm" <fvalarm(at)rapidnet.net> |
Yes,
Why would you want two (or more) transponders in an your aircraft?
Bevan
RV7A Finishing kit
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Bill
Denton
Sent: Thursday, September 14, 2006 6:52 AM
Subject: RE: AeroElectric-List: Transponders
-->
It's also used in instances where you have two (or more!) transponders in an
aircraft...
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Brian
Lloyd
Sent: Thursday, September 14, 2006 8:08 AM
Subject: Re: AeroElectric-List: Transponders
-->
On Sep 13, 2006, at 6:03 PM, Dennis Jones wrote:
> In a transponder what is considered suppression out and remote ground
> when used in the wire harness.
The suppression pin there there to effectively mute the reply from your
transponder when the signal comes from your DME.
The DME is at a frequency very near to that of the transponder. When the DME
transmitter sends out a couple hundred watt pulse the transponder's receiver
is overloaded. It may generate a reply. To get around this problem the DME
puts a pulse on the suppression line when it is getting ready to transmit.
This inhibits the transponder from responding and sending out a bogus reply.
If you have a DME you should connect its suppression output to the
suppression input of the transponder. No DME? No worry.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | OldBob Siegfried <oldbob(at)BeechOwners.com> |
Good Morning Bevan,
For the same reason many aircraft have two VORs or two
GPSs.
Redundancy.
Most air carrier, and many corporate aircraft, have
dual transponders.
If I were based in an area such as the SFO bay area, I
would also consider having two installed. Without a
transponder in such an area, even VFR flight is
difficult.
Happy Skies,
Old Bob
--- B Tomm wrote:
>
>
> Yes,
>
> Why would you want two (or more) transponders in an
> your aircraft?
>
> Bevan
> RV7A Finishing kit
>
>
________________________________________________________________________________
| From: | "Terry Watson" <terry(at)tcwatson.com> |
| Subject: | Re: What I learned today |
Obedience? Where did that come from? All Bob -- and I suspect 90% of the
rest of us are asking for -- is simple commonsense courtesy; that
characteristic (also called manners) that allows people to interact for
their common benefit. It requires not turning a technical discussion into a
personal attack; it requires honesty; it requires consideration. It also
requires becoming familiar with the rules of the road for this discussion
group carefully defined and posted by its sponsor, Matt Dralle.
Terry
But don't look for obedience...some of us just can't do it.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: What I learned today |
>
>The Final Solution:
>
>(Apologies to Rev. Martin Niemoeller)
>
>First they banned the discourteous,
>And I didn't speak up because I was a follower.
>Then they banned the insubordinate,
>And I didn't speak up because I was easily cowed by authority.
>Then they came for the passionately contentious,
>And I didn't speak up because I was a follower.
>Then they came for the independent technological thinkers,
>And I didn't speak up because I wasn't an independent thinker.
>Then they came for me, And by that time no one was left to speak up.
>
>The REAL issue Bob, is that people who disagree are a thousand times more
>valuable than those who merely follow--albeit the discussion could be more
>civil--and we seek not to confuse the beginner too much. But you and I are
>not above being jerks. None of your foils started their interchanges with
>you in an intemperate tone. They react to what they consider your
>intransigence and arrogance. And it makes them go bonkers.
Yup, the popular media outlets are loaded with folks who
disagree . . . about everything, but offer no "plan"
of their own. Further, they NEVER answer a direct question
that might illuminate their lack of understanding or
emphasizes their willingness to sacrifice the liberties of everyone
else for the false philanthropy that assuages someone's
discomforts. And yes, when pressed for specific answers, those
individuals DO go bonkers. Disagreement adds value ONLY when more
attractive or more honorable alternatives are offered.
>When I see that you are prepared to fight seemingly innocuous points like
>my recent disagreement that "copper is a very active metal" (chapter 8), I
>am nonplussed. You obviosly fight to defend territory. Hell, I just
>thought I would do you a favor. Fool me once....
Eric, Eric . . . "very" is non-quantified. Disagree
all you want but the meaning of the phrase is inarguable
unless you're attempting to but quantified bounds on "little,
more, a lot, and gobs". Would you feel better if I simply
wrote, "Copper is a reactive metal"?
>Bob, you are obviously a man of exceptional talents and a lot of people,
>including me, and I would guess your difficult list characters, depend on
>you and respect you.
>
>But don't look for obedience...some of us just can't do it.
Eric, you don't seem to have a grasp of the issues
here. No society of individuals should even consider themselves
a instrument or benefit of "the people". Every society
has charter, goals, and acceptable modes of behavior which
every member is expected to embrace . . . or leave. Nobody
has a duty to compromise a society's goals to accommodate
anyone's feelings of exclusion; buy in or get out. One
may always gather up a society of like minded individuals
who share alternative goals.
I cannot help that you've glossed over George's blatant
dishonorable behavior and his obfuscation of the
issues. The List IS a society of inclusion but with
LIMITED tolerance for behavior that does not move the
mission forward. You seem to mistake an expectation of
logical, honorable discourse and exchange of simple-ideas
as a demand for obedience. How you "feel" about any
of what transpires is beyond anyone's expectations or
duty to address. However, if you have thoughts or
questions about simple-ideas, new inventions or a novel
philosophy for making our airplanes cost less, fly better,
last longer, work better, etc. . . . you're most welcome
and encouraged to join in.
Bob . . .
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Re: What I learned today |
Doug Windhorn
P.S. Now, my pet peeve. My browser opens a message at the top. If one has
important something to say, post it at the top of the message, not the
bottom (I probably have already read the prior messages, that the meaty
content is the resolution of a thread - why should I have to wade through
all the other stuff to get to the conclusion?) Exception: when responding
to several subjects with embedded comments, that is OK, but say you are
doing that at the top.
And now my pet peeve. People trying to impose their pet peeves on others.
The announcement of my pet peeve is likely to have little effect either.
Stan Sutterfield
________________________________________________________________________________
| From: | "6440 Auto Parts" <sales(at)6440autoparts.com> |
| Subject: | Re: What I learned today |
Delete, delete, delete
----- Original Message -----
From: Speedy11(at)aol.com
To: aeroelectric-list(at)matronics.com
Sent: Thursday, September 14, 2006 12:22 PM
Subject: AeroElectric-List: Re: What I learned today
Doug Windhorn
P.S. Now, my pet peeve. My browser opens a message at the top. If
one has
important something to say, post it at the top of the message, not
the
bottom (I probably have already read the prior messages, that the
meaty
content is the resolution of a thread - why should I have to wade
through
all the other stuff to get to the conclusion?) Exception: when
responding
to several subjects with embedded comments, that is OK, but say you
are
doing that at the top.
And now my pet peeve. People trying to impose their pet peeves on
others.
The announcement of my pet peeve is likely to have little effect
either.
Stan Sutterfield
________________________________________________________________________________
| From: | "6440 Auto Parts" <sales(at)6440autoparts.com> |
| Subject: | Re: What I learned today |
Now I suppose we're going to compare a moderators actions to that of
the Nazi's. Bob made a decission right or wrong. I'll bet if George wanted
back on the list he could come up with something creative like rejoining
under another email address. I'm sorry but the poor horse can't stand much
more of a beating. Poor old Rev Niemoeller probably turns over in his grave
every time someone uses his poem in small circumstances. But I'm sure the
christian he was he would forgive and let it be. For me I'm going back
to delete delete delete.
Randy
> (Apologies to Rev. Martin Niemoeller)
>
> First they banned the discourteous,
> And I didn't speak up because I was a follower.
> Then they banned the insubordinate,
> And I didn't speak up because I was easily cowed by authority.
> Then they came for the passionately contentious,
> And I didn't speak up because I was a follower.
> Then they came for the independent technological thinkers,
> And I didn't speak up because I wasn't an independent thinker.
> Then they came for me, And by that time no one was left to speak up.
>
________________________________________________________________________________
| From: | "Bill Denton" <bdenton(at)bdenton.com> |
Dunno, but Piper offers them in their "big" aircraft, and I think they may
be used in the turboprop world...
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of B Tomm
Sent: Thursday, September 14, 2006 11:27 AM
Subject: RE: AeroElectric-List: Transponders
Yes,
Why would you want two (or more) transponders in an your aircraft?
Bevan
RV7A Finishing kit
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Bill
Denton
Sent: Thursday, September 14, 2006 6:52 AM
Subject: RE: AeroElectric-List: Transponders
-->
It's also used in instances where you have two (or more!) transponders in an
aircraft...
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Brian
Lloyd
Sent: Thursday, September 14, 2006 8:08 AM
Subject: Re: AeroElectric-List: Transponders
-->
On Sep 13, 2006, at 6:03 PM, Dennis Jones wrote:
> In a transponder what is considered suppression out and remote ground
> when used in the wire harness.
The suppression pin there there to effectively mute the reply from your
transponder when the signal comes from your DME.
The DME is at a frequency very near to that of the transponder. When the DME
transmitter sends out a couple hundred watt pulse the transponder's receiver
is overloaded. It may generate a reply. To get around this problem the DME
puts a pulse on the suppression line when it is getting ready to transmit.
This inhibits the transponder from responding and sending out a bogus reply.
If you have a DME you should connect its suppression output to the
suppression input of the transponder. No DME? No worry.
Brian Lloyd 361 Catterline Way
brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Radio shields |
>
>
>
>>I m wiring the harness for a Terra TX-760D radio. My question is the
>>interconnect diagram shows the shield for the mic. audio, mic. key and
>>the headphone attach to the ground. I plan on using the daisy chain
>>system shown by Bob, however I m confused about the shields connecting
>>into the ground wire itself or do they connect to the shield of the
>>ground wire?
>
> Can you scan the wiring from the instruction manual
> and send it to me?
>
> It would be useful to see how they've depicted their
> suggestions for the installation.
Okay, got the scans. Great.
I guess I'm not sure what the question is. The schematic shows
two aircraft ground (A/C Ground) connections to pins 4 and 15.
Wires that the manufacturer recommends be shielded have their
shield grounds returned to specific pins. They also show how
the shield can double as a ground return for mic, headphone,
speaker leads, etc. Further, their wiring suggests exactly
the same daisy-chaining technique I described in:
http://aeroelectric.com/articles/pigtail/pigtail.html
OOPS! I just re-read your question and I think missed
something the first time. You talk about a "shield of
the ground wire".
The drawings show single strands of wire from pins 4 and
15 to ground. Your pigtails would either solder onto the
shared solder cups or splice into the ground wires immediately
adjacent to where they drop into the crimped on pin pocket.
The ground wires are not shielded.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Replacement led lights |
>
>Bob,
>
>
>Do you have a suggestion for a source for reasonably priced LED replacement
>bulbs for my non aircraft related project. T3-1/4 and T1-3/4 cases, 14 or
>28V.
>
>Bevan
>RV7A finish kit
I guess I don't know what you mean by "reasonably priced". We're
evaluating some devices at RAC but I think they're quite expensive.
Probably over $10 each in production lots.
If you're going to LED, consider removing the lamp sockets and
replacing with application led-resistor combos specific to the
task. The lamps are getting DIRT cheap. See Ebay.
Bob . . .
________________________________________________________________________________
| From: | "Tony Babb" <tonybabb(at)alejandra.net> |
| Subject: | Re: What I learned today |
Good morning all,
I'm electronically challenged but have been lurking on this list for a
couple of years now, it's invaluable to me, I learn something from most
posts and the discussions when disagreements occur so thanks to all
especially Bob and the regular contributors like Brian, Eric et al. I agree
with Terry's comments below. It seems to me that if anyone is really
offended by asking GMC and Paul to take off they can always unsubscribe from
this list and maybe start their own. The rest of us I suspect would like to
get back to our electrical systems.
Cheers,
Tony
Velocity SEFG 62% done, 78% to go
www.alejandra.net/velocity
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Terry
Watson
Sent: Thursday, September 14, 2006 9:40 AM
Subject: RE: AeroElectric-List: Re: What I learned today
-->
Obedience? Where did that come from? All Bob -- and I suspect 90% of the
rest of us are asking for -- is simple commonsense courtesy; that
characteristic (also called manners) that allows people to interact for
their common benefit. It requires not turning a technical discussion into a
personal attack; it requires honesty; it requires consideration. It also
requires becoming familiar with the rules of the road for this discussion
group carefully defined and posted by its sponsor, Matt Dralle.
Terry
But don't look for obedience...some of us just can't do it.
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
So that when you are in the middle of the DC ADIZ and one quits
squawking you don't get interecpted by F-16s.
>
> Yes,
>
> Why would you want two (or more) transponders in an your aircraft?
>
> Bevan
> RV7A Finishing kit
>
________________________________________________________________________________
| From: | Deems Davis <deemsdavis(at)cox.net> |
| Subject: | Mic plug / PTT wiring |
The example on Bob's web site shows that the PTT switch is wired to the
Ground/common on the Mic plug recepticle (in addition to the
key/terminal) is there any reason why the PTT switch (in my case on a
control stick/grip) can't be wired to a common ground for the control/
grip rather than to the mic plug common?
Deems Davis RV-10 # 406
Panel/wiring
http://deemsrv10.com/
>
________________________________________________________________________________
| From: | "Bill Denton" <bdenton(at)bdenton.com> |
| Subject: | Mic plug / PTT wiring |
A properly installed aircraft mic jack uses an insulating washer (or other
means) to ensure that the jack is NOT connected to a common ground...
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Deems
Davis
Sent: Thursday, September 14, 2006 2:12 PM
Subject: AeroElectric-List: Mic plug / PTT wiring
The example on Bob's web site shows that the PTT switch is wired to the
Ground/common on the Mic plug recepticle (in addition to the
key/terminal) is there any reason why the PTT switch (in my case on a
control stick/grip) can't be wired to a common ground for the control/
grip rather than to the mic plug common?
Deems Davis RV-10 # 406
Panel/wiring
http://deemsrv10.com/
>
________________________________________________________________________________
| From: | "B Tomm" <fvalarm(at)rapidnet.net> |
| Subject: | Replacement led lights |
Yip $10 each is about the best price I have seen (Newark) but still too
pricing because of the quantity I would need, Also, the sockets on some are
not changeable because they are special lighted switches that are tough
enough as it is to get. I would have to completely redo the applications to
replace the sockets.
I'll look on ebay. Hadn't thought of that. Thanks.
Bevan
RV7A finishing kit
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Thursday, September 14, 2006 11:51 AM
Subject: Re: AeroElectric-List: Replacement led lights
-->
>-->
>
>Bob,
>
>
>Do you have a suggestion for a source for reasonably priced LED
>replacement bulbs for my non aircraft related project. T3-1/4 and
>T1-3/4 cases, 14 or 28V.
>
>Bevan
>RV7A finish kit
I guess I don't know what you mean by "reasonably priced". We're
evaluating some devices at RAC but I think they're quite expensive.
Probably over $10 each in production lots.
If you're going to LED, consider removing the lamp sockets and
replacing with application led-resistor combos specific to the
task. The lamps are getting DIRT cheap. See Ebay.
Bob . . .
________________________________________________________________________________
| From: | John Morgensen <john(at)morgensen.com> |
| Subject: | Re: Mic plug / PTT wiring |
Hope I can contribute here. I encountered an FBO Cessna that was not
grounded properly. The symptoms were PTT produced a side-tone with old
cheap headsets but no side-tone with brand new ANR headsets.
John Morgensen RV-9A QB
Deems Davis wrote:
>
> The example on Bob's web site shows that the PTT switch is wired to the
> Ground/common on the Mic plug recepticle (in addition to the
> key/terminal) is there any reason why the PTT switch (in my case on a
> control stick/grip) can't be wired to a common ground for the control/
> grip rather than to the mic plug common?
>
> Deems Davis RV-10 # 406
> Panel/wiring
> http://deemsrv10.com/
>
>
>>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | Deems Davis <deemsdavis(at)cox.net> |
| Subject: | Re: Mic plug / PTT wiring |
I think I understand the need to isolate the mic plug with the
insulating washers. My question which remains is does the PTT switch
need to be wired directly to the common terminal (as depicted on the web
site example) on the mic plug? In my case this will be difficult as I
plan to use a switch on a control stick which already is wired with a
common ground. I'm 'assuming' that I can wire the control grip switch to
the mic plug 'key' terminal, and the common/ground will be through the
common/ground in the control grip wiring. (?)
Deems Davis RV10 # 406
Panel/wiring
http://deemsrv10.com/
John Morgensen wrote:
>
>
> Hope I can contribute here. I encountered an FBO Cessna that was not
> grounded properly. The symptoms were PTT produced a side-tone with old
> cheap headsets but no side-tone with brand new ANR headsets.
>
> John Morgensen RV-9A QB
>
> Deems Davis wrote:
>
>>
>>
>> The example on Bob's web site shows that the PTT switch is wired to
>> the Ground/common on the Mic plug recepticle (in addition to the
>> key/terminal) is there any reason why the PTT switch (in my case on a
>> control stick/grip) can't be wired to a common ground for the
>> control/ grip rather than to the mic plug common?
>>
>> Deems Davis RV-10 # 406
>> Panel/wiring
>> http://deemsrv10.com/
>>
>>
>>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
________________________________________________________________________________
| From: | djones(at)northboone.net |
| Subject: | Re: Transponders |
Thank you Brian
What is the remote ground used for?
Quoting Brian Lloyd :
>
>
> On Sep 13, 2006, at 6:03 PM, Dennis Jones wrote:
>
>> In a transponder what is considered suppression out and remote
>> ground when used in the wire harness.
>
> The suppression pin there there to effectively mute the reply from
> your transponder when the signal comes from your DME.
>
> The DME is at a frequency very near to that of the transponder. When
> the DME transmitter sends out a couple hundred watt pulse the
> transponder's receiver is overloaded. It may generate a reply. To get
> around this problem the DME puts a pulse on the suppression line
> when it is getting ready to transmit. This inhibits the transponder
> from responding and sending out a bogus reply.
>
> If you have a DME you should connect its suppression output to the
> suppression input of the transponder. No DME? No worry.
>
> Brian Lloyd 361 Catterline Way
> brian HYPHEN av AT lloyd DOT com Folsom, CA 95630
> +1.916.367.2131 (voice) +1.270.912.0788 (fax)
>
> I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
________________________________________________________________________________
| From: | "Bill Denton" <bdenton(at)bdenton.com> |
| Subject: | Mic plug / PTT wiring |
What brand of control stick are you using?
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Deems
Davis
Sent: Thursday, September 14, 2006 3:46 PM
Subject: Re: AeroElectric-List: Mic plug / PTT wiring
I think I understand the need to isolate the mic plug with the
insulating washers. My question which remains is does the PTT switch
need to be wired directly to the common terminal (as depicted on the web
site example) on the mic plug? In my case this will be difficult as I
plan to use a switch on a control stick which already is wired with a
common ground. I'm 'assuming' that I can wire the control grip switch to
the mic plug 'key' terminal, and the common/ground will be through the
common/ground in the control grip wiring. (?)
Deems Davis RV10 # 406
Panel/wiring
http://deemsrv10.com/
John Morgensen wrote:
>
>
> Hope I can contribute here. I encountered an FBO Cessna that was not
> grounded properly. The symptoms were PTT produced a side-tone with old
> cheap headsets but no side-tone with brand new ANR headsets.
>
> John Morgensen RV-9A QB
>
> Deems Davis wrote:
>
>>
>>
>> The example on Bob's web site shows that the PTT switch is wired to
>> the Ground/common on the Mic plug recepticle (in addition to the
>> key/terminal) is there any reason why the PTT switch (in my case on a
>> control stick/grip) can't be wired to a common ground for the
>> control/ grip rather than to the mic plug common?
>>
>> Deems Davis RV-10 # 406
>> Panel/wiring
>> http://deemsrv10.com/
>>
>>
>>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
________________________________________________________________________________
| From: | Nancy Ghertner <nghertner(at)verizon.net> |
| Subject: | Re: What I learned today |
Bob, put a stop to this banter; you guys are driving me nuts.
Lory Ghertner
________________________________________________________________________________
| From: | djones(at)northboone.net |
| Subject: | Re: Radio shields |
Thanks Bob
If one solders the wire to the cup, would the pig tail solder literally
onto the
side of the cup or in the cup and would you join the wires first? If I splice
the wires using the pin pocket what would be the best way to splice the wires
together prior to installing into the pocket, i.e. wrapped, soldered?
Dennis
Quoting "Robert L. Nuckolls, III" :
>
>
>
>>
>>
>>
>>> I m wiring the harness for a Terra TX-760D radio. My question is
>>> the interconnect diagram shows the shield for the mic. audio, mic.
>>> key and the headphone attach to the ground. I plan on using the
>>> daisy chain system shown by Bob, however I m confused about the
>>> shields connecting into the ground wire itself or do they connect
>>> to the shield of the ground wire?
>>
>> Can you scan the wiring from the instruction manual
>> and send it to me?
>>
>> It would be useful to see how they've depicted their
>> suggestions for the installation.
>
> Okay, got the scans. Great.
>
> I guess I'm not sure what the question is. The schematic shows
> two aircraft ground (A/C Ground) connections to pins 4 and 15.
> Wires that the manufacturer recommends be shielded have their
> shield grounds returned to specific pins. They also show how
> the shield can double as a ground return for mic, headphone,
> speaker leads, etc. Further, their wiring suggests exactly
> the same daisy-chaining technique I described in:
>
> http://aeroelectric.com/articles/pigtail/pigtail.html
>
> OOPS! I just re-read your question and I think missed
> something the first time. You talk about a "shield of
> the ground wire".
>
> The drawings show single strands of wire from pins 4 and
> 15 to ground. Your pigtails would either solder onto the
> shared solder cups or splice into the ground wires immediately
> adjacent to where they drop into the crimped on pin pocket.
> The ground wires are not shielded.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | djones(at)northboone.net |
| Subject: | Re: Radio shields |
Bob
When you speak of the "shield grounds return to specific pins" are you talking
about pins 4 and 15? The shield doubling as a ground return are you
refering to
the shield attaching to the mic and headphone jack lugs?
Dennis
Quoting "Robert L. Nuckolls, III" :
>
>
>
>>
>>
>>
>>> I m wiring the harness for a Terra TX-760D radio. My question is
>>> the interconnect diagram shows the shield for the mic. audio, mic.
>>> key and the headphone attach to the ground. I plan on using the
>>> daisy chain system shown by Bob, however I m confused about the
>>> shields connecting into the ground wire itself or do they connect
>>> to the shield of the ground wire?
>>
>> Can you scan the wiring from the instruction manual
>> and send it to me?
>>
>> It would be useful to see how they've depicted their
>> suggestions for the installation.
>
> Okay, got the scans. Great.
>
> I guess I'm not sure what the question is. The schematic shows
> two aircraft ground (A/C Ground) connections to pins 4 and 15.
> Wires that the manufacturer recommends be shielded have their
> shield grounds returned to specific pins. They also show how
> the shield can double as a ground return for mic, headphone,
> speaker leads, etc. Further, their wiring suggests exactly
> the same daisy-chaining technique I described in:
>
> http://aeroelectric.com/articles/pigtail/pigtail.html
>
> OOPS! I just re-read your question and I think missed
> something the first time. You talk about a "shield of
> the ground wire".
>
> The drawings show single strands of wire from pins 4 and
> 15 to ground. Your pigtails would either solder onto the
> shared solder cups or splice into the ground wires immediately
> adjacent to where they drop into the crimped on pin pocket.
> The ground wires are not shielded.
>
> Bob . . .
>
>
________________________________________________________________________________
| Subject: | Warning alarms into Flightcom403 |
| From: | "Allan Aaron" <aaaron(at)tvp.com.au> |
I would like to pipe the warning tones from my EIS4000, my transponder
and my GPS into my intercom (FC403D). I have an IPOD jack set up to go
through the auxiliary audio input and thought I would simply use one of
the unused mic inputs for the warning tones. I realize that this may not
be ideal if the pilot isolate switch is on ... I can live with that. The
mic has two wires into the intercom but the warning outputs just have
single wires out of the devices. How would I go about wiring up the
mike jack in this configuration? Thanks for the advice.
Allan
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Re: Fuel Pump Switch(es |
On 14 Sep 2006, at 09:33, Gary Casey wrote:
>
>
>> Subject: Re: AeroElectric-List: Fuel Pump Switch(es)
>>
>> Fuel system problems are a major cause of engine stoppage in
>> homebuilt aircraft. Any fuel system that deviates from the norm, in
>> either design or installation details, opens the door to unexpected
>> problems. You have made a bunch of assumptions on how the system
>> will perform following various types of failures. It would be wise
>> to validate those assumptions via actual tests, either on the ground,
>> or in the air over a nice long runway.
>>
>> Kevin Horton
>
> Here is the reply below the reference, as suggested by another
> lister..
> Yes, perhaps the biggest disadvantage of using two separate fuel
> valves is the one you suggest - it deviates from the "norm." And
> changing tanks takes two motions - opening the new valve, followed
> by closing the old valve. Since the weakest link in any safety
> system is usually the operator, what would happen if he (me) did
> something wrong? If you shut off one tank before turning the other
> on the engine will quit immediately - instant feedback and
> obviously correctable. If you turn one on and forget to turn the
> other off nothing will immediately happen, but before the engine
> will suck air one tank has to go completely empty and in the case
> of my installation there are gages and both audio and visual
> warnings of that event. I felt these disadvantages are compensated
> for by the advantages of being able to shut the fuel off before it
> enters the cockpit, reduction in the number of fittings in the
> cockpit (someone correctly pointed out that the total number of
> fittings might not change), and completely independent fuel
> controls. But I don't think I've made any "assumptions" regarding
> the operation - the failure modes and results are fairly
> straightforward - valve off, no flow - valve on, flow. Perhaps the
> only unknown is what happens with low tanks and both valves open,
> and that has been discovered by others - the empty tank can allow
> air into the system, preventing the use of the fuel in the other
> tank. To verify this one would have to fly with one tank empty and
> the other almost empty, and I am not willing to do that. Regarding
> the number of fittings I recall counting the possible in-cockpit
> leaks in the standard ES system at something over 30 with one
> moving seal and quite a number of those remain "wet" even though
> the fuel valve is turned off. My system has a total of 7 potential
> leak paths in the cockpit and no moving seals, all of which go
> "dry" with the fuel valves off. The builder with the "electric"
> engine and one electric pump in each wing can probably has even
> fewer, except he can't positively shut anything off.
I've worked full time in the flight test world since 1987. I've seen
numerous cases where aircraft systems did not perform as expected.
In every case the system designer had an apparently solid analysis
that predicted how the system should perform, yet he overlooked some
aspect, and tests showed that the system did not perform as
expected. If this is not a critical system, then it doesn't really
matter. But, here we have a critical system, and you have based the
decision on the system architecture on some assumptions about how the
system will work. Someday those assumptions will be tested. If you
test the assumptions during the flight test program, you can
structure the test so you are still safe even if the system does not
perform as expected. If you don't do the test then, someday you may
stumble across that condition when you hadn't planned it. If the
system works as expected, then everything is OK. But if the system
does not perform, then you may lose the aircraft.
For example, what is the engine restart procedure after you have shut
one tank down, and were slow opening the other fuel valve, resulting
in engine stoppage? When would you rather try out your planned
restart procedure for the first time? Overhead a long runway at
5,000 ft when you were mentally prepared for problems? Or over rough
country with no fields or runways in sight when a stoppage would be a
complete surprise?
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Radio shields |
>
>Bob
>
>When you speak of the "shield grounds return to specific pins" are you talking
>about pins 4 and 15?
Yes . . . the schematic clearly shows that both shield grounds -and-
power grounds to airframe connect to pins 15 and 4.
> The shield doubling as a ground return are you refering to
>the shield attaching to the mic and headphone jack lugs?
Yes . . . the outer shield braid doubles as electrostatic
shield -AND- signal ground for the remote components.
This is a common technique. I use it several places in
the wiring diagrams shown in.
http://www.aeroelectric.com/Catalog/AEC/9009/9009-700J.pdf
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Radio shields |
>
>Thanks Bob
>
>If one solders the wire to the cup, would the pig tail solder literally
>onto the
>side of the cup or in the cup and would you join the wires first? If I splice
>the wires using the pin pocket what would be the best way to splice the wires
>together prior to installing into the pocket, i.e. wrapped, soldered?
The cups are obviously too small to accept a pair of wires.
September 07, 2006 - September 14, 2006
AeroElectric-Archive.digest.vol-gc