AeroElectric-Archive.digest.vol-dt
November 30, 2004 - December 15, 2004
________________________________________________________________________________
| From: | "Ted Palamarek" <temco(at)telusplanet.net> |
| Subject: | out of town for a few days |
Bob
Where are these transistors used. Are they a pressurized on
non pressurized environment??. If unpressurized then you do
not have the same ambient cooling. Just a thought
Ted Palamarek
Edmonton
<<<>>>
Subject: AeroElectric-List: out of town for a few days
Nuckolls, III"
I'm off on a trip to Tucson AZ for Raytheon. Gotta go figure
out why some transistors in a new product are overheating at
51,000' . . . any guesses?
If I can access my e-mail accounts from the hotel, I'll
be on line in the evenings. Otherwise, see you all Friday
night.
Bob . . .
------------------------------------------------------
--
< Throughout history, poverty is the normal condition
>
< of man. Advances which permit this norm to be
>
< exceeded -- here and there, now and then -- are the
>
< work of an extremely small minority, frequently
>
< despised, often condemned, and almost always opposed
>
< by all right-thinking people. Whenever this tiny
>
< minority is kept from creating, or (as sometimes
>
< happens) is driven out of a society, the people
>
< then slip back into abject poverty.
>
<
>
< This is known as "bad luck".
>
< -Lazarus Long-
>
<------------------------------------------------------>
http://www.aeroelectric.com
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===========
________________________________________________________________________________
| Subject: | Re: Out of town for a few days OT |
| From: | "Matt Prather" <mprather(at)spro.net> |
Is the primary radiation source the sun? Is there significantly less
radiation when flying at night? Does the system fail when flying at
51,000' at night?
Matt-
>
>
>
>>I'm off on a trip to Tucson AZ for Raytheon. Gotta go figure
>>out why some transistors in a new product are overheating at
>>51,000' . . . any guesses? Bob . . .
>
> Assuming the wax is not melting, being so close to the sun...
> Furthermore assuming the requisite performance testing was done, then
> consider two possibilities:
>
> 1) The T.I.D.E. (total ionizing dose effect) on the semiconductor
> junctions. Remember-- every hour above 30,000 feet is the REM equivalent
> of one chest photocurrents.
> 2) Environmental test chamber fans. The most devious sort of failure is
> sometimes designed in because stirring fans in test chambers induce
> cooling.
>
> When all else fails....Google it! And good luck.
>
> Regards,
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge MA 01550-2705
> Phone (508) 764-2072
> Email: emjones(at)charter.net
>
> Teamwork: " A lot of people doing exactly what I say."
> (Marketing exec., Citrix Corp.)
>
>
________________________________________________________________________________
| From: | mkejrj(at)comcast.net |
| Subject: | Cross feed voltage on Z 14 and EI VA 1 Volt/ammeter |
Bob and Others,
I'm installing the Z 14 electric system with 2 Alternators , 2 Busses, and 2
Batterys. In order to know theAmperage and Voltage of each system I installed
an Electronics Intl. guage... Their model VA 1. The guage is supplied with operating
power from theMain Alternator/ Battery Bus with a 2 Amp fuse.
In order to check each system independantly I also installed a 2-3 type switch
ordered from EI which they indicate is used by Twin engine aircraft to independently
moniter either Alternator. The switch has inputs from both the Main
and the Aux Shunt and enables the Pilot to select either ,but not both.
When we installed the VA 1 with the 2-3 switch we noted a back feeding of voltage
from the Main Bus to the Aux Buss in some operating configurations. Specifically
we measured 6 Volts on the Aux Buss when :
TheMain Master switch is ON
The Aux Master switch is OFF
The Cross feed switch is OFF
The VA 1 is switched to the Aux Shunt/Alternator
According to our understanding of Z 14 no power should be distributed to the
Aux system when the switches are in the configuration above and yet we measured
6 Volts.This configuration could present a problem if, for example, a Gyro
type instrument fed from the Aux Buss was, unknown to the Pilot, operating at
a reduced RPM due to a reduced Voltage.
We determined that the EI guage was cross feeding from the Main Buss (which supplies
it's power ) through the guages internal wiring and through the Aux Shunt
to the Aux Buss.
We called EI and discovered that the VA 1 is designed to be used in a system
where BOTH THE POWER TO THE GUAGE AND THE SHUNT MEASURED ARE ON THE SAME SYSTEM.
Apparently most production twin aircraft have a common Buss supplied by both
Alternators and so the VA 1 works fine for them. It could be a problem with
Z 14 when the Main and Aux Buss can be independant as outlined above.
The only "fix "for the problem that we contrived is to replace EI's 2-3 switch
with a 3 Pole, Double Throw (on/on ) type. This would supply the EI guage with
both operating power and Shunt data from the same system.
If you or any other Listers have any thoughts or solutions I would be pleased
to hear em.
Thanks,
Dick Jordan
RV 8A Finishing
N888BZ Reserved
Bob and Others,
I'm installing the Z 14 electric system with 2 Alternators, 2 Busses, and 2 Batterys.
In order to know theAmperage and Voltage of each system I installed an
Electronics Intl. guage... Their model VA 1. The guage is supplied with operating
power from theMain Alternator/ Battery Bus with a 2 Amp fuse.
In order to check each system independantly I also installed a 2-3 type switch
ordered from EI which they indicate is used by Twin engine aircraft to independently
moniter either Alternator. The switch has inputs fromboth the Mainand
the Aux Shunt and enables the Pilot to select either ,but not both.
When we installed the VA 1 with the 2-3 switch we noted a back feeding of voltage
from the Main Bus to the Aux Buss in some operating configurations. Specifically
we measured 6 Volts on the Aux Buss when :
TheMain Master switch is ON
The Aux Master switch is OFF
The Cross feed switch is OFF
The VA 1 is switched to the Aux Shunt/Alternator
According to our understanding of Z 14 no power should be distributed to the Aux
system when the switches are in the configuration above and yet we measured
6 Volts.This configuration could present a problem if, for example, a Gyro type
instrument fed from the Aux Buss was, unknown to the Pilot, operating at a
reduced RPM due to a reduced Voltage.
We determined that the EI guage was cross feeding from the Main Buss (which supplies
it's power ) through the guages internal wiring and through the Aux Shunt
to the Aux Buss.
We called EI and discovered that the VA 1 is designed to be used in a system where
BOTH THE POWER TO THE GUAGE AND THE SHUNT MEASUREDARE ON THE SAME SYSTEM.
Apparently most production twin aircraft have a common Buss supplied by both
Alternators and so the VA 1 works fine for them. It could be a problem with Z
14 when the Main and Aux Buss can be independant as outlined above.
The only "fix "for the problem that we contrived is to replace EI's 2-3 switch
with a 3 Pole, Double Throw (on/on ) type. This would supply the EI guage with
both operating power and Shunt data from the same system.
If you or any other Listers have any thoughts or solutions I would be pleased
to hear em.
Thanks,
Dick Jordan
RV 8A Finishing
N888BZ Reserved
________________________________________________________________________________
| From: | Phil Birkelbach <phil(at)petrasoft.net> |
| Subject: | Re: hall effect current sensor ammeter |
Grand Rapids supplies a hall effect sensor with their engine monitors.
Phil
thomas a. sargent wrote:
>
>I have been looking for an ammeter that uses a Hall effect sensor
>(instead of a shunt) to use to show battery charge/discharge current.
>There don't seem to be any in the aircraft instrument catalogs. I did
>some web searching and found these nifty sensors that run on 12-15v and
>output 1 ma for each amp sensed. It looks like you could use this
>instead of a shunt with just the approriate choice of sense resistor and
>connect it to an ordinary battery meter from ACS or a generic LCD panel
>meter. Any reason this wouldn't work?
>
>http://www.fwbell.com/stm/content.asp?page_id=673
>
>Before the flames start, I realize that shunts are cheap and pretty fool
>proof (these sensors cost about $36 from Newark Electronics). However,
>shunts do add a bit of resistance and a couple more connections, which
>is bad to put in a 200 amp circuit, which your battery is in. The Hall
>effect sensor does not connect electrically to the battery cable. The
>cable just goes thru it. Hall effect also rates high on the
>slick-o-meter. I note that my VM1000 uses a hall effect sensor on the
>alternator B lead, so Vision Micro thought a Hall effect sensor was a
>good idea.
>
>I've emailed F.W. Bell to ask what happens if you over load the 50amp
>sensor with 200 amps. I suspect that, since this is a nulling device, it
>just rails its output current at 50ma and sits there.
>
>--
>Tom Sargent
>RV-6A
>
>
>
>
________________________________________________________________________________
| From: | "LarryRobertHelming" <lhelming(at)sigecom.net> |
| Subject: | Re: hall effect current sensor ammeter |
So does ACS2002.
Indiana Larry
----- Original Message -----
From: "Phil Birkelbach" <phil(at)petrasoft.net>
>
> Grand Rapids supplies a hall effect sensor with their engine monitors.
>
> Phil
>
> thomas a. sargent wrote:
>
> >
> >I have been looking for an ammeter that uses a Hall effect sensor
> >(instead of a shunt) to use to show battery charge/discharge current.
> >There don't seem to be any in the aircraft instrument catalogs. I did
> >some web searching and found these nifty sensors that run on 12-15v and
> >output 1 ma for each amp sensed. It looks like you could use this
> >instead of a shunt with just the approriate choice of sense resistor and
> >connect it to an ordinary battery meter from ACS or a generic LCD panel
> >meter. Any reason this wouldn't work?
> >
> >http://www.fwbell.com/stm/content.asp?page_id=673
> >
> >Before the flames start, I realize that shunts are cheap and pretty fool
> >proof (these sensors cost about $36 from Newark Electronics). However,
> >shunts do add a bit of resistance and a couple more connections, which
> >is bad to put in a 200 amp circuit, which your battery is in. The Hall
> >effect sensor does not connect electrically to the battery cable. The
> >cable just goes thru it. Hall effect also rates high on the
> >slick-o-meter. I note that my VM1000 uses a hall effect sensor on the
> >alternator B lead, so Vision Micro thought a Hall effect sensor was a
> >good idea.
> >
> >I've emailed F.W. Bell to ask what happens if you over load the 50amp
> >sensor with 200 amps. I suspect that, since this is a nulling device, it
> >just rails its output current at 50ma and sits there.
> >
> >--
> >Tom Sargent
> >RV-6A
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Out of town for a few days OT |
clamav-milter version 0.80j
on juliet.albedo.net
Matt Prather wrote:
>
>Is the primary radiation source the sun?
>
No.
> Is there significantly less
>radiation when flying at night?
>
No.
Unless a solar event happens to be occuring it is 24 hour a day galactic
background radiation.
My rough rule of thumb is that the dose increases 70% with every 4000
foot of altitude increase above sea level. I consider the dose totally
benign at unpressurized cruising altitudes. A number of commercial
sensors optimised for something else are relatively insensitive to this
radiation but a common geiger counter is quite interesting.
Ken
> Does the system fail when flying at
>51,000' at night?
>
>Matt-
>
>
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: RG-400 connector |
clamav-milter version 0.80j
on juliet.albedo.net
Hi Lucky
I believe that the standard BNC connectors for (one not both) either
RG58 or RG59 fit RG400 but I don't remember which one it is. Hopefully
someone will tell us.
Ken
lucky wrote:
>
>I bought some RG-400 cable for my VHF Comm with connectors already on. But the
wire length is turning out to be about twice what's actually needed.
>Is there a RG-400 specific crimp on BNC connector type I should specifically ask
for? ie, is this going to be a Radio Shack item or should I turn to mail order
for this one?
>TIA,
>Lucky
>
>
>I bought some RG-400 cable for my VHF Comm with connectors already on. But the
wire length is turning out to be about twice what's actually needed.
>
>
>Is there a RG-400 specific crimp on BNCconnector type I should specifically ask
for? ie, is this going to be a Radio Shack item or should I turn to mail order
for this one?
>
>
>TIA,
>
>
>Lucky
>
>
>
________________________________________________________________________________
| From: | luckymacy(at)comcast.net (lucky) |
| Subject: | Re: RG-400 connector clamav-milter version 0.80j on |
juliet.albedo.net
yeah, that's the kind of detailed info I am still looking for since I've been told
the cable is designed differently than RG-58 so I thought there was a good
chance the connector might be slightly different. I got back advise on tools
but not the connector type info I originally asked for...
-------------- Original message --------------
>
> Hi Lucky
> I believe that the standard BNC connectors for (one not both) either
> RG58 or RG59 fit RG400 but I don't remember which one it is. Hopefully
> someone will tell us.
> Ken
>
>
> lucky wrote:
>
> >
> >I bought some RG-400 cable for my VHF Comm with connectors already on. But the
> wire length is turning out to be about twice what's actually needed.
> >Is there a RG-400 specific crimp on BNC connector type I should specifically
> ask for? ie, is this going to be a Radio Shack item or should I turn to mail
> order for this one?
> >TIA,
> >Lucky
> >
> >
> >I bought some RG-400 cable for my VHF Comm with connectors already on. But the
> wire length is turning out to be about twice what's actually needed.
> >
> >
> >Is there a RG-400 specific crimp on BNCconnector type I should specifically
ask
> for? ie, is this going to be a Radio Shack item or should I turn to mail order
> for this one?
> >
> >
> >TIA,
> >
> >
> >Lucky
> >
> >
> >
>
>
>
>
>
>
yeah, that's the kind of detailed info I am still looking for since I've been told
thecable is designed differently than RG-58 so I thought there was a good
chance the connector might be slightly different. I got back advise on tools but
not the connector type info I originally asked for...
-------------- Original message --------------
-- AeroElectric-List message posted by: Ken
Hi Lucky
I believe that the standard BNC connectors for (one not both) either
RG58 or RG59 fit RG400 but I don't remember which one it is. Hopefully
someone will tell us.
Ken
lucky wrote:
-- AeroElectric-List message posted by: luckymacy(at)comcast.net (lucky)
I bought some RG-400 cable for my VHF Comm with connectors already on. But the
wire length is turning out to be about twice what's actually needed.
Is there a RG-400 specific crimp on BNC connector type I should specifically
ask for? ie, is this going to be a Radio Shack item or should I turn to mail
order for this one?
TIA, Lucky
I bought some RG-400 cable for my VHF Comm with connectors already on. But the
wire length is turning out to be about twice what's actually needed.
Is there a RG-400 specific crimp on BNCconnector type I should specifically ask
for? ie, is this going to be a Radio Shack item or should I turn to mail order
for this one?
TIA,
Lucky
fts provided by the
Engine: http://www.matronics.com/search
________________________________________________________________________________
| From: | "Bobby Hester" <bhester(at)hopkinsville.net> |
| Subject: | Re: RG-400 connector clamav-milter version 0.80j |
on juliet.albedo.net
> -----Original Message-----
> From: luckymacy(at)comcast.net (lucky)
> To: aeroelectric-list(at)matronics.com
> Date: Fri, 03 Dec 2004 13:23 (CDT)
> Subject: Re: AeroElectric-List: RG-400 connector clamav-milter version 0.80j
> on juliet.albedo.net
>
>
> yeah, that's the kind of detailed info I am still looking for since I've
> been told the cable is designed differently than RG-58 so I thought there
> was a good chance the connector might be slightly different. I got back
> advise on tools but not the connector type info I originally asked for...
>
http://www.steinair.com/connectors.htm
3 Piece BNC Male Crimp Connector for RG400 & RG58 Coax Cable. by Amphenol
-------
Surfing the web from Hopkinsville, KY
RV7A web site: http://www.geocities.com/hester-hoptown/RVSite
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | ELT Antenna length |
Hi,
I'm having trouble finding a good place to put my ELT
antenna, and I'd like to know if I can shorten the
antenna that came with my ELT. I've read through
the archives, which seem to have conflicting information.
I've read that a rubber duckie antenna will work, but
it will take more power than the antenna that came with
the Ameriking ELT. Is this correct? Anyone have a good
source for these rubber duckie antennas?
I calculated the recommended length of the ELT 121.5 MHz
quarter-wave antenna to be about 24.3 inches
(299,792,458 meters/second / 121.5MHz / 4 = .6168569 meters).
Does this sound right? I guess this assumes a good
ground plane, which I won't have if I mount this thing under the VS.
I need to shorten the antenna to fit under
my VS, since that seems to be where Van's installs
them on the RV8. I can't find a better place for this
thing. Some people have installed them under the right
elbow of the passenger, but that does not seem much
better than the tail.
Any and all suggestions welcome!
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | "James Redmon" <james(at)berkut13.com> |
| Subject: | Toggle Switch Knob |
All,
I have a MS24659-21A toggle switch being used for the landing gear select
switch. It's the lock up/lock down variety toggle switch with the large
"bat" lever. I have seen small "gear wheel" shaped knobs (a little over an
1" in diameter) that can be attached to the switch lever itself making the
assembly look like a production gear selector switch. I would like to add
that to my bird.
Does anyone know a part number or where to search for that "wheel shaped"
knob to fit that style toggle switch?
You can see what my current install looks like at:
http://www.berkut13.com/intior35.jpg
James Redmon
Berkut #013 N97TX
http://www.berkut13.com
________________________________________________________________________________
| From: | "923te" <923te(at)cox.net> |
| Subject: | Alternator Off During Start Up? |
I searched the archives for a response to this AOPA article from April 2003 and
found none. Anyone have an opinion about the practice of starting on battery
only, with alternator turned off? Should we be starting with the alternator off?
Thanks,
Ned
April 2003 Article "Charge It!" by Steven W. Ells
(Second from last paragraph: )
"Many pilots with split master switches have modified the owners manual starting
procedure by leaving the alternator half of the switch in the Off position until
after the start sequence. After starting, but before turning on any other
equipment such as radios or lights, the pilot turns on the alternator half of
the switch and checks for positive movement of the ammeter needle. This verifies
that the charging system is online. Engine starting is a time when the contactors
that control large current flows are opening and closing. The potential
for large voltage spikes ripping through the electrical system is very high
during this brief moment. Since rectifiers, switches, and other solid state
devices are adversely affected by spikes, it's a good idea to isolate charging-system
components during starting - unless you have a generator on your airplane."
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Alternator Off During Start Up? |
On Dec 3, 2004, at 1:17 PM, 923te wrote:
>
> I searched the archives for a response to this AOPA article from April
> 2003 and found none. Anyone have an opinion about the practice of
> starting on battery only, with alternator turned off? Should we be
> starting with the alternator off?
The only down side to starting with the alternator on is the 5A or so
drain on the battery to energize the field circuit during the period of
time that the engine is not rotating, i.e. between the time the battery
master is turned on and the engine is started. Given the 200A or so
drain by the starter, the extra 5A drain just doesn't seem that
crucial.
> and checks for positive movement of the ammeter needle. This verifies
> that the charging system is online.
This isn't a bad thing but you can just turn the alternator switch off
then on to verify that the alternator is working. Of course, if the
buss voltage is 13.5V or so you already know that the alternator is
working.
> Engine starting is a time when the contactors that control large
> current flows are opening and closing. The potential for large
> voltage spikes ripping through the electrical system is very high
> during this brief moment.
Oh, what hogwash. When you turn on a big load the voltage goes down,
not up. I think we have already learned that there aren't 'spikes
ripping through the electrical system.' Bob has the 'scope traces to
show that. Do people ever bother to do any research?
> Since rectifiers, switches, and other solid state devices are
> adversely affected by spikes, it's a good idea to isolate
> charging-system components during starting - unless you have a
> generator on your airplane."
Oh, what hogwash. Has anyone noticed that alternators and charging
systems rarely fail? Let's look at automobiles. Lots more of them
than airplanes and they have even less protection for their charging
systems. I don't see alternators in cars dropping like flies.
One thing I learned a long time ago is the most of the problems you can
think up aren't real.
Bah! Humbug!
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: Alternator Off During Start Up? |
>Oh, what hogwash. When you turn on a big load the voltage goes down,
>not up. I think we have already learned that there aren't 'spikes
>ripping through the electrical system.' Bob has the 'scope traces to
>show that. Do people ever bother to do any research?
I love it when Old Wife's Tales get blown out of the water.
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | "Matthew Brandes" <matthew(at)n523rv.com> |
| Subject: | RE: Alternator Off During Start Up? |
I was thinking of a similar thing... but with a twist.
Instead of having a seperate avionics master switch (I don't think Bob likes
these), could you use a 3-pole, 3-position switch (like the 2-10 with an
extra pole)? Flip to middle position for start (battery only) then flip up
to 3rd position to turn on the Alternator and ALSO the avionics.
(Don't shoot me.. I'm just starting to wrap my head around all this
electrical stuff... I have some other questions but need to read through the
book and archives first before I embarrass myself.)
Matthew
RV-9A Finish Kit
________________________________________________________________________________
| From: | Gary Liming <gary(at)liming.org> |
| Subject: | Stereo Headphone jacks |
Sorry if this information has been previously covered, but a search in the
archives didn't turn up an answer to the following two questions:
1. When a mono headset is plugged into a stereo jack, one of the channels
gets grounded (gets connected to the plug sleeve, which also is the jack
ground.) I am using the Stereo Iso Amp of Aeroelectric Connection to drive
the phones, so is it ok for the amp to run for long periods with one of the
channels like this? (Most of the time there will be stereo phones used,
but I am building a 4 seater, and the rear seats may have to accommodate an
occasional mono headset.)
2. When wiring the stereo jacks, does the audio ground really need to be
separate from the shield? In other words, is 3 conductor wire + shield
necessary, or will 2 conductor + shield be just as noise immune? Note, I
am not grounding the shield locally, it is run back for connection to the
amp, and the jacks are isolated from frame ground.
Thanks in advance,
Gary Liming
________________________________________________________________________________
| From: | John Grosse <grosseair(at)ameritech.net> |
| Subject: | Re: Alternator Off During Start Up? |
Okay, I don't want to start another war here, and please don't shoot me
if I turn out to be wrong, but... The issue with taking the alternator
off line with a separate switch during startup as I understand it is not
voltage spikes. So far I agree with the debunkers. The issue is the
alternator trying to supply 200 amps to the starter which, of course, it
can't do. This, as I've been led to understand, is not a good thing for
the alternator because it creates an overload or something? I don't
totally understand the dynamics inside the alternator, but it supposedly
stress something in there out and causes premature failures.
As far as the "automobiles don't do it" argument goes... I'm not so sure
they don't actually do it. They just do it automatically for you. When
you turn the key to energize the starter power is shut off to all the
accessories... and the alternator??
A little empirical data... I went through 2 alternators in about a 1000
hrs before I put in a split switch. Since I put in the switch I've had
no failures... knock on wood.
Whatever is going on in our airplanes sure causes the alternator to fail
a lot more often than in our cars, and it's not just vibration.
Mickey Coggins wrote:
>
>
>
>
>>Oh, what hogwash. When you turn on a big load the voltage goes down,
>>not up. I think we have already learned that there aren't 'spikes
>>ripping through the electrical system.' Bob has the 'scope traces to
>>show that. Do people ever bother to do any research?
>>
>>
>
>I love it when Old Wife's Tales get blown out of the water.
>
>
>--
>Mickey Coggins
>http://www.rv8.ch/
>#82007 QB Wings/Fuselage
>
>
>
>
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: ELT Antenna length |
Mickey
Best location I've seen so far is on the right side of the pilot's seat
back weldment. I spotted an RV-8 at Sun N' Fun with this setup. I took a
photo of it, but can't seem to find it now! :-(
Charlie Kuss
>
>
>Hi,
>
>I'm having trouble finding a good place to put my ELT
>antenna, and I'd like to know if I can shorten the
>antenna that came with my ELT. I've read through
>the archives, which seem to have conflicting information.
>I've read that a rubber duckie antenna will work, but
>it will take more power than the antenna that came with
>the Ameriking ELT. Is this correct? Anyone have a good
>source for these rubber duckie antennas?
>
>I calculated the recommended length of the ELT 121.5 MHz
>quarter-wave antenna to be about 24.3 inches
>(299,792,458 meters/second / 121.5MHz / 4 = .6168569 meters).
>Does this sound right? I guess this assumes a good
>ground plane, which I won't have if I mount this thing under the VS.
>
>I need to shorten the antenna to fit under
>my VS, since that seems to be where Van's installs
>them on the RV8. I can't find a better place for this
>thing. Some people have installed them under the right
>elbow of the passenger, but that does not seem much
>better than the tail.
>
>Any and all suggestions welcome!
>
>Thanks,
>Mickey
>
>
>--
>Mickey Coggins
>http://www.rv8.ch/
>#82007 QB Wings/Fuselage
>
>
________________________________________________________________________________
| From: | "Bob White" <bob(at)whitek.com> |
| Subject: | Re: Alternator Off During Start Up? |
Automobiles live with a thing called "load dump" or "load dump transient,"
where if something shuts off or a wire breaks, the alternator output voltage
will jump way up momentarily. I forget if they design to 40 or 70 volts,
and somewhere in the car or an accessory is a huge zener to limit
overvoltage beyond that. Try googling "load dump" for more info (a guess, I
haven't bothered). To me, the surprising thing was that the battery doesn't
filter the transient. I guess, while the battery is a lot like a big
capacitor, it does have internal resistance which limits its response time.
Bob White
----- Original Message -----
From: "John Grosse" <grosseair(at)ameritech.net>
Subject: Re: AeroElectric-List: Alternator Off During Start Up?
Okay, I don't want to start another war here, and please don't shoot me
if I turn out to be wrong, but... The issue with taking the alternator
off line with a separate switch during startup as I understand it is not
voltage spikes. So far I agree with the debunkers. The issue is the
alternator trying to supply 200 amps to the starter which, of course, it
can't do. This, as I've been led to understand, is not a good thing for
the alternator because it creates an overload or something? I don't
totally understand the dynamics inside the alternator, but it supposedly
stress something in there out and causes premature failures.
As far as the "automobiles don't do it" argument goes... I'm not so sure
they don't actually do it. They just do it automatically for you. When
you turn the key to energize the starter power is shut off to all the
accessories... and the alternator??
A little empirical data... I went through 2 alternators in about a 1000
hrs before I put in a split switch. Since I put in the switch I've had
no failures... knock on wood.
Whatever is going on in our airplanes sure causes the alternator to fail
a lot more often than in our cars, and it's not just vibration.
Mickey Coggins wrote:
>
>
>>Oh, what hogwash. When you turn on a big load the voltage goes down,
>>not up. I think we have already learned that there aren't 'spikes
>>ripping through the electrical system.' Bob has the 'scope traces to
>>show that. Do people ever bother to do any research?
>>
>>
>
>I love it when Old Wife's Tales get blown out of the water.
>
>
>--
>Mickey Coggins
>http://www.rv8.ch/
>#82007 QB Wings/Fuselage
>
>
________________________________________________________________________________
| From: | Richard Riley <richard(at)RILEY.NET> |
| Subject: | Re: Alternator Off During Start Up? |
At 02:46 PM 12/3/04, you wrote:
>
>Okay, I don't want to start another war here, and please don't shoot me
>if I turn out to be wrong, but... The issue with taking the alternator
>off line with a separate switch during startup as I understand it is not
>voltage spikes. So far I agree with the debunkers. The issue is the
>alternator trying to supply 200 amps to the starter which, of course, it
>can't do. This, as I've been led to understand, is not a good thing for
>the alternator because it creates an overload or something? I don't
>totally understand the dynamics inside the alternator, but it supposedly
>stress something in there out and causes premature failures.
One more point of anecdotal information. I have a high compression 540 and
long starter leads. Several times I've had difficulty starting the engine
with the alt. field on. When I turn the field off it seems to crank faster
and starts easily.
Is the alt putting a lot of drag on the engine when the voltage drops on
cranking?
________________________________________________________________________________
| From: | "Mark Sletten" <marknlisa(at)hometel.com> |
| Subject: | Re: Toggle Switch Knob |
Why don't you just carve one out of wood? I carved a flap lever out of
aluminum using a grinder, but the round shape of the wheel might be
easier with wood.
Mark & Lisa Sletten
Legacy FG N828LM
http://web.hometel.com/~legacyfgkit
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
| Subject: | Re: Alternator Off During Start Up? |
<>
I think when push comes to shove I believe the average car will have a
slightly "quieter" electrical system than a plane. Since weight is not an
issue they have a much larger battery and larger-gage ground wires, both of
which tend to keep voltage transients down. Although, since we supply
electronic components to the auto industry we are constantly being surprised
with weird glitches that - of course - are all our fault. The "load dump"
phenomena is caused by the inductance of the field in the alternator -
imagine the alternator cranking out full current to supply a load and then
that load is suddenly removed. The voltage regulator senses the increasing
system voltage and shuts off the field. However, the field, being created
by a large coil of wire surrounding an iron core, can't be instantly
changed, so the alternator continues to produce now-excess current until the
field current decays, which takes 10's of milliseconds. The effect is
usually very slight as the battery serves to hold the voltage at a
near-constant level, absorbing the momentary excess current. The load dump
that causes big problems is when there is an open circuit at the battery and
in this case there is nothing that will absorb the current that was being
taken by the battery, whereupon the system voltage can rise to over 100
volts. Automotive systems are designed to survive this type of voltage
transient even though it is quite rare. No, there is nothing in an
automotive system specifically designed to ABSORB that transient -
everything is designed to TOLERATE it. No "huge zener."
<>
The alternator is putting negligible torque on the engine during cranking,
but it does draw a few amps (less than 5 as I recall). Would this make the
difference? I've found that the usual "observation" is that the starter has
trouble torquing the engine over the first compression stroke so the driver
tries a couple of times (then shuts off the alternator?). By that time the
compression pressure has leaked down sufficiently so that it will go past
the first compression and the rest are easy as there is some momentum built
up by then.
And by the way, in passenger cars the alternator is "on" during cranking.
Most of the accessories are turned off during cranking to reduce battery
load, NOT to protect them against any mythical voltage transients.
Incidentally, according to the wiring diagram my Cessna was originally
equipped with a relay in the avionics bus that shut it off during cranking -
long since removed.
Gary Casey
________________________________________________________________________________
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
s=s1024; d=yahoo.com;
b=gCIEa2h9GAe6HZudWzy8xT/u0J83z9Q6unllZkJiOTjKadhlcCI9V/BDGtXhoGLO77znPBDxl7fFdiSCTyPxxc3enXIMOxIyS01omd7ORqFBAcPVNumwQ2oWL0+mwXLzrxin1pbikyzK4OeWIKdRTS44jv8WOr7342MqHPFcUWA;
| From: | D Fritz <dfritzj(at)yahoo.com> |
| Subject: | Re: Toggle Switch Knob |
I'd be interested in getting one of these as well. Also, while we're discussing
switch ergonomics, does anyone know of a source of T-shaped landing light switches?
All the commercial and military aircraft I've flown have these shaped
so you can tell it's for the landing lights without looking.
Dan Fritz
---------------------------------
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: Toggle Switch Knob |
Eaton makes a ton of the stuff. If Marine Air Supply 800-678-6085 doesn't
have the switch tips I would be surprised.
http://www.marineairsupply.com/
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
"Life may have no meaning. Or even worse, it may have a meaning of which I
disapprove." -- Ashleigh Brilliant
________________________________________________________________________________
| From: | "thomas a. sargent" <sarg314(at)comcast.net> |
| Subject: | koroseal cable lacing |
I just got some koroseal. I'm familiar with ordinary nylon cable
lacing. Koroseal is a lot thicker and stiffer. Is it used in exactly
the same way as the thin lacing (which looks to be difficult), or is
there some better practice to follow?
--
Tom Sargent
RV-6A, firewall.
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
| Subject: | larnin' 'lectrics |
Matthew,
I saw your email on AeroElectric list and note that you are new
to this form of the art............
May I recommend the AeroElectrics Connection book produced by
Bob Nuckolls, who frequents and replies to this list? Far from shooting you,
he and several others, including Brian Lloyd and many others have extensive
experience in this and radio fields.
However, I suggest that as a minimum step, you buy Bob's book
above and become familiar with the particular chapters of interest. It is
excellent, and in spite of 40 years of Amateur Radio (and 55 years in
flying), have learned much from Bob and others. Your familiarity with the
details will qualify you for serious answers we all need to complete our
favourite projects.
Good hunting!
Ferg
Europa A064
________________________________________________________________________________
| From: | "Matthew Brandes" <matthew(at)n523rv.com> |
| Subject: | E-Bus Usage Procedure / Question |
I think I'm getting closer to understanding all this electrical stuff.. but I have
a question about the E-bus procedure.
(Ref. Dwg 11) So your toodling along and your alternator craps out. No big deal...
you've planned for it. The alternator is taken offline and you are ready
to switch over to your E-Bus. So you flip the e-bus switch, so the e-bus is
now drawing current from the battery side of the contactor. The diode is keeping
current from flowing back to the Main bus, HOWEVER, if the battery contactor
circuit is still closed (BAT switch On), the main bus would still be drawing
current through the contactor, yes? So with this design, if the alternator
craps out and you want to switch over to the e-bus, you need to put the master
switch in the off position, opening the battery contactor cicuit, keeping the
main bus from drawing current.
Did that make sense? Am I missing something? Procedure: Turn on the E-Bus then
turn off the Master Switch.
Matthew
RV-9A Finish Kit
'lectric newbie
________________________________________________________________________________
| From: | "Dan Checkoway" <dan(at)rvproject.com> |
| Subject: | Re: E-Bus Usage Procedure / Question |
Matthew,
Yes, you got it...but...I always fly with my E-Bus switch ON. Constantly.
That way it's just one switch flip if and when the alternator dies, and
voltage to my "essentials" (some of which need initialization time, such as
the GPS) is NOT interrupted.
If you fly with the E-Bus switch ON all the time, when the alternator dies,
flip the master switch all the way off and keep flying.
Plus, this way, the devices on the E-Bus theoretically don't see the voltage
drop they otherwise would if the E-Bus was being fed through the diode. The
E-Bus is being fed from the battery bus (I think!).
Hope this makes sense, and please correct me if I'm wrong.
)_( Dan
RV-7 N714D
http://www.rvproject.com
----- Original Message -----
From: "Matthew Brandes" <matthew(at)n523rv.com>
Subject: AeroElectric-List: E-Bus Usage Procedure / Question
>
> I think I'm getting closer to understanding all this electrical stuff..
but I have a question about the E-bus procedure.
>
> (Ref. Dwg 11) So your toodling along and your alternator craps out. No
big deal... you've planned for it. The alternator is taken offline and you
are ready to switch over to your E-Bus. So you flip the e-bus switch, so
the e-bus is now drawing current from the battery side of the contactor.
The diode is keeping current from flowing back to the Main bus, HOWEVER, if
the battery contactor circuit is still closed (BAT switch On), the main bus
would still be drawing current through the contactor, yes? So with this
design, if the alternator craps out and you want to switch over to the
e-bus, you need to put the master switch in the off position, opening the
battery contactor cicuit, keeping the main bus from drawing current.
>
> Did that make sense? Am I missing something? Procedure: Turn on the
E-Bus then turn off the Master Switch.
>
> Matthew
> RV-9A Finish Kit
> 'lectric newbie
>
>
________________________________________________________________________________
| Subject: | Re: E-Bus Usage Procedure / Question |
On 4 Dec 2004 at 21:18, Matthew Brandes wrote:
>
>
> I think I'm getting closer to understanding all this electrical
> stuff.. but I have a question about the E-bus procedure.
>
> (Ref. Dwg 11) So your toodling along and your alternator craps out.
> No big deal... you've planned for it. The alternator is taken offline
> and you are ready to switch over to your E-Bus. So you flip the e-bus
> switch, so the e-bus is now drawing current from the battery side of
> the contactor. The diode is keeping current from flowing back to the
> Main bus, HOWEVER, if the battery contactor circuit is still closed
> (BAT switch On), the main bus would still be drawing current through
> the contactor, yes?
Yes
So with this design, if the alternator craps out
> and you want to switch over to the e-bus, you need to put the master
> switch in the off position, opening the battery contactor cicuit,
> keeping the main bus from drawing current.
Correct
>
> Did that make sense?
Yes
Am I missing something?
No
Procedure: Turn on the
> E-Bus then turn off the Master Switch.
Correct
Peter
RV9A wings
>
> Matthew
> RV-9A Finish Kit
> 'lectric newbie
>
>
> _
________________________________________________________________________________
Hello Wire Stringers,
Everyone pretty well beat up the postings on Zip-Ties, Tie-Wraps, Ny-Wraps,
Plastic Zips or whatever you choose to call them. I have an idea that some
of you may be interested in.
This is an idea that worked very well for me some years back when building
up electronic/electrical panels for non-aviation purposes. The problem is the
same. You need to run wires in bundles from point A to point B. A
combination of waxed string and/or zip ties will be the final tie method. You
want
it to look neat and be secure.
Well, in my opinion the secret weapon is....BREAD BAG PLASTIC TWIST TIES!
_http://www.chiswick.com//product/dept.asp?dept%5fid=11007&deptpath%5fid=11007
&clickedsku=no&requestimagefile=no&headername=twist+ties?GoogleCH_twist_tie_
(http://www.chiswick.com//product/dept.asp?dept_id=11007&deptpath_id=11007&clic
kedsku=no&requestimagefile=no&headername=twist+ties?GoogleCH_twist_tie)
These can be used as temporary ties at all tie points until you are
completely finished adding/subtracting wires and routing them. Lay a wire in
and
give the tie a twist. Need to change something, un-twist and re-twist as
needed. When the final layout is complete, you just go through your panel and
replace each bread tie with a zip-tie or waxed string.
A couple of other notes on the final tie up: The ideal wire bundle has all
wires run in PARALLEL. To accomplish this you need to run the longest
distance wire in the center of the bundle. In other words, it gets run first.
The
next longest run goes second, etc. This way, no wires have to penetrate out
of the bundle through a bunch of other wires. This may sound like a big
hassle but wires that cross each other in a bundle create pressure points that
could bite you later.
Zip-ties or string should be the tie device for the WHOLE bundle. Don't go
adding that new transponder later and running its cable next to the existing
tied up bundle and adding more zip-ties over all. No, no, no, Cut all
zip-ties off the first bundle and marry the new wires into the "new" bundle and
tie
as a group. All wires will be snug and parallel as a unit. Each wire's
break out point will have a small slack loop in it to absorb slight movement as
it goes to its wire landing point.
It will look pretty too! I know you guys like pretty.
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Alternator Off During Start Up? |
On Dec 3, 2004, at 6:46 PM, John Grosse wrote:
> voltage spikes. So far I agree with the debunkers. The issue is the
> alternator trying to supply 200 amps to the starter which, of course,
> it
> can't do.
You are right, it can't. It can't even come close to generating 200A
even if it were working into a dead short at high speed.
> This, as I've been led to understand, is not a good thing for
> the alternator because it creates an overload or something?
No, it isn't even that. I doubt that the alternator could even
generate an amp at those cranking speeds so there is no effective load
on the alternator.
The primary stress on an alternator comes from heat. Usually that heat
comes from I*R losses in the stator (current times the resistance of
the stator windings). Those losses are in the form of heat generated
in the stator windings. If you can't generate any current the losses
and heat generated are negligible hence no stress on the alternator.
> I don't
> totally understand the dynamics inside the alternator, but it
> supposedly
> stress something in there out and causes premature failures.
No, there are no stresses on it at that point other than the fact that
full field current is flowing through the rotor/armature and the
alternator is designed to handle that forever.
The output of an alternator is self-limiting. We come back to the I*R
losses in the stator again. If you recall Ohm's law, E = I * R
(voltage equals current times resistance). As the alternator delivers
more current there is more voltage drop across the stator. Eventually
the voltage drop is high enough that the alternator cannot produce
enough voltage and its output voltage begins to drop in spite of the
field current being full-on. This causes the current to drop too.
Therefore the output of the alternator is current limited.
> As far as the "automobiles don't do it" argument goes... I'm not so
> sure
> they don't actually do it. They just do it automatically for you. When
> you turn the key to energize the starter power is shut off to all the
> accessories... and the alternator??
It depends on which type of alternator and alternator wiring in the
automobile. There really isn't an appreciable difference between an
automotive charging system and an aircraft charging system. You will
find that the alternators and regulators used in aircraft are virtually
identical to their automotive counterparts. The switching may be
slightly different but that is all.
> A little empirical data... I went through 2 alternators in about a 1000
> hrs before I put in a split switch. Since I put in the switch I've had
> no failures... knock on wood.
Interesting but Anecdotal. You just don't have a big enough
statistical sample.
> Whatever is going on in our airplanes sure causes the alternator to
> fail
> a lot more often than in our cars, and it's not just vibration.
Well, what does kill alternators? As I see it, they suffer from heat,
vibration, and overspeed. At higher altitude the air needed for
cooling is much less dense and you get less cooling effect and higher
temps. And of course the vibration is much higher in an aircraft
engine. If the pulley is too small in an attempt to get a lot of
output at low engine RPM you may turn the alternator too fast and cause
premature bearing failure.
The alternator charging system is amazingly reliable. If you keep the
output of the alternator well below its stated rating, deal properly
with vibration, and don't spin it too fast, it will last a long, long
time. Oh, and make sure you have proper cooling to the regulator and
good wiring that is properly sized and protected against vibration.
None of this is rocket science. Bob has been writing about this stuff
for years and years.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| Subject: | Re: E-Bus Usage Procedure / Question |
On 4 Dec 2004 at 20:20, Dan Checkoway wrote:
>
>
> Matthew,
>
> Yes, you got it...but...I always fly with my E-Bus switch ON.
> Constantly. That way it's just one switch flip if and when the
> alternator dies, and voltage to my "essentials" (some of which need
> initialization time, such as the GPS) is NOT interrupted.
>
> If you fly with the E-Bus switch ON all the time, when the alternator
> dies, flip the master switch all the way off and keep flying.
>
> Plus, this way, the devices on the E-Bus theoretically don't see the
> voltage drop they otherwise would if the E-Bus was being fed through
> the diode. The E-Bus is being fed from the battery bus (I think!).
>
> Hope this makes sense, and please correct me if I'm wrong.
Dan
That is correct. But, The voltage drop across the diode should not affect the items
that are being powered by the e- buss.
Moreover, I've seen one design where an avionics buss was powered by the e-buss
through a relay. Yep-
If one forgets to turn the e-buss switch off, the battery will drain.
Peter
RV9A wings
> )_( Dan
> RV-7 N714D
> http://www.rvproject.com
>
> ----- Original Message -----
> From: "Matthew Brandes" <matthew(at)n523rv.com>
> To:
> Subject: AeroElectric-List: E-Bus Usage Procedure / Question
>
>
>
> >
> > I think I'm getting closer to understanding all this electrical
> > stuff..
> but I have a question about the E-bus procedure.
> >
> > (Ref. Dwg 11) So your toodling along and your alternator craps out.
> > No
> big deal... you've planned for it. The alternator is taken offline
> and you are ready to switch over to your E-Bus. So you flip the e-bus
> switch, so the e-bus is now drawing current from the battery side of
> the contactor. The diode is keeping current from flowing back to the
> Main bus, HOWEVER, if the battery contactor circuit is still closed
> (BAT switch On), the main bus would still be drawing current through
> the contactor, yes? So with this design, if the alternator craps out
> and you want to switch over to the e-bus, you need to put the master
> switch in the off position, opening the battery contactor cicuit,
> keeping the main bus from drawing current. > > Did that make sense?
> Am I missing something? Procedure: Turn on the E-Bus then turn off
> the Master Switch. > > Matthew > RV-9A Finish Kit > 'lectric newbie >
> >
>
>
> advertising on the Matronics Forums.
> >
>
>
>
________________________________________________________________________________
| From: | "thomas a. sargent" <sarg314(at)comcast.net> |
| Subject: | fuse block location |
You want your fuse blocks mounted in a place that is easy to get at.
Airplanes have darn few places that are easy to get at. I keep thinking
in terms of mounting them on something that is movable over a limited
range, such as a panel that hinges open or a small "drawer" that slides
out. You'd have to be careful to leave enough of a service loop on the
wiring to permit the motion, of course and cable dress would be
imprtant. It would probably only be 5 or 6 inches of extra wire. I
think it could be done safely. I recall seeing something like this on
one builder's web page a long time ago.
So, where/how are people mounting their fuse blocks?
--
Tom Sargent
RV-6A, firewall.
________________________________________________________________________________
| Subject: | Re: Bread Bag Ties? |
I goofed, try this for vinyl twist ties. 10 inch length are good.
_http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=viny
l+twist+ties&cpage=2_
(http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=vinyl+twist+ties&cpage=2)
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
________________________________________________________________________________
| From: | "Jeff Orear" <jorear(at)new.rr.com> |
| Subject: | Re: fuse block location |
Tom:
I have my fuseblocks on a flip down panel that is hinged on the subpanel
and is then screwed to the bottom flange of the instrument panel. REmove
two screws and it is flipped down for fuse access. I can send you pics if
you like.
Jeff Orear
RV6A N782P
cowling and windshield fairing
Peshtigo, WI
----- Original Message -----
From: "thomas a. sargent" <sarg314(at)comcast.net>
Subject: AeroElectric-List: fuse block location
>
>
> You want your fuse blocks mounted in a place that is easy to get at.
> Airplanes have darn few places that are easy to get at. I keep thinking
> in terms of mounting them on something that is movable over a limited
> range, such as a panel that hinges open or a small "drawer" that slides
> out. You'd have to be careful to leave enough of a service loop on the
> wiring to permit the motion, of course and cable dress would be
> imprtant. It would probably only be 5 or 6 inches of extra wire. I
> think it could be done safely. I recall seeing something like this on
> one builder's web page a long time ago.
>
> So, where/how are people mounting their fuse blocks?
> --
> Tom Sargent
> RV-6A, firewall.
>
>
>
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: Alternator Off During Start Up? |
>Well, what does kill alternators? As I see it, they suffer from heat,
>vibration, and overspeed. At higher altitude the air needed for
>cooling is much less dense and you get less cooling effect and higher
>temps. ...
>
>... Oh, and make sure you have proper cooling to the regulator and
>good wiring that is properly sized and protected against vibration.
Hi Brian,
Would you recommend a dedicated scat tube to the alternator? The
one I plan to use is internally regulated, unless I can figure
out how to remove the internal regulator, which I will try to do
when I receive it. Any issue with the water that would probably
be contained in the cooling air?
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: fuse block location |
Good question. I have not yet decided exactly where I will put
mine, but one question I have is do fuses blow very often? I
have not had one blow in one of my cars or motorcycles for at
least 25 years. Of course, the spam cans I fly have circuit
breakers, and I have never experienced a tripped breaker, either.
Mickey
>So, where/how are people mounting their fuse blocks?
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: fuse block location |
clamav-milter version 0.80j
on juliet.albedo.net
Hi Tom
My 3 fuseblocks (electric dependant engine) are on the firewall. Well
actually on a bracket an inch
from the firewall. The plan is that none will ever be replaced in
flight so I don't care much about accessability. It also helped keep the
wires feeding them short.
More than one fuse would have to pop to stop the engine and if that
happens I'll be busy flying. With that large of an electrical problem I
would want to be on the ground with a fire extinguisher in hand to
repower things anyway...
Ken
thomas a. sargent wrote:
>
>You want your fuse blocks mounted in a place that is easy to get at.
>Airplanes have darn few places that are easy to get at. I keep thinking
>in terms of mounting them on something that is movable over a limited
>range, such as a panel that hinges open or a small "drawer" that slides
>out. You'd have to be careful to leave enough of a service loop on the
>wiring to permit the motion, of course and cable dress would be
>imprtant. It would probably only be 5 or 6 inches of extra wire. I
>think it could be done safely. I recall seeing something like this on
>one builder's web page a long time ago.
>
>So, where/how are people mounting their fuse blocks?
>--
>Tom Sargent
>RV-6A, firewall.
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Alternator Off During Start Up? |
Embedded comments
----- Original Message -----
From: "Gary Casey" <glcasey(at)adelphia.net>
Subject: Re: AeroElectric-List: Alternator Off During Start Up?
>
> < where if something shuts off or a wire breaks, the alternator output
voltage
> will jump way up momentarily. I forget if they design to 40 or 70 volts,
> and somewhere in the car or an accessory is a huge zener to limit
> overvoltage beyond that.>>
Automobiles are wired DIFFERENTLY than aircraft. The critical difference is
the alternator "B" lead is hard wired in an auto and is run thru a contactor
in an aircraft. This is a very important difference. Disconnection the
battery in an auto with the alternator producing current is a failure
condition and is not fully protected against. We take this (auto) design and
internally disconnect the battery and then get upset when things fail :-).
Our designs need to make it impossible to disconnect the alternator "B" lead
from the battery when the alternator is producing current except in the case
of a failure.
The "load dump" is a non event in an auto (voltage peak is very small) with
the battery always connected to the alternator. However if you disconnect
the battery from the alternator when the battery is being charged and or
later remove an alternator load (like turning off landing lights) when the
battery is disconnected you produce the "load dump". As the alternator takes
time to react to a reduced load and is a current generator not a voltage
producer the output voltage jumps up to what ever voltage is needed to
source the original current into the new reduced load. The voltage peak is
what ever it needs to be to maintain the current. In extreme cases that
voltage can exceed 100V. Depending on the amount of current being reduced
and the remaining load the "load dump" current; Overvoltage can take more
than 1/10 of a second (this is quite long compared to what is needed to
damage electronics or even the alternator regulator). I have observed load
dumps exceeding 1/5 (200 ms) long and voltage peaks over 60V. Only happens
with no battery connected to absorb the excess current.
When considering design of electrical systems its important to remember that
alternator is a current generator with a slow response to current load
changes. Reducing the load suddenly by removing one load component requires
the rest of the load to maintain the prior current for a short time. The
battery does this when there is a battery as a load. If there is no battery
the system voltage increases as needed to absorb the current until the
alternator stabilizes at the lower current load.
The system design is different with internally regulated alternators Vs. the
externally regulated alternators but the "load dump" is still a design
concern.
>
> I think when push comes to shove I believe the average car will have a
> slightly "quieter" electrical system than a plane. Since weight is not an
> issue they have a much larger battery and larger-gage ground wires, both
of
> which tend to keep voltage transients down.
In this case both applications have generally the same size wire (for the
"B" lead). The AGM batteries used in aircraft are lighter but have much
lower internal resistance and thus are better at absorbing "load dumps".
The typical auto has a very quiet electrical power system because it has FAR
more noise suppression and noise immunity designed components. The DO-160
that Bob talks about is often not complied with (either partially or fully)
and even if it was; its far short of the requirements contained in the
automotive industry similar specifications.
Thanks to Eric and Bob I have copies of both DO-160 and the automotive
equivalent and what a difference!
> The load dump
> that causes big problems is when there is an open circuit at the battery
and
> in this case there is nothing that will absorb the current that was being
> taken by the battery, whereupon the system voltage can rise to over 100
> volts. Automotive systems are designed to survive this type of voltage
> transient even though it is quite rare. No, there is nothing in an
> automotive system specifically designed to ABSORB that transient -
> everything is designed to TOLERATE it. No "huge zener."
There is designed into every automotive component so called transorbs that
are special designed "zeners" that have a response time 10,000 times faster
and can handle huge peak currents. You are correct however that since the
battery is never disconnected in an automobile its components are not
designed to work under extreme cases of load dump, just those occurring
under normal load on/off cycles.
The load dump discussions resurfaced when Vans internally regulated
alternators started failing. As there alternators are not new but rebuilt
some have suggested its a poorly designed aftermarket regulator that is the
cause. I have seen on data to suggest this is the cause. Some pilots have
reported that the alternator was internally turned off as part of preflight.
This will always cause a load dump and its not clear even OEM regulators
could survive this as its never possible in a an auto where the alternator
was designed for use.
> And by the way, in passenger cars the alternator is "on" during cranking.
> Most of the accessories are turned off during cranking to reduce battery
> load, NOT to protect them against any mythical voltage transients.
Remember the auto battery typically has less cranking power than our AGM
smaller in AH but higher (double in most cases) Cranking power.
> Incidentally, according to the wiring diagram my Cessna was originally
> equipped with a relay in the avionics bus that shut it off during
cranking -
> long since removed.
Unless you are sure ALL of your avionics have been designed to the FULL
specifications of at least DO-160 its not a good idea to subject them to the
starting load voltage excursions/transients (yes there are some of concern).
More in the coming report.
Paul
________________________________________________________________________________
| From: | "Dan Checkoway" <dan(at)rvproject.com> |
| Subject: | Re: E-Bus Usage Procedure / Question |
> That is correct. But, The voltage drop across the diode should not affect
the items
> that are being powered by the e- buss.
Do you mean to say the 0.7V drop won't cause a *noticeable* affect -- i.e.
the avionics won't perform any differently? I agree with that, but one
thing that I do notice is a 0.2 to 0.3A difference on my hall effect driven
ammeter when I switch the E-Bus on and off in flight.
If I can save my alternator from having to producing that extra quarter of
an amp, it's a minor victory. ;-)
)_( Dan
RV-7 N714D
http://www.rvproject.com
________________________________________________________________________________
| Subject: | fuse block location |
On my 1st -6 I used a hinged plate under the instrument panel. I didn't like
it because I had to mount the hinge too far forward to keep it hidden. If
you try to hinge it at the panel, with a std height panel, there is no room
to angle the plate upward or use a "Z" offset to hide the blocks & wires. On
the Phoenix I'm mounting the blocks directly on the left fuselage side just
fwd of F-604, below the panel and above the rudder cable. I plan to put an
interior panel over that area and will put in a pop-out door to access the
blocks - automotive style. I countersunk the blocks so I could dimple the
skin and mount them with flat head screws. You just have to get past the
idea of drilling holes in the fuselage skin. Once flying I'm sure I'll get
questions about the screw heads.
Regards,
Greg Young - Houston (DWH)
RV-6 N6GY ...project Phoenix
Navion N5221K - just an XXL RV-6A
> -->
>
> You want your fuse blocks mounted in a place that is easy to get at.
> Airplanes have darn few places that are easy to get at. I
> keep thinking in terms of mounting them on something that is
> movable over a limited range, such as a panel that hinges
> open or a small "drawer" that slides out. You'd have to be
> careful to leave enough of a service loop on the wiring to
> permit the motion, of course and cable dress would be
> imprtant. It would probably only be 5 or 6 inches of extra wire. I
> think it could be done safely. I recall seeing something
> like this on
> one builder's web page a long time ago.
>
> So, where/how are people mounting their fuse blocks?
> --
> Tom Sargent
> RV-6A, firewall.
>
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Ergonomic Switch Knobs |
12/5/2004
Subject: Ergonomic Switch Knobs
Previous messages:
<>
<>
Hello Fellow Builders, For those looking for ergonomic switch knobs such as wheels,
etc. I suggest that you look in the direction of the suppliers to those who
make home made wooden toys.
There are dozens of such companies with a huge supply of offerings. Here is just one <http://www.craftparts.com/mall/page38.asp>
OC
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: fuse block location |
>
>
>Good question. I have not yet decided exactly where I will put
>mine, but one question I have is do fuses blow very often? I
>have not had one blow in one of my cars or motorcycles for at
>least 25 years. Of course, the spam cans I fly have circuit
>breakers, and I have never experienced a tripped breaker, either.
Good anecdotal data. I'll suggest that 99.99+ percent of all breakers
and fuses installed in any vehicle will never be called upon to protect
the system over the lifetime of the vehicle . . . when they ARE
needed, the most likely cause is some condition that cannot be
mitigated by replacing the fuse or resetting the breaker. So if any
particular system is desirable for comfortable completion of flight,
you'd do well to have a backup for it.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Alternator Off During Start Up? |
>
>
>
> >Well, what does kill alternators? As I see it, they suffer from heat,
> >vibration, and overspeed. At higher altitude the air needed for
> >cooling is much less dense and you get less cooling effect and higher
> >temps. ...
> >
> >... Oh, and make sure you have proper cooling to the regulator and
> >good wiring that is properly sized and protected against vibration.
>
>Hi Brian,
>
>Would you recommend a dedicated scat tube to the alternator? The
>one I plan to use is internally regulated, unless I can figure
>out how to remove the internal regulator, which I will try to do
>when I receive it. Any issue with the water that would probably
>be contained in the cooling air?
>
>Thanks,
>Mickey
Ask around the list-server for your particular airplane
and inquire as to the experience of the group on alternator
failures due to overheating. Obviously, if your heart's desire
is to have a forced air cooled alternator, you can certainly
have one. As you've noted, there are potential un-intended
consequences for adding the cooling duct. If you want to
discover for yourself how well your alternator is cooled,
you can easily thermocouple the critter and find out during
your fly-off interval.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: fuse block location |
>
>
>You want your fuse blocks mounted in a place that is easy to get at.
>Airplanes have darn few places that are easy to get at. I keep thinking
>in terms of mounting them on something that is movable over a limited
>range, such as a panel that hinges open or a small "drawer" that slides
>out. You'd have to be careful to leave enough of a service loop on the
>wiring to permit the motion, of course and cable dress would be
>imprtant. It would probably only be 5 or 6 inches of extra wire. I
>think it could be done safely. I recall seeing something like this on
>one builder's web page a long time ago.
>
>So, where/how are people mounting their fuse blocks?
If it is your intention to make fuses accessible in flight,
consider the probability that you're more likely to have an
unhappy ending to the day by switching your attention from
pilot duties so that you can hammer on an electrical problem.
Design you system for failure tolerance and leave the toolbox
closed until on the ground. The more INACCESSIBLE you make the
fuseblock, the less likely it is to detract from your duties
as pilot.
Bob . . .
________________________________________________________________________________
| From: | "Jim Jewell" <jjewell(at)telus.net> |
| Subject: | Re: fuse block location |
Tom,
On my 6a I have added a 2" recessed subpanel across the bottom of the main
panel. The center section is for the engine controls.
Like Jeff I hinged the co-pilot side fuse panel, it is held in place with
two screws. The pilot side switch panel also drops down for maintenance
access, two screws hold it up.
The two drop down panel's hinge pins clip in and can be re-moved allowing
them to be moved out and away for better under panel access.
The center section is held in place with four screws.
This addition did represent extra work and build time. The driving force for
going this route is a stiff old arthritic back that aches at the thought of
spending any time at all under the panel.
A drop down fuse panel under the standard vans panel should be do-able but
the sub panel does offer much more space to work in.
If you have very long boned people that want to fly with you the added 2"
subpanel might get in the way of their knees
I can send pics
Jim in Kelowna
----- Original Message -----
From: "Jeff Orear" <jorear(at)new.rr.com>
Subject: Re: AeroElectric-List: fuse block location
>
> Tom:
>
> I have my fuseblocks on a flip down panel that is hinged on the subpanel
> and is then screwed to the bottom flange of the instrument panel. REmove
> two screws and it is flipped down for fuse access. I can send you pics if
> you like.
>
>
> Jeff Orear
> RV6A N782P
> cowling and windshield fairing
> Peshtigo, WI
> ----- Original Message -----
> From: "thomas a. sargent" <sarg314(at)comcast.net>
> To:
> Subject: AeroElectric-List: fuse block location
>
>
>>
>>
>> You want your fuse blocks mounted in a place that is easy to get at.
>> Airplanes have darn few places that are easy to get at. I keep thinking
>> in terms of mounting them on something that is movable over a limited
>> range, such as a panel that hinges open or a small "drawer" that slides
>> out. You'd have to be careful to leave enough of a service loop on the
>> wiring to permit the motion, of course and cable dress would be
>> imprtant. It would probably only be 5 or 6 inches of extra wire. I
>> think it could be done safely. I recall seeing something like this on
>> one builder's web page a long time ago.
>>
>> So, where/how are people mounting their fuse blocks?
>> --
>> Tom Sargent
>> RV-6A, firewall.
>>
>>
>>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Toggle Switch Knob |
>
>I'd be interested in getting one of these as well. Also, while we're
>discussing switch ergonomics, does anyone know of a source of T-shaped
>landing light switches? All the commercial and military aircraft I've
>flown have these shaped so you can tell it's for the landing lights
>without looking.
>
>Dan Fritz
You can consider making your own switch enhancements like for landing
gear, flaps, etc. See:
http://www.aeroelectric.com/Pictures/Flap_Switch.jpg
http://www.aeroelectric.com/Pictures/FLAPS1.JPG
http://www.aeroelectric.com/Pictures/FLAPS2.JPG
http://www.aeroelectric.com/Pictures/FLAPS3.JPG
Delrin and aluminum are both excellent materials for carving special
knobs.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Alternator Off During Start Up? |
>
>I searched the archives for a response to this AOPA article from April
>2003 and found none. Anyone have an opinion about the practice of starting
>on battery only, with alternator turned off? Should we be starting with
>the alternator off?
>
>Thanks,
>Ned
>
>April 2003 Article "Charge It!" by Steven W. Ells
>
>(Second from last paragraph: )
>
>"Many pilots with split master switches have modified the owners manual
>starting procedure by leaving the alternator half of the switch in the Off
>position until after the start sequence. After starting, but before
>turning on any other equipment such as radios or lights, the pilot turns
>on the alternator half of the switch and checks for positive movement of
>the ammeter needle. This verifies that the charging system is online.
>Engine starting is a time when the contactors that control large current
>flows are opening and closing. The potential for large voltage spikes
>ripping through the electrical system is very high during this brief
>moment. Since rectifiers, switches, and other solid state devices are
>adversely affected by spikes, it's a good idea to isolate charging-system
>components during starting - unless you have a generator on your airplane."
Many folks are fond of the word "spike" . . . it has a really
sharp sound to it and conjures up images of weapons dating back
to medieval times and still popular in contemporary blood-n-gore
flicks. Needless to say, individuals with a mission of persuasion
that life will be better when you adopt some new behavior find
it useful to embellish their sermon with colorful words . . .
especially when those words underscore some sense of urgency
for heeding their advice.
I've been a student of the elusive "spike" for decades. I've
qualified dozens of new products both to withstand normal
bus transients and to limit their output of transients to
industry standard acceptable levels. I've observed many
dozens more suppliers jump the same hoops in order to prove
their products flightworthy.
It's not difficult to live in the world of DC power
generated on any vehicle. Let's examine cited paragraph
for what real data it offers:
"Many pilots with split master switches have modified the owners manual
starting procedure by leaving the alternator half of the switch in the Off
position until after the start sequence."
Hmmmm . . . this may indeed be factual . . . but he doesn't
say how anyone arrives at the conclusion that the factory
supplied, FAA approved owner's manual is deficient.
"After starting, but before turning on any other equipment such as radios
or lights, the pilot
turns on the alternator half of the switch . . .
What is the significance or importance of not turning anything
else on before turning on the alternator?
. . . and checks for positive movement of the ammeter needle. This verifies
that the charging system is on-line."
Of course, it's unlikely that his airplane has a low voltage
warning light. If he did, the light would be flashing all
during pre-flight and would go dark as soon as the alternator
comes up . . . an even better
Engine starting is a time when the contactors that control large current
flows are
opening and closing. The potential for large voltage spikes ripping through
the electrical system is very high during this brief moment.
Lots of un-quantified, un-substantiated repetition of ol'
pilot's tales. These words have been simmering in the pot
of aviation folklore ever since I can remember.
"Since rectifiers, switches, and other solid state devices are adversely
affected
by spikes, it's a good idea to isolate charging-system components during
starting
- unless you have a generator on your airplane."
Hmmm . . . this one is REALLY mystifying. The author seems to be
implying that leaving an alternator turned off during starting
has some benefit for protecting the alternator . . . a benefit
that generators do not need.
The alternator (or generator) control switch serves only to
disconnect the field excitation circuits from the system.
The only solid state devices "isolated" by leaving the alternator/
generator switch OFF are in the regulator. Modern regulators
for generators are solid state too. So, if the alternator's regulator
is to be "protected" by leaving the switch OFF, any modern
generator regulator would appreciate this benefit also. There
is no "isolating" benefit to the alternator itself for leaving
it off line during cranking.
I've seen individuals try to make a case for overshoot events
in alternator output voltage being hazardous if one starts the
engine with the alternator ON. I've studied both conditions and
there are subtle differences in start-up behavior but neither condition
represents a hazard to any of the ship's components.
Other individuals offer that the battery is already taxed
for getting the engine started . . . adding the extra load
represented by alternator field current is a significant performance
issue. Okay, 200+ amps to crank the engine and 3 amps to run
the alternator field at normal bus voltage - closer to 2 amps
during cranking. I'm not convinced that the engine or battery
will benefit from a 1% reduction in system loads during cranking
and the pilot is certainly not going to perceive any difference.
The oft cited spikes-of-evil-intent simply do not exist. Yes,
there are excursions of bus voltage in the course of NORMAL
operations of the airplane that every accessory is designed to
accommodate.
Bottom line is that all the articles one reads in the aviation
journals concerning this matter are simple repetitions of
unfounded blue smoke and folk-lore. You may operate your
alternator switch any way you wish but there is no foundation
in physics that make one methodology more desirable or
practical than the other.
Bob . . .
________________________________________________________________________________
| From: | "thomas a. sargent" <sarg314(at)comcast.net> |
| Subject: | Re: fuse block location |
Robert L. Nuckolls, III wrote:
>
>
>
>>
>>
>>You want your fuse blocks mounted in a place that is easy to get at.
>>Airplanes have darn few places that are easy to get at. I keep thinking
>>
>>
>>
>
> If it is your intention to make fuses accessible in flight,
> consider the probability that you're more likely to have an
> unhappy ending to the day by switching your attention from
> pilot duties so that you can hammer on an electrical problem.
> Design you system for failure tolerance and leave the toolbox
> closed until on the ground. The more INACCESSIBLE you make the
> fuseblock, the less likely it is to detract from your duties
> as pilot.
>
> Bob . . .
>
Bob:
No, if I intended to "fix" things in flight, I'd use circuit
breakers instead fuses. If a fuse blows, it's staying blown until I
land. But still, if I can make it easier to get to when I'm on the
ground that's, good too. Automobiles continually infuriate me with the
difficulty they present for repair. I ought to be able to do better
engineeering than that.
(Actually, if you take a tour thru the auto factory, you'll see why they
have that "layered" design - it goes together faster on the assembly
line that way. Each station is installing the next layer so nothing's
in the way. They're much more concerned with putting them together than
taking them apart.)
--
Tom Sargent
RV-6A
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: Alternator Off During Start Up? |
> ... If you want to
> discover for yourself how well your alternator is cooled,
> you can easily thermocouple the critter and find out during
> your fly-off interval.
That sounds like a good idea. Adding a scat tube later would
not be a big deal if it is necessary.
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | "923te" <923te(at)cox.net> |
| Subject: | Re: Alternator Off During Start Up? |
Hi Bob,
I have enjoyed attending your seminars and studying your book and when it is
fresh on my mind I am confident that I "get" it and then I go work on my
experimental panel. Then a few years pass and not being a daily user the
electrical theories get cloudy in my mind. Then I read an article like this
and think that maybe I remember things wrong. So thanks for the
reinforcement. What confused me is that the author of this article wrote in
the last paragraph to visit www.aerolectric.com for learning more. It would
seem that the Author is due a trip to the your web site.... It seems hard
to find a good journalist these days...
Your Fellow Aviation Enthusiast,
Ned
----- Original Message -----
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: Alternator Off During Start Up?
>
> >
> >I searched the archives for a response to this AOPA article from April
> >2003 and found none. Anyone have an opinion about the practice of
starting
> >on battery only, with alternator turned off? Should we be starting with
> >the alternator off?
> >
> >Thanks,
> >Ned
> >
> >April 2003 Article "Charge It!" by Steven W. Ells
> >
> >(Second from last paragraph: )
> >
> >"Many pilots with split master switches have modified the owners manual
> >starting procedure by leaving the alternator half of the switch in the
Off
> >position until after the start sequence. After starting, but before
> >turning on any other equipment such as radios or lights, the pilot turns
> >on the alternator half of the switch and checks for positive movement of
> >the ammeter needle. This verifies that the charging system is online.
> >Engine starting is a time when the contactors that control large current
> >flows are opening and closing. The potential for large voltage spikes
> >ripping through the electrical system is very high during this brief
> >moment. Since rectifiers, switches, and other solid state devices are
> >adversely affected by spikes, it's a good idea to isolate charging-system
> >components during starting - unless you have a generator on your
airplane."
>
> Many folks are fond of the word "spike" . . . it has a really
> sharp sound to it and conjures up images of weapons dating back
> to medieval times and still popular in contemporary blood-n-gore
> flicks. Needless to say, individuals with a mission of persuasion
> that life will be better when you adopt some new behavior find
> it useful to embellish their sermon with colorful words . . .
> especially when those words underscore some sense of urgency
> for heeding their advice.
>
> I've been a student of the elusive "spike" for decades. I've
> qualified dozens of new products both to withstand normal
> bus transients and to limit their output of transients to
> industry standard acceptable levels. I've observed many
> dozens more suppliers jump the same hoops in order to prove
> their products flightworthy.
>
> It's not difficult to live in the world of DC power
> generated on any vehicle. Let's examine cited paragraph
> for what real data it offers:
>
> "Many pilots with split master switches have modified the owners manual
> starting procedure by leaving the alternator half of the switch in the Off
> position until after the start sequence."
>
> Hmmmm . . . this may indeed be factual . . . but he doesn't
> say how anyone arrives at the conclusion that the factory
> supplied, FAA approved owner's manual is deficient.
>
> "After starting, but before turning on any other equipment such as radios
> or lights, the pilot
> turns on the alternator half of the switch . . .
>
> What is the significance or importance of not turning anything
> else on before turning on the alternator?
>
> . . . and checks for positive movement of the ammeter needle. This
verifies
> that the charging system is on-line."
>
> Of course, it's unlikely that his airplane has a low voltage
> warning light. If he did, the light would be flashing all
> during pre-flight and would go dark as soon as the alternator
> comes up . . . an even better
>
> Engine starting is a time when the contactors that control large current
> flows are
> opening and closing. The potential for large voltage spikes ripping
through
> the electrical system is very high during this brief moment.
>
> Lots of un-quantified, un-substantiated repetition of ol'
> pilot's tales. These words have been simmering in the pot
> of aviation folklore ever since I can remember.
>
> "Since rectifiers, switches, and other solid state devices are adversely
> affected
> by spikes, it's a good idea to isolate charging-system components during
> starting
> - unless you have a generator on your airplane."
>
> Hmmm . . . this one is REALLY mystifying. The author seems to be
> implying that leaving an alternator turned off during starting
> has some benefit for protecting the alternator . . . a benefit
> that generators do not need.
>
> The alternator (or generator) control switch serves only to
> disconnect the field excitation circuits from the system.
> The only solid state devices "isolated" by leaving the alternator/
> generator switch OFF are in the regulator. Modern regulators
> for generators are solid state too. So, if the alternator's regulator
> is to be "protected" by leaving the switch OFF, any modern
> generator regulator would appreciate this benefit also. There
> is no "isolating" benefit to the alternator itself for leaving
> it off line during cranking.
>
> I've seen individuals try to make a case for overshoot events
> in alternator output voltage being hazardous if one starts the
> engine with the alternator ON. I've studied both conditions and
> there are subtle differences in start-up behavior but neither
condition
> represents a hazard to any of the ship's components.
>
> Other individuals offer that the battery is already taxed
> for getting the engine started . . . adding the extra load
> represented by alternator field current is a significant performance
> issue. Okay, 200+ amps to crank the engine and 3 amps to run
> the alternator field at normal bus voltage - closer to 2 amps
> during cranking. I'm not convinced that the engine or battery
> will benefit from a 1% reduction in system loads during cranking
> and the pilot is certainly not going to perceive any difference.
> The oft cited spikes-of-evil-intent simply do not exist. Yes,
> there are excursions of bus voltage in the course of NORMAL
> operations of the airplane that every accessory is designed to
> accommodate.
>
> Bottom line is that all the articles one reads in the aviation
> journals concerning this matter are simple repetitions of
> unfounded blue smoke and folk-lore. You may operate your
> alternator switch any way you wish but there is no foundation
> in physics that make one methodology more desirable or
> practical than the other.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Alternator Off During Start Up? |
>
><where if something shuts off or a wire breaks, the alternator output voltage
>will jump way up momentarily. I forget if they design to 40 or 70 volts,
>and somewhere in the car or an accessory is a huge zener to limit
>overvoltage beyond that.>>
This is an event un-related to position of the switch during startup.
>I think when push comes to shove I believe the average car will have a
>slightly "quieter" electrical system than a plane. Since weight is not an
>issue they have a much larger battery and larger-gage ground wires, both of
>which tend to keep voltage transients down.
But finer wires, they're still fond of flooded batteries and
they don't use single point ground systems.
An RV with a less than year-old RG battery and 4AWG or larger
fat-wires and ground system like Z-15 would give most automobiles
a really good run for their money with respect to noise. Howver,
BOTH vehicles will have noise and transient signatures well within
the operating limitations of accessories designed to live on
airplanes.
> Although, since we supply
>electronic components to the auto industry we are constantly being surprised
>with weird glitches that - of course - are all our fault. The "load dump"
>phenomena is caused by the inductance of the field in the alternator -
>imagine the alternator cranking out full current to supply a load and then
>that load is suddenly removed. The voltage regulator senses the increasing
>system voltage and shuts off the field. However, the field, being created
>by a large coil of wire surrounding an iron core, can't be instantly
>changed, so the alternator continues to produce now-excess current until the
>field current decays, which takes 10's of milliseconds. The effect is
>usually very slight as the battery serves to hold the voltage at a
>near-constant level, absorbing the momentary excess current. The load dump
>that causes big problems is when there is an open circuit at the battery and
>in this case there is nothing that will absorb the current that was being
>taken by the battery, whereupon the system voltage can rise to over 100
>volts. Automotive systems are designed to survive this type of voltage
>transient even though it is quite rare. No, there is nothing in an
>automotive system specifically designed to ABSORB that transient -
>everything is designed to TOLERATE it. No "huge zener."
The "huge zener" or Transorb is a practical consideration.
I'm still waiting the data from testing in progress to help
us define the size and characteristics of such a device.
><long starter leads. Several times I've had difficulty starting the engine
>with the alt. field on. When I turn the field off it seems to crank faster
>and starts easily. Is the alt putting a lot of drag on the engine when the
>voltage drops on cranking?>>
>
>The alternator is putting negligible torque on the engine during cranking,
>but it does draw a few amps (less than 5 as I recall). Would this make the
>difference? I've found that the usual "observation" is that the starter has
>trouble torquing the engine over the first compression stroke so the driver
>tries a couple of times (then shuts off the alternator?). By that time the
>compression pressure has leaked down sufficiently so that it will go past
>the first compression and the rest are easy as there is some momentum built
>up by then.
Good call . . . as mentioned in another post, the 3A or less
current draw by energizing the alternator field during cranking
is a tiny percentage of total battery draw. It's unlikely that
anyone's perception of "slower cranking due to energized alternator"
is real.
>And by the way, in passenger cars the alternator is "on" during cranking.
>Most of the accessories are turned off during cranking to reduce battery
>load, NOT to protect them against any mythical voltage transients.
Cars with two-wire alternators (b-lead and control lead) get a
ready-to-load signal from the EFI system after the engine is running.
My '90 Voyager would delay as much as two seconds after releasing
the start switch before the bus voltage would suddenly jump up. Once
turned on by the control lead, they cannot be turned off by this
same lead, hence the need for special treatment of alternators with
built in regulators as depicted in figure Z-24.
>Incidentally, according to the wiring diagram my Cessna was originally
>equipped with a relay in the avionics bus that shut it off during cranking -
>long since removed.
Yeah, the reliability of the power relay was pretty low compared to
the manual avionics switch. Many of our larger aircraft have
avionics master relays mostly because the "avionics" suite draws
too much current to be controlled by a panel mounted switch. I'll have
to go look at the wirebooks and see if we auto-disconnect the avionics
when a starter is energized.
Bob . . .
________________________________________________________________________________
| From: | Fiveonepw(at)aol.com |
| Subject: | Re: fuse block location |
In a message dated 12/05/2004 9:51:23 AM Central Standard Time,
mick-matronics(at)rv8.ch writes:
Good question. I have not yet decided exactly where I will put
mine, but one question I have is do fuses blow very often?
>>>
My fuse blocks are on a swing-down panel on the pax side- came in real handy
when I was blowing flap fuses during test phase. I could swing down the panel
and connect meter for current readings while using flaps in flight for
t-shooting. (before y'all start bitching, it's kinda hard to simulate real air
loads on flaps on the ground!) I also rigged an LED on a long lead
alligator-clipped to the fuse output and taped to the top of the glareshield so
I could tell
exactly when the fuse went t**s up. (wound up being the flap switch was
slightly loose and was also close enough to a ground that it would rotate a bit
on
application and short a terminal)
Other benefit is it's just darn handy not having to stand on my head to get
to stuff when necessary...
From The PossumWorks in TN
Mark -RV-6A, 130 hours on a Z-11 and working great (confirmed Nuckollhead)
8-)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Stereo Headphone jacks |
>
>
>Sorry if this information has been previously covered, but a search in the
>archives didn't turn up an answer to the following two questions:
>
>1. When a mono headset is plugged into a stereo jack, one of the channels
>gets grounded (gets connected to the plug sleeve, which also is the jack
>ground.) I am using the Stereo Iso Amp of Aeroelectric Connection to drive
>the phones, so is it ok for the amp to run for long periods with one of the
>channels like this? (Most of the time there will be stereo phones used,
>but I am building a 4 seater, and the rear seats may have to accommodate an
>occasional mono headset.)
Why not install two headset jacks. One for stereo and the other for
mono? Mount them side-by-side and labeled as to their functionality
so that you can use a mix of headsets without having one mono headset
kill one channel for the other stereo headsets.
>2. When wiring the stereo jacks, does the audio ground really need to be
>separate from the shield? In other words, is 3 conductor wire + shield
>necessary, or will 2 conductor + shield be just as noise immune? Note, I
>am not grounding the shield locally, it is run back for connection to the
>amp, and the jacks are isolated from frame ground.
You can do as you've suggested with two-wire shielded or run an
unshielded twisted trio and it will work just fine too.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Toggle Switch Knob |
>
>All,
>
>I have a MS24659-21A toggle switch being used for the landing gear select
>switch. It's the lock up/lock down variety toggle switch with the large
>"bat" lever. I have seen small "gear wheel" shaped knobs (a little over an
>1" in diameter) that can be attached to the switch lever itself making the
>assembly look like a production gear selector switch. I would like to add
>that to my bird.
>
>Does anyone know a part number or where to search for that "wheel shaped"
>knob to fit that style toggle switch?
>
>You can see what my current install looks like at:
>http://www.berkut13.com/intior35.jpg
You can make one in a few minutes with a band saw and belt sander
you can make one from a chunk of aluminum or machineable plastic
like the example I show in:
http://www.aeroelectric.com/Pictures/Flap_Switch.jpg
http://www.aeroelectric.com/Pictures/FLAPS1.JPG
http://www.aeroelectric.com/Pictures/FLAPS2.JPG
http://www.aeroelectric.com/Pictures/FLAPS3.JPG
Bob . . .
________________________________________________________________________________
| From: | "DonVS" <dsvs(at)comcast.net> |
I find that double sided velcro works great. It is reusable and easy to
remove. It is a little pricy at first but if you are building a complicated
system you may spend more cutting of tie wraps each time you add a wire.
Just my .02. Don
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of
KITFOXZ(at)aol.com
Subject: Re: AeroElectric-List: Bread Bag Ties?
I goofed, try this for vinyl twist ties. 10 inch length are good.
_http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=vi
ny
l+twist+ties&cpage=2_
(http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=vi
nyl+twist+ties&cpage=2)
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Alternator Off During Start Up? |
>
>Hi Bob,
>
>I have enjoyed attending your seminars and studying your book and when it is
>fresh on my mind I am confident that I "get" it and then I go work on my
>experimental panel. Then a few years pass and not being a daily user the
>electrical theories get cloudy in my mind. Then I read an article like this
>and think that maybe I remember things wrong. So thanks for the
>reinforcement. What confused me is that the author of this article wrote in
>the last paragraph to visit www.aerolectric.com for learning more. It would
>seem that the Author is due a trip to the your web site.... It seems hard
>to find a good journalist these days...
>
>Your Fellow Aviation Enthusiast,
>Ned
Thanks for the kind words and for the heads-up on the website
citation in the article. This is not the first time someone has
produced an article short on simple-ideas and long on traditional
folklore and then cited my website as a useful reference! I appreciate
the links but I hope people are not disappointed when they find
that the website is not very supportive of the original article.
It makes you wonder if they've really looked over what the website
has to offer or just echoed the suggestion of some search-engine.
I had an interesting experience a few weeks ago. A very earnest
young lady called me hopeful of selling me a service that guaranteed
to put my website into the top-ten listings of popular search-engines
based on twenty key-words of my own choosing. The service was a bargain
at $5,000!
I thought about it for awhile and couldn't really come up with
twenty keywords. I suggested bob nuckolls, aeroelectric connection,
and aircraft electrical systems. She was sitting at her computer
running through all the popular search engines and was surprised
to report that aeroelectric.com was already ensconced in the top
ten for all of those search terms. I suggested and she had to agree
that she could not offer much improvement on the status quo and that
my money would not be well spent.
Problem is that in spite of accommodating search engines, the website
has too much material to access randomly. I've got a project outlined
to organize and index the articles sometime this winter.
Bob . . .
>----- Original Message -----
>From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
>To:
>Subject: Re: AeroElectric-List: Alternator Off During Start Up?
>
>
>
> >
> > >
> > >I searched the archives for a response to this AOPA article from April
> > >2003 and found none. Anyone have an opinion about the practice of
>starting
> > >on battery only, with alternator turned off? Should we be starting with
> > >the alternator off?
> > >
> > >Thanks,
> > >Ned
> > >
> > >April 2003 Article "Charge It!" by Steven W. Ells
> > >
> > >(Second from last paragraph: )
> > >
> > >"Many pilots with split master switches have modified the owners manual
> > >starting procedure by leaving the alternator half of the switch in the
>Off
> > >position until after the start sequence. After starting, but before
> > >turning on any other equipment such as radios or lights, the pilot turns
> > >on the alternator half of the switch and checks for positive movement of
> > >the ammeter needle. This verifies that the charging system is online.
> > >Engine starting is a time when the contactors that control large current
> > >flows are opening and closing. The potential for large voltage spikes
> > >ripping through the electrical system is very high during this brief
> > >moment. Since rectifiers, switches, and other solid state devices are
> > >adversely affected by spikes, it's a good idea to isolate charging-system
> > >components during starting - unless you have a generator on your
>airplane."
> >
> > Many folks are fond of the word "spike" . . . it has a really
> > sharp sound to it and conjures up images of weapons dating back
> > to medieval times and still popular in contemporary blood-n-gore
> > flicks. Needless to say, individuals with a mission of persuasion
> > that life will be better when you adopt some new behavior find
> > it useful to embellish their sermon with colorful words . . .
> > especially when those words underscore some sense of urgency
> > for heeding their advice.
> >
> > I've been a student of the elusive "spike" for decades. I've
> > qualified dozens of new products both to withstand normal
> > bus transients and to limit their output of transients to
> > industry standard acceptable levels. I've observed many
> > dozens more suppliers jump the same hoops in order to prove
> > their products flightworthy.
> >
> > It's not difficult to live in the world of DC power
> > generated on any vehicle. Let's examine cited paragraph
> > for what real data it offers:
> >
> > "Many pilots with split master switches have modified the owners manual
> > starting procedure by leaving the alternator half of the switch in the Off
> > position until after the start sequence."
> >
> > Hmmmm . . . this may indeed be factual . . . but he doesn't
> > say how anyone arrives at the conclusion that the factory
> > supplied, FAA approved owner's manual is deficient.
> >
> > "After starting, but before turning on any other equipment such as radios
> > or lights, the pilot
> > turns on the alternator half of the switch . . .
> >
> > What is the significance or importance of not turning anything
> > else on before turning on the alternator?
> >
> > . . . and checks for positive movement of the ammeter needle. This
>verifies
> > that the charging system is on-line."
> >
> > Of course, it's unlikely that his airplane has a low voltage
> > warning light. If he did, the light would be flashing all
> > during pre-flight and would go dark as soon as the alternator
> > comes up . . . an even better
> >
> > Engine starting is a time when the contactors that control large current
> > flows are
> > opening and closing. The potential for large voltage spikes ripping
>through
> > the electrical system is very high during this brief moment.
> >
> > Lots of un-quantified, un-substantiated repetition of ol'
> > pilot's tales. These words have been simmering in the pot
> > of aviation folklore ever since I can remember.
> >
> > "Since rectifiers, switches, and other solid state devices are adversely
> > affected
> > by spikes, it's a good idea to isolate charging-system components during
> > starting
> > - unless you have a generator on your airplane."
> >
> > Hmmm . . . this one is REALLY mystifying. The author seems to be
> > implying that leaving an alternator turned off during starting
> > has some benefit for protecting the alternator . . . a benefit
> > that generators do not need.
> >
> > The alternator (or generator) control switch serves only to
> > disconnect the field excitation circuits from the system.
> > The only solid state devices "isolated" by leaving the alternator/
> > generator switch OFF are in the regulator. Modern regulators
> > for generators are solid state too. So, if the alternator's regulator
> > is to be "protected" by leaving the switch OFF, any modern
> > generator regulator would appreciate this benefit also. There
> > is no "isolating" benefit to the alternator itself for leaving
> > it off line during cranking.
> >
> > I've seen individuals try to make a case for overshoot events
> > in alternator output voltage being hazardous if one starts the
> > engine with the alternator ON. I've studied both conditions and
> > there are subtle differences in start-up behavior but neither
>condition
> > represents a hazard to any of the ship's components.
> >
> > Other individuals offer that the battery is already taxed
> > for getting the engine started . . . adding the extra load
> > represented by alternator field current is a significant performance
> > issue. Okay, 200+ amps to crank the engine and 3 amps to run
> > the alternator field at normal bus voltage - closer to 2 amps
> > during cranking. I'm not convinced that the engine or battery
> > will benefit from a 1% reduction in system loads during cranking
> > and the pilot is certainly not going to perceive any difference.
> > The oft cited spikes-of-evil-intent simply do not exist. Yes,
> > there are excursions of bus voltage in the course of NORMAL
> > operations of the airplane that every accessory is designed to
> > accommodate.
> >
> > Bottom line is that all the articles one reads in the aviation
> > journals concerning this matter are simple repetitions of
> > unfounded blue smoke and folk-lore. You may operate your
> > alternator switch any way you wish but there is no foundation
> > in physics that make one methodology more desirable or
> > practical than the other.
> >
> > Bob . . .
> >
> >
>
>
Bob . . .
--------------------------------------------------------
< Throughout history, poverty is the normal condition >
< of man. Advances which permit this norm to be >
< exceeded -- here and there, now and then -- are the >
< work of an extremely small minority, frequently >
< despised, often condemned, and almost always opposed >
< by all right-thinking people. Whenever this tiny >
< minority is kept from creating, or (as sometimes >
< happens) is driven out of a society, the people >
< then slip back into abject poverty. >
< >
< This is known as "bad luck". >
< -Lazarus Long- >
<------------------------------------------------------>
http://www.aeroelectric.com
________________________________________________________________________________
| From: | Fiveonepw(at)aol.com |
| Subject: | Re: Stereo Headphone jacks |
In a message dated 12/05/2004 3:19:35 PM Central Standard Time,
b.nuckolls(at)cox.net writes:
Why not install two headset jacks. One for stereo and the other for
mono? Mount them side-by-side and labeled as to their functionality
>>>>>
As an additional idiot-proof (something I need more&more of lately!) I
installed a "transfer" jack for the "mono" position and a spring-loaded cover on
the
stereo jack- you have to really try hard to short the sucker out! I'll send
you off-list an ACAD (R14) of my setup (Microair 760 with your audio iso amp
and stereo music source)
Mark
________________________________________________________________________________
| From: | "Steve & Denise" <sjhdcl(at)kingston.net> |
| Subject: | Single mag, single elec ign operation |
Reference RV7A with IO-360.
I'm planning a single mag and single Plasma III elec ign.
I would like to use the popular keyed ignition switch used with dual mag
systems.
Is this possible with a single elec ign setup or will I require a separate
switch to power the elec ign?
Are there any benefits of doing it either way?
Steve
RV7A #2
________________________________________________________________________________
| Subject: | Single mag, single elec ign operation |
| From: | "David Chalmers" <David(at)ChalmersFamily.com> |
My Plasma II 'Plus' ignition specifically supports control from a keyswitch. You
power the unit directly from the battery bus (i.e. always on) and connect the
control wire to the key switch. When the control wire is grounded the unit shuts
off and draws no power from the battery. I imagine the Plasma III has the
same functionality, maybe with the 'Plus' option if they still have such a thing.
David Chalmers
-----Original Message-----
From: Steve & Denise [mailto:sjhdcl(at)kingston.net]
Subject: AeroElectric-List: Single mag, single elec ign operation
Reference RV7A with IO-360.
I'm planning a single mag and single Plasma III elec ign.
I would like to use the popular keyed ignition switch used with dual mag
systems.
Is this possible with a single elec ign setup or will I require a separate
switch to power the elec ign?
Are there any benefits of doing it either way?
Steve
RV7A #2
________________________________________________________________________________
| From: | Bobby Hester <bhester(at)hopkinsville.net> |
| Subject: | Re: fuse block location |
thomas a. sargent wrote:
>
>So, where/how are people mounting their fuse blocks?
>--
>Tom Sargent
>RV-6A, firewall.
>
>
>
I'm using an Affordable Panels instrument panel and mounting the main
and essential fuse buss where they can be accessed easily.
http://www.geocities.com/hester-hoptown/RVSite/FinishKitAssyPg3.html
--
Surfing the Web from Hopkinsville, KY
Visit my web site at: http://www.geocities.com/hester-hoptown/RVSite/
RV7A Slowbuild wings-QB Fuse :-)
________________________________________________________________________________
| From: | "James E. Clark" <james(at)nextupventures.com> |
| Subject: | Single mag, single elec ign operation |
Steve,
We have such a setup on our RV6 .. the keyswitch is used just as with two
mags. Our electronic ignition is from Jeff Rose. (I am also building an RV6A
and it has a Lightspeed EI).
Jeff suggested that I **also** add a switch to switch off the power to the
unit after shutdown (originally it was wired "hot" (through a fuse) and was
controlled by the "mag switch). I think his reasoning was that the internals
might last longer if they weren't always sitting there with an internal
charge or something. Worked fine before. Added additonal switch and it works
fine afterwards.
I have the drawings from Klaus on using the keyswitch but they are at the
airport.
James
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Steve
> & Denise
> Sent: Sunday, December 05, 2004 6:51 PM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: Single mag, single elec ign operation
>
>
>
>
> Reference RV7A with IO-360.
>
> I'm planning a single mag and single Plasma III elec ign.
>
> I would like to use the popular keyed ignition switch used with dual mag
> systems.
>
> Is this possible with a single elec ign setup or will I require a separate
> switch to power the elec ign?
>
> Are there any benefits of doing it either way?
>
> Steve
> RV7A #2
>
>
________________________________________________________________________________
| From: | "Jim Jewell" <jjewell(at)telus.net> |
| Subject: | Re: Alternator Off During Start Up? |
Does anyone know of a source for temperature sensitive stick-on tabs that
might be useful for determining physical item and area temperatures? I think
such a things exist. I wonder if it could be of use in the cowling
environment?
Jim in Kelowna
----- Original Message -----
From: "Mickey Coggins" <mick-matronics(at)rv8.ch>
Subject: Re: AeroElectric-List: Alternator Off During Start Up?
>
>
>
>> ... If you want to
>> discover for yourself how well your alternator is cooled,
>> you can easily thermocouple the critter and find out during
>> your fly-off interval.
>
> That sounds like a good idea. Adding a scat tube later would
> not be a big deal if it is necessary.
>
> Thanks,
> Mickey
>
>
> --
> Mickey Coggins
> http://www.rv8.ch/
> #82007 QB Wings/Fuselage
>
>
>
________________________________________________________________________________
| From: | "Rob W M Shipley" <rob(at)robsglass.com> |
| Subject: | E bus switching. |
Subject: Re: AeroElectric-List: E-Bus Usage Procedure / Question
"Matthew,
Yes, you got it...but...I always fly with my E-Bus switch ON. Constantly.
That way it's just one switch flip if and when the alternator dies, and
voltage to my "essentials" (some of which need initialization time, such as
the GPS) is NOT interrupted.
If you fly with the E-Bus switch ON all the time, when the alternator dies,
flip the master switch all the way off and keep flying.
Plus, this way, the devices on the E-Bus theoretically don't see the voltage
drop they otherwise would if the E-Bus was being fed through the diode. The
E-Bus is being fed from the battery bus (I think!).
Hope this makes sense, and please correct me if I'm wrong.
)_( Dan
RV-7 N714D
http://www.rvproject.com"
Dan I'm probably asking a dumb question here but since this seems O.K to me why
do we bother with a switch for the e-bus. Why not hard wire this circuit to
be on continuously.
If it is deemed necessary an lED could be used as an annunciator to monitor that
the circuit is active.
________________________________________________________________________________
| From: | "Jim Jewell" <jjewell(at)telus.net> |
| Subject: | Re: Bread Bag Ties? |
After trying some of the things recently mentioned I settled on using
colorless nylon spiral wrap that comes in several diameters.
I picked a size that most suited the application then cut off pieces three
to four coils long. These short sections were then temporarily coiled around
the wire bundles at various locations.
In use I could either uncoil the spiral wrap section somewhat or most often
just push the wire through inside the spiral wrap section. Because the
spiral wrap sections are almost clear and short, patching in additional
wires was quite easy.
A helpful suggestion is to trim the corners off (round off) the ends so that
they don't catch on the wires in the growing wire bundles. Using one of
these sections while tying the finished bundles also helped, (tie next to
the bundle, push the spiral wrap ahead, tie again and so on)
Per foot this product was not a cost consideration.
I got the product from bulk supply at a local area electronics supplier.
Jim in Kelowna
----- Original Message -----
From: "DonVS" <dsvs(at)comcast.net>
Subject: RE: AeroElectric-List: Bread Bag Ties?
>
> I find that double sided velcro works great. It is reusable and easy to
> remove. It is a little pricy at first but if you are building a
> complicated
> system you may spend more cutting of tie wraps each time you add a wire.
> Just my .02. Don
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of
> KITFOXZ(at)aol.com
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Bread Bag Ties?
>
>
> I goofed, try this for vinyl twist ties. 10 inch length are good.
>
> _http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=vi
> ny
> l+twist+ties&cpage=2_
> (http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=vi
> nyl+twist+ties&cpage=2)
>
>
> John P. Marzluf
> Columbus, Ohio
> Kitfox Outback (out back in the garage)
>
>
>
________________________________________________________________________________
| From: | "Brian Kraut" <brian.kraut(at)engalt.com> |
| Subject: | Alternator Off During Start Up? |
They do exist and I have seen them although I am not sure where to get them,
but thank you for solving my problem of making sure the EGT gauge is on the
hottest cylinder without having to keep moving it around.
I know that there are some types that change color and stay the color at the
max temp seen. I have seen them in lower temp ranges in shipping supply
catalogs and seen higher temp ranges other places. Edmund scientific maybe?
Brian Kraut
Engineering Alternatives, Inc.
www.engalt.com
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Jim
Jewell
Subject: Re: AeroElectric-List: Alternator Off During Start Up?
Does anyone know of a source for temperature sensitive stick-on tabs that
might be useful for determining physical item and area temperatures? I think
such a things exist. I wonder if it could be of use in the cowling
environment?
Jim in Kelowna
----- Original Message -----
From: "Mickey Coggins" <mick-matronics(at)rv8.ch>
Subject: Re: AeroElectric-List: Alternator Off During Start Up?
>
>
>
>> ... If you want to
>> discover for yourself how well your alternator is cooled,
>> you can easily thermocouple the critter and find out during
>> your fly-off interval.
>
> That sounds like a good idea. Adding a scat tube later would
> not be a big deal if it is necessary.
>
> Thanks,
> Mickey
>
>
> --
> Mickey Coggins
> http://www.rv8.ch/
> #82007 QB Wings/Fuselage
>
>
________________________________________________________________________________
| From: | "Tinne maha" <tinnemaha(at)hotmail.com> |
List,
Figure Z-11 shows an awg 22 wire running from the battery contactor to the
master switch. As my battery is in the tail, this wire will be about 14 ft
long. Generally one would want to increase wire size for a longer run due
to voltage drop, but I can't see that being an issue here.
Any recommendations or opinions to the contrary?
Thanks,
Grant
________________________________________________________________________________
| From: | "Tinne maha" <tinnemaha(at)hotmail.com> |
| Subject: | Small Wire, Big Ring Terminal |
Hello Again List,
The awg 16 wire from the battery contactor to the main battery bus requires
a 5/16" ring terminal on one end (at least that's what size my contactor
has), but I can't find a terminal that large for a wire that small. What is
the best solution?
My current best guess would be to just strip off extra wire & double it back
to fill the next size larger terminal like Bob's shop notes say to do for an
awg 24 fuselink. Any comments?
Thanks again,
Grant
________________________________________________________________________________
| From: | "Kingsley Hurst" <khurst(at)taroom.qld.gov.au> |
| Subject: | Small Wire, Big Ring Terminal |
Grant,
B & C Specialty have what you are looking for.
Try http://www.bandc.biz/parts.html and look under Insulated Terminals
Listed is 14-16 awg Ring Terminal 5/16" stud
Regards
Kingsley Hurst in Oz.
________________________________________________________________________________
| From: | "Franck ILMAIN" <f_ilmain(at)hotmail.com> |
Anyone know where to find or have a user manual for a KMA 20 ?
________________________________________________________________________________
| From: | Robert McCallum <robert.mccallum2(at)sympatico.ca> |
| Subject: | Re: Small Wire, Big Ring Terminal |
Use the proper terminal. They are available for 16 gauge wire from
Digikey up to 1/2" stud size and from B&C to 5/16" as well as from
several other sources. They are made by AMP in their PIDG series so
presumably would be available through most AMP distributors.
Bob McC
Tinne maha wrote:
>
>Hello Again List,
>
>The awg 16 wire from the battery contactor to the main battery bus requires
>a 5/16" ring terminal on one end (at least that's what size my contactor
>has), but I can't find a terminal that large for a wire that small. What is
>the best solution?
>
>My current best guess would be to just strip off extra wire & double it back
>to fill the next size larger terminal like Bob's shop notes say to do for an
>awg 24 fuselink. Any comments?
>
> Thanks again,
> Grant
>
>
________________________________________________________________________________
| From: | "Franz Fux" <franz(at)lastfrontierheli.com> |
Hi Jim,
Which supplier are you talking about,
Franz in Vernon
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Jim
Jewell
Subject: Re: AeroElectric-List: Bread Bag Ties?
After trying some of the things recently mentioned I settled on using
colorless nylon spiral wrap that comes in several diameters.
I picked a size that most suited the application then cut off pieces three
to four coils long. These short sections were then temporarily coiled around
the wire bundles at various locations.
In use I could either uncoil the spiral wrap section somewhat or most often
just push the wire through inside the spiral wrap section. Because the
spiral wrap sections are almost clear and short, patching in additional
wires was quite easy.
A helpful suggestion is to trim the corners off (round off) the ends so that
they don't catch on the wires in the growing wire bundles. Using one of
these sections while tying the finished bundles also helped, (tie next to
the bundle, push the spiral wrap ahead, tie again and so on)
Per foot this product was not a cost consideration.
I got the product from bulk supply at a local area electronics supplier.
Jim in Kelowna
----- Original Message -----
From: "DonVS" <dsvs(at)comcast.net>
Subject: RE: AeroElectric-List: Bread Bag Ties?
>
> I find that double sided velcro works great. It is reusable and easy to
> remove. It is a little pricy at first but if you are building a
> complicated
> system you may spend more cutting of tie wraps each time you add a wire.
> Just my .02. Don
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of
> KITFOXZ(at)aol.com
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Bread Bag Ties?
>
>
> I goofed, try this for vinyl twist ties. 10 inch length are good.
>
>
_http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=vi
> ny
> l+twist+ties&cpage=2_
>
(http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=vi
> nyl+twist+ties&cpage=2)
>
>
> John P. Marzluf
> Columbus, Ohio
> Kitfox Outback (out back in the garage)
>
>
--
Checked by AVG Anti-Virus.
--
Checked by AVG Anti-Virus.
________________________________________________________________________________
| From: | "Jim Jewell" <jjewell(at)telus.net> |
| Subject: | Re: Bread Bag Ties? |
Hi Franz,
Interior Eelectronics
Jim
----- Original Message -----
From: "Franz Fux" <franz(at)lastfrontierheli.com>
Subject: RE: AeroElectric-List: Bread Bag Ties?
>
>
> Hi Jim,
> Which supplier are you talking about,
> Franz in Vernon
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Jim
> Jewell
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Bread Bag Ties?
>
>
> After trying some of the things recently mentioned I settled on using
> colorless nylon spiral wrap that comes in several diameters.
> I picked a size that most suited the application then cut off pieces three
> to four coils long. These short sections were then temporarily coiled
> around
> the wire bundles at various locations.
>
> In use I could either uncoil the spiral wrap section somewhat or most
> often
> just push the wire through inside the spiral wrap section. Because the
> spiral wrap sections are almost clear and short, patching in additional
> wires was quite easy.
> A helpful suggestion is to trim the corners off (round off) the ends so
> that
> they don't catch on the wires in the growing wire bundles. Using one of
> these sections while tying the finished bundles also helped, (tie next to
> the bundle, push the spiral wrap ahead, tie again and so on)
> Per foot this product was not a cost consideration.
> I got the product from bulk supply at a local area electronics supplier.
>
> Jim in Kelowna
>
>
> ----- Original Message -----
> From: "DonVS" <dsvs(at)comcast.net>
> To:
> Subject: RE: AeroElectric-List: Bread Bag Ties?
>
>
>>
>> I find that double sided velcro works great. It is reusable and easy to
>> remove. It is a little pricy at first but if you are building a
>> complicated
>> system you may spend more cutting of tie wraps each time you add a wire.
>> Just my .02. Don
>>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server(at)matronics.com
>> [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of
>> KITFOXZ(at)aol.com
>> To: aeroelectric-list(at)matronics.com
>> Subject: Re: AeroElectric-List: Bread Bag Ties?
>>
>>
>>
>> I goofed, try this for vinyl twist ties. 10 inch length are good.
>>
>>
> _http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=vi
>> ny
>> l+twist+ties&cpage=2_
>>
> (http://www.chiswick.com//searchresults.asp?searchtype=Basic&searchstring=vi
>> nyl+twist+ties&cpage=2)
>>
>>
>> John P. Marzluf
>> Columbus, Ohio
>> Kitfox Outback (out back in the garage)
>>
>>
>
>
> --
> Checked by AVG Anti-Virus.
>
> --
> Checked by AVG Anti-Virus.
>
>
>
________________________________________________________________________________
| Subject: | Re: Small Wire, Big Ring Terminal |
In a message dated 12/5/2004 9:58:08 P.M. Eastern Standard Time,
tinnemaha(at)hotmail.com writes:
Hello Again List,
The awg 16 wire from the battery contactor to the main battery bus requires
a 5/16" ring terminal on one end (at least that's what size my contactor
has), but I can't find a terminal that large for a wire that small. What is
the best solution?
My current best guess would be to just strip off extra wire & double it back
to fill the next size larger terminal like Bob's shop notes say to do for an
awg 24 fuselink. Any comments?
Thanks again,
Grant
That's exactly what I do in a pinch for the right terminal and then I use a
short piece of heat shrink on it for additional support. The important thing
to remember is to completely fill the crimp with wire BEFORE it is crimped.
Many people in the electrical/electronic trades incorrectly try to crimp a
large terminal on a small wire with all kinds of space around the wire and it
is BAD! You are trying to obtain a near gas tight seal of terminal material
and wire here.
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
________________________________________________________________________________
| Subject: | Re: Master Ground |
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Grant -
Our batteries are in the tail - 15 ft away from the switches on the panel.
We are using Z-14. We used 20 AWG for these runs.
John
> Figure Z-11 shows an awg 22 wire running from the battery contactor to
> the
> master switch. As my battery is in the tail, this wire will be about 14
> ft
> long. Generally one would want to increase wire size for a longer run
> due to voltage drop, but I can't see that being an issue here.
________________________________________________________________________________
| Subject: | Re: Master Ground |
Hello Grant,
Regardless of wire size needed to properly carry the current that distance
without voltage drop, I can't bring myself to run a wire that distance with a
22 Ga. wire. I would like to keep the physical size to an 18 or a 20 just
for mechanical/physical survivability.
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
________________________________________________________________________________
| From: | "Bryan Hooks" <bryanhooks(at)comcast.net> |
| Subject: | fuse block location |
I recently had one blow in my wifes' SUV. Not quite sure why though.
All she did was plug an inverter into the cig lighter, plug a hair dryer
into that and turned it on. :)
On an unfortunate note, she didn't quite have enough time to get her
hair dry before the fuse had blown.
I now have the inverter put up out of her reach, so to speak since it
apparently is my fault for not telling her not to plug her hair dryer
into it.
-bryan
-----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
Subject: Re: AeroElectric-List: fuse block location
>
>
>Good question. I have not yet decided exactly where I will put
>mine, but one question I have is do fuses blow very often? I
>have not had one blow in one of my cars or motorcycles for at
>least 25 years. Of course, the spam cans I fly have circuit
>breakers, and I have never experienced a tripped breaker, either.
Good anecdotal data. I'll suggest that 99.99+ percent of all
breakers
and fuses installed in any vehicle will never be called upon to
protect
the system over the lifetime of the vehicle . . . when they ARE
needed, the most likely cause is some condition that cannot be
mitigated by replacing the fuse or resetting the breaker. So if any
particular system is desirable for comfortable completion of flight,
you'd do well to have a backup for it.
Bob . . .
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | EGT indications, was:Alternator Off During Start Up? |
In a message dated 12/5/2004 8:33:38 P.M. Central Standard Time,
brian.kraut(at)engalt.com writes:
They do exist and I have seen them although I am not sure where to get them,
but thank you for solving my problem of making sure the EGT gauge is on the
hottest cylinder without having to keep moving it around.
Good Morning Brian,
Why do you want your EGT gauge to be on the "hottest" cylinder?
For the purposes we aviators use the EGT information, any EGT indication is
only a relative measurement. The exact temperature developed is totally
irrelevant to the operation of the engine. If you really want to see how your
engine is responding, you need to have an EGT probe on every cylinder.
However, if you have confidence that the fuel distribution to all cylinders is
well
balanced, you can control the mixture to all by reference to only one
cylinder.
The important thing to realize is that the temperature you are seeing is not
at all pertinent to how the engine is running or whether or not any damage
is being done to the engine.
All it provides is a means of economically telling you what the cylinder is
doing in relation to data that has been previously developed in an engine test
cell.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| Subject: | Re: EGT indications, was:Alternator Off During Start |
Up?
| From: | "Matt Prather" <mprather(at)spro.net> |
I basically agree with Mr Siegfried's comments, with only a couple
of additional comments. On turbocharged engines, the actual EGT
value becomes critical - the same as TIT or ITT. For NA 4 cycle
engines, only the relative temps are useful.
The fuel distribution for most common engine airframe combinations
should be known. If you get in touch with someone else who has the
same setup as you and also has all of the instrumentation, you can
probably copy their data, and get the EGT probe on the right cylinder.
When leaning with the intent of running the engine rich of peak (ROP)
EGT - as recommended for best power, if you have only one probe, it
needs to be located on the cylinder which reachs peak first (at the richest
setting - the leanest cylinder). Then all other cylinders will be operating
richer and cooler than the cylinder you have instrumented. Safe.
If the fuel distribution is good enough to allow lean of peak operation
(LOP), and you wish to run there in cruise, the probe needs to be on
the cylinder that peaks last (the richest cylinder). Then when you lean
for cruise based on that cylinder, you can be confident that all other
cylinders will be cooler than the one you have instrumented.
Finally, in the scheme of things, EGT probes are relatively inexpensive.
So too is setting up a rotary switch to be able to monitor each probe on
a single display. The weight of the wire is negligible, so why not go
ahead a wire it all up?
Regards,
Matt-
>
>
> In a message dated 12/5/2004 8:33:38 P.M. Central Standard Time,
> brian.kraut(at)engalt.com writes:
>
> They do exist and I have seen them although I am not sure where to get
> them, but thank you for solving my problem of making sure the EGT gauge
> is on the hottest cylinder without having to keep moving it around.
>
>
> Good Morning Brian,
>
> Why do you want your EGT gauge to be on the "hottest" cylinder?
>
> For the purposes we aviators use the EGT information, any EGT indication
> is only a relative measurement. The exact temperature developed is
> totally irrelevant to the operation of the engine. If you really want
> to see how your engine is responding, you need to have an EGT probe on
> every cylinder. However, if you have confidence that the fuel
> distribution to all cylinders is well balanced, you can control the
> mixture to all by reference to only one cylinder.
>
> The important thing to realize is that the temperature you are seeing is
> not at all pertinent to how the engine is running or whether or not
> any damage is being done to the engine.
>
> All it provides is a means of economically telling you what the cylinder
> is doing in relation to data that has been previously developed in an
> engine test
> cell.
>
> Happy Skies,
>
> Old Bob
> AKA
> Bob Siegfried
> Ancient Aviator
> Stearman N3977A
> Brookeridge Airpark LL22
> Downers Grove, IL 60516
> 630 985-8502
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Master Ground |
>
>List,
>
>Figure Z-11 shows an awg 22 wire running from the battery contactor to the
>master switch. As my battery is in the tail, this wire will be about 14 ft
>long. Generally one would want to increase wire size for a longer run due
>to voltage drop, but I can't see that being an issue here.
>
>Any recommendations or opinions to the contrary?
>
> Thanks,
> Grant
Voltage drop is predicated on resistance of the wire multiplied by
the current flowing in the wire. The battery contactor draws about .8
amps. 22AWG wire is 22 milliohms per foot so drop on a 14 foot run
will be 22 x 14 x 0.8 or 245 millivolts . . . a quite acceptable
value.
Bob . . .
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: EGT indications, was:Alternator Off During Start |
Up?
In a message dated 12/6/2004 10:44:33 A.M. Central Standard Time,
mprather(at)spro.net writes:
Finally, in the scheme of things, EGT probes are relatively inexpensive.
So too is setting up a rotary switch to be able to monitor each probe on
a single display. The weight of the wire is negligible, so why not go
ahead a wire it all up?
Regards,
Matt-
Totally agree Matt,
I might even add a pitch for getting an instrument that will not require a
switch. There are several manufacturers of good monitoring equipment available.
All of them are good.
JPI is the eight hundred pound gorilla on this playing field, but
Electronics International and Insight Avionics, along with others, have good equipment
as well.
For anyone who has more interest engine operations, may I recommend reading
the articles written by John Deakin.
Try: _http://www.avweb.com/news/columns/182544-1.html_
(http://www.avweb.com/news/columns/182544-1.html)
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | "Ronald J. Parigoris" <rparigor(at)SUFFOLK.LIB.NY.US> |
| Subject: | O2 sensor for Rotax 914? |
Putting together a panel for our europa and got to the decision about an EGT.
Since the Mixture in flight is not adjustable, the EGT information would not be
tremendous useful. If you were monitoring all 4 cylinders, it could show difference,
but
most I don't think install 4 probes. As far as an absolute temperature, I doubt
you
could look in Rotax manual and get a specific temp that it should be and actual
read
that on gauge because of exact position of probe and calibration of gauge.
I got to thinking perhaps an O2 sensor with a readout would be more useful. I see
Spruce
sells one with a simple circuit that lets you lean till a light goes on, then go
slight
richer.
Hmmm.
What if you had a circuit that drove a bar graph LED where the center was ideal
mixture. Granted it would be for all cylinders, and 1 side could be lean and the
other
rich, but once you knew your motor you could see a change.
Could be used for diagnosing problems, a specific setting and roughness, is it
too rich
or too lean?
Anyway is such a thing sold? Anybody have an idea how to build one? I plan on mostly
using MoGas but on trips 100LL, so need a sensor that could tolerate it for a while.
Spruce says theirs is good for ~200 hours. On cars some use 2 wire and some 3 wire.
I had a 1983 Volvo Wagon with 2 wire O2 sensor that needed replacement every 30K.
It was
located before the Turbo. I let it go to 45K near car life and it broke a tab off,
went
through turbo and it busted a tip of as blade. I just broke off the opposite side
and it
worked till I got rid of car without whistle.
My 92 Turbo wagon has a 3 wire that is after the turbo, i change it ~ 100K but
seemed OK
when I do.
I would prefer to have one after the turbo on 914.
Thx.
Ron Parigoris
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: EGT indications, was:Alternator Off During Start |
Up?
In a message dated 12/6/2004 10:44:33 A.M. Central Standard Time,
mprather(at)spro.net writes:
When leaning with the intent of running the engine rich of peak (ROP)
EGT - as recommended for best power, if you have only one probe, it
needs to be located on the cylinder which reaches peak first (at the richest
setting - the leanest cylinder). Then all other cylinders will be operating
richer and cooler than the cylinder you have instrumented. Safe.
Oh! One more thing.
Note that Matt said the leanest cylinder, not the hottest cylinder. The
purpose of the EGT is to locate that point where the EGT shows the mixture of
that individual cylinder is going from rich to lean. You don't have any need
at all for knowing what the temperature actually is unless, as Matt stated,
you are running that exhaust into a turbo charger which IS sensitive to high
temperatures
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | "Bobby Hester" <bhester(at)hopkinsville.net> |
| Subject: | Bob Nockolls question |
Bob, I got your response last week but you missed a question I had and I was hoping
to hear your response.
I have a friend that knows more than I do about wiring. He has questioned me about
the 4 AWG wire going from the Battery side of the 80 AMP fuse to the main
fuse buss. He said that wire is not protected (by a fuse) from the battery current
to the fuse box and should be.
I plan on using 8 AWG there insted of 4 AWG now, because the load will only req.
8 AWG, but I still want to be able to explain to my friend that nothing else
is needed on the wire run, if that is true.
Here was the link that I had posted:
http://www.geocities.com/hester-hoptown/RVSite/WiringPlan.html
Thanks!
-------
Surfing the web from Hopkinsville, KY
RV7A web site: http://www.geocities.com/hester-hoptown/RVSite
________________________________________________________________________________
| Subject: | Re: Alternator Off During Start Up? |
http://www.omega.com will sell you various kinds of temperature tabs. I
used some right on my cylinder heads when I was checking the CHT readings.
Greg
----------------------------------------------
Original Message
From: "Jim Jewell"<jjewell(at)telus.net>
Subject: Re: AeroElectric-List: Alternator Off During Start Up?
Date: Sun, 5 Dec 2004 17:53:01 -0800
>
>Does anyone know of a source for temperature sensitive stick-on tabs that
>might be useful for determining physical item and area temperatures? I
think
>such a things exist. I wonder if it could be of use in the cowling
>environment?
>
>Jim in Kelowna
>
>----- Original Message -----
>From: "Mickey Coggins" <mick-matronics(at)rv8.ch>
>To:
>Subject: Re: AeroElectric-List: Alternator Off During Start Up?
>
>
>>
>>
>>
>>> ... If you want to
>>> discover for yourself how well your alternator is cooled,
>>> you can easily thermocouple the critter and find out during
>>> your fly-off interval.
>>
>> That sounds like a good idea. Adding a scat tube later would
>> not be a big deal if it is necessary.
>>
>> Thanks,
>> Mickey
>>
>>
>> --
>> Mickey Coggins
>> http://www.rv8.ch/
>> #82007 QB Wings/Fuselage
>>
>>
>>
>
>
http://www.MyOwnEmail.com
________________________________________________________________________________
| Subject: | Alternator Off During Start Up? |
Crayon-like Tempilstistiks can be used to measure surface temperatures.
See: http://www.tempil.com/
Best regards,
Rob Housman
Europa XS Tri-Gear A070
Airframe complete
Irvine, CA
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Jim Jewell
Subject: Re: AeroElectric-List: Alternator Off During Start Up?
Does anyone know of a source for temperature sensitive stick-on tabs that
might be useful for determining physical item and area temperatures? I think
such a things exist. I wonder if it could be of use in the cowling
environment?
Jim in Kelowna
----- Original Message -----
From: "Mickey Coggins" <mick-matronics(at)rv8.ch>
Subject: Re: AeroElectric-List: Alternator Off During Start Up?
>
>
>
>> ... If you want to
>> discover for yourself how well your alternator is cooled,
>> you can easily thermocouple the critter and find out during
>> your fly-off interval.
>
> That sounds like a good idea. Adding a scat tube later would
> not be a big deal if it is necessary.
>
> Thanks,
> Mickey
>
>
> --
> Mickey Coggins
> http://www.rv8.ch/
> #82007 QB Wings/Fuselage
>
>
________________________________________________________________________________
| Subject: | temperature sensitive stick-on tabs |
Do a google search on "Tempilstick" They are used by auto racing folks and
are used in the welding industry.
________________________________________________________________________________
| From: | "923te" <923te(at)cox.net> |
| Subject: | Re: O2 sensor for Rotax 914? |
There are severl O2 sensors or Air Fuel Ratio Monitors available. Even kits
to build them. I listed some links below but just do a google on it and
you'll find lots. The lead in 100LL eventually slows the response time of
the O2 sensor but since we do not need fast response times (with out using a
fuel controller computer) it will work for a long time
There used to be a fellow that sold a conversion kit to make the Bing carb
mixture manually controllable. I understand that these carbs are pressure
compensated to only 10,000ft after that you are burning too rich.
http://www.techedge.com.au/vehicle/wbo2/default.htm
ARM1 Air Fuel Ratio Monitor
http://www.racerpartswholesale.com/afratio.htm
http://www.kemparts.com/TechTalk/tt07.asp
----- Original Message -----
From: "Ronald J. Parigoris" <rparigor(at)suffolk.lib.ny.us>
Subject: AeroElectric-List: O2 sensor for Rotax 914?
>
> Putting together a panel for our europa and got to the decision about an
EGT.
>
> Since the Mixture in flight is not adjustable, the EGT information would
not be
> tremendous useful. If you were monitoring all 4 cylinders, it could show
difference, but
> most I don't think install 4 probes. As far as an absolute temperature, I
doubt you
> could look in Rotax manual and get a specific temp that it should be and
actual read
> that on gauge because of exact position of probe and calibration of gauge.
>
> I got to thinking perhaps an O2 sensor with a readout would be more
useful. I see Spruce
> sells one with a simple circuit that lets you lean till a light goes on,
then go slight
> richer.
>
> Hmmm.
>
> What if you had a circuit that drove a bar graph LED where the center was
ideal
> mixture. Granted it would be for all cylinders, and 1 side could be lean
and the other
> rich, but once you knew your motor you could see a change.
>
> Could be used for diagnosing problems, a specific setting and roughness,
is it too rich
> or too lean?
>
> Anyway is such a thing sold? Anybody have an idea how to build one? I plan
on mostly
> using MoGas but on trips 100LL, so need a sensor that could tolerate it
for a while.
> Spruce says theirs is good for ~200 hours. On cars some use 2 wire and
some 3 wire.
>
> I had a 1983 Volvo Wagon with 2 wire O2 sensor that needed replacement
every 30K. It was
> located before the Turbo. I let it go to 45K near car life and it broke a
tab off, went
> through turbo and it busted a tip of as blade. I just broke off the
opposite side and it
> worked till I got rid of car without whistle.
>
> My 92 Turbo wagon has a 3 wire that is after the turbo, i change it ~ 100K
but seemed OK
> when I do.
>
> I would prefer to have one after the turbo on 914.
>
> Thx.
> Ron Parigoris
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Bob Nockolls question |
>
>
>Bob, I got your response last week but you missed a question I had and I
>was hoping to hear your response.
>
>I have a friend that knows more than I do about wiring. He has questioned
>me about the 4 AWG wire going from the Battery side of the 80 AMP fuse to
>the main fuse buss. He said that wire is not protected (by a fuse) from
>the battery current to the fuse box and should be.
>I plan on using 8 AWG there insted of 4 AWG now, because the load will
>only req. 8 AWG, but I still want to be able to explain to my friend that
>nothing else is needed on the wire run, if that is true.
These wires are classically not protected assuming the wires are
large enough that any fault currents they carry are likely to "burn clear"
as opposed to setting a wire on fire. Check out the wiring diagrams for
any single engine certified airplane and you'll find the main bus
feeder is not fused or protected in any way other than to make sure
it's well supported and isolated from potential rub-through situations.
So for that reason, I'd recommend leaving the wire large (4AWG) and
un-protected. I'm assuming your airplane includes an e-bus . . .
so if you wanted to drop to 8 AWG and put a 40A fuse in line with it,
that would be fine too although about a quarter-million airplanes have
flown for decades without experiencing any problems due to this design
feature.
Quoting FAR23:
Sec. 23.1357 Circuit protective devices.
(a) Protective devices, such as fuses or circuit breakers, must be
installed in all electrical circuits other than--
(1) Main circuits of starter motors used during starting only; and
(2) Circuits in which no hazard is presented by their omission.
In the case we're discussing, circuit protection has been left
out because it's easy to install these wires so that they're
well shielded from abrasion. There may be a certified S.E. aircraft
that fuses the main bus feeder but I'm only aware of the huge
quantities that are not so protected . . .
Bob . . .
________________________________________________________________________________
| From: | Richard Tasker <retasker(at)optonline.net> |
| Subject: | Re: O2 sensor for Rotax 914? |
These are good suggestions. However, be aware that there two types of
oxygen sensors - and therefore two types of ratio meters.
The first are the so-called narrow band sensors that have their entire
0-1V nominal (typically 0.3 to 0.7V) change in output over a very narrow
range around the ideal 14.7:1 ratio. These are what are normally used
with most automobile engines where they are just trying to optimize the
mixture for minimum emissions. Devices using these sensors are
relatively cheap (US$100-200) but only show a relative rich to lean
readout typically using a set of LEDS or a bar graph - no numbers.
The second type are the so-called wide band sensors which typically have
a wider output voltage change and will sense a wide range of mixtures -
from way too lean to way too rich. These are typically not used in
automobile engines, but are used in purpose built air-fuel ratio
meters. They will read out the ratio in numbers (e.g. 14.7) and can be
used to set accurate air fuel ratios. They are much more expensive
(US$450 and up) and typically come with the appropriate wide band sensor.
Depending on what you want to do, either could be acceptable.
Dick Tasker
923te wrote:
>
>There are severl O2 sensors or Air Fuel Ratio Monitors available. Even kits
>to build them. I listed some links below but just do a google on it and
>you'll find lots. The lead in 100LL eventually slows the response time of
>the O2 sensor but since we do not need fast response times (with out using a
>fuel controller computer) it will work for a long time
>
>There used to be a fellow that sold a conversion kit to make the Bing carb
>mixture manually controllable. I understand that these carbs are pressure
>compensated to only 10,000ft after that you are burning too rich.
>
>http://www.techedge.com.au/vehicle/wbo2/default.htm
>
>ARM1 Air Fuel Ratio Monitor
>http://www.racerpartswholesale.com/afratio.htm
>
>http://www.kemparts.com/TechTalk/tt07.asp
>
>
>----- Original Message -----
>From: "Ronald J. Parigoris" <rparigor(at)suffolk.lib.ny.us>
>To:
>Subject: AeroElectric-List: O2 sensor for Rotax 914?
>
>
>
>
>>
>>
>
>
>
>>Putting together a panel for our europa and got to the decision about an
>>
>>
>EGT.
>
>
>>Since the Mixture in flight is not adjustable, the EGT information would
>>
>>
>not be
>
>
>>tremendous useful. If you were monitoring all 4 cylinders, it could show
>>
>>
>difference, but
>
>
>>most I don't think install 4 probes. As far as an absolute temperature, I
>>
>>
>doubt you
>
>
>>could look in Rotax manual and get a specific temp that it should be and
>>
>>
>actual read
>
>
>>that on gauge because of exact position of probe and calibration of gauge.
>>
>>I got to thinking perhaps an O2 sensor with a readout would be more
>>
>>
>useful. I see Spruce
>
>
>>sells one with a simple circuit that lets you lean till a light goes on,
>>
>>
>then go slight
>
>
>>richer.
>>
>>Hmmm.
>>
>>What if you had a circuit that drove a bar graph LED where the center was
>>
>>
>ideal
>
>
>>mixture. Granted it would be for all cylinders, and 1 side could be lean
>>
>>
>and the other
>
>
>>rich, but once you knew your motor you could see a change.
>>
>>Could be used for diagnosing problems, a specific setting and roughness,
>>
>>
>is it too rich
>
>
>>or too lean?
>>
>>Anyway is such a thing sold? Anybody have an idea how to build one? I plan
>>
>>
>on mostly
>
>
>>using MoGas but on trips 100LL, so need a sensor that could tolerate it
>>
>>
>for a while.
>
>
>>Spruce says theirs is good for ~200 hours. On cars some use 2 wire and
>>
>>
>some 3 wire.
>
>
>>I had a 1983 Volvo Wagon with 2 wire O2 sensor that needed replacement
>>
>>
>every 30K. It was
>
>
>>located before the Turbo. I let it go to 45K near car life and it broke a
>>
>>
>tab off, went
>
>
>>through turbo and it busted a tip of as blade. I just broke off the
>>
>>
>opposite side and it
>
>
>>worked till I got rid of car without whistle.
>>
>>My 92 Turbo wagon has a 3 wire that is after the turbo, i change it ~ 100K
>>
>>
>but seemed OK
>
>
>>when I do.
>>
>>I would prefer to have one after the turbo on 914.
>>
>>Thx.
>>Ron Parigoris
>>
>>
>>
>>
>
>
>
>
________________________________________________________________________________
| From: | "Ronald J. Parigoris" <rparigor(at)SUFFOLK.LIB.NY.US> |
| Subject: | Re: O2 sensor for Rotax 914? |
Hello Richard
Thanks for your help.
Once flying will post how useful the ARM1 will be.
Ron Parigoris
Richard Tasker wrote:
>
> These are good suggestions. However, be aware that there two types of
> oxygen sensors - and therefore two types of ratio meters.
>
> The first are the so-called narrow band sensors that have their entire
> 0-1V nominal (typically 0.3 to 0.7V) change in output over a very narrow
> range around the ideal 14.7:1 ratio. These are what are normally used
> with most automobile engines where they are just trying to optimize the
> mixture for minimum emissions. Devices using these sensors are
> relatively cheap (US$100-200) but only show a relative rich to lean
> readout typically using a set of LEDS or a bar graph - no numbers.
>
> The second type are the so-called wide band sensors which typically have
> a wider output voltage change and will sense a wide range of mixtures -
> from way too lean to way too rich. These are typically not used in
> automobile engines, but are used in purpose built air-fuel ratio
> meters. They will read out the ratio in numbers (e.g. 14.7) and can be
> used to set accurate air fuel ratios. They are much more expensive
> (US$450 and up) and typically come with the appropriate wide band sensor.
>
> Depending on what you want to do, either could be acceptable.
>
> Dick Tasker
>
> 923te wrote:
>
> >
> >There are severl O2 sensors or Air Fuel Ratio Monitors available. Even kits
> >to build them. I listed some links below but just do a google on it and
> >you'll find lots. The lead in 100LL eventually slows the response time of
> >the O2 sensor but since we do not need fast response times (with out using a
> >fuel controller computer) it will work for a long time
> >
> >There used to be a fellow that sold a conversion kit to make the Bing carb
> >mixture manually controllable. I understand that these carbs are pressure
> >compensated to only 10,000ft after that you are burning too rich.
> >
> >http://www.techedge.com.au/vehicle/wbo2/default.htm
> >
> >ARM1 Air Fuel Ratio Monitor
> >http://www.racerpartswholesale.com/afratio.htm
> >
> >http://www.kemparts.com/TechTalk/tt07.asp
> >
> >
> >----- Original Message -----
> >From: "Ronald J. Parigoris" <rparigor(at)suffolk.lib.ny.us>
> >To:
> >Subject: AeroElectric-List: O2 sensor for Rotax 914?
> >
> >
> >
> >
> >>
> >>
> >
> >
> >
> >>Putting together a panel for our europa and got to the decision about an
> >>
> >>
> >EGT.
> >
> >
> >>Since the Mixture in flight is not adjustable, the EGT information would
> >>
> >>
> >not be
> >
> >
> >>tremendous useful. If you were monitoring all 4 cylinders, it could show
> >>
> >>
> >difference, but
> >
> >
> >>most I don't think install 4 probes. As far as an absolute temperature, I
> >>
> >>
> >doubt you
> >
> >
> >>could look in Rotax manual and get a specific temp that it should be and
> >>
> >>
> >actual read
> >
> >
> >>that on gauge because of exact position of probe and calibration of gauge.
> >>
> >>I got to thinking perhaps an O2 sensor with a readout would be more
> >>
> >>
> >useful. I see Spruce
> >
> >
> >>sells one with a simple circuit that lets you lean till a light goes on,
> >>
> >>
> >then go slight
> >
> >
> >>richer.
> >>
> >>Hmmm.
> >>
> >>What if you had a circuit that drove a bar graph LED where the center was
> >>
> >>
> >ideal
> >
> >
> >>mixture. Granted it would be for all cylinders, and 1 side could be lean
> >>
> >>
> >and the other
> >
> >
> >>rich, but once you knew your motor you could see a change.
> >>
> >>Could be used for diagnosing problems, a specific setting and roughness,
> >>
> >>
> >is it too rich
> >
> >
> >>or too lean?
> >>
> >>Anyway is such a thing sold? Anybody have an idea how to build one? I plan
> >>
> >>
> >on mostly
> >
> >
> >>using MoGas but on trips 100LL, so need a sensor that could tolerate it
> >>
> >>
> >for a while.
> >
> >
> >>Spruce says theirs is good for ~200 hours. On cars some use 2 wire and
> >>
> >>
> >some 3 wire.
> >
> >
> >>I had a 1983 Volvo Wagon with 2 wire O2 sensor that needed replacement
> >>
> >>
> >every 30K. It was
> >
> >
> >>located before the Turbo. I let it go to 45K near car life and it broke a
> >>
> >>
> >tab off, went
> >
> >
> >>through turbo and it busted a tip of as blade. I just broke off the
> >>
> >>
> >opposite side and it
> >
> >
> >>worked till I got rid of car without whistle.
> >>
> >>My 92 Turbo wagon has a 3 wire that is after the turbo, i change it ~ 100K
> >>
> >>
> >but seemed OK
> >
> >
> >>when I do.
> >>
> >>I would prefer to have one after the turbo on 914.
> >>
> >>Thx.
> >>Ron Parigoris
> >>
> >>
> >>
> >>
> >
> >
> >
> >
>
________________________________________________________________________________
| From: | "Steve & Denise" <sjhdcl(at)kingston.net> |
| Subject: | Dual alt single battery setup |
I have another question for the group.
I'm planning a single battery dual alternator setup. I'm planning to fly to
some very
remote airports in northern Canada and an alternator failure is a bad day.
With reference to the Z diagram for dual alternator system I have a few
questions.
In normal flight the aux alternator is off. If the field switch is off does
the voltage lamp
still work. In other words if the backup alt fails for some reason and the
main alt fails,
would the aux alt voltage lamp come on still?
Is there any reasons the have the backup alt on even though the main alt is
functioning
properly?
With respect to how this system works. Suppose the main alternator fails,
the backup alt is
turned on, main alt turned off, and continue on flying. The backup alt is
powering the main
power bus. However I have now gone from 60A capability to 20A capability. I
start conserving
power by turning off the none essentials. My question is this:
There are several items on the main power bus such as fuel senders, trim
indicators, etc that
can not be switched off. Should item like this have a small switch somewhere
so they can
be turned off to conserve power?
If the backup alt fails as well then the same process as mentioned a few
days ago. Alt off,
battery master off and now running on battery power alone to the essential
bus.
Why does the backup alt power the main battery bus and not the essential bus
exclusively?
Thanks list.
Steve
RV7A #2
________________________________________________________________________________
| From: | "Mark Taylor" <mtaylo17(at)msn.com> |
Tom, check out my site, I have a hinged fuse panel, an idea I borrowed from
somebody else.
www.4sierratango.com and go to the electrical page. There are a few
different images here.
Mark
RV7 Slow QB
Finish Kit
| From: | "thomas a. sargent" <sarg314(at)comcast.net> |
Subject: AeroElectric-List: fuse block location
You want your fuse blocks mounted in a place that is easy to get at.
Airplanes have darn few places that are easy to get at. I keep thinking
in terms of mounting them on something that is movable over a limited
range, such as a panel that hinges open or a small "drawer" that slides
out. You'd have to be careful to leave enough of a service loop on the
wiring to permit the motion, of course and cable dress would be
imprtant. It would probably only be 5 or 6 inches of extra wire. I
think it could be done safely. I recall seeing something like this on
one builder's web page a long time ago.
So, where/how are people mounting their fuse blocks?
--
Tom Sargent
RV-6A, firewall.
________________________________________________________________________________
| From: | "thomas a. sargent" <sarg314(at)comcast.net> |
Mark:
Lots of great pictures. Thanks very much
--
Tom Sargent
Mark Taylor wrote:
>
>Tom, check out my site, I have a hinged fuse panel, an idea I borrowed from
>somebody else.
>
>www.4sierratango.com and go to the electrical page. There are a few
>different images here.
>
>
>
________________________________________________________________________________
| From: | "Brian Kraut" <brian.kraut(at)engalt.com> |
| Subject: | EGT indications, was:Alternator Off During Start |
Up?
I actually meant to say CHT, not EGT.
Brian Kraut
Engineering Alternatives, Inc.
www.engalt.com
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of
BobsV35B(at)aol.com
Subject: AeroElectric-List: EGT indications, was:Alternator Off During
Start Up?
In a message dated 12/5/2004 8:33:38 P.M. Central Standard Time,
brian.kraut(at)engalt.com writes:
They do exist and I have seen them although I am not sure where to get
them,
but thank you for solving my problem of making sure the EGT gauge is on
the
hottest cylinder without having to keep moving it around.
Good Morning Brian,
Why do you want your EGT gauge to be on the "hottest" cylinder?
For the purposes we aviators use the EGT information, any EGT indication is
only a relative measurement. The exact temperature developed is totally
irrelevant to the operation of the engine. If you really want to see how
your
engine is responding, you need to have an EGT probe on every cylinder.
However, if you have confidence that the fuel distribution to all cylinders
is well
balanced, you can control the mixture to all by reference to only one
cylinder.
The important thing to realize is that the temperature you are seeing is
not
at all pertinent to how the engine is running or whether or not any damage
is being done to the engine.
All it provides is a means of economically telling you what the cylinder is
doing in relation to data that has been previously developed in an engine
test
cell.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | "Brian Kraut" <brian.kraut(at)engalt.com> |
| Subject: | O2 sensor for Rotax 914? |
I had an O2 sensor in my KR-2 and really loved it. It worked a whole lot
better and faster than the EGT. Westach does not advertize it, but they can
put an air/fuel display in a custom made dual or quad instrument. I had one
made with air/fuel, manifold pressure, OAT, and EGT.
Brian Kraut
Engineering Alternatives, Inc.
www.engalt.com
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of 923te
Subject: Re: AeroElectric-List: O2 sensor for Rotax 914?
There are severl O2 sensors or Air Fuel Ratio Monitors available. Even kits
to build them. I listed some links below but just do a google on it and
you'll find lots. The lead in 100LL eventually slows the response time of
the O2 sensor but since we do not need fast response times (with out using a
fuel controller computer) it will work for a long time
There used to be a fellow that sold a conversion kit to make the Bing carb
mixture manually controllable. I understand that these carbs are pressure
compensated to only 10,000ft after that you are burning too rich.
http://www.techedge.com.au/vehicle/wbo2/default.htm
ARM1 Air Fuel Ratio Monitor
http://www.racerpartswholesale.com/afratio.htm
http://www.kemparts.com/TechTalk/tt07.asp
----- Original Message -----
From: "Ronald J. Parigoris" <rparigor(at)suffolk.lib.ny.us>
Subject: AeroElectric-List: O2 sensor for Rotax 914?
>
> Putting together a panel for our europa and got to the decision about an
EGT.
>
> Since the Mixture in flight is not adjustable, the EGT information would
not be
> tremendous useful. If you were monitoring all 4 cylinders, it could show
difference, but
> most I don't think install 4 probes. As far as an absolute temperature, I
doubt you
> could look in Rotax manual and get a specific temp that it should be and
actual read
> that on gauge because of exact position of probe and calibration of gauge.
>
> I got to thinking perhaps an O2 sensor with a readout would be more
useful. I see Spruce
> sells one with a simple circuit that lets you lean till a light goes on,
then go slight
> richer.
>
> Hmmm.
>
> What if you had a circuit that drove a bar graph LED where the center was
ideal
> mixture. Granted it would be for all cylinders, and 1 side could be lean
and the other
> rich, but once you knew your motor you could see a change.
>
> Could be used for diagnosing problems, a specific setting and roughness,
is it too rich
> or too lean?
>
> Anyway is such a thing sold? Anybody have an idea how to build one? I plan
on mostly
> using MoGas but on trips 100LL, so need a sensor that could tolerate it
for a while.
> Spruce says theirs is good for ~200 hours. On cars some use 2 wire and
some 3 wire.
>
> I had a 1983 Volvo Wagon with 2 wire O2 sensor that needed replacement
every 30K. It was
> located before the Turbo. I let it go to 45K near car life and it broke a
tab off, went
> through turbo and it busted a tip of as blade. I just broke off the
opposite side and it
> worked till I got rid of car without whistle.
>
> My 92 Turbo wagon has a 3 wire that is after the turbo, i change it ~ 100K
but seemed OK
> when I do.
>
> I would prefer to have one after the turbo on 914.
>
> Thx.
> Ron Parigoris
>
>
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: E bus switching. |
----- Original Message -----
From: "Dan Checkoway" <dan(at)rvproject.com>
Subject: Re: AeroElectric-List: E bus switching.
> Don't forget that most people put stuff like electric gyros and/or turn
> coordinators and stuff on their e-bus. Most of these items don't have
> integral power switches like avionics do.
> Which would you rather have, one convenient e-bus alternate feed switch,
or
> a separate switch for every gadget that doesn't already have a switch of
its
> own?
. . . . So, if turn needle and attitude indicator, don't have a switch
normally, I'd not add one - just let 'em run. That's why they are on the
"endureance bus" (used to be "essential bus") So, they are a non-issue for
whether or not to have an "e-bus on-off switch".
- Maybe the only legit, but small, reason for a "full e-bus kill switch"
would be if something on that bus started smoking or burning and you wanted
to, and were in flight conditions to, kill everything.
- Otherwise, let it all run - or turn off what you have normal switches
for, if you really need to stretch battery life that badly - which raises
another whole issue of flight discipline and judgement about whether to land
"as soon as practical" or "as soon as possible". Our OBAM concept is to be
comfortable going on to destination with more than enough electrons from the
battery and enough gas after the alternator fails. David
> )_( Dan
> RV-7 N714D
> http://www.rvproject.com
________________________________________________________________________________
| From: | "923te" <923te(at)cox.net> |
| Subject: | Re: O2 sensor for Rotax 914? |
Hi Brian,
Thanks for reminding me of the Westach. here is a link to their instrument.
Is this similar to what you had?
Ned
http://www.westach.com/images/showcase/2C5-56-Air_Fuel_Ratio.jpg
----- Original Message -----
From: "Brian Kraut" <brian.kraut(at)engalt.com>
Subject: RE: AeroElectric-List: O2 sensor for Rotax 914?
>
> I had an O2 sensor in my KR-2 and really loved it. It worked a whole lot
> better and faster than the EGT. Westach does not advertize it, but they
can
> put an air/fuel display in a custom made dual or quad instrument. I had
one
> made with air/fuel, manifold pressure, OAT, and EGT.
>
> Brian Kraut
> Engineering Alternatives, Inc.
> www.engalt.com
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of 923te
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: O2 sensor for Rotax 914?
>
>
> There are severl O2 sensors or Air Fuel Ratio Monitors available. Even
kits
> to build them. I listed some links below but just do a google on it and
> you'll find lots. The lead in 100LL eventually slows the response time of
> the O2 sensor but since we do not need fast response times (with out using
a
> fuel controller computer) it will work for a long time
>
> There used to be a fellow that sold a conversion kit to make the Bing carb
> mixture manually controllable. I understand that these carbs are pressure
> compensated to only 10,000ft after that you are burning too rich.
>
> http://www.techedge.com.au/vehicle/wbo2/default.htm
>
> ARM1 Air Fuel Ratio Monitor
> http://www.racerpartswholesale.com/afratio.htm
>
> http://www.kemparts.com/TechTalk/tt07.asp
>
>
> ----- Original Message -----
> From: "Ronald J. Parigoris" <rparigor(at)suffolk.lib.ny.us>
> To:
> Subject: AeroElectric-List: O2 sensor for Rotax 914?
>
>
>
> >
> > Putting together a panel for our europa and got to the decision about an
> EGT.
> >
> > Since the Mixture in flight is not adjustable, the EGT information
would
> not be
> > tremendous useful. If you were monitoring all 4 cylinders, it could show
> difference, but
> > most I don't think install 4 probes. As far as an absolute temperature,
I
> doubt you
> > could look in Rotax manual and get a specific temp that it should be and
> actual read
> > that on gauge because of exact position of probe and calibration of
gauge.
> >
> > I got to thinking perhaps an O2 sensor with a readout would be more
> useful. I see Spruce
> > sells one with a simple circuit that lets you lean till a light goes on,
> then go slight
> > richer.
> >
> > Hmmm.
> >
> > What if you had a circuit that drove a bar graph LED where the center
was
> ideal
> > mixture. Granted it would be for all cylinders, and 1 side could be
lean
> and the other
> > rich, but once you knew your motor you could see a change.
> >
> > Could be used for diagnosing problems, a specific setting and roughness,
> is it too rich
> > or too lean?
> >
> > Anyway is such a thing sold? Anybody have an idea how to build one? I
plan
> on mostly
> > using MoGas but on trips 100LL, so need a sensor that could tolerate it
> for a while.
> > Spruce says theirs is good for ~200 hours. On cars some use 2 wire and
> some 3 wire.
> >
> > I had a 1983 Volvo Wagon with 2 wire O2 sensor that needed replacement
> every 30K. It was
> > located before the Turbo. I let it go to 45K near car life and it broke
a
> tab off, went
> > through turbo and it busted a tip of as blade. I just broke off the
> opposite side and it
> > worked till I got rid of car without whistle.
> >
> > My 92 Turbo wagon has a 3 wire that is after the turbo, i change it ~
100K
> but seemed OK
> > when I do.
> >
> > I would prefer to have one after the turbo on 914.
> >
> > Thx.
> > Ron Parigoris
> >
> >
>
>
________________________________________________________________________________
| From: | "Brian Kraut" <brian.kraut(at)engalt.com> |
| Subject: | O2 sensor for Rotax 914? |
That is their automotive instrument. I was using that one while I was
waiting for them to make me the custom quad gauge. It was cheap, something
like $35 or so, and worked great. I would highly recommend it over the ones
with LED bar graphs. The only thing I don't like about it is that it
doesn't fit in a standard 2 1/4" hole and look like a standard aircraft
instrument. I needed the other instruments also so the quad was the best
way for me to go.
I don't think I have mentioned it lately, but the customer service and tech
support at Westach are top notch. And if you ever need something that is
not standard they will even do custom instrument faces. On my quad they did
the air/fuel, manifold pressure with an internal pressure to voltage
converter so I could just plug the hose into the back of the instrument, and
temp sensors with ranges that I picked. The price was only about $30 more
than buying a standard quad from the catalogs and it took two weeks to get.
I bet they would do an air fuel in a standard 2 1/4" aircraft instrument
case with your choice of high and low readings if you asked.
If I remeber correctly, the thread for the O2 sensor was 18mm diameter and
1.5mm pitch. You can buy welding bosses for them, but they are expensive.
I got a stainless nut from McMaster Carr and welded it to my exhaust. I
couldn't find that big fine thread nut anywhere locally.
Brian Kraut
Engineering Alternatives, Inc.
www.engalt.com
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of 923te
Subject: Re: AeroElectric-List: O2 sensor for Rotax 914?
Hi Brian,
Thanks for reminding me of the Westach. here is a link to their instrument.
Is this similar to what you had?
Ned
http://www.westach.com/images/showcase/2C5-56-Air_Fuel_Ratio.jpg
----- Original Message -----
From: "Brian Kraut" <brian.kraut(at)engalt.com>
Subject: RE: AeroElectric-List: O2 sensor for Rotax 914?
>
> I had an O2 sensor in my KR-2 and really loved it. It worked a whole lot
> better and faster than the EGT. Westach does not advertize it, but they
can
> put an air/fuel display in a custom made dual or quad instrument. I had
one
> made with air/fuel, manifold pressure, OAT, and EGT.
>
> Brian Kraut
> Engineering Alternatives, Inc.
> www.engalt.com
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of 923te
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: O2 sensor for Rotax 914?
>
>
> There are severl O2 sensors or Air Fuel Ratio Monitors available. Even
kits
> to build them. I listed some links below but just do a google on it and
> you'll find lots. The lead in 100LL eventually slows the response time of
> the O2 sensor but since we do not need fast response times (with out using
a
> fuel controller computer) it will work for a long time
>
> There used to be a fellow that sold a conversion kit to make the Bing carb
> mixture manually controllable. I understand that these carbs are pressure
> compensated to only 10,000ft after that you are burning too rich.
>
> http://www.techedge.com.au/vehicle/wbo2/default.htm
>
> ARM1 Air Fuel Ratio Monitor
> http://www.racerpartswholesale.com/afratio.htm
>
> http://www.kemparts.com/TechTalk/tt07.asp
>
>
> ----- Original Message -----
> From: "Ronald J. Parigoris" <rparigor(at)suffolk.lib.ny.us>
> To:
> Subject: AeroElectric-List: O2 sensor for Rotax 914?
>
>
>
> >
> > Putting together a panel for our europa and got to the decision about an
> EGT.
> >
> > Since the Mixture in flight is not adjustable, the EGT information
would
> not be
> > tremendous useful. If you were monitoring all 4 cylinders, it could show
> difference, but
> > most I don't think install 4 probes. As far as an absolute temperature,
I
> doubt you
> > could look in Rotax manual and get a specific temp that it should be and
> actual read
> > that on gauge because of exact position of probe and calibration of
gauge.
> >
> > I got to thinking perhaps an O2 sensor with a readout would be more
> useful. I see Spruce
> > sells one with a simple circuit that lets you lean till a light goes on,
> then go slight
> > richer.
> >
> > Hmmm.
> >
> > What if you had a circuit that drove a bar graph LED where the center
was
> ideal
> > mixture. Granted it would be for all cylinders, and 1 side could be
lean
> and the other
> > rich, but once you knew your motor you could see a change.
> >
> > Could be used for diagnosing problems, a specific setting and roughness,
> is it too rich
> > or too lean?
> >
> > Anyway is such a thing sold? Anybody have an idea how to build one? I
plan
> on mostly
> > using MoGas but on trips 100LL, so need a sensor that could tolerate it
> for a while.
> > Spruce says theirs is good for ~200 hours. On cars some use 2 wire and
> some 3 wire.
> >
> > I had a 1983 Volvo Wagon with 2 wire O2 sensor that needed replacement
> every 30K. It was
> > located before the Turbo. I let it go to 45K near car life and it broke
a
> tab off, went
> > through turbo and it busted a tip of as blade. I just broke off the
> opposite side and it
> > worked till I got rid of car without whistle.
> >
> > My 92 Turbo wagon has a 3 wire that is after the turbo, i change it ~
100K
> but seemed OK
> > when I do.
> >
> > I would prefer to have one after the turbo on 914.
> >
> > Thx.
> > Ron Parigoris
> >
> >
>
>
________________________________________________________________________________
| From: | Charlie Brame <chasb(at)satx.rr.com> |
| Subject: | ELT Antenna Length |
Rubber Ducky antennas are available from Aircraft Spruce. Look under the
ICOM Handheld Radio Accessories. Mine was $36. They attach with a
standard female B&C connector. The Vertec rubber ducky is cheaper, but
screws on.
Can't speak to the power requirements, but I know of several RVs that
are flying with rubber ducky ELT antennas, some in the baggage
compartment and some under the empennage fairing. Mine is going under
the empennage fairing.
Charlie
RV-6A N11CB
San Antonio
-----------------------------------------
> From: Mickey Coggins
> Subject: AeroElectric-List: ELT Antenna length
>
>
> Hi,
>
> I'm having trouble finding a good place to put my ELT
> antenna, and I'd like to know if I can shorten the
> antenna that came with my ELT. I've read through
> the archives, which seem to have conflicting information.
> I've read that a rubber duckie antenna will work, but
> it will take more power than the antenna that came with
> the Ameriking ELT. Is this correct? Anyone have a good
> source for these rubber duckie antennas?
>
> I calculated the recommended length of the ELT 121.5 MHz
> quarter-wave antenna to be about 24.3 inches
> (299,792,458 meters/second / 121.5MHz / 4 = .6168569 meters).
> Does this sound right? I guess this assumes a good
> ground plane, which I won't have if I mount this thing under the VS.
>
> I need to shorten the antenna to fit under
> my VS, since that seems to be where Van's installs
> them on the RV8. I can't find a better place for this
> thing. Some people have installed them under the right
> elbow of the passenger, but that does not seem much
> better than the tail.
>
> Any and all suggestions welcome!
>
> Thanks,
> Mickey
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Dual alt single battery setup |
>
>
>I have another question for the group.
>
>I'm planning a single battery dual alternator setup. I'm planning to fly to
>some very
>remote airports in northern Canada and an alternator failure is a bad day.
>
>With reference to the Z diagram for dual alternator system I have a few
>questions.
I presume you're talking about Z-12.
>In normal flight the aux alternator is off. If the field switch is off does
>the voltage lamp still work.
Yes
>In other words if the backup alt fails for some reason and the
>main alt fails, would the aux alt voltage lamp come on still?
Not for the aux alternator. If your using Z-12 then the aux
alternator regulator is DIFFERENT than for the main alternator.
It's light says "AUX ALTERNATOR LOADED" meaning that if you
set it up according to instructions, then the aux alternator
automatically switches on when the main alternator fails and
assuming that total loads are within capability of the aux
alternator, the LOW VOLTS light would never come on . . . hence
the need to annunciate main alternator failure.
>Is there any reasons the have the backup alt on even though the main alt is
>functioning properly?
If you want the auto-switch feature yes. If you want to manually
switch the aux alternator on, no. The recommended operating
procedure is to run it ON all the time for a Z-12 system.
>With respect to how this system works. Suppose the main alternator fails,
>the backup alt is
>turned on, main alt turned off, and continue on flying. The backup alt is
>powering the main
>power bus. However I have now gone from 60A capability to 20A capability. I
>start conserving
>power by turning off the none essentials. My question is this:
>There are several items on the main power bus such as fuel senders, trim
>indicators, etc that
>can not be switched off. Should item like this have a small switch somewhere
>so they can
>be turned off to conserve power?
The very first thing you need to do in configuring your electrcial
system is a load analysis. KNOW what each piece of equipment draws
in normal flight and PLAN which items will be shut down to stay within
limits of your auxiliary alternator. The aux alternator warning light
will flash if you've overloaded the alternator. So if the main alternator
fails and the light comes on, you can either turn off things according to
a plan, or conduct an in-flight experiment to determine how many things
need to be off to stop the light from flashing . . . I'd recommend the
former.
>If the backup alt fails as well then the same process as mentioned a few
>days ago. Alt off,
>battery master off and now running on battery power alone to the essential
>bus.
yes . . . but this is about as likely as wing bolts coming loose.
>Why does the backup alt power the main battery bus and not the essential bus
>exclusively?
because Z-12 was designed to illustrate a means for adding
a second alternator to an existing system and in particular,
spam cans. Getting the #2 alternator blessed was agonizing enough,
re-shaping the architecture to add an e-bus was too much to
contemplate. If one chooses to have a robust backup like the
SD-20, then Figure Z-14 with no e-bus is recommended.
Are you sure you NEED 20A of backup for endurance? Can't you
get en-route running loads below 10A so that approach to landing
has the battery in 100% state of charge for the approach?
This is why I emphasize the load analysis and PLANS for each
contingency. I believe many builders are spending too much
money on hardware and adding pounds that do not materially
add value to the airplane.
Keep in mind folks that a belt-driven ND alternator is already
10X better than the piece-o-crap alternators bolted to most
spam cans. Doing preventative maintenance to insure minimal
battery capacity boosts probability for comfortable termination
of flight another 10X. Adding the e-bus puts yet another
multiplier on it. So, without having to make the system any
more complex than Figure Z-11, it is unlikely that any OBAM
aircraft will feature in an electrical system driven, dark-n-stormy
night story. Adding an SD-8 per Figure Z-13 should cover 98% of
all OBAM aircraft requirements for extended en-route operations
sans main alternator.
But if you don't do a load analysis or don't understand the
reasons for considering one architecture over another, then
you'll find yourself participating in threads like this
one and making decisions the democratic way . . . whatever
the majority of folks recommend. If that's the most comfortable
way to configure your project, fine. But I'd much rather you
get to the final configuration and operating philosophy by
understanding how all of the simple-ideas available to you
fit together. You'll find that you don't need backups, to backups
on top of more backups. You'll save dollars and time. Your
airplane will be lighter and simpler to operate. The spam-can
drivers can only dream of the advantages offered to the
OBAM aircraft pilot.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: E bus switching. |
>
>
>Without the switch, the E-bus becomes a larger branch of a/the "battery
>bus". The switch would provide an easy way to save the battery by turning
>off all the stuff (radios) on the e-bus for 15' at a time. Of couse, could
>just turn off individual e-bus items instead of having an e-bus sw (to shut
>off the entire bus).
>
>With switch left on all the time, or with no switch at all, the diode would
>stop flow to "main bus" when master switch ("main bus" switch?) was turned
>off following alternator failure. Or, diode - and wire between main bus &
>e-bus - could be eliminated for reduced parts count.
. . . and your battery would run down while the airplane is parked.
Further, you would have no way to take the electrical system
to a max-cold condition in an approach to the rocks.
Bob . . .
________________________________________________________________________________
| From: | f1rocket(at)comcast.net |
| Subject: | Re: Dual alt single battery setup |
Steve,
I went with a dual alternator, one battery system with an essential bus, although
I call it an avionics bus. In doing an analysis of the various offerings,
I found this arrangement to best fit my intended flight operations. I don't necessarily
agree that it adds additional weight. It is marginally more complex
to wire because you need the controller, switch, and breaker, but it's not that
bad. I actually think it's lighter than having a dual battery system especially
if your batteries are in the back. If you need the redundancy, I think
this is a good way to go.
My auxiliary alternator is on all the time. I like the convenience of it just
picking up the load should the main alternator fail. While I believe the B&C
alternators are way better than the automotive junk, I'm willing to pay extra
for the piece of mind that any flight can be continued unabated in the event of
alternator failure. Relying on a battery to carry the load is one way to achieve
this, having a backup alternator in another way. I simply prefer the later.
I also like having the avionics bus switchable from the main bus. I know all the
arguments against the avionics bus (I've been on the List for about 8 years),
but it is convenient to fire it up on the gound to get my clearance and my
radios/autopilot/EFIS are on all the time for every flight so one switch brings
up all the electronic goddies right where I left them. The fact that some manufacturers
recommend protecting their equipment from the phantom "spike" doesn't
prove that they exist, but it sure does void the warranty of some pretty
expensive equipment.
Study the options and pick the one that fits your intended use. I think they all
have a role to play.
Randy
F1 Rocket
http://f1rocket.home.comcast.net/
Steve,
I went with a dual alternator, one battery system with an essential bus, although
I call it an avionics bus. In doing an analysis of the various offerings, I
found this arrangement to best fit my intended flight operations. I don't necessarily
agree that it adds additional weight. It is marginally more complex to
wire because you need the controller, switch, and breaker, but it's not that
bad. I actually think it's lighter than having a dual battery system especially
if your batteries are in the back. If you need the redundancy, I think this
is a good way to go.
My auxiliary alternator is on all the time. I like the convenience of it just picking
up the load should the main alternator fail. While I believe the BC alternators
are way better than the automotive junk, I'm willing to pay extra for
the piece of mind that any flight can be continued unabated in the event of alternator
failure. Relying on a battery to carry the load is one way to achieve
this, having a backup alternator in another way. I simply prefer the later.
I also like having the avionics bus switchable from the main bus. I know all the
arguments against the avionics bus (I've been on the List for about 8 years),
but it is convenient to fire it up on the gound to get my clearance and my radios/autopilot/EFIS
are on all the time for every flight so one switch brings
up all the electronic goddies right where I left them. The fact that some manufacturers
recommend protecting their equipment from the phantom "spike" doesn't
prove that they exist, but it sure does void the warranty of some pretty expensive
equipment.
Study the options and pick the one that fits your intended use. I think they all
have a role to play.
Randy
F1 Rocket
http://f1rocket.home.comcast.net/
________________________________________________________________________________
| Subject: | Re: Dual alt single battery setup |
| From: | sjhdcl(at)kingston.net |
I will definitely do a load analyisis and I do have a plan in the event of
alt failure and loads. I do not have all the avionics and equipment yet
and I've learned that measured the required current of each component is
far more accurate then asking the manufacturer.
I do have questions about the SD-8 however. I did consider this in the
beginning and of course the answer will lie in the load analysis as well.
But according the B&C publications the alterator is capable of about 6.8
amps during normal cruise engine RPM settings. While this is still enough
to 'limp' home if I get into icing conditions and turn the pitot heat on,
the alt will be overloaded. I know all these scenarios are very unlikely
but the planned mission for this aircraft does require extended fuel and
'electron' range. The 20A alt os much bigger and heavier. Not to mention
the additional $240 for the reg. I'm not a dark a story night kind of guy.
Most of those stories have nothing to do with the actual causes of the
incident.
On a previous homebuilt I was able to get the load down to about 2 amps on
'limp' mode. Running a wing leveler and GPS. It was only a test but it is
quite feasible to run a very low load and still get home safely. Once I
got close to the airport, I turned the radio, transponder, VOR/ILS,
landing lights, flap power, etc back on and was running 16A for the
approach phase which lasted only about 15 minutes.
Thanks for the great information and the push back to the SD-8 alternator.
Much lighter and cheaper. I will verify the load analysis in modes and
post my findings in the months to come.
Great answer,
Steve
RV7A
>
>
>>
>>
>>I have another question for the group.
>>
>>I'm planning a single battery dual alternator setup. I'm planning to fly
>> to
>>some very
>>remote airports in northern Canada and an alternator failure is a bad
>> day.
>>
>>With reference to the Z diagram for dual alternator system I have a few
>>questions.
>
> I presume you're talking about Z-12.
>
>
>>In normal flight the aux alternator is off. If the field switch is off
>> does
>>the voltage lamp still work.
>
> Yes
>
>
>>In other words if the backup alt fails for some reason and the
>>main alt fails, would the aux alt voltage lamp come on still?
>
> Not for the aux alternator. If your using Z-12 then the aux
> alternator regulator is DIFFERENT than for the main alternator.
> It's light says "AUX ALTERNATOR LOADED" meaning that if you
> set it up according to instructions, then the aux alternator
> automatically switches on when the main alternator fails and
> assuming that total loads are within capability of the aux
> alternator, the LOW VOLTS light would never come on . . . hence
> the need to annunciate main alternator failure.
>
>
>>Is there any reasons the have the backup alt on even though the main alt
>> is
>>functioning properly?
>
>
> If you want the auto-switch feature yes. If you want to manually
> switch the aux alternator on, no. The recommended operating
> procedure is to run it ON all the time for a Z-12 system.
>
>
>>With respect to how this system works. Suppose the main alternator fails,
>>the backup alt is
>>turned on, main alt turned off, and continue on flying. The backup alt is
>>powering the main
>>power bus. However I have now gone from 60A capability to 20A capability.
>> I
>>start conserving
>>power by turning off the none essentials. My question is this:
>>There are several items on the main power bus such as fuel senders, trim
>>indicators, etc that
>>can not be switched off. Should item like this have a small switch
>> somewhere
>>so they can
>>be turned off to conserve power?
>
> The very first thing you need to do in configuring your electrcial
> system is a load analysis. KNOW what each piece of equipment draws
> in normal flight and PLAN which items will be shut down to stay within
> limits of your auxiliary alternator. The aux alternator warning light
> will flash if you've overloaded the alternator. So if the main
> alternator
> fails and the light comes on, you can either turn off things according
> to
> a plan, or conduct an in-flight experiment to determine how many
> things
> need to be off to stop the light from flashing . . . I'd recommend the
> former.
>
>
>>If the backup alt fails as well then the same process as mentioned a few
>>days ago. Alt off,
>>battery master off and now running on battery power alone to the
>> essential
>>bus.
>
> yes . . . but this is about as likely as wing bolts coming loose.
>
>
>>Why does the backup alt power the main battery bus and not the essential
>> bus
>>exclusively?
>
> because Z-12 was designed to illustrate a means for adding
> a second alternator to an existing system and in particular,
> spam cans. Getting the #2 alternator blessed was agonizing enough,
> re-shaping the architecture to add an e-bus was too much to
> contemplate. If one chooses to have a robust backup like the
> SD-20, then Figure Z-14 with no e-bus is recommended.
>
> Are you sure you NEED 20A of backup for endurance? Can't you
> get en-route running loads below 10A so that approach to landing
> has the battery in 100% state of charge for the approach?
> This is why I emphasize the load analysis and PLANS for each
> contingency. I believe many builders are spending too much
> money on hardware and adding pounds that do not materially
> add value to the airplane.
>
> Keep in mind folks that a belt-driven ND alternator is already
> 10X better than the piece-o-crap alternators bolted to most
> spam cans. Doing preventative maintenance to insure minimal
> battery capacity boosts probability for comfortable termination
> of flight another 10X. Adding the e-bus puts yet another
> multiplier on it. So, without having to make the system any
> more complex than Figure Z-11, it is unlikely that any OBAM
> aircraft will feature in an electrical system driven, dark-n-stormy
> night story. Adding an SD-8 per Figure Z-13 should cover 98% of
> all OBAM aircraft requirements for extended en-route operations
> sans main alternator.
>
> But if you don't do a load analysis or don't understand the
> reasons for considering one architecture over another, then
> you'll find yourself participating in threads like this
> one and making decisions the democratic way . . . whatever
> the majority of folks recommend. If that's the most comfortable
> way to configure your project, fine. But I'd much rather you
> get to the final configuration and operating philosophy by
> understanding how all of the simple-ideas available to you
> fit together. You'll find that you don't need backups, to backups
> on top of more backups. You'll save dollars and time. Your
> airplane will be lighter and simpler to operate. The spam-can
> drivers can only dream of the advantages offered to the
> OBAM aircraft pilot.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
| Subject: | Many a good man....... |
From: "Bryan Hooks" <bryanhooks(at)comcast.net>
Subject: RE: AeroElectric-List: fuse block location
I recently had one blow in my wifes' SUV. Not quite sure why though.
All she did was plug an inverter into the cig lighter, plug a hair dryer
into that and turned it on. :)
On an unfortunate note, she didn't quite have enough time to get her
hair dry before the fuse had blown.
I now have the inverter put up out of her reach, so to speak since it
apparently is my fault for not telling her not to plug her hair dryer
into it.
-bryan
Thank you, Brian.......... After having flown crew and pax for some years I
remember the same script for the stews who would always complain about the
loss of the 'ground' circuit on the leg outbound to some coral reef. The
ground circuit was for vacuum cleaners and so forth.
You guessed it . So I would explain that it comes back to life by
resetting by a qualified mechanic at home base. Fortunately most coral reefs
(etc) used 220Vac/50cycle and so did not tip my hand.
The scenario complicates when one stew is married to the First Officer.
Pillow talk has destroyed many an aviator.
Ferg
Europa 064
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Dual alt single battery setup |
>
>I will definitely do a load analyisis and I do have a plan in the event of
>alt failure and loads. I do not have all the avionics and equipment yet
>and I've learned that measured the required current of each component is
>far more accurate then asking the manufacturer.
>
>I do have questions about the SD-8 however. I did consider this in the
>beginning and of course the answer will lie in the load analysis as well.
>But according the B&C publications the alterator is capable of about 6.8
>amps during normal cruise engine RPM settings.
If you cruise at 2300, that is the rated output assuming a 1.3:1 step
up ratio for the vacuum pump pad.
> While this is still enough
>to 'limp' home if I get into icing conditions and turn the pitot heat on,
>the alt will be overloaded.
Yes . . . but this is when you do the prudent 180 and depart icing
conditions.
> I know all these scenarios are very unlikely
>but the planned mission for this aircraft does require extended fuel and
>'electron' range. The 20A alt os much bigger and heavier. Not to mention
>the additional $240 for the reg.
and alternator is about $250 more expensive as well . . .
> I'm not a dark a story night kind of guy.
>Most of those stories have nothing to do with the actual causes of the
>incident.
>
>On a previous homebuilt I was able to get the load down to about 2 amps on
>'limp' mode. Running a wing leveler and GPS. It was only a test but it is
>quite feasible to run a very low load and still get home safely. Once I
>got close to the airport,
Which is exactly what the e-bus is for . . . minimal draw in the
en-route mode . . .
>I turned the radio, transponder, VOR/ILS,
>landing lights, flap power, etc back on and was running 16A for the
>approach phase which lasted only about 15 minutes.
which needed only 25% of your reserve capacity as long as it
wasn't tapped in the en-route mode.
>Thanks for the great information and the push back to the SD-8 alternator.
>Much lighter and cheaper. I will verify the load analysis in modes and
>post my findings in the months to come.
Good idea.
Bob . . .
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: E bus switching. |
Yikes! I did it again - forgot something I used to know! Thanks again, Bob,
for keeping us straight.
- It must be true that one must "learn and forget" something 3 to 5
times before it is indelibly impressed into one's memory. I'm getting close
to the upper limit!
David Carter
----- Original Message -----
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: E bus switching.
>
> >
> >
> >Without the switch, the E-bus becomes a larger branch of a/the "battery
> >bus". The switch would provide an easy way to save the battery by
turning
> >off all the stuff (radios) on the e-bus for 15' at a time. Of couse,
could
> >just turn off individual e-bus items instead of having an e-bus sw (to
shut
> >off the entire bus).
> >
> >With switch left on all the time, or with no switch at all, the diode
would
> >stop flow to "main bus" when master switch ("main bus" switch?) was
turned
> >off following alternator failure. Or, diode - and wire between main bus
&
> >e-bus - could be eliminated for reduced parts count.
>
> . . . and your battery would run down while the airplane is parked.
> Further, you would have no way to take the electrical system
> to a max-cold condition in an approach to the rocks.
>
> Bob . . .
________________________________________________________________________________
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| From: | D Fritz <dfritzj(at)yahoo.com> |
| Subject: | High Current Switch or Battery Contactor |
Hey folks,
Here's an idea for those of you trying to keep current within a small budget.
Instead of using a battery contactor, why not use a high current switch like this
one:
http://www.mpja.com/directview.asp?product=8373-sw
Are there any regulations against using something like this instead of a contactor?
Are there any reasons why something like this doesn't make sense?
Dan Fritz
---------------------------------
________________________________________________________________________________
| From: | "DonVS" <dsvs(at)comcast.net> |
| Subject: | High Current Switch or Battery Contactor |
This would require either the fat wire be brought into the cockpit or some
way of activating the switch would be needed.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of D
Fritz
Subject: AeroElectric-List: High Current Switch or Battery Contactor
Hey folks,
Here's an idea for those of you trying to keep current within a small
budget. Instead of using a battery contactor, why not use a high current
switch like this one:
http://www.mpja.com/directview.asp?product=8373-sw
Are there any regulations against using something like this instead of a
contactor? Are there any reasons why something like this doesn't make
sense?
Dan Fritz
---------------------------------
________________________________________________________________________________
| From: | Denis Walsh <denis.walsh(at)comcast.net> |
| Subject: | Re: High Current Switch or Battery Contactor |
I have been pondering this for years. My contactor uses the better
part of an amp, not to mention another fail mode. A few years ago I
saw something very like this on a Mooney so it is or was ok back then
with FAA. It was operated by a cable and lever.
The biggest down side I see is that it needs to be very close to the
battery for crash safety purposes. If you do this, then you need a
cable or lever to remotely operate it. This introduces what is
probably a bigger failure probability, and weight issues too.
So in the end, since the ones I found were just as heavy as the
solenoid, I stayed with the solenoid, which I think gets the nod on
parts count and simplicity for remote operation.
Post script. The only time the solenoid load is an issue for me is
when the alternator fails. In that case, the master contactor goes off
anyway and its function is replace with a low or no drain relay/switch.
Also it is a very reliable device, and lasts a long time, unlike its
starter contactor brethren, which gets heavier wear in use.
Interested in hearing other slants on this.
Denis
On Dec 7, 2004, at 6:49 PM, D Fritz wrote:
>
> Hey folks,
> Here's an idea for those of you trying to keep current within a small
> budget. Instead of using a battery contactor, why not use a high
> current switch like this one:
>
> http://www.mpja.com/directview.asp?product=8373-sw
>
> Are there any regulations against using something like this instead of
> a contactor? Are there any reasons why something like this doesn't
> make sense?
>
> Dan Fritz
>
>
> ---------------------------------
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: High Current Switch or Battery Contactor |
>
>Hey folks,
>Here's an idea for those of you trying to keep current within a small
>budget. Instead of using a battery contactor, why not use a high current
>switch like this one:
>
>http://www.mpja.com/directview.asp?product=8373-sw
Sure. Lots of times. Smaller airplanes with rotax engines
needing remotely operated battery switches have modified
speed-shop battery switches to rotate by means of a fabricated
bellcrank operated by what is generically called a Bowden
control cable. These are used on gazillions of vehicles
including airplanes for remote control of chokes, heater
valves, carburetor heat doors, etc. etc.
You can purchase these cables from MANY sources but one
of my favorites is this choke conversion kit:
http://www.jcwhitney.com/autoparts/ProductDisplay/s-10101/p-2745/c-10101
The stock control cable for this kit is 60" long and the ad
alludes to a 108" version for trucks but no catalog number
is offered. At least folks MAKE very long versions of these
cables.
If you use one of these in your airplane . . . ESPECIALLY
if it's a long one, pull the control wire totally out of
the spiral shell and lubricate the wire with a good, sticky
grease like wheel bearing grease. They will come dry but
after 10 years in your airplane, operating friction will go
up risking malfunction. Design your system so that you PULL
the control to turn the battery OFF. If you fail the control,
it will be during preflight when you PUSH to turn the battery
ON and you won't go flying before you fix it.
What you don't want is to fail the control when you're
PUSHING on it in hopes that the battery is going to become
disconnected.
Consider this same technology for fabricating firewall
fuel shutoff valves. There are lots of low-cost ball-valves
with gasoline friendly seals that can be fitted with bellcranks
for operation with similar technology . . . again, PULL for
FUEL OFF.
>Are there any regulations against using something like this instead of a
>contactor? Are there any reasons why something like this doesn't make sense?
There are no regulations that pertain to the design and
installation of any system in your OBAM aircraft.
Bob . . .
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
| Subject: | FAA style harness |
Hi,
I have no expertise in this topic, certainly not Ira's - but
having dusted off the brain case, wish to feed an idea or two into the fray.
My tired brain is addicted to the few split seconds of potential
damage during a prang involving excessive G. Having learnt of Graham's
experience (and the apparent difference in injuries 'twixt him and other
occupant), repeat trhe suggestion that those foam 'worms' may have had a
beneficial effect. Also, I wonder at the dispersion/deflection of a sealed
airbag [not explosive] during that deceleration.
There is not much space available for deceleration at a controlled
rate (cars and some aircraft presumably utilise this) but any experience I
have leads me to believe that any/all design directed toward this end would
have a measureable effect during those few inches of travel.
Certainly the angle of tether of the shoulder straps must be
revised, but attaching the tether to the aircraft too far back leads to
thoughts of greater harm from fuselage distortion - i.e: tethering to the
tail might sting if that portion separated {as this has been successfully
experienced early on].
I just don't like to 'waste' those precious inches on uncontrolled
collapse.
My $.02.
Ferg
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
| Subject: | Re: High Current Switch or Battery Contactor |
<budget. Instead of using a battery contactor, why not use a high current
>switch like this one:>>
I've been thinking about the same thing and there is one failure mode that
bothers me: Let's say that in flight you need to shut off the master bus,
so you turn off the manual switch. Oops, the alternator and voltage
regulator are connected "downstream" of the master switch and hence keep
right on working, keeping the master bus live. You have to disconnect the
alternator (at least the regulator) to shut the system off. The
conventional split master switch/contactor combination won't let you shut
off the master without also shutting off the alternator. So with a manual
switch the procedure has to be to pull the alternator breaker(s) and then
turn off the battery. Does this change the desirability of the manual
switch? I'm not sure.
Gary Casey
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> Contactor |
| Subject: | Re: High Current Switch or Battery |
Contactor
Contactor
>
>< >budget. Instead of using a battery contactor, why not use a high current
> >switch like this one:>>
>
>I've been thinking about the same thing and there is one failure mode that
>bothers me: Let's say that in flight you need to shut off the master bus,
>so you turn off the manual switch. Oops, the alternator and voltage
>regulator are connected "downstream" of the master switch and hence keep
>right on working, keeping the master bus live. You have to disconnect the
>alternator (at least the regulator) to shut the system off. The
>conventional split master switch/contactor combination won't let you shut
>off the master without also shutting off the alternator. So with a manual
>switch the procedure has to be to pull the alternator breaker(s) and then
>turn off the battery. Does this change the desirability of the manual
>switch? I'm not sure.
Only from the perspective of reducing pilot workload. There are
LOTS of procedures for doing things that suggest a serial list
of activities for pullilng levers and twisting knobs.
The combined battery and alternator control on the DC power
master switch works toward workload reduction and risk mitigation.
I've kept the recommendation for the el-cheapo, RPM/WhiteRogers/Stancore
contactors in my writings because they are an excellent value.
Their track record goes back to the 1940's on the C-140, C-170 when
batteries and generators went in for the first times. They're
not the best contactor you can buy but use within their
well-known limitations, they've demonstrated their capabilities
quite dramatically.
If one designs for failure tolerance, the occasional loss of
a contactor is no big deal and it's power drain is insignificant
any time a capable alternator is running. It seems that any
efforts to eliminate the device are more a matter of personal
preferences than for system gains based on simple-ideas. Personally,
I'd use the contactor on any aircraft that is not power-starved
in normal operations. This condition generally includes all
aircraft not powered by a PM alternator.
Bob . . .
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | OBAM Regulations |
AeroElectric-List message previously posted by: "Robert L. Nuckolls, III"
<<....skip....There are no regulations that pertain to the design and
installation of any system in your OBAM aircraft. Bob . . .>>
12/08/2004
Hello Bob Nuckolls, There are some exceptions to your statement above. Those
exceptions should be recognized lest some builder be led astray. The
exceptions usually deal with items that must interface correctly with
outside equipment or are specifically safety oriented. Some items that come
to mind that apply to OBAM aircraft, as well as standard type certificated
aircraft, are:
(1) Transponders installed in OBAM aircraft (amateur built experimental
aircraft) must meet the certification requirements of FAR Sec 91.215.
Periodic inspection criteria of the transponder (and altimeter of aircraft
flown IFR) also apply to OBAM aircraft.
(2) FAR Sec 91.207 requires that Emergency Locator Transmitters (ELT's)
installed in OBAM aircraft must be "approved" in some fashion. Normal
current approval method would be by TSO-C91a.
(3) FAR Sec 91.205 (c) (2) requires that position lights installed on OBAM
aircraft be "appproved". This approval could be granted by the inspector who
makes the initial airworthiness inspection of the OBAM aircraft. The
inspector could logically use the position light criteria set forth for
standard type certificated aircraft in FAR Secs 23.1387 through 23.1397.
(4) FAR Sec 91.205 (c) (3) requires that the anti collision light system
installed on OBAM aircraft be "approved". This approval could be granted by
the inspector who makes the initial airworthiness inspection of the OBAM
aircraft. The inspector could logically use the position light criteria set
forth for standard type certificated aircraft in FAR Sec 23.1401.
(5) FAR Secs 91.205 (13) and (14) require that the OBAM aircraft be equipped
with "approved" safety belts (lap restraints) and shoulder harnesses. This
approval could be granted by the inspector who makes the initial
airworthiness inspection of the OBAM aircraft. Since there is no
certification requirement for OBAM aircraft in this regard it is not
required that the belts be approved and marked through a TSO process. (Some
inspectors mistakenly try to insist on TSO marked belts and harnesses.)
(6) FAR Sec 91.205 (c) (6) says that if the OBAM builder builds his aircraft
so that he has access to his electrical fuses while in flight that he must
have one spare set of fuses, or three spare fuses of each kind that are
required.
(7) FAR Sec 91.205 lists, in general, the equipment that an OBAM aircraft
must have, but does not require this equipment to be approved.
There may be some other regulatory "gotchas" that relate to OBAM aircraft
(such as "approved" DME in certain circumstances), but those above are what
come to mind. My point is that it behooves our builders and operators to
know what the regulatory requirements are and not make the blanket
assumption that regulations do not apply to our OBAM aircraft and their
operations.
OC
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: High Current Switch or Battery Contactor |
>
>I have been pondering this for years. My contactor uses the better
>part of an amp, not to mention another fail mode. A few years ago I
>saw something very like this on a Mooney so it is or was ok back then
>with FAA. It was operated by a cable and lever.
A Tri-Pacer I flew in 1961 had the battery under the co-pilot's
seat. The battery master was a high current switch on the forward
side of the bulkhead under the co-pilot's knees.
>The biggest down side I see is that it needs to be very close to the
>battery for crash safety purposes. If you do this, then you need a
>cable or lever to remotely operate it. This introduces what is
>probably a bigger failure probability, and weight issues too.
The manually operated switch can generally be implemented
for about the same weight as a contactor unless the control
cable is VERY long.
>So in the end, since the ones I found were just as heavy as the
>solenoid, I stayed with the solenoid, which I think gets the nod on
>parts count and simplicity for remote operation.
>
>Post script. The only time the solenoid load is an issue for me is
>when the alternator fails. In that case, the master contactor goes off
>anyway and its function is replace with a low or no drain relay/switch.
> Also it is a very reliable device, and lasts a long time, unlike its
>starter contactor brethren, which gets heavier wear in use.
>
>Interested in hearing other slants on this.
You're perceptions and deductions are, in my opinion,
quite accurate.
Bob . . .
________________________________________________________________________________
| Subject: | Re: FAA style harness |
| From: | "Matt Prather" <mprather(at)spro.net> |
Interesting that you should mention this... Recently, a fellow I know
(not closely) was involved in a crash of an Extra 300L - bottom of loop
just slightly too low. The force of the impact caused the fuselage structure
to be severed just behind the pilot's (back) seat. However, apparently, the
shoulder harness are attached to the tail section. (!) Though this fellow
survived (lucky), he was pretty beat up from having the load of the severed
tail section pulling down on his back and shoulders as the aircraft tumbled
across the desert. It is indeed important to be sure that whateveryou tie
the seatbelts to is designed to stay with the seat.
Regards,
Matt-
>
> Hi,
> I have no expertise in this topic, certainly not Ira's - but
> having dusted off the brain case, wish to feed an idea or two into the
> Certainly the angle of tether of the shoulder straps must be
> revised, but attaching the tether to the aircraft too far back leads to
> thoughts of greater harm from fuselage distortion - i.e: tethering to
> the tail might sting if that portion separated {as this has been
> successfully experienced early on].
> I just don't like to 'waste' those precious inches on
> uncontrolled
> collapse.
> My $.02.
> Ferg
>
>
________________________________________________________________________________
| From: | "Jim Ellsworth" <ellsworj(at)m33access.com> |
| Subject: | Genave Alpha 200B Radio wiring schematic |
I have on old Genave Alpha 200B radio I would like to hook up in my hanger
and need the wiring layout of the 12 pin plug.
I need to know what terminals are for power, speaker, mic, etc. Any help
would be appreciated.
Thanks
Jim Ellsworth
RV7A wings
ellsworj(at)m33access.com
________________________________________________________________________________
| From: | "Fred Fillinger" <n3eu(at)comcast.net> |
| Subject: | Re: Genave Alpha 200B Radio wiring schematic |
Jim Ellsworth wrote:
>
> I have on old Genave Alpha 200B radio I would like to hook up in
> my hanger and need the wiring layout of the 12 pin plug.
>
> I need to know what terminals are for power, speaker, mic, etc. Any
> help would be appreciated.
The Alpha 200A is as follows; 200B likely the same:
1 - 14VDC
4 - Mic key
5 - Mic audio
9 - Speaker audio
11 - Phone audio
12 - Ground
Note also, that the nav antenna is used for Comm receive. The comm
antenna jack is for xmit only.
Reg,
Fred F.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: E-Bus Usage Procedure / Question |
>
> > That is correct. But, The voltage drop across the diode should not affect
>the items
> > that are being powered by the e- buss.
>
>Do you mean to say the 0.7V drop won't cause a *noticeable* affect -- i.e.
>the avionics won't perform any differently? I agree with that, but one
>thing that I do notice is a 0.2 to 0.3A difference on my hall effect driven
>ammeter when I switch the E-Bus on and off in flight.
>
>If I can save my alternator from having to producing that extra quarter of
>an amp, it's a minor victory. ;-)
Consider that when the alternator is running, the bus voltage is not
less than 13.8 and maybe as high as 14.5 volts. Subtract a diode drop
of as high as 1 volt and you have 12.8 or MORE on the e-bus.
When the alternator quits, and you're operating battery only, we expect
things on the e-bus to operate well . . . in fact, it's a design goal
for electro-whizzies for aircraft to function to the intended task over
a range of 11-15 volts. A battery delivers energy over the range of 11-12.7
volts or so.
So, in spite of the potential for loss of as much as 1.0 volts in an
e-bus isolation diode, performance of goodies on the e-bus should
not be affected in any significant way. Yes, a comm transmitter's power
output may be reduced by 10% but nobody at the far end will know the
difference.
So the answer is, "No, the diode voltage drop is not significant
in terms of how well accessories on the e-bus function."
Bob . . .
________________________________________________________________________________
| From: | "Brian Sowell Home" <bsowell(at)digitex.net> |
| Subject: | EXP BUS 2V idea - what do you think? |
In order to use the Keep Alive and Clearance Delivery features of the
EXP BUS 2V, AND use a firewall mounted Master Contactor to be able to
swtich off the #8 AWG Main Battery lead running into the cockpit, I'm
considering doing the following. Please tell me what you think.
Desired State:
I want to use the Keep Alive terminal to power my Dynon EFIS so that
internal battery stays charged and the clock stays current, and
I want to use the Keep Alive terminal to power the Clearance Delivery
feature so I can use my comm intercom & music system with the master
off.
I want the large #8 wire running into my cockpit to the EXP BUS to be
switched off for safety reasons.
Everything is installed, so going back and making big changes is not
desireable. I want the solution to be simple to install.
I'm currently using the 40-amp-rated master relay on the EXP BUS with
the battery lead coming directly from the battery (no master
contactor, fuse, or any other protection). I have a firewall mounted
Master Contactor installed that is currently only supplying power to
the starter through the starter contactor. I installed the master
contactor 'just in case I need it someday', and to allow me to swtich
off the starter if the starter relay got stuck closed. When I close
the master switch, both the 40 amp EXP BUS relay, and the Master
Contactor close.
Proposed Solution:
Move the EXP BUS battery lead to the switched side of the firewall
mounted Master Contactor. Normally this would switch the EXP BUS off
completely when the master is off, disabling the Keep Alive and the
Clearance Delivery features.
But, if I also install a fuse, fuseable link, or other (say, 10 amp
protection) between the two terminals on the master contactor, then
the EXP BUS could draw up to 10 amps through the main battery lead
through this fuse. If a short occurred in the main battery lead with
the master off, the fuse would protect it.
Discussion:
Since the EXP BUS Master relay opens when the firewall mounted master
contactor opens (they're on the same switch), then the only way the
the EXP BUS could continue to draw through this 10 amp 'short
circuit' is through the keep alive feature which is limited by a 3
amp polyfuse, and the #6 avionics bus connector (for comm and
intercomm) which is limited by a 7 amp polyfuse.
The only down side I can see with this is that the EXP BUS now has
both the master contactor and the 40 amp master relay through which
to draw power. It would work fine, but not a good idea from a
reliability standpoint. However, I do not have any critical systems
on the EXP BUS. If one of these fail, my dynon has a battery backup,
as does my GPS. My comm and intercom could be turned on using the
Clearance Delivery feature. I would lose my lights, my engine
instruments, and my transponder.
Any downside I'm not seeing?
Brian
________________________________________________________________________________
| From: | "James E. Clark" <james(at)nextupventures.com> |
| Subject: | EXP BUS 2V idea - what do you think? |
Brian,
We have an EXP-BUS installation with similar functionality but a slightly
different approach.
** You probably are most aware of all of what I am about to say so no insult
intended. There may be others just starting to sort out what they might do.
**
CV points out that there is an option to *remove* their little relay and use
an external contactor. It involves soldering a good size wire across to
points and pulling out the little relay. The EXP Bus is then feed by your
switched contactor (presumbably mounted on the engine side of the firewall).
1. I made this change.
Next, I decided that I wanted the rightmost three switches to serve "kinda
like" an "E-bus". Bear with me as I am a bit liberal with my definition
here. The three switches control a) autopilot, b) AUX DC power and c)
"Clearance Delivery
I make the assumption that if I have to switch OFF the EXP BUS (for whatever
reason) and I am "over the mountains in the middle of the night and it is
IFR, blah, blah" (yeah, I am exaggerating a bit) there are a couple of
things that would be nice to be able to power. Namely the autopilot to keep
the wings level, DC power for maybe a little light and in case the "fresh"
batteries in the handheld GPS are dead and the COM radio (with intercom). I
should be able to make it home with that. :-) The Jeff Rose Electronic
ignition used to be "hard wired" but he suggested having a switch so the
power could be turned off separately from the "mag switch" and thus does not
enter the EXP BUS equation. That switch is used to power the autopilot.
2. TO accomplish this I fed the BBAT circuit (I think) with power in a
manner somewhat as you describe. It is taken DIRECTLY from the battery with
protection via a small fuseblock on the ENGINE side of the firewall. I wired
BBAT this way as well so that later if for some reason I chose, a small
"backup battery" could be put under the cowl and it supply power. But for
now the BBAT lead is tied to the "pain ole BAT".
This approach has worked fine for over 400 hours now in two years.
Don't have my drawings before me or I would bemore specific and comment on
your specifics.
I gues the only thing that I did that was REALLY different from what you
propose is to bite the bullet and make their changeover to a heavy duty
contactor via the big "jumper".
James
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: High Current Switch or Battery Contactor |
On Dec 8, 2004, at 9:17 AM, Gary Casey wrote:
> I've been thinking about the same thing and there is one failure mode
> that
> bothers me: Let's say that in flight you need to shut off the master
> bus,
> so you turn off the manual switch. Oops, the alternator and voltage
> regulator are connected "downstream" of the master switch and hence
> keep
> right on working, keeping the master bus live.
Hmm, I just don't see how that would happen. The battery master switch
is a double-pole, single-throw switch. One pole activates the battery
master contactor and the other pole provides power to the alternator
controller/field circuit. When you turn off the battery master you
automatically turn off the alternator field circuit. No split-master
required. If you want to deactivate the alternator while leaving the
battery on, you just pull the alternator field breaker. The alternator
field was the only circuit breaker I had in my RV-4. Everything else
was on fuse blocks, one for the main buss and one for the e-buss.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: O2 sensor for Rotax 914? |
clamav-milter version 0.80j
on juliet.albedo.net
There have been links posted for both wide and narrow band O2 sensors.
Hopefully it is common knowledge that any display connected to a narrow
band sensor can only tell rich or lean of stoich (14.7). A narrow band
sensor is really more of a stoich switch than anything. It generates a
voltage that goes off and on depending on whether the mixture is rich or
lean of stoich. If it is alternating on and off we assume a stoich
mixture. Which is all fine if that is sufficient for your needs. However
there are several sold with displays (typically in the $100. range) that
pretend to give more information. I wouldn't put a lot of meaning in
them other than rich or lean of stoich. IMO a one light bulb display
gives the same amount of information (On-off-flashing) but it would
require a bit more effort to interpret.
O2 sensors first appeared as a way of controlling the mixture at stoich
so that enough unburned hydrocarbons would get to the catalytic
converter to keep it lit during cruise and idle. (OK in poorly setup
engines that cruised way too rich, it did occasionally help mileage).
Engine computers assume a fault if the sensor stops switching and stays
on or off too long.
Kits for wide band sensing systems have become available for a couple of
hundred dollars. Somewhat sophisticated control electronics is required
to run the sensor, and the sensors are pricier, but they may be a better
value depending on what you want to do. I think that it is safe to say
that it is a narrow band sensor unless it has at least 5 wires.
Ken
923te wrote:
>
>Hi Brian,
>
>Thanks for reminding me of the Westach. here is a link to their
instrument.
>Is this similar to what you had?
>
>
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Electrical system ergonomics (was: EXP BUS 2V idea |
- what do you think?)
As someone who is working on the ergonomics of several different
systems (not just aircraft) right now, I find the tendency toward
complexity interesting. The first rule is to make normal operation as
simple and obvious as possible. (I eschew the word 'intuitive' here as
there is nothing intuitive about an airplane cockpit unless you are
already a pilot.) Could your pilot buddy who has never flown your
airplane before climb in and have a snowball's chance of making your
electrical system work? If not, go back to the drawing board.
Think about it. Why would you need external switches for things that
have their own switches already? Joe 6-pack pilot knows that if he/she
wants to turn off a radio he/she reaches up to the radio and turns off
its power switch. No need to hunt around the cockpit for YAFS (yet
another switch) and no additional point of failure.
We spend so much time thinking about all the clever ways we want to
have to deal with failure that we forget that it just doesn't happen
often enough to try to streamline the process. Heck, think about your
engine-out or aircraft fire litany. It just isn't all that simple and
it involves much pushing, pulling, and switching but you manage anyway.
Why should electrical system failure be any different. Here:
Electrical system failure emergency checklist:
1. turn on e-buss switch;
2. turn off battery master switch;
3. turn off all unnecessary loads (usually extra radios) on the e-buss;
4. fly to a place where a landing may be effected most safely for
troubleshooting.
It just isn't all that difficult to do even in the heat of dealing with
an emergency.
And one other thing about alternator failure. They don't fail all that
often but when they do our tendency is to think that the failure is
electrical in nature rather than mechanical. I had an alternator
failure once that involved one of the bearings. The only symptom I had
was that the alternator just dropped off-line. You see, the armature
has started to wander around inside the case and had started to chew up
the stator but there was no hint of that in the cockpit. If I had
continued instead of landing the damage might have been much worse.
Imagine the case of the alternator shattering and the armature merrily
wandering around the engine compartment visiting all its friends in
there.
So even if you have all the continue-on capability you can design into
your system, any sort of failure that could be construed as possibly
being mechanical is grounds to get on the ground. The life you save me
be that of your wallet.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
I fly because it releases my mind from the tyranny of petty things . . .
Antoine de Saint-Exupry
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: High Current Switch or Battery Contactor |
On Dec 9, 2004, at 8:34 AM, Brian Lloyd wrote:
>
> On Dec 8, 2004, at 9:17 AM, Gary Casey wrote:
>
>> I've been thinking about the same thing and there is one failure mode
>> that
>> bothers me: Let's say that in flight you need to shut off the master
>> bus,
>> so you turn off the manual switch. Oops, the alternator and voltage
>> regulator are connected "downstream" of the master switch and hence
>> keep
>> right on working, keeping the master bus live.
>
> Hmm, I just don't see how that would happen. The battery master switch
> is a double-pole, single-throw switch. One pole activates the battery
> master contactor and the other pole provides power to the alternator
> controller/field circuit. When you turn off the battery master you
> automatically turn off the alternator field circuit. No split-master
> required. If you want to deactivate the alternator while leaving the
> battery on, you just pull the alternator field breaker. The alternator
> field was the only circuit breaker I had in my RV-4. Everything else
> was on fuse blocks, one for the main buss and one for the e-buss.
BTW, you can get high-current switches with low-current additional
poles. Usually these other poles are used to control a remote
indicator to tell someone the state of the switch. You can use one of
these other poles to control your alternator field circuit.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
There is a time to laud one's country and a time to protest. A good
citizen is prepared to do either as the need arises.
________________________________________________________________________________
| From: | "James E. Clark" <james(at)nextupventures.com> |
| Subject: | Electrical system ergonomics |
Excellent points Brian.
A couple of comments embedded. Actually several now. So this has gotten to
be long.
James
{SNIP}
>
> As someone who is working on the ergonomics of several different
> systems (not just aircraft) right now, I find the tendency toward
> complexity interesting. The first rule is to make normal operation as
> simple and obvious as possible. (I eschew the word 'intuitive' here as
> there is nothing intuitive about an airplane cockpit unless you are
> already a pilot.) Could your pilot buddy who has never flown your
> airplane before climb in and have a snowball's chance of making your
> electrical system work? If not, go back to the drawing board.
You are **SO** right here! I also believe if the system "cannot" be simple
then you must "hide" the complexity. Complexity should not reach out to the
user. In a former life one of my organizations was a "human interface
technology center". One cannot image how "non-intuitive" even a "simple" (to
someone who is already aware) system can be.
Funny, I used the same thinking ("... pilot buddy climb in ... snowball's
chance of making (it) work...") in panel layout and other stuff for our RV6.
Currently I have one label that technically needs changing and two that need
the words spelled out. Otherwise I think any "Cessna/Piper" pilot would be
able do just fine.
>
> Think about it. Why would you need external switches for things that
> have their own switches already? Joe 6-pack pilot knows that if he/she
> wants to turn off a radio he/she reaches up to the radio and turns off
> its power switch. No need to hunt around the cockpit for YAFS (yet
> another switch) and no additional point of failure.
Some people will though look for the "Avionics Master Switch" as that is
what they have become accustomed to.
>
> We spend so much time thinking about all the clever ways we want to
> have to deal with failure that we forget that it just doesn't happen
> often enough to try to streamline the process. Heck, think about your
> engine-out or aircraft fire litany. It just isn't all that simple and
> it involves much pushing, pulling, and switching but you manage anyway.
> Why should electrical system failure be any different. Here:
>
> Electrical system failure emergency checklist:
>
> 1. turn on e-buss switch;
>
> 2. turn off battery master switch;
>
> 3. turn off all unnecessary loads (usually extra radios) on the e-buss;
>
> 4. fly to a place where a landing may be effected most safely for
> troubleshooting.
>
> It just isn't all that difficult to do even in the heat of dealing with
> an emergency.
>
Though not an "emergency", I recall having an alternator failure some years
ago during a return FROM Sun-N-Fun. The real problem was that I did NOT know
it had happened until just before stopping about half-way home. When I went
to announce my position, someone came back and told me what a piece of junk
radio I had and they could not understand a thing. That got me trying to
figure stuff out as I **WANT** to be heard in this busy pattern. Basically
when I found I was short on juice, I just turned stuff off and landed with
an extra bit of pattern vigilance (along with my passenger looking out as
well).
> And one other thing about alternator failure. They don't fail all that
> often but when they do our tendency is to think that the failure is
> electrical in nature rather than mechanical. I had an alternator
> failure once that involved one of the bearings. The only symptom I had
> was that the alternator just dropped off-line. You see, the armature
> has started to wander around inside the case and had started to chew up
> the stator but there was no hint of that in the cockpit. If I had
> continued instead of landing the damage might have been much worse.
> Imagine the case of the alternator shattering and the armature merrily
> wandering around the engine compartment visiting all its friends in
> there.
Similar event but with a STARTER. Was about to take a mom and her kids for
an airplane ride (the mom was the "concerned" one). Spent a lot of time
talking about safety and its a "no-go" if even the slightest thing is out of
order. During taxi I notice a "low voltage" warning on my engine monitor
(added so I would not duplicate problem above :-) ). Told her about it and
said airplane will fly just fine here around the pattern even if there was
no alternator etc... BUT .... I said we are going back and check it "just to
be safe". Well I am so glad I did as when I taxied up, my friend immediately
had me SHUT DOWN! Lots of grinding noise from the starter (bendix??? hung?).
If I had run up the engine or maybe during takeoff I can imagine parts
flying everywhere. A mechanical problem that manifest itself as electrical
(the starter was pulling way more juice than the alternator wanted to
provide at the low taxi RPMs). Mis-diagnosed by me as electrical. Glad I
stopped to check the "electrical"problem.
James
>
> So even if you have all the continue-on capability you can design into
> your system, any sort of failure that could be construed as possibly
> being mechanical is grounds to get on the ground. The life you save me
> be that of your wallet.
>
> Brian Lloyd 6501 Red Hook Plaza
> brianl(at)lloyd.com Suite 201
> +1.340.998.9447 St. Thomas, VI 00802
>
> I fly because it releases my mind from the tyranny of petty things . . .
> Antoine de Saint-Exupry
>
>
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Electrical system ergonomics |
On Dec 9, 2004, at 11:21 AM, James E. Clark wrote:
>> already a pilot.) Could your pilot buddy who has never flown your
>> airplane before climb in and have a snowball's chance of making your
>> electrical system work? If not, go back to the drawing board.
>
> You are **SO** right here! I also believe if the system "cannot" be
> simple
> then you must "hide" the complexity. Complexity should not reach out
> to the
> user. In a former life one of my organizations was a "human interface
> technology center". One cannot image how "non-intuitive" even a
> "simple" (to
> someone who is already aware) system can be.
Actually, I disagree on this point. As Albert Einstein once said,
"Everything should be made as simple as possible, but not simpler." If
something needs a knob, put the knob on the panel and label it. If
something needs a switch, put the switch on the panel and label it.
Hiding the complexity is the Microsoft, "don't worry your pretty little
head about it," approach to interface design. It works only if
everything is done exactly right. When there is a problem, people
can't find the necessary "switch" to help work around the problem.
> Funny, I used the same thinking ("... pilot buddy climb in ...
> snowball's
> chance of making (it) work...") in panel layout and other stuff for
> our RV6.
> Currently I have one label that technically needs changing and two
> that need
> the words spelled out. Otherwise I think any "Cessna/Piper" pilot
> would be
> able do just fine.
That is a good idea.
>> Think about it. Why would you need external switches for things that
>> have their own switches already? Joe 6-pack pilot knows that if
>> he/she
>> wants to turn off a radio he/she reaches up to the radio and turns off
>> its power switch. No need to hunt around the cockpit for YAFS (yet
>> another switch) and no additional point of failure.
>
> Some people will though look for the "Avionics Master Switch" as that
> is
> what they have become accustomed to.
But you don't want to turn everything off, just the things you don't
need at the moment. No one is going to try to turn off one radio by
turning off the avionics master switch.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
There is a time to laud one's country and a time to protest. A good
citizen is prepared to do either as the need arises.
________________________________________________________________________________
| From: | "Brian Sowell Home" <bsowell(at)digitex.net> |
| Subject: | Re: Electrical system ergonomics |
Still I haven't heard if there are any issues with putting a small, fused
jumper across the master contactor leads to keep a small current going
through the main EXP BUS lead to keep the Keep Alive tab hot. This was my
real question in my really long initial post. Any thoughts?
----- Original Message -----
From: "Brian Lloyd" <brianl(at)lloyd.com>
Subject: Re: AeroElectric-List: Electrical system ergonomics
>
> On Dec 9, 2004, at 11:21 AM, James E. Clark wrote:
>
>>> already a pilot.) Could your pilot buddy who has never flown your
>>> airplane before climb in and have a snowball's chance of making your
>>> electrical system work? If not, go back to the drawing board.
>>
>> You are **SO** right here! I also believe if the system "cannot" be
>> simple
>> then you must "hide" the complexity. Complexity should not reach out
>> to the
>> user. In a former life one of my organizations was a "human interface
>> technology center". One cannot image how "non-intuitive" even a
>> "simple" (to
>> someone who is already aware) system can be.
>
> Actually, I disagree on this point. As Albert Einstein once said,
> "Everything should be made as simple as possible, but not simpler." If
> something needs a knob, put the knob on the panel and label it. If
> something needs a switch, put the switch on the panel and label it.
> Hiding the complexity is the Microsoft, "don't worry your pretty little
> head about it," approach to interface design. It works only if
> everything is done exactly right. When there is a problem, people
> can't find the necessary "switch" to help work around the problem.
>
>> Funny, I used the same thinking ("... pilot buddy climb in ...
>> snowball's
>> chance of making (it) work...") in panel layout and other stuff for
>> our RV6.
>> Currently I have one label that technically needs changing and two
>> that need
>> the words spelled out. Otherwise I think any "Cessna/Piper" pilot
>> would be
>> able do just fine.
>
> That is a good idea.
>
>>> Think about it. Why would you need external switches for things that
>>> have their own switches already? Joe 6-pack pilot knows that if
>>> he/she
>>> wants to turn off a radio he/she reaches up to the radio and turns off
>>> its power switch. No need to hunt around the cockpit for YAFS (yet
>>> another switch) and no additional point of failure.
>>
>> Some people will though look for the "Avionics Master Switch" as that
>> is
>> what they have become accustomed to.
>
> But you don't want to turn everything off, just the things you don't
> need at the moment. No one is going to try to turn off one radio by
> turning off the avionics master switch.
>
> Brian Lloyd 6501 Red Hook Plaza
> brianl(at)lloyd.com Suite 201
> +1.340.998.9447 St. Thomas, VI 00802
>
> There is a time to laud one's country and a time to protest. A good
> citizen is prepared to do either as the need arises.
>
>
>
________________________________________________________________________________
| From: | "James E. Clark" <james(at)nextupventures.com> |
| Subject: | Electrical system ergonomics |
More comments ...
James
{SNIP}
>
> On Dec 9, 2004, at 11:21 AM, James E. Clark wrote:
>
> >> already a pilot.) Could your pilot buddy who has never flown your
> >> airplane before climb in and have a snowball's chance of making your
> >> electrical system work? If not, go back to the drawing board.
> >
> > You are **SO** right here! I also believe if the system "cannot" be
> > simple
> > then you must "hide" the complexity. Complexity should not reach out
> > to the
> > user. In a former life one of my organizations was a "human interface
> > technology center". One cannot image how "non-intuitive" even a
> > "simple" (to
> > someone who is already aware) system can be.
>
> Actually, I disagree on this point. As Albert Einstein once said,
> "Everything should be made as simple as possible, but not simpler." If
> something needs a knob, put the knob on the panel and label it. If
> something needs a switch, put the switch on the panel and label it.
> Hiding the complexity is the Microsoft, "don't worry your pretty little
> head about it," approach to interface design. It works only if
> everything is done exactly right. When there is a problem, people
> can't find the necessary "switch" to help work around the problem.
>
Maybe we are on different pages here. The point I was trying to get across
goes something like this ...
Early cars had chokes, spark advances, mechanical starter linkages
(pushbutton with foot).
Now there is a much greater complexity about running the engine efficiently.
Clearly a lot of that could be "shared" with the user and a LOT of
adjustments could be made available for the user to deal with. In this case
we "hide" the complexity in an effort to "simply" the interaction.
So in that sense yes, I mean "don't you worry your little head about" all
the timing adjustments needed as you go from the flatlands in the desert at
100 degrees up the mountains to subzero temps at 10,000 feet. There is a lot
of complex stuff going on that you *might* feel you could improve on but
mabe not.
The same is true yes for Microsoft offerings to some extent and I agree with
that. It was also true to some extent with the various incarnations of the
UNIX OS and Linux variants. Many users don't care that much about the code
surrounding "pipes".
If I have several pieces of equipment in my plane and when things go bad I
want to get down to just the basics running, I don't think it is necessarily
bad to be able to throw a switch and have just the basics be running. That
is a variant of "hiding the complexity" to me.
Maybe this is just a point where we disagree. No big deal but good to have
the dialogue.
James
________________________________________________________________________________
| From: | "James E. Clark" <james(at)nextupventures.com> |
| Subject: | Electrical system ergonomics |
Sorry if I was not clear.
I think it will wok OK. Controlvision will give the definitive answer but I
infact did that, but **BEFORE** the contactor (the "hot" side ... directly
from the battery) and this has worked fine.
Of course the standard "your mileage may vary" applies.
James
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Brian
> Sowell Home
> Sent: Thursday, December 09, 2004 9:01 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Electrical system ergonomics
>
>
>
>
> Still I haven't heard if there are any issues with putting a small, fused
> jumper across the master contactor leads to keep a small current going
> through the main EXP BUS lead to keep the Keep Alive tab hot. This was my
> real question in my really long initial post. Any thoughts?
>
> -{SNIP}
>
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Electrical system ergonomics |
On Dec 10, 2004, at 2:53 AM, James E. Clark wrote:
>> Actually, I disagree on this point. As Albert Einstein once said,
>> "Everything should be made as simple as possible, but not simpler."
>> If
>> something needs a knob, put the knob on the panel and label it. If
>> something needs a switch, put the switch on the panel and label it.
>> Hiding the complexity is the Microsoft, "don't worry your pretty
>> little
>> head about it," approach to interface design. It works only if
>> everything is done exactly right. When there is a problem, people
>> can't find the necessary "switch" to help work around the problem.
>>
>
> Maybe we are on different pages here. The point I was trying to get
> across
> goes something like this ...
>
> Early cars had chokes, spark advances, mechanical starter linkages
> (pushbutton with foot).
>
> Now there is a much greater complexity about running the engine
> efficiently.
> Clearly a lot of that could be "shared" with the user and a LOT of
> adjustments could be made available for the user to deal with. In this
> case
> we "hide" the complexity in an effort to "simply" the interaction.
Ah, I see where you are going with this. Technology tends to go
through three phases:
1. A simple technology demonstrator. Think of the earliest aircraft
to know what I am talking about here.
2. Fully functional but complex technology. Think of the last of the
piston-powered transport aircraft, vis a vis the Lockheed
'Constellation'. There was a knob, a switch, and a gauge for just
about everything. There was a real reason to have a flight engineer on
board.
3. Fully-functional but simple technology. Think of the current crop
of airliners with glass cockpits. You see what you need to see and the
automation takes care of the rest for you.
The latter has much more functionality but much greater simplicity and
lower workload for the pilot. To me this is *real* simplicity not the
pseudo-simplicity of 'hiding the knobs.'
Another example of this shows up with turbocharger systems. The
earliest systems had manual waste-gate controls. They increased the
pilot's workload. Some bright boy came up with the idea of a fixed
waste-gate (The evil Continental TSI0-360-GB comes to mind here) so
that the pilot's work load was sort-of reduced (no waste-gate knob) by
hiding. (Think, 'Microsoft solution'.) The mature technology added an
automatic density controller to manage the waste-gate which truly
reduced the pilot's workload.
> So in that sense yes, I mean "don't you worry your little head about"
> all
> the timing adjustments needed as you go from the flatlands in the
> desert at
> 100 degrees up the mountains to subzero temps at 10,000 feet. There is
> a lot
> of complex stuff going on that you *might* feel you could improve on
> but
> mabe not.
I agree.
> The same is true yes for Microsoft offerings to some extent and I
> agree with
> that. It was also true to some extent with the various incarnations of
> the
> UNIX OS and Linux variants. Many users don't care that much about the
> code
> surrounding "pipes".
Regardless, Microsoft is very bad about hiding necessary knobs. They
don't make the adjustments automatic, they just hide them (like the
fixed waste-gate). As someone who ends up supporting users with
Microsoft systems, I speak from experience. This is NOT the way to
build an operating system OR an airplane.
And pipes are a lousy form of interprocess communications anyway. ;-)
> If I have several pieces of equipment in my plane and when things go
> bad I
> want to get down to just the basics running, I don't think it is
> necessarily
> bad to be able to throw a switch and have just the basics be running.
> That
> is a variant of "hiding the complexity" to me.
Then what you have is a necessary knob or switch. (Frankly, that sounds
like the e-bus switch.) OTOH, think in terms of something like the
ubiquitous avionics master. What purpose does it really serve? It is
another level of complexity and another point of failure. You already
have an on/off switch on each of your radios.
> Maybe this is just a point where we disagree. No big deal but good to
> have
> the dialogue.
No, we really don't disagree. I think we were just looking at the
problem from a different angle. I refer to this as 'agreeing
violently.'
Bottom line: ask yourself if you really need it and if the answer is
'no', don't put it in.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
There is a time to laud one's country and a time to protest. A good
citizen is prepared to do either as the need arises.
________________________________________________________________________________
| From: | Ernest Christley <echristley(at)nc.rr.com> |
| Subject: | Re: Electrical system ergonomics |
Mickey Coggins wrote:
>
>
>>...
>>And pipes are a lousy form of interprocess communications anyway. ;-)
>>...
>
>
> Yeah, they are clunky, difficult to use, and not very powerful. :-)
>
>
> --
They're also heavy and add a funky echo when you yell down them. 8*)
--
http://www.ernest.isa-geek.org/
"This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: Electrical system ergonomics |
Flying back from Catalina to Santa Monica with my little sister...sweeping
her hand across the C172 instrument panel she said, "What are all these
gauges?" I pretended to study them for a few moments, shrugged my
shoulders,
feigned a puzzled expression and replied, "Ah....Some sort of clocks I
think...."
From Brian,
>3. Fully-functional but simple technology. Think of the current crop
>of airliners with glass cockpits. You see what you need to see and the
>automation takes care of the rest for you.
Yes! Futurists among us are often criticized for getting fascinated by the
technology, but I think the opposite is more often true. I start from
fundamentals and try to see unneeded complexities and how they got that way.
Integrate, simplify, throw it out...!
Ideally the computer will take over almost all flight management details.
Will this detract from the joy of flight? Of course not. Did the word
processor detract from the joy of writing? Did the ECU detract from the joy
of driving? I hardly think so. A lot of the discussion on the AeroElectric
list is just how to handle the details and hammer out configurations.
The day is not far off when you might have an in-flight problem, and you can
push a red button marked "Panic" to ask Bob N, "Hey what do I do now?"
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
"A terrorist is one who has a bomb but no air force."
---BBC listener comment.
________________________________________________________________________________
| Subject: | This was in one of my books |
I would like to share some definititions pertaining to aircraft bussing.
1 ELECTRICAL SYSTEM The electrical power source,power distribution and
electrical loads
2 ELECTRICAL SOURCE- The electrical equipment which produces, converts
or transforms electrical power. Some common DC sources are generators,
convertors, and batteries. In practice an electrical source could be a combination
of these units connected in parallel.
3 ELECTRICAL SOURCE - PRIMARY This is equipment that generates
electrical power from energy other than electrical, and is independent of any
other
electrical source. The primary source of a DC electrical system may be the
battery , main engine driven generator.
4 ELECTRICAL SOURCE - SECONDARY This is equipment that transforms and/or
converts Primary power to supply electrical power to either AC or DC powered
equipment. A secondary source is entirely dependent upon the primary source
and is considered part of the load of the primary source.
5 ELECTRICAL SOURCE- NORMAL Is the source which provides electrical
power throughout the routine aircraft
6 ELECTRICAL SOURCE - ALTERNATE Is a second power source which may be
used in lieu of the normal source, usually upon failure of the Normal source.
The use of alternate sources creates a new load and power configuration, and
therefore a new electrical system , which may require separate source
capacity analysis.
7 NOMINAL RATING Rating found on data plate of the power source. This
rating may be considered its continuous duty rating
8 GROWTH CAPACITY This is the measure ot the power source capacity
avaliable to the aircraft electrical system to supply future load equipment.
Expressed in percent.
9 NORMAL ELECTRICAL POWER OPERATION This condition assumes that all of
the avaliable electrical power system is functioning correctly with in
published limitations.
10 ABNORMAL ELECTRICAL POWER OPERATION This condition occurs when a
malfunction or failure in the electric system has taken place and the protective
devices of the system are operating to remove the malfunction of the failure
from the remainder of the system before the limits of the abnormal operations
are exceeded. The power source may operate degraded mode on a continuous basis
where the power characteristics supplied to the utilization equipment exceed
normal operation limits but remain within the limits for abnormal operation.
.
11 EMERGENCY ELECTRICAL POWER OPERATION This condition occurs followinga
loss of all normal electrical generating power sources or other
malfunctioninthat results in operation on standby power. operation with out normal
electrical power.
Can a reccomend an affordable SWR checker for GA type COMM Transcevers
Thanks in advance
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | toggle switch guards |
Hi,
I've been searching the web for quite some time, and I have
not found a source for the various types of toggle switch guards
that are available. Here is a link to a distributor that won't
sell to the average dude like me:
http://www.edmo.com/s2/eaton3.asp
I believe the switch guard I want is a MS27752-1 which does
not change the position of the switch when the guard is
closed. All the guards I've found from the usual sources
move the toggle switch when the cover is closed. I would
also be happy with a switch guard that holds the switch
in whatever position it is in.
Anyone know of a source for these switches that sells to
the average guy?
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | Harley <harley(at)AgelessWings.com> |
| Subject: | Re: toggle switch guards |
Googled it with 'MS27752-1 switch guard' as the search term and came up
with this link at the top of the list:
http://www.edmo.com/s2/eaton3.asp
At that page, clicked on the "Find Dealers" at the bottom, picked my
state, and nearby city (Rochester, NY) and it displayed 4 distributors
all within just a few miles of me here in Henrietta.
Worth a try to see if there are any in your area.
As far as online, I used to deal a lot with Newark Electronics and
although they had a $25 minimum, a couple of these guards should cover
that. You can find them, online at www.newark.com . A quick search
there 9after picking Eaton) showed a bunch of guards that looked like
it, although I didn't see that particular part number..
Harley Dixon
Mickey Coggins wrote:
>
>Hi,
>
>I've been searching the web for quite some time, and I have
>not found a source for the various types of toggle switch guards
>that are available. Here is a link to a distributor that won't
>sell to the average dude like me:
>
> http://www.edmo.com/s2/eaton3.asp
>
>I believe the switch guard I want is a MS27752-1 which does
>not change the position of the switch when the guard is
>closed. All the guards I've found from the usual sources
>move the toggle switch when the cover is closed. I would
>also be happy with a switch guard that holds the switch
>in whatever position it is in.
>
>Anyone know of a source for these switches that sells to
>the average guy?
>
>Thanks,
>Mickey
>
>--
>Mickey Coggins
>http://www.rv8.ch/
>#82007 QB Wings/Fuselage
>
>
>
>
--
Checked by AVG Anti-Virus.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: toggle switch guards |
>
>
>Hi,
>
>I've been searching the web for quite some time, and I have
>not found a source for the various types of toggle switch guards
>that are available. Here is a link to a distributor that won't
>sell to the average dude like me:
>
> http://www.edmo.com/s2/eaton3.asp
>
>I believe the switch guard I want is a MS27752-1 which does
>not change the position of the switch when the guard is
>closed. All the guards I've found from the usual sources
>move the toggle switch when the cover is closed. I would
>also be happy with a switch guard that holds the switch
>in whatever position it is in.
>
>Anyone know of a source for these switches that sells to
>the average guy?
When you run across a surplus guard that forces the
switch to a particular position when closed, you can easily
modify this part with a Dremel Mototool and a router bit.
You need to carve out cavity within the cover to remove
the ramp that bears against the toggle when the cover
closes. It's never "purddy" but it's always out of sight.
Bob . . .
________________________________________________________________________________
| From: | jerb <ulflyer(at)verizon.net> |
| Subject: | Re: toggle switch guards |
Check out Mouser Electronics - they have a large diverse product line and
are good people to deal with. jerb
http://www.mouser.com/index.cfm?handler=home
>
>
>Hi,
>
>I've been searching the web for quite some time, and I have
>not found a source for the various types of toggle switch guards
>that are available. Here is a link to a distributor that won't
>sell to the average dude like me:
>
> http://www.edmo.com/s2/eaton3.asp
>
>I believe the switch guard I want is a MS27752-1 which does
>not change the position of the switch when the guard is
>closed. All the guards I've found from the usual sources
>move the toggle switch when the cover is closed. I would
>also be happy with a switch guard that holds the switch
>in whatever position it is in.
>
>Anyone know of a source for these switches that sells to
>the average guy?
>
>Thanks,
>Mickey
>
>--
>Mickey Coggins
>http://www.rv8.ch/
>#82007 QB Wings/Fuselage
>
>
________________________________________________________________________________
| From: | "Brian Sowell Home" <bsowell(at)digitex.net> |
| Subject: | Fuseable link for 35 amp alternator protection |
I bought and ruined an ANL fuse and holder when I decided I wanted to move it from
its original location and, well, the rest is irrelevant. But now I'm considering
using a fuseable link instead. I have a 35 amp alternator with an 8awg
wire lead. Can I use a 12awg fuseable link instead?
________________________________________________________________________________
| From: | Tailgummer(at)aol.com |
| Subject: | Re: toggle switch guards |
Mickey you may wish to see Eric Jones' version
_http://periheliondesign.com/ion_ (http://periheliondesign.com/ion) :
I'm using them in my 8 for my mag switches (no EI).
John D'Onofrio _Tailgummer(at)aol.com_ (mailto:Tailgummer(at)aol.com)
________________________________________________________________________________
| From: | Gert <gert.v(at)sbcglobal.net> |
| Subject: | Re: toggle switch guards |
Mickey
if you find them and the dealer does not want to ship to Switserland, I
am sure we can find a temp shipping address for you over here and then
forward it to you.
Gert
Harley wrote:
>
> Googled it with 'MS27752-1 switch guard' as the search term and came up
> with this link at the top of the list:
>
> http://www.edmo.com/s2/eaton3.asp
>
> At that page, clicked on the "Find Dealers" at the bottom, picked my
> state, and nearby city (Rochester, NY) and it displayed 4 distributors
> all within just a few miles of me here in Henrietta.
>
> Worth a try to see if there are any in your area.
>
> As far as online, I used to deal a lot with Newark Electronics and
> although they had a $25 minimum, a couple of these guards should cover
> that. You can find them, online at www.newark.com . A quick search
> there 9after picking Eaton) showed a bunch of guards that looked like
> it, although I didn't see that particular part number..
>
> Harley Dixon
>
>
> Mickey Coggins wrote:
>
>
>>
>>Hi,
>>
>>I've been searching the web for quite some time, and I have
>>not found a source for the various types of toggle switch guards
>>that are available. Here is a link to a distributor that won't
>>sell to the average dude like me:
>>
>>http://www.edmo.com/s2/eaton3.asp
>>
>>I believe the switch guard I want is a MS27752-1 which does
>>not change the position of the switch when the guard is
>>closed. All the guards I've found from the usual sources
>>move the toggle switch when the cover is closed. I would
>>also be happy with a switch guard that holds the switch
>>in whatever position it is in.
>>
>>Anyone know of a source for these switches that sells to
>>the average guy?
>>
>>Thanks,
>>Mickey
>>
>>--
>>Mickey Coggins
>>http://www.rv8.ch/
>>#82007 QB Wings/Fuselage
>>
>>
>>
>>
>
>
>
--
is subject to a download and archival fee in the amount of $500
________________________________________________________________________________
| Subject: | Re: toggle switch guards |
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Mickey -
Have you thought of the lever-lock switches. You have to pull the toggle
out to move it. They make a variety of them. NKK makes a good mini
lever-lock, as does Honeywell-Micro.
John
> I've been searching the web for quite some time, and I have
> not found a source for the various types of toggle switch guards
> that are available.
________________________________________________________________________________
| From: | Chuck Jensen <cjensen(at)dts9000.com> |
I recently installed UMA instrument bezel lighting. The UMA system uses an
inverter to power the bezel lights with up to 115v. I like the soft
blue/green flow and by dimming, instrument lighting is great under all
conditions. However, when the bezel lights are turned on, a very noticeable
whine is present in the background during transmit or intercom
communications. The avionics shop said "some installations are quiet but
its pretty common to have the RFI from the UMA bezel lighting system and
there's no way to fix it without a lot of research (re: dollars). It seems
hard to believe that a system would be design and sold that 'commonly'
induces whine into the radio system--and there's no cure. Is this true or
just a cop-out?
Chuck
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
| Subject: | Re: toggle switch guards |
I don't know what type they are, but Steinair has them
(www.steinair.com) in three colors.
Dick Tasker
Mickey Coggins wrote:
>
>Hi,
>
>I've been searching the web for quite some time, and I have
>not found a source for the various types of toggle switch guards
>that are available. Here is a link to a distributor that won't
>sell to the average dude like me:
>
> http://www.edmo.com/s2/eaton3.asp
>
>I believe the switch guard I want is a MS27752-1 which does
>not change the position of the switch when the guard is
>closed. All the guards I've found from the usual sources
>move the toggle switch when the cover is closed. I would
>also be happy with a switch guard that holds the switch
>in whatever position it is in.
>
>Anyone know of a source for these switches that sells to
>the average guy?
>
>Thanks,
>Mickey
>
>--
>Mickey Coggins
>http://www.rv8.ch/
>#82007 QB Wings/Fuselage
>
>
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: toggle switch guards |
Hi John,
Which of Eric's switch guards are you using? Do you have any photos?
I've got the simple ring type, but they don't come up high
enough to protect the switch. I'm considering the space
shuttle guards.
If that does not work, I'll probably fall back to Bob's
idea of getting busy with the dremel tool on the switch
guards that Stein sells.
Thanks to all that offered suggestions, they were very
helpful.
Best regards,
Mickey
>Mickey you may wish to see Eric Jones' version
>_http://periheliondesign.com/ion_ (http://periheliondesign.com/ion) :
>
>I'm using them in my 8 for my mag switches (no EI).
>
>John D'Onofrio _Tailgummer(at)aol.com_ (mailto:Tailgummer(at)aol.com)
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: toggle switch guards |
Mickey
Waytek Wire ( www.waytekwire.com ) has them. They also carry the same
brand and series of toggle switches sold by B&C Specialties. They are on
page 46 of their online catalog. Check out
http://order.waytekwire.com/IMAGES/M37/catalog/217_046
Charlie Kuss
>
>
>Hi,
>
>I've been searching the web for quite some time, and I have
>not found a source for the various types of toggle switch guards
>that are available. Here is a link to a distributor that won't
>sell to the average dude like me:
>
> http://www.edmo.com/s2/eaton3.asp
>
>I believe the switch guard I want is a MS27752-1 which does
>not change the position of the switch when the guard is
>closed. All the guards I've found from the usual sources
>move the toggle switch when the cover is closed. I would
>also be happy with a switch guard that holds the switch
>in whatever position it is in.
>
>Anyone know of a source for these switches that sells to
>the average guy?
>
>Thanks,
>Mickey
>
>--
>Mickey Coggins
>http://www.rv8.ch/
>#82007 QB Wings/Fuselage
>
>
________________________________________________________________________________
| From: | "thomas a. sargent" <sarg314(at)comcast.net> |
| Subject: | KT-76C lighting power draw |
I have an old (late 1990's) King KT-76C transponder which I bought
yellow tagged several years ago. The installation manual says the
brightness of the display is varied by changing the voltage on one of
the inputs, but does not specify how much current the display draws.
Does any one know how I can find this information?
Thanks,
--
Tom Sargent, RV-6A
________________________________________________________________________________
| From: | "Maureen & Bob Christensen" <mchriste(at)danvilletelco.net> |
| Subject: | Re: Fuseable link for 35 amp alternator protection |
I doesn't seem like a good idea to me. If I understand correctly, in this
situation you would want to allow at least 35A and possibly a bit more for
"spikes"?~
Regards,
Bob Christensen
RV-8 Builder - SE Iowa
----- Original Message -----
From: "Brian Sowell Home" <bsowell(at)digitex.net>
Subject: AeroElectric-List: Fuseable link for 35 amp alternator protection
>
> I bought and ruined an ANL fuse and holder when I decided I wanted to move
it from its original location and, well, the rest is irrelevant. But now I'm
considering using a fuseable link instead. I have a 35 amp alternator with
an 8awg wire lead. Can I use a 12awg fuseable link instead?
>
>
________________________________________________________________________________
| From: | "Paul" <greif8(at)mindspring.com> |
| Subject: | rv7 tail light wiring |
Hello and Merry Christmas everyone,
I hope this is an appropriate question for this form. I am getting
ready to close the VS, and the wires for the tail light strobe need to be
run through the VS first.
Can anyone give me a heads up on how this should be accomplished? I
have a Whelen system 6.
I've been lurking for the past 6 months and have found that the
learning curve will be this side of vertical. Wiring this bird will be more
intimidating that the construction. Thanks in advance for the help.
Paul
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Fuseable link for 35 amp alternator protection |
clamav-milter version 0.80j
on juliet.albedo.net
Doesn't sound like a good idea to me either. A piece of fibreglass
sleeving can be expected to contain the wreckage and prevent further
shorting from a melted 26 awg fuse link but I don't think I'd count on
that for 12 awg. That is a lot more heat and molten metal. The only
heavy gauge fuse link on my car is completely contained within the fuse
block and both ends terminate at a solid terminal. Fuse links won't be
fast acting like a fuse. Another option might be the MAXI fuses
mentioned here a week or three ago.
I have found the 26 awg fuselinks handy for branching out from a heavy
circuit to small gauge wire. For example this morning I used one at the
crossfeed contactor coil to feed a 22 awg wire out to the indicator light.
Ken
Maureen & Bob Christensen wrote:
>
>I doesn't seem like a good idea to me. If I understand correctly, in this
>situation you would want to allow at least 35A and possibly a bit more for
>"spikes"?~
>
>Regards,
>Bob Christensen
>RV-8 Builder - SE Iowa
>----- Original Message -----
>From: "Brian Sowell Home" <bsowell(at)digitex.net>
>To:
>Subject: AeroElectric-List: Fuseable link for 35 amp alternator protection
>
>
>
>
>>
>>
>
>
>
>>I bought and ruined an ANL fuse and holder when I decided I wanted to move
>>
>>
>it from its original location and, well, the rest is irrelevant. But now I'm
>considering using a fuseable link instead. I have a 35 amp alternator with
>an 8awg wire lead. Can I use a 12awg fuseable link instead
>
>
>>
>>
________________________________________________________________________________
| From: | "Dan Checkoway" <dan(at)rvproject.com> |
| Subject: | Re: rv7 tail light wiring |
Do you mean the strobe on the rudder? If so, don't even worry about it
now -- the wiring doesn't go through the VS proper, just its spar.
If you're talking about a strobe on TOP of the VS, yeah, you'd need to wire
that, but I'd recommend against it. That thing will be flashing right into
the cockpit.
My recommendation is to go with a rudder-mounted strobe/position light. The
wire will pass through the tailcone of the fuselage and poke through the
very bottom of the VS spar where it attaches to the fuselage. You don't
have to do anything about it at this phase.
The only thing you might want to do is put some grommets or snap bushings in
the VS ribs in case you need to wire something through there later. If I
were doing my project over again I'd consider mounting a camera in the tip
on top of the VS. ;-)
Best of luck,
)_( Dan
RV-7 N714D
http://www.rvproject.com
P.S. -- This has most likely been covered in the archives of the Matronics
rv-list, rather than the aeroelectric-list. Also on the RV7and7A Yahoo
group.
----- Original Message -----
From: "Paul" <greif8(at)mindspring.com>
Subject: AeroElectric-List: rv7 tail light wiring
>
> Hello and Merry Christmas everyone,
>
> I hope this is an appropriate question for this form. I am getting
> ready to close the VS, and the wires for the tail light strobe need to be
> run through the VS first.
> Can anyone give me a heads up on how this should be accomplished? I
> have a Whelen system 6.
> I've been lurking for the past 6 months and have found that the
> learning curve will be this side of vertical. Wiring this bird will be
more
> intimidating that the construction. Thanks in advance for the help.
>
> Paul
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> protection |
| Subject: | Re: Fuseable link for 35 amp alternator |
protection
protection
>
>
>I bought and ruined an ANL fuse and holder when I decided I wanted to move
>it from its original location and, well, the rest is irrelevant. But now
>I'm considering using a fuseable link instead. I have a 35 amp alternator
>with an 8awg wire lead. Can I use a 12awg fuseable link instead?
Fusible links are not appropriate for this kind
of service.
Check with local automotive parts suppliers for a
MAXI series plastic fuse in at least 40A and 50A
better yet. This installs in a HHX fuseholder like
this:
http://www.bussmann.com/library/bifs/2129.pdf
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re:Fuseable link for 35 amp alternator protection |
>
>Doesn't sound like a good idea to me either. A piece of fibreglass
>sleeving can be expected to contain the wreckage and prevent further
>shorting from a melted 26 awg fuse link but I don't think I'd count on
>that for 12 awg. That is a lot more heat and molten metal. The only
>heavy gauge fuse link on my car is completely contained within the fuse
>block and both ends terminate at a solid terminal. Fuse links won't be
>fast acting like a fuse. Another option might be the MAXI fuses
>mentioned here a week or three ago.
Good call.
>I have found the 26 awg fuselinks handy for branching out from a heavy
>circuit to small gauge wire. For example this morning I used one at the
>crossfeed contactor coil to feed a 22 awg wire out to the indicator light.
This is an excellent example of good fusible link usage.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: DC motor braking diagram |
>
>
>Bob;
>Not meaning to be critical, but in the schematics at this link, it would
>appear that the flap limit switches are wired incorrectly in flaps.pdf,
>flaps_4.pdf, and flaps_5.pdf. In the drawing flaps_1.pdf they appear to
>be correct and the remaining two schematics show no limits switches and
>seem correct. Am I misinterpreting something or are these drawings in
>error?? I believe that in all the drawings with limits they should be
>wired as shown in flaps_1.pdf. Is this correct?? Thank you
>Bob McC
Please DO be critical . . . those drawings have been posted
for quite some time and you're the first to pick up on the
errors. Thank you!
I've correct the drawings and posted them at:
http://www.aeroelectric.com/PPS/Flight/Flaps/Flaps.pdf
I appreciate your diligence and time to bring this to my
attention.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: KT-76C lighting power draw |
>
>
>I have an old (late 1990's) King KT-76C transponder which I bought
>yellow tagged several years ago. The installation manual says the
>brightness of the display is varied by changing the voltage on one of
>the inputs, but does not specify how much current the display draws.
>Does any one know how I can find this information?
>
>Thanks,
>--
>Tom Sargent, RV-6A
The very best way is to power it up on the bench and measure it.
If you need to wait until it's installed, a reasonable estimate
is 200 mA max. It doesn't take too many lamps to light up this
small of a panel. But in any case, your direct measurement is
the best deduction/confirmation of the current required.
Bob . . .
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Physical wiring question |
Hi,
How tightly can we pack a snap bushing with wires before
it's considered too tight?
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Physical wiring question |
>
>
>Hi,
>
>How tightly can we pack a snap bushing with wires before
>it's considered too tight?
"Tight" suggests that you were able to push the wires into
the bushing . . . if you can push the wire and the bundle
will slip in the bushing with force from the fingers,
then pressures on the wire insulation is not excessive.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Server Glitch Fixed |
Orders and direct-email inquiries entered on the
aeroelectric.com website between 12/9/4 and 12/13/4
got dumped into a black hole. We installed a new
faster/larger server and the IT guy missed a little
detail in the e-mail management instructions. Even
though your order/message was echoed back correctly
to your browser, the the data was never forwarded
to our system here in Wichita.
Anyone who believe their communication was "black-holed",
drop me an email directly or call 316-685-8617 . . .
Sorry for the inconvenience.
Bob . . .
________________________________________________________________________________
| From: | "Wayne Berg" <wfberg(at)msn.com> |
| Subject: | Re: Server Glitch Fixed |
Bob,
I have dual Plasma III ignition in my RV-8 and I would like to have my annunciator
system sense a failure of either ignition system. I am using light bar LED's
and need either pull them high or low. Klaus suggested I use the tach output
as a failure signal. Any suggestions on how I can wire this up.
Thanks,
Wayne Berg
----- Original Message -----
From: Robert L. Nuckolls, III<mailto:b.nuckolls(at)cox.net>
To: aeroelectric-list(at)matronics.com
Sent: Monday, December 13, 2004 2:32 PM
Subject: AeroElectric-List: Server Glitch Fixed
Orders and direct-email inquiries entered on the
aeroelectric.com website between 12/9/4 and 12/13/4
got dumped into a black hole. We installed a new
faster/larger server and the IT guy missed a little
detail in the e-mail management instructions. Even
though your order/message was echoed back correctly
to your browser, the the data was never forwarded
to our system here in Wichita.
Anyone who believe their communication was "black-holed",
drop me an email directly or call 316-685-8617 . . .
Sorry for the inconvenience.
Bob . . .
________________________________________________________________________________
| From: | Mcculleyja(at)aol.com |
| Subject: | Re: AeroElectric-List Digest: 7 Msgs - 12/12/04 |
In a message dated 12/13/04 2:57:44 AM Eastern Standard Time,
aeroelectric-list-digest(at)matronics.com writes:
> I've correct the drawings and posted them at:
>
> http://www.aeroelectric.com/PPS/Flight/Flaps/Flaps.pdf
>
Bob, two of the drawings also list the motor as a Trim Actuator, while the
others all show it as a Flap Motor or Flap Actuator, if you might wish to change
that also.
Jim McCulley
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> 12/12/04 |
| Subject: | Re: AeroElectric-List Digest: 7 Msgs - |
12/12/04
12/12/04
>
>In a message dated 12/13/04 2:57:44 AM Eastern Standard Time,
>aeroelectric-list-digest(at)matronics.com writes:
>
> > I've correct the drawings and posted them at:
> >
> > http://www.aeroelectric.com/PPS/Flight/Flaps/Flaps.pdf
> >
>Bob, two of the drawings also list the motor as a Trim Actuator, while the
>others all show it as a Flap Motor or Flap Actuator, if you might wish to
>change
>that also.
>
>Jim McCulley
Done. Thanks!
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
>
>I recently installed UMA instrument bezel lighting. The UMA system uses an
>inverter to power the bezel lights with up to 115v. I like the soft
>blue/green flow and by dimming, instrument lighting is great under all
>conditions. However, when the bezel lights are turned on, a very noticeable
>whine is present in the background during transmit or intercom
>communications. The avionics shop said "some installations are quiet but
>its pretty common to have the RFI from the UMA bezel lighting system and
>there's no way to fix it without a lot of research (re: dollars). It seems
>hard to believe that a system would be design and sold that 'commonly'
>induces whine into the radio system--and there's no cure. Is this true or
>just a cop-out?
It's a cop-out. If UMA were asked to conduct the very rudimentary
tests per DO-160 that would be expected for qualifying these products
onto certified aircraft, there would be no noticeable noise. It should
NOT be common to have any noise in the system due to the effects of this
product.
The techniques for fixing this are the same as outlined in Chapter
16. You know the victim, you know the antagonist, now deduce the
propagation path and attenuate or break it. Then publish your
findings here on the list and elsewhere.
Bob . . .
________________________________________________________________________________
| From: | "Dr. Andrew Elliott" <a.s.elliott(at)cox.net> |
| Subject: | Computer power supplies |
Anyone using a computer power supply for shop power? You can get these
with one of the 12V output rated at 20 or 25 amps, for <$10 usually. Is
the 12V too low? Most "regular" regulated switching power supplies are
13.8V, like your VR output.
Andy Elliott
Lycoming owner, Corvair wannabe!
________________________________________________________________________________
| Subject: | DO-160 - - again |
| From: | "George Braly" <gwbraly(at)gami.com> |
Bob, A friend who is involved in a certified project was doing DO-160 testing
for the 80 volt spoke on the power leads.
He was blowing equipment - - when I quizzed him about the duration of the pulse.
He said they were testing at 80volts for 400 ms.
I pulled out the DO-160 and it only specifies the 80 volts for 100ms.
He was surprised - - but it turns out the OEM for which the equipment is being
developed specified the 400ms duration.
Can you think of any reason why they would do that ?
Have you come across this before?
Regards, George
---
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | VHF antenna placement wrt transponder antenna |
Hi,
I've read in the archives that one should place two
VHF antennas as far apart as possible, and Brian
recommends one on the top, and one on the bottom.
I also read that Garmin recommends 30 inches distance
between a VHF Comm antenna and one of their GPS antennas.
My question is should a VHF Comm antenna be placed a
certain distance from a transponder antenna?
Many thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | Chuck Jensen <cjensen(at)dts9000.com> |
Actually, UMA has conducted extensive testing and confirms the RFI is
neither normal or acceptable. They were very helpful in making several
suggestions of places to look for the problem and I will read your Chapter
16 as part of my OEP (Ongoing Education Program). I will certainly post the
results for all to assimilate.
Chuck
-----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
Subject: Re: AeroElectric-List: Headset RFI
>
>I recently installed UMA instrument bezel lighting. The UMA system uses an
>inverter to power the bezel lights with up to 115v. I like the soft
>blue/green flow and by dimming, instrument lighting is great under all
>conditions. However, when the bezel lights are turned on, a very
noticeable
>whine is present in the background during transmit or intercom
>communications. The avionics shop said "some installations are quiet but
>its pretty common to have the RFI from the UMA bezel lighting system and
>there's no way to fix it without a lot of research (re: dollars). It seems
>hard to believe that a system would be design and sold that 'commonly'
>induces whine into the radio system--and there's no cure. Is this true or
>just a cop-out?
It's a cop-out. If UMA were asked to conduct the very rudimentary
tests per DO-160 that would be expected for qualifying these products
onto certified aircraft, there would be no noticeable noise. It should
NOT be common to have any noise in the system due to the effects of this
product.
The techniques for fixing this are the same as outlined in Chapter
16. You know the victim, you know the antagonist, now deduce the
propagation path and attenuate or break it. Then publish your
findings here on the list and elsewhere.
Bob . . .
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | DO-160 - - again |
>I pulled out the DO-160 and it only specifies the 80 volts for 100ms.
>He was surprised - - but it turns out the OEM for which the equipment is
being
>developed specified the 400ms duration.
>Can you think of any reason why they would do that ?
George,
As Bob Might Say.....
Google "SC135 DO-160E". This is the working group on the NEW-THIS-MONTH
DO-160E. Basically two forces, harmonization and the gradual attempt to
civilize us have conspired to boost immunity levels. I don't have the
patience to download from this website, but if it's anywhere, It's here.
Good luck.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
________________________________________________________________________________
| From: | "Johann G." <johann(at)gi.is> |
| Subject: | Ground and braded wire. |
Hello Bob.
I am very confused but willing to learn.
My problem is not major but misleading when I look at different wire schematics
for my radio and intercom.
The work I am doing is connecting the mic/headphone jack connections to my radio
and intercom.
On your homepage you show how to connect the mike jack and where you refer to the
ground as the shield ground.
My plane will be a two seater, so I will have one cable with three wires and the
shield wire. One for mic high and one with ptt. Then ground with the shield
wire?
When I look at the wire schematic for the PM 1000 intercom, it indicates that I
should "connect the shields at intercom only".
My question is: Should I use the shield wire as the ground on both ends in the
mic and headphone connections?
Sorry for the long and confusing question.
Thank you in advance.
Johann G.
________________________________________________________________________________
| From: | HAL KEMPTHORNE <hal_kempthorne(at)sbcglobal.net> |
| Subject: | Skymap GPS display has lines missing |
Hi,
My Skyforce Skymap II monochrome unit is now missing a line. Line near top does
not light up. Works fine otherwise.
Can this be reasonably fixed or should I find a newer unit - this one is about
8 years old.
hal
________________________________________________________________________________
DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws;
s=s1024; d=yahoo.com;
b=CYnkeniLtafPes5RXZ2PNFpZym7zJQzVhVfN5N1uaQBfuMnPZ3OH5NqNQJxSRMikPzoZXrQ5OYPmH7xTuGDKf1bPTj3uY1cb5um7T8LICOZ1+g40+ktlC/5gYB9V64mexdUoAhEykIOe46FnQTMi1dBs+gH9pmcw6O0GaNO5nL8;
| From: | John <m2mustang(at)yahoo.com> |
| Subject: | Re: Ground and braded wire. |
No. It's my understanding that the shield will cease
to be a shield if it's connected at both ends.
Only effective when terminated at the end indicated.
JD
--- "Johann G." wrote:
>
>
> Hello Bob.
>
> I am very confused but willing to learn.
> My problem is not major but misleading when I look
> at different wire schematics for my radio and
> intercom.
> The work I am doing is connecting the mic/headphone
> jack connections to my radio and intercom.
> On your homepage you show how to connect the mike
> jack and where you refer to the ground as the shield
> ground.
> My plane will be a two seater, so I will have one
> cable with three wires and the shield wire. One for
> mic high and one with ptt. Then ground with the
> shield wire?
> When I look at the wire schematic for the PM 1000
> intercom, it indicates that I should "connect the
> shields at intercom only".
> My question is: Should I use the shield wire as the
> ground on both ends in the mic and headphone
> connections?
>
> Sorry for the long and confusing question.
> Thank you in advance.
> Johann G.
>
>
>
> -
> Contributions
> any other
> Forums.
>
> http://www.matronics.com/subscription
> http://www.matronics.com/FAQ/AeroElectric-List.htm
> http://www.matronics.com/archives
> http://www.matronics.com/photoshare
> http://www.matronics.com/emaillists
>
>
>
>
>
>
__________________________________
http://my.yahoo.com
________________________________________________________________________________
| Subject: | Re: Skymap GPS display has lines missing |
In a message dated 12/14/04 3:33:41 PM Eastern Standard Time,
hal_kempthorne(at)sbcglobal.net writes:
> Can this be reasonably fixed or should I find a newer unit - this one is
> about 8 years old.
>
>
________________________________________________________________________________
| From: | "Johann G." <johann(at)gi.is> |
| Subject: | Re: Ground and braded wire. |
Hello John.
Thanks for the reply,
Yes, this was my understanding too, so this is why I am all confused on the
connecting according to the picture from Bob at aeroelectric.
The picture for the mike jack connection indicates that the
sleeve(common)terminal is the shield ground???? and to get a ground
connection at the other end i.e. radio and intercom, it will also need to be
connected on that end.
This just gets very confusing for someone like me who do not know much about
electrical stuff.
Best regards,
Johann G.
----- Original Message -----
From: "John" <m2mustang(at)yahoo.com>
Subject: Re: AeroElectric-List: Ground and braded wire.
>
> No. It's my understanding that the shield will cease
> to be a shield if it's connected at both ends.
> Only effective when terminated at the end indicated.
> JD
> --- "Johann G." wrote:
>
> >
> >
> > Hello Bob.
> >
> > I am very confused but willing to learn.
> > My problem is not major but misleading when I look
> > at different wire schematics for my radio and
> > intercom.
> > The work I am doing is connecting the mic/headphone
> > jack connections to my radio and intercom.
> > On your homepage you show how to connect the mike
> > jack and where you refer to the ground as the shield
> > ground.
> > My plane will be a two seater, so I will have one
> > cable with three wires and the shield wire. One for
> > mic high and one with ptt. Then ground with the
> > shield wire?
> > When I look at the wire schematic for the PM 1000
> > intercom, it indicates that I should "connect the
> > shields at intercom only".
> > My question is: Should I use the shield wire as the
> > ground on both ends in the mic and headphone
> > connections?
> >
> > Sorry for the long and confusing question.
> > Thank you in advance.
> > Johann G.
> >
> >
> >
> > -
> > Contributions
> > any other
> > Forums.
> >
> > http://www.matronics.com/subscription
> > http://www.matronics.com/FAQ/AeroElectric-List.htm
> > http://www.matronics.com/archives
> > http://www.matronics.com/photoshare
> > http://www.matronics.com/emaillists
> >
> >
> >
> >
> >
> >
>
>
> __________________________________
> http://my.yahoo.com
>
>
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Ground and braded wire. |
In a message dated 12/14/2004 3:31:55 P.M. Central Standard Time,
johann(at)gi.is writes:
Thanks for the reply,
Yes, this was my understanding too, so this is why I am all confused on the
connecting according to the picture from Bob at aeroelectric.
The picture for the mike jack connection indicates that the
sleeve(common)terminal is the shield ground???? and to get a ground
connection at the other end i.e. radio and intercom, it will also need to be
connected on that end.
This just gets very confusing for someone like me who do not know much about
electrical stuff.
Best regards,
Johann G.
Good Evening Johan and John,
This is way out of my area of expertise, but as I understand it, what you
want to do is isolate the wiring and the jacks from any airframe ground.
Use the shield as the return to the intercom unit. The jacks themselves
also want to be isolated from the airframe ground. The intent is to shield the
data wires and avoid any potential for a ground loop via an airframe ground.
Dopes that muddy the waters sufficiently?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Ground and braded wire. |
In a message dated 12/14/2004 4:26:21 P.M. Central Standard Time,
BobsV35B(at)aol.com writes:
Dopes that muddy the waters sufficiently
OOOPS!
Should read: "Does that muddy the water sufficiently?"
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| Subject: | Re: Ground and braded wire. |
| From: | "Matt Prather" <mprather(at)spro.net> |
You have to consider what is going on in the circuit. Is the outer
conductor (shield) which is wrapped around an (some) inner
conductor(s) providing a signal connection in a circuit? Or is it there
to block the electrostatic propagation of noise?
Moving low frequency electrical energy (audio) from one device to
another (microphone to radio) requires a pair of conducting paths - a
circuit must exist - a signal ("+") and a reference ("-", "ground") conductor
must be used. Two wires can used, as can shielded, single strand
wire. In the case of shielded wire, normally, the center conductor
carries the "+" signal, and the outer shield carries the "-" (ground/
reference) signal. This isn't really a case of shielding so much as
a coaxially oriented signal pair.
To correctly wire a microphone to an intercom using shielded wire,
one terminal on the mic is connected to the center conductor, and the
other terminal is connected to the shield. On the intercom end, connect
the center conductor to the "+" input, and connect the shield to the "-"
terminal. Many devices like this have the "-" terminal connected to
the chassis or power supply ground. Don't think about this too much.
Just remember that a mic needs to be connected to 2 conductors and
the two conductors need to be connected to intercom. Don't consider
making any "extra" connections, by "grounding," etc.
Additionally, I recommend that the PTT circuit does not share any
conductors with the microphone circuit. If you have shielded wire that
has 3 wires plus the shield (4 conductors), using 2 of the wires for PTT,
1 for the mic, and the shield for the mic "-" side should be safe. None
the less, I'd still use seperate wires for this circuit.
One common source of confusion with regard to "grounding" and
"shielding" is magneto wiring... To turn off a magneto (disable its spark),
the p-lead terminal is connected to the body of the magneto (Don't use
the word "ground." Lots of things are electrically connected to the body
of the magneto - it's metal and it's bolted to the engine). To make the
magneto controllable from the cockpit, the p-lead connection to the body
is wired through a switch on the panel. When the magneto is running, the
p-lead is electrically disconnected from the magneto body by opening a
switch in the cockpit. The only down side of this is that the p-lead is
still
connected to the noise generating part of the magneto, and thus can radiate
some noise into other circuits in the airplane. To reduce this effect, the
conductor that goes from the switch in the cockpit to the body of the
magneto can be arranged such that it electrostatically shields the noisy
part of the p-lead. Hence, there is shielded wire between the magneto switch
and magneto. No other connections should be made. Some people say you
"ground" the shield, but really you are just completing the circuit from the
p-lead terminal to the switch in the panel to the body of the mag. Making a
connection between the outer shield and a ground in the cockpit would be
extraneous to the function of the circuit and would be inviting trouble.
In general, if you consider where you have to move electrons, what things
you make wire connections to will become obvious. If you don't have to
allow electrons to get from one thing to another, they don't need (shouldn't
have) wires (conducting paths) connecting them.
Sorry if this was too long to help.. :)
Regards,
Matt-
>
> Hello John.
>
> Thanks for the reply,
> Yes, this was my understanding too, so this is why I am all confused on
> the connecting according to the picture from Bob at aeroelectric.
> The picture for the mike jack connection indicates that the
> sleeve(common)terminal is the shield ground???? and to get a ground
> connection at the other end i.e. radio and intercom, it will also need
> to be connected on that end.
> This just gets very confusing for someone like me who do not know much
> about electrical stuff.
> Best regards,
> Johann G.
>
>
> ----- Original Message -----
> From: "John" <m2mustang(at)yahoo.com>
> To:
> Subject: Re: AeroElectric-List: Ground and braded wire.
>
>
>>
>> No. It's my understanding that the shield will cease
>> to be a shield if it's connected at both ends.
>> Only effective when terminated at the end indicated.
>> JD
>> --- "Johann G." wrote:
>>
>> >
>> >
>> > Hello Bob.
>> >
>> > I am very confused but willing to learn.
>> > My problem is not major but misleading when I look
>> > at different wire schematics for my radio and
>> > intercom.
>> > The work I am doing is connecting the mic/headphone
>> > jack connections to my radio and intercom.
>> > On your homepage you show how to connect the mike
>> > jack and where you refer to the ground as the shield
>> > ground.
>> > My plane will be a two seater, so I will have one
>> > cable with three wires and the shield wire. One for
>> > mic high and one with ptt. Then ground with the
>> > shield wire?
>> > When I look at the wire schematic for the PM 1000
>> > intercom, it indicates that I should "connect the
>> > shields at intercom only".
>> > My question is: Should I use the shield wire as the
>> > ground on both ends in the mic and headphone
>> > connections?
>> >
>> > Sorry for the long and confusing question.
>> > Thank you in advance.
>> > Johann G.
>> >
>> >
>> >
>> > -
>> > Contributions
>> > any other
>> > Forums.
>> >
>> > http://www.matronics.com/subscription
>> > http://www.matronics.com/FAQ/AeroElectric-List.htm
>> > http://www.matronics.com/archives
>> > http://www.matronics.com/photoshare
>> > http://www.matronics.com/emaillists
>> >
>> >
>> >
>> >
>> >
>> >
>>
>>
>> __________________________________
>> http://my.yahoo.com
>>
>>
>
>
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Skymap GPS display has lines missing |
HAL KEMPTHORNE wrote:
>
>
>Hi,
>
>My Skyforce Skymap II monochrome unit is now missing a line. Line near top does
not light up. Works fine otherwise.
>
>Can this be reasonably fixed or should I find a newer unit - this one is about
8 years old.
>
>hal
>
Can't speak directly to the Skymap, but it's almost universal that there
will be a cable & connector between the display & the rest of the
product. It's fairly common for connectors to corrode and/or come loose
& if that's happened, you could get that sort of symptom.
If it's out of warranty & you're confident of your ability to handle
tiny fragile stuff, open it up & reseat the connector.
Charlie
(Just had to do that to wife's in-warranty Dell laptop, at the direction
of tech support.)
________________________________________________________________________________
| From: | Robert McCallum <robert.mccallum2(at)sympatico.ca> |
| Subject: | Re: Ground and braded wire. |
Johann
The part that you're missing is in using the term "ground". In your
description stop at the word "shield" and forget the word "ground". It
will make understanding easier. "Shield" and "ground" are NOT synonymous
and are two totally separate things. The braid or shield on the wire is,
in fact, connected to the sleeve of your microphone jack, but because
the jack is electrically isolated from the airframe (or should be) this
does not constitute a "ground", only a return path to the radio/audio
panel etc. to complete the circuit for the microphone. (this wire may
actually be "grounded" at the radio but if you ignore the "ground" bit
and think of it as a return path for the mic signal it becomes easier to
understand)
Hope I haven't added to the confusion;
Bob McC
Johann G. wrote:
>
>Hello John.
>
>Thanks for the reply,
>Yes, this was my understanding too, so this is why I am all confused on the
>connecting according to the picture from Bob at aeroelectric.
>The picture for the mike jack connection indicates that the
>sleeve(common)terminal is the shield ground???? and to get a ground
>connection at the other end i.e. radio and intercom, it will also need to be
>connected on that end.
>This just gets very confusing for someone like me who do not know much about
>electrical stuff.
>Best regards,
>Johann G.
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: DO-160 - - again |
>
>
>Bob, A friend who is involved in a certified project was doing DO-160
>testing for the 80 volt spoke on the power leads.
>
>He was blowing equipment - - when I quizzed him about the duration of the
>pulse. He said they were testing at 80volts for 400 ms.
>
>I pulled out the DO-160 and it only specifies the 80 volts for 100ms.
>
>He was surprised - - but it turns out the OEM for which the equipment is
>being developed specified the 400ms duration.
>
>Can you think of any reason why they would do that ?
>
>Have you come across this before?
Yeah . . . from time to time, someone decides there's a reason
to exceed requirements of DO-160 for being able to withstand
applied stresses. Does this product go into a certified
airplane? Most of our new black boxes are tested to category
B . . . battery of significant capacity on bus and category
A for airplanes like the Hawker Horizon (AC generators with
TR sets to develop DC). Both of these requirements are much
easier to meet than category Z (assumes generator runaway
happens with no battery on line too). Actually, ov protection
circuits are so much better than 30 years ago when the values
were selected, I'd have no problems with testing all 28VDC
stuff for category B as long as the ov protection system was
modern.
The guy needs to inquire as to the rationale for departing
from the 80v, 100 mS values as described in 16.5.4.4.b
of DO-160.
While DO-160 defines ability to withstand, MIL-STD-704
describes the ability to limit aberrations on the bus.
and 80v, 400 mS transient is certainly well outside the
design goals suggested by MIL-STD-704.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Ground and braded wire. |
>
>Hello Bob.
>
>I am very confused but willing to learn.
>My problem is not major but misleading when I look at different wire
>schematics for my radio and intercom.
>The work I am doing is connecting the mic/headphone jack connections to my
>radio and intercom.
>On your homepage you show how to connect the mike jack and where you refer
>to the ground as the shield ground.
>My plane will be a two seater, so I will have one cable with three wires
>and the shield wire. One for mic high and one with ptt. Then ground with
>the shield wire?
>When I look at the wire schematic for the PM 1000 intercom, it indicates
>that I should "connect the shields at intercom only".
>My question is: Should I use the shield wire as the ground on both ends in
>the mic and headphone connections?
First, when instructions and schematics for any product are
specific as to how shields should be handled, follow the
instructions. A shield need be connected one-end only
in order to be an effective shield. A shield may also
DOUBLE as one of the signal conductors in the system
and may be connected at both ends. When this is
technique is used by the manufacturer for the accessory
you're installing, their installation instructions
will be specific as to how shields are treated.
In the case of the PM1000, the wiring diagram they
posted at:
http://www.ps-engineering.com/docs/PM1000IISpecial.pdf
is quite specific for not using shields as signal return
path for components remote to the intercom. I can tell you
that a shielded, twisted pair will nicely substitute for
the shielded trio and you can then use the shield as
ground return for the microphone jacks. An example of this
wiring is illustrated in the schematic for the radio harness
I used to build for the Microair 760 which you can see
on page 2.1 of the schematics in:
http://www.aeroelectric.com/Catalog/avionics/760imB.pdf
Either way will work. The prohibition is for connecting
signal returns to ground system at both ends . . . whether
the signal return is a separate wire under the shield -OR-
the shield itself. Use insulating bushings at the mic and
headset jacks if they're installed on metalic brackets
that are bolted to the airframe.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Ground and braded wire. |
>
>No. It's my understanding that the shield will cease
>to be a shield if it's connected at both ends.
>Only effective when terminated at the end indicated.
Not true. Greg tried to perpetuate this myth in
is one-size-fits-all guide for wiring airplanes.
When I asked him to discuss the simple-ideas
behind the uses of shield conductors, he ignored
the questions.
A shield will work perfectly well to protect interior
wires from the ravages of fast risetime noises in
other conductors while simultaneously serving
as one of the signal lines.
Bob . . .
________________________________________________________________________________
| From: | "Johann G." <johann(at)gi.is> |
| Subject: | Re: Ground and braded wire. |
Hello Bob L and Bob McC.
Thank you very much for your advise on the braded wire connection. Not
confused any more.
Best wishes,
Johann G.
Zenith 701
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> antenna |
| Subject: | Re: VHF antenna placement wrt transponder |
antenna
antenna
>
>
>Hi,
>
>I've read in the archives that one should place two
>VHF antennas as far apart as possible, and Brian
>recommends one on the top, and one on the bottom.
>
>I also read that Garmin recommends 30 inches distance
>between a VHF Comm antenna and one of their GPS antennas.
The top/bottom scenario is ideal but many systems
have functioned satisfactorily side by side and
with less than 30 inches of separation. See older
Cessnas with dual comm antennas on top of wing.
Do the best you can but don't loose any sleep over
it. Whatever you do has a high probability of
satisfactory operation.
>My question is should a VHF Comm antenna be placed a
>certain distance from a transponder antenna?
No, they are so far apart in frequency and function
as to be of very little hazard to each other.
Bob . . .
________________________________________________________________________________
| From: | "Bob Kuc" <bkuc1(at)tampabay.rr.com> |
| Subject: | Re: Ground and braded wire. |
I remember seeing that when wiring the rear seat jacks that separate wires
should be used or all the wires going to all the jacks should be the same
length. I believe that the reasoning for this was that the audio from the
jacks that are closely connected would be louder than the farthest one.
From the schematic, this does not seem to be the case. In fact, I found it
hard to believe that with the distances that we are using it would be the
case. The only reason I could think of would be a single point of failure
then more than one jack could be affected. Now this was before I started on
this list way back a long time ago. So then my question would be, other than
single point of failure, there should not be any reason to extent the
wirings from one jack to another to another to another?
Bob K
> ground return for the microphone jacks. An example of this
> wiring is illustrated in the schematic for the radio harness
> I used to build for the Microair 760 which you can see
> on page 2.1 of the schematics in:
>
> http://www.aeroelectric.com/Catalog/avionics/760imB.pdf
>
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | VHF antenna placement wrt transponder antenna |
>>I've read in the archives that one should place two
>>VHF antennas as far apart as possible, and Brian
>>recommends one on the top, and one on the bottom.
>>
>>I also read that Garmin recommends 30 inches distance
>>between a VHF Comm antenna and one of their GPS antennas.
>
> The top/bottom scenario is ideal but many systems
> have functioned satisfactorily side by side and
> with less than 30 inches of separation. See older
> Cessnas with dual comm antennas on top of wing.
>
> Do the best you can but don't loose any sleep over
> it. Whatever you do has a high probability of
> satisfactory operation.
Got it. The radios I will use (Icom IC-A200) have a
"transmit/receive" interlock that is wired between
the two radios, so hopefully this will also help
mitigate any trouble.
>>My question is should a VHF Comm antenna be placed a
>>certain distance from a transponder antenna?
>
> No, they are so far apart in frequency and function
> as to be of very little hazard to each other.
That was my thinking after looking at the
differences in lengths of the antennas, and I am
happy to hear this is true based on your experience.
Thanks a lot for the info.
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | Drdavevk30(at)aol.com |
| Subject: | Power Contactors |
Dear Bob:
I want to use EV200 contactors made by Kilovac/Tyco for my project ( Cirrus
VK-30). They are sealed and very similar to CAP200 contactors made for
certified aircraft. My problem is that the contactors come with a built in coil
economizer circuit. The coil leads are polarized red/black (pos/neg). I don't know
how to take this into account when using as a substitute for contactors in your
Z-14 system. Specifically, 1) do I need to use separate diodes and, if so,
what polarity. Second, can you help me to decide which lead on the EV200 (red or
black) corresponds to which leads in Z-14.
I have attached the schematic for the coil economizer circuit, the EV200
datasheet, as well as the wave forms of the economizer.
Thanks,
drdavevk30(at)cs.com
________________________________________________________________________________
| From: | "John B. Szantho" <szantho(at)usa.com> |
| Subject: | Strobe Power supply |
I have the Whelen Remote Strobe Light Power Supply mounted under the baggage
floor
on my RV-9A. Is it better to run the shielded cable from the power supply to
the lights in
the wings without using any connectors or can I cut this cable for the
connectors between the
wings and the fuselage and splice the braided shield together at this point?
I am worried
about noise on the system. The connectors would make installation a bit
easier since I
could run the wires in the conduits in both the wings and the fuselage and
close up everything.
John
RV-9A
________________________________________________________________________________
| From: | f1rocket(at)comcast.net |
| Subject: | Re: Strobe Power supply |
John,
I have a connector installed at the wing root, as you describe. I wired the shield
wire to pins on both sides of the Molex fitting in order to have shield wire
continuity all the way from the strobe fixture in the wing to the power supply
in my baggage compartment.
You'll likely see comments about the need to break your wires at the root because
the wings never come off, etc. I chose to do it for convenience sake during
the build process. I like to wire things up as complete as I can while the
project is still at home in the garage. Then, when I get to the cold airport
hangar, all I need to do is insert the wings, snap together the Molex fittings,
and I'm done. If done properly with the proper tools, I don't see this fitting
as adding any significant complexity or risk to my electrical system.
Randy
F1 Rocket
www.pflanzer-aviation.com
-------------- Original message --------------
>
> I have the Whelen Remote Strobe Light Power Supply mounted under the baggage
> floor
>
> on my RV-9A. Is it better to run the shielded cable from the power supply to
> the lights in
>
> the wings without using any connectors or can I cut this cable for the
> connectors between the
>
> wings and the fuselage and splice the braided shield together at this point?
> I am worried
>
> about noise on the system. The connectors would make installation a bit
> easier since I
>
> could run the wires in the conduits in both the wings and the fuselage and
> close up everything.
>
>
> John
>
> RV-9A
>
>
>
>
>
>
John,
I have a connector installed at the wing root, as you describe. I wired the shield
wire topins on both sides of the Molex fittingin order to have shield wire
continuity all the way from the strobe fixture in the wing to the power supply
in my baggage compartment.
You'll likely see comments about the need to break your wires at the root because
the wings never come off, etc. I chose to do it for convenience sake during
the build process. I like to wire things up as complete as I can while the project
is still at home in the garage. Then, when I get to the cold airport hangar,
all I need to do is insert the wings, snap together the Molex fittings, and
I'm done. If done properly with the proper tools, I don't see this fitting
as adding any significant complexity or risk to my electrical system.
Randy
F1 Rocket
www.pflanzer-aviation.com
-------------- Original message --------------
-- AeroElectric-List message posted by: "John B. Szantho"
I have the Whelen Remote Strobe Light Power Supply mounted under the baggage
floor
on my RV-9A. Is it better to run the shielded cable from the power supply to
the lights in
the wings without using any connectors or can I cut this cable for the
connectors between the
wings and the fuselage and splice the braided shield together at this point?
I am worried
about noise on the system. The connectors would make installation a bit
easier since I
could run the wires in the conduits in both the wings and the fuselage and
close up everything.
John
RV-9A
.com/archives
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Strobe Power supply |
>
>I have the Whelen Remote Strobe Light Power Supply mounted under the baggage
>floor
>
>on my RV-9A. Is it better to run the shielded cable from the power supply to
>the lights in
>
>the wings without using any connectors or can I cut this cable for the
>connectors between the
>
>wings and the fuselage and splice the braided shield together at this point?
>I am worried
>
>about noise on the system. The connectors would make installation a bit
>easier since I
>
>could run the wires in the conduits in both the wings and the fuselage and
>close up everything.
You can install wing-root connectors without adversely affecting
performance. I discourage this practice as it adds to numbers of
joints in wires that you will probably wish would stay mated and
functional for the lifetime of the airplane. Having said that,
know that Cessna used AMP mate-n-lock connectors in all the SE
fleet beginning in late 60s and to my knowledge, these have NOT
be a problem.
In the spirit of minimizing parts count I'll suggest that you
leave the wires from tips to root full length to route to the
supply. Coil excess wire up at the root until your very close
to first flight and the wings are likely to stay on for the
duration. Run the wires into the power supply and leave about 6"
of slack before you install connectors to mate with power supply.
If you need to pull the wings later, cut the connector off
(or extract the pins) and pull the cable out. Even if you
cut it off, you'll have plenty of slack for future re-installation
of new connectors which are cheap and easy to install.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Power Contactors |
>
>Dear Bob:
>
>I want to use EV200 contactors made by Kilovac/Tyco for my project ( Cirrus
>VK-30). They are sealed and very similar to CAP200 contactors made for
>certified aircraft. My problem is that the contactors come with a built in
>coil
>economizer circuit. The coil leads are polarized red/black (pos/neg). I
>don't know
>how to take this into account when using as a substitute for contactors in
>your
>Z-14 system. Specifically, 1) do I need to use separate diodes and, if so,
>what polarity. Second, can you help me to decide which lead on the EV200
>(red or
>black) corresponds to which leads in Z-14.
Attachements don't propagate through the list server but I was able to
find the data sheet for Tyco-Kilovac EV200 contactors which I've posted
at:
http://www.aeroelectric.com/Mfgr_Data/Tyco_Kilovac/ev200.pdf
I've modified a copy of Figure Z-14 to show how these contactors
would be used. You can eliminate the spike catcher diodes from all
three locations (this is built in on the EV200) but you still
need the two steering diodes on the crossfeed contactor.
Download both of these pages:
http://www.aeroelectric.com/PPS/DCPwr/z14h_EV200_1.pdf
http://www.aeroelectric.com/PPS/DCPwr/z14h_EV200_2.pdf
. . . and cut the lap-edge of
one page with a scissors so that you can overlap the two
pages and have cut ends of features on one page match up
with same features on other page. Use transparent tape to join
the pages into a one-page drawing.
Bob . . .
November 30, 2004 - December 15, 2004
AeroElectric-Archive.digest.vol-dt