AeroElectric-Archive.digest.vol-bt
March 09, 2003 - March 17, 2003
>Maybe not related, when I checked the 760 wiring after noticing the noise,
>I realized I had forgotten to hook up the ground wires. Except for the
>noise it had worked just fine. Hooking the ground wires up didn't change
>anything. Must be that the chassis is grounded where it fastens to the
>panel, or is that a problem too? Thanks for your help.
Whoops! If it worked AT ALL with the power ground wire
disconnected, then it's probable that the radio was
finding an operating ground from some path that it
shouldn't have . . . are your microphone and headset
jacks insulated from ground?
>P.S. I downloaded AEC7_1.zip in about ten minutes on a cable modem. No
>problems.
See paragraph 2.4 in http://216.55.140.222/Catalog/avionics/760imB.pdf
Check for proper mic/headset jack wiring before
trying the battery test or adding a filter.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Microair Transponder harness and |
encoder package???
>
>Bob,
>I know that you guys pulled the Microair xpndr from your site for the time
>being due to delivery pipeline problems, but are you still offering the
>previously mentioned harness and encoder "package" for the T2000 SFL ?
>
>I've managed to finally take delivery of one, and would like to take
>advantage of the "up front work" you guys have done on the harness.
>
>Let me know.
I'm not going to add the radios back onto the website
until we have a bunch of harness kits finished. I'm
hiring some help for this but it's going to be awhile.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Battery bus location |
>Bob,
>I'm wiring my airplane as discussed in all electric on a budget. This is a
>Harmon Rocket where the battery is in the back (baggage compartment). On
>your diagram you have a battery bus for hot equipment connected to the
>battery contactor by a 14 AWG wire noted not to exceed 6 inches. This
>would mean that I will need multiple wires going from the bus (presumably
>located close to the battery) all the way to the front of the airplane to
>supply my clock, essential bus, electronic ignition (single mag
>airplane)etc. Is there an alternative such that I can have a single wire
>going to the front to a battery bus adjacent to the main and essential buses?
Some people have located their battery bus remote
from the battery but it's not recommended.
If you do remote mount it, then include an in-line
fuse at the battery for the bus feed. Problem
is that you now have an always hot wire of considerable
length protected at greater than 5A. The FAA wouldn't
allow it for crash safety reasons. If it were my
airplane, the battery bus goes right next to the battery.
Bob . . .
________________________________________________________________________________
| From: | Mark Phillips <ripsteel(at)edge.net> |
| Subject: | Re: Battery bus location |
> Problem is that you now have an always hot wire of considerable
> length protected at greater than 5A. The FAA wouldn't
> allow it for crash safety reasons. If it were my
> airplane, the battery bus goes right next to the battery.
Is this because a shorted wire would cause a considerable arc when protected above
5A?
(potential fire hazard?) My e-bus alt feed switch is located near my master,
(left side of
panel) resulting in a 5' long wire protected at 15A by an in-line fuse at the battery.
(batt
is FWF, right side, e-bus fuseblock is under right side of panel- forgetting to
kill the
e-bus makes this "hot" wire 3' longer). IIRC, you have mentioned in the past to
locate this
switch near the batt, I assume for this reason? Any other way to reduce this risk?
I'd
really rather not re-locate the switch...
Thanks as always
Mark
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
| Subject: | FAST-ON RELIABILITY |
In wiring the Booster Fuel Pump switch - is it ok to use a switch with fast-on
tabs - i'm not yet sure what to think of these - they are easy to install - but
i'm worried about an airplane full of loose fast-on connections? has anyone
ever had a problem with loose fast-on tabs or is it not something I need to worry
about as long as I install them correctly.
would it be better with the fuel booster pump to use a switch with screw terminals?
thanks
---------------------------------
________________________________________________________________________________
| From: | RSwanson <rswan19(at)comcast.net> |
| Subject: | Re: FAST-ON RELIABILITY |
Just give it a try. Install one then "try" to remove it. I too, was
skeptical until I found out how difficult they are to remove.
R
----- Original Message -----
From: "Julia" <wings97302(at)yahoo.com>
Subject: AeroElectric-List: FAST-ON RELIABILITY
>
>
> In wiring the Booster Fuel Pump switch - is it ok to use a switch with
fast-on tabs - i'm not yet sure what to think of these - they are easy to
install - but i'm worried about an airplane full of loose fast-on
connections? has anyone ever had a problem with loose fast-on tabs or is
it not something I need to worry about as long as I install them correctly.
>
> would it be better with the fuel booster pump to use a switch with screw
terminals?
>
> thanks
>
>
> ---------------------------------
>
>
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
| Subject: | Firewall Penetration |
I just dug out a SS bath tub towel holder which I did not yet install in the home
I've been building and it's perfect for a firewall penetration gadget. Someone
else mentioned this earlier and now that i've got one in my hands it looks
perfect.
it's stainless - it's got the 90 degree bend and the flange is welded on - just
cut the tube to length and you get two of these - one off each end.
The one I have I got at home depot - made by Franklin Brass (a Masco Company) -
item #6424 - it's 1 1/4 inch diameter tubing - 24 inch grab bar (usp code #79171
64245 6) - so I think just one would handle ALL my wires.
now that i've got this in my hands and am looking at my RV - it sure looks like
the easy way to do this.
my 2 cents for the day.
---------------------------------
________________________________________________________________________________
| From: | "Dan Checkoway" <dan(at)rvproject.com> |
http://store.yahoo.com/azmotorsports/battenjr12vb.html
Seems like a good product. I just ordered one for my Odyssey PC680
battery...we'll see how it works.
)_( Dan
RV-7 N714D (canopy)
http://www.rvproject.com
________________________________________________________________________________
| From: | "Neville Kilford" <nkilford(at)etravel.org> |
| Subject: | Re: FAST-ON RELIABILITY |
I'd go along with that. They're definitely not easy to get off. Put them on
with caution!
Nev
----- Original Message -----
From: "RSwanson" <rswan19(at)comcast.net>
Subject: Re: AeroElectric-List: FAST-ON RELIABILITY
> Just give it a try. Install one then "try" to remove it. I too, was
> skeptical until I found out how difficult they are to remove.
> R
> ----- Original Message -----
> From: "Julia" <wings97302(at)yahoo.com>
> To:
> Subject: AeroElectric-List: FAST-ON RELIABILITY
>
> > In wiring the Booster Fuel Pump switch - is it ok to use a switch with
> fast-on tabs - i'm not yet sure what to think of these - they are easy to
> install - but i'm worried about an airplane full of loose fast-on
> connections? has anyone ever had a problem with loose fast-on tabs or is
> it not something I need to worry about as long as I install them correctly.
> >
> > would it be better with the fuel booster pump to use a switch with screw
> terminals?
> >
________________________________________________________________________________
| From: | "MARK H DELANO" <delano60(at)email.msn.com> |
Last week I asked a Question about a Turn & Bank that sounded like a vacuum cleaner
when the com was turned on. The offending imported non TSOd instrument is
a Falcon Gage P/N TC02E-3-1. You Provided a link to the Radio Shack 270-030
filter which I installed as the wire diagram instructed with little reduction
in the RF output. The filter assembly came with a 220 uF cap and your drawing
calls for a 10uF. will this matter? Any other suggestion to kill the RF interference
before I return the gage to Spruce.
Thanks
Mark Delano
RV6A ready go to the A/P
________________________________________________________________________________
| From: | Duncan McBride <duncanmcbride(at)comcast.net> |
| Subject: | Re: Noise in 760 installation |
The microphone and headset jacks are mounted in a plastic Radio Shack box
that is bolted to the panel - that shouldn't be a problem but I'll double
check. Sounds like I have something wired wrong, if the 760 is not grounded
where it mounts to the panel,
I wired the stick mounted switch leads to the center poles of a double pole
single throw switch on the panel. On one side I wired the PTT lead of the
MicroAir and the Mic Lo. On the other side I wired the Intercom lead and
panel ground. Depending on the panel switch position, the stick switch will
activate either the PTT or the intercom. Seemed like an ok idea - I'll
double check that wiring too. The problem might be where the microphone
jack leads are connected to all of this. I'll let you know what I find.
Thanks again,
Duncan McBride
319DM
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: AeroElectric-List: Re: Noise in 760 installation
>
> >
> >
> >
> >----- Original Message -----
> >From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
> >To:
> >Subject: AeroElectric-List: Re: 10378 Fluent
> >
> > > If you experience any kind of noise problems (don't
> > > know what, if any, noise filtering may be part of
> > > Icom's adapter), you may need to do something
> > > like:
> > >
> > > http://www.aeroelectric.com/articles/filter/filter.html
> > >
> > > to clean up ship's power to the Icom's liking.
> > >
> > > Bob . . .
> > >
> >
> >I have the MicroAir 760 in my Rotax 912 powered Kolb Twinstar. It's
wired
> >as in your diagram, with the shields from the headphone and mic going to
the
> >mic lo pin on the MicroAir. The only wires going to the panel ground are
> >from the two ground pins and the intercom ground, through a switch. I'm
> >getting a very loud alternator or ignition whine when I use the PTT or
> >intercom switch. The noise frequency and volume is directly proportional
to
> >rpm. Same noise with transmit or intercom, so would it be the antenna?
I
> >have a computer grade electrolytic capacitor in the charging circuit 14V,
> >22k mf (wiring is appendix Z-7 all the way) Would trying the RadioShack
> >filter above be the next thing to try?
>
> Try running the radio from a 12 battery independent of
> the ship's electrical system. A couple of 6v lantern
> batteries from WalMart will work fine. If the radio
> is quiet with independent battery, then a filter
> like the one cited will probably fix it.
>
>
> >Maybe not related, when I checked the 760 wiring after noticing the
noise,
> >I realized I had forgotten to hook up the ground wires. Except for the
> >noise it had worked just fine. Hooking the ground wires up didn't change
> >anything. Must be that the chassis is grounded where it fastens to the
> >panel, or is that a problem too? Thanks for your help.
>
>
> Whoops! If it worked AT ALL with the power ground wire
> disconnected, then it's probable that the radio was
> finding an operating ground from some path that it
> shouldn't have . . . are your microphone and headset
> jacks insulated from ground?
>
> >P.S. I downloaded AEC7_1.zip in about ten minutes on a cable modem. No
> >problems.
>
> See paragraph 2.4 in http://216.55.140.222/Catalog/avionics/760imB.pdf
>
> Check for proper mic/headset jack wiring before
> trying the battery test or adding a filter.
>
> Bob . . .
>
>
________________________________________________________________________________
| Subject: | Clock consumption |
Bob and all,
Is it wise to run a panel electric clok from the auxilliary battery bus ?
According to A&S catalog, the current draw is in the order of 2.3 mA. Won't
the clock run the battery down wihin a month or two if the airplane is left
sitting in the hangar ?
Thanks,
Gilles
________________________________________________________________________________
| From: | Kevin Horton <khorto1537(at)rogers.com> |
| Subject: | Re: FAST-ON RELIABILITY |
>
>
>In wiring the Booster Fuel Pump switch - is it ok to use a switch
>with fast-on tabs - i'm not yet sure what to think of these - they
>are easy to install - but i'm worried about an airplane full of
>loose fast-on connections? has anyone ever had a problem with loose
>fast-on tabs or is it not something I need to worry about as long as
>I install them correctly.
>
>would it be better with the fuel booster pump to use a switch with
>screw terminals?
>
>thanks
>
I'd be more worried about a screw coming loose than a fast tab
falling off. Good quality fast-on tabs are reputed to be very
reliable. Cheap ones may be less reliable. Even the good ones are
pretty cheap ($9.50 for a package of 50 AMP Fast-Ons from B&C:), so I
don't see any good reason to experiment with cheap ones:
http://www.aeroelectric.com/Catalog/wiring/wiring.html#faston
--
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://go.phpwebhosting.com/~khorton/rv8/
________________________________________________________________________________
| From: | RSwanson <rswan19(at)comcast.net> |
| Subject: | Re: Noise in 760 installation |
I also have a 760, but I chose to use a Flightcom 430MC intercom to avoid
the problem of two switches, since I didn't like the hot mike on the 760.
No problem with noise, even with the engine running. The radio does have a
ground wire in the harness and does not use the case as a ground, at least
on purpose.
Is a little confusing to wire, though.
R
----- Original Message -----
From: "Duncan McBride" <duncanmcbride(at)comcast.net>
Subject: Re: AeroElectric-List: Re: Noise in 760 installation
>
> The microphone and headset jacks are mounted in a plastic Radio Shack box
> that is bolted to the panel - that shouldn't be a problem but I'll
double
> check. Sounds like I have something wired wrong, if the 760 is not
grounded
> where it mounts to the panel,
>
> I wired the stick mounted switch leads to the center poles of a double
pole
> single throw switch on the panel. On one side I wired the PTT lead of
the
> MicroAir and the Mic Lo. On the other side I wired the Intercom lead and
> panel ground. Depending on the panel switch position, the stick switch
will
> activate either the PTT or the intercom. Seemed like an ok idea - I'll
> double check that wiring too. The problem might be where the microphone
> jack leads are connected to all of this. I'll let you know what I find.
>
> Thanks again,
> Duncan McBride
> 319DM
>
>
> ----- Original Message -----
> From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
> To:
> Subject: AeroElectric-List: Re: Noise in 760 installation
>
>
>
> >
> > >
> > >
> > >
> > >----- Original Message -----
> > >From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
> > >To:
> > >Subject: AeroElectric-List: Re: 10378 Fluent
> > >
> > > > If you experience any kind of noise problems (don't
> > > > know what, if any, noise filtering may be part of
> > > > Icom's adapter), you may need to do something
> > > > like:
> > > >
> > > > http://www.aeroelectric.com/articles/filter/filter.html
> > > >
> > > > to clean up ship's power to the Icom's liking.
> > > >
> > > > Bob . . .
> > > >
> > >
> > >I have the MicroAir 760 in my Rotax 912 powered Kolb Twinstar. It's
> wired
> > >as in your diagram, with the shields from the headphone and mic going
to
> the
> > >mic lo pin on the MicroAir. The only wires going to the panel ground
are
> > >from the two ground pins and the intercom ground, through a switch.
I'm
> > >getting a very loud alternator or ignition whine when I use the PTT or
> > >intercom switch. The noise frequency and volume is directly
proportional
> to
> > >rpm. Same noise with transmit or intercom, so would it be the
antenna?
> I
> > >have a computer grade electrolytic capacitor in the charging circuit
14V,
> > >22k mf (wiring is appendix Z-7 all the way) Would trying the
RadioShack
> > >filter above be the next thing to try?
> >
> > Try running the radio from a 12 battery independent of
> > the ship's electrical system. A couple of 6v lantern
> > batteries from WalMart will work fine. If the radio
> > is quiet with independent battery, then a filter
> > like the one cited will probably fix it.
> >
> >
> > >Maybe not related, when I checked the 760 wiring after noticing the
> noise,
> > >I realized I had forgotten to hook up the ground wires. Except for
the
> > >noise it had worked just fine. Hooking the ground wires up didn't
change
> > >anything. Must be that the chassis is grounded where it fastens to
the
> > >panel, or is that a problem too? Thanks for your help.
> >
> >
> > Whoops! If it worked AT ALL with the power ground wire
> > disconnected, then it's probable that the radio was
> > finding an operating ground from some path that it
> > shouldn't have . . . are your microphone and headset
> > jacks insulated from ground?
> >
> > >P.S. I downloaded AEC7_1.zip in about ten minutes on a cable modem.
No
> > >problems.
> >
> > See paragraph 2.4 in
http://216.55.140.222/Catalog/avionics/760imB.pdf
> >
> > Check for proper mic/headset jack wiring before
> > trying the battery test or adding a filter.
> >
> > Bob . . .
> >
> >
>
>
________________________________________________________________________________
| Subject: | strobe wire extension |
I've installed aeroflash nav/pos/strobe units on the wingtips of my RV-6A.
I've installed the strobe power supplies on the forward wing spar just
inboard of the wingtips. The three leads from the strobes came with
open-barrel type pins already crimped on and ready to insert into the
plastic holder.
My problem is that the wires aren't long enough to reach the power supplies,
specifically the wires that run along the leading edge of the Archer VOR
antenna (I haven't tried the other wing yet, but I don't think they're long
enough either).
So, is it ok to just splice in a short length of wire using two butt
splices? If I had the appropriate crimper I could get by with just one butt
splice and crimp on new pins, but I hate to have to buy yet another crimper
for just six wires. Would using two butt splices in a wire run (short) be
bad?
TIA
Robert Dickson
RV-6A electrical
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: FAST-ON RELIABILITY |
>
>
>In wiring the Booster Fuel Pump switch - is it ok to use a switch with
>fast-on tabs - i'm not yet sure what to think of these - they are easy to
>install - but i'm worried about an airplane full of loose fast-on
>connections? has anyone ever had a problem with loose fast-on tabs or is
>it not something I need to worry about as long as I install them correctly.
>
>would it be better with the fuel booster pump to use a switch with screw
>terminals?
>
>thanks
Fast-ons have been used on the Cessna single engine airplanes
since the mid 60's with great success. The significance of
their capability didn't register with me until the mid 80's
when a Bussmann rep dropped a fuseblock on the counter at
B&C's booth at OSH . . . My first impression was negative
but after researching it a bit and recalling that they
had been used on certified singles for two decades, I wrote
the following:
http://www.aeroelectric.com/articles/faston3.pdf
If you get terminals made from the right copper
alloy (and all PIDG terminals ARE) then you can
expect excellent service from these devices.
Bob . . .
________________________________________________________________________________
| From: | Sam Buchanan <sbuc(at)hiwaay.net> |
| Subject: | Re: strobe wire extension |
Robert Dickson wrote:
>
>
> I've installed aeroflash nav/pos/strobe units on the wingtips of my RV-6A.
> I've installed the strobe power supplies on the forward wing spar just
> inboard of the wingtips. The three leads from the strobes came with
> open-barrel type pins already crimped on and ready to insert into the
> plastic holder.
>
> My problem is that the wires aren't long enough to reach the power supplies,
> specifically the wires that run along the leading edge of the Archer VOR
> antenna (I haven't tried the other wing yet, but I don't think they're long
> enough either).
>
> So, is it ok to just splice in a short length of wire using two butt
> splices? If I had the appropriate crimper I could get by with just one butt
> splice and crimp on new pins, but I hate to have to buy yet another crimper
> for just six wires. Would using two butt splices in a wire run (short) be
> bad?
>
> TIA
>
> Robert Dickson
> RV-6A electrical
You described the exact situation I had in the wing tips of my RV-6 when
I retrofitted a Sportcraft internal VOR antenna. I used crimped butt
splices in order to get the strobe and nav light leads to follow the
leading edge of the antenna...........and everything works perfectly.
Sam Buchanan
http://home.hiwaay.net/~sbuc/journal/sportcraft.htm
________________________________________________________________________________
| From: | "John Slade" <sladerj(at)bellsouth.net> |
| Subject: | Transponder antenna position |
I'm about to install my transponder antenna in my (plastic) Cozy IV. Ideal
location choices are a bit limited since the prewired tray comes with a very
short wire. I'd rather not poke the antenna through the floor. I presume
this isnt necessary with a fiberglass airplane.
My main question is this - how important is it that the antenna has an
unblocked "view" below the airplane? For example, one handy spot would put
the nose wheel aft of the antenna when the gear is retracted. Another has a
couple of pipes fairly close by. I'm guessing that installing it close to a
wire bundle or ground bus would be a bad idea.
Comments please.
John Slade
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Battery bus location |
>
> > Problem is that you now have an always hot wire of considerable
> > length protected at greater than 5A. The FAA wouldn't
> > allow it for crash safety reasons. If it were my
> > airplane, the battery bus goes right next to the battery.
>
>Is this because a shorted wire would cause a considerable arc when
>protected above 5A?
>(potential fire hazard?) My e-bus alt feed switch is located near my
>master, (left side of
>panel) resulting in a 5' long wire protected at 15A by an in-line fuse at
>the battery. (batt
>is FWF, right side, e-bus fuseblock is under right side of panel-
>forgetting to kill the
>e-bus makes this "hot" wire 3' longer). IIRC, you have mentioned in the
>past to locate this
>switch near the batt, I assume for this reason? Any other way to reduce
>this risk? I'd
>really rather not re-locate the switch...
The original concept for an e-bus was to get these loads
down into the 2-3 amp range so that you could get airport
in sight, battery only and then turn the main bus back on.
A 5A feeder to the e-bus was adequate for most systems.
With the advent of All-Electric-on-a-Budget, adding
gyros to the e-bus has pushed the alternate feedpath
to less comfortable levels for crash safety. I've got
a client who wants to incorporate the e-bus into a
certifiable design and his DER is most comfortable
with a remote relay as shown in:
http://216.55.140.222/Page_Per_System/Power_Distribution/Heavy_E-Bus.pdf
This operates as a sort of mini-battery relay for e-bus
loads only. The relay draws only 100mA (about 1/7th
that of a contactor) and still gives the pilot a
way to shut off all long hot leads preceding a
potentially airplane-bending arrival.
This diagram will become Figure Z-32 in the next
revision to the 'Connection.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Clock consumption |
><Gilles.Thesee@ac-grenoble.fr>
>
>Bob and all,
>
>Is it wise to run a panel electric clok from the auxilliary battery bus ?
>According to A&S catalog, the current draw is in the order of 2.3 mA. Won't
>the clock run the battery down wihin a month or two if the airplane is left
>sitting in the hangar ?
Yup . . . 2.3 mA 24/7 works out to 20 a.h. per year but only
1.6 a.h. month. Surely you're going to fly more often than
once a month! Dee's Saturn didn't get driven for about 8 weeks
and I found it had a dead battery . . . a nearly new battery
at that. I suspect it's got some keep-alive requirements
too. Soon as the weather warms up a bit more, I'm going to
go measure it.
If you're going to store an airplane for that long, you might
want to run the clock from the e-bus and just re-set it
every time you go fly.
Hmmm . . . that seems like a lot of power for a clock,
my wristwatch runs for over a year on a 25 maH battery.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
>
>Last week I asked a Question about a Turn & Bank that sounded like a
>vacuum cleaner when the com was turned on. The offending imported non
>TSOd instrument is a Falcon Gage P/N TC02E-3-1. You Provided a link to the
>Radio Shack 270-030 filter which I installed as the wire diagram
>instructed with little reduction in the RF output. The filter assembly
>came with a 220 uF cap and your drawing calls for a 10uF. will this
>matter? Any other suggestion to kill the RF interference before I return
>the gage to Spruce.
Try the heavier cap. . . also try wrapping
a sleeve of thin sheet steel (flashing metal
from lumber yard works good) around the
body of the instrument. The metal is pretty
thin so I usually use three layers. This can
be held in place with long tye wraps or with
a couple of string ties. This will attenuate
strong magnetic radiation common to many of these
instruments. You may also see some benefit for
making an electrical connection between the
metal shield and the ground power wire coming
into the back of the instrument.
Will be interested to see what, if any effects
these actions have.
Bob . . .
________________________________________________________________________________
| From: | "Jon Finley" <jon(at)finleyweb.net> |
| Subject: | Transponder antenna position |
Hi John,
I have a Q2 with the transponder antenna mounted inside the tailcone.
ATC has never complained so I assume it works fine. Mine is mounted to
an aluminum plate about 8-10" square.
Jon Finley
N90MG Q2 - Subaru EJ-22 DD - 440 Hrs. TT - 0 Hrs Engine
Apple Valley, Minnesota
http://www.FinleyWeb.net/default.asp?id=96
> -----Original Message-----
> -->
>
> I'm about to install my transponder antenna in my (plastic)
> Cozy IV. Ideal location choices are a bit limited since the
> prewired tray comes with a very short wire. I'd rather not
> poke the antenna through the floor. I presume this isnt
> necessary with a fiberglass airplane.
>
> My main question is this - how important is it that the
> antenna has an unblocked "view" below the airplane? For
> example, one handy spot would put the nose wheel aft of the
> antenna when the gear is retracted. Another has a couple of
> pipes fairly close by. I'm guessing that installing it close
> to a wire bundle or ground bus would be a bad idea.
>
> Comments please.
> John Slade
________________________________________________________________________________
| From: | "John Slade" <sladerj(at)bellsouth.net> |
| Subject: | Transponder antenna position |
> Mine is mounted to an aluminum plate about 8-10" square.
I need an aluminum plate? The antenna didnt come with any instructions.
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
I have an Artex ELT-200 with a 18.75" whip antenna. My plan is to mount it
on a composite prepreg shelf inside the aft fueselage. My guess is I need a
ground plane. How large does it need to be?
I also have a CI-101 Transponder antenna that I'm mounting under the rear
seat. What size should the ground plane be?
Mike Easley
Lancair ES
________________________________________________________________________________
| From: | SportAV8R(at)aol.com |
| Subject: | Re: Transponder antenna position |
John, FWIW, I recently moved my belly-mounted transponder antenna to a small
aluminum ground plane in the aft section of the wheel pant on my RV-6A. It
is near to the metal axle and wheel/brake assembly, but this does not seem to
affect its operation in the least. I get interrogation lights where I expect
them while flying, and ATC has never fussed about my transponder's
accessibility to their radar. I am happy with a drag-free and visually clean
installation. I'd say you have far more option is a plastic airplane, and
most all of them will work just fine, provided that a small metal ground
plane is there for the antenna to work against.
Bill B.
> My main question is this - how important is it that the antenna has an
> unblocked "view" below the airplane? For example, one handy spot would put
> the nose wheel aft of the antenna when the gear is retracted. Another has a
> couple of pipes fairly close by. I'm guessing that installing it close to a
> wire bundle or ground bus would be a bad idea.
>
> Comments please.
> John Slade
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)tenforward.com> |
| Subject: | Re: Clock consumption |
If the auto has an internal regulated alt consider that many mfgr's designs
leak back thru the "B" lead to the tune of 70-80ma.
This will drain things fast.
Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: Clock consumption
>
> ><Gilles.Thesee@ac-grenoble.fr>
> >
> >Bob and all,
> >
> >Is it wise to run a panel electric clok from the auxilliary battery bus ?
> >According to A&S catalog, the current draw is in the order of 2.3 mA.
Won't
> >the clock run the battery down wihin a month or two if the airplane is
left
> >sitting in the hangar ?
>
> Yup . . . 2.3 mA 24/7 works out to 20 a.h. per year but only
> 1.6 a.h. month. Surely you're going to fly more often than
> once a month! Dee's Saturn didn't get driven for about 8 weeks
> and I found it had a dead battery . . . a nearly new battery
> at that. I suspect it's got some keep-alive requirements
> too. Soon as the weather warms up a bit more, I'm going to
> go measure it.
>
> If you're going to store an airplane for that long, you might
> want to run the clock from the e-bus and just re-set it
> every time you go fly.
>
> Hmmm . . . that seems like a lot of power for a clock,
> my wristwatch runs for over a year on a 25 maH battery.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | Philip Hildebrand <phildebrand(at)pritchardindustrial.com> |
Just did the same thing on my ES, and when I called Atrex they
said that the ground plane should be the diameter of the length of the
antenna. Since this was not suitable in my case, I opted for the
antenna designed for composite airplanes that do not require a ground
plane. (available from Artex).
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
MikeEasley(at)aol.com
Subject: AeroElectric-List: Ground Planes
I have an Artex ELT-200 with a 18.75" whip antenna. My plan is to mount
it
on a composite prepreg shelf inside the aft fueselage. My guess is I
need a
ground plane. How large does it need to be?
I also have a CI-101 Transponder antenna that I'm mounting under the
rear
seat. What size should the ground plane be?
Mike Easley
Lancair ES
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Transponder antenna position |
>
> > My transponder antenna is mounted to an aluminum plate about 8-10" square.
>
>I need an aluminum plate? The antenna didnt come with any instructions.
Check the chapter on antennas in the 'Connection
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Ground Planes |
>
>I have an Artex ELT-200 with a 18.75" whip antenna. My plan is to mount it
>on a composite prepreg shelf inside the aft fueselage. My guess is I need a
>ground plane. How large does it need to be?
>
>I also have a CI-101 Transponder antenna that I'm mounting under the rear
>seat. What size should the ground plane be?
See antenna chapter in the 'Connection
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: starter feed protection? |
>Good Morning Bob,
>We are planning to use your Dual Alternator, Dual Battery design in the
>fiberglass Velocity pusher we're building (Continental IO550N
>engine). Our batteries are up front in the nose gear well and the starter
>is in the rear on the engine. We would like to put the starter contactor
>in the engine compartment to avoid the weight (about 20 ft length) of the
>extra alternator wire required if we don't share the main alternator and
>starter on the same heavy gauge wire.
>
>Our concern is that if we put the starter contactor in the rear, there
>will be a long, un-protected, heavy gauge wire running all the way from
>the batteries to the starter contactor that if shorted, could cause a
>fire. If we put a large ANL fuse (400 amp?), big enough to survive the
>starter motor engage current, it will be so large that it won't protect us
>from say a 100 amp "short" to this wire somewhere along the way -- a short
>plenty large enough to cause serious problems or fire aloft, but not big
>enough to blow the 400 amp starter fuse. We're also not sure how large a
>starter motor fuse would be needed, and whether we can find one that
>wouldn't weigh more than the extra alternator wire!
>
>Do you see this as a problem that should be protected against? We could
>add the "starter fuse" and shrink wrap extra insulation around the "over"
>protected wire (and ground wire) in the fiberglass duct that runs from the
>batteries back to the engine for more protection, or even double wrap it
>in the trouble spots like where the wire comes out of the duct and onto
>the stainless firewall where the starter contactor would be mounted.
>
>Your thoughts and suggestions would be greatly appreciated. Your book has
>been extremely helpful. Thanks for all you've done for the experimental
>community.
What's it going to short against? Batteries have been
mounted in tails of airplanes for 60 years with no
special protection for large, always hot wires. These
wires are easy to install with a little attention
to eliminating risks to the wire. Obviously, you
don't run the wire next to moving mechanisms or
over sharp edges without rudimentary attention to
eliminating risks.
I will invite you to join us on the AeroElectric List
to continue this and similar discussions. It's useful to
share the information with as many folks as possible.
You can join at . . .
http://www.matronics.com/subscribe/
Thanks!
Bob . . .
|---------------------------------------------------|
| A lie can travel half way around the world while |
| the truth is till putting on its shoes . . . |
| -Mark Twain- |
|---------------------------------------------------|
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Transponder antenna position |
>
>I'm about to install my transponder antenna in my (plastic) Cozy IV. Ideal
>location choices are a bit limited since the prewired tray comes with a very
>short wire. I'd rather not poke the antenna through the floor. I presume
>this isnt necessary with a fiberglass airplane.
>
>My main question is this - how important is it that the antenna has an
>unblocked "view" below the airplane? For example, one handy spot would put
>the nose wheel aft of the antenna when the gear is retracted. Another has a
>couple of pipes fairly close by. I'm guessing that installing it close to a
>wire bundle or ground bus would be a bad idea.
Mount it a "clear" as you can and give it a try.
Any info from other builders, while useful, is anecdotal
as to degree of performance. It will depend a great
deal on the situations in which you operate your
airplane. This is an experimental airplane which
means you may have to experiment with what works
best for you.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Firewall Wire Penetration |
>
>
>I just dug out a SS bath tub towel holder which I did not yet install in
>the home I've been building and it's perfect for a firewall penetration
>gadget. Someone else mentioned this earlier and now that i've got one in
>my hands it looks perfect.
>it's stainless - it's got the 90 degree bend and the flange is welded on -
>just cut the tube to length and you get two of these - one off each end.
>The one I have I got at home depot - made by Franklin Brass (a Masco
>Company) - item #6424 - it's 1 1/4 inch diameter tubing - 24 inch grab bar
>(usp code #79171 64245 6) - so I think just one would handle ALL my wires.
>now that i've got this in my hands and am looking at my RV - it sure looks
>like the easy way to do this.
>my 2 cents for the day.
You beat me to it. I was planning to scrounge through
the various fixtures at local stores and see what was
offered. I'd like to identify some smaller ones . . . 1-1/4"
takes care of ALL the wires in a high performance
single engine airplane with MOST of the passageway left over.
However, a cheap one that's a bit too big is, in my never humble
opinion, a better deal than a more expensive one exactly the
right size.
I would encourage everyone to keep an eye open for
off-the-shelf opportunities to acquire suitable
fittings to this task. Watch for both straight
and right angle fittings and let everyone know
about it when you spot a likely candidate.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
>
> Just did the same thing on my ES, and when I called Atrex they
>said that the ground plane should be the diameter of the length of the
>antenna. Since this was not suitable in my case, I opted for the
>antenna designed for composite airplanes that do not require a ground
>plane. (available from Artex).
The "ground plane" does not need to be a flat disk.
It's easy to install on any composite airplane.
See antenna chapter in 'Connection
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Clock consumption |
>
>
>If the auto has an internal regulated alt consider that many mfgr's designs
>leak back thru the "B" lead to the tune of 70-80ma.
>
>This will drain things fast.
That's HUGE! Got any idea where the energy goes?
Bob . . .
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)tenforward.com> |
| Subject: | Re: Clock consumption |
Sure, Its a "sneak" circuit back into the internal regulator.
Remember the internal regulator on say a ND (and many others) are only
powered up externally on initial startup. There is an internal "B" lead
connection to the regulator power. This internal connection makes the
alternator a "one wire type" after startup. In fact you can pull the small
wire connections and it keeps on working until the engine is turned off.
This connection is "another" failure mode of internal regulators that cannot
be stopped by removing the connection to the ign switch. Sure the field
power transistor can short but its also likely that a failure can be
internal to the regulator that turns on that transistor.
This can lead to a rare alternator failure where an internal output circuit
short (diodes perhaps) can result in a self excited overload that ends up in
a fire. Why its so important to have control of the field supply and why I
would never have an internal regulated setup on my aircraft where the "B"
lead supplied the internal regulator.
Modern auto imports from Japan must be run for 1/2 hour or so at least once
a week to keep the battery charged. This is not common knowledge and is
frustrating to the auto stores which have a healthy business on replacement
batteries and also arguing with the unhappy customer who's battery keeps
failing to hold a charge.
Anyway, I have tried three different brands of Japan mfgr alternators and
the "off" drain was around 70ma.
This from dead battries on a truck (of mine) that is not run often and where
I had replaced the alternator with a surplus (to me) import unit.
Once the problem was detected, it was checked out and both auto stores and
dealers said sure "did you not know of the need to run the car weekly?" :-)
Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: Clock consumption
>
> >
> >
> >If the auto has an internal regulated alt consider that many mfgr's
designs
> >leak back thru the "B" lead to the tune of 70-80ma.
> >
> >This will drain things fast.
>
> That's HUGE! Got any idea where the energy goes?
>
> Bob . . .
>
>
________________________________________________________________________________
| Subject: | Antennas that really don't need a ground plane ? |
Hi Bob and all,
Is it true some comm or XPDR antennas can dispense with a ground plane ? I
seem to remember having read this claim (Artex, Archer, Advanced Aircraft
Electronics antennas from A&S).
How come ?
Or maybe they are not quarterwave antennas ?
Thanks
Gilles
________________________________________________________________________________
| From: | SportAV8R(at)aol.com |
| Subject: | Re: Antennas that really don't need a ground plane |
?
In a message dated 03/10/2003 12:53:02 PM Eastern Standard Time,
Gilles.Thesee@ac-grenoble.fr writes:
> Is it true some comm or XPDR antennas can dispense with a ground plane ? I
> seem to remember having read this claim (Artex, Archer, Advanced Aircraft
> Electronics antennas from A&S).
> How come ?
> Or maybe they are not quarterwave antennas ?
>
I think you answered your own question, Gilles. These ground-plane-less
types tend to be voltage-fed longer resonators, a J-pole, for instance, or
some gamma-matched iteration of same, like the Archer. Many are
self-resonant half wave radiators and hence work better without a nearby
ground of any sort.
Bill B
RV-6A
MFJ-259B on its way from eBay, so I can roll & tweak my own aeronautical
mobile antenna farm.
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
| Subject: | Alternator hookup |
My alternator doesn't seem to have any #'s or markings to indicate it origin -
I was once told it was off a Mazda RX-7 - with built in regulator. I know it
has a built in regulator.
I was told the large output terminal goes to the Bat. - I knew that one.
Then we have two small terminals - fast-on male tabs - one vertical and one horizontal
- like a "T" . I"m told the top of the "T" is the switched 12V - supply
which feeds the alternator field. Then the vertical stem of the "T" would
be for a light - you could run this to a light and then to ground - then if the
alternator failed, the light would light up.
I"m hoping this is a standard way in which alternators are configued on the hook
up - does this sound right to anyone.
Can I tell using an ohm meter - which terminal goes to the alternator field and
which would switch a light on and off? If I take the Top of the "T" and put
a positive ohm probe and then put the other ohm probe to ground, I would get
some resistance reading - but current should flow. Well then what if I reverse
the probes - are there perhaps diodes in there which would prevent the current
from flowing backwards?? if so would this help indicate which terminal was
for the alternator field?
The Mazda technicians don't seem to know much either - they were no help at all.
does it sound right that the only alternator ground would just be the contact it
makes when bolted to the engine? I see not terminal on my alternator for a
ground hook up?
thanks.
---------------------------------
________________________________________________________________________________
| Subject: | Re: FAST-ON RELIABILITY |
In a message dated 3/9/03 12:00:15 PM Pacific Standard Time,
wings97302(at)yahoo.com writes:
<< In wiring the Booster Fuel Pump switch - is it ok to use a switch with
fast-on tabs - i'm not yet sure what to think of these - they are easy to
install - but i'm worried about an airplane full of loose fast-on
connections? has anyone ever had a problem with loose fast-on tabs or is it
not something I need to worry about as long as I install them correctly.
would it be better with the fuel booster pump to use a switch with screw
terminals?
thanks >>
I'm no expert but FWIW if you have ever tried to remove a properly engaged
fast on terminal you might be less concerned, I sure no longer have any
concern about one accidentally coming loose.
Harry Crosby
Pleasanton, California
RV-6, firewall forward
________________________________________________________________________________
| From: | Randy Pflanzer <F1Rocket(at)comcast.net> |
| Subject: | Alt. Field Circuit Breaker |
Bob,
I'm using the dual alternator (Z-10) on my Rocket. In order to get
power to the two 5 amp circuit breakers in my panel for the alternator
field current, I need to run a wire from the power post on the bus to
the breakers. This will be a distance of only a foot or so. What size
wire would be sufficient? Can I run the wire without a fusible link?
Thank you as always.
Randy
F1 Rocket #95
http://mywebpages.comcast.net/f1rocket/
________________________________________________________________________________
| From: | Mark Steitle <msteitle(at)mail.utexas.edu> |
Another racing site that carries halon fire systems is Baker Precision in
Signal Hill, Ca. Their system uses what they claim to be "aircraft
approved" Halon 1301. Their systems come in 5 and 10 lb.
sizes. See: http://www.bakerprecision.com/firesys.htm
Mark S.
>
>thanks David, I looked around and found one from a race car supply house
>http://www.howeracing.com/cockpit/cockpit4/indexbottle.htm
>
>They have 2lb and 5lb models. Do you know what size would be needed?
>
>Ron
>
>----- Original Message -----
>From: "David Carter" <dcarter(at)datarecall.net>
>To:
>Subject: Re: AeroElectric-List: Re: Halon
>
>
>
> >
> > This web site has the most info: http://www.h3r.com/ Has lots of
> > informative articles explaining Halon and its use and legal status.
> >
> > David Carter
> >
> > ----- Original Message -----
> > From: "Ron Raby" <ronr(at)advanceddesign.com>
> > To:
> > Subject: Re: AeroElectric-List: Re: Halon
> >
> >
> >
> > >
> > >
> > > Where do you get these halon systems? Does the bottle get mounted remote
> > > from the firewall and then plumbed through a fitting in the firewall? Is
> > the
> > > acuation of these systems mechanical or electrical?
> > >
> > > Thanks
> > >
> > > Ron Raby
> > >
> > > N829R
> > > ----- Original Message -----
> > > From: "Jerzy Krasinski" <krasinski(at)direcway.com>
> > > To:
> > > Subject: Re: AeroElectric-List: Re: Halon
> > >
> > >
> > >
> > > >
> > > > Actually halons do much more than just "displacing oxygen and
>removing
> > > > enormous amounts of heat through evaporation". Halons absorb a lot of
> > > > radiation from the flame, mostly in the infrared, and they prevent
> > > > excitation of molecules ahead of the front of the flame. Excited
> > > > molecules of fuel and oxygen have electrons far away from the core of
> > > > the molecule, and such excited molecules are very eager to get
>involved
> > > > in a transfer of these electrons to other molecules, which is the
>base
> > > > of chemical reactions. Excitation of molecules ahead of the flame by
> > > > radiation heating is the basic mechanism for a flame propagation.
> > > > Chemically inert halons absorbing radiation prevent excitation of fuel
> > > > and oxygen molecules ahead of the front of the flame, and they make
> > > > propagation of the flame difficult or impossible. Even as little as a
> > > > few percent of halon stops propagation of the flame which makes it
>easy
> > > > to blow it off - halons are extremely efficient as fire
> > > > extinguishers. You would need much higher concentration for a
> > > > conventional displacement of oxygen like in a CO2 extinguisher. A
>few
> > > > percent concentration would not make any difference if the
>displacement
> > > > was the main mechanism. Classical cooling by small amounts of halon is
> > > > not that important in fighting fire because chemical reaction of
>burning
> > > > fuel generates huge amounts of heat, and cold gasoline vapor burns
>quite
> > > > well anyway. I worked on halons some thirty years ago.
> > > > Jerzy
> > > >
> > > > Alex Peterson wrote:
> > > >
> > >
> > > > >
> > > > >I talked to an engineer at the outfit that makes halotron, and asked
> > him
> > > > >what the scoop was between halon and halotron. He said that pound
>for
> > > > >pound, halotron is about 80% (going on memory here, but the number is
> > > > >close) as effective in fire fighting as halon. Shouldn't be any
> > > > >more/less safe than halon for us, but it makes the greenies happy.
>Of
> > > > >course, we need to burn more fuel to lift the extra pound of halotron
> > > > >around, so I guess there are no free lunches. The halon that is
>still
> > > > >available is from reclaimed sources, as it is no longer legal to
> > > > >manufacture halon. Either one puts out fires by displacing oxygen
>and
> > > > >removing enormous amounts of heat through evaporation.
> > > > >
> > > > >Alex Peterson
> > > > >Maple Grove, MN
> > > > >RV6-A N66AP 265 hours, dragging an extra pound of extinguisher with
> > the
> > > > >whole way
> > > > >www.usfamily.net/web/alexpeterson
> > > > >
> > > > >
> > > > >
> > > > >>
> > > > >>
> > > >
> > > >
> > >
> > >
> >
> >
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Antennas that really don't need a |
ground plane ?
><Gilles.Thesee@ac-grenoble.fr>
>
>Hi Bob and all,
>
>Is it true some comm or XPDR antennas can dispense with a ground plane ? I
>seem to remember having read this claim (Artex, Archer, Advanced Aircraft
>Electronics antennas from A&S).
>How come ?
>Or maybe they are not quarterwave antennas ?
right . . . they're center-fed, half-wave dipoles.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Clock consumption |
>
>
>Sure, Its a "sneak" circuit back into the internal regulator.
>
>Remember the internal regulator on say a ND (and many others) are only
>powered up externally on initial startup. There is an internal "B" lead
>connection to the regulator power. This internal connection makes the
>alternator a "one wire type" after startup. In fact you can pull the small
>wire connections and it keeps on working until the engine is turned off.
. . . heard that
>This connection is "another" failure mode of internal regulators that cannot
>be stopped by removing the connection to the ign switch. Sure the field
>power transistor can short but its also likely that a failure can be
>internal to the regulator that turns on that transistor.
>
>This can lead to a rare alternator failure where an internal output circuit
>short (diodes perhaps) can result in a self excited overload that ends up in
>a fire. Why its so important to have control of the field supply and why I
>would never have an internal regulated setup on my aircraft where the "B"
>lead supplied the internal regulator.
sure . . . this is where the b-lead contactor for ov disconnect
came into being . . .
>Modern auto imports from Japan must be run for 1/2 hour or so at least once
>a week to keep the battery charged. This is not common knowledge and is
>frustrating to the auto stores which have a healthy business on replacement
>batteries and also arguing with the unhappy customer who's battery keeps
>failing to hold a charge.
>
>Anyway, I have tried three different brands of Japan mfgr alternators and
>the "off" drain was around 70ma.
>
>This from dead battries on a truck (of mine) that is not run often and where
>I had replaced the alternator with a surplus (to me) import unit.
>
>Once the problem was detected, it was checked out and both auto stores and
>dealers said sure "did you not know of the need to run the car weekly?" :-)
Hmmmm . . . it's still cold in the garage but I couldn't stand
the suspense any more. Went out to put an ammeter between the
battery and the rest of the system on my wife's Saturn.
DAMN!!!! 430 milliampers !!!! Now, I don't know where all
the juice is going. She's got a whizzy, 50-disc CD changer that
does things all by itself whether or not the ignition switch
is on. The CD changer may have been in some kind of initialization
activity as soon as I re-connected the battery. The battery's
open circuit voltage was down to 11.50 volts (it's been setting
about 5 days since last run).
Soooo . . . I've got a charger on the battery and will go
out this evening for some more detailed studies. That 400+
mA may go down to some lower value after a few minutes . . .
but I'm going to bring the battery back up first.
I am mystified as to why a manufacturer would build such
a product. I don't see why it's so difficult to let the
"control" lead have better control . . .
Of course, this is of little interest to airplane builders
since we have battery masters and b-lead disconnect contactors
but it's a bummer for "modern" car owners. Will let you
know what I find out later this evening. Thanks for the
head's up . . .
Bob . . .
________________________________________________________________________________
| Subject: | Re: Antennas that really don't need a ground plane |
?
----- Message d'origine -----
De : "Robert L. Nuckolls, III"
:
Envoy : lundi 10 mars 2003 21:46
Objet : Re: AeroElectric-List: Antennas that really don't need a ground
plane ?
> >Or maybe they are not quarterwave antennas ?
>
> right . . . they're center-fed, half-wave dipoles.
>
> Bob . . .
Bob and Bill,
Thank you.
Then they must be about twice as long, right ?
Gilles
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Alternator hookup |
>
>
>My alternator doesn't seem to have any #'s or markings to indicate it
>origin - I was once told it was off a Mazda RX-7 - with built in
>regulator. I know it has a built in regulator.
>
>I was told the large output terminal goes to the Bat. - I knew that one.
>
>Then we have two small terminals - fast-on male tabs - one vertical and
>one horizontal - like a "T" . I"m told the top of the "T" is the switched
>12V - supply which feeds the alternator field. Then the vertical stem of
>the "T" would be for a light - you could run this to a light and then to
>ground - then if the alternator failed, the light would light up.
>
>I"m hoping this is a standard way in which alternators are configued on
>the hook up - does this sound right to anyone.
I seem to recall a similar
>Can I tell using an ohm meter - which terminal goes to the alternator
>field and which would switch a light on and off? If I take the Top of
>the "T" and put a positive ohm probe and then put the other ohm probe to
>ground, I would get some resistance reading - but current should
>flow. Well then what if I reverse the probes - are there perhaps diodes
>in there which would prevent the current from flowing backwards?? if so
>would this help indicate which terminal was for the alternator field?
The ohmmeter check isn't going to be very helpful
without knowing more about the alternator's internals . . .
but if we knew those, we'd already have the answer to
your question.
>The Mazda technicians don't seem to know much either - they were no help
>at all.
>
>does it sound right that the only alternator ground would just be the
>contact it makes when bolted to the engine? I see not terminal on my
>alternator for a ground hook up?
People who work on cars are generally not much help. You need to talk
to a tech in an OVERHAUL shop that works on the alternator's internals
and even this might be a mixed bag.
Usually the "Light" terminal pulls to ground to turn on the
idiot light . . . so the other end of the light would go to
(+) . . . When you're ready to run the engine for the first
time, put a 100 ohm/1 watt resistor in series with the control lead
to the alternator. Try one and then the other. The alternator
will come on line only with the wire hooked to right terminal
and the 100 ohm resistor will prevent damage to the regulator
if it's the "wrong" terminal.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Alt. Field Circuit Breaker |
>
>Bob,
>
>I'm using the dual alternator (Z-10) on my Rocket. In order to get
>power to the two 5 amp circuit breakers in my panel for the alternator
>field current, I need to run a wire from the power post on the bus to
>the breakers. This will be a distance of only a foot or so. What size
>wire would be sufficient? Can I run the wire without a fusible link?
>Thank you as always.
You can do anything you want to. 1-foot isn't all that
much more at-risk wire than the rule-of-thumb 6" that
the FAA will bless. Your risks are minimal.
Bob . . .
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
| Subject: | Re: Ground Planes |
So I can just run copper tape ~18" in all directions even though it will
curve up the sides of the fuselage? What about aluminum foil?
Mike
________________________________________________________________________________
| From: | "I-Blackler, Wayne R" <wayne.blackler(at)boeing.com> |
When I was considering an ADF (used as primary Navaid in Australia) for my Long
EZ, I decided I needed a ground plane for the combined sense and loop antenna
that came with the King KR-87 unit. Other than simply placing a large sheet of
ground plane material in the structure (almost impossible in a Long EZ due to
the compound curves and bulkheads), the plan was to create cross-hatch grid
on the entire floor (longitudinally and laterally) of copper tape spaced 1" apart
(ie.producing 1" squares) extending down the length of the fuselage bottom,
then vacuum bag a ply of glass down onto the surface over the grid for protection.
Each individual overlaid copper tape would be (read: needed to be) soldered
to eachother with a 'jumper', and a small sheet of copper (the size of the
antenna base) would be installed in the centre, and used to bolt the antenna
in place, hence providing ground plane continuity. I would then have been able
to sink the antenna into the fuselage bottom, and have no antenna mounted externally
on the aircraft. A test showed the ground plane worked really well. Would
work well also for XPDR and LORAN in glass composite regions of any aircraft..
Make sure you don't block out other antennas.
NB: In the end I didn't do the installation, I sold the KR-87 and bought a GPS.
Sorry fellas, no airtime.
I remember years ago people also using aluminium foil (failures occurred if used
in flexing structure, particularly gear leg comm antennas), and copper screen
(difficult to hold in place without bagging, although it reportedly worked very
well).
Hope that helps.
Cheers
- Wayne Blackler
IO-360 Long EZ
Seattle, WA
-----Original Message-----
From: MikeEasley(at)aol.com [mailto:MikeEasley(at)aol.com]
Subject: Re: AeroElectric-List: Ground Planes
So I can just run copper tape ~18" in all directions even though it will
curve up the sides of the fuselage? What about aluminum foil?
Mike
________________________________________________________________________________
| From: | "Neville Kilford" <nkilford(at)etravel.org> |
| Subject: | Re: Ground Planes |
FWIW, I'm planning to make my ground planes from .020" alum. sheet. It's
leftover stock from making stabilator trailing edges. I'm installing a 5 or
6" disc for the transponder, and six "spokes" for the COM. You can pick up
the stuff from ACS.
Hope this helps.
Nev
--
Neville Kilford
Jodel D-150 in progress
UK
----- Original Message -----
From: "I-Blackler, Wayne R" <wayne.blackler(at)boeing.com>
Subject: RE: AeroElectric-List: Ground Planes
>
> When I was considering an ADF (used as primary Navaid in Australia) for my
Long EZ, I decided I needed a ground plane for the combined sense and loop
antenna that came with the King KR-87 unit. Other than simply placing a large
sheet of ground plane material in the structure (almost impossible in a Long
EZ due to the compound curves and bulkheads), the plan was to create
cross-hatch grid on the entire floor (longitudinally and laterally) of copper
tape spaced 1" apart (ie.producing 1" squares) extending down the length of
the fuselage bottom, then vacuum bag a ply of glass down onto the surface
over the grid for protection. Each individual overlaid copper tape would be
(read: needed to be) soldered to eachother with a 'jumper', and a small sheet
of copper (the size of the antenna base) would be installed in the centre,
and used to bolt the antenna in place, hence providing ground plane
continuity. I would then have been able to sink the antenna into the fuselage
bottom, and !
> have no antenna mounted externally on the aircraft. A test showed the
ground plane worked really well. Would work well also for XPDR and LORAN in
glass composite regions of any aircraft.. Make sure you don't block out other
antennas.
>
> NB: In the end I didn't do the installation, I sold the KR-87 and bought a
GPS. Sorry fellas, no airtime.
>
> I remember years ago people also using aluminium foil (failures occurred if
used in flexing structure, particularly gear leg comm antennas), and copper
screen (difficult to hold in place without bagging, although it reportedly
worked very well).
>
> Hope that helps.
>
> Cheers
>
> - Wayne Blackler
> IO-360 Long EZ
> Seattle, WA
>
>
> -----Original Message-----
> From: MikeEasley(at)aol.com [mailto:MikeEasley(at)aol.com]
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Ground Planes
>
>
> So I can just run copper tape ~18" in all directions even though it will
> curve up the sides of the fuselage? What about aluminum foil?
>
> Mike
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Ground Planes |
>
>So I can just run copper tape ~18" in all directions even though it will
>curve up the sides of the fuselage? What about aluminum foil?
I like to solder the tapes to a center disk upon which
the antenna is mounted. If you make the disk out of
thin brass and the radials out of copper, the whole
installation process is much easier.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Antennas that really don't need a |
ground plane ?
><Gilles.Thesee@ac-grenoble.fr>
>
>
>----- Message d'origine -----
>De : "Robert L. Nuckolls, III"
> :
>Envoy : lundi 10 mars 2003 21:46
>Objet : Re: AeroElectric-List: Antennas that really don't need a ground
>plane ?
>
>
> > >Or maybe they are not quarterwave antennas ?
> >
> > right . . . they're center-fed, half-wave dipoles.
> >
> > Bob . . .
>
>Bob and Bill,
>
>Thank you.
>Then they must be about twice as long, right ?
yup . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Ground Planes |
>
>
>FWIW, I'm planning to make my ground planes from .020" alum. sheet. It's
>leftover stock from making stabilator trailing edges.
> I'm installing a 5 or 6" disc for the transponder,
If the ground plane is "small" . . . like less than a wavelength
at frequency of interest, then it works best if "tuned" . . . i.e.
exactly same radius as height of antenna or 5.3" diameter.
>and six "spokes" for the COM. You can pick up
>the stuff from ACS.
The "spokes" should also be same as length of antenna
when measured from the BASE of the antenna. If you mount
on a brass plate for the purpose of commoning all the
radials, then trim the radials for length from base
of antenna, not from edge of mounting plate.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
>
>When I was considering an ADF (used as primary Navaid in Australia) for my
>Long EZ, I decided I needed a ground plane for the combined sense and loop
>antenna that came with the King KR-87 unit. Other than simply placing a
>large sheet of ground plane material in the structure (almost impossible
>in a Long EZ due to the compound curves and bulkheads), the plan was to
>create cross-hatch grid on the entire floor (longitudinally and laterally)
>of copper tape spaced 1" apart (ie.producing 1" squares) extending down
>the length of the fuselage bottom, then vacuum bag a ply of glass down
>onto the surface over the grid for protection. Each individual overlaid
>copper tape would be (read: needed to be) soldered to eachother with a
>'jumper', and a small sheet of copper (the size of the antenna base) would
>be installed in the centre, and used to bolt the antenna in place, hence
>providing ground plane continuity. I would then have been able to sink the
>antenna into the fuselage bottom, and !
>have no antenna mounted externally on the aircraft. A test showed the
>ground plane worked really well. Would work well also for XPDR and LORAN
>in glass composite regions of any aircraft.. Make sure you don't block out
>other antennas.
>
>NB: In the end I didn't do the installation, I sold the KR-87 and bought a
>GPS. Sorry fellas, no airtime.
What you propose would be fine . . . but much too busy.
When the opening in a sheet is less than 1/20th of a wavelength
at frequency of interest, the hole is for all practical purposes
non-existent. The smallest wavelength of interest for ADF
happens at the upper end of broadcast band (300/1.7MHz = 176
METERS for full wavelength, 8 meters for 1/20th). Going to
that much trouble for an ADF installation is overkill.
The ADF sense antenna is a super-short, pure e-field antenna
(like the am antenna on your car) and is totally independent
of effects of what might be considered a classic ground plane.
The loop is an h-field antenna which doesn't use/need
a ground plane either . . . with a small caveat. Accuracy
of the nulled signal for good direction finding is affected
by local fields. These effects can be minimized by mounting
the loop in what might be called a ground plane . . . but
as I recall, this was really useful only at the fringes
of the ADF's receiving range. When shooting ADF approaches,
you are so close to the ground-based facilities that
the local ground plane didn't make much improvement.
Haven't messed with an ADF installation in over 25 years.
Don't miss 'em one bit.
For vhf antennas, the simple radial ground plane is very
easy to implement with strips of copper tape. 4 radials is
the minimum, for more than 8 radials is difficult to measure
the improvement when the 9th one is added.
>I remember years ago people also using aluminium foil (failures occurred
>if used in flexing structure, particularly gear leg comm antennas), and
>copper screen (difficult to hold in place without bagging, although it
>reportedly worked very well).
I've heard lots of stories about broken antennas glassed
into gear legs. Copper and aluminum are both pretty poor
materials for conductors that need to withstand routine
flexing. Inside surface of fuselage is pretty stable.
Bob . . .
________________________________________________________________________________
| From: | John Loram <johnl(at)loram.org> |
Ideally the ground plane would be flat and infinite. Once you are greater
that the length of the antenna, extending the ground plane has rapidly
diminishing effects. Curling the ground plane up around the radiating
element will both lower the resonance of the antenna (push the center of the
effective band of frequencies downward), and impact the omnidirectionality
of the antenna. Assuming only a small amount of upward curl (a few inches),
there shouldn't be much trouble. Try it, if you feel you aren't getting out
like you've experienced in other a/c, get some help from a radio shop or a
smart radio amateur.
-john-
johnl(at)loram.org
www.loram.org
-----Original Message-----
From: MikeEasley(at)aol.com [mailto:MikeEasley(at)aol.com]
Subject: Re: AeroElectric-List: Ground Planes
So I can just run copper tape ~18" in all directions even though it will
curve up the sides of the fuselage? What about aluminum foil?
Mike
________________________________________________________________________________
| From: | bernieC(at)erols.com |
| Subject: | Re: Hall Effect Ammeters] |
-------- Original Message --------
Subject: Re: AeroElectric-List: Hall Effect Ammeters
Date: Fri, 07 Mar 2003 19:46:54 -0500
I can confirm that a hall effect sensor is included in the
MicroMonitor kit. This one is impressed with the name "MICRO
SWITCH, Freeport, Ill. U.S.A.". It is also inked with a number
'9948' followed by 'CSLA1CE'. I wonder what the
Mircoswitch/Honeywell relationship is. Looks like it is a 75 amp
device vice the 'f' version 100 amp rating.
Bernie C.
"Robert L. Nuckolls, III" wrote:
>
>
> The MicroMonitor uses a hall effect device. The
> last time I saw one installed they were using
> a Honeywell product. You can browse the
> complete line of Honeywell current sensors
> at
>
> http://content.honeywell.com/sensing/prodinfo/current/
>
> check out the CSLA1CF open loop sensor at
>
> http://catalog.sensing.honeywell.com/printfriendly.asp?FAM=current&PN=CSLA1CF
>
> and a closed loop sensor at
>
> http://catalog.sensing.honeywell.com/printfriendly.asp?FAM=current&PN=CSNA111-500
>
> Didn't find anyone other than MicroMonitor
> taking advantage of this technology in a
> product.
>
> Bob . . .
>
________________________________________________________________________________
| From: | "Rick Fogerson" <rickf(at)cableone.net> |
| Subject: | Dual E.I. and Batteries, single Alt. |
Hi Bob,
I'm about ready to order my electrical stuff and wanted to confirm some things
about my wiring diagram.
Background:
I'm building a fairly simple panel for a day-VFR RV3. I took fig. Z-11 and added
Z-23 (test adapter), Z-28 (dual E.I.), and Z-30 (aux battery & bus). I am
placing the dual batteries with their contactors and buses in back and installing
B&C's starter, alternator, and voltage regulator.
Questions:
1) I am co-locating the buses in back even though you have to run more wires from
each bus foreward. I assume this is still true with my system?
2) I used 10AWG for the aux bat bus and 16AWG for the main. Can't remember why
though?
3) Is it a good idea to combine the aux bat master sw with the essential bus alt
feed sw into an S700-2-10 switch so that when you open the aux bat master sw
you also close the essential bus alt feed sw (power from main bus to lead 5 and
lead 6 to essential bus)?
________________________________________________________________________________
| From: | Rino <lacombr(at)nbnet.nb.ca> |
| Subject: | Re: Ground Planes |
A transponder antenna that close to your passengers "private parts"
might not be the best thing to do.
The radiation may do some damage.
Rino
MikeEasley(at)aol.com wrote:
>
>
> I have an Artex ELT-200 with a 18.75" whip antenna. My plan is to mount it
> on a composite prepreg shelf inside the aft fueselage. My guess is I need a
> ground plane. How large does it need to be?
>
> I also have a CI-101 Transponder antenna that I'm mounting under the rear
> seat. What size should the ground plane be?
>
> Mike Easley
> Lancair ES
>
--
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: defending the "familiy jewels" . . . |
>
>A transponder antenna that close to your passengers "private parts"
>might not be the best thing to do. The radiation may do some damage.
>
>Rino
A hangar myth. Folks have looked at the
peak output power rating of a transponder (100 to 250W)
and tried to make a connection between a desire to
make one's airplane visible to a distant radar receiver
and cooking meat.
When you buy a microwave, it too is rated in the
hundreds of watts . . . but CONTINUOUS duty. A
good 700W microwave will boil a cup of water in
about 2 minutes. (Remember the traveler's immersion
heaters in the hardware store? They're 300W heaters
and take about 4 minutes to boil a cup of water).
If you measure the current draw of this machine,
it will be on the order of 8-9 amps or 1000W total
input.
Your transponder draws about 1.5 amps while being
interrogated for a total input power of 18W. The
output comes in the form of a series of 0.5 uSec
pulses in respond to an interrogation that represent
a string of binary numbers representing either your
squawk code (mode A) or altitude (mode C). Assuming
you are interrogated once per second (quite often)
your average output power for a 250W transponder
is on the order of 250W x 20 pulses x 0.0000005
seconds/1 second or 2.5 milliwatts per second.
This isn't going even going to warm up much less cook
anything.
Another fallacy of the myth concerns body parts
most sensitive to microwave radiation . . . turns
out that your eyes are the most vulnerable . . .
but the story isn't nearly so interesting to
really macho pilots. None the less, there are
folks who have armor-shielded their seat bottoms
in deference to this myth. The story was REALLY
popular about 15 years ago in the heyday of
the Long-Ezs
Here's a post I did on a canard pusher list
server about 5 years ago:
> Location away from the pilot/co-pilot is also
>recommended but over ten feet requires a different cable. Yes?? I was
>thinking about locating it aft of the pilot in the baggage area. Is that
>distance safe?
A totally bogus recommendation. A few years back, someone observed
that their transponder was rated for 200 watts output . . . 1/3rd
that of the family microwave. Our hero was immediately concerned for
preservation of the family jewels and proceeded to line the bottom
of his composite seat pan with aluminum foil. What he failed to
understand was that his RF coffee warmer and popcorn popper was
rated in continuous watts while the transponder was in peak watts.
The average power output from a transponder is less than 1 watt . . .
BTW, the eyes are about 100 times more sensitive to the effects of
microwave heating than are any deep organs . . . you'll go blind
you quit making babies.
Bob . . .
////
(o o)
===========o00o=(_)=o00o=========
=================================
http://www.aeroelectric.com
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
| Subject: | Re: Hall Effect Ammeters] |
Honeywell owns Microswitch.
bernieC(at)erols.com wrote:
>
>
>-------- Original Message --------
>Subject: Re: AeroElectric-List: Hall Effect Ammeters
>Date: Fri, 07 Mar 2003 19:46:54 -0500
>To: aeroelectric-list(at)matronics.com
>
>I can confirm that a hall effect sensor is included in the
>MicroMonitor kit. This one is impressed with the name "MICRO
>SWITCH, Freeport, Ill. U.S.A.". It is also inked with a number
>'9948' followed by 'CSLA1CE'. I wonder what the
>Mircoswitch/Honeywell relationship is. Looks like it is a 75 amp
>device vice the 'f' version 100 amp rating.
>
>Bernie C.
>
>
>"Robert L. Nuckolls, III" wrote:
>
>
>>
>> The MicroMonitor uses a hall effect device. The
>> last time I saw one installed they were using
>> a Honeywell product. You can browse the
>> complete line of Honeywell current sensors
>> at
>>
>>http://content.honeywell.com/sensing/prodinfo/current/
>>
>> check out the CSLA1CF open loop sensor at
>>
>>http://catalog.sensing.honeywell.com/printfriendly.asp?FAM=current&PN=CSLA1CF
>>
>> and a closed loop sensor at
>>
>>http://catalog.sensing.honeywell.com/printfriendly.asp?FAM=current&PN=CSNA111-500
>>
>> Didn't find anyone other than MicroMonitor
>> taking advantage of this technology in a
>> product.
>>
>> Bob . . .
>>
>>
>>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Hall Effect Ammeters |
>
>
>-------- Original Message --------
>Subject: Re: AeroElectric-List: Hall Effect Ammeters
>Date: Fri, 07 Mar 2003 19:46:54 -0500
>To: aeroelectric-list(at)matronics.com
>
>I can confirm that a hall effect sensor is included in the
>MicroMonitor kit. This one is impressed with the name "MICRO
>SWITCH, Freeport, Ill. U.S.A.". It is also inked with a number
>'9948'
This is a date code. 48th week of 1999 for manufacture.
> followed by 'CSLA1CE'. I wonder what the
>Mircoswitch/Honeywell relationship is. Looks like it is a 75 amp
>device vice the 'f' version 100 amp rating.
Sounds right.
Bob . . .
________________________________________________________________________________
| From: | "Alex Peterson" <alexpeterson(at)usjet.net> |
| Subject: | Re: defending the "familiy jewels" . . . |
> >
> >A transponder antenna that close to your passengers "private parts"
> >might not be the best thing to do. The radiation may do some damage.
> >
> >Rino
>
> A hangar myth. Folks have looked at the
> peak output power rating of a transponder (100 to 250W)
> and tried to make a connection between a desire to
> make one's airplane visible to a distant radar receiver
> and cooking meat.
OK, here are true stories: There is a guy at my work who wears an
aluminum foil hat, somewhat reminiscent of a dunce cap, interestingly,
because our building is near some 230kv power lines. No kidding.
30 years ago when a new power transmission line was being built across
some farmland in my state, the news "reporters" were reporting, without
questioning it, of course, that farmers were putting electric motors in
the fields under the new power lines and that they were running without
any cords.
We do indeed have some education to do in this country...
Alex Peterson
Maple Grove, MN
RV6-A N66AP 265 hours, dialing up the power on my transponder to make
me more comfortable in the winter.
www.usfamily.net/web/alexpeterson
________________________________________________________________________________
| Subject: | Re: defending the "familiy jewels" . . . |
Alex Peterson wrote:
.
>
> 30 years ago when a new power transmission line was being built across
> some farmland in my state, the news "reporters" were reporting, without
> questioning it, of course, that farmers were putting electric motors in
> the fields under the new power lines and that they were running without
> any cords.
>
> We do indeed have some education to do in this country...
Don't laugh too hard.
When I was 12 I did a science fair project, where I did something
similar... I set up a resonant circuit at some harmonic of 60 Hz, and
did manage to pull energy "out of the air", rectify it, and show a
voltage on a meter - I did get enough voltage, but not enough current to
run anything, but I figured if I got a big enough cap I just might.
I didn't, though, as I was informed that I could be charged with theft
of the power line energy. That sounded pretty ridiculous to me, but now
people are going to jail for "stealing" EM energy from satellites... I
guess I was just ahead of my time??
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Dual E.I. and Batteries, single Alt. |
>
>Hi Bob,
>I'm about ready to order my electrical stuff and wanted to confirm some
>things about my wiring diagram.
>
>Background:
>I'm building a fairly simple panel for a day-VFR RV3. I took fig. Z-11
>and added Z-23 (test adapter), Z-28 (dual E.I.), and Z-30 (aux battery &
>bus). I am placing the dual batteries with their contactors and buses in
>back and installing B&C's starter, alternator, and voltage regulator.
>
>Questions:
>1) I am co-locating the buses in back even though you have to run more
>wires from each bus foreward. I assume this is still true with my system?
yes . . .
>2) I used 10AWG for the aux bat bus and 16AWG for the main. Can't
>remember why though?
hmmm . . . 16 is probably adequate for a battery bus
>3) Is it a good idea to combine the aux bat master sw with the essential
>bus alt feed sw into an S700-2-10 switch so that when you open the aux bat
>master sw you also close the essential bus alt feed sw (power from main
>bus to lead 5 and lead 6 to essential bus)?
having trouble visualizing the wiring and your intent. I'm
not sure how/why you want to tie closure of alternate feed
path with the act of turning the aux battery master off.
Can you elaborate on the value of doing this?
Bob . . .
________________________________________________________________________________
| From: | Duncan McBride <duncanmcbride(at)comcast.net> |
| Subject: | Re: Noise in 760 installation |
The headphone and microphone wiring appears to be ok. Here's the thing -
the aluminum chassis is connected to ground. With the radio removed from
the panel and disconected from everything, I've checked the resistance
between the two ground pins and the chassis and it is zero. Unless there is
some kind of short inside the box, it looks like the ground wires are only
necessary if the radio is not installed in a grounded panel. I suppose I
could use nylon machine screws to mount it, but as soon as I connected the
ground wires the chassis is grounded. And here's another consideration:
the antenna jack is fixed to the rear of the chassis, too, so the antenna
ground will be directly connected to the airplane ground, whether you use
the ground pins or the panel connection. This isn't recommended from what
I've read in the archives. Can this be normal?
I'll try a separate battery source tomorrow and if that works I'll try the
filter. I'll try an email to MicroAir to see if the radio should be working
this way. Thanks.
>
> Try running the radio from a 12 battery independent of
> the ship's electrical system. A couple of 6v lantern
> batteries from WalMart will work fine. If the radio
> is quiet with independent battery, then a filter
> like the one cited will probably fix it.
>
>
> >Maybe not related, when I checked the 760 wiring after noticing the
noise,
> >I realized I had forgotten to hook up the ground wires. Except for the
> >noise it had worked just fine. Hooking the ground wires up didn't change
> >anything. Must be that the chassis is grounded where it fastens to the
> >panel, or is that a problem too? Thanks for your help.
>
>
> Whoops! If it worked AT ALL with the power ground wire
> disconnected, then it's probable that the radio was
> finding an operating ground from some path that it
> shouldn't have . . . are your microphone and headset
> jacks insulated from ground?
>
> See paragraph 2.4 in http://216.55.140.222/Catalog/avionics/760imB.pdf
>
> Check for proper mic/headset jack wiring before
> trying the battery test or adding a filter.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | Duncan McBride <duncanmcbride(at)comcast.net> |
| Subject: | Re: defending the "familiy jewels" . . . |
I do remember flying my old Ringmaster control-line stunt plane too close to
the power lines one afternoon and getting an electric shock through the
EZ-Just handle, which routed a braided cable around the grip, attached to
the steel lines at either end. The back of your hand laid alongside the
cable. I remember walking the plane away from the power lines until the
shock went away. Probably why I'm childless to this day.
----- Original Message -----
From: "John Rourke" <jrourke@allied-computer.com>
Subject: Re: AeroElectric-List: Re: defending the "familiy jewels" . . .
<jrourke@allied-computer.com>
>
>
> Alex Peterson wrote:
>
> .
>
> >
> > 30 years ago when a new power transmission line was being built across
> > some farmland in my state, the news "reporters" were reporting, without
> > questioning it, of course, that farmers were putting electric motors in
> > the fields under the new power lines and that they were running without
> > any cords.
> >
> > We do indeed have some education to do in this country...
>
> Don't laugh too hard.
>
> When I was 12 I did a science fair project, where I did something
> similar... I set up a resonant circuit at some harmonic of 60 Hz, and
> did manage to pull energy "out of the air", rectify it, and show a
> voltage on a meter - I did get enough voltage, but not enough current to
> run anything, but I figured if I got a big enough cap I just might.
>
> I didn't, though, as I was informed that I could be charged with theft
> of the power line energy. That sounded pretty ridiculous to me, but now
> people are going to jail for "stealing" EM energy from satellites... I
> guess I was just ahead of my time??
>
>
________________________________________________________________________________
| From: | John Loram <johnl(at)loram.org> |
| Subject: | Re: defending the "familiy jewels" . . . |
I hesitate to perpetuate this story (and reveal my gullibility); My dad was
a civil engineer who worked for the Pacific Gas & Electric company laying
out long transmission lines and supervising their installation. I spent one
summer about 50 years ago with him, driving the back roads of California on
his job and he told me that one of the reasons that the transmission lines
are rotated every few thousand feet (they don't just stay in the same
relative position for the full run) was to prevent farmers from laying a
loop of lines parallel to the transmission lines and inductively coupling
some free watt hours.
I went on to become an electrical engineer (electronics, not power) and
still don't know if he was pulling my leg, though it wasn't in his nature.
-john-
john(at)loram.org
www.loram.org
-----Original Message-----
From: Alex Peterson [mailto:alexpeterson(at)usjet.net]
Subject: RE: AeroElectric-List: Re: defending the "familiy jewels" . . .
> >
> >A transponder antenna that close to your passengers "private parts"
> >might not be the best thing to do. The radiation may do some damage.
> >
> >Rino
>
> A hangar myth. Folks have looked at the
> peak output power rating of a transponder (100 to 250W)
> and tried to make a connection between a desire to
> make one's airplane visible to a distant radar receiver
> and cooking meat.
OK, here are true stories: There is a guy at my work who wears an
aluminum foil hat, somewhat reminiscent of a dunce cap, interestingly,
because our building is near some 230kv power lines. No kidding.
30 years ago when a new power transmission line was being built across
some farmland in my state, the news "reporters" were reporting, without
questioning it, of course, that farmers were putting electric motors in
the fields under the new power lines and that they were running without
any cords.
We do indeed have some education to do in this country...
Alex Peterson
Maple Grove, MN
RV6-A N66AP 265 hours, dialing up the power on my transponder to make
me more comfortable in the winter.
www.usfamily.net/web/alexpeterson
________________________________________________________________________________
| Subject: | Fast-on current ratings? |
| From: | czechsix(at)juno.com |
What is the max current rating for Fastons (particularly the .250 and .11
sizes)? I don't recall seeing a published number anywhere but I'm sure
the data must exist...
Thanks,
--Mark Navratil
Cedar Rapids, Iowa
RV-8A N2D firewall forward and wiring...
________________________________________________________________________________
| Subject: | Microair com to intercom wiring schematic? |
| From: | czechsix(at)juno.com |
Bob,
Didn't you have a wiring diagram for the Microair com radio to an
voice-activated intercom? Seems like I recall seeing you post a link to
it on your website some time ago (for the harness you sell) but I can't
find it now.
I'm connecting the Microair to the popular FlightComm 403 intercom that
Vans sells....pretty sure I know how to hook it up correctly but thought
I'd save myself the trouble of drawing it out if it's already been
done...
Thanks,
--Mark Navratil
Cedar Rapids, Iowa
RV-8A N2D firewall forward and wiring...
________________________________________________________________________________
| Subject: | Free electricity |
Yes it is true about tapping electricity out of the air. About 25-30 years ago
there was a story on 60 minutes about some people who had high voltage lines through
there property. They took and old whisky barrel and wound it with wire
with two leads running off it. They stuck it on a telephone pole and placed between
the lines. The electric company sued but lost.
page 2
ED
________________________________________________________________________________
| Subject: | Re: defending the "familiy jewels" . . . |
Back in high school I built a "Tesla Coil" using a 115-400+ volt transformer, a
couple of #50 (maybe #51) tubes, oatmeal box primary and mailing tube (36") secondary.
Emitted sparks about 2"-3" long. Could light flouresent tubes by holding
them near the sparks. Could run my hand right over the sparks. Made a
small electirc jet engine that would rotate on top. Won a ribbon in the Science
Fair. I now have 2 wonderful children after all that exposure. Wish I had
the tubes to fire that old Tesla coil up again...
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
| Subject: | Ground Planes, Family Jewels |
My fuselage is about 18" to 20" diameter in the ELT mounting area. Assuming
a 36" diameter ground plane, is that too much curling of the ends? My guess
is that the ground plane would curl up to about the middle of the antenna.
Where do I get the Copper tape?
Artex sells an antenna designed for mounting inside composite aircraft that's
about 31" long. Maybe that's the way to go if it's not too expensive.
I read in the Connection about the false fear about the transponder zapping
the family jewels. I had heard the same concern from a Lancair builder at my
airport.
Mike Easley
Lancair ES
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
Bill,
"MFJ-259B on its way from eBay, so I can roll & tweak my own aeronautical
mobile antenna farm."
Good man. My experience is not to lend it out, as the slightest
bit of RF will blow its brains out. I offer to test anyone's antennas but
won't leave it out of sight. Also, make certain you don't power it up with
the Power switch on. It eats batteries, but wallwart power must be added
with the power switch OFF. Some guys won't use a wallwart.
Cheers, Ferg
________________________________________________________________________________
| From: | Miller Robert <rmiller3(at)earthlink.net> |
| Subject: | Re: defending the "familiy jewels" . . . |
Current will flow in a wound coil placed in an electro-magnetic field.
This principle is used in all sorts of applications.
Robert
Duncan McBride wrote:
>
> I do remember flying my old Ringmaster control-line stunt plane too close to
> the power lines one afternoon and getting an electric shock through the
> EZ-Just handle, which routed a braided cable around the grip, attached to
> the steel lines at either end. The back of your hand laid alongside the
> cable. I remember walking the plane away from the power lines until the
> shock went away. Probably why I'm childless to this day.
>
> ----- Original Message -----
> From: "John Rourke" <jrourke@allied-computer.com>
> To:
> Subject: Re: AeroElectric-List: Re: defending the "familiy jewels" . . .
>
> <jrourke@allied-computer.com>
> >
> >
> > Alex Peterson wrote:
> >
> > .
> >
> > >
> > > 30 years ago when a new power transmission line was being built across
> > > some farmland in my state, the news "reporters" were reporting, without
> > > questioning it, of course, that farmers were putting electric motors in
> > > the fields under the new power lines and that they were running without
> > > any cords.
> > >
> > > We do indeed have some education to do in this country...
> >
> > Don't laugh too hard.
> >
> > When I was 12 I did a science fair project, where I did something
> > similar... I set up a resonant circuit at some harmonic of 60 Hz, and
> > did manage to pull energy "out of the air", rectify it, and show a
> > voltage on a meter - I did get enough voltage, but not enough current to
> > run anything, but I figured if I got a big enough cap I just might.
> >
> > I didn't, though, as I was informed that I could be charged with theft
> > of the power line energy. That sounded pretty ridiculous to me, but now
> > people are going to jail for "stealing" EM energy from satellites... I
> > guess I was just ahead of my time??
> >
> >
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: defending the "familiy jewels" . . . |
>
>I hesitate to perpetuate this story (and reveal my gullibility); My dad was
>a civil engineer who worked for the Pacific Gas & Electric company laying
>out long transmission lines and supervising their installation. I spent one
>summer about 50 years ago with him, driving the back roads of California on
>his job and he told me that one of the reasons that the transmission lines
>are rotated every few thousand feet (they don't just stay in the same
>relative position for the full run) was to prevent farmers from laying a
>loop of lines parallel to the transmission lines and inductively coupling
>some free watt hours.
Actually, that's done to improve the transmission line characteristics
of the parallel run of wires (same thing as twisting wires under
the shields for reduced coupling to environment). It reduces the
need for power factor correction and has a small but beneficial
improvement on transmission efficiency.
A friend of mine (PhD EE) was asked to testify in a personal
damages case against a power line company wherein the plaintiff
alleges he was injured by the proximity to a high voltage transmission
line running near his property.
Coupling energy from a power line via either magnetic parallel
conductors or electrostatic means at 60Hz was calculated as
very difficult to do. Close proximity effects of high-voltage,
high-current conductors falls off as the square of the distance.
Further, instead of using magnetically friendly laminated iron
as the core of a transformer, you are limited to using very
unfriendly air as the magnetic conduction medium. Tesla
did a lot of work to prove his theories for wireless
transmission of energy . . . he succeeded in doing a lot
of spectacular lightning like displays but never succeeded
in piping significant energy through the ether for more
than a few yards . . . and it wasn't in a form friendly
to running your toaster.
Bottom line is that all such stories were cooked up at
the expense of the listeners. People who worked in and
around such equipment all their careers showed no
particular increase in incidence of any health problems.
If any farmer was able to conduct any energy away from the
vicinity of a power line, it would have been measured in
milliwatts.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Fast-on current ratings? |
>
>What is the max current rating for Fastons (particularly the .250 and .11
>sizes)? I don't recall seeing a published number anywhere but I'm sure
>the data must exist...
>
>Thanks,
They're as good as the wire that you crimp into the terminals.
How much do you NEED to load them? Pitot heat and 100 to 150
watt landing lights are the biggest loads in most airplanes
and for the sake of longevity, we've de-rated the fuseblocks
to 15A max for any one fuse tap . . . about 30% more than
anything you should need.
Really ugly loads like hydraulic pumps should enjoy their
own ANL current limiters tied to fat wires for power
source.
Bob . . .
________________________________________________________________________________
| From: | Miller Robert <rmiller3(at)earthlink.net> |
| Subject: | Re: defending the "familiy jewels" . . . |
"Robert L. Nuckolls, III" wrote:
> . People who worked in and
> around such equipment all their careers showed no
> particular increase in incidence of any health problems.
>
> Bob . . .
Bob... I'd refer you to the Swedish study on this.
Good study, five years, prospective, peer reviewed.... all the stuff we require
for a study
to meet scientific rigor.
They did find health effects from many low level fields... including household
appliances.
Robert
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Ground Planes, Family Jewels |
>
>My fuselage is about 18" to 20" diameter in the ELT mounting area. Assuming
>a 36" diameter ground plane, is that too much curling of the ends? My guess
>is that the ground plane would curl up to about the middle of the antenna.
How do I quantify "too much"? Antennas on airplanes
(except for LORAN) invariably talk/listen to facilities
in line-of-sight. A wet string hung out the window
will suffice for most conditions. It is impossible
to install the IDEAL antenna on any light aircraft
but without going to the laboratory to make detailed
measurements, one cannot quantify losses or gains
of efficiency due to any particular characteristic
of the installation. So for me to tell you that
your installation will suffer "too much" for
the conditions you propose is to suppose that
my crystal ball works better than anyone else's.
Besides, were I to offer the practical truth of
the matter and assert that your antenna will
be 30-50% of ideal in performance, you might
get all wound around the axles of concerns that
don't matter. Most EVERYBODY's antennas fall in this
range of operation.
Bottom line is bolt it on and don't worry about
it.
>Where do I get the Copper tape?
http://www.taperoll.com/Pricelst.htm
See #18, 1" x 36 yds copper tape.
>Artex sells an antenna designed for mounting inside composite aircraft that's
>about 31" long. Maybe that's the way to go if it's not too expensive.
That's going to be a half-wave dipole, suited
ONLY for installation in glass airplanes. Graphite
is too conductive to allow any useful operation of
internally mounted antennas.
Bob . . .
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
| Subject: | Re: Ground Planes, Family Jewels |
My ES is fiberglass, not graphite. I have several "glued to the inside skin"
antennas already.
Mike
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Microair com to intercom wiring |
schematic?
>
>Bob,
>
>Didn't you have a wiring diagram for the Microair com radio to an
>voice-activated intercom? Seems like I recall seeing you post a link to
>it on your website some time ago (for the harness you sell) but I can't
>find it now.
You can download my installation manual at
http://www.aeroelectric.com/Installation_Data
My drawings show the hot-mic intercom installation
wiring.
>I'm connecting the Microair to the popular FlightComm 403 intercom that
>Vans sells....pretty sure I know how to hook it up correctly but thought
>I'd save myself the trouble of drawing it out if it's already been
>done...
The instructions that came with the 403 should be
sufficiently lluminating for your task.
Bob . . .
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
| Subject: | Re: Ground Planes, Family Jewels |
The more I think about it, all metal aircraft don't have a large flat surface
to attach the ELT antenna to. They are curved away from the antenna at about
the same radius as I would have. So now I'll continue to beat a dead
horse....
Is it better/worse/same for the ground plane to curve towards the antenna tip
or away from it?
Mike
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
| Subject: | Re: Ground Planes, Family Jewels |
Aircraft Spruce sells "Copper Antenna Tape" that's adhesive backed and about
3/8" wide. It's not in the catalog, but I found it on an Internet search.
Part # 11-12900 and they sell it by the foot, 30 cents/foot.
The tape on taperoll.com is 1" wide. Would the 3/8" work? Would I need more
radials?
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Ground Planes |
>
>The more I think about it, all metal aircraft don't have a large flat surface
>to attach the ELT antenna to. They are curved away from the antenna at about
>the same radius as I would have. So now I'll continue to beat a dead
>horse....
>
>Is it better/worse/same for the ground plane to curve towards the antenna tip
>or away from it?
Without going to the lab to measure it, one would
be on thin ice to predict.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Copper tape for radials |
>
>Aircraft Spruce sells "Copper Antenna Tape" that's adhesive backed and about
>3/8" wide. It's not in the catalog, but I found it on an Internet search.
>
>Part # 11-12900 and they sell it by the foot, 30 cents/foot.
>
>The tape on taperoll.com is 1" wide. Would the 3/8" work? Would I need more
>radials?
3/8 will work. You don't need more radials.
Bob . . .
________________________________________________________________________________
| From: | "Ron Raby" <ronr(at)advanceddesign.com> |
| Subject: | Re: Ground Planes, Family Jewels |
I have the artex elt- 200 with the whip antenna. I installed it in the back
of my Lancair ES. The antenna is mounted along the side of the fuselage
conforming to the side of the plane. When I called artex for installation
info there was no mention of a ground plane for this antenna. The tech that
I talked to new that it was going into a glass plane and suggested that I
mount it this way. My question is: does this antenna need a ground plane?
What happens if the plane is upside down with the ground plane on top of the
antenna? Will this block the signal?
Thanks
Ron Raby
N829R
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: AeroElectric-List: Re: Ground Planes, Family Jewels
>
> >
> >My fuselage is about 18" to 20" diameter in the ELT mounting area.
Assuming
> >a 36" diameter ground plane, is that too much curling of the ends? My
guess
> >is that the ground plane would curl up to about the middle of the
antenna.
>
> How do I quantify "too much"? Antennas on airplanes
> (except for LORAN) invariably talk/listen to facilities
> in line-of-sight. A wet string hung out the window
> will suffice for most conditions. It is impossible
> to install the IDEAL antenna on any light aircraft
> but without going to the laboratory to make detailed
> measurements, one cannot quantify losses or gains
> of efficiency due to any particular characteristic
> of the installation. So for me to tell you that
> your installation will suffer "too much" for
> the conditions you propose is to suppose that
> my crystal ball works better than anyone else's.
> Besides, were I to offer the practical truth of
> the matter and assert that your antenna will
> be 30-50% of ideal in performance, you might
> get all wound around the axles of concerns that
> don't matter. Most EVERYBODY's antennas fall in this
> range of operation.
>
> Bottom line is bolt it on and don't worry about
> it.
>
> >Where do I get the Copper tape?
>
> http://www.taperoll.com/Pricelst.htm
>
> See #18, 1" x 36 yds copper tape.
>
> >Artex sells an antenna designed for mounting inside composite aircraft
that's
> >about 31" long. Maybe that's the way to go if it's not too expensive.
>
> That's going to be a half-wave dipole, suited
> ONLY for installation in glass airplanes. Graphite
> is too conductive to allow any useful operation of
> internally mounted antennas.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: defending the "familiy jewels" . . . |
>
>
>
>"Robert L. Nuckolls, III" wrote:
>
> > . People who worked in and
> > around such equipment all their careers showed no
> > particular increase in incidence of any health problems.
> >
> > Bob . . .
>
>Bob... I'd refer you to the Swedish study on this.
>Good study, five years, prospective, peer reviewed.... all the stuff we
>require for a study
>to meet scientific rigor.
>They did find health effects from many low level fields... including
>household appliances.
>
>Robert
I've seen some publications on this. Some studies purported
to show several times increase in certain illnesses due
to electromagnetic effects while others claimed "small
but statistically significant effects". Here's a small
sampling of a large body of work.
http://www.niwl.se/wl2000/workshops/workshop36/report_en.asp
http://www.niwl.se/wl2000/workshops/workshop36/report_en.asp
http://www.radprotection.com/radiation_update4.html
http://www.mcw.edu/gcrc/cop/static-fields-cancer-FAQ/toc.html#Q14
Dr. Johnson's study of the published works at the time
of his investigation (about 10 years ago) showed was that
there was no consistent data (nobody had repeatable
experiments in separate labs that produced commensurate results)
and that "statistically significant" was on orders
of magnitude smaller than risks from other stresses like
pollutants and UV radiation from the sun.
I think my chances of demise are far greater for getting
into an automobile every day than from contracting
out-of-the-ordinary illness from the power lines
running through my neighborhood or sleeping under an
electric blanket. The general public is horrible at
even rudimentary risk assessment . . . the talking
heads on TV aren't any better at it.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Ground Planes |
>
>I have the artex elt- 200 with the whip antenna. I installed it in the back
>of my Lancair ES. The antenna is mounted along the side of the fuselage
>conforming to the side of the plane. When I called artex for installation
>info there was no mention of a ground plane for this antenna. The tech that
>I talked to new that it was going into a glass plane and suggested that I
>mount it this way. My question is: does this antenna need a ground plane?
yes
>What happens if the plane is upside down with the ground plane on top of the
>antenna? Will this block the signal?
it won't do it any good . . . but I wouldn't worry about
it. ELT's are a demonstrated abject failure in years past.
AOPA published a study some years ago that showed fewer
than 5% of folks who where saved by rescuers had their
ELT's to thank. The newer transmitters and satellites
may have improved on this but I'll bet it didn't double
it.
Bob . . .
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
| Subject: | Re: Ground Planes |
After tremendous overthinking and wonderfull help from the group, I'm going
to mount the antenna low in the rear fuselage, run 6 radials of 3/8" copper
tape, cover them with a 1 bid layup and NEVER CRASH MY PLANE!
Thanks,
Mike
________________________________________________________________________________
| From: | Mark Steitle <msteitle(at)mail.utexas.edu> |
| Subject: | Re: Copper tape for radials |
>
> >The tape on taperoll.com is 1" wide. Would the 3/8" work? Would I need
> more
> >radials?
>
> 3/8 will work. You don't need more radials.
>
> Bob . . .
>I tried to order a roll of 1" copper foil tape from taperoll.com this
>morning and was told that their minimum order is 10 rolls. I have some
>3/8" copper tape that I will use instead.
>
>Mark S.
>
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
| Subject: | understanding mag switches |
Bob:
In Z-11 - could you explain the mag switchs - I thought they were to ground a mag
- when off and just open a connection when hot - are these mags not regular
Slick mags - but instead some kind of electronic mags - that nead power?
one switch is listed as off-start/on and the other is off/on/start - what's this
all about - I also just got the switches and notice they are spring loaded in
one direction - so they return to center.
could you just explain how there switches are positions when you start and what
you do after the start - etc.
what's the advantage of these switches over just a regular on/off switch to ground
the mags.
thanks
---------------------------------
________________________________________________________________________________
| From: | John Mireley <mireley(at)pilot.msu.edu> |
| Subject: | Re: Copper tape for radials |
Copper tape is used to make some stained glass objects. An art shop or a
glass shop
should have it.
________________________________________________________________________________
| From: | MikeEasley(at)aol.com |
| Subject: | Re: Copper tape for radials |
I called the local stained glass shop and they have it in many different
sizes and IT'S CHEAP!
Mike
________________________________________________________________________________
| From: | Randy Pflanzer <F1Rocket(at)comcast.net> |
| Subject: | Re: understanding mag switches |
----- Original Message -----
From: Julia <wings97302(at)yahoo.com>
Date: Tuesday, March 11, 2003 12:54 pm
Subject: AeroElectric-List: understanding mag switches
>
>
> Bob:
>
> In Z-11 - could you explain the mag switchs - I thought they were
> to ground a mag - when off and just open a connection when hot -
> are these mags not regular Slick mags - but instead some kind of
> electronic mags - that nead power?
Julia, the power is needed to trigger the starter contactor. It
doesn't go to the mags. The spring-loaded up position of the left mag
switch is used as the starter switch.
>
> one switch is listed as off-start/on and the other is off/on/start
> - what's this all about - I also just got the switches and notice
> they are spring loaded in one direction - so they return to
> center.
Normal procedure would be to place the right mag swich in the down
(off/start) position while placing the left mag switch in the middle
(On) position. Then move the left mag switch to the start (Up)
position to engage the starter. When the engine starts, the left mag
switch returns to the middle (on) position. Then move the right mag
switch to the middle (on) position to fire both mags.
The up position of the right switch is really not used, but is paired
with the left mag switch so they are both in the same relative position
when on and off.
Two of the benefits is that these switches remove the need for a push-
to-start switch and they eliminate the inferior key switch.
Randy
F1 Rocket #95
http://mywebpages.comcast.net/f1rocket/
________________________________________________________________________________
| From: | SportAV8R(at)aol.com |
| Subject: | Re: Ground Planes |
In a message dated 03/11/2003 10:09:40 AM Eastern Standard Time,
bob.nuckolls(at)cox.net writes:
> Is it better/worse/same for the ground plane to curve towards the antenna
> tip
> >or away from it?
>
> Without going to the lab to measure it, one would
> be on thin ice to predict.
>
> Bob . . .
>
I'll risk a vote: sloping the radials away from a 1/4 wave vertical is a
technique used successfully to match to 50 ohms... 90 degree radials give
about 36 ohms feedpoint Z, and a dipole (essentially a single ground radial
at 180 degree slope from its quarter wave radiator counterpart) should come
in at 72 ohms, if I recall correctly. I seem to recall that the optimum
slope is about 120 degrees between radiator and ground plane (or radials) but
I could be hallucinating. Seems to me that sloping the radials toward the
tip of the antenna (or curving the ground plane in a similar fashion) would
invite a feedpoint Z of even less than 36 ohms (VSWR getting worse) as well
as mechanically shielding the radiator, thus interfering with its
performance. OTOH, maybe as you "pull the sides in," it behaves more like an
open length of tapered transmission line, and the characteristic Z could
begin to rise toward 50 ohms and even beyond... do I know what I'm talking
about? I doubt it.
Bob is right, however, to state that theory and real-world practice differ in
antenna work. It's mostly magic. Now that I have my MFJ-259 (thanks for
your note, Ferg), I could mock up such an antenna and try it out, but that
must wait till I get off work.
Will post results later ;-)
Bill B
RV-6A
________________________________________________________________________________
| From: | SportAV8R(at)aol.com |
| Subject: | Re: Ground Planes, Family Jewels |
In a message dated 03/11/2003 9:52:43 AM Eastern Standard Time,
MikeEasley(at)aol.com writes:
> 3/8" wide. It's not in the catalog, but I found it on an Internet search.
>
> Part # 11-12900 and they sell it by the foot, 30 cents/foot.
>
>
I have a roll of this stuff from RST engineering.. 1/2 inch wide if I recall
correctly. Contact me off list for availability. For small quantities, the
price might be the same as I paid for my film canister of fuel lube a long
time ago... thanks and bless you, whoever that was!
Bill B
________________________________________________________________________________
| Subject: | Re: understanding mag switches |
| From: | "Matt Prather" <mprather(at)spro.net> |
Please see comments below.
>
>
> ----- Original Message -----
> From: Julia <wings97302(at)yahoo.com>
> Date: Tuesday, March 11, 2003 12:54 pm
> Subject: AeroElectric-List: understanding mag switches
>
>>
>>
>> Bob:
>>
>> In Z-11 - could you explain the mag switchs - I thought they were to
>> ground a mag - when off and just open a connection when hot - are
>> these mags not regular Slick mags - but instead some kind of
>> electronic mags - that nead power?
>
> Julia, the power is needed to trigger the starter contactor. It
> doesn't go to the mags. The spring-loaded up position of the left mag
> switch is used as the starter switch.
If you look at the switch diagram, you can see where the 12V input lead
is routed when its in the up position - the starter, not the mag.
>>
>> one switch is listed as off-start/on and the other is off/on/start -
>> what's this all about - I also just got the switches and notice they
>> are spring loaded in one direction - so they return to
>> center.
>
> Normal procedure would be to place the right mag swich in the down
> (off/start) position while placing the left mag switch in the middle
> (On) position. Then move the left mag switch to the start (Up)
> position to engage the starter. When the engine starts, the left mag
> switch returns to the middle (on) position. Then move the right mag
> switch to the middle (on) position to fire both mags.
>
I would add that the reason to only use the left mag for starting is that
many airplane save a little money and weight by only equipping one of the
mags with an impulse coupling (as shown in Z-11). The mag without the
coupling cannot be used while starting because its timing is fixed in the
25-30deg BTDC range. If the mag sparked (which it might not at slow
cranking speeds) it would cause kickback.
> The up position of the right switch is really not used, but is paired
> with the left mag switch so they are both in the same relative position
> when on and off.
>
> Two of the benefits is that these switches remove the need for a push-
> to-start switch and they eliminate the inferior key switch.
>
> Randy
> F1 Rocket #95
> http://mywebpages.comcast.net/f1rocket/
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Copper tape for radials |
>
>
> >I tried to order a roll of 1" copper foil tape from taperoll.com this
> >morning and was told that their minimum order is 10 rolls. I have some
> >3/8" copper tape that I will use instead.
> >
> >Mark S.
> >
Hmmm . . . I bought two rolls from them about two years
ago . . . but that was probably combined with another
large order. I'll look around for another supplier. There
have been posts for other sources. Another source I used
to use years ago was foil from hobby shops used for embossed
artwork. This stuff came in rolls 6 to 12" wide and no adhesive.
Not a big deal since you want to put down a layer of glass
and epoxy over the radials anyhow. You can cut 1" wide
strips and put them end-to-end as needed to make up the
total desired length (as measured from the bottom of the
antenna). Splices can be soldered at the same time you
solder the radials to your grounding plate at the base.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Ground Planes |
>
>Bob is right, however, to state that theory and real-world practice differ in
>antenna work. It's mostly magic. Now that I have my MFJ-259 (thanks for
>your note, Ferg), I could mock up such an antenna and try it out, but that
>must wait till I get off work.
Actually, it's pretty predicable . . . IF . . . you have
the right tools. We have a department within the RAC
hierarchy that owns a kind of finite-element analysis
for conductors excited with radio frequency energy.
We've used them to get us in the ball park for predicting
antenna performance on several biz jets.
But for us little guys, it's a cut-n-try activity.
>Will post results later ;-)
Take some pics and show us the results. I'll publish
it on the website.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Alt. Field Circuit Breaker |
We have an SNJ-4 with 24 volt electrical system, they tell me
the battery will last for about 20 starts and then goes dead. I inquired
about their trouble shooting and was advised they had replaced the reverse
current relay and flashed the generator field, no help. I suggested, rather
than a no charge situation, they have a low amp drain? Any suggestions on
trouble shooting.
________________________________________________________________________________
| From: | Howard Ogle <pub(at)macrotechcorp.com> |
| Subject: | RG battery location |
Bob,
What are your thoughts with placing the battery(s) inside the cockpit behind the
instrument panel?
I'm building an all electric Glasair III with dual alternators, dual batteries,
electronic ignition, etc. One of the results of having EFIS flat screens as
primary displays, combined with the compactness of RG batteries, there is space
for the battery behind the instrument panel. Conventionally, the battery in
Glasairs has either been located on the firewall or behind the pilot or copilot
seats. The majority of Glasair IIIs that I have seen have their battery(s)
located on the firewall, partially due to CG and partially due to convenience.
Now with the advent of RG batteries and EFIS with smaller electronics, what are
the pros and cons to having the battery(s) in the panel? (I say battery(s),
because I haven't made a final decision on whether I want to carry the extra
weight of two batteries, verses, the extra redundancy.)
I see some advantage inside the cabin. The battery would not see the same
temperature extremes as it would on the firewall. Contactors would also enjoy a
more friendly environment. Taking the battery off the firewall allows more room
for engine maintenance or more room for that inverted oil system. In my case,
I'm mounting two oil coolers at the rear of the engine with the air exiting down
and out the cowl flaps. Having no firewall battery offers some extra room for
controlling airflow aft of the engine. Plus, it keeps warm air away from the
batteries and contactors.
Another advantage is fewer wires to run through the firewall. Even though there
certainly are plenty of other wires (EGT, CHT, temp, pressure, etc.). The more
critical wires that control battery contactors, crossfeed, and starter relay
would remain inside. Presumably, a slightly more reliable relay system would
result. Also, the main and aux bus feeds would originate and stay inside with
very short runs. A central ground point can still be maintained. However, the
fat starter, alternator and engine ground runs would lengthen about a foot.
As far as gaining access to the battery, I've devised a panel design that would
allow access to the battery probably as easy or easier than removing the Glasair
cowl. A counter point to this would be that now there would be another location
(the panel mounted battery) that would require routine maintenance (regular
battery replacement).
RG batteries are ideally maintenance free. Under normal conditions; they don't
expel gases or puke acid. Yet, they have a small vent hole. Extreme over
charging an RG battery can cause it to overheat and vent some gases. I have not
found any information that quantifies this. Nonetheless, I would think that a
proper system with OV protection, maintained and monitored at a reasonable
charging level (assuming 13.8V) should not cause any gases to be expelled.
Obviously there are concerns of dripping acid or battery fumes this close to
pilot and passenger. Additionally, there are nearby expensive electronics, as
well. Traditional thinking would lead one to think a battery in this location
would be no good. But, everyday I walk past a room full of expensive internet
computers that are battery backed up with the same battery technology. There is
not even a second thought given to the same twenty 17Ah batteries in the
equipment racks within inches of other electronics. Yes, they are inside
aluminum UPS cases. But, the cases are vented alongside the computers. So, if
designers of computer UPS systems see no problem with RG batteries being in
close proximity to expensive electronics, why should we worry about this issue?
Although, unlike the computer room, our airplane environment sees extreme
altitude and pressure changes. Does this have an effect on the environmental
cleanliness of RG batteries?
One thought would be to put the battery in a sealed box only vented to the
outside world. But, this might be completely unnecessary and certainly
complicates a panel mounted installation. Not to mention, it makes routine
battery replacement a little more difficult. At some point, the battery might as
well be back out on the firewall.
Of course, there is the concern of safety. First, let's assume the battery mount
can withstand at least 10Gs. Beyond that in a crash hard enough to potentially
rupture an RG battery, I don't think it makes much difference which side of
firewall the battery is located. A crash this hard is probably fatal anyway. As
far as sparks, having the master switch OFF is the best defense against post
crash fire caused by electrical faults. I don't see where battery location makes
much difference. Sparks generally come from wires, not the battery. Regardless
of battery location, precautions need to be made with wires running near header
fuel lines, either way.
After many years of having the battery located on firewall or in a compartment
away from occupants and equipment, there is something emotionally wrong with
locating it in the panel. But, unless my logic is flawed, what are the negatives
to a panel location? With ever shrinking electronics, flat panel displays and RG
batteries, why not put the battery behind the panel, even in close proximity to
occupants and electronics? I welcome comments and feedback.
Howard Ogle
________________________________________________________________________________
| From: | John Loram <johnl(at)loram.org> |
| Subject: | Re: defending the "familiy jewels" . . . |
Well, I must confess that this all peaked my interest, so I did a bit of
Internet searching and it appears that my dad was not pulling my leg. Here
are some references:
http://www.pipe-line.com/archive/archive_99-06/99-06_induced-smart.html
This describes some of the problems that occur when a well insulated pipe
line follows a power line corridor. I spoke with the primary author of this
paper and he said that a 1/2 mile of wire will work just fine for
substantial currents. He said power companies "really don't like it"!
http://www.sestech.com/software_packages/row.asp
This is a software package from a Canadian company that computes "the
voltages and currents transferred from electric power lines and cables to
pipelines and railways, whether buried or above ground."
http://www.mitton.co.nz/emf.html
A New Zealand consulting company that helps power companies solve these
problems.
http://www.ewh.ieee.org/r5/denver/rockymountainemc/2001symposium/2001techpro
g.htm#Title:%20Interference%20of%20AC%20Power%20Transmission%20Lines%20with%
20Railroad%20Signal%20Systems
An IEEE paper describing the problems that railroads have.
http://www.usbr.gov/power/data/fist/fist5~1/5~1_14.htm
This US Bureau of Reclamation document has a table of voltages and currents
found on deenergized power lines that parallel energized lines. I know that
the Tracy-Contra Costa line (600 volts, 49 amps) is tens of miles long.
So, the bottom bottom line is that there are significant safety issues for
pipe lines, telecommunication lines, and railway workers due to induced and
through-earth coupling and apparently you can deliberately pick up useful
and sometimes dangerous amounts of electrical energy.
All this said, there's no good science that indicates a problem with an
individual standing near an electrical transmission line.
-john-
p.s. No, I never did find any stories about farmers... ;-)
-----Original Message-----
From: Robert L. Nuckolls, III [mailto:bob.nuckolls(at)cox.net]
Subject: AeroElectric-List: Re: defending the "familiy jewels" . . .
>
>I hesitate to perpetuate this story (and reveal my gullibility); My dad was
>a civil engineer who worked for the Pacific Gas & Electric company laying
>out long transmission lines and supervising their installation. I spent one
>summer about 50 years ago with him, driving the back roads of California on
>his job and he told me that one of the reasons that the transmission lines
>are rotated every few thousand feet (they don't just stay in the same
>relative position for the full run) was to prevent farmers from laying a
>loop of lines parallel to the transmission lines and inductively coupling
>some free watt hours.
Actually, that's done to improve the transmission line characteristics
of the parallel run of wires (same thing as twisting wires under
the shields for reduced coupling to environment). It reduces the
need for power factor correction and has a small but beneficial
improvement on transmission efficiency.
A friend of mine (PhD EE) was asked to testify in a personal
damages case against a power line company wherein the plaintiff
alleges he was injured by the proximity to a high voltage transmission
line running near his property.
Coupling energy from a power line via either magnetic parallel
conductors or electrostatic means at 60Hz was calculated as
very difficult to do. Close proximity effects of high-voltage,
high-current conductors falls off as the square of the distance.
Further, instead of using magnetically friendly laminated iron
as the core of a transformer, you are limited to using very
unfriendly air as the magnetic conduction medium. Tesla
did a lot of work to prove his theories for wireless
transmission of energy . . . he succeeded in doing a lot
of spectacular lightning like displays but never succeeded
in piping significant energy through the ether for more
than a few yards . . . and it wasn't in a form friendly
to running your toaster.
Bottom line is that all such stories were cooked up at
the expense of the listeners. People who worked in and
around such equipment all their careers showed no
particular increase in incidence of any health problems.
If any farmer was able to conduct any energy away from the
vicinity of a power line, it would have been measured in
milliwatts.
Bob . . .
________________________________________________________________________________
| From: | "Tom Schiff" <tomschiff(at)attbi.com> |
I am beginning to scrounge "Stuff" for my GlaStar that should be
finished in the fall of 2004. Just wondered if most homebuilts are 12
volt. I keep hearing about automotive alternators and I assume that they
are 12 volt or can they be regulated out to 28 volt.
Can most avionics (not the newest King KX155's which are 28 volt only)
be had in 12 volt versions?
________________________________________________________________________________
| From: | Miller Robert <rmiller3(at)earthlink.net> |
| Subject: | Re: defending the "familiy jewels" . . . |
John Loram wrote:
> All this said, there's no good science that indicates a problem with an
> individual standing near an electrical transmission line.
> -john-
>
I can't agree here. I think that that statement may have been true until about
a decade ago (as Bob said). But since, several good prospective studies have
been completed showing health risks with exposure over time to common
electromagnetic fields. I reference again the Swedish study that identified
risk in many household items and even the fields around the flourescent lights
we all work under. A number, now, of good studies have appeared supporting
these results, which are as good science as any of us do.
Unfortunately, I've been around long enough to know that even good science
isn't always going to be everlasting reality. (Witness the new view of neutron
stars and "strange quark stars" published this past year. A lot of people got
their degrees writing theses using the old model, now turned on its head.
That's the fun of doing science.) But until, and if, equally good opposing
studies are published, it is not fair to say "there is no good science." The
science showing risk is good.
Robert
>
> Well, I must confess that this all peaked my interest, so I did a bit of
> Internet searching and it appears that my dad was not pulling my leg. Here
> are some references:
>
> http://www.pipe-line.com/archive/archive_99-06/99-06_induced-smart.html
> This describes some of the problems that occur when a well insulated pipe
> line follows a power line corridor. I spoke with the primary author of this
> paper and he said that a 1/2 mile of wire will work just fine for
> substantial currents. He said power companies "really don't like it"!
>
> http://www.sestech.com/software_packages/row.asp
> This is a software package from a Canadian company that computes "the
> voltages and currents transferred from electric power lines and cables to
> pipelines and railways, whether buried or above ground."
>
> http://www.mitton.co.nz/emf.html
> A New Zealand consulting company that helps power companies solve these
> problems.
>
> http://www.ewh.ieee.org/r5/denver/rockymountainemc/2001symposium/2001techpro
> g.htm#Title:%20Interference%20of%20AC%20Power%20Transmission%20Lines%20with%
> 20Railroad%20Signal%20Systems
> An IEEE paper describing the problems that railroads have.
>
> http://www.usbr.gov/power/data/fist/fist5~1/5~1_14.htm
> This US Bureau of Reclamation document has a table of voltages and currents
> found on deenergized power lines that parallel energized lines. I know that
> the Tracy-Contra Costa line (600 volts, 49 amps) is tens of miles long.
>
> So, the bottom bottom line is that there are significant safety issues for
> pipe lines, telecommunication lines, and railway workers due to induced and
> through-earth coupling and apparently you can deliberately pick up useful
> and sometimes dangerous amounts of electrical energy.
>
> All this said, there's no good science that indicates a problem with an
> individual standing near an electrical transmission line.
> -john-
> p.s. No, I never did find any stories about farmers... ;-)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Dual E.I. and Batteries, single Alt. |
>
> > Bob . . .
>Perhaps I didn't give this as much thought as I should have. I only saw an
>opportunity to eliminate a switch.
>My thought was that with a low voltage light, I would open both the main
>battery and the aux battery contactor to remove power from the main power
>bus. I would at the same time need to close the essential bus alternate
>feed switch to keep power to the essential bus. I see now that when I shut
>down, I would be leaving power to the essential bus. Not a good idea. Is
>there any good way to reduce from three switches
Probably . . . but keep in mind that the "elegant solutions"
minimize the sharing of hardware between functions that back
each other up. For example, I just mailed a power distribution
diagram back to a reader who was proposing that ign #1, and ign #2
share a common fuse and be selected from a single-pole,
double-throw switch. With this arrangement, mechanical failures
of switch or wiring between switch and bus disables both ignition
systems. Also, electrical failure of one blows the fuse and
kills both.
Failure tolerance is achieved by maximizing the distance
between complimentary systems, not bringing them closer
together.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: RG battery location |
>
>Bob,
>
>What are your thoughts with placing the battery(s) inside the cockpit
>behind the
>instrument panel?
>
>I'm building an all electric Glasair III with dual alternators, dual
>batteries,
>electronic ignition, etc. One of the results of having EFIS flat screens as
>primary displays, combined with the compactness of RG batteries, there is
>space
>for the battery behind the instrument panel. Conventionally, the battery in
>Glasairs has either been located on the firewall or behind the pilot or
>copilot
>seats. The majority of Glasair IIIs that I have seen have their battery(s)
>located on the firewall, partially due to CG and partially due to convenience.
>Now with the advent of RG batteries and EFIS with smaller electronics,
>what are
>the pros and cons to having the battery(s) in the panel? (I say battery(s),
>because I haven't made a final decision on whether I want to carry the extra
>weight of two batteries, verses, the extra redundancy.)
Keep in mind that two batteries does not have to mean 2x
the weight. First, a properly maintained RG battery is going
to be the most reliable power source in your airplane. If you
want/need the reliability offered by separate batteries,
then how about two SMALLER batteries. Besides if you're doing
all-electric with two alternators and assuming further that
you choose B&C alternators, then you are on solid ground
running your airplane battery like your car battery. Flog
it until it quits cranking. You're not going to find
yourself aloft with a dark panel. Assembled and maintained
with due diligence, Figure Z-11 with B&C hardware gives you
reliability with simplicity unequaled anywhere else in aviation.
>I see some advantage inside the cabin. The battery would not see the same
>temperature extremes as it would on the firewall. Contactors would also
>enjoy a
>more friendly environment. Taking the battery off the firewall allows more
>room
>for engine maintenance or more room for that inverted oil system. In my case,
>I'm mounting two oil coolers at the rear of the engine with the air
>exiting down
>and out the cowl flaps. Having no firewall battery offers some extra room for
>controlling airflow aft of the engine. Plus, it keeps warm air away from the
>batteries and contactors.
>
>Another advantage is fewer wires to run through the firewall. Even though
>there
>certainly are plenty of other wires (EGT, CHT, temp, pressure, etc.). The more
>critical wires that control battery contactors, crossfeed, and starter relay
>would remain inside. Presumably, a slightly more reliable relay system would
>result. Also, the main and aux bus feeds would originate and stay inside with
>very short runs. A central ground point can still be maintained. However, the
>fat starter, alternator and engine ground runs would lengthen about a foot.
>
>As far as gaining access to the battery, I've devised a panel design that
>would
>allow access to the battery probably as easy or easier than removing the
>Glasair
>cowl. A counter point to this would be that now there would be another
>location
>(the panel mounted battery) that would require routine maintenance (regular
>battery replacement).
>
>RG batteries are ideally maintenance free. Under normal conditions; they don't
>expel gases or puke acid. Yet, they have a small vent hole. Extreme over
>charging an RG battery can cause it to overheat and vent some gases. I
>have not
>found any information that quantifies this. Nonetheless, I would think that a
>proper system with OV protection, maintained and monitored at a reasonable
>charging level (assuming 13.8V) should not cause any gases to be expelled.
>Obviously there are concerns of dripping acid or battery fumes this close to
>pilot and passenger. Additionally, there are nearby expensive electronics, as
>well. Traditional thinking would lead one to think a battery in this location
>would be no good. But, everyday I walk past a room full of expensive internet
>computers that are battery backed up with the same battery technology.
>There is
>not even a second thought given to the same twenty 17Ah batteries in the
>equipment racks within inches of other electronics. Yes, they are inside
>aluminum UPS cases. But, the cases are vented alongside the computers. So, if
>designers of computer UPS systems see no problem with RG batteries being in
>close proximity to expensive electronics, why should we worry about this
>issue?
>Although, unlike the computer room, our airplane environment sees extreme
>altitude and pressure changes. Does this have an effect on the environmental
>cleanliness of RG batteries?
A characteristic of smaller RG batteries that makes them so very
inexpensive these days is the fact that they are manufactured
by the millions for use as backup power in un-interruptible power
supplies for computers. These batteries live quietly under the
desks of countless workers who will never be aware of their
existence. Not true should the battery be of the flooded variety.
Had one charging on my workbench a few months ago, could smell
it from across the room.
Van's designs have mounted batteries in the cabin since
day-one. A Tri-Pacer I used to fly had the battery under
the right-front seat. There is no good reason why a battery
cannot comfortably co-exist with people in the same space . . .
even if it's flooded but ESPECIALLY an RG design.
RG batteries are the product of choice. They don't need a battery
box (in fact are safer if you DON'T have a battery box). They
deliver superior performance compared to flooded batteries of
yesteryear in EVERY environmental regard.
>One thought would be to put the battery in a sealed box only vented to the
>outside world. But, this might be completely unnecessary and certainly
>complicates a panel mounted installation. Not to mention, it makes routine
>battery replacement a little more difficult. At some point, the battery
>might as
>well be back out on the firewall.
>
>Of course, there is the concern of safety. First, let's assume the battery
>mount
>can withstand at least 10Gs. Beyond that in a crash hard enough to potentially
>rupture an RG battery, I don't think it makes much difference which side of
>firewall the battery is located. A crash this hard is probably fatal
>anyway. As
>far as sparks, having the master switch OFF is the best defense against post
>crash fire caused by electrical faults. I don't see where battery location
>makes
>much difference. Sparks generally come from wires, not the battery. Regardless
>of battery location, precautions need to be made with wires running near
>header
>fuel lines, either way.
>
>After many years of having the battery located on firewall or in a compartment
>away from occupants and equipment, there is something emotionally wrong with
>locating it in the panel. But, unless my logic is flawed, what are the
>negatives
>to a panel location? With ever shrinking electronics, flat panel displays
>and RG
>batteries, why not put the battery behind the panel, even in close
>proximity to
>occupants and electronics? I welcome comments and feedback.
Let not your heart be troubled . . . for all the fire-breathing
capabilities of an RG battery, you have never had a greater
opportunity to design your airplane for efficiency of space and
function with virtually no risk from the concerns cited. Mount
it where it fits best.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: 12 vs 28 volts |
>
>I am beginning to scrounge "Stuff" for my GlaStar that should be
>finished in the fall of 2004. Just wondered if most homebuilts are 12
>volt. I keep hearing about automotive alternators and I assume that they
>are 12 volt or can they be regulated out to 28 volt.
>
>Can most avionics (not the newest King KX155's which are 28 volt only)
>be had in 12 volt versions?
The majority of homebuilts are indeed 12/14 volt systems.
This allows one to maximize utilization of automotive
hardware that for the most part, is equal to or better than
much of what's 'certified'.
If it were my airplane, I'd build a 14v machine and select
hardware that runs in that environment. I've never understood
the rational for building a 28v machine because "the radio(s)
I want to put in the plane are only available in 28v".
In the long run, the cost of ownership in time and maintenance
dollars for a 14v electrical system will be much less than
a 28v system.
Bob . . .
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
"> Is it better/worse/same for the ground plane to curve towards the antenna
> tip> >or away from it?"
It is worse. The ideal 1/4wavelength Monopole (or vertical
quarterwave) GENERALLY requires the radiator to be a small percentage
shorter than [1/4 wavelength in air] because it is in metal which has
different transmission speed, reversal delays and end effects. For the same
reason, the groundplane against which the 1/4wave works, is very slightly
longer. We're talking 1 or 2%.
Secondly, the ideal groundplane for a vertical 1/4wave should
droop away from the vertical element at 45deg in order to concentrate the
transmission horizontally at 360deg. Also, any disassociated metal material
within about 1/2wavelength will distort an ideal radiation pattern.
Thirdly, the size and extent of the groundplane affects the
impedance of the antenna at the working frequency.
Fourth, since most ground antennas are vertical [vertically
polarised], the ideal antenna should be too, since a horizontal antenna will
lose up to 20db when 90deg out of plane. 20db is a discernable amount to
most ears.
While all of this is true (viz.ARRL Antenna Book, 2nd to 7th
ed.), the practicality of all this is that one attempts to approach the
ideal to 'tweak' the signal for maximum strength in most directions. Bob is
as usual right about not fussing too much about perfection, but to follow
common sense in achieving the above, to instal it and to try it out.
Vertical 1/4waves are the simplest, and easiest, and most common
in homebuilts. Of course there are other forms of transceiver antenna, and
since we are not designers, it's best to follow the maker's instructions in
those. i hope this corrects the impression of many that if the connector
matches, the hookup is perfect. If you really want to perfect the system, I
suggest again to contact the local Amateur Radio Club and fish for an old
ham - he's probably built and tested 30 antennas.
Good hunting,
Ferg
diesel Europa
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: defending the "familiy jewels" . . . |
>
>Well, I must confess that this all peaked my interest, so I did a bit of
>Internet searching and it appears that my dad was not pulling my leg. Here
>are some references:
>So, the bottom bottom line is that there are significant safety issues for
>pipe lines, telecommunication lines, and railway workers due to induced and
>through-earth coupling and apparently you can deliberately pick up useful
>and sometimes dangerous amounts of electrical energy.
>
>All this said, there's no good science that indicates a problem with an
>individual standing near an electrical transmission line.
>-john-
>p.s. No, I never did find any stories about farmers... ;-)
Sure. Keep in mind that all of the instances cited are
situations where there are LONG, parallel conductors
involved. Large floating (insulated) conductors become
an issue too (remember grounding leads attached to
airplanes before the line man approaches the tank
with a fuel hose?). I got the snot knocked out of
me on an antenna maintenance climb in the oil patch
about 40 years ago. The tower had been put up by
the owner. Somewhere, he got the idea that it was
a good thing to put insulators in both ends of his
guy lines. I didn't know enough to look and pay attention.
At the top of the tower, I grabbed the insulated
portion of a guy line than was probably 300+ feet in
length. The static charge on this line was really
attention getting.
My boss told the owner that we were going to make
some "modifications" to his installation and bill
him for them before we would do any more maintenance
on his system. This was a 170' tower with guy lines
every 30'. We went back out and put bonding
jumpers over the insulators on all 15 guy wires.
The problem is that all of these things which are
calculable, predictable and have operational
considerations for folks in the businesses cited,
tend to be extrapolated into new stories and ideas.
The idea that any farmer owns enough land under
a power line to "steal" useful amounts of energy from
it just doesn't fly in the real world.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Alt. Field Circuit Breaker |
>
>
> We have an SNJ-4 with 24 volt electrical system, they
> tell me
>the battery will last for about 20 starts and then goes dead. I inquired
>about their trouble shooting and was advised they had replaced the reverse
>current relay and flashed the generator field, no help. I suggested, rather
>than a no charge situation, they have a low amp drain? Any suggestions on
>trouble shooting.
Get a meter out and find out. What's the bus voltage with the
engine running and generator on? What's a "low-amp drain"? Are there
things attached to the battery when the master switch is off?
On what evidence of malfunction was the relay replaced?
Bob . . .
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)tenforward.com> |
| Subject: | Re: Clock consumption |
Comments at end of snipped reply.
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: Clock consumption
>
> >
>
> >This connection is "another" failure mode of internal regulators that
cannot
> >be stopped by removing the connection to the ign switch. Sure the field
> >power transistor can short but its also likely that a failure can be
> >internal to the regulator that turns on that transistor.
> >
> >This can lead to a rare alternator failure where an internal output
circuit
> >short (diodes perhaps) can result in a self excited overload that ends up
in
> >a fire. Why its so important to have control of the field supply and why
I
> >would never have an internal regulated setup on my aircraft where the "B"
> >lead supplied the internal regulator.
>
> sure . . . this is where the b-lead contactor for ov disconnect
> came into being . . .
I agreed with the above "protection" until recently when I looked into the
result of the failure mode after the "B" lead was disconnected as above.
More analysis showed me that while protecting the aircraft electronics, the
"B" lead contactor did nothing to protect the alternator from severe over
heating and possible fire. Thus I have concluded that the above protection
circuit is only a partial fix and that ANY alternator protection circuit for
aircraft must also disconnect the field current.
Thus its necessary to either use an externally connected regulator or break
the internal regulator to "B" lead connection. In some alternators this is a
very simple cut and in others its not practical to do.
The "B" lead contactor is opened due to an alternator overvoltage from some
failure in the internal regulator. Its reasonable to assume this is from a
total loss of control of field current and one likely result is full
alternator output voltage is applied to the field thru the internal "B" lead
connection.
Alternators can be considered current sources and the output voltage will
rise (with unregulated field current) to what ever level is needed to find a
load that will sink the output current. Thus when the "B" lead contactor
opens, the alternator voltage will rise as there is only the field load
remaining (plus any internal shorted components).
The rising output voltage will rise until the internal diodes start shorting
out from overvoltage and this provides additional load (HEAT).
In aircraft there is no way to stop the turning of the alternator and my
analysis suggests the overheated alternator can really get hot and start to
affect nearby engine components.
In conclusion I am not sure that protecting the avionics and letting the
engine compartment overheat and possibly catching fire is worth the use of
an internally regulated alternator and blissfully thinking that the OV
controlled "B" lead contactor is sufficient protection.
Short of a actual test, I remain unconvinced that a simple disconnect of the
output ("B") lead of an 'out of control alternator' is safe for aircraft.
Also testing would need to be performed on each brand etc of proposed
alternator as internal failure modes are likely to differ due to internal
construction. Would the load burn the windings open before the unit got hot
enough to cause secondary damage??
The additional cost for an externally regulated alternator is likely to be
far less than 1% of the cost of the total aircraft it seems foolish to me to
even consider using an internally regulated alternator.
Paul
________________________________________________________________________________
| From: | "Phil Birkelbach" <phil(at)petrasoft.net> |
| Subject: | Re: 12 vs 28 volts |
What about using a DC-DC converter? I found a bunch of them on Google.
Here is the search that I did...
http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=dc+to+dc+converter+12
v+24v
Don't know if there are any drawbacks (noise issues, etc) They seem
somewhat heavy, and I didn't find any prices so they may cost a mint but it
would allow you to use a 24VDC radio in a 12VDC system.
Godspeed,
Phil Birkelbach - Houston Texas
RV-7 N727WB (Reserved) - Fuselage
http://www.myrv7.com
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: 12 vs 28 volts
>
> >
> >I am beginning to scrounge "Stuff" for my GlaStar that should be
> >finished in the fall of 2004. Just wondered if most homebuilts are 12
> >volt. I keep hearing about automotive alternators and I assume that they
> >are 12 volt or can they be regulated out to 28 volt.
> >
> >Can most avionics (not the newest King KX155's which are 28 volt only)
> >be had in 12 volt versions?
>
> The majority of homebuilts are indeed 12/14 volt systems.
> This allows one to maximize utilization of automotive
> hardware that for the most part, is equal to or better than
> much of what's 'certified'.
>
> If it were my airplane, I'd build a 14v machine and select
> hardware that runs in that environment. I've never understood
> the rational for building a 28v machine because "the radio(s)
> I want to put in the plane are only available in 28v".
>
> In the long run, the cost of ownership in time and maintenance
> dollars for a 14v electrical system will be much less than
> a 28v system.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: runaway, self regulated alternators |
>
> >
> > sure . . . this is where the b-lead contactor for ov disconnect
> > came into being . . .
>
>
>I agreed with the above "protection" until recently when I looked into the
>result of the failure mode after the "B" lead was disconnected as above.
>More analysis showed me that while protecting the aircraft electronics, the
>"B" lead contactor did nothing to protect the alternator from severe over
>heating and possible fire. Thus I have concluded that the above protection
>circuit is only a partial fix and that ANY alternator protection circuit for
>aircraft must also disconnect the field current.
The risk is to the field windings which get mucho volts applied
to them during the runaway event . . . which doesn't last long.
Perhaps 10 seconds before the field wires burn in two. Where
is the concentration of energy liberation adjacent to combustibles that
poses a risk of fire?
>Thus its necessary to either use an externally connected regulator or break
>the internal regulator to "B" lead connection. In some alternators this is a
>very simple cut and in others its not practical to do.
>
>The "B" lead contactor is opened due to an alternator overvoltage from some
>failure in the internal regulator. Its reasonable to assume this is from a
>total loss of control of field current and one likely result is full
>alternator output voltage is applied to the field thru the internal "B" lead
>connection.
>
>Alternators can be considered current sources and the output voltage will
>rise (with unregulated field current) to what ever level is needed to find a
>load that will sink the output current. Thus when the "B" lead contactor
>opens, the alternator voltage will rise as there is only the field load
>remaining (plus any internal shorted components).
>
>The rising output voltage will rise until the internal diodes start shorting
>out from overvoltage and this provides additional load (HEAT).
But consider that an alternator is incapable of delivering
any more current than it's magnetics will support . . . even
in a runaway condition, a 60A alternator is still a 60A alternator.
(our technique for running 14 volt alternators in a 28v system
using a special regulator might be called a "controlled runaway"
except that we go to pains to make sure the field is not over
driven . . . but it's still a 40/60A alternator).
So any degree of heating (I-squared*R) is relatively constant
irrespective of how much voltage the machine is generating during
an open circuit runaway. Shorting diodes is the best thing
you could hope for. A shorted diode is a cooler diode. Further,
as soon as you take out an upper/lower pair of diodes in the
full-wave array, output voltage goes to zero, field excitation
goes away and the critter stalls and shuts itself down. The
worst case is that the diodes hang in there (most are capable of a LOT
more that we might suspect) and 100+ volts makes raises
field current to 25 amps or so . . . that 22AWG copper field
winding won't stay in place very long. Exposed leadwires
would fuse before the field winding proper even has a chance
to warm up. It's all over in seconds.
>In aircraft there is no way to stop the turning of the alternator and my
>analysis suggests the overheated alternator can really get hot and start to
>affect nearby engine components.
>
>In conclusion I am not sure that protecting the avionics and letting the
>engine compartment overheat and possibly catching fire is worth the use of
>an internally regulated alternator and blissfully thinking that the OV
>controlled "B" lead contactor is sufficient protection.
>
>Short of a actual test, I remain unconvinced that a simple disconnect of the
>output ("B") lead of an 'out of control alternator' is safe for aircraft.
>Also testing would need to be performed on each brand etc of proposed
>alternator as internal failure modes are likely to differ due to internal
>construction. Would the load burn the windings open before the unit got hot
>enough to cause secondary damage??
>
>The additional cost for an externally regulated alternator is likely to be
>far less than 1% of the cost of the total aircraft it seems foolish to me to
>even consider using an internally regulated alternator.
We've see the test. There was at least one builder
who sent his alternator back for overhaul wherein he
failed to provide ANY kind of ov protection and assumed
that the alternator had a built in regulator. So through
a combination of mis-wiring and poor choice of switch
arrangements, he managed to get an alternator on line
without a battery or regulator. The alternator didn't
even smell really bad. The leadwire between slip ring
and field winding had opened like a fusible link. We
could probably have spliced it and the alternator would
have worked fine.
Disconnecting the B-lead insures the behavior we've
observed. Output voltage goes very high until the
relatively small field wire opens. If diodes do
short very quickly, the alternator may shut itself
down before the field wire has a chance to fuse.
Bob . . .
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
bob:
since the OVM-14's are relatively tiny and light units, could one put two of these
in and that way if one failed, the other would be there to work? My worry
with things like this is always what do I do if 6 years from now, this OVM-14
fails and B&C Electirical doesn't sell it anymore? Would a typical A&P mechanic
have a clue as to how to replace this particular module - if we were so fortunate
as to be able to figure out that it even failed?
What do you think - would this work? See Z-11 - the OVM-14 just goes from the
pin 4 wire to ground - so just add another in beside it going from pin #4 to ground.
thanks
---------------------------------
________________________________________________________________________________
| Subject: | Good deals on hardware from B&B Aircraft |
| From: | czechsix(at)juno.com |
Guys,
Just a heads up for those wanting to save a few bucks on misc hardware and electrical
stuff. Give B&B Aircraft a call at (913) 884-5930. I just ordered a 5
A Klixon circuit breaker from them for $7.50 (surplus but new/unused condition).
Normally these are over $20 new. Also got some of the little camloc wheel
pant access doors (for filling tires) for $7.50 each, Aircraft Spruce charges
$10 for these last I checked. They have good prices on pop rivets, misc AN
hardware, etc. too....
--Mark Navratil
Cedar Rapids, Iowa
RV-8A N2D fwf and wiring...
________________________________________________________________________________
| From: | czechsix(at)juno.com |
Guys,
This is not to take business away from 'Lectric Bob, just if you are like me and
need a fuseblock something in between the 6/10/20 slots Bob carries I found
some at JCWhitney. In my case I wanted about a dozen slots but didn't want to
go all the way to 20 slots just for a few spares.
See the assortment at:
http://www.jcwhitney.com/product.jhtml?CATID=5650&BQ=jcw2
6-slot $14.99
8-slot $16.99
10-slot $17.99
12-slot $17.99
14-slot $20.99
18-slot $22.99
Not sure if they are the same quality that Bob sells but they are rated at 25 amps
per circuit, and since I don't plan to put more than 8 amps max on any one
circuit that should be more than adequate for my purposes.
--Mark Navratil
Cedar Rapids, Iowa
RV-8A N2D firewall forward and wiring...
________________________________________________________________________________
| From: | Rob Miller <rmill2000(at)yahoo.com> |
| Subject: | Electric RC Allen A/H Woes Part 2 |
Hi Listers
You may remember back in December I was having trouble with my new, nearly
$2000 RC Allen artificial horizon. It failed less than an hour after
installation without warning. I sent it back to the factory under
warranty and it was returned one month later following "repairs."
I recently reinstalled the unit and it again failed within minutes. After
about ten minutes it started a gentle roll to the right then began
tumbling like a washing machine on the spin cycle.
Fearing that this item is going to get me killed, I'm removing it
permanently. Here's to Dynon, Blue Mountain or anyone else who can build
something that is reliable!!
Rob Miller
RV-8 N262RM "Bad Cat" 48 hours
________________________________________________________________________________
| From: | Freddie Freeloader <lists(at)stevet.net> |
| Subject: | Re: RG battery location |
Hello Howard,
Tuesday, March 11, 2003, 3:06:01 PM, you wrote:
HO> Bob,
HO> What are your thoughts with placing the battery(s) inside the cockpit behind
the
HO> instrument panel?
HO> I'm building an all electric Glasair III with dual alternators, dual batteries,
HO> electronic ignition, etc.
HO> >snip<
Howard, I, too, am building a Glasair with all electric panel. I was
wondering if you can share your secret for easier access to the
behind-panel area. I tried your private address and it bounced.
Please contact me off-list at the address below.
--
Best regards,
Freddie mailto:lists(at)stevet.net
________________________________________________________________________________
| Subject: | Re: Electric RC Allen A/H Woes Part 2 |
did they expalin what failed the first time?
-John R.
Rob Miller wrote:
>
> Hi Listers
>
> You may remember back in December I was having trouble with my new, nearly
> $2000 RC Allen artificial horizon. It failed less than an hour after
> installation without warning. I sent it back to the factory under
> warranty and it was returned one month later following "repairs."
>
> I recently reinstalled the unit and it again failed within minutes. After
> about ten minutes it started a gentle roll to the right then began
> tumbling like a washing machine on the spin cycle.
>
> Fearing that this item is going to get me killed, I'm removing it
> permanently. Here's to Dynon, Blue Mountain or anyone else who can build
> something that is reliable!!
>
> Rob Miller
>
> RV-8 N262RM "Bad Cat" 48 hours
>
>
________________________________________________________________________________
| Subject: | Re: Double OVM-14's |
| From: | "Matt Prather" <mprather(at)spro.net> |
Julia,
If the electrical system is well documented, and the docs are made
available to your mechanic he should have no trouble figuring out
how things are put together. At least any mechanic that I would
allow to work on my plane would.
Have you read the docs about the OVM? Bob has specified an easy,
yearly check of the OVM device, as well as documents for how to
build a new one of your own. If you are concerned about B&C not
having any in the future, it would probably be smart to include the
design for this simple device in your aircraft docs. Then if after testing
it, you find it broken, you or your mechanic might be able to build
another. The worst case scenario is that you can just remove it and
go back to the level of OV protection that lots of cars and airplanes
already have (none).
> > since the OVM-14's are relatively tiny and light units, could one put
> two of these in and that way if one failed, the other would be there to
> work? My worry with things like this is always what do I do if 6 years
> from now, this OVM-14 fails and B&C Electirical doesn't sell it anymore?
> Would a typical A&P mechanic have a clue as to how to replace this
> particular module - if we were so fortunate as to be able to figure out
> that it even failed?
>
I believe what you have suggested would work, but this is similar to fault
scenarios already discussed. The chances that the both the OVM would fail
AND the alt/reg system would runaway on the same flight are very low.
Similarly,
it has already been discussed that occassionally the OVM's fail by shorting
(which disables your charging system..). Having 2 of the devices in parallel
increases this risk.
> What do you think - would this work? See Z-11 - the OVM-14 just goes
> from the pin 4 wire to ground - so just add another in beside it going
> from pin #4 to ground.
>
> thanks
>
>
Regards,
Matt-
________________________________________________________________________________
| From: | "Neil McLeod" <bedrock(at)theriver.com> |
www.terminaltown.com has 'em even a little cheaper.
Neil McLeod
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
czechsix(at)juno.com
Subject: AeroElectric-List: Fuseblocks
Guys,
This is not to take business away from 'Lectric Bob, just if you are
like me and need a fuseblock something in between the 6/10/20 slots Bob
carries I found some at JCWhitney. In my case I wanted about a dozen
slots but didn't want to go all the way to 20 slots just for a few
spares.
See the assortment at:
http://www.jcwhitney.com/product.jhtml?CATID=5650&BQ=jcw2
6-slot $14.99
8-slot $16.99
10-slot $17.99
12-slot $17.99
14-slot $20.99
18-slot $22.99
Not sure if they are the same quality that Bob sells but they are rated
at 25 amps per circuit, and since I don't plan to put more than 8 amps
max on any one circuit that should be more than adequate for my
purposes.
--Mark Navratil
Cedar Rapids, Iowa
RV-8A N2D firewall forward and wiring...
________________________________________________________________________________
| From: | "David.vonLinsowe" <David.vonLinsowe(at)delphi.com> |
On a side note.
Some time in the near future the automotive industry is looking into
switching to a 42 volt system...
Dave
RV-6
>From: "Tom Schiff" <tomschiff(at)attbi.com>
>Subject: AeroElectric-List: 12 vs 28 volts
>I am beginning to scrounge "Stuff" for my GlaStar that should be
>finished in the fall of 2004. Just wondered if most homebuilts are 12
>volt. I keep hearing about automotive alternators and I assume that
they
>are 12 volt or can they be regulated out to 28 volt.
>Can most avionics (not the newest King KX155's which are 28 volt only)
>be had in 12 volt versions?
________________________________________________________________________________
| From: | Peter Laurence <dr.laurence(at)mbdi.org> |
| Subject: | Re: Electric RC Allen A/H Woes Part 2 |
----- Original Message -----
From: "Rob Miller" <rmill2000(at)yahoo.com>
Subject: AeroElectric-List: Electric RC Allen A/H Woes Part 2
>
Rob,
Let the list know how RC Allen handles the problem.
Thanks
Peter Laurence
> Hi Listers
>
> You may remember back in December I was having trouble with my new, nearly
> $2000 RC Allen artificial horizon. It failed less than an hour after
> installation without warning. I sent it back to the factory under
> warranty and it was returned one month later following "repairs."
>
> I recently reinstalled the unit and it again failed within minutes. After
> about ten minutes it started a gentle roll to the right then began
> tumbling like a washing machine on the spin cycle.
>
> Fearing that this item is going to get me killed, I'm removing it
> permanently. Here's to Dynon, Blue Mountain or anyone else who can build
> something that is reliable!!
>
> Rob Miller
>
> RV-8 N262RM "Bad Cat" 48 hours
>
>
________________________________________________________________________________
| From: | "Matt Prather" <mprather(at)spro.net> |
I bought a 6 and a 10 slot version of these blocks from Del City which
can be accessed through the shopping.yahoo page. I think the price
was a little lower there. I am happy with the quality and design, but I
don't think they are as robust as the ones that Bob sells.
>
> Guys,
>
> This is not to take business away from 'Lectric Bob, just if you are
> like me and need a fuseblock something in between the 6/10/20 slots Bob
> carries I found some at JCWhitney. In my case I wanted about a dozen
> slots but didn't want to go all the way to 20 slots just for a few
> spares.
>
> See the assortment at:
>
> http://www.jcwhitney.com/product.jhtml?CATID=5650&BQ=jcw2
>
> 6-slot $14.99
> 8-slot $16.99
> 10-slot $17.99
> 12-slot $17.99
> 14-slot $20.99
> 18-slot $22.99
>
> Not sure if they are the same quality that Bob sells but they are rated
> at 25 amps per circuit, and since I don't plan to put more than 8 amps
> max on any one circuit that should be more than adequate for my
> purposes.
>
> --Mark Navratil
> Cedar Rapids, Iowa
> RV-8A N2D firewall forward and wiring...
________________________________________________________________________________
| From: | "David.vonLinsowe" <David.vonLinsowe(at)delphi.com> |
Has anyone seen or used a (inexpensive) data logger that would record
A.S., RoC, RPM and M.P.?
I'm doing some flight testing and it sure would come in handy.
I've used one in a Madera R/C racer years ago, but I don't think it
would
handle enough inputs.
Thanks
Dave RV-6
The need for (more) speed---->
________________________________________________________________________________
| From: | "Matt Prather" <mprather(at)spro.net> |
How about a camcorder (or two)?
Regards,
Matt Prather
N34RD
>
>
> Has anyone seen or used a (inexpensive) data logger that would record
> A.S., RoC, RPM and M.P.?
>
> I'm doing some flight testing and it sure would come in handy.
>
> I've used one in a Madera R/C racer years ago, but I don't think it
> would
> handle enough inputs.
>
> Thanks
> Dave RV-6
> The need for (more) speed---->
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: 12 vs 28 volts |
>
>
>On a side note.
>
>Some time in the near future the automotive industry is looking into
>switching to a 42 volt system...
yup, that's been discussed in various aviation circles including
some focused on OBAM aircraft. Of course, spares for the last
production 14v vehicles will be in plentiful supply for some
time after the onset of 42v systems . . . just how that will
shake out in our world isn't clear. Switching becomes more
difficult, but solid state switches will take care of it,
alternators are not likely to be belt driven accessories
so automotive takeoffs will be difficult to bolt to your
Lyc . . . but then, perhaps the whole engine out of a
2010 Chevy will be the OBAM power plant of choice.
For the moment, I'm content to joust with the 14v
dragons and see how it works out. Should be
exciting and challenging.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
>Guys,
>
>This is not to take business away from 'Lectric Bob, just if you are like
>me and need a fuseblock something in between the 6/10/20 slots Bob carries
>I found some at JCWhitney. In my case I wanted about a dozen slots but
>didn't want to go all the way to 20 slots just for a few spares.
>
>See the assortment at:
>
>http://www.jcwhitney.com/product.jhtml?CATID=5650&BQ=jcw2
>
>6-slot $14.99
>8-slot $16.99
>10-slot $17.99
>12-slot $17.99
>14-slot $20.99
>18-slot $22.99
>
>Not sure if they are the same quality that Bob sells but they are rated at
>25 amps per circuit, and since I don't plan to put more than 8 amps max on
>any one circuit that should be more than adequate for my purposes.
I don't sell them any more, B&C does. But I've ordered
one to see how it's put together and will report findings
here. BTW, they have a standard minimum shipping charge of
nearly $10 . . . so you don't want to order just one little
thing . . .
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Double OVM-14's |
>
>
>bob:
>
>since the OVM-14's are relatively tiny and light units, could one put two
>of these in and that way if one failed, the other would be there to
>work? My worry with things like this is always what do I do if 6 years
>from now, this OVM-14 fails and B&C Electirical doesn't sell it
>anymore? Would a typical A&P mechanic have a clue as to how to replace
>this particular module - if we were so fortunate as to be able to figure
>out that it even failed?
They should be tested every annual like every other OV protection
product on any airplane. It's easy to do. Instructions for doing
so should have come with it. As an all solid-state
device, probability of decades of trouble-free service is quite
good. There will always be a direct replacement for this device
from either B&C, AeroElectric Connection, and perhaps others . . .
Documentation on how to build your own is downloadable from
my website. If push came to shove, you can build one. The parts
are not critical. This circuit has been built by a number
of builders with success.
If the device does fail to function, it can be repaired. The
heat shrink can be cut off for troubleshooting.
>What do you think - would this work? See Z-11 - the OVM-14 just goes from
>the pin 4 wire to ground - so just add another in beside it going from pin
>#4 to ground.
I think this would be a waste of money.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
>
>Has anyone seen or used a (inexpensive) data logger that would record
>A.S., RoC, RPM and M.P.?
>
>I'm doing some flight testing and it sure would come in handy.
The expensive part are sensors for these parameters. I use
a lot of products from these guys:
http://www.weedtech.com/
They're cheap, reasonably fast and stone simple to set up
and use. If you need more speed and have a USB port
to talk to it, you can use:
http://www.labjack.com/labjack_u12.html
Again, cheap and easy to use . . . grab your wallet with
both hands when you price the sensors, especially
the low delta-pressure devices. I've got plans for
a super sensitive, temperature compensated pressure
transducer that gives me +/- 20 foot accuracy to
60,000 feet and better than 1% accuracy for pitot
pressures to 300 kts. We derive ROC from altitude
data. The transducers have a relatively low bill of
materials cost . . . under $100 . . . but you need
some pretty good lab equipment to calibrate them.
I have access to such things at RAC . . . kind of
hard to come by out in the wild. Off the shelf
sensors with this capability will run $1000 to $2500
each.
Bob . . .
________________________________________________________________________________
In a message dated 3/12/2003 4:22:51 PM US Mountain Standard Time,
bob.nuckolls(at)cox.net writes:
> >Not sure if they are the same quality that Bob sells but they are rated at
> >25 amps per circuit, and since I don't plan to put more than 8 amps max on
>
> >any one circuit that should be more than adequate for my purposes.
>
> I don't sell them any more, B&C does. But I've ordered
> one to see how it's put together and will report findings
> here. BTW, they have a standard minimum shipping charge of
> nearly $10 . . . so you don't want to order just one little
> thing . . .
>
Just my two cents worth. I have been reading this list for many months,
gathering much needed information on how to properly construct the electrical
system on my RV-8A. I also have the "connection" and read it every time I
have a question. As for me, I purchase All I can from your web site as a way
of supporting what you do and would urge everyone else to do likewise!
Ron Smith
N566U(at)aol.com
________________________________________________________________________________
| From: | "C J Heitman" <cjh(at)execpc.com> |
Even cheaper here: http://pegasusautoracing.com and exact same Bussman parts
as B&C (rated 30 amps per position) and just pay actual UPS charge (no
handling fee added).
4402-06 (6 position) $9.99
4402-10 (10 position) $11.99
4402-20 (20 position) $17.99
Page 49 of on-line catalog.
Chris Heitman
RV-9A N94ME (reserved)
http://my.execpc.com/~cjh/rv9a.html
Original Message:
------------------
Guys,
This is not to take business away from 'Lectric Bob, just if you are like me
and need a fuseblock something in between the 6/10/20 slots Bob carries I
found some at JCWhitney. In my case I wanted about a dozen slots but didn't
want to go all the way to 20 slots just for a few spares.
See the assortment at:
http://www.jcwhitney.com/product.jhtml?CATID=5650&BQ=jcw2
6-slot $14.99
8-slot $16.99
10-slot $17.99
12-slot $17.99
14-slot $20.99
18-slot $22.99
Not sure if they are the same quality that Bob sells but they are rated at
25 amps per circuit, and since I don't plan to put more than 8 amps max on
any one circuit that should be more than adequate for my purposes.
--Mark Navratil
---
________________________________________________________________________________
| From: | Ed Holyoke <bicyclop(at)pacbell.net> |
| Subject: | multi-wire cable |
Hey guys,
Does anybody make a multi-wire 24 gauge cable to hook up autopilot
servos and such? It'd be nice to find something that's insulated with
tefzel and color coded. The Ray Allen wire is 26 gauge and really
expensive and is only in 20' lengths. It is nice and skinny, though.
Thanks,
Ed Holyoke
RV-6 N86ED (reserved)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
>In a message dated 3/12/2003 4:22:51 PM US Mountain Standard Time,
>bob.nuckolls(at)cox.net writes:
>
> > >Not sure if they are the same quality that Bob sells but they are
> rated at
> > >25 amps per circuit, and since I don't plan to put more than 8 amps
> max on
> >
> > >any one circuit that should be more than adequate for my purposes.
> >
> > I don't sell them any more, B&C does. But I've ordered
> > one to see how it's put together and will report findings
> > here. BTW, they have a standard minimum shipping charge of
> > nearly $10 . . . so you don't want to order just one little
> > thing . . .
> >
>
>Just my two cents worth. I have been reading this list for many months,
>gathering much needed information on how to properly construct the electrical
>system on my RV-8A. I also have the "connection" and read it every time I
>have a question. As for me, I purchase All I can from your web site as a way
>of supporting what you do and would urge everyone else to do likewise!
I appreciate that. I've spent $thousands$ for ads and promotional
activities over the years that produced not a single phone call
much less a sale. I've decided that my "advertising budget" is better
spent as time-on-the-lists as opposed to time-to-earn-dollars
expended on activities that don't add value.
Having said that, I don't expect that anyone should feel
obligated to patronize my products that are not good
value when compared to the products of others. The reason that
we can buy $69 VCRs and $600 super byte-thrashers is because
we've enjoyed a competitive market place where those who best
supply consumer needs get the privilege of servicing those
needs. Learn to play in the sand box or go play somewhere
else.
That's just one of the reasons why I got out of the parts business
two years ago. I want to focus on products that are uniquely
my own -AND- have the control to make them best serve
consumer needs. There are some new things coming over
the hill. Watch this space. In the mean time, let's
the best we can to build the greatest possible value
into our airplanes . . . that must include alternative
sources for useful parts and products.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: multi-wire cable |
>
>Hey guys,
>
>Does anybody make a multi-wire 24 gauge cable to hook up autopilot
>servos and such? It'd be nice to find something that's insulated with
>tefzel and color coded. The Ray Allen wire is 26 gauge and really
>expensive and is only in 20' lengths. It is nice and skinny, though.
>
>Thanks,
How many wires total do you need? The shielded triple
from B&C would give you 6 wires in only two runs.
Bob . . .
________________________________________________________________________________
| From: | "MARK H DELANO" <delano60(at)email.msn.com> |
I have tried all your suggestions to eliminate the RFI produced by this Turn
& Bank indicator. The iron wrap helped quite a bit but did not eliminate
the noise buy itself, however when I would move my hand within 5 or 6 in. of
the gyro, but not touching it, the RFI would almost completely disappear.
Since I will operate in Class B airspace the com radio is an absolute
requirement, so this Chinese knock off is going back to Spruce and a high
quality unit will replace it.
Thanks for the help.
Mark Delano
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: RFI
>
> >
> >
> >Last week I asked a Question about a Turn & Bank that sounded like a
> >vacuum cleaner when the com was turned on. The offending imported non
> >TSOd instrument is a Falcon Gage P/N TC02E-3-1. You Provided a link to
the
> >Radio Shack 270-030 filter which I installed as the wire diagram
> >instructed with little reduction in the RF output. The filter assembly
> >came with a 220 uF cap and your drawing calls for a 10uF. will this
> >matter? Any other suggestion to kill the RF interference before I return
> >the gage to Spruce.
>
> Try the heavier cap. . . also try wrapping
> a sleeve of thin sheet steel (flashing metal
> from lumber yard works good) around the
> body of the instrument. The metal is pretty
> thin so I usually use three layers. This can
> be held in place with long tye wraps or with
> a couple of string ties. This will attenuate
> strong magnetic radiation common to many of these
> instruments. You may also see some benefit for
> making an electrical connection between the
> metal shield and the ground power wire coming
> into the back of the instrument.
>
> Will be interested to see what, if any effects
> these actions have.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | Ed Holyoke <bicyclop(at)pacbell.net> |
| Subject: | multi-wire cable |
Hi Bob,
How thick is the shielded trio?
Ed Holyoke
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-
> aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls,
> III
> Sent: Wednesday, March 12, 2003 8:39 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: multi-wire cable
>
>
>
>
> >
> >Hey guys,
> >
> >Does anybody make a multi-wire 24 gauge cable to hook up autopilot
> >servos and such? It'd be nice to find something that's insulated with
> >tefzel and color coded. The Ray Allen wire is 26 gauge and really
> >expensive and is only in 20' lengths. It is nice and skinny, though.
> >
> >Thanks,
>
> How many wires total do you need? The shielded triple
> from B&C would give you 6 wires in only two runs.
>
> Bob . . .
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Terry Watson" <terry(at)tcwatson.com> |
I really have to agree with you on that one, Ron. Maybe RV-8A builders
think alike. I remember when I started building about five years ago, I
found that I could buy metal snips a lot cheaper than Avery sold them, but
then after I had experienced the outstanding service from Avery, I decided I
wanted to do business with them, and if that cost a bit more for a tool I
might find once in awhile at Home Depot, it was still money very well spent.
I just bought an engine from Aerosport Power, a Superior XP-IO-360 with
Airflow Performance fuel injection and Lightspeed electronic ignition on one
side. I was reading through the Airflow Performance manual and decided I
should order the optional purge valve and install it, but when I looked at
the engine, there it was, already installed. And that oil line I was
wondering about ordering for the constant speed control unit to the prop was
all hooked up and fire sleeved too. It's really great to do business with
people who are more interested in solving your problem than getting your
money. Bob takes that concept to a new level, and besides that, he is a
true gentleman. I don't know where he finds the time and the energy to
answer our questions and lead us through this learning process, but I'm
damned glad he does.
Terry
RV-8A
Seattle
>
Just my two cents worth. I have been reading this list for many months,
gathering much needed information on how to properly construct the
electrical
system on my RV-8A. I also have the "connection" and read it every time I
have a question. As for me, I purchase All I can from your web site as a way
of supporting what you do and would urge everyone else to do likewise!
Ron Smith
N566U(at)aol.com
________________________________________________________________________________
| From: | "Jones, Michael" <MJones(at)hatch.ca> |
Bob
If I get the volt/load meter from westach to use in my kit plane as a stand
alone meter should I install a switch with it.
I seem to recall reading that when you sold it as a package with other
components it would switch automatically between main and back up
alternator.
I am planning on the 8 amp B&C alternator as backup to main 60 amp.
Mike
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
>
>I have tried all your suggestions to eliminate the RFI produced by this Turn
>& Bank indicator. The iron wrap helped quite a bit but did not eliminate
>the noise buy itself, however when I would move my hand within 5 or 6 in. of
>the gyro, but not touching it, the RFI would almost completely disappear.
>Since I will operate in Class B airspace the com radio is an absolute
>requirement, so this Chinese knock off is going back to Spruce and a high
>quality unit will replace it.
Interesting! Thank you for sharing that with us. I wish
I were doing something useful in the RFI lab at RAC, I'd
really like to borrow your problem-child and get a
laboratory-grade look at it.
Be sure and rattle Spruce's cage pretty good over this.
They ought to give you a discount on the replacement.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | multi-wire cable |
>
>Hi Bob,
>
>How thick is the shielded trio?
.120"
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: volt/load meter |
>
>Bob
>
>If I get the volt/load meter from westach to use in my kit plane as a stand
>alone meter should I install a switch with it.
>
>I seem to recall reading that when you sold it as a package with other
>components it would switch automatically between main and back up
>alternator.
>
>I am planning on the 8 amp B&C alternator as backup to main 60 amp.
Perhaps two switches. One to switch the ammeter from aux to main
alternators, one to switch voltmeter from main to e-bus.
Bob . . .
________________________________________________________________________________
| Subject: | Bendix King KY 97A question |
I purchased a RV-4 with a blank spot in the comm tray. The previous owner,
whom I cannot contact had a Bendix King KY-97A installed. I'm trying to
locate one to plug into the existing tray and wiring. Is there a way for me
to tell which model he had? The current tray is wired to a Sigtronics
Intercom SPA-400-TSO with no speaker and headphone jacks for two persons.
Kinda hate to buy a KY-97A without knowing the model number he had. Below is
the information I got from a Bendix King website. Hopefully, the wiring is
the same for all. If not, is there a specific could I look for that would
identify the unit from the existing connection wiring? I do have the KY 97
wiring diagram that Bob has on his website.
KY-97A VHF Communications Transceiver Description
Model:
064-1051-10 25Khz receiver selectivity, 500ohm headphone audio output, 720
channels
064-1051-30 25Khz receiver selectivity, 500ohm headphone audio output, 760
channels
064-1051-50 25Khz receiver selectivity, 4W into 4ohm audio output, 720
channels
064-1051-51 50Khz receiver selectivity, 4W into 4ohm audio output, 720
channels
064-1051-60 25Khz receiver selectivity, 4W into 4ohm audio output, 760
channels
064-1051-61 50Khz receiver selectivity, 4W into 4ohm audio output, 760
channels
064-1051-70 Crown series version of -60 unit with solid black face and no
silver lining trim
Thanks for your input
Pat Long
Working on an RV-4
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
<>
That brings up another question: For an RG battery, how far from an upright
orientation can you go? Many of the potential surfaces for mounting aren't
vertical.
Gary Casey
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
| Subject: | Re: Double OVM-14's |
But would it work? if one failed, would the other one do the trick?
"Robert L. Nuckolls, III" wrote:--> AeroElectric-List message
posted by: "Robert L. Nuckolls, III"
>
>
>bob:
>
>since the OVM-14's are relatively tiny and light units, could one put two
>of these in and that way if one failed, the other would be there to
>work? My worry with things like this is always what do I do if 6 years
>from now, this OVM-14 fails and B&C Electirical doesn't sell it
>anymore? Would a typical A&P mechanic have a clue as to how to replace
>this particular module - if we were so fortunate as to be able to figure
>out that it even failed?
They should be tested every annual like every other OV protection
product on any airplane. It's easy to do. Instructions for doing
so should have come with it. As an all solid-state
device, probability of decades of trouble-free service is quite
good. There will always be a direct replacement for this device
from either B&C, AeroElectric Connection, and perhaps others . . .
Documentation on how to build your own is downloadable from
my website. If push came to shove, you can build one. The parts
are not critical. This circuit has been built by a number
of builders with success.
If the device does fail to function, it can be repaired. The
heat shrink can be cut off for troubleshooting.
>What do you think - would this work? See Z-11 - the OVM-14 just goes from
>the pin 4 wire to ground - so just add another in beside it going from pin
>#4 to ground.
I think this would be a waste of money.
Bob . . .
---------------------------------
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
| Subject: | Crimping vs. soldering wires? |
I heard someone say don't solder wires as the vibrations will crack at some point?
I installed a battery cable last night and after crimping it I soldered it. Now
if the solder cracks, it's still been crimped - so wouldn't that be the best
of both worlds?
I had intended to solder all of my connections everywhere - what is the general
recommended procedure?
---------------------------------
________________________________________________________________________________
| From: | Benford2(at)aol.com |
In a message dated 3/13/2003 7:20:07 AM Mountain Standard Time,
bob.nuckolls(at)cox.net writes:
>
> Interesting! Thank you for sharing that with us. I wish
> I were doing something useful in the RFI lab at RAC, I'd
> really like to borrow your problem-child and get a
> laboratory-grade look at it.
>
I have the same T&B and I have not powered up the panel yet. If it does the
same thing I will donate it to ya so you can do an autopsy on it and expose
the weakness of this unit to all of us loyal readers. Ben Haas N801BH.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Bendix King KY 97A question |
>
>I purchased a RV-4 with a blank spot in the comm tray. The previous owner,
>whom I cannot contact had a Bendix King KY-97A installed. I'm trying to
>locate one to plug into the existing tray and wiring. Is there a way for me
>to tell which model he had? The current tray is wired to a Sigtronics
>Intercom SPA-400-TSO with no speaker and headphone jacks for two persons.
>Kinda hate to buy a KY-97A without knowing the model number he had. Below is
>the information I got from a Bendix King website. Hopefully, the wiring is
>the same for all. If not, is there a specific could I look for that would
>identify the unit from the existing connection wiring? I do have the KY 97
>wiring diagram that Bob has on his website.
there are generally no variations in wiring between production
changes of a specific model. The pin-out reference I have doesn't
list any variations on the KY-97 other than the KY-97A.
Any one of the products you listed will play in your airplane.
Bob . . .
________________________________________________________________________________
| From: | "Charlie Dunn" <cdunn(at)fhtc.kansas.net> |
| Subject: | Crimping vs. soldering wires? |
We have had a series of planes having problems with wires breaking because
the solder flowing back into the wire
3/8 to 1/2" and making a solid to flexible junction a little ways back from
the terminal. The wire will break at this
junction after a while. If it is the wrong wire things get very Quite.
Charles Dunn
Flint Hills Technical School
I heard someone say don't solder wires as the vibrations will crack at some
point?
I installed a battery cable last night and after crimping it I soldered it.
Now if the solder cracks, it's still been crimped - so wouldn't that be the
best of both worlds?
________________________________________________________________________________
| Subject: | Crimping vs. soldering wires? |
| From: | "Matt Prather" <mprather(at)spro.net> |
Have these breakages occurred only in places where the wire runs
some distance from the solder joint unsupported by other forms of
strain relief? I don't know what the standard is, and it probably varies
by wire gauge, but it seems like a properly installed wire should have
strain relief (support, adel clamp, or similar) within 4-6" from the
terminal,
and then every 12" beyond that. This should reduce the effects of
vibration which might be causing the wire to "whip" and fatigue.
Regards,
Matt-
>
>
> We have had a series of planes having problems with wires breaking
> because the solder flowing back into the wire
> 3/8 to 1/2" and making a solid to flexible junction a little ways back
> from the terminal. The wire will break at this
> junction after a while. If it is the wrong wire things get very Quite.
> Charles Dunn
> Flint Hills Technical School
>
>
> I heard someone say don't solder wires as the vibrations will crack at
> some point?
>
> I installed a battery cable last night and after crimping it I soldered
> it. Now if the solder cracks, it's still been crimped - so wouldn't that
> be the best of both worlds?
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)tenforward.com> |
| Subject: | Re: runaway, self regulated alternators |
Comments in context and some snipping.
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
Subject: AeroElectric-List: Re: runaway, self regulated alternators
Thus I have concluded that the above protection
> >circuit is only a partial fix and that ANY alternator protection circuit
for
> >aircraft must also disconnect the field current.
>
> The risk is to the field windings which get mucho volts applied
> to them during the runaway event . . . which doesn't last long.
> Perhaps 10 seconds before the field wires burn in two. Where
> is the concentration of energy liberation adjacent to combustibles
that
> poses a risk of fire?
Many years ago I saw such a failure and the alternator housing was partially
melted. My point is that each alternator is different and its hard to say
what fails and how long it takes. Why even consider the risk??
>
> >The rising output voltage will rise until the internal diodes start
shorting
> >out from overvoltage and this provides additional load (HEAT).
>
> But consider that an alternator is incapable of delivering
> any more current than it's magnetics will support . . . even
> in a runaway condition, a 60A alternator is still a 60A alternator.
> (our technique for running 14 volt alternators in a 28v system
> using a special regulator might be called a "controlled runaway"
> except that we go to pains to make sure the field is not over
> driven . . . but it's still a 40/60A alternator).
Years ago there were "Kits" to convert the alternator to 120V operation.
Other than controlling field current the 120V alternator has the same output
current rating as the 12V version IE 60 amps. Some actually could be driven
to over 200V as it depended on the voltage rating of the diodes.
>
> So any degree of heating (I-squared*R) is relatively constant
> irrespective of how much voltage the machine is generating during
> an open circuit runaway. Shorting diodes is the best thing
> you could hope for. A shorted diode is a cooler diode. Further,
> as soon as you take out an upper/lower pair of diodes in the
> full-wave array, output voltage goes to zero, field excitation
> goes away and the critter stalls and shuts itself down. The
> worst case is that the diodes hang in there (most are capable of a
LOT
> more that we might suspect) and 100+ volts makes raises
> field current to 25 amps or so . . . that 22AWG copper field
> winding won't stay in place very long. Exposed leadwires
> would fuse before the field winding proper even has a chance
> to warm up. It's all over in seconds.
I do not agree that shorting diodes will always reduce the heat. What
shorted diodes do is short windings out that still generate current and that
current generates heat.
Perhaps but then again your 10 seconds is a lot of heat and included the
possibility of the external feed to the regulator getting on line and
supplying HV back to the source. Your designs do not have any overvoltage
protection I can find other than for the alternator output. Relying on the
Mfgrs to meet the latest transient design rules is a foolish position on
this list as many will not use the latest main line mfgrs products etc. Use
of transient absorbers is so simple and low cost its perhaps belt and
suspenders in some cases and the only line of defense in others.
> We've see the test. There was at least one builder
> who sent his alternator back for overhaul wherein he
> failed to provide ANY kind of ov protection and assumed
> that the alternator had a built in regulator. So through
> a combination of mis-wiring and poor choice of switch
> arrangements, he managed to get an alternator on line
> without a battery or regulator. The alternator didn't
> even smell really bad. The leadwire between slip ring
> and field winding had opened like a fusible link. We
> could probably have spliced it and the alternator would
> have worked fine.
Incomplete analysis if you did not look for the cause. Your comment on the
lead wire failure is the result, not the cause and perhaps only a secondary
result.
Also that is only an example of one from one mfgr.
Regardless we are both entitled to our opinions and I am unwilling to take
even a remote chance when the solution is clearly available and easy to do.
I feel that not disconnecting the field for at least your stated 10 seconds
is 10 seconds more then is necessary and simply another unnecessary risk.
Without a Failure Modes and Effects Analysis (FMEA) its risky to base
conclusions on theory and one example.
Paul
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Double OVM-14's |
>
>
>But would it work? if one failed, would the other one do the trick?
Depends on how it failed. All of the failures I've repaired
were failed shorted. In this case, the field breaker cannot
be reset and the system is down. In each case, the ovm
failed because it was mis-wired into the system and didn't
have a circuit breaker in series with it to open up when
the crowbar fired.
IF they fail to operate, then having a second OVM in parallel
with it will still get a runaway alternator under control.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Crimping vs. soldering wires? |
>
>
>We have had a series of planes having problems with wires breaking because
>the solder flowing back into the wire
>3/8 to 1/2" and making a solid to flexible junction a little ways back from
>the terminal. The wire will break at this
>junction after a while. If it is the wrong wire things get very Quite.
>Charles Dunn
>Flint Hills Technical School
>
>
>I heard someone say don't solder wires as the vibrations will crack at some
>point?
>
>I installed a battery cable last night and after crimping it I soldered it.
>Now if the solder cracks, it's still been crimped - so wouldn't that be the
>best of both worlds?
See http://www.aeroelectric.com/articles/terminal.pdf
and http://www.aeroelectric.com/articles/rules/review.html
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
>< capabilities of an RG battery, you have never had a greater
> opportunity to design your airplane for efficiency of space and
> function with virtually no risk from the concerns cited. Mount
> it where it fits best.
>
> Bob . . .>>
>
>That brings up another question: For an RG battery, how far from an upright
>orientation can you go? Many of the potential surfaces for mounting aren't
>vertical.
Mount it in any position. Upside down if you like.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
> > I've got plans for
> > a super sensitive, temperature compensated pressure
> > transducer that gives me +/- 20 foot accuracy to
> > 60,000 feet and better than 1% accuracy for pitot
> > pressures to 300 kts.
>
>Does this mean we will be seeing a reasonably accurate, affordable
>altitude control device in
>the near future? How much panel space do I need to reserve and when can
>we expect delivery
>or requests for beta testers?
That's a possibility but it's way down on the list . . .
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
>
>In a message dated 3/13/2003 7:20:07 AM Mountain Standard Time,
>bob.nuckolls(at)cox.net writes:
>
>
> >
> > Interesting! Thank you for sharing that with us. I wish
> > I were doing something useful in the RFI lab at RAC, I'd
> > really like to borrow your problem-child and get a
> > laboratory-grade look at it.
> >
>
>I have the same T&B and I have not powered up the panel yet. If it does the
>same thing I will donate it to ya so you can do an autopsy on it and expose
>the weakness of this unit to all of us loyal readers. Ben Haas N801BH.
Thank you!
Bob . . .
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
| Subject: | Re: Double OVM-14's |
So does the breaker you show in z-11 - the 5 amp alternator field breaker - take
care of this issue -
thanks
"Robert L. Nuckolls, III" wrote:--> AeroElectric-List message
posted by: "Robert L. Nuckolls, III"
>
>
>But would it work? if one failed, would the other one do the trick?
Depends on how it failed. All of the failures I've repaired
were failed shorted. In this case, the field breaker cannot
be reset and the system is down. In each case, the ovm
failed because it was mis-wired into the system and didn't
have a circuit breaker in series with it to open up when
the crowbar fired.
IF they fail to operate, then having a second OVM in parallel
with it will still get a runaway alternator under control.
Bob . . .
---------------------------------
________________________________________________________________________________
| From: | "Cy Galley" <cgalley(at)qcbc.org> |
| Subject: | Re: Crimping vs. soldering wires? |
On something that big, Shouldn't see a problem.
The problem with the soldering is when the wire flexes, it will break at the
edge of the soldering to the wire. Solution is always to provide good
support to the wire to prevent flexing or not to solder.
Crimping and Soldering is an effort in futility.
Just crimping alone is better because it doesn't have the sharp transition
between the wire and the heavy soldering.
Cy Galley, TC - Chair, Emergency Aircraft Repair, Oshkosh
Editor, EAA Safety Programs
cgalley(at)qcbc.org or experimenter(at)eaa.org
Always looking for articles for the Experimenter
----- Original Message -----
From: "Julia" <wings97302(at)yahoo.com>
Subject: AeroElectric-List: Crimping vs. soldering wires?
>
>
> I heard someone say don't solder wires as the vibrations will crack at
some point?
>
> I installed a battery cable last night and after crimping it I soldered
it. Now if the solder cracks, it's still been crimped - so wouldn't that be
the best of both worlds?
>
> I had intended to solder all of my connections everywhere - what is the
general recommended procedure?
>
>
> ---------------------------------
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Double OVM-14's |
>
>
>So does the breaker you show in z-11 - the 5 amp alter
>nator field breaker - take care of this issue -
>thanks
yes
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Crimping vs. soldering wires? |
>
>On something that big, Shouldn't see a problem.
>
>The problem with the soldering is when the wire flexes, it will break at the
>edge of the soldering to the wire. Solution is always to provide good
>support to the wire to prevent flexing or not to solder.
>
>Crimping and Soldering is an effort in futility.
>
>Just crimping alone is better because it doesn't have the sharp transition
>between the wire and the heavy soldering.
How so? If your crimp tool puts enough mash on the
joint to become gas-tight, then the terminal and
every strand of the wire have become a single entity
with zero volume of airspace between parts . . . which
is exactly what happens when you solder.
Wires need support outside the gas-tight area whether
you crimp or solder. That's how the PIDG terminals
(and lesser cousins) came to be. A terminal soldered
to the end of a wire needs some heat shrink support
too (Figure 9-3 in the 'Connection).
Bob . . .
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
| Subject: | Firewall Flange sealant? |
What's the best thing to use for sealant on the flanges which make up my firewall
wire penetration - i'm using SS tubing welded to a flange - so what would
go between the flange and the firewall - to make it airtight? I"m not talking
about around the wires - but just between the flange and firewall? how about
proseal - would that be ok -or should it be some kind of fireproof silicone
- I think someone mentinoed that once, I cannot seem to find anything in aircraft
spruce - can anyone point me in the right direction for of where I might
get the correct product here?
thanks
---------------------------------
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)tenforward.com> |
Many mfgrs include insytructions to not mount that way as the vents can then
discharge caustic materials.
Concord told me to not even mount on its side.
What ever
Paul
> Mount it in any position. Upside down if you like.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: runaway, self regulated alternators |
>
>
>Comments in context and some snipping.
>
>----- Original Message -----
>From: "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net>
>To:
>Subject: AeroElectric-List: Re: runaway, self regulated alternators
>
>
> Thus I have concluded that the above protection
> > >circuit is only a partial fix and that ANY alternator protection circuit
>for
> > >aircraft must also disconnect the field current.
> >
> > The risk is to the field windings which get mucho volts applied
> > to them during the runaway event . . . which doesn't last long.
> > Perhaps 10 seconds before the field wires burn in two. Where
> > is the concentration of energy liberation adjacent to combustibles
>that
> > poses a risk of fire?
>
>Many years ago I saw such a failure and the alternator housing was partially
>melted. My point is that each alternator is different and its hard to say
>what fails and how long it takes. Why even consider the risk??
There are lots of things that can come unhooked, broken
or leak that increase the risk of fire in every
engine flying. We work to drive those risks down by
understanding weak points of every component
and deciding if the level of robustness justifies its
use in our airplane. What were the circumstances that
produced the outcome you observed? I too have seen
toasted alternators. Too many of them came off of crashes
where people were hurt or killed. NONE of them
were the result of an uncontrolled, ov condition.
> >
> > >The rising output voltage will rise until the internal diodes start
>shorting
> > >out from overvoltage and this provides additional load (HEAT).
> >
> > But consider that an alternator is incapable of delivering
> > any more current than it's magnetics will support . . . even
> > in a runaway condition, a 60A alternator is still a 60A alternator.
> > (our technique for running 14 volt alternators in a 28v system
> > using a special regulator might be called a "controlled runaway"
> > except that we go to pains to make sure the field is not over
> > driven . . . but it's still a 40/60A alternator).
>
>Years ago there were "Kits" to convert the alternator to 120V operation.
>Other than controlling field current the 120V alternator has the same output
>current rating as the 12V version IE 60 amps. Some actually could be driven
>to over 200V as it depended on the voltage rating of the diodes.
Yup. When I went to work for Electro-Mech for the first time
in about 1974, they were in the middle of a recall on just such
a kit. Based on an article in Popular Science or some similar
magazine, you disconnect the b-lead and tie it to a wall
receptacle in a box under the hood of your car. Install a throttle
so that you can adjust engine rpm to some relatively fixed level.
Start the engine. Regulator sees low bus volts and turns on
hard. Pull out throttle until the voltmeter in the kit reads
90 volts DC. Most series wound motors ran better on DC than
AC and 90 volts or so gave nearly equal performance.
The recall was initiated because several disgruntled customers
were fixing to sue us for replacement alternators after installing
our kit . . . seems the diodes in their alternators wouldn't
take the voltage and failed. In this case, the field sees
a fixed voltage from the battery of about 12v. So in spite of
the alternator's tortured diodes failing, abuse to the inner
workings would continue as long as the engine was running.
> >
> > So any degree of heating (I-squared*R) is relatively constant
> > irrespective of how much voltage the machine is generating during
> > an open circuit runaway. Shorting diodes is the best thing
> > you could hope for. A shorted diode is a cooler diode. Further,
> > as soon as you take out an upper/lower pair of diodes in the
> > full-wave array, output voltage goes to zero, field excitation
> > goes away and the critter stalls and shuts itself down. The
> > worst case is that the diodes hang in there (most are capable of a
>LOT
> > more that we might suspect) and 100+ volts makes raises
> > field current to 25 amps or so . . . that 22AWG copper field
> > winding won't stay in place very long. Exposed leadwires
> > would fuse before the field winding proper even has a chance
> > to warm up. It's all over in seconds.
>
>I do not agree that shorting diodes will always reduce the heat. What
>shorted diodes do is short windings out that still generate current and that
>current generates heat.
But the current is generated because the field winding has
mucho volts fed to it by virtue of the runaway condition. If
you get an upper/lower pair shorted (equal to shorting the b-lead
terminal to ground) then output of the alternator (and field voltage)
goes to zero . . . the system dies.
>Perhaps but then again your 10 seconds is a lot of heat and included the
>possibility of the external feed to the regulator getting on line and
>supplying HV back to the source. Your designs do not have any overvoltage
>protection I can find other than for the alternator output. Relying on the
>Mfgrs to meet the latest transient design rules is a foolish position on
>this list as many will not use the latest main line mfgrs products etc. Use
>of transient absorbers is so simple and low cost its perhaps belt and
>suspenders in some cases and the only line of defense in others.
You lost me there. If an alternator is in a runaway condition
and isolated from the aircraft by virtue of an open b-lead contactor
then there is only one load on the alternator's output . . .
field current. Fields are wound with 22AWG wire or smaller. A
14V alternator has a field resistance of about 4 ohms. A runaway
alternator is easily capable of 100 volts divided by 4 ohms
is 25A. Way OVER what the 22AWG wire will carry for more than
a few seconds; way UNDER what the alternator is capable of
generating. This condition has nothing to do with transient
design rules. It does have to do with where energy is being
dissipated in the failed machine. I'm suggesting that the
lion's share of energy produced in all failure modes ends
up in a field winding rated for 50W.
Now, should a battery remain connected to the alternator,
it will do its best to take the alternator's excess output;
the event will be protracted and really messy. The act of
cutting the alternator loose with the intent of allowing it
to self-destruct the field is the intent of the design.
> > We've see the test. There was at least one builder
> > who sent his alternator back for overhaul wherein he
> > failed to provide ANY kind of ov protection and assumed
> > that the alternator had a built in regulator. So through
> > a combination of mis-wiring and poor choice of switch
> > arrangements, he managed to get an alternator on line
> > without a battery or regulator. The alternator didn't
> > even smell really bad. The leadwire between slip ring
> > and field winding had opened like a fusible link. We
> > could probably have spliced it and the alternator would
> > have worked fine.
>
>Incomplete analysis if you did not look for the cause. Your comment on the
>lead wire failure is the result, not the cause and perhaps only a secondary
>result.
We were told the cause. Full bus voltage applied to an externally
regulated alternator. Battery switch ON, Alternator switch ON,
start engine, too much voltage. Battery switch got turned off
but the alternator did not, voltage went much higher. By the
time he recognized that the alternator switch was still on
and reacted to it, the event was over. Field wire fused.
>Also that is only an example of one from one mfgr.
>
>Regardless we are both entitled to our opinions and I am unwilling to take
>even a remote chance when the solution is clearly available and easy to do.
>
>I feel that not disconnecting the field for at least your stated 10 seconds
>is 10 seconds more then is necessary and simply another unnecessary risk.
Risks to what? How much energy is being liberated
and where is it concentrated? If the diodes remain
intact, then ALL power (2500 watts or more) is being
pumped into a field winding designed for 50 watts
max continuous. If certain diodes begin to fail, output
voltage may drop but it still remains much higher than
the rated operating voltage of the field. If the right
combination of diodes fail, output voltage goes to
zero and you get passive shutdown of the runaway.
I've seen schematics for at least one alternator
wherein the manufacturer included a shunt zener and
series fuse in their field wiring. This was similar to
the zener-crowbar ov protection certified onto many
American/Grumman aircraft of years gone by. The notion
here was that during a runaway, the zener would open
the field fuse in a few seconds. FAA agreed
this was adequate ov protection for those aircraft.
I don't recall now which alternator it was . . .
and there may indeed be some in current
production that offer that feature. But without
knowing which ones they are, I have to take the
fallback position of assuming no such feature exists.
Even if it did exist, I've demonstrated many times
that the response time of the fuse/zener combination
for ov protection is longer than the recommended response
times for qualifying ov protection in airplanes.
B-lead disconnect to precipitate timely field failure
(especially on a Lyc where the alternator cruises at
over 10,000 RPM) has what I believe to be a sound
analytical basis.
>Without a Failure Modes and Effects Analysis (FMEA) its risky to base
>conclusions on theory and one example.
An FMEA is an analysis. You said you have analysis that
indicates a hazardous failure mode. I have analysis
that indicates a timely forced failure into a benign outcome.
I have one example of it having occurred in exactly
that way. I'm trying to understand your analysis that
suggests otherwise. How does an 14v alternator field
wound with 22AWG wire maintain continuity for more than the
cited time interval with over 100 volts applied to it?
During this time, which components liberate energy
with so much temperature rise that there is risk of fire?
Bob . . .
________________________________________________________________________________
| Subject: | Re: ectric-List: |
| From: | "Matt Prather" <mprather(at)spro.net> |
If its truly a starved electrolyte, or recombinant gas battery then
there isn't any liquid in it to spill out. Mounting it at any angle
shouldn't be a problem.
Regards,
Matt-
>
>
> Many mfgrs include insytructions to not mount that way as the vents can
> then discharge caustic materials.
>
> Concord told me to not even mount on its side.
>
> What ever
>
> Paul
>
>> Mount it in any position. Upside down if you like.
>>
>> Bob . . .
>>
>>
>
>
________________________________________________________________________________
| From: | "David Swartzendruber" <dswartzendruber(at)earthlink.net> |
| Subject: | RE: RG battery mounting positions |
Don Grunke, who is an engineer that works for Concorde Battery out of
their Wichita office, happens to be sitting down the hall from me as I
write. I just asked him about mounting Concorde RG batteries in strange
orientations and he said that on their side is fine. The only reason
they don't recommend upside down mounting is because it's possible that
some liquid could escape through the safety vent if the battery was
overcharged and forced to vent a little. This vent is normally closed
and only opens briefly if the pressure inside the battery becomes too
great.
Dave in Wichita
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-
> aeroelectric-list-server(at)matronics.com] On Behalf Of Matt Prather
> Sent: Thursday, March 13, 2003 2:56 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List:
>
>
>
> If its truly a starved electrolyte, or recombinant gas battery then
> there isn't any liquid in it to spill out. Mounting it at any angle
> shouldn't be a problem.
>
> Regards,
>
> Matt-
>
>
> >
> >
> > Many mfgrs include insytructions to not mount that way as the vents
can
> > then discharge caustic materials.
> >
> > Concord told me to not even mount on its side.
> >
> > What ever
> >
> > Paul
> >
> >> Mount it in any position. Upside down if you like.
> >>
> >> Bob . . .
> >>
> >>
> >
> >
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: RG battery operating positions |
>
>
>Many mfgrs include insytructions to not mount that way as the vents can then
>discharge caustic materials.
>
>Concord told me to not even mount on its side.
>
>What ever
>
>Paul
Interesting! I need to ask Skip about this. When the
question came up, the first thought that came to mind
was the Panasonic data sheets for their RG batterier
where we find:
"Panasonic's tough Valve Regulated Lead Acid rechargeable
batteries are designed to provide outstanding performance
in withstanding overcharge, overdischarge, and resisting
vibration and shock. Compact, these batteries save installation
space, while providing full and reliable power. The use of
special sealing epoxies, tongue and groove case and cover
construction, and long-sealing paths for posts and connectors,
assures that the Valve Regulated Lead Acid battery will offer
exceptional leak resistance, and allows them to be used in
any position."
I have several RV-8 builders who have been operating
the 17 a.h. battery on it's side for several years.
The UPS on the desk behind my computer has the battery
standing on the small end. It didn't occur to me
that our friends at Concord might not be able to
sign up to this too.
I'll see what explanation Skip Koss has about
differences in Concord products. Thanks for the
heads up.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: RE: RG battery mounting positions |
>
>
>Don Grunke, who is an engineer that works for Concorde Battery out of
>their Wichita office, happens to be sitting down the hall from me as I
>write. I just asked him about mounting Concorde RG batteries in strange
>orientations and he said that on their side is fine. The only reason
>they don't recommend upside down mounting is because it's possible that
>some liquid could escape through the safety vent if the battery was
>overcharged and forced to vent a little. This vent is normally closed
>and only opens briefly if the pressure inside the battery becomes too
>great.
>
>Dave in Wichita
Okay . . . that makes sense. Skip told me that their
batteries are 100% saturated which means there IS
a small potential for free liquid that would
be pushed out during an outgassing event.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Firewall Flange sealant? |
>
>
>What's the best thing to use for sealant on the flanges which make up my
>firewall wire penetration - i'm using SS tubing welded to a flange - so
>what would go between the flange and the firewall - to make it
>airtight? I"m not talking about around the wires - but just between the
>flange and firewall? how about proseal - would that be ok -or should it
>be some kind of fireproof silicone - I think someone mentinoed that
>once, I cannot seem to find anything in aircraft spruce - can anyone
>point me in the right direction for of where I might get the correct
>product here?
The installation I posted uses a fire-stop compound. Any
stuff you can find at a builder's supply would probably
be okay here. It's a thin, ideally zero-thickness interface
and about any fire-resistant material is going to be hard
to displace. I suspect silicone sealant would work okay
there too.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | off line for a few days . . . |
My business expenses credit card awards frequent flyer
miles for cash flow on the card. A few months ago, the
card announced an upcoming re-scheduling of "points"
needed to get a round trip ticket so Dee and I bought
up some tickets to use our present stash at the more
generous rate of exchange.
One set of tickets we bought was to have her folks
join us on a junket to the Pacific NW for a few days.
We'll be leaving in the morning and not be back until
next Wednesday night. I'm not even taking a computer
on this trip to write with.
See you folks Thursday. In the mean time, the older
salts on the list can use this time to exercise
your "learn'n" over the past couple of years.
I WILL have pad and paper . . . need to work on some
new product ideas while in the tender loving care
of the airlines . . . helps keep my blood pressure
down.
Bob . . .
|-------------------------------------------------------|
| The man who does not read good books has no advantage |
| over the man who cannot read them. |
| - Mark Twain |
|-------------------------------------------------------|
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: 12 vs 28 volts |
>
>
>What about using a DC-DC converter? I found a bunch of them on Google.
>Here is the search that I did...
>
>http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=dc+to+dc+converter+12
>v+24v
>
>Don't know if there are any drawbacks (noise issues, etc) They seem
>somewhat heavy, and I didn't find any prices so they may cost a mint but it
>would allow you to use a 24VDC radio in a 12VDC system.
>
>Godspeed,
This IS done. My distributor offers several up and down
converters for going each way. On occasion, a builder
has wanted to buy a converter large enough to run all
his radios . . . a high power device who's failure
brings down all radios. Not a really big deal if you
carry flight-bag backups and spend very little time
in clouds.
Bob . . .
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)tenforward.com> |
| Subject: | Re: RE: RG battery mounting positions |
Bob's reply to the original question was upside down was fine. As for on the
side i am just quoting what the tect department at concord told me on the
phone some 5 years ago. Any position is fine for discharge but strongly
recommended upright for charging.
Paul
----- Original Message -----
From: "David Swartzendruber" <dswartzendruber(at)earthlink.net>
Subject: AeroElectric-List: RE: RG battery mounting positions
>
> Don Grunke, who is an engineer that works for Concorde Battery out of
> their Wichita office, happens to be sitting down the hall from me as I
> write. I just asked him about mounting Concorde RG batteries in strange
> orientations and he said that on their side is fine. The only reason
> they don't recommend upside down mounting is because it's possible that
> some liquid could escape through the safety vent if the battery was
> overcharged and forced to vent a little. This vent is normally closed
> and only opens briefly if the pressure inside the battery becomes too
> great.
>
> Dave in Wichita
>
>
>> >
> > >
> > >
> > > Many mfgrs include insytructions to not mount that way as the vents
> can
> > > then discharge caustic materials.
> > >
> > > Concord told me to not even mount on its side.
> > >
> > > What ever
> > >
> > > Paul
> > >
> > >> Mount it in any position. Upside down if you like.
> > >>
> > >> Bob . . .
> > >>
> > >>
> > >
> > >
> >
> >
> >
> >
> >
> >
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)tenforward.com> |
| Subject: | Re: runaway, self regulated alternators |
Bob
Thanks for the extended reply.
However its hard to ignore the melted alternator I had in my hands years
ago. That convinced me that an internal failure could keep the voltage low
enough so the shorted current had time to heat things up and one could not
count on the field acting as a fuse. The theory was a diode failure started
things.
Regardless of our differences I personally would never consider a regulator
that could not be controlled fully. Thus no internal regulator with
connections to the "B" lead. Its just not worth the small cost savings.
Paul
________________________________________________________________________________
| Subject: | Re: RE: RG battery mounting positions |
The folks at Optima said their batteries are mounted in every position,
even upside-down, from commercial to military uses. Their most common
battery, though is 56AH at 37#; I understand there is one that is
somewhat lighter (but still well over 20#)
They even offered to provide me the same bracket they sell to the
military to mount it in strange positions; normally it is $10, but for
some reason they offered to send it to me gratis...
-John R.
Paul Messinger wrote:
>
> Bob's reply to the original question was upside down was fine. As for on the
> side i am just quoting what the tect department at concord told me on the
> phone some 5 years ago. Any position is fine for discharge but strongly
> recommended upright for charging.
>
> Paul
>
> ----- Original Message -----
> From: "David Swartzendruber" <dswartzendruber(at)earthlink.net>
> To:
> Subject: AeroElectric-List: RE: RG battery mounting positions
>
>
>
>
>
>
>>Don Grunke, who is an engineer that works for Concorde Battery out of
>>their Wichita office, happens to be sitting down the hall from me as I
>>write. I just asked him about mounting Concorde RG batteries in strange
>>orientations and he said that on their side is fine. The only reason
>>they don't recommend upside down mounting is because it's possible that
>>some liquid could escape through the safety vent if the battery was
>>overcharged and forced to vent a little. This vent is normally closed
>>and only opens briefly if the pressure inside the battery becomes too
>>great.
>>
>>Dave in Wichita
>>
>>
>>
>>>>
>>>>
>>>>Many mfgrs include insytructions to not mount that way as the vents
>>>
>>can
>>
>>>>then discharge caustic materials.
>>>>
>>>>Concord told me to not even mount on its side.
>>>>
>>>>What ever
>>>>
>>>>Paul
>>>>
>>>>
>>>>> Mount it in any position. Upside down if you like.
>>>>>
>>>>> Bob . . .
>>>>>
>>>>>
>>>>
>>>>
>>>
>>>
>>>
>>>
>>>
>>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "David Swartzendruber" <dswartzendruber(at)earthlink.net> |
| Subject: | Re: runaway, self regulated alternators |
> I personally would never consider a regulator
> that could not be controlled fully. Thus no internal regulator with
> connections to the "B" lead. Its just not worth the small cost
savings.
>
> Paul
>
Have you considered the routing of the field wire and "B" lead from
alternator? Often, they are routed together for at least some distance.
If they were to ever short together, you would have a runaway alternator
that would not be shut down even if power to the regulator was
disconnected. I saw a Cessna 206 once where the "B" lead and field
passed through the front engine baffle together. The bundle was
chaffing against the cat grommet, and had worn clear through the
insulation of the "B" lead. I don't recall what the insulation on the
field wire looked like. Nothing had happened yet, but it looked like it
could if given enough time. The issue was resolved by clamping the
bundle right there at the hole in the baffle, not allowing it to get
against the edge of the hole any more.
I bring this up just to remind everyone that even with an externally
regulated alternator, how you route, secure, and protect the field wire
and "B" lead is important to insure you don't completely bypass your
super duper crowbar OV protection.
Dave in Wichita
________________________________________________________________________________
| From: | Hebeard2(at)aol.com |
| Subject: | Firewall penetraton for wires |
Subject: Firewall Penetration for Wires.
All,
A short time ago some kind soul (whose name I have forgotten) told us all the
identification of stainless steel towel Bars available from Home Depot to be
used for firewall penetration. Being one of the certified dummies building an
airplane, I went to my neighborhood Home Depot today, and had the following
experience.
First of all I couldn't find any stainless steel towel bars, but with the
help of a sales person I found stainless steel Grab Bars. I couldn't find any
with the stock number given, but they did have quite a selection. Most were
1.5" in diameter rather than 1.25". The various stock numbers referred to
varying finishes available to facilitate good friction when grasping. There
were some 1.25" diameter in 24" length which cost $33.00. Searching for a
shorter length, I found an 18" length in 1.5" diameter for $19.96 (Stock #
6318, Satin Stainless Steel). Since length means nothing for our purposes,
and I am cheap, this is the one I bought. I figure the firestop to plug the
extra .25" wouldn't cost $13.00. Don't get too hung up on stock numbers, look
at the product under Grab Bars.
Harley E. Beard
RV-6A, Finishing Kit
________________________________________________________________________________
| From: | "Ron Triano" <rondefly(at)pacbell.net> |
| Subject: | Firewall penetraton for wires |
Hi Harvey, since I was the one with the stainless towel/ grab bar
suggestion, I am supprised you found a salesman in Home depot that knew
what supplies were in their department. If you happen to be a capable
stainless welder you could just use a piece of tubing with a flange
welded to the end. I am squishing mine with the flange on the firewall
side with fire caulking then over filling the interior of the tube and
wire with the same caulking. The caulking is readilly available in
varying temp's.
Hope this helps
Ron Triano
Soon to be a Q-200 driver.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Hebeard2(at)aol.com
Subject: AeroElectric-List: Firewall penetraton for wires
Subject: Firewall Penetration for Wires.
All,
A short time ago some kind soul (whose name I have forgotten) told us
all the
identification of stainless steel towel Bars available from Home Depot
to be
used for firewall penetration. Being one of the certified dummies
building an
airplane, I went to my neighborhood Home Depot today, and had the
following
experience.
First of all I couldn't find any stainless steel towel bars, but with
the
help of a sales person I found stainless steel Grab Bars. I couldn't
find any
with the stock number given, but they did have quite a selection. Most
were
1.5" in diameter rather than 1.25". The various stock numbers referred
to
varying finishes available to facilitate good friction when grasping.
There
were some 1.25" diameter in 24" length which cost $33.00. Searching for
a
shorter length, I found an 18" length in 1.5" diameter for $19.96 (Stock
#
6318, Satin Stainless Steel). Since length means nothing for our
purposes,
and I am cheap, this is the one I bought. I figure the firestop to plug
the
extra .25" wouldn't cost $13.00. Don't get too hung up on stock numbers,
look
at the product under Grab Bars.
Harley E. Beard
RV-6A, Finishing Kit
direct advertising on the Matronics Forums.
________________________________________________________________________________
| From: | Scott Richardson <scott_m_richardson(at)sbcglobal.net> |
| Subject: | Wire Gauge for Whelen strobes? |
I had a some questions on wiring Whelen strobe lights
that I just can't seem to find answers to in the
archive.
I'm intending to run shielded wire from a single power
supply (HDA,CF) to two A600 units in the wingtips -
this
distance is about 15' max on each side. The Whelen
install kit cabling is 16 ga 3/c shielded. My
questions are:
o Do I really need this large a wire for this length
run or would 18 ga (or smaller) suffice? I figure
that Whelen used 16 ga as a catch-all to allow runs
of arbitary (within limits) length. I'd rather save
some money and weight by using lighter gauge.
o Do all three wires need to be the same gauge?
I'm guessing that the Anode (red) and Ground
(black)
should be the same, but can the Trigger (white)
which is carrying half the voltage (200v vs 425v)
be
smaller? (There doesn't seem to be any info
I can find on the amperage on these lines).
o Along those lines, if I'm running three separate
wires, do they all need to be shielded? And if
not, which ones?
o Other than easier wiring, is there an advantage to
3/c shielded vs having three separately shielded
conductors?
Thanks for any and all help.
Scott
________________________________________________________________________________
| From: | Tom Brusehaver <cozytom(at)mn.rr.com> |
| Subject: | Genave Beta 5000 |
I just picked up a Genave Beta 5000 Transponder,
looks great, yellow tag and all (3-3-03).
Anyone know where I can get a plug that matches
the one attached? It is about 1-1/2" round.
Looks similar to an old octal tube. There are
12-15 pins out of it.
I do have a wiring diagram, so I am ok there,
I'd just rather have the correct plug before
I chop off what is there already.
Thanks
________________________________________________________________________________
| From: | Benford2(at)aol.com |
| Subject: | Re: Firewall penetraton for wires |
In a message dated 3/14/2003 12:58:18 PM Mountain Standard Time,
Hebeard2(at)aol.com writes:
>
>
> First of all I couldn't find any stainless steel towel bars, but with the
> help of a sales person I found stainless steel Grab Bars. I couldn't find
> any
> with the stock number given, but they did have quite a selection. Most were
>
> 1.5" in diameter rather than 1.25". The various stock numbers referred to
> varying finishes available to facilitate good friction when grasping. There
>
> were some 1.25" diameter in 24" length which cost $33.00. Searching for a
> shorter length, I found an 18" length in 1.5" diameter for $19.96 (Stock #
> 6318, Satin Stainless Steel). Since length means nothing for our purposes,
> and I am cheap, this is the one I bought. I figure the firestop to plug the
>
> extra .25" wouldn't cost $13.00. Don't get too hung up on stock numbers,
> look
> at the product under Grab Bars.
>
> Harley E. Beard
> RV-6A, Finishing Kit
>
Thanks for doing all the leg work on this. I will be using those same grab
bars too. Ben Haas N801BH.
________________________________________________________________________________
| Subject: | Starter concerns with FADEC and EFIS |
In a message dated 3/14/2003 5:25:57 PM Eastern Standard Time,
cozytom(at)mn.rr.com writes:
> aeroelectric-list(at)matronics.com
Bob and others:
Ive been thinking of solutions to some of the things we have been discussing
concerning voltage drop when starting FADEC engines. Also concern over
voltage spikes or low voltage problems with the EFIS/ONE during starting.
Here is what I came up with. Using Z-14 DBDA Put all avionics one one bus.
For me I think this will be a avionics bus with quad feed. One from main bus
through diode and avionics master switch. Second from Alternate bus through
diode and avionics secondary master switch. Master switches are included in
case EFIS systems need isolated as Greg Ricktor seems to think they should
be. Third and fourth essential feeds from main batt buss and alternate batt
buss on one switch that would choose one or the other. Cross feed contactor
will not have starter switch included. Starter switch will be seperate. Here
is how I envision it working. During start up sequence the avionics bus can
be feed through the alternative electrical system. So the Efis/One is powered
up from that source. Also the FADEC ignition is powered from the Alternate
battery. The main battery is used to start the engine The cross feed is kept
open at this point so the two electrical systems never affect each other. If
you needed both batteries to start you would not turn on avionics bus until
engine started. You wouldnt have you oil pressure immediatly but this
shouldnt be a common occurance to need both batteries for starting. It seem
to me that this allows the Efis/One and the FADEC ing. to be at 12.5 volts
continually during engine start-up. What do you think?
________________________________________________________________________________
| From: | "Phil Birkelbach" <phil(at)petrasoft.net> |
| Subject: | Re: Wire Gauge for Whelen strobes? |
I am installing the Nova power supply in my RV-7 with about the same
distance you are discussing and Nova told me to use 18AWG 3C Sheilded. I
have not run the strobes yet with this wire so I can't comment on whether it
works or not.
If you find a better way don't tell me because I don't want to know AFTER I
spent all the money. :-)
Godspeed,
Phil Birkelbach - Houston Texas
RV-7 N727WB (Reserved) - Fuselage
http://www.myrv7.com
----- Original Message -----
From: "Scott Richardson" <scott_m_richardson(at)sbcglobal.net>
Subject: AeroElectric-List: Wire Gauge for Whelen strobes?
>
> I had a some questions on wiring Whelen strobe lights
> that I just can't seem to find answers to in the
> archive.
>
> I'm intending to run shielded wire from a single power
> supply (HDA,CF) to two A600 units in the wingtips -
> this
> distance is about 15' max on each side. The Whelen
> install kit cabling is 16 ga 3/c shielded. My
> questions are:
>
> o Do I really need this large a wire for this length
> run or would 18 ga (or smaller) suffice? I figure
> that Whelen used 16 ga as a catch-all to allow runs
> of arbitary (within limits) length. I'd rather save
>
> some money and weight by using lighter gauge.
>
> o Do all three wires need to be the same gauge?
> I'm guessing that the Anode (red) and Ground
> (black)
> should be the same, but can the Trigger (white)
> which is carrying half the voltage (200v vs 425v)
> be
> smaller? (There doesn't seem to be any info
> I can find on the amperage on these lines).
>
> o Along those lines, if I'm running three separate
> wires, do they all need to be shielded? And if
> not, which ones?
>
> o Other than easier wiring, is there an advantage to
> 3/c shielded vs having three separately shielded
> conductors?
>
> Thanks for any and all help.
>
> Scott
>
>
________________________________________________________________________________
| From: | John Loram <johnl(at)loram.org> |
| Subject: | Wire Gauge for Whelen strobes? |
Aeroflash techsupport recommends shielded 18 gauge three wire cable with the
shield connected at the powersuppy end (not used to provide a ground
connection at the outboard end).
-john-
john(at)loram.org
www.loram.org
-----Original Message-----
From: Phil Birkelbach [mailto:phil(at)petrasoft.net]
Subject: Re: AeroElectric-List: Wire Gauge for Whelen strobes?
I am installing the Nova power supply in my RV-7 with about the same
distance you are discussing and Nova told me to use 18AWG 3C Sheilded. I
have not run the strobes yet with this wire so I can't comment on whether it
works or not.
If you find a better way don't tell me because I don't want to know AFTER I
spent all the money. :-)
Godspeed,
Phil Birkelbach - Houston Texas
RV-7 N727WB (Reserved) - Fuselage
http://www.myrv7.com
----- Original Message -----
From: "Scott Richardson" <scott_m_richardson(at)sbcglobal.net>
Subject: AeroElectric-List: Wire Gauge for Whelen strobes?
>
> I had a some questions on wiring Whelen strobe lights
> that I just can't seem to find answers to in the
> archive.
>
> I'm intending to run shielded wire from a single power
> supply (HDA,CF) to two A600 units in the wingtips -
> this
> distance is about 15' max on each side. The Whelen
> install kit cabling is 16 ga 3/c shielded. My
> questions are:
>
> o Do I really need this large a wire for this length
> run or would 18 ga (or smaller) suffice? I figure
> that Whelen used 16 ga as a catch-all to allow runs
> of arbitary (within limits) length. I'd rather save
>
> some money and weight by using lighter gauge.
>
> o Do all three wires need to be the same gauge?
> I'm guessing that the Anode (red) and Ground
> (black)
> should be the same, but can the Trigger (white)
> which is carrying half the voltage (200v vs 425v)
> be
> smaller? (There doesn't seem to be any info
> I can find on the amperage on these lines).
>
> o Along those lines, if I'm running three separate
> wires, do they all need to be shielded? And if
> not, which ones?
>
> o Other than easier wiring, is there an advantage to
> 3/c shielded vs having three separately shielded
> conductors?
>
> Thanks for any and all help.
>
> Scott
>
>
________________________________________________________________________________
| From: | Aucountry(at)aol.com |
| Subject: | Re: RE: RG battery mounting positions |
Anyone on this list ever get an RG battery approved in a cerified plane?
Especially now with the way the FAA is (more) messed up?
Gary
________________________________________________________________________________
| From: | "Jim Jewell" <jjewell(at)telus.net> |
| Subject: | Re: RE: RG battery mounting positions |
Hello Gary,
Seek out the Concord Battery site for one. They sell Certified RG sealed
lead acid batteries for Certified aircraft and have done so for some number
of years now.
Jim in Kelowna
----- Original Message -----
From: <Aucountry(at)aol.com>
Subject: Re: AeroElectric-List: RE: RG battery mounting positions
>
> Anyone on this list ever get an RG battery approved in a cerified plane?
> Especially now with the way the FAA is (more) messed up?
>
> Gary
>
>
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: RE: RG battery mounting positions |
In a message dated 3/15/03 1:13:34 AM Central Standard Time,
jjewell(at)telus.net writes:
> Seek out the Concord Battery site for one. They sell Certified RG sealed
> lead acid batteries for Certified aircraft and have done so for some number
> of years now.
>
Teledyne-Gill also has RG batteries that are approved.
Happy Skies,
Old Bob
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
| Subject: | Altitude control |
<<> I've got plans for
> a super sensitive, temperature compensated pressure
> transducer that gives me +/- 20 foot accuracy to
> 60,000 feet and better than 1% accuracy for pitot
> pressures to 300 kts.
Does this mean we will be seeing a reasonably accurate, affordable altitude
control
device in
the near future?>>
Pardon me if I don't hold my breath for this one. 20 feet of accuracy at
60,000 equates to a maximum error of .00098 psi, or 0.007% of full scale, an
accuracy not attainable by even laboratory grade sensors. At sea level 20
feet equates to 0.01 psi or 0.07% of full scale, within reach of high-end
pressure sensors, but only over a very limited temperature range. Typical
autopilots (S-TEC) use the altitude encoder with 100-foot resolution and
about 100-foot accuracy to capture an altitude, but then use a fairly
rudimentary pressure sensor to hold that altitude. A typical sensor for
that application (which we build) is about 1 to 2% accuracy over a wide
temperature range. Any modern manifold absolute pressure (MAP) sensor would
be easily capable of doing the altitude hold feature of an autopilot. I'm
using an standard Chrysler MAP sensor right now for that purpose. If one
were to use a 1% MAP sensor at a retail cost of $20 to $50 for altitude
capture the accuracy would be 274 feet at sea level and 524 feet at 20,000
feet altitude. However, the REPEATABILITY of an automotive MAP sensor over
a limited temperature range will be about 0.1% so if one were willing to do
a one-time setting of the error you could have an altitude capture error
about 1/10 of the above, or 27 feet at sea level and 52 feet at 20,000 feet.
I would think that would be about as accurate as we care about and all that
can be had today with sensors built in quantities of several million a year.
Gary Casey
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
Any pointers on mounting EGT probes - i'm having a hard time finding the courage
to drill the holes in my $1,200 4-into-1 stainless exhaust sytem?
If a probe were mounted so it stuck straight out - would that hit the cowl?? is
there plenty of clearance so any direction is ok?
thanks
---------------------------------
________________________________________________________________________________
| From: | Kevin Horton <khorto1537(at)rogers.com> |
| Subject: | Re: Altitude control |
>
><<> I've got plans for
>> a super sensitive, temperature compensated pressure
>> transducer that gives me +/- 20 foot accuracy to
>> 60,000 feet and better than 1% accuracy for pitot
>> pressures to 300 kts.
>
>Does this mean we will be seeing a reasonably accurate, affordable altitude
>control
>device in
>the near future?>>
>
>Pardon me if I don't hold my breath for this one. 20 feet of accuracy at
>60,000 equates to a maximum error of .00098 psi, or 0.007% of full scale, an
>accuracy not attainable by even laboratory grade sensors. At sea level 20
>feet equates to 0.01 psi or 0.07% of full scale, within reach of high-end
>pressure sensors, but only over a very limited temperature range. Typical
>autopilots (S-TEC) use the altitude encoder with 100-foot resolution and
>about 100-foot accuracy to capture an altitude, but then use a fairly
>rudimentary pressure sensor to hold that altitude. A typical sensor for
>that application (which we build) is about 1 to 2% accuracy over a wide
>temperature range. Any modern manifold absolute pressure (MAP) sensor would
>be easily capable of doing the altitude hold feature of an autopilot. I'm
>using an standard Chrysler MAP sensor right now for that purpose. If one
>were to use a 1% MAP sensor at a retail cost of $20 to $50 for altitude
>capture the accuracy would be 274 feet at sea level and 524 feet at 20,000
>feet altitude. However, the REPEATABILITY of an automotive MAP sensor over
>a limited temperature range will be about 0.1% so if one were willing to do
>a one-time setting of the error you could have an altitude capture error
>about 1/10 of the above, or 27 feet at sea level and 52 feet at 20,000 feet.
>I would think that would be about as accurate as we care about and all that
>can be had today with sensors built in quantities of several million a year.
>
>Gary Casey
>
Personally, I would be willing to settle for a system where you had
to manually level the aircraft at the desired altitude, and then
engage the altitude hold mode. That way the system just has to
memorize the current pressure altitude, and react to changes. That
gets us around many of the sensor accuracy issues, as long as the
sensor accuracy doesn't drift much over an hour or so.
I'm encouraged to read that there are cheap sensors available that
would suit this simple altitude hold system. Maybe someday after I
get flying I'll look into what it would take to design such a system.
________________________________________________________________________________
| From: | "Cliff Shaw" <flyinggpa(at)attbi.com> |
| Subject: | Re: Altitude control |
All
I found this web page and built the EZ Trim. It works with the Electric
trim that I already had installed.
http://hometown.aol.com/ccady/eztrim.htm
Cliff Shaw
1041 Euclid ave.
Edmonds WA 98020
(425) 776-5555
N229WC "Wile E Coyote"
> >about 1/10 of the above, or 27 feet at sea level and 52 feet at 20,000
feet.
> >I would think that would be about as accurate as we care about and all
that
> >can be had today with sensors built in quantities of several million a
year.
> >
> >Gary Casey
> >
>
> Personally, I would be willing to settle for a system where you had
> to manually level the aircraft at the desired altitude, and then
> engage the altitude hold mode. That way the system just has to
________________________________________________________________________________
| Subject: | Re: Altitude control |
| From: | Gerry Holland <gnholland(at)onetel.com> |
Kevin Hi!
> I'm encouraged to read that there are cheap sensors available that
> would suit this simple altitude hold system. Maybe someday after I
> get flying I'll look into what it would take to design such a system.
>
Not sure if you were aware or not but the EZ-Trim does this task.
Website - http://members.aol.com/_ht_a/ccady/eztrim.htm
I'm building the Circuit at this time but unfortunately my Europa will
not being flying until later this year to tell you the results.
My inclination to have this function of simple Altitude hold was as a
complimentary capability to Navaid Wing Leveller/Autopilot.
Regards
Gerry
Gerry Holland
mailto://gnholland(at)onetel.com
+44 7808 402404
Europa XS 384
G-FIZY
The greatest enjoyment from existence is living dangerously....
Friedrich Nietzsche
________________________________________________________________________________
| From: | "Tinnemaha" <Tinnemaha(at)charter.net> |
Hello List,
Thank You (especially Bob Nuckolls) for the responses to my question about de-rating
mini switches a while back......the answers made great sense and convinced
me what a great resource this list is. I will be contributing a touch of $
to the list soon.
I am in the process of re-designing the panel for my Kitfox....basically going
to use fuses instead of breakers and changing from a panel mounted GPS/Com to
a comm & a hand held GPS (mainly for economic reasons). Could You please recommend
the Comm & GPS that will give me the best value as well as the best place
to get them? I'm assuming a Terra Comm & Garmin GPS but recommendations from
experienced people will be very helpful.
Thanks,
Grant
________________________________________________________________________________
During building my Glasair, I've had many courageous incidents.... like
cutting out the fuselage for the wing and the horizontal stab... and also
drilling for the EGT probes.
Before doing mine, I of course mounted the exhaust system on the engine. I
looked at other installations, and discovered that generally the probes are
mounted on the inside of the pipes - toward the engine. That way, you are
in complete control of the clearances, because anything that could cause
interference is already there. The wire routing is easier, too.
Also, I discovered that the holes were pretty easy to drill.
Good luck.
Jim Oberst
----- Original Message -----
From: "Julia" <wings97302(at)yahoo.com>
Subject: AeroElectric-List: EGT PROBES
>
>
> Any pointers on mounting EGT probes - i'm having a hard time finding the
courage to drill the holes in my $1,200 4-into-1 stainless exhaust sytem?
>
> If a probe were mounted so it stuck straight out - would that hit the
cowl?? is there plenty of clearance so any direction is ok?
>
> thanks
>
>
> ---------------------------------
>
>
________________________________________________________________________________
| From: | Jerry2DT(at)aol.com |
Listers...
I too, feel that the least we can do is to support Bob so that it is somewhat
of a two-way street. I'll buy everything I can from him, after all the
excellent advise he dispenses in an ongoing effort here. We are way too
fortunate to have him here to help us.
Jerry Cochran
________________________________________________________________________________
| From: | John Loram <johnl(at)loram.org> |
| Subject: | Altitude control |
Don't know what you consider to be "reasonable", but Trutrak
(http://www.trutrakflightsystems.com/index.html) has just announced a $1600
(?) standalone altitude hold, complete with servo. Looks like it's not on
their web site yet.
-john-
john(at)loram.org
www.loram.org
-----Original Message-----
From: Gary Casey [mailto:glcasey(at)adelphia.net]
Subject: AeroElectric-List: Altitude control
<<> I've got plans for
> a super sensitive, temperature compensated pressure
> transducer that gives me +/- 20 foot accuracy to
> 60,000 feet and better than 1% accuracy for pitot
> pressures to 300 kts.
Does this mean we will be seeing a reasonably accurate, affordable altitude
control
device in
the near future?>>
Pardon me if I don't hold my breath for this one. 20 feet of accuracy at
60,000 equates to a maximum error of .00098 psi, or 0.007% of full scale, an
accuracy not attainable by even laboratory grade sensors. At sea level 20
feet equates to 0.01 psi or 0.07% of full scale, within reach of high-end
pressure sensors, but only over a very limited temperature range. Typical
autopilots (S-TEC) use the altitude encoder with 100-foot resolution and
about 100-foot accuracy to capture an altitude, but then use a fairly
rudimentary pressure sensor to hold that altitude. A typical sensor for
that application (which we build) is about 1 to 2% accuracy over a wide
temperature range. Any modern manifold absolute pressure (MAP) sensor would
be easily capable of doing the altitude hold feature of an autopilot. I'm
using an standard Chrysler MAP sensor right now for that purpose. If one
were to use a 1% MAP sensor at a retail cost of $20 to $50 for altitude
capture the accuracy would be 274 feet at sea level and 524 feet at 20,000
feet altitude. However, the REPEATABILITY of an automotive MAP sensor over
a limited temperature range will be about 0.1% so if one were willing to do
a one-time setting of the error you could have an altitude capture error
about 1/10 of the above, or 27 feet at sea level and 52 feet at 20,000 feet.
I would think that would be about as accurate as we care about and all that
can be had today with sensors built in quantities of several million a year.
Gary Casey
________________________________________________________________________________
| From: | "Tinnemaha" <Tinnemaha(at)charter.net> |
I'm in the (very frustrating) process of designing an electrical system for my
first experimental (Kitfox w/ Lyc O-235):
I'm confused about over voltage protection devices(for alternators):
I understand that their basic purpose is to protect the electrical system if
the voltage output gets too high, but isn't that the function of any other type
of cirquit protection device (fuses, breakers, fusible links)? I'm planning
on installing a 35 amp fusible link between the alternator and the main bus.
Does that only protect against over-amperage? I saw the 'crow-bar' type of
OV protection devices from B&C on the web site - does that get installed between
the alternator and the fusible link?
Any comments or clarifications would be helpful
Thanks,
Grant
________________________________________________________________________________
| From: | "Tinnemaha" <Tinnemaha(at)charter.net> |
| Subject: | Electronic Ignition? |
I am putting a Lycoming O-235 that was re-built by a local & reputable FBO on my
Kitfox. I saw the engine run on a test stand & paid an independent mechanic
check it out before I bought it - I feel I got a great deal but am not sure what
condition the Slick Magnetos are in. I have a general idea that it would
be good to replace the mags with electronic ignition some day.
Could You please advise about the cost/benefit of re-building/re-placing mags verses
installing electronic ignition? (Money IS an issue for me)
Thanks,
Grant
________________________________________________________________________________
| Subject: | Re: Electronic Ignition? |
If you have working mags, replacing them with electronic ignition is
generally a money-loser. People do it for performance or to feel that they
have a high-tech engine. You should be able to decide whether the mags need
service by how much time is on them. I think Slick recommends rebuilds in
500 hours, but I'm not sure - you'd have to check, and most people leave
them much longer than this.
Jim Oberst
----- Original Message -----
From: "Tinnemaha" <Tinnemaha(at)charter.net>
Subject: AeroElectric-List: Electronic Ignition?
>
> I am putting a Lycoming O-235 that was re-built by a local & reputable FBO
on my Kitfox. I saw the engine run on a test stand & paid an independent
mechanic check it out before I bought it - I feel I got a great deal but am
not sure what condition the Slick Magnetos are in. I have a general idea
that it would be good to replace the mags with electronic ignition some day.
>
> Could You please advise about the cost/benefit of re-building/re-placing
mags verses installing electronic ignition? (Money IS an issue for me)
>
>
Thanks,
>
Grant
>
>
________________________________________________________________________________
| From: | Rino <lacombr(at)nbnet.nb.ca> |
| Subject: | Re: RE: Microair radio |
Anyone have information about the new radio similar to the Microair.
I am looking for a supplier of this radio
Rino
________________________________________________________________________________
| From: | RSwanson <rswan19(at)comcast.net> |
| Subject: | Re: RE: Microair radio |
Michael Coates has one. May be the one you're thinking of.
http://www.mcp.com.au/xcom760/
R
----- Original Message -----
From: "Rino" <lacombr(at)nbnet.nb.ca>
Subject: Re: AeroElectric-List: RE: Microair radio
>
> Anyone have information about the new radio similar to the Microair.
> I am looking for a supplier of this radio
>
> Rino
>
>
>
>
>
>
________________________________________________________________________________
| From: | Rino <lacombr(at)nbnet.nb.ca> |
| Subject: | Re: RE: Microair radio |
Thanks, I think that is the one I am looking for.
RSwanson wrote:
>
>
> Michael Coates has one. May be the one you're thinking of.
> http://www.mcp.com.au/xcom760/
> R
>
> ----- Original Message -----
> From: "Rino" <lacombr(at)nbnet.nb.ca>
> To:
> Subject: Re: AeroElectric-List: RE: Microair radio
>
> >
> > Anyone have information about the new radio similar to the Microair.
> > I am looking for a supplier of this radio
> >
> > Rino
> >
> >
> >
> >
> >
> >
>
--
________________________________________________________________________________
| Subject: | Re: Altitude control |
We should be installing our EZtrims in a Cozy MKIV and a Glastar by the end
of the month. My Europa box is built, but alas my Europa is not. I'll let you
know how flight tests go.
SteveD.
http://homepage.mac.com/sdunsmuir/Europa.html
________________________________________________________________________________
| From: | "Jim Jewell" <jjewell(at)telus.net> |
| Subject: | Re: Electronic Ignition? |
Hello Grant,
E.I. pluses:
Less overall system weight.
Better GPH. at cruise altitude 6000' and up.
Less failure prone.
Lower spark plug costs.
lower overhaul costs.
More power if that is your focus over GPH.
Smoother idle.
Starting improvements.
E.I. negatives:
In the field repair service less convenient.
Warranty and performance issues with Hartzell Co.constant speed props.
-
Keep in mind that the replaced mag can be sold to cover some of the initial
EI. cost.
You can also just run what you have until a pricey service or repair becomes
an issue.
Jim in Kelowna
----- Original Message -----
From: "Tinnemaha" <Tinnemaha(at)charter.net>
Subject: AeroElectric-List: Electronic Ignition?
Could You please advise about the cost/benefit of
re-building/re-placing mags verses installing electronic ignition? (Money IS
an issue for me)
Thanks,
Grant
________________________________________________________________________________
| From: | Julia <wings97302(at)yahoo.com> |
| Subject: | Re: OV Protection |
Grant:
make sure you get the Aeroconnection book - and read it from cover to cover - then
follow Z-11 I think it is - that seems to be a pretty good layout - that's
what i'm following. once the basic layout is down, you should find it easy to
wire everything up.
good luck
"Tinnemaha"
I'm in the (very frustrating) process of designing an electrical system for my
first experimental (Kitfox w/ Lyc O-235):
I'm confused about over voltage protection devices(for alternators):
I understand that their basic purpose is to protect the electrical system if the
voltage output gets too high, but isn't that the function of any other type
of cirquit protection device (fuses, breakers, fusible links)? I'm planning on
installing a 35 amp fusible link between the alternator and the main bus. Does
that only protect against over-amperage? I saw the 'crow-bar' type of OV protection
devices from B&C on the web site - does that get installed between the
alternator and the fusible link?
Any comments or clarifications would be helpful
Thanks,
Grant
---------------------------------
________________________________________________________________________________
| From: | "KeithHallsten" <KeithHallsten(at)quiknet.com> |
| Subject: | Fw: Spike-catcher diode failures |
Here's a thread that's been going on the Velocity builder's list server. Food
for thought for all!
---- Original Message -----
From: Al Gietzen
Sent: Friday, March 14, 2003 11:55 AM
Subject: REFLECTOR: Speaking of diodes
It is obviously common practice to use diodes and Transient voltage suppressors
(TVS) to kill the backward inducted current from devices with coils (relays,
motors, etc.) to protect the contacts in switches and relys from arcing.
Have we also considered the consequences of these little jewels failing; especially
failing in a shorted condition; which, I believe is the most likely failure
mode.
I had installed a TVS (a P6KE27DICT TVS from Digikey rated 27v 600W) across
the coil on a battery contactor. It has been there for a year or two and has
worked well as I cycled the gear or whatever. Also in testing circuits I have
many times closed the contactor by touching an alligator clip from battery
- to the ground terminal of the coil for momentary closing, and was pleased to
note that there was little or no arcing. Until the other day, when I went to
do that and got a bunch of sparks. What! I put it on again and realized quickly
that I had a dead short and things were getting hot in a hurry. The TVS
had failed shorted.
In a typical circuit, the battery switch on your panel closes that contactor
coil circuit to ground. A shorted TVS, or diode, makes that an unprotected
short to ground, and I'd think could smoke some #22 awg pretty fast. What's
wrong with this picture? Are we assuming that these things don't fail?
Similarly; a shorted diode that you have across your trim motor relay would
cause the trim to run all the way to one extreme and stay there. Can you fly
and land your plane with full up or down trim? Could be be real tough, especially
if you haven't trimmed the trim spring to allow full travel in the opposite
direction with some hard pulling on the stick.
I have a bunch of the 1N4001 diodes that I planned using across small relays.
I think a diode across a contactor needs a higher current rating, but how
high? And how does one determine the rating required. Us electronically challenged
nuclear engineers, educated mostly before the advent of semiconductors,
want to know.
Thanks,
Al
----- Original Message -----
Al
You are correct, this had been a problem and has resulted in problems with general
and commercial aircraft. I could not find my notes for an IA conference in
early 90's but did find info in notes from a conference this year. AD 90 03
19 R1 required all spike suppression devices to be removed from a commercial
transport because of fire in the heater elements that was caused by the spike
diode that shorted the relay to ground. The FAA will not allow any electrical
system to be installed in an aircraft that has a spike suppression device across
the coil of a relay that is connected to a high current power source. The key
is "HIGH CURRENT".
On low-current systems it is still ok but as you noted this type of system will
almost always bypass the circuit breaker and burn something up. If using a spike
suppression device, try to use a transorb (Mosorb), try 1N6284A/ 1.5kE36A,
Motorola. Cost less than $1 and works much much faster. Remember, low current
only.
Johnny Thompson XLRG N5UP
----------------------------------------------
----- Original Message -----
Subject: Re: REFLECTOR: Speaking of diodes
It would be informative to connect the shorted diode to a piece of 22 ga mil spec
wire then apply 13 volts and see which melts first. I'll bet the diode burns
open before the insulation is damaged.
----- Original Message -----
From: Al Gietzen
To: reflector(at)tvbf.org
Sent: Saturday, March 15, 2003 5:58 PM
Subject: RE: REFLECTOR: Speaking of diodes
Well; I did just that. Based on two tests, you lose your bet 50% of the time.
I first did the test on the TVS that had failed short the other day. Recall
that it had heated pretty seriously before I opened the circuit. I put it between
two 10" lengths of #22 wire and applied 12 volts. The TVS opened in less
than a second and not much else happened.
I then failed a 1N4001 diode by passing a pulse of forward current exceeding
its rating. I then connected 12v in the other direction. The results were dramatic.
The diode and its leads were the first things that got red hot; followed
quickly by the #22 wire becoming red hot and essentially vaporizing all of
the tefzel insulation. A couple seconds more (at least it seemed that long) and
the insulation began melting on my #18 wire jumper; at which point I gave quick
tug on the alligator clips which pulled the diode apart.
My Conclusion: DO NOT put a diode across a relay where the relay coil is in a
circuit that closes to ground. In fact; look closely at any circuit where you
have used diodes to increase the life of the contacts in a switch or relay and
consider the consequences of a shorted diode.
Possible solution:
My son (who is not electronically challenged, and makes his living designing
microprocessors and other circuits, suggests the following:
There are two other "snubbing" approaches you can use which won't have a single
point failure.
1) Diode and resistor in series. Resistor value would be chosen to match resistance
of coil. Unlike the purely resistive snubbing which would place additional
drain on the battery, the diode will prevent the current from flowing through
the resistor in normal mode. The resistor protects your circuit in the
event of a diode failure, and still allows the relay to operate. In snubbing
mode, the current flows through the resistor and the diode.
2) Resistor and capacitor in series. With this approach, the capacitor is chosen
to "absorb" the energy from the coil. However, the circuit will now resonate.
The resistor is added to dampen the resonance. Choosing the values of
both the R and C would depend on the inductance of the coil, which is something
you probably don't know. So, there would be some trial and error involved
with choosing values.
I think approach #1 will work very well.
Sounds right to me. The resistance of the battery contactor coil is about 15
ohms. Put a 15 ohm resistor in series with the diode, and the current in the
rare event of the shorted diode would be less than an amp. Keep the resistor
in the open air where it can dissipate some heat. Typical 15 A relays have coil
resistance of about 150 Ohms. Put in a 150 Ohm resistor with your diode and
shorted current is limited to less than 0.1 amps. Not enough to drive your
trim motor.
Anyway; it makes sense to me not to risk myself and my plane in an effort to
prolong the life of the contacts in a relay. Failure of the relay is likely to
be inconsequential.
Best, Al
________________________________________________________________________________
| From: | "Larry Bowen" <Larry(at)BowenAero.com> |
| Subject: | advanced aircraft electronics |
Can anyone offer an opinion on the antennas from advanced aircraft
electronics (http://www.advancedaircraft.com/)? I'm considering their
nav ant for installation in my RV-8 wing-tip.
-
Larry Bowen
Larry(at)BowenAero.com
http://BowenAero.com
2003 - The year of flight!
________________________________________________________________________________
| From: | Howard Ogle <pub(at)macrotechcorp.com> |
| Subject: | Re: OV Protection |
Circuit protection devices, like fuses, breakers, fusible links, are only
intended to protect the WIRE from an overload condition (to much amperage). The
danger when a wire conducts two much current is overheating of the wire and the
resulting damage that can occur.
Electricity 101: Using water theory to explain electricity... You can think of
voltage as pressure in a pipe. Whereas amperage can be thought of as volume of
water flowing past a point, just as it is the number of electrons flowing past
a
point in a wire. (For this discussion, I'm going to keep it simple and leave
resistance out of the picture.)
So, your fuses and circuit breakers protect you from to much current or amperage
flowing through a given wire. But, they do nothing to prevent a run away
alternator from offering up to much voltage which can destroy avionics or other
electrical equipment. It can only take a fraction of a second for high voltage
to do it's damage.
A fusible link or other current protection device inline with the alternator
B-lead is designed to prevent a shorted B-lead or shorted alternator from
killing the battery or smoking the B-lead wire. If we lose the alternator, it
sure would be nice (in some cases absolutely necessary) to still have the
battery to get us on the ground. Not to mention, if we didn't have some sort of
current limit on the B-lead, we could end up with an electrical fire.
There are several ways an alternator can fail. However, the one that we are not
protected from yet, unless we have OV protection, is the so called run away
condition. This is where the alternator can supply relatively high voltage to
our system. Current protection does nothing here. The OV protection that Bob
recommends, and I agree, shorts the field lead of the alternator to ground as
soon as an OV condition is detected. This causes the alternator's magnetic field
to immediately collapse (within milliseconds). This is followed by the
alternator field circuit breaker popping, due to the field circuit being shorted
to ground by the OV circuitry. This happens so fast that this is your clue that
you just had an OV condition. The good news is that you still have battery
power, radios and avionics.
A proper system should have both current (fuses, breakers, fusible links)
protection as well as OV protection.
Howard Ogle
> I'm in the (very frustrating) process of designing an electrical system for my
> first experimental (Kitfox w/ Lyc O-235):
> I'm confused about over voltage protection devices(for alternators):
> I understand that their basic purpose is to protect the electrical system if
> the voltage output gets too high, but isn't that the function of any other
type
> of cirquit protection device (fuses, breakers, fusible links)? I'm planning
> on installing a 35 amp fusible link between the alternator and the main bus.
> Does that only protect against over-amperage? I saw the 'crow-bar' type of
> OV protection devices from B&C on the web site - does that get installed
between
> the alternator and the fusible link?
> Any comments or clarifications would be helpful
> Thanks,
> Grant
________________________________________________________________________________
| From: | "Donald Maziarz" <n2va(at)arrl.net> |
You Can Fly Them,
But Can You Wire Them?
What: Weekend seminar presented by The AeroElectric
Connection
Hosted by the National Capital Area
Chapter 186,
Experimental Aircraft Association (EAA)
When: June 7 0800 - 1700
June 8 0800 - 1200
Where: Manassas, VA at the Manassas Regional Airport
(HEF),
EAA 186 Chapter House, at the base of the
tower
Learn the ins and outs of wiring your homebuilt or
restoration project airplane.
Not building or restoring, then get a general
understanding of the aircraft
electrical systems.
Bob Nuckolls has 40 years of knowledge to share with
you.
Cost: $150 per person including a copy of Bob's super
book The AeroElectric Connection
Door Prizes
For more information and to register go to the seminar
area at http://www.aeroelectric.com/
Also note Bob's satisfaction guarantee.
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
<< My Conclusion: DO NOT put a diode across a relay where the relay coil is
in a
circuit that closes to ground. In fact; look closely at any circuit where
you
have used diodes to increase the life of the contacts in a switch or relay
and
consider the consequences of a shorted diode.
another post:
There are two other "snubbing" approaches you can use which won't have a
single
point failure.
1) Diode and resistor in series. Resistor value would be chosen to match
resistance
of coil. Unlike the purely resistive snubbing which would place additional
drain on the battery, the diode will prevent the current from flowing
through
the resistor in normal mode. The resistor protects your circuit in the
event of a diode failure, and still allows the relay to operate. In
snubbing
mode, the current flows through the resistor and the diode.
2) Resistor and capacitor in series. With this approach, the capacitor
is chosen
to "absorb" the energy from the coil. However, the circuit will now
resonate.
The resistor is added to dampen the resonance.>>
Very interesting, and excellent thoughts. But I don't think it matters
whether or not the relay coil goes to ground - the failure mode would be the
same if the switch was in the ground leg. One problem with method 1 above
is that with that value resistor the heat dissipation in the diode-shorted
mode would likely be greater than the rating of the resistor, causing the
resistor to fail as well. I wonder if there isn't a 3rd method - and that
is to simply put a capacitor across the coil without the series resistor (in
fact, I've seen some done this way). Sure, the coil/capacitor will
oscillate, but why do I care? The only thing I'm trying to accomplish is to
increase the life of the switch by reducing the arcing, which the capacitor
will do, even if it's not perfect. I assume it would have to be a fairly
large capacitor and it needs to be rated at a fairly high voltage of maybe
50 volts (a 1 mfd, 50-volt electrolytic?) Further, I would think the
capacitor would be more effecting in reducing the EMC signature as it will
conduct with less delay. A diode requires time to turn on and hence there
is always a voltage spike of very short duration just prior to turn-on. It
is my understanding that these diode turn-on spikes are the principle source
of noise in an alternator, not the voltage ripple. In the passenger car
world there are no parallel diodes to my knowledge as it was found to be
cheaper and more reliable to beef up the switches to tolerate the arcing.
Any exposed semiconductors (not in boxes on circuit boards) are avoided like
the plague due to vibration and reliability issues.
Gary Casey
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
<http://hometown.aol.com/ccady/eztrim.htm
Cliff Shaw
1041 Euclid ave.
Edmonds WA 98020
(425) 776-5555
N229WC "Wile E Coyote"
> >about 1/10 of the above, or 27 feet at sea level and 52 feet at 20,000
feet.
> >I would think that would be about as accurate as we care about and all
that
> >can be had today with sensors built in quantities of several million a
year.
> >>>
The sensor in the "EZ Trim" shown above is exactly what I was talking
about - it is a MAP sensor in a catalog-available package. Unfortunately,
it is from one of our competitors. But it brings up another question,
especially related to the ES I'm building that has 3-axis electric trim.
What is the disadvantage of using the trim as the autopilot actuator? That
would certainly reduce the overall weight and potential cost. The problem I
see is that there is no convenient way to override the system. For
instance, if it makes an uncommanded dive and the pilot pulls it back up the
trim will continue to go to full nose-down position. I suppose the reaction
could be to disconnect and then manually correct the trim? Is the trim
typically fast enough to make for a good autopilot response? I have played
with the manual pitch trim in my Cardinal and with a little practice I can
do a very nice job of flying the plane with the trim only. The EZ Trim idea
is an intriguing one. Comments anyone?
Gary Casey
________________________________________________________________________________
| Subject: | Re: Fw: Spike-catcher diode failures |
In a message dated 3/15/2003 11:22:23 PM Eastern Standard Time,
KeithHallsten(at)quiknet.com writes:
> KeithHallsten(at)quiknet.com>
>
> Here's a thread that's been going on the Velocity builder's list server.
> Food for thought for all!
>
>
> ---- Original Message -----
>
> From: Al Gietzen
>
> Sent: Friday, March 14, 2003 11:55 AM
> Subject: REFLECTOR: Speaking of diodes
>
>
> It is obviously common practice to use diodes and Transient voltage
> suppressors (TVS) to kill the backward inducted current from devices with
> coils (relays, motors, etc.) to protect the contacts in switches and relys
> from arcing. Have we also considered the consequences of these little
> jewels failing; especially failing in a shorted condition; which, I believe
> is the most likely failure mode.
>
>
> I had installed a TVS (a P6KE27DICT TVS from Digikey rated 27v 600W)
> across the coil on a battery contactor. It has been there for a year or
> two and has worked well as I cycled the gear or whatever. Also in testing
> circuits I have many times closed the contactor by touching an alligator
> clip from battery - to the ground terminal of the coil for momentary
> closing, and was pleased to note that there was little or no arcing. Until
> the other day, when I went to do that and got a bunch of sparks. What! I
> put it on again and realized quickly that I had a dead short and things
> were getting hot in a hurry. The TVS had failed shorted.
>
>
> In a typical circuit, the battery switch on your panel closes that
> contactor coil circuit to ground. A shorted TVS, or diode, makes that an
> unprotected short to ground, and I'd think could smoke some #22 awg pretty
> fast. What's wrong with this picture? Are we assuming that these things
> don't fail?
>
>
> Similarly; a shorted diode that you have across your trim motor relay
> would cause the trim to run all the way to one extreme and stay there. Can
> you fly and land your plane with full up or down trim? Could be be real
> tough, especially if you haven't trimmed the trim spring to allow full
> travel in the opposite direction with some hard pulling on the stick.
>
>
> I have a bunch of the 1N4001 diodes that I planned using across small
> relays. I think a diode across a contactor needs a higher current rating,
> but how high? And how does one determine the rating required. Us
> electronically challenged nuclear engineers, educated mostly before the
> advent of semiconductors, want to know.
>
>
> Thanks,
>
> Al
>
The first thing that caught my eye in this posting from Al Gietzen begs the
question: Why is he using a transorb rated at 27 V for this application? He
is obviously trying to absorb the inductive kick from his battery contactor's
coil in order to protect his master switch's contact life. He doesn't say
whether his electrical system is 14 or 28 volt. If it is a 28 V system, his
27 V transorb will conduct anyway the first time he brings his alternator
online. He is in the building phase right now I am assuming because he says
that he has "made" the battery contactor in order to swing his (landing)
gear. This transorb's failure is a good event for him now instead of on
engine start day.
If he has a 14 V system, using a 27 V transorb is short changing himself and
his system. The transorb he has chosen only begins to conduct above 27
volts. This means that in practice, the kick from his coil is only
suppressed above 27 volts. This will allow an amount of energy to be handled
by his master switch's contacts that need not be. Using a diode across the
coil will bring it's kick all the way down to .6 V.
He mentions the fear of such an event occurring on his trim relay circuit
causing a trim motor to run away. No matter what device is used to absorb
the kick from the coil of a relay/contactor, be it a transorb, diode,
capacitor, neon, etc., if that device shorts it will not cause a run away
relay/contactor because the relay/contactor's coil is shorted by the bad
device in parallel with that coil. The over current protector (circuit
breaker, fuse, fusible link) will open the circuit.
What Al's issue is, is the lack of over current protection of the 22ga. wire
in his battery contactor coil's grounding circuit. The only failure that
would make this an issue is if the coil's suppression device shorted (or the
coil itself). A diode across the contactor's coil is probably best overall
here. This diode should be robust enough to do the job well. A fusible link
or a fuse could be added in series with the diode/coil ground circuit but
that would be overkill in my opinion. Chose a good diode that will do the
job. A 1N4001 is ideal in all respects here.
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
________________________________________________________________________________
| From: | Canyon <steve.canyon(at)verizon.net> |
Gary Casey wrote:
>A diode requires time to turn on and hence there
>is always a voltage spike of very short duration just prior to
>turn-on. It
>is my understanding that these diode turn-on spikes are the principle
>source
>of noise in an alternator, not the voltage ripple. In the passenger car
>world there are no parallel diodes to my knowledge as it was found to be
>cheaper and more reliable to beef up the switches to tolerate the arcing.
>Any exposed semiconductors (not in boxes on circuit boards) are
>avoided like
>the plague due to vibration and reliability issues.
---
All of this is far afield of the reality and/or actual physics of
proper suppression of transient energy developed when circuits through
coils are suddenly broken. In truth, the best, most effective and
safest transient suppression is accomplished with a diode placed
immediately across the inductive element - period. All other methods
using resistors, capacitors, varistors, transorbs etc are far inferior
and thus far less desirable. Don't know how these myths get started...
Steve
________________________________________________________________________________
| From: | Jos Okhuijsen <josok(at)ukolo.fi> |
The diode in this case will die of overvoltage only. The better the
switch, the shorter the cutoff time, and the higher the spike which
will stand over the diode. Overvoltage kills a diode instantly, as
opposed to overcurrent, which will first heat up and then kill.
Adding a capacitor to a coil changes the circuit into a tuned circuit,
much like a magneto, and if the components are sufficiently wrong
chosen, the end result will be more destructing then imaginable. A large
capacitor has an notable impedance of it's own, so is out of the
question. So the first step is to choose the diode with an sufficienty
high reverse voltage, the 1n4001 is (or was) availble from 100 to 800
volts. 800 is the minimum. If nethertheless the diode would fail a
fusable! resistor could prevent the next disaster. Fusable resistors
will not induce a fire hazard, not on 12 volts at least. A normal
resistor will, and could even short out instead of open.
Problem here is that the the resister would have to be inspected at
regular intervals, otherwise a failed diode would never be noticed.
Jos
Gary Casey wrote:
>
><< My Conclusion: DO NOT put a diode across a relay where the relay coil is
>in a
>circuit that closes to ground. In fact; look closely at any circuit where
>you
>have used diodes to increase the life of the contacts in a switch or relay
>and
>consider the consequences of a shorted diode.
>
>another post:
>
> There are two other "snubbing" approaches you can use which won't have a
>single
>point failure.
>
> 1) Diode and resistor in series. Resistor value would be chosen to match
>resistance
>of coil. Unlike the purely resistive snubbing which would place additional
>drain on the battery, the diode will prevent the current from flowing
>through
>the resistor in normal mode. The resistor protects your circuit in the
>event of a diode failure, and still allows the relay to operate. In
>snubbing
>mode, the current flows through the resistor and the diode.
>
> 2) Resistor and capacitor in series. With this approach, the capacitor
>is chosen
>to "absorb" the energy from the coil. However, the circuit will now
>resonate.
>The resistor is added to dampen the resonance.>>
>
>Very interesting, and excellent thoughts. But I don't think it matters
>whether or not the relay coil goes to ground - the failure mode would be the
>same if the switch was in the ground leg. One problem with method 1 above
>is that with that value resistor the heat dissipation in the diode-shorted
>mode would likely be greater than the rating of the resistor, causing the
>resistor to fail as well. I wonder if there isn't a 3rd method - and that
>is to simply put a capacitor across the coil without the series resistor (in
>fact, I've seen some done this way). Sure, the coil/capacitor will
>oscillate, but why do I care? The only thing I'm trying to accomplish is to
>increase the life of the switch by reducing the arcing, which the capacitor
>will do, even if it's not perfect. I assume it would have to be a fairly
>large capacitor and it needs to be rated at a fairly high voltage of maybe
>50 volts (a 1 mfd, 50-volt electrolytic?) Further, I would think the
>capacitor would be more effecting in reducing the EMC signature as it will
>conduct with less delay. A diode requires time to turn on and hence there
>is always a voltage spike of very short duration just prior to turn-on. It
>is my understanding that these diode turn-on spikes are the principle source
>of noise in an alternator, not the voltage ripple. In the passenger car
>world there are no parallel diodes to my knowledge as it was found to be
>cheaper and more reliable to beef up the switches to tolerate the arcing.
>Any exposed semiconductors (not in boxes on circuit boards) are avoided like
>the plague due to vibration and reliability issues.
>
>Gary Casey
>
>
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)tenforward.com> |
| Subject: | Re: Fw: Spike-catcher diode failures |
Transorbs act the same way as a normal diode in the forward direction (they
conduct at under 1 v ) so using the normal transorb or a 1N4001 works the
same when placed across the relay coil to protect the coils inductive "kick"
from potential upstream switch contacts. There are also bi-directional
transorbs same part number but with a "C" after the voltage.
Basically a transorb is a special purpose Zener diode designed for high peak
currents and extremely fast action.
ANY diode can fail short and the primary diode failure is short. In a 12V
acft the failure of a 27V transorb is likely completely random and could
have happened with a 1N4001. The peak current rating of the transorb is huge
compared to the 1N4001. The steady state current rating is similar and is
limited by the package getting too hot.
The intent of a transorb is to clip any high voltage that might get back to
electronics and cause a failure from the HV spike. A 1N4001 diode across the
relay coil is used to continue the coils current around and around the coil
and let the coils resistance absorb the potential inductive spike.
In spacecraft applications we used two diodes in series across every relay.
The dual diodes were special two diodes in a single package. Thus a single
failure of a diode did no harm.
In any case properly fused circuits would prevent any wire overheating etc.
Paul
----- Original Message -----
From: "KeithHallsten" <KeithHallsten(at)quiknet.com>
Subject: AeroElectric-List: Fw: Spike-catcher diode failures
>
> Here's a thread that's been going on the Velocity builder's list server.
Food for thought for all!
>
>
> ---- Original Message -----
>
> From: Al Gietzen
>
> Sent: Friday, March 14, 2003 11:55 AM
> Subject: REFLECTOR: Speaking of diodes
>
>
> It is obviously common practice to use diodes and Transient voltage
suppressors (TVS) to kill the backward inducted current from devices with
coils (relays, motors, etc.) to protect the contacts in switches and relys
from arcing. Have we also considered the consequences of these little
jewels failing; especially failing in a shorted condition; which, I believe
is the most likely failure mode.
>
>
> I had installed a TVS (a P6KE27DICT TVS from Digikey rated 27v 600W)
across the coil on a battery contactor. It has been there for a year or two
and has worked well as I cycled the gear or whatever. Also in testing
circuits I have many times closed the contactor by touching an alligator
clip from battery - to the ground terminal of the coil for momentary
closing, and was pleased to note that there was little or no arcing. Until
the other day, when I went to do that and got a bunch of sparks. What! I
put it on again and realized quickly that I had a dead short and things were
getting hot in a hurry. The TVS had failed shorted.
>
>
> In a typical circuit, the battery switch on your panel closes that
contactor coil circuit to ground. A shorted TVS, or diode, makes that an
unprotected short to ground, and I'd think could smoke some #22 awg pretty
fast. What's wrong with this picture? Are we assuming that these things
don't fail?
>
>
> Similarly; a shorted diode that you have across your trim motor
relay would cause the trim to run all the way to one extreme and stay there.
Can you fly and land your plane with full up or down trim? Could be be real
tough, especially if you haven't trimmed the trim spring to allow full
travel in the opposite direction with some hard pulling on the stick.
>
>
> I have a bunch of the 1N4001 diodes that I planned using across
small relays. I think a diode across a contactor needs a higher current
rating, but how high? And how does one determine the rating required. Us
electronically challenged nuclear engineers, educated mostly before the
advent of semiconductors, want to know.
>
>
> Thanks,
>
> Al
>
>
> ----- Original Message -----
>
>
> Al
>
>
> You are correct, this had been a problem and has resulted in problems with
general and commercial aircraft. I could not find my notes for an IA
conference in early 90's but did find info in notes from a conference this
year. AD 90 03 19 R1 required all spike suppression devices to be removed
from a commercial transport because of fire in the heater elements that was
caused by the spike diode that shorted the relay to ground. The FAA will not
allow any electrical system to be installed in an aircraft that has a spike
suppression device across the coil of a relay that is connected to a high
current power source. The key is "HIGH CURRENT".
>
>
> On low-current systems it is still ok but as you noted this type of system
will almost always bypass the circuit breaker and burn something up. If
using a spike suppression device, try to use a transorb (Mosorb), try
1N6284A/ 1.5kE36A, Motorola. Cost less than $1 and works much much faster.
Remember, low current only.
>
>
> Johnny Thompson XLRG N5UP
>
>
> ----------------------------------------------
>
> ----- Original Message -----
>
> Subject: Re: REFLECTOR: Speaking of diodes
>
>
> It would be informative to connect the shorted diode to a piece of 22 ga
mil spec wire then apply 13 volts and see which melts first. I'll bet the
diode burns open before the insulation is damaged.
>
>
> ----- Original Message -----
> From: Al Gietzen
> To: reflector(at)tvbf.org
> Sent: Saturday, March 15, 2003 5:58 PM
> Subject: RE: REFLECTOR: Speaking of diodes
>
>
> Well; I did just that. Based on two tests, you lose your bet 50% of the
time. I first did the test on the TVS that had failed short the other day.
Recall that it had heated pretty seriously before I opened the circuit. I
put it between two 10" lengths of #22 wire and applied 12 volts. The TVS
opened in less than a second and not much else happened.
>
>
> I then failed a 1N4001 diode by passing a pulse of forward current
exceeding its rating. I then connected 12v in the other direction. The
results were dramatic. The diode and its leads were the first things that
got red hot; followed quickly by the #22 wire becoming red hot and
essentially vaporizing all of the tefzel insulation. A couple seconds more
(at least it seemed that long) and the insulation began melting on my #18
wire jumper; at which point I gave quick tug on the alligator clips which
pulled the diode apart.
>
>
> My Conclusion: DO NOT put a diode across a relay where the relay coil is
in a circuit that closes to ground. In fact; look closely at any circuit
where you have used diodes to increase the life of the contacts in a switch
or relay and consider the consequences of a shorted diode.
>
>
> Possible solution:
>
>
> My son (who is not electronically challenged, and makes his living
designing microprocessors and other circuits, suggests the following:
>
>
> There are two other "snubbing" approaches you can use which won't have a
single point failure.
>
> 1) Diode and resistor in series. Resistor value would be chosen to
match resistance of coil. Unlike the purely resistive snubbing which would
place additional drain on the battery, the diode will prevent the current
from flowing through the resistor in normal mode. The resistor protects
your circuit in the event of a diode failure, and still allows the relay to
operate. In snubbing mode, the current flows through the resistor and the
diode.
>
> 2) Resistor and capacitor in series. With this approach, the capacitor
is chosen to "absorb" the energy from the coil. However, the circuit will
now resonate. The resistor is added to dampen the resonance. Choosing the
values of both the R and C would depend on the inductance of the coil, which
is something you probably don't know. So, there would be some trial and
error involved with choosing values.
>
> I think approach #1 will work very well.
>
>
> Sounds right to me. The resistance of the battery contactor coil is
about 15 ohms. Put a 15 ohm resistor in series with the diode, and the
current in the rare event of the shorted diode would be less than an amp.
Keep the resistor in the open air where it can dissipate some heat. Typical
15 A relays have coil resistance of about 150 Ohms. Put in a 150 Ohm
resistor with your diode and shorted current is limited to less than 0.1
amps. Not enough to drive your trim motor.
>
>
> Anyway; it makes sense to me not to risk myself and my plane in an
effort to prolong the life of the contacts in a relay. Failure of the relay
is likely to be inconsequential.
>
>
> Best, Al
>
>
________________________________________________________________________________
| From: | Canyon <steve.canyon(at)verizon.net> |
| Subject: | Re: Fw: Spike-catcher diode failures |
Paul Messinger wrote:
>ANY diode can fail short and the primary diode failure is short. In a 12V
>acft the failure of a 27V transorb is likely completely random and could
>have happened with a 1N4001. The peak current rating of the transorb
>is huge
>compared to the 1N4001. The steady state current rating is similar and is
>limited by the package getting too hot.
---
Paul, can't argue the point -- it's true. However, it leads one not
skilled in the art to think they have protection they don't have for
OV. 27V is far too late to help any typical sophisticated
system/device likely to be in the circuit. There are simply better
ways to handle OV, IMO. And in fact, 1N4001 diodes are rated at only
50V, IIRC -- the ones that should be used are at least 1N4006 and IIRC,
the IN52XX (? it's been awhile) series would be even better, and two in
series should be fine, though not many folks are likely to ever be
aware if one of them shorted and then you're back to a single. :-)
Steve
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | RE: Altitude control |
Altitude....
The Swiss make a wristwatch for climbers that has an barometric altimeter function
accurate to 1 meter at 10,000 meters. So 0.001% accuracy ON YOUR WRIST! is
no big deal. Fifteen years ago at an aerospace show, I saw a (REAL BIG DEAL)
laboratory altimeter that had ten decimal places and the last couple digits were
dancing. I asked about its precision and the salesman said, "watch this", and
he slipped a thin product flyer under the sensor. The 8th place (or so) jumped
up a digit and stayed there. It hurts my head to think how good that thing
was.
Theoretically, ultimate barometric altitude precision is exactly equivalent to
the size the smallest bubble that has buoyancy. There it goes, ouch, my head hurts
again.
It is important to realize that barometric altitude is sloppy compared to other
ways of measuring altitude. Differential GPS, radar, and all the fancy ways formerly
unaffordable to home builders are becoming affordable.
Regards,
Eric M. Jones
________________________________________________________________________________
| From: | Jerzy Krasinski <krasinski(at)direcway.com> |
>
>
> All of this is far afield of the reality and/or actual physics of
> proper suppression of transient energy developed when circuits through
> coils are suddenly broken. In truth, the best, most effective and
> safest transient suppression is accomplished with a diode placed
> immediately across the inductive element - period. All other methods
> using resistors, capacitors, varistors, transorbs etc are far inferior
> and thus far less desirable. Don't know how these myths get started...
>
> Steve
>
>
Steve,
I wonder what is wrong with varistors. These seem to be among the most
reliable electronic elements. The damage mechanism of varistors is
thermal, however, you have to heat all the big device, rather than a
tiny junction of the diode. Varistors can take incredible abuse, they
can absorb an incredible current with no damage, and the only limit is
the total energy of the spike. That is the reason why varistors and not
discrete diodes are used for lightning protection of power lines. In
addition they are made using ceramic process and they are cheap. Most of
them are fast enough to turn on and absorb a voltage spike generated in
a coil.
In fact varistors on a micro level are diodes. There are millions of
strings of junctions formed between the grains of the ceramic material
of varistor and that explains why varistors survive so much of bad
treatment. To ruin a varistor you would have to ruin millions of the
micro diodes and that requires to make the WHOLE pellet heated to a
very high termperature.
I use varistors in my work to protect 200V electronics from periodic (20
times a second) 20 kV voltage spikes with ~50 ns risetime. I put a 250V
big varistor across the 200V output. That took care of the problem.
These 20kV pulses just sink into the varistor. Living in a rural area I
had problems with lightning strikes in the power line wiping out my TV,
computer equipment, telephones etc. I got exhausted fighting each time
with my insurance company to get replacement $$ for lightning damaged
property, that is included in my policy. I put varistors between the
power wires, and between the wires and the ground wire. The Oklahoma
strength lightnings are still there, but neither my equipment nor
varistors failed. If something takes abuse of a lightning why it would
fail from a much weaker pulse generated in a coil? It seems that a tiny
varistor would be sufficient to handle the coil generated spikes.
Attaching a 15 - 17 V varistor across the relay coil in a 13.5V system
would limit voltage on the coil roughly to 15 - 17 V in any direction,
since voltage/current characteristic of the varistor is symmetric. That
should protect the coil.
Does anyone on this list know a reason why the varistor would be
inferior in a relay coil voltage spike protection circuit?
Jerzy
________________________________________________________________________________
| From: | Canyon <steve.canyon(at)verizon.net> |
Jerzy Krasinski wrote:
>Attaching a 15 - 17 V varistor across the relay coil in a 13.5V system
>would limit voltage on the coil roughly to 15 - 17 V in any direction,
>since voltage/current characteristic of the varistor is symmetric. That
>should protect the coil.
---
Jerzy, the answer lies in the dynamics of the transient. In the case
of a diode across the coil, the transient is generated by the fact the
coil wants to continue the current flow after the current source has
been switched off and a diode will circulate that small transient
energy through the diode, quenching the transient energy, almost
instantly limiting the voltage to ~0.6 or so volts above the relatively
stiff current sink of a battery circuit voltage. What else could one
desire?
Compare the varistor clip voltage to this and I think it is obvious
which is most appropriate for the task intended.
For other applications you describe, in AC circuits, varistors are very
effective. And for your situation with lightning, if possible, bury
the power underground for the final run to your house/barn whatever and
you will also see considerable improvement in protection. Adding the
varistors as you describe then adds even more effective protection with
this arrangement for household power.
Steve
________________________________________________________________________________
| From: | Jerzy Krasinski <krasinski(at)direcway.com> |
>
>
>Jerzy, the answer lies in the dynamics of the transient. In the case
>of a diode across the coil, the transient is generated by the fact the
>coil wants to continue the current flow after the current source has
>been switched off and a diode will circulate that small transient
>energy through the diode, quenching the transient energy, almost
>instantly limiting the voltage to ~0.6 or so volts above the relatively
>stiff current sink of a battery circuit voltage. What else could one
>desire?
>
>Compare the varistor clip voltage to this and I think it is obvious
>which is most appropriate for the task intended.
>
>
>
Steve,
The purpose of the circuit we discuss is to safely discharge the energy
stored in the relay core. Safely means without unnecessary overvoltage.
In case of a diode voltage will get clipped at ~ 0.6 V, in case of a 15
V varistor voltage will get clipped at ~15 V. In both cases the energy
will get dissipated safely from the coil's point of view, since 12 V
coil would handle 15 V with no problem.
Diodes are widely accepted as damping elements for inductice loads, and
if you asked me a few days ago, before I learned that diodes fail more
frequently than acceptable in aviation, I would recommend a diode for
that task. But now, having FAA against the diodes, and looking for a
difficult to damage damping element for the coil, I noticed that the
varistor's resistance to damage by current pulses or inverse voltage
spike would be very difficult to beat.
Jerzy
________________________________________________________________________________
| From: | Canyon <steve.canyon(at)verizon.net> |
Jerzy Krasinski wrote:
>Diodes are widely accepted as damping elements for inductice loads, and
>if you asked me a few days ago, before I learned that diodes fail more
>frequently than acceptable in aviation, I would recommend a diode for
>that task. But now, having FAA against the diodes, and looking for a
>difficult to damage damping element for the coil, I noticed that the
>varistor's resistance to damage by current pulses or inverse voltage
>spike would be very difficult to beat.
---
Diodes are widely accepted because they are the right device in the
right application, but this is for experimental planes, right? Try it
out if you're determined and let us know how it works out. Personally,
I'll stick with diodes and avoid the +- 15V ringing of the inductor
about the power rail(s).
Steve
________________________________________________________________________________
| From: | "Leonard Garceau" <lhgcpg(at)westriv.com> |
| Subject: | Re: Starter concerns with FADEC and EFIS |
Hi Bob,
I have a question about wiring the fuel injected and coil over plug engines.
I see how you wire two hot busses from 2 batteries to the two computers.
But how do I wire the fuel injectors and the coils to the two separate
batteries? What do you think would work the best?
Thanks,
Leonard
----- Original Message -----
From: <TimRhod(at)aol.com>
Subject: AeroElectric-List: Starter concerns with FADEC and EFIS
>
> In a message dated 3/14/2003 5:25:57 PM Eastern Standard Time,
> cozytom(at)mn.rr.com writes:
>
> > aeroelectric-list(at)matronics.co
m
>
> Bob and others:
> Ive been thinking of solutions to some of the things we have been
discussing
> concerning voltage drop when starting FADEC engines. Also concern over
> voltage spikes or low voltage problems with the EFIS/ONE during
starting.
> Here is what I came up with. Using Z-14 DBDA Put all avionics one one
bus.
> For me I think this will be a avionics bus with quad feed. One from main
bus
> through diode and avionics master switch. Second from Alternate bus
through
> diode and avionics secondary master switch. Master switches are included
in
> case EFIS systems need isolated as Greg Ricktor seems to think they should
> be. Third and fourth essential feeds from main batt buss and alternate
batt
> buss on one switch that would choose one or the other. Cross feed
contactor
> will not have starter switch included. Starter switch will be seperate.
Here
> is how I envision it working. During start up sequence the avionics bus
can
> be feed through the alternative electrical system. So the Efis/One is
powered
> up from that source. Also the FADEC ignition is powered from the Alternate
> battery. The main battery is used to start the engine The cross feed is
kept
> open at this point so the two electrical systems never affect each other.
If
> you needed both batteries to start you would not turn on avionics bus
until
> engine started. You wouldnt have you oil pressure immediatly but this
> shouldnt be a common occurance to need both batteries for starting. It
seem
> to me that this allows the Efis/One and the FADEC ing. to be at 12.5 volts
> continually during engine start-up. What do you think?
>
>
________________________________________________________________________________
| From: | CBFLESHREN(at)aol.com |
Hi Jerzy, I've been lurking here & can't help but recall that "Bob" had
MOV's shown in some of his earlier drawings for the protection of various
Start & Master relays. I asked him about their use back then & as I recall,
he stated the reason for his preference over a diode, for the MOV was that no
concern for polarity made them slightly easier for us "lay" homebuilders to
cope with. FWIW ---- Chris Fleshren
________________________________________________________________________________
| From: | "William Slaughter" <willslau(at)alumni.rice.edu> |
| Subject: | Starter concerns with FADEC and EFIS |
Hi Leonard,
I'm not Bob, but I am an Aerosance FADEC owner. If this is the unit you're
referring to, there are no external battery connections for the ignition
coils or fuel injectors. The ECU's (Engine Control Units) integrate the
computers, ignition coils and fuel injector drivers all into the two
"computer" boxes (three boxes if you've got a six cylinder). Aerosance will
supply you with all the wiring to connect everything from the ECUs out to
the engine components.
William
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of
Leonard Garceau
Subject: Re: AeroElectric-List: Starter concerns with FADEC and EFIS
Hi Bob,
I have a question about wiring the fuel injected and coil over plug engines.
I see how you wire two hot busses from 2 batteries to the two computers.
But how do I wire the fuel injectors and the coils to the two separate
batteries? What do you think would work the best?
Thanks,
Leonard
----- Original Message -----
From: <TimRhod(at)aol.com>
Subject: AeroElectric-List: Starter concerns with FADEC and EFIS
>
> In a message dated 3/14/2003 5:25:57 PM Eastern Standard Time,
> cozytom(at)mn.rr.com writes:
>
> > aeroelectric-list(at)matronics.co
m
>
> Bob and others:
> Ive been thinking of solutions to some of the things we have been
discussing
> concerning voltage drop when starting FADEC engines. Also concern over
> voltage spikes or low voltage problems with the EFIS/ONE during
starting.
> Here is what I came up with. Using Z-14 DBDA Put all avionics one one
bus.
> For me I think this will be a avionics bus with quad feed. One from main
bus
> through diode and avionics master switch. Second from Alternate bus
through
> diode and avionics secondary master switch. Master switches are included
in
> case EFIS systems need isolated as Greg Ricktor seems to think they should
> be. Third and fourth essential feeds from main batt buss and alternate
batt
> buss on one switch that would choose one or the other. Cross feed
contactor
> will not have starter switch included. Starter switch will be seperate.
Here
> is how I envision it working. During start up sequence the avionics bus
can
> be feed through the alternative electrical system. So the Efis/One is
powered
> up from that source. Also the FADEC ignition is powered from the Alternate
> battery. The main battery is used to start the engine The cross feed is
kept
> open at this point so the two electrical systems never affect each other.
If
> you needed both batteries to start you would not turn on avionics bus
until
> engine started. You wouldnt have you oil pressure immediatly but this
> shouldnt be a common occurance to need both batteries for starting. It
seem
> to me that this allows the Efis/One and the FADEC ing. to be at 12.5 volts
> continually during engine start-up. What do you think?
>
>
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
| Subject: | Coil connections |
<>
There are some (Engineair, I think) that have just connected the drivers
from the ECU's in parallel to the coils and injectors. That works if the
failure mode is simply loss of power to a computer. However, there are
several failure modes of the driver circuitry that would cause a channel to
fail regardless of which computer was being used, such as a shorted driver
or a shorted snubber circuit. What to do? Maybe have a relay bank to
switch the outputs, but that gets pretty complex. But those are the only
two options I know of. Some people have used high-voltage diodes to switch
the outputs of distributor-type ignition systems, but I'm not sure I trust
the reliability of those either.
Gary Casey
________________________________________________________________________________
| From: | "Gary Casey" <glcasey(at)adelphia.net> |
| Subject: | relay switch protection |
<>
The question, though, is not which is the most effective device, but which
is most likely to be safe from a shorted failure mode. That is the
rationale for using a capacitor instead of a diode. As I understand it
there is little chance for it failing in a way that would produce a short,
while that is a common failure mode for a diode. If one were to use a relay
for a master contactor the failure modes that could result in a "no power"
condition are an open switch, open or shorted coil, open wire and a shorted
diode. The reason people use the low side of the relay to ground to turn it
on is, I think, that a likely failure mode of the wire to the switch would
be a short to ground and in that case the relay just stays on.
Gary Casey
________________________________________________________________________________
| From: | "Stucklen, Frederic IFC" <Fred.Stucklen(at)UTCFuelCells.com> |
Guys,
Properly selected and mounted, a diode will outlast the life of
the contactor. Their failure rate is better than that of any other
component in your electrical design. Even if the diode in the Master
contactor circuit (coil switched to ground) were to fail, the coil
resistance still protects the wires and switch. Same with the started
contactor... So what's the fuss????
Due to the large inrush current through the switch, putting a
large cap across the contactor, (without the diode of resistor in a snubber
circuit) would cause the switch to fail prematurely. A traditional snubber
(could work if the parts were properly selected to absorb the coils spike,
without causing excessive switch current ( with ON or OFF action). This
solution is also harder to tune to the different contactors that are
available.
Varistors can and do work, but are more expensive than diodes.
In short, keep your design simple. Select a diode that is over
rated for the job (1N5400), install it properly, with good strain relief
(use a dab of RTV to "mount" it to the side of the contactor) and don't
worry about it.
Fred Stucklen
RV-6A N926RV Reserved
The diode in this case will die of overvoltage only. The better the
switch, the shorter the cutoff time, and the higher the spike which
will stand over the diode. Overvoltage kills a diode instantly, as
opposed to overcurrent, which will first heat up and then kill.
Adding a capacitor to a coil changes the circuit into a tuned
circuit,
much like a magneto, and if the components are sufficiently wrong
chosen, the end result will be more destructing then imaginable. A
large
capacitor has an notable impedance of it's own, so is out of the
question. So the first step is to choose the diode with an
sufficienty
high reverse voltage, the 1n4001 is (or was) availble from 100 to
800
volts. 800 is the minimum. If nethertheless the diode would fail a
fusable! resistor could prevent the next disaster. Fusable
resistors
will not induce a fire hazard, not on 12 volts at least. A normal
resistor will, and could even short out instead of open.
Problem here is that the the resister would have to be inspected at
regular intervals, otherwise a failed diode would never be noticed.
Jos
________________________________________________________________________________
| From: | John Schroeder <jschroeder(at)perigee.net> |
Bob has since stoped recommending the use of MOV's and uses diodes instead. He
has explained the reasoning before but I can't find my notes on it. Check the
archives.
> Hi Jerzy, I've been lurking here & can't help but recall that "Bob" had
>MOV's shown in some of his earlier drawings for the protection of various
>Start & Master relays. I asked him about their use back then & as I recall,
>he stated the reason for his preference over a diode, for the MOV was that no
>concern for polarity made them slightly easier for us "lay" homebuilders to
>cope with. FWIW ---- Chris Fleshren
________________________________________________________________________________
| Subject: | Re: relay switch protection |
In a message dated 3/17/2003 8:14:59 AM Eastern Standard Time,
glcasey(at)adelphia.net writes:
> The question, though, is not which is the most effective device, but which
> is most likely to be safe from a shorted failure mode. That is the
> rationale for using a capacitor instead of a diode. As I understand it
> there is little chance for it failing in a way that would produce a short,
> while that is a common failure mode for a diode. If one were to use a
> relay
> for a master contactor the failure modes that could result in a "no power"
> condition are an open switch, open or shorted coil, open wire and a shorted
> diode. The reason people use the low side of the relay to ground to turn
> it
> on is, I think, that a likely failure mode of the wire to the switch would
> be a short to ground and in that case the relay just stays on.
>
> Gary Casey
>
>
Hello Gary,
This discussion got started over a shorted battery contactor coil dampening
device and the concern of smoke or fire from an UN-fused circuit wired with
22ga. wire used to supply the ground to the battery contactor. Although very
unlikely, the contactor's coil could short, and again not very likely, the
diode used to dampen the contactor's coil could short. All things
considered, a diode is best for coil dampening performance. Most other
devices will be a source for ringing or not clamp the voltage as low as can
be done with a diode. We really are splitting hairs here though. An MOV
will clamp it at some voltage just over 15 volts -not bad. While a diode
will clamp it at .6 volts -better. I am going to insert a 5A fuse in my
grounding leg at the contactor end of the 22ga. wire to be safe I think. One
could increase the size of the wire to say 16, 12, 10 , etc., and let the
shorted diode or coil become the fuse! I am not concerned about a failure
that results in an open circuit. That will just have to be a failure that
requires picking a spot to land. I just want to be reasonable enough to
protect my ship from smoke in the cockpit.
Again, this one circuit may be cause for concern only in the very remote
chance that the contactor's coil shorts or the diode punches through. A
simple fuse can set us all at ease.
John P. Marzluf
Columbus, Ohio
Outback, (out back in the garage)
________________________________________________________________________________
| From: | "Jim Pack" <jpack(at)igs3.com> |
| Subject: | Crossover Warning Light |
I would like to put a light on the panel that indicates that the Crossover
Contactor is on (Dual bat, Dual Alt system). Where should I take the lead
for the light?
- Jim
________________________________________________________________________________
| Subject: | Re: Crossover Warning Light |
In a message dated 3/17/2003 9:24:38 AM Eastern Standard Time, jpack(at)igs3.com
writes:
> I would like to put a light on the panel that indicates that the Crossover
> Contactor is on (Dual bat, Dual Alt system). Where should I take the lead
> for the light?
>
> - Jim
>
>
Jim, I would wire it in parallel with the cross feed contactor's coil.
John P. Marzluf
Columbus, Ohio
Kitfox Outback (out back in the garage)
________________________________________________________________________________
| From: | Canyon <steve.canyon(at)verizon.net> |
Stucklen, Frederic IFC wrote:
> In short, keep your design simple. Select a diode that is
> over
>rated for the job (1N5400), install it properly, with good strain relief
>(use a dab of RTV to "mount" it to the side of the contactor) and don't
>worry about it.
---
Well said and I think the 5400 series is probably what I was trying to
remember. After 40 years of system design, too many p/ns have passed
this way. :-)
Steve
________________________________________________________________________________
| From: | Canyon <steve.canyon(at)verizon.net> |
| Subject: | Re: relay switch protection |
KITFOXZ(at)aol.com wrote:
>Again, this one circuit may be cause for concern only in the very remote
>chance that the contactor's coil shorts or the diode punches through. A
>simple fuse can set us all at ease.
---
Good advice, John. Safety is best handled at the system architecture
level, not at the device level. Of course, this doesn't mean one
should not use the best, most reliable devices in all places. It is
simply a fancy way of saying that one should anticipate sudden failure
of ANY device as any of them can fail at any time. The key to overall
safety lies in forethought about the consequences of ANY device failure.
In the case of diode snubbers on typical relay coils common to these
planes, failure caused by OV from some external source is more likely
than a half cycle or so of current from transient current -- use the
higher PIV (PRV) rated diodes like 1N4006 or an equivalent from the 1N
54XX series.
Thanks, John.
Steve
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)tenforward.com> |
| Subject: | Re: Fw: Spike-catcher diode failures |
I was not recommending dual series diodes. Just an example where you cannot
fix it and it must work. IE space.
There really is two different cases being discussed.
First there is the controlling device (switch) contact that needs to be
protected. But then if the switch is rated for the specific inductive DC
loads it will likely outlast the aircraft with no diode. This is where the
simple rectifier diode is recommended. The reverse voltage of the diode is
not a real factor as it only sees the coil dc voltage. more reliable diode.
In this application the diode simply recirculates the coil current when the
switch opens and there is never any higher voltage produced. The relay takes
very slightly longer to open but this is rarely a problem and never a
problem with a manual open command.
HV spikes are clipped with devices like Transorbs that are 1000 times as
fast as normal zener diodes and are used to protect electronics from short
HV transients.
Transorbs were developed as the more common MOV and Zener diodes were simply
too slow for some applications and electronics. Even capacitors can be far
too slow to react to a fast moving HV transient.
Its a large subject. I still think a single diode is fine for our uses.
Paul
----- Original Message -----
From: "Canyon" <steve.canyon(at)verizon.net>
Subject: Re: AeroElectric-List: Fw: Spike-catcher diode failures
>
> Paul Messinger wrote:
> >ANY diode can fail short and the primary diode failure is short. In a 12V
> >acft the failure of a 27V transorb is likely completely random and could
> >have happened with a 1N4001. The peak current rating of the transorb
> >is huge
> >compared to the 1N4001. The steady state current rating is similar and is
> >limited by the package getting too hot.
> ---
> Paul, can't argue the point -- it's true. However, it leads one not
> skilled in the art to think they have protection they don't have for
> OV. 27V is far too late to help any typical sophisticated
> system/device likely to be in the circuit. There are simply better
> ways to handle OV, IMO. And in fact, 1N4001 diodes are rated at only
> 50V, IIRC -- the ones that should be used are at least 1N4006 and IIRC,
> the IN52XX (? it's been awhile) series would be even better, and two in
> series should be fine, though not many folks are likely to ever be
> aware if one of them shorted and then you're back to a single. :-)
>
> Steve
>
>
________________________________________________________________________________
| From: | "Neville Kilford" <nkilford(at)etravel.org> |
| Subject: | Nervous about 17Ah battery |
Hello there,
I've been pondering a 17Ah Yuasa RG battery for my Jodel build. It's nice
and light, but the terminals look pretty small for delivering perhaps 200 or
250A to a B&C starter during cranking.
Does anyone have any thoughts about it or experiences with such a low
capacity battery deliverying such a big current? I have to be honest -- I'd
never even heard of an RG battery before I read the Aeroelectric Connection
and I am, of course, tempted by Bob's praise of small RG batteries.
By the way, terminals are .43" x .08" (12 x 2mm).
Many thanks in anticipation.
Nev
--
Neville Kilford
Jodel D-150
UK
________________________________________________________________________________
| From: | "Mark Means" <rgvelocity(at)lmf.net> |
| Subject: | GM low oil sensor |
I have an auto conversion in the works with a low oil sensor which I'm not sure
how to hook up to a warning light and hoped someone could offer some advice.
I am afraid to route some juice up to it for fear of damage as I can't find out
(so far) what the usual input is.
When unscrewed from the side of the oil pan it looks like a small rod with a small
donut on it, with a knob on the end to keep the donut from falling off. The
donut is weighted so it hangs in one position. I checked the continuity of
the two wires coming out of the base. Moving the donut up and down against the
rod opens and closes the circuit. Anyone out there with any experience with this
sort of thing and advice on wiring this up? Thanks.
Mark Means
________________________________________________________________________________
| Subject: | Re: Nervous about 17Ah battery |
| From: | Denis Walsh <denis.walsh(at)attbi.com> |
>
>
> Hello there,
>
> I've been pondering a 17Ah Yuasa RG battery for my Jodel build. It's nice
> and light, but the terminals look pretty small for delivering perhaps 200 or
> 250A to a B&C starter during cranking.
>
> Does anyone have any thoughts about it or experiences with such a low
> capacity battery deliverying such a big current? I have to be honest -- I'd
> never even heard of an RG battery before I read the Aeroelectric Connection
> and I am, of course, tempted by Bob's praise of small RG batteries.
>
> By the way, terminals are .43" x .08" (12 x 2mm).
>
> Many thanks in anticipation.
>
> Nev
>
> --
> Neville Kilford
> Jodel D-150
> UK
>
>
>
I had the same concern about the terminals on the Odyssey 17 ah which I
believe are about the same size.
Now after two years of flawless cranking on my ampere hungry sky tec
starter pulling an O-360 with 50 lb prop, it is still hanging in there. Now
I wonder why we had those big studs on the old ones?
Denis
________________________________________________________________________________
| From: | Benford2(at)aol.com |
| Subject: | Re: GM low oil sensor |
In a message dated 3/17/2003 9:13:59 AM Mountain Standard Time,
rgvelocity(at)lmf.net writes:
>
>
> When unscrewed from the side of the oil pan it looks like a small rod with
> a small donut on it, with a knob on the end to keep the donut from falling
> off. The donut is weighted so it hangs in one position. I checked the
> continuity of the two wires coming out of the base. Moving the donut up
> and down against the rod opens and closes the circuit. Anyone out there
March 09, 2003 - March 17, 2003
AeroElectric-Archive.digest.vol-bt