AeroElectric-Archive.digest.vol-hv
May 12, 2008 - May 26, 2008
________________________________________________________________________________
Subject: | Use of 700-2-10 switch for Voltage Sense - how to wire? |
From: | "mikef" <mikefapex(at)gmail.com> |
I am building a Z-19 type electrical system and I have a question
about a switch configuration. I was planning to use a 2-10 / three
position to view voltage on different buses, depending
on the position:
1. E Bus voltage
2. Main Battery Bus voltage
3. Engine Battery Bus voltage
I have a digital volt meter with simple +/- inputs.
First, do you think this switch 2-10 will work or should I use something else?
I've played around with various wire combinations and a 2-10 switch but have come
up short (not a short, ha!). I just cannot seem to figure out the right combination
that provides the power feed to a single switch position/combination.
So that is the crux of my problem, the right wiring for this switch (if possible).
I know that all three PLUS leads from the bus to switch to meter need
to be isolated through the switch. I seem to get one source isolated but then
another switch position lights up two power leads.
The ground is common across all buses and batteries.
2-10 switch layout
KEYWAY UP
3 6
2 5
1 4
Thanks for any wiring suggestions,
Mike
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=182750#182750
________________________________________________________________________________
From: | Joe Dubner <jdubner(at)yahoo.com> |
Subject: | Re: GPS antennas with miniature connector |
On 05/12/2008 09:14 Carlos Trigo wrote:
>
> Can somebody else please indicate me a way of getting rid of those 2 useless
> coils of GPS antenna cable?
Carlos,
I had a similar dilemma a few years ago and decided to retain the
connector rather than install a new one. I cut the cable near the
connector, cut the antenna end of the cable to the desired length, and
spliced the two pieces of the cable back together. This is also a
viable technique if you need to "temporarily" remove the connector for
cable routing through a small conduit or to lengthen the cable.
The pundits will tell you that you can't splice this coax as it carries
a very weak 1.575 GHz signal but I never noticed any degradation in the
performance of the GPS.
Of course, I paid attention to detail in the splice by keeping the
splice length to a minimum, re-insulating the center conductor well, and
then restoring the shield coverage to as near 100% as possible.
Best,
Joe
Long-EZ 821RP
Lewiston, ID
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: GPS antennas with miniature connector |
>Listers
>
>I have 2 GPS antennas to install, one is for my Trutrak ADI and the other
>for the GRT - EFIS, both having internal GPS.
>I attached 2 pictures of one of them, they are similar, both use a thin
>cable (less than 1/8" outer diameter) and a miniature brass connector.
>
>Since we must always seek to save some weight in our birds, I have 2
>questions:
>
>First question, which is probably dumb, but here it goes: can I install only
>one antenna and T the cable for both devices?
No, for a couple of reasons. One is that this antenna . . .
http://www.laipac.com/ant_GLP1_RA_eng.htm
is a powered device that gets its operating voltage from the
associated GPS receiver. Mixing two receivers onto a single
antenna offers some system integration as well as some
system reliability (single point of failure for both
receivers) issues. Recommend you stick with dual antennas.
>Second question: if I want to get rid of that much cable length, can I cut
>it somewhere in the middle, remove the unnecessary length, and reconnect the
>cable ends? If yes, how do I do it?
>Or is it better to forget the existing connector, cut the necessary length
>and use a new connector? In this case, where can I find these miniature
>connectors and is there a special crimper for these?
From the photos, I deduce that your antennas are fitted with
the SMB series connectors. But these come in several styles that
include screw on and push-on. It looks like you have the
push-on style.
http://www.aeroelectric.com/Pictures/Connectors/Coax/SMB_push-on_1.jpg
http://www.aeroelectric.com/Pictures/Connectors/Coax/SMB_push-on_2.jpg
http://www.aeroelectric.com/Pictures/Connectors/Coax/SMB_push-on_3.jpg
Digikey sells these connectors but a quick look for tools
did not produce any hits.
The task of shortening these cables is trivial
for anyone with the skills, tools and connectors. You
may be able to find someone locally who routinely works
with these connectors and get the job done.
However, keep in mind that the antenna assembly's performance
IS BASED on the as-supplied condition . . . meaning that it
will perform as advertised with the long cables. It's
doubtful that you'll improve on that performance in any
way that you can perceived so this leaves you with the
goal of shortening the cables because it looks better
and saves a little weight.
Obviously we need to leave it to you to deduce the
trade-off for accepting the costs and risks for a
DIY cable shortening effort and the return on
investment for achieving a slicker looking installation
and a few ounces of weight.
My best recommendation is that (unless you can find
some local support in skills/materials/tools) you
leave them as supplied.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
Subject: | Re: GPS antennas with miniature connector |
From: | simon(at)synchronousdesign.com |
Matt,
If his GPS antenna is powered by the receivers, then a T no doubt will
interfere with that function, as DC doesn't pass through transformers. If
Carlos can give us more details pertaining to the specific antenna and GPS
receiver models, then his problem can be analyzed further.
Joe Dubner earlier said he spliced his GPS antenna cable in the middle,
and it performed well. I am surprised, but I've seen stranger stuff
happen. I'd rather remove the connector, cut the cable, run it through
the small opening, and reinstall a new connector.
Simon
Oviedo, FL USA
>
>
> Aren't many GPS antennas active (amplified, powered)? If so, it
> should be possible to design an impedance match circuit from the
> output of the antenna to the input of the two receivers. It's
> also possible that the output of the amplified antenna is robust
> enough to not require any match circuitry for adequate
> performance...
>
> Regards,
>
> Matt-
________________________________________________________________________________
Subject: | Re: GPS antennas with miniature connector |
From: | "Matt Prather" <mprather(at)spro.net> |
Right.. You'd have to admit though that it wouldn't be rocket science to
make 5VDC available to the antenna - from the antenna side of the matcher.
Then again, I'd likely try to find antennae that's smaller/lighter, and
with shorter cables..
Matt-
>
> Matt,
>
> If his GPS antenna is powered by the receivers, then a T no doubt will
> interfere with that function, as DC doesn't pass through transformers. If
> Carlos can give us more details pertaining to the specific antenna and GPS
> receiver models, then his problem can be analyzed further.
>
> Joe Dubner earlier said he spliced his GPS antenna cable in the middle,
> and it performed well. I am surprised, but I've seen stranger stuff
> happen. I'd rather remove the connector, cut the cable, run it through
> the small opening, and reinstall a new connector.
>
> Simon
> Oviedo, FL USA
>
>
>>
>>
>> Aren't many GPS antennas active (amplified, powered)? If so, it
>> should be possible to design an impedance match circuit from the
>> output of the antenna to the input of the two receivers. It's
>> also possible that the output of the amplified antenna is robust
>> enough to not require any match circuitry for adequate
>> performance...
>>
>> Regards,
>>
>> Matt-
>
>
________________________________________________________________________________
Subject: | Re: Use of 700-2-10 switch for Voltage Sense - how |
to wire?
From: | "Glaeser, Dennis A" <dennis.glaeser(at)eds.com> |
Mike,
The 2-10 is an ON-ON-ON switch, which is useful as a Bat/Alt master, but
not suited for your task because it provides for multiple simultaneous
connections, and you only want one at a time.
Z-19 shows how to connect a 1-7 switch to check the voltage of each of
the batteries - any reason not to do it that way?
However you do it, you need a way to leave the voltmeter disconnected,
or else it is a constant drain on the battery.
Dennis Glaeser
RV-7A Egg H6 Subaru - flying (Phase 1)
------------------------------------------------------------------------
------
I am building a Z-19 type electrical system and I have a question
about a switch configuration. I was planning to use a 2-10 / three
position to view voltage on different buses, depending
on the position:
1. E Bus voltage
2. Main Battery Bus voltage
3. Engine Battery Bus voltage
I have a digital volt meter with simple +/- inputs.
First, do you think this switch 2-10 will work or should I use
something else?
I've played around with various wire combinations and a 2-10 switch but
have come
up short (not a short, ha!). I just cannot seem to figure out the right
combination
that provides the power feed to a single switch position/combination.
So that is the crux of my problem, the right wiring for this switch (if
possible).
I know that all three PLUS leads from the bus to switch to meter need
to be isolated through the switch. I seem to get one source isolated but
then
another switch position lights up two power leads.
The ground is common across all buses and batteries.
2-10 switch layout
KEYWAY UP
3 6
2 5
1 4
Thanks for any wiring suggestions,
Mike
________________________________________________________________________________
Subject: | Re: GPS antennas with miniature connector |
From: | simon(at)synchronousdesign.com |
Matt,
I admit it is not rocket science to provide DC voltage if you have the
source and delivery system for it. In Carlos' case, though, I believe his
goal was to squeeze nano-tons of weight out of whatever he was doing, and
an additional wire from one receiver or power supply to the antenna would
defeat this purpose. He might as well stay with the extra cable length.
In an earlier email, Bob said that two receivers supplying VDC will
introduce further complications, and one antenna feeding two receivers is
a single-failure point. These two statements are valid. If two GPS
receivers were going into my airplane, I would have two separate antennas.
Of course, I'm not as worried about weight as Carlos is either. I know a
guy who wants to cross the Atlantic in July and August, and he's in the
same "bloat."
Simon
Oviedo, FL USA
> Right.. You'd have to admit though that it wouldn't be rocket science to
> make 5VDC available to the antenna - from the antenna side of the matcher.
>
> Then again, I'd likely try to find antennae that's smaller/lighter, and
> with shorter cables..
>
> Matt-
________________________________________________________________________________
From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
Subject: | GPS antennas with miniature connector |
OK, I surrender. I will use 2 antennas and keep those lengthy cables.
A 3 month diet will save weight on myself, which seems easier (apart from
being better for my health).
Thanks to everybody who answered.
Carlos
________________________________________________________________________________
Subject: | Re: Use of 700-2-10 switch for Voltage Sense - how |
to wire?
From: | "mikef" <mikefapex(at)gmail.com> |
>>Z-19 shows how to connect a 1-7 switch to check the voltage of each of
the batteries - any reason not to do it that way?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=182793#182793
________________________________________________________________________________
From: | "Henry Trzeciakowski" <hammer408(at)comcast.net> |
Subject: | Re: EFIS Battery Back-up Power |
Ron:
I'm using Z-11 architecture: single battery/single alternator. My e-bus
is already carring about 12 amps, so the idea behind the internal
battery EFIS was to wire to main bus. With that in mind, your
explaination of the Alternator Failure Procedure is what I wasn't
certain of and I believe you clarified and confirmed it.
Alternator Failure: 1- E-bus alternate feed is turned ON which powers
the
e-bus directly from the battery.
2- Immediately turn the Main Battery
Contactor OFF (DC Master Power
Switch) - Main Bus is now off-
line, main bus drops below about 12
volts and the EFIS resorts to it's
internal battery.
and no additional switches would be necessary.
Thanks
Hank
----- Original Message -----
From: Ron Shannon
To: aeroelectric-list(at)matronics.com
Sent: Sunday, May 11, 2008 10:42 AM
Subject: Re: AeroElectric-List: Re: EFIS Battery Back-up Power
Hank,
If you have just one EFIS, it (or if you have two, the first one)
should be wired to the e-bus -- assuming you want to have the EFIS
available during endurance (battery only) flight ops -- as most of us
would like to have.
If you have two EFIS's, you may want to shut one down during endurance
ops, and the second one would therefore be wired to the main bus. (If
that second EFIS already has an automatic internal battery, you may have
to shut it down manually even though it's on the main bus, to save that
internal battery.) This is the way my dual AFS-3400 EFIS system is
wired.
The e-bus is normally fed from the main bus through a one-way diode.
When the alternator(s) fail, the e-bus alternate feed is turned ON which
powers the e-bus direct from the battery, i.e., not through the main
battery contactor. (For brief moment, the e-bus is then effectively fed
from two places: the battery upstream of the battery contactor, and the
main bus, from downstream of the battery contactor.) After the e-bus
alternate feed has been turned ON, you immediately turn the main battery
contactor OFF, to rapidly and positively shed those non-essential main
bus loads. That's the sequence (e-bus alt feed ON, then main battery
contactor OFF) to keep the e-bus powered and avoid rebooting things like
your EFIS that are on the e-bus when you shut down the main.
When the e-bus alternate feed is ON, and the main battery contactor
and main bus are OFF, the e-bus will not back feed the main bus because
the diode keeps current from flowing from the e-bus to the main bus.
I hope that helps explain the desired function and results.
Ron
On Sun, May 11, 2008 at 12:58 PM, Henry Trzeciakowski
wrote:
Bob:
I'm planning to install a AFS 3400 with it's own internal battery
back-up...... fused it to my Main Bus..
How I visualize: main alternator goes off line, I kill the
alternator via
the master switch, turn on the E-Bus alternator feed switch....
Since the Main Bus will be de-energized due to a failed alternator,
I assume
that the EFIS will utilize it's internal battery to keep the EFIS
energized..... OR
is my thought process all wrong !!!
Do I need a seperate switch on my panel to turn the EFIS off,
eventhough the
Main Bus is de-energized....
What would the wiring architect be in this case ??
Thanks
Hank
________________________________________________________________________________
From: | Fiveonepw(at)aol.com |
Subject: | Re: GPS antennas with miniature connector |
In a message dated 05/12/2008 12:18:32 PM Central Daylight Time,
simon(at)synchronousdesign.com writes:
> Second question: if I want to get rid of that much cable length,
>>>
I recently installed a Garmin 430W (WAAS) that has a dedicated GPS antenna
with a "required" MINIMUM cable length of something like 18 FEET. Being a
"certified" navcom, I kinda surmised that Garmin requires this because they have
to
make sure there is sufficient signal strength getting to the receiver.
Huh?
Picture a 430W installed in a King Air with the antenna halfway aft on the
top of the fuse- might take 30-40' of cable to connect the two. Using the same
certified antenna for all certified installations, how does a manufacturer
offer a unit that ALSO works in Katanas? By making sure the signal strength is
sufficient for either installation, hence the minumum/maximum cable length for
which the unit is guaranteed it will work.
Really wanting to avoid wadding up an extra 15 feet of RG400, I called Garmin
tech and they confirmed my theory. If I had shortened the cable to a
convenient minimun length (about 3") the signal would have been too powerful for
the
receiver due to insufficient attenuation. OK, but how about shortening the
cable and adding an attenuator, being on an experimental. The guy basically
said fine, but you're on your own! After a couple of hours researching this
option and coming up with no simple answers, I decided the path of least
resistance was to do as instructed. I wadded up the extra 15 feet of RG400, and
the
sucker works just great. Still got a warranty, too! Win-win!
I'd guess you have the same situation with the smaller GPS antennas(ae?) and
that is why they come with all that extra cable. Just wad it up (like I did
for the GRT & ADI GPS & XM cables) and be glad it ain't RG400!
Mark
**************Wondering what's for Dinner Tonight? Get new twists on family
favorites at AOL Food.
(http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001)
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Use of 700-2-10 switch for Voltage Sense - how |
to wire?
>
>I am building a Z-19 type electrical system and I have a question
>about a switch configuration. I was planning to use a 2-10 / three
>position to view voltage on different buses, depending
> on the position:
>
> 1. E Bus voltage
> 2. Main Battery Bus voltage
> 3. Engine Battery Bus voltage
>
>I have a digital volt meter with simple +/- inputs.
>
> First, do you think this switch 2-10 will work or should I use
> something else?
>
> I've played around with various wire combinations and a 2-10 switch but
> have come up short (not a short, ha!). I just cannot seem to figure out
> the right combination that provides the power feed to a single switch
> position/combination. So that is the crux of my problem, the right wiring
> for this switch (if possible). I know that all three PLUS leads from the
> bus to switch to meter need to be isolated through the switch. I seem to
> get one source isolated but then another switch position lights up two
> power leads.
>
>The ground is common across all buses and batteries.
The 2-10 would work but as others have noted, leaving a
voltmeter connected to a battery bus for long periods of
time may present a battery service readiness issue. If you
use the 2-70 architecture (spring loaded to center) you can
use the center position to read e-bus (which goes down with
the master switches). The extremes are used to measure
batteries and cannot be inadvertently left ON after the
airplane is shut down.
A miniature version of the 2-70 is a C&K 7215SYZQ available
from Digikey at:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CKN1134-ND
Wiring for this switch is illustrated at:
http://www.aeroelectric.com/Pictures/Schematics/3-Ch_Voltmeter.pdf
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "r falstad" <bobair8(at)msn.com> |
Subject: | 14 VDC Power Cord for Digital Video Camera? |
Folks,
I have a new digital video camera (Canon FS-11) that I want to rig up in
the cabin of my GlaStar for its test flight program. I intend to use a
patch cord to connect my intercom with the "Mic In" function on the
camera so I can dictate information to the video instead of having to
write it down. I'd also like to power the camera from ship's power but
Canon doesn't sell a "car cord" for this camera. The Canon tech rep
says the camera is sensitive to its input voltage (8.4 VDC) from the
output of the 110 VAC power converter.
I don't want the extra wires and weight of an inverter -- I'd rather
make up my own power cord to plug directly from ship's power to the
camera. I can put a resistor in to drop the voltage but I'm worried
about spikes and their possible adverse effects on the camera. Is there
a circuit that would regulate the output close to 8.4 VDC with the
expected input voltages from ship's power?
(FYI, the compact power adapter is Canon P/N CA-590 and its input specs
are 100 - 240 VAC at 50/60 Hz drawing 0.14 - 0.08 Amps with output at
8.4 VDC at 0.6 Amps. The tech rep wouldn't/couldn't tell me the
tolerance on the input voltage to the camera.)
Should I put in a smaller capacity (1 Amp) fuse instead of the 5 Amp
fuse I've got in there now?
Bob
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | SMB connnectors on small coax (RG-174 et. als.) |
>>Second question: if I want to get rid of that much cable length, can I cut
>>it somewhere in the middle, remove the unnecessary length, and reconnect the
>>cable ends? If yes, how do I do it?
>>Or is it better to forget the existing connector, cut the necessary length
>>and use a new connector? In this case, where can I find these miniature
>>connectors and is there a special crimper for these?
I was just looking for materials and tools on another
task an ran across these items that may be of interest to
folks who need to re-work or fabricate cables with SMB
Push-Ons. See SMB-Push-on male connectors at:
http://www.jameco.com/Jameco/catalogs/c261/P143.pdf
and installation tool at:
http://www.jameco.com/Jameco/catalogs/c261/P279.pdf
Bob . . .
________________________________________________________________________________
From: | "Carl Morgan" <zk-vii(at)rvproject.gen.nz> |
Subject: | 14 VDC Power Cord for Digital Video Camera? |
Hi Bob,
I've just been through this with ours, although we are a RV7A and I'm using
older MV400i DV Canon tape technology. I actually made a small switched
power supply board - the primary problem was finding the power cord plug, In
the end I went lo-tech and used a larger battery! The battery lasts 2
hours, the tape media lasts 1.5 hours and most flight tests were less than
an hour. I added a 3.5mm jack to jack which was connected to the stereo
headphone lines from the Garmin 340 - although I did need to add a couple of
resitors to attenuate the volume down a bit. The video recorder tended to
auto-gain on the audio and struggled with over loading - but for the
purposes needed it worked fine.
The footage came out ok ( see http://www.youtube.com/zkvii ) and the
learning aspect of reviewing your flying was much more benefical than I had
expected - things like cockpit resourcing, radio calls, checks all can be
critically reviewed later.
Regards,
Carl
--
Carl Morgan - ZK-VII - RV 7A
http://www.rvproject.gen.nz/
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of r falstad
Sent: 13 May 2008 15:10
To: AEROELECTRIC LIST
Subject: AeroElectric-List: 14 VDC Power Cord for Digital Video Camera?
Folks,
I have a new digital video camera (Canon FS-11) that I want to rig up in
the cabin of my GlaStar for its test flight program. I intend to use a
patch cord to connect my intercom with the "Mic In" function on the camera
so I can dictate information to the video instead of having to write it
down. I'd also like to power the camera from ship's power but Canon doesn't
sell a "car cord" for this camera. The Canon tech rep says the camera is
sensitive to its input voltage (8.4 VDC) from the output of the 110 VAC
power converter.
I don't want the extra wires and weight of an inverter -- I'd rather make
up my own power cord to plug directly from ship's power to the camera. I
can put a resistor in to drop the voltage but I'm worried about spikes and
their possible adverse effects on the camera. Is there a circuit that would
regulate the output close to 8.4 VDC with the expected input voltages from
ship's power?
(FYI, the compact power adapter is Canon P/N CA-590 and its input specs
are 100 - 240 VAC at 50/60 Hz drawing 0.14 - 0.08 Amps with output at 8.4
VDC at 0.6 Amps. The tech rep wouldn't/couldn't tell me the tolerance on
the input voltage to the camera.)
Should I put in a smaller capacity (1 Amp) fuse instead of the 5 Amp fuse
I've got in there now?
Bob
Checked by AVG.
18:14
________________________________________________________________________________
From: | John Morgensen <john(at)morgensen.com> |
Subject: | Fuse Block Locations |
I am seeking pictures and advice on fuse block locations, panel ground,
firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture.
Thanks,
John Morgensen
775 771-5791
________________________________________________________________________________
From: | "Richard Dudley" <rhdudley1(at)bellsouth.net> |
Subject: | Re: Fuse Block Locations |
Hi John,
I have attached a photo of my solution to the fuse panel location. It is
hinged to the bottom of the instrument panel and swings back to a horizontal
position and is secured by two Camlocks. Since plan is to deal with fuses
only on the ground, it is out of the way during flight. My architecture is
based on Bob Nuccols Z-11. The diode connection to the e-buss is mounted on
the backside of the panel.
Hope this is some help.
Regards,
Richard Dudley
-6A flying
----- Original Message -----
From: "John Morgensen" <john(at)morgensen.com>
Sent: Tuesday, May 13, 2008 9:30 AM
Subject: AeroElectric-List: Fuse Block Locations
>
>
> I am seeking pictures and advice on fuse block locations, panel ground,
> firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture.
>
> Thanks,
> John Morgensen
> 775 771-5791
>
>
>
________________________________________________________________________________
Subject: | Re: Use of 700-2-10 switch for Voltage Sense - how |
to wire?
From: | "mikef" <mikefapex(at)gmail.com> |
Bob,
That was the info I was looking for. Thanks very much, seems like a straightforward
solution.
Mike
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=182910#182910
________________________________________________________________________________
From: | "Joe" <fran5sew(at)banyanol.com> |
Subject: | Re: Use of 700-2-10 switch for Voltage Sense - how |
to wire?
Mike,
You need a triple throw switch, either single pole or double pole,
commonly known as SP3T or DP3T. You can buy them at electronic supply
companies such as Digikey or Mouser or Allied. Parenthesis ( ) in the
description indicates a momentary position. Avoid those unless you want
that feature. You have to hold the switch in that position and when you
let go, it moves to the previous position.
http://www.mouser.com/search/Default.aspx has several triple-throw
switches to choose from:
SP3T $14.08 part number: 506-MTG206PA gold contacts
SP3T $9.43 part number: 506-MTA206PA gold contacts
SP3T $7.50 part number: 633-M202401-RO silver contacts
SP3T $8.50 part number: 633-M202402-RO silver contacts
SP3T $9.70 part number: 633-M202404-RO silver contacts
DP3T $14.90 part number: 633M204401-RO silver contacts
You can look at a catalog page here:
http://www.mouser.com/catalog/634/1582.pdf
Gold contacts have less resistance and will not corrode but they can NOT
handle very much current. But they should be good for measuring
voltage. Silver contacts can handle more current. The double pole
switch is more versatile and can be used for other applications such as
in place of the 2-10 switch in the Z drawings (if external jumpers are
connected properly). You could wire the DP3T contacts in parallel and
thus cut the resistance in half and make the switch more reliable. If
one half of the DP3T switch develops high resistance, the other half
will carry the current and you would not see a problem.
The reason that the 2-10 switch would not work for you is that it has
internal jumpers connecting some of the contacts.
Joe
________________________________________________________________________________
From: | "Bret Smith" <smithhb(at)tds.net> |
Subject: | Re: Fuse Block Locations |
John, I have the same setup as you. I also made a drop-down tray.
http://www.flightinnovations.com/wiring.html
Bret Smith
RV-9A "Canopy"
Blue Ridge, GA
www.FlightInnovations.com
----- Original Message -----
From: "John Morgensen" <john(at)morgensen.com>
Sent: Tuesday, May 13, 2008 9:30 AM
Subject: AeroElectric-List: Fuse Block Locations
>
>
> I am seeking pictures and advice on fuse block locations, panel ground,
> firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture.
>
> Thanks,
> John Morgensen
> 775 771-5791
>
>
>
________________________________________________________________________________
Subject: | Fuse Block Locations |
From: | James H Nelson <rv9jim(at)juno.com> |
John,
There are many positions but you need to examine your
requirements. I am using the 13-8 system. I put my drop down panel just
to the right of the left side vent. Look at my pix on my web site.
http://www.websites.expercraft.com/jimn Then scroll down on the left
side to Panel, then to flight instrument and then to Oct 6 2005. I
mounted my ground system very close to the fire wall pass through. I
used a stainless steel handicap grab bar as my starting structure. I cut
off one end which gave my a 90* ell as it passed into the engine
compartment. In my pic. you can see where I put the ground block for
each side. There is one thing I needed to do and that is to use a bigger
(more terminals) ground block on the cabin side. I ended up putting some
grounds thru the pass thru and hooking up to the ground bolck on the
engine side. Count up the number of grounds you think you will need and
then add at least 50% to that number. I also put my "always hot" fuse
block very close to the firewall. This way I can run the always hot
lead thru the fire wall and directly to the fuse block. Since it is
short, it will not need protection. Lots of ideas, just freeze it and
build it.
Jim
99% done, 20% to go
________________________________________________________________________________
Subject: | Fuse Block Locations |
I mounted my fuse blocks directly to the fuselage side - dimpled the skin
and countersunk the holes in the blocks. They'll be covered by a sidewall
panel when the interior goes in.
Regards,
Greg Young
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On
> Behalf Of John Morgensen
> Sent: Tuesday, May 13, 2008 8:31 AM
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: Fuse Block Locations
>
> -->
>
> I am seeking pictures and advice on fuse block locations,
> panel ground, firewall ground, etc. My project is an RV-9A
> using a Z-13/8 architecture.
>
> Thanks,
> John Morgensen
> 775 771-5791
>
>
________________________________________________________________________________
Subject: | Use of 700-2-10 switch for nav/strobe combo lights |
I am using the 2-10 as defined in the manual to turn on the nav lights
in the center position and then add the strobe lights in the up
position. Sounds simple enough. When I first turn on the nav lights, the
strobe lights start blinking. I then add the strobe lights to the nav
lights and they work normally.
After cycling the switch once, only the nav lights come on at the first
position (desired) and I can add the strobe lights by moving the switch
to the top position. The behavior does not repeat itself unless the
switch is turned off for a period of time.
I have wired as described in Bob's manual.
I am using the strobe/nav combo from
________________________________________________________________________________
From: | John Morgensen <john(at)morgensen.com> |
Subject: | Re: Fuse Block Locations |
Thanks for all the responses!
john
John Morgensen wrote:
>
>
> I am seeking pictures and advice on fuse block locations, panel
> ground, firewall ground, etc. My project is an RV-9A using a Z-13/8
> architecture.
>
> Thanks,
> John Morgensen
> 775 771-5791
>
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Use of 700-2-10 switch for nav/strobe combo lights |
>I am using the 2-10 as defined in the manual to turn on the nav lights in
>the center position and then add the strobe lights in the up position.
>Sounds simple enough. When I first turn on the nav lights, the strobe
>lights start blinking. I then add the strobe lights to the nav lights and
>they work normally.
>
>After cycling the switch once, only the nav lights come on at the first
>position (desired) and I can add the strobe lights by moving the switch to
>the top position. The behavior does not repeat itself unless the switch is
>turned off for a period of time.
The only thing that can cause unexpected sequencing
is a faulty switch.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Dennis Jones" <djones(at)northboone.net> |
Subject: | Antenna coax splice |
What ramifications if any are there to using a connector to extend the
run for antenna coax? Or should I start over and run it as a single
cable?
Thanks
Jonsey
________________________________________________________________________________
From: | Bill Putney <billp(at)wwpc.com> |
Subject: | Re: Antenna coax splice |
Dennis,
If you are using BNC or TNC connectors and good quality cable you should
be able to extend almost any antenna cable in your airplane. A connector
adds .25-.5 db loss per connector. Anything should be able to handle
this extra loss without a detectable loss in performance.
- Bill
You can "splice" the cable by Dennis Jones wrote:
> What ramifications if any are there to using a connector to extend the
> run for antenna coax? Or should I start over and run it as a single cable?
>
>
> Thanks
> Jonsey
> *
>
>
> *
________________________________________________________________________________
From: | "RALPH HOOVER" <hooverra(at)verizon.net> |
Subject: | Fuse Block Locations |
John,
Here is yet another hinged option. This fuse block uses insert able
crimped contacts (no fastons and one less electrical interface). It is also
split 20 Main Buss, 8 Essential Buss. The two buses are tied by a schottky
diode bolted to brass busses (the stuff in the center of the rear of the
panel). The fuse panel swings down and forward from the front edge of the
panel and all of the wiring is in the rear.
Ralph & Laura Hoover
RV7A N527LR
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John
Morgensen
Sent: Tuesday, May 13, 2008 9:31 AM
Subject: AeroElectric-List: Fuse Block Locations
I am seeking pictures and advice on fuse block locations, panel ground,
firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture.
Thanks,
John Morgensen
775 771-5791
________________________________________________________________________________
From: | "RALPH HOOVER" <hooverra(at)verizon.net> |
Subject: | Fuse Block Locations |
I didn't mention that the Battery Buss fuse block is a 6 fuse surface mount
block like others you have seen. It is mounted on the Forward side of the
firewall inboard of the Brake fluid reservoir.
Ralph
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John
Morgensen
Sent: Tuesday, May 13, 2008 9:31 AM
Subject: AeroElectric-List: Fuse Block Locations
I am seeking pictures and advice on fuse block locations, panel ground,
firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture.
Thanks,
John Morgensen
775 771-5791
________________________________________________________________________________
From: | "Allen Fulmer" <afulmer(at)charter.net> |
Subject: | Fuse Block Locations |
My favorite so far! And where, pray tell, did you get that beautiful fuse
block with cover? Surely must be automotive!
Allen Fulmer
RV7 Avionics and Electrical
>>>-----Original Message-----
>>>From: owner-aeroelectric-list-server(at)matronics.com
>>>[mailto:owner-aeroelectric-list-server(at)matronics.com]On
>>>Behalf Of RALPH
>>>HOOVER
>>>Sent: Tuesday, May 13, 2008 8:43 PM
>>>To: aeroelectric-list(at)matronics.com
>>>Subject: RE: AeroElectric-List: Fuse Block Locations
>>>
>>>
>>>John,
>>> Here is yet another hinged option. This fuse block uses
>>>insert able
>>>crimped contacts (no fastons and one less electrical
>>>interface). It is also
>>>split 20 Main Buss, 8 Essential Buss. The two buses are tied
>>>by a schottky
>>>diode bolted to brass busses (the stuff in the center of the
>>>rear of the
>>>panel). The fuse panel swings down and forward from the
>>>front edge of the
>>>panel and all of the wiring is in the rear.
>>>
>>>Ralph & Laura Hoover
>>>RV7A N527LR
>>>
>>>-----Original Message-----
>>>From: owner-aeroelectric-list-server(at)matronics.com
>>>[mailto:owner-aeroelectric-list-server(at)matronics.com] On
>>>Behalf Of John
>>>Morgensen
>>>Sent: Tuesday, May 13, 2008 9:31 AM
>>>To: aeroelectric-list(at)matronics.com
>>>Subject: AeroElectric-List: Fuse Block Locations
>>>
>>>
>>>
>>>I am seeking pictures and advice on fuse block locations,
>>>panel ground,
>>>firewall ground, etc. My project is an RV-9A using a Z-13/8
>>>architecture.
>>>
>>>Thanks,
>>>John Morgensen
>>>775 771-5791
>>>
>>>
>>>
>>>
________________________________________________________________________________
From: | Fiveonepw(at)aol.com |
Subject: | Re: Fuse Block Locations |
In a message dated 05/13/2008 8:59:52 AM Central Daylight Time,
rhdudley1(at)bellsouth.net writes:
> I am seeking pictures and advice on fuse block locations, panel ground,
> firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture.
>>>
I recently helped with wiring on a -7A and came up with a solution that
worked out pretty well. Radio stack is centered on panel, dual GRT EFIS, ADI,
A/P
& EIS4000 on pilots side, nothing but blank panel on right. Made this area
into a large glovebox, with a door that was the same shape as the dual EFIS
panels, hinged at the bottom. All four fuse blocks are mounted directly to the
sub-panel behind the glove box. The glovebox has a bottom-hinged rear panel
that exposes the fuse blocks, with a fuse legend on its back side. You simply
open the glovebox door, pull out anything in the way, pull down the cover panel
(held with velcro), and all the fuses are right there. The empty slots have
spare fuses as indicated by the legend.
Photos if ya really want them-
Still brain-fartin' at The PossumWorks in TN
Mark
**************Wondering what's for Dinner Tonight? Get new twists on family
favorites at AOL Food.
(http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001)
________________________________________________________________________________
Subject: | Re: PMA-6000 intercom 28V install |
From: | Etienne Phillips <etienne.phillips(at)gmail.com> |
You're quite right Ralph, there is a noise concern. I doubt that the
noise would be of a value that would cause damage, so my suggestion
would be to try it, and if it doesn't work then replace it with a
resistor...
An alternative would be to use a switcher to get from 28V to 14V,
then use an analogue voltage regulator to go to 12V. Something like a
7812 chip (connection details are identical to that of the switcher)
would work quite nicely, and would only dissipate 2W at 1A, which is
still somewhat better than 15W!
You could also smooth the noise by putting a few (around 5) 100uF
capacitors in parallel, upstream and downstream of the switching
regulator. I suggest this rather than a two 500uF caps, as it will
handle a much wider range of noise frequencies, as well as offer a
degree of redundancy. They could even be wired into the loom at
regular intervals between the bus, switcher and intercom ;-)
I'm of a mindset that anything that gets hot will eventually cause
problems somewhere... Also in case of an alternator failure, the last
thing you want is for some minor component to start wasting precious
energy by converting it to heat!
I hope that this helps :-)
Etienne
On 09 May 2008, at 1:04 PM, RALPH HOOVER wrote:
> Etienne,
>
> I suspect that PS engineering is using an analog regulator for
> noise concerns (cost can figure in as well). Use care inserting a
> switcher without properly considering the noise concern. A switcher
> would certainly allow for a wide input voltage range without a lot
> of heat. Not a show stopper but a design challenge to address.
> This is just my take I have no knowledge of PS Engineering=92s design
> or the process and decisions they have taken to arrive at their
> design. I have used a switcher for my ANR power supply I=92ll soon
> find out if I have any issues!
>
> Ralph & Laura Hoover
> RV7A N527LR
________________________________________________________________________________
From: | "RALPH HOOVER" <hooverra(at)verizon.net> |
Subject: | Fuse Block Locations |
Allen,
I found it on the internet, I will search my records and see if I
can find out where. I have lost a bunch of stuff due to a computer crash.
I will be on the road for a few days so I will look when I return.
It is a Bussman product 15710 series.
Ralph
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Allen
Fulmer
Sent: Tuesday, May 13, 2008 10:10 PM
Subject: RE: AeroElectric-List: Fuse Block Locations
My favorite so far! And where, pray tell, did you get that beautiful fuse
block with cover? Surely must be automotive!
Allen Fulmer
RV7 Avionics and Electrical
>>>-----Original Message-----
>>>From: owner-aeroelectric-list-server(at)matronics.com
>>>[mailto:owner-aeroelectric-list-server(at)matronics.com]On
>>>Behalf Of RALPH
>>>HOOVER
>>>Sent: Tuesday, May 13, 2008 8:43 PM
>>>To: aeroelectric-list(at)matronics.com
>>>Subject: RE: AeroElectric-List: Fuse Block Locations
>>>
>>>
>>>John,
>>> Here is yet another hinged option. This fuse block uses
>>>insert able
>>>crimped contacts (no fastons and one less electrical
>>>interface). It is also
>>>split 20 Main Buss, 8 Essential Buss. The two buses are tied
>>>by a schottky
>>>diode bolted to brass busses (the stuff in the center of the
>>>rear of the
>>>panel). The fuse panel swings down and forward from the
>>>front edge of the
>>>panel and all of the wiring is in the rear.
>>>
>>>Ralph & Laura Hoover
>>>RV7A N527LR
>>>
>>>-----Original Message-----
>>>From: owner-aeroelectric-list-server(at)matronics.com
>>>[mailto:owner-aeroelectric-list-server(at)matronics.com] On
>>>Behalf Of John
>>>Morgensen
>>>Sent: Tuesday, May 13, 2008 9:31 AM
>>>To: aeroelectric-list(at)matronics.com
>>>Subject: AeroElectric-List: Fuse Block Locations
>>>
>>>
>>>
>>>I am seeking pictures and advice on fuse block locations,
>>>panel ground,
>>>firewall ground, etc. My project is an RV-9A using a Z-13/8
>>>architecture.
>>>
>>>Thanks,
>>>John Morgensen
>>>775 771-5791
>>>
>>>
>>>
>>>
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: PMA-6000 intercom 28V install |
>PS Engineering s PMA-6000 intercom has the following note:
>
>
>To reduce the amount of heat dissipated in the audio selector panel, when
>used in a 28
>
>Volt aircraft, it is required that the 15-Ohm, 15-Watt dropping resistor
>(p/n 701-015-1501) be in-
>
>stalled in series with the power input.
>
>
>The install manual goes on to say failure to do so will generate
>unnecessary heat inside the unit and may void PS Engineering s warranty
>. Does anyone have experience installing one of these units in a 28V
>environment? Is the dropping resistor really required? The only reason I
>ask is the local radio shops don t seem to know much about it which makes
>me wonder if they ever used them. They all say they can order one but
>nobody has one in stock.
It is risky to disregard the words of the manufacturer's
installation manuals. It's also disappointing that the
manufacturers of this device did not craft a user-friendly
design.
The simplest thing to do is comply with the instructions.
The simplest way to do this is acquire a component like
this:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=FVTS10-15-ND
Note that it can be mounted to some handy, out of the
way surface on a long screw. The data sheet at:
http://www.heiresistors.com/PDF/FVT_FST20%20spec.pdf
tells us the hole through the middle of this device is
0.19" in diameter . . .
The drill versus threaded sizes chart at:
http://www.phy.mtu.edu/~suits/tapsizes.html
says this is too small for a 10-32 screw but will
be just fine for an 8-32. The resistor data sheet suggests
we need one with 2" or so of over-all length. You'll
be cranking a hard force down against a ceramic tube.
Put a soft washer (some kind of rubber, plastic or even
two layers of paper from the box that comes with a tube
of toothpaste) between the end of the resistor and the
mounting surface. Tighten the screw down to finger
tight + 1 turn and spot the threads with some runny
super-glue to keep it from drifting off that pressure setting.
If your resistor comes with wires, clip them off.
Attach lead wires for intercom power to the resistor's
solder-tabs. Put double layer of heat-shrink over these
joints for vibration support.
This process has been used thousands of designs in
various vehicular products including airplanes. Simple,
lean, works as the manufacturer wishes and lasts a long
time.
BTW . . . the 15W rating is super conservative. The
intercom may draw 1A peak current but the AVERAGE
current will be much lower unless you're particularly
fond of playing Wagner at 100dB in the headphones.
Now, if you're REALLY wanting to make this more
complicated, you can purchase one of B&C's DIM3-28
dimmers at:
http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?10X358218#dim3-28
and instead of installing the dimmer potentiometer,
you put the appropriate resistor between pins 1 and 3
to achieve a constant 14-volt output from the "dimmer".
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Henry Trzeciakowski" <hammer408(at)comcast.net> |
Subject: | Re: Fuse Block Locations |
John:
I'm also building an RV 9tip-up, but I did not go with a hinged panel. My
thought was that it should be very rare that I need to change fuses. If I
do, it will be on the ground and all I'd have to do is back under the
passanger side to change or troubleshoot.
When I mounted them, I didn't take any pictures before I removed my
sub-panel, but plan on it when I rivet my sub-panel on for the last time.
That said, I mounted the Main Bus and Diode and heatsink (25watt - B&C) on
the outboard side of the 745rib on the passanger side and used nutplates. I
mounted the Eudurance Bus, which will basically be my avionics bus, on the
inboard surface of the same rib. That way the e-bus will be just about 8 "
from my avionic's stack. The Battery Bus I mounted just below the brake
reservior and to the left of the battery. So'll I have a shor run to the
Master Battery COntactor and no unfused wires penetrating the firewall. I
purchased a fuse block with cover, so I wouldn't have issues with dirt,
grease, etc.
When I get pictures, I'll get them to you..
Henry
----- Original Message -----
From: "John Morgensen" <john(at)morgensen.com>
Sent: Tuesday, May 13, 2008 6:30 AM
Subject: AeroElectric-List: Fuse Block Locations
>
> I am seeking pictures and advice on fuse block locations, panel ground,
> firewall ground, etc. My project is an RV-9A using a Z-13/8 architecture.
>
> Thanks,
> John Morgensen
> 775 771-5791
>
>
________________________________________________________________________________
From: | "Terry McMillan" <terryml5c2p6(at)sympatico.ca> |
Subject: | Dual redundant electrical system |
This is my first time on the AeroElectric list server, though Ive been
lurking in the forums for some time. Im looking for comments/critiques on a
dual alternator dual battery system Ive designed. Right off the bat I have
to acknowledge the contributions made in this area by Bob Knucolls, Ive
read his book several times, and his ideas and philosophies have strongly
influenced my design. Greg Richter of Blue Mountain Avionics has also been a
major source of information and inspiration.
My application is an all-electric plane, an RV7 Im building with
Aerosance FADEC and an all-glass cockpit (AFS3400, GRT Horizon HX, and
Trutrak EFIS). Im an electrical engineer with 22 years experience in a
large electrical power utility doing protection and control work. Duplicate
redundant protection systems for ultra high reliability are the core work in
this field. In 1988 I left to start my own company, designing and
manufacturing complex expensive microprocessor-based test equipment for use
in that field. Ive flown my own Cessna 172 since 1992. Im comfortable with
electricity and flying, but Im incorporating some non-standard ideas in
this design and would appreciate comments. My prime concern is
technical/safety aspects of the electrical system, but ergonomics is
something Ive also considered important, and feel is too often neglected in
the design of complex hardware systems.
Ive attached reduced size jpg files to respect the bandwidth guidelines,
based on the original dxf files, but will verbally describe the unusual
aspects as well. I can also make available the dxf files showing clearer
detail if anyone wants them.
The first component after the battery in most aircraft systems is the master
relay, which isolates both the starter solenoid and the feed to the main
and/or essential buses. Its usually a large heavy solenoid that must be
rated to carry starter current but normally carries only a small fraction of
that current, and it takes about an amp to keep it picked up. My design uses
a 60A ANL fuse at the battery, feeding a heavy-duty automotive 70A relay in
the cockpit next to the master switch and fuse bus. I expect the smaller
lighter relay will be more reliable than a $17 solenoid, especially because
it is in a cooler lower vibration location, plus it will draw only one-tenth
of the hold-in current which means more flying time in the event of battery
only operation. In my specific system this is not insignificant, the 2 amp
draw of two master relays would be ~10% of the typical main bus load.
In a conventional system, there is no high-speed protection of the several
feet of cable that can exist from the master relay through the firewall to
the buses, other than how fast the pilot can smell smoking insulation and
turn off the switch, by which time major damage can be done to the wiring
bundle. Once I discovered ANL fuses, I saw they could offer fast automatic
protection of this major cable run. There are some good photos at
http://www.highrf.com/gallery/Power-Grids of a Legacy power grid using ANL
fuses. In my system, because I require separate FADEC buses, Ive used an
additional fuse plus relay and fuse bus mounted at the battery, to eliminate
power wiring runs into and then back out of the cockpit, which cuts weight,
simplifies wiring, and minimizes wiring exposure to damage.
A reason given for the conventional system layout is that it can isolate a
stuck starter solenoid. In my experience however, properly sized starter
solenoids are far more likely to fail open than closed, especially since
there is often an additional solenoid internal to the starter, and in worst
case its an on-ground event.
The master relays are controlled by double pole 3 position rocker switches
with internal LED annunciators (see attached Switchgear.jpg). This allows
replacement of the traditional split control switch by providing a battery
only/alternator disabled configuration in the middle position, with the
normal configuration in the upper position. Illuminated rocker switches,
apart from being more visually appealing than the typical steel toggle
switch, can provide rapid day/night visual confirmation of true operational
status since the indicator is driven by the voltage of the actual controlled
circuit. Arranging the switches in close functional groupings also makes it
easy for pre-landing checks- just brush a finger across the tops of all the
switches to verify they are in the upper position.
>From there, power flows to the master bus via 60A Schottky diodes, which
generate much less heat than conventional diodes, reducing heat sink
requirements. There is only one main bus. I spent a lot of time trying to
decide what would go on an essential bus and what would not, plus
considering what kind of interlocks and switching would be necessary to
operate from the essential bus. In the end, given my dual batteries, dual
alternators, and better protection of the main battery feed lines, I
realized that a large essential bus is just as secure as a small one, and
not having to set up an emergency configuration during a high-stress
situation is a big advantage. Greg Richters comments about unnecessarily
complex emergency systems (page 7 of his Aircraft Wiring pdf) are spot on in
my opinion. Modern avionics and LED nav & panel lights dont draw a lot of
power, so normal daytime flight requirements are well under 20 amps for my
setup, which can be carried by the 20A backup alternator, never mind the
dual batteries. Many engine monitor systems, like the AFS3400, can monitor
alternator loading and bus voltage plus provide programmable high/low limit
alarms to these parameters, helping to keep track of loading during loss of
a power source.
I dont have an avionics master switch. I know this is controversial, and
apposed to common procedure, but here is my rationale:
1) Modern avionics are not susceptible to switching transients the way a lot
of earlier commercial gear was, especially during the early days of discrete
transistors. Additionally, though its not shown on my schematics, diode
suppression is fitted to all relays, something that wasnt usually done in
the past.
2) A single avionics master switch provides a single contingency failure
point for the avionics, after all the work to provide full redundancy.
3) Battery voltage drop during starting can cause some avionics to drop out,
but because of the dual diode isolation of the main bus, the avionics will
automatically be fed only from the normal-voltage alternate battery when the
main battery sags during start.
My fuel boost pump switch is a bit different in that there is an additional
(AUTO) position, controlled by the FADEC system. However, takeoff/landing
(MANUAL) position is up, consistent with the master switches, and as with
them LED annunciators provide additional status information.
There is no Pitot Heat control, this is a personal thing. Ive found that
after flying the same plane for a while I rarely look at airspeed, and my
setup gives me dual airspeed info plus AOA. Also, Im a VFR pilot. Doesnt
mean I wont decide to add it if I hear compelling reasons to.
Lighting is traditionally done with a row of toggle switches, one for every
circuit, and here again I have departed from tradition, but in this case
mainly with an eye to improved ergonomics. Details are on a separate drawing
(Lights.jpg). Note that the labels on the rotary switch on the above panel
layout jpg are one revision behind the schematic. I have shown just a 2-pole
rotary switch, as high-reliability sealed switches usually have fewer
configuration choices than cheaper switches. A single rotary switch, common
in automotive applications, makes more sense to me than individual toggles.
Just turn clockwise for more lights. The first position BEACON gives nav
lights and strobes. Because strobes can be disorienting in reduced
visibility they can be disabled via the STROBE ENABLE rocker switch, but the
LED nav lights are always on given their miniscule power draw. APPROACH as
shown energizes the landing lights in a wig-wag mode for high visibility,
though this wouldnt appeal to everyone. TAXI and LANDING are the last two
positions respectively. Taxi lights are on in both positions, but one
rotation counterclockwise on the ground eliminates the long-range landing
light to avoid glare to other pilots. The small rotary knob beside the
larger lighting switch controls dimming of cockpit lights. The STROBE ENABLE
rocker switch status LED gives instant visual confirmation of strobe status,
and the tight group of 3 controls in their separate location can be operated
by touch only, like the master and fuel boost controls. This is difficult to
accomplish in the traditional row of identical toggle switches which are
often mixed in with other identical toggle controls.
I dont have panel controls for trim or flaps, these are provided on the
pilot and copilot control stick handles. A junction box is provided as a
convenient local plug-in terminus for the control stick switches, trim &
flap servos and controller, radio control lines, and power/ground lines. I
have a schematic of this if anyone wants to see it.
My instrument panel will obviously have a lot fewer controls on it than is
now common. I know that banks of toggle switches look impressive to the
uninitiated, but realistically this doesnt contribute to safety by reducing
the pilots workload. Colour coding and grouping can help a little bit, but
it still leaves something to be desired for night operations and status
checks by touch while keeping focused outside the cockpit.
Thats about it for the design highlights. One thing not evident but also
important is, wherever possible, separate physical routing of the main and
alternate system wiring, including firewall penetrations. Ive tried to
envision how the system would handle a variety of failures and havent come
up yet with any realistic scenario that would bring the plane down before
you could get to a reasonable destination point. My only minor concern at
this point is how load sharing is controlled, since the secondary alternator
is just 20A. Ive talked to Bill Bainbridge at B&C, and he said that he sets
the voltage regulator about a volt lower on the alternate. This seems like a
lot to me, Im not sure what effect this has on keeping the alternate
battery in optimum condition. I couldnt find much in Bobs book or the
forums on this point.
Anyway, Im completely open to suggestions and/or criticism. Ego should
never get in the way of safety. Id appreciate anything in the way of
comment. Im now at the point of being almost ready to start wiring things
up, and need a reality check that what I intend to do makes sense.
Thanks, Terry McMillan
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: PMA-6000 intercom 28V install |
>PS Engineering s PMA-6000 intercom has the following note:
>
>
>To reduce the amount of heat dissipated in the audio selector panel, when
>used in a 28
>
>Volt aircraft, it is required that the 15-Ohm, 15-Watt dropping resistor
>(p/n 701-015-1501) be in-
>
>stalled in series with the power input.
>
>
>The install manual goes on to say failure to do so will generate
>unnecessary heat inside the unit and may void PS Engineering s warranty
>. Does anyone have experience installing one of these units in a 28V
>environment? Is the dropping resistor really required? The only reason I
>ask is the local radio shops don t seem to know much about it which makes
>me wonder if they ever used them. They all say they can order one but
>nobody has one in stock.
It is risky to disregard the words of the manufacturer's
installation manuals. It's also disappointing that the
manufacturers of this device did not craft a user-friendly
design.
The simplest thing to do is comply with the instructions.
The simplest way to do this is acquire a component like
this:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=FVTS10-15-ND
Note that it can be mounted to some handy, out of the
way surface on a long screw. The data sheet at:
http://www.heiresistors.com/PDF/FVT_FST20%20spec.pdf
tells us the hole through the middle of this device is
0.19" in diameter . . .
The drill versus threaded sizes chart at:
http://www.phy.mtu.edu/~suits/tapsizes.html
says this is too small for a 10-32 screw but will
be just fine for an 8-32. The resistor data sheet suggests
we need one with 2" or so of over-all length. You'll
be cranking a hard force down against a ceramic tube.
Put a soft washer (some kind of rubber, plastic or even
two layers of paper from the box that comes with a tube
of toothpaste) between the end of the resistor and the
mounting surface. Tighten the screw down to finger
tight + 1 turn and spot the threads with some runny
super-glue to keep it from drifting off that pressure setting.
If your resistor comes with wires, clip them off.
Attach lead wires for intercom power to the resistor's
solder-tabs. Put double layer of heat-shrink over these
joints for vibration support.
This process has been used thousands of designs in
various vehicular products including airplanes. Simple,
lean, works as the manufacturer wishes and lasts a long
time.
BTW . . . the 15W rating is super conservative. The
intercom may draw 1A peak current but the AVERAGE
current will be much lower unless you're particularly
fond of playing Wagner at 100dB in the headphones.
Now, if you're REALLY wanting to make this more
complicated, you can purchase one of B&C's DIM3-28
dimmers at:
http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?10X358218#dim3-28
and instead of installing the dimmer potentiometer,
you put the appropriate resistor between pins 1 and 3
to achieve a constant 14-volt output from the "dimmer".
Bob . . .
________________________________________________________________________________
Subject: | Fuse Block Locations |
Allen,
Try MIH Industries. That's where I purchased mine about a year ago.
http://home.earthlink.net/~dswartzendruber/
Peter Laurence
-----Original Message-----
My favorite so far! And where, pray tell, did you get that beautiful fuse
block with cover? Surely must be automotive!
Allen Fulmer
RV7 Avionics and Electrical
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Dual redundant electrical system |
>X-MIME-Autoconverted: from 8bit to quoted-printable by matronics.com id
>m4F09XD3009485
>Content-Type: text/plain; x-avg-checked=avg-ok-7F1173FE; format=flowed
>I've attached reduced size jpg files to respect the bandwidth guidelines,
>based on the original dxf files, but will verbally describe the unusual
>aspects as well. I can also make available the dxf files showing clearer
>detail if anyone wants them.
Can you .pdf the .dxf drawings from your CAD application?
The .jpg files are kind of "swiss-cheesy" difficult to
deduce the details of your design. I'll .pdf them and repost.
>The first component after the battery in most aircraft systems is the
>master relay, which isolates both the starter solenoid and the feed to the
>main and/or essential buses. It's usually a large heavy solenoid that must
>be rated to carry starter current but normally carries only a small
>fraction of that current, and it takes about an amp to keep it picked up.
>My design uses a 60A ANL fuse at the battery, feeding a heavy-duty
>automotive 70A relay in the cockpit next to the master switch and fuse
>bus. I expect the smaller lighter relay will be more reliable than a $17
>solenoid, especially because it is in a cooler lower vibration location,
>plus it will draw only one-tenth of the hold-in current which means more
>flying time in the event of battery only operation. In my specific system
>this is not insignificant, the 2 amp draw of two master relays would be
>~10% of the typical main bus load.
Terry, you've obviously spent a great deal of time and thought
on this. At first blush, the system you propose is a relative
of Figure Z-14 as published at:
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z14L_1.pdf
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z14L_2.pdf
This dual-alternator/dual-battery architecture was crafted over
a period of 15 or so years and embodies practices well demonstrated
in aircraft for over 60 years.
>Anyway, I'm completely open to suggestions and/or criticism. Ego should
>never get in the way of safety. I'd appreciate anything in the way of
>comment. I'm now at the point of being almost ready to start wiring things
>up, and need a reality check that what I intend to do makes sense.
What you've proposed will probably function as you envision it.
It's more complex than the Z-14 drawings in many respects
and may not meet design goals for aircraft systems design
where we strive for low parts count and failure tolerance.
This translates directly to reductions in weight, cost, and
pilot workload. This approach also increases reliability . . .
a part that isn't there cannot be a failure item in your finished
system.
You've cited rationale for features of your proposed
system that are not a concern for most folks in aviation. It
would be a much more direct path to "architectural nirvana"
to build on what's gone before than to stir a bunch of
parts into a totally new recipe.
At the risk of sounding like I'm suffering a "not invented
here" moment, could you take a bit of time and tell us where
you perceive that Z-14 does not meet personal design goals?
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: PMA-6000 Intercom - 28v install |
>PS Engineering s PMA-6000 intercom has the following note:
>
>
>To reduce the amount of heat dissipated in the audio selector panel, when
>used in a 28
>
>Volt aircraft, it is required that the 15-Ohm, 15-Watt dropping resistor
>(p/n 701-015-1501) be in-
>
>stalled in series with the power input.
>
>
>The install manual goes on to say failure to do so will generate
>unnecessary heat inside the unit and may void PS Engineering s warranty
>. Does anyone have experience installing one of these units in a 28V
>environment? Is the dropping resistor really required? The only reason I
>ask is the local radio shops don t seem to know much about it which makes
>me wonder if they ever used them. They all say they can order one but
>nobody has one in stock.
It is risky to disregard the words of the manufacturer's
installation manuals. It's also disappointing that the
manufacturers of this device did not craft a user-friendly
design.
The simplest thing to do is comply with the instructions.
The simplest way to do this is acquire a component like
this:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=FVTS10-15-ND
Note that it can be mounted to some handy, out of the
way surface on a long screw. The data sheet at:
http://www.heiresistors.com/PDF/FVT_FST20%20spec.pdf
tells us the hole through the middle of this device is
0.19" in diameter . . .
The drill versus threaded sizes chart at:
http://www.phy.mtu.edu/~suits/tapsizes.html
says this is too small for a 10-32 screw but will
be just fine for an 8-32. The resistor data sheet suggests
we need one with 2" or so of over-all length. You'll
be cranking a hard force down against a ceramic tube.
Put a soft washer (some kind of rubber, plastic or even
two layers of paper from the box that comes with a tube
of toothpaste) between the end of the resistor and the
mounting surface. Tighten the screw down to finger
tight + 1 turn and spot the threads with some runny
super-glue to keep it from drifting off that pressure setting.
If your resistor comes with wires, clip them off.
Attach lead wires for intercom power to the resistor's
solder-tabs. Put double layer of heat-shrink over these
joints for vibration support.
This process has been used thousands of designs in
various vehicular products including airplanes. Simple,
lean, works as the manufacturer wishes and lasts a long
time.
BTW . . . the 15W rating is super conservative. The
intercom may draw 1A peak current but the AVERAGE
current will be much lower unless you're particularly
fond of playing Wagner at 100dB in the headphones.
Now, if you're REALLY wanting to make this more
complicated, you can purchase one of B&C's DIM3-28
dimmers at:
http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?10X358218#dim3-28
and instead of installing the dimmer potentiometer,
you put the appropriate resistor between pins 1 and 3
to achieve a constant 14-volt output from the "dimmer".
Bob . . .
________________________________________________________________________________
From: | "Dr. Andrew Elliott" <a.s.elliott(at)cox.net> |
Subject: | Avoiding strobe noise? |
I am building a 601XL (all aluminum), and have located the COMM antenna
on the bottom of the fuselage between the seats. (It's a taildragger,
so this is behind the gear.) I have the primary battery under the right
seat and am holding off locating the second battery until I see how the
W&B turns out.
It has turned out to be convenient, wiring-wise, to locate the strobe
power supply, an XPAK-604X-HR, under the left seat. In this location,
the coax to the COMM antenna and at least one of the wires to the strobe
heads will end up in close proximity.
My question is: Assuming the coax is properly terminated and the strobe
cables' shields are properly grounded at one end, is there going to be a
problem with strobe noise interfering with communications? (The strobe
cables have a foil shield with a drain wire. The drain wire is grounded
to the wing structure at the tip.)
If a problem is likely, are there any additional precautions I could
take to avoid one?
Thanks,
Andy Elliott, Mesa, AZ
N601GE (reserved)
601XL/TD, Corvair, building...
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Avoiding strobe noise? |
>I am building a 601XL (all aluminum), and have located the COMM antenna on
>the bottom of the fuselage between the seats. (It's a taildragger, so
>this is behind the gear.) I have the primary battery under the right seat
>and am holding off locating the second battery until I see how the W&B
>turns out.
>
>It has turned out to be convenient, wiring-wise, to locate the strobe
>power supply, an XPAK-604X-HR, under the left seat. In this location, the
>coax to the COMM antenna and at least one of the wires to the strobe heads
>will end up in close proximity.
>
>My question is: Assuming the coax is properly terminated and the strobe
>cables' shields are properly grounded at one end, is there going to be a
>problem with strobe noise interfering with communications? (The strobe
>cables have a foil shield with a drain wire. The drain wire is grounded to
>the wing structure at the tip.)
>
>If a problem is likely, are there any additional precautions I could take
>to avoid one?
>
Every time someone reports a "noise problem cured
by repositioning wiring" it was a demonstration of
some OTHER root cause.
When products are qualified to be used on airplanes,
they are qualified to both control emissions and
withstand certain stresses that are known to exist
in the aircraft environment.
The wiring you've cited are not particularly
communicative with respect to noise . . . assuming
that the installation of said wires is in accordance
with manufacturer's instructions.
In the heavy iron birds, we are seldom blessed with
enough room to run all the wires that are necessary
for operation much less comb them into potentially
antagonistic and/or victim systems.
The short answer is run them neatly together and
you'll be fine.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
Subject: | Re: PMA-6000 intercom 28V install |
From: | "rampil" <ira.rampil(at)gmail.com> |
To be clear, a switching power brick (aka DC-DC converter) turns DC
into AC then processes it and reconverts to DC. This process makes
audio and potentially RF noise. Noise injected into your intercom
will be a much worse problem than an old resistor hung on your firewall.
A resistor should also be about 1/10 the cost of a power brick. I
would guess available of amps to squander in a voltage dropping resistor
would not be an issue in your RV-10.
Cheers,
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=183349#183349
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: PMA-6000 intercom 28V install |
>
>To be clear, a switching power brick (aka DC-DC converter) turns DC
>into AC then processes it and reconverts to DC. This process makes
>audio and potentially RF noise. Noise injected into your intercom
>will be a much worse problem than an old resistor hung on your firewall.
DC to DC converters come in all flavors. Modern devices have
internal operating frequencies in the hundreds of kilohertz
and generally do not present a noise issue to audio systems.
They have been BIG issues to low frequency nav aids like
VLF Omega and LORAN but few folks use these technologies.
The next most vulnerable system would be an AM radio . . .
generally used for listening to ball games while airborne.
They have packaging issues. I'm aware of no bolt-in-and-wire-
it-up product suited to this task. DC to DC converters come
packaged as components for a larger assembly. Here's an
exemplar device:
http://www.lambdapower.com/ftp/Manuals/pxe_single_ins.pdf
So after you've selected a device with the right power
ratings, now you have to put it in a package of some kind
with screw terminals, push on tabs or perhaps a connector
of some kind. Of course this also offers an opportunity to
add whatever filtering is necessary to live responsibly with
the DO-160 rules of engagement.
>A resistor should also be about 1/10 the cost of a power brick. I
>would guess available of amps to squander in a voltage dropping resistor
>would not be an issue in your RV-10.
Dropping resistors are, as a rule, to be avoided if there
are more elegant solutions at hand. Back when 12v cars were
coming into the marketplace, one could purchase a "Glo-Bar"
resistor designed to drop 12v down to 6v for the purpose of
installing a legacy 6v radio in a new 12v car. These ran
rather warm (30 watts or so) and the "squandering" of energy
was significant but not overtaxing to the system that produced
300+ watts.
In this case, we're considering a system that draws perhaps
100 mA in a quiescent state (1.5 volts dropped across the
15-ohm resistor and tossing off 150 MILLIwatts) and averages
perhaps 300 mA while listening to some music (4.5v drop and
1.3 watts). Peak currents pushing 1A would run the PEAK
dissipation in the dropping resistor up to 10-15 watts or
so . . . but this is exceedingly transient . . . in a system
that produces over 1000 watts of useable power makes this
decision electrically trivial.
The BIG driver in these deliberations is the hassle and
expense of $time$ that it would take to put a DC to DC
converter in a system that probably should have been fitted
with such capabilities from the factory.
Bob . . .
________________________________________________________________________________
Subject: | Close to the battery |
I have two of the six pack fuse blocks from B & C that I want to use for
battery 1 & 2 respectively (Z19). The diagram indicates "close to the
battery". I take that as on the firewall if batteries are mounted as
such.
Does anyone know if B & C or other makes covers for this fuse block?
Naturally If I mount them on the firewall, I want to keep the rif-raf
out. There's always duct tape, but we need a little style here.
Thanks
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Close to the battery |
>
>I have two of the six pack fuse blocks from B & C that I want to use for
>battery 1 & 2 respectively (Z19). The diagram indicates "close to the
>battery". I take that as on the firewall if batteries are mounted as
>such.
>
>Does anyone know if B & C or other makes covers for this fuse block?
>Naturally If I mount them on the firewall, I want to keep the rif-raf
>out. There's always duct tape, but we need a little style here.
The easiest cover is to use threaded spacers as 'nuts'
to mount the fuse block. Bring screws through the mounting
surface and cut them just long enough to get good thread
engagement. Make spacers long enough to extend just above
the tops of seated fuses. Cut a plate of the right size
to cover the block. You could consider bending flanges on
it that would droop down over the fuses and offer more
coverage. A piece of sheet rubber on the underside of
the cover would let you screw the cover down 'solid' and
still not put the supper-munch on the fuses.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Dual redundant electrical system |
>Bob, thanks for the reply. As requested, I'm sending you the 2 schematic
>files in .pdf format for reposting. They are much larger than the .dwg and
>.dxf files, so I am sending them right to you rather than via the Matrox
>file server. I can also give them to you in a variety of AutoCad formats
>if that would be better.
The .pdf files are fine. I've posted them to my
server at:
http://www.aeroelectric.com/_temp/
I'll invite folks on the List to go get them and
participate in this thread as the spirit moves them . . .
>I think from some of your comments that you may have misunderstood my
>intentions in sending out a request for comments. I am not trying to
>propose a new standard. The standard as far as I can see is your Z14
>design, I have seen numerous references to it in my research on the Net,
>and as I indicated I have read your book several times. I have thoroughly
>analysed Z13 and Z14. You have a lot of good ideas, which is why right up
>front in my letter I acknowledged your contributions. However there are
>some drawbacks to Z14 from my perspective, and since you have requested
>it, I will mention a few specifics. below.
Not at all. The works published in the 'Connection are not
intended to be the "final solution". They're drawings that
were evolved to meet certain design goals.
>However, my intention was not to knock your design, but to see if in fact
>anyone could find any safety or reliability flaws in something I came up
>with. Also, it may be more obvious when you get a look at a clearer
>drawing that a significant part of the complexity you refer to is due to
>the AeroSance FADEC system. That is specified by AeroSance, not me, and
>includes 2 additional switch controlled buses dedicated to the control
>system, and their own starter switch, fuel pump control switch, and fuel
>pump relay.
Absolutely understand . . . and no offense taken. My
mission with channeling this discussion is to offer it
as a learning experience for folks on the List. Another
element of the mission is to justify a modicum of my
time to participate without asking for a indenturship
documents on your first-born.
We can increase the depth of the study by involving
lots of folks on the List while not taxing my presently
tight schedule.
>Regarding the lighting circuit, if you concede that wig-wag landing lights
>enhance safety, the traditional toggle-switch approach would require 5
>toggle switches; Nav, Strobes, Wig-Wag/Steady, Taxi and Landing. I don't
>see how this could reduce pilot workload compared to a rotary switch plus
>a rocker switch. The circuits behind those controls would appear less
>complex if there was a readily-available high-reliability switch to
>control each circuit directly, but for my application- again, I'm not
>proposing this as a standard- 4 relays, a rocker and a rotary switch vs 5
>toggle switch is a good tradeoff against reduced pilot workload and more
>time looking outside the cockpit.
>
>As requested, here are some reasons why Z14 did not meet my needs. One of
>the things I wanted to ensure enhanced reliability was minimal firewall
>penetration by power circuits, and fuse protection where this was
>unavoidable. As I began looking at integrating Z14 with the FADEC
>circuits, some conflicts became apparent. The RV7 standard battery
>configuration is on the engine side of the firewall, and there are quite a
>few power circuits to the FADEC on the engine side as well. Using a
>grounding cockpit switch to remotely control the FADEC bus meant all the
>critical power circuits for the FADEC would remain in the engine
>compartment- shorter wires, fewer firewall penetrations, and greater
>reliability.
>
>This still left an unavoidable firewall penetration by the main battery
>feed to the cockpit circuitry however, and a fault on that extended cable
>would do serious damage before it could be switched off manually via the
>traditional master relay. Fuse protecting this line and using a lighter
>lower power master relay in the cockpit right next to the bus it fed was
>to me a logical step, I've already noted that I don't see isolating the
>starter solenoid as necessary.
>
>There are 3 issues with the Z14 cross-feed contactor from my perspective.
>First is that according to Bill Bainbridge of B&C I won't need to parallel
>batteries with his starter. Second is that I would need an avionics master
>switch- single contingency failure point and one more part to fail as you
>have noted- to isolate the EFISs from the batteries during start. Third is
>that if a fault appeared in the wrong spot-such as the unprotected line
>between master relay and bus- switching in the cross-feed contactor to
>bring on the backup alternator would immediately fail that circuit as
>well. An additional objection to the circuit as shown, from my
>perspective, is combining the starter and cross-feed control into a single
>switch. If there is to be manual intervention required in an emergency, it
>should be with a separate dedicated clearly marked switch, not the switch
>you've used a thousand times to start the engine.
>
>The diode-isolated bus automatically brings the backup system on line (no
>pilot intervention) to sustain the critical circuits, prevents backfeeding
>into a fault on the failed side, and it is less complex and more reliable
>than a manual switch, relay and warning lamp.
>
>Let me make it clear that I'm not bashing your design- you asked me why it
>doesn't meet my personal goals, and that's what I've done. In fact, what
>I've done above is what I was hoping to have done to my design; have clear
>specific points made about what might be problematic. Comments like more
>complex, may not meet design goals of failure tolerance, reduced weight &
>workload etc don't really help me if I don't know where it fails in these
>regards. Everyone benefits when specific construction criticism advances
>the state of the art and/or encourages people to keep contributing new ideas.
Very good sir. I've looked this over briefly but I'll
throw it out to the folks on the List with the
notion of joining in as time permits.
Bob . . .
________________________________________________________________________________
Subject: | Dynon , sl40, pm1000II, and GTX327 Pinout numbers |
From: | "gcarnforth" <greg(at)chesterpools.com> |
Hello!
I have been motoring along on my RV7 and have always been able to find answers
in the archives.
I am having troubles firing up my panel and am in the process of going back through
the harness.
Does anyone have the pin numbers for connecting these units?
Flightdek to GTX327
SL40 to PM1000II
I have the diagrams but anyone with the pin numbers would help verify what I have
done right/wrong
Thanks
G carnforth RV7 louisville KY
--------
G. Carnforth
Louisville, KY
RV7
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=183459#183459
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Close to the battery |
>
>Thanks Bob,
> Great idea. I believe I have seen suitable spacers made from
>nylock. We'll give it a go.
You may need to make them. Got access to a lathe?
If push comes to shove, you can use aluminum rod stock.
Cut length just longer than you need for finished part.
Chuck stock in drill press and grab bit in drill press
vise. By turning the stock and holding drill stationary,
you can take advantage of tendency for drill to center
automatically. Start out with small pilot drill and then
finally drill with size appropriate to thread size you
plan to use (probably 6-32 or 8-32).
Tread both ends of the part before sanding carefully
to achieve proper length and flatness of ends. Then
use countersink or oversized drill to chamfer/de-burr
edges of finished holes.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
Subject: | Dynon , sl40, pm1000II, and GTX327 Pinout numbers |
G.
Not to confuse you, but I have them for the Dynon, sl30 and GTX330. Not
exact, but close family.
If you get stuck, they may help. They are hard copy so I'll need to scan
them in (Monday).
I'll bet the sl40 is the same as the sl30 w/o the nav junk. Don't know
about the 330 since it has different options than the 327.
Thanks
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
gcarnforth
Sent: Friday, May 16, 2008 1:54 PM
Subject: AeroElectric-List: Dynon , sl40, pm1000II, and GTX327 Pinout
numbers
-->
Hello!
I have been motoring along on my RV7 and have always been able to find
answers in the archives.
I am having troubles firing up my panel and am in the process of going
back through the harness.
Does anyone have the pin numbers for connecting these units?
Flightdek to GTX327
SL40 to PM1000II
I have the diagrams but anyone with the pin numbers would help verify
what I have done right/wrong
Thanks
G carnforth RV7 louisville KY
--------
G. Carnforth
Louisville, KY
RV7
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=183459#183459
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: ANL Distribution Panel |
>
>I was reading my Porsche Boxster repair manual the other day...
>
>Porsche uses a distribution box which has 5-6 ANL fuses mounted inside.
>Picture it as a fuse block with hookups for ANL type fuses. The purpose
>is to distribute current protected by various amperage ANL's to fuse
>blocks segments which are organized by function and size.
>
>Has anyone attempted this kind of design and is there any value of which
>surpasses the increased part count?
The ANL style fuse is the easiest device to
accommodate with a DIY fuse block. Further,
know that there are some miniature siblings to
the relatively 'boss-hogg' ANL devices. Here's
an ANL base:
http://www.aeroelectric.com/Pictures/Fuses/Fuse_Holders/ANN-ANL_Base.jpg
Here's a base intended to mount the MEGA series
current limiters:
http://www.aeroelectric.com/Pictures/Fuses/Fuses/all_mega.JPG
http://www.aeroelectric.com/Pictures/Fuses/Fuses/megafuse250.gif
http://www.aeroelectric.com/Pictures/Fuses/Fuse_Holders/mfb736_angle.gif
http://www.aeroelectric.com/Pictures/Fuses/Fuse_Holders/mfb736_dwg.jpg
Here are some alternative, high current, stud mounted
devices:
http://www.aeroelectric.com/Pictures/Fuses/Fuses/ABI_fuses.jpg
http://www.aeroelectric.com/Pictures/Fuses/Fuses/BF2.jpg
The common thread for mounting these or similar fuses
is a pair of sturdy, captive threaded posts. These
can be steel bolts (we don't depend on bolt for
current carrying). Fabricate a block from sturdy,
insulating material like phenolic, Delrin, Polysulphone,
etc. You need some sheet material with a thickness on
the order of 1/2 to 5/8 inch. Drill hole pattern for
installation of one or more fuses. Counter bore back
side to take heads of bolts just under flush. Install
bolts with one nut and no washer. Pot the head of the
bolt with JB Weld. After epoxy sets up, remove nut
and re=install using thread locker on nut. JB Weld
works here too. Torque down real good.
Of course, you'll need mounting holes in the base
for installation. You may also need a copper sheet
or brass bus-bar between studs at one end. Go
3/4" wide x .062 or more thickness.
After the stud-nuts cure, install in a/c and
set your fuse down first before stacking terminals
onto the studs. Put flat washer on and secure with
fiber lock-nut torqued to value recommended by AC43.13 for
steel parts of same size. Hold your wires stationary
while applying final torque so that you avoid
this:
http://www.aeroelectric.com/Pictures/Fuses/Fuses/ANL_Twisted.jpg
Once assembled, the system is quite stable due to
rigidity of the potted heads on studs.
Bottom line is that with a little time at the table
saw, drill press and belt sander, you can build
a perfectly acceptable fuse block for any of the
many choices of stud-mounted protective devices.
Here's a multi-fuse installation on a production
aircraft:
http://www.aeroelectric.com/Pictures/Wiring_Technique/Contactor_Interconnect/Contactor_Strap_3.jpg
We COULD have made a much smaller and lighter
installation from scratch but the qualification
costs were prohibitive. You folks are not so
hindered . . .
Bob . . .
________________________________________________________________________________
From: | "Henry Trzeciakowski" <hammer408(at)comcast.net> |
Subject: | Re: 6 AWG vs Copper Bar |
Bob:
Insteard of using 6 AWG from starter contctor to Current Limiter, I want to
use .063 copper bar...is that adequate or should I use .125.
thanks
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Sent: Thursday, May 15, 2008 12:33 PM
Subject: Re: AeroElectric-List: Avoiding strobe noise?
>
>
> >I am building a 601XL (all aluminum), and have located the COMM antenna
on
> >the bottom of the fuselage between the seats. (It's a taildragger, so
> >this is behind the gear.) I have the primary battery under the right
seat
> >and am holding off locating the second battery until I see how the W&B
> >turns out.
> >
> >It has turned out to be convenient, wiring-wise, to locate the strobe
> >power supply, an XPAK-604X-HR, under the left seat. In this location,
the
> >coax to the COMM antenna and at least one of the wires to the strobe
heads
> >will end up in close proximity.
> >
> >My question is: Assuming the coax is properly terminated and the strobe
> >cables' shields are properly grounded at one end, is there going to be a
> >problem with strobe noise interfering with communications? (The strobe
> >cables have a foil shield with a drain wire. The drain wire is grounded
to
> >the wing structure at the tip.)
> >
> >If a problem is likely, are there any additional precautions I could take
> >to avoid one?
> >
>
> Every time someone reports a "noise problem cured
> by repositioning wiring" it was a demonstration of
> some OTHER root cause.
>
> When products are qualified to be used on airplanes,
> they are qualified to both control emissions and
> withstand certain stresses that are known to exist
> in the aircraft environment.
>
> The wiring you've cited are not particularly
> communicative with respect to noise . . . assuming
> that the installation of said wires is in accordance
> with manufacturer's instructions.
>
> In the heavy iron birds, we are seldom blessed with
> enough room to run all the wires that are necessary
> for operation much less comb them into potentially
> antagonistic and/or victim systems.
>
> The short answer is run them neatly together and
> you'll be fine.
>
> Bob . . .
>
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
________________________________________________________________________________
From: | "Henry Trzeciakowski" <hammer408(at)comcast.net> |
Subject: | Re: Avoiding strobe noise? |
So Bob:
as long as all wires are installed and grounded per maunfacture's spec,
running (stringing) wires like Strobe Power Supply, Nav/Com, Transponder,
Flaps, Pitot Heat together along the bottom of a fuselage and thru bulkheads
together are OK ?
Hank
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Sent: Thursday, May 15, 2008 12:33 PM
Subject: Re: AeroElectric-List: Avoiding strobe noise?
>
>
> >I am building a 601XL (all aluminum), and have located the COMM antenna
on
> >the bottom of the fuselage between the seats. (It's a taildragger, so
> >this is behind the gear.) I have the primary battery under the right
seat
> >and am holding off locating the second battery until I see how the W&B
> >turns out.
> >
> >It has turned out to be convenient, wiring-wise, to locate the strobe
> >power supply, an XPAK-604X-HR, under the left seat. In this location,
the
> >coax to the COMM antenna and at least one of the wires to the strobe
heads
> >will end up in close proximity.
> >
> >My question is: Assuming the coax is properly terminated and the strobe
> >cables' shields are properly grounded at one end, is there going to be a
> >problem with strobe noise interfering with communications? (The strobe
> >cables have a foil shield with a drain wire. The drain wire is grounded
to
> >the wing structure at the tip.)
> >
> >If a problem is likely, are there any additional precautions I could take
> >to avoid one?
> >
>
> Every time someone reports a "noise problem cured
> by repositioning wiring" it was a demonstration of
> some OTHER root cause.
>
> When products are qualified to be used on airplanes,
> they are qualified to both control emissions and
> withstand certain stresses that are known to exist
> in the aircraft environment.
>
> The wiring you've cited are not particularly
> communicative with respect to noise . . . assuming
> that the installation of said wires is in accordance
> with manufacturer's instructions.
>
> In the heavy iron birds, we are seldom blessed with
> enough room to run all the wires that are necessary
> for operation much less comb them into potentially
> antagonistic and/or victim systems.
>
> The short answer is run them neatly together and
> you'll be fine.
>
> Bob . . .
>
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
________________________________________________________________________________
From: | Ernest Christley <echristley(at)nc.rr.com> |
Subject: | Re: PMA-6000 intercom 28V install |
Robert L. Nuckolls, III wrote:
>
> They have packaging issues. I'm aware of no bolt-in-and-wire-
> it-up product suited to this task. DC to DC converters come
> packaged as components for a larger assembly. Here's an
> exemplar device:
>
check mpja.com
part number 14335-PS
They have a number of other DC-to-DC converters available, but if it was
just one low power device, I would use a 4-legged bridge rectifier or
eight, lined up on a circuit board. The negative output of one feeding
the positive input of the next. No noise. Compact. Useful for several
amps.
--
http://www.ronpaultimeline.com
________________________________________________________________________________
From: | "Ron Quillin" <rjquillin(at)gmail.com> |
Subject: | Re: Dual redundant electrical system |
On Fri, May 16, 2008 at 8:51 AM, Robert L. Nuckolls, III
wrote:
>
>
>
> The .pdf files are fine. I've posted them to my
> server at:
>
> http://www.aeroelectric.com/_temp/
>
> I'll invite folks on the List to go get them and
> participate in this thread as the spirit moves them . . .
>
Incomplete or incorrect url Bob?
Ron Q.
________________________________________________________________________________
From: | "Ron Shannon" <rshannon(at)CRUZCOM.COM> |
Subject: | Re: Dual redundant electrical system |
>
>
> > http://www.aeroelectric.com/_temp/
> >
> > I'll invite folks on the List to go get them and
> > participate in this thread as the spirit moves them . . .
> >
>
> Incomplete or incorrect url Bob?
>
> Ron Q.
>
The link works from here. Note there is an underscore character preceding
"temp".
FWIW, as a former IT geek, I discouraged webmasters from using underscores
in web URL's because when the whole link is automatically highlighted and
the whole link becomes underscored (as it does in most email programs) the
unaware reader may not realize there's a separate underscore character. If
spacing is necessary, hyphens are better. Of course, spaces never work in a
URL.
Ron
________________________________________________________________________________
Subject: | Re: Dual redundant electrical system |
From: | Ron Quillin <rjquillin(at)gmail.com> |
About 10-15 minutes after the post, it also worked for me...
Sigh.
Also paid to be an IT geek at work.
Ron Q.
At 17:57 5/16/2008, you wrote:
> > <http://www.aeroelectric.com/_temp/>http://www.aeroelectric.com/_temp/
> >
> > I'll invite folks on the List to go get them and
> > participate in this thread as the spirit moves them . . .
> >
>
>Incomplete or incorrect url Bob?
>
>Ron Q.
>
>
>The link works from here. Note there is an underscore character
>preceding "temp".
>
>FWIW, as a former IT geek, I discouraged webmasters from using
>underscores in web URL's because when the whole link is
>automatically highlighted and the whole link becomes underscored (as
>it does in most email programs) the unaware reader may not realize
>there's a separate underscore character. If spacing is necessary,
>hyphens are better. Of course, spaces never work in a URL.
>
>Ron
>
>
><http://www.matronics.com/Navigator?AeroElectric-List>http://www.matronics.com/Navigator?AeroElectric-List
><http://www.matronics.com/contribution>http://www.matronics.com/contribution
>
________________________________________________________________________________
From: | "Ron Shannon" <rshannon(at)CRUZCOM.COM> |
Subject: | Re: Dynon , sl40, pm1000II, and GTX327 Pinout numbers |
On Fri, May 16, 2008 at 10:54 AM, gcarnforth wrote:
> greg(at)chesterpools.com>
> ...
> Does anyone have the pin numbers for connecting these units?
>
> Flightdek to GTX327
> SL40 to PM1000II
>
SL-40 pin outs are:
1 DC power
2 (reserved)
3 RS232 serial data out (TxD)
4 TxKey,pulled low to transmit
5 (no contact -- do not connect)
6 speaker
7 mic ground
8 Mic 1 input
9 DC power ground
10 RS232 serial data in (RxD)
11 RS232 signal ground
12 Intercom select, pulled low to turn on intercom
13 Audio ground (speaker & headphone)
14 Headphone terminal out
15 Mic 1 input
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Dual redundant electrical system |
>
>On Fri, May 16, 2008 at 8:51 AM, Robert L. Nuckolls, III
> wrote:
> >
> >
>
> >
> > The .pdf files are fine. I've posted them to my
> > server at:
> >
> > http://www.aeroelectric.com/_temp/
> >
> > I'll invite folks on the List to go get them and
> > participate in this thread as the spirit moves them . . .
> >
>
>Incomplete or incorrect url Bob?
Don't think so. This is a link to a directory where
you will find two separate .pdf files each of which
needs to be downloaded independently.
This is not unlike the general files archives
on my server like:
http://www.aeroelectric.com/Pictures/
and
http://www.aeroelectric.com/Reference_Docs/
where you don't get a particular document
but a directory structure for many documents.
You should be able to double-click the link
cited and it should take you to the appropriate
directory(ies).
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Avoiding strobe noise? |
>
>
>So Bob:
>
>as long as all wires are installed and grounded per maunfacture's spec,
>running (stringing) wires like Strobe Power Supply, Nav/Com, Transponder,
>Flaps, Pitot Heat together along the bottom of a fuselage and thru bulkheads
>together are OK ?
yup . . /
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: 6 AWG vs Copper Bar |
>
>
>Bob:
>
>Insteard of using 6 AWG from starter contctor to Current Limiter, I want to
>use .063 copper bar...is that adequate or should I use .125.
>
>thanks
.063 x .75" copper is fine.
Bob . . .
________________________________________________________________________________
From: | "Scott Freeman" <sgfreeman(at)smyth.net> |
Subject: | Schematic Review |
I am building an RV-7A. The panel will be all electric and set-up for
light IFR. I have completed my schematic and would like some input
since I am new at this electrical stuff.
The basic configuration is a single alternator/two battery system. The
primary and aux battery are the same size (17 amp-hr) and can both be
used for starting. There is a main and essential (avionics) buss that
can be isolated on either battery.
I envision the modes to be:
1) Normal operation: Start with primary batt, run system off alternator
and primary batt, only turn aux batt on long enough to "top off" its
charge and then isolate it back off.
2) Alternator failure and/or main batt failure: Power the avionics buss
with the isolated aux battery for emergency power until able to land.
This will be up to 2 hours for the avionics. Note: If there is remaining
power in the Primary Batt- I would be able to get some time with it
also.
3) Ground Start- If the Primary Batt is drained during a hard start
situation, the option to switch to the aux battery for start is there.
Since these are smaller dry cells, I like this option.
4) Plan is to rotate the aux battery to the Main Battery every other
year or as necessary and replace the aux battery with a fresh one. This
will provide preventative maintenance for the batteries.
Thanks for any input you can provide to make sure the schematic doesn't
have errors.
Scott Freeman
________________________________________________________________________________
From: | "Terry McMillan" <terryml5c2p6(at)sympatico.ca> |
Subject: | Schematic Review |
Scott, a couple of things I noticed; you have 2 unprotected unswitched
circuits directly connected to the Aux battery, namely the Aux Battery Bus
and the Aux Battery Switch. These both pass thru the firewall to the
cockpit, and if a fault to ground occured they could not be turned off. My
suggestion would be an in-line fuse for the Aux Bat Bus, and move the feed
to terminal 2 of the Aux Bat Master Switch to the other side of the Aux Bat
Relay. As shown turning on the Aux Bat Switch will energize both the Main
and Avionics buses, so presumably you would manually turn off the loads on
the main bus. To me it would make more sense to wire the fuse-protected lead
from the Aux Battery direct to the Aux Bat Avionics Master, this way it
would be an emergency-only switch, and the Aux Batt Master switch would just
be used to parallel the batteries for starting or to charge the Aux battery.
Personally I see it as a bad idea to mix emergency control functions with
routine functions on the same switch. FWIW, a good suggestion I've seen is
to put the DC power receptacle on the alway-hot bus. One advantage of this
is that you can recharge the battery on the ground without opening the
cowling.
Terry McMillan
RV7 FADEC dual electrical
>From: "Scott Freeman" <sgfreeman(at)smyth.net>
>Reply-To: aeroelectric-list(at)matronics.com
>To:
>Subject: AeroElectric-List: Schematic Review
>Date: Sat, 17 May 2008 12:00:56 -0400
>
>I am building an RV-7A. The panel will be all electric and set-up for
>light IFR. I have completed my schematic and would like some input since I
>am new at this electrical stuff.
>
>The basic configuration is a single alternator/two battery system. The
>primary and aux battery are the same size (17 amp-hr) and can both be used
>for starting. There is a main and essential (avionics) buss that can be
>isolated on either battery.
>
>I envision the modes to be:
>1) Normal operation: Start with primary batt, run system off alternator and
>primary batt, only turn aux batt on long enough to "top off" its charge and
>then isolate it back off.
>
>2) Alternator failure and/or main batt failure: Power the avionics buss
>with the isolated aux battery for emergency power until able to land. This
>will be up to 2 hours for the avionics. Note: If there is remaining power
>in the Primary Batt- I would be able to get some time with it also.
>
>3) Ground Start- If the Primary Batt is drained during a hard start
>situation, the option to switch to the aux battery for start is there.
>Since these are smaller dry cells, I like this option.
>
>4) Plan is to rotate the aux battery to the Main Battery every other year
>or as necessary and replace the aux battery with a fresh one. This will
>provide preventative maintenance for the batteries.
>
>Thanks for any input you can provide to make sure the schematic doesn't
>have errors.
>
>Scott Freeman
><< N246SFElectricalSystemDesignRev2-forReview.xls >>
________________________________________________________________________________
From: | BobsV35B(at)aol.com |
Subject: | Schematic Review |
Good Afternoon Scott,
I keep seeing reference to Light IFR and an occasional reference to heavy
IFR.
Would you mind telling me what you consider to be light IFR?
If you were on top of coastal fog with a two hundred foot ceiling below,
would a full ILS to a fully approach lit runway be light or heavy IFR?
Or, if you are enroute, constantly in cloud, but with ceilings along your
route and at destination well above one thousand and three, would that be
light IFR?
I have a hard time discerning just what is meant by light IFR.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
628 West 86th Street
Downers Grove, IL 60516
630 985-8502
Stearman N3977A
Brookeridge Air Park LL22
Do Not Archive
In a message dated 5/17/2008 11:08:54 A.M. Central Daylight Time,
sgfreeman(at)smyth.net writes:
I am building an RV-7A. The panel will be all electric and set-up for light
IFR.
**************Wondering what's for Dinner Tonight? Get new twists on family
favorites at AOL Food.
(http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001)
________________________________________________________________________________
From: | BobsV35B(at)aol.com |
Subject: | Re: Schematic Review |
I Like It! l Like It!!
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
628 West 86th Street
Downers Grove, IL 60516
630 985-8502
Stearman N3977A
Brookeridge Air Park LL22
In a message dated 5/17/2008 6:32:48 P.M. Central Daylight Time,
icubob(at)newnorth.net writes:
hi bob,
light ifr is if i am right seat with a very competent and proficient ifr
pilot. hard ifr is if i am solo!
bob noffs
**************Wondering what's for Dinner Tonight? Get new twists on family
favorites at AOL Food.
(http://food.aol.com/dinner-tonight?NCID=aolfod00030000000001)
________________________________________________________________________________
From: | "S. Ramirez" <simon(at)synchronousdesign.com> |
Subject: | Schematic Review |
Scott, your version of "light IFR" sounds like non-commercial flying to me.
I think it's wise for us guys that don't fly in IMC too much to want to fly
only in light IMC. Those are good rules, and the goods don't have to be
there by a certain time.
Simon
Copyright C 2008
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Scott
Freeman
Sent: Saturday, May 17, 2008 10:33 PM
Subject: Re: Getting Off Topic, Was: AeroElectric-List: Schematic Review
Bob,
Sorry for the "light IFR" nomenclature. I knew after I sent it that it
would probably raise some eyebrows. To me it means it means I have some
personal limits that I want to stay within for single pilot IFR.
Rule 1: Never fly on purpose into sustained IMC conditions
Rule 2: Use IFR as a means to get on top only if the layer is less than 2000
ft thick. If it is more than 2000' thick, stay home.
Rule 3: When ever possible, use IFR flight plans to work on flying skills
and to have constant contact with ATC
Rule 4: Use IFR to get down through a layer for an approach to an airport
with ceilings at least 300 ft. above minimums. If ceilings are less than
300 above, try to find another airport that meets that criteria even if you
miss getting home when you wanted.
Rule 5: Never, Never, Never fly when the slightest possibility of icing
conditions or sustained IMC conditions are forecast for any part of your
route
Rule 6: Practice VFR navigation, including pilotage and dead reckoning on a
regular basis to keep well rounded
Rule 7: Plan on sleeping on some airport couches once in a while
Rule 8: Since we are human and things don't always go as we expect,
practice, practice, and practice so if unfortunate and unforseen
circumstances lead to one of the rules being violated, you can survive and
come home to your family in one piece
To me it boils down to the old saying: It is better to be on the ground
wishing you were in the air than in the air wishing your were on the ground.
Scott
________________________________________________________________________________
From: | "Sam Hoskins" <shoskins(at)MCHSI.COM> |
Subject: | Peer review - Z-19RB with RWS controller |
________________________________________________________________________________
From: | "Sam Hoskins" <shoskins(at)MCHSI.COM> |
Subject: | Try it again. Z-19RB Peer Review |
________________________________________________________________________________
Subject: | Again? - Peer review - Z-19RB with RWS controller |
From: | "Sam" <sam.hoskins(at)GMAIL.COM> |
Bob & all, (third try at posting this request)
I'm looking for a review of my electrical system, based on Z-19RB. This is a retrofit
in my little 22 year-old composite Quickie Q-200. I do a lot of day VFR
cross country with this little buggy and do some cross country racing. Since
I am converting to "all electric" I would be interested in your thoughts about
my proposed system which is attached as a PDF file.
Besides the Dynon FlightDEK 180 the biggest change is the conversion to electronic fuel injection. I am using the EC-3 controller from Real World Solutions (RWS). You can see more about the controller here: http://www.rotaryaviation.com/eficont.html
The EC-3 controller is divided into two sides, A & B. The fuel injector control
and ignition outputs exit the box from a single connector via a shared relay.
The controller can receive either a primary or secondary 12V power source.
A few bullet points:
* I am using a primary fuel pump and a backup fuel pump. I also have two transfer
pumps.
* I have not yet sized the batteries.
* I have an existing AEC9005-201 low voltage monitor, without the relay control.
* Output of the ECU will be shown on another page, perhaps later in the week.
* I have not yet properly sized the fuses or the wires in this drawing.
My concerns:
* By the time I add strobes and position lights, I will have around 14 or 15
switches, which seems like a lot for a 650 lb. (empty weight) airplane. Is
there a way I could minimize the switch count?
* There seem to be a lot of components connected to the unswitched battery
busses. I wonder if I should use CBs instead of fuses?
* Since I rarely fly at night, is the main buss, as depicted, really needed?
Maybe I could combine the main and E busses.
Anything else? Your input is very welcome.
Thanks!
Sam Hoskins
Murphysboro, IL
http://samhoskins.blogspot.com/
--------
Sam Hoskins
www.samhoskins.blogspot.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=183649#183649
Attachments:
http://forums.matronics.com//files/n202sh_peer_review_01_178.pdf
________________________________________________________________________________
From: | "Henry Trzeciakowski" <hammer408(at)comcast.net> |
Subject: | Re: Avoiding strobe noise? |
Thanks.....
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Sent: Friday, May 16, 2008 7:26 PM
Subject: Re: AeroElectric-List: Avoiding strobe noise?
>
>
> >
> >
> >So Bob:
> >
> >as long as all wires are installed and grounded per maunfacture's spec,
> >running (stringing) wires like Strobe Power Supply, Nav/Com, Transponder,
> >Flaps, Pitot Heat together along the bottom of a fuselage and thru
bulkheads
> >together are OK ?
>
> yup . . /
>
> Bob . . .
>
>
________________________________________________________________________________
From: | "Henry Trzeciakowski" <hammer408(at)comcast.net> |
Subject: | Re: 6 AWG vs Copper Bar |
Bob:
I have .063 X .50"; can I double up and make 2 bars thus giving me .125 x
.50"
Thanks
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Sent: Friday, May 16, 2008 7:25 PM
Subject: Re: AeroElectric-List: Re: 6 AWG vs Copper Bar
>
>
> >
> >
> >Bob:
> >
> >Insteard of using 6 AWG from starter contctor to Current Limiter, I want
to
> >use .063 copper bar...is that adequate or should I use .125.
> >
> >thanks
>
> .063 x .75" copper is fine.
>
> Bob . . .
>
>
________________________________________________________________________________
Subject: | Re: Getting Off Topic, Was: Schematic Review |
Scott,
An excellent set of rules for Light IFR for the recreational
(non-commercial) flyer!
I have been flying my Velocity for the past 5 years with very much the
same rules. It has allowed me to get out before the low level fog burns
off, out of Hilton Head and Florida before the marine layer burns off,
and into airports that have a broken or solid layer above them but a
1500 - 2000' ceiling.
I also flew single pilot IFR to Oshkosh in between layers at 8000' but
with plenty of good ceilings below the underlying layer.
It gives me tremendous flexibility that I didn't have when I was trying
to scud run and didn't have my instrument rating - downright
dangerous!!!!
Getting your instrument rating and using your "Light IFR Rules" is VERY
HIGHLY RECOMMENDED if you are going to be flying much cross country.
Ronnie Brown
________________________________________________________________________________
Subject: | Re: Schematic Review |
From: | "user9253" <fran5sew(at)banyanol.com> |
Suggestion 1. An avionics master switch is controversial because it becomes a single
point failure for all of your avionics. Modern avionics are not supposed
to be affected by voltage spikes. If concerned about expensive avionics, one
could shut off individual units, not as convenient as a master switch but safer.
If you must have an avionics master, consider using a double pole switch
wired in parallel. If one half of the switch fails, the other half will carry
the load.
Suggestion 2. Feed the Aux Battery Avionics Master Switch directly from the battery
without going through the Aux Battery Master Switch. Having two switches
in series doubles the chances of switch failure. Re-label the Aux Bat Avionics
Master switch as "Avionics Aux Feed".
Suggestion 3. Remove the ground wire from terminal 4 of the Aux Battery Master
Switch. Instead, connect terminal 4 to terminal 2 of the Main Master switch.
This essentially connects the two battery contactors in parallel for normal operation.
Re-label the Aux Bat Master switch to Aux Bat Isolate. This switch
would be normally closed, even after engine shut down. You would only open this
switch in case of an emergency. This wiring change will simplify your system.
There will be only one master switch to deal with. There will be more cranking
amps available. And the aux battery will be kept fully charged.
Suggestion 4. Mount and wire the "Avionics Aux Feed" and "Aux Bat Isolate" switches
so that they are normally in the down position. They would be toggled up
in case of an emergency.
Suggestion 5. How about using a variation of Bob Nuckolls' Z-19? I like the feature
of the low voltage module automatically isolating the aux battery without
pilot intervention.
These are only suggestions to help and are not meant to criticize.
Joe Gores
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=183666#183666
________________________________________________________________________________
From: | "bob noffs" <icubob(at)newnorth.net> |
since battery tenders have become popular the last few years i acquired
1/2 dz from harbor frt. they were 3-5 $ each and seem to work well.
snowmobile, atv, skidsteer, motorcycle, etc have never had a low battery
since. output varied, so much that i would take a voltmeter along to
test units before they went in my shopping cart. one unit put out too
much voltage and i lowered it with a diode. it keeps the battery at
13.7-13.8 volts now. is the diode inhibiting any function of the tender
to regulate current supplied to the battery? does a $5 unit even have
the brains to regulate anything?
thanks for any input
bob noffs
________________________________________________________________________________
Subject: | Help for English translation |
Hi all,
One of my buddies is trying to convince French civil aviation
authorities (DGAC) to let him install an Odyssey EFIS in his kitplane
project.
He is asking for help from naturally English speakers to correct his
English translation of the DGAC relevant document.
Would any of you gentlemen and ladies care to help correcting the
following document for understandable English ?
http://contrails.free.fr/translate.php
Any inputs appreciated,
Thanks in advance,
Best regards,
--
Gilles
http://contrails.free.fr
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: battery tenders |
>since battery tenders have become popular the last few years i acquired
>1/2 dz from harbor frt. they were 3-5 $ each and seem to work well.
>snowmobile, atv, skidsteer, motorcycle, etc have never had a low battery
>since. output varied, so much that i would take a voltmeter along to test
>units before they went in my shopping cart. one unit put out too much
>voltage and i lowered it with a diode. it keeps the battery at 13.7-13.8
>volts now. is the diode inhibiting any function of the tender to regulate
>current supplied to the battery? does a $5 unit even have the brains to
>regulate anything?
> thanks for any input
Can't tell without tearing it open and also
running tests to deduce performance. What we
want to see from a true "tender" is a recharge
curve with a behavior like this:
http://www.aeroelectric.com/Pictures/Curves/Battery_Tender_Recharge.pdf
Note the top-off dwell during the interval
before it drops to the "tending" mode.
There are some semi-smart chargers like:
http://www.aeroelectric.com/Pictures/Curves/Battery_Minder_Recharge.pdf
That don't have a top-off dwell. Further, the voltage
at which full-charge is expected is somewhat shy
of optimal. I've purchased only one Battery Minder
and pitched it after seeing the tests. I have a
three or four Battery Tenders in the stable of
battery maintenance tools along with a number of
Schumacher products.
About the best bargain I've seen so far is the
Schumacher WM-1562A charger often offered by
Wallmart and others. It has a very intelligent
recharge profile . . .
http://www.aeroelectric.com/Pictures/Curves/schumacher_3.jpg
. . . and sells for under $20.
Schumacher builds some larger, equally sophisticated
devices at attractive prices . . .
http://www.aeroelectric.com/Pictures/Curves/schumacher_5.jpg
I failed to write down the charger I was evaluating
here but I think it was a middle-sized device and probably
sold for under $60.
Unless you have the equipment to grab plots like these
it's sort a pig-in-a-poke deal. At first blush, I'd
guess that the $5 H.F. devices behave more like the
Battery Minder and while much better than a trickle
charger (no smarts at all) it fall far short of the
best we know how to do for just a few dollars more.
Just went to the H.F. website and got pictures and
stock numbers on their current offerings. I posted
them at:
http://www.aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/
I'm guessing that the charger you're asking about
is one of these two:
http://www.aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/42292.gif
http://www.aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/Junk_1.jpg
There's another interesting one . . .
http://www.aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/93258.gif
designed to mount permanently in the vehicle where
a battery is to be maintained.
I've already looked at the Junker . . . next
time I'm in the store, I'll pick up copies of the
other small chargers and test them. I note further
that H.F. is offering Schumacher products as well
as their own. Everything we've been talking about sells
for under $70 with some devices in the $18 range.
Short answer is that anything with Schumacher's
name on it is a pretty good bet. The other devices
may offer good value and performance too . . . but
you don't know without testing. Which H.F. stock
number device are you wondering about?
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: 6 AWG vs Copper Bar |
>
>
>Bob:
>
>I have .063 X .50"; can I double up and make 2 bars thus giving me .125 x
>.50"
Sure . . . but the .50" width doesn't leave you much edge
margin at the clearance holes for 5/16" studs and there's some
concern for spreading the high currents across the hole
through 3/32" connections at the edges. But lots of folk
have used this width of material and I've not heard of
any problems. In fact, a single layer offers a cross-
section of .063 x .50 = .031 square inches. 4AWG
wire is two, 3AWG-doubling steps larger than 10AWG.
10 AWG is .1" diameter or 3.14 x .05^2 = 0.0078
square inches. Taken times 4 yields .031 square
inches for 4AWG wire. The same as your proposed
straps which will cool better because of larger
surface area and heat-sinks at the studs.
So electrically and thermally, the proposed strips
are fine. How about this? Go to your local well-stocked
hardware store and get some 5/16" brass washers.
Solder to one side of your 0.5" copper strap at the
5/16" hole locations. I think you said you were
working with a shunt at the other end which is a
1/4" stud. No "reinforcement" necessary.
"Doubling up" the strap makes it more difficult
to get the two pieces to lay together. A soldered
on doubler at the 5/16" holes is easier and will
look better when you're finished.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Henry Trzeciakowski" <hammer408(at)comcast.net> |
Subject: | Re: 6 AWG vs Copper Bar |
Thanks Bob: I like the idea of soldering brass washers.....or better yet, I
may just order .063 x .75" wide copper bar and KISS.
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Sent: Sunday, May 18, 2008 11:15 AM
Subject: Re: AeroElectric-List: Re: 6 AWG vs Copper Bar
>
>
> >
> >
> >Bob:
> >
> >I have .063 X .50"; can I double up and make 2 bars thus giving me .125
x
> >.50"
>
> Sure . . . but the .50" width doesn't leave you much edge
> margin at the clearance holes for 5/16" studs and there's some
> concern for spreading the high currents across the hole
> through 3/32" connections at the edges. But lots of folk
> have used this width of material and I've not heard of
> any problems. In fact, a single layer offers a cross-
> section of .063 x .50 = .031 square inches. 4AWG
> wire is two, 3AWG-doubling steps larger than 10AWG.
> 10 AWG is .1" diameter or 3.14 x .05^2 = 0.0078
> square inches. Taken times 4 yields .031 square
> inches for 4AWG wire. The same as your proposed
> straps which will cool better because of larger
> surface area and heat-sinks at the studs.
>
> So electrically and thermally, the proposed strips
> are fine. How about this? Go to your local well-stocked
> hardware store and get some 5/16" brass washers.
> Solder to one side of your 0.5" copper strap at the
> 5/16" hole locations. I think you said you were
> working with a shunt at the other end which is a
> 1/4" stud. No "reinforcement" necessary.
>
> "Doubling up" the strap makes it more difficult
> to get the two pieces to lay together. A soldered
> on doubler at the 5/16" holes is easier and will
> look better when you're finished.
>
> Bob . . .
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
________________________________________________________________________________
From: | "Henry Trzeciakowski" <hammer408(at)comcast.net> |
Subject: | Re: S704-1 Relay Question |
Bob:
I'm going to install a "Heavy E-bus and use your architecture: Bat-bus
(14AWG) to 704-1 relay with S700-1-3(22AWG) switch coming off relay and 14
awg from relay to e-bus. I'm a little confused on how the Relay is wired.
I've printed the wiring picture of the Relay off the aeroelectric website
and it didn't help.
The diode, via fastabs is wired or jumps the - to + terminal and there are
also 2 wires crimped to the same fasttabs. I'm assuming the black goes to
ground, but where does the one wired to the + terminal go to ??
Also where does the "COM" wire and N.O. wire go?
OR...keeping the question simple ---how do you wire the Relay utilizing
Heavy E-Bus architecture?
Thanks
________________________________________________________________________________
From: | "Ron Quillin" <rjquillin(at)gmail.com> |
Subject: | Re: battery tenders |
>From some research I have done in the past couple of years, I've noted
Concorde has gotten touchy regarding maximum charge voltage in
maintenance or float mode. They assert some units have been applying
an excessive, for the ambient temperature, voltage and this has caused
a decrease in service life of their AGM type batteries.
BatteryMINDer, and perhaps others, have responded by including sensors
to adjust float voltage for ambient temperature (it needs to increase
with decreasing temperature) even to the point of recalling some of
their non compensating units. I suppose one could argue this is just
a marketing ploy to sell more chargers, but they are, or at least
were, offering replacement units at a 50% discount. Battery details
can be found at
http://www.concordebattery.com/otherpdf/ownermanual.pdf
on page 16.
Ron Q.
On Sun, May 18, 2008 at 10:55 AM, Robert L. Nuckolls, III
wrote:
>
>
>
>> since battery tenders have become popular the last few years i acquired
>> 1/2 dz from harbor frt. they were 3-5 $ each and seem to work well.
>> does a $5 unit even have the brains to
>> regulate anything?
>> thanks for any input
>
> Can't tell without tearing it open and also
> running tests to deduce performance. What we
> want to see from a true "tender" is a recharge
> curve with a behavior like this:
>
> That don't have a top-off dwell. Further, the voltage
> at which full-charge is expected is somewhat shy
> of optimal. I've purchased only one Battery Minder
> and pitched it after seeing the tests. I have a
> three or four Battery Tenders in the stable of
> battery maintenance tools along with a number of
> Schumacher products.
>
> About the best bargain I've seen so far is the
> Schumacher WM-1562A charger often offered by
> Wallmart and others. It has a very intelligent
> recharge profile . . .
>
> Short answer is that anything with Schumacher's
> name on it is a pretty good bet. The other devices
> may offer good value and performance too . . . but
> you don't know without testing. Which H.F. stock
> number device are you wondering about?
>
> Bob . . .
________________________________________________________________________________
From: | "bob noffs" <icubob(at)newnorth.net> |
hi bob,
the h.f. unit i am talking about is the #42292. appreciate your input.
bob noffs
________________________________________________________________________________
Subject: | Re: Use of 700-2-10 switch for Voltage Sense - how |
to wire?
From: | "mikef" <mikefapex(at)gmail.com> |
I obtained both the Digikey and B&C 2-7 switches.
When wired as indicated on the diagram the Digikey version worked as expected.
However the B&C 2-7 did not. The middle position does not show the expected
voltage (or any voltage). When I substitute a 2-10 switch it, like the Digikey
version, works as expected.
I will play further with the B&C 2-7 but it is either not designed for wiring that
way or just a bad switch.
Mike
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=183735#183735
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Use of 700-2-10 switch for Voltage Sense |
- how to wire?
>
>I obtained both the Digikey and B&C 2-7 switches.
>
>When wired as indicated on the diagram the Digikey version worked as
>expected. However the B&C 2-7 did not. The middle position does not show
>the expected voltage (or any voltage). When I substitute a 2-10 switch it,
>like the Digikey version, works as expected.
>
>I will play further with the B&C 2-7 but it is either not designed for
>wiring that way or just a bad switch.
You lost me. Did our conversation start out talking
about the 2-7 functionality?
A 2-7 is double pole, three position, (ON)-OFF-(ON) device
where the parens around the 'ON' denotes a spring-loaded
momentary position.
The 2-10 is a double pole, three position, PROGRESSIVE
TRANSFER, ON-ON-ON device that is stable at all three
positions. No spring loading.
A few of the ways these two switches can be used
are illustrated in:
http://aeroelectric.com/Pictures/Schematics/2-Pole_Switch_Options.pdf
and in Figure 11-14 in the 'Connection.
The 2-7 cannot substitute for a 2-10. A 2-70 (progressive
transfer version of a 2-7) can do the same switching
job as a 2-10 where you WANT the two extreme positions to
be momentary.
I don't think B&C stocks the 2-70 so if you got a 2-7
from them, I would predict mystifying results. The Digikey
number I gave you was for a 2-70 equivalent in a miniature
switch by C&K . . . not a 2-10.
If you've already drilled a hole for a standard size
2-70, there's a version of the miniature 2-70
that sports a standard size toggle and mounting hole.
See:
http://aeroelectric.com/Pictures/Switches/7215TZQE.jpg
and
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=CKN1495-ND
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: battery tenders |
>hi bob,
> the h.f. unit i am talking about is the #42292. appreciate your input.
>
> bob noffs
Okay. I'll pick one up and test it.
Bob . . .
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: battery tenders |
>
> >From some research I have done in the past couple of years, I've noted
>Concorde has gotten touchy regarding maximum charge voltage in
>maintenance or float mode. They assert some units have been applying
>an excessive, for the ambient temperature, voltage and this has caused
>a decrease in service life of their AGM type batteries.
Has this shown up in print anywhere? I mean something that
illustrates Concord's increasing tension?
>BatteryMINDer, and perhaps others, have responded by including sensors
>to adjust float voltage for ambient temperature (it needs to increase
>with decreasing temperature) even to the point of recalling some of
>their non compensating units. I suppose one could argue this is just
>a marketing ploy to sell more chargers, but they are, or at least
>were, offering replacement units at a 50% discount. Battery details
>can be found at
>http://www.concordebattery.com/otherpdf/ownermanual.pdf
>on page 16.
This document hasn't been changed with respect to charging
recommendations for many moons. You can go to . . .
http://aeroelectric.com/Mfgr_Data.html
and get the Concorde battery poop I've posted on
website.
The maintenance data speaks to fast-charging situations
and the techniques are essentially the same for both
flooded and AGM batteries . . . including the recommended
BUS voltages versus for in-flight recharging.
None of this data is particularly relevant to a
smart battery maintainer which spends only a limited
amount of time in the top-off mode before dropping
to a sustain level that is not even mentioned in
the Concorde data.
Any words from the manufacturers of battery maintainers
as to the "tailoring" of their product to the "special
needs" of an AGM battery is mostly marketing hype. However
the device tops a battery off is not terribly relevant
to battery life . . . the event lasts but a few hours at
modest current levels compared to the comparatively
much larger abuse the battery receives while being
replenished by a 60A alternator!
As long as the maintainer drops to a true maintenance
level (hundreds of millivolts above the battery's
open circuit voltage) then the battery is not at-risk
for abuse from the maintainer. That temperature
compensating stuff doesn't hurt but don't spend a lot
of money on it cause it doesn't make that much difference
in battery service life.
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: S704-1 Relay Question |
>
>
>Bob:
>
>I'm going to install a "Heavy E-bus and use your architecture: Bat-bus
>(14AWG) to 704-1 relay with S700-1-3(22AWG) switch coming off relay and 14
>awg from relay to e-bus. I'm a little confused on how the Relay is wired.
>I've printed the wiring picture of the Relay off the aeroelectric website
>and it didn't help.
>
>The diode, via fastabs is wired or jumps the - to + terminal and there are
>also 2 wires crimped to the same fasttabs. I'm assuming the black goes to
>ground, but where does the one wired to the + terminal go to ??
>
>Also where does the "COM" wire and N.O. wire go?
>
>OR...keeping the question simple ---how do you wire the Relay utilizing
>Heavy E-Bus architecture?
>
>Thanks
As shown in
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z32K.pdf
The picture at:
http://aeroelectric.com/Pictures/Relays/s704inst.jpg
shows how to get the diode leads into the same terminals
with the wires that go to ends of the relay coil . . . but
according to Z32K you'll need to drop two wires into the
COM terminal too.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | Ken <klehman(at)albedo.net> |
Subject: | Re: Schematic Review |
I am skeptical whether paralleling a double pole switch really helps
reliability. Mechanical switch failure would take out both poles. A
lightly loaded switch might suffer corrosion and wear issues at a
similar rate for both poles. One would not know if one pole failed
prematurely. For heavily loaded contacts perhaps the second pole would
help share the arc damage though??
Ken
user9253 wrote:
>
> Suggestion 1. An avionics master switch is controversial because it becomes a
single point failure for all of your avionics. Modern avionics are not supposed
to be affected by voltage spikes. If concerned about expensive avionics,
one could shut off individual units, not as convenient as a master switch but
safer. If you must have an avionics master, consider using a double pole switch
wired in parallel. If one half of the switch fails, the other half will carry
the load.
>
________________________________________________________________________________
From: | "Andrew Butler" <andrewbutler(at)ireland.com> |
Subject: | Re: S704-1 Relay Question |
Hello,
At what level of load does an E-Bus become "heavy duty"?
Also, what is the purpose of the diode? I know what a diode does, but
what is its practical use in this instance?
Cheers,
Andrew.
----- Original Message -----
From: "Robert L. Nuckolls, III"
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
Date: Sun, 18 May 2008 22:31:42 -0500
>
> Bob:
>
> I'm going to install a "Heavy E-bus and use your architecture:
Bat-bus
> (14AWG) to 704-1 relay with S700-1-3(22AWG) switch coming off relay
and 14
> awg from relay to e-bus. I'm a little confused on how the Relay is
wired.
> I've printed the wiring picture of the Relay off the aeroelectric
website
> and it didn't help.
>
> The diode, via fastabs is wired or jumps the - to + terminal and
there are
> also 2 wires crimped to the same fasttabs. I'm assuming the black
goes to
> ground, but where does the one wired to the + terminal go to ??
>
> Also where does the "COM" wire and N.O. wire go?
>
> OR...keeping the question simple ---how do you wire the Relay
utilizing
> Heavy E-Bus architecture?
>
> Thanks
As shown in
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z32K.pdf
The picture at:
http://aeroelectric.com/Pictures/Relays/s704inst.jpg
shows how to get the diode leads into the same terminals
with the wires that go to ends of the relay coil . . . but
according to Z32K you'll need to drop two wires into the
COM terminal too.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
===========
===========
===========
===========
________________________________________________________________________________
From: | "Ron Shannon" <rshannon(at)CRUZCOM.COM> |
Subject: | Re: S704-1 Relay Question |
On Mon, May 19, 2008 at 6:11 AM, Andrew Butler
wrote:
> Hello,
>
> At what level of load does an E-Bus become "heavy duty"?
>
> Also, what is the purpose of the diode? I know what a diode does, but what
> is its practical use in this instance?
>
> Cheers,
>
> Andrew.
>
The level at which an E-bus becomes "heavy duty" is not a precise point, but
certainly occurs when the E-bus is expected to carry loads that would strain
or exceed limits for a standalone toggle switch. Although the S700 series
switches are rated to 15A, you should probably be seriously considering a
separate relay whenever load approaches 10A, IMHO.
The diode keeps the E-bus from back feeding the Main bus when the E-bus
alternate feed (direct from battery or battery bus) is ON. If the E-bus were
allowed to back feed the Main bus, it would defeat the purpose of the E-bus,
which is rapid, positive reduction of load upon alternator failure. Use of a
diode instead of another switch eliminates the need to flip another switch
(i.e., reduces chance for error, also, see "heavy duty" discussion above).
Ron
________________________________________________________________________________
From: | "Andrew Butler" <andrewbutler(at)ireland.com> |
Subject: | Re: S704-1 Relay Question |
Thanks Ron, though the diode I was referring is the 1N4001 across the
coil of the S704 relay. There is something I don't know, cause I don't
see it adding any functionality.......
Andrew.
----- Original Message -----
From: "Ron Shannon"
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
Date: Mon, 19 May 2008 07:07:20 -0700
On Mon, May 19, 2008 at 6:11 AM, Andrew Butler
wrote:
Hello,
At what level of load does an E-Bus become "heavy duty"?
Also, what is the purpose of the diode? I know what a diode does,
but what is its practical use in this instance?
Cheers,
Andrew.
The level at which an E-bus becomes "heavy duty" is not a precise
point, but certainly occurs when the E-bus is expected to carry loads
that would strain or exceed limits for a standalone toggle switch.
Although the S700 series switches are rated to 15A, you should
probably be seriously considering a separate relay whenever load
approaches 10A, IMHO.
The diode keeps the E-bus from back feeding the Main bus when the
E-bus alternate feed (direct from battery or battery bus) is ON. If
the E-bus were allowed to back feed the Main bus, it would defeat the
purpose of the E-bus, which is rapid, positive reduction of load upon
alternator failure. Use of a diode instead of another switch
eliminates the need to flip another switch (i.e., reduces chance for
error, also, see "heavy duty" discussion above).
Ron
===========
========
===
________________________________________________________________________________
Subject: | Re: Schematic Review |
From: | "user9253" <fran5sew(at)banyanol.com> |
Hi Ken,
I agree with you that a mechanical failure will disable both poles of a double
pole switch. It has been my experience that the majority of switches fail because
of high resistance between contacts, especially in switches that are not
used frequently. I also agree that one would not know if only one pole failed.
But who cares as long as the load keeps working? I am not suggesting that
double pole switches be used in place of every single pole switch, only for essential
applications. The added cost and weight for a couple of DPST switches
is not much. Depending on one's panel, it could be a hassle replacing a switch.
I would want to delay doing that by using a more reliable switch. I believe
that a double pole switch wired in parallel has an extended life compared
to a single pole switch. Maybe someone has already done tests to prove or disprove
this theory.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=183819#183819
________________________________________________________________________________
Subject: | Re: Use of 700-2-10 switch for Voltage Sense - how |
to wire?
From: | "mikef" <mikefapex(at)gmail.com> |
Bob,
My bad, I mixed up the switch types. I think I will stick with the small Digikey
switch and be happy.
Thanks again,
Mike
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=183822#183822
________________________________________________________________________________
From: | "Etienne Phillips" <etienne.phillips(at)gmail.com> |
Subject: | Re: S704-1 Relay Question |
It's called a fly-back diode.
The coil of a relay is a fairly sizeable inductor, which means that a
step-change in current is not really possible. What happens when the current
to the coil is removed, the "inertia" of the inductor will force a current
to continue flowing for a short while, generating large voltages and arcing
across switch contacts. The fly-back diode gives this current a path to flow
without interfering with the rest of the electrical system, and only comes
into play when the coil is de-energized.
For more info, go to http://en.wikipedia.org/wiki/Flyback_diode
:-)
Etienne
2008/5/19 Andrew Butler :
> Thanks Ron, though the diode I was referring is the 1N4001 across the coil
> of the S704 relay. There is something I don't know, cause I don't see it
> adding any functionality.......
>
> Andrew.
>
> ----- Original Message -----
> From: "Ron Shannon"
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
> Date: Mon, 19 May 2008 07:07:20 -0700
>
> On Mon, May 19, 2008 at 6:11 AM, Andrew Butler
> wrote:
>
>> Hello,
>>
>> At what level of load does an E-Bus become "heavy duty"?
>>
>> Also, what is the purpose of the diode? I know what a diode does, but what
>> is its practical use in this instance?
>>
>> Cheers,
>>
>> Andrew.
>>
>
>
> The level at which an E-bus becomes "heavy duty" is not a precise point,
> but certainly occurs when the E-bus is expected to carry loads that would
> strain or exceed limits for a standalone toggle switch. Although the S700
> series switches are rated to 15A, you should probably be seriously
> considering a separate relay whenever load approaches 10A, IMHO.
>
> The diode keeps the E-bus from back feeding the Main bus when the E-bus
> alternate feed (direct from battery or battery bus) is ON. If the E-bus were
> allowed to back feed the Main bus, it would defeat the purpose of the E-bus,
> which is rapid, positive reduction of load upon alternator failure. Use of a
> diode instead of another switch eliminates the need to flip another switch
> (i.e., reduces chance for error, also, see "heavy duty" discussion above).
>
> Ron
>
> *
>
> ist">http://www.matronics.com/Navigator?AeroElectric-Listics.com
> .matronics.com/contribution
> *
>
>
> *
>
> *
>
>
________________________________________________________________________________
From: | "Ron Shannon" <rshannon(at)CRUZCOM.COM> |
Subject: | Re: S704-1 Relay Question |
On Mon, May 19, 2008 at 8:16 AM, Andrew Butler
wrote:
> Thanks Ron, though the diode I was referring is the 1N4001 across the coil
> of the S704 relay. There is something I don't know, cause I don't see it
> adding any functionality.......
>
> Andrew.
>
Ooops! So much for unwarranted assumptions.
As for the diode across the coil, see
http://www.aeroelectric.com/articles/spikecatcher.pdf
Ron
________________________________________________________________________________
From: | "Andrew Butler" <andrewbutler(at)ireland.com> |
Subject: | Re: S704-1 Relay Question |
Perfect! Thanks.
----- Original Message -----
From: "Ron Shannon"
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
Date: Mon, 19 May 2008 08:43:42 -0700
On Mon, May 19, 2008 at 8:16 AM, Andrew Butler
wrote:
Thanks Ron, though the diode I was referring is the 1N4001 across
the coil of the S704 relay. There is something I don't know,
cause I don't see it adding any functionality.......
Andrew.
Ooops! So much for unwarranted assumptions.
As for the diode across the coil, see
http://www.aeroelectric.com/articles/spikecatcher.pdf
Ron
===========
========
===
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: S704-1 Relay Question |
>Hello,
>
>At what level of load does an E-Bus become "heavy duty"?
The e-bus was born of a time when many if not most
builders could plan on and implement an endurance
load of 5A or less. The rule-of-thumb for maximum
protection level of an always hot wire in TC aircraft
is 5A . . . so the idea of taking a 5A fused feeder
off the battery bus to supply an e-bus through a panel
mounted switch was well within the parameters of
accepted practice in TC aircraft.
As folks piled more stuff on the e-bus, 5A feeders
wouldn't cut it any more so it became a tribute
to accepted practice to add a mini battery contactor
at the battery bus to provide a local control point for
the e-bus alternate feed path.
From a reliability perspective I really like the
idea of staying with a toggle switch. Further,
given that a 7A fuse is on the order of 5-10 times
faster than a 5A breaker, it seems a reasonable
tribute to accepted practice to say that anything
over a 7A FUSED alternate feed path is "heavy duty"
and justifies the complexity of an additional
relay. 7A or less can be handled with a toggle
switch.
Bob . . .
________________________________________________________________________________
Subject: | Re: Help for English translation |
Mickey Coggins a crit :
>
>
> Hi Gilles,
>
> There is a MGL representative in France - perhaps he has already
> contacted the DGAC.
>
> http://www.stratomaster.eu/
>
> If the document you need translated is going to the boys in South
> Africa, I'd say it is quite understandable. To make sure the
> translation is accurate, it would help to have a link to the French
> version.
>
Mickey and all,
Thanks to all who responded, on-list and off-list.
I added a link to the original French version at the bottom of the page
http://contrails.free.fr/translate.php
I understand that the translation is for the use of the French MGL
representative.
Thanks again,
Best regards,
--
Gilles
http://contrails.free.fr
________________________________________________________________________________
From: | skyking135 <skyking135(at)bellsouth.net> |
Subject: | Re: battery tenders |
I have one of the 42292 units and measured the output voltage on my
particular unit to be around 12.7 volts, noload. It was only getting the
battery up to about 12.3 volts; not enough to keep a good charge on a
battery. So, being the curious one that I am, I popped open the cover to
see if I could figure out how to adjust the output voltage. I found a
spot on the circuit board for a varistor (VR1) that had a 55ohm resistor
soldered in that postion. I figured that must adjust the output voltage.
I simply replaced the 55ohm resistor with a 22ohm one I had on hand.
That boosted the ouptut to a more respectable 13.2 volts. It still will
only charge up to about 12.9 volts which is better than the 12.3 is was
reaching before. I think I will adjust the resistor again to see if I
can squeeze out a little more performance.
Quality control is not high on the list of priorities with Harbor
Freight. You get what you pay for.
db
________________________________________________________________________________
From: | "Dave Leikam" <daveleikam(at)wi.rr.com> |
Subject: | Re: Schematic Review |
I flew an Archer for a few years that had two avionics masters side by side
wired parallel. Toggles will usually fail when turned on or off. If one
failed (never did), you knew it and the other was available.
Dave Leikam
#40496 N89DA (Reserved)
Muskego, WI
----- Original Message -----
From: "Ken" <klehman(at)albedo.net>
Sent: Monday, May 19, 2008 7:30 AM
Subject: Re: AeroElectric-List: Re: Schematic Review
>
> I am skeptical whether paralleling a double pole switch really helps
> reliability. Mechanical switch failure would take out both poles. A
> lightly loaded switch might suffer corrosion and wear issues at a similar
> rate for both poles. One would not know if one pole failed prematurely.
> For heavily loaded contacts perhaps the second pole would help share the
> arc damage though??
> Ken
>
> user9253 wrote:
>>
>>
>> Suggestion 1. An avionics master switch is controversial because it
>> becomes a single point failure for all of your avionics. Modern avionics
>> are not supposed to be affected by voltage spikes. If concerned about
>> expensive avionics, one could shut off individual units, not as
>> convenient as a master switch but safer. If you must have an avionics
>> master, consider using a double pole switch wired in parallel. If one
>> half of the switch fails, the other half will carry the load.
>>
>
>
>
________________________________________________________________________________
From: | Kevin Horton <khorton01(at)rogers.com> |
Subject: | Re: Help for English translation |
On 19 May 2008, at 17:25, Gilles Thesee wrote:
> <Gilles.Thesee@ac-grenoble.fr>
>
> Mickey Coggins a crit :
>> matronics(at)rv8.ch>
>>
>> Hi Gilles,
>>
>> There is a MGL representative in France - perhaps he has already
>> contacted the DGAC.
>>
>> http://www.stratomaster.eu/
>>
>> If the document you need translated is going to the boys in South
>> Africa, I'd say it is quite understandable. To make sure the
>> translation is accurate, it would help to have a link to the
>> French version.
>>
>
> Mickey and all,
>
> Thanks to all who responded, on-list and off-list.
> I added a link to the original French version at the bottom of the
> page
> http://contrails.free.fr/translate.php
>
> I understand that the translation is for the use of the French MGL
> representative.
>
Many elements of these requirements appear to be lifted directly from
CS 23, the European equivalent to FAR 23. You can find the accepted
English wording for some sections by looking at FAR 23.1301, 23.1309,
23.1311, 23.1322, etc. Available on the FAA web site.
--
Kevin Horton
RV-8 (FInal Assembly)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
From: | "earl_schroeder(at)juno.com" <earl_schroeder(at)juno.com> |
Subject: | Re: battery tenders |
Hi db,
The older 42292 [or whatever (the previous generation)]did have a variable resister
on the circuit board. Nearly every one needed some adjustment as I have
a dozen or so.
I purchased a minimum order of 100 ohm pots to install in the newer units. I adjust
them for 13.8 open circuit.
I've repaired six or so [mine and others] as the common failure is the transformer
wire disconnects where it attaches to the plug that plugs into the 110VAC.
A sharp knife will separate the plastic housing around the transformer providing
access. I thought originally that trying to start an engine with the unit
connected would melt the solder at that joint but I'm not sure.
For the money they are hard to beat but as some say, you get what you pay for..
Earl
-- skyking135 wrote:
<
I have one of the 42292 units and measured the output voltage on my
particular unit to be around 12.7 volts, noload. It was only getting the
battery up to about 12.3 volts; not enough to keep a good charge on a
battery. So, being the curious one that I am, I popped open the cover to
see if I could figure out how to adjust the output voltage. I found a
spot on the circuit board for a varistor (VR1) that had a 55ohm resistor
soldered in that postion. I figured that must adjust the output voltage.
I simply replaced the 55ohm resistor with a 22ohm one I had on hand.
That boosted the ouptut to a more respectable 13.2 volts. It still will
only charge up to about 12.9 volts which is better than the 12.3 is was
reaching before. I think I will adjust the resistor again to see if I
can squeeze out a little more performance.
Quality control is not high on the list of priorities with Harbor
Freight. You get what you pay for.
db
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Any legacy regulator gurus out there? |
I received some pictures from a reader who is looking for an
adjustment procedure for a Delco-Remy generator regulator.
http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_4.jpg
http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_3.jpg
http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_2.jpg
http://aeroelectric.com/Pictures/Regulators/12VN7E_Delco-Remy_1.jpg
I've never seen an electro-mechanical regulator that was this
sophisticated. It appears to have airgap adjustments as well
as spring tension adjustments for both the V-reg and I-lim
relays.
I'm wondering if anyone on this IS or KNOWS someone WHO IS
familiar adjustment of these devices. I'm afraid that the
"offical" procedure will require test equipment common to
a generator/regulator overhaul shop. Unless I can find
data specific to this device (I think the 12VN7E
numbers on the base plate are a part number) I'm going
to recommend that he not mess with anything other than
the tension spring on the voltage regulator which can
be adjusted with the engine running and a light load
on the system.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | Les Kearney <kearney(at)shaw.ca> |
Subject: | Contactor Locations |
Hi
I am trying to plan my RV10 electrical system and have a question for the
electrical mavens. That is, how far from avionics should battery contactors
be? I am looking at mounting my batteries in the sub panel area and would
like to co-locate the contactors in the same area. Access is not an issue
but I am concerned about possible interference with the avionics. I may end
up locating the starter contactor on the same area as well. Would this be a
problem?
Cheers
Les Kearney
________________________________________________________________________________
From: | "Andrew Butler" <andrewbutler(at)ireland.com> |
Subject: | Re: S704-1 Relay Question |
Okay, I've read the Wikipedia and aeroelectric articles. So far so good.
So, in the absence of the diode, where is the "arc" likely to occur? If I
have understood correctly I'm saying at the E-BUS feed switch rather than
at the switch in the relay. Am I correct?
If not, why does the arc occur at the relay switch and not the feed
switch. It has to do with the current flow path.........
Thanks for your help.
Andrew.
----- Original Message -----
From: "Etienne Phillips"
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
Date: Mon, 19 May 2008 17:40:15 +0200
It's called a fly-back diode.
The coil of a relay is a fairly sizeable inductor, which means that a
step-change in current is not really possible. What happens when the
current to the coil is removed, the "inertia" of the inductor will
force a current to continue flowing for a short while, generating
large voltages and arcing across switch contacts. The fly-back diode
gives this current a path to flow without interfering with the rest
of the electrical system, and only comes into play when the coil is
de-energized.
For more info, go to http://en.wikipedia.org/wiki/Flyback_diode
:-)
Etienne
2008/5/19 Andrew Butler :
Thanks Ron, though the diode I was referring is the 1N4001 across
the coil of the S704 relay. There is something I don't know,
cause I don't see it adding any functionality.......
Andrew.
----- Original Message -----
From: "Ron Shannon"
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
Date: Mon, 19 May 2008 07:07:20 -0700
On Mon, May 19, 2008 at 6:11 AM, Andrew Butler <andrewbutler@ireland.
com>
wrote:
Hello,
At what level of load does an E-Bus become "heavy duty"?
Also, what is the purpose of the diode? I know what a
diode does, but what is its practical use in this
instance?
Cheers,
Andrew.
The level at which an E-bus becomes "heavy duty" is not a
precise point, but certainly occurs when the E-bus is
expected to carry loads that would strain or exceed limits
for a standalone toggle switch. Although the S700 series
switches are rated to 15A, you should probably be seriously
considering a separate relay whenever load approaches 10A,
IMHO.
The diode keeps the E-bus from back feeding the Main bus when
the E-bus alternate feed (direct from battery or battery bus)
is ON. If the E-bus were allowed to back feed the Main bus,
it would defeat the purpose of the E-bus, which is rapid,
positive reduction of load upon alternator failure. Use of a
diode instead of another switch eliminates the need to flip
another switch (i.e., reduces chance for error, also, see
"heavy duty" discussion above).
Ron
ist"> http://www.matronics.com/Navigator?AeroElectric-List
ics.com . matronics.com/contribution
===========
========
===
________________________________________________________________________________
Subject: | Re: Any legacy regulator gurus out there? |
From: | "jetboy" <sanson.r(at)xtra.co.nz> |
Sir, I dont quite want to claim guru status, working on my previous C150A from
'61 it was similar and I did reset the V reg to around 14.4 - it was sitting
about 13 - and reset the I reg with a wirewound resistor (one of those old monster
types with the sliding clamp) to get the output up to 12 amps or so from
the 'as found' 6 amps. It was actually a 20 amp generator but 12 is enough when
the professional fix would be 100s of miles and $ away
I dont recall whether I altered the gaps or tension for this but I did it after
cleaning the contacts from 40 years of pitting with a burnishing tool.
Some time later I had a low charge again and discovered the aircraft master switch
- which thoughtfully includes cutoff contacts for the generator field line
- was in need of similar refurbishing. love these old systems because they are
actually repairable - just go to where the smoke last escaped from...
Moral of the story for me was I had wrongly assumed I knew enough not to check
the aircraft schematics first. In all probability the regulator may have been
OK but the worn switch in the field line had reduced the drive. It did no harm
checking the regulator and it would have been a shame to have it binned as it
looked like new inside just as the ones pictured. So I concur with your notion
to have him only mess with the V reg - perhaps after cleaning the contacts and
checking the other wiring for hidden resistance.
Ralph
--------
Ralph - CH701 / 2200a
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=183994#183994
________________________________________________________________________________
From: | "bob noffs" <icubob(at)newnorth.net> |
earl,
a few years ago when battery tenders was a topic here i got started on
the h. f. units. i ran into a low voltagw problem. i remember a post
back then about the adjustable pots. i opened one up and no adjustable
pot. this was probably 2 years ago. that is why i shopped for them with
my voltmeter. i dont believe h. f. management will let me take them in
the backroom and test them anymore.
bob
noffs
________________________________________________________________________________
From: | "Etienne Phillips" <etienne.phillips(at)gmail.com> |
Subject: | Re: S704-1 Relay Question |
That is correct, in the E-bus Alternate Feed Switch in this case, or in a
more general case when dealing with inductor-like components, it'll arc
across whatever component tries to remove power to the relay. In the case of
a solid-state IC, this will normally be the silicon wafer, which would let
out the smoke and kill the chip.
I know someone who lost a starter switch in his Cozy after about 15 engine
starts because the fly-back diode was missing from the starter contactor,
that's how marked the effect is... A new switch and one 50c fly-back diode
later and no more problems.
Hope that helps :-)
Etienne
2008/5/20 Andrew Butler :
> Okay, I've read the Wikipedia and aeroelectric articles. So far so good.
>
> So, in the absence of the diode, where is the "arc" likely to occur? If I
> have understood correctly I'm saying at the E-BUS feed switch rather than at
> the switch in the relay. Am I correct?
>
> If not, why does the arc occur at the relay switch and not the feed switch.
> It has to do with the current flow path.........
>
> Thanks for your help.
>
> Andrew.
>
> ----- Original Message -----
> From: "Etienne Phillips"
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
> Date: Mon, 19 May 2008 17:40:15 +0200
>
> It's called a fly-back diode.
>
> The coil of a relay is a fairly sizeable inductor, which means that a
> step-change in current is not really possible. What happens when the current
> to the coil is removed, the "inertia" of the inductor will force a current
> to continue flowing for a short while, generating large voltages and arcing
> across switch contacts. The fly-back diode gives this current a path to flow
> without interfering with the rest of the electrical system, and only comes
> into play when the coil is de-energized.
>
> For more info, go to http://en.wikipedia.org/wiki/Flyback_diode
>
> :-)
>
> Etienne
>
> 2008/5/19 Andrew Butler :
>
>> Thanks Ron, though the diode I was referring is the 1N4001 across the
>> coil of the S704 relay. There is something I don't know, cause I don't see
>> it adding any functionality.......
>>
>> Andrew.
>>
>> ----- Original Message -----
>> From: "Ron Shannon"
>> To: aeroelectric-list(at)matronics.com
>> Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
>> Date: Mon, 19 May 2008 07:07:20 -0700
>>
>> On Mon, May 19, 2008 at 6:11 AM, Andrew Butler
>> wrote:
>>
>>> Hello,
>>>
>>> At what level of load does an E-Bus become "heavy duty"?
>>>
>>> Also, what is the purpose of the diode? I know what a diode does, but
>>> what is its practical use in this instance?
>>>
>>> Cheers,
>>>
>>> Andrew.
>>>
>>
>>
>> The level at which an E-bus becomes "heavy duty" is not a precise point,
>> but certainly occurs when the E-bus is expected to carry loads that would
>> strain or exceed limits for a standalone toggle switch. Although the S700
>> series switches are rated to 15A, you should probably be seriously
>> considering a separate relay whenever load approaches 10A, IMHO.
>>
>> The diode keeps the E-bus from back feeding the Main bus when the E-bus
>> alternate feed (direct from battery or battery bus) is ON. If the E-bus were
>> allowed to back feed the Main bus, it would defeat the purpose of the E-bus,
>> which is rapid, positive reduction of load upon alternator failure. Use of a
>> diode instead of another switch eliminates the need to flip another switch
>> (i.e., reduces chance for error, also, see "heavy duty" discussion above).
>>
>> Ron
>>
>> *
>>
>> ist">http://www.matronics.com/Navigator?AeroElectric-Listics.com
>> .matronics.com/contribution
>> *
>>
>>
>> *
>>
>> *
>>
>>
> *
>
> ist">http://www.matronics.com/Navigator?AeroElectric-Listics.com
> .matronics.com/contribution
> *
>
>
> *
>
>
> *
>
>
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Contactor Locations |
>Hi
>
>
>I am trying to plan my RV10 electrical system and have a question for the
>electrical mavens. That is, how far from avionics should battery
>contactors be? I am looking at mounting my batteries in the sub panel area
>and would like to co locate the contactors in the same area. Access is not
>an issue but I am concerned about possible interference with the avionics.
>I may end up locating the starter contactor on the same area as well.
>Would this be a problem?
>
>
>Cheers
>
>
>Les Kearney
Contactors are not high level antagonists to other
components of the system. You mount contactors where
it makes the most sense for their function. Battery
contactors close to batteries, starter contactors
close to starters, ect. In some architectures, they
can be clustered together.
In any case, there are no characteristics of a
contactor that makes them a threat to anything
other than the switch that controls them. See:
http://www.aeroelectric.com/articles/spikecatcher.pdf
http://www.aeroelectric.com/articles/spike.pdf
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: S704-1 Relay Question |
>Okay, I've read the Wikipedia and aeroelectric articles. So far so good.
>
>So, in the absence of the diode, where is the "arc" likely to occur? If I
>have understood correctly I'm saying at the E-BUS feed switch rather than
>at the switch in the relay. Am I correct?
>
>If not, why does the arc occur at the relay switch and not the feed
>switch. It has to do with the current flow path.........
>
>Thanks for your help.
>
>Andrew.
Not sure what you're calling the "feed switch". With
respect to contactors and relays, there is potential for
effects of field collapse in an inductor to erode
the contacts of the device that controls that contactor
or relay. Hence, the long standing practice of adding
spike suppression across the coils of such devices as
illustrated in the Z-figures.
Now, ANY time you break a circuit with the opening
of hard contacts as in a switch, relay or contactor
(that is carrying any amount of current at any voltage)
there WILL be an arc formed in spreading gap between
opening contacts. There was a school of thought circulated
in the OBAM aircraft community a few years ago that
for voltages and/or currents below some low level
(I don't recall the numbers now) that no arcing would
occur.
So as an experiment, I took a miniature switch and
sanded out the side of it like this:
http://aeroelectric.com/Pictures/Switches/sm_switch_cutaway.jpg
I fixtured it under the microscope and caused the
NO contacts to carry 1 or 1/2 amp of current at 1.5
volts (alkaline d-cell). In a dark room I could clearly
observe a tiny but bright blue arc in the spreading
gap between the contacts when the circuit was broken.
THIS ARCING IS NOT the phenomenon of concern with
respect to noise or debilitating effects on controlling
or controlled devices. Hence we rarely see arc suppression
techniques applied to these effects. One exception
is the quest for achieving the Beech Aircraft ov relay
trip-life using relays some 30+ years ago as described
in the chapter on OV Protection in the 'Connection.
There is also a school of thought that suggests plain
vanilla diodes across relay and contactor coils will
cause a slowing of contact spreading velocity and is
therefore an inducement to prolonged arcing at the
opening contacts.
Experiments on my bench showed that while adding a
diode did indeed cause a DELAY IN OPENING of the
contacts . . .
http://www.aeroelectric.com/Pictures/Curves/704-1DelayNoDiode.gif
http://www.aeroelectric.com/Pictures/Curves/704-1DelayWithDiode.gif
. . . use of the plain vanilla diode produced no
significant slowing of contact spreading velocity
once they started to move.
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gif
In any case, the arcing produced either at controlling
switches -OR- contacts of the controlled devices IS
NOT a widespread threat for damage to other components
in the system. The strongest effect you'll experience
from the behavior of an unsuppressed relay or contactor
coil is a transient interference event. A few years ago
I helped a builder track down why opening his avionics
bus relay on an off-the-shelf integrated power distribution
system caused his ov protection to trip. A diode
across the relay coil fixed the problem.
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Any legacy regulator gurus out there? |
>
>Sir, I dont quite want to claim guru status, working on my previous C150A
>from '61 it was similar and I did reset the V reg to around 14.4 - it was
>sitting about 13 - and reset the I reg with a wirewound resistor (one of
>those old monster types with the sliding clamp) to get the output up to 12
>amps or so from the 'as found' 6 amps. It was actually a 20 amp generator
>but 12 is enough when the professional fix would be 100s of miles and $ away
>
>I dont recall whether I altered the gaps or tension for this but I did it
>after cleaning the contacts from 40 years of pitting with a burnishing tool.
>
>Some time later I had a low charge again and discovered the aircraft
>master switch - which thoughtfully includes cutoff contacts for the
>generator field line - was in need of similar refurbishing. love these old
>systems because they are actually repairable - just go to where the smoke
>last escaped from...
>
>Moral of the story for me was I had wrongly assumed I knew enough not to
>check the aircraft schematics first. In all probability the regulator may
>have been OK but the worn switch in the field line had reduced the drive.
>It did no harm checking the regulator and it would have been a shame to
>have it binned as it looked like new inside just as the ones pictured. So
>I concur with your notion to have him only mess with the V reg - perhaps
>after cleaning the contacts and checking the other wiring for hidden
>resistance.
>
>Ralph
Thank you for sharing this. I'll include it in my compilation
of hands-on experiences to forward to the gentleman who also
has an old C-150!
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: battery tenders |
>
>
>Hi db,
>The older 42292 [or whatever (the previous generation)]did have a variable
>resister on the circuit board. Nearly every one needed some adjustment as
>I have a dozen or so.
>
>I purchased a minimum order of 100 ohm pots to install in the newer
>units. I adjust them for 13.8 open circuit.
>
>I've repaired six or so [mine and others] as the common failure is the
>transformer wire disconnects where it attaches to the plug that plugs into
>the 110VAC. A sharp knife will separate the plastic housing around the
>transformer providing access. I thought originally that trying to start
>an engine with the unit connected would melt the solder at that joint but
>I'm not sure.
>
>For the money they are hard to beat but as some say, you get what you pay
>for..
>Earl
Yup. The first "Battery Charger" I purchased from H.F. was
this guy.
http://aeroelectric.com/Pictures/Battery_Chargers/HF_Chargers/Junk_1.jpg
It was simply a loosely regulated, low-level charger that
might be classed as a "trickle-charger". No smarts at all
meaning that its design did not attempt to produce a top-off
charge followed by a non-charging support of terminal voltage
for the purpose of offsetting internal leakage that would
eventually discharge the battery.
That device was evaluated years ago and it's a certainty
that newer devices intended to compete in an increasingly
sophisticated market will have improved features.
The problem is a simple experiment to benchmark their
performance for behavior and calibration which I will
do as time permits.
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: battery tenders |
>
>
>Hi db,
>The older 42292 [or whatever (the previous generation)]did have a variable
>resister on the circuit board. Nearly every one needed some adjustment as
>I have a dozen or so.
>
>I purchased a minimum order of 100 ohm pots to install in the newer
>units. I adjust them for 13.8 open circuit.
>
>I've repaired six or so [mine and others] as the common failure is the
>transformer wire disconnects where it attaches to the plug that plugs into
>the 110VAC. A sharp knife will separate the plastic housing around the
>transformer providing access. I thought originally that trying to start
>an engine with the unit connected would melt the solder at that joint but
>I'm not sure.
>
>For the money they are hard to beat but as some say, you get what you pay
>for..
>Earl
>
>
>-- skyking135 wrote:
><
>
>I have one of the 42292 units and measured the output voltage on my
>particular unit to be around 12.7 volts, noload. It was only getting the
>battery up to about 12.3 volts; not enough to keep a good charge on a
>battery. So, being the curious one that I am, I popped open the cover to
>see if I could figure out how to adjust the output voltage. I found a
>spot on the circuit board for a varistor (VR1) that had a 55ohm resistor
>soldered in that postion. I figured that must adjust the output voltage.
>I simply replaced the 55ohm resistor with a 22ohm one I had on hand.
>That boosted the ouptut to a more respectable 13.2 volts. It still will
>only charge up to about 12.9 volts which is better than the 12.3 is was
>reaching before. I think I will adjust the resistor again to see if I
>can squeeze out a little more performance.
>
>Quality control is not high on the list of priorities with Harbor
>Freight. You get what you pay for.
The question that is more difficult to answer is how does
this product behave when LOADED with a discharged battery.
How much current does it put out, for how long and to what
terminal voltage? Does it produce a recharge voltage curve
that looks anything like this?
http://www.aeroelectric.com/Pictures/Curves/schumacher_2.jpg
The voltage you're measuring at very low output current
(open circuit) may be spoofing the charger into believing
that it's connected to a fully charged battery and causes
it to drop into the MAINTENANCE mode where the 12.9 volt
level you cited is quite acceptable.
A smart-charger is a crafty little bugger that takes
a bit more than a one-time voltmeter check to deduce
its capabilities. Adjusting them for a MAINTENANCE level
of 13.8 volts would be contrary to the design goals
for a true battery maintainer.
Bob . . .
________________________________________________________________________________
From: | "Andrew Butler" <andrewbutler(at)ireland.com> |
Subject: | Re: S704-1 Relay Question |
All I ever wanted to know about that particular component on the
Z-figures and then some.
I very much appreciate this valuable resource (all things Aeroelectric)
and your attention to detail Bob. I wired up my first harness last
weekend and attached it to my TruTrak servo. I did so with a relative
amount of confidence in what I was doing, how I was doing it, why I was
doing it and how I would continue doing it for the rest of the electrical
system. Fantastic!
Without this resource, I can honestly say that I would have been groping
in the dark ending up with a low quality piecemeal whole rather than a
high quality coherent one.
Very many thanks for this and for the answers to my future questions.
Andrew.
----- Original Message -----
From: "Robert L. Nuckolls, III"
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
Date: Tue, 20 May 2008 09:06:38 -0500
> Okay, I've read the Wikipedia and aeroelectric articles. So far so
good.
>
> So, in the absence of the diode, where is the "arc" likely to
occur? If I have understood
> correctly I'm saying at the E-BUS feed switch rather than at the
switch in the relay. Am I
> correct?
>
> If not, why does the arc occur at the relay switch and not the feed
switch. It has to do with
> the current flow path.........
>
> Thanks for your help.
>
> Andrew.
Not sure what you're calling the "feed switch". With
respect to contactors and relays, there is potential for
effects of field collapse in an inductor to erode
the contacts of the device that controls that contactor
or relay. Hence, the long standing practice of adding
spike suppression across the coils of such devices as
illustrated in the Z-figures.
Now, ANY time you break a circuit with the opening
of hard contacts as in a switch, relay or contactor
(that is carrying any amount of current at any voltage)
there WILL be an arc formed in spreading gap between
opening contacts. There was a school of thought circulated
in the OBAM aircraft community a few years ago that
for voltages and/or currents below some low level
(I don't recall the numbers now) that no arcing would
occur.
So as an experiment, I took a miniature switch and
sanded out the side of it like this:
http://aeroelectric.com/Pictures/Switches/sm_switch_cutaway.jpg
I fixtured it under the microscope and caused the
NO contacts to carry 1 or 1/2 amp of current at 1.5
volts (alkaline d-cell). In a dark room I could clearly
observe a tiny but bright blue arc in the spreading
gap between the contacts when the circuit was broken.
THIS ARCING IS NOT the phenomenon of concern with
respect to noise or debilitating effects on controlling
or controlled devices. Hence we rarely see arc suppression
techniques applied to these effects. One exception
is the quest for achieving the Beech Aircraft ov relay
trip-life using relays some 30+ years ago as described
in the chapter on OV Protection in the 'Connection.
There is also a school of thought that suggests plain
vanilla diodes across relay and contactor coils will
cause a slowing of contact spreading velocity and is
therefore an inducement to prolonged arcing at the
opening contacts.
Experiments on my bench showed that while adding a
diode did indeed cause a DELAY IN OPENING of the
contacts . . .
http://www.aeroelectric.com/Pictures/Curves/704-1DelayNoDiode.gif
http://www.aeroelectric.com/Pictures/Curves/704-1DelayWithDiode.gif
. . . use of the plain vanilla diode produced no
significant slowing of contact spreading velocity
once they started to move.
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gif
In any case, the arcing produced either at controlling
switches -OR- contacts of the controlled devices IS
NOT a widespread threat for damage to other components
in the system. The strongest effect you'll experience
from the behavior of an unsuppressed relay or contactor
coil is a transient interference event. A few years ago
I helped a builder track down why opening his avionics
bus relay on an off-the-shelf integrated power distribution
system caused his ov protection to trip. A diode
across the relay coil fixed the problem.
Bob . . .
===========
===========
===========
===========
________________________________________________________________________________
Subject: | Re: S704-1 Relay Question |
Great thread...
In our world it seems like we take relays for granted. They are amazing
gadgets and I wanted to find more information on them. Below is a great
link with detail on the very popular Bosch relay. It should be very
clear as to their great benefit. There is no reason to stress a switch
with a few of these in-line.
http://www.bcae1.com/relays.htm#demo
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Andrew Butler
Sent: Tuesday, May 20, 2008 10:45 AM
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Re: S704-1 Relay Question
All I ever wanted to know about that particular component on the
Z-figures and then some.
I very much appreciate this valuable resource (all things
Aeroelectric) and your attention to detail Bob. I wired up my first
harness last weekend and attached it to my TruTrak servo. I did so with
a relative amount of confidence in what I was doing, how I was doing it,
why I was doing it and how I would continue doing it for the rest of the
electrical system. Fantastic!
Without this resource, I can honestly say that I would have been
groping in the dark ending up with a low quality piecemeal whole rather
than a high quality coherent one.
Very many thanks for this and for the answers to my future
questions. Andrew.
----- Original Message -----
From: "Robert L. Nuckolls, III"
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Re: S704-1 Relay
Question
Date: Tue, 20 May 2008 09:06:38 -0500
Nuckolls, III"
> Okay, I've read the Wikipedia and aeroelectric
articles. So far so good.
>
> So, in the absence of the diode, where is the "arc"
likely to occur? If I have understood
> correctly I'm saying at the E-BUS feed switch rather
than at the switch in the relay. Am I
> correct?
>
> If not, why does the arc occur at the relay switch and
not the feed switch. It has to do with
> the current flow path.........
>
> Thanks for your help.
>
> Andrew.
Not sure what you're calling the "feed switch". With
respect to contactors and relays, there is potential for
effects of field collapse in an inductor to erode
the contacts of the device that controls that contactor
or relay. Hence, the long standing practice of adding
spike suppression across the coils of such devices as
illustrated in the Z-figures.
Now, ANY time you break a circuit with the opening
of hard contacts as in a switch, relay or contactor
(that is carrying any amount of current at any voltage)
there WILL be an arc formed in spreading gap between
opening contacts. There was a school of thought
circulated
in the OBAM aircraft community a few years ago that
for voltages and/or currents below some low level
(I don't recall the numbers now) that no arcing would
occur.
So as an experiment, I took a miniature switch and
sanded out the side of it like this:
http://aeroelectric.com/Pictures/Switches/sm_switch_cutaway.jpg
I fixtured it under the microscope and caused the
NO contacts to carry 1 or 1/2 amp of current at 1.5
volts (alkaline d-cell). In a dark room I could clearly
observe a tiny but bright blue arc in the spreading
gap between the contacts when the circuit was broken.
THIS ARCING IS NOT the phenomenon of concern with
respect to noise or debilitating effects on controlling
or controlled devices. Hence we rarely see arc
suppression
techniques applied to these effects. One exception
is the quest for achieving the Beech Aircraft ov relay
trip-life using relays some 30+ years ago as described
in the chapter on OV Protection in the 'Connection.
There is also a school of thought that suggests plain
vanilla diodes across relay and contactor coils will
cause a slowing of contact spreading velocity and is
therefore an inducement to prolonged arcing at the
opening contacts.
Experiments on my bench showed that while adding a
diode did indeed cause a DELAY IN OPENING of the
contacts . . .
http://www.aeroelectric.com/Pictures/Curves/704-1DelayNoDiode.gif
http://www.aeroelectric.com/Pictures/Curves/704-1DelayWithDiode.gif
. . . use of the plain vanilla diode produced no
significant slowing of contact spreading velocity
once they started to move.
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gi
f
In any case, the arcing produced either at controlling
switches -OR- contacts of the controlled devices IS
NOT a widespread threat for damage to other components
in the system. The strongest effect you'll experience
from the behavior of an unsuppressed relay or contactor
coil is a transient interference event. A few years ago
I helped a builder track down why opening his avionics
bus relay on an off-the-shelf integrated power
distribution
system caused his ov protection to trip. A diode
across the relay coil fixed the problem.
Bob . . .
==========
==========
==========
==========
________________________________________________________________________________
From: | Les Kearney <kearney(at)shaw.ca> |
Subject: | Contactor Locations |
Bob
Thanks for the help. I read in the Aeroelectric Guide that the contactor
locations was not a big issue but wasn't sure how much flexibility I really
had.
A quick follow-up question: Will the electromagnets in the contactors be a
problem for any avionics. My Magnometers will be in the tail so that is not
a concern.
Cheers
Les
-----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: May-20-08 7:45 AM
Subject: Re: AeroElectric-List: Contactor Locations
>Hi
>
>
>I am trying to plan my RV10 electrical system and have a question for the
>electrical mavens. That is, how far from avionics should battery
>contactors be? I am looking at mounting my batteries in the sub panel area
>and would like to co locate the contactors in the same area. Access is not
>an issue but I am concerned about possible interference with the avionics.
>I may end up locating the starter contactor on the same area as well.
>Would this be a problem?
>
>
>Cheers
>
>
>Les Kearney
Contactors are not high level antagonists to other
components of the system. You mount contactors where
it makes the most sense for their function. Battery
contactors close to batteries, starter contactors
close to starters, ect. In some architectures, they
can be clustered together.
In any case, there are no characteristics of a
contactor that makes them a threat to anything
other than the switch that controls them. See:
http://www.aeroelectric.com/articles/spikecatcher.pdf
http://www.aeroelectric.com/articles/spike.pdf
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Contactor Locations |
>
>Bob
>
>Thanks for the help. I read in the Aeroelectric Guide that the contactor
>locations was not a big issue but wasn't sure how much flexibility I really
>had.
>
>A quick follow-up question: Will the electromagnets in the contactors be a
>problem for any avionics. My Magnometers will be in the tail so that is not
>a concern.
>
Magnetometers ARE a potential victim of stray magnetic
leakage from contactors but as a rule, if your magnetometer
is at least 3' away from a potential antagonist, you're
on solid ground. Another potential worry is stray field
from the SD-20 alternator. We had problems with interference
for a whisky compass mounted on the glare shield of
the A36 . . . but the problem went away when the compass
was moved upward about 10" onto the windshield.
The effects of a potential antagonist on a magnetic
navigation instrument is greatly attenuated by distance
. . . a few more inches separation can make a lot of
difference.
On heavy iron birds, we usually mount magnetometers
out in a wing just ahead of ailerons and use non-magnetic
stainless fasteners in the immediate vicinity.
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: S704-1 Relay Question |
>All I ever wanted to know about that particular component on the Z-figures
>and then some.
>
>I very much appreciate this valuable resource (all things Aeroelectric)
>and your attention to detail Bob. I wired up my first harness last weekend
>and attached it to my TruTrak servo. I did so with a relative amount of
>confidence in what I was doing, how I was doing it, why I was doing it and
>how I would continue doing it for the rest of the electrical system. Fantastic!
>
>Without this resource, I can honestly say that I would have been groping
>in the dark ending up with a low quality piecemeal whole rather than a
>high quality coherent one.
>
>Very many thanks for this and for the answers to my future questions. Andrew.
You're most welcome my friend. I'm pleased that you've
found the work so useful.
Bob . . .
________________________________________________________________________________
From: | "Chris" <toaster73(at)embarqmail.com> |
Subject: | Fuse and Breaker - one bus |
I have been lurking here for a few years trying to absorb the power of
aeroelectric but I am having trouble jumping from the schematics to the
physical configuration.
I am having trouble with the physical configuration of my RV-10 electrical
system design. I am trying to draw up a Z-13 style system but I think I
want my E-Bus to have a breaker for trim, flaps etc but the rest I want to
use a fuse block. What would be a good way to combine the fuse and breaker
block into one bus? Just run same gage wire to the e-bus primary and
alternate feed to the fuse block and split off from block with same gage
wire to the bar for the breakers?
thanks in advance
Chris Lucas
RV-10 #40072
________________________________________________________________________________
From: | "Gaye and Vaughn" <vaughnray(at)bvunet.net> |
Subject: | Re: Fuse and Breaker - one bus |
The fuse block is your endurance bus. I would run a wire to the fuse block
post that would handle the combined loads on the fuse block and the load on
your breaker bar. I would then run a wire from the post on the fuse block to
the breaker bar that was large enough to handle the combined loads of all
the breakers.
I once had an MGTF with Lucas electrics. Are you should be wiring? ;-)
Vaughn Teegarden
Trying to figure it out myself...Don't listen to me.
----- Original Message -----
From: "Chris" <toaster73(at)embarqmail.com>
Sent: Tuesday, May 20, 2008 9:16 AM
Subject: AeroElectric-List: Fuse and Breaker - one bus
>
>
> I have been lurking here for a few years trying to absorb the power of
> aeroelectric but I am having trouble jumping from the schematics to the
> physical configuration.
> I am having trouble with the physical configuration of my RV-10 electrical
> system design. I am trying to draw up a Z-13 style system but I think I
> want my E-Bus to have a breaker for trim, flaps etc but the rest I want to
> use a fuse block. What would be a good way to combine the fuse and
> breaker block into one bus? Just run same gage wire to the e-bus primary
> and alternate feed to the fuse block and split off from block with same
> gage wire to the bar for the breakers?
> thanks in advance
> Chris Lucas
> RV-10 #40072
>
>
>
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Fuse and Breaker - one bus |
>
>I have been lurking here for a few years trying to absorb the power of
>aeroelectric but I am having trouble jumping from the schematics to the
>physical configuration.
>I am having trouble with the physical configuration of my RV-10 electrical
>system design. I am trying to draw up a Z-13 style system but I think I
>want my E-Bus to have a breaker for trim, flaps etc but the rest I want to
>use a fuse block. What would be a good way to combine the fuse and
>breaker block into one bus? Just run same gage wire to the e-bus primary
>and alternate feed to the fuse block and split off from block with same
>gage wire to the bar for the breakers?
>thanks in advance
The e-bus is for things that you need during the en-route
mode of flight to maximize utilization of a limited resource.
If you're planning Z-13/8, then the e-bus can be easily
configured to handle an endurance load of 8 amps.
The idea is that when the airport is in sight that you
can bring the main bus back on for using the battery to
run anything on the main bus using a battery that's held
completely in reserve for approach to landing.
What's your rationale for breakers on these two systems?
Runaway disconnect? Breakers are exceedingly poor substitutes
for master disconnect systems . . . if indeed runaway is
a high order probability for creating a hazard. It's
probably easier to design a system that can't run away.
In other words, trim is an exceedingly low duty-cycle
load that runs happily from the e-bus . . . Flaps too
for that matter . . . but they aren't needed until approach
to landing and could stay on the main bus. I guess we
need to understand your concnerns.
Bob . . .
________________________________________________________________________________
Subject: | Coil Suppression Techniques. |
From: | "Eric M. Jones" <emjones(at)charter.net> |
I have this weird Deja Vu feeling that we have covered this subject before. And
I will save you the trouble Bob....I know you'll never agree, and you'll retort
with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION.
Coil suppression and relay contact arcing have been well studied: See:
http://relays.tycoelectronics.com/appnotes/
Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless
you're hoping for greatly reduced relay/contactor life, so you can get stuck
in a remote area and have an adventure. I know people like this but they
usually don't build airplanes. Gotta'-Have-Drama-Dammit!
Here's what sane people have figured out:
Mechanical relays and contactors depend upon magnetism generated by an electric
current running through a wire coil. When the current stops, the magnetic field
collapses. But the relay does not know the difference between a wire coil moving
in a magnetic field (as in a generator) or a magnetic field moving in a
wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V
typicallyis induced in the coil. This current goes the same direction the
original current didso it slows the contact openingallowing arcing, chatter, bouncing,
contact welding and even re-closure! Yikes!
The common palliative is a diode AND zener in series, or better yet, a bidirectional
zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs,
TransGuards, Mosorbs; the list is endless. (Over-paid executives dream
up these names.) They are generic P6KE18CA bidirectional zeners.
Jeeeeeze........
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184184#184184
Attachments:
http://forums.matronics.com//files/snapjack_101.pdf
http://forums.matronics.com//files/snapjack_182.pdf
________________________________________________________________________________
From: | "sam(at)fr8dog.net" <sam.marlow(at)adelphia.net> |
Subject: | Re: Coil Suppression Techniques. |
So Eric, do I just order a P6KE18CA, from Radio Shack, or do I need a specific
Voltage rating for my relays on my 12v homebuilt?
Sam
---- "Eric M. Jones" wrote:
============
I have this weird Deja Vu feeling that we have covered this subject before. And
I will save you the trouble Bob....I know you'll never agree, and you'll retort
with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION.
Coil suppression and relay contact arcing have been well studied: See:
http://relays.tycoelectronics.com/appnotes/
Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless
you're hoping for greatly reduced relay/contactor life, so you can get stuck
in a remote area and have an adventure. I know people like this but they
usually don't build airplanes. Gotta'-Have-Drama-Dammit!
Here's what sane people have figured out:
Mechanical relays and contactors depend upon magnetism generated by an electric
current running through a wire coil. When the current stops, the magnetic field
collapses. But the relay does not know the difference between a wire coil moving
in a magnetic field (as in a generator) or a magnetic field moving in a
wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V
typicallyis induced in the coil. This current goes the same direction the
original current didso it slows the contact openingallowing arcing, chatter, bouncing,
contact welding and even re-closure! Yikes!
The common palliative is a diode AND zener in series, or better yet, a bidirectional
zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs,
TransGuards, Mosorbs; the list is endless. (Over-paid executives dream
up these names.) They are generic P6KE18CA bidirectional zeners.
Jeeeeeze........
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184184#184184
Attachments:
http://forums.matronics.com//files/snapjack_101.pdf
http://forums.matronics.com//files/snapjack_182.pdf
________________________________________________________________________________
From: | "John Cleary" <john_rv10(at)yahoo.com> |
Subject: | Coil Suppression Techniques |
Eric,
Thank you for this contribution.
I am planning to use a relay to switch power to my avionics/endurance busses. Normal
loads at switch on/turn off would be in the order of 10 amps at 12 volts.
What relay would you recommend and would you draw a simple diagram for a non
electrical person showing how and where to wire the P6KE18CA bidirectional zener?
Thanks once again,
John
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of sam(at)fr8dog.net
Sent: Thursday, 22 May 2008 5:43 AM
Subject: Re: AeroElectric-List: Coil Suppression Techniques - use generic P6KE18CA
bidirectional zener
So Eric, do I just order a P6KE18CA, from Radio Shack, or do I need a specific
Voltage rating for my relays on my 12v homebuilt?
Sam
---- "Eric M. Jones" wrote:
============
I have this weird Deja Vu feeling that we have covered this subject before. And
I will save you the trouble Bob....I know you'll never agree, and you'll retort
with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION.
Coil suppression and relay contact arcing have been well studied: See:
http://relays.tycoelectronics.com/appnotes/
Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless
you're hoping for greatly reduced relay/contactor life, so you can get stuck
in a remote area and have an adventure. I know people like this but they
usually don't build airplanes. Gotta'-Have-Drama-Dammit!
Here's what sane people have figured out:
Mechanical relays and contactors depend upon magnetism generated by an electric
current running through a wire coil. When the current stops, the magnetic field
collapses. But the relay does not know the difference between a wire coil moving
in a magnetic field (as in a generator) or a magnetic field moving in a
wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V
typicallyis induced in the coil. This current goes the same direction the
original current didso it slows the contact openingallowing arcing, chatter, bouncing,
contact welding and even re-closure! Yikes!
The common palliative is a diode AND zener in series, or better yet, a bidirectional
zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs,
TransGuards, Mosorbs; the list is endless. (Over-paid executives dream
up these names.) They are generic P6KE18CA bidirectional zeners.
Jeeeeeze........
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184184#184184
Attachments:
http://forums.matronics.com//files/snapjack_101.pdf
http://forums.matronics.com//files/snapjack_182.pdf
Checked by AVG.
Checked by AVG.
________________________________________________________________________________
Subject: | Coil Suppression Techniques. |
So are we saying that people who market and sell relays bragging about 240,000
life clicks are full of mumbo jumbo? I know Radio Shack is. Should we buy a 40A
relay to run a 30 A load and prolong the life of the switch? Jeeze, they're
only a $1 more.
Are we worried about something that will only be used for the life of the airplane?
Ok, in reality I only turn the headlight on say, 100 times / year. That's
probably 30 times more than average. At that rate I'll be long dead before I
achieve 240k clicks.
Radio Shack sells a lot of diodes to people who assume they provide feedback suppression.
My BMW has an awful lot of Bosch relays that have never worn out. What are they
doing to ensure long life? I crank up the headlights, horn etc in my car 10 X
more than anything I do in the airplane.
At $6 a piece I can carry a few into the backwoods.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of sam(at)fr8dog.net
Sent: Wednesday, May 21, 2008 3:43 PM
Subject: Re: AeroElectric-List: Coil Suppression Techniques.
-->
So Eric, do I just order a P6KE18CA, from Radio Shack, or do I need a specific
Voltage rating for my relays on my 12v homebuilt? Sam
---- "Eric M. Jones" wrote:
============
-->
I have this weird Deja Vu feeling that we have covered this subject before. And
I will save you the trouble Bob....I know you'll never agree, and you'll retort
with a long quasi-techno piece and then stumble TO EXACTLY THE WRONG CONCLUSION.
Coil suppression and relay contact arcing have been well studied: See:
http://relays.tycoelectronics.com/appnotes/
Basically (ESPECIALLY with contactors) Do not use diodes for coil suppression unless
you're hoping for greatly reduced relay/contactor life, so you can get stuck
in a remote area and have an adventure. I know people like this but they
usually don't build airplanes. Gotta'-Have-Drama-Dammit!
Here's what sane people have figured out:
Mechanical relays and contactors depend upon magnetism generated by an electric
current running through a wire coil. When the current stops, the magnetic field
collapses. But the relay does not know the difference between a wire coil moving
in a magnetic field (as in a generator) or a magnetic field moving in a
wire coil (as in a collapsing magnetic field). Thus a large voltage1000V to 1500V
typicallyis induced in the coil. This current goes the same direction the
original current didso it slows the contact openingallowing arcing, chatter, bouncing,
contact welding and even re-closure! Yikes!
The common palliative is a diode AND zener in series, or better yet, a bidirectional
zener across the coil. They call these Transils, Surmetics, Transorbs, TranZorbs,
TransGuards, Mosorbs; the list is endless. (Over-paid executives dream
up these names.) They are generic P6KE18CA bidirectional zeners.
Jeeeeeze........
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184184#184184
Attachments:
http://forums.matronics.com//files/snapjack_101.pdf
http://forums.matronics.com//files/snapjack_182.pdf
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Coil Suppression Techniques. |
>
>I have this weird Deja Vu feeling that we have covered this subject
>before. And I will save you the trouble Bob....I know you'll never agree,
>and you'll retort with a long quasi-techno piece and then stumble TO
>EXACTLY THE WRONG CONCLUSION.
>
>Coil suppression and relay contact arcing have been well studied: See:
>http://relays.tycoelectronics.com/appnotes/
>
>Basically (ESPECIALLY with contactors) Do not use diodes for coil
>suppression unless you're hoping for greatly reduced relay/contactor life,
>so you can get stuck in a remote area and have an adventure. I know people
>like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit!
You've cited that document before. And I've
read it several times both before you cited it
and after you cited it.
Kindly point out to me where the authors offer DATA
supporting an assertion that the plain vanilla
diode coil suppression has a profound effect on relay life.
They correctly asserted and I confirmed that
diodes do indeed extend the time from switch
opening until energized contacts begin to move.
This is opening delay. They went on to extrapolate
that opening delay translates directly into slower
contact spreading velocity and extrapolated further
that this translated to increased contact wear.
I did the experiments and published the results
that argue against their extrapolations. If you
have some data to the contrary, please share it
with us.
Just because you've read some words under the
letter head and over the signatures of persons
in high places does not make their words golden
unless they're supported by data from and
understanding of repeatable experiments.
>Here's what sane people have figured out:
. . . are you suggesting I am less than sane??
>Mechanical relays and contactors depend upon magnetism generated by an
>electric current running through a wire coil. When the current stops, the
>magnetic field collapses. But the relay does not know the difference
>between a wire coil moving in a magnetic field (as in a generator) or a
>magnetic field moving in a wire coil (as in a collapsing magnetic field).
>Thus a large voltage1000V to 1500V typicallyis induced in the coil.
>This current goes the same direction the original current didso it
>slows the contact openingallowing arcing, chatter, bouncing, contact
>welding and even re-closure! Yikes!
Go to your workbench, measure it, document
it and share it with us. Show me where my
data and interpretation of my data is wrong.
The important feature of relay and contactor
operation that you're overlooking is the extreme
relationship between magnetic force and air-gap.
Air is an exceedingly poor conductor of magnetic
lines of force. So while a diode does indeed slow
the rate of drop in coil current (hence increased
delay) once the armature comes unstuck from its
seated condition, the effect of increasing
air-gap is many times more influential than rate
of decay in coil current.
Went back to the workbench to look at the S704-1 in
more detail. Here's the test setup:
http://aeroelectric.com/Pictures/Schematics/Relay_Test_Setup.pdf
Relay response with no coil suppression looks
like this:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_without_Diode.jpg
where we see the high voltage spike on the coil
trace and a 2.5 mS dropout delay.
WITH a coil suppression diode, we get
relay response like this:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_with_Diode.jpg
Dropout Delay is increased to 12.5 mS or about 5x
longer than with the diode. This was the feature
pointed out in the article you cited . . . where
the authors extrapolated this into a commensurate
slowing in contact spreading velocity (longer fires).
However, when we take the diode off and look at
transition time . . .
http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_NoSuppression.jpg
From the time the contacts FIRST open until they
first contact the opposite side is 0.6 mS. Let's
put the diode back on and we get . . .
http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_Diode_Suppression.jpg
Hmmm . . . transition increases to 0.75 mS, about
a 25% increase NOT A 500% INCREASE.
Let's go back an look at the traces I took where
we were observing the arc in a spreading set of
contacts with no diode . . .
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif
Here I could see about 0.21 mS of "fire" as compared
with . . .
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif
about 0.23 mS arcing when the diode was in place. Hmmm,
there was an increase but not a very big one. In both
cases, observed arcing times were about 1/3 the total
transition time.
Now let us consider another feature of relays and contactors
that REALLY drives service life issues. Take a look at:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_with_Diode.jpg
Where we see that after the first time the contacts
touch, really get with the high-tempo hat-dance
for perhaps several dozen closure and re-opening
events. This means that for every operation of the
switch on the panel, the contacts are getting
5-25 times more activity than the single switching
event might suggest. Now look at:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_without_Diode.jpg
Well fooey . . . even with the diode off the contacts
do the cat-on-a-hot-tin-roof routine.
Let us further consider that when folks like those Tyco
engineers evaluate service life, they're working in
the laboratory test environment and evaluating products
where service life is measured in the tens of thousands
of operations . . . 50,000 typical. 250,000 is not
unusual. Let us suppose that their paper was based on
real statistical studies of dozens of relays with
various coil suppression techniques and yes, there
was an observable increase in mean operations between
failures from 45,744 to 49,666 by "optimizing" the
coil suppression. Hmmm . . . 10% . . . that IS significant
to Tyco and probabably most of their customers.
They didn't speak to this kind of study in the paper
you cited and I'd like to believe they've done their
homework.
Let us assume their undocumented assertions
WERE correct on the scale I suggested. How does this
affect the OBAM aircraft builder who's switches,
relays and contactors probably won't see 5,000
operations over the lifetime of the airplane?
Further, environmental stresses will be root cause
for most replacements of such devices in personally owned,
non-revenue generating light aircraft, not electrical
stresses. In any case, the 5x increase in drop-out delay
DOES NOT extrapolate into a proportionate drop in contact
life.
>The common palliative is a diode AND zener in series, or better yet, a
>bidirectional zener across the coil. They call these Transils,
>Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the
>list is endless. (Over-paid executives dream up these names.) They are
>generic P6KE18CA bidirectional zeners.
>
>Jeeeeeze........
Eric,
Of all the contributors to this list I expect
more of you. We had some substantive discussions
on the inner technical workings of various products
and ideas in Plymouth a couple of years ago. You
struck me as one who appreciates understanding
and having a handle on the simple-ideas that go
into your recipes for success.
Please don't wave anyone's documents in the air as
justification for an extrapolation of my infirmities.
Let's not make this about you or me. May I suggest
we explore, understand and then explain the
physics. Make my day. Show me were I'm wrong.
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Coil Suppression Techniques (With Corrected Link) |
I have this weird Deja Vu feeling that we have covered this subject before.
And I will save you the trouble Bob....I know you'll never agree, and
you'll retort with a long quasi-techno piece and then stumble TO EXACTLY
THE WRONG CONCLUSION.
Coil suppression and relay contact arcing have been well studied: See:
http://relays.tycoelectronics.com/appnotes/
Basically (ESPECIALLY with contactors) Do not use diodes for coil
suppression unless you're hoping for greatly reduced relay/contactor life,
so you can get stuck in a remote area and have an adventure. I know people
like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit!
You've cited that document before. And I've
read it several times both before you cited it
and after you cited it.
Kindly point out to me where the authors offer DATA
supporting an assertion that the plain vanilla
diode coil suppression has a profound effect on relay life.
They correctly asserted and I confirmed that
diodes do indeed extend the time from switch
opening until energized contacts begin to move.
This is opening delay. They went on to extrapolate
that opening delay translates directly into slower
contact spreading velocity and extrapolated further
that this translated to increased contact wear.
I did the experiments and published the results
that argue against their extrapolations. If you
have some data to the contrary, please share it
with us.
Just because you've read some words under the
letter head and over the signatures of persons
in high places does not make their words golden
unless they're supported by data from and
understanding of repeatable experiments.
Here's what sane people have figured out:
. . . are you suggesting I am less than sane??
Mechanical relays and contactors depend upon magnetism generated by an
electric current running through a wire coil. When the current stops, the
magnetic field collapses. But the relay does not know the difference
between a wire coil moving in a magnetic field (as in a generator) or a
magnetic field moving in a wire coil (as in a collapsing magnetic field).
Thus a large voltage1000V to 1500V typicallyis induced in the coil.
This current goes the same direction the original current didso it slows
the contact openingallowing arcing, chatter, bouncing, contact welding
and even re-closure! Yikes!
Go to your workbench, measure it, document
it and share it with us. Show me where my
data and interpretation of my data is wrong.
The important feature of relay and contactor
operation that you're overlooking is the extreme
relationship between magnetic force and air-gap.
Air is an exceedingly poor conductor of magnetic
lines of force. So while a diode does indeed slow
the rate of drop in coil current (hence increased
delay) once the armature comes unstuck from its
seated condition, the effect of increasing
air-gap is many times more influential than rate
of decay in coil current.
Went back to the workbench to look at the S704-1 in
more detail. Here's the test setup:
http://aeroelectric.com/Pictures/Schematics/Relay_Test_Setup.pdf
Relay response with no coil suppression looks
like this:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_without_Diode.jpg
where we see the high voltage spike on the coil
trace and a 2.5 mS dropout delay.
WITH a coil suppression diode, we get
relay response like this:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_with_Diode.jpg
Dropout Delay is increased to 12.5 mS or about 5x
longer than with the diode. This was the feature
pointed out in the article you cited . . . where
the authors extrapolated this into a commensurate
slowing in contact spreading velocity (longer fires).
However, when we take the diode off and look at
transition time . . .
http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_NoSuppression.jpg
From the time the contacts FIRST open until they
first contact the opposite side is 0.6 mS. Let's
put the diode back on and we get . . .
http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_Diode_Suppression.jpg
Hmmm . . . transition increases to 0.75 mS, about
a 25% increase NOT A 500% INCREASE.
Let's go back an look at the traces I took where
we were observing the arc in a spreading set of
contacts with no diode . . .
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif
Here I could see about 0.21 mS of "fire" as compared
with . . .
(Here's the right trace)
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gif
about 0.23 mS arcing when the diode was in place. Hmmm,
there was an increase but not a very big one. In both
cases, observed arcing times were about 1/3 the total
transition time.
Now let us consider another feature of relays and contactors
that REALLY drives service life issues. Take a look at:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_with_Diode.jpg
Where we see that after the first time the contacts
touch, really get with the high-tempo hat-dance
for perhaps several dozen closure and re-opening
events. This means that for every operation of the
switch on the panel, the contacts are getting
5-25 times more activity than the single switching
event might suggest. Now look at:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_without_Diode.jpg
Well fooey . . . even with the diode off the contacts
do the cat-on-a-hot-tin-roof routine.
Let us further consider that when folks like those Tyco
engineers evaluate service life, they're working in
the laboratory test environment and evaluating products
where service life is measured in the tens of thousands
of operations . . . 50,000 typical. 250,000 is not
unusual. Let us suppose that their paper was based on
real statistical studies of dozens of relays with
various coil suppression techniques and yes, there
was an observable increase in mean operations between
failures from 45,744 to 49,666 by "optimizing" the
coil suppression. Hmmm . . . 10% . . . that IS significant
to Tyco and probabably most of their customers.
They didn't speak to this kind of study in the paper
you cited and I'd like to believe they've done their
homework.
Let us assume their undocumented assertions
WERE correct on the scale I suggested. How does this
affect the OBAM aircraft builder who's switches,
relays and contactors probably won't see 5,000
operations over the lifetime of the airplane?
Further, environmental stresses will be root cause
for most replacements of such devices in personally owned,
non-revenue generating light aircraft, not electrical
stresses. In any case, the 5x increase in drop-out delay
DOES NOT extrapolate into a proportionate drop in contact
life.
The common palliative is a diode AND zener in series, or better yet, a
bidirectional zener across the coil. They call these Transils,
Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the
list is endless. (Over-paid executives dream up these names.) They are
generic P6KE18CA bidirectional zeners.
Jeeeeeze........
Eric,
Of all the contributors to this list I expect
more of you. We had some substantive discussions
on the inner technical workings of various products
and ideas in Plymouth a couple of years ago. You
struck me as one who appreciates understanding
and having a handle on the simple-ideas that go
into your recipes for success.
Please don't wave anyone's documents in the air as
justification for an extrapolation of my infirmities.
Let's not make this about you or me. May I suggest
we explore, understand and then explain the
physics. Make my day. Show me were I'm wrong.
Bob . . .
--
Date: 5/20/2008 4:45 PM
incoming mail is certified Virus Free.
Checked by AVG.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
Subject: | Re: Coil Suppression Techniques. |
From: | "Eric M. Jones" <emjones(at)charter.net> |
Sam,
P6KE18CA is 0.6kW 18V contained in the part number. Digikey has them. I
wouldn't ever buy airplane parts from Radio Shack. They use fallouts, defects,
out of tolerance, rejects, mismarked, etc. The last parts I got from them went
right into the trash can. This is another issue Bob and I always disagree on.
Or you can buy mine...."SnapJacks". I include free shipping, a handful of
Fastons, insulating tubing, etc. But whatever you do, just don't use diodes
(especially on CONTACTORS). If you REALLY don't want to use bidirectional zeners,
then use the several other recommended methods better than the diode.
Eric
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184277#184277
________________________________________________________________________________
From: | "sam(at)fr8dog.net" <sam.marlow(at)adelphia.net> |
Subject: | Re: Coil Suppression Techniques. |
Should I just use a diode in series with the snapjack, is it that simple? What
about sizing the components?
Thanks,
Sam
---- "Eric M. Jones" wrote:
============
Sam,
P6KE18CA is 0.6kW 18V contained in the part number. Digikey has them. I
wouldn't ever buy airplane parts from Radio Shack. They use fallouts, defects,
out of tolerance, rejects, mismarked, etc. The last parts I got from them went
right into the trash can. This is another issue Bob and I always disagree on.
Or you can buy mine...."SnapJacks". I include free shipping, a handful of
Fastons, insulating tubing, etc. But whatever you do, just don't use diodes
(especially on CONTACTORS). If you REALLY don't want to use bidirectional zeners,
then use the several other recommended methods better than the diode.
Eric
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184277#184277
________________________________________________________________________________
Subject: | Coil Suppression Techniques |
From: | <max.johansson(at)nokia.com> |
Eric
This seems to be a well studied subject and after studying your results
the method of parallelling a relay or contactor with an opposite
direction diode seems to be the quick and dirty but still quite adequate
method for the homebuilder.
Now a very practical question:
Is a 0.1 dollar 1N4001...4004 or similar diode strong enough to handle
the collapsing energy of any relay or contactor used in a homebuilt ?
best regards
Max
(just now wiring my 701 starter circuit)
________________________________________________________________________________
Subject: | Re: Coil Suppression Techniques |
From: | "jetboy" <sanson.r(at)xtra.co.nz> |
Max,
1N5404 thru -8 series should do well with much more margin. I fitted one to the
master solenoid on a Cessna150 once because the A&P in their collective wisdom
neglected that small part as depicted it the Cessna parts book when replacing
the old solenoid and damaged my master switch.
My CH701 has a diode installed as required by the ACS ignition/start switch instructions
and I think this one may have come with the switch.
Ralph
--------
Ralph - CH701 / 2200a
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184325#184325
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Coil Suppression Techniques |
>Eric
>
>This seems to be a well studied subject and after studying your results
>the method of parallelling a relay or contactor with an opposite direction
>diode seems to be the quick and dirty but still quite adequate method for
>the homebuilder.
>
>Now a very practical question:
>
>Is a 0.1 dollar 1N4001...4004 or similar diode strong enough to handle the
>collapsing energy of any relay or contactor used in a homebuilt
Yes. Electrically the 1A diode is fine for about everything
on the airplane. Recall that in the realm of reactive devices
that store energy, the discharge begins at the same magnitude
as the charging source. If you charge a capacitor to 100 volts, you
get a reaction that starts at 100v and goes down from there
when you discharge it.
If you charge and inductor up to 1A, then when you release
it from the charging source, the delivered reaction starts
a 1A and goes down from there. Diodes have a steady state
capability which is exemplified in their ratings . . . I.e,
the 1N4001 is a 1A device. However, they also have transient
ratings at much higher currents. For example, consulting the
1N400x data sheet at:
http://aeroelectric.com/Mfgr_Data/Semiconductors/1N4001.pdf
we read about an 8.3 mS non repetitive peak forward surge
current rating of 30A. By "non-repeating", they don't
mean "one time ever" but "just don't do this often." So as
a transient current clamp on a manually operated contactor
found in our airplanes the 1N400x series devices are
electrically fine.
However, I have often suggested that the larger siblings
to the 1N400x (1N540x) devices have some mechanical
advantages. They're still small but MUCH more robust
than the little fellers. I selected these parts as
power steering and coil suppressors of choice for the
line of contactors I used to sell (which B&C still
does). See:
http://www.aeroelectric.com/Pictures/Contactors/s701-1l.jpg
http://www.aeroelectric.com/Pictures/Contactors/s701-2.jpg
The red PIDG terminal gets a good connection on
the larger wires for these devices and the wires
are robust enough to support the diode body under
vibration levels typical of installations for
these contactors.
Radio Shack offers both sizes of diode:
http://aeroelectric.com/Pictures/Misc/RS_Diodes.jpg
Since a prohibition against Radio Shack parts has
been suggested, I'll share an observation that there
were times in the history of many suppliers of consumer/
experimenter parts where their offerings included
industrial surplus parts of unknown but not necessarily
evil pedigree. This includes a now premier supplier
of goods (Digikey) who started out as a mail
order supplier of industrial surplus that advertised
in ham radio and experimenter electronics magazines.
RS still handles experimenter's assortments of components
that are reminiscent of "grab bags" offered in years
gone by . . .
http://tinyurl.com/5jhbu6
http://tinyurl.com/42jn9v
. . . but these days, when you are responsible for
managing inventory in thousands of stores, millions
of catalogs, and a really big website, you don't
spend time scrounging the back alleys of industrial
trash cans looking for "floor sweepings".
These components are so cheap that it simply doesn't
pay to spend the time to salvage and then inventory
less than factory-fresh components.
The times they are a changing.
As a final note, this thread is not intended to
discourage anyone from using more sophisticated
transient control techniques if that process rings
their chimes. Information provided here is offered
as a prophylactic against decision making based
on poorly interpreted data, marketing hype, or sage
advice from those who would disseminate but will not
or cannot also teach.
Bob . . .
________________________________________________________________________________
From: | "bob noffs" <icubob(at)newnorth.net> |
i believe b and c supplies a diode when you order a solenoid.
bob noffs
________________________________________________________________________________
From: | "John Cleary" <john_rv10(at)yahoo.com> |
Subject: | Re: Coil Suppression Techniques (With Corrected |
Link)
Great data Bob.
Thanks,
John
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III
Sent: Thursday, 22 May 2008 9:50 AM
Subject: AeroElectric-List: Re: Coil Suppression Techniques (With Corrected Link)
I have this weird Deja Vu feeling that we have covered this subject before.
And I will save you the trouble Bob....I know you'll never agree, and
you'll retort with a long quasi-techno piece and then stumble TO EXACTLY
THE WRONG CONCLUSION.
Coil suppression and relay contact arcing have been well studied: See:
http://relays.tycoelectronics.com/appnotes/
Basically (ESPECIALLY with contactors) Do not use diodes for coil
suppression unless you're hoping for greatly reduced relay/contactor life,
so you can get stuck in a remote area and have an adventure. I know people
like this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit!
You've cited that document before. And I've
read it several times both before you cited it
and after you cited it.
Kindly point out to me where the authors offer DATA
supporting an assertion that the plain vanilla
diode coil suppression has a profound effect on relay life.
They correctly asserted and I confirmed that
diodes do indeed extend the time from switch
opening until energized contacts begin to move.
This is opening delay. They went on to extrapolate
that opening delay translates directly into slower
contact spreading velocity and extrapolated further
that this translated to increased contact wear.
I did the experiments and published the results
that argue against their extrapolations. If you
have some data to the contrary, please share it
with us.
Just because you've read some words under the
letter head and over the signatures of persons
in high places does not make their words golden
unless they're supported by data from and
understanding of repeatable experiments.
Here's what sane people have figured out:
. . . are you suggesting I am less than sane??
Mechanical relays and contactors depend upon magnetism generated by an
electric current running through a wire coil. When the current stops, the
magnetic field collapses. But the relay does not know the difference
between a wire coil moving in a magnetic field (as in a generator) or a
magnetic field moving in a wire coil (as in a collapsing magnetic field).
Thus a large voltage1000V to 1500V typicallyis induced in the coil.
This current goes the same direction the original current didso it slows
the contact openingallowing arcing, chatter, bouncing, contact welding
and even re-closure! Yikes!
Go to your workbench, measure it, document
it and share it with us. Show me where my
data and interpretation of my data is wrong.
The important feature of relay and contactor
operation that you're overlooking is the extreme
relationship between magnetic force and air-gap.
Air is an exceedingly poor conductor of magnetic
lines of force. So while a diode does indeed slow
the rate of drop in coil current (hence increased
delay) once the armature comes unstuck from its
seated condition, the effect of increasing
air-gap is many times more influential than rate
of decay in coil current.
Went back to the workbench to look at the S704-1 in
more detail. Here's the test setup:
http://aeroelectric.com/Pictures/Schematics/Relay_Test_Setup.pdf
Relay response with no coil suppression looks
like this:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_without_Diode.jpg
where we see the high voltage spike on the coil
trace and a 2.5 mS dropout delay.
WITH a coil suppression diode, we get
relay response like this:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_with_Diode.jpg
Dropout Delay is increased to 12.5 mS or about 5x
longer than with the diode. This was the feature
pointed out in the article you cited . . . where
the authors extrapolated this into a commensurate
slowing in contact spreading velocity (longer fires).
However, when we take the diode off and look at
transition time . . .
http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_NoSuppression.jpg
From the time the contacts FIRST open until they
first contact the opposite side is 0.6 mS. Let's
put the diode back on and we get . . .
http://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_Diode_Suppression.jpg
Hmmm . . . transition increases to 0.75 mS, about
a 25% increase NOT A 500% INCREASE.
Let's go back an look at the traces I took where
we were observing the arc in a spreading set of
contacts with no diode . . .
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif
Here I could see about 0.21 mS of "fire" as compared
with . . .
(Here's the right trace)
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeWithDiode.gif
about 0.23 mS arcing when the diode was in place. Hmmm,
there was an increase but not a very big one. In both
cases, observed arcing times were about 1/3 the total
transition time.
Now let us consider another feature of relays and contactors
that REALLY drives service life issues. Take a look at:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_with_Diode.jpg
Where we see that after the first time the contacts
touch, really get with the high-tempo hat-dance
for perhaps several dozen closure and re-opening
events. This means that for every operation of the
switch on the panel, the contacts are getting
5-25 times more activity than the single switching
event might suggest. Now look at:
http://www.aeroelectric.com/Pictures/Curves/S704-1_Contact_Bounce_without_Diode.jpg
Well fooey . . . even with the diode off the contacts
do the cat-on-a-hot-tin-roof routine.
Let us further consider that when folks like those Tyco
engineers evaluate service life, they're working in
the laboratory test environment and evaluating products
where service life is measured in the tens of thousands
of operations . . . 50,000 typical. 250,000 is not
unusual. Let us suppose that their paper was based on
real statistical studies of dozens of relays with
various coil suppression techniques and yes, there
was an observable increase in mean operations between
failures from 45,744 to 49,666 by "optimizing" the
coil suppression. Hmmm . . . 10% . . . that IS significant
to Tyco and probabably most of their customers.
They didn't speak to this kind of study in the paper
you cited and I'd like to believe they've done their
homework.
Let us assume their undocumented assertions
WERE correct on the scale I suggested. How does this
affect the OBAM aircraft builder who's switches,
relays and contactors probably won't see 5,000
operations over the lifetime of the airplane?
Further, environmental stresses will be root cause
for most replacements of such devices in personally owned,
non-revenue generating light aircraft, not electrical
stresses. In any case, the 5x increase in drop-out delay
DOES NOT extrapolate into a proportionate drop in contact
life.
The common palliative is a diode AND zener in series, or better yet, a
bidirectional zener across the coil. They call these Transils,
Surmetics, Transorbs, TranZorbs, TransGuards, Mosorbs; the
list is endless. (Over-paid executives dream up these names.) They are
generic P6KE18CA bidirectional zeners.
Jeeeeeze........
Eric,
Of all the contributors to this list I expect
more of you. We had some substantive discussions
on the inner technical workings of various products
and ideas in Plymouth a couple of years ago. You
struck me as one who appreciates understanding
and having a handle on the simple-ideas that go
into your recipes for success.
Please don't wave anyone's documents in the air as
justification for an extrapolation of my infirmities.
Let's not make this about you or me. May I suggest
we explore, understand and then explain the
physics. Make my day. Show me were I'm wrong.
Bob . . .
--
Date: 5/20/2008 4:45 PM
incoming mail is certified Virus Free.
Checked by AVG.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Checked by AVG.
Checked by AVG.
________________________________________________________________________________
Subject: | Re: Coil Suppression Techniques |
From: | "Eric M. Jones" <emjones(at)charter.net> |
> Eric
> This seems to be a well studied subject and after studying your results the method
of parallelling a relay or contactor with an opposite direction diode seems
to be the quick and dirty but still quite adequate method for the homebuilder.
Now a very practical question: Is a 0.1 dollar 1N4001...4004 or similar diode
strong enough to handle the collapsing energy of any relay or contactor used
in a homebuilt ?
> best regards
> Max
The coil's collapsing magnetic field when the contactor is de-energized induces
a high current that travels in the same direction as the original holding current,
but is of much greater magnitude. This is why the relay contacts chatter
and arc on opening, can re-close (and even weld closed). This is bad for everything
electrical, especially contacts.
The bidirectional zeners are very cheap, and well worth it. The kit I sell will
do your whole airplane, or go to Digikey if you want to save a few bucks and
buy a dozen P6KE18CA.
The question you imply, "Would it do for the homebuilder?"....My answer is NO,
Bob's is YES. Take your pick.
But Tyco, Potter and Brumfield, Kilovac, Gigavac, Zettler,
Here's what Gigavac says: COIL SUPRESSION
"....coil suppression techniques such as single diode, resistor capacitor combination,
resistor, or varistor noticeably slow down the release time of the relay
and can effect the life of the relay or the use of the relay in the application.
In carry-only applications, the release time may not be important so these
less expensive coil suppression techniques can be used. However, if the release/reset
time is important, or if the contacts are to interrupt a load, do not
use these techniques and use the recommended zener-zener or diode-zener combination."
(underlining mine) Gigavac makes the GX-11 which is a great battery
and starter contactor for your airplane, they also make really big high-current,
high-voltage stuff.
Diodes were 1960's technology. There's a better way now.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184398#184398
________________________________________________________________________________
Subject: | Re: Coil Suppression Techniques |
"Eric M. Jones" wrote:
>
> The coil's collapsing magnetic field when the contactor is de-energized induces
a high current that travels in the same direction as the original holding current,
but is of much greater magnitude. This is why the relay contacts chatter
and arc on opening, can re-close (and even weld closed). This is bad for everything
electrical, especially contacts.
>
> The bidirectional zeners are very cheap, and well worth it. The kit I sell will
do your whole airplane, or go to Digikey if you want to save a few bucks and
buy a dozen P6KE18CA.
>
> The question you imply, "Would it do for the homebuilder?"....My answer is NO,
Bob's is YES. Take your pick.
>
> But Tyco, Potter and Brumfield, Kilovac, Gigavac, Zettler,
>
> Here's what Gigavac says: COIL SUPRESSION
>
> "....coil suppression techniques such as single diode, resistor capacitor combination,
resistor, or varistor noticeably slow down the release time of the relay
and can effect the life of the relay or the use of the relay in the application.
In carry-only applications, the release time may not be important so these
less expensive coil suppression techniques can be used. However, if the release/reset
time is important, or if the contacts are to interrupt a load, do
not use these techniques and use the recommended zener-zener or diode-zener combination."
(underlining mine) Gigavac makes the GX-11 which is a great battery
and starter contactor for your airplane, they also make really big high-current,
high-voltage stuff.
>
> Diodes were 1960's technology. There's a better way now.
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones(at)charter.net
>
>
I think we need to revisit the physics here. The collapsing field
induces a high VOLTAGE which is the opposite polarity of the applied
voltage. The faster the current decreases, the higher the voltage
spike. The suppression diode gives the current a place to go allowing
it to decay more slowly, producing a lower voltage, reducing the
arcing on the switch controlling the relay. The current will never
exceed the original current flowing in the coil.
Use of the suppression diode delays opening the relay because the
current continues to flow for a longer time. The important point is
that the suppression diode protects the switch controlling the relay.
The effects on the relay contact arcing are secondary.
Bob W.
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/cables/
________________________________________________________________________________
Subject: | Coil Suppression Techniques |
Thanks Bob et al,
This is all very academic and provides excellent reading. Unfortunately
I won't soon be a fellow in the IEEE and I have an airplane to build.
Given the list of manufacturer's provided is there one who makes a
quality relay with built in zener or combo protection for which I won't
need to break out the heath kit?
I want to use the relay to load my essential bus (alternate feed) as in
Z-19. My expect load will be 25 amps. This is in keeping with the max
load for the heat sink'd diode coming from the main bus.
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Robert L. Nuckolls, III
Sent: Thursday, May 22, 2008 9:13 AM
Subject: Re: AeroElectric-List: Coil Suppression Techniques
-->
>Eric
>
>This seems to be a well studied subject and after studying your results
>the method of parallelling a relay or contactor with an opposite
>direction diode seems to be the quick and dirty but still quite
>adequate method for the homebuilder.
>
>Now a very practical question:
>
>Is a 0.1 dollar 1N4001...4004 or similar diode strong enough to handle
>the
>collapsing energy of any relay or contactor used in a homebuilt
Yes. Electrically the 1A diode is fine for about everything
on the airplane. Recall that in the realm of reactive devices
that store energy, the discharge begins at the same magnitude
as the charging source. If you charge a capacitor to 100 volts, you
get a reaction that starts at 100v and goes down from there
when you discharge it.
If you charge and inductor up to 1A, then when you release
it from the charging source, the delivered reaction starts
a 1A and goes down from there. Diodes have a steady state
capability which is exemplified in their ratings . . . I.e,
the 1N4001 is a 1A device. However, they also have transient
ratings at much higher currents. For example, consulting the
1N400x data sheet at:
http://aeroelectric.com/Mfgr_Data/Semiconductors/1N4001.pdf
we read about an 8.3 mS non repetitive peak forward surge
current rating of 30A. By "non-repeating", they don't
mean "one time ever" but "just don't do this often." So as
a transient current clamp on a manually operated contactor
found in our airplanes the 1N400x series devices are
electrically fine.
However, I have often suggested that the larger siblings
to the 1N400x (1N540x) devices have some mechanical
advantages. They're still small but MUCH more robust
than the little fellers. I selected these parts as
power steering and coil suppressors of choice for the
line of contactors I used to sell (which B&C still
does). See:
http://www.aeroelectric.com/Pictures/Contactors/s701-1l.jpg
http://www.aeroelectric.com/Pictures/Contactors/s701-2.jpg
The red PIDG terminal gets a good connection on
the larger wires for these devices and the wires
are robust enough to support the diode body under
vibration levels typical of installations for
these contactors.
Radio Shack offers both sizes of diode:
http://aeroelectric.com/Pictures/Misc/RS_Diodes.jpg
Since a prohibition against Radio Shack parts has
been suggested, I'll share an observation that there
were times in the history of many suppliers of consumer/
experimenter parts where their offerings included
industrial surplus parts of unknown but not necessarily
evil pedigree. This includes a now premier supplier
of goods (Digikey) who started out as a mail
order supplier of industrial surplus that advertised
in ham radio and experimenter electronics magazines.
RS still handles experimenter's assortments of components
that are reminiscent of "grab bags" offered in years
gone by . . .
http://tinyurl.com/5jhbu6
http://tinyurl.com/42jn9v
. . . but these days, when you are responsible for
managing inventory in thousands of stores, millions
of catalogs, and a really big website, you don't
spend time scrounging the back alleys of industrial
trash cans looking for "floor sweepings".
These components are so cheap that it simply doesn't
pay to spend the time to salvage and then inventory
less than factory-fresh components.
The times they are a changing.
As a final note, this thread is not intended to
discourage anyone from using more sophisticated
transient control techniques if that process rings
their chimes. Information provided here is offered
as a prophylactic against decision making based
on poorly interpreted data, marketing hype, or sage
advice from those who would disseminate but will not
or cannot also teach.
Bob . . .
________________________________________________________________________________
Subject: | Re: Coil Suppression Techniques |
From: | "Eric M. Jones" <emjones(at)charter.net> |
> induces a high VOLTAGE which is the opposite polarity of the applied voltage.
The faster the current decreases, the higher the voltage
> spike. The suppression diode gives the current a place to go allowing
> it to decay more slowly, producing a lower voltage, reducing the
> arcing on the switch controlling the relay. The current will never
> exceed the original current flowing in the coil.
>
> Use of the suppression diode delays opening the relay because the
> current continues to flow for a longer time. The important point is
> that the suppression diode protects the switch controlling the relay.
> The effects on the relay contact arcing are secondary. Bob W.
> --
> N93BD - Rotary Powered BD-4 - http://www.bob-white.com
> 3.8 Hours Total Time and holding
> Cables for your rotary installation - http://roblinstores.com/cables/
>
If it were only so, what a nice world it would be! Please read:
http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3311.pdf
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184415#184415
________________________________________________________________________________
Subject: | Re: Coil Suppression Techniques |
"Eric M. Jones" wrote:
>
>
> > induces a high VOLTAGE which is the opposite polarity of the applied voltage.
The faster the current decreases, the higher the voltage
> > spike. The suppression diode gives the current a place to go allowing
> > it to decay more slowly, producing a lower voltage, reducing the
> > arcing on the switch controlling the relay. The current will never
> > exceed the original current flowing in the coil.
> >
> > Use of the suppression diode delays opening the relay because the
> > current continues to flow for a longer time. The important point is
> > that the suppression diode protects the switch controlling the relay.
> > The effects on the relay contact arcing are secondary. Bob W.
> > --
> > N93BD - Rotary Powered BD-4 - http://www.bob-white.com
> > 3.8 Hours Total Time and holding
> > Cables for your rotary installation - http://roblinstores.com/cables/
> >
>
>
> If it were only so, what a nice world it would be! Please read:
>
> http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3311.pdf
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones(at)charter.net
>
OK, I've read it. What's your point?
Quote:
"When an electromechanical relay is de-energized rapidly by a mechanical
switch or semiconductor, the collapsing magnetic field produces a
substantial voltage transient in its effort to disperse the stored
energy and oppose the sudden change of current flow."
Note that this high voltage is not connected to the relay contacts and
there is no mention of high currents being generated. It just doesn't
happen. The high voltage is impressed across the switch controlling
the relay. As Ralph (jetboy) recently posted, the A&P left off the
diode resulting in the master switch being destroyed in his C150.
All the problems with relay contact opening are associated with the
slower opening time.
Another quote:
"The optimum switching life (for normally-open contacts) is therefore
obtainew with a totally unsuppressed relay and statements of rated
electrical life are usually based on this premise."
In other words, for best contact life, don't use suppression. So why
do we use it? To protect the controlling switch!
Bob W.
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/cables/
________________________________________________________________________________
From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
Subject: | Previous Master solonoid clicking |
A while back, I discussed a clicking sound that I heard after I turned the
alternator on when the engine was running.
Today I discovered that my low voltage module was not working and when I
removed it, the clicking went away.
I tested the module by putting +9V on pin 4, grounded pin 5, and looked for
the LED to come on and also for a ground to show up on pin 1. No light, no
ground. Must have crapped out??!!
I also noticed that when the module was disconnected, If I had the main
battery set to "Alternator", and the engine battery set to "ON", I got about
13.4V. If I flipped the engine battery switch to "Auto", the voltage went
up to about 14.6V.
I was at a loss as to why this would be. I didn't try it with the engine
battery set to "OFF", so I don't know what would have happened if I did.
Does anyone have any ideas as to what was happening to cause the clicking if
the module caused it, and why the voltage increase? I at first thought..I
am turning one of the batteries off, so the voltage went up, but then I
thought...why wouldn't the voltage regulator bring it back down in that
case.
Thanks for the help!
Bill B
________________________________________________________________________________
From: | "John Cleary" <john_rv10(at)yahoo.com> |
Subject: | Coil Suppression Techniques |
Bob,
Reading all these comments, two questions come to mind.
1. Have you done the tests below with a zener-zener or a diode-zener
combination to see how they compare with their IN 540x cousins?
2. Have you collected data on the effect on the switch controlling the relay
to compare the four conditions:-
No protection
IN540x protection
Zener-zerner protection
Diode-zener protection?
The data from question 1 will show us the effects on the relay under the
various conditions being discussed. The data from Q2 will show us the
effects on the switch controlling the relay under those same conditions. It
seems both lots of data are required to determine the best way to protect
the switch and at the same time protect the relay? - or am I missing
something in this debate?
Thanks once again,
John
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Thursday, 22 May 2008 11:13 PM
Subject: Re: AeroElectric-List: Coil Suppression Techniques
>Eric
>
>This seems to be a well studied subject and after studying your results
>the method of parallelling a relay or contactor with an opposite direction
>diode seems to be the quick and dirty but still quite adequate method for
>the homebuilder.
>
>Now a very practical question:
>
>Is a 0.1 dollar 1N4001...4004 or similar diode strong enough to handle the
>collapsing energy of any relay or contactor used in a homebuilt
Yes. Electrically the 1A diode is fine for about everything
on the airplane. Recall that in the realm of reactive devices
that store energy, the discharge begins at the same magnitude
as the charging source. If you charge a capacitor to 100 volts, you
get a reaction that starts at 100v and goes down from there
when you discharge it.
If you charge and inductor up to 1A, then when you release
it from the charging source, the delivered reaction starts
a 1A and goes down from there. Diodes have a steady state
capability which is exemplified in their ratings . . . I.e,
the 1N4001 is a 1A device. However, they also have transient
ratings at much higher currents. For example, consulting the
1N400x data sheet at:
http://aeroelectric.com/Mfgr_Data/Semiconductors/1N4001.pdf
we read about an 8.3 mS non repetitive peak forward surge
current rating of 30A. By "non-repeating", they don't
mean "one time ever" but "just don't do this often." So as
a transient current clamp on a manually operated contactor
found in our airplanes the 1N400x series devices are
electrically fine.
However, I have often suggested that the larger siblings
to the 1N400x (1N540x) devices have some mechanical
advantages. They're still small but MUCH more robust
than the little fellers. I selected these parts as
power steering and coil suppressors of choice for the
line of contactors I used to sell (which B&C still
does). See:
http://www.aeroelectric.com/Pictures/Contactors/s701-1l.jpg
http://www.aeroelectric.com/Pictures/Contactors/s701-2.jpg
The red PIDG terminal gets a good connection on
the larger wires for these devices and the wires
are robust enough to support the diode body under
vibration levels typical of installations for
these contactors.
Radio Shack offers both sizes of diode:
http://aeroelectric.com/Pictures/Misc/RS_Diodes.jpg
Since a prohibition against Radio Shack parts has
been suggested, I'll share an observation that there
were times in the history of many suppliers of consumer/
experimenter parts where their offerings included
industrial surplus parts of unknown but not necessarily
evil pedigree. This includes a now premier supplier
of goods (Digikey) who started out as a mail
order supplier of industrial surplus that advertised
in ham radio and experimenter electronics magazines.
RS still handles experimenter's assortments of components
that are reminiscent of "grab bags" offered in years
gone by . . .
http://tinyurl.com/5jhbu6
http://tinyurl.com/42jn9v
. . . but these days, when you are responsible for
managing inventory in thousands of stores, millions
of catalogs, and a really big website, you don't
spend time scrounging the back alleys of industrial
trash cans looking for "floor sweepings".
These components are so cheap that it simply doesn't
pay to spend the time to salvage and then inventory
less than factory-fresh components.
The times they are a changing.
As a final note, this thread is not intended to
discourage anyone from using more sophisticated
transient control techniques if that process rings
their chimes. Information provided here is offered
as a prophylactic against decision making based
on poorly interpreted data, marketing hype, or sage
advice from those who would disseminate but will not
or cannot also teach.
Bob . . .
Checked by AVG.
7:21 AM
Checked by AVG.
7:06 AM
________________________________________________________________________________
From: | Tony Gibson <umgibso1(at)yahoo.com> |
Subject: | Coil Suppression Techniques. |
Hi Bob, on-behalf of myself and many others I'm sure I'd like to thank yo
u for - first of all, your restraint, and of course-your informative post
s that make it so easy for the rest of us to click-on the links of your
-experiments.=0AI joined this list probably two years ago and a great dea
l of what was discussed was over my head (and still is!) ... I received the
daily emails and for the longest time would-check out the subject titles
and more often than not delete the email.- Over time I've 'gotten up to
speed', read your book, and spent the time to-learn-(whether the partic
ular subject concerned my airplane or not).-=0AIt's all too easy to "gold
plate the spec" to cover ALL conceivable conditions that a particular comp
onent may see whether applicable or not.- It is of GREAT value to me that
you repeatedly base your responses on OBAM-aircraft.- Meaning... if ag
e/environmental factors, etc is going to kill my component before I or my d
esigned system does then thats exactly what I need to know.--I have alw
ays found your posts and advice to be practical in the real world (where mo
st of us live with our little homebuilt airplanes)-and considerate of my
time & money.=0AI continue to learn from all the contributors and contribut
ions to the site.- Best Regards to all and my apologies for feeling the n
eed to 'waste' bandwidth!- ;)=0ATony Gibson=0AWinnipeg, Manitoba-=0A=0A
x.net>=0ASubject: Re: AeroElectric-List: Coil Suppression Techniques.=0A=0A
Vu feeling that we have covered this subject =0A>before. And I will save y
ou the trouble Bob....I know you'll never agree, =0A>and you'll retort with
a long quasi-techno piece and then stumble TO =0A>EXACTLY THE WRONG CONCLU
SION.=0A>=0A>Coil suppression- and relay contact arcing have been well st
udied: See:=0A=0A>http://relays.tycoelectronics.com/appnotes/=0A>=0A>Basica
lly (ESPECIALLY with contactors) Do not use diodes for coil =0A>suppression
unless you're hoping for greatly reduced relay/contactor life, =0A>so you
can get stuck in a remote area and have an adventure. I know people =0A>lik
e this but they usually don't build airplanes. Gotta'-Have-Drama-Dammit!=0A
=0A- You've cited that document before. And I've=0A- read it several ti
mes both before you cited it=0A- and after you cited it.=0A=0A- Kindly
point out to me where the authors offer DATA=0A- supporting an assertion
that the plain vanilla=0A- diode coil suppression has a profound effect o
n relay life.=0A=0A- They correctly asserted and I confirmed that=0A- d
iodes do indeed extend the time from switch=0A- opening until energized c
ontacts begin to move.=0A- This is opening delay. They went on to extrapo
late=0A- that opening delay translates directly into slower=0A- contact
spreading velocity and extrapolated further=0A- that this translated to
increased contact wear.=0A=0A- I did the experiments and published the re
sults=0A- that argue against their extrapolations. If you=0A- have some
data to the contrary, please share it=0A- with us.=0A=0A- Just because
you've read some words under the=0A- letter head and over the signatures
of persons=0A- in high places does not make their words golden=0A- unl
ess they're supported by data from and=0A- understanding of repeatable ex
periments.=0A=0A>Here's what sane people have figured out:=0A=0A- . . .
- are you suggesting I am less than sane??=0A=0A>Mechanical relays and co
ntactors depend upon magnetism generated by an =0A>electric current running
through a wire coil. When the current stops, the =0A>magnetic field collap
ses. But the relay does not know the difference =0A>between a wire coil mov
ing in a magnetic field (as in a generator) or a =0A>magnetic field moving
in a wire coil (as in a collapsing magnetic field). =0A>Thus a large voltag
e1000V to 1500V typicallyis induced in the coil. =0A>This current goes the
same direction the original current didso it =0A>slows the contact openinga
llowing arcing, chatter, bouncing, contact =0A>welding and even re-closure!
Yikes!=0A=0A- Go to your workbench, measure it, document=0A- it and sh
are it with us. Show me where my=0A- data and interpretation of my data i
s wrong.=0A=0A- The important feature of relay and contactor=0A- operat
ion that you're overlooking is the extreme=0A- relationship between magne
tic force and air-gap.=0A- Air is an exceedingly poor conductor of magnet
ic=0A- lines of force. So while a diode does indeed slow=0A- the rate o
f drop in coil current (hence increased=0A- delay) once the armature come
s unstuck from its=0A- seated condition, the effect of increasing=0A- a
ir-gap is many times more influential than rate=0A- of decay in coil curr
ent.=0A=0A- Went back to the workbench to look at the S704-1 in=0A- mor
e detail. Here's the test setup:=0A=0A=0Ahttp://aeroelectric.com/Pictures/S
chematics/Relay_Test_Setup.pdf=0A=0A- Relay response with no coil suppres
sion looks=0A- like this:=0A=0Ahttp://www.aeroelectric.com/Pictures/Curve
s/S704-1_Drop-Out_Delay_without_Diode.jpg=0A=0A- where we see the high vo
ltage spike on the coil=0A- trace and a 2.5 mS dropout delay.=0A=0A- WI
TH a coil suppression diode, we get=0A- relay response like this:=0A=0Aht
tp://www.aeroelectric.com/Pictures/Curves/S704-1_Drop-Out_Delay_with_Diode.
jpg=0A=0A- Dropout Delay is increased to 12.5 mS or about 5x=0A- longer
than with the diode. This was the feature=0A- pointed out in the article
you cited . . . where=0A- the authors extrapolated this into a commensur
ate=0A- slowing in contact spreading velocity (longer fires).=0A=0A- Ho
wever, when we take the diode off and look at=0A- transition time . . .
=0A=0Ahttp://www.aeroelectric.com/Pictures/Curves/S704-1_D-E_Transition_NoS
uppression.jpg=0A=0A- From the time the contacts FIRST open until they=0A
- first contact the opposite side is 0.6 mS. Let's=0A- put the diode ba
ck on and we get . . .=0A=0Ahttp://www.aeroelectric.com/Pictures/Curves/S70
4-1_D-E_Transition_Diode_Suppression.jpg=0A=0A- Hmmm . . . transition inc
reases to 0.75 mS, about=0A- a 25% increase NOT A 500% INCREASE.=0A=0A-
Let's go back an look at the traces I took where=0A- we were observing t
he arc in a spreading set of=0A- contacts with no diode . . .=0A=0Ahttp:/
/www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif=0A=0A-
Here I could see about 0.21 mS of "fire" as compared=0A- with . . .=0A=0A
http://www.aeroelectric.com/Pictures/Curves/704-1OpeningTimeNoDiode.gif=0A
=0A- about 0.23 mS arcing when the diode was in place. Hmmm,=0A- there
was an increase but not a very big one. In both=0A- cases, observed arcin
g times were about 1/3 the total=0A- transition time.=0A=0A- Now let us
consider another feature of relays and contactors=0A- that REALLY drives
service life issues. Take a look at:=0A=0Ahttp://www.aeroelectric.com/Pict
ures/Curves/S704-1_Contact_Bounce_with_Diode.jpg=0A=0A- Where we see that
after the first time the contacts=0A- touch, really get with the high-te
mpo hat-dance=0A- for perhaps several dozen closure and re-opening=0A-
events. This means that for every operation of the=0A- switch on the pane
l, the contacts are getting=0A- 5-25 times more activity than the single
switching=0A- event might suggest. Now look at:=0A=0Ahttp://www.aeroelect
ric.com/Pictures/Curves/S704-1_Contact_Bounce_without_Diode.jpg=0A=0A- We
ll fooey . . . even with the diode off the contacts=0A- do the cat-on-a-h
ot-tin-roof routine.=0A=0A- Let us further consider that when folks like
those Tyco=0A- engineers evaluate service life, they're working in=0A-
the laboratory test environment and evaluating products=0A- where service
life is measured in the tens of thousands=0A- of operations . . . 50,000
typical. 250,000 is not=0A- unusual. Let us suppose that their paper was
based on=0A- real statistical studies of dozens of relays with=0A- var
ious coil suppression techniques and yes, there=0A- was an observable inc
rease in mean operations between=0A- failures from 45,744 to 49,666 by "o
ptimizing" the=0A- coil suppression. Hmmm . . . 10% . . . that IS signifi
cant=0A- to Tyco and probabably most of their customers.=0A- They didn'
t speak to this kind of study in the paper=0A- you cited and I'd like to
believe they've done their=0A- homework.=0A=0A- Let us assume their und
ocumented assertions=0A- WERE correct on the scale I suggested. How does
this=0A- affect the OBAM aircraft builder who's switches,=0A- relays an
d contactors probably won't see 5,000=0A- operations over the lifetime of
the airplane?=0A=0A- Further, environmental stresses will be root cause
=0A- for most replacements of such devices in personally owned,=0A- non
-revenue generating light aircraft, not electrical=0A- stresses. In any c
ase, the 5x increase in drop-out delay=0A- DOES NOT extrapolate into a pr
oportionate drop in contact=0A- life.=0A=0A=0A>The common palliative is a
diode AND zener in series, or better yet, a =0A>bidirectional zener across
the coil. They call these Transils, =0A>Surmetics, Transorbs, TranZorbs, T
ransGuards, Mosorbs; the =0A>list is endless. (Over-paid executives dream u
p these names.)- They are =0A>generic P6KE18CA bidirectional zeners.=0A>
=0A>Jeeeeeze........=0A=0A- Eric,=0A=0A- Of all the contributors to thi
s list I expect=0A- more of you. We had some substantive discussions=0A
- on the inner technical workings of various products=0A- and ideas in
Plymouth a couple of years ago. You=0A- struck me as one who appreciates
understanding=0A- and having a handle on the simple-ideas that go=0A- i
nto your recipes for success.=0A=0A- Please don't wave anyone's documents
in the air as=0A- justification for an extrapolation of my infirmities.
=0A- Let's not make this about you or me. May I suggest=0A- we explore,
understand and then explain the=0A- physics. Make my day. Show me were I
'm wrong.=0A=0A- Bob . . .=0A=0A=0A
________________________________________________________________________________
From: | "Chris" <toaster73(at)embarqmail.com> |
Subject: | Re: Fuse and Breaker - one bus |
Thanks Bob. I see your point and will continue along those lines you
describe. I have been thinking I may want to see an indication of a failure
on certain items by seeing that breaker button pop out. Is that really
something I need to see or know or do I use another indicator like a light?
-Chris
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Sent: Tuesday, May 20, 2008 11:33 PM
Subject: Re: AeroElectric-List: Fuse and Breaker - one bus
>
>
>
>>
>>
>>I have been lurking here for a few years trying to absorb the power of
>>aeroelectric but I am having trouble jumping from the schematics to the
>>physical configuration.
>>I am having trouble with the physical configuration of my RV-10 electrical
>>system design. I am trying to draw up a Z-13 style system but I think I
>>want my E-Bus to have a breaker for trim, flaps etc but the rest I want to
>>use a fuse block. What would be a good way to combine the fuse and
>>breaker block into one bus? Just run same gage wire to the e-bus primary
>>and alternate feed to the fuse block and split off from block with same
>>gage wire to the bar for the breakers?
>>thanks in advance
>
> The e-bus is for things that you need during the en-route
> mode of flight to maximize utilization of a limited resource.
> If you're planning Z-13/8, then the e-bus can be easily
> configured to handle an endurance load of 8 amps.
>
> The idea is that when the airport is in sight that you
> can bring the main bus back on for using the battery to
> run anything on the main bus using a battery that's held
> completely in reserve for approach to landing.
>
> What's your rationale for breakers on these two systems?
> Runaway disconnect? Breakers are exceedingly poor substitutes
> for master disconnect systems . . . if indeed runaway is
> a high order probability for creating a hazard. It's
> probably easier to design a system that can't run away.
> In other words, trim is an exceedingly low duty-cycle
> load that runs happily from the e-bus . . . Flaps too
> for that matter . . . but they aren't needed until approach
> to landing and could stay on the main bus. I guess we
> need to understand your concnerns.
>
> Bob . . .
>
>
>
________________________________________________________________________________
From: | "Chris" <toaster73(at)embarqmail.com> |
Subject: | Re: Fuse and Breaker - one bus |
Vaughn,
I had an MGB and am familiar with the Prince of Darkness. Your right I
probably should not be doing wiring - to me this is the coolest part of the
project when its done, but the worst to figure out and build. I am a
mechanical guy through and through.
-Chris
----- Original Message -----
From: "Gaye and Vaughn" <vaughnray(at)bvunet.net>
Sent: Tuesday, May 20, 2008 10:48 PM
Subject: Re: AeroElectric-List: Fuse and Breaker - one bus
>
>
> The fuse block is your endurance bus. I would run a wire to the fuse block
> post that would handle the combined loads on the fuse block and the load
> on your breaker bar. I would then run a wire from the post on the fuse
> block to the breaker bar that was large enough to handle the combined
> loads of all the breakers.
>
> I once had an MGTF with Lucas electrics. Are you should be wiring? ;-)
>
> Vaughn Teegarden
> Trying to figure it out myself...Don't listen to me.
>
> ----- Original Message -----
> From: "Chris" <toaster73(at)embarqmail.com>
> To:
> Sent: Tuesday, May 20, 2008 9:16 AM
> Subject: AeroElectric-List: Fuse and Breaker - one bus
>
>
>>
>>
>> I have been lurking here for a few years trying to absorb the power of
>> aeroelectric but I am having trouble jumping from the schematics to the
>> physical configuration.
>> I am having trouble with the physical configuration of my RV-10
>> electrical system design. I am trying to draw up a Z-13 style system but
>> I think I want my E-Bus to have a breaker for trim, flaps etc but the
>> rest I want to use a fuse block. What would be a good way to combine the
>> fuse and breaker block into one bus? Just run same gage wire to the e-bus
>> primary and alternate feed to the fuse block and split off from block
>> with same gage wire to the bar for the breakers?
>> thanks in advance
>> Chris Lucas
>> RV-10 #40072
>>
>>
>>
>>
>
>
>
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Coil Suppression Techniques |
>
>Bob,
>
>Reading all these comments, two questions come to mind.
>
>1. Have you done the tests below with a zener-zener or a diode-zener
>combination to see how they compare with their IN 540x cousins?
Absolutely. The the worse case voltage spike occurs with zero
suppression (where all energies are dissipated in the arcing
across spreading switch contacts). The best scenario for arcing
control is the plain vanilla diode where arcing is minimal
because the negative going spike that would normally go -300 volts
plus is clamped off at ground thus limiting the voltage stress
across the switch contacts to 14 volts.
>2. Have you collected data on the effect on the switch controlling the relay
>to compare the four conditions:-
> No protection
> IN540x protection
> Zener-zerner protection
> Diode-zener protection?
Sure. They all work within the limits of their physics.
Even a plain resistor adds significant value for arc
reduction . . . even if the least efficient of the lot.
A capacitor/resistor combination works too. Recall the
"condenser" across the points on an Kettering ignition
system distributor? There's a LOT of ways each offering
trade offs. But to date, I've discovered no simpler, easier
to implement technique than use of the plain-vanilla
diode.
>The data from question 1 will show us the effects on the relay under the
>various conditions being discussed. The data from Q2 will show us the
>effects on the switch controlling the relay under those same conditions. It
>seems both lots of data are required to determine the best way to protect
>the switch and at the same time protect the relay? - or am I missing
>something in this debate?
I looked at all these variations and quite frankly they
performed well. I thought I had the traces on
my hard drive but I don't find them. If I get time tomorrow,
I'll go plot them again.
I've not included them in my offerings of data because
they are all middle-ground for performance between NO
suppression and the ULTIMATE suppression of a plain-vanilla
diode.
With one exception. At one time I personally embraced low
voltage MOV's as viable contact preservation devices
but discarded them after I went to the bench to check
performance when a reader told me of his own experiments
where visible arcing was not attenuated by any observable
amount with MOVs. I was properly embarrassed and dutiful
in correcting the gaff. It's one of those things that
happens when understanding based on data sheets does
not mesh with real world experiences.
The debate here is not whether the alternative systems
do their job. The debate is whether there is return
on investment for acquiring "specialized"
components sold not upon hard data and repeatable
experiment. The only support is a kind of "new and
improved" marketing hype based on poorly extrapolated
conclusions in a "celebrity" document. In this case,
engineers that published under the Tyco trade name.
It appears Eric is unwilling to be a teacher based on
his personal understanding of the physics supported
by a willingness to explain it. I am saddened by
this. I'll go get the data on the alternative techniques
tomorrow.
Bob . . .
________________________________________________________________________________
From: | "John Cleary" <john_rv10(at)yahoo.com> |
Subject: | Coil Suppression Techniques |
Bob,
You are a LEGEND.
Thanks again,
John
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Friday, 23 May 2008 1:33 PM
Subject: RE: AeroElectric-List: Coil Suppression Techniques
>
>Bob,
>
>Reading all these comments, two questions come to mind.
>
>1. Have you done the tests below with a zener-zener or a diode-zener
>combination to see how they compare with their IN 540x cousins?
Absolutely. The the worse case voltage spike occurs with zero
suppression (where all energies are dissipated in the arcing
across spreading switch contacts). The best scenario for arcing
control is the plain vanilla diode where arcing is minimal
because the negative going spike that would normally go -300 volts
plus is clamped off at ground thus limiting the voltage stress
across the switch contacts to 14 volts.
>2. Have you collected data on the effect on the switch controlling the
relay
>to compare the four conditions:-
> No protection
> IN540x protection
> Zener-zerner protection
> Diode-zener protection?
Sure. They all work within the limits of their physics.
Even a plain resistor adds significant value for arc
reduction . . . even if the least efficient of the lot.
A capacitor/resistor combination works too. Recall the
"condenser" across the points on an Kettering ignition
system distributor? There's a LOT of ways each offering
trade offs. But to date, I've discovered no simpler, easier
to implement technique than use of the plain-vanilla
diode.
>The data from question 1 will show us the effects on the relay under the
>various conditions being discussed. The data from Q2 will show us the
>effects on the switch controlling the relay under those same conditions. It
>seems both lots of data are required to determine the best way to protect
>the switch and at the same time protect the relay? - or am I missing
>something in this debate?
I looked at all these variations and quite frankly they
performed well. I thought I had the traces on
my hard drive but I don't find them. If I get time tomorrow,
I'll go plot them again.
I've not included them in my offerings of data because
they are all middle-ground for performance between NO
suppression and the ULTIMATE suppression of a plain-vanilla
diode.
With one exception. At one time I personally embraced low
voltage MOV's as viable contact preservation devices
but discarded them after I went to the bench to check
performance when a reader told me of his own experiments
where visible arcing was not attenuated by any observable
amount with MOVs. I was properly embarrassed and dutiful
in correcting the gaff. It's one of those things that
happens when understanding based on data sheets does
not mesh with real world experiences.
The debate here is not whether the alternative systems
do their job. The debate is whether there is return
on investment for acquiring "specialized"
components sold not upon hard data and repeatable
experiment. The only support is a kind of "new and
improved" marketing hype based on poorly extrapolated
conclusions in a "celebrity" document. In this case,
engineers that published under the Tyco trade name.
It appears Eric is unwilling to be a teacher based on
his personal understanding of the physics supported
by a willingness to explain it. I am saddened by
this. I'll go get the data on the alternative techniques
tomorrow.
Bob . . .
Checked by AVG.
7:06 AM
Checked by AVG.
7:06 AM
________________________________________________________________________________
From: | "Sam Hoskins" <shoskins(at)mchsi.com> |
Subject: | Simplicate my all-electric Electronic Fuel Injection |
I'm looking some feedback of my electrical system, based on Z-19RB. You can
get the pdf here:
http://www.mistakeproofing.net/transfer/N202SH-Z-19RB.pdf
This is a retrofit in my 20 year old composite Quickie Q-200. I do a lot of
day VFR cross country with this plane and do some cross country racing.
Since I am converting to "all electric" I would be interested in your
thoughts about my proposed system.
Besides the Dynon FlightDEK 180 the biggest change is the conversion to
electronic fuel injection. I am using the EC-3 controller from Real World
Solutions (RWS). You can see more about the controller here:
http://www.rotaryaviation.com/eficont.html
The EC-3 controller is divided into two sides, A & B. The fuel injector
control and ignition outputs exit the box from a single connector via a
shared relay. The controller can receive either a primary or secondary 12V
power source.
A few bullet points:
- I am using a primary fuel pump and a backup fuel pump. I also have two
transfer pumps.
- I have not yet sized the batteries.
- I have an existing AEC9005-201 low voltage monitor, without the relay
control.
- Output of the ECU will be shown on another page, perhaps later in the
week.
- I have not yet properly sized the fuses or the wires in this drawing.
My concerns:
- By the time I add strobes and position lights, I will have around 14
or 15 switches, which seems like a lot for a 650 lb. (empty weight)
airplane. Is there a way I could minimize the switch count?
- I am thinking about combining the E-buss and the main power bus to
reduce switch count and the number of fuse blocks. I could easily shed the
loads myself.
- There seem to be a lot of components connected to the unswitched
battery busses. I wonder if I should use CBs instead of fuses so I would
have a shutoff during servicing.
Anything else? Your input is very welcome.
Thanks!
Sam Hoskins
Murphysboro, IL
http://samhoskins.blogspot.com/
________________________________________________________________________________
From: | "Sam Hoskins" <sam.hoskins(at)gmail.com> |
Subject: | Z-19RB - review and simplify? |
I'm looking some feedback on my electrical system, based on Z-19RB. You can
get the pdf here:
http://www.mistakeproofing.net/transfer/N202SH-Z-19RB.pdf
This is a retrofit in my 20 year old composite Quickie Q-200. I do a lot of
day VFR cross country with this plane and do some cross country racing.
Since I am converting to "all electric" I would be interested in your
thoughts about my proposed system.
Besides the Dynon FlightDEK 180 the biggest change is the conversion to
electronic fuel injection. I am using the EC-3 controller from Real World
Solutions (RWS). You can see more about the controller here:
http://www.rotaryaviation.com/eficont.html
The EC-3 controller is divided into two sides, A & B. The fuel injector
control and ignition outputs exit the box from a single connector via a
shared relay. The controller can receive either a primary or secondary 12V
power source.
A few bullet points:
- I am using a primary fuel pump and a backup fuel pump. I also have two
transfer pumps.
- I have not yet sized the batteries.
- I have an existing AEC9005-201 low voltage monitor, without the relay
control.
- Output of the ECU will be shown on another page, perhaps later in the
week.
- I have not yet properly sized the fuses or the wires in this drawing.
My concerns:
- By the time I add strobes and position lights, I will have around 14
or 15 switches, which seems like a lot for a 650 lb. (empty weight)
airplane. Is there a way I could minimize the switch count?
- I am thinking about combining the E-buss and the main power bus to
reduce switch count and the number of fuse blocks. I could easily shed the
loads myself.
- There seem to be a lot of components connected to the unswitched
battery busses. I wonder if I should use CBs instead of fuses so I would
have a shutoff during servicing.
Anything else? Your input is very welcome.
Thanks!
Sam Hoskins
Murphysboro, IL
http://samhoskins.blogspot.com/
________________________________________________________________________________
Subject: | Re: Coil Suppression Techniques |
From: | "Eric M. Jones" <emjones(at)charter.net> |
> induces a high VOLTAGE which is the opposite polarity of the applied voltage.
The faster the current decreases, the higher the voltage
> spike. The suppression diode gives the current a place to go allowing
> it to decay more slowly, producing a lower voltage, reducing the
> arcing on the switch controlling the relay. The current will never
> exceed the original current flowing in the coil.
>
> Use of the suppression diode delays opening the relay because the
> current continues to flow for a longer time. The important point is
> that the suppression diode protects the switch controlling the relay.
> The effects on the relay contact arcing are secondary.
>
> Bob W.
Actually, Eric is in bed with the cold/flu. And Paul M. keeps calling me up to
rant about politics.....Jeeeze.
Let's clear the air regarding coil suppression.
When the relay is closed (and as I said this is targeted mainly at contactor relays),
the relay coil has a large amount of energy stored in its inductor. When
the relay coil switch is opened, the field collapses and a problematic high
voltage is produced (the voltage depends on the several construction variables).
I think we agree to this point.
Now, it might seem that the current produced by the collapsing field is opposite
its normal direction. This is not so. The coil current is in the same direction,
but the relay coil has changed from being the Load to being the Generator.
If you look at the diode direction, you will see that a current in the opposite
direction could not flow at all, and the diode would serve no purpose.
I agree with Bob W. that the coil suppressor protects the switch and anything else
that provides power to the relay. It also provides other beneficial effect.
However, not having a coil suppressor is not an option.
Indeed, the best way to preserve the contactor's own power contacts is to have
NO coil suppressor and just rip them apart as fast and as far as possible as possible.
But everything else would suffer.
The common (and historic) coil suppression technique that minimized damage to other
components like the on/off switch was to shunt the coil with a reversed bias
diode (a diode arranged so that it does not normally conduct current). Now
when the coil's magnetic field collapses, it induces a
current that is shorted by the diode. The current flows through the coil and stops
in a very short time, lowering the voltage by lengthening the field collapse
time.
This longer field collapse time is deleterious to the power contacts, and (by Tyco
P&B's information) can actually cause momentary re-closure which manifests
as chatter, bouncing, etc. I assume this depends on the load, and the particulars
of the contactor.
But this approach raises some red flags:
1) The diode must not be driven over-current.
2) The delay to opening must be minimized.
3) The suppression device should last longer than the contactor.
4) The ground bounce oscillations should be handled. (for inductive loads)
Now this is where Bob N. and I part company. Bob runs tests and depends on experience,
I just read technical papers and study spec sheets. I claim one should
dump the diode and use a newer approach. Bob N. claims the diode is good enough.
I claim the major purveyors of contactors now use back-to-back zeners or bidirectionals.
Bob N. can show lots of relays that use diodes.
There you go.
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184508#184508
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Coil Suppression Techniques. |
>Hi Bob, on behalf of myself and many others I'm sure I'd like to thank you
>for - first of all, your restraint, and of course your informative posts
>that make it so easy for the rest of us to click on the links of your
>experiments.
>
>I joined this list probably two years ago and a great deal of what was
>discussed was over my head (and still is!) ... I received the daily emails
>and for the longest time would check out the subject titles and more often
>than not delete the email. Over time I've 'gotten up to speed', read your
>book, and spent the time to learn (whether the particular subject
>concerned my airplane or not).
That's what Richard Feynman describes as "The
Pleasure of Finding Things Out". Virtually every
classroom we all sat in for the first time offered
tons of information sometimes accompanied with
lucid explanation and even real-life connections.
It is not uncommon when "getting a drink from the
fire hose" that certain simple-ideas don't catch
on or fit into the current library of life experiences.
But as you've alluded, there is an osmosis
effect . . . tiny bits of the big drink soak
in. At some point in the future, a sort of
epiphany may take place when one realizes that
"Yeah, I KNOW how that works".
It still happens to me regularly.
>
>It's all too easy to "gold plate the spec" to cover ALL conceivable
>conditions that a particular component may see whether applicable or
>not. It is of GREAT value to me that you repeatedly base your responses
>on OBAM aircraft. Meaning... if age/environmental factors, etc is going
>to kill my component before I or my designed system does then thats
>exactly what I need to know. I have always found your posts and advice to
>be practical in the real world (where most of us live with our little
>homebuilt airplanes) and considerate of my time & money.
To me, being an engineer was the ideal connection
between pure physics and people. I was exceedingly
fortunate in my career to have some good teachers
AND a charter to make my ideas play in the marketplace.
I.e, offer competitive value that was attractive
for performance, price and after-the-sale service.
VERY few of my contemporaries have enjoyed so broad
an experience.
>
>I continue to learn from all the contributors and contributions to the
>site. Best Regards to all and my apologies for feeling the need to
>'waste' bandwidth! ;)
Forgive me but that "wasted bandwidth" canard is
really raises the ol' blood pressure. It seems most
often used by individuals who complain to other
individuals about the use of a communications tool
that is nobody's property . . . a term almost never
used in a exchange that quests for understanding of
simple ideas.
If one wants to bemoan "wasted bandwidth", just
hit any cable channel for an hour and make notes on
what one learns that adds any value to their lives.
I.e., how did the $time$ spent today make one's life
any more enjoyable or confident tomorrow?
I view $time$ spent here as an opportunity to
fine tune my own skills as well as encouragement
to broaden my own understanding. Folks on the List
are not always aware of the $time$ spent to firm
up a foundation for an reply before I post it.
You folks are as useful to me as I hope I am to
all of you. $Time$ and 'bandwidth' used in that
endeavor is never a waste.
Everyone on the List has an opportunity to be both
student and teacher. It has nothing to do with
the total experience of either individual. Any
instance where understanding supported by repeatable
experiment is exchanged, there is opportunity
for growth for everyone who chooses to
participate.
Bob . . .
________________________________________________________________________________
From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
Subject: | Previous Master solonoid clicking |
I left out that my plane is wired closely to the Z-19 architecture.
Also the low voltage module is one that I built using one of Bob's boards
from the old model.
Bill B
A while back, I discussed a clicking sound that I heard after I turned the
alternator on when the engine was running.
Today I discovered that my low voltage module was not working and when I
removed it, the clicking went away.
I tested the module by putting +9V on pin 4, grounded pin 5, and looked for
the LED to come on and also for a ground to show up on pin 1. No light, no
ground. Must have crapped out??!!
I also noticed that when the module was disconnected, If I had the main
battery set to "Alternator", and the engine battery set to "ON", I got about
13.4V. If I flipped the engine battery switch to "Auto", the voltage went
up to about 14.6V.
I was at a loss as to why this would be. I didn't try it with the engine
battery set to "OFF", so I don't know what would have happened if I did.
Does anyone have any ideas as to what was happening to cause the clicking if
the module caused it, and why the voltage increase? I at first thought..I
am turning one of the batteries off, so the voltage went up, but then I
thought...why wouldn't the voltage regulator bring it back down in that
case.
Thanks for the help!
Bill B
________________________________________________________________________________
Subject: | Re: Coil Suppression Techniques |
"Eric M. Jones" wrote:
>
>
> > induces a high VOLTAGE which is the opposite polarity of the applied voltage.
The faster the current decreases, the higher the voltage
> > spike. The suppression diode gives the current a place to go allowing
> > it to decay more slowly, producing a lower voltage, reducing the
> > arcing on the switch controlling the relay. The current will never
> > exceed the original current flowing in the coil.
> >
> > Use of the suppression diode delays opening the relay because the
> > current continues to flow for a longer time. The important point is
> > that the suppression diode protects the switch controlling the relay.
> > The effects on the relay contact arcing are secondary.
> >
> > Bob W.
>
>
> Actually, Eric is in bed with the cold/flu. And Paul M. keeps calling me up to
rant about politics.....Jeeeze.
>
> Let's clear the air regarding coil suppression.
>
> When the relay is closed (and as I said this is targeted mainly at contactor
relays), the relay coil has a large amount of energy stored in its inductor. When
the relay coil switch is opened, the field collapses and a problematic high
voltage is produced (the voltage depends on the several construction variables).
I think we agree to this point.
>
> **** Now, it might seem that the current produced by the collapsing field is
opposite its normal direction. This is not so. The coil current is in the same
direction, but the relay coil has changed from being the Load to being the Generator.
If you look at the diode direction, you will see that a current in the
opposite direction could not flow at all, and the diode would serve no purpose.
>
> I agree with Bob W. that the coil suppressor protects the switch and anything
else that provides power to the relay. It also provides other beneficial effect.
However, not having a coil suppressor is not an option.
>
> Indeed, the best way to preserve the contactor's own power contacts is to have
NO coil suppressor and just rip them apart as fast and as far as possible as
possible. But everything else would suffer.
>
> The common (and historic) coil suppression technique that minimized damage to
other components like the on/off switch was to shunt the coil with a reversed
bias diode (a diode arranged so that it does not normally conduct current). Now
when the coil's magnetic field collapses, it induces a
> current that is shorted by the diode. The current flows through the coil and
stops in a very short time, lowering the voltage by lengthening the field collapse
time.
>
> This longer field collapse time is deleterious to the power contacts, and (by
Tyco P&B's information) can actually cause momentary re-closure which manifests
as chatter, bouncing, etc. I assume this depends on the load, and the particulars
of the contactor.
>
> But this approach raises some red flags:
> 1) The diode must not be driven over-current.
> 2) The delay to opening must be minimized.
> 3) The suppression device should last longer than the contactor.
> 4) The ground bounce oscillations should be handled. (for inductive loads)
>
> Now this is where Bob N. and I part company. Bob runs tests and depends on experience,
I just read technical papers and study spec sheets. I claim one should
dump the diode and use a newer approach. Bob N. claims the diode is good enough.
I claim the major purveyors of contactors now use back-to-back zeners or
bidirectionals. Bob N. can show lots of relays that use diodes.
>
> There you go.
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones(at)charter.net
>
>
>
OK, that's better. You have stated the physics correctly.
The only minor point I might make is that the fourth paragraph is not
entirely accurate (marked **** above). I wouldn't expect the current
produced by the collapsing field to be in the opposite direction. What
I did say was that the voltage generated by the collapsing field was
of the opposite polarity to the originally applied voltage. If that
weren't true, the diode wouldn't provide any benefit.
As to the usefulness of a suppression technique more complex than a
diode, it seems to me that Bob N.'s test have shown that the effect on
the contactors used in OBAM aircraft is fairly minor. It's interesting
that the table shown in the PDF you referenced earlier shows the
relationship between various suppression techniques and drop out time
when the important factor is armature velocity. Did the engineers that
wrote this paper take any data on armature velocity? They don't say.
Did they test hundreds of relays to failure? The don't say. A tech
paper needs to be based on experience or it's of little value. Bob's
data shows a reduction in armature velocity. That is consistent with
statements in the PDF. Bob has characterized the reduction and
concluded that it's minor, based on his invaluable experience.
Bob W.
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/cables/
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Coil Suppression Techniques |
>
>
> > induces a high VOLTAGE which is the opposite polarity of the applied
> voltage. The faster the current decreases, the higher the voltage
> > spike. The suppression diode gives the current a place to go allowing
> > it to decay more slowly, producing a lower voltage, reducing the
> > arcing on the switch controlling the relay. The current will never
> > exceed the original current flowing in the coil.
> >
> > Use of the suppression diode delays opening the relay because the
> > current continues to flow for a longer time. The important point is
> > that the suppression diode protects the switch controlling the relay.
> > The effects on the relay contact arcing are secondary.
> >
> > Bob W.
>
>
>Actually, Eric is in bed with the cold/flu. And Paul M. keeps calling me
>up to rant about politics.....Jeeeze.
>
>Let's clear the air regarding coil suppression.
>
>When the relay is closed (and as I said this is targeted mainly at
>contactor relays), the relay coil has a large amount of energy stored in
>its inductor. When the relay coil switch is opened, the field collapses
>and a problematic high voltage is produced (the voltage depends on the
>several construction variables). I think we agree to this point.
yes except that "large" is not quantified. We're
talking a handful of millijoules.
>Now, it might seem that the current produced by the collapsing field is
>opposite its normal direction. This is not so. The coil current is in the
>same direction, but the relay coil has changed from being the Load to
>being the Generator. If you look at the diode direction, you will see that
>a current in the opposite direction could not flow at all, and the diode
>would serve no purpose.
>
>I agree with Bob W. that the coil suppressor protects the switch and
>anything else that provides power to the relay. It also provides other
>beneficial effect. However, not having a coil suppressor is not an option.
???? Tens of thousands of aircraft have flown out their
lifetimes (and millions of cars ditto) with no coil
collapse suppression on a variety of inductive loads.
Service life of the controlling devices was perhaps
less than what MIGHT be achieved but running without
it was and still is AN OPTION in numerous antique
vehicles including airplanes.
>Indeed, the best way to preserve the contactor's own power contacts is to
>have NO coil suppressor and just rip them apart as fast and as far as
>possible as possible. But everything else would suffer.
Agreed . . . but "everything else" and "suffering"
are non-identified and non-quantified.
>The common (and historic) coil suppression technique that minimized damage
>to other components like the on/off switch was to shunt the coil with a
>reversed bias diode (a diode arranged so that it does not normally conduct
>current). Now when the coil's magnetic field collapses, it induces a
>current that is shorted by the diode. The current flows through the coil
>and stops in a very short time, lowering the voltage by lengthening the
>field collapse time.
agreed
>This longer field collapse time is deleterious to the power contacts, and
>(by Tyco P&B's information) can actually cause momentary re-closure which
>manifests as chatter, bouncing, etc. I assume this depends on the load,
>and the particulars of the contactor.
I've never seen a spreading contact re-reclose. Have
you some examples of where this has been observed?
Chatter, bouncing . . . yes ALL contacts in switches,
relays and contactors do not close and stay closed
on first contact. I've seen as few as 2 or 3 closures-
before-stable and as many as dozens. I counted over 25
bounces in one of traces I recently published Mercury
wetted relays and solid-state switches are some exceptions.
>But this approach raises some red flags:
>1) The diode must not be driven over-current.
Sure . . . but even the most delicate of silicon
power rectifiers is not at risk for over-current
in situations common to our aircraft.
>2) The delay to opening must be minimized.
Why? There ARE the occasional condition where
TIMING is important. I've wrestled with "relay
races" in circuits where relay-logic combinations
were polluted because relay timing was not consistent
or carefully accommodated.
In every situation we're considering here, the
relay or contactor is manually operated by
crew . . . whether or not the contacts begin
to move 1 mS or 50 mS after the pilot hits
the switch is transparent to both the operator
and to system performance.
>3) The suppression device should last longer than the contactor.
??? Have you seen a contactor kill its own
collapse suppressor? I just measured the inductance
of an S701-1 contactor at 45 mH. LI^2/2 = (.045 x
.9 x .9)/2 = 18 millijoules. The 1N4001
is rated to take 30A (1v drop) for 8.3 mS for
250 millijoles. My favorite diode 1N5400
is good for 200A for 8.3 mS for a spike
catching capability of 1660 millijoules.
I can't imagine where we'd encounter an energy-
stress situation for coil suppression.
>4) The ground bounce oscillations should be handled. (for inductive loads)
Not sure how you're using "ground bounce". Inductance
across a ground system is an issue within devices
where very fast, tiny signals are handled. The
ground system in a vehicle is exceedingly variable,
difficult to control which is why we assume that
products installed in an airplane should be able to
withstand a variety of butt-ugly noises including
"ground bounce". A diode across a relay coil has no
significance to the generation or suppression of
ground bounce as I perceive the phrase. If you
have another perception, I'll need to understand
it before I can intelligently discuss it.
>Now this is where Bob N. and I part company. Bob runs tests and depends on
>experience,
. . . repeatable experiments are the ingredients
that go into recipes for success.
>I just read technical papers and study spec sheets.
the printed word is an exceedingly important
communications tool for teachers with simple-ideas
to explain. At the same time, anyone can write down
ideas that are easily mis-interpreted or are just
plain wrong. One must always be wary of poorly
explained ideas promoted only with convincing words.
No teacher is insulted by honorable skepticism.
> I claim one should dump the diode and use a newer approach. Bob N.
> claims the diode is good enough.
. . . for relays and contactors as WE use them
in OUR airplanes. I will happily use any alternative
technique that improves on performance, reliability
or cost of ownership. Here's an example of arc
suppression added across the contacts of my products
control relay:
http://aeroelectric.com/Pictures/Relays/Relay_with_Arc_Suppression_s.jpg
Here the concern was for the effects of an inductive
load on ME as the controlling device. I had no
control over configuration of load so I had to
cover the bases in the design of my product and
put suppression on not on my coil but my contacts!
> I claim the major purveyors of contactors now use back-to-back zeners or
> bidirectionals. Bob N. can show lots of relays that use diodes.
I don't thing we have "parted company" if you're
agreeing that the diode is . . .
(1) the ultimate transient suppressor from a energy
management perspective, convenience and cost
of ownership and . . .
(2) causes an extended but insignificant
drop-out delay for the ways we use relays
and contactors and . . .
(3) offers an insignificant influence upon
service life for applications under discussion.
I'll go plot the performance characteristics
of 6-8 different ways to manage stored energy
in a contactor coil. I'll also discuss the
fact that selection of arc suppression techniques
depend on the whole suite of design considerations
that may go beyond starter/master switch and starter/
battery contactor service life.
Bob . . .
________________________________________________________________________________
Subject: | Z-19 hypothetical question |
From: | "user9253" <fran5sew(at)banyanol.com> |
Here is a hypothetical question for you electrical gurus. A pilot is flying on
trip in a plane wired according to schematic Z-19. Shortly after takeoff the
main battery contactor fails open. The pilot does not notice anything wrong
because the engine battery contactor is closed and the alternator is still functioning.
Eventually the main battery discharges due to loads on the main battery
bus, and the pilot notices some things not working. He knows there is a
problem but does not know the cause. Just to be safe, he closes the Endurance-Bus
Alternate-Feed switch. The question is, does the charging current blow a
fuse? (either one or both fuses) The current path is from the Main Power Distribution
Bus, 7A fuse, diode, Endurance Bus, Alternate-Feed switch, fuse, Main
Battery Bus, to the main battery.
If the answer to the above question is yes, then everything on the Endurance Bus
might not work for the remainder of the flight. I think the best solution is
to increase the wire and fuse sizes in the above circuit. What size is required?
Other possible solutions such as another diode or relay create additional
problems.
Joe Gores
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184591#184591
________________________________________________________________________________
Subject: | Re: Z-19RB - review and simplify? |
From: | "user9253" <fran5sew(at)banyanol.com> |
Do any of your electronic displays have voltage monitoring and alarm features?
If so, you would not have to use that low voltage module.
I would use fuses. They have several advantages. You will not be servicing equipment
very often and you can pull a fuse.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184595#184595
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Previous Master solonoid clicking |
>
>
>I left out that my plane is wired closely to the Z-19 architecture.
>Also the low voltage module is one that I built using one of Bob's boards
>from the old model.
>
>Bill B
>
>
>A while back, I discussed a clicking sound that I heard after I turned the
>alternator on when the engine was running.
>Today I discovered that my low voltage module was not working and when I
>removed it, the clicking went away.
How long has the system been in operation? Has it worked as
expected for any period of time and is now behaving differntly?
>I tested the module by putting +9V on pin 4, grounded pin 5, and looked for
>the LED to come on and also for a ground to show up on pin 1. No light, no
>ground. Must have crapped out??!!
Send it back for evaluation/repair. You pay the postage
to me, I'll pay it back to you.
>I also noticed that when the module was disconnected, If I had the main
>battery set to "Alternator", and the engine battery set to "ON", I got about
>13.4V. If I flipped the engine battery switch to "Auto", the voltage went
>up to about 14.6V.
>I was at a loss as to why this would be. I didn't try it with the engine
>battery set to "OFF", so I don't know what would have happened if I did.
>
>Does anyone have any ideas as to what was happening to cause the clicking if
>the module caused it, and why the voltage increase? I at first thought..I
>am turning one of the batteries off, so the voltage went up, but then I
>thought...why wouldn't the voltage regulator bring it back down in that
>case.
A reasonable hypothesis suggests that the engine battery
was discharged and was pulling the alternator down while
it was huffing to push energy back into the battery. Putting
the LVWarn/ABMM switch in the AUTO position with the module
disconnected is the same as turning that battery OFF which
would relieve the alternator of that re-charge load. You
didn't mention what RPM the engine was running while these
observations were made. It seems likely that the bus
voltage would come raise while charging the battery if
RPMs were high enough for alternator to develop full output.
Suggest you put battery maintainers on both batteries.
Let's evaluate/repair the LVWarn/ABMM module as needed
before we carry the study further.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Robert Feldtman" <bobf(at)feldtman.com> |
Subject: | Re: Coil Suppression Techniques. |
Cable TV is wasted bandwidth (except for cool channels like military
channel, national geographic, NASCAR etc..) Otherwise I think cable TV kills
Betz cells.. (that'll send folks heading for wikipedpia!)
bobf
On 5/23/08, Robert L. Nuckolls, III wrote:
>
> nuckolls.bob(at)cox.net>
>
>
> Hi Bob, on behalf of myself and many others I'm sure I'd like to thank you
>> for - first of all, your restraint, and of course your informative posts
>> that make it so easy for the rest of us to click on the links of your
>> experiments.
>>
>> I joined this list probably two years ago and a great deal of what was
>> discussed was over my head (and still is!) ... I received the daily emails
>> and for the longest time would check out the subject titles and more often
>> than not delete the email. Over time I've 'gotten up to speed', read your
>> book, and spent the time to learn (whether the particular subject concerned
>> my airplane or not).
>>
>
> That's what Richard Feynman describes as "The
> Pleasure of Finding Things Out". Virtually every
> classroom we all sat in for the first time offered
> tons of information sometimes accompanied with
> lucid explanation and even real-life connections.
> It is not uncommon when "getting a drink from the
> fire hose" that certain simple-ideas don't catch
> on or fit into the current library of life experiences.
>
> But as you've alluded, there is an osmosis
> effect . . . tiny bits of the big drink soak
> in. At some point in the future, a sort of
> epiphany may take place when one realizes that
> "Yeah, I KNOW how that works".
>
> It still happens to me regularly.
>
>>
>> It's all too easy to "gold plate the spec" to cover ALL conceivable
>> conditions that a particular component may see whether applicable or not.
>> It is of GREAT value to me that you repeatedly base your responses on OBAM
>> aircraft. Meaning... if age/environmental factors, etc is going to kill my
>> component before I or my designed system does then thats exactly what I need
>> to know. I have always found your posts and advice to be practical in the
>> real world (where most of us live with our little homebuilt airplanes) and
>> considerate of my time & money.
>>
>
> To me, being an engineer was the ideal connection
> between pure physics and people. I was exceedingly
> fortunate in my career to have some good teachers
> AND a charter to make my ideas play in the marketplace.
> I.e, offer competitive value that was attractive
> for performance, price and after-the-sale service.
> VERY few of my contemporaries have enjoyed so broad
> an experience.
>
>
>> I continue to learn from all the contributors and contributions to the
>> site. Best Regards to all and my apologies for feeling the need to 'waste'
>> bandwidth! ;)
>>
>
> Forgive me but that "wasted bandwidth" canard is
> really raises the ol' blood pressure. It seems most
> often used by individuals who complain to other
> individuals about the use of a communications tool
> that is nobody's property . . . a term almost never
> used in a exchange that quests for understanding of
> simple ideas.
>
> If one wants to bemoan "wasted bandwidth", just
> hit any cable channel for an hour and make notes on
> what one learns that adds any value to their lives.
> I.e., how did the $time$ spent today make one's life
> any more enjoyable or confident tomorrow?
>
> I view $time$ spent here as an opportunity to
> fine tune my own skills as well as encouragement
> to broaden my own understanding. Folks on the List
> are not always aware of the $time$ spent to firm
> up a foundation for an reply before I post it.
> You folks are as useful to me as I hope I am to
> all of you. $Time$ and 'bandwidth' used in that
> endeavor is never a waste.
>
> Everyone on the List has an opportunity to be both
> student and teacher. It has nothing to do with
> the total experience of either individual. Any
> instance where understanding supported by repeatable
> experiment is exchanged, there is opportunity
> for growth for everyone who chooses to
> participate.
>
> Bob . . .
>
>
________________________________________________________________________________
From: | Harley <harley(at)AgelessWings.com> |
Subject: | Re: Coil Suppression Techniques. |
Right...thanks Bob...now I have to look up a web page full of more terms
and words!
Excerpt from Wikipedia:
"Betz cells have one apical dendrite typical to pyramidal neurons, they
have more primary dendritic shafts, and these do not leave the soma only
at basal angles but rather branch out from almost any point asymmetrically."
Harley
------------------------------------------------------------------------
Robert Feldtman wrote:
> Cable TV is wasted bandwidth (except for cool channels like military
> channel, national geographic, NASCAR etc..) Otherwise I think cable TV
> kills Betz cells.. (that'll send folks heading for wikipedpia!)
>
> bobf
>
>
________________________________________________________________________________
From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
Subject: | Previous Master solonoid clicking |
Bob,
Thanks for the evaluation/repair offer. I will send it in, but please
remember that you only supplied the board. I supplied the components. You
don't owe me any free repair!
The engine, with this module working, has been running on the ground for
probably 2 hours. I am not ready for flight yet.
Bill
-----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: Saturday, May 24, 2008 8:32 AM
Subject: RE: AeroElectric-List: Previous Master solonoid clicking
-->
>
>
>I left out that my plane is wired closely to the Z-19 architecture.
>Also the low voltage module is one that I built using one of Bob's
>boards from the old model.
>
>Bill B
>
>
>A while back, I discussed a clicking sound that I heard after I turned
>the alternator on when the engine was running.
>Today I discovered that my low voltage module was not working and when
>I removed it, the clicking went away.
How long has the system been in operation? Has it worked as
expected for any period of time and is now behaving differntly?
>I tested the module by putting +9V on pin 4, grounded pin 5, and looked
>for the LED to come on and also for a ground to show up on pin 1. No
>light, no ground. Must have crapped out??!!
Send it back for evaluation/repair. You pay the postage
to me, I'll pay it back to you.
>I also noticed that when the module was disconnected, If I had the main
>battery set to "Alternator", and the engine battery set to "ON", I got
>about 13.4V. If I flipped the engine battery switch to "Auto", the
>voltage went up to about 14.6V.
>I was at a loss as to why this would be. I didn't try it with the
>engine battery set to "OFF", so I don't know what would have happened if I
did.
>
>Does anyone have any ideas as to what was happening to cause the
>clicking if the module caused it, and why the voltage increase? I at
>first thought..I am turning one of the batteries off, so the voltage
>went up, but then I thought...why wouldn't the voltage regulator bring
>it back down in that case.
A reasonable hypothesis suggests that the engine battery
was discharged and was pulling the alternator down while
it was huffing to push energy back into the battery. Putting
the LVWarn/ABMM switch in the AUTO position with the module
disconnected is the same as turning that battery OFF which
would relieve the alternator of that re-charge load. You
didn't mention what RPM the engine was running while these
observations were made. It seems likely that the bus
voltage would come raise while charging the battery if
RPMs were high enough for alternator to develop full output.
Suggest you put battery maintainers on both batteries.
Let's evaluate/repair the LVWarn/ABMM module as needed
before we carry the study further.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
From: | "Sam Hoskins" <shoskins(at)mchsi.com> |
Subject: | Re: Z-19RB - review and simplify? |
I believe the D180 does have warnings, but since I already own Bob's LV
warning gizmo, I thought I'd go ahead and use it anyway.
Thanks for the input.
Sam
On Fri, May 23, 2008 at 8:03 PM, user9253 wrote:
> >
>
> Do any of your electronic displays have voltage monitoring and alarm
> features? If so, you would not have to use that low voltage module.
>
> I would use fuses. They have several advantages. You will not be
> servicing equipment very often and you can pull a fuse.
>
> Joe
>
> --------
> Joe Gores
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=184595#184595
>
>
________________________________________________________________________________
From: | "Sam Hoskins" <sam.hoskins(at)gmail.com> |
Subject: | Re: Z-19RB - review and simplify? |
I believe the D180 does have warnings, but since I already own Bob's LV
warning gizmo, I thought I'd go ahead and use it anyway.
Thanks for the input.
Sam
On Fri, May 23, 2008 at 8:03 PM, user9253 wrote:
> >
>
> Do any of your electronic displays have voltage monitoring and alarm
> features? If so, you would not have to use that low voltage module.
>
> I would use fuses. They have several advantages. You will not be
> servicing equipment very often and you can pull a fuse.
>
> Joe
>
> --------
> Joe Gores
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=184595#184595
>
>
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Z-19 hypothetical question |
>
>Here is a hypothetical question for you electrical gurus. A pilot is
>flying on trip in a plane wired according to schematic Z-19. Shortly
>after takeoff the main battery contactor fails open. The pilot does not
>notice anything wrong because the engine battery contactor is closed and
>the alternator is still functioning. Eventually the main battery
>discharges due to loads on the main battery bus, and the pilot notices
>some things not working. He knows there is a problem but does not know
>the cause. Just to be safe, he closes the Endurance-Bus Alternate-Feed
>switch. The question is, does the charging current blow a fuse? (either
>one or both fuses) The current path is from the Main Power Distribution
>Bus, 7A fuse, diode, Endurance Bus, Alternate-Feed switch, fuse, Main
>Battery Bus, to the main battery.
EXCELLENT question!
It's that "just to be safe" thinking that causes
joe-pilot to stubs his toe. Every design feature
of a system is (or at least should be) put in place
for a specific purpose. In this case, the E-bus alternate
feed switch is intended to provide an alternative power
for e-bus powered electro-whizzies WHEN the main bus
voltage falls too low to be a practical source of energy.
99.9+ percent of the time this is because the
alternator is no longer supporting ship's loads for
what ever reason.
>If the answer to the above question is yes, then everything on the
>Endurance Bus might not work for the remainder of the flight. I think the
>best solution is to increase the wire and fuse sizes in the above
>circuit. What size is required? Other possible solutions such as another
>diode or relay create additional problems.
Controls in our aircraft have beneficial
effects that are addressed as part of a constellation
of design goals. Some controls are not totally
free of misadventure or even hazard for having been
operated at an inappropriate time or inappropriate
way.
The only time I would close the e-bus alternate feed
switch is after the low voltage warning light has
informed me of a need for completing the flight battery(ies)
only.
Referring to . . .
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z19m_1.pdf
http://www.aeroelectric.com/PPS/Adobe_Architecture_Pdfs/Z19m_2.pdf
In the hypothetical you posed, electro-whizzies to
first start spinning down would be the clock and the
#2 fuel pump. Also, the engine would be complaining if
the current configuration of switches had the engine
running from the main battery instead of the engine
battery. In this case, the first thing to do is bring
the engine's alternative power switch ON to see if the
engine gets happier. This is the hazard-free thing
to do irrespective of how the engine was being powered
before the "event".
Once the engine is happy, use the voltmeter to explore
the condition of the two batteries. One would quickly
discover that for whatever reason, one of the batteries
is low.
Now is not the time to initiate trouble shooting
procedures with switch-flipitis and non-piloting
thought processes. Save all that fun stuff until
parked on the ramp.
Now, suppose a contactor fails during flight but
the battery does not fall so low that electro-whizzies
start complaining. It's conceivable that the airplane
gets parked with an undiscovered latent failure. This
is why the pre-flight check for dual battery airplanes
is to turn battery switches on one at a time before starting
the engine and comparing similarity of voltage readings
for the two batteries under the same load.
This will catch the latent failure before next flight.
This brings up the rationale for separate normal
and alternative engine power control switches as opposed
to the multi-pole, two-position switches suggested by
other designers. This hypothetical illustrates the
feature of being able to ADD the alternative engine
source to the current engine source . . . I.e. disturb
as few controls in the present configuration as possible
while resolving the appropriate plan-B for comfortable
termination of flight. It also eliminates having mechanical
failure of the single switch taking the engine power down.
More than one dark-n-stormy night story has related
situations where pilot fiddle-itis made things
progressively worse. I had this conversation with
a client just yesterday when the question was asked,
"what happens if the warning light comes on, the pilot
pulls the breaker and resets it, the warning light goes
out and he tries to operate the system AGAIN and
further aggravates the out-of-rig condition?"
My answer was, "If the pilot survives to tell you
about it, yank his job if not also his ticket". If the POH
or the check-pilot that approved him for the aircraft
doesn't cover the proper procedure for responding to
that particular warning, then yank HIS job and/or ticket."
The point is that carefully crafted systems need to
be supported not just with good systems and human
factors engineering. The teachers charged with
insuring skill and understanding on the part of
future users are just as critical as the designers.
More folks die out of apathy/ignorance than of systems
failure.
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Previous Master solonoid clicking |
>
>
>Bob,
>Thanks for the evaluation/repair offer. I will send it in, but please
>remember that you only supplied the board. I supplied the components. You
>don't owe me any free repair!
But I do owe you a "grade" on your efforts with
a goal of honing your skills. It also affords me a data
point which may have future value.
I've fielded a ton of incoming cabbages and tomatoes
for allegedly faulty design and/or advice . . . all
based on situations about which I was honorably skeptical
but unable to defend for lack of hands-on experience.
This was in spite of life-time, money-back guarantees
so I suspect the allegations were bogus. But my warranty
extends to both ideas and product so we're doing each
other a favor here my friend.
>The engine, with this module working, has been running on the ground for
>probably 2 hours. I am not ready for flight yet.
Understand. Let's see if we can figure out
what's going on.
Bob . . .
________________________________________________________________________________
From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Subject: | Re: Z-19 hypothetical question |
P.S. A product under development . . .
http://www.aeroelectric.com/Catalog/AEC/9011/9011-700-1C.pdf
has two channels of LOW Voltage warning. The second specifically intended
to watch the aux battery for failure of contactor or failure of
pilot to close said contactor.
I don't think I'd put a low voltage warning in just for that purpose
but in this case, it was about a 7% increase in parts count to
add the feature to an existing design.
Just some additional food for thought.
Bob . . .
________________________________________________________________________________
From: | LarryMcFarland <larry(at)macsmachine.com> |
Subject: | memory versus tape |
Hi Guys,
Im wondering if anyone has plugged in a small voice recorder for ATC
communications. The latest requirements have ATC providing total taxi
instructions. That guidance has the tower rapidly describing a 7-point
guidance that used to be 2 or 3-points. Its always been required to do
a read-back to ATC in its entirety. Every ATC controller has his own
creatively unique delivery that also complicates the pickup and
read-back. Has anyone found a better way of dealing with this excessive
mental-bandwidth aside from just more practice or a tape recorder?
We need a better idea here,,,,,,,,,,,,
Thanks,
Larry McFarland 601HDS at www.macsmachine.com
________________________________________________________________________________
From: | "earl_schroeder(at)juno.com" <earl_schroeder(at)juno.com> |
Subject: | Re: memory versus tape |
Hi Larry,
I had a 'solid state' device sold by someone at Oshkosh years ago wired in but
I could not figure how I was going to read back the recording short of just playing
it to ATC. Somehow, I didn't think they would be happy with that solution..
As time passed, I figured out that they always deliver clearances in the exact
order so I printed some address labels with blanks to insert the items that change..
worked for me.
Now if ATC has no standard phraseology for taxi clearances, I would constantly
ask for progressive instructions. I'll bet if a lot would, standardization would
soon follow. :)
Maybe this isn't a 'better idea' but my best shot. Earl
-- LarryMcFarland wrote:
Hi Guys,
Im wondering if anyone has plugged in a small voice recorder for ATC
communications. The latest requirements have ATC providing total taxi
instructions. That guidance has the tower rapidly describing a 7-point
guidance that used to be 2 or 3-points. Its always been required to do
a read-back to ATC in its entirety. Every ATC controller has his own
creatively unique delivery that also complicates the pickup and
read-back. Has anyone found a better way of dealing with this excessive
mental-bandwidth aside from just more practice or a tape recorder?
We need a better idea here,,,,,,,,,,,,
Thanks,
Larry McFarland 601HDS at www.macsmachine.com
________________________________________________________________________________
From: | "Scott Freeman" <sgfreeman(at)smyth.net> |
Subject: | Re: memory versus tape |
Look at the PS-Engineering PMA-4000 audio panel with voice record. It has a
lot of functionality price and takes up little panel space.
----- Original Message -----
From: "LarryMcFarland" <larry(at)macsmachine.com>
Sent: Saturday, May 24, 2008 7:44 PM
Subject: AeroElectric-List: memory versus tape
>
>
> Hi Guys,
>
> Im wondering if anyone has plugged in a small voice recorder for ATC
> communications. The latest requirements have ATC providing total taxi
> instructions. That guidance has the tower rapidly describing a 7-point
> guidance that used to be 2 or 3-points. Its always been required to do a
> read-back to ATC in its entirety. Every ATC controller has his own
> creatively unique delivery that also complicates the pickup and read-back.
> Has anyone found a better way of dealing with this excessive
> mental-bandwidth aside from just more practice or a tape recorder?
>
> We need a better idea here,,,,,,,,,,,,
>
> Thanks,
>
> Larry McFarland 601HDS at www.macsmachine.com
>
>
>
________________________________________________________________________________
From: | "Robert Feldtman" <bobf(at)feldtman.com> |
Subject: | Re: memory versus tape |
short term memory, repitition and read back comes with practice, but at a
towered airport with expected complex taxi instructions, have a pencil in
your hand and paper on the knee before you call - and use some sort of
"shorthand" to abbreviate as it comes across. More important than reading it
back is following exactly what they tell you to do. I also almost always
call the ground control before crossing any runway "Is 125GS cleared to
cross 34?" Sometimes they get upset and say "your taxi clearance assumes
that" but I don't care. I'd rather use 15 secs of radio than get twanged.
Having the shorthand written instructions in front of you helps - you can
also have on the other knee the airport diagram -
No electronic gizmo is going to accomplish all that. But it is cool to show
off to people.
bobf
On Sat, May 24, 2008 at 6:44 PM, LarryMcFarland
wrote:
> larry(at)macsmachine.com>
>
> Hi Guys,
>
> I'm wondering if anyone has plugged in a small voice recorder for ATC
> communications. The latest requirements have ATC providing total taxi
> instructions. That guidance has the tower rapidly describing a 7-point
> guidance that used to be 2 or 3-points. It's always been required to do a
> read-back to ATC in its entirety. Every ATC controller has his own
> creatively unique delivery that also complicates the pickup and read-back.
> Has anyone found a better way of dealing with this excessive
> mental-bandwidth aside from just more practice or a tape recorder?
>
> We need a better idea here,,,,,,,,,,,,
>
> Thanks,
>
> Larry McFarland 601HDS at www.macsmachine.com
>
>
________________________________________________________________________________
From: | "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net> |
I recently heard that all aircraft to be flown IFR must have a Faraday Cage
in the structure. In other words it must be surrounded with a conductive
material in the skin. This is to conduct static electricity.
Does anyone know anything about this?? Or is it another myth? If there are
any regulations, can you please point me to them.
Thanks for your input.
Roger
________________________________________________________________________________
From: | "Robert Feldtman" <bobf(at)feldtman.com> |
Subject: | Re: Faraday Cage |
myth
bobf
W5RF
On 5/26/08, ROGER & JEAN CURTIS wrote:
>
>
> I recently heard that all aircraft to be flown IFR must have a Faraday Cage
> in the structure. In other words it must be surrounded with a conductive
> material in the skin. This is to conduct static electricity.
>
>
> Does anyone know anything about this?? Or is it another myth? If there are
> any regulations, can you please point me to them.
>
>
> Thanks for your input.
>
>
> Roger
>
>
________________________________________________________________________________
Subject: | Re: memory versus tape |
From: | "Eric M. Jones" <emjones(at)charter.net> |
Don't try to look cool and pretend you know what you're doing if you are uncertain
of the instructions, just say "Request Progressive Taxi Instructions." Progressive
being the key word. Remember in all cases YOU are the customer who is
to be served, not the ground controller. Remember "Confess, Communicate, Comply."
always trumps, "Hold my beer...Watch this!"
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=184849#184849
________________________________________________________________________________
From: | BobsV35B(at)aol.com |
Subject: | Re: memory versus tape |
Good Morning Eric,
The statement "Remember in all cases YOU are the customer who is to be
served, not the ground controller"
was the mantra used by the last two female leaders of the FAA.
An order has recently been issued at the direction of Congressman Oberstar,
that the FAA's business is not to be conducted in that manner. Instead, they
are to consider that their mission is to issue violations.
While the air traffic controllers are not, and most do not want to be,
issuers of violations, they are in the same boat as we pilots when it comes to
anything which jeopardize their employment.
The new attitude stinks and it comes not only from congress, but from the
current white house.
Be careful out there.
In addition to our needing to avoid physical danger, we need to be aware
that the FAA is definitely not there to help.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
628 West 86th Street
Downers Grove, IL 60516
630 985-8502
Stearman N3977A
Brookeridge Air Park LL22
In a message dated 5/26/2008 8:29:16 A.M. Central Daylight Time,
emjones(at)charter.net writes:
Don't try to look cool and pretend you know what you're doing if you are
uncertain of the instructions, just say "Request Progressive Taxi Instructions."
Progressive being the key word. Remember in all cases YOU are the customer
who is to be served, not the ground controller. Remember "Confess,
Communicate, Comply." always trumps, "Hold my beer...Watch this!"
**************Get trade secrets for amazing burgers. Watch "Cooking with
Tyler Florence" on AOL Food.
(http://food.aol.com/tyler-florence?video=4&?NCID=aolfod00030000000002)
________________________________________________________________________________
From: | "Mark Means" <mtmeans(at)cox.net> |
Subject: | OV protection - internally regulated alternator |
I have been building an automotive conversion Velocity for many years now
and have gone through the OV protection is good (I actually have an OV
module I built and tested) to the "no longer recommended nor do we recommend
internally regulated alternators". I am running my engine successfully, have
Eaton contactors to isolate redundant batteries as well as the B lead which
is controllable via CB. I also have the monster fuse in the B lead. I
searched the archives for a couple hours and have seen much discussion on
nuisance OV breaker trips and alternator problems. My questions are:
- what are the odds of a runaway and is this usually a slow increase in
voltage or rapid?
- what is the problem with the OV protection with the internally regulated
alternators if the module works as designed and pulls the alternator offline
in a runaway situation?
- if the alternative is electronic monitoring and pulling the alternator
offline, is there a downside to this other than slow reflexes?
- what are the foreseeable consequences of delays of pulling it offline?
Thanks for any help sorting this out.
Mark Means
________________________________________________________________________________
From: | Henador Titzoff <henador_titzoff(at)yahoo.com> |
Subject: | Re: Faraday Cage |
Roger,
I am willing to bet that you did NOT hear that from an FAA guy. I have never read
that in the FARs. Just because I've never read it, though, doesn't mean it
doesn't exist; however, I 've never heard it before, and there are many aircraft
manufacturers out there like Cirrus, Diamond, etc. who have never it either.
My experimental airplane is a composite fiberglass/foam airplane, and it's
never heard of it. I will be very surprised if anyone on this email list will
be able to quote a FAR that says so.
Sounds like a good myth in the making to me.
Henador Titzof
----- Original Message ----
From: ROGER & JEAN CURTIS <mrspudandcompany(at)verizon.net>
Sent: Monday, May 26, 2008 8:33:19 AM
Subject: AeroElectric-List: Faraday Cage
I recently heard that all aircraft to be flown IFR must have
a Faraday Cage in the structure. In other words it must be surrounded
with a conductive material in the skin. This is to conduct static
electricity.
Does anyone know anything about this?? Or is it another myth?
If there are any regulations, can you please point me to them.
Thanks for your input.
Roger
________________________________________________________________________________
From: | Henador Titzoff <henador_titzoff(at)yahoo.com> |
Subject: | Re: Faraday Cage |
Roger,
I am willing to bet that you did NOT hear that from an FAA guy. I have never read
that in the FARs. Just because I've never read it, though, doesn't mean it
doesn't exist; however, I 've never heard it before, and there are many aircraft
manufacturers out there like Cirrus, Diamond, etc. who have never it either.
My experimental airplane is a composite fiberglass/foam airplane, and it's
never heard of it. I will be very surprised if anyone on this email list will
be able to quote a FAR that says so.
Sounds like a good myth in the making to me.
Henador Titzof
----- Original Message ----
From: ROGER & JEAN CURTIS <mrspudandcompany(at)verizon.net>
Sent: Monday, May 26, 2008 8:33:19 AM
Subject: AeroElectric-List: Faraday Cage
I recently heard that all aircraft to be flown IFR must have
a Faraday Cage in the structure. In other words it must be surrounded
with a conductive material in the skin. This is to conduct static
electricity.
Does anyone know anything about this?? Or is it another myth?
If there are any regulations, can you please point me to them.
Thanks for your input.
Roger
________________________________________________________________________________
Subject: | Re: Z-19 hypothetical question |
From: | "user9253" <fran5sew(at)banyanol.com> |
May 12, 2008 - May 26, 2008
AeroElectric-Archive.digest.vol-hv