Today's Message Index:
----------------------
0. 12:10 AM - [Please Read] Why I Have A Fund Raiser... (Matt Dralle)
1. 01:07 AM - SD-8/SD20 question (B Tomm)
2. 01:32 AM - Location of battery bus (B Tomm)
3. 06:37 AM - Re: Radio interlock (Jeff Page)
4. 08:08 AM - Re: Location of battery bus (Robert L. Nuckolls, III)
5. 08:33 AM - Re: SD-8/SD20 question (Robert L. Nuckolls, III)
6. 09:44 AM - Question about Relays/Switches (Scott R. Shook)
7. 10:46 AM - Re: Question about Relays/Switches (Jonathan B. Cook)
8. 11:42 AM - Re: Question about Relays/Switches (Robert L. Nuckolls, III)
9. 11:48 AM - Re: Question about Relays/Switches (Jonathan B. Cook)
10. 01:13 PM - Re: Question about Relays/Switches (Robert L. Nuckolls, III)
11. 01:24 PM - Re: Pullable 60 Amp Breaker ()
12. 02:16 PM - Re: Re: Pullable 60 Amp Breaker (Richard T. Schaefer)
13. 03:02 PM - Re: Question about Relays/Switches (Scott R. Shook)
14. 09:22 PM - Re: Location of battery bus (Bill Schlatterer)
15. 09:37 PM - Z-19/RB question Re: Internally shunted ammeter (Johnny Johnson)
16. 10:18 PM - Re: Location of battery bus (B Tomm)
17. 10:32 PM - Re: Radio interlock (Ed)
Message 0
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Subject: | [Please Read] Why I Have A Fund Raiser... |
Dear Listers,
Each year I like to explain why I have a Fund Raiser and also take the opportunity
to express why I think the List Services here provide a superior experience
over the commercial equivalents.
I use the List Fund Raiser each year to offset the costs involved with running
a high performance email list site such as this one. With the annual support from
the List members through the PBS-like Fund Raiser, I have found I can run
the entire site without having to inflect any of the members with those annoying
banner ads flashing up all the time trying to sell little-blue-pills or other
garbage nobody wants or needs. From the comments I've received over the years
regarding the Lists, the great majority of the members really appreciate the
non-commercialism of my List systems and don't mind my 'go-team-go' banter once
a year during November to encourage members to support the Lists.
I believe that the Lists services that I provide here offer many benefits over
the commercial equivalents in a number of ways. The first feature I believe to
be significant is that you cannot receive a computer v*rus from any of these
Lists directly. Each incoming message is filtered and dangerous attachments stripped
off prior to posting. I also provide a Photo and File Share feature that
allows members to share files and bitmaps with other members and everyone can
be assured that these files will be prescanned for any sort of v*rus before
they are posted. More recently, I have enabled limited posting of a number of
file formats including pictures and PDFs.
Another very important feature of this system in my opinion is the extensive List
Archives that are available for download, browsing, and searching. The Archives
go all the way back to the very beginning of each List and with the very
fast Search Engine, the huge size of some of the Archives is a non-issue in quickly
finding the data you're looking for.
And added just a couple of years ago is the new Email List Forum that allows members who prefer the Web BBS-style of List interaction. The beauty of the new List Forums is that they contain the exact same content that is distributed via email. Messages posted via email are cross-posted to the respective Forum and vice versa. The Forums also allow for another convenient method of sharing pictures and other files (http://forums.matronics.com ). Additionally, added recently is the List Wiki that allows members to build their own "Online List Encyclopedia" of sorts, documenting various aspects of their project for all to share ( http://wiki.matronics.com ).
I've been running email Lists and services under the matronics.com domain since
about 1989 starting with RV-List and 30 guys I knew and who where also building
RVs. It has grown into nearly 70 different aviation-related Email Lists and
an associated web site that receives over 34,000,000 hits each year!! Additionally,
the List Email system forwarded well over 77,000 postings last year, accounting
for an unbelievable 33,000,000 (yes, that's 33 MILLION) email messages
delivered to Matronics List subscribers! I think there's a lot of value in supporting
a service that has gone the long haul and is still providing and improving
a high quality service all _without any advertising budget_!
I have to admit running these Lists is a labor of love and I hope it shows in the
quality of the experience that you receive when you get a List Email Message,
Search the Archives, use the List Browser, or surf the Forums and Wiki sites.
The Lists will be here for a long time to come. If you just want to lurk a
while for free, that's great and I encourage you to do so. If you use, appreciate,
and receive value from these Lists, then please support them during the Annual
List Fund Raiser!
List Contribution Web Site:
http://www.matronics.com/contribution
Thank you,
Matt Dralle
Matronics Email List Administrator
Message 1
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Subject: | SD-8/SD20 question |
Bob,
The SD8/SD20 alternators are vacuum pad mounted. The output chart shows the
alt output at various RPMs. Obviously there is a "gear-ratio" between the
engine and the vacuum pump pad. Do you know what this ratio is and does it
vary? In other words, what RPM can I expect the alt to turn at a cruise RPM
of say 2000-2300 RPM? My engine will be IO-360 ECI or Superior, all
electric. This is needed to know what to expect for amp output.
Also, How much does a battery contactor weigh?
Thanks for your excellent resource and discussion list.
Bevan
RV7A All electric
Trying to decide between SD8 as backup Alt or SD20 for a few pounds more
including second contactor.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Wednesday, January 31, 2007 1:46 PM
Subject: Re: AeroElectric-List: Z-13/8 Switch Question
--> <nuckollsr@cox.net>
At 01:21 PM 1/31/2007 -0700, you wrote:
><george@georgejenson.com>
>
>
>Listers / Bob,
>
>I'm planning my electrical system (Z-13/8, Plane Power main alt) and
>panel and want the switches and layout to be as simple and logical as
possible.
>I am considering using two 2-1 switches for the master and the
>alternators as follows:
>
>Master Switch
>Down EBUS: Closes circuit between battery bus and E-bus.
>Middle BATT: Only Battery bus is live.
>Up MAIN: Normal flight position, grounds contacter making Main bus
>live, E-bus is live via diode from Main.
>
>Alternator Switch
>Down BKUP: Grounds contactor making SD-8 backup live to battery.
>Middle OFF: No power source available.
>Up MAIN: Closes circuit between Main bus and main alternator field.
>
>To my thinking, this is plenty logical and user-friendly. In effect,
>these two would replace the following three switches in Z-13/8:
>1. DC Power Master Switch (2-3)
>2. E-Bus Alternate Feed (1-3)
>3. Aux Alt Off/On (1-3)
>
>Questions:
>1. Is this a bad idea in terms of failure exposure - does my risk go up
>by using fewer switches or by using 3-position switches? If so, the
>next three questions are largely moot.
Combined functions open opportunities for single
failures of a switch to affect more than one function.
Choose your combinations carefully. Also be aware that
fewer switches is "simpler" but combined functionality
is more "complex."
>2. Can it be done such that the first is BATT / EBUS / MAIN and the
>second is OFF / BKUP / MAIN such that fully down is off, fully up is
>normal, and middle is "Houston, we have a problem"? This is my first
>choice, but I haven't been able to work out a way to do it with any
>other 3-position switch that I'm aware of. If there is an Off-On-On
>like a 2-1 but with Off on bottom, that would do it, if there is some
>cool way to do it with a 2-10 I haven't conjured it.
This could turn into a long debate as to the desirability
of doing (or not doing) any particular thing. Keep in mind that
the Z-figures have been combed for a number of years to keep
the operation logical and produced an attractive failure mode
effects analysis. While the switch panels illustrated to support
Z-13/8 may have a lot of features, I've resisted efforts to
combine functionality for systems other than cabin comfort,
landing/taxi/wig-wag and other lighting. See:
http://www.aeroelectric.com/PPS/Switch_Panels/Z13-30-ElexIgn.pdf
>3. I lose the ability to have both alternators plugging away at the
>battery at the same time, is this a bug or a feature?
13/8 is not intended to be run with two alternators.
>4. I also lose the ability of having both the Main bus live, and the
>E-Bus live direct from the Battery bus w/o the attendant voltage drop
>from the diode. Again, bug or feature?
What you propose will predictably function as you've suggested.
Just be aware that the considerations for architecture and
functionality goes deeper than numbers of switches and occupied
panel space. Consider further that you'll no doubt want to
sell this airplane at some future date. The more familiar your
prospective customer is with the functionality of the controls,
the better.
Bob . . .
Message 2
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Subject: | Location of battery bus |
Good morning Bob,
Considering Z-13/20 architecture in an RV7A. The Vans recommended position
for the battery is on the firewall in the engine compartment which I agree
with. That being said, the contactors would be located nearby. Would it
follow that the battery bus should also be located on the engine side of the
firewall and if so, would it be appropriate to use a fuse block style as
we've come to appreciate? In other words, would the fuse block style and
associated faston terminals stand up in the FF environment? I would prefer
to see the fuses inside the cockpit just aft of the firewall (cleaner
environment), but to get to here there would be a little more than 6 inches
of unprotected wire.
Thanks again.
Bevan
Message 3
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Subject: | Re: Radio interlock |
> >I had interesting plans to install my com antennas on each wing to
> >keep them farther apart. The idea was that two pilots could each
> use >one of the radios simultaneously - say to talk with ATC and
> FSS (as >opposed to merely monitoring the second channel).
> Do you really need it? I fly two crew planes and we rarely if ever are
> chatting on two radios at the some time, even though we have 4 radios.
> I think one antenna on top of the plane and bottom would be a better
> separation than wing tips. G
Yes. When flying in the USA, I am often trying with difficulty to
raise FSS so I can open my flight plan immediately after takeoff.
This is a high workload time, since I am watching for other traffic
near the airport and also contacting departure to get flight
following. With two pilots and two radios, one can talk with ATC and
the other to FSS.
Top and bottom would be better separation, but I will be installing
amphibious floats, so I am concerned that the wires and floats will
interfere with the radio (assuming I don't manage to break the antenna
off by accident).
Jeff Page
Dream Aircraft Tundra #10
Message 4
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Subject: | Re: Location of battery bus |
At 01:28 AM 11/20/2007 -0800, you wrote:
>Good morning Bob,
>
>Considering Z-13/20 architecture in an RV7A. The Vans recommended
>position for the battery is on the firewall in the engine compartment
>which I agree with. That being said, the contactors would be located
>nearby. Would it follow that the battery bus should also be located on
>the engine side of the firewall and if so, would it be appropriate to use
>a fuse block style as we've come to appreciate? In other words, would the
>fuse block style and associated faston terminals stand up in the FF
>environment? I would prefer to see the fuses inside the cockpit just aft
>of the firewall (cleaner environment), but to get to here there would be a
>little more than 6 inches of unprotected wire.
Don't agonize over it. Do as you've suggested.
Make sure the always-hot wire coming through
the firewall is well absolutely not going to
suffer insulation failure by reason of poor
mechanical support/protection.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 5
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Subject: | Re: SD-8/SD20 question |
At 01:01 AM 11/20/2007 -0800, you wrote:
>
> Bob,
>
>The SD8/SD20 alternators are vacuum pad mounted. The output chart shows the
>alt output at various RPMs. Obviously there is a "gear-ratio" between the
>engine and the vacuum pump pad. Do you know what this ratio is and does it
>vary? In other words, what RPM can I expect the alt to turn at a cruise RPM
>of say 2000-2300 RPM? My engine will be IO-360 ECI or Superior, all
>electric. This is needed to know what to expect for amp output.
You need to check with an engine guru. Call B&C. The
pad gear ratio is either 1:1.5 or 1:1.3 depending on
whether it's a Lycoming or Continental product and
the details escape me at the moment.
>Also, How much does a battery contactor weigh?
The S701 series are 0.8 pounds.
>Thanks for your excellent resource and discussion list.
Your most welcome.
>Trying to decide between SD8 as backup Alt or SD20 for a few pounds more
>including second contactor.
The SD20 is really intended for those unfortunate
individuals who are locked into the ever-safer,
ever-more-expensive, ever-less-efficient, ever-
less-useful world of TC aircraft. These airplanes
benefit greatly from an SD-20 installed like Z-12.
In the OBAM aircraft world, you're first free
to architecture, craft and understand a system that
will get you to airport of intended destination
BATTERY-ONLY if that is your design goal. Adding
the SD-8 on top of an artfully crafted system
increases your endurance capacity to 8A while
holding a battery completely in reserve for
approach to landing.
Given the demonstrated reliability of modern
alternators teamed with the capability offered
by a properly maintained RG battery, there is
no practical reason to burden your airplane and
your budget with an SD-20. I illustrate it in
the 'Connection because it's out there, it's a
good product and it satisfies a rarely encountered
suite of design goals which I humbly suggest
applies to an exceedingly small number of OBAM aircraft.
I keep reminding folks that the vast majority
of light aircraft flown in IMC environments
are architectured like a 1968 C-172. Yet in
all the years of crappy alternators, generally
ignored, flooded-batteries, and woefully ignorant
pilots, a very small number of unhappy arrivals
with the earth have root cause in electrical system
failure. Let's not jack up the worry-pressure by
praying over Z-11, Z-12, Z-13/8 and Z-14 hoping
for a life-preserving epiphany.
If you're planning an all-electric airplane
then Z-13/8 combined with a modern alternator
and dutifully maintained battery gives you
system reliability exceeding that which costs
$tens of thousands$ and $hundreds of pounds$
in the heavy-iron birds.
Bob . . .
Message 6
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Subject: | Question about Relays/Switches |
Morning All,
I am working on some of the electronics of our -7A slider and have a couple
of questions.
Here are some details of our installation:
* I am going with a modified Z19RB electrical system and I am using
some suggestions from Gary at Eggenfellner for wiring our E-Bus.
* We are using Honeywell AML34 lighted rockers and all the information
I see is that they handle 15A - I know we will need some relays.
* One of those switches will be an On-Off-On for switching between
Primary Bus and Essential Bus in the event of an alternator failure.
Questions:
Is there a relay out there that is capable of switching between two
different power sources and outputting to a single power source?
Would I have to use two separate relays for switching between the Primary
Bus and Essential Bus?
While I am using an auto conversion, I am not shopping the local Auto Zone
for electrical equipment. What type of relays would I get? Are Bosch
(insert Amperage) Solid State Relays suitable for our uses?
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
Message 7
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Subject: | Question about Relays/Switches |
Hello Scott,
I am also planning on using the Honeywell AML switches.
The 34 series will handle 15A, but only comes in ON-OFF.
To have the On-Off-On switch you would use a AML 24 series. (like AML24
F B C 2 CA 04) The AML 24 series can switch 5A which should be able
fine for switching a relay.
Jonathan Cook
RV7
________________________________
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Scott
R. Shook
Sent: Tuesday, November 20, 2007 12:39 PM
Subject: AeroElectric-List: Question about Relays/Switches
Morning All,
I am working on some of the electronics of our -7A slider and have a
couple of questions...
Here are some details of our installation:
* I am going with a modified Z19RB electrical system and I am
using some suggestions from Gary at Eggenfellner for wiring our E-Bus.
* We are using Honeywell AML34 lighted rockers and all the
information I see is that they handle 15A - I know we will need some
relays.
* One of those switches will be an On-Off-On for switching between
Primary Bus and Essential Bus in the event of an alternator failure.
Questions:
Is there a relay out there that is capable of switching between two
different power sources and outputting to a single power source?
Would I have to use two separate relays for switching between the
Primary Bus and Essential Bus?
While I am using an auto conversion, I am not shopping the local Auto
Zone for electrical equipment. What type of relays would I get? Are
Bosch (insert Amperage) Solid State Relays suitable for our uses?
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
Message 8
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Subject: | Re: Question about Relays/Switches |
At 10:39 AM 11/20/2007 -0700, you wrote:
>Morning All,
>
>I am working on some of the electronics of our -7A slider and have a
>couple of questions&
>
>Here are some details of our installation:
>
> I am going with a modified Z19RB electrical system and I am using
>some suggestions from Gary at Eggenfellner for wiring our E-Bus.
>
> We are using Honeywell AML34 lighted rockers and all the
>information I see is that they handle 15A I know we will need some relays.
>
> One of those switches will be an On-Off-On for switching between
>Primary Bus and Essential Bus in the event of an alternator failure.
>
>Questions:
>
>Is there a relay out there that is capable of switching between two
>different power sources and outputting to a single power source?
Why solid state? Your AML switch is mechanical,
why not drive a mechanical relay too?
>Would I have to use two separate relays for switching between the Primary
>Bus and Essential Bus?
Probably . . .
>While I am using an auto conversion, I am not shopping the local Auto Zone
>for electrical equipment. What type of relays would I get? Are Bosch
>(insert Amperage) Solid State Relays suitable for our uses?
Where have you found a solid state relay by Bosch.
I've seen some Hella products. See:
http://tinyurl.com/yuvyt9
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
Message 9
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Subject: | Question about Relays/Switches |
Hello Scott,
I also wanted to Add that I and other have/are using AMP automotive
fuses. One of the benefits is that you can use 1/4 " fast on
connectors. I plan on using AMP type fuses that have a tap with a hole
so I can bolt these fuses to some structure in the fuselage. Dan
Checkoway shows this on his site.
Dan Describes McMaster-carr relays 9672k12
http://www.rvproject.com/20030608.html http://www.mcmaster.com/
Dan Shows the relays http://www.rvproject.com/20030610.html
________________________________
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Jonathan B. Cook
Sent: Tuesday, November 20, 2007 1:46 PM
Subject: RE: AeroElectric-List: Question about Relays/Switches
Hello Scott,
I am also planning on using the Honeywell AML switches.
The 34 series will handle 15A, but only comes in ON-OFF.
To have the On-Off-On switch you would use a AML 24 series. (like AML24
F B C 2 CA 04) The AML 24 series can switch 5A which should be able
fine for switching a relay.
Jonathan Cook
RV7
________________________________
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Scott
R. Shook
Sent: Tuesday, November 20, 2007 12:39 PM
Subject: AeroElectric-List: Question about Relays/Switches
Morning All,
I am working on some of the electronics of our -7A slider and have a
couple of questions...
Here are some details of our installation:
* I am going with a modified Z19RB electrical system and I am
using some suggestions from Gary at Eggenfellner for wiring our E-Bus.
* We are using Honeywell AML34 lighted rockers and all the
information I see is that they handle 15A - I know we will need some
relays.
* One of those switches will be an On-Off-On for switching between
Primary Bus and Essential Bus in the event of an alternator failure.
Questions:
Is there a relay out there that is capable of switching between two
different power sources and outputting to a single power source?
Would I have to use two separate relays for switching between the
Primary Bus and Essential Bus?
While I am using an auto conversion, I am not shopping the local Auto
Zone for electrical equipment. What type of relays would I get? Are
Bosch (insert Amperage) Solid State Relays suitable for our uses?
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
http://www.matronics.com/contribution
http://www.matronics.com/Navigator?AeroElectric-List
http://forums.matronics.com
http://www.matronics.com/contribution
Message 10
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Subject: | Question about Relays/Switches |
At 02:44 PM 11/20/2007 -0500, you wrote:
>Hello Scott,
>
>
>I also wanted to Add that I and other have/are using AMP automotive fuses.
AMP automotive fuses? Did you mean Relays?
> One of the benefits is that you can use 1/4 fast on connectors. I plan
> on using AMP type fuses that have a tap with a hole so I can bolt these
> fuses to some structure in the fuselage. Dan Checkoway shows this on his site.
>
>Dan Describes McMaster-carr relays 9672k12
><http://www.rvproject.com/20030608.html>http://www.rvproject.com/20030608.html
>http://www.mcmaster.com/
>
>Dan Shows the relays
><http://www.rvproject.com/20030610.html>http://www.rvproject.com/20030610.html
These are plain vanilla electro-mechanical relays,
not solid state.
The part number Dan cites (9672K12)
is no longer available. McMaster
suggests a 9672K32 (or weatherproof
9672K44) which you can see at:
http://www.aeroelectric.com/Mfgr_Data/Misc/McMaster_p865.pdf
It takes two pass transistors in a solid
state relay to effect double pole, double
throw functionality. If there's much interest
in such a device, we could look into supplying
it . . . probably in the same package as
http://aeroelectric.com/Catalog/AEC/9030/9030.jpg
Bob . . .
Message 11
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Subject: | RE: Pullable 60 Amp Breaker |
>From: "Robert L. Nuckolls, III" <nuckolls.bob@cox.net>
>Subject: RE: AeroElectric-List: Pullable 60 Amp Breaker
>First, know that designers of upper-end production aircraft
>have made a effort to get high-current, noise-carrying
>conductors off the panel.
Never heard noise in my plane with B-lead CB in panel.
I would just say prove it. Modern internally regulated alternators
are not noisy so it's a moot point. Old Gen from days gone by, yes
noisy.
>Second, I cringe when concerns for the actions of
>"curious passengers" are raised as drivers for how a
>cockpit is laid out or fitted . . .
You are stretching. Does the passenger have a control
yoke or stick they could shove right after takeoff or
right before landing? No Bozo allowed.
>Third, it has been suggested that a breaker might serve
>as the last-ditch means by which a pilot can bring a runaway
>alternator to heel . . . or at least disconnect it from the
>system. This logic is flawed for several reasons: (1) breakers
>are designed to disconnect hard downstream faults in a system
>where the voltage are on the order of 32 volts or less. (2)
>A runaway alternator is capable of raising the b-lead terminal
>to hundreds of volts in milliseconds where it is NOT reasonable
>to expect the breaker to also serve as a SWITCH for reliable
>disconnect of the offending alternator. Any attempt to use
>a breaker (particularly a miniature one with plastic housing!)
>or this purpose is to flirt with probability of cockpit fire
>and much smoke.
With all due respect I think your logic is flawed. It may fit for external
regulated alternators but not for internally regulated ones.
A CB is RATED to disconnect at 32volts many many times, however
it can handle much more. No I don't have an absolute number but
when most 12 volt alternators with a so called over voltage rarely
exceeds 17 v much less 32 v, your point is moot, 32v good enough.
When you say 100's of VOLTS and Cockpit FIRE, it's fear mongering
not based on facts. Science and engineering are based on facts not
emotional reasons. CB catch on fire? Really? OK, prove it.
Small 40 / 60 amp alternators are not pumping 100's of volts or amps.
Internally regulated alternators typically go to 16 or 17 volts, if
regulation fails, easily controlled by a CB. Yes there may have
been one "screw lose" case where voltage was truly out of control,
but it's rare, and the voltage was undetermined. I doubt it got to
over 32 volts.
Also an ANL fuse will not blow with 100's of volts, it's a current
device. If you want to wire your airplane like a Toyota with fuses, fine,
but there is no need to make stuff up against CB's in the panel.
>Finally, know that a 60A breaker on a 60A alternator is
>DESIGNED to nuisance trip. The b-lead protection on an alternator
>should stay closed at current levels perhaps 20% higher than
>the nameplate rating of the alternator. The GA spam-can community
>really blew it when 60A b-lead breakers were installed in 100,000+
>aircraft with 60A alternators.
Easily solved by sizing the CB properly. I guess they don't have
smart people working for the GA spam-can community. Frankly CB's
can take slight overloads for a period of time with out a trip. Again
moot point Bob, if the alternator can only put out 45 amps.
>In my humble opinion, ignoring a lot of experience and
>thoughtful reasoning suggesting that panel a mounted, b-lead
>breaker is not the best-we-know-how-to-do.
>Bob . . .
What?
Fuses are fine. Buth with (stock) internal regulation the CB is a good
reason to use a B-lead CB. Other engineers have worked on this
Bob. The pull-able CB for the B-lead is specified. It's irresponsible of
you to be so stubborn and opinionated, making ONE blanked edict
that one size fits all. Fuses are not a BE ALL solution for every
application. Follow the manufactures recommendation!
In my humble opinion, I disagree with Bob with my thoughtful reasoning
and facts. I don't care what you use but know why you are using it. I
don't believe you will have noise or won't be able to disconnect the
b-lead manually if you want to. When people talk 100's of volts & fire
they are exaggerating in non-scientific emotional arguments, not
engineering. Have Bob prove these are real problems. I could come
up with lots of NIT PICK reasons a fuse really is a poor choice.
Cheers George
---------------------------------
Never miss a thing. Make Yahoo your homepage.
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Subject: | RE: Pullable 60 Amp Breaker |
Why would anyone want to reset a tripped 60A breaker in flight ?
If you want to disable the alternator than switching off the alternator
field would generate a lot less transients that components have to deal
with.
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Subject: | Question about Relays/Switches |
Bob,
Thank you much for the information. Those look like the regular vanilla
automotive relays that I have used for years in cars.
Are those suitable for our applications? I am just not certain I want to
entrust tens of thousands of dollars of my airplane and its ESSENTIAL BUS to
a $9 relay.
If that's the case, I could use a SPDT continuous duty relay (like a Marine
application) found here -
http://www.ebasicpower.com/pc/ARCR038/ALLRELAYS/Relay%2C+12V%2C+85+Amp%2C+S.
P.D.T. to power my E-Bus from my Main Battery.
I could even get radical and have the Main Battery power my E-Bus when the
coil is energized and have it switch to my Aux Battery when coil is not
energized. Since there is already a SPST Continuous Duty Relay upstream of
both my main battery and aux battery, powering down the plane shouldn't be a
problem.
Thoughts?
Scott R. Shook
RV-7A (Building)
N696JS (Reserved)
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Tuesday, 20 November, 2007 14:12
Subject: RE: AeroElectric-List: Question about Relays/Switches
<nuckolls.bob@cox.net>
At 02:44 PM 11/20/2007 -0500, you wrote:
>Hello Scott,
>
>
>I also wanted to Add that I and other have/are using AMP automotive fuses.
AMP automotive fuses? Did you mean Relays?
> One of the benefits is that you can use 1/4 fast on connectors. I plan
> on using AMP type fuses that have a tap with a hole so I can bolt these
> fuses to some structure in the fuselage. Dan Checkoway shows this on his
site.
>
>Dan Describes McMaster-carr relays 9672k12
><http://www.rvproject.com/20030608.html>http://www.rvproject.com/20030608.h
tml
>http://www.mcmaster.com/
>
>Dan Shows the relays
><http://www.rvproject.com/20030610.html>http://www.rvproject.com/20030610.h
tml
These are plain vanilla electro-mechanical relays,
not solid state.
The part number Dan cites (9672K12)
is no longer available. McMaster
suggests a 9672K32 (or weatherproof
9672K44) which you can see at:
http://www.aeroelectric.com/Mfgr_Data/Misc/McMaster_p865.pdf
It takes two pass transistors in a solid
state relay to effect double pole, double
throw functionality. If there's much interest
in such a device, we could look into supplying
it . . . probably in the same package as
http://aeroelectric.com/Catalog/AEC/9030/9030.jpg
Bob . . .
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Subject: | Location of battery bus |
Bevan, this is what I did on my 7a for block locations. Small Tab forest on
FW side to large forest on cabin side. Fuse blocks on the inside are on a
swing down tray. Ran the battery lead to the always hot bus to a fuse slot
which really protects the wrong end of the wire but it seemed better than
nothing (maybe a fusible link on the battery end would be better). Wire is
about 14" from Battery to bus as I remember it but not likely to have a
problem.
Bill S
7a
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of B Tomm
Sent: Tuesday, November 20, 2007 3:28 AM
Subject: AeroElectric-List: Location of battery bus
Good morning Bob,
Considering Z-13/20 architecture in an RV7A. The Vans recommended position
for the battery is on the firewall in the engine compartment which I agree
with. That being said, the contactors would be located nearby. Would it
follow that the battery bus should also be located on the engine side of the
firewall and if so, would it be appropriate to use a fuse block style as
we've come to appreciate? In other words, would the fuse block style and
associated faston terminals stand up in the FF environment? I would prefer
to see the fuses inside the cockpit just aft of the firewall (cleaner
environment), but to get to here there would be a little more than 6 inches
of unprotected wire.
Thanks again.
Bevan
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Subject: | Z-19/RB question re: Internally shunted ammeter |
Bob, my ammeter has an internal shunt (VDO gauge). This may be a dumb
question but... Is there any way to get away from running the heavy B-lead
cable thru the firewall to the ammeter and then back thru the firewall to
the current limiter and starter contactor?
The second logical question, I guess, is this: is it unwise to hang the
integrity of my alternator's output on the innards of a cheap gauge, or is a
shunt a shunt? This didn't occur to me when I bought the gauges.
BTW, my alternator has an internal regulator so I am incorporating your
interim schematic that puts a Crowbar Contactor in the B-lead to unload the
alternator if the crowbar trips the circuit breaker.
Thanks for all your help... :=))
Johnny Johnson
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Subject: | Location of battery bus |
Thanks Bill
Looks very good. Nice fuse block mount. Can you access it without taking a
control stick out and crawling underneath? Maybe just leaning over sideways
from the pilot seat?
I see a SD8 ? alternator. Can I assume you've wired up per Z13/8? Just a
guess, correct me if I'm wrong. Based on Bob's comments, I'm thinking that
Z13/8 will be ideal for me. Not sure what size Odyssey batt I need. Have
not completed a load analysis yet. If you are flying yet, I would like to
know what schematic Z drawing you're using and how you like it.
Bevan
Attached is a pic of my panel so far. No real wiring done yet. Just making
everything fit.
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill
Schlatterer
Sent: Tuesday, November 20, 2007 9:21 PM
Subject: RE: AeroElectric-List: Location of battery bus
Bevan, this is what I did on my 7a for block locations. Small Tab forest on
FW side to large forest on cabin side. Fuse blocks on the inside are on a
swing down tray. Ran the battery lead to the always hot bus to a fuse slot
which really protects the wrong end of the wire but it seemed better than
nothing (maybe a fusible link on the battery end would be better). Wire is
about 14" from Battery to bus as I remember it but not likely to have a
problem.
Bill S
7a
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of B Tomm
Sent: Tuesday, November 20, 2007 3:28 AM
Subject: AeroElectric-List: Location of battery bus
Good morning Bob,
Considering Z-13/20 architecture in an RV7A. The Vans recommended position
for the battery is on the firewall in the engine compartment which I agree
with. That being said, the contactors would be located nearby. Would it
follow that the battery bus should also be located on the engine side of the
firewall and if so, would it be appropriate to use a fuse block style as
we've come to appreciate? In other words, would the fuse block style and
associated faston terminals stand up in the FF environment? I would prefer
to see the fuses inside the cockpit just aft of the firewall (cleaner
environment), but to get to here there would be a little more than 6 inches
of unprotected wire.
Thanks again.
Bevan
href="http://www.matronics.com/contribution">http://www.matronics.com/chref
"http://www.matronics.com/Navigator?AeroElectric-List">http://www.matronics.
com/Navigator?AeroElectric-List
href="http://forums.matronics.com">http://forums.matronics.com
Message 17
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Subject: | Re: Radio interlock |
Bob Archer used to sell (and probably still does) an antenna switch
which allows for reception on two radios simultaneously and locks out
the non-transmitting radio (whichever one it is) upon closing the PTT of
either.
Pax,
Ed Holyoke
Robert L. Nuckolls, III wrote:
> <nuckolls.bob@cox.net>
>
> At 10:02 PM 11/18/2007 -0700, you wrote:
>
>> <mprather@spro.net>
>>
>> Thanks Bob.. That jogged my memory. The real challenge would be to run
>> multiple transceivers through a single antenna..
>
>
> That CAN be done. It's most commonly accomplished with
> carefully crafted filters that go in series with the antenna
> feedlines for each radio. A good example of this technology
> is a critter called a "duplexer".
>
> Back in the days when I was working with amateur radio repeater
> stations, it was useful have a single antenna for both
> RECEIVING an exceedingly tiny incoming signal (0.5 microvolts)
> on one frequency while simultaneously TRANSMITTING that same
> information on a second frequency (typically 600 KHz removed from
> receive) with a strength on the order of 50 volts or 10 million
> times stronger!
>
> I've built the device shown here several times:
>
> http://www.repeater-builder.com/rbtip/2mduplexer.html
>
> The thing is built of pieces of 4" copper tubing. The
> six cavities are distributed with three in the transmitter
> antenna line, three in the receiver. They are crafted with
> mirror image band-pass/band-reject response curves
> shown here:
>
> http://www.repeater-builder.com/pix/dupfig15.jpg
>
> Note that each cavity set strongly rejects one
> frequency while strongly passing another. With these
> devices properly crafted and tuned to match the
> frequencies of the transmitter and receiver, full
> duplex operation of the two devices can be accomplished
> on one antenna.
>
> Obviously, this technology is useful ONLY for one
> pair of frequencies. For example, I could craft a
> duplexer to allow a pair of transceivers to use
> a single antenna on 119.5 and 121.6 . . . but as
> soon as I rotated set the frequencies to any other
> combination, this finely tuned isolation between
> the two transceivers would be lost. The other down
> side of this technology is that the duplexer would use
> up most of your baggage compartment!
>
> Bob . . .
>
>
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