Today's Message Index:
----------------------
1. 05:01 AM - Re: Splicing wire (N395V)
2. 06:38 AM - Re: 12 volt 3 or 4 pole relay for 1 to 2 amp load? (Robert L. Nuckolls, III)
3. 07:18 AM - Re: Re: Splicing wire (Bob Collins)
4. 08:34 AM - E-Buss and Master Switches (David Nelson)
5. 09:50 AM - Re: Re: Splicing wire (Robert L. Nuckolls, III)
6. 10:23 AM - Re: E-Buss and Master Switches (Jay Hyde)
7. 11:37 AM - Re: E-Buss and Master Switches (Robert L. Nuckolls, III)
8. 11:38 AM - Re: 12 volt 3 or 4 pole relay for 1 to 2 amp load? (Robert L. Nuckolls, III)
9. 12:45 PM - Re: E-Buss and Master Switches (David Nelson)
10. 01:12 PM - Re: E-Buss and Master Switches (David Nelson)
11. 01:54 PM - Re: E-Buss and Master Switches (Jay Hyde)
12. 02:24 PM - Re: E-Buss and Master Switches (Robert L. Nuckolls, III)
13. 02:37 PM - Re: E-Buss and Master Switches (Robert L. Nuckolls, III)
14. 03:12 PM - Re: E-Buss and Master Switches (David Nelson)
15. 03:26 PM - VOM Troubles (Dennis Johnson)
16. 05:07 PM - Re: Check this out (Walter Fellows)
17. 06:50 PM - Re: Check this out (Robert L. Nuckolls, III)
18. 07:48 PM - Re: 12 volt 3 or 4 pole relay for 1 to 2 amp load? (Allen Fulmer)
Message 1
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Subject: | Re: Splicing wire |
Bob,
I would consider a lash splice............
http://workmanship.nasa.gov/guidadv_recmeth_lashsplice.jsp
covered with heatshrink.
--------
Milt
2003 F1 Rocket
2006 Radial Rocket
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=257954#257954
Attachments:
http://forums.matronics.com//files/guidadv_recmeth_lash0_213.jpg
Message 2
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Subject: | Re: 12 volt 3 or 4 pole relay for 1 to 2 amp load? |
At 09:18 PM 8/15/2009, you wrote:
>Hello Bob,
>
>I want to add a little 3 pole relay to turn a Trutrak Flight Systems
>Automatic Pitch Trim on and off. (I did not consider this
>capability when I was running my wire bundle to the pitch servo area
>though I do have a spare pair that could be used to control a relay.)
>
>Page 7 of the Trutrak manual has the wiring diagram for their Auto
>Trim module.
>
><http://www.trutrakflightsystems.com/documents/AutomaticPitchTrim.pdf>http://www.trutrakflightsystems.com/documents/AutomaticPitchTrim.pdf
>
>Can you recommend a relay that might be carried by Allied
>Electronics? <http://www.alliedelec.com/>http://www.alliedelec.com/
>
>I don't think you sell such a critter.
Allied has a lot of choices. This one is suited
to your task:
http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=8210912&MPN=LY3F-DC12
http://www.alliedelec.com/Images/Products/Datasheets/BM/OMRON_ELECTRONICS_LLC/821-0906.PDF
Emacs!
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 3
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Subject: | Re: Splicing wire |
Excellent, Milt. Thank you.
B
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of N395V
Sent: Sunday, August 16, 2009 6:59 AM
Subject: AeroElectric-List: Re: Splicing wire
--> <Bearcat@bearcataviation.com>
Bob,
I would consider a lash splice............
http://workmanship.nasa.gov/guidadv_recmeth_lashsplice.jsp
covered with heatshrink.
--------
Milt
2003 F1 Rocket
2006 Radial Rocket
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=257954#257954
Attachments:
http://forums.matronics.com//files/guidadv_recmeth_lash0_213.jpg
Message 4
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Subject: | E-Buss and Master Switches |
Hi Bob,
I'm going over the finer details of a design based largely upon Z-11. Why
wouldn't one, for normal ops, have both the E-Buss and Master in the 'On'
position?
My reasoning being:
- In the event of some electrical problems, you only have to contend with
switching off one switch rather than remembering to turn the E-buss 'On'
followed by turning the Master 'Off'.
- If the problem persists, we aren't in any different position than if we
turned on the E-Buss followed by turning off the Master.
Am I missing something fundamental here or was I always assuming that the
E-Buss was always originally 'Off' during normal ops?
Thank you,
/\/elson
Message 5
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Subject: | Re: Splicing wire |
At 06:59 AM 8/16/2009, you wrote:
>
>Bob,
>
>I would consider a lash splice............
>
>http://workmanship.nasa.gov/guidadv_recmeth_lashsplice.jsp
>
>covered with heatshrink.
That works good. We've published similar processes
on aeroelectric.com
Solder and insulate techniques range from the
simple processes described above to the more
sophisticated (and expensive) process illustrated
here:
http://parts.digikey.com/1/parts-kws/solder-sleeve
Any methodology that achieves good mechanical
and electrical joining of the wires followed by
robust insulation will serve your purposes. The
simplest processes are recommended.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 6
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Subject: | E-Buss and Master Switches |
Hi there David,
I had to write a procedure on how to use a system that I wired to one of the
Z diagrams and then it became clear why one does not want to leave the e-bus
alt feed on. In the event of a fault, smoke, what have you, the first thing
that you want to do is isloate the power sources from the fault as fast as
possible- hence the DC master; once its off only the short fat wire between
the battery and your solenoid is live (and the E-bus alt to the switch
wire). So, unless the fault is right there (usually unlikely), then you
have removed the power that is driving the fault. In a mag equipped
aircraft the engine should still run and in an all electric aircraft the ECU
and fuel pumps should have directly connected wires that bypass the DC
master. If you still have smoke and trouble then you know that you are now
seriously in the dwang, as the fault is somewhere in those, non-isolatable,
wires.
However, if switching the DC master off clears the fault you can now switch
the E-bus alt feed on and see what happens; then maybe switch off a few
circuits on the main bus; switch the DC master back on, etc. This is
assuming that landing is not a luxury that you are presently afforded- such
as if you are crossing the Atlantic and you're 10 hours into a 22 hour
flight... ;-)
If you can land, better to figure the problem out on the ground of course,
using just the E-bus to get you down.
Jay
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David
Nelson
Sent: 16 August 2009 05:30 PM
Subject: AeroElectric-List: E-Buss and Master Switches
<david.nelson@pobox.com>
Hi Bob,
I'm going over the finer details of a design based largely upon Z-11. Why
wouldn't one, for normal ops, have both the E-Buss and Master in the 'On'
position?
My reasoning being:
- In the event of some electrical problems, you only have to contend with
switching off one switch rather than remembering to turn the E-buss 'On'
followed by turning the Master 'Off'.
- If the problem persists, we aren't in any different position than if we
turned on the E-Buss followed by turning off the Master.
Am I missing something fundamental here or was I always assuming that the
E-Buss was always originally 'Off' during normal ops?
Thank you,
/\/elson
Message 7
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Subject: | Re: E-Buss and Master Switches |
At 10:30 AM 8/16/2009, you wrote:
>
>
>Hi Bob,
>
>I'm going over the finer details of a design based largely upon
>Z-11. Why wouldn't one, for normal ops, have both the E-Buss and
>Master in the 'On' position?
Could, but not necessary. Doesn't hurt. But you DO
want to pre-flight test the dual power path philosophy
for the e-bus.
>My reasoning being:
>
>- In the event of some electrical problems, you only have to contend
>with switching off one switch rather than remembering to turn the
>E-buss 'On' followed by turning the Master 'Off'.
Remember? It's recommended that you have a checklist
for shutdown. It's also recommended that you consider
an ergonomic arrangement of switches wherein ship's
DC power controls are grouped. Leaving the airplane
should be preceded by placing all switches down (OFF).
>- If the problem persists, we aren't in any different position than
>if we turned on the E-Buss followed by turning off the Master.
>
>Am I missing something fundamental here or was I always assuming
>that the E-Buss was always originally 'Off' during normal ops?
That was the original design philosophy. But failure
mode effects analysis for the system's design included
consideration of risk for having the switch ON under
any flight conditions. Wired as shown, you may operate
it with any philosophy you choose.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 8
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|
Subject: | Re: 12 volt 3 or 4 pole relay for 1 to 2 amp load? |
At 09:18 PM 8/15/2009, you wrote:
>Hello Bob,
>
>I want to add a little 3 pole relay to turn a Trutrak Flight Systems
>Automatic Pitch Trim on and off. (I did not consider this
>capability when I was running my wire bundle to the pitch servo area
>though I do have a spare pair that could be used to control a relay.)
>
>Page 7 of the Trutrak manual has the wiring diagram for their Auto
>Trim module.
>
><http://www.trutrakflightsystems.com/documents/AutomaticPitchTrim.pdf>http://www.trutrakflightsystems.com/documents/AutomaticPitchTrim.pdf
>
>Can you recommend a relay that might be carried by Allied
>Electronics? <http://www.alliedelec.com/>http://www.alliedelec.com/
>
>I don't think you sell such a critter.
Allied has a lot of choices. This one is suited
to your task:
http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=8210912&MPN=LY3F-DC12
http://www.alliedelec.com/Images/Products/Datasheets/BM/OMRON_ELECTRONICS_LLC/821-0906.PDF
Emacs!
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: | E-Buss and Master Switches |
Hi Jay,
I certainly understand your reasoning for the below and I had a similar
argument in my head. But then this scenario popped up in my head. Currently,
I'm only VFR rated but plan to go for the IFR ticket within a couple of years
of project completion. I imagined flying in the soup and would I want to reset
all my avionics and wait for them to reinitialize? I'll be honest, I don't how
long it will take for my equipment to re-initialize while flying - I'll add it
as a 'todo' item for further investigation.
Ugh - this is making my head hurt. To me, I guess what it comes down to is that
we must architect our systems for fault tolorance, know how the systems are
designed and how they work, understand the associated risks and trade-offs, and
train for emergencies. Thanks to Bob, we can thank him for the 1st three.
/\/elson
On Sun, 16 Aug 2009, Jay Hyde wrote:
>
>
> Hi there David,
>
> I had to write a procedure on how to use a system that I wired to one of the
> Z diagrams and then it became clear why one does not want to leave the e-bus
> alt feed on. In the event of a fault, smoke, what have you, the first thing
> that you want to do is isloate the power sources from the fault as fast as
> possible- hence the DC master; once its off only the short fat wire between
> the battery and your solenoid is live (and the E-bus alt to the switch
> wire). So, unless the fault is right there (usually unlikely), then you
> have removed the power that is driving the fault. In a mag equipped
> aircraft the engine should still run and in an all electric aircraft the ECU
> and fuel pumps should have directly connected wires that bypass the DC
> master. If you still have smoke and trouble then you know that you are now
> seriously in the dwang, as the fault is somewhere in those, non-isolatable,
> wires.
> However, if switching the DC master off clears the fault you can now switch
> the E-bus alt feed on and see what happens; then maybe switch off a few
> circuits on the main bus; switch the DC master back on, etc. This is
> assuming that landing is not a luxury that you are presently afforded- such
> as if you are crossing the Atlantic and you're 10 hours into a 22 hour
> flight... ;-)
>
> If you can land, better to figure the problem out on the ground of course,
> using just the E-bus to get you down.
>
> Jay
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David
> Nelson
> Sent: 16 August 2009 05:30 PM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: E-Buss and Master Switches
>
> <david.nelson@pobox.com>
>
>
> Hi Bob,
>
> I'm going over the finer details of a design based largely upon Z-11. Why
> wouldn't one, for normal ops, have both the E-Buss and Master in the 'On'
> position?
>
> My reasoning being:
>
> - In the event of some electrical problems, you only have to contend with
> switching off one switch rather than remembering to turn the E-buss 'On'
> followed by turning the Master 'Off'.
>
> - If the problem persists, we aren't in any different position than if we
> turned on the E-Buss followed by turning off the Master.
>
> Am I missing something fundamental here or was I always assuming that the
> E-Buss was always originally 'Off' during normal ops?
>
> Thank you,
> /\/elson
>
>
Message 10
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Subject: | Re: E-Buss and Master Switches |
Hi Bob,
100% agree that the pre-flight checklist should involve toggling both swithches
to ensure proper operation. That should be item regardless of normal ops.
I'm giving an awful lot of thought to switch placement and overall cockpit
ergonomics. Being my 1st time, I'm learning that it is not as easy as a task as
I had thought it would be....and I am making progress.
/\/elson
On Sun, 16 Aug 2009, Robert L. Nuckolls, III wrote:
> <nuckolls.bob@aeroelectric.com>
>
> At 10:30 AM 8/16/2009, you wrote:
>> <david.nelson@pobox.com>
>>
>>
>> Hi Bob,
>>
>> I'm going over the finer details of a design based largely upon Z-11. Why
>> wouldn't one, for normal ops, have both the E-Buss and Master in the 'On'
>> position?
>
> Could, but not necessary. Doesn't hurt. But you DO
> want to pre-flight test the dual power path philosophy
> for the e-bus.
>
>> My reasoning being:
>>
>> - In the event of some electrical problems, you only have to contend with
>> switching off one switch rather than remembering to turn the E-buss 'On'
>> followed by turning the Master 'Off'.
>
> Remember? It's recommended that you have a checklist
> for shutdown. It's also recommended that you consider
> an ergonomic arrangement of switches wherein ship's
> DC power controls are grouped. Leaving the airplane
> should be preceded by placing all switches down (OFF).
>
>> - If the problem persists, we aren't in any different position than if we
>> turned on the E-Buss followed by turning off the Master.
>>
>> Am I missing something fundamental here or was I always assuming that the
>> E-Buss was always originally 'Off' during normal ops?
>
> That was the original design philosophy. But failure
> mode effects analysis for the system's design included
> consideration of risk for having the switch ON under
> any flight conditions. Wired as shown, you may operate
> it with any philosophy you choose.
>
>
> Bob . . .
>
> ---------------------------------------
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ---------------------------------------
>
>
Message 11
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Subject: | E-Buss and Master Switches |
Hey David,
I kinda agree... re waiting for stuff to reset; I suppose that the best is
exactly what we are arming ourselves with right here- a pretty good
understanding of exactly how our sytems work.
As an aside, the MGL EFIS systems that I am using a lot now have the option
(as many others also do) of their own standby and backup battery ( a little
isty bitsy thing) that keeps them all running when you switch off the DC
master- sort of like an airborne UPS you might say; so the reset doesn't
really happen :-) I hope... ;-)
Jay
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David
Nelson
Sent: 16 August 2009 09:44 PM
Subject: RE: AeroElectric-List: E-Buss and Master Switches
<david.nelson@pobox.com>
Hi Jay,
I certainly understand your reasoning for the below and I had a similar
argument in my head. But then this scenario popped up in my head.
Currently,
I'm only VFR rated but plan to go for the IFR ticket within a couple of
years
of project completion. I imagined flying in the soup and would I want to
reset
all my avionics and wait for them to reinitialize? I'll be honest, I don't
how
long it will take for my equipment to re-initialize while flying - I'll add
it
as a 'todo' item for further investigation.
Ugh - this is making my head hurt. To me, I guess what it comes down to is
that
we must architect our systems for fault tolorance, know how the systems are
designed and how they work, understand the associated risks and trade-offs,
and
train for emergencies. Thanks to Bob, we can thank him for the 1st three.
/\/elson
On Sun, 16 Aug 2009, Jay Hyde wrote:
>
>
> Hi there David,
>
> I had to write a procedure on how to use a system that I wired to one of
the
> Z diagrams and then it became clear why one does not want to leave the
e-bus
> alt feed on. In the event of a fault, smoke, what have you, the first
thing
> that you want to do is isloate the power sources from the fault as fast as
> possible- hence the DC master; once its off only the short fat wire
between
> the battery and your solenoid is live (and the E-bus alt to the switch
> wire). So, unless the fault is right there (usually unlikely), then you
> have removed the power that is driving the fault. In a mag equipped
> aircraft the engine should still run and in an all electric aircraft the
ECU
> and fuel pumps should have directly connected wires that bypass the DC
> master. If you still have smoke and trouble then you know that you are
now
> seriously in the dwang, as the fault is somewhere in those,
non-isolatable,
> wires.
> However, if switching the DC master off clears the fault you can now
switch
> the E-bus alt feed on and see what happens; then maybe switch off a few
> circuits on the main bus; switch the DC master back on, etc. This is
> assuming that landing is not a luxury that you are presently afforded-
such
> as if you are crossing the Atlantic and you're 10 hours into a 22 hour
> flight... ;-)
>
> If you can land, better to figure the problem out on the ground of course,
> using just the E-bus to get you down.
>
> Jay
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David
> Nelson
> Sent: 16 August 2009 05:30 PM
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: E-Buss and Master Switches
>
> <david.nelson@pobox.com>
>
>
> Hi Bob,
>
> I'm going over the finer details of a design based largely upon Z-11. Why
> wouldn't one, for normal ops, have both the E-Buss and Master in the 'On'
> position?
>
> My reasoning being:
>
> - In the event of some electrical problems, you only have to contend with
> switching off one switch rather than remembering to turn the E-buss 'On'
> followed by turning the Master 'Off'.
>
> - If the problem persists, we aren't in any different position than if we
> turned on the E-Buss followed by turning off the Master.
>
> Am I missing something fundamental here or was I always assuming that the
> E-Buss was always originally 'Off' during normal ops?
>
> Thank you,
> /\/elson
>
>
Message 12
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Subject: | Re: E-Buss and Master Switches |
At 02:56 PM 8/16/2009, you wrote:
>
>
>Hi Bob,
>
>100% agree that the pre-flight checklist should involve toggling
>both swithches to ensure proper operation. That should be item
>regardless of normal ops.
>
>I'm giving an awful lot of thought to switch placement and overall
>cockpit ergonomics. Being my 1st time, I'm learning that it is not
>as easy as a task as I had thought it would be....and I am making progress.
Add this drawing to your sources of ideas . . .
http://www.aeroelectric.com/PPS/Switch_Panels/Switches.pdf
In several variations I've suggested an ordering of
switches that groups function and mitigates the
effects of mistakenly grabbing an adjacent switch.
Operating the wrong switch is high on the list
of concerns for some builders.
Here I've built the switch strings where the
least used are at the far left and most used
at far right with power distribution and control
in the middle. You may have other design goals in
mind but these drawings may offer a place to start.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 13
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|
Subject: | E-Buss and Master Switches |
>I imagined flying in the soup and would I want to reset all my
>avionics and wait for them to reinitialize? I'll be honest, I don't
>how long it will take for my equipment to re-initialize while flying
>- I'll add it as a 'todo' item for further investigation.
I forgot another item from your posting.
If it's ever necessary to force any piece of equipment
to re-boot, it's ill-advised to initiate it with any
part of the power distribution system that affects more
than one piece of equipment. Any such processes are
best accomplished on one piece at a time with controls
unique to that piece of equipment and then perhaps only
if you really need that piece of equipment for
comfortable completion of that flight.
More than one dark-n-stormy night story advanced to
higher levels of interest and intrigue as pilot
attempts to diagnose/fix some problem by manipulation
that serves only distracted him or made other things
happen that worsened the situation.
>Ugh - this is making my head hurt. To me, I guess what it comes down
>to is that we must architect our systems for fault tolorance, know
>how the systems are designed and how they work, understand the
>associated risks and trade-offs, and train for emergencies. Thanks
>to Bob, we can thank him for the 1st three.
It shouldn't be painful. It's called failure mode effects
analysis and generally takes a LONG time to do a good
job. Not that it's difficult . . . but new possibilities
or combinations arise with thought, time and conversation with
others. I'm pretty sure that every FMEA report I've submitted
was considered by others "complete" and suitable for
publication. Personally, I've considered them perhaps
99 percent complete while keeping an eye out for new
ideas. Don't rush it. The thing that's nice about the
airplanes we build here is that the last 1% item can be
accommodated in a timely manner and at our convenience.
The TC airplane guys HAD to call the work 100% complete
because any changes after certification was a horribly
protracted process.
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 14
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Subject: | E-Buss and Master Switches |
Hi Jay,
"Airborne UPS" - haha - I like that. I had been resistant to using the
internal battery option of the AFS unit. Instead opting for a small aux
battery. I've recently changed my mind on that front as it somewhat simplyflied
my panel and wiring while still maintaining the goal of being able to power up
the EFIS before engine startup. After that, everthing else can get turned on.
/\/elson
On Sun, 16 Aug 2009, Jay Hyde wrote:
>
>
> Hey David,
>
> I kinda agree... re waiting for stuff to reset; I suppose that the best is
> exactly what we are arming ourselves with right here- a pretty good
> understanding of exactly how our sytems work.
>
> As an aside, the MGL EFIS systems that I am using a lot now have the option
> (as many others also do) of their own standby and backup battery ( a little
> isty bitsy thing) that keeps them all running when you switch off the DC
> master- sort of like an airborne UPS you might say; so the reset doesn't
> really happen :-) I hope... ;-)
>
> Jay
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David
> Nelson
> Sent: 16 August 2009 09:44 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: E-Buss and Master Switches
>
> <david.nelson@pobox.com>
>
>
> Hi Jay,
>
> I certainly understand your reasoning for the below and I had a similar
> argument in my head. But then this scenario popped up in my head.
> Currently,
> I'm only VFR rated but plan to go for the IFR ticket within a couple of
> years
> of project completion. I imagined flying in the soup and would I want to
> reset
> all my avionics and wait for them to reinitialize? I'll be honest, I don't
> how
> long it will take for my equipment to re-initialize while flying - I'll add
> it
> as a 'todo' item for further investigation.
>
> Ugh - this is making my head hurt. To me, I guess what it comes down to is
> that
> we must architect our systems for fault tolorance, know how the systems are
> designed and how they work, understand the associated risks and trade-offs,
> and
> train for emergencies. Thanks to Bob, we can thank him for the 1st three.
>
> /\/elson
>
> On Sun, 16 Aug 2009, Jay Hyde wrote:
>
>>
>>
>> Hi there David,
>>
>> I had to write a procedure on how to use a system that I wired to one of
> the
>> Z diagrams and then it became clear why one does not want to leave the
> e-bus
>> alt feed on. In the event of a fault, smoke, what have you, the first
> thing
>> that you want to do is isloate the power sources from the fault as fast as
>> possible- hence the DC master; once its off only the short fat wire
> between
>> the battery and your solenoid is live (and the E-bus alt to the switch
>> wire). So, unless the fault is right there (usually unlikely), then you
>> have removed the power that is driving the fault. In a mag equipped
>> aircraft the engine should still run and in an all electric aircraft the
> ECU
>> and fuel pumps should have directly connected wires that bypass the DC
>> master. If you still have smoke and trouble then you know that you are
> now
>> seriously in the dwang, as the fault is somewhere in those,
> non-isolatable,
>> wires.
>> However, if switching the DC master off clears the fault you can now
> switch
>> the E-bus alt feed on and see what happens; then maybe switch off a few
>> circuits on the main bus; switch the DC master back on, etc. This is
>> assuming that landing is not a luxury that you are presently afforded-
> such
>> as if you are crossing the Atlantic and you're 10 hours into a 22 hour
>> flight... ;-)
>>
>> If you can land, better to figure the problem out on the ground of course,
>> using just the E-bus to get you down.
>>
>> Jay
>>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server@matronics.com
>> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of David
>> Nelson
>> Sent: 16 August 2009 05:30 PM
>> To: aeroelectric-list@matronics.com
>> Subject: AeroElectric-List: E-Buss and Master Switches
>>
>> <david.nelson@pobox.com>
>>
>>
>> Hi Bob,
>>
>> I'm going over the finer details of a design based largely upon Z-11. Why
>> wouldn't one, for normal ops, have both the E-Buss and Master in the 'On'
>> position?
>>
>> My reasoning being:
>>
>> - In the event of some electrical problems, you only have to contend with
>> switching off one switch rather than remembering to turn the E-buss 'On'
>> followed by turning the Master 'Off'.
>>
>> - If the problem persists, we aren't in any different position than if we
>> turned on the E-Buss followed by turning off the Master.
>>
>> Am I missing something fundamental here or was I always assuming that the
>> E-Buss was always originally 'Off' during normal ops?
>>
>> Thank you,
>> /\/elson
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
Message 15
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|
I have a Fluke model 87 digital VOM (Volt-Ohm-Milliammeter) that has just started
discharging the internal 9 volt battery in less than a month while it is turned
OFF. I've had this meter for 15 years and used it throughout building my
airplane, as well as various hobbies before that, so I guess I got my money's
worth out of it, but I'm puzzled.
Using another meter, I measured about 10 microamps current out of the Fluke's internal
9 volt transistor radio battery while it's turned OFF. If a 9 volt transistor
radio battery holds 0.5 amp-hours, then with 10 microamps, the battery
should last 50,000 hours. But the last two batteries lasted about a month each.
They test good before I put them in and have an expiration date of 2013.
First, is my arithmetic correct? I think a milliamp is 0.001 amps and a microamp
is 0.000001 amps. I think a 10 microamp current through a half amp-hour battery
would take 50,000 hours to deplete the battery.
Second, did I read my digital VOM correctly? Using a nice German BBC VOM, set
on the 2 milliamp scale, it reads .009. Using a cheap Harbor Freight digital
VOM, set on the 200 microamp scale, it reads 09.5.
You can see that something is wrong, either with my math or the way I'm reading
the scale on the VOMs. Or maybe the Duracell fairies are sneaking in and sucking
all the juice out of my batteries?
I talked to Fluke customer support and he said there was no published spec on the
current draw from the battery while it was turned off and couldn't say if mine
was bad or not. My model 87 isn't supported anymore and he wanted me to buy
the new version.
Any ideas?
Dennis Johnson
Lancair Legacy, 330 flight hours
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=258060#258060
Message 16
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Subject: | Re: Check this out |
There is wisdom in your message but it will be helpful to those of focusing
on aeroelectrics if you can mark it off topic.
at, Aug 8, 2009 at 6:49 PM, <jaybannist@cs.com> wrote:
> It happened sometime during my generation (born 1935). Up until and duri
ng
> WWII, it was =93honorable=94 to be in the trades, working with your hands
.
> Sometime after WWII, and before the =93information age=94, in my world, i
t
> became imperative to go to college and earn a degree so that one didn=92t
*
> have* to work with ones hands. Somehow, using brainpower instead of
> muscle power became =93noble=94. There are those among us that choose to
use
> both. We are the =93tinkerers=94. We are driven to learn, experiment an
d to
> create. But we are the dinosaurs, a dying breed. Beyond the time when i
t
> was a given that a college education was all that was necessary to succee
d,
> along came the computer. Today=92s youth (and some ancients) think that y
ou
> can do anything if you can conquer the computer. Never mind what makes i
t
> work. You only need to master the keyboard, the display and a host of
> programming tricks. This mentality leads one to believe that =93stuff=94
> happens without human intervention, except through the computer=92s omnip
otent
> power. Thus the decline in people that really make =93stuff=94 happen - t
he
> carpenters, millwrights, farmers, machinist, plumbers, mechanics - all th
ose
> that work with their hands. Of course, they are still out there, doing t
he
> everyday jobs that must be done, but their numbers are rapidly declining;
> =91cause it=92s just not E2cool=94 to work with your hands these days. B
y all
> means, allow and encourage the kids to master the computer. Just don=92t
let
> it get in the way of learning about and doing things manually, creating a
nd
> above all - =93TINKERING=94.
>
> Jay Bannister
> ------------------------------
> Email message sent from CompuServe - visit us today at http://www.cs.com
>
> *
>
===========
===========
===========
===========
> *
>
>
Message 17
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Subject: | Re: Check this out |
At 06:56 PM 8/16/2009, you wrote:
>There is wisdom in your message but it will be helpful to those of
>focusing on aeroelectrics if you can mark it off topic.
But it was on topic to the thread I originally posted under that
subject . . .
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
Message 18
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Subject: | 12 volt 3 or 4 pole relay for 1 to 2 amp load? |
Thank you BobN and BobMc.
Do not archive
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Sunday, August 16, 2009 1:38 PM
Subject: Re: AeroElectric-List: 12 volt 3 or 4 pole relay for 1 to 2 amp
load?
At 09:18 PM 8/15/2009, you wrote:
Hello Bob,
I want to add a little 3 pole relay to turn a Trutrak Flight Systems
Automatic Pitch Trim on and off. (I did not consider this capability when I
was running my wire bundle to the pitch servo area though I do have a spare
pair that could be used to control a relay.)
Page 7 of the Trutrak manual has the wiring diagram for their Auto Trim
module.
http://www.trutrakflightsystems.com/documents/AutomaticPitchTrim.pdf
Can you recommend a relay that might be carried by Allied Electronics?
http://www.alliedelec.com/
I don't think you sell such a critter.
Allied has a lot of choices. This one is suited
to your task:
http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=8210912
<http://www.alliedelec.com/Search/ProductDetail.aspx?SKU=8210912&MPN=LY3F-DC
12> &MPN=LY3F-DC12
http://www.alliedelec.com/Images/Products/Datasheets/BM/OMRON_ELECTRONICS_LL
C/821-0906.PDF
Emacs!
Bob . . .
---------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
---------------------------------------
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