Today's Message Index:
----------------------
1. 03:00 AM - Re: B-787 Li-Ion battery story continues (Jan de Jong)
2. 04:36 AM - Re: B-787 Li-Ion battery story continues (James Kilford)
3. 05:11 AM - Re: iPad charger? (Bill Watson)
4. 05:18 AM - Congratulations, Bob! (Henador Titzoff)
5. 05:31 AM - Re: iPad charger? (Henador Titzoff)
6. 05:41 AM - Re: B-787 Li-Ion battery story continues (Peter Pengilly)
7. 07:06 AM - Re: iPad charger? (earl_schroeder@juno.com)
8. 07:07 AM - Re: Congratulations, Bob! (Robert L. Nuckolls, III)
9. 07:18 AM - Re: iPad charger? ()
10. 07:19 AM - Re: iPad charger? (Eric M. Jones)
11. 07:23 AM - Re: Congratulations, Bob! ()
12. 07:26 AM - Re: iPad charger? (Robert L. Nuckolls, III)
13. 07:30 AM - Re: Re: iPad charger? ()
14. 07:37 AM - Re: Congratulations, Bob! (Peter Pengilly)
15. 08:00 AM - Re: iPad charger? (earl_schroeder@juno.com)
16. 08:36 AM - Re: Charge battery thru Ground Power Jack (jonlaury)
17. 09:34 AM - Re: Re: Charge battery thru Ground Power Jack (Robert L. Nuckolls, III)
18. 09:37 AM - Cover of Revision 13 (Robert L. Nuckolls, III)
19. 09:50 AM - Re: B-787 Li-Ion battery story continues (BobsV35B@aol.com)
20. 09:53 AM - Re: Cover of Revision 13 (James Kilford)
21. 09:55 AM - Re: iPad charger? (Eric Page)
22. 09:58 AM - Re: B-787 Li-Ion battery story continues (Eric Page)
23. 10:13 AM - Words as parts (Robert L. Nuckolls, III)
24. 10:18 AM - Re: Charge battery thru Ground Power Jack (user9253)
25. 10:26 AM - Re: Cover of Revision 13 (Robert L. Nuckolls, III)
26. 10:32 AM - Re: Re: Charge battery thru Ground Power Jack (Robert L. Nuckolls, III)
27. 10:50 AM - Re: Re: iPad charger? (Sacha)
28. 11:19 AM - Relay for Critical Power Feed (Thomas E Blejwas)
29. 11:47 AM - Re: Cover of Revision 13 (Gerry van Dyk)
30. 02:48 PM - Re: Re: iPad charger? (Eric Page)
31. 04:30 PM - Re: Relay for Critical Power Feed (Eric Page)
32. 04:59 PM - Re: Re: iPad charger? (Eric Page)
33. 06:14 PM - Re: Cover of Revision 13 (Robert L. Nuckolls, III)
34. 08:04 PM - Re: Cover of Revision 13 (Sacha)
35. 08:12 PM - Re: Re: iPad charger? (Sacha)
36. 08:49 PM - Re: Cover of Revision 13 (Bill)
37. 10:01 PM - Re: Re: iPad charger? (Verso Electronics)
38. 11:36 PM - EXP 2 Bus workaround (Fred Klein)
Message 1
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Subject: | Re: B-787 Li-Ion battery story continues |
Hi Bob,
I agree. Over-discharging and then recharging at full speed is a
reported safety issue.
I wondered about the mention of discharge by itself ("starting an APU")
as a safety issue.
Maybe the increased internal resistance (50 to 100% increase at 15% SOC
I saw somewhere) makes it so.
On the other hand, the exothermal reaction starts more slowly and is
less violent in a discharged cell.
Bottom line - I should have kept my peace.
Jan de Jong
On 10/10/2013 3:29 PM, Robert L. Nuckolls, III wrote:
> <nuckolls.bob@aeroelectric.com>
>
> At 06:46 AM 10/10/2013, you wrote:
>> <jan_de_jong@casema.nl>
>>
>> I am puzzled by the article of the recent addition, that states that
>> a li-ion battery is especially prone to destructive thermal runaway
>> when discharged.
>> I do not believe this is true, on the contrary.
>
> Can you elaborate? I've read from several sources that
> the Li-Ion technologies are at greatest risk for unhappy
> thermal events when they're discharged and then RECHARGED
> without regard to their special needs.
>
> The cell's tendency to dissipate heat internally is highest
> when at a low state of charge (a state if higher internal
> resistance?) is combined with legacy recharge philosophies
> for allowing say a 60A alternator to run essentially full-bore to
> bring the battery back up to full charge.
>
> Hence, the "special chargers" that plug into dedicated
> connectors on some products for the purpose of achieving
> a fully charged battery after deep discharge.
>
> I think this is the condition being described in the
> article. It's also a condition that seems to be ignored
> the literature by some suppliers of Li-Ion products.
> It's a fundamental question to be explored about the
> suitability of an Li-Ion product as a drop-in, plug-n-play
> replacement for a lead-acid battery.
>
> Boeing seems to have given due diligence to this
> phenomenon by stating that a battery allowed to discharge
> below some value is considered 'scrap' . . . hence the
> multiple replacements of batteries in the field . . .
> batteries that were retired much too early. I wonder if
> these were 'recycled' in any way . . . perhaps returned
> to a battery lab where they were carefully recharged and
> perhaps returned to service?
>
> I think I've read elsewhere that some suppliers of
> commercial off the shelf Li-Ion batteries suggest that
> a battery not be discharged below 30% of full capacity.
> If this is good advice, then one would want to (1) either
> select new batteries with 30% more headroom for capacity
> in the endurance mode and then monitored for load-shedding
> at 30% and/or (2) take extra care in recharging the
> battery should you take it down too far . . . don't let
> your alternator do it.
>
> Our friends at Cessna are still sifting the simple-ideas
> that drive this technology. I'll be working in the same
> building with these folks which may add to my own
> understanding along with some simple-ideas that can be
> shared. Got to be careful here. Contractors
> and employees alike sign non-disclosure agreements. But
> no doubt, the simple ideas that drive the physics of
> battery performance are not going to be any kind of
> 'secret' . . . these are the ingredients that drive
> risks and successes in the marketplace and will have
> to be well understood by everybody. There is still much to
> learn my friends. I'll remain cautious with any advice I
> have for dropping this technology into an OBAM aircraft.
> Setting airplanes on fire is really bad for business.
>
>
> Bob . . .
>
Message 2
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Subject: | Re: B-787 Li-Ion battery story continues |
Some interesting stuff in there Bob. Two things in particular stood out:
1) Are customers going to have the appetite for the increase in useful load
when compared with the risk associated with the new battery technology,
when such benign alternatives exist?
2) What is the wisdom of making things so different for ground crew on one
Boeing aeroplane? It seems to be tempting fate by making ground operations
different. In my line of work the non-functional requirements are often
the ones that bite you, and perhaps this is a similar case.
James
On 10 October 2013 04:03, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> nuckolls.bob@aeroelectric.com**>
>
> I've published a compendium of articles on the B787
> battery story at:
>
> http://tinyurl.com/ag2e9xk
>
> but in particular, there's a recent addition that
> adds a lot of useful information
>
> http://tinyurl.com/lyc5845
>
>
> Bob . . .
>
>
Message 3
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Subject: | Re: iPad charger? |
Add me to the list - I already have the panel spot and fuse slot identified.
Is there an 'easy' way to determine externally whether a given cheapo or
high price cig plug usb charger is the switcher/linear regulator type or
the type that has some chance of working for awhile? 'Easy' being
defined as with a multi-meter or perhaps even a quick peek inside.
I've been thru a number myself. I have one that seems to work on my
other non-iPad devices but I've been saving it for an emergency iPad charge.
In the end, I was so ashamed of having cigarette plug in my '10 that I
hid it behind a back seat cushion. Given the variety of devices needing
a USB charge, I can't wait to put something up front. I figure by the
time I get it, the USB standard will change but that's life.
Bill
On 10/10/2013 8:48 PM, Eric Page wrote:
>
> Rumen: No worries. I think I've seen three Erics on the List! I haven't seen
the charger you've got, but I'm sure it's a switcher. They all are. Getting
enough current at 5V to rapid-charge an iPad through a linear regulator fed
with 14V would make an 18-watt heater!
>
> Marvin: Panel mounted and hard wired is exactly my plan. Nice, neat installation
and zero hassle during use.
>
> Michael and Earl: Thanks for your interest; I'll add you to my contact list.
>
> Cheers,
>
> Eric
>
> do not archive
>
>
Message 4
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Subject: | Congratulations, Bob! |
Bob,=0A=0AMany people have chimed in about your contract job with Cessna. I
want to congratulate you, too.- I think you are a great asset in the OBA
M world and will help Cesspool become Cessna again.=0A=0ASuch jobs require
a lot of time. I can't help but think that your AE activities will slow dow
n, since there's only so many femtoseconds in a day. It's okay. Do a great
job at Cessna and- whatever time you have left is good enough for us. Hop
efully your home lab activities will be supplanted by Cessna lab activities
, which means you will be helping both entities.=0A=0AIf contracting pays o
ff big time, perhaps you will find it in your heart to send us all $100 so
we can get through the shutdown. :)=0A=0A-=0AHenador Titzoff
Message 5
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Subject: | Re: iPad charger? |
Eric, as you can see, there's quite a bit of interest in your iPad charger. Not
sure what switching IC you will use, but I woild like to see an automotive charger
that provides two USB outputs. The ones I've used are flakier than hell,
and I'm starting a 6,000 mile USA round trip in December. I want to take my
Garmin 496 so I can capture breadcrumb trails to send home to mama. That will
require one 12 cigarette socket and two USB outputs. Anyone know of something
reliable that exists today?
Henador Titzoff
--------------------------------------------
On Thu, 10/10/13, Eric Page <edpav8r@yahoo.com> wrote:
Subject: Re: AeroElectric-List: iPad charger?
To: "aeroelectric-list@matronics.com" <aeroelectric-list@matronics.com>
Date: Thursday, October 10, 2013, 5:48 PM
--> AeroElectric-List message
posted by: Eric Page <edpav8r@yahoo.com>
Rumen: No worries. I think I've seen three Erics
on the List! I haven't seen the charger you've got,
but I'm sure it's a switcher. They all are.
Getting enough current at 5V to rapid-charge an iPad through
a linear regulator fed with 14V would make an 18-watt
heater!
Marvin: Panel mounted and hard wired is exactly my
plan. Nice, neat installation and zero hassle during
use.
Michael and Earl: Thanks for your interest; I'll add
you to my contact list.
Cheers,
Eric
do not archive
AeroElectric-List Email Forum -
- MATRONICS WEB FORUMS -
List Contribution Web Site -
-Matt
Dralle, List Admin.
Message 6
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Subject: | Re: B-787 Li-Ion battery story continues |
I think Boeing have got themselves into a difficult place - possibly
involving considerable politics.
Its clear the original decision was based on saving weight - I don't
know what the value per pound would have been but I project I was
involved with not too long ago was up to $10,000 per pound saved and was
talking of going to $50K - that's development $$ spent to save one
pound. A Li battery was probably very attractive and a low cost weight
save. But the technology maturity assessment now seems to be inaccurate.
It has become clear that the actual in service weight saving is
negligible with the extra metal work, the maintenance overhead is large,
and the reputational impact for all concerned is is difficult to
quantify. The big picture view seems to say fit a NiCad for a quiet
life, I'm guessing that most airlines would accept a small weight
increase (on a 260,000 lb airframe) - is the weight saving equation now
around the other way? But what are the internal Boeing political
implications of such a change? We'll probably never know ...
Its an interesting saga to watch from the outside and try to guess what
is going on!
Peter
On 11/10/2013 12:35, James Kilford wrote:
> Some interesting stuff in there Bob. Two things in particular stood out:
>
> 1) Are customers going to have the appetite for the increase in useful
> load when compared with the risk associated with the new battery
> technology, when such benign alternatives exist?
>
> 2) What is the wisdom of making things so different for ground crew on
> one Boeing aeroplane? It seems to be tempting fate by making ground
> operations different. In my line of work the non-functional
> requirements are often the ones that bite you, and perhaps this is a
> similar case.
>
> James
>
>
> On 10 October 2013 04:03, Robert L. Nuckolls, III
> <nuckolls.bob@aeroelectric.com <mailto:nuckolls.bob@aeroelectric.com>>
> wrote:
>
> <nuckolls.bob@aeroelectric.com <mailto:nuckolls.bob@aeroelectric.com>>
>
> I've published a compendium of articles on the B787
> battery story at:
>
> http://tinyurl.com/ag2e9xk
>
> but in particular, there's a recent addition that
> adds a lot of useful information
>
> http://tinyurl.com/lyc5845
>
>
> Bob . . .
>
> ===================================
> -
> ric-List"
> target="_blank">http://www.matronics.com/Navigator?AeroElectric-List
> ===================================
> MS -
> k">http://forums.matronics.com
> ===================================
> e -
> -Matt Dralle, List Admin.
> t="_blank">http://www.matronics.com/contribution
> ===================================
>
>
> *
>
>
> *
Message 7
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Subject: | Re: iPad charger? |
I have taken a 12V to 110VAC device and used a multiple outlet adapter for power
on long trips. Messy but workable. Earl
---------- Original Message ----------
Eric, as you can see, there's quite a bit of interest in your iPad charger. Not
sure what switching IC you will use, but I woild like to see an automotive charger
that provides two USB outputs. The ones I've used are flakier than hell,
and I'm starting a 6,000 mile USA round trip in December. I want to take my
Garmin 496 so I can capture breadcrumb trails to send home to mama. That will
require one 12 cigarette socket and two USB outputs. Anyone know of something
reliable that exists today?
Henador Titzoff
--------------------------------------------
do not archive
Message 8
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Subject: | Re: Congratulations, Bob! |
At 07:18 AM 10/11/2013, you wrote:
>Bob,
>
>Many people have chimed in about your contract job with Cessna. I
>want to congratulate you, too. I think you are a great asset in the
>OBAM world and will help Cesspool become Cessna again.
Certainly Cessna, (like EVERY other manufacturer of goods
and services) has suffered from the stubbing of technological
and marketing toes. But such is the nature of success/failure
in the free-market exchange of value. They are, after all,
managed by mere mortals.
I think the measure of an institution is defined not
so much by the nature of their blunders but by what is done
repair damage to stature and to prevent them from happening
again. My boss has identified some shortcomings in his domain that
he has asked me to consider and then apply skills specific
to mitigation of those weaknesses. I cannot speak for other
bosses throughout the Cessna hierarchy but this one seems to have a
solid grip on his mission and design goals.
>Such jobs require a lot of time. I can't help but think that your AE
>activities will slow down, since there's only so many femtoseconds
>in a day. It's okay. Do a great job at Cessna and whatever time you
>have left is good enough for us. Hopefully your home lab activities
>will be supplanted by Cessna lab activities, which means you will be
>helping both entities.
Actually, my work there probably won't have much to do
with the hammer-n-tongs implementation of their technology.
Those folks are WAaaaayy out ahead of anything we did
at Beech on the airplanes. Now . . . If I could round
up all those guys I used to work with at the Targets
Division, I'm confident that they would fit nicely
into the herding of bytes and electrons at Cessna.
My greatest attention will be on communication. The
use of English words in a manner that describes design
goals and requirements as accurately and unambiguously
as their words in C describe functions in their airplanes.
>If contracting pays off big time, perhaps you will find it in your
>heart to send us all $100 so we can get through the shutdown. :)
Understand. Dr. Dee was bullied from her
chairmanship of the psychology department at
Bethany College. She has been looking at replacement
opportunities for the last 6 months or so. Just yesterday
she received a phone call from her 1st choice of
opportunities that not only got her a healthy raise
but relieved her of much of the $overhead$ associated
with the Bethany job. She loved the work with Bethany
students and the honorable amongst her colleagues.
However, tariffs levied on her finances and the
attacks on her integrity made it seem as if she were
paying to work there!
The AeroElectric-List came into being and grew during
my full time tenure at Beech . . . I'm not expecting
that pressures on my 'spare' time will be any greater
at Cessna. In fact, the efficient conversion of time
to cash gives us the opportunity to exercise the
principals of Spontaneous Order to allocation of
time. I'll be able to hire some maintenance and
upgrade work on the house instead of making my own sawdust.
You guys should have seen Dr. Dee yesterday. She got
up on the roof and cleaned some gutters before
patching some leaks at the joints. Scared the @#^#$ out
of me, but she was grin'n ear-to-ear when she got down
with the job done. I'm hanging new gutters on the other
end of the house today.
I thank you all for the kind thoughts and wishes. Compared
with two months ago we are now more optimistic for the
future than ever. I'm running low on R12 books. Need to
get the next revision done and printed.
Bob . . .
Message 9
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Subject: | Re: iPad charger? |
Eric-
yes, it is a switcher allright, judging by its size. I am going to subject the
critter to some harsh testing before I use it on a 24 V bus. It didn't smoke the
first time I used it.
The question is how to safely protect equipment these things power - would a fast
fuse suffice ?
Wondering if something like ebay item 321224237532 could do the job reliably (need
just to add a panel USB receptacle).
Add me please as well to your contact list.
Rumen
---- Eric Page <edpav8r@yahoo.com> wrote:
============
Rumen: No worries. I think I've seen three Erics on the List! I haven't seen
the charger you've got, but I'm sure it's a switcher. They all are. Getting
enough current at 5V to rapid-charge an iPad through a linear regulator fed with
14V would make an 18-watt heater!
Marvin: Panel mounted and hard wired is exactly my plan. Nice, neat installation
and zero hassle during use.
Michael and Earl: Thanks for your interest; I'll add you to my contact list.
Cheers,
Eric
do not archive
Message 10
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Subject: | Re: iPad charger? |
I've made one of these 10-37V input, variable output 5A linear chargers for a customer.
I don't like switch mode power supplies where they can be avoided due
to the unknowns of RFI/EMI. Better quality switchers CAN be found.
I might be persuaded to make a run of these in about a month.
--------
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=410314#410314
Attachments:
http://forums.matronics.com//files/5a_avr_850.pdf
Message 11
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Subject: | Re: Congratulations, Bob! |
Congratulations from me too, Bob.
Cessna just added an excellent asset.
Rumen
do not archive
---- "Robert L. Nuckolls wrote:
============
At 07:18 AM 10/11/2013, you wrote:
>Bob,
>
>Many people have chimed in about your contract job with Cessna. I
>want to congratulate you, too. I think you are a great asset in the
>OBAM world and will help Cesspool become Cessna again.
Certainly Cessna, (like EVERY other manufacturer of goods
and services) has suffered from the stubbing of technological
and marketing toes. But such is the nature of success/failure
in the free-market exchange of value. They are, after all,
managed by mere mortals.
I think the measure of an institution is defined not
so much by the nature of their blunders but by what is done
repair damage to stature and to prevent them from happening
again. My boss has identified some shortcomings in his domain that
he has asked me to consider and then apply skills specific
to mitigation of those weaknesses. I cannot speak for other
bosses throughout the Cessna hierarchy but this one seems to have a
solid grip on his mission and design goals.
>Such jobs require a lot of time. I can't help but think that your AE
>activities will slow down, since there's only so many femtoseconds
>in a day. It's okay. Do a great job at Cessna and whatever time you
>have left is good enough for us. Hopefully your home lab activities
>will be supplanted by Cessna lab activities, which means you will be
>helping both entities.
Actually, my work there probably won't have much to do
with the hammer-n-tongs implementation of their technology.
Those folks are WAaaaayy out ahead of anything we did
at Beech on the airplanes. Now . . . If I could round
up all those guys I used to work with at the Targets
Division, I'm confident that they would fit nicely
into the herding of bytes and electrons at Cessna.
My greatest attention will be on communication. The
use of English words in a manner that describes design
goals and requirements as accurately and unambiguously
as their words in C describe functions in their airplanes.
>If contracting pays off big time, perhaps you will find it in your
>heart to send us all $100 so we can get through the shutdown. :)
Understand. Dr. Dee was bullied from her
chairmanship of the psychology department at
Bethany College. She has been looking at replacement
opportunities for the last 6 months or so. Just yesterday
she received a phone call from her 1st choice of
opportunities that not only got her a healthy raise
but relieved her of much of the $overhead$ associated
with the Bethany job. She loved the work with Bethany
students and the honorable amongst her colleagues.
However, tariffs levied on her finances and the
attacks on her integrity made it seem as if she were
paying to work there!
The AeroElectric-List came into being and grew during
my full time tenure at Beech . . . I'm not expecting
that pressures on my 'spare' time will be any greater
at Cessna. In fact, the efficient conversion of time
to cash gives us the opportunity to exercise the
principals of Spontaneous Order to allocation of
time. I'll be able to hire some maintenance and
upgrade work on the house instead of making my own sawdust.
You guys should have seen Dr. Dee yesterday. She got
up on the roof and cleaned some gutters before
patching some leaks at the joints. Scared the @#^#$ out
of me, but she was grin'n ear-to-ear when she got down
with the job done. I'm hanging new gutters on the other
end of the house today.
I thank you all for the kind thoughts and wishes. Compared
with two months ago we are now more optimistic for the
future than ever. I'm running low on R12 books. Need to
get the next revision done and printed.
Bob . . .
Message 12
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Subject: | Re: iPad charger? |
At 07:10 AM 10/11/2013, you wrote:
>
>Add me to the list - I already have the panel spot and fuse slot identified.
>
>Is there an 'easy' way to determine externally whether a given
>cheapo or high price cig plug usb charger is the switcher/linear
>regulator type or the type that has some chance of working for
>awhile? 'Easy' being defined as with a multi-meter or perhaps even
>a quick peek inside.
Interesting question. While all the discussion has been
centered on I-Pad supplies, the problems are not limited
to the I-Pad. If somebody had told me 10 years ago that
the whole world will run out of a USB port in the future,
I would have scoffed.
But here we are. At first the USB port was a serial data
specialty connection that just happened to include a
5VDC source that would support a half-amp or so of
load by some accessory . . . like a mouse or a keyboard.
But the mobile phone industry jumped on that 5v source
as a means by which batteries could be charged. This prompted
a huge growth in 5v power conditioners from wall-warts,
cigar-lighter adapters and a boost in power output ratings
of USB ports on appliances. I have a USB hub on my desktop
that comes with a 5v, 2A wall wart intended to augment the
5v, 1/2A capability of the port on the computer.
Now comes the I-Pad and similar devices with screens that
need power. Dr. Dee has a Kindle that charges with a 5v
wall-wart . . . or USB port on a computer . . . but charging
times are long (6+ hours) and these chargers will not support
simultaneous charging and operation of the device.
I found a 5v 2A wall wart that will both charge and power
her Kindle. The key feature is to identify a power
source that offers several times the current carrying
ability of the run-of-the-mill adapters that have served
us well with mobile phones and MP3 players over the past
ten years.
My gut feeling is that the contemporary 5v adapters
that are failing are simply being taxed beyond their
design ratings. JUST BECAUSE the thing plugs into
a USB mini or micro port doesn't mean that it was
ever intended to supply 5 to 10 watt power demands
of the new devices.
I've never seen a cigar lighter adapter where the
nameplate rating exceeded 600 mA (3 watts). I suspect
that most are not rated for even that much.
I have ordered some 5v, 3A current limited, voltage
regulated step-down converters that will accept up
to 33 volts of DC input. I'll test these on the bench
and then craft a project that will offer a row of
USB connectors (DC power only) and a wide range of
DC input voltages with the design goal of grunting
the greater demands of contemporary devices for
5v power while paying due diligence to noise issues.
Those who are interested in measuring demands and
qualifying their adapters could build adapter
harnesses that would permit a multimeter view of
both current demand and supply voltage under load.
Bob . . .
Message 13
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Subject: | Re: iPad charger? |
Yes Eric,
the linear 24->19 V PS you made for me works beautifully.
Rumen
---- "Eric M. Jones" <emjones@charter.net> wrote:
============
I've made one of these 10-37V input, variable output 5A linear chargers for a customer.
I don't like switch mode power supplies where they can be avoided due
to the unknowns of RFI/EMI. Better quality switchers CAN be found.
I might be persuaded to make a run of these in about a month.
--------
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=410314#410314
Attachments:
http://forums.matronics.com//files/5a_avr_850.pdf
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Subject: | Re: Congratulations, Bob! |
Good luck, sir! I have always found that the English language, in either
the Queen's or US dialect, was a remarkably poor tool for such a task.
Its a challenge to which we must all pay particular heed as the
alternatives are not very attractive.
Peter
On 11/10/2013 15:03, Robert L. Nuckolls, III wrote:
> My greatest attention will be on communication. The
> use of English words in a manner that describes design
> goals and requirements as accurately and unambiguously
> as their words in C describe functions in their airplanes.
Message 15
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Subject: | Re: iPad charger? |
Another item to throw into the mix:
The iPad cable is more than 'just' a cable. If you slide down the sleeve on the
connector that plugs into the mini iPad you will find a circuit board containing
a bunch of components. Buying a 'cheap' replacement cord from eBay will
probably charge the mini but the new iOS upgrade will pop up a warning message
informing you it may not..
The 'wall-mart' 110VAC is not the cause of the warning.. I have tried them from
three different suppliers with the same results. Only the original cord mutes
the warning.
I've read somewhere that the charging rate of the iPad is also controlled by the
cord. Buyer beware... ;)
Earl
>>Now comes the I-Pad and similar devices with screens that
need power. Dr. Dee has a Kindle that charges with a 5v
wall-wart . . . or USB port on a computer . . . but charging
times are long (6+ hours) and these chargers will not support
simultaneous charging and operation of the device.
My gut feeling is that the contemporary 5v adapters
that are failing are simply being taxed beyond their
design ratings. JUST BECAUSE the thing plugs into
a USB mini or micro port doesn't mean that it was
ever intended to supply 5 to 10 watt power demands
of the new devices.
I've never seen a cigar lighter adapter where the
nameplate rating exceeded 600 mA (3 watts). I suspect
that most are not rated for even that much.
Bob . . . <<
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Subject: | Re: Charge battery thru Ground Power Jack |
user9253 wrote:
> This is a catch 22 situation. A smart battery charger will not turn on and start
charging a battery unless it first sees a battery connected. And the aircraft
ground power circuit will not turn on unless it first sees ground power
connected.
> Even if a battery maintainer was able to energize the aircraft ground power
contactor, that contactor might consume all of the maintainer output. The maintainer
might not have enough energy left to charge or maintain the aircraft
battery.
> I do not see a simple solution to this problem.
> There is an error in the schematic. The wire coming out of the top of the OV
module should connect to the top of contactor coil, not the bottom of the coil.
Bad things could happen if wired as drawn.
> Joe
Joe, thanks for having my back on the OVM wiring. Got that corrected on the schematic.
In exploring Charles' idea of a manual switch, intuitively I thought that drawing
power from the battery while trying to charge it might mess up the charging
side of things. But what about attaching a 12 v wall wart supply to the positive
of the GPJ to provide the necessary current to close the contactor and light
the indicator lamp? Upon contactor closure, the batt maitainer would sense
battery 12.5v (+/-) and supply the necessary V+ to charge the batt. The fly in
the ointment that I can see is that the higher voltage of the batt would takeover
the current demands of the contactor and lamp and we're back to square one.
UNLESS... the charger can provide enough amperage for both contactor demand
and battery demand now that the connection to the batt has been accomplished.
I think I may be chasing my tail.
John
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=410329#410329
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Subject: | Re: Charge battery thru Ground Power Jack |
>
>In exploring Charles' idea of a manual switch, intuitively I thought
>that drawing power from the battery while trying to charge it might
>mess up the charging side of things.
Truly 'smart chargers' will tolerate this. For
example:
http://tinyurl.com/mzzselv
Here, a load applied during a sustaining state
the charter went to work to grunt the load and
stayed in the top-off mode. It returned to
the sustaining mode when the load was removed.
A still heavier load would have overwhelmed
the charger's ability to grunt the load and
no doubt the voltage would have sagged. But
recovery after removal of load would have
been the same.
I cannot speak to this capability in other
maintainers without tests.
> But what about attaching a 12 v wall wart supply to the positive
> of the GPJ to provide the necessary current to close the contactor
> and light the indicator lamp? Upon contactor closure, the batt
> maitainer would sense battery 12.5v (+/-) and supply the necessary
> V+ to charge the batt. The fly in the ointment that I can see is
> that the higher voltage of the batt would takeover the current
> demands of the contactor and lamp and we're back to square one.
> UNLESS... the charger can provide enough amperage for both
> contactor demand and battery demand now that the connection to the
> batt has been accomplished.
>I think I may be chasing my tail.
Why not simply provide a ground maintenance
connector for the battery? Take a 5A fuse from
your battery bus to any handy connector situated
for easy access in the hangar. Plug your maintainer
into this jack while parked.
But even before that, what is the perceived
value of 'plugging-in'? RG batteries exhibit
very low self discharge rates . . . and those
rates are temperature dependent. A battery
stored in a hangar over the winter would
probably start the engine next spring. Plugging-
in between flights during the flying season probably
doesn't add much to the utility or service
life of the battery.
But assume you are plugged-in. Assume further
that the charger-maintainer is in the same
league as the Schumacher 1562 series devices.
Hitting the battery with some load for ground
ops while the charger is attached will not
chase the charger into the weeds; proper
charging/maintaining of the battery will resume
when the load is removed.
Bob . . .
Message 18
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Subject: | Cover of Revision 13 |
Still looking for suggestions/photos as candidtates
for the front cover of Revision 13. Many of you will
recall that we had a run-off here on the list to
choose from several options on R12. At the moment,
there's nothing in the hopper . . .
Bob . . .
Message 19
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Subject: | Re: B-787 Li-Ion battery story continues |
Along that same venue, is the model T Ford really any better than a good
horse? Is that new fangled and short lived electric light any better than
those nice whale oil lamps we already have?
Inquiring minds want to know?
Happy Skies,
Old Bob
Do Not Archive
In a message dated 10/11/2013 11:17:36 A.M. Central Daylight Time,
peter@sportingaero.com writes:
I think Boeing have got themselves into a difficult place - possibly
involving considerable politics.
Its clear the original decision was based on saving weight - I don't know
what the value per pound would have been but I project I was involved with
not too long ago was up to $10,000 per pound saved and was talking of going
to $50K - that's development $$ spent to save one pound. A Li battery was
probably very attractive and a low cost weight save. But the technology
maturity assessment now seems to be inaccurate.
It has become clear that the actual in service weight saving is negligible
with the extra metal work, the maintenance overhead is large, and the
reputational impact for all concerned is is difficult to quantify. The big
picture view seems to say fit a NiCad for a quiet life, I'm guessing that most
airlines would accept a small weight increase (on a 260,000 lb airframe) -
is the weight saving equation now around the other way? But what are the
internal Boeing political implications of such a change? We'll probably never
know ...
Its an interesting saga to watch from the outside and try to guess what is
going on!
Peter
Message 20
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Subject: | Re: Cover of Revision 13 |
How about a mosaic made up of lots of small photos of people's
installations? Or perhaps specific detail from people's installations,
e.g. a fuse, a regulator, an alternator, etc. In fact, given the name of
Aeroelectric Connection... how about they're each of a connection used in
an installation, e.g, a crimp, a spade, a lug, a contactor bolt, etc.
I'll volunteer to assemble them into one mosaic.
Cheers,
James
On 11 October 2013 17:36, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> nuckolls.bob@aeroelectric.com**>
>
> Still looking for suggestions/photos as candidtates
> for the front cover of Revision 13. Many of you will
> recall that we had a run-off here on the list to
> choose from several options on R12. At the moment,
> there's nothing in the hopper . . .
>
>
> Bob . . .
>
>
Message 21
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Subject: | Re: iPad charger? |
That would be my recommendation too. Get a Y-splitter for your cigarette lighter
socket. Plug the Garmin into one side and a small 110V inverter into the other.
Use the OEM wall-wart USB chargers that came with your portables. As Earl
said, messy but functional.
Eric
On Oct 11, 2013, at 2:02 PM, "earl_schroeder@juno.com" <earl_schroeder@juno.com>
wrote:
>
>
> I have taken a 12V to 110VAC device and used a multiple outlet adapter for power
on long trips. Messy but workable. Earl
>
> ---------- Original Message ----------
>
>
>
> Eric, as you can see, there's quite a bit of interest in your iPad charger. Not
sure what switching IC you will use, but I woild like to see an automotive
charger that provides two USB outputs. The ones I've used are flakier than hell,
and I'm starting a 6,000 mile USA round trip in December. I want to take
my Garmin 496 so I can capture breadcrumb trails to send home to mama. That will
require one 12 cigarette socket and two USB outputs. Anyone know of something
reliable that exists today?
>
> Henador Titzoff
>
> --------------------------------------------
>
> do not archive
>
>
>
>
>
>
>
>
>
>
>
>
>
>
Message 22
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Subject: | Re: B-787 Li-Ion battery story continues |
All true. And GS Yuasa hasn't come out smelling of roses either!
Eric
do not archive
On Oct 11, 2013, at 5:40 AM, Peter Pengilly <peter@sportingaero.com> wrote:
> I think Boeing have got themselves into a difficult place - possibly invol
ving considerable politics.
>
> Its clear the original decision was based on saving weight - I don't know w
hat the value per pound would have been but I project I was involved with no
t too long ago was up to $10,000 per pound saved and was talking of going to
$50K - that's development $$ spent to save one pound. A Li battery was prob
ably very attractive and a low cost weight save. But the technology maturity
assessment now seems to be inaccurate.
>
> It has become clear that the actual in service weight saving is negligible
with the extra metal work, the maintenance overhead is large, and the reput
ational impact for all concerned is is difficult to quantify. The big pictur
e view seems to say fit a NiCad for a quiet life, I'm guessing that most air
lines would accept a small weight increase (on a 260,000 lb airframe) - is t
he weight saving equation now around the other way? But what are the interna
l Boeing political implications of such a change? We'll probably never know .
..
>
> Its an interesting saga to watch from the outside and try to guess what is
going on!
>
> Peter
>
> On 11/10/2013 12:35, James Kilford wrote:
>> Some interesting stuff in there Bob. Two things in particular stood out:
>>
>> 1) Are customers going to have the appetite for the increase in useful lo
ad when compared with the risk associated with the new battery technology, w
hen such benign alternatives exist?
>>
>> 2) What is the wisdom of making things so different for ground crew on on
e Boeing aeroplane? It seems to be tempting fate by making ground operation
s different. In my line of work the non-functional requirements are often t
he ones that bite you, and perhaps this is a similar case.
>>
>> James
>>
>>
>> On 10 October 2013 04:03, Robert L. Nuckolls, III <nuckolls.bob@aeroelect
ric.com> wrote:
olls.bob@aeroelectric.com>
>>>
>>> I've published a compendium of articles on the B787
>>> battery story at:
>>>
>>> http://tinyurl.com/ag2e9xk
>>>
>>> but in particular, there's a recent addition that
>>> adds a lot of useful information
>>>
>>> http://tinyurl.com/lyc5845
>>>
>>>
>>>
>>>
>>> Bob . . .
>>>
>>> ========================
===========
>>> -
>>> ric-List" target="_blank">http://www.matronics.com/Navigator?AeroElect
ric-List
>>> ========================
===========
>>> MS -
>>> k">http://forums.matronics.com
>>> ========================
===========
>>> e -
>>> -Matt Dralle, List Admin.
>>> t="_blank">http://www.matronics.com/contribution
>>> ========================
===========
>
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
Message 23
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At 09:37 AM 10/11/2013, you wrote:
><peter@sportingaero.com>
>
>Good luck, sir! I have always found that the English language, in
>either the Queen's or US dialect, was a remarkably poor tool for
>such a task. Its a challenge to which we must all pay particular
>heed as the alternatives are not very attractive.
Yes, it'a a challenge . . . combined with infinite
opportunity. Consider a bucket-load of assorted
electronics components, nuts, bolts, enclosures
and wire. Then consider the dictionary occupying
a place of high stature on stands in thousands
of libraries . . . 500,000+ words?
These two conglomerates have a common
opportunity to craft parts/words into an
assembly with value to others. Words can be used
to inform, entertain, persuade and injure.
So it is with that bucket full of parts.
Efficient use of words/parts is an acquired
skill. Design goals must be tailored to the
work-product's end-use. Design goals for
technical writing MAY include elements of
information, persuasion and entertainment.
That's the stuff I like to do in my writing
for the OBAM aviation readers.
Technical writing for industry needs to
be as trim, direct and invariable as the words
used to program a computer or to describe the recipe
for a fine dish. It's a different kind of
writing. Technical writing often speaks to
individuals for whom English is not a first
language.
This job will dictate that I trade the fun-hat
for the information-hat. First to craft
a sub-set dictionary of words that have singular
meaning and chosen to be the preferred term
for that meaning within the discipline. Then
study and teach ways to craft the elegant
sentence. A task no different than crafting
the elegant circuit or software routine.
Minimize the variety and numbers of parts/words
while meeting design goals. The writing goal is
to maximize concentricity of images/ideas between
a writer and reader.
My task would be no different were the root
language anything other than English.
Bob . . .
Message 24
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Subject: | Re: Charge battery thru Ground Power Jack |
Any new switching circuit should be carefully analyzed to be sure that the reverse
polarity and over-voltage protection is not defeated.
Momentarily connecting a 12 volt wall wart is worth a try, or any 12 volt external
battery for that matter, to get the battery maintainer operating. Without
knowing the characteristics of the battery maintainer, experimenting is required.
Consider charging the aircraft battery with a direct connection instead of using
the ground power port. This charger from Walmart comes with a cord that attaches
permanently to a battery. On the end of the cord is a plug that connects
to another plug on the end of the battery charger cord.
http://www.walmart.com/ip/Schumacher-Automotive-SpeedCharge-Battery-Maintainer-and-Charger/13005742
The hard part is finding a place on the aircraft to mount the plug so that the
charger can be plugged in without opening the cowl.
On my RV-12, I plug my battery maintainer into the always hot cigarette lighter
outlet inside of the cockpit.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=410341#410341
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Subject: | Re: Cover of Revision 13 |
At 11:53 AM 10/11/2013, you wrote:
>How about a mosaic made up of lots of small
>photos of people's installations? Or perhaps
>specific detail from people's installations,
>e.g. a fuse, a regulator, an alternator, etc.
>In fact, given the name of Aeroelectric
>Connection... how about they're each of a
>connection used in an installation, e.g, a
>crimp, a spade, a lug, a contactor bolt, etc.
>
>I'll volunteer to assemble them into one mosaic.
>
>Cheers,
>
>James
Sounds good to me! But you're going to have
to sell it to the List. I'll put any and
all offerings into a folder on the website.
About a month before I have to finalize the
content for printing, we'll have a run-off.
Bob . . .
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Subject: | Re: Charge battery thru Ground Power Jack |
>This charger from Walmart comes with a cord that attaches
>permanently to a battery. On the end of the cord is a plug that
>connects to another plug on the end of the battery charger cord.
>http://www.walmart.com/ip/Schumacher-Automotive-SpeedCharge-Battery-Maintainer-and-Charger/13005742
Geesh . . . the thing is down to $17. That has to
be the greatest bang for the buck of any similar
product offered.
Bob . . .
Message 27
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Subject: | Re: iPad charger? |
Eric
Would it be a simple matter to hook up a couple of USB ports to such a device to
be able to charge two iDevices simultaneously?
Sacha
On Oct 11, 2013, at 16:29, <rd2@dejazzd.com> wrote:
>
> Yes Eric,
> the linear 24->19 V PS you made for me works beautifully.
> Rumen
>
> ---- "Eric M. Jones" <emjones@charter.net> wrote:
>
> ============
>
> I've made one of these 10-37V input, variable output 5A linear chargers for a
customer. I don't like switch mode power supplies where they can be avoided due
to the unknowns of RFI/EMI. Better quality switchers CAN be found.
>
> I might be persuaded to make a run of these in about a month.
>
> --------
> 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=410314#410314
>
>
>
>
> Attachments:
>
> http://forums.matronics.com//files/5a_avr_850.pdf
>
>
>
>
>
>
>
>
>
>
>
>
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Subject: | Relay for Critical Power Feed |
Bob,
In Z-19, you use a diode bridge for critical power feeds. Can a relay be used
instead? For example: connect Power Source #1 to terminal 86 and to the critical
component; connect Power Source #2 to terminal 30; and 87a to the critical
component. If both switched on, power comes from #1, otherwise power comes
from whichever is switched on. Seems that this has the advantage of no need for
a heat sink and failure of the relay does not prevent power to the critical
component. What am I missing? Thanks.
Tom
Sent from my iPad
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Subject: | Cover of Revision 13 |
How about a central image of a nice homebuilt airplane with the images of
electrical goodies and installations making a border for it?
Gerry
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: October 11, 2013 11:26 AM
Subject: Re: AeroElectric-List: Cover of Revision 13
<nuckolls.bob@aeroelectric.com>
At 11:53 AM 10/11/2013, you wrote:
>How about a mosaic made up of lots of small
>photos of people's installations? Or perhaps
>specific detail from people's installations,
>e.g. a fuse, a regulator, an alternator, etc.
>In fact, given the name of Aeroelectric
>Connection... how about they're each of a
>connection used in an installation, e.g, a
>crimp, a spade, a lug, a contactor bolt, etc.
>
>I'll volunteer to assemble them into one mosaic.
>
>Cheers,
>
>James
Sounds good to me! But you're going to have
to sell it to the List. I'll put any and
all offerings into a folder on the website.
About a month before I have to finalize the
content for printing, we'll have a run-off.
Bob . . .
Message 30
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Subject: | Re: iPad charger? |
On Oct 11, 2013, at 10:49 AM, Sacha <uuccio@gmail.com> wrote:
> Eric
> Would it be a simple matter to hook up a couple of USB ports to such a dev
ice to be able to charge two iDevices simultaneously?
> Sacha
Sadly, no. The proprietary charging scheme adopted by Apple prevents rapid-
charging from a USB port that doesn't follow their standard. iDevices look f
or signaling voltages on the USB data pins to indicate available charging cu
rrent. Absent those signals, they assume they're attached to a standard USB
data port and limit themselves to 500mA (2.5W) -- that is, if they don't gi
ve you the dreaded, "Charging is not supported with this accessory" message.
2.5W won't even keep up with usage for an iPad with the screen at full bri
ghtness. The iPad 4 consumes ~8W in this state; the 2-4W of overhead in App
le's 10- and newer 12-watt chargers is left for the battery.
Eric
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Subject: | Re: Relay for Critical Power Feed |
That's a novel idea, Tom. It would work, if you assume that failure of PS#1 always
means instantaneous loss of power output. This would immediately de-energize
the relay coil and allow feed from PS#2.
If, however, PS#1 suffered a slow ramp-down of output voltage (as with a failed
alternator leaving a battery to supply the bus), then bus voltage would likely
sag below the minimum for operation of the critical component before the relay
de-energized.
Relay coils exhibit substantial hysteresis; they require a higher voltage to energize
than to de-energize. A 12V-rated relay might energize at 9V rising, but
not de-energize until 6V falling. A 12V battery would be effectively dead long
before the relay opened.
This is why the diode bridge works so well. Whichever main bus has the higher
voltage supplies the critical bus, and switchover is seamless, with no dropout
during the change.
I have a bag of automotive relays on the shelf. I'll try to remember to characterize
their behavior when I get home on Monday and report back.
Eric
On Oct 11, 2013, at 11:18 AM, Thomas E Blejwas <tomblejwas@yahoo.com> wrote:
> Bob,
>
> In Z-19, you use a diode bridge for critical power feeds. Can a relay be used
instead? For example: connect Power Source #1 to terminal 86 and to the critical
component; connect Power Source #2 to terminal 30; and 87a to the critical
component. If both switched on, power comes from #1, otherwise power comes
from whichever is switched on. Seems that this has the advantage of no need
for a heat sink and failure of the relay does not prevent power to the critical
component. What am I missing? Thanks.
>
> Tom
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Subject: | Re: iPad charger? |
It's certainly a truism that switchers are noisier than linear regs. I have a
switch-mode horror show in my car to charge my phone. It makes the AM radio unlistenable
when I plug it in!
That said, I've learned through my own product development process just what you
suggested: that you *can* make a quiet switcher. Board layout is critical to
the effort. If the switched node is kept as small as possible -- preferably
short and wide -- so as not to create an unintentional antenna, you've won half
the battle. A shielded inductor is a given, and judicious use of snubbers
to tame ringing and overshoot bring you closer still. Most remaining noise can
be blocked with carefully tuned filtering (thanks, Bob!).
The main advantage of switchers, of course, is their efficiency: greater than 85%
is common. That means less wasted electrons in capacity-limited applications
(admittedly not an issue in a vehicle, as long as the alternator is online)
and less heat in many cases.
Eric
On Oct 11, 2013, at 7:18 AM, "Eric M. Jones" <emjones@charter.net> wrote:
> I've made one of these 10-37V input, variable output 5A linear chargers for a
customer. I don't like switch mode power supplies where they can be avoided due
to the unknowns of RFI/EMI. Better quality switchers CAN be found.
>
> I might be persuaded to make a run of these in about a month.
>
> --------
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge, MA 01550
> (508) 764-2072
> emjones(at)charter.net
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Subject: | Cover of Revision 13 |
At 01:47 PM 10/11/2013, you wrote:
><gerry.vandyk@shaw.ca>
>
>How about a central image of a nice homebuilt airplane with the images of
>electrical goodies and installations making a border for it?
You're the artist . . . assemble a composite to propose
and we'll add it to the mix of options.
The front cover is of pretty high resolution and,
of course, 8.5 x 11 inches. So the candidate image
would probably want to be something on the order
of 8500 pixels wide by 1100 tall.
Bob . . .
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Subject: | Re: Cover of Revision 13 |
> The front cover is of pretty high resolution and, of course, 8.5 x 11 inches.
So the candidate image would probably want to be something on the order
of 8500 pixels wide by 1100 tall.
Theres a missing zero: 8500 x 11000 is what you meant I think
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Subject: | Re: iPad charger? |
> iDevices look for signaling voltages on the USB data pins to indicate available
charging current. Absent those signals, they assume they're attached to a
standard USB data port and limit themselves to 500mA (2.5W)
Yup. What I was wondering is, suppose you have a 5V supply with the right signaling
voltages and plenty of power? Does paralleling two USB ports onto its output
work to supply two iPads (or an iPad and fast-charge an iPhone) or does one
need some kind of circuit to isolate one from the other?
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Subject: | Re: Cover of Revision 13 |
Here are some sterling examples of what this list, Aero Electric Connection
is about, *and *that give a nod to our list-master Matt Dralle at the same
time.
See:
http://alturl.com/jwgiu
By the way Bob - I'd like to see something personal that you pick for the
cover too.
Bill
SF bay area
On Fri, Oct 11, 2013 at 8:03 PM, Sacha <uuccio@gmail.com> wrote:
>
> > The front cover is of pretty high resolution and, of course, 8.5 x
> 11 inches. So the candidate image would probably want to be something on
> the order of 8500 pixels wide by 1100 tall.
>
> Theres a missing zero: 8500 x 11000 is what you meant I think
>
>
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Subject: | Re: iPad charger? |
On Oct 11, 2013, at 8:11 PM, Sacha <uuccio@gmail.com> wrote:
> Yup. What I was wondering is, suppose you have a 5V supply with the right signaling
voltages and plenty of power? Does paralleling two USB ports onto its output
work to supply two iPads (or an iPad and fast-charge an iPhone) or does
one need some kind of circuit to isolate one from the other?
I can't think of any reason paralleling them wouldn't work, assuming you only want
to charge Apple devices. I haven't paralleled the data pins in my design
(because I want the ports to be able to charge two different brands of devices
simultaneously) but the bulk charging current is shared.
Eric
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Subject: | EXP 2 Bus workaround |
Guys...electrical wizards...
With full knowledge of my ignorance of all things electric but
with only scant knowledge of the challenges which lay ahead, some time
ago I purchased an EXP 2 Bus, thinking that having one would simplify
many issues and offset some of the novelty inherent with my auto engine
conversion, a MPEFIed derivative of a EA81 Subaru built by RAM
Performance Aero Engines which is liquid cooled. Aircraft is a Europa XS
monowheel which is typically powered w/ a 912S or 914.
I've been struggling to layout a circuit diagram which combines
the EXP 2 BUS configured for an external solenoid with the dual battery
/ single alternator diagram Z-19 in the "Connection".
I have made a number of decisions which have committed me to the
digital world including:
- an engine w/ electronic ignition, fuel injection, and an ECU (EC3,
Real World Systems) which came w/ the engine,
- a digital EMS (EM3, Real World Systems) which "talks" w/ the ECU,
- a digital EFIS (Skyview) including moving map, digital terrain,
Transponder, COM, and Intercom.
By selecting an auto engine conversion, I have committed to:
- one alternator, belt driven,
- one coolant pump, belt driven,
- single spark plug in each cylinder.
Additionally, in order to provide redundancy, the engine and
control system includes:
- dual batteries, presently planned to be Odyssey 680's,
- two independent high pressure fuel pumps, each w/ their own filter,
- independent back up battery for Skyview,
- independent back up battery for stand-alone GPS, Garmin 396,
- redundant motherboards (A and B) for the ECU which are toggled from
the panel.
OK...about the EXP BUS...I've now read many reports (including
the VAF threads) which point out its shortcomings...but having spent
$550 for it and its companion Indicator Module, and given my
inexperience and lack of knowledge of things electrical, I still believe
it has a place in my panel, so I hope any critique of what I'm up to
doesn't focus on simply getting rid of it.
The main problem I'm having with the EXP BUS is that it simply
does not have the two 20 amp circuits my engine guy sez are
essential...one for the fuel injectors, and one for the coils. On my
circuit diagram, I attempt to address it by running those two circuits
off an Endurance bus which avoids the EXP BUS entirely.
I do use available circuits in the EXP BUS for the ECU, the EMS,
and the fuel pumps; these components are also fed from the Endurance
bus.
I have space on my panel (just above the EXP BUS, and below the
Skyview flat screen) for a row of 6 - CB / switches which are presently
planned to be:
- rocker or toggle between Fuel Pump #1 and Fuel Pump #2,
- Endurance Master Switch / 50 amp CB,
- Battery #2 ON / OFF,
- 20 amp CB for Fuel Injectors,
- 20 amp CB for Coils,
- spare
Attached are pixs of my instrument panel in its present state,
and a proposed circuit diagram.
I'd be most appreciative of any comments, and particularly those which
point our errors or weakness in the diagram.
Fred
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