Today's Message Index:
----------------------
1. 06:32 AM - Re: So you can't wait for window's Vista? (Ernest Christley)
2. 06:38 AM - Re: Radio interference when receiving (Robert L. Nuckolls, III)
3. 06:53 AM - Re: Hobbyist ECB services (Robert L. Nuckolls, III)
4. 07:08 AM - Re: 8AWG Wire to Fast-On Connection (Robert L. Nuckolls, III)
5. 07:13 AM - Re: 8AWG Wire to Fast-On Connection (Eric M. Jones)
6. 08:10 AM - Re: So you can't wait for window's Vista? (Steve Thomas)
7. 08:10 AM - Re: Need low cost schematic program (=?iso-8859-1?Q?Mich=E8le_Delsol?=)
8. 08:32 AM - D-Sub EMI Filters (Kevin Kinney)
9. 08:37 AM - Re: Re: 8AWG Wire to Fast-On Connection (Robert L. Nuckolls, III)
10. 09:55 AM - Re: 8AWG Wire to Fast-On Connection (LarryRosen@comcast.net)
11. 10:06 AM - Re: Need low cost schematic program (Ernest Christley)
12. 11:05 AM - Re: So you can't wait for window's Vista? (Ernest Christley)
13. 11:21 AM - Re: D-Sub EMI Filters (Robert L. Nuckolls, III)
14. 11:27 AM - Re: 8AWG Wire to Fast-On Connection (Robert L. Nuckolls, III)
15. 11:45 AM - Re: So you can't wait for window's Vista? (C Smith)
16. 05:25 PM - how to wire basic resistive Isspro fuel gauges (Bill Boyd)
17. 06:14 PM - Re: how to wire basic resistive Isspro fuel gauges (Robert L. Nuckolls, III)
18. 07:42 PM - Re: how to wire basic resistive Isspro fuel gauges (Kenneth Melvin)
19. 08:35 PM - Re: how to wire basic resistive Isspro fuel gauges (Steve Allison)
20. 09:10 PM - Re: how to wire basic resistive Isspro fuel gauges (ECLarsen81@aol.com)
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Subject: | Re: So you can't wait for window's Vista? |
Steve Thomas wrote:
> You're right, Harley. Buy a Mac.
>
> Best Regards,
>
> Steve
8*) Or download Kubuntu Live* CD, and keep your money to buy airplane
parts with. Then you can use Adept to install gEDA and PCB, and be on
your way to making circuit boards.
I finished the board layout for my version of a capacitive fuel level
sensor. I use a second plate along the bottom of the tank instead of a
capacitor as the second input to the comparator. That should make it
more resistant to changes in dielectric constants due to fuel
reformulations. I also chose to forego the audible alarm and opted for
the alarm circuit to provide a ground for an external LED. If anyone
would care to critique/review/ogle the layout, I'd be happy to send a
PDF copy of the schematic and the output of PCB.
* - Kubuntu Live. Live CD's are a relatively new phenomena in Linux,
started by Knoppix distribution. You download an image and burn it to a
CD, making it bootable. You boot the PC from the CD, and you're
presented with a complete Linux destop. Play around. See what all the
fuss is about. Determine for yourself if it is hip or hype. Remove the
CD. Reboot. And you're right back where you started with nothing changed.
> ____________________________________________________________________
>
>
> On Jan 16, 2007, at 4:40 PM, Harley wrote:
>
>> So you can't wait for Windows new Vista to be released this week?
>> Saw a review of the final version on PC Magazine online,
>> today...Here's some of the results of the testing and review that PC
>> Magazine did on it. They tested the SAME versions that you'll get in
>> the store, and on all types of new machines, laptops, low end, high
>> end, minimum memory and speed, maximum, etc...
>>
>> I only included some more general cons, but you'll hear about all the
>> claimed pluses from Windows ads that you will be seeing shortly. Of
>> course, they probably won't mention these...
>>
>> Looks like it needs a lot of work yet to improve on XP...
>>
>> Harley
>
>
>*
>
>
> *
>
--
,|"|"|, Ernest Christley |
----===<{{(oQo)}}>===---- Dyke Delta Builder |
o| d |o http://ernest.isa-geek.org |
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Subject: | Re: Radio interference when receiving |
At 01:25 PM 1/16/2007 +0000, you wrote:
I have a new Jabiru 2200 (85hp) installed in a Murphy Maverick with an Icom
IC-A200 panel mount VHFand an external antenna mounted through the fuselage
skin midway between the cabin and fin using the fuselage for a groundplane.
I am picking up ignition interference when receiving which increases with
engine speed.
I have tried running the radio from an independent power supply to
eliminate installation
wiring and still get the same problem, which seems to indicate that the
antenna is picking
up the radiated noise.
The engine has suppressed ht leads to the plugs but I am not sure about the
leads to
the coils.I checked the rotor arms for security and they seem fine.
Does anyone have any suggestions on how to cure the problem?
Hmmmm . . . when problems arise from a "per-the-factory"
ignition system installation, this can get sticky. I've
never had occasion to get a problem ignition system
into the lab to fix a noise problem. Our production piston
aircraft still use the classic shielded magneto installations
which have evolved into pretty radio-friendly products
over the years.
Are you on a list-server for either the Maverick, the
engine or both? I'd also contact the service rep for
the engine. You may find that he/she is aware of the
occasional odd problem that's easily fixed.
Try running from one ignition at a time. The problem
may be isolated to a single system. If this is true,
likelihood of it being a simple fix is improved.
How much of the wiring is stuff that's used as-supplied
and how much do you install? I did a quick look-see on the
'net for the installation manual. Don't have time to chase
it right now. Do you know where it can be acquired? I'd
like to see the schematic for the ignition system.
Bob . . .
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Subject: | Re: Hobbyist ECB services |
At 09:51 PM 1/15/2007 -0500, you wrote:
><eanderson@carolina.rr.com>
>
>While I have been a satisfied customer of ExpressPCB for a number of years
>and think they are indeed a great PCB provider, I have lately found some
>of there limitations - well, rather limiting. I have decided to convert
>my project design from through-hole to surface Mount (ugh! those
>components are almost invisible!).
>
>In order to keep my sanity, I decided that using a stencil to lay on the
>bare board for a limited number of units would be an ideal way to
>go. This stencil is simply a thin metal (or plastic) sheet with holes
>very precisely cut to fit over those component pads you wish to have a
>solder paste deposited on. So you put the paste on the stencil and use a
>squeegee to pull the paste across all the holes in the stencil thereby
>depositing the solder paste only where you are going to put a component.
Gave up on solder paste in a skunk-werks environment.
The stuff has a shelf life and is not the friendliest
material compared to wire solder.
>Then you use a magnifying glass and tweezers to put the tiny components
>on their pads and pop them into an oven and voila (if everything goes
>right) you have a solder surface mount board.
We've settled on 1206 or larger components as the
smallest we'll use in a hand-assembled design. We
lay down a wire solder dot on one of the pads, then
slide the part into the hot pad with a tweezer. After
the part is tacked into place, we solder the free end.
The tack end occasionally needs touch-up but not often.
>Now the problem is that ExpressPCB does not offer the stencil service,
>furthermore most firms offering the stencil service require a set of
>Gerber files (normal CAD output of most PC board software). You can not
>directly produce one from the ExpressPCB software. You must pay an
>additional $60 for a Gerber file from ExpressPCB. This is the file that
>EAGLE and some of the other readily available PC board software produces
>that file as a normal course. So $60 just seems a bit much when there are
>package that produce it free.
ExpressPCB was designed to support the
few-of-a-kind, hobbyist/skunk-werks market.
Our engineering overhead is $800/man-day
. . . turn-time is critical to achieving
low-cost proof of concept solutions.
In this venue, I've found their service
to be invaluable. On one occasion I was
able to order, stuff and test three different
board configurations in a 15-day window.
There may be others with similar services but
what they offer for $59 a pop is pretty attractive.
>A PCB software package that produces such non-proprietary Gerber files
>also give you a much greater range of service providers including all the
>way to China (very nice prices if you can stand the transportation delay).
>
>So I believe, as Bob pointed out - it all depends on what your needs are.
>For one of a kind, or a few, ExpressPCB offers a valued service at a
>reasonable price. Up to now, I have used no other. But, some of their
>limitations in face of my current needs are causing me to reconsider.
Once I've proven a design, others are most
welcome to repackage and/or modify the design
to suit their particular manufacturing requirements
and favorite materials.
For the guy who wants to build a one-of-a-kind
electro-whizzy for his project, I'll suggest that
ExpressPCB offers some attractive and practical
support.
Bob . . .
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Subject: | Re: 8AWG Wire to Fast-On Connection |
At 10:30 PM 1/16/2007 -0500, you wrote:
>
>Bob,
>The Fast-On connection is to a mosfet switch solid state relay sold by
>perihelion design <http://www.periheliondesign.com/powerlinkjr.htm> rated
>for 35 amps continuous. But your statement "30A is pushing a Fast-On
>pretty hard" got me thinking, which generated more questions, so now I
>need some guidance.
>
>I am using the a Z-13/20 architecture that is modified for a battery in
>the tail cone (RV-10) The solid state relay is for the endurance bus
>feed. The circuit goes from the battery to a 30 amp ANL limiter to the
>relay and then to the endurance bus, the run is 17 feet. The continuous
>e-bus load is just under 10 amps, but the maximum possible load is 30 amps
>(no diversity at all, everything running at once, flaps, auto pilot
>servos, com transmit, etc). The drivers for the high load are pitot heat
>and landing light. [I know it could be debated whether or not these
>deserve to be on the e-bus, but IMHO this design is to allow me to fly
>safely in IMC and land]
I'll suggest that nobody should plan to depend on a battery-feed
e-bus to extract themselves from an IMC environment. In
retrospect, I'm not too happy with the 13/20 configuration,
it's pretty messy. I'm beginning to think that Z-12 is the
best way to incorporate the SD-20 . . . this is how it's
done on thousands of TC aircraft that used to fly routinely
in IMC with NO second alternator and NO e-bus.
Given that you have two engine driven power sources, I'll
recommend that you pare the E-bus down to the minimum endurance loads
suggested in chapter 17. Likelihood of EVER needing to
recover from dual alternator failure using the e-bus all the
way to the ground is exceedingly low and to PLAN for it
is making your system get a bit messy.
If you're down to battery only, then the original e-bus
philosophy is critical to graceful recovery. You can always
close master contactors during approach to landing
for recovery. If you're looking at servicing a 30 amp
load under these conditions, then adding one or two
contactors at 1A each is insignificant.
>So, if my calculations are correct for a 14 volt system:
>a] 10 amps @ 17 feet 10AWG has a voltage drop of 0.17 volts
>b] 10 amps @ 17 feet 8 AWG has a voltage drop of 0.11 volts
>c] 30 amps @ 17 feet 10 AWG has a voltage drop of 0.51 volts
>d] 30 amps @ 17 feet 8 AWG has a voltage drop of 0.32 volts
>
>This is only the voltage drop to the e-bus fuse block and does not account
>for the voltage drop to the final device.
>
>So, I believe I am justified in using a 30 amp fuse, but am I being way to
>conservative in using 8 AWG wire to account for a very unlikely full max load?
Let's re-think this a bit and see if we can take
some weight and operating complexity out of your proposed
design. This is an excellent case where MORE is NOT BETTER.
Bob . . .
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Subject: | Re: 8AWG Wire to Fast-On Connection |
Larry,
Pushing hardware gets everybody into trouble. Please recalculate this based on
my Super-4-CCA. Also, have you looked at the ground return? Pushing 30A makes
me concerned with ground return currents through the control cables or structural
parts...an insidious killer.
As for the Fastons. I puzzled over this for years. Connectors are sold for 10 AWG
wires but no larger, and that firmly sets the amp limit. Splicing larger wires
to the connectors concerns me and I advise against it.
Email me offline and we can discuss some options.
(I will still send a sample of Super-2 and Super-4-CCA to interested parties...see
my website).
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones@charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=88281#88281
Message 6
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Subject: | Re: So you can't wait for window's Vista? |
Well, it seems to be either time or money. Spend the money on a Mac
and it just works. Or spend hours and hours trying to configure
Linux and get all your peripherals working, time that could be spent
building. Most of us want to build airplanes, not circuit boards.
Do Not Archive
Best Regards,
Steve
____________________________________________________________________
On Jan 17, 2007, at 6:30 AM, Ernest Christley wrote:
> 8*) Or download Kubuntu Live* CD, and keep your money to buy
> airplane parts with. Then you can use Adept to install gEDA and
> PCB, and be on your way to making circuit boards.
Message 7
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Subject: | Need low cost schematic program |
As a newbie to electrical circuits for my RV8, I looked around for a cheap
schematic program and hit upon ExpressSCH. It has already been said that it
is a very good little program for general schematic work and FWIW I agree.
What has not been said is that one can make one's own components and that it
has a nifty component export feature. Each item in my schematics is
identified as a component, including wires. Each component has three items
of information that one can use as one likes. This means that I get my bill
of materials and all sorts of other information by carefully coding the
information on the schematic, exporting into a text file, importing into
Excel and by applying formulas on the three fields of each component, I get
lots of useful information, such as:
Components are grouped into parts, wires, junctions from one drawing to
another.
Each wire is identified as to drawing it belongs to, circuit it is attached
to, gauge, color, parts the wire connects to
Parts are identified as to drawings, name, type, source and other info
Junctions connect a wire on one drawing to the same wire or to a part on
another drawing. In my Excel sheet I maintain coherence by requiring that
there should be exactly two identical junction components for each junction.
This ExpressSCH export feature enables me to maintain coherence between the
schematic and the parts list.
Since all I need is to have clear up-to-date schematics and parts, junctions
and wire lists, I find that this program fulfils my needs. I am sure that
there are more powerful and more user friendly programs out there but they
may cost a fair amount and may have steep learning curve.
Michele
RV8 Finishing
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: lundi 15 janvier 2007 19:29
Subject: Re: AeroElectric-List: Need low cost schematic program
<nuckollsr@cox.net>
At 03:53 PM 1/15/2007 +0100, you wrote:
<jan.de.jong@xs4all.nl>
>
>It seems that ExpressPCB output format is proprietary - no Gerber files -
>and not supported by other prototype PCB makers.
>A possible consideration.
>Jan de Jong
Correct . . . but after years of doing business with
them (and considering/using a variety of options) their
pricing and service for the low volume OBAM aircraft
market has over-ridden these concerns.
It's exceedingly unlikely that anyone on the List is
going to regret having used ExpressPCB because of a
future wish to have a few thousand boards fabricated.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
Message 8
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Subject: | D-Sub EMI Filters |
I'm still learning about electronics and avionics. EMI still leaves me in the
dark, though I'm learning about it too.
Assume someone were to have a noisy radio: Would EMI shielded D-sub connectors help with this in any way? For example - http://specemc.com/series100.asp
How applicable would this be to correcting that problem?
Regards,
Kevin Kinney
--
Non-Parent - I don't see how you can raise children & stay sane.
Parent - You don't. You pick one and go with it.
Message 9
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Subject: | Re: 8AWG Wire to Fast-On Connection |
At 07:12 AM 1/17/2007 -0800, you wrote:
>
>Larry,
>
>Pushing hardware gets everybody into trouble. Please recalculate this
>based on my Super-4-CCA. Also, have you looked at the ground return?
>Pushing 30A makes me concerned with ground return currents through the
>control cables or structural parts...an insidious killer.
Hmmmm . . . I'm not aware of any well considered
design situation where local grounding was discouraged
for the protection of control cables or structural
parts. We ground things ALL OVER the airframes on
everything from A36 to Hawker 850 and with return
currents that run a lot more than 30A.
I've heard a variety of stories but none were supported
by any critical review of hard data. Until we're
offered good data supported by simple-ideas, I'll
suggest that the eroded cables, loose rivets and
pitted skins are the result of some stresses OTHER
than ground return currents.
For example, a few years ago we identified a case where
drive-end bearings on starter generators were being
eroded by small voltage drops in structure (tens of
millivolts) but at hundreds of amps. This was supported
by good data, repeatable experiments and obvious
mitigation of a recurring problem by electrically
insulating one end of the quill shaft. It would have
been much BETTER to re-arrange some wiring but the
cost of modifying hundreds of airplanes was reduced by
building a special drop-in replacement for the
starter-generator.
>As for the Fastons. I puzzled over this for years. Connectors are
>sold for 10 AWG wires but no larger, and that firmly sets the amp limit.
My design philosophy for the use of Fastons has more
to do with longevity than for "ratings". Yes, one might
safely assume that 'cause AMP supplies a Faston to fit
a 10AWG wire, that the same Faston and it's mating
tab are capable of carrying the same current as the
wire.
But keep in mind that wire current "ratings" are based
on temperature rise . . . a 10AWG wire is not in danger
in a room temperature environment at 50 amps. Should we
out-of-hand assume that it's okay to load the 10AWG
Faston to 50A in the same environment?
Probably okay when new but consider the case of the
bouncing ammeters in many Cessna and Piper singles.
This is a case where multitudinous connections in
the voltage-sense/field-supply lead have increased
loop resistance by perhaps 100 milliohms. Not enough
voltage drop to case the system to fail . . . but enough
to upset the voltage regulator's servo loop stability.
This takes perhaps 20-30 years in the field. EXCEEDINGLY
difficult to diagnose if you don't understand the simple-
ideas behind system functionality.
This is why I de-rate the fuse blocks to 15A per slot
while the manufacturer rates them for 30A per slot.
Recall that heating effects are an I-squared effect.
Limiting the design loads on any one fuse by 50%
reduces heating stresses on the fuses connections by
75%. This is a element of an overall design philosophy
that has nothing to do with things you read in the
manufacturer's data sheets.
As I write these words, I'm in conversation with some
poor tech in Europe trying to fix a paralleling stability
problem on a 30 year old Hawker. This beast uses
MAGNETIC AMPLIFIERS in the generator control units.
The paralleling system has 30-50 joints in the loop . . .
ANY or ALL of which can be contributing to the malfunction.
The sad part is that we may find that LOTS of joints need
to be renewed to bring this airplane back to designed
performance. This is a case were the joints are carrying
perhaps less than 3A.
Just one of many examples of a situation where loading
decisions and architectures are fine-tuned NOT to
accommodate out-of-the-box ratings but to reduce
probability of disappointing performance 10-20 years from now.
The question that started this thread had to do with
running an 30A e-bus feeder through a Faston . . .
all the bells went off and red flags went up. Assume
this system checks out just fine for first flight
and then sits quietly waiting for the a some years
hence when its called upon to perform its intended
purpose. How much are we willing to bet that it's
going to take this 30A load for long enough to get
down? If you're betting your life on it, would
it not be more prudent to design this potential weakness
out from square one? This seems especially smart when
that one joint becomes single point of failure for
the e-bus alternate feed.
> Splicing larger wires to the connectors concerns me and I advise against it.
Keep in mind that the wire was up-sized to meet a voltage
drop requirement, not to increase max current in the
line. Splicing "too-big" wires in for the purpose
of mitigating voltage drop is a sound principal (See
chapter 8 in 'Connection) but maybe not practical after
we consider the big picture for system architecture and
the failure modes we're proposing to handle.
I'm about 80% convinced that Z-13/20 is going to come out
of Rev 12 in favor of recommending Z-12 as the most
practical way to incorporate the SD-20 into a light
aircraft.
Bob . . .
Message 10
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Subject: | Re: 8AWG Wire to Fast-On Connection |
Thanks Bob and Eric for your guidance. I will need to rethink my load analysis
once again.
Bob,
You said " I'm about 80% convinced that Z-13/20 is going to come out
of Rev 12 in favor of recommending Z-12 as the most
practical way to incorporate the SD-20 into a light
aircraft."
But, doesn't this defeat the elegance of the e-bus concept. The main alternator
fails and with 3 switches (Aux Alternator on, e-bus feed on and master off)
you would have an electrical design that would out last the fuel on board. With
Z-12 you would have to manually shed the load.
Larry
-------------- Original message ----------------------
From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
> <nuckollsr@cox.net>
>
> At 10:30 PM 1/16/2007 -0500, you wrote:
>
> >
> >Bob,
> >The Fast-On connection is to a mosfet switch solid state relay sold by
> >perihelion design <http://www.periheliondesign.com/powerlinkjr.htm> rated
> >for 35 amps continuous. But your statement "30A is pushing a Fast-On
> >pretty hard" got me thinking, which generated more questions, so now I
> >need some guidance.
> >
> >I am using the a Z-13/20 architecture that is modified for a battery in
> >the tail cone (RV-10) The solid state relay is for the endurance bus
> >feed. The circuit goes from the battery to a 30 amp ANL limiter to the
> >relay and then to the endurance bus, the run is 17 feet. The continuous
> >e-bus load is just under 10 amps, but the maximum possible load is 30 amps
> >(no diversity at all, everything running at once, flaps, auto pilot
> >servos, com transmit, etc). The drivers for the high load are pitot heat
> >and landing light. [I know it could be debated whether or not these
> >deserve to be on the e-bus, but IMHO this design is to allow me to fly
> >safely in IMC and land]
>
> I'll suggest that nobody should plan to depend on a battery-feed
> e-bus to extract themselves from an IMC environment. In
> retrospect, I'm not too happy with the 13/20 configuration,
> it's pretty messy. I'm beginning to think that Z-12 is the
> best way to incorporate the SD-20 . . . this is how it's
> done on thousands of TC aircraft that used to fly routinely
> in IMC with NO second alternator and NO e-bus.
>
> Given that you have two engine driven power sources, I'll
> recommend that you pare the E-bus down to the minimum endurance loads
> suggested in chapter 17. Likelihood of EVER needing to
> recover from dual alternator failure using the e-bus all the
> way to the ground is exceedingly low and to PLAN for it
> is making your system get a bit messy.
>
> If you're down to battery only, then the original e-bus
> philosophy is critical to graceful recovery. You can always
> close master contactors during approach to landing
> for recovery. If you're looking at servicing a 30 amp
> load under these conditions, then adding one or two
> contactors at 1A each is insignificant.
>
>
> >So, if my calculations are correct for a 14 volt system:
> >a] 10 amps @ 17 feet 10AWG has a voltage drop of 0.17 volts
> >b] 10 amps @ 17 feet 8 AWG has a voltage drop of 0.11 volts
> >c] 30 amps @ 17 feet 10 AWG has a voltage drop of 0.51 volts
> >d] 30 amps @ 17 feet 8 AWG has a voltage drop of 0.32 volts
> >
> >This is only the voltage drop to the e-bus fuse block and does not account
> >for the voltage drop to the final device.
> >
> >So, I believe I am justified in using a 30 amp fuse, but am I being way to
> >conservative in using 8 AWG wire to account for a very unlikely full max load?
>
> Let's re-think this a bit and see if we can take
> some weight and operating complexity out of your proposed
> design. This is an excellent case where MORE is NOT BETTER.
>
> Bob . . .
>
>
>
>
>
Message 11
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Subject: | Re: Need low cost schematic program |
Michle Delsol wrote:
>
>As a newbie to electrical circuits for my RV8, I looked around for a cheap
>schematic program and hit upon ExpressSCH. It has already been said that it
>is a very good little program for general schematic work and FWIW I agree.
>What has not been said is that one can make one's own components and that it
>has a nifty component export feature. Each item in my schematics is
>identified as a component, including wires. Each component has three items
>of information that one can use as one likes. This means that I get my bill
>of materials and all sorts of other information by carefully coding the
>information on the schematic, exporting into a text file, importing into
>Excel and by applying formulas on the three fields of each component, I get
>lots of useful information, such as:
>
>Components are grouped into parts, wires, junctions from one drawing to
>another.
>
>Each wire is identified as to drawing it belongs to, circuit it is attached
>to, gauge, color, parts the wire connects to
>
>Parts are identified as to drawings, name, type, source and other info
>
>Junctions connect a wire on one drawing to the same wire or to a part on
>another drawing. In my Excel sheet I maintain coherence by requiring that
>there should be exactly two identical junction components for each junction.
>
>This ExpressSCH export feature enables me to maintain coherence between the
>schematic and the parts list.
>
>Since all I need is to have clear up-to-date schematics and parts, junctions
>and wire lists, I find that this program fulfils my needs. I am sure that
>there are more powerful and more user friendly programs out there but they
>may cost a fair amount and may have steep learning curve.
>
>Michele
>RV8 Finishing
>
>
Excellent, Michele. It's just a tool that we hope to leave on the
ground someday 8*)
I was up to speed with gEDA in just a few days. Producing what I think
is a usable print in about 12 hours total time. The gEDA tool chain
uses ASCII files to maintain all its information, which has a lot of
valuable implications. I had a problem last night where I had misnamed
one of the pins on a custom component I created. I called it 'c'
instead of '3'. Opened the file in a text editor, made the changes, and
then auto-routed all the tracks. Slight modifications of component
sizing or pin spacing could be accomplish without even using the
program. I was also suprised that the print command automatically
produces 10 different views of the layout (solder, component,
componentmask, soldermask, plated-drill, topsilk, bottomsilk,
topassembly, bottomassembly, and fab).
--
,|"|"|, Ernest Christley |
----===<{{(oQo)}}>===---- Dyke Delta Builder |
o| d |o http://ernest.isa-geek.org |
Message 12
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Subject: | Re: So you can't wait for window's Vista? |
Steve Thomas wrote:
>
> Well, it seems to be either time or money. Spend the money on a Mac
> and it just works. Or spend hours and hours trying to configure
> Linux and get all your peripherals working, time that could be spent
> building. Most of us want to build airplanes, not circuit boards.
>
Ahh, but how do you count the time if it is a circuit board FOR an
airplane? 8*)
Macs just work, because Apple has total control over both the software
and hardware. Not a bad system, but you're necessarily limited to the
hardware they recommend. Step out of line and install the random piece
of hardware and it doesn't necessarily just work anymore.
Two months ago, I wouldn't have had an argument about Linux needing
hours and hours of configuration. I was getting fed-up with all the
fiddling that I had to do to keep my Fedora box running. So I tried
Kubuntu on the suggestion of a friend. It was "here we go again" at
first, because I was trying to switch to 64-bit computing. Got tired of
that game and went with the 32-bit version of the distribution. I have
been tickled goofy by how everything just works. It has taken
everything that I've thrown at it.
Burn a Kubuntu Live CD and boot the odd computer up with it. Look for
"Hardware Browser" under "System Tools" in the menu, and note which
hardware the OS didn't find and configure. Do it on multiple systems.
Make sure some of them have really old, cheap, no-name hardware so that
the OS can get a little exercise. If that doesn't convince you that
times have changed, call up "Adept" from the "System Tools". This is
your open-source software shop. Enable all the repositories, then type
something that interests you in the search bar. "flight simulator"
would be a good example. Up pops FlightGear and a few supporting
files. Click the "Request Install" button and then "Process Queue". A
couple downloads, a little disk churning, and there's a new icon in your
system menu for your new flight simulator. If you really like the
simulator, you can construct your own airplane or terrain models and
share them back to the community. Except for initial installation and
installing new programs, I've spent very little time configuring Kubuntu
and much more time actually using it. In this case, Linux just works
(for a change).
--
,|"|"|, Ernest Christley |
----===<{{(oQo)}}>===---- Dyke Delta Builder |
o| d |o http://ernest.isa-geek.org |
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Subject: | Re: D-Sub EMI Filters |
At 11:27 AM 1/17/2007 -0500, you wrote:
>
>
>I'm still learning about electronics and avionics. EMI still leaves me in
>the dark, though I'm learning about it too.
>
>Assume someone were to have a noisy radio: Would EMI shielded D-sub
>connectors help with this in any way? For example -
>http://specemc.com/series100.asp
>
>How applicable would this be to correcting that problem?
>
>Regards,
>Kevin Kinney
Check out the chapter on noise in the 'Connection.
The short answer to your question is, "Yes, filters
may be useful in mitigating noise problems."
The facts one needs to secure before selecting any
noise mitigation tool or technique are:
(1) who is the victim?
(2) who is the antagonist?
(3) what is the propagation mode for coupling
the noise between 2 and 1?
One then needs to evaluate one or a combination
of (1) reduce noise from antagonist, (2) increase
ability of victim to operate satisfactorily with
noise presented and/or (3) consider ways to
attenuate if not eliminate the propagation mode(s).
It may well be that the filter connector you've cited
will help . . . but simply adding such a device as
an experiment is commonly called "Swaptronics . . .
let's replace or add things until something good
happens."
If this sounds like a daunting task, don't feel bad.
It CAN be an engineer's worst nightmare. To date,
I've not worked a noise problem we couldn't
fix . . . but some of them have been exceedingly
$time$ consuming. For example, see:
http://www.aeroelectric.com/Pictures/Misc/Too_Close.jpg
Here's a photo of a ground fault detection
transformer on a biz jet that's mounted too close
to a bleed air tube that is excited by field flux
leakage from a starter generator.
A variety of techs spent 4 weeks chasing this
one before they moved the airplane to Wichita.
Our techs fought it for a week before one of
them joined me during the xmas holiday and an
ice storm to struggle with the beast. We found
the propagation mode by accident. I still don't
know root cause. The airplane was 13 years old
and something changed to allow coupling of the
starter generator to the engine and ultimately
generate an AC magnetic field around the bleed
air tube.
The "fix" was to build an adapter plate to
increase clearance between tube and transformer
to 1" . . . i.e. we broke the propagation mode.
Now, we COULD have chased down the change to the
engine but after the airplane was down for 6 weeks,
nobody was to eager to let me take the engine
apart. We COULD have substituted a modern torroidal
transformer but that would have generated a
certification effort. So . . . moving the transformer
turned out to be the practical solution.
Since the first happenstance of this condition,
a second airplane presented with the same problem
and the spacer kit fixed it too.
It's useful to consider the LONG answer. Not necessarily for
examples of things to keep in one's bag of tricks for
noise mitigation. The long answer is an illustration of
the variabilities one might encounter. It further
illustrates the fact that systems can become troublesome
after a long history of satisfactory performance.
The likelihood that a filtered D-sub will fix a problem
in the field is low. It's rare that supplier of
a product has failed to design their electro-whizzy
to live in the real world. If a device using d-sub
connectors presents with a noise problem, it's more
likely that the solution will not include addition
of a filtered d-sub connector.
Bob . . .
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Subject: | Re: 8AWG Wire to Fast-On Connection |
At 05:53 PM 1/17/2007 +0000, you wrote:
>
>Thanks Bob and Eric for your guidance. I will need to rethink my load
>analysis once again.
>
>Bob,
>You said " I'm about 80% convinced that Z-13/20 is going to come out
> of Rev 12 in favor of recommending Z-12 as the most
> practical way to incorporate the SD-20 into a light
> aircraft."
>
>But, doesn't this defeat the elegance of the e-bus concept. The main
>alternator fails and with 3 switches (Aux Alternator on, e-bus feed on and
>master off) you would have an electrical design that would out last the
>fuel on board.
Absolutely . . .
> With Z-12 you would have to manually shed the load.
. . . and there are features in the SB-1 regulator that assists
the pilot in the load reduction task.
I'm going to catch a lot of flack when I pull the drawing. No doubt
many folks have installed it . . . and I'll have to explain that
there's nothing functionally BAD about Z-13/20. Nonetheless, after
working with builders over the time the drawing has been published,
I've determined that it doesn't conform to my personal standards
of "the best we know how to do." It's simply too complex.
Bob . . .
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Subject: | So you can't wait for window's Vista? |
I made a kubuntu boot cd awhile back for my wife, as their office software
is linux based. Never used it though, but now I'm curious to try it out.
Thanks for the tips.
Craig Smith
Do not archive
8*) Or download Kubuntu Live* CD, and keep your money to buy airplane
parts with. Then you can use Adept to install gEDA and PCB, and be on
your way to making circuit boards.
I finished the board layout for my version of a capacitive fuel level
sensor. I use a second plate along the bottom of the tank instead of a
capacitor as the second input to the comparator. That should make it
more resistant to changes in dielectric constants due to fuel
reformulations. I also chose to forego the audible alarm and opted for
the alarm circuit to provide a ground for an external LED. If anyone
would care to critique/review/ogle the layout, I'd be happy to send a
PDF copy of the schematic and the output of PCB.
* - Kubuntu Live. Live CD's are a relatively new phenomena in Linux,
started by Knoppix distribution. You download an image and burn it to a
CD, making it bootable. You boot the PC from the CD, and you're
presented with a complete Linux destop. Play around. See what all the
fuss is about. Determine for yourself if it is hip or hype. Remove the
CD. Reboot. And you're right back where you started with nothing changed.
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Subject: | how to wire basic resistive Isspro fuel gauges |
I find myself in need of the wiring schematic for the Isspro fuel
gauges that Van's sells - I think they're #8690, and am unable to find
it at the company website or with Google. I need to know how the
senders wire to the gauges and where the 12V and GND connections are
made.
Confession time: I have these gauges in my plane now, but have lost
the old wiring diagram I drew at the time (which would have been an
embarassment if it still existed, like the rat's nest behind my
present panel). I need the info to design relevant parts of the
diagram for the new electrical system.
Thanks,
-Bill B.
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Subject: | Re: how to wire basic resistive Isspro fuel gauges |
At 08:23 PM 1/17/2007 -0500, you wrote:
>
>I find myself in need of the wiring schematic for the Isspro fuel
>gauges that Van's sells - I think they're #8690, and am unable to find
>it at the company website or with Google. I need to know how the
>senders wire to the gauges and where the 12V and GND connections are
>made.
>
>Confession time: I have these gauges in my plane now, but have lost
>the old wiring diagram I drew at the time (which would have been an
>embarassment if it still existed, like the rat's nest behind my
>present panel). I need the info to design relevant parts of the
>diagram for the new electrical system.
>
>Thanks,
If someone has relevant data to share with Bill . . . send
it to me also. I'll scan it and add to the library of installation
data at aeroelectric.com
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
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Subject: | how to wire basic resistive Isspro fuel gauges |
Herewith the required schematic.
Kenneth Melvin, RV-9A N669TJ
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bill Boyd
Sent: Wednesday, January 17, 2007 5:24 PM
Subject: AeroElectric-List: how to wire basic resistive Isspro fuel gauges
--> <sportav8r@gmail.com>
I find myself in need of the wiring schematic for the Isspro fuel gauges
that Van's sells - I think they're #8690, and am unable to find it at the
company website or with Google. I need to know how the senders wire to the
gauges and where the 12V and GND connections are made.
Confession time: I have these gauges in my plane now, but have lost the old
wiring diagram I drew at the time (which would have been an embarassment if
it still existed, like the rat's nest behind my present panel). I need the
info to design relevant parts of the diagram for the new electrical system.
Thanks,
-Bill B.
Message 19
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Subject: | Re: how to wire basic resistive Isspro fuel gauges |
Bill Boyd wrote:
> I find myself in need of the wiring schematic for the Isspro fuel
> gauges that Van's sells - I think they're #8690, and am unable to find
> it at the company website or with Google. I need to know how the
> senders wire to the gauges and where the 12V and GND connections are
> made.
I still have a pair of these in the boxes. No documentation with them
(wouldn't have thrown it out, so they probably didn't come with any).
The three studs are marked on the back +, ground symbol, and S. This is
basically the same setup as the new Van's gages marked I (input +12v), G
(ground), and S (signal from the sender).
The new Van's gages install drawing is here:
http://www.vansaircraft.com/pdf/Gauge_Install.pdf
Steve
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Subject: | Re: how to wire basic resistive Isspro fuel gauges |
The ISSPRO gages were designed by Van's and manufactured by ISSPRO. ACS&S
carrries them without the a Logo and Chief carries them with the Chief Logo.
I ran into the lack of paperwork problem on the ACS&S ordered gages and
contacted ISS and got that info. Since then the ACS&S gages I have ordered have
a
copy of the PDF from Van's tucked in the box.
I also downloaded and printed the page from the Van's site for my files.
Oh, the gages don't like to work properly below 11 VDC, bear that in mind
when figuring your depleat battery time during charge failure. (or when running
tests in the shop..hehe..ask me how I know)
Ed Larsen
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