Today's Message Index:
----------------------
1. 06:35 AM - Re: wire size for charging battery (Bob Gibson)
2. 06:57 AM - Re: Source of Toroid Baluns (Jon Finley)
3. 07:06 AM - Shielded wire for special use (Alfred Buess)
4. 07:20 AM - Re: Source of Toroid Baluns (Dave Morris)
5. 08:04 AM - noise from strobes (Greg Milner)
6. 10:02 AM - Re: Source of Toroid Baluns (David Chalmers)
7. 10:27 AM - Re: SD-8 low voltage warning revisited (Robert L. Nuckolls, III)
8. 11:41 AM - Re: noise from strobes (Robert L. Nuckolls, III)
9. 12:05 PM - Re: A new Z-figure drawing? (Robert L. Nuckolls, III)
10. 12:07 PM - Re: Future replacement for Rotax (Robert L. Nuckolls, III)
11. 03:40 PM - Z-13 discussion continued (Scott Diffenbaugh)
12. 04:38 PM - Re: Z-13 discussion continued (Robert L. Nuckolls, III)
13. 04:53 PM - Re: A new Z-figure drawing? (Robert L. Nuckolls, III)
14. 06:24 PM - Re: Z-13 discussion continued (Charles Becker)
15. 06:36 PM - Re: A new Z-figure drawing? (Dave Morris)
16. 06:48 PM - Re: A new Z-figure drawing? (Dave Morris)
17. 07:04 PM - Re: Z-13 discussion continued (Robert L. Nuckolls, III)
18. 07:54 PM - Cool schematic CAD program (Dave Morris)
19. 08:49 PM - Re: Cool schematic CAD program (John Schroeder)
20. 11:51 PM - Re: Future replacement for Rotax rectifier/regulator ? (owner-aeroelectric-list-server@matronics.com)
Message 1
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| Subject: | Re: wire size for charging battery |
--> AeroElectric-List message posted by: "Bob Gibson" <bgibson@scientech.com>
This is my first post to this list (just joined Friday), but I wanted to
offer the following suggestion:
If you are doing this to simplify charging the battery, why not consider a
"ground service plug" which you could install near the battery, with a flush
door, adjacent to the battery? That way, you would eliminate the long cable
run, and have a service plug which could be accommodated at FBOs around the
country.
I'm a Grumman Traveler owner, and several of the later model (post 75)
Grummans had such a plug located on the battery frame (the battery in the
Grummans is firewall forward), with a flush door that opens for connection
to the service plug. I can look up the part numbers next time I go out to
the hangar.
Bob Gibson
AA5 - N5826L
Clearwater Airpark (CLW)
Mobile 727.644.8361
Web www.geocities.com/n5826l
Message 2
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| Subject: | Source of Toroid Baluns |
--> AeroElectric-List message posted by: "Jon Finley" <jon@finleyweb.net>
Super! Thanks Bob.
Jon
DO NOT ARCHIVE
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> --> <bob.nuckolls@cox.net>
>
> The toroidal cores slipped over the coax feedline
> of some popular antenna designs adds no measurable
> improvement of performance vis-a-vis leaving them
> off entirely. I saw this demonstrated in an antenna
> lab on two different occasions. Just tie the coax
> center and shield to the two halves of a diple and
> drive on without the toroids. The antenna will work
> just fine.
>
> Cessna did this for a lot of years.
>
> Bob . . .
Message 3
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| Subject: | Shielded wire for special use |
--> AeroElectric-List message posted by: "Alfred Buess" <Alfred.Buess@shl.bfh.ch>
For different reasons I'd like to use one conductor AWG20 shielded wire to power
interior lights and some electronic devices with power consumptions of less
than 1 Amp. Is this a problem if I use the center conductor for power (+) and
the shield for ground (-)?
The instructions for my radio (UPS SL30) say that the wires to the PTT buttons
should be twisted. Is one conductor shielded wire a suitable alternative for a
pair of twisted wires for the PTT buttons? Any drawbacks?
Thanks to Bob and all the other specialists for their advice!
Alfred Buess
Message 4
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| Subject: | Re: Source of Toroid Baluns |
--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
I agree with Bob. I'm a ham operator with a lot of years of antenna
experimentation. Slipping a toroid over a coax cable should have no effect
by design. The whole point of coaxial cable is to make the feedline as
immune as possible to outside influences and to permit the length to be
independent of the antenna's design frequency.
But Jon, since you have a Q, you might want to look at my full wavelength
loop for composite aircraft. It's at
http://www.davemorris.com/dave/morrisdfloop.html and there should be a spot
in the tailcone where the diameter fits the design length of the wire
loop. This antenna won't work in a metal airplane.
Dave Morris
Dragonfly N55UP under construction
At 12:54 AM 11/16/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><bob.nuckolls@cox.net>
>
>At 11:32 PM 11/15/2003 -0600, you wrote:
> >--> AeroElectric-List message posted by: "Jon Finley" <jon@finleyweb.net>
> >
> >Hi all,
> >
> >Anyone know if the toroid balun's (beads) used on copper foil antenna
> >coax is available at a local supplier (Radio Shack??). I've found them
> >at AS&S and RST - just seems like a waste to have to order three of the
> >little things.
> >
> >Thanks!
>
> The toroidal cores slipped over the coax feedline
> of some popular antenna designs adds no measurable
> improvement of performance vis-a-vis leaving them
> off entirely. I saw this demonstrated in an antenna
> lab on two different occasions. Just tie the coax
> center and shield to the two halves of a diple and
> drive on without the toroids. The antenna will work
> just fine.
>
> Cessna did this for a lot of years.
>
> Bob . . .
>
>
Message 5
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| Subject: | noise from strobes |
--> AeroElectric-List message posted by: "Greg Milner" <tldrgred@execpc.com>
I have a whooping noise in my headsets witch is louder on the ground. In flight
it`s barely noticable except for who receives my transmissions. Where to start?
Red Milner RV-4 79KM
Message 6
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| Subject: | Source of Toroid Baluns |
--> AeroElectric-List message posted by: "David Chalmers" <David@ChalmersFamily.com>
Jon, if you still decide to install Baluns I have several left over from my antenna
install that I can send you.
Dave Chalmers
-----Original Message-----
From: Jon Finley [mailto:jon@finleyweb.net]
Subject: AeroElectric-List: Source of Toroid Baluns
--> AeroElectric-List message posted by: "Jon Finley" <jon@finleyweb.net>
Hi all,
Anyone know if the toroid balun's (beads) used on copper foil antenna
coax is available at a local supplier (Radio Shack??). I've found them
at AS&S and RST - just seems like a waste to have to order three of the
little things.
Thanks!
Jon Finley
N90MG Q2 - Subaru EJ-22 DD - 461 Hrs. TT
Apple Valley, Minnesota
http://www.FinleyWeb.net/Q2Subaru
Message 7
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| Subject: | Re: SD-8 low voltage warning revisited |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 11:22 AM 11/15/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: "Scott Diffenbaugh"
><diff@foothill.net>
>
>Hi Bob,
> Just when I thought I had it, I was ambushed. I had wondered
> about the
>need for a low voltage warning light if running on SD-8 back up alternator
>and you responded it wasn't really necessary if I designed my E bus
>properly, but if I wanted to monitor it I could either hook up my voltmeter
>to my E bus or use one of your AEC 9005 warning lights. I decided to plan
>on hooking my ACS-2000 voltmeter display to my E bus and set the parameter
>to warn me of low voltage. Problem solved until I discovered that the B&C
>PM/OV kit #504-1 comes with a low voltage warning light, but it is set to
>light for overvoltage (I assume when the breaker trips) or if the alt switch
>is left off (I have learned there is no field on a pm alt & if the rpm is
>sufficient, it is always on).
that light is wired like Figure Z-16 to the normally closed
contacts of the alternator disconnect relay. If the COMmon
contact is wire to bus as shown, the light will illuminate
when the relay is relaxed. This happens when the alternator
switch is OFF or the breaker pulled, or breaker popped due
to OV condition. This light WILL NOT annunciate alternator
failure that produces a low voltage. If you plan active
notification of LOW VOLTAGE on the e-bus for SD-8 operations,
then you'll need to add the circuitry I cited earlier.
> So, do I just leave out the light, or can I
>benefit from it (might be a nice backup) by maybe wiring it through a 2 pole
>alt switch? Many thanks. Scott
Leave the light out, run the voltmeter from the e-bus
as you described and set any alarm function it may offer at
13.0 volts.
Bob . . .
Message 8
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| Subject: | Re: noise from strobes |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 10:03 AM 11/16/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Greg Milner" <tldrgred@execpc.com>
>
>I have a whooping noise in my headsets witch is louder on the ground. In
>flight it`s barely noticable except for who receives my transmissions.
>Where to start?
First, run strobes from a pair of 6v lantern batteries
by powering it up right at the strobe supply. If noise
goes away, this says that the noise is CONDUCTED on the
+14v power line coming out of the strobe supply. You can
try a filter of the variety shown at:
http://www.aeroelectric.com/articles/filter/filter.html
A simpler alternative is to mount a fat capacitor like
http://www.aeroelectric.com/Pictures/s251_3.jpg
next to the power supply and wire it across the incoming power
(observe polarity). These caps can be ordered from B&C
at http://www.bandc.biz or call 316.283.8000
This will take a bit of cut-n-try but it IS a problem
that can be cured.
Bob . . .
Message 9
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| Subject: | Re: A new Z-figure drawing? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:34 PM 11/15/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
>
>At 01:36 PM 11/15/2003 -0600, Robert L. Nuckolls, III wrote:
>
> > >I've spent the last several years reading over your articles and studying
> > >your diagrams. I'm building a Dragonfly and since I'm a software guy, I
> > >am planning to do a lot of experimenting with glass cockpit designs, EFIS
> > >systems, and homegrown autopilot systems. So I have not only an
> > >all-electric airplane, but a VFR all-computerized panel. Obviously the
> > >integrity of the electrical system is of paramount importance to me.
> >
> > Why? Keep in mind that when you have an item that is necessary for
> >comfortable
> > completion of flight, keeping power available to that device is only
> > part of
> > the equation. There are any number of single component failures that can
> > take that particular piece of equipment down.
> >
>
>I don't mean that the electrical system is more important than, say, the
>fuel system. What I mean is that, since I am using a Rocky Mountain
>MicroEncoder as altimeter and airspeed indicator, and since I am not using
>magnetos to drive the ignition of my Corvair engine, I cannot simply shut
>off the master and keep flying; I MUST have power or I become a glider. I
>realize that's not the choice many would make, but I feel the risk can be
>mitigated by providing redundancy either in the form of 2 batteries or 2
>alternators. I am thinking I would rather have 2 alternators because 1)
>the Corvair has a convenient way of doing it, and 2) the alternator weight
>considerably less than another battery.
Okay, these are important points to the failure mode effects analysis
(FMEA). It's a toss-up for reliability on 1-bat/two-alt versus 2-bat/1-alt
architectures. Batteries well maintained are very dependable but they
DO require yearly expenditure of $time$.
<snip>
> >
> > Let's talk about failure mode effects analysis and
> > the development of plan-A, plan-B and perhaps even Plan-C
> > for dealing with all failures we can think of. I belive
> > you'll ultimately come to understand that many of your
> > present concerns are unworthy of the effort, and many
> > if not most of the real concerns are easily and comfortably
> > managed.
> >
>
>OK, the main question I have about Z-13 is what types of battery failures
>can be expected, and what will happen in those failures. I know that in my
>car, I have replaced many more batteries than I have replaced
>alternators. The battery failures usually only manifested themselves when
>trying to crank the car, and often involved "shorted plates" or whatever
>they are calling it nowadays when the battery only puts out 8 or 10
>volts. And I've seen it happen a few times with fairly new batteries. I
>have no experience with RG batteries, and I don't know what the effect
>would be on the alternator of such a battery failure in flight. That was
>the reason I thought it would be a good idea to be able to isolate the
>battery completely from the rest of the system. Am I worrying about nothing?
RG batteries do not suffer from shorted cells (there's a physical
barrier glass mat between plates) . . . further, only batteries
pressed long beyond useable service life will short.
I think a Figure Z-11 with Z-30 battery added on would provide
a very robust system. Yearly roll-over of main battery to aux
battery with aux battery rotated out at end of two years will
offer failure free battery performance with guaranteed capacity
levels. You can buy 17 a.h. RG batteries for as low as $45 over
the counter. In spite of weight penalty (15# battery versus 4#
alternator) I think this would be the easiest to implement
but I'd be equally comfortable with a Z-13 and one 17 a.h.
battery (changed out every two years max).
> > May I suggest that you get your Dragonfly airborne by the
> > shortest practical pathway. This might include a first-flight
> > instrument panel that looks like a J-3 Cub. The the
> > platform completed and debugged before you begin to
> > add new, unproven features upon which you will ultimately
> > depend.
>
>I agree in principal, and would love to get this thing flying ASAP. In
>practice it is difficult with the Dragonfly to come back later and make
>extensive modifications, because the composite construction makes it
>difficult to get access to things later on after you've closed everything
>up with epoxy.
Sure, plan ahead for stuff that takes hammers, saws and axes
to change . . . but the panel should be plug-n-play stuff.
Bob . . .
Message 10
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| Subject: | Re: Future replacement for Rotax |
rectifier/regulator ?
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
rectifier/regulator ?
At 08:56 PM 11/15/2003 +0100, you wrote:
>--> AeroElectric-List message posted by: "Gilles.Thesee"
><Gilles.Thesee@ac-grenoble.fr>
>
>Hi Bob and all,
>
>This is to let you know that a fellow pilot and electrics researcher is
>willing to undertake the design of a more modern rectifier/regulator for the
>Rotax 912/914 PM alternator. He is talking about switching and chopping and
>low heat.
>We happily offered to flight test the future design.
>We just spent the afternoon sorting out the schematics of the present
>regulator. I passed him a stator and rotor to allow for basic measurements
>and components dimensioning.
I've considered this approach for years . . . the pot's just too far back
on the stove to stir. If he'd like to collaborate, I'll offer a sounding
board for ideas and hawk the product for him here on the AEC site if
the result is suitably impressive.
Bob . . .
Message 11
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| Subject: | Z-13 discussion continued |
--> AeroElectric-List message posted by: "Scott Diffenbaugh" <diff@foothill.net>
Hi Bob,
In actuality my E bus continuous load design is up to about 6A, with
intermittent full load possibly 12A during transmit, autopilot servos
working, and panel lights on, which should be well within the capability of
the SD-8, fuel, and reserve battery power.
I understand the E bus purpose, how to hook it up, and basically how it
works. What I am still not totally clear on is how the whole electrical
system interacts. Here are my questions in a different form. (I'm not
saying I would do this but I would like to know the dynamics of what is
happening electrically).
1) If I have an SD-8 putting out 10A, and my load is 10A, will my B lead
ammeter read 10A & my E bus voltmeter read around 14 volts?
2) For my educational purposes only, if I switched on my battery contactor
& switched on a 10A additional load, I presume my ammeter would still read
10A SD-8 output, but would my voltmeter initially read the same 14 volts and
then start decreasing as time goes on, or does it immediately go to 12.5 v?
3) What is the lowest voltage that can be reached before typical devices
start to fail?
4) Would the SD-8 trip its breaker or smoke its current limiter from being
overworked?
Thank you! Scott RV7A
Time: 11:45:22 AM PST US
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Z-13 questions
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
At 06:25 PM 11/14/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: "Scott Diffenbaugh"
><diff@foothill.net>
>
>Bob,
>Just finished reviewing the Z-13 archives again and found answers to a
bunch
>of my questions. A great resource--Thank you! A couple questions
>outstanding:
>
>1) Found this question but couldn't find your response: How about hooking
>the main alt field switch to the battery bus in case the battery contactor
>fails? The alternator would then remain on line and continue to power the
>main bus.
If the battery contactor opens, battery voltage would fall and
the regulator would full-field the alternator producing a voltage
runaway condition.
>Assuming the alternator would be unstable without a battery, could you
close
>the E bus aux feed switch and backfeed the battery through the diode? I
>believe I read in one of the archives that the fuselink is located at the E
>bus in case of backfeed.
>2) To help me better understand the E bus operation, I would like to pose
a
>hypothetical situation. If I have an SD-8 back up alternator, and my E bus
>load is set up for a hypothetical 20A (it will actually be about 6A typical
>to 12A max), and I have my ACS 2002 voltmeter hooked to the E bus, and my
>ACS hall amp sensor around the SD-8 "B" lead, and I have a low voltage
>warning light installed on the backup circuit, would you mind outlining
what
>I will see and/or read from the point when I close the aux feed switch
until
>my E bus devices fail?
I don't understand the question. Why would the e-bus devices fail?
The goals of Z-13 design are to supply dual pathways and dual engine
driven power sources for the e-bus that are on TOP of the battery
as a last ditch power source. For the most part, we've said that
multiple failures on any single tank of gas are so remote as to
be insignificant for consideration in our design. Is the "12A max"
load a continuous load you intend to support while en route? All
you have to do is get this down to 10A and you're 100% covered by
the SD-8. So before you really have to sweat, you have to loose
both alternators and then you still have a well-maintained,
RG battery to get you down. A yeary-fresh 17 a.h. battery is
1-hour plus endurance and I have to believe you can get your
endurance loads lower than 10A.
Bob . . .
Scott Diffenbaugh
diff@foothill.net
Message 12
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| Subject: | Re: Z-13 discussion continued |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 03:38 PM 11/16/2003 -0800, you wrote:
>--> AeroElectric-List message posted by: "Scott Diffenbaugh"
><diff@foothill.net>
>
>Hi Bob,
>
>In actuality my E bus continuous load design is up to about 6A, with
>intermittent full load possibly 12A during transmit, autopilot servos
>working, and panel lights on, which should be well within the capability of
>the SD-8, fuel, and reserve battery power.
>
>I understand the E bus purpose, how to hook it up, and basically how it
>works. What I am still not totally clear on is how the whole electrical
>system interacts. Here are my questions in a different form. (I'm not
>saying I would do this but I would like to know the dynamics of what is
>happening electrically).
>
>1) If I have an SD-8 putting out 10A, and my load is 10A, will my B lead
>ammeter read 10A & my E bus voltmeter read around 14 volts?
Yes, sorta . . . you can load the SD-8 until the bus sags to something
on the order of 12.5 to 12.8 volts without taxing the battery. This is
the neat thing about lead acid batteries, they take 14.0 to charge
but deliver energy at 12.5 and below. The SD-8 has to be called an
8A machine to run goodies -AND- charge a battery. But as a backup
it only needs to PROTECT the battery so it will support heavier loads
than 8A . . .
>2) For my educational purposes only, if I switched on my battery contactor
>& switched on a 10A additional load, I presume my ammeter would still read
>10A SD-8 output, but would my voltmeter initially read the same 14 volts and
>then start decreasing as time goes on, or does it immediately go to 12.5 v?
As you add load, the voltmeter will creep down until the battery begins to
help. For example, if you put a 20A load on, I would expect the system to
drop somewhere around 12.5 volts with and the SD-8 shouldering perhaps
11-12A of the total and the rest coming from the battery.
>3) What is the lowest voltage that can be reached before typical devices
>start to fail?
?DO-160 calls for usable performance down to 9.0 volts. Folks
who design things to work in the real world will honor this
suggestion. Batteries are 95% gone at 10.5 volts . . . so there's
plenty of headroom between total loss of operation and the point
where operational limits are inconsequential 'cause your outta juice.
>4) Would the SD-8 trip its breaker or smoke its current limiter from being
>overworked?
No. Continuous operation in the "overworked" state puts the
regulator at risk. I'd heat sink that puppy or use a more robust
regulator (like the KeyWest regulator for Rotax 18A machines).
B&C used to sell a heavy duty regulator but I don't see it on
their website any more. Gilles over in France has a friend considering
a new, low-loss design for Rotax that would run stone cold on an
SD-8. The best thing to do is get steady state e-bus loads down
to 8A or less until cleared to land. Then, with a fully charged
battery held in reserve, pile it on.
Bob . . .
Message 13
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| Subject: | Re: A new Z-figure drawing? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>
> >I don't mean that the electrical system is more important than, say, the
> >fuel system. What I mean is that, since I am using a Rocky Mountain
> >MicroEncoder as altimeter and airspeed indicator, and since I am not using
> >magnetos to drive the ignition of my Corvair engine, I cannot simply shut
> >off the master and keep flying; I MUST have power or I become a glider.
I missed a point in my earlier reply to this thread. I wasn't
suggesting that you were making too much of electrical system
importance. The point was to get some discussion about what's
going to back up the systems you've deemed essential enough
to require multiple power sources. A dozen power sources
won't help if the MicroEncoder goes belly up. Back-up of
needful things is as important as keeping needful things
happy with power.
That's the thing about steam gages . . . they're
independent of each other and relatively dependable to boot.
I've never suffered gross failure of any instruments in the
pitot-static system . . . and loss of one gage doesn't take
them all down. Now you wrap all those functions about one
micro-controller. You have to (1) figure out how pilotage
and skills make ALL those things less needful or (2) have
Plan-B in place should it become necessary to use it.
Now, suppose you find that your hand-held GPS altitude
readout (after level flight cruise for several minutes)
reads quite closely to altimeter readings and you find
further that with certain power settings and trimmed for
level flight insures your operation well within comfortable
bounds for airspeed. Hmmmm . . . can you deduce a modus
operandi where a descent to landing can be made with some
degree of comfort if the MicroEncoder decides to go on
strike? If yes, then you have Plan-B and the MicroEncoder
has just been dethroned as "critical". If no, the perhaps
some 2" steam gages tucked into the corner (even if non-
sensitive) might provide an alternative plan-B.
What ever the plan-B turns out to be, the goal is
to drive "criticality" of equipment under plan-A down
such that you've crafted a failure tolerant system.
Bob . . .
Message 14
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| Subject: | Re: Z-13 discussion continued |
--> AeroElectric-List message posted by: "Charles Becker" <ctbecker@charter.net>
I a new RV8A builder and have been following the list serv for a while. I
am not clear about the references to Z-13 etc. Where are they located? Is
it a book you published? It will be a while until I get that far, but it is
never too early to begin to fully understand the electrical system.
Charles Becker
N474CB - RV8A
Empennage
Message 15
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| Subject: | Re: A new Z-figure drawing? |
--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
At 06:53 PM 11/16/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><bob.nuckolls@cox.net>
>
>
> >
> > >I don't mean that the electrical system is more important than, say, the
> > >fuel system. What I mean is that, since I am using a Rocky Mountain
> > >MicroEncoder as altimeter and airspeed indicator, and since I am not using
> > >magnetos to drive the ignition of my Corvair engine, I cannot simply shut
> > >off the master and keep flying; I MUST have power or I become a glider.
>
>
> I missed a point in my earlier reply to this thread. I wasn't
> suggesting that you were making too much of electrical system
> importance. The point was to get some discussion about what's
> going to back up the systems you've deemed essential enough
> to require multiple power sources. A dozen power sources
> won't help if the MicroEncoder goes belly up. Back-up of
> needful things is as important as keeping needful things
> happy with power.
>
> That's the thing about steam gages . . . they're
> independent of each other and relatively dependable to boot.
> I've never suffered gross failure of any instruments in the
> pitot-static system . . . and loss of one gage doesn't take
> them all down. Now you wrap all those functions about one
> micro-controller. You have to (1) figure out how pilotage
> and skills make ALL those things less needful or (2) have
> Plan-B in place should it become necessary to use it.
>
> Now, suppose you find that your hand-held GPS altitude
> readout (after level flight cruise for several minutes)
> reads quite closely to altimeter readings and you find
> further that with certain power settings and trimmed for
> level flight insures your operation well within comfortable
> bounds for airspeed. Hmmmm . . . can you deduce a modus
> operandi where a descent to landing can be made with some
> degree of comfort if the MicroEncoder decides to go on
> strike? If yes, then you have Plan-B and the MicroEncoder
> has just been dethroned as "critical". If no, the perhaps
> some 2" steam gages tucked into the corner (even if non-
> sensitive) might provide an alternative plan-B.
>
> What ever the plan-B turns out to be, the goal is
> to drive "criticality" of equipment under plan-A down
> such that you've crafted a failure tolerant system.
Yes, I see what you're talking about. The glass cockpit I've created takes
both RMI MicroEncoder and also GPS inputs and displays them as aircraft
instruments on a tablet computer LCD display. If the MicroEncoder quits
sending airspeed, then the software switches to using the GPS ground speed
instead, and makes an appropriate indication to that effect on the
display. Similarly, if the magnetic compass of the MicroEncoder goes
south, it displays GPS ground track instead. I don't have enough
experience with GPS altitude indications to know if I'll use the GPS
altitude as a backup or not. But your point is well taken, and I did a
similar analysis when I designed my fuel system, to make sure there was a
Plan B for every Plan A failure.
Dave Morris
Dragonfly N55UP under construction
Message 16
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| Subject: | Re: A new Z-figure drawing? |
--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
At 02:04 PM 11/16/2003 -0600, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><bob.nuckolls@cox.net>
>
> >OK, the main question I have about Z-13 is what types of battery failures
> >can be expected, and what will happen in those failures. I know that in my
> >car, I have replaced many more batteries than I have replaced
> >alternators. The battery failures usually only manifested themselves when
> >trying to crank the car, and often involved "shorted plates" or whatever
> >they are calling it nowadays when the battery only puts out 8 or 10
> >volts. And I've seen it happen a few times with fairly new batteries. I
> >have no experience with RG batteries, and I don't know what the effect
> >would be on the alternator of such a battery failure in flight. That was
> >the reason I thought it would be a good idea to be able to isolate the
> >battery completely from the rest of the system. Am I worrying about
> nothing?
>
> RG batteries do not suffer from shorted cells (there's a physical
> barrier glass mat between plates) . . . further, only batteries
> pressed long beyond useable service life will short.
>
> I think a Figure Z-11 with Z-30 battery added on would provide
> a very robust system. Yearly roll-over of main battery to aux
> battery with aux battery rotated out at end of two years will
> offer failure free battery performance with guaranteed capacity
> levels. You can buy 17 a.h. RG batteries for as low as $45 over
> the counter. In spite of weight penalty (15# battery versus 4#
> alternator) I think this would be the easiest to implement
> but I'd be equally comfortable with a Z-13 and one 17 a.h.
> battery (changed out every two years max).
Yes, Z-11 and Z-30 look like they would work well. It looks like in Z-30
you have opted to have two separate battery buses in lieu of just tying the
two batteries together. I seem to remember reading your article on battery
isolators a while back and thinking that you preferred to just parallel the
batteries. I think the 2 buses requires one to make a choice at
design-time of which loads are more critical than others, whereas just
linking them together requires one to make that choice in flight and
manually switch off loads to match the remaining battery capacity. Is that
a correct interpretation?
> > > May I suggest that you get your Dragonfly airborne by the
> > > shortest practical pathway. This might include a first-flight
> > > instrument panel that looks like a J-3 Cub. The the
> > > platform completed and debugged before you begin to
> > > add new, unproven features upon which you will ultimately
> > > depend.
> >
> >I agree in principal, and would love to get this thing flying ASAP. In
> >practice it is difficult with the Dragonfly to come back later and make
> >extensive modifications, because the composite construction makes it
> >difficult to get access to things later on after you've closed everything
> >up with epoxy.
>
> Sure, plan ahead for stuff that takes hammers, saws and axes
> to change . . . but the panel should be plug-n-play stuff.
Yeah, I agree with that, and I've put some access doors in places that
other Dragonfly airplanes don't have them, in order to buy myself more
flexibility.
Dave Morris
Dragonfly N55UP under construction
Message 17
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| Subject: | Re: Z-13 discussion continued |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:19 PM 11/16/2003 -0500, you wrote:
>--> AeroElectric-List message posted by: "Charles Becker"
><ctbecker@charter.net>
>
>
>I a new RV8A builder and have been following the list serv for a while. I
>am not clear about the references to Z-13 etc. Where are they located? Is
>it a book you published? It will be a while until I get that far, but it is
>never too early to begin to fully understand the electrical system.
You got that right . . . and I can't think of a better place
to start than right here on the AeroElectric-List . . .
Yes, the Z-figures are published in a book I sell but you can
download the latest two updates which include latest version
of appendix Z at:
http://www.aeroelectric.com/articles.html
and you can buy the whole book at:
http://www.aeroelectric.com/Catalog/AECcatalog.html
Bob . . .
Message 18
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| Subject: | Cool schematic CAD program |
--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
By the way, Bob, I was the guy that walked up to you at Sullivan and asked
if you knew of any free schematic drawing programs. I had IntelliCAD from
your CDROM and had tried to use it to draw up a schematic of my aircraft
system by modifying one of your Z diagrams. I never did like it very much
as it was not intuitive and had a long learning curve. So I have been on a
quest for a better CAD program for schematics ever since. I've looked at 3
or 4 different free or "very cheap" programs and never was impressed with
any of them.
But last week I found a really sweet program that immediately became my
favorite. It's called DesignWorks Lite, and can be downloaded from
http://www.designworks4.com with a fully functional version. The program
is $39.95 if you register it. (By the way, I have utterly no financial
interest in the program.. I just like it!) I tried it and was immediately
productive, without reading any help screens or manuals. It works the way
other Windows applications do, so it's very intuitive. The screen
background is light. There are scroll bars. It behaves the way a
schematic drawing program should, for instance, once you attach wires to a
component, you can move the component around and the wires stay
attached. It comes with a library of a bunch of symbols, and a symbol
designer that lets you create your own. The only drawback I've found is
that it does not use .DWG files, so you can't load the Z diagrams but have
to re-draw them yourself.
If anybody wants an easy-to-learn schematic diagramming tool that is really
cheap and really good (but not compatible with Bob's CAD files), check out
DesignWorks Lite.
Dave Morris
Dragonfly N55UP under construction
Message 19
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| Subject: | Re: Cool schematic CAD program |
--> AeroElectric-List message posted by: John Schroeder <jschroeder@perigee.net>
Dave -
Does it/ can it import .DXF files? If so, Bob can post the Z's in .DXF
files. .DXF is the standard CAD interchange file format.
DO NOT Archive
Cheers,
John
On Sun, 16 Nov 2003 21:53:04 -0600, Dave Morris <dave@davemorris.com>
wrote:
> --> AeroElectric-List message posted by: Dave Morris
> <dave@davemorris.com>
>
> By the way, Bob, I was the guy that walked up to you at Sullivan and
> asked
> if you knew of any free schematic drawing programs. I had IntelliCAD
> from
> your CDROM and had tried to use it to draw up a schematic of my aircraft
> system by modifying one of your Z diagrams. I never did like it very
> much
> as it was not intuitive and had a long learning curve. So I have been
> on a
> quest for a better CAD program for schematics ever since. I've looked
> at 3
> or 4 different free or "very cheap" programs and never was impressed with
> any of them.
>
> But last week I found a really sweet program that immediately became my
> favorite. It's called DesignWorks Lite, and can be downloaded from
> http://www.designworks4.com with a fully functional version. The program
> is $39.95 if you register it. (By the way, I have utterly no financial
> interest in the program.. I just like it!) I tried it and was
> immediately
> productive, without reading any help screens or manuals. It works the
> way
> other Windows applications do, so it's very intuitive. The screen
> background is light. There are scroll bars. It behaves the way a
> schematic drawing program should, for instance, once you attach wires to
> a
> component, you can move the component around and the wires stay
> attached. It comes with a library of a bunch of symbols, and a symbol
> designer that lets you create your own. The only drawback I've found is
> that it does not use .DWG files, so you can't load the Z diagrams but
> have
> to re-draw them yourself.
>
> If anybody wants an easy-to-learn schematic diagramming tool that is
> really
> cheap and really good (but not compatible with Bob's CAD files), check
> out
> DesignWorks Lite.
>
> Dave Morris
> Dragonfly N55UP under construction
>
>
--
Message 20
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| Subject: | Re: Future replacement for Rotax rectifier/regulator |
?
--> AeroElectric-List message posted by:
Gilles
What is the problem with the original rectifier/regulator from Rotax?
Lorenz Malmstrm
MCR 4S (#39)
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