Today's Message Index:
----------------------
1. 05:37 AM - Re: Re: Odyssey % of charge (Correction) (Brian Lloyd)
2. 05:37 AM - Alternator conversion (Bill Bradburry)
3. 06:19 AM - Re: Alternator conversion (Robert L. Nuckolls, III)
4. 06:19 AM - Re: Alternator conversion (Ken)
5. 06:22 AM - Re: Odyssey % of charge (Robert L. Nuckolls, III)
6. 06:47 AM - Re: What happens if OV trips? (Ken)
7. 06:53 AM - Shutting off Ignition on Running Car (Alexander, Don)
8. 07:11 AM - An Architecture Question - Z13 (Todd Richmond)
9. 07:15 AM - Re: Re: Odyssey % of charge (Brian Lloyd)
10. 07:22 AM - Re: SD8 Alternator Install - Z-12 vs. Manual (Steve & Denise)
11. 07:42 AM - Re: An Architecture Question - Z13 (Hinde, Frank George (Corvallis))
12. 07:50 AM - Re: Baclup Battery monitor (Mitchell Goodrich)
13. 07:56 AM - SD-20 Alt performance chart? (Alan K. Adamson)
14. 08:24 AM - Re: Baclup Battery monitor (Hinde, Frank George (Corvallis))
15. 08:36 AM - Re: An Architecture Question - Z13 (Dave Morris \)
16. 08:46 AM - Re: Baclup Battery monitor (Dave Morris \)
17. 09:02 AM - Re: Z-14 FADEC Version Question with P.S. (dannylsmith)
18. 09:02 AM - Re: Baclup Battery monitor (Robert L. Nuckolls, III)
19. 09:03 AM - Re: Baclup Battery monitor (Hinde, Frank George (Corvallis))
20. 09:04 AM - Re: Baclup Battery monitor (Mickey Coggins)
21. 09:06 AM - Re: SD-20 Alt performance chart? (Robert L. Nuckolls, III)
22. 09:17 AM - Re: What happens if OV trips? (Robert L. Nuckolls, III)
23. 09:20 AM - Re: Re: Odyssey % of charge (Bill Dube)
24. 09:24 AM - Re: Re: SD8 Alternator Install - Z-12 vs. Manual (Robert L. Nuckolls, III)
25. 09:27 AM - Re: Re: Odyssey % of charge (Robert L. Nuckolls, III)
26. 09:27 AM - Re: Baclup Battery monitor (Hinde, Frank George (Corvallis))
27. 09:35 AM - Re: SD-20 Alt performance chart? (Alan K. Adamson)
28. 09:54 AM - Re: An Architecture Question - Z13 (Robert L. Nuckolls, III)
29. 11:32 AM - Rotax Battery/Regulator Questions (Bill Denton)
30. 11:38 AM - Re: An Architecture Question - Z13 (Todd Richmond)
31. 12:36 PM - Re: Strange alternator behavior at Startup (Mickey and Bob N.) ()
32. 12:48 PM - Re: SD-20 Alt performance chart? (BobsV35B@aol.com)
33. 12:48 PM - Re: Re: Odyssey % of charge (Brian Lloyd)
34. 01:03 PM - Re: Baclup Battery monitor (Matt Prather)
35. 01:34 PM - Re: SD-20 Alt performance chart? (Alan K. Adamson)
36. 02:00 PM - Re: Baclup Battery monitor (Hinde, Frank George (Corvallis))
37. 05:12 PM - Re: Spam> Re: SD-20 Alt performance chart? (George Braly)
38. 05:31 PM - AGM longevity (was: Odyssey % of charge) (Bill Dube)
39. 05:52 PM - Re: Spam> Re: SD-20 Alt performance chart? (Alan K. Adamson)
40. 06:43 PM - Re: Spam> Re: SD-20 Alt performance chart? (Matt Prather)
41. 06:56 PM - Re: Spam> Re: SD-20 Alt performance chart? (Bob McCallum)
42. 07:19 PM - Re: An Architecture Question - Z13 (Robert G. Wright)
43. 07:50 PM - Re: AGM longevity (was: Odyssey % of charge) (Brian Lloyd)
44. 07:50 PM - Re: Spam> Re: SD-20 Alt performance chart? (Alan K. Adamson)
45. 08:15 PM - Transponder/EFIS Gray code (DEAN PSIROPOULOS)
46. 08:32 PM - Re: SD-20 Alt performance chart? (BobsV35B@aol.com)
47. 08:45 PM - Re: An Architecture Question - Z13 (Robert Sultzbach)
48. 08:45 PM - Re: Transponder/EFIS Gray code (Malcolm Thomson)
49. 08:47 PM - Re: SD-20 Alt performance chart? (Alan K. Adamson)
50. 11:12 PM - LED position lights + strobe (sarg314)
Message 1
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Subject: | Re: Odyssey % of charge (Correction) |
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Robert L. Nuckolls, III wrote:
> HERE'S THE POT HOLE - THE 30 MINUTE DISCHARGE CURVE
> OF 26.4 AMPS SAYS THE CAPACITY IS 26.4A X 0.5 HOURS
> OR 13.2 A.H., NOT 26 A.H.
>
> I SHOULD HAVE CAUGHT THAT . . . A 33 TO 26 REDUCTION
> IN APPARENT CAPACITY FOR A 15X LARGER DISCHARGE
> RATE DIDN'T RAISE THE FLAGS. FOUND IT WHILE ARCHIVING
> THE POST.
Welcome to Peukert's exponent. If you know the capacity at two different
discharge rates you can interpolate or extrapolate the capacity off the
battery at other discharge rates.
--
Brian Lloyd 361 Catterline Way
brian-yak at lloyd dot com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 2
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Subject: | Alternator conversion |
--> AeroElectric-List message posted by: "Bill Bradburry" <bbradburry@allvantage.com>
Bob and others.
I have seen several instructions on how to convert MI and ND alternators
to either external regulation or to internal regulation such that the
field wire can be used to shut the alternator down. These instructions
seem simple enough that I feel that I could do it.
My question is why has this never?? been a topic on this list and what
are the pros and cons of these modifications? Is this safe? If not,
why? And Bob, no one so far has stumped you on an electrical question,
so why have you not told us how to do these modifications?
I understand that at some time in the past, there was some information
on internally regulated alternators on your web site, but they were
removed. Is this the information that was removed?
I am ready to modify an MI alternator for internal regulation where the
field can be interrupted by the OV module just like it is in the
external regulator, but have started to get second thoughts since this
has not been covered here. Please give me some guidance.
Thanks,
Bill Bradburry
-Snip-
Okay, in the simplest terms:
Install any internally regulated alternator of your choice.
Know that the reliability of whatever you choose (as long as
it's not a junkyard dog) is as good or better than anything
flying in certified ships . . . and we don't avoid flying
that rental machine because of our perceptions of alternators
and batteries they may carry.
Probability of OV condition is very low but not zero. Given
the current capability of the alternator, it's prudent to ASSUME
an OV condition can happen and plan for it . . . just as we've
done in certified ships for 70 years.
Know that some alternators recommended to the OBAM aircraft
community have control issues. Some if not most cannot be
turned ON/OFF at will any time under any conditions. If this
is a design goal you embrace, know that techniques are in
development
to meet that goal. If this is not a goal you embrace, then
the system as recommended by Van's and others does what it
says it will do . . . power your airplane with relatively low
risk even if you cannot control it.
99% of the past year's discussion on this topic dragged a
lot of peripheral and mostly irrelevant discourse that
did not advance the state of our art and science. We'll
endeavor to stay focused on simple-ideas and elegant
solutions for the future.
Not too much of a good thing my friend . . . too much of
irrelevant things. I've been taking flack from some cool
headed observers for letting "my List" get out of control.
I've never wanted to consider this List as a personal
possession. I did start it . . . but with the idea of planting
seeds that would grow on their own. However, it's entirely
appropriate to treat the List as a classroom where
ALL teachers are invited to practice their art and craft.
Seeds need water, sun, nutrients and protection from
destructive forces. Folks who just dig up seedlings and
throw dirt should be invited to modify their modus operandi
or take their shovels someplace else. I'll invite other
teachers who participate on this List to join me in maintaining
the loftiest goals in classroom atmosphere and decorum.
Keep in mind that anytime you have simple-ideas (obvious
truths) to share that will assemble into elegant solutions, you
too have an opportunity to be a teacher.
Bob . . .
Message 3
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Subject: | Re: Alternator conversion |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 08:32 AM 2/24/2006 -0500, you wrote:
>--> AeroElectric-List message posted by: "Bill Bradburry"
><bbradburry@allvantage.com>
>
>Bob and others.
>I have seen several instructions on how to convert MI and ND alternators
>to either external regulation or to internal regulation such that the
>field wire can be used to shut the alternator down. These instructions
>seem simple enough that I feel that I could do it.
>My question is why has this never?? been a topic on this list and what
>are the pros and cons of these modifications?
Excellent question. When one crafts a "curriculum" for instruction
and study, trade offs need to be made for time to develop the
materials to be delivered, how universal are the instructions for
any one task (is there risk that unforeseen variability raises risks
for success), etc.
There HAVE been a number of conversion articles pointed out here
on the list . . . and I've encouraged folks to make their discoveries
of such data known to the rest of us. It's a task I wouldn't mind
doing but there are lots of tasks I don't mind doing and I have perhaps
10% of the time available necessary to take them all on.
>Is this safe?
If you mean TOTALLY RISK FREE, no. Nothing we do in life is SAFE.
By means of our study and verification by repeatable experiment,
we develop skills that mitigate risk. On top of that, we can craft
systems that are failure tolerant such that the failure of
a "conversion experiment" does not represent intolerable risk.
I.e., having your alternator crap should not cause you to break
a sweat whether or not it's a DIY conversion.
> If not,
>why? And Bob, no one so far has stumped you on an electrical question,
>so why have you not told us how to do these modifications?
It's all a matter of time . . .
>I understand that at some time in the past, there was some information
>on internally regulated alternators on your web site, but they were
>removed. Is this the information that was removed?
No, I don't think the info was posted on the website but it
was discussed here on the List.
>I am ready to modify an MI alternator for internal regulation where the
>field can be interrupted by the OV module just like it is in the
>external regulator, but have started to get second thoughts since this
>has not been covered here. Please give me some guidance.
You can give US some guidance. Get out your camera. Tear into the
thing and take photos. Share your findings as to how power is routed
within the machine and what you've deduced is a means by which you
can get in series with the field power for accomplishment of this
DESIGN GOAL.
We all have opportunities to become teachers here. And all of us
as students have the ability to help teachers refine their presentations.
It's an evolutionary process of discovery, experiment, and perhaps
abandonment of ideas for a better way. Ultimately the process moves
forward to the point where the experiment is repeatable and is ready
for prime time.
Bob . . .
Message 4
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Subject: | Re: Alternator conversion |
--> AeroElectric-List message posted by: Ken <klehman@albedo.net>
Hi Bill
Sure you can do this if you wish and there is nothing wrong with that.
The subject comes up periodically and several folks have posted
suggested methods for some specific alternators. Some look to be easier
to mod than others. There are a couple of companies that offer such units.
I was not particularly interested as it seemed somewhat
counterproductive. You must do the mod and not cause a related problem
by doing so which is probably not too difficult. However it wouldn't be
the first time that a problem was caused just by opening a factory
assembled device. You must purchase and install a separate voltage
regulator which may not be as good as what is already in the alternator
depending on which one you choose. The remote Regulator will not be able
to monitor the alternator's temperature although I guess that is a
pretty minor consideration. You must find a place to put that regulator
and wire it reliably. Most important perhaps, you can no longer purchase
a replacement off the shelf alternator and quickly install it.
In addition I have little concern with using an OV contactor and a few
transorbs on my IR alternator. I'm betting that eventually Bob will
likely confirm that approach with some real testing and actual numbers.
Risks are low either way I think.
Ken
Bill Bradburry wrote:
>--> AeroElectric-List message posted by: "Bill Bradburry" <bbradburry@allvantage.com>
>
>Bob and others.
>I have seen several instructions on how to convert MI and ND alternators
>to either external regulation or to internal regulation such that the
>field wire can be used to shut the alternator down. These instructions
>seem simple enough that I feel that I could do it.
>My question is why has this never?? been a topic on this list and what
>are the pros and cons of these modifications? Is this safe? If not,
>why? And Bob, no one so far has stumped you on an electrical question,
>so why have you not told us how to do these modifications?
>I understand that at some time in the past, there was some information
>on internally regulated alternators on your web site, but they were
>removed. Is this the information that was removed?
>I am ready to modify an MI alternator for internal regulation where the
>field can be interrupted by the OV module just like it is in the
>external regulator, but have started to get second thoughts since this
>has not been covered here. Please give me some guidance.
>Thanks,
>Bill Bradburry
>
>
Message 5
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Subject: | Re: Odyssey % of charge |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 05:30 AM 2/24/2006 -0800, you wrote:
>--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
>
>Robert L. Nuckolls, III wrote:
>
> > HERE'S THE POT HOLE - THE 30 MINUTE DISCHARGE CURVE
> > OF 26.4 AMPS SAYS THE CAPACITY IS 26.4A X 0.5 HOURS
> > OR 13.2 A.H., NOT 26 A.H.
> >
> > I SHOULD HAVE CAUGHT THAT . . . A 33 TO 26 REDUCTION
> > IN APPARENT CAPACITY FOR A 15X LARGER DISCHARGE
> > RATE DIDN'T RAISE THE FLAGS. FOUND IT WHILE ARCHIVING
> > THE POST.
>
>Welcome to Peukert's exponent. If you know the capacity at two different
>discharge rates you can interpolate or extrapolate the capacity off the
>battery at other discharge rates.
Yeah . . . sorta. I'm working on that question along with the
notion that owning one of those super-charge-all smart battery
chargers is a good thing to do to. I'll give you all a forecast
on present findings:
An $80 smart charger and $??$ capacity meter are not well suited
to our ultimate design goals (1) know that the battery is mission
capable every time we walk up to the airplane and (2) have tools
requiring minimum expense and user time/attention to track that
capability. None of the devices I cited above do a very good job
of meeting those goals. An article on alternative hardware proposals
is in the works.
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 6
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Subject: | Re: What happens if OV trips? |
--> AeroElectric-List message posted by: Ken <klehman@albedo.net>
Hi Scott
I don't believe any of the Z architectures run two alternators in
parallel such that both would trip together.
However if a crowbar activates it becomes a momentary short until the CB
pops. Reset the CB and everything goes back to normal unless the voltage
goes high again in which case the breaker will immediately pop again.
Nuisance tripping seems to be quite rare and IMO one should not tolerate
any nuisance trips but rather find out why that is happening and fix it.
While I don't have much engine running time accumulated yet, I have not
been able to instigate a single nuisance trip with the latest homemade
version of Bob's crowbar circuit dated Jan 2006. I could instigate them
with earlier homemade versions.
Ken
Scott wrote:
>--> AeroElectric-List message posted by: "Scott" <scott@randolphs.net>
>
>If the "crowbar" overvoltage protection trips, is it a permanent fault or
>something that can be reset on the fly?
>
>I'm interested in general in how it works, but specificly thinking now about
>the possibility of one alternator tripping both OV circuits if both
>alternators happen to be on (by design or switchology error). If that
>happened, would both alternators be permanently disabled or would turning
>off the faulty one allow the other to be brought back online?
>
>Thanks!
>
>Scott.
>
>
Message 7
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Subject: | Shutting off Ignition on Running Car |
--> AeroElectric-List message posted by: "Alexander, Don" <Don.Alexander@astenjohnson.com>
>Quick question - what happens if you are driving down the highway
>at 100 mph, everything working fine, and you turn the key off?
>Will the alternator stop generating juice? Will all your stuff
>fry? I have not tried this in my car in a long time, probably
>since the 70s - back before the key locked the steering wheel.
>
My personal observation regarding this issue was rather dramatic.
If you take a 1964 Chevy BelAir with carbureted engine (of course) and
manual transmission and turn off the engine without first engaging the
clutch, you will be treated to a huge explosion in the muffler when you
turn the ignition back on :-(
My 20 year old junker which cost me $25 to buy and never let me down
with its gasoline-cooled engine doubled in value when I had to replace
what remained of the muffler. It also cost me a pair of pants if you
catch my drift...
Regards,
Don
Do not archive
Message 8
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|
Subject: | An Architecture Question - Z13 |
--> AeroElectric-List message posted by: "Todd Richmond" <trichmond@obermeyer.com>
All,
I have been reading the AeroElectric posts for several weeks now and find
the forum extremely useful as I begin designing the electrical system for my
RV-7A (that and re-reading the AeroElectric Connection several times). I am
planning an all electric airplane based on the Grand Rapids EFIS/EIS system,
Garmin 430, E-Mag / P-Mag combo and all the other little gizmos I can fit
(afford). At this point, I'm basing my architecture on the Z-13 with a 60
Amp alternator and SD-20 auxiliary alternator.
So my first question is this. do I need an e-bus? The only reason I can
figure is that without the e-bus, the master battery contactor becomes a
single point of failure. If true, could I simply wire two battery
contactors in parallel and run them via a 2-10 switch? To me the advantage
of this approach is that in case of an alternator failure, I can simply
switch to the auxiliary alternator and systematically reduce my loads until
the alternator is picking up the full load without worrying what is attached
to each bus.
My second question is would it make sense to wire both alternators to a DP3T
switch? My thought being that this approach ensures only one alternator may
be operating at a time and thus would prevent them from inadvertently
fighting one another.
Any input is gratefully appreciated.
Todd R. Richmond
RV-7A Wings
<mailto:trichmond@obermeyer.com> trichmond@obermeyer.com
Message 9
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Subject: | Re: Odyssey % of charge |
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Robert L. Nuckolls, III wrote:
> An $80 smart charger and $??$ capacity meter are not well suited
> to our ultimate design goals (1) know that the battery is mission
> capable every time we walk up to the airplane and (2) have tools
> requiring minimum expense and user time/attention to track that
> capability. None of the devices I cited above do a very good job
> of meeting those goals. An article on alternative hardware proposals
> is in the works.
Having a smart energy monitor is necessary in a system where you will
have irregular charge/discharge cycles and want to know how much is left
in the battery. If you always recharge the battery to full every time,
you can have a much simpler energy monitor that isn't quite so smart.
The biggest issue as I see it is that you need to make sure you don't
overcharge the battery in summer but that you do actually charge the
battery in winter. That implies temperature compensation.
--
Brian Lloyd 361 Catterline Way
brian-yak at lloyd dot com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 10
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Subject: | Re: SD8 Alternator Install - Z-12 vs. Manual |
--> AeroElectric-List message posted by: "Steve & Denise" <sjhdcl@kingston.net>
I thought the point in having the warning light for the aux alternator is
tell you it is overloaded and
equipment needs to be turned off??
Steve
RV7A
> Time: 08:14:15 AM PST US
> From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
> Subject: Re: AeroElectric-List: SD8 Alternator Install - Z-12 vs. Manual
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<nuckollsr@cox.net>
>
> At 05:36 PM 2/19/2006 -0500, you wrote:
>
> >--> AeroElectric-List message posted by: "Steve & Denise"
> ><sjhdcl@kingston.net>
> >
> >I comparing the SD8 install manual to Z-12 and I'm a bit confused of why
the
> >wiring difference.
> >
> >The install manual (Drawing 504-500 from B&C) details the following:
> > 1. Aux Alt field breaker connected to main power bus via 2A
breaker
> >and aux alt switch then on to yellow OV crowbar module wire and onto 20
amp
> >relay.
> > 2. Install manual shows alt warning light coming off of relay
> > 3. Install manual shows a second power connection via 10A breaker
to
> >main bus
> >
> >
> >Z-13 details
> > 1. Aux alt field connected breaker connected to 20Amp relay then
onto
> >aux alt switch. Black wire of OV module is connected to relay.
> > 2. Z-13 does not show any aux alt warning light
> > 3. Z-13 shows 16Awg fuselink coming from Battery contactor
> >
> >There are more differences but can someone recommend which diagram to
follow
> >and the reasoning for the differences.
>
> First, keep in mind that you're comparing two different architectures.
> You're trying to blend the difference between a pickup truck and a
> sedan.
>
>
> >When does the warning light come on for the aux alt? Some instructions
say
> >the alt light comes on when the aux alt switch is off or it is OV.
> >
> >I plan on leaving the aux alt switch off all the time. Some have
> >recommended to leave it on but in this scenario how does one diagnose a
> >failed main alt if the backup alt has the ability to absorb all of the
load?
> >
> >I'm also running a B&C 60 Amp alt with LR3 reg.
> >
> >Thanks for some clarification,
>
> Start with tossing out the B&C papers that show you how to
> wire up the SD-8 as the only power generating source for
> an airplane.
>
> Figure Z-13/8 does not have a warning light for the SD-8
> because it's the standby alternator and you don't want
> a warning light starring you in the face for 99.9% of your
> flight where the SD-8 is never used.
>
> Yes, the SD-8 is left off all times the 60A machine is
> running. The LV warning in the LR-3 is to tell you when
> you need the SD-8. Under max endurance operations SD-8
> only, there are no warnings . . . you already KNOW that
> your operating with limited capabilities so you'll have
> to watch a voltmeter -OR- install LV warning on the
> e-bus but this would be a bit of over kill.
>
> Bob . . .
Message 11
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Subject: | An Architecture Question - Z13 |
--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
Remember switches fail too and if I read your proposal correctly you
have mentioned two additional points of failure in your design...I
would'nt do it put it that way.
If you look at Bobs Z figures you will see that single points of failure
are not an issue, the back fed e bus is quite elaegant in this regard.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Todd
Richmond
Sent: Friday, February 24, 2006 7:09 AM
Subject: AeroElectric-List: An Architecture Question - Z13
--> AeroElectric-List message posted by: "Todd Richmond"
--> <trichmond@obermeyer.com>
All,
I have been reading the AeroElectric posts for several weeks now and
find the forum extremely useful as I begin designing the electrical
system for my RV-7A (that and re-reading the AeroElectric Connection
several times). I am planning an all electric airplane based on the
Grand Rapids EFIS/EIS system, Garmin 430, E-Mag / P-Mag combo and all
the other little gizmos I can fit (afford). At this point, I'm basing
my architecture on the Z-13 with a 60 Amp alternator and SD-20 auxiliary
alternator.
So my first question is this. do I need an e-bus? The only reason I can
figure is that without the e-bus, the master battery contactor becomes a
single point of failure. If true, could I simply wire two battery
contactors in parallel and run them via a 2-10 switch? To me the
advantage of this approach is that in case of an alternator failure, I
can simply switch to the auxiliary alternator and systematically reduce
my loads until the alternator is picking up the full load without
worrying what is attached to each bus.
My second question is would it make sense to wire both alternators to a
DP3T switch? My thought being that this approach ensures only one
alternator may be operating at a time and thus would prevent them from
inadvertently fighting one another.
Any input is gratefully appreciated.
Todd R. Richmond
RV-7A Wings
<mailto:trichmond@obermeyer.com> trichmond@obermeyer.com
Message 12
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Subject: | Baclup Battery monitor |
--> AeroElectric-List message posted by: "Mitchell Goodrich" <mgoodrich@tampabay.rr.com>
Hello All,
I am installing a backup battery for a dual EI installation.
I'm looking for a way to monitor w/warning, the voltage and
possibly load on it. Any ideas??
Mitchell Goodrich
VEZE 60P
Tampa,FL
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Mickey
Coggins
Sent: Thursday, February 23, 2006 3:24 PM
Subject: AeroElectric-List: Avionics ground bus kit
--> AeroElectric-List message posted by: Mickey Coggins
<mick-matronics@rv8.ch>
Hi,
I vaguely recall hearing that someone was putting together
a kit or perhaps a finished avionics ground bus like Bob
shows in this photo:
http://www.aeroelectric.com/Pictures/Grounding/Avionics_Bus_3.jpg
Does anyone know where I can purchase either the kit or
(preferably) the finished product?
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
Message 13
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Subject: | SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "Alan K. Adamson" <aadamson@highrf.com>
Bob, did you ever put together one of these for the SD-20? B&C specify 20A
output at 3500rpm, so I would assume that you could use the same "ratios"
and determine that on a continental for example, that is a 1.15:1, that
you'd have full output at 2900ish rpm?
http://www.aeroelectric.com/Reference_Docs/Alternator_Data/SD8-Performance.p
df
Message 14
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Subject: | Baclup Battery monitor |
--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
Simplest way is to take a second battery and charge it through a diode
from the main bettery. That way if the main battry has a major short
somewhere it will not drag down the second batery with it.
The problem with diodes is they all have a forward volt drop, standard
diodes are about 1 volt drop. So if your system charges at say 14.2
volts, your second battery will only see 13.2V.
I believe the Shotkey (sp?) diode has a much lower drop...Althouigh I
don't know what it is.
My way round this issue on my current plane is to use a smaller battery
for the second ignition that requires a lower charging voltage.
So my first battery is a 18AH and my backup is a 3AH, and is used to run
one EI and a Facet fuel pump, nothing else.
No points of interconnect between the systems except for the diode.
Make sure the diode is sized to flow enough current to run your backup
EI and you can simply run your backup EI from the second battery all the
time, i.e no chageover contactors or other components that could fail.
If you do it this way there is really no need to montior the second
battery as you will be changing it every year or so anyway...I use a
simple digital voltmeter and check it before each flight.
All the best
Frank
Zenair zodiac 400 hours
RV7a...ALMOST finished..:)
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Mitchell Goodrich
Sent: Friday, February 24, 2006 7:48 AM
Subject: RE: AeroElectric-List: Baclup Battery monitor
--> AeroElectric-List message posted by: "Mitchell Goodrich"
--> <mgoodrich@tampabay.rr.com>
Hello All,
I am installing a backup battery for a dual EI installation.
I'm looking for a way to monitor w/warning, the voltage and possibly
load on it. Any ideas??
Mitchell Goodrich
VEZE 60P
Tampa,FL
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Mickey Coggins
Sent: Thursday, February 23, 2006 3:24 PM
Subject: AeroElectric-List: Avionics ground bus kit
--> AeroElectric-List message posted by: Mickey Coggins
<mick-matronics@rv8.ch>
Hi,
I vaguely recall hearing that someone was putting together a kit or
perhaps a finished avionics ground bus like Bob shows in this photo:
http://www.aeroelectric.com/Pictures/Grounding/Avionics_Bus_3.jpg
Does anyone know where I can purchase either the kit or
(preferably) the finished product?
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
Message 15
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Subject: | Re: An Architecture Question - Z13 |
--> AeroElectric-List message posted by: "Dave Morris \"BigD\"" <BigD@DaveMorris.com>
If I understand your point correctly, you probably should think through the
scenario wherein you would feel comfortable doing that level of detective
work in a potentially busy cockpit. The beauty of the e-bus is that you
just flip a switch (or it gets flipped for you), and then you have a known
quantity of time remaining before you need to think about landing. No
systematic reduction of things, no long division in your head, no thinking
required. Just flip the switch and go to Plan B.
Dave Morris
At 09:09 AM 2/24/2006, you wrote:
>in case of an alternator failure, I can simply
>switch to the auxiliary alternator and systematically reduce my loads until
>the alternator is picking up the full load without worrying what is attached
>to each bus.
Message 16
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Subject: | Baclup Battery monitor |
--> AeroElectric-List message posted by: "Dave Morris \"BigD\"" <BigD@DaveMorris.com>
Facet pumps draw about 1.5A, don't they? And your EI draws how much? 3AH
seems awfully small to me. I'm guessing the Duration vs Current curve for
that battery gives you 3A for 30 minutes. Is that enough?
Dave Morris
www.N75UP.com
At 10:22 AM 2/24/2006, you wrote:
>So my first battery is a 18AH and my backup is a 3AH, and is used to run
>one EI and a Facet fuel pump, nothing else.
Message 17
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Subject: | Re: Z-14 FADEC Version Question with P.S. |
--> AeroElectric-List message posted by: "dannylsmith" <dsmit132@bellsouth.net>
Thanks for the help Bob!
--------
Danny
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=14679#14679
Message 18
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Subject: | Baclup Battery monitor |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 08:22 AM 2/24/2006 -0800, you wrote:
>--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)"
><frank.hinde@hp.com>
>
>Simplest way is to take a second battery and charge it through a diode
>from the main bettery. That way if the main battry has a major short
>somewhere it will not drag down the second batery with it.
>
>The problem with diodes is they all have a forward volt drop, standard
>diodes are about 1 volt drop. So if your system charges at say 14.2
>volts, your second battery will only see 13.2V.
Which is a major issue for recharging the standby battery
to 100% of capacity.
>I believe the Shotkey (sp?) diode has a much lower drop...Althouigh I
>don't know what it is.
>
>My way round this issue on my current plane is to use a smaller battery
>for the second ignition that requires a lower charging voltage.
Battery size does not drive ideal charging voltage. We use the
same Battery Tender products to maintain 1.5 a.h. batteries as
for 50 a.h. batteries. Ideal voltage for charging is driven by
chemistry first and temperature second.
There's been some discussion about optimizing charging protocols
based on flooded vs. gel vs. RG which have proven to be a third
order concern. IF you use a battery as motive/standby power
and IF it's regularly discharged to a fraction of capacity and
immediately recharged then you MIGHT see some increase in service
life with a pampering suggested by folks who program smart chargers.
For all others where you crank first, stabilize alternators second
and supply standby power perhaps once in a lifetime of the battery,
the magic charging protocols yield no measurable return on investment.
>So my first battery is a 18AH and my backup is a 3AH, and is used to run
>one EI and a Facet fuel pump, nothing else.
>
>No points of interconnect between the systems except for the diode.
>
>Make sure the diode is sized to flow enough current to run your backup
>EI and you can simply run your backup EI from the second battery all the
>time, i.e no chageover contactors or other components that could fail.
>
>If you do it this way there is really no need to montior the second
>battery as you will be changing it every year or so anyway...I use a
>simple digital voltmeter and check it before each flight.
As described in other posts, an open circuit voltage check
of a battery is a very gross examination of battery condition
(at least it's not discharged) and yields no accurate data
as to capacity. The yearly change-out is the practical hedge
against the unknown.
A series of articles have been crafted dealing with second battery
management techniques:
http://aeroelectric.com/articles/lvwarn/LVWarn-ABMM.html
http://aeroelectric.com/articles/lvwarn/9021-620.pdf
http://aeroelectric.com/Catalog/AEC/9005/9005.html
http://aeroelectric.com/Catalog/AEC/9005/9005-701B.pdf
These are illustrated in appendix Z, most notably
Figure Z-30 of:
http://aeroelectric.com/Catalog/AEC/9005/9005-701B.pdf
where the aux battery switching device can be any
size of switch or contactor suited to the task and the
battery can also be selected for capacity suited to
the task.
Key considerations are: (1) connect the standby battery
to the main system via lowest practical resistance i.e.
toggle switch or relay. (2) Have active notification of
low voltage that prompts you to open the switch or automatically
opens a relay or contactor . . . it doesn't matter.
You have PLENTY of time to react and there's little
advantage in making this function automatic. The hard
connection through a switch or relay insures that your
standby battery gets the same benefits of recharge as
your main battery.
Bob . . .
Message 19
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Subject: | Baclup Battery monitor |
--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
I measured the Facet and it was less than an amp...Can't remember what
the EI draws but I did measure it at the time.
The Zodiac is strictly a VFR airplane and most failure modes would leave
some juice left in the main battery.
So I think I assumed about 20 minutes of flight on Batt #2.
If I were re-doing it today I think the more modern diode (with lower
volt drop) would mean I could use a bigger battery.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dave
Morris "BigD"
Sent: Friday, February 24, 2006 8:44 AM
Subject: RE: AeroElectric-List: Baclup Battery monitor
--> AeroElectric-List message posted by: "Dave Morris \"BigD\""
--> <BigD@DaveMorris.com>
Facet pumps draw about 1.5A, don't they? And your EI draws how much?
3AH seems awfully small to me. I'm guessing the Duration vs Current
curve for that battery gives you 3A for 30 minutes. Is that enough?
Dave Morris
www.N75UP.com
At 10:22 AM 2/24/2006, you wrote:
>So my first battery is a 18AH and my backup is a 3AH, and is used to
>run one EI and a Facet fuel pump, nothing else.
Message 20
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Subject: | Re: Baclup Battery monitor |
--> AeroElectric-List message posted by: Mickey Coggins <mick-matronics@rv8.ch>
> The problem with diodes is they all have a forward volt drop, standard
> diodes are about 1 volt drop. So if your system charges at say 14.2
> volts, your second battery will only see 13.2V.
>
> I believe the Shotkey (sp?) diode has a much lower drop...Althouigh I
> don't know what it is.
Use one of Eric's Power Schotty diodes - they don't have much
voltage drop at all.
http://www.periheliondesign.com/powerschottkydiodes.htm
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
Message 21
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Subject: | Re: SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 10:51 AM 2/24/2006 -0500, you wrote:
>--> AeroElectric-List message posted by: "Alan K. Adamson"
><aadamson@highrf.com>
>
>Bob, did you ever put together one of these for the SD-20? B&C specify 20A
>output at 3500rpm, so I would assume that you could use the same "ratios"
>and determine that on a continental for example, that is a 1.15:1, that
>you'd have full output at 2900ish rpm?
>
>http://www.aeroelectric.com/Reference_Docs/Alternator_Data/SD8-Performance.p
>df
The SD-20 is an L-40 with different shoes. It's limited in output
only because of the reduced speed on the vacuum pump pad. It's
performance is described on B&C's website at:
http://bandc.biz/SD20REVC.pdf
Bob . . .
Message 22
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Subject: | Re: What happens if OV trips? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 08:25 AM 2/24/2006 -0500, you wrote:
>--> AeroElectric-List message posted by: Ken <klehman@albedo.net>
>
>Hi Scott
>I don't believe any of the Z architectures run two alternators in
>parallel such that both would trip together.
Z-12 does and the regulators specified are 'smart' enough to know
if an ov condition is caused by local failure or is coming from another
alternator.
>However if a crowbar activates it becomes a momentary short until the CB
>pops. Reset the CB and everything goes back to normal unless the voltage
>goes high again in which case the breaker will immediately pop again.
>Nuisance tripping seems to be quite rare and IMO one should not tolerate
>any nuisance trips but rather find out why that is happening and fix it.
>While I don't have much engine running time accumulated yet, I have not
>been able to instigate a single nuisance trip with the latest homemade
>version of Bob's crowbar circuit dated Jan 2006. I could instigate them
>with earlier homemade versions.
>Ken
Absolutely. Nuisance trips are a fact of life in virtually every
design that stands as close as practical to the edge. You DESIRE
sensitivity to the failure but in some cases, there is overlap
between things that should and should not be reacted to.
Of all the OV systems I've worked in the past 30 years, I'll guess
that perhaps 1/3 of them needed some tweaking after first delivery.
This is the nature of the beast that is a quest for best response to
a hazard and ability to filter and ignore conditions that are not
hazardous.
>Scott wrote:
>
> >--> AeroElectric-List message posted by: "Scott" <scott@randolphs.net>
> >
> >If the "crowbar" overvoltage protection trips, is it a permanent fault or
> >something that can be reset on the fly?
> >
> >I'm interested in general in how it works, but specificly thinking now about
> >the possibility of one alternator tripping both OV circuits if both
> >alternators happen to be on (by design or switchology error). If that
> >happened, would both alternators be permanently disabled or would turning
> >off the faulty one allow the other to be brought back online?
Virtually all ov systems for aircraft have allowed resetting by
the pilot with one notable exception. American/Grumman had a po' boy's
crowbar OV system using a zener and an upstream fuse. A trip event
took out a fuse and most often shorted the zener. However, while
crude in implementation, this system was immune to nuisance trips.
Cheap, effective and few downsides.
Bob . . .
Message 23
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Subject: | Re: Odyssey % of charge |
--> AeroElectric-List message posted by: Bill Dube <william.p.dube@noaa.gov>
State-of-charge meters, like the Link-10
<http://www.xantrex.com/web/id/97/p/1/pt/5/product.asp> add up the
amp-hrs in and out (in a fancy manner) to figure the state-of-charge.
If the battery is damaged or worn out, (or the unit loses track of what
has happened lately,) the remaining capacity displayed is incorrect.
The high-tech battery testers like
<http://www.batterymart.com/battery.mv?p=ACC-SB-300> often use the
impedance of the battery to judge its health. If you measure voltage,
current, and temperature, and play them against each other, you can
estimate the state-of-charge and the health of the battery. This is more
what you want for an aircraft instrument. The key is measuring impedance
(along with an estimate of OCV) and comparing it to what had been
measured before under similar conditions.
Robert L. Nuckolls, III wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
>
>At 05:30 AM 2/24/2006 -0800, you wrote:
>
>
>
>>--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
>>
>>Robert L. Nuckolls, III wrote:
>>
>>
>>
>>> HERE'S THE POT HOLE - THE 30 MINUTE DISCHARGE CURVE
>>> OF 26.4 AMPS SAYS THE CAPACITY IS 26.4A X 0.5 HOURS
>>> OR 13.2 A.H., NOT 26 A.H.
>>>
>>> I SHOULD HAVE CAUGHT THAT . . . A 33 TO 26 REDUCTION
>>> IN APPARENT CAPACITY FOR A 15X LARGER DISCHARGE
>>> RATE DIDN'T RAISE THE FLAGS. FOUND IT WHILE ARCHIVING
>>> THE POST.
>>>
>>>
>>Welcome to Peukert's exponent. If you know the capacity at two different
>>discharge rates you can interpolate or extrapolate the capacity off the
>>battery at other discharge rates.
>>
>>
>
> Yeah . . . sorta. I'm working on that question along with the
> notion that owning one of those super-charge-all smart battery
> chargers is a good thing to do to. I'll give you all a forecast
> on present findings:
>
> An $80 smart charger and $??$ capacity meter are not well suited
> to our ultimate design goals (1) know that the battery is mission
> capable every time we walk up to the airplane and (2) have tools
> requiring minimum expense and user time/attention to track that
> capability. None of the devices I cited above do a very good job
> of meeting those goals. An article on alternative hardware proposals
> is in the works.
>
> 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 24
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Subject: | Re: SD8 Alternator Install - Z-12 vs. Manual |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
Manual
At 10:31 AM 2/24/2006 -0500, you wrote:
>--> AeroElectric-List message posted by: "Steve & Denise"
><sjhdcl@kingston.net>
>
>I thought the point in having the warning light for the aux alternator is
>tell you it is overloaded and
>equipment needs to be turned off??
That's a special feature that is built into B&C's regulators for the
SD-20 only when used as aux alternators. These regulators are fitted with
a current sensor. See:
http://aeroelectric.com/articles/Rev11/AppZ_R11E.pdf
. . . latest revision to Z-12 where the SD-20 is controlled by
an SB-1 regulator.
This is an excellent example of how you need to UNDERSTAND exactly
what is meant by "warning light" and exactly what functions come
with it.
I'm doing an article on the MC33092A voltage regulator chip mentioned
by Jon earlier this week. A careful analysis of the regulator's
functionality
yields some interesting things about how the warning light works, what
it means, and whether or not the chip is suited for use in our airplanes
to meed certain design goals.
A wire coming out of a black box to drive a "warning light" tells
you nothing about the functionality of the light. This must be gleaned
from more detailed data as to how the lamp driver works . . . as will
be illustrated for the MC33092.
Bob . . .
Message 25
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Subject: | Re: Odyssey % of charge |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 07:14 AM 2/24/2006 -0800, you wrote:
>--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
>
>Robert L. Nuckolls, III wrote:
>
> > An $80 smart charger and $??$ capacity meter are not well suited
> > to our ultimate design goals (1) know that the battery is mission
> > capable every time we walk up to the airplane and (2) have tools
> > requiring minimum expense and user time/attention to track that
> > capability. None of the devices I cited above do a very good job
> > of meeting those goals. An article on alternative hardware proposals
> > is in the works.
>
>Having a smart energy monitor is necessary in a system where you will
>have irregular charge/discharge cycles and want to know how much is left
>in the battery.
Agreed . . . but how does this happen on an airplane and how
often might one expect to encounter it? . . . and are there
less complicated and more positive ways to achieve the desired
mission/maintenance conditions?
>If you always recharge the battery to full every time,
>you can have a much simpler energy monitor that isn't quite so smart.
Yup.
>The biggest issue as I see it is that you need to make sure you don't
>overcharge the battery in summer but that you do actually charge the
>battery in winter. That implies temperature compensation.
Agreed . . . and it's not clear that we have really practical
ways to achieve that. The LR-3 from B&C offers a battery temp
sensor option. But it's not clear to me that this option will
produce really meaningful differences in battery performance for
most of our fellow airplane drivers.
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 26
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Subject: | Baclup Battery monitor |
--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
Interesting,
The battery manufacturer actually dictated the charging voltage as being
lower for the smaller battery. Both are SLA's.
The other piece I missed about my battery maintenance is that they are
connected to a smart charger when left in the hangar, so at least I have
a good charge when I start out.
Based on the above would you recommend raising the charging voltage by
using a lower loss diode?...I could change for a switch but that gives
me something else I have to remember.
Cheers
Frank
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L. Nuckolls, III
Sent: Friday, February 24, 2006 9:02 AM
Subject: RE: AeroElectric-List: Baclup Battery monitor
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
--> <nuckollsr@cox.net>
At 08:22 AM 2/24/2006 -0800, you wrote:
>--> AeroElectric-List message posted by: "Hinde, Frank George
(Corvallis)"
><frank.hinde@hp.com>
>
>Simplest way is to take a second battery and charge it through a diode
>from the main bettery. That way if the main battry has a major short
>somewhere it will not drag down the second batery with it.
>
>The problem with diodes is they all have a forward volt drop, standard
>diodes are about 1 volt drop. So if your system charges at say 14.2
>volts, your second battery will only see 13.2V.
Which is a major issue for recharging the standby battery
to 100% of capacity.
Message 27
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|
Subject: | SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "Alan K. Adamson" <aadamson@highrf.com>
Cuz the ignorance, but what ALT rpm would I expect to see on a continental
io-550 vacuum pad, when the engine is turning 2500 RPM?
Alan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Friday, February 24, 2006 12:05 PM
Subject: Re: AeroElectric-List: SD-20 Alt performance chart?
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
--> <nuckollsr@cox.net>
At 10:51 AM 2/24/2006 -0500, you wrote:
>--> AeroElectric-List message posted by: "Alan K. Adamson"
><aadamson@highrf.com>
>
>Bob, did you ever put together one of these for the SD-20? B&C specify
>20A output at 3500rpm, so I would assume that you could use the same
"ratios"
>and determine that on a continental for example, that is a 1.15:1, that
>you'd have full output at 2900ish rpm?
>
>http://www.aeroelectric.com/Reference_Docs/Alternator_Data/SD8-Performa
>nce.p
>df
The SD-20 is an L-40 with different shoes. It's limited in output
only because of the reduced speed on the vacuum pump pad. It's
performance is described on B&C's website at:
http://bandc.biz/SD20REVC.pdf
Bob . . .
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Subject: | Re: An Architecture Question - Z13 |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 08:09 AM 2/24/2006 -0700, you wrote:
>--> AeroElectric-List message posted by: "Todd Richmond"
><trichmond@obermeyer.com>
>
>All,
>
>
>I have been reading the AeroElectric posts for several weeks now and find
>the forum extremely useful as I begin designing the electrical system for my
>RV-7A (that and re-reading the AeroElectric Connection several times). I am
>planning an all electric airplane based on the Grand Rapids EFIS/EIS system,
>Garmin 430, E-Mag / P-Mag combo and all the other little gizmos I can fit
>(afford). At this point, I'm basing my architecture on the Z-13 with a 60
>Amp alternator and SD-20 auxiliary alternator.
Why so much snort? 'lectric toe heaters? Hot prop? Air conditioning?
Where does Z-13/8 fall short of your requirements for operational power?
>
>
>So my first question is this. do I need an e-bus? The only reason I can
>figure is that without the e-bus, the master battery contactor becomes a
>single point of failure. If true, could I simply wire two battery
>contactors in parallel and run them via a 2-10 switch? To me the advantage
>of this approach is that in case of an alternator failure, I can simply
>switch to the auxiliary alternator and systematically reduce my loads until
>the alternator is picking up the full load without worrying what is attached
>to each bus.
It would be presumptuous of us to tell you what you 'need'.
After a review of chapter 17, what are your power requirements
to continue flight sweat-free in spite of any single failure?
One should never "worry" about any aspect of operating your
electrical system. This isn't a jazz combo where one should
be prepared to improvise an impressive new rift at a moment's
notice.
EVERYTHING you might expect to encounter is 100% predictable
which includes loads, numbers and sizes of available energy
sources and combinations of sources and loads really useful
for the various phases of flight.
>My second question is would it make sense to wire both alternators to a DP3T
>switch? My thought being that this approach ensures only one alternator may
>be operating at a time and thus would prevent them from inadvertently
>fighting one another.
>
>Any input is gratefully appreciated.
Keep in mind that the Z-figures have been crafted over 15 years
of sifting the options. The features shown all have reasons
for their incorporation. I'll respectfully suggest that
you do a load analysis first. How much snort is necessary
for normal en-route operations, how much is necessary for
alternator-out operations and for how long. Answers to these
questions drive sizing of alternator(s) and battery(ies).
Then pick a Z-figure that seems closest to your NEEDS and
then tell us how that figure falls short of some perceived
NEED. I'm not suggesting for a moment that the z-figures are
"golden" . . . but at the same time, if any figure is deficient
in some feature that makes sense, I'd be pleased to revise the
the drawing or create a new one. That's how new figures find their
way into the book.
You are presently at the stage where it's important to know
the difference between what's needed and what's simply cool
(wanted). We wouldn't presume to tell you that what you want
shouldn't be considered either . . . but it's important that
you have those two buckets understood. A watchword of system
reliability is simplicity. Keep parts count down, avoid single
points of failure, keep operational options down (ZERO probability
of in-flight worries).
Bob . . .
Message 29
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|
Subject: | Rotax Battery/Regulator Questions |
--> AeroElectric-List message posted by: "Bill Denton" <bdenton@bdenton.com>
I am referencing the Rotax wiring diagrams at the following link:
http://www.rotax-aircraft-engines.com/pdf/dokus/d00287.pdf
The diagrams are located on Adobe Acrobat page 53 of 68, which is Rotax page number
18-5.
There are three diagrams on the page, I am referring to the bottom two, labeled
"wiring diagram in conjuction with a battery" which I will call "No Starter",
and "wiring diagram for electric starter", which I will call "Starter".
On the No Starter diagram, it calls for a 12V 9Ah minimum battery, while on the
Starter diagram, it calls for a 12V 16Ah minimum battery. I am assuming that
the additional capacity of the battery on the Starter diagram is specified in
order to provide adequate starting power.
My question has to do with the No Starter diagram. Why is the "9Ah minimum" specified,
and what would be the result of using a lower capacity battery?
In one of the (many!) projects I am considering, I would be using a Rotax 477 without
an electric starter. However, I would have Nav/Strobe/Landing lights, a
couple of small electronic gauges, a handheld NAV/COM, a handheld GPS, and a
panel mount transponder, all connected to ship's power.
My reasons for considering the use of a battery would be to provide pre-start power
for the radio and GPS and to provide power in an engine-out situation. I'm
also thinking that it would keep the available power up during low RPM operations,
and possibly "smooth" the power a bit.
Is my reasoning okay on this?
Would I actually need a 9Ah battery for these purposes, or would a smaller unit
suffice?
If a battery smaller than 9Ah is acceptable from a load standpoint, would a smaller
battery create a problem with the regulator/rectifier?
Now a question specific to the No Starter diagram:
Would it be acceptable to install a toggle-switch circuit breaker in place of the
16A fuse in the black wire which runs between the regulator and the battery?
Would it be desirable to have a means of isolating the regulator in this way?
What size circuit breaker should be used?
Thanks in advance for anyone's help, and if my questions are less than clear or
less than properly worded, please feel free to read between the lines!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=14740#14740
Message 30
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|
Subject: | An Architecture Question - Z13 |
--> AeroElectric-List message posted by: "Todd Richmond" <trichmond@obermeyer.com>
All good points, which lead to two operational questions assuming the
Z-13/8. First, I would assume that normal operations would include closing
the alternate feed switch to the e-bus, true? And second, is there a risk
of damage should the SD-8 inadvertently become activated while the primary
alternator is running?
Hopefully these aren't ignorant questions. Thanks.
Todd R. Richmond
trichmond@obermeyer.com
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Friday, February 24, 2006 10:52 AM
Subject: Re: AeroElectric-List: An Architecture Question - Z13
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<nuckollsr@cox.net>
At 08:09 AM 2/24/2006 -0700, you wrote:
>--> AeroElectric-List message posted by: "Todd Richmond"
><trichmond@obermeyer.com>
>
>All,
>
>
>I have been reading the AeroElectric posts for several weeks now and find
>the forum extremely useful as I begin designing the electrical system for
my
>RV-7A (that and re-reading the AeroElectric Connection several times). I
am
>planning an all electric airplane based on the Grand Rapids EFIS/EIS
system,
>Garmin 430, E-Mag / P-Mag combo and all the other little gizmos I can fit
>(afford). At this point, I'm basing my architecture on the Z-13 with a 60
>Amp alternator and SD-20 auxiliary alternator.
Why so much snort? 'lectric toe heaters? Hot prop? Air conditioning?
Where does Z-13/8 fall short of your requirements for operational power?
>
>
>So my first question is this. do I need an e-bus? The only reason I can
>figure is that without the e-bus, the master battery contactor becomes a
>single point of failure. If true, could I simply wire two battery
>contactors in parallel and run them via a 2-10 switch? To me the advantage
>of this approach is that in case of an alternator failure, I can simply
>switch to the auxiliary alternator and systematically reduce my loads until
>the alternator is picking up the full load without worrying what is
attached
>to each bus.
It would be presumptuous of us to tell you what you 'need'.
After a review of chapter 17, what are your power requirements
to continue flight sweat-free in spite of any single failure?
One should never "worry" about any aspect of operating your
electrical system. This isn't a jazz combo where one should
be prepared to improvise an impressive new rift at a moment's
notice.
EVERYTHING you might expect to encounter is 100% predictable
which includes loads, numbers and sizes of available energy
sources and combinations of sources and loads really useful
for the various phases of flight.
>My second question is would it make sense to wire both alternators to a
DP3T
>switch? My thought being that this approach ensures only one alternator
may
>be operating at a time and thus would prevent them from inadvertently
>fighting one another.
>
>Any input is gratefully appreciated.
Keep in mind that the Z-figures have been crafted over 15 years
of sifting the options. The features shown all have reasons
for their incorporation. I'll respectfully suggest that
you do a load analysis first. How much snort is necessary
for normal en-route operations, how much is necessary for
alternator-out operations and for how long. Answers to these
questions drive sizing of alternator(s) and battery(ies).
Then pick a Z-figure that seems closest to your NEEDS and
then tell us how that figure falls short of some perceived
NEED. I'm not suggesting for a moment that the z-figures are
"golden" . . . but at the same time, if any figure is deficient
in some feature that makes sense, I'd be pleased to revise the
the drawing or create a new one. That's how new figures find their
way into the book.
You are presently at the stage where it's important to know
the difference between what's needed and what's simply cool
(wanted). We wouldn't presume to tell you that what you want
shouldn't be considered either . . . but it's important that
you have those two buckets understood. A watchword of system
reliability is simplicity. Keep parts count down, avoid single
points of failure, keep operational options down (ZERO probability
of in-flight worries).
Bob . . .
Message 31
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Subject: | Re: Strange alternator behavior at Startup (Mickey |
and Bob N.)
--> AeroElectric-List message posted by: <gmcjetpilot@yahoo.com>
Mickey wants to turn his car off at 100 mph and
AND
Bob N. wants proof.
Fair enough.
Also I'll take any failed VOLTAGE regulator for professional evaluation.
Mickey wrote:
"What happens if you are driving down the highway at 100 mph,
everything working fine, and you turn the key off?"
Dear Mickey:
I am so laughing out loud. I hope you are trying to be funny. To
answer your question you would DIE when the steering locks and
you fly off the road.
Do you often turn your car's ignition OFF at 100 mph?
I'll repeat the intended purpose of the IGN lead is a small signal
current/voltage to tell the alternator to come alive or go to sleep.
IT IS NOT designed to "CONTROL" high amp loads of the
alternator under load. It is also does not control the field directly.
To answer your question, if you turn the ignition off at 100 MPH,
it's no different than at zero MPH.
In a car the first position, normal driving is ignition. The next
position is accessory, than off.
Now in your scenario if you kill the ignition the engine will shut
down even at 100 mph with an automatic. With a manual and the
clutch out the engine will turn a little?
Now lets say you turn the ignition switch OFF/locked steering!
Now let's turn the ignition off, alternator off and load at 100 MPH?
Only the head lights and brake lights work. The alternator is still
connected to battery and the engine will lets assume keep turning
(manual transmission going down a steep hill). Now lets say you
turn the IGN on again to run? Could you do some ALT damage?
NOW TELL ME IF THIS IS realistic? Ha ha ha ha ha
Now when you look at the key function on a car, I think most bring
the alternator on first than the load (master realy). I could be wrong.
Reagardless your senerio is not going to happen in the real worlds.
Mickey I think you need to test this and get back to us. : - )
Mickey your are my idol, smart and have a beautiful airplane
project (you do nice work), but you need to get out of the shop
and get fresh air. : -) This is not how they are designed to work.
To clarify, I think most of the damage of IGN switching under
load is not turning it OFF, but happens when you turn it BACK
ON under load. Now I know many ND alternator will shut down
with the IGN lead and come back ON under load with IGN lead.
I suspect Van's alternator in question may already be damaged.
The first sign of damage, after controlling the alternator under
load successfully with the IGN lead, both OFF and ON, is it stops
responding to the IGN. Why? Not sure, send me the I-VR and I'll
have it tested and failure mode tested.
There may be some ND alternators that will be happy to switch
the IGN lead all day under load, but it seems that they protest after
a while. Sorry Bob N., no proof just seen it 3-4 times, there is a
pattern. Repeatable? Looks that way. My proof is how they are
wired in the application it was designed for. Nuff said.
Look at how cars and industrial applications use these alternators,
designed so you CAN'T turn it OFF or ON under load normally,
except for the wild 100 mph scenario Mickey (get help) came up
with above. Even than I don't think it makes a difference.
Bob N. wrote:
"Can you point us to any published literature on this? Please
understand that I'm not attacking your assertions with any kind of
"PROVE IT" attitude."
Bob, I know you dislike internal regulation but everything Jon said
is true & typical of an I-VR. They DO have *soft start, they do have
RPM drop out and they do have temperature compensation. I am
no expert, but I talk to experts. The temperature compensation
function I know monitors high temp protection, but I do not know
about a cold weather temp control function. It should be noted
that EXTERNAL voltage regulators have no idea of alternators internal
temps and do not protect the alternator from high temps like I-VR's
do. (one for the internal voltage regulators!)
*(soft start, ramps-up slow, also combined with time delay after
target RPM is reached.)
Bob, I know you will never believe me, no matter what evidence I
show, so I won't try. I have seen you dismiss too many people and
too set in your opinions to play that game, so Bob I suggest you
contact TRANSPO engineering, world wide producers of almost
every voltage regulator ever made. They will clue you into the
intelligent and logic functions of I-VR's. They really are smart
devices, not dumb VR's. They have all the features mentioned.
http://www.transpo-usa.com/
For the record I do not think the cold temp is the reason for this
problem, but I could be wrong. I think the I-VR may have been
damaged already from the crow-bar or switching the IGN lead
ON/OFF under load. Also for the record the IGN can and do
control the alternator under load on many ND models, but NOT
designed for this routinely and eventually damage results.
As far as control of I-VR alternators, it would be wonderful to use
and trust the IGN wire. We could put a crow-bar on the CB to the
IGN lead. However you can't depend on it (apparently from
historical & empirical data). That's why a pullable CB on the B-
lead, to positively isolate the alternator, independent of anything is
suggested. Another way to achieve the same isolation is the crow
bar and over voltage relay on the B-lead. That works also but its
heavy, costly, complicated and potentially can cause nuisance
trips. In defense of the crow-bar it is automatic. The pullable CB
needs pilot action. The choice is the builders. As Bob N. says if
you can't take the small chance of an OV, than use an External
Regulator and OV module of some kind. if for no other reason
it is simple. However there is no guarantee that will work 100%
There's no 100% system.
Cheers George
---------------------------------
Bring photos to life! New PhotoMail makes sharing a breeze.
Message 32
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|
Subject: | Re: SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 2/24/2006 11:37:58 A.M. Central Standard Time,
aadamson@highrf.com writes:
Cuz the ignorance, but what ALT rpm would I expect to see on a continental
io-550 vacuum pad, when the engine is turning 2500 RPM?
Alan
7500
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Air Park LL22
Downers Grove, IL 60516
630 985-8503
Message 33
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|
Subject: | Re: Odyssey % of charge |
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Robert L. Nuckolls, III wrote:
>> Having a smart energy monitor is necessary in a system where you will
>> have irregular charge/discharge cycles and want to know how much is left
>> in the battery.
>
>
> Agreed . . . but how does this happen on an airplane and how
> often might one expect to encounter it? . . . and are there
> less complicated and more positive ways to achieve the desired
> mission/maintenance conditions?
Oh, I agree that you don't need a complex energy monitor nor do you need
a fancy charger. OTOH, I have had experience with batteries failing due
to overcharge in hot weather and failing to charge properly in cold weather.
>> If you always recharge the battery to full every time,
>> you can have a much simpler energy monitor that isn't quite so smart.
>
> Yup.
>
>
>> The biggest issue as I see it is that you need to make sure you don't
>> overcharge the battery in summer but that you do actually charge the
>> battery in winter. That implies temperature compensation.
>
> Agreed . . . and it's not clear that we have really practical
> ways to achieve that. The LR-3 from B&C offers a battery temp
> sensor option. But it's not clear to me that this option will
> produce really meaningful differences in battery performance for
> most of our fellow airplane drivers.
I believe that this is one of the key reasons why current crop of
"sealed" AGM aircraft batteries have such a poor service record. Flooded
cell batteries shrug off overcharge by just boiling off excess water
which gets topped off by the owner or mechanic. AGMs build up pressure
in the case and valves open and relieve the pressure, letting the water
go to the atmosphere. The AGM battery, having no excess
electrolyte/water, quickly quits working. I have never had an AGM
battery (Concorde especially) survive longer than two years in a
standard aircraft electrical system.
Brian Lloyd
brian-yak@lloyd.com
Message 34
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|
Subject: | Baclup Battery monitor |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Is the Facet pump used continuously? Or only for takeoff, landing, or in
the event of a main (engine driven) pump failure? If only intermittent
duty, leave it out of the backup battery power budget. The chances of an
alternator failure, and an engine driven pump failure on the same flight
are exceedingly low...
Matt-
> --> AeroElectric-List message posted by: "Hinde, Frank George
> (Corvallis)" <frank.hinde@hp.com>
>
> I measured the Facet and it was less than an amp...Can't remember what
> the EI draws but I did measure it at the time.
> The Zodiac is strictly a VFR airplane and most failure modes would leave
> some juice left in the main battery.
>
> So I think I assumed about 20 minutes of flight on Batt #2.
>
> If I were re-doing it today I think the more modern diode (with lower
> volt drop) would mean I could use a bigger battery.
>
> Frank
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dave
> Morris "BigD"
> Sent: Friday, February 24, 2006 8:44 AM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: Baclup Battery monitor
>
> --> AeroElectric-List message posted by: "Dave Morris \"BigD\""
> --> <BigD@DaveMorris.com>
>
> Facet pumps draw about 1.5A, don't they? And your EI draws how much?
> 3AH seems awfully small to me. I'm guessing the Duration vs Current
> curve for that battery gives you 3A for 30 minutes. Is that enough?
>
> Dave Morris
> www.N75UP.com
>
> At 10:22 AM 2/24/2006, you wrote:
>>So my first battery is a 18AH and my backup is a 3AH, and is used to
>> run one EI and a Facet fuel pump, nothing else.
>
>
Message 35
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|
Subject: | SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "Alan K. Adamson" <aadamson@highrf.com>
Bob, does that make sense. 7500 would give almost 40amps out of the SD-20,
is a continental really 3:1 on the vacuum pad? Engine rpm 2500, vacuum pad
7500?
Alan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
BobsV35B@aol.com
Sent: Friday, February 24, 2006 3:47 PM
Subject: Re: AeroElectric-List: SD-20 Alt performance chart?
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 2/24/2006 11:37:58 A.M. Central Standard Time,
aadamson@highrf.com writes:
Cuz the ignorance, but what ALT rpm would I expect to see on a continental
io-550 vacuum pad, when the engine is turning 2500 RPM?
Alan
7500
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Air Park LL22
Downers Grove, IL 60516
630 985-8503
Message 36
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|
Subject: | Baclup Battery monitor |
--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
I have two electric pumps One in each wing root. No mechanical fuel
pump.
The FI RV is being set up the same way.
To switch tanks I simply switch pumps.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt
Prather
Sent: Friday, February 24, 2006 1:03 PM
Subject: RE: AeroElectric-List: Baclup Battery monitor
--> AeroElectric-List message posted by: "Matt Prather"
--> <mprather@spro.net>
Is the Facet pump used continuously? Or only for takeoff, landing, or
in the event of a main (engine driven) pump failure? If only
intermittent duty, leave it out of the backup battery power budget. The
chances of an alternator failure, and an engine driven pump failure on
the same flight are exceedingly low...
Matt-
> --> AeroElectric-List message posted by: "Hinde, Frank George
> (Corvallis)" <frank.hinde@hp.com>
>
> I measured the Facet and it was less than an amp...Can't remember what
> the EI draws but I did measure it at the time.
> The Zodiac is strictly a VFR airplane and most failure modes would
> leave some juice left in the main battery.
>
> So I think I assumed about 20 minutes of flight on Batt #2.
>
> If I were re-doing it today I think the more modern diode (with lower
> volt drop) would mean I could use a bigger battery.
>
> Frank
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
> Dave Morris "BigD"
> Sent: Friday, February 24, 2006 8:44 AM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: Baclup Battery monitor
>
> --> AeroElectric-List message posted by: "Dave Morris \"BigD\""
> --> <BigD@DaveMorris.com>
>
> Facet pumps draw about 1.5A, don't they? And your EI draws how much?
> 3AH seems awfully small to me. I'm guessing the Duration vs Current
> curve for that battery gives you 3A for 30 minutes. Is that enough?
>
> Dave Morris
> www.N75UP.com
>
> At 10:22 AM 2/24/2006, you wrote:
>>So my first battery is a 18AH and my backup is a 3AH, and is used to
>>run one EI and a Facet fuel pump, nothing else.
>
>
Message 37
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|
Subject: | SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "George Braly" <gwbraly@gami.com>
Six cylinder vacuum pads that are on the same drive shaft as the
magnetos turn at 1.5 x crank RPM.
George
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alan
K. Adamson
Sent: Friday, February 24, 2006 11:31 AM
Subject: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
--> AeroElectric-List message posted by: "Alan K. Adamson"
<aadamson@highrf.com>
Cuz the ignorance, but what ALT rpm would I expect to see on a
continental
io-550 vacuum pad, when the engine is turning 2500 RPM?
Alan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L.
Nuckolls, III
Sent: Friday, February 24, 2006 12:05 PM
Subject: Re: AeroElectric-List: SD-20 Alt performance chart?
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
--> <nuckollsr@cox.net>
At 10:51 AM 2/24/2006 -0500, you wrote:
>--> AeroElectric-List message posted by: "Alan K. Adamson"
><aadamson@highrf.com>
>
>Bob, did you ever put together one of these for the SD-20? B&C specify
>20A output at 3500rpm, so I would assume that you could use the same
"ratios"
>and determine that on a continental for example, that is a 1.15:1, that
>you'd have full output at 2900ish rpm?
>
>http://www.aeroelectric.com/Reference_Docs/Alternator_Data/SD8-Performa
>nce.p
>df
The SD-20 is an L-40 with different shoes. It's limited in output
only because of the reduced speed on the vacuum pump pad. It's
performance is described on B&C's website at:
http://bandc.biz/SD20REVC.pdf
Bob . . .
Message 38
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|
Subject: | AGM longevity (was: Odyssey % of charge) |
--> AeroElectric-List message posted by: Bill Dube <william.p.dube@noaa.gov>
There are four main reasons why AGMs wear out.
1) Loss of electrolyte
2) Grid corrosion
3) Sulfation
4) Paste degradation
If you overcharge an AGM excessively, it will lose electrolyte and
dry out. This is NOT why they wear out in airplanes and cars (typically.)
Typically, AGMs go bad because they are not properly charged. If you
don't over charge them a little bit on a regular basis, the negative
plate gets further and further behind the positive plate. The negative
plate then sulfates and you lose capacity and cranking power. (In the
short term, you lose capacity simply because the negative plate is not
fully charged.)
Why you don't need to add water to an AGM is that the oxygen and
hydrogen gas recombine in the separator to form water. This
recombination process is not 100% efficient, and it causes the negative
plate to take slightly less charge than the positive plate when you
re-charge the battery. Each cycle gets the negative plate a bit more behind.
Occasionally, you need to purposely overcharge the battery to let the
negative plate catch up with the positive plate. A couple times per
year, you bring the battery up to 14.8 volts and let the current taper
off to less than an amp. You then push in a constant current of about 4%
of the amp-hr rating of the battery for about an hour. This cleans off
the negative plate.
High-end voltage regulators do something like this (like on boats
and motor homes). Every time you start up the engine, it charges up the
battery to normal voltage, then it gives the battery a slight overcharge
for a few minutes. Makes the big expensive AGM batteries last much longer.
>>>> What causes the other types of failures, just in case you wanted
to know. <<<
Excessive overcharging will cause the loss of electrolyte. Severe
discharge, causing reversal of a cell or two, will also cause
electrolyte loss.
Grid corrosion occurs if you leave the battery on float for a long
time. The oxygen gas formed eats at the grids that support the paste.
Sulfation is caused by leaving the battery discharged for extended
periods of time. Not fully charging the battery and leaving that way
will also cause sulfation.
Paste degradation is caused by repeated severe and/or deep
discharges. Cranking the battery flat over and over is a good way to
cause paste degradation.
Brian Lloyd wrote:
>--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
>
>Robert L. Nuckolls, III wrote:
>
>
>
>>>Having a smart energy monitor is necessary in a system where you will
>>>have irregular charge/discharge cycles and want to know how much is left
>>>in the battery.
>>>
>>>
>> Agreed . . . but how does this happen on an airplane and how
>> often might one expect to encounter it? . . . and are there
>> less complicated and more positive ways to achieve the desired
>> mission/maintenance conditions?
>>
>>
>
>Oh, I agree that you don't need a complex energy monitor nor do you need
>a fancy charger. OTOH, I have had experience with batteries failing due
>to overcharge in hot weather and failing to charge properly in cold weather.
>
>
>
>>>If you always recharge the battery to full every time,
>>>you can have a much simpler energy monitor that isn't quite so smart.
>>>
>>>
>> Yup.
>>
>>
>>
>>
>>>The biggest issue as I see it is that you need to make sure you don't
>>>overcharge the battery in summer but that you do actually charge the
>>>battery in winter. That implies temperature compensation.
>>>
>>>
>> Agreed . . . and it's not clear that we have really practical
>> ways to achieve that. The LR-3 from B&C offers a battery temp
>> sensor option. But it's not clear to me that this option will
>> produce really meaningful differences in battery performance for
>> most of our fellow airplane drivers.
>>
>>
>
>I believe that this is one of the key reasons why current crop of
>"sealed" AGM aircraft batteries have such a poor service record. Flooded
>cell batteries shrug off overcharge by just boiling off excess water
>which gets topped off by the owner or mechanic. AGMs build up pressure
>in the case and valves open and relieve the pressure, letting the water
>go to the atmosphere. The AGM battery, having no excess
>electrolyte/water, quickly quits working. I have never had an AGM
>battery (Concorde especially) survive longer than two years in a
>standard aircraft electrical system.
>
>Brian Lloyd
>brian-yak@lloyd.com
>
>
>
>
>
>
>
>
>
Message 39
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|
Subject: | SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "Alan K. Adamson" <aadamson@highrf.com>
Thanks George, so for 2500 RPM indicated engine speed, the vacuum pump pad
would be turning at 5000 rpm correct? That makes a little more sense.
Alan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of George
Braly
Sent: Friday, February 24, 2006 8:13 PM
Subject: RE: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
--> AeroElectric-List message posted by: "George Braly"
--> <gwbraly@gami.com>
Six cylinder vacuum pads that are on the same drive shaft as the magnetos
turn at 1.5 x crank RPM.
George
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alan K.
Adamson
Sent: Friday, February 24, 2006 11:31 AM
Subject: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
--> AeroElectric-List message posted by: "Alan K. Adamson"
<aadamson@highrf.com>
Cuz the ignorance, but what ALT rpm would I expect to see on a continental
io-550 vacuum pad, when the engine is turning 2500 RPM?
Alan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L.
Nuckolls, III
Sent: Friday, February 24, 2006 12:05 PM
Subject: Re: AeroElectric-List: SD-20 Alt performance chart?
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
--> <nuckollsr@cox.net>
At 10:51 AM 2/24/2006 -0500, you wrote:
>--> AeroElectric-List message posted by: "Alan K. Adamson"
><aadamson@highrf.com>
>
>Bob, did you ever put together one of these for the SD-20? B&C specify
>20A output at 3500rpm, so I would assume that you could use the same
"ratios"
>and determine that on a continental for example, that is a 1.15:1, that
>you'd have full output at 2900ish rpm?
>
>http://www.aeroelectric.com/Reference_Docs/Alternator_Data/SD8-Performa
>nce.p
>df
The SD-20 is an L-40 with different shoes. It's limited in output
only because of the reduced speed on the vacuum pump pad. It's
performance is described on B&C's website at:
http://bandc.biz/SD20REVC.pdf
Bob . . .
Message 40
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|
Subject: | SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "Matt Prather" <mprather@spro.net>
Err... Math in public isn't a good idea.. 2500 * 1.5 = 3750..
Matt-
> --> AeroElectric-List message posted by: "Alan K. Adamson"
> <aadamson@highrf.com>
>
> Thanks George, so for 2500 RPM indicated engine speed, the vacuum pump
> pad would be turning at 5000 rpm correct? That makes a little more
> sense.
>
> Alan
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
> George Braly
> Sent: Friday, February 24, 2006 8:13 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
>
> --> AeroElectric-List message posted by: "George Braly"
> --> <gwbraly@gami.com>
>
>
> Six cylinder vacuum pads that are on the same drive shaft as the
> magnetos turn at 1.5 x crank RPM.
>
> George
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alan
> K. Adamson
> Sent: Friday, February 24, 2006 11:31 AM
> To: aeroelectric-list@matronics.com
> Subject: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
>
> --> AeroElectric-List message posted by: "Alan K. Adamson"
> <aadamson@highrf.com>
>
> Cuz the ignorance, but what ALT rpm would I expect to see on a
> continental io-550 vacuum pad, when the engine is turning 2500 RPM?
>
> Alan
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
> Robert L. Nuckolls, III
> Sent: Friday, February 24, 2006 12:05 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: SD-20 Alt performance chart?
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" -->
> <nuckollsr@cox.net>
>
> At 10:51 AM 2/24/2006 -0500, you wrote:
>
>>--> AeroElectric-List message posted by: "Alan K. Adamson"
>><aadamson@highrf.com>
>>
>>Bob, did you ever put together one of these for the SD-20? B&C specify
>
>>20A output at 3500rpm, so I would assume that you could use the same
> "ratios"
>>and determine that on a continental for example, that is a 1.15:1, that
>
>>you'd have full output at 2900ish rpm?
>>
>>http://www.aeroelectric.com/Reference_Docs/Alternator_Data/SD8-Performa
>> nce.p
>>df
>
> The SD-20 is an L-40 with different shoes. It's limited in output
> only because of the reduced speed on the vacuum pump pad. It's
> performance is described on B&C's website at:
>
> http://bandc.biz/SD20REVC.pdf
>
> Bob . . .
>
>
Message 41
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|
Subject: | Re: SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "Bob McCallum" <robert.mccallum2@sympatico.ca>
Alan
1.5 x 2500 = 3750 NOT 5000
Bob McC
----- Original Message -----
From: "Alan K. Adamson" <aadamson@highrf.com>
Sent: Friday, February 24, 2006 8:47 PM
Subject: RE: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
> --> AeroElectric-List message posted by: "Alan K. Adamson"
<aadamson@highrf.com>
>
> Thanks George, so for 2500 RPM indicated engine speed, the vacuum pump pad
> would be turning at 5000 rpm correct? That makes a little more sense.
>
> Alan
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of George
> Braly
> Sent: Friday, February 24, 2006 8:13 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
>
> --> AeroElectric-List message posted by: "George Braly"
> --> <gwbraly@gami.com>
>
>
> Six cylinder vacuum pads that are on the same drive shaft as the magnetos
> turn at 1.5 x crank RPM.
>
> George
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alan K.
> Adamson
> Sent: Friday, February 24, 2006 11:31 AM
> To: aeroelectric-list@matronics.com
> Subject: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
>
> --> AeroElectric-List message posted by: "Alan K. Adamson"
> <aadamson@highrf.com>
>
> Cuz the ignorance, but what ALT rpm would I expect to see on a continental
> io-550 vacuum pad, when the engine is turning 2500 RPM?
>
> Alan
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert
L.
> Nuckolls, III
> Sent: Friday, February 24, 2006 12:05 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: SD-20 Alt performance chart?
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> --> <nuckollsr@cox.net>
>
> At 10:51 AM 2/24/2006 -0500, you wrote:
>
> >--> AeroElectric-List message posted by: "Alan K. Adamson"
> ><aadamson@highrf.com>
> >
> >Bob, did you ever put together one of these for the SD-20? B&C specify
>
> >20A output at 3500rpm, so I would assume that you could use the same
> "ratios"
> >and determine that on a continental for example, that is a 1.15:1, that
>
> >you'd have full output at 2900ish rpm?
> >
> >http://www.aeroelectric.com/Reference_Docs/Alternator_Data/SD8-Performa
> >nce.p
> >df
>
> The SD-20 is an L-40 with different shoes. It's limited in output
> only because of the reduced speed on the vacuum pump pad. It's
> performance is described on B&C's website at:
>
> http://bandc.biz/SD20REVC.pdf
>
> Bob . . .
>
>
Message 42
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|
Subject: | An Architecture Question - Z13 |
--> AeroElectric-List message posted by: "Robert G. Wright" <armywrights@adelphia.net>
A thought I keep having during these double alternator discussions is:
What's wrong with having two alternators online at the same time, with the
standby set to a volt less than the main? The standby would only then
support the load of the bus it's attached to if the main went offline (this
assumes that a "nonessential" bus goes away automatically when the main alt
fails).
Rob
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Todd
Richmond
Sent: Friday, February 24, 2006 9:09 AM
Subject: AeroElectric-List: An Architecture Question - Z13
--> AeroElectric-List message posted by: "Todd Richmond"
<trichmond@obermeyer.com>
All,
I have been reading the AeroElectric posts for several weeks now and find
the forum extremely useful as I begin designing the electrical system for my
RV-7A (that and re-reading the AeroElectric Connection several times). I am
planning an all electric airplane based on the Grand Rapids EFIS/EIS system,
Garmin 430, E-Mag / P-Mag combo and all the other little gizmos I can fit
(afford). At this point, I'm basing my architecture on the Z-13 with a 60
Amp alternator and SD-20 auxiliary alternator.
So my first question is this. do I need an e-bus? The only reason I can
figure is that without the e-bus, the master battery contactor becomes a
single point of failure. If true, could I simply wire two battery
contactors in parallel and run them via a 2-10 switch? To me the advantage
of this approach is that in case of an alternator failure, I can simply
switch to the auxiliary alternator and systematically reduce my loads until
the alternator is picking up the full load without worrying what is attached
to each bus.
My second question is would it make sense to wire both alternators to a DP3T
switch? My thought being that this approach ensures only one alternator may
be operating at a time and thus would prevent them from inadvertently
fighting one another.
Any input is gratefully appreciated.
Todd R. Richmond
RV-7A Wings
<mailto:trichmond@obermeyer.com> trichmond@obermeyer.com
Message 43
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|
Subject: | Re: AGM longevity (was: Odyssey % of charge) |
--> AeroElectric-List message posted by: Brian Lloyd <brian-yak@lloyd.com>
Bill Dube wrote:
> Occasionally, you need to purposely overcharge the battery to let the
> negative plate catch up with the positive plate. A couple times per
> year, you bring the battery up to 14.8 volts and let the current taper
> off to less than an amp. You then push in a constant current of about 4%
> of the amp-hr rating of the battery for about an hour. This cleans off
> the negative plate.
Right. This is called an equalization charge.
> High-end voltage regulators do something like this (like on boats
> and motor homes). Every time you start up the engine, it charges up the
> battery to normal voltage, then it gives the battery a slight overcharge
> for a few minutes. Makes the big expensive AGM batteries last much longer.
Hmm. The big, expensive AGM and gel-cell batteries I used on my boat
came with warnings from the manufacturer to never do an equalization
charge, that the normal charging regimen would ensure proper charging.
So when it comes to batteries, I read and follow the manufacturer's
recommendations.
Good information by the way.
--
Brian Lloyd 361 Catterline Way
brian-yak at lloyd dot com Folsom, CA 95630
+1.916.367.2131 (voice) +1.270.912.0788 (fax)
I fly because it releases my mind from the tyranny of petty things . . .
- Antoine de Saint-Exupery
Message 44
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|
Subject: | SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "Alan K. Adamson" <aadamson@highrf.com>
Now, guys... It's been a long day... Guess I can't even play the Markup vs.
Margin game on this one... :) OR, can you, perhaps I did the divide by .5
instead of times by 1.5...
Sorry, you are right
Alan - tail between legs and going back to sanding... I knew I should have
even questioned 5000 rpm, let alone 7500 :)
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob
McCallum
Sent: Friday, February 24, 2006 9:54 PM
Subject: Re: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
--> AeroElectric-List message posted by: "Bob McCallum"
--> <robert.mccallum2@sympatico.ca>
Alan
1.5 x 2500 = 3750 NOT 5000
Bob McC
----- Original Message -----
From: "Alan K. Adamson" <aadamson@highrf.com>
Sent: Friday, February 24, 2006 8:47 PM
Subject: RE: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
> --> AeroElectric-List message posted by: "Alan K. Adamson"
<aadamson@highrf.com>
>
> Thanks George, so for 2500 RPM indicated engine speed, the vacuum pump pad
> would be turning at 5000 rpm correct? That makes a little more sense.
>
> Alan
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of George
> Braly
> Sent: Friday, February 24, 2006 8:13 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
>
> --> AeroElectric-List message posted by: "George Braly"
> --> <gwbraly@gami.com>
>
>
> Six cylinder vacuum pads that are on the same drive shaft as the magnetos
> turn at 1.5 x crank RPM.
>
> George
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alan K.
> Adamson
> Sent: Friday, February 24, 2006 11:31 AM
> To: aeroelectric-list@matronics.com
> Subject: Spam> RE: AeroElectric-List: SD-20 Alt performance chart?
>
> --> AeroElectric-List message posted by: "Alan K. Adamson"
> <aadamson@highrf.com>
>
> Cuz the ignorance, but what ALT rpm would I expect to see on a continental
> io-550 vacuum pad, when the engine is turning 2500 RPM?
>
> Alan
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert
L.
> Nuckolls, III
> Sent: Friday, February 24, 2006 12:05 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: SD-20 Alt performance chart?
>
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> --> <nuckollsr@cox.net>
>
> At 10:51 AM 2/24/2006 -0500, you wrote:
>
> >--> AeroElectric-List message posted by: "Alan K. Adamson"
> ><aadamson@highrf.com>
> >
> >Bob, did you ever put together one of these for the SD-20? B&C specify
>
> >20A output at 3500rpm, so I would assume that you could use the same
> "ratios"
> >and determine that on a continental for example, that is a 1.15:1, that
>
> >you'd have full output at 2900ish rpm?
> >
> >http://www.aeroelectric.com/Reference_Docs/Alternator_Data/SD8-Performa
> >nce.p
> >df
>
> The SD-20 is an L-40 with different shoes. It's limited in output
> only because of the reduced speed on the vacuum pump pad. It's
> performance is described on B&C's website at:
>
> http://bandc.biz/SD20REVC.pdf
>
> Bob . . .
>
>
Message 45
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|
Subject: | Transponder/EFIS Gray code |
--> AeroElectric-List message posted by: "DEAN PSIROPOULOS" <dean.psiropoulos@verizon.net>
Thanks for the help Brian, I think you mis-understood my question on the
Gray Code connection to the transponder. You are correct that the SL70 has
both Gray code and serial encoder inputs. But.....my EFIS D10 is an
original production model and does NOT have an encoder serial data OUTPUT
like the newer EFIS D10-A model. So I have to use the Gray code signals out
of the EFIS to drive the transponder. The EFIS has "A", "B" and "C" Gray
code signals (out) which correspond to the transponder Gray code inputs with
one exception. The Transponder has one additional Gray code input labeled
"D4" but the EFIS does NOT have a "D4" output (I assume this extra input
allows the Transponder to encode and transmit higher altitudes than those
with just A/B/C inputs). In any case, my question is what to do with this
"D4" input at the transponder end. Is it ok to leave it unconnected
(floating) or do I need to connect it to a positive voltage or...to ground?
Can't find any direction in the manual so I assume leaving it float will not
cause a problem but would really like to know for sure. Sorry for the
initial confusion.
Dean Psiropoulos
RV-6A N197DM
Autocad-only the Radio Stack remains
----------------original message-------------------------
>From: Brian Lloyd <brian-yak@lloyd.com>
>Subject: Re: AeroElectric-List: Transponder/ RS-232
>I don't remember if the SL-70 accepts serial data in instead of gray code.
>I *think* it does but I am not sure. If it does not you will need a
serial->to-grey-code converter to get the data from the Dynon to the
SL-70....
Message 46
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|
Subject: | Re: SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: BobsV35B@aol.com
Good Evening Alan,
I had my head up and locked when I responded. The regular alternator drive
on most 520 or 550 Continentals spins the alternator at three times crankshaft
speed. That is what I had in mind. The accessory drive that often runs the
vacuum pump will spin at one and a half times crankshaft speed on all six
cylinder Continentals.
Sorry, I goofed!
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Air Park LL22
Downers Grove, IL 60516
630 985-8503
In a message dated 2/24/2006 6:58:53 P.M. Central Standard Time,
aadamson@highrf.com writes:
--> AeroElectric-List message posted by: "Alan K. Adamson"
<aadamson@highrf.com>
Bob, does that make sense. 7500 would give almost 40 amps out of the SD-20,
is a continental really 3:1 on the vacuum pad? Engine rpm 2500, vacuum pad
7500?
Alan
Message 47
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Subject: | An Architecture Question - Z13 |
--> AeroElectric-List message posted by: Robert Sultzbach <endspeed@yahoo.com>
Todd,
In regards to the e-bus question, it is not just to
protect against a contactor failure. Let me
illustrate this with a real live incident that
happened to a roommate of mine. Picture being IFR in
solid clag when you smell smoke and see thick smoke
instantly start billowing from under the bottom of
your instrument panel. A quick flip to off with the
master switch makes the smoke start to lessen. Now,
you have no radios working though your radio stack is
probably o.k. Your electrical system is now caput.
Nada, zilch. Now remember you are in the clag. What
will you do? At any rate, with the e-bus, you turn
off the master and then energize the e-bus to maintain
whatever you have determined is required for safety of
flight in your flight regime. If it is IFR I would
have one navcom with an ils hopefully still available.
You get the gist and this really did happen. The guy
did get the rental aircraft down safely but he was a
real solid CFI II MEI and you name it he had it for a
rating. More importantly he was proficient. I prefer
the e-bus method to avoid this superior display of
airmanship.
Take care.
Bob Sultzbach
> I have been reading the AeroElectric posts for
> several weeks now and find
> the forum extremely useful as I begin designing the
> electrical system for my
> RV-7A (that and re-reading the AeroElectric
> Connection several times). I am
> planning an all electric airplane based on the Grand
> Rapids EFIS/EIS system,
> Garmin 430, E-Mag / P-Mag combo and all the other
> little gizmos I can fit
> (afford). At this point, I'm basing my architecture
> on the Z-13 with a 60
> Amp alternator and SD-20 auxiliary alternator.
>
>
>
> So my first question is this. do I need an e-bus?
> The only reason I can
> figure is that without the e-bus, the master battery
> contactor becomes a
> single point of failure. If true, could I simply
> wire two battery
> contactors in parallel and run them via a 2-10
> switch? To me the advantage
> of this approach is that in case of an alternator
> failure, I can simply
> switch to the auxiliary alternator and
> systematically reduce my loads until
> the alternator is picking up the full load without
> worrying what is attached
> to each bus.
>
>
>
> My second question is would it make sense to wire
> both alternators to a DP3T
> switch? My thought being that this approach ensures
> only one alternator may
> be operating at a time and thus would prevent them
> from inadvertently
> fighting one another.
>
>
>
> Any input is gratefully appreciated.
>
>
>
> Todd R. Richmond
>
> RV-7A Wings
>
> <mailto:trichmond@obermeyer.com>
> trichmond@obermeyer.com
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> browse
> Subscriptions page,
> FAQ,
> http://www.matronics.com/Navigator?AeroElectric-List
>
> Admin.
>
>
>
>
>
>
>
>
>
>
>
Message 48
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Subject: | Transponder/EFIS Gray code |
--> AeroElectric-List message posted by: "Malcolm Thomson" <mthomson@showmeproductions.com>
>From my experience with other EFIS and encoder systems, just leave
unconnected. Your assumption is correct and it is used only for higher
altitudes.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of DEAN
PSIROPOULOS
Sent: Friday, February 24, 2006 9:13 PM
Subject: AeroElectric-List: Transponder/EFIS Gray code
--> AeroElectric-List message posted by: "DEAN PSIROPOULOS"
--> <dean.psiropoulos@verizon.net>
Thanks for the help Brian, I think you mis-understood my question on the
Gray Code connection to the transponder. You are correct that the SL70 has
both Gray code and serial encoder inputs. But.....my EFIS D10 is an
original production model and does NOT have an encoder serial data OUTPUT
like the newer EFIS D10-A model. So I have to use the Gray code signals out
of the EFIS to drive the transponder. The EFIS has "A", "B" and "C" Gray
code signals (out) which correspond to the transponder Gray code inputs with
one exception. The Transponder has one additional Gray code input labeled
"D4" but the EFIS does NOT have a "D4" output (I assume this extra input
allows the Transponder to encode and transmit higher altitudes than those
with just A/B/C inputs). In any case, my question is what to do with this
"D4" input at the transponder end. Is it ok to leave it unconnected
(floating) or do I need to connect it to a positive voltage or...to ground?
Can't find any direction in the manual so I assume leaving it float will not
cause a problem but would really like to know for sure. Sorry for the
initial confusion.
Dean Psiropoulos
RV-6A N197DM
Autocad-only the Radio Stack remains
----------------original message-------------------------
>From: Brian Lloyd <brian-yak@lloyd.com>
>Subject: Re: AeroElectric-List: Transponder/ RS-232
>I don't remember if the SL-70 accepts serial data in instead of gray
>code. I *think* it does but I am not sure. If it does not you will need
>a
serial->to-grey-code converter to get the data from the Dynon to the
SL-70....
--
--
Message 49
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Subject: | SD-20 Alt performance chart? |
--> AeroElectric-List message posted by: "Alan K. Adamson" <aadamson@highrf.com>
It's ok, I did too.... :)... I think we have it straight now tho...
Nite all,
Alan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
BobsV35B@aol.com
Sent: Friday, February 24, 2006 11:31 PM
Subject: Re: AeroElectric-List: SD-20 Alt performance chart?
--> AeroElectric-List message posted by: BobsV35B@aol.com
Good Evening Alan,
I had my head up and locked when I responded. The regular alternator drive
on most 520 or 550 Continentals spins the alternator at three times
crankshaft speed. That is what I had in mind. The accessory drive that
often runs the vacuum pump will spin at one and a half times crankshaft
speed on all six cylinder Continentals.
Sorry, I goofed!
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Air Park LL22
Downers Grove, IL 60516
630 985-8503
In a message dated 2/24/2006 6:58:53 P.M. Central Standard Time,
aadamson@highrf.com writes:
--> AeroElectric-List message posted by: "Alan K. Adamson"
<aadamson@highrf.com>
Bob, does that make sense. 7500 would give almost 40 amps out of the
SD-20, is a continental really 3:1 on the vacuum pad? Engine rpm 2500,
vacuum pad 7500?
Alan
Message 50
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Subject: | LED position lights + strobe |
--> AeroElectric-List message posted by: sarg314 <sarg314@comcast.net>
Some months ago I saw a small outfit selling small LED position lights
which also accomodated a strobe light and would fit in the van's
recessed (enclosed) wingtips. I thought I saved a reference to it, but
can't find it. Does this ring a bell with any one?
--
Tom Sargent
engine
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