Today's Message Index:
----------------------
1. 12:14 AM - Re: Power buss alt field breaker (Kingsley Hurst)
2. 06:05 AM - Re: Power buss alt field breaker (Robert L. Nuckolls, III)
3. 06:07 AM - Re: CESSNA SPLIT MASTER SWITCH (Robert L. Nuckolls, III)
4. 06:56 AM - Re: OVP, Alternators, and stuff (Eric M. Jones)
5. 07:43 AM - Re: battery maintenance (Robert L. Nuckolls, III)
6. 07:54 AM - Re: Regulator output (Robert L. Nuckolls, III)
7. 08:22 AM - Re: Regulator output (Dave Morris)
8. 08:32 AM - Re: Re: battery maintenance (Paul Wilson)
9. 08:33 AM - Re: Re: OVP, Alternators, and stuff (Mickey Coggins)
10. 10:15 AM - List Digest Truncation Fixed!! (Matt Dralle)
11. 10:26 AM - Re: Re: battery maintenance (Hinde, Frank George (Corvallis))
12. 10:34 AM - Re: OVP, Alternators, and stuff (Robert L. Nuckolls, III)
13. 11:20 AM - Auto Pilot Servo Ground wire ()
14. 12:07 PM - Re: Regulator output (Robert L. Nuckolls, III)
15. 01:02 PM - Re: A question on my crossbar overvoltage protection (Robert L. Nuckolls, III)
16. 01:10 PM - Re: Re: battery maintenance (Robert L. Nuckolls, III)
17. 01:13 PM - Re: Re: battery maintenance (Robert L. Nuckolls, III)
18. 01:19 PM - Re: Auto Pilot Servo Ground wire (Robert L. Nuckolls, III)
19. 01:20 PM - Re: Auto Pilot Servo Ground wire (Robert L. Nuckolls, III)
20. 02:10 PM - Re: Re: Spam Can Architecture (Robert L. Nuckolls, III)
21. 02:21 PM - Re: flight over Wichita/battery,contactor (Robert L. Nuckolls, III)
22. 02:48 PM - Re: Re: A question on my crossbar overvoltage (Ken)
23. 04:11 PM - Narco 122D mounting? (Kevin Horton)
24. 04:25 PM - Re: Narco 122D mounting? (Kevin Horton)
25. 05:32 PM - Re: Re: OVP, Alternators, and stuff (Paul Messinger)
Message 1
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| Subject: | Power buss alt field breaker |
--> AeroElectric-List message posted by: "Kingsley Hurst" <khurst@taroom.qld.gov.au>
Bob,
You said :-
> Z-13 illustrates a fuse block were we're EXTENDING the
bus to a remote breaker for crowbar ov protection. That
piece of wire from the bus to the breaker would benefit
from some degree of SLOW protection, like a fusible link.
This is one of a FEW places where the fusible link is
a recommended wire protection device.
Would it be okay to omit the fusible link if the OV CB is within 4" of
the BUS and say a 10 or 12awg wire is used to join the BUS to the CB or
should I make a 4" fusible link ?
In my case, the BUS is an integral part of the Bussman Fuse Block.
Thank you in advance.
Regards
Kingsley in Oz.
Message 2
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| Subject: | Power buss alt field breaker |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 05:11 PM 7/14/2005 +1000, you wrote:
>--> AeroElectric-List message posted by: "Kingsley Hurst"
><khurst@taroom.qld.gov.au>
>
>Bob,
>
>You said :-
>
> > Z-13 illustrates a fuse block were we're EXTENDING the
> bus to a remote breaker for crowbar ov protection. That
> piece of wire from the bus to the breaker would benefit
> from some degree of SLOW protection, like a fusible link.
> This is one of a FEW places where the fusible link is
> a recommended wire protection device.
>
>Would it be okay to omit the fusible link if the OV CB is within 4" of
>the BUS and say a 10 or 12awg wire is used to join the BUS to the CB or
>should I make a 4" fusible link ?
>
>In my case, the BUS is an integral part of the Bussman Fuse Block.
The FAA's pulled-out-of-thin-air rule of thumb for
unprotected wire segments is 6" . . . so your 4" proposal
wouldn't raise any eyebrows in the certified world and
it's certainly acceptable here.
Bob . . .
Message 3
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| Subject: | Re: CESSNA SPLIT MASTER SWITCH |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 05:07 PM 7/13/2005 -0700, you wrote:
>--> AeroElectric-List message posted by: "Travis Hamblen"
><TravisHamblen@cox.net>
>
>I have the CESSNA SPLIT MASTER SWITCH which came with nothing in the way of
>wiring diagrams or schematics. Does anyone have a schematic or wiring
>diagram for this thing?? I know it is stone simple, as I know where the
>wires route to and basically how it works, but I don=92t know which wire goes
>onto which terminal. If you want you can e-mail me directly.
I used to have one of those things laying around here but can't
put my hands on it.
Use your ohmmeter to determine sequence of operation between
the two sides. While holding the switch in an "operating" position,
the contacts which close first and in response to operating the left
side only is your battery master switch. The other set of contacts
should close in response to operating the right side, those are
your alternator control.
If the desired switching sequences don't seem be evident, you
may have the switch upside down.
Bob . . .
Message 4
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| Subject: | Re: OVP, Alternators, and stuff |
0.60 COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
I've been considering posting a list of 95 Theses and nailing them to the
hangar door....Disputations on the Power and Efficiacy of Electrons, etc. It
is difficult to ascertain the best state of knowledge of how to build an
aircraft electrical system when so much seems up in the air. Here's my
biased summary of the recent discussion:
1) Internally vs. Externally Regulated Alternators: There are advantages and
disadvantages to both. I suspect the externally regulated alternator will
become less common and is probably a bit less reliable. In the rare OV event
in and externally regulated system, the external regulator is probably the
faulty part. For internally regulated alternators especially, a B-lead
contactor of the B&C Stancor type has not been shown to be capable of
interrupting the B-lead circuit. The documentation regarding its breaking
performance against high voltages possible in a runaway does not exist--(I
checked into this thoroughly.) However, the Kilovac Czonka III P/N
EV200AAANA will do the job easily--200A Interrupt at 320V. As a bonus its
coil draws only 100 milliamps.
2) Crowbars--The Z-figure crowbar is a poor way to do the job. The circuit
breaker cannot be show to open against the current induced by the crowbar.
Crowbars have no place in battery systems. How do you think the modern
alternator regulator IC's terminate the field?---They simply latch off the
field with a mosfet. No crowbars Bubela.
3) E-bus Diodes--Use a big fat Schottky for bus isolation. The arguments
against not doing this trigger my Attention Deficit Disorder--knocking me
into the ozone. What were we discussing....?
4) LEDs--Automakers are planning to introduce LED headlights in the 2008
model year. Then the efficacy will be 100 lumens-per-watt (as good as
fluorescents). Bet on it.
More later, only 91 more theses to go....
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
Teamwork: "A lot of people doing exactly what I say."
(Marketing exec., Citrix Corp.)
Message 5
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| Subject: | Re: battery maintenance |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
>
>Related question to bolster my confidence.
>2) Am I correct that the Schumacher WM1562A charger/maintainer meets the
>criteria for a properly charging these RG batteries?
Yes. ALL the Schumacher products I've looked at have
well designed charge/maintenance modes of operation.
The Harbor Freight device I looked at a few months ago
did not.
Another manufacturer of charger/maintainer/desulphator
products is sending me some samples. I suspect I'll
find that the charger/maintainer functions are adequate.
I'm not convinced that the desulphating technology is
useful (or even effective). There are several approaches
to "desulphating" batteries.
Watch this space. In the mean time, I've tested and
routinely use Battery Tenders . . .
http://www.batterytender.com/
and Schumacher products (some models offered by Walmart)
http://www.batterychargers.com/chargers.cfm
have proven quite satisfactory. I'll report on others
as time and opportunity permit.
>I like your method of just putting a smart charger on the batt an then one
>knows it is charged fully.
We have $many thousands$ worth of batteries in storage
and an unreasonably high rates of loss in storage due
to variability in manufacturer's and local handling rules
and tools. I've suggested that we can save $bundles$ by
tossing all the current rules and tools and install
maintenance racks with battery maintainers and mating
connectors for all stocked batteries.
A new battery can be placed on the shelf and IGNORED
for years if 100% supported by active maintainer
as opposed to being handled every 90 days for a "boost
charge" . . . the labor to maintain a battery under
the old rules is high. Risks to batteries is also high.
100% solution is to plug-em-in and forget them until
time to ship to a customer.
Bob . . .
Message 6
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| Subject: | Regulator output |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
> Could you not also run with the Essential Buss Bypass switch on.
>This would allow the current to flow through the switch and not the
>diode, whereby eliminating the voltage drop across the diode. The down
>side with this is that if you don't get an early indication that your
>alternator failed, you would have used up some of your reverse battery
>power while the master was still on.
??? Not so. If you have ACTIVE NOTIFICATION of low voltage,
alternator failure is annunciated immediately irrespective
of the position of any switches.
> On the plus side, there is no
>voltage drop on the essential bus and no high current via the diode.
>The diode would simply ensure that if the master is off and the
>essential bus bypass is no, then current will not flow from the
>essential buss to the main buss.
What are the concerns about "voltage drop"? This issue gets
elevated to discussion status and prayed over several times
a year but without putting any numbers on when "voltage drop"
becomes a real concern. We don't install silver wire to reduce
voltage drop because our design goals and the underlying physics
says there's no return on investment for doing so. If
"voltage drop" across the e-bus diode IS a real operational
concern, then it should be an easy sell with NUMBERS.
The design goals that include a normal feedpath diode to the
e-bus show that .8 volts of drop in an operating system with
a 14.2 volt (or greater) bus is no big deal. When the alternator
quits and the ENDURANCE-bus is running barefoot through battery
land, the diode is not in the loop.
If one is going to hypothesize about the merits of one operating
mode over another, then it's necessary to consider the ramifications
with numbers. One of my heros once noted:
"When you can measure what you are speaking about, and
express it in numbers, you know something about it; but
when you cannot measure it, when you cannot express it in
numbers, your knowledge of it is of a meager and
unsatisfactory kind; it may be the beginning of knowledge,
but you have scarcely, in your thoughts, advanced it to the
stage of science."
Sir William Thompson, Lord Kelvin (1824-1907)
Bob . . .
Message 7
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| Subject: | Regulator output |
--> AeroElectric-List message posted by: Dave Morris <BigD@DaveMorris.com>
That's a pretty cool statement, since I presume the number ZERO was named
in his honor on the temperature scale.
Dave Morris
At 09:50 AM 7/14/2005, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><nuckollsr@cox.net>
>
> "When you can measure what you are speaking about, and
> express it in numbers, you know something about it; but
> when you cannot measure it, when you cannot express it in
> numbers, your knowledge of it is of a meager and
> unsatisfactory kind; it may be the beginning of knowledge,
> but you have scarcely, in your thoughts, advanced it to the
> stage of science."
>
> Sir William Thompson, Lord Kelvin (1824-1907)
Message 8
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| Subject: | Re: battery maintenance |
--> AeroElectric-List message posted by: Paul Wilson <pwilson@climber.org>
Bob, Thanks for the info.
Input My WalMart now carries Black & Decker charger/maintainers:
Black & Decker VEC 0808D $17.44, Vector #VEC 10863 $24.83, & others which
cost much more.
Paul
===============
At 08:39 AM 7/14/2005, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><nuckollsr@cox.net>
>
>
> >
> >Related question to bolster my confidence.
> >2) Am I correct that the Schumacher WM1562A charger/maintainer meets the
> >criteria for a properly charging these RG batteries?
>
> Yes. ALL the Schumacher products I've looked at have
> well designed charge/maintenance modes of operation.
> The Harbor Freight device I looked at a few months ago
> did not.
>
> Another manufacturer of charger/maintainer/desulphator
> products is sending me some samples. I suspect I'll
> find that the charger/maintainer functions are adequate.
> I'm not convinced that the desulphating technology is
> useful (or even effective). There are several approaches
> to "desulphating" batteries.
>
> Watch this space. In the mean time, I've tested and
> routinely use Battery Tenders . . .
>
>http://www.batterytender.com/
>
> and Schumacher products (some models offered by Walmart)
>
>http://www.batterychargers.com/chargers.cfm
>
> have proven quite satisfactory. I'll report on others
> as time and opportunity permit.
>
>
> >I like your method of just putting a smart charger on the batt an then one
> >knows it is charged fully.
>
> We have $many thousands$ worth of batteries in storage
> and an unreasonably high rates of loss in storage due
> to variability in manufacturer's and local handling rules
> and tools. I've suggested that we can save $bundles$ by
> tossing all the current rules and tools and install
> maintenance racks with battery maintainers and mating
> connectors for all stocked batteries.
>
> A new battery can be placed on the shelf and IGNORED
> for years if 100% supported by active maintainer
> as opposed to being handled every 90 days for a "boost
> charge" . . . the labor to maintain a battery under
> the old rules is high. Risks to batteries is also high.
> 100% solution is to plug-em-in and forget them until
> time to ship to a customer.
>
> Bob . . .
>
>
Message 9
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| Subject: | Re: OVP, Alternators, and stuff |
--> AeroElectric-List message posted by: Mickey Coggins <mick-matronics@rv8.ch>
> ... The documentation regarding its breaking
> performance against high voltages possible in a runaway does not exist--(I
> checked into this thoroughly.) However, the Kilovac Czonka III P/N
> EV200AAANA will do the job easily--200A Interrupt at 320V. As a bonus its
> coil draws only 100 milliamps.
Eric, are you saying this is the relay you recommend in this
diagram: http://www.periheliondesign.com/OVP/OVschems.gif
(Sorry, don't know where to put the ? in that kind of sentence.)
I found one at http://www.onlinecomponents.com/tyco.cfm and they
want over 111 USD for it in quantities of one. They drop
all the way to 68 USD for quantities of 500.
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
Message 10
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| Subject: | List Digest Truncation Fixed!! |
--> AeroElectric-List message posted by: Matt Dralle <dralle@matronics.com>
Dear Listers,
I finally figured out today what was causing the occasional
truncation of the daily List Digest emails. Seems that every once in
a while a message would contain a single "." (period) on line all by
itself. The mailers would see this and assume that this was the
universal emailer signal for "end of message", and consequently
wouldn't process any of the rest of the Digest message.
I've put in a filter today to remove any of these sequences so we
should be back in business on the Digests.
Best regards,
Matt Dralle
Matronics Email List Admin.
Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551
925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email
http://www.matronics.com/ WWW | Featuring Products For Aircraft
Message 11
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| Subject: | Re: battery maintenance |
--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)" <frank.hinde@hp.com>
Out of interest (cus I have 4 of them) what was wrong with the HF
device?
I assume you are talking about the little black trickle charger the
transformer is on the plug with a 1" square box on the supply line.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Robert L. Nuckolls, III
Subject: AeroElectric-List: Re: battery maintenance
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
--> <nuckollsr@cox.net>
>
>Related question to bolster my confidence.
>2) Am I correct that the Schumacher WM1562A charger/maintainer meets
>the criteria for a properly charging these RG batteries?
Yes. ALL the Schumacher products I've looked at have
well designed charge/maintenance modes of operation.
The Harbor Freight device I looked at a few months ago
did not.
Another manufacturer of charger/maintainer/desulphator
products is sending me some samples. I suspect I'll
find that the charger/maintainer functions are adequate.
I'm not convinced that the desulphating technology is
useful (or even effective). There are several approaches
to "desulphating" batteries.
Watch this space. In the mean time, I've tested and
routinely use Battery Tenders . . .
http://www.batterytender.com/
and Schumacher products (some models offered by Walmart)
http://www.batterychargers.com/chargers.cfm
have proven quite satisfactory. I'll report on others
as time and opportunity permit.
>I like your method of just putting a smart charger on the batt an then
>one knows it is charged fully.
We have $many thousands$ worth of batteries in storage
and an unreasonably high rates of loss in storage due
to variability in manufacturer's and local handling rules
and tools. I've suggested that we can save $bundles$ by
tossing all the current rules and tools and install
maintenance racks with battery maintainers and mating
connectors for all stocked batteries.
A new battery can be placed on the shelf and IGNORED
for years if 100% supported by active maintainer
as opposed to being handled every 90 days for a "boost
charge" . . . the labor to maintain a battery under
the old rules is high. Risks to batteries is also high.
100% solution is to plug-em-in and forget them until
time to ship to a customer.
Bob . . .
Message 12
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| Subject: | Re: OVP, Alternators, and stuff |
0.60 COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 09:52 AM 7/14/2005 -0400, you wrote:
>--> AeroElectric-List message posted by: "Eric M. Jones" <emjones@charter.net>
>
>I've been considering posting a list of 95 Theses and nailing them to the
>hangar door....Disputations on the Power and Efficiacy of Electrons, etc. It
>is difficult to ascertain the best state of knowledge of how to build an
>aircraft electrical system when so much seems up in the air. Here's my
>biased summary of the recent discussion:
>
>1) Internally vs. Externally Regulated Alternators: There are advantages and
>disadvantages to both. I suspect the externally regulated alternator will
>become less common and is probably a bit less reliable. In the rare OV event
>in and externally regulated system, the external regulator is probably the
>faulty part. For internally regulated alternators especially, a B-lead
>contactor of the B&C Stancor type has not been shown to be capable of
>interrupting the B-lead circuit. The documentation regarding its breaking
>performance against high voltages possible in a runaway does not exist--(I
>checked into this thoroughly.) However, the Kilovac Czonka III P/N
>EV200AAANA will do the job easily--200A Interrupt at 320V. As a bonus its
>coil draws only 100 milliamps.
Agreed.
>2) Crowbars--The Z-figure crowbar is a poor way to do the job. The circuit
>breaker cannot be show to open against the current induced by the crowbar.
Paul's assertions that the I-T operating curves for response
times should also be interpreted as limits was in error.
All breakers produced under mil-spec (and by inference, any
identical, commercial breaker produced on the same line)
a qualified by demonstrating an ability to interrupt a fault
current many times higher than the limits Paul inferred.
See http://www.aeroelectric.com/Reference_Docs/Circuit_Breaker/Mil-C-5806G.pdf
After being subjected to the high fault current interrupt, the breaker
must still meet all other performance requirements.
I've discussed Paul's inference with two experienced and
learned engineer/reps for circuit breaker manufacturers and
they've never even heard of any fault limits that put
a breaker at-risk when used in the crowbar ov protection system.
Paul's assertions were without foundation in fact and easily
discounted by researching the test specifications and consulting
the people who BUILD circuit breakers.
>Crowbars have no place in battery systems.
How so? Paul tossed out lots of hyperbole to support
the same hypothesis and then picked up his marbles and
left when I began to explore the real numbers in . . .
http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_C.pdf
If crowbar ov protection is such an evil concept,
then I'll ask you the same question. Show the numbers
from a repeatable experiment that support the
premise. There are plenty of folks flying thousands of regulators
fitted with crowbar ovp systems (some certified) who
are as interested as I am in any illumination you have
to offer. I'll pick up on the next revision to the document
cited above if you'll describe the setup that will prove/
disprove any premise you wish to discuss.
> How do you think the modern
>alternator regulator IC's terminate the field?---They simply latch off the
>field with a mosfet. No crowbars Bubela.
There are plenty of alternative philosophies, any or all
of which will be acceptable under some design. These
may be perfectly acceptable competing philosophies and
products. It depends on the system design goals.
Paul suggested a new paradigm that offered 18v upper bounds
for DC power system transients. If we had enjoyed the
benefit of that limit in 1980, we would have offered
pure series, solid state ov protection too . . . but our
paradigm of the time called for an 80v/40v limit and
crowbar made more sense. Until we can demonstrate the
physics that support your proposed prohibition, I'll suggest
that the crowbar ovp module offers a useful alternative
yet today.
>3) E-bus Diodes--Use a big fat Schottky for bus isolation. The arguments
>against not doing this trigger my Attention Deficit Disorder--knocking me
>into the ozone. What were we discussing....?
Who is arguing AGAINST? I am suggesting that the
argument FOR has no foundation under the design goals
under which the Z-figures and specifically the e-bus
were created. There's nothing WRONG with a Schottky
device but there's no compelling RIGHT either.
I've never suggested that builders should not consider
using your (or anyone else's) Schottky product . . .
however, there are no compelling reasons they shouldn't
consider an equally suitable device from Radio Shack.
Bob . . .
Message 13
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| Subject: | Auto Pilot Servo Ground wire |
--> AeroElectric-List message posted by: <chaztuna@adelphia.net>
Bob & Listers,
Should the servo ground wires for the Trutrak (or other) auto pilot servos & control
boxs be grounded locally or should they be run up to the common ground
point?
I have a rear mounted battery on my RV-8A project. The pitch servo & controller
are only 6 - 8" from my battery. Should I ground them directly to the battery?
Charlie Kuss
Message 14
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| Subject: | Regulator output |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 10:19 AM 7/14/2005 -0500, you wrote:
>--> AeroElectric-List message posted by: Dave Morris <BigD@DaveMorris.com>
>
>That's a pretty cool statement, since I presume the number ZERO was named
>in his honor on the temperature scale.
Correct. Kelvin was a big energy guy and temperature
is one of the most rudimentary manifestations of energy.
See http://inventors.about.com/library/inventors/blthermometer.htm
Bob . . .
Message 15
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| Subject: | Re: A question on my crossbar overvoltage protection |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 11:13 AM 7/14/2005 -0700, you wrote:
>Hi Bob,
>
>Thanks to your fine book and mailing list I wired up my RV-7A and
>everything works swimmingly. In theory I'm an EE, but in practice I'm
>more of a software guy/ASIC/Verilog sort of EE. ;-)
Understand! But I'm confident that we can do some good
science together . . .
>I did notice one problem:
>
>I have the little two wire OV protection circuit wired per your "OV
>protection for an internally regulated alternator". During early testing
>I noticed that the OV protection component was pulling the circuit down to
>ground and thus popping the field breaker. This makes me think the OV
>circuit thought there was an OV condition. These events seemed to occur
>when switching on different components - i.e. the primer solenoid, flaps
>or strobes.
>
>My GRT EIS alarm for over voltage did not trigger. When I hooked up my
>DVM, I didn't see any high voltage when the occasional events would occur.
>
>I've temporarily disconnected the OVP circuit to allow other flight
>testing to continue.
>What do you recommend? Ideas that occur to me:
>1) Could this be a one-off problem with my OV circuit and I should just
>call B&C and get another one?
Possibly but I kind of doubt it. The fact that the system
is stable until triggered by a switching event is interesting.
In ten years or so of building these things, I've seen a hand-full
of special cases where un-anticipated characteristics in
the ship's electrical system would nuisance trip the SCR in
the ov module.
In fact, I have an OVM-14 on my bench right now that's shown
some tendency to nuisance trip. It's very early serial number.
By the way, how long have you had yours and what color are the
leads?
>2) If necessary, I can borrow a digital scope from work and see if the bus
>really is going over voltage briefly? How long of an over voltage
>condition should be required before the OV circuit pulls things to ground.
That wouldn't hurt but the event we're looking for is not
a "OV" event. I.e., it's not being triggered through the
OV detection circuit which has tens of milliseconds time
constant. It's probably a dv/dt sensitivity.
Let's try an experiment or two. Don't worry about
things we do to the module because I'm going to replace the
one you have.
Get a low ESR 0.1 uf capacitor and tie it across the
OVM's leadwires with shortest practical capacitor leads.
A Radio Shack 272-109 is suitable. See if the tripping
stops with this capacitor in place. If not, try a 1.0 uF
(RS 272-1055).
>Thank you for any ideas. Feel free to forward this to the list - I wasn't
>sure if you prefer these sorts of queries via the list or directly.
Thanks for bringing this up and I don't mind
carrying this out on the list. I'll carbon-copy this reply
to the list and we can continue the investigation where
others may benefit also. We're not going to do a thing
we wouldn't want others to know about.
Bob . . .
Message 16
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| Subject: | Re: battery maintenance |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 09:00 AM 7/14/2005 -0600, you wrote:
>--> AeroElectric-List message posted by: Paul Wilson <pwilson@climber.org>
>
>Bob, Thanks for the info.
> Input My WalMart now carries Black & Decker charger/maintainers:
>Black & Decker VEC 0808D $17.44, Vector #VEC 10863 $24.83, & others which
>cost much more.
I went to Wallyworld to see if I could buy one. My local store
is still stocked with the Schumacher WM1562 (still at $18 too).
I'll watch for the Black & Decker products and snap one up for
examination under the microscope when and if they appear on
the shelves.
Bob . . .
Message 17
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| Subject: | Re: battery maintenance |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 10:22 AM 7/14/2005 -0700, you wrote:
>--> AeroElectric-List message posted by: "Hinde, Frank George (Corvallis)"
><frank.hinde@hp.com>
>
>Out of interest (cus I have 4 of them) what was wrong with the HF
>device?
>
>I assume you are talking about the little black trickle charger the
>transformer is on the plug with a 1" square box on the supply line.
No. I purchased a #33895 . . .
http://www.aeroelectric.com/Pictures/HF_Battery_Maintainer.jpg
and it performed badly. I don't recall right now in exactly what
way. Further, this MIGHT be a one-of-a-kind event. I opened the
thing up and it has enough 'stuff' inside to do a good job. This
one may simply be broke.
Bob . . .
Message 18
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| Subject: | Re: Auto Pilot Servo Ground wire |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 02:16 PM 7/14/2005 -0400, you wrote:
>--> AeroElectric-List message posted by: <chaztuna@adelphia.net>
>
>Bob & Listers,
> Should the servo ground wires for the Trutrak (or other) auto pilot
> servos & control boxs be grounded locally or should they be run up to the
> common ground point?
> I have a rear mounted battery on my RV-8A project. The pitch servo &
> controller are only 6 - 8" from my battery. Should I ground them directly
> to the battery?
What do the instructions say? Posting a question
like that on the List is fraught with risk. You need
to do it only when the instructions are not clear -AND-
attempts to clarify ambiguous instructions with
the manufacturer has failed or is impossible.
Then your ONLY recourse is to seek learned advice.
However, unless the responding individuals have first hand
knowledge unique to the product, then the best you
can hope for is an educated guess.
I'll suggest it's FAR better to exhaust all opportunities
for the "good" advice before you resort to "best guess"
advice.
Bob . . .
Message 19
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| Subject: | Re: Auto Pilot Servo Ground wire |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 02:16 PM 7/14/2005 -0400, you wrote:
P.S. if you get a good answer from Trutrak, please
share it with us on the list so that it gets stashed
in the archives. Let us know who you talked, their
phone number and what was advised along with any
explanations they may have to offer.
Bob . . .
>--> AeroElectric-List message posted by: <chaztuna@adelphia.net>
>
>Bob & Listers,
> Should the servo ground wires for the Trutrak (or other) auto pilot
> servos & control boxs be grounded locally or should they be run up to the
> common ground point?
> I have a rear mounted battery on my RV-8A project. The pitch servo &
> controller are only 6 - 8" from my battery. Should I ground them directly
> to the battery?
What do the instructions say? Posting a question
like that on the List is fraught with risk. You need
to do it only when the instructions are not clear -AND-
attempts to clarify ambiguous instructions with
the manufacturer has failed or is impossible.
Then your ONLY recourse is to seek learned advice.
However, unless the responding individuals have first hand
knowledge unique to the product, then the best you
can hope for is an educated guess.
I'll suggest it's FAR better to exhaust all opportunities
for the "good" advice before you resort to "best guess"
advice.
Bob . . .
Message 20
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| Subject: | Re: Spam Can Architecture |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
At 10:31 AM 3/31/2005 -0500, you wrote:
>--> AeroElectric-List message posted by: "P. Van Caulart" <etivc@iaw.on.ca>
>
>Bob et al;
>
>Firstly, thanks to all Aeroelectric digest contributors for advancing
>our knowledge base. I'm continually humbled and indebted. Electron
>wrangling is a mighty task.
>
>Next, I like to ask about spam can electrical architecture, specifically
>the Cessna stuff from the late 60's early 70's. My aircraft is a '68 177
> 150hp fixed gear and prop. It's a simple 4 place cruiser.
>
>Now as it's age is creeping up to 40 years old, I have doubts about the
>integrity of the electrical system. Putting obvious certification issues
>aside and looking at just flight safety and reliability, what
>technologies could be considered to advance the integrity of the
>electrical system? Maintenance of items like batteries, switches and
>breakers, contactors and wiring seemed to be addressed in the certified
>world on a breakdown basis rather than predictive maintenance.
You haven't got many choices. If it were MY airplane and I
was allowed to DE-certify it (like you can on some airplanes
in Canada) then I would consider the following:
First, an RG battery would go in. Probably a big Panasonic (cheep)
so I could replace it every year or so without bashing the checkbook.
There are no options for a better alternator but I'd certainly
change the avionics bus to an e-bus and move a few selected items
from the main bus to the e-bus. The old avionics master becomes
an e-bus alternate feed switch.
For alternator regulation stability, I'd probably replace all wiring,
components and connectors between the bus and the alternator with
new including breaker, split rocker, and all connections/connectors.
You can keep the regulator and ov module.
Having done that, there's not much to really be worried about.
I'd certainly keep an eye on condition of insulation on wires,
particularly under the cowl.
There's a boat-load of hand-ringers writing articles about
ageing aircraft . . . Sport Aviation is right up there with
the big guys for circulating the Chicken-Little stories. See:
http://www.aeroelectric.com/articles/Wired_for_Disaster.pdf
Your biggest hedge against an unhappy day is to posture yourself
for failure tolerance. I approach every rental airplane with the
mindset that it doesn't matter what is or is not working on
the panel . . . I have enough stuff in my flight bag to get
to airport of intended destination with the panel completely
dark if necessary.
I recall a flight instructor who used to sing the "go-around
waltz" every time we sailed down the glideslope. His point was
virtually every pilot approaches the missed approach point with
a gonna-put-the-wheels-on-the-ground mindset. Pilots don't
practice go-arounds, they don't like go-arounds, they don't
expect or want a go-around so when a real one is force upon
them, they're a mixture of surprised/disappointed. His philosophy
was to slide down the chute PRAYING for the opportunity to do
a go-around and being primed to do all the right things when
it happened.
I'll suggest a corollary approach to owning and operating
an aged airplane. In this case, you can even practice operating
your airplane in the "J-3 mode" under benign conditions just
to be sure you're outfitted and mentally prepared to get
the job done with confidence and competence. This will be
a lot safer and less expensive than anything you can legally
do to your airplane.
If you smell something bad, shut it ALL off and get where you
intended to go (or back to the home field) and fix it there . . .
not on some grass strip in Podunk. If you manage to get an
e-bus installation on your airplane, so much the better but
it should not be a show stopper.
Bob . . .
Message 21
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| Subject: | flight over Wichita/battery,contactor |
location
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
location
>. .
>
>
>Bob: Cruised by Wichita Monday last. We left Tucson at 06:20MST and
>landed at Adrian, MI (ADG)at 18:10EST with two stops. Most of the trip
>was at 9500'. The air was surprisingly smooth at altitude but there was
>significant turbulence on landing in Missouri and Michigan.
>
>Questions: If I place the battery (RV-8)aft of the baggage compartment
>along with the contacter are there reasons other than weight (and
>work)not to put the starter contacter there as well? It would mean
>bringing a buss lead forward and if I decide to add electric heating
>(garments or seats) a 60A alternator and probably a 6AWG buss lead would
>be required. If this is done, how best to provide protection for the
>buss lead? Should a temperature sensor be used with the LR-3?
Sorry for the delayed response.
If you put the starter contactor back there, then you need TWO
fat wires forward . . one for the bus and one for the starter.
It's much better to put the starter contactor on the firewall
and use it as a tie-point for the fat wire to the bus.
6AWG would be adequate for a 60A bus but I'd rather see it
come off the firewall than of the battery contactors in the tail.
"Protection" for fat wires is usually purely mechanical. I.e.,
like all big cranking and battery wires from rear mounted
batteries, we take extra precautions to support these wires
and provide separation from moving parts. Experience has shown
little value in doing more on small airplanes.
I wouldn't recommend temperature compensating the LR-3 unless
your battery gets REALLY cold on long cruising flight. You might
put a thermocouple on it and see how cold it gets. The problem comes
from second segment of a trip where the battery is too cold to
take a charge after long soak on first segment. It's pretty
rare that this becomes an issue.
Next time I let you drop into a black hole, drop me a direct
email or give me a call.
>Hope to see you at Oshkosh.
Can't make it this year.
Bob . . .
Message 22
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| Subject: | Re: A question on my crossbar overvoltage |
protection
--> AeroElectric-List message posted by: Ken <klehman@albedo.net>
I wonder if this is related to what I reported a month or so ago?
"While tracking down a electrical problem ( haven't run the engine yet)
I was sidetracked for awhile by the circuit breaker that feeds a 40 amp
OV relay on my permanent magnet alternator popping. It seems that
wiggling a loose connection between the breaker and the relay will trip
the OVP and open the breaker. The crowbar OVP is constructed from the
new design. It tests OK and it doesn't trip if the alternator switch is
operated. It does trip if I intentionally rapidly connect and disconnect
the wire to the relay. The relay coil draws about 130 mA. If I
disconnect the OVP I am unable to make the C/B trip so it would seem
that the OVP is activating. It doesn't seem to make any difference
whether a diode is across the relay coil.
I'm guessing this is normal and I'm making voltage spikes at a faster
rate than the OVP time delay resets but I would have expected negative
spikes rather than positive spikes. "
At that time I also said that "temporarilly adding a unidirectional
transorb across it makes it more resistant to tripping which seems to
confirm that I am generating positive spikes" but in retrospect I'm not
certain that the transorb made much difference. Since I can't cycle the
switch fast enough to cause a problem and nobody commented, I tightened
my loose connection and did not persue this further.
Ken
>>I did notice one problem:
>>
>>I have the little two wire OV protection circuit wired per your "OV
>>protection for an internally regulated alternator". During early testing
>>I noticed that the OV protection component was pulling the circuit down to
>>ground and thus popping the field breaker. This makes me think the OV
>>circuit thought there was an OV condition. These events seemed to occur
>>when switching on different components - i.e. the primer solenoid, flaps
>>or strobes.
>>
>>
Message 23
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| Subject: | Narco 122D mounting? |
--> AeroElectric-List message posted by: Kevin Horton <khorton01@rogers.com>
I just received a Narco 122D, and am struggling to get the thing in
the panel. I want to mount it on the aft side (front side?, engine
side?, you know what I mean) of the panel, rather than cut an ATI
shaped hole and slip it in from the cockpit side of the panel. I've
cut the hole and its various cutouts, as shown in the install
manual. But I can't get the darned thing in the hole - the knobs are
in the way. It is like a Chinese puzzle. As near as I can figure, I
need to remove every knob to get it to slip into the hole. It seems
like the long shaft at the top right has to slip into its hole first,
and that limits how much you can jockey the unit around to get the
knobs into the cutouts.
I've managed to remove the Power/Volume knob, and the Course Select
knob, but, I can't get the frequency changing knobs off. One set
screw doesn't seem to fit anything I've got to turn it with. It is
so deep in the hole that I can't see what it looks like
What is the trick? Is there a set screw in every hole in the
frequency knobs? Are they all Torx T-5, or is one of something else
like a tiny Allen headed screw?
Thanks for any information.
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
Message 24
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| Subject: | Re: Narco 122D mounting? |
--> AeroElectric-List message posted by: Kevin Horton <khorton01@rogers.com>
On 14 Jul 2005, at 19:10, Kevin Horton wrote:
> I just received a Narco 122D, and am struggling to get the thing in
> the panel. I want to mount it on the aft side (front side?, engine
> side?, you know what I mean) of the panel, rather than cut an ATI
> shaped hole and slip it in from the cockpit side of the panel.
> I've cut the hole and its various cutouts, as shown in the install
> manual. But I can't get the darned thing in the hole - the knobs
> are in the way. It is like a Chinese puzzle. As near as I can
> figure, I need to remove every knob to get it to slip into the
> hole. It seems like the long shaft at the top right has to slip
> into its hole first, and that limits how much you can jockey the
> unit around to get the knobs into the cutouts.
>
> I've managed to remove the Power/Volume knob, and the Course Select
> knob, but, I can't get the frequency changing knobs off. One set
> screw doesn't seem to fit anything I've got to turn it with. It is
> so deep in the hole that I can't see what it looks like
>
> What is the trick? Is there a set screw in every hole in the
> frequency knobs? Are they all Torx T-5, or is one of something
> else like a tiny Allen headed screw?
>
> Thanks for any information.
>
> Kevin
I knew I would figure this out as soon as I sent the e-mail.
I had messed around with that blasted thing for 30 minutes, and
couldn't do it. But I just went back out in the garage for one more
try, and I found the solution. I swear I tried this before, and it
wouldn't work, but it does now.
Solution - remove the Power/Volume and Course Select knobs. Insert
the long Power/Volume shaft in its hole, and slid the unit towards
the panel, so it is at an angle, touching the panel on the right
edge. You should be able to twist it just so to rotate the lower
right portion into place, with the shaft below the frequency changing
knobs slipping into its cutout. Then you can slip the Course Select
knob shaft into its hole. Insert the screws, then replace all the
knobs. Piece of cake :)
Problem solved.
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
Message 25
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| Subject: | Re: OVP, Alternators, and stuff |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
BOB.
I was not INFERRING anything I was QUOTING DIRECTLY FROM A MANUFACTURERS
DATA SHEET and using the INDUSTRY STANDARD definitions for the terms used
therein. No inference, no opinion, no weasel wording etc. Just simple facts.
I have seen CB specifications that do allow one time extremely high current
breaking but the subject specification does not address any such terms.
Also, in general, this hi current is one time only sacrificial use.
If the data sheet is in error it needs to be corrected. OPINION from
engineers who build the devices (as you say "they've never even heard of any
fault limits") do not trump the engineering REQUIREMENTS that we have in the
aerospace industry that PREVENTS ANY violation of the manufacturers data
sheet. Also the CB you used in your tests is not normally available to the
general builders of OBAM aircraft. Clearly the Mil spec specifies fault
limits but as below I cannot read what they are.
I downloaded the mil spec data sheet and regardless of image processing its
not possible for me to read any info relating to the test hi current trip
currents but it appears to start with a 1xx current, clearly not hundreds of
amps but that is a guess as its truly useless to read the specific page in
the spec relating to this subject that you provided for our reading.
I guess we need to check our sources as when I called a CB mfgr the engineer
I talked to said they would not recommend exceeding the limits on the spec
sheet. Perhaps it's being conservative but as there is absolutely no reason
for the hi current WHY?? have it?
I would like to hear from engineers that Designed the original breakers.
From what I can find, none are still around and the current crop of
engineers and reps lack of knowledge is understandable but clearly not a
fact to rely on. Not useful to rely on "lack of info" as info in a
discussion of FACTS. Consider this "latest version of the Mil spec is dated
1967!"
I believe we should NEVER design by inference, opinion etc.. My aerospace
experience says that parts are not necessarily the same quality. Many times
the coml testing is less and or the mil spec failed parts are redefined as
commercial.
I am not aware of any requirements from you that specify the exact circuit
breaker brand and style that also has an identical mil spec equivalent. Its
extremely common for production lines to select parts for mil spec quality
and the rest go to commercial usage (if there is a mil spec and commercial
identical CB which is not always true.
So, if your Crow Bar design depends on a specific mil spec equivalent CB you
should so state that requirement. But WHY? as its so simple to limit the
current with ONE low cost part and the debate and potential problem is
history.
Finally I posted how I got 400 amps thru your crow bar using normal wiring
practices but different from your sample of one test that only shows one
possible short current and ignores worst case possible design currents. You
have apparently ignored the details of my 400 amp circuit that you can
easily duplicate for your own edification.
MY circuit was not a wild example but an exact replica of what is in my
aircraft. I did pick the CB for lowest resistance but the rest is a real
duplicate with the actual batteries etc.
Finally there is absolutely no reason for such a hi short current thru the
crow bar when the addition of a simple resistor can correct this (to many of
us, a glaring design fault) extremely hi current short.
I guess we need to check our sources as when I called a CB mfgr, the
engineer I talked to said they would not recommend exceeding the limits on
the spec sheet. Perhaps it's just being conservative ( I think its simply
there is no testing to document out of spec conditions so its UNK as to the
resulting conditions) but as there is clearly no reason for the hi current
WHY have it?
Please consider being accurate when quoting me. Its fine to disagree but as
you often suggest just the facts so I resent being accused of false or
misleading statements.
Please consider running the test that I detailed to you (in a post to this
list some months ago) that consistently produced 400 amp crow bar currents
when 50 amps is an overkill to open the CB. These currents and the setup was
done under lab conditions (and measured with quality lab calibrated
equipment and while 400 amps was measured there was no worst case analysis
to see what the real max current might be. I saw no reason to do further
analysis as the basic design of the crow bar was unacceptable in my opinion
and has a propensity to false trip (again in a repeatable lab environment,
and You did agree with this in one of our past exchanges) and is another
simple crow bar circuit design error that seldom is seen as its triggered by
a uncommon set of circumstances but still should be corrected. I suspect
this may be one source for the dozens of reported trips that have resulted
in off this list removal of the device from aircraft. Both Eric and I have
had many reports of this.
Regardless I continue to be astounded that you have failed to simply add a
simple resistor and limit the current to a reasonable value.
NO this not mean a return to posting but I will respond to what I feel are
mistatements of my words.
Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
Subject: AeroElectric-List: Re: OVP, Alternators, and stuff 0.60
COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
> <nuckollsr@cox.net>
> Paul's assertions that the I-T operating curves for response
> times should also be interpreted as limits was in error.
> All breakers produced under mil-spec (and by inference, any
> identical, commercial breaker produced on the same line)
> a qualified by demonstrating an ability to interrupt a fault
> current many times higher than the limits Paul inferred.
>
> See
> http://www.aeroelectric.com/Reference_Docs/Circuit_Breaker/Mil-C-5806G.pdf
>
> After being subjected to the high fault current interrupt, the breaker
> must still meet all other performance requirements.
>
> I've discussed Paul's inference with two experienced and
> learned engineer/reps for circuit breaker manufacturers and
> they've never even heard of any fault limits that put
> a breaker at-risk when used in the crowbar ov protection system.
> Paul's assertions were without foundation in fact and easily
> discounted by researching the test specifications and consulting
> the people who BUILD circuit breakers.
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