Today's Message Index:
----------------------
1. 07:32 AM - Re: Duracells again... (n395v)
2. 08:01 AM - Re: Z-14 Switch Combos (bcondrey)
3. 08:02 AM - Re: Question about 16V POLYFUSER Radial Leaded Resettable PTC Available at Digi-Key (Ian)
4. 08:49 AM - Re: Questions about circuit protection (user9253)
5. 09:15 AM - Re: Question about 16V POLYFUSER Radial Leaded Resettable PTC Available at Digi-Key (Robert L. Nuckolls, III)
6. 09:24 AM - Re: Duracells again... (fox5flyer)
7. 09:44 AM - Re: Re: Duracells again... (Robert L. Nuckolls, III)
8. 09:45 AM - Re: Re: Z-14 Switch Combos (Robert L. Nuckolls, III)
9. 09:51 AM - Re: Re: Questions about circuit protection (Robert L. Nuckolls, III)
10. 09:57 AM - Re: Max Alternator Voltage ? (Robert L. Nuckolls, III)
11. 10:32 AM - Re: Re: Response (Robert L. Nuckolls, III)
12. 10:40 AM - Re: Max Alternator Voltage ? (Ron Quillin)
13. 10:49 AM - Re: Questions about circuit protection. (Robert L. Nuckolls, III)
14. 11:28 AM - Re: Re: Z-14 Switch Combos (Bill Mauledriver Watson)
15. 11:28 AM - Re: Re: Questions about circuit protection (Matthew Schumacher)
16. 11:48 AM - Re: Questions about circuit protection. (Matthew Schumacher)
17. 11:49 AM - Re: Question about 16V POLYFUSER Radial Leaded Resettable PTC Available at Digi-Key (Etienne Phillips)
18. 11:59 AM - Re: Re: Questions about circuit protection (Matthew Schumacher)
19. 12:02 PM - Re: Re: Simplicity and circuit protection (Robert L. Nuckolls, III)
20. 12:03 PM - Re: Questions about circuit protection (user9253)
21. 12:09 PM - Re: Z-14 Switch Combos (Robert L. Nuckolls, III)
22. 12:15 PM - Re: Simplicity and circuit protection (Robert L. Nuckolls, III)
23. 12:26 PM - Re: Questions about circuit protection (user9253)
24. 12:55 PM - Re: THE VIRTUE OF SIMPLICITY (Robert L. Nuckolls, III)
25. 12:55 PM - Re: Re: Questions about circuit protection (Tim Andres)
26. 03:46 PM - Re: Question about 16V POLYFUSER Radial Leaded Resettable PTC Available at Digi-Key (Carlos Trigo)
27. 03:55 PM - Re: Re: Questions about circuit protection (Matthew Schumacher)
28. 04:28 PM - Re: Questions about circuit protection. (Robert L. Nuckolls, III)
29. 06:07 PM - Re: Re: Questions about circuit protection (Carlos Trigo)
30. 06:07 PM - Re: THE VIRTUE OF SIMPLICITY (Ralph & Maria Finch)
31. 06:30 PM - Re: Question about 16V POLYFUSER Radial Leaded Resettable PTC (marcausman)
32. 06:45 PM - Re: Z-14 Switch Combos (Perry, Phil)
33. 06:47 PM - A reminder (Bill Hibbing)
34. 07:03 PM - Re: GTX337 ON or OFF? (thomas sargent)
35. 07:43 PM - Re: Z-14 Switch Combos (William Slaughter)
36. 07:49 PM - Re: Z-14 Switch Combos (Neal George)
37. 08:13 PM - Re: Z-14 Switch Combos (Bob McCallum)
38. 08:21 PM - Re: Battery Bus Location (Robert L. Nuckolls, III)
39. 08:25 PM - Re: Re: Questions about circuit protection (Robert L. Nuckolls, III)
40. 09:02 PM - Re: Z-14 Switch Combos (Perry, Phil)
Message 1
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| Subject: | Re: Duracells again... |
> Is this BS ? You can put this myth to bed for all of us. If they really do replace
stuff leaking cells damage then two things will happen.
> 1- They will replace all items damaged, fix their manufacturing process and go
on the be a premier battery seller.
> 2- They will go out of business for cramming crap down our throats.
> Marketplace, and its side effects are a wonderful thing ya know.
>
A couple of data points to ponder.
I suspect the reason we see primarily Duracell quality being complained about is
the fact that they probably supply 70% of the alkaline batteries that we use.
I once worked for Duracell and it is amazing to see how they are made at high speed.
They go through the line so fast that it is hard to see even with the fastest
strobe.
Given the noxious chemicals that they are made from it is amazing they do not start
leaking day 1.
All of them are rigorously tested for leakage before shipment after several weeks
of storage and aging.
Duracell has always had a policy (and has always honored it) of replacing or compensating
for any damage their batteries cause. They even honored this policy
when the customer has left the batteries in their camera, etc. for 10 years.
This pretty much no questions asked policy is the benefit of paying a bit more
for a Duracell.
As to the el cheapos being a better deal( as in cheaper, longer life, less leakage)........
With the exception of Eveready I have watched pretty much every other brand of
alkaline battery run down the assembly lines at the Duracell factory. This includes
Ray O Vac and many of the brands mentioned in several of the battery life
studies. My guess is when you buy any alkaline battery other than Eveready you
are assuming a 50-60% probability that it came down the same assembly line
as the Duracell you replaced with it. Only difference is that the marketers of
the el cheapo ain't gonna replace your mag lite when it leaks.
Given the billions of batteries sold the number of leakers that leak within the
expected battery life is miniscule. It just seems like a lot when it gets our
favorite maglite.
--------
Milt
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=280022#280022
Message 2
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| Subject: | Re: Z-14 Switch Combos |
Phil,
There isn't anything bad that will happen regardless of switch positions for Z-14
as depicted in the stock diagrams. You've got 2 bus power switches and either
can be on or off irrespective of the other (they are isolated). Further,
the x-feed switch can be on even if both alternators are online with no ill effect
(at least with B&C externally regulated devices).
Bob
RV-10 N442PM (flying with Z-14)
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=280027#280027
Message 3
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| Subject: | Re: Question about 16V POLYFUSER Radial Leaded Resettable |
PTC Available at Digi-Key
This is the same technology as used in the EXP2BUS. It's what attracted
me to that device and it seems to work well. I have had an occasion
where one circuit has tripped and reset itself after having been
unloaded for a few seconds. Of course that doesn't remove the necessity
to find out why the circuit tripped in the first place, and in general
circuit boards tend to need to stay cleaner, and cooler than circuit
breakers and switches. I found the price was about the same, when you
compare the cost of ten or so circuit breakers and ten switches etc. to
the bare board version.
http://www.aircraftspruce.com/catalog/elpages/expbus.php
But I'd have to say that, to do it all again, I'd go with a vanilla
version of one of Mr. Nuckolls designs, with circuit breakers and
switches.
Ian Brown,
Bromont, Quebec
-----Original Message-----
From: Jeffrey W. Skiba <jskiba@icosa.net>
Subject: AeroElectric-List: Question about 16V POLYFUSER Radial Leaded
Resettable PTC Available at Digi-Key
But my question is do these trip the same as typical fuses ? I know they
can reset but would it work like a fuse for time to trip or protection
of the wire ?
Message 4
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| Subject: | Re: Questions about circuit protection |
Schu,
No switch is shown for the Hobbs meter. I assume that an oil pressure switch will
be connected in series with it.
The diode across the E-Bus relay is backwards.
The spike protection diode is missing from the dynamo relay coil. The arrow should
point towards positive.
No over-voltage protection is shown for the main alternator. Over-voltage protection
will do more towards safeguarding avionics than an avionics master switch.
Since there are only two devices connected to the avionics bus, an avionics bus
is not needed. Just connect those two devices to the switch without having a
bus. Better yet, use two switches. If one of the devices starts smoking, you
can shut it off and continue to use the other. Wire the E-Bus diode directly
to the main power bus without a switch. An avionics master switch makes it
convenient to shut off all of the avionics at once. But when it fails, so will
everything connected to it. In addition, individual downstream switches will
not get exercised, leading to corrosion and eventual failure of seldom used
switches.
Fuses offer better protection than circuit breakers. And fuses are less expensive.
Yes, more than one load can be connected to a fuse or circuit breaker.
But if one of the loads shorts out, it will blow the fuse and remove power from
the other loads. It is better to install a larger fuse block so that each load
can have its own fuse. Regulations for type certificated aircraft require
that critical fuses be replaceable in flight. However, it is better not to have
any critical equipment. Backup equipment makes critical devices non-critical.
Fuses should be replaced on the ground, not in the air.
I like your schematic. What program do you use to draw it and to convert it a
pdf?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=280034#280034
Message 5
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| Subject: | Re: Question about 16V POLYFUSER Radial Leaded Resettable |
PTC Available at Digi-Key
At 09:41 PM 1/3/2010, you wrote:
>I just noticed these at digikey web site as a new product=85.
>
>Looks like one could use these instead of fuses
>or the traditional circuit breakers (for the average range of protection)
>
>But my question is do these trip the same as
>typical fuses ? I know they can reset but would
>it work like a fuse for time to trip or protection of the wire ?
>
>Catalog page:
><http://media.digikey.com/pdf/New%20Cat%20Page/101/Littelfuse/Polyfuse%20PT
C%20Reset%20Devices.pdf>http://media.digikey.com/pdf/New%20Cat%20Page/101/Li
ttelfuse/Polyfuse%20PTC%20Reset%20Devices.pdf
>
>
>Here is a link to the Data sheet
>
><http://www.littelfuse.com/data/en/Data_Sheets/Littelfuse_PTC_16R.pdf>http:
//www.littelfuse.com/data/en/Data_Sheets/Littelfuse_PTC_16R.pdf
>
>it looks like they are used in a max volts of
>16v (good, my system runs at 13.8 volts)
>
>and they have ones that range from: 2.5a to 14a
>
>
>Price looks cheap
>
>Light weight
>
>Small in size
>
>Other thoughts ' comments ' concerns ?
>
>Thanks
>
>Jeff
>
Go to http://tinyurl.com/yzs2u65 and review the
discussions on Exp Bus and Greg Richter's polyswitch
based products.
The polyfuse has been around for 30+ years. We
looked at them for general circuit protection in
the GP-180 program at Lear. We looked at them
at least twice that I know of at Beech/Ratheon/
Hawker-Beech. In no instance were we able to
integrate these products into either legacy or
current design goals for TC aircraft.
These devices are intended for integration inside
a product where their unique issues of wiring
(20AWG solid wires soldered to ECB), mounting for
vibration resistance, self-resetting, etc could
be smoothly integrated into the product.
None of the studies lasted more than a couple
of days before we agreed that they're fine
in a clock radio or toaster . . . or even
some automotive applications.
My cars use poly-fuses in series with the
window lift motors. They are used in lieu
of limit switches for actuator travel. In this
case, the lift mechanism hits a hard mechanical
stop at travel limits whereupon you are expected
to release the switch. But if you continue to hold
the switch for say 30 seconds. You'll find that
the motor mysteriously goes dead. You'll have to
wait a minute or two for the polyswitch to cool
off before the system ops return to nomral.
Interestingly enough, the polyswitch does not
protect the window lift motor feeders from the
bus. There's still a fuse in that slot.
They're a fine product and perform as advertised
in gazillions of situations. But they were never
intended for and do not integrate well into
general protection of power distribution feeders off
a bus. This is especially true of aircraft when the
owner-operator wants to be aware of any fault that
generates a trip so that the difficulty can be
accommodated (plan b) and fixed on the ground.
The only instances I've observed attempts
to pull this off are on EXP-Bus and on Richter's
proposed product described in the articles
cited in the above literature search.
Bob . . .
Message 6
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| Subject: | Re: Duracells again... |
Thanks for the feedback, Bob. That old volt meter was a good one and
had sentimental value. It's still in my workshop trash can so I think
I'll send it in to see what happens. It will only cost me the price of
postage.
Can you point me to a link at Duracell that addresses this return
procedure?
Deke
Message 7
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| Subject: | Re: Duracells again... |
<snip>
>With the exception of Eveready I have watched pretty much every
>other brand of alkaline battery run down the assembly lines at the
>Duracell factory. This includes Ray O Vac and many of the brands
>mentioned in several of the battery life studies. My guess is when
>you buy any alkaline battery other than Eveready you are assuming a
>50-60% probability that it came down the same assembly line as the
>Duracell you replaced with it. Only difference is that the
>marketers of the el cheapo ain't gonna replace your mag lite when it leaks.
>
>Given the billions of batteries sold the number of leakers that leak
>within the expected battery life is miniscule. It just seems like a
>lot when it gets our favorite maglite.
Milt. Thank you so much for your insight on this topic.
A similar discussion on battery contactors came up many
years ago . . . don't recall if it was Compuserve AVSIG
or here on this List.
Folks were bad-mouthing the el-cheeso contactors that
I was selling which were descendants of the RBM Controls
that put batteries into the first S.E. TC aircraft back
in the 40s.
Ask any mechanic how many of these contactors . . .
http://www.aeroelectric.com/Pictures/Contactors/s701-1l.jpg
are replaced in comparison to these contactors . . .
http://www.aeroelectric.com/Pictures/Contactors/6041_Contactor.jpg
and they universally state . . . "Oh man! We replace those
tin cans 10x more often than the gold plated ones." What's
seldom asked and answered or even investigated is what are
the flight hours on both styles of device when replacement
is made . . . and what is the fielded population of both
contactors?
I'm certain that in the big picture, the el-cheeso
contactor does not suffer failure rates so great that one is
encouraged to replace it with a device that costs 10x as
much. It's a matter of cost of ownership versus risk in
a marketplace so large that perfectly ordinary failure rates
make the el-cheeso contactor look like trash.
I've suspected . . . and your own observations confirm . . .
that the Duracell folks who buy $millions$ in VERY effective
advertising are suffering from success. Their market penetration
is so huge (like comparing Cessna+Piper versus Beech+Mooney) that
taking a telescopic, narrow view of failure rates will
yield distorted perceptions.
We've had similar discussions on $value$ of various
brands of alternators . . . particularly those that are
artfully re-manufactured. I visited a reman operation in
California/Mexico a year or so ago. Once a particular
brand of alternator passes through a MPA facility, it's
now an MPA part no matter who manufactured it originally.
When I asked the chief engineer at MPA, "Who makes the best
stock alternator?", he admitted to not having a clue. He
said something to the effect, "We do the best we know how
to do on every part that passes through our facility. Once
it leaves here, it's OUR part. We don't see any extra-ordinary
failure rates that can be attributed to the original
manufacturers. So I cannot tell you nor would I even care
who is king-of-the-hill for new parts. My job is to make
every MPA product worthy of our customer's branding . . .
of which there are DOZENS."
I suspect that an artfully crafted study of the alkaline
battery market would produce similar revelations. Thanks
for sharing.
Bob . . .
Message 8
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| Subject: | Re: Z-14 Switch Combos |
At 10:00 AM 1/4/2010, you wrote:
><bob.condrey@baesystems.com>
>
>Phil,
>
>There isn't anything bad that will happen regardless of switch
>positions for Z-14 as depicted in the stock diagrams. You've got 2
>bus power switches and either can be on or off irrespective of the
>other (they are isolated). Further, the x-feed switch can be on
>even if both alternators are online with no ill effect (at least
>with B&C externally regulated devices).
There are no "gotchas" lurking in the design
or operation of Figure Z-14 . . . nothing is
at risk for damage due to mis-positioning of
switches.
Bob . . .
Message 9
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| Subject: | Re: Questions about circuit protection |
>Wire the E-Bus diode directly to the main power bus without a
>switch. An avionics master switch makes it convenient to shut off
>all of the avionics at once. But when it fails, so will everything
>connected to it. In addition, individual downstream switches will
>not get exercised, leading to corrosion and eventual failure of
>seldom used switches.
True with one minor exception. Assuming one adds an "avionics master switch"
in series with the normal feed path diode, it's still backed up by the
alternate feed path switch. So its addition doesn't offer an increased
risk for loss of the bus. Both the AV master and E-bus Alt Feed switches
will get operated once per flight cycle as a part of pre-flight . . .
so corrosion from dis-use is not a concern either.
Otherwise . . . well stated sir.
Bob . . .
Message 10
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| Subject: | Re: Max Alternator Voltage ? |
At 10:28 PM 1/3/2010, you wrote:
>John,
>A proper voltage regulator, whether mechanical or solid state, has
>temperature compensation built in. The lower the ambient
>temperature the higher the charging voltage allowed from the
>alternator. Essentially, the colder the battery, the higher the
>charging voltage must be to get the proper chemical reaction with in
>the battery. In really hot weather, you will see the reverse; could
>see the charging voltage drop to under 13 volts.
We used to see temperature compensation of regulators
when they were external to the alternator. Even the old
electro-mechanical generator regulators had bi-metal springs
to stiffen the spring rate at cold temps.
As soon as the regulators moved inside the alternator,
the regulator's sense of battery environment was
clouded by alternator heating. We considered built
in compensation on the B&C regulators and rejected
the idea as greater potential for problems than
potential for benefit.
I suspect that the phenomenon Ron is reporting
has more to do with a regulator problem than an
expected reaction to temperature.
Bob . . .
Message 11
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At 06:04 PM 1/3/2010, you wrote:
>Bob,
>I didn't take it personally. But, I do hate bullies and "my way is
>the only right way" types. And bullies can appear in print as well
>as in person. I am not bashful about responding to what I perceive
>as bullying. The people on this forum are intelligent, learned
>people. There are ways to present one's ideas to the group without
>acting bullish.
>I relish responding to bullies.
But is it fair/wise to assign motivation to what
may be a simply passionate outpouring of ideas
and encouragement? Some folks have no doubt labeled
me a bombastic and narrow minded. I've certainly
been accused of dishonorable motivations on numerous
occasions. I responded to Jerry's posting with some detail
. . . I didn't feel that his offering was demeaning
or contrary to the best interest of folks on the
List.
I recall that some individuals were given
miles of ribbon here on the List . . . which
they capably used to tie up a package of their true
colors over YEARS. I'll suggest it's useful to allow all
contributors to validate membership on the
List by our thoughtful responses to their words.
A vigorous response to poorly interpreted impressions
have a risk of being unnecessarily hurtful now and
embarrassing later.
Bob . . .
>Stan Sutterfield
>Do not archive
> >Jerry,
> >All interesting information.
> >But, your assumption is that you are the only safety conscious one
> >on the forum and the rest of us are idiots. That simply is not the
> >case. (If you doubt this comment, then refer to your comments below
> >"I have a plan" and "overly complicated equipment and redundant
> >backup systems, much of which you barely understand.")
> >I wonder - why you think the rest of us are stupid?
>
> <snip>
>
> Gently my friend. Why do you take this as a
> personal attack? This is a forum for the exchange
> of ideas, crafting elegant design goals and the
> perfection of recipes for success.
>
> Please speak to ideas in the light of what I
> cited above. There's no reason for or value
> in pitching cabbages, tomatoes or rocks at
> each other.
>
> Bob . . .
>
>
Bob . . .
////
(o o)
===========o00o=(_)=o00o========
< Go ahead, make my day . . . >
< show me where I'm wrong. >
================================
Message 12
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| Subject: | Re: Max Alternator Voltage ? |
At 09:55 1/4/2010, you wrote:
>I suspect that the phenomenon Ron is reporting
> has more to do with a regulator problem than an
> expected reaction to temperature.
>
> Bob . . .
Thanks for reading the post Bob.
Not sure I was reporting a problem, all's well with me,
but rather attempting to provide some guidance WRT charge voltages,
as suggested by battery manufacturers'...
Ron Q.
do not archive
Message 13
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| Subject: | Questions about circuit protection. |
At 03:01 PM 1/2/2010, you wrote:
>
>Hi Bob;
>
>I think some of us may be dealing with conflicting information from two
>respected sources, yourself and in some cases the manufacturers. Garmin and
>Grand Rapids for example specify their equipment to be off during starter
>engagement, the Grand Rapids units do not have an on/off switch and as we
>have recently learned the GTX 327 may not really be off just because you
>selected off, and the use of a "A" bus is mentioned in the install manual.
>So in Matt's defense it may not be his following an "ill conceived notion"
>as you mentioned, but a desire to serve two masters.
It's an unfortunate condition of our culture that
so many exceedingly talented and capable suppliers
of products are so ignorant of the environment to
which they market.
There's a mountain of analysis, laboratory and field
testing that promulgated DO-160 and Mil-Std-704 along
with a host of other design guides for DC electrical
systems. At the same time, the "starter spike"
bug-a-boo is one of those deeply held beliefs that
is simply not supported by data.
Nevertheless, manufacturers of devices with
transistors in them seem to embrace some sort
of fragility in their own products after they
spent buckets of money to certify them into
the type-certificated aircraft environment.
I have designed dozens of products and put my
hands on hundreds more that were just as complex
and potentially 'fragile' as the panel mounted
radios . . . yet NONE of these manufacturers
suggest that the pilot pull a breaker on the
device while cranking the engine. Somehow, as
soon as the electro-whizzy is mounted to the
panel where the pilot can see it . . . it's
suddenly worthy of special protection from a
risk that (1) doesn't exist and (2) the product
has been demonstrated to withstand even if it
did exist.
I'll invite anyone on the list to contact the
manufacturer of any product where the operating
manual calls for turning it off during cranking.
Ask them to identify the waveform, magnitude
and duration of any cranking transient that
exceeds their DO-160 certification testing.
I've done this many times over 30 years. I've
never had a lucid defense of the idea. In a few
cases (King and Terra) the guy said, "yeah,
it's all B.S. . . . but we've been doing it
for decades and nobody wants to change it.
So I leave it up to you. If adding a switch to
the normal feed path diode makes you feel
better, by all means do it. It doesn't add
risk because the alternate feed path switch
backs it up.
Bob . . .
Message 14
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| Subject: | Re: Z-14 Switch Combos |
Phil, that's been my understanding too but I have no actual experience.
Bob C. here knows what he's talking about.
Bill
bcondrey wrote:
>
> Phil,
>
> There isn't anything bad that will happen regardless of switch positions for
Z-14 as depicted in the stock diagrams. You've got 2 bus power switches and either
can be on or off irrespective of the other (they are isolated). Further,
the x-feed switch can be on even if both alternators are online with no ill
effect (at least with B&C externally regulated devices).
>
> Bob
> RV-10 N442PM (flying with Z-14)
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=280027#280027
>
>
>
Message 15
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| Subject: | Re: Questions about circuit protection |
user9253 wrote:
>
> Schu,
>
> No switch is shown for the Hobbs meter. I assume that an oil pressure switch
will be connected in series with it.
>
> The diode across the E-Bus relay is backwards.
>
> The spike protection diode is missing from the dynamo relay coil. The arrow
should point towards positive.
>
> No over-voltage protection is shown for the main alternator. Over-voltage protection
will do more towards safeguarding avionics than an avionics master switch.
>
> Since there are only two devices connected to the avionics bus, an avionics bus
is not needed. Just connect those two devices to the switch without having
a bus. Better yet, use two switches. If one of the devices starts smoking,
you can shut it off and continue to use the other. Wire the E-Bus diode directly
to the main power bus without a switch. An avionics master switch makes it
convenient to shut off all of the avionics at once. But when it fails, so will
everything connected to it. In addition, individual downstream switches will
not get exercised, leading to corrosion and eventual failure of seldom used
switches.
>
> Fuses offer better protection than circuit breakers. And fuses are less expensive.
Yes, more than one load can be connected to a fuse or circuit breaker.
But if one of the loads shorts out, it will blow the fuse and remove power from
the other loads. It is better to install a larger fuse block so that each
load can have its own fuse. Regulations for type certificated aircraft require
that critical fuses be replaceable in flight. However, it is better not to
have any critical equipment. Backup equipment makes critical devices non-critical.
Fuses should be replaced on the ground, not in the air.
>
> I like your schematic. What program do you use to draw it and to convert it
a pdf?
>
> Joe
>
>
Joe,
Thanks for your helpful comments.
I would like to get an oil pressure switch for the hobbs (and for an
idiot light) but I don't know where to source that. I looked around at
Aircraft Spruce but didn't find anything. Do you know where I can find
this?
Thanks for finding the diode issues. I'll correct them in the drawing.
There is over voltage protection internal to the main alternator since
it is a plane power unit.
The schematic was written in visio with the aeroelectric stencil set:
http://www.lucubration.com/open-source-projects/aeroelectric-visio-symbols.html
Converting to pdf is a little bit more involved but not bad (right
Tim?). Simply install any postscript compatible printer (I like the
apple color laser PS models), then tell windows that the port used is
"save as file." When you print to that printer then it will prompt you
for a file name, call the file drawing.ps or whatever, then use a
postscript to pdf converter to make the pdf. A free online one is
http://ps2pdf.com . The advantage to doing it this way is postscript is
a vector based image not raster. This means that it isn't a 'picture'
as much as a set of points what the printer fills in (not unlike a cad
file.) This is why the file size is so small and why you can zoom in as
close as you want and the edges are still sharp. The pdf viewer can
re-render the image at any ratio.
Clear as mud?
schu
Message 16
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| Subject: | Re: Questions about circuit protection. |
Robert L. Nuckolls, III wrote:
> I'll invite anyone on the list to contact the
> manufacturer of any product where the operating
> manual calls for turning it off during cranking.
> Ask them to identify the waveform, magnitude
> and duration of any cranking transient that
> exceeds their DO-160 certification testing.
Are the experimental avionics from Advanced Flight Systems, TruTrak
Flight Systems, Dynon Avionics, and Grand Rapids certified to DO-160?
I'm running the AFS box and don't see anything in the manual about
starting, but I do see this:
"All aircraft must have protection diodes installed on their Master
Relay, Starter Relay and any other large relay. If your aircraft does
not have the protection diode on the Master Relay your electrical buss
will experience a voltage spike of 500+ Volts every time you turn off
the master switch. If your EFIS or Engine Monitor is wired directly to
the electrical buss it will be the device that absorbs the voltage spike
and will eventually fail. All users must verify that they have the
protection diodes installed before powering the EFIS or Engine Monitor."
schu
Message 17
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| Subject: | Re: Question about 16V POLYFUSER Radial Leaded Resettable |
PTC Available at Digi-Key
Hi Jeff
I designed and have been using an electrical system similar to the EXP
bus for over a year, for no reason other than experimentation. I chose
a variety of these, ranging from 1A up to 16A... They work as
advertised, and have found their trip performance similar to that of
CB's, i.e. a 2A polyswitch probably won't trip at 2A, unless the
device draws 2A for minutes almost. 2.5A will trip after a few
seconds, 5A will trip after a second, and 100A will trip almost
instantaneously.
However, as has been mentioned by a fellow respondent, if your
downstream device is something like an EFIS, or a device with an
intelligent power supply that turns off when the supply voltage drops
below a threshold, the polyswitch will probably reset itself, as the
current draw that it sees goes to 0A and it cools down. To fix this,
you need to add a dummy load with enough current flowing through it to
keep the polyswitch tripped until you cycle the power to it manually.
As soon as you start adding in this functionality, you need to start
weighing up the added complexity of many failure-prone components, on
one failure-prone fiberglass sheet, with micron-thick failure-prone
copper tracking, against a couple robust tefzel wires crimped and
bolted onto a robust CB... As an electrical engineer (yes, I've been
following the Engineers in the real-world discussion!) and I'm a fan
of blinking lights and push buttons when it affords me the opportunity
to get some experience designing something more complex than a
matchbox. However I fly VFR by day only and have complete steam backup
and a handheld radio, so if I lose all electrics, it has no impact on
my ability to complete the flight safely and with no discomfort.
So to answer your questions, yes I think they can replace CB's or
standard fuses, but I don't think they should. The fact that they
reset themselves whenever power is cycled means that a tripped system
will not stay tripped if you turn off the master switch. Standard
fuses are much better-suited to the task. And that's in my humble
opinion ;-)
Thanks
Etienne
On 04 Jan 2010, at 5:41 AM, Jeffrey W. Skiba wrote:
> I just noticed these at digikey web site as a new product=85.
>
> Looks like one could use these instead of fuses or the traditional
> circuit breakers (for the average range of protection)
>
> But my question is do these trip the same as typical fuses ? I know
> they can reset but would it work like a fuse for time to trip or
> protection of the wire ?
>
> Catalog page:
>
http://media.digikey.com/pdf/New%20Cat%20Page/101/Littelfuse/Polyfuse%20PT
C%20Reset%20Devices.pdf
>
>
> Here is a link to the Data sheet
>
> http://www.littelfuse.com/data/en/Data_Sheets/Littelfuse_PTC_16R.pdf
>
> it looks like they are used in a max volts of 16v (good, my system
> runs at 13.8 volts)
>
> and they have ones that range from: 2.5a to 14a
>
>
> Price looks cheap
>
> Light weight
>
> Small in size
>
> Other thoughts ' comments ' concerns ?
>
> Thanks
>
> Jeff
>
>
Message 18
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| Subject: | Re: Questions about circuit protection |
user9253 wrote:
> The spike protection diode is missing from the dynamo relay coil. The arrow
should point towards positive.
Joe,
I looked at the dynamo relay coil but it is wired exactly as shown in
Z-25 and Z-13/8.
Bob, I would be very grateful if you could explain what the two diodes
are for on the self exciting SD-8 drawing since since they are wired
differently than the other relays.
Thanks,
schu
Message 19
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| Subject: | Re: Simplicity and circuit protection |
At 07:16 PM 1/2/2010, you wrote:
I've always agreed that breakers can be useful, but not because they
can be reset after they automatically trip.
On both the military aircraft and passenger jets I've flown, the most
useful thing about circuit breakers was always:
1) the ability to manually trip them when smoke starts pouring out of
a system which is still powered (happened once to a colleague of mine).
Certainly possible but exceedingly low risk. It
also presumes the pilot can identify the specific
system.
2) the ability to pull then reset non-tripped breakers, usually under
engineering guidance, to get a glitchy system to restart itself.
Not unusual in a revenue generating environment
manned by professionals. But after a couple
of "glitches" in my OBAM aircraft electro-whizzy,
I think I'd be sending it back to the factory
for a fix or my money back.
For 25 years in my experience, resetting an already tripped breaker
was discouraged or prohibited by SOPs in most circumstances, ground
or flight, until maintenance action was carried out. I'm not sure why
this concept should be a surprise to anyone.
Just read the dark-n-stormy night stories offered
in the so-called aviation education journals. When
electrical systems issues are part of story, there's
plenty of breaker pulling, switch flipping and
real time mis-interpretation of symptoms that
drive the story-teller's probability of success
(both UP and DOWN) during his/her narrow escape.
As a professional, you had a different set of
teachers than did us lowly tin-can drivers. Unless
a pilot takes a special interest in understanding
things like failure mode effects analysis and
deducing actions that are useful or at least
don't make things worse, then the outcome
is problematic. To make matters worse, those
who publish such stories seem never offer a de-briefing
and lessons-learned study by teachers who DO
understand the system. (See chapter 17 of the
'Connection) The 'education' may be worse than
having not printing the story in the first place.
It is difficult to perform to standards any greater
than our level of education makes possible.
Bob . . .
Message 20
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| Subject: | Re: Questions about circuit protection |
Schu,
Thanks for the info about using Visio.
As for an oil pressure switch, your engine needs an oil pressure port and the switch
threads would have to match. I do not know where to buy it.
There was a recent discussion on AeroElectric about Hobbs meters. Read what others
said:
http://forums.matronics.com/viewtopic.php?t=66204&highlight=hobbs
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=280101#280101
Message 21
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| Subject: | Re: Z-14 Switch Combos |
At 09:08 PM 1/2/2010, you wrote:
>I'm getting a handle on Z-14 from an operational perspective and
>have a couple of questions about the switch combinations that could
>create issues.
>
>Obviously with the added complexity of managing two batteries, two
>alternators, and a cross feed can create some interesting combinations.
>
>Are there any combo's that we should be aware of that would create
>over voltage or any other scenarios of concern?
>
>In the event of a failure (for example Alt 2 failure), is there a
>specific order for shutting off the bad alt and then enabling the cross feed?
No . . . there's no risks for any 'mis management' of
switches. But you may not close the cross-feed ever.
Depending on what YOU power from each of the two busses,
how YOU use the airplane and which alternator quit, you
need to re-configure the system to maximize probablity
of a no sweat arrival at airport of intended destination.
This MIGHT call for immediate closure of the cross-feed
(but probably not). Or it might remain open with one
bus shut down completely until airport is in sight.
Z-14 is just a fancier version of Z-13/8 which is a
fancier version of Z-11 with an E-bus. The level
of fanciness only drives your decisions on best
utilization of limited resources for engine driven
power. That procedure is something that you have
to develop.
Bob . . .
Message 22
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| Subject: | Re: Simplicity and circuit protection |
At 02:42 PM 1/2/2010, you wrote:
>The FAA has just released SAIB CE-10-11 "Electrical: Fire Hazard in
>Resetting Circuit Breakers" for operators of TC aircraft and
>transports, but the implications of it gives Bob's advice that much
>more teeth, IMHO. To summarize, the Feds are recommending that
>circuit breakers NOT be reset once they trip except under specific
>circumstances. The complete SAIB can be found here:
>
><https://www.faasafety.gov/files/notices/2009/Dec/SAIB_CE-10-11.pdf>https://www.faasafety.gov/files/notices/2009/Dec/SAIB_CE-10-11.pdf
>
>
> So, if you shouldn't reset them, what good are they?
Exactly what they were designed for . . . keep a single
system fault from propagating to other systems or more
serious symptoms. In hindsight, we would have been
better off since day-one had TC aircraft designers
had be chartered to design for failure tolerance (el-
cheeso parts not necessarily poor value) as
opposed to failure avoidance (gross reliability).
After all, the earliest electrical systems were
pure automotive bolt-on hardware. Not necessarily
evil but they could have evolved in more practical
directions if we had no placed them on pedestals
and started certifying their socks off.
If I were chartered to craft a system with breakers
I'm pretty certain I'd figure out a way to make
the breaker panel just as inaccessible as the fuse
blocks. This forces the design off in new and
more useful directions.
Bob . . .
Message 23
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| Subject: | Re: Questions about circuit protection |
> I looked at the dynamo relay coil but it is wired exactly as shown in
> Z-25 and Z-13/8.
Schu,
It looks like I was wrong about the diode missing from your dynamo relay coil.
The over-voltage protection probably shorts out any spike and thus the diode
is not needed.
As for the two diodes, they isolate the two power sources from each other. The
dynamo is one source and the other source is a combination of the battery and
main alternator.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=280106#280106
Message 24
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| Subject: | THE VIRTUE OF SIMPLICITY |
At 12:10 PM 1/2/2010, you wrote:
<ralphmariafinch@gmail.com>
To play the part of the loyal opposition:
Yes, but.
Do any of us really want to depend on one of the old cars for daily
transportation? I have memories, almost all bad, of the old
clunkers. I love my modern autos, turn the switch and they start and
run. Oil changes at greatly increased intervals, hardly any
"tune-ups" and such.
How does "simplicity" translate into "old" hardware or
degraded service life?
<snip>
These are, after all, experimental. Experiment as you wish. Let's
just be aware of all the costs of adding equipment.
BTW, I'm flying an Aircoupe now. When my RV-9A is finished I don't
think I'll notice a few extra pounds in comparison...and besides,
most of us Americans could easily make up for added equipment weight
by losing our spare tires
I think you missed the significance. The kind of
simplicity we strive for is the minimum cost, parts count,
weight and therefore maximum reliability of any one
system. If your design goals call for lots of bells
and whistles in your airplane, the minimalist rule
for selection of systems suggests that those accessories
with fewest components while meeting design goals are
a better value.
I'm having a good time designing accessories
with micro-controllers where software replaces a bucket-load
of components while allowing me to do more with fewer
parts. Capability goes up while parts count goes down.
I think this tread got started with a List member's
notions of adding more busses and switches to Z-13/8
followed by questions of design goals to be met
while doing so.
Bob . . .
Message 25
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| Subject: | Re: Questions about circuit protection |
Matt wont your EFIS track your hours for you? Maybe you don't need a Hobbs
at all. I know the GRT stuff does this, I believe it tracks engine and
flight time separately and automatically. I bet your AFS does as well.
Tim
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matthew
Schumacher
Sent: Monday, January 04, 2010 11:27 AM
Subject: Re: AeroElectric-List: Re: Questions about circuit protection
user9253 wrote:
<fran4sew@banyanol.com>
>
> Schu,
>
> No switch is shown for the Hobbs meter. I assume that an oil pressure
switch will be connected in series with it.
>
> The diode across the E-Bus relay is backwards.
>
> The spike protection diode is missing from the dynamo relay coil. The
arrow should point towards positive.
>
> No over-voltage protection is shown for the main alternator. Over-voltage
protection will do more towards safeguarding avionics than an avionics
master switch.
>
> Since there are only two devices connected to the avionics bus, an
avionics bus is not needed. Just connect those two devices to the switch
without having a bus. Better yet, use two switches. If one of the devices
starts smoking, you can shut it off and continue to use the other. Wire the
E-Bus diode directly to the main power bus without a switch. An avionics
master switch makes it convenient to shut off all of the avionics at once.
But when it fails, so will everything connected to it. In addition,
individual downstream switches will not get exercised, leading to corrosion
and eventual failure of seldom used switches.
>
> Fuses offer better protection than circuit breakers. And fuses are less
expensive. Yes, more than one load can be connected to a fuse or circuit
breaker. But if one of the loads shorts out, it will blow the fuse and
remove power from the other loads. It is better to install a larger fuse
block so that each load can have its own fuse. Regulations for type
certificated aircraft require that critical fuses be replaceable in flight.
However, it is better not to have any critical equipment. Backup equipment
makes critical devices non-critical. Fuses should be replaced on the
ground, not in the air.
>
> I like your schematic. What program do you use to draw it and to convert
it a pdf?
>
> Joe
>
>
Joe,
Thanks for your helpful comments.
I would like to get an oil pressure switch for the hobbs (and for an
idiot light) but I don't know where to source that. I looked around at
Aircraft Spruce but didn't find anything. Do you know where I can find
this?
Thanks for finding the diode issues. I'll correct them in the drawing.
There is over voltage protection internal to the main alternator since
it is a plane power unit.
The schematic was written in visio with the aeroelectric stencil set:
http://www.lucubration.com/open-source-projects/aeroelectric-visio-symbols.h
tml
Converting to pdf is a little bit more involved but not bad (right
Tim?). Simply install any postscript compatible printer (I like the
apple color laser PS models), then tell windows that the port used is
"save as file." When you print to that printer then it will prompt you
for a file name, call the file drawing.ps or whatever, then use a
postscript to pdf converter to make the pdf. A free online one is
http://ps2pdf.com . The advantage to doing it this way is postscript is
a vector based image not raster. This means that it isn't a 'picture'
as much as a set of points what the printer fills in (not unlike a cad
file.) This is why the file size is so small and why you can zoom in as
close as you want and the edges are still sharp. The pdf viewer can
re-render the image at any ratio.
Clear as mud?
schu
Message 26
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| Subject: | Question about 16V POLYFUSER Radial Leaded Resettable |
PTC Available at Digi-Key
Polyfuses only reset themselves IF the cause that made them to trip
disappears.
Carlos
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Ron
Quillin
Sent: segunda-feira, 4 de Janeiro de 2010 4:28
Subject: Re: AeroElectric-List: Question about 16V POLYFUSER Radial Leaded
Resettable PTC Available at Digi-Key
At 19:41 1/3/2010, you wrote:
Looks like one could use these instead of fuses or the traditional circuit
breakers (for the average range of protection)
But my question is do these trip the same as typical fuses ? I know they can
reset but would it work like a fuse for time to trip or protection of the
wire ?
Are we sure we want a device that can reset itself?
Doesn't that pretty much violate the premise of not resetting a tripped
breaker?
http://www.littelfuse.com/design/literature/fuse-vs-ptc/resettable-ptcs.html
Message 27
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| Subject: | Re: Questions about circuit protection |
Tim Andres wrote:
>
> Matt wont your EFIS track your hours for you? Maybe you don't need a Hobbs
> at all. I know the GRT stuff does this, I believe it tracks engine and
> flight time separately and automatically. I bet your AFS does as well.
> Tim
It does, but I want something more reliable than the EFIS, and it also
serves as total time which is nice, but your right, I can go without it.
schu
Message 28
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| Subject: | Re: Questions about circuit protection. |
>
>Are the experimental avionics from Advanced Flight Systems, TruTrak
>Flight Systems, Dynon Avionics, and Grand Rapids certified to DO-160?
Don't know if they're "certified" . . . i.e. have conducted
formal testing for which a report is produced.
In any case, they should certainly be DESIGNED to DO-160
limits and capabilities. First, because its a good thing
to do and secondly, because it's an easy thing to do.
>I'm running the AFS box and don't see anything in the manual about
>starting, but I do see this:
>
>"All aircraft must have protection diodes installed on their Master
>Relay, Starter Relay and any other large relay. If your aircraft does
>not have the protection diode on the Master Relay your electrical buss
>will experience a voltage spike of 500+ Volts every time you turn off
>the master switch. If your EFIS or Engine Monitor is wired directly to
>the electrical buss it will be the device that absorbs the voltage spike
>and will eventually fail. All users must verify that they have the
>protection diodes installed before powering the EFIS or Engine Monitor."
This is hogwash. When a relay's coil is un-suppressed, the
energy stored on the coil's magnetic core is dissipated
in the highest impedance portion of the loop. The bus
structure's impedance is a tiny fraction of that which
appears across the spreading contacts of the controlling
switch or relay. Further, consider that while the spike
from a coil collapse can be large, as an energy source
its ability to transfer energy is limited to the same
current that energizes the relay. For example, suppose
you DID have a 500v battery that was absolutely limited
to 1 amp of output current. Now, connect that battery
across the bus that's got several amps of load already
present along with a battery and several capacitors
inside sundry appliances. Folks like to cite that
500v spike without telling you that its current delivery
is limited to 1A. I.e. it's trivial to all devices except
the controlling switch.
This is stone simple to demonstrate in the lab, on an
airplane or in any dc powered vehicle. Who ever wrote
those words was simply repeating something they'd been
misled into writing.
Bob . . .
Message 29
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| Subject: | Re: Questions about circuit protection |
Whenever this "fuses versus circuit breakers" discussion comes afloat, I
always wonder why TC aircraft always used circuit breakers.
Carlos
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-
> server@matronics.com] On Behalf Of user9253
> Sent: segunda-feira, 4 de Janeiro de 2010 16:47
> To: aeroelectric-list@matronics.com
> Subject: AeroElectric-List: Re: Questions about circuit protection
>
<fran4sew@banyanol.com>
....... snip .....
>
>
> Fuses offer better protection than circuit breakers. And fuses are less
expensive.
> Yes, more than one load can be connected to a fuse or circuit breaker.
But if one
> of the loads shorts out, it will blow the fuse and remove power from the
other loads.
> It is better to install a larger fuse block so that each load can have its
own fuse.
> Regulations for type certificated aircraft require that critical fuses be
replaceable in
> flight. However, it is better not to have any critical equipment. Backup
equipment
> makes critical devices non-critical. Fuses should be replaced on the
ground, not in
> the air.
>
>
> Joe
>
Message 30
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| Subject: | THE VIRTUE OF SIMPLICITY |
I think you missed the significance. The kind of
simplicity we strive for is the minimum cost, parts count,
weight and therefore maximum reliability of any one
system.
I think you missed my point. For example, the OP equated simplicity with
less weight, which might be literally true but is irrelevant, because the
weight saved is probably trivial. That's a notion from value
engineering...those evil and arrogant engineers again.
Minimum cost? Minimum parts count? Really? The least cost, greatest
simplicity, maximum safety, minimum parts count, and least weight, is...no
plane at all. Seriously. Absurd? Probably, but it makes the point that it's
foolish to use "minimum", "maximum", and similar extreme or unbalanced terms
in a discussion like this.
If your design goals call for lots of bells
and whistles in your airplane
No. Don't be silly. My design goals include better reliability, ease of use,
and maintenance than certificated aircraft, balanced with cost
considerations. To achieve those goals I will use modern systems where I
think appropriate. It doesn't include gizmotrons for the sake of gadgetry,
or saving a few pounds because the "airplane will perform better". Other
friends of mine have different goals, or perhaps the same goals but
different decisions to arrive at the same goals.
I'm having a good time designing accessories
with micro-controllers where software replaces a bucket-load
of components while allowing me to do more with fewer
parts. Capability goes up while parts count goes down.
I'm sincerely glad to hear this. I would be quite interested if you
provided lessons in two related areas:
1. How to design the few conventional electrical parts a microcontroller
needs, that is, the resistors, inductors, caps and perhaps transistor or two
needed.
2. Basic programming of a microcontroller. I'm comfortable with programming
several high-level languages, and years ago knew some assembly, but a class
or lessons would be great. I'd be very willing to pay for a well-designed
set of lessons for this knowledge.
At this time--a couple of years before I actually must decide--I intend to
use Vertical Power's electrical system to wire my aircraft. Many
electromechanical devices are replaced with a few solid-state devices and
software...approaching what cars have had for decades. I consider it a
significant step towards greater simplicity, fewer parts, less weight, and
greater reliability. Of course many differ. I know builders who consider
round gages the way to go for greater reliability; to each their own in the
OBAM world.
I think this tread got started with a List member's
notions of adding more busses and switches to Z-13/8
followed by questions of design goals to be met
while doing so.
I'll take your word for it. The OP's post didn't say anything about that.
BTW Bob, have you thought about memristors, and how they might change
electrical/electronic design (not just for aircraft systems, but in
general). They are the fourth, long forgotten basic electrical component,
just now coming into practical use. I wonder how much of a change in design
and future device capability they might start.
__________ Information from ESET Smart Security, version of virus signature
database 4742 (20100104) __________
The message was checked by ESET Smart Security.
Message 31
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| Subject: | Re: Question about 16V POLYFUSER Radial Leaded Resettable |
PTC
See AC 43.13, chapter 11 quoted below:
11-50. RESETTABLE CIRCUIT PROTECTION
DEVICES.
a. All resettable type circuit breakers
must open the circuit irrespective of the position
of the operating control when an overload
or circuit fault exists. Such circuit breakers are
referred to as trip free.
b. Automatic reset circuit breakers, that
automatically reset themselves periodically, are
not recommended as circuit protection devices
for aircraft.
--------
Marc Ausman
http://www.verticalpower.com "Move up to a modern electrical system"
RV-7 IO-390 Flying
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=280156#280156
Message 32
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| Subject: | Z-14 Switch Combos |
So we were on a good path until, "But you may not close the cross-feed
ever."
If that's the case, what good is the cross-feed if the switch is off
limits??? I think your intentions were to say only in an emergency when
it is required?
Let's looks a scenario where I forget to open the cross-feed after
start. The other two contactors for the Alt/Batt are closed too. What
are the effects of the electrical system for prolonged cross-feed
closure on a cross country tour across the southern states? Any battery
damage?
My guess is that the alternators would be shedding load back and forth
for the flight and never stabilize.
I think I'm getting closer to understanding it. I just want to make
sure I understand everything operationally before I dedicate myself to a
specific diagram only to be disappointed later.
Thanks again for your help,
Phil
-----Original Message-----
From: Robert L. Nuckolls, III [mailto:nuckolls.bob@aeroelectric.com]
Sent: Monday, January 04, 2010 2:07 PM
Subject: Re: AeroElectric-List: Z-14 Switch Combos
<nuckolls.bob@aeroelectric.com>
At 09:08 PM 1/2/2010, you wrote:
>I'm getting a handle on Z-14 from an operational perspective and
>have a couple of questions about the switch combinations that could
>create issues.
>
>Obviously with the added complexity of managing two batteries, two
>alternators, and a cross feed can create some interesting combinations.
>
>Are there any combo's that we should be aware of that would create
>over voltage or any other scenarios of concern?
>
>In the event of a failure (for example Alt 2 failure), is there a
>specific order for shutting off the bad alt and then enabling the
cross feed?
No . . . there's no risks for any 'mis management' of
switches. But you may not close the cross-feed ever.
Depending on what YOU power from each of the two busses,
how YOU use the airplane and which alternator quit, you
need to re-configure the system to maximize probablity
of a no sweat arrival at airport of intended destination.
This MIGHT call for immediate closure of the cross-feed
(but probably not). Or it might remain open with one
bus shut down completely until airport is in sight.
Z-14 is just a fancier version of Z-13/8 which is a
fancier version of Z-11 with an E-bus. The level
of fanciness only drives your decisions on best
utilization of limited resources for engine driven
power. That procedure is something that you have
to develop.
Bob . . .
Message 33
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|
This is off the aero electric topic but I thought that I would pass
along a reminder that the paper pilot certificates become invalid I
believe sometime in March. Also, if you do have the new plastic
certificate make sure that you have the "English proficient" endorsement
on the back and if not it's just $2.00 to get a new one. Service has
been pretty quick from the FAA.
Bill
Glasair SIIS-FT
Message 34
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| Subject: | Re: GTX337 ON or OFF? |
The GTX-327 in my plane has the same undesirable behavior. I called Garmin
who said it was due to harness wiring and I should call Stark Avionics, who
I bought the thing from. John Stark says they wire the connector assuming
there is going to be an avionics master switch, which he strongly
recommends. I am convinced by Bob K. that the avionics master is not
necessary. John tells me that the fix (which I haven't tried yet) is to cut
the wire to pin 1 on the connector and cover up the loose wire with heat
shrink or something so it won't short to anything.
I wish I'd known this when the thing was easier to get at. It's fully
installed now. Sigh.
On Fri, Jan 1, 2010 at 12:22 PM, <bakerocb@cox.net> wrote:
>
> 1/1/2010
>
> Hello Allen Fullmer, You wrote:
>
> "........skip.....I have also noticed that the GTX337 transponder cannot be
> set to remain off when power is supplied. It will remain in the standby
> position but, once again, when I am playing and fiddling around I just hate
> to see it go up and down unnecessarily. Haven't decided on a switch for it
> or not."
>
> I also can not program my GTX327 to remain OFF when power is applied or
> reapplied to the avionics buss.** But the GTX327 has some options on which
> pins electrical power can be supplied to. If you pick the correct pin(s) the
> box will remain OFF until you push the ON button on the face of the box.
>
> I suspect that the GTX337 may be built the same way. So if you desire, and
> have the capability, you could rewire your GTX337 so that it would remain
> OFF until you pushed the ON button on the face of the box.
>
> 'OC' Says: "The best investment we can make is the effort to gather and
> understand knowledge."
>
> **PS: I suspect that the person who wired my panel set it up that way so
> that it would take a very deliberate OFF button action on my part in order
> to take off with the transponder OFF. I am with you, I'd like to have total
> ON - OFF control of the box with the buttons on the face of the box.
>
>
--
Tom Sargent
Message 35
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| Subject: | Z-14 Switch Combos |
I believe that "may not..." should be translated as "may never have occasion
to", rather than "you must not do that". At least that's the way I read it.
William
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Perry,
Phil
Sent: Monday, January 04, 2010 2:35 PM
Subject: RE: AeroElectric-List: Z-14 Switch Combos
<Phil.Perry@netapp.com>
So we were on a good path until, "But you may not close the cross-feed
ever."
If that's the case, what good is the cross-feed if the switch is off
limits??? I think your intentions were to say only in an emergency when
it is required?
Let's looks a scenario where I forget to open the cross-feed after
start. The other two contactors for the Alt/Batt are closed too. What
are the effects of the electrical system for prolonged cross-feed
closure on a cross country tour across the southern states? Any battery
damage?
My guess is that the alternators would be shedding load back and forth
for the flight and never stabilize.
I think I'm getting closer to understanding it. I just want to make
sure I understand everything operationally before I dedicate myself to a
specific diagram only to be disappointed later.
Thanks again for your help,
Phil
-----Original Message-----
From: Robert L. Nuckolls, III [mailto:nuckolls.bob@aeroelectric.com]
Sent: Monday, January 04, 2010 2:07 PM
Subject: Re: AeroElectric-List: Z-14 Switch Combos
<nuckolls.bob@aeroelectric.com>
At 09:08 PM 1/2/2010, you wrote:
>I'm getting a handle on Z-14 from an operational perspective and
>have a couple of questions about the switch combinations that could
>create issues.
>
>Obviously with the added complexity of managing two batteries, two
>alternators, and a cross feed can create some interesting combinations.
>
>Are there any combo's that we should be aware of that would create
>over voltage or any other scenarios of concern?
>
>In the event of a failure (for example Alt 2 failure), is there a
>specific order for shutting off the bad alt and then enabling the
cross feed?
No . . . there's no risks for any 'mis management' of
switches. But you may not close the cross-feed ever.
Depending on what YOU power from each of the two busses,
how YOU use the airplane and which alternator quit, you
need to re-configure the system to maximize probablity
of a no sweat arrival at airport of intended destination.
This MIGHT call for immediate closure of the cross-feed
(but probably not). Or it might remain open with one
bus shut down completely until airport is in sight.
Z-14 is just a fancier version of Z-13/8 which is a
fancier version of Z-11 with an E-bus. The level
of fanciness only drives your decisions on best
utilization of limited resources for engine driven
power. That procedure is something that you have
to develop.
Bob . . .
Message 36
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|
| Subject: | Z-14 Switch Combos |
Phil -
I think you misinterpreted Bob's comment. It appears you read it to say
"you're never ALLOWED to close the cross-feed switch", when Bob meant "you
might not ever have a reason to close it".
Neal
<Phil.Perry@netapp.com>
So we were on a good path until, "But you may not close the cross-feed
ever."
If that's the case, what good is the cross-feed if the switch is off
limits??? I think your intentions were to say only in an emergency when
it is required?
Phil
Message 37
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| Subject: | Z-14 Switch Combos |
Phil and William;
My reading of the statement agrees with William's translation as well.
Bob McC
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-
> server@matronics.com] On Behalf Of William Slaughter
> Sent: Monday, January 04, 2010 10:39 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: Z-14 Switch Combos
>
> <william_slaughter@att.net>
>
> I believe that "may not..." should be translated as "may never have
occasion
> to", rather than "you must not do that". At least that's the way I read
it.
>
> William
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Perry,
> Phil
> Sent: Monday, January 04, 2010 2:35 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: Z-14 Switch Combos
>
> <Phil.Perry@netapp.com>
>
> So we were on a good path until, "But you may not close the cross-feed
> ever."
>
> If that's the case, what good is the cross-feed if the switch is off
> limits??? I think your intentions were to say only in an emergency when
> it is required?
>
> Let's looks a scenario where I forget to open the cross-feed after
> start. The other two contactors for the Alt/Batt are closed too. What
> are the effects of the electrical system for prolonged cross-feed
> closure on a cross country tour across the southern states? Any battery
> damage?
>
> My guess is that the alternators would be shedding load back and forth
> for the flight and never stabilize.
>
> I think I'm getting closer to understanding it. I just want to make
> sure I understand everything operationally before I dedicate myself to a
> specific diagram only to be disappointed later.
>
> Thanks again for your help,
> Phil
>
>
>
>
>
>
>
> -----Original Message-----
> From: Robert L. Nuckolls, III [mailto:nuckolls.bob@aeroelectric.com]
> Sent: Monday, January 04, 2010 2:07 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Z-14 Switch Combos
>
> <nuckolls.bob@aeroelectric.com>
>
> At 09:08 PM 1/2/2010, you wrote:
> >I'm getting a handle on Z-14 from an operational perspective and
> >have a couple of questions about the switch combinations that could
> >create issues.
> >
> >Obviously with the added complexity of managing two batteries, two
> >alternators, and a cross feed can create some interesting combinations.
> >
> >Are there any combo's that we should be aware of that would create
> >over voltage or any other scenarios of concern?
> >
> >In the event of a failure (for example Alt 2 failure), is there a
> >specific order for shutting off the bad alt and then enabling the
> cross feed?
>
> No . . . there's no risks for any 'mis management' of
> switches. But you may not close the cross-feed ever.
>
> Depending on what YOU power from each of the two busses,
> how YOU use the airplane and which alternator quit, you
> need to re-configure the system to maximize probablity
> of a no sweat arrival at airport of intended destination.
> This MIGHT call for immediate closure of the cross-feed
> (but probably not). Or it might remain open with one
> bus shut down completely until airport is in sight.
>
> Z-14 is just a fancier version of Z-13/8 which is a
> fancier version of Z-11 with an E-bus. The level
> of fanciness only drives your decisions on best
> utilization of limited resources for engine driven
> power. That procedure is something that you have
> to develop.
>
> Bob . . .
>
>
>
>
>
>
>
>
>
>
>
>
> _-
> ===================================================
> =======
> _-
> ===================================================
> =======
> _-
> ===================================================
> =======
> _-
> ===================================================
> =======
>
>
Message 38
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| Subject: | Re: Battery Bus Location |
At 08:17 AM 1/3/2010, you wrote:
>
>I'm working on locating items on the firewall and have a question on
>location of the alway hot battery bus. I know that there is a
>length limit on the wire powering this bus and with that in mind, it
>seems the ideal location for the fuse block is on the hot side of
>the firewall.
>
>Is this block and fuse combination okay to put on the hot
>side? Seems like it defeats the purpose of this bus if it's feeder
>line is fused and then put on the cool side of the firewall.
Where do you want to put it? Lots of fuse/relay boxes
go under the hood on cars. However, they're generally
covered. The Bussmann fuse-blocks are open. If
you want to put it inside, you can run the bus feeder
through the fire wall with some judicious attention
to support and insulation. Here's an example of a
small ceramic (thus fireproof) feed through insulator:
Emacs!
This one is available from
http://www.surplussales.com/antennas/antennas-6.html
for about $5. Use fire-seal putty as an
installation sealant.
Bob . . .
Message 39
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|
| Subject: | Re: Questions about circuit protection |
At 01:56 PM 1/4/2010, you wrote:
>
>user9253 wrote:
> > The spike protection diode is missing from the dynamo relay
> coil. The arrow should point towards positive.
>
>Joe,
>
>I looked at the dynamo relay coil but it is wired exactly as shown in
>Z-25 and Z-13/8.
>
>Bob, I would be very grateful if you could explain what the two diodes
>are for on the self exciting SD-8 drawing since since they are wired
>differently than the other relays.
Those are "steering" diodes that make power available
from either the battery or a spinning alternator to
get the relay to energize.
The relay doesn't need an coil suppression diode
with an OV module installed.
Bob . . .
Message 40
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| Subject: | Z-14 Switch Combos |
Awesome.. I get it now..
Thanks for the help and clarification...
Phil
-----Original Message-----
From: Bob McCallum [mailto:robert.mccallum2@sympatico.ca]
Sent: Monday, January 04, 2010 10:11 PM
Subject: RE: AeroElectric-List: Z-14 Switch Combos
<robert.mccallum2@sympatico.ca>
Phil and William;
My reading of the statement agrees with William's translation as well.
Bob McC
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-
> server@matronics.com] On Behalf Of William Slaughter
> Sent: Monday, January 04, 2010 10:39 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: Z-14 Switch Combos
>
> <william_slaughter@att.net>
>
> I believe that "may not..." should be translated as "may never have
occasion
> to", rather than "you must not do that". At least that's the way I
read
it.
>
> William
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Perry,
> Phil
> Sent: Monday, January 04, 2010 2:35 PM
> To: aeroelectric-list@matronics.com
> Subject: RE: AeroElectric-List: Z-14 Switch Combos
>
> <Phil.Perry@netapp.com>
>
> So we were on a good path until, "But you may not close the cross-feed
> ever."
>
> If that's the case, what good is the cross-feed if the switch is off
> limits??? I think your intentions were to say only in an emergency
when
> it is required?
>
> Let's looks a scenario where I forget to open the cross-feed after
> start. The other two contactors for the Alt/Batt are closed too.
What
> are the effects of the electrical system for prolonged cross-feed
> closure on a cross country tour across the southern states? Any
battery
> damage?
>
> My guess is that the alternators would be shedding load back and forth
> for the flight and never stabilize.
>
> I think I'm getting closer to understanding it. I just want to make
> sure I understand everything operationally before I dedicate myself to
a
> specific diagram only to be disappointed later.
>
> Thanks again for your help,
> Phil
>
>
>
>
>
>
>
> -----Original Message-----
> From: Robert L. Nuckolls, III [mailto:nuckolls.bob@aeroelectric.com]
> Sent: Monday, January 04, 2010 2:07 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Z-14 Switch Combos
>
> <nuckolls.bob@aeroelectric.com>
>
> At 09:08 PM 1/2/2010, you wrote:
> >I'm getting a handle on Z-14 from an operational perspective and
> >have a couple of questions about the switch combinations that could
> >create issues.
> >
> >Obviously with the added complexity of managing two batteries, two
> >alternators, and a cross feed can create some interesting
combinations.
> >
> >Are there any combo's that we should be aware of that would create
> >over voltage or any other scenarios of concern?
> >
> >In the event of a failure (for example Alt 2 failure), is there a
> >specific order for shutting off the bad alt and then enabling the
> cross feed?
>
> No . . . there's no risks for any 'mis management' of
> switches. But you may not close the cross-feed ever.
>
> Depending on what YOU power from each of the two busses,
> how YOU use the airplane and which alternator quit, you
> need to re-configure the system to maximize probablity
> of a no sweat arrival at airport of intended destination.
> This MIGHT call for immediate closure of the cross-feed
> (but probably not). Or it might remain open with one
> bus shut down completely until airport is in sight.
>
> Z-14 is just a fancier version of Z-13/8 which is a
> fancier version of Z-11 with an E-bus. The level
> of fanciness only drives your decisions on best
> utilization of limited resources for engine driven
> power. That procedure is something that you have
> to develop.
>
> Bob . . .
>
>
>
>
>
>
>
>
>
>
>
>
> _-
> ===================================================
> =======
> _-
> ===================================================
> =======
> _-
> ===================================================
> =======
> _-
> ===================================================
> =======
>
>
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