Today's Message Index:
----------------------
1. 03:49 AM - Re: AN 3087-8 Connector (Robert L. Nuckolls, III)
2. 08:23 AM - Re: Should a tripped circuit breaker be reset in flight? (Eric M. Jones)
3. 09:31 AM - Re: Re: Should a tripped circuit breaker be reset in flight? (Robert L. Nuckolls, III)
4. 10:03 AM - Re: Re: Should a tripped circuit breaker be reset in flight? (Ken Ryan)
5. 11:38 AM - Re: Re: Should a tripped circuit breaker be reset in flight? (Robert L. Nuckolls, III)
6. 06:10 PM - Re: Lee KR-2 System Architecture (stickid)
7. 07:28 PM - Welding cable ring connectors (John Morgensen)
8. 07:36 PM - Re: Welding cable ring connectors (Robert L. Nuckolls, III)
Message 1
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| Subject: | Re: AN 3087-8 Connector |
At 18:42 2014-10-12, you wrote:
><handainc@madisoncounty.net>
>
>What is the proper way to install an AN 3087-8 Connector on a 5 wire
>cable? Can the connector be removed and reused? I've got to
>replace the power cable on my Tig welder.
Are you sure the number isn't AN3057-8?
[]
The 3057 strain-relief fits a variety of connectors. The
most common being the MIL-C-5015 series devices that
have been around since WWII. They are offered in both
soldered and crimped contacts.
The strain relief is threaded onto the back shell
which is, in turn, threaded onto the connector
housing.
Emacs!
If your connector is soldered, then yes, it's easy
to de-solder the wires and re-use the connector. The
crimped pins cannot be salvaged. With the right tools,
you can extract the pins and use the original housing
to take new pins crimped to your replacement wire.
Check out the catalog from my website here . . .
http://tinyurl.com/ohxmtzc
Find out which contact arrangement is appropriate
to your connector. You may be able to find another
number stamped onto the connector retaining ring
that will help you define the size and insert. For
example, the connector above has an 18-1 insert as
described on page 12 of the catalog.
If your existing connector is crimped, the short path
to success is probably to replace it with it's solder-on
brother.
Newark Electronics is one of many sources for
these connectors . . . should you find that replacement
is preferable to salvage . . .
http://tinyurl.com/p6x5jbo
They're not a terribly expensive connector . . .
Bob . . .
Message 2
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| Subject: | Re: Should a tripped circuit breaker be reset in flight? |
There has been some remarkably good discussion on this subject and I want to add
my two cents:
1) Breakers themselves fail or degrade. Abused breakers are difficult to detect.
Resetting them after they cool down may be possible. But diagnosis should be
a ground-repair issue. Remember to Fly the Airplane.
2) The classic "breaker for every wire" seems old fashioned and indeed breakers
sometimes pop in commercial a/c and nobody notices. An LED warning on every breaker
seems to be a great idea.
3) Switch-Breaker combos save weight and panel space. These SBs have become much
better, smaller and cheaper than the early ones.
4) New approaches like solid state resettables certainly have their place.
5) If you don't have to change a fuse during flight, a fuse works well. This includes,
wig-wags, entertainment systems, seat heaters, baggage compartment lights,
convenience lights, rear intercoms, and others.
6) Inherently Safe Buses are low-current or current-limited buses where no fuse
is required because a dead short will not generate enough power to ignite anything.
Worth considering in this low-current world of Cmos, Fet gates and LEDs.
7) A design goal might be to eliminate the breaker panel by employing a variety
of other circuit protection methods. Are there some breakers that never pop?
Why have them?
--------
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge, MA 01550
(508) 764-2072
emjones(at)charter.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=431800#431800
Message 3
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| Subject: | Re: Should a tripped circuit breaker be reset |
in flight?
There has been some remarkably good discussion on this subject and I
want to add my two cents:
1) Breakers themselves fail or degrade. Abused breakers are difficult
to detect. Resetting them after they
cool down may be possible. But diagnosis should be a ground-repair
issue. Remember to Fly the Airplane.
That's a pretty broad brush . . . SOME breakers are less robust than we might
like for use in an extra-ordinarily abusive environment. Consider the inner
monkey-motion and parts count of the switch-breaker (on left) and the
commercial,
off-the shelf appliance breaker on the right . . . with the military qualified
device in the center that is RATED and TESTED for thousands of
high-fault current
trips without degradation of performance. I've never encountered a pre-mature
failure in this style breaker when used solely as a circuit protective device
and not a crew-operated power control.
Emacs!
2) The classic "breaker for every wire" seems old fashioned and
indeed breakers sometimes
pop in commercial a/c and nobody notices. An LED warning on every
breaker seems to be a great idea.
Three points to ponder here. Legacy design goals call limiting failure
effects to one system only. It's generally not a good thing to have one
failure take down multiple appliances. Hence, one protective device per
feeder.
If a protective device operates then some system is off line as a
result. If nobody notices, then that appliance is not being used.
As soon as the crew expects that appliance to be available, the
popped breaker will, no doubt, be noticed . . . whereupon Plan-B
for that failure will be implemented.
Adding indicator lights to breaker/fuses only complicates the
monkey-motion built into the device. It does not reduce risks
to comfortable termination of flight. It might be a troubleshooting
aid . . . but then . . . you already know that appliance is inop
or you will know before next flight . . . it's on your preflight
checklist . . . right?
3) Switch-Breaker combos save weight and panel space. These SBs have
become much better,
smaller and cheaper than the early ones.
. . . but still MUCH more expensive than a fuse and they
FORCE a modification of architecture to move a portion of
the ship's bus structure onto the panel.
4) New approaches like solid state resettables certainly have their place.
But what is the return on investment? If you're not going to
reset breakers or replace fuses in flight . . . what is the
value of incorporating a 'more modern' approach to hardware
that is more convenient to reset?
5) If you don't have to change a fuse during flight, a fuse works well. This
includes, wig-wags, entertainment systems, seat heaters, baggage
compartment lights,
convenience lights, rear intercoms, and others.
Under what conditions would it EVER be necessary/useful/
prudent to replace a fuse in flight? Are there design
goals to exercise that would eliminate any such condition?
6) Inherently Safe Buses are low-current or current-limited buses
where no fuse is
required because a dead short will not generate enough power to
ignite anything.
Worth considering in this low-current world of Cmos, Fet gates and LEDs.
Yes, feeders current limited at the bus can be considered
intrinsically immune to damage as a consequence of a faulted
wire. I've encountered perhaps a dozen such opportunities in
my lifetime.
7) A design goal might be to eliminate the breaker panel by employing a variety
of other circuit protection methods. Are there some breakers that
never pop? Why
have them?
Exactly. This question prompted an essay published in Sport Aviation
21 years ago: http://tinyurl.com/o9joztv The decision process
for circuit protective philosophy has almost nothing to do
with convenience or the performance issues unique to devices being
considered. To be sure, devices like this http://tinyurl.com/oka6z2a
may offer some unique opportunities for adding some appliance to
an airplane but in general, a clean piece of paper design should
strive for minimum risk, minimum cost, minimum complexity, minimum weight
in that order of prominence.
Emacs!
. . . at the present time, I'm unable to suggest a superior
alternative to the rudimentary fuse for keeping all the smoke
inside your wires . . .
Bob . . .
Message 4
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| Subject: | Re: Should a tripped circuit breaker be reset |
in flight?
Respectfully, your dictate of placement of "minimum cost" above "minimum
complexity" and "minimum weight" is purely opinion.
On Mon, Oct 13, 2014 at 8:30 AM, Robert L. Nuckolls, III <
nuckolls.bob@aeroelectric.com> wrote:
> There has been some remarkably good discussion on this subject and I want
> to add my two cents:
>
> 1) Breakers themselves fail or degrade. Abused breakers are difficult to
> detect. Resetting them after they
> cool down may be possible. But diagnosis should be a ground-repair issue.
> Remember to Fly the Airplane.
>
> *That's a pretty broad brush . . . SOME breakers are less robust than we
> might **like for use in an extra-ordinarily abusive environment. Consider
> the inner **monkey-motion and parts count of the switch-breaker (on left)
> and the commercial, **off-the shelf appliance breaker on the right . . .
> with the military qualified **device in the center that is RATED and
> TESTED for thousands of high-fault current **trips without degradation of
> performance. I've never encountered a pre-mature **failure in this style
> breaker when used solely as a circuit protective device *
>
> *and not a crew-operated power control.* [image: Emacs!]
>
> 2) The classic "breaker for every wire" seems old fashioned and indeed
> breakers sometimes
> pop in commercial a/c and nobody notices. An LED warning on every breaker
> seems to be a great idea.
>
> *Three points to ponder here. Legacy design goals call limiting failure **effects
> to one system only. It's generally not a good thing to have one **failure
> take down multiple appliances. Hence, one protective device per *
>
> *feeder. **If a protective device operates then some system is off line
> as a **result. If nobody notices, then that appliance is not being used. **As
> soon as the crew expects that appliance to be available, the **popped
> breaker will, no doubt, be noticed . . . whereupon Plan-B *
>
> *for that failure will be implemented. **Adding indicator lights to
> breaker/fuses only complicates the **monkey-motion built into the device.
> It does not reduce risks **to comfortable termination of flight. It might
> be a troubleshooting **aid . . . but then . . . you already know that
> appliance is inop **or you will know before next flight . . . it's on
> your preflight *
>
>
> *checklist . . . right? * 3) Switch-Breaker combos save weight and panel
> space. These SBs have become much better,
> smaller and cheaper than the early ones.
>
> *. . . but still MUCH more expensive than a fuse and they **FORCE a
> modification of architecture to move a portion of *
>
>
> *the ship's bus structure onto the panel. * 4) New approaches like solid
> state resettables certainly have their place.
>
> *But what is the return on investment? If you're not going to **reset
> breakers or replace fuses in flight . . . what is the **value of
> incorporating a 'more modern' approach to hardware **that is more
> convenient to reset?* 5) If you don't have to change a fuse during
> flight, a fuse works well. This
> includes, wig-wags, entertainment systems, seat heaters, baggage
> compartment lights,
> convenience lights, rear intercoms, and others.
>
> *Under what conditions would it EVER be necessary/useful/ **prudent to
> replace a fuse in flight? Are there design *
>
>
> *goals to exercise that would eliminate any such condition? * 6)
> Inherently Safe Buses are low-current or current-limited buses where no
> fuse is
> required because a dead short will not generate enough power to ignite
> anything.
> Worth considering in this low-current world of Cmos, Fet gates and LEDs.
>
> *Yes, feeders current limited at the bus can be considered **intrinsically
> immune to damage as a consequence of a faulted **wire. I've encountered
> perhaps a dozen such opportunities in *
>
>
> *my lifetime. * 7) A design goal might be to eliminate the breaker panel
> by employing a variety
> of other circuit protection methods. Are there some breakers that never
> pop? Why
> have them?
>
> *Exactly. This question prompted an essay published in Sport Aviation **21
> years ago: http://tinyurl.com/o9joztv <http://tinyurl.com/o9joztv> The
> decision process **for circuit protective philosophy has almost nothing
> to do **with convenience or the performance issues unique to devices
> being **considered. To be sure, devices like this
> http://tinyurl.com/oka6z2a <http://tinyurl.com/oka6z2a> **may offer some
> unique opportunities for adding some appliance to **an airplane but in
> general, a clean piece of paper design should **strive for minimum risk,
> minimum cost, minimum complexity, minimum weight *
>
> *in that order of prominence. * [image: Emacs!]
>
>
> *. . . at the present time, I'm unable to suggest a superior **alternative
> to the rudimentary fuse for keeping all the smoke *
>
> *inside your wires . . .*
>
> Bob . . .
>
Message 5
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| Subject: | Re: Should a tripped circuit breaker be reset |
in flight?
At 12:01 2014-10-13, you wrote:
>Respectfully, your dictate of placement of "minimum cost" above
>"minimum complexity" and "minimum weight" is purely opinion.
No problem . . . order your design goals as they
suit your wishes . . . but DO have design goals
crafted with argument that makes sense to you.
As a general rule, cost and complexity go hand-in-hand
a lower cost design is generally less complex. Furhter,
costs should be global and embrace cost of ownership.
In the electronics business, a great many parts are tiny,
exceedingly inexpensive and reliable. So cost and
complexity often swap priorities. It's the project
manager's call . . .
Bob . . .
Message 6
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| Subject: | Re: Lee KR-2 System Architecture |
I have just bought Bob Lee's Kr2 project and am trying to gather any info that
may pertain to the project. Do you have nay more posts or information about the
electronics he used?
Thanks
Bob R
Winnipeg Canada
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=431818#431818
Message 7
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| Subject: | Welding cable ring connectors |
I just acquired some #4 welding wire to fashion ground cables and
looking at the available connectors the #6 connectors seem to fit with
little or no slack. Am I missing something? Can I use the #6 connectors
with #4 cable?
Thanks,
johninreno
Message 8
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| Subject: | Re: Welding cable ring connectors |
At 21:27 2014-10-13, you wrote:
>
>I just acquired some #4 welding wire to fashion ground cables and
>looking at the available connectors the #6 connectors seem to fit
>with little or no slack. Am I missing something? Can I use the #6
>connectors with #4 cable?
Seems that connector sizing is a lot like shoe and
dress sizing . . . that is . . . in the ballpark.
Go by what fits best, not necessarily what's printed
on the box.
Bob . . .
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