Today's Message Index:
----------------------
1. 09:36 AM - Re: Re: Battery dumps (Robert L. Nuckolls, III)
2. 11:21 AM - Re: Re: batteries and diode isolation (Robert L. Nuckolls, III)
3. 11:50 AM - Re: Help with Diagnosis (Dale Martin)
4. 12:11 PM - Re: Weird LED fuse behavior (Phil Birkelbach)
5. 12:13 PM - Re: Re: batteries and diode isolation (Dave Morris)
6. 12:14 PM - Re: Help with Diagnosis (Matt Jurotich)
7. 12:32 PM - Re: Re: Battery dumps (David Carter)
8. 01:45 PM - Re: Weird LED fuse behavior (Robert L. Nuckolls, III)
9. 01:49 PM - Altitude Encoder data sharing (Robert L. Nuckolls, III)
10. 04:34 PM - ?punch for Carling? (Troy Scott)
11. 04:36 PM - Re: Battery dumps and Environmental Robustness (Robert L. Nuckolls, III)
12. 04:42 PM - Re: Re: batteries and diode isolation (George Braly)
13. 04:42 PM - Runaway stab trim prevention (bryan hooks)
14. 04:44 PM - Re: ?punch for Carling? (Alex Peterson)
15. 04:48 PM - Re: Runaway stab trim prevention (Alex Peterson)
16. 05:02 PM - Re: Runaway stab trim prevention (bryan hooks)
17. 05:43 PM - Re: ?punch for Carling? (Charlie Kuss)
18. 06:10 PM - Re: ?punch for Carling? (Bruce Gray)
19. 06:24 PM - Re: Runaway stab trim prevention (Tammy and Mike Salzman)
20. 07:15 PM - Re: ?punch for Carling? (Robert L. Nuckolls, III)
21. 07:17 PM - Re: ?punch for Carling? (Robert L. Nuckolls, III)
22. 07:18 PM - Re: Runaway stab trim prevention (Dave Morris)
23. 07:39 PM - Re: Re: batteries and diode isolation (Robert L. Nuckolls, III)
24. 07:56 PM - Re: Re: Help with Diagnosis (Robert L. Nuckolls, III)
25. 07:59 PM - RCT-3 crimper (Ted Lemen)
26. 07:59 PM - Crimper (Ted Lemen)
27. 07:59 PM - Crimper (Ted Lemen)
28. 08:03 PM - Re: Runaway stab trim prevention (Fiveonepw@aol.com)
29. 08:05 PM - Re: Runaway stab trim prevention (Fiveonepw@aol.com)
30. 09:06 PM - Re: Re: batteries and diode isolation (Dave Morris)
31. 09:23 PM - Re: Runaway stab trim prevention (Jeffrey W. Skiba)
32. 09:42 PM - Re: Harmonic Balancer (Dale Martin)
33. 10:21 PM - Re: RCT-3 crimper (Robert L. Nuckolls, III)
34. 10:23 PM - Re: Crimper (Robert L. Nuckolls, III)
35. 10:24 PM - Re: Runaway stab trim prevention (Mickey Coggins)
36. 10:35 PM - Re: Re: batteries and diode isolation (Robert L. Nuckolls, III)
37. 10:40 PM - Re: Re: Battery dumps (Paul Messinger)
38. 11:31 PM - Official Usage Guideline [Please Read] [Monthly Posting] (Matt Dralle)
Message 1
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| Subject: | Re: Battery dumps |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:23 PM 2/29/2004 -0600, you wrote:
>--> AeroElectric-List message posted by: "David Carter"
><dcarter@datarecall.net>
>
>For Bob N. & Paul Messinger, especially, and Eric Jones: I've studied the
>sharing of ideas and views on this Battery Dump thing. I believe Mike
>Holland's e-mail below (part), which mentions "big in-line fuse" type
>device. Fuses & CB all have a "time rating". I believe a big B-Lead fuse
>or limiter would be a "slow blow" item.
Correct. Like all "fuses" and breakers, these devices are for one
purpose only, protect wires and the rest of the system from the effects
from hard faults (very high current up to dead shorts). These devices
never figure into the OV (failed regulator) or battery-dump (transient
surges) event. Many folks confuse the role of the 5A alternator
control breaker as an integral part of the OV protection scheme when
teamed with a crowbar OV module. Yes, the breaker does open in
response to a high current DELIBERATELY GENERATED BY THE CROWBAR
OV MODULE. The breaker is not providing a first order response to
the ov condition, only a second order response to the protection
module which is the actual OV event sensor. If no first order OV
protection is provided (crowbar OV module or OV relay) then a
failed regulator can precipitate a series of very expensive events
without opening a single breaker or fuse.
> - I think the discussion should be momentarily limited so we (you!)
>focus on the 1 thing that I believe has not, so far, been isolated out and
>clearly addressed/responded to: "Time or Duration of the Event before it is
>'killed'. "
Correct.
> - Seems to me, if we set aside the reasonable assessment of risk that Bob
>has given, and we do that so we can address the "root technical issue", I
>believe that issue to be this one of "time".
and energy to be contained during that time.
> -- Can the OverVoltageProtection module & associated contactor (OVP
>system) open fast enough to prevent the Dump's hi-voltage from getting onto
>"main bus" for a long enough time to damage non-DO-160 gadgets?
No. OV protection is deliberately delayed in it's response time
to reduce the likelihood of nuisance trips. Further, if one subscribes
to the traditional notions of delay time as defined by Mil-STD-704
(and subscribed to by the certified aviation community), then delay
times are inversely related to the magnitude of the OV event. I.e.,
the higher the voltage, the shorter the time. The acceptance test
for many OV protection devices calls for stepping bus voltage from
14 to 20 volts and observing the trip time to be 30-50 milliseconds.
An 80 volt step will trip it in 3-5 milliseconds.
> -- To repeat & expand: If ANYTHING or WHATEVER causes a
>"significant" Battery Dump event (i.e., a non-PM alternator producing high
>enough volts and current to damage non-DO-160 gadgets if left unmitigated),
>then will the OVP system (contactor) open fast enough to limit the time to
>____ ms? __ ms being short enough so that there will be no damage caused
>by the HI VOLTAGE that WILL go downstream, past the OVP contactor, and into
>the "electrical distribution bus" and (potentially finicky) equipment
>connected thereto?
Excellent questions sir that require illustrative answers. DO-160
suggests that any device intended for installation on 14V aircraft
be capable of withstanding 20 volts for 1 second and 30 volts for
100 milliseconds for level B certification (level Z calls for 40
surge for 100 milliseconds). I've been building black boxes for
aircraft and testing to level Z for over 25 years. As I've mentioned
before, it's not difficult and it's hard for me to understand
why folks who sell to the OBAM aircraft community don't rise to
the occasion and make lots of folks worries go away.
The 20/1.0 and 30/0.1 surge envelopes are based on a runaway
alternator/generator event. The times and voltages are
suggested to have some headroom between what the accessory
can withstand and how fast we can expect a nuisance-trip-free
OV protection system to react to the failure and bring the
runaway alternator/generator to heal.
The battery-dump event is a completely separate beast.
On a 14V aircraft, there is a potential for higher voltages
but the timing is (I belive) much shorter. Further, while
a runaway alternator event is capable of delivering hundreds
of watt-seconds of energy to the system, I belive the
battery-dump event is limited to a small fraction of that.
In answer to your last question, a battery-dump event
triggered by actual disconnection of the battery will
have a magnitude and duration of transient that is
a function of alternator RPM, proportions and magnitude
of loads represented by accessories and the battery.
For example, a battery disconnect with a full or nearly
full charge battery is a non-event irrespective of
system accessory loads. A battery disconnect event with
system accessory loads taking a major portion of the
alternator's output capacity is also a non-event
irrespective of battery state of charge.
Given all these independent variables, I think it's
easy to visualize why risks to life and hardware from
the battery-dump event are so low . . . especially if
builders of aircraft accessories have an ounce of
knowledge/integrity with respect to DO-160 recommended
robustness.
The more specific case of battery/load-dump involves
opening the b-lead disconnect contactor in response
to an OV event (in which case the alternator's regulator
was already toast) or pilot operation of the alternator
control switch. Here, the alternator doesn't know
and doesn't care what proportion of total load
is represented by battery and system accessories.
Further, only the alternator's regulator is at-risk.
Here the scenario is more problematical. Total load
on alternator goes to zero. The alternator may or
may not run indefinitely as a self excited, yet unloaded
source of power. Opening the alternator b-lead
contactor doesn't actually shut the alternator off,
it simply unhooks it from the airplane.
If the b-lead contactor opens due to a real
OV event, disconnection will save the system but
the alternator will continue to produce whatever
energy it is capable of. In this case, any TVS
we put across the output to stand-off a battery
dump event is toast. If it shorts and doesn't
self-destruct (some plastic devices literally
explode leaving two lead wires dangling in the
breeze) then the dead short will stall the alternator
and effect a complete shutdown. If the TVS comes
apart, then the alternator may well continue to
run at max output until either the field winding
burns up or diodes short.
If the b-lead contactor is purposefully opened
and the regulator is okay, then independent
variables of RPM and total load stack up to
size both magnitude and duration of the surge. If
the surge is below levels hazardous to the
regulator, it's all over in a tens of milliseconds
and the alternator drops to a self excited mode
of reasonably stable but certainly non-hazardous
operation. Adding a TVS device is probably
the mitigating device to protect the regulator
(an perhaps other system accessories in case of
a battery disconnect cited above) . . . but I
hope it's clear that it's not the holy grail
of protection nor is the grail itself invulnerable.
Last, I think we're going to find that there
are NO TVS devices that will limit stresses to
less than 20v during a battery disconnect event
where system loads are light and battery recharge
loads are high. If folks like Microair with their
published 16v limits are accurate and serious about
this limit, then there is NOTHING short of designing
an input power conditioner that will protect this
radio . . . something they should have put in from
the get-go. See where that 20 volts for one second
number came from?
The short answer to your question is, "no, the
OV protection system's duties and capabilities
do not include protection from the battery-dump
event."
In the interest of clarity of speech, I'll suggest
we use "surge" to describe the battery-dump event.
It's an event bounded by perhaps 100 volts and
100 milliseconds and 100 watt seconds. The "spikes"
produced by contactor and relay coils are bounded
by 1000v, 10 milliseconds and tens of MILLIJOULES
of energy. Very different critters.
Bob . . .
Message 2
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| Subject: | Re: batteries and diode isolation |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:46 AM 2/25/2004 -0600, you wrote:
>--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
>
>Bob, I'd like to understand better why you prefer to use contactors and
>separate buses for 2 batteries, as opposed to diodes and allowing both
>batteries to feed the same bus.
>
>I recently saw an elegant circuit that does this and allows both batteries
>to be charged by the alternator at the same time.
>
>I have read your treatise on battery isolation so many times I can almost
>quote it, but nowhere do you address the possibility that there might be a
>way of allowing 3 electrical sources to "automatically" determine - using
>diodes - which ones will be feeding the loads. It would seem to require so
>much less pilot workload than flipping switches to cut in and out
>batteries, requires less current than supporting 2 battery contactors, and
>would still elegantly support the concept of annual battery rotation, low
>voltage notification, etc.
>
>Diodes are available now with voltage drop of 0.3V and with max forward
>currents of 240A, so the diodes themselves would not seem to be an issue.
Without seeing a schematic of what you propose, it's difficult
to assess characteristics of the system. How would you incorporate
diodes into a system that (1) provides pilot-operated disconnection
of batteries and (2) parallels batteries as needed for cranking?
It's not that diodes are evil devices, for all the benefits they
bring, they do not substitute for some system requirements
include the items cited above. Once you add switches or contactors
to orchestrate these features, the diodes are not especially
helpful and certainly not necessary.
We use lots of diodes in the power distribution of biz-jets
and the like . . . but they're always used like the e-bus
normal feed path diode - to provide no-moving parts isolation between
sections of the distribution system where cranking and
disconnection issues are not part of the design.
Bob . . .
Message 3
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| Subject: | Re: Help with Diagnosis |
--> AeroElectric-List message posted by: "Dale Martin" <niceez@cableone.net>
I have had this similar thing happen to me (28v system).
However, if I turned on the electric heater (draws either 20 or 35 amps),
the breaker would never pop. And it never popped at low RPM. The B&C
engineer and I think its a ground loop problem or a possible short. The
FIX -- I removed my whole electrical system for an update and what little
14 volt items were in the system are ALL removed. So, when it gets running
again I'll let you know. B&C want $45 to look at it and verify it was not
there regulator.
Hope this helps,
Dale Martin
Lewiston, ID
LEZ-235
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Help with Diagnosis
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 09:50 PM 2/28/2004 -0500, you wrote:
> >--> AeroElectric-List message posted by: Matt Jurotich
> ><mjurotich@hst.nasa.gov>
> >
> >My already flying when I bought it RV 6 A has a B&C alternator and a
> >LR3C-14 voltage regulator. The builder used a 10 amp fuse in the Field
> >line.
>
> This is contrary to recommended installation. Suggest you consider
> rewiring to include the suggested 5A breaker per installation
> instructions.
>
> > Some months ago when I had a low battery, an attempt to jump the
> >battery got a lot of sparks in the vicinity of the LR3C-14.
>
> I am always concerned about reports of "sparks" wherein their
> source is not researched and identified. See chapter 17 of
> the 'Connection for another sparks-outta-nowhere story.
>
>
> > About 3 flying
> >hours later the fuse blew and we got home on the battery. Today the fuse
> >blew again. We landed and replaced the fuse. Everything seemed OK
during
> >taxi and run-up, but the fuse blew again shortly after take-off. Got home
> >on battery again. Since my home airport is in the DC ADIZ this needs to
be
> >fixed properly. Where do I start to look? A short in the field wire is
> >the first place, what next? Thanks in advance for the help.
>
> Do you have any idea where the sparks came from? How
> did you observe them? You either have a wiring problem
> or the crowbar ov system in the LR3 is being tripped.
> How old is the LR-3? There was a mod to the design to
> fix an nuisance tripping problem with the OV system but
> since your problems seem to post-date another issue
> (sparks) with un-explained origin, the LR-3 may be fine
> and only the wiring needs investigation. If it were my
> airplane, I'd install the recommended 5A breaker, install
> ALL new wiring in the field supply circuit and see if
> the problem goes away.
>
> If it's still tripping the breaker, we'll need to dig
> further.
>
> Bob . . .
>
>
Message 4
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| Subject: | Re: Weird LED fuse behavior |
--> AeroElectric-List message posted by: "Phil Birkelbach" <phil@petrasoft.net>
I have seen some fuses lately that had some resistance in them. If there is
any resistance in the fuse the LED will glow. Try replacing the fuse and
see if that helps.
Godspeed,
Phil Birkelbach - Houston Texas
RV-7 N727WB (Reserved) - Baffles / Cowling
http://www.myrv7.com
----- Original Message -----
From: "John Slade" <sladerj@bellsouth.net>
Subject: AeroElectric-List: Weird LED fuse behavior
> --> AeroElectric-List message posted by: "John Slade"
<sladerj@bellsouth.net>
>
> Here's a strange one for someone....
>
> I have those fuses with an LED that lights up when they blow.
>
> When running my engine for the first time I notice that the LED for the
fuel
> injection computer (on the essential buss) is glowing, and that the glow
> changes in intensity with rpm - i.e. I can light it up more by pushing the
> throttle. On shut down I find that the fuse is not blown. I'm not seeing
any
> charge on the buss from the alternator, and I'm wondering if this may have
> something to do with it. Perhaps the alternator solenoid is open, but I
> can't see how that would affect voltage or cause some sort of reverse flow
> effect.
>
> Any ideas anyone?
> John Slade
> Cozy IV turbo rotary - making noise
>
>
Message 5
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| Subject: | Re: batteries and diode isolation |
--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
Well, the circuit I'm referring to is here:
http://sharkey.servebeer.com/~michael/christavia/electrics/batt_schematic_rev3.jpg
It would seem to have all the features we want.
Dave Morris
At 01:20 PM 3/1/2004 -0600, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><bob.nuckolls@cox.net>
>
>At 09:46 AM 2/25/2004 -0600, you wrote:
> >--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
> >
> >Bob, I'd like to understand better why you prefer to use contactors and
> >separate buses for 2 batteries, as opposed to diodes and allowing both
> >batteries to feed the same bus.
> >
> >I recently saw an elegant circuit that does this and allows both batteries
> >to be charged by the alternator at the same time.
> >
> >I have read your treatise on battery isolation so many times I can almost
> >quote it, but nowhere do you address the possibility that there might be a
> >way of allowing 3 electrical sources to "automatically" determine - using
> >diodes - which ones will be feeding the loads. It would seem to require so
> >much less pilot workload than flipping switches to cut in and out
> >batteries, requires less current than supporting 2 battery contactors, and
> >would still elegantly support the concept of annual battery rotation, low
> >voltage notification, etc.
> >
> >Diodes are available now with voltage drop of 0.3V and with max forward
> >currents of 240A, so the diodes themselves would not seem to be an issue.
>
> Without seeing a schematic of what you propose, it's difficult
> to assess characteristics of the system. How would you incorporate
> diodes into a system that (1) provides pilot-operated disconnection
> of batteries and (2) parallels batteries as needed for cranking?
>
> It's not that diodes are evil devices, for all the benefits they
> bring, they do not substitute for some system requirements
> include the items cited above. Once you add switches or contactors
> to orchestrate these features, the diodes are not especially
> helpful and certainly not necessary.
>
> We use lots of diodes in the power distribution of biz-jets
> and the like . . . but they're always used like the e-bus
> normal feed path diode - to provide no-moving parts isolation between
> sections of the distribution system where cranking and
> disconnection issues are not part of the design.
>
> Bob . . .
>
>
Dave Morris
Message 6
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| Subject: | Re: Help with Diagnosis |
--> AeroElectric-List message posted by: Matt Jurotich <mjurotich@hst.nasa.gov>
My already flying when I bought it RV 6 A has a B&C alternator and a
LR3C-14 voltage regulator. The builder used a 10 amp fuse in the Field line.
This is contrary to recommended installation. Suggest you consider
rewiring to include the suggested 5A breaker per installation instructions.
Agreed, plan to make a major panel upgrade to IFR and electrical system
upgrade to Z13, dual alt -single battery in about 2 months. Plane has 320
plus hours with this screwy setup and wanted to fly the spring season VFR
without moding existing panel.
> Some months ago when I had a low battery, an attempt to jump the
>battery got a lot of sparks in the vicinity of the LR3C-14.
I am always concerned about reports of "sparks" wherein their
source is not researched and identified. See chapter 17 of
the 'Connection for another sparks-outta-nowhere story.
SPARKs came from my clumsy attempt to attach positive of jumper cable to
amp-meter (load meter?) shunt. Cable not attached to source nor to ground
side of planes battery. Sparks melted insulation on wires to voltmeter and
amp-meter. Taped the melted sections. Took battery out of plane and
charged it on the ground. LR 3C-14 is vintage 1994. Plane has been flying
since 1995. Put in new battery last month--B&C 25 amp hour. Last 2 trips
were with new battery in place.
Big snip
When I did an archive search, I read many posts about nuisance trips and I
inferred they could be caused by a significant load increase. Therefore I
am concerned that I need to be looking for an intermittent short in
something other than field wire or an intermittent load increase in
something like my noisy RC Allen electrical Attitude Indicator. But no
other fuses blow and and every thing works. Could sparks have caused
degraded insulation more than a few inches from their location?
Thanks
Matthew M. Jurotich
NASA/Goddard Space Flight Center
Swales contractor to the
JWST ISIM Systems Engineer
m/c : 443
e-mail mail to: <mjurotich@hst.nasa.gov>
phone : 301-286-5919
fax : 301-286-7021
JWST URL: <http://ngst1.gsfc.nasa.gov
Message 7
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| Subject: | Re: Battery dumps |
--> AeroElectric-List message posted by: "David Carter" <dcarter@datarecall.net>
Bob & Paul,
Thank you for the continuing excellent analysis and discussion - I feel sure
that "at the end of the tunnel" of this "thread", we are going to 1) have
another innovative, well-peer-reviewed addition to our OBAM bus
architecture - to deal with this "battery dump/surge" phenomenon, or, 2)
have some really clear understanding of some "required" "pilot operating
procedures to avoid 'economically un-fixable' bus architecture limitations",
and, maybe, 3) an optional 'economically stressful fix' to the problem
(e.g., "power conditioner" that Bob mentioned - many of us are using engine
monitors and electronic fuel injection and electronic ignition controllers
with computer boards and some are likely NOT DO-160 qual'd - stuff that we
need to protect in order to stay airborne, as well as MicroEncoders and
other NON-essential gadgets that we'd like to keep out of the "frying pan"
so as to save our wallets.)
Looking forward to the evolution of this thing. Both of you are being real
gentlemen as you discuss this - and no, I don't believe Bob "has his mind
made" up [on 'everything' - my words] - just strong and reasonable
"engineering-economic-opertor tradeoff" views on some parts of the problem
and its analysis. You are both hanging in there quite well. Thank you
both for what you are doing for our OBAM community.
Paul, if this project stresses your finances, don't hesitate to ask us to
make contributions to help out.
Perhaps (hopefully) a 4th outcome will occur - a "consumer campaign" to have
all of our OBAM equipment vendors add "surge" protection, if not already
there. However, this current study by Paul and supported by Bob will likely
provide some additional "technical foundation" and some "tested solutions"
that may well be the basis for introducing this topic to those vendors who
have not yet considered or designed for the DO-160 surge issue. This would
be a great topic for an Oshkosh Forum Tent. That would be a great way to
get fast and widespread distribution of the essential features of "problem
analysis and range of solutions".
David Carter
----- Original Message -----
From: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
Subject: Re: AeroElectric-List: Re: Battery dumps
> --> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
<bob.nuckolls@cox.net>
>
> At 09:23 PM 2/29/2004 -0600, you wrote:
> >--> AeroElectric-List message posted by: "David Carter"
> ><dcarter@datarecall.net>
> >
> >For Bob N. & Paul Messinger, especially, and Eric Jones: I've studied
the
> >sharing of ideas and views on this Battery Dump thing. I believe Mike
> >Holland's e-mail below (part), which mentions "big in-line fuse" type
> >device. Fuses & CB all have a "time rating". I believe a big B-Lead
fuse
> >or limiter would be a "slow blow" item.
>
> Correct. Like all "fuses" and breakers, these devices are for one
> purpose only, protect wires and the rest of the system from the effects
> from hard faults (very high current up to dead shorts). These devices
> never figure into the OV (failed regulator) or battery-dump (transient
> surges) event. Many folks confuse the role of the 5A alternator
> control breaker as an integral part of the OV protection scheme when
> teamed with a crowbar OV module. Yes, the breaker does open in
> response to a high current DELIBERATELY GENERATED BY THE CROWBAR
> OV MODULE. The breaker is not providing a first order response to
> the ov condition, only a second order response to the protection
> module which is the actual OV event sensor. If no first order OV
> protection is provided (crowbar OV module or OV relay) then a
> failed regulator can precipitate a series of very expensive events
> without opening a single breaker or fuse.
>
> > - I think the discussion should be momentarily limited so we (you!)
> >focus on the 1 thing that I believe has not, so far, been isolated out
and
> >clearly addressed/responded to: "Time or Duration of the Event before it
is
> >'killed'. "
>
> Correct.
<snipped rest of msg>
Message 8
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| Subject: | Re: Weird LED fuse behavior |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 02:06 PM 3/1/2004 -0600, you wrote:
>--> AeroElectric-List message posted by: "Phil Birkelbach"
><phil@petrasoft.net>
>
>I have seen some fuses lately that had some resistance in them. If there is
>any resistance in the fuse the LED will glow. Try replacing the fuse and
>see if that helps.
>
>Godspeed,
I'm mystified by this symptom. Red LEDs take about 2 volts
to get any light out of them. There's no fuse that should
have a 2 volt drop across it without being blown open.
Bob . . .
Message 9
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| Subject: | Altitude Encoder data sharing |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
>
>Comments/Questions: Hi Bob! I'm looking for a clean way to "tee" into my
>encoder for a GPS install.
>I hate to use butt connectors. Wondering if someone makes a D sub tee or
>breakout of some kind.
> Thanks for any ideas! Tim
Don't know of anyone that makes such a critter. It would
be difficult to do a "universal" device because some
items of equipment added to the altitude data lines
also need isolation diodes in the circuit. This needs
to be researched and complied with as necessary
for your particular pieces of equipment.
Bob . . .
-----------------------------------------
( Experience and common sense cannot be )
( replaced with policy and procedures. )
( R. L. Nuckolls III )
-----------------------------------------
Message 10
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| Subject: | ?punch for Carling? |
--> AeroElectric-List message posted by: "Troy Scott" <tscott1217@bellsouth.net>
Gentlemen,
I'm thinking there must be a better way to mount the Carling switches than
drilling two holes in the panel. I don't want the extra "position locking"
hole. Is there a punch that cuts the hole and leaves the key that keeps the
switch from rotating?
Regards,
Troy Scott
tscott1217@bellsouth.net
Message 11
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| Subject: | Re: Battery dumps and Environmental Robustness |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 02:30 PM 3/1/2004 -0600, you wrote:
>--> AeroElectric-List message posted by: "David Carter"
><dcarter@datarecall.net>
>
>Bob & Paul,
>
>Thank you for the continuing excellent analysis and discussion - I feel sure
>that "at the end of the tunnel" . . .
Dave, thank you for the kind words along with your perceptions
of where we think we're going and how we're planning to get there.
I am pleased that the goals appear as you have described them for that
is certainly my wish . . .
>Perhaps (hopefully) a 4th outcome will occur - a "consumer campaign" to have
>all of our OBAM equipment vendors add "surge" protection, if not already
>there. However, this current study by Paul and supported by Bob will likely
>provide some additional "technical foundation" and some "tested solutions"
>that may well be the basis for introducing this topic to those vendors who
>have not yet considered or designed for the DO-160 surge issue. This would
>be a great topic for an Oshkosh Forum Tent. That would be a great way to
>get fast and widespread distribution of the essential features of "problem
>analysis and range of solutions".
Years ago, I published a list of questions that folks could
paste to a note-card and carry around during their visits to
the various booths at OSH and elsewhere. The questions had to
do with information gathering about the manufacturer's awareness
and willingness to apply any level of environmental robustness
to his/her products. Whether or not DO-160 was embraced
was immaterial. The point was that EVERY manufacturer should
be aware of a degree of consumer concerns about such matters and
find it to be in their own best interests to address those concerns.
This is exactly how the free market is supposed to work and WILL
if we properly exercise our prerogatives as knowledgeable,
responsible consumers.
I suggested that if answers to the questions at the booth were
less than satisfactory, one could say, "Gee, I REALLY do like your
product and I'd consider getting one right away . . . but there
IS a matter of environmental fragility. I'm going to have to think
about this awhile. I think I'll check with your competitors to see
how they've address the issues of learning to live in the real world
of airplanes."
Now, if you really want to install the product in your
airplane, you can call them on the phone or perhaps order it on
the Internet later. The value in this exercise is the view
of your retreating backside by the person(s) in the booth who
could not sell you a product for what just might be silly
reasons. You don't have to tell them later that you were the
"sale they missed" at the booth. That bit of data needs to
simmer in their marketing minds for awhile if it's going to
bear fruit.
I'd be pleased to do such a forum at OSH . . . if I can
ever figure out a practical way to make another trip to
OSH. B&C used to pay most of my expenses if I helped in
their booth. Sales of books would just about wash out
out-of-pocket expenses for making the trip. Hmmmm . . .
maybe I could do a weekend seminar just before OSH
and in the vicinity so that I could tie the two activities
together. That MIGHT play.
Further, I'll renew my offer that should any of you on
the list discover an otherwise desirable product lacking
in environmental robustness, I'd be pleased to advise
those folks at no charge for the initial consultation
and recommendations. I have lots of customers who compete
with each other that know I can keep their secrets.
Give them my e-mail address. I've had several takers
over the past ten years . . . but far too few.
Bob . . .
Message 12
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| Subject: | Re: batteries and diode isolation |
--> AeroElectric-List message posted by: "George Braly" <gwbraly@gami.com>
Dave,
After a quick look, I wonder just exactly you would try to sense the
buss voltage for the voltage regulator for the alternator???
George
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Dave
Morris
Subject: Re: AeroElectric-List: Re: batteries and diode isolation
--> AeroElectric-List message posted by: Dave Morris
<dave@davemorris.com>
Well, the circuit I'm referring to is here:
http://sharkey.servebeer.com/~michael/christavia/electrics/batt_schemati
c_rev3.jpg
It would seem to have all the features we want.
Dave Morris
At 01:20 PM 3/1/2004 -0600, you wrote:
>--> AeroElectric-List message posted by: "Robert L. Nuckolls, III"
><bob.nuckolls@cox.net>
>
>At 09:46 AM 2/25/2004 -0600, you wrote:
> >--> AeroElectric-List message posted by: Dave Morris
<dave@davemorris.com>
> >
> >Bob, I'd like to understand better why you prefer to use contactors
and
> >separate buses for 2 batteries, as opposed to diodes and allowing
both
> >batteries to feed the same bus.
> >
> >I recently saw an elegant circuit that does this and allows both
batteries
> >to be charged by the alternator at the same time.
> >
> >I have read your treatise on battery isolation so many times I can
almost
> >quote it, but nowhere do you address the possibility that there might
be a
> >way of allowing 3 electrical sources to "automatically" determine -
using
> >diodes - which ones will be feeding the loads. It would seem to
require so
> >much less pilot workload than flipping switches to cut in and out
> >batteries, requires less current than supporting 2 battery
contactors, and
> >would still elegantly support the concept of annual battery rotation,
low
> >voltage notification, etc.
> >
> >Diodes are available now with voltage drop of 0.3V and with max
forward
> >currents of 240A, so the diodes themselves would not seem to be an
issue.
>
> Without seeing a schematic of what you propose, it's difficult
> to assess characteristics of the system. How would you incorporate
> diodes into a system that (1) provides pilot-operated disconnection
> of batteries and (2) parallels batteries as needed for cranking?
>
> It's not that diodes are evil devices, for all the benefits they
> bring, they do not substitute for some system requirements
> include the items cited above. Once you add switches or contactors
> to orchestrate these features, the diodes are not especially
> helpful and certainly not necessary.
>
> We use lots of diodes in the power distribution of biz-jets
> and the like . . . but they're always used like the e-bus
> normal feed path diode - to provide no-moving parts isolation
between
> sections of the distribution system where cranking and
> disconnection issues are not part of the design.
>
> Bob . . .
>
>
Dave Morris
==
==
==
==
Message 13
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| Subject: | Runaway stab trim prevention |
--> AeroElectric-List message posted by: "bryan hooks" <hook3607@bellsouth.net>
Saw a post today on one of the other email groups about the effects of
runaway stab trim on an RV. Does anyone have (or know how to make) some
sort of automatic cutout switch that would stop a runaway trim if it ran
continuously for some number of seconds? Maybe some sort of setup with
a reset switch.
I bet Bob could lick this in less time than it took me to write this
email. :-)
Bryan Hooks
RV-7A, slow, empennage
Knoxville, TN
Hook3607@bellsouth.net
Message 14
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| Subject: | ?punch for Carling? |
--> AeroElectric-List message posted by: "Alex Peterson" <alexpeterson@earthlink.net>
> Gentlemen,
>
> I'm thinking there must be a better way to mount the Carling
> switches than drilling two holes in the panel. I don't want
> the extra "position locking" hole. Is there a punch that
> cuts the hole and leaves the key that keeps the switch from rotating?
>
> Regards,
> Troy Scott
> tscott1217@bellsouth.net
Troy, another option is to drill the locking hole only about half the
depth of the panel, from the back (foreward in plane) side. You might
be able to put a threaded drill bit into a microstop to limit the depth.
It would not be hard to make a little jig to locate the locking hole.
Then, bend the locking tab enough so that it can be used on the switch
side of the panel.
Alex Peterson
Maple Grove, MN
RV6-A N66AP 443 hours
http://www.home.earthlink.net/~alexpeterson/
Message 15
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| Subject: | Runaway stab trim prevention |
--> AeroElectric-List message posted by: "Alex Peterson" <alexpeterson@earthlink.net>
> Saw a post today on one of the other email groups about the
> effects of runaway stab trim on an RV. Does anyone have (or
> know how to make) some sort of automatic cutout switch that
> would stop a runaway trim if it ran continuously for some
> number of seconds? Maybe some sort of setup with a reset switch.
>
> I bet Bob could lick this in less time than it took me to
> write this email. :-)
>
> Bryan Hooks
> RV-7A, slow, empennage
> Knoxville, TN
> Hook3607@bellsouth.net
What for? I'd put some sort of pullable breaker or disconnect switch on
the panel for that situation. These things fly without much effort with
trim full, provided one keeps the speed down to flap speed or not far
above.
Alex Peterson
Maple Grove, MN
RV6-A N66AP 443 hours
http://www.home.earthlink.net/~alexpeterson/
Message 16
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| Subject: | Runaway stab trim prevention |
--> AeroElectric-List message posted by: "bryan hooks" <hook3607@bellsouth.net>
I would still advocate having a CB or a fuse, but an automatic cut-out
switch that stopped it at say, 2 seconds of continual trim, would stop
it before it ever became an issue. There would be no need to find a CB
while flying an out of trim airplane in the weather, etc...
I'm not necessarily sold on the idea or anything, it was just a thought.
But if it's a cheap addition, I think it'd be pretty slick.
-bryan
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alex
Peterson
Subject: RE: AeroElectric-List: Runaway stab trim prevention
--> AeroElectric-List message posted by: "Alex Peterson"
<alexpeterson@earthlink.net>
> Saw a post today on one of the other email groups about the
> effects of runaway stab trim on an RV. Does anyone have (or
> know how to make) some sort of automatic cutout switch that
> would stop a runaway trim if it ran continuously for some
> number of seconds? Maybe some sort of setup with a reset switch.
>
> I bet Bob could lick this in less time than it took me to
> write this email. :-)
>
> Bryan Hooks
> RV-7A, slow, empennage
> Knoxville, TN
> Hook3607@bellsouth.net
What for? I'd put some sort of pullable breaker or disconnect switch on
the panel for that situation. These things fly without much effort with
trim full, provided one keeps the speed down to flap speed or not far
above.
Alex Peterson
Maple Grove, MN
RV6-A N66AP 443 hours
http://www.home.earthlink.net/~alexpeterson/
==
==
==
==
Message 17
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| Subject: | Re: ?punch for Carling? |
--> AeroElectric-List message posted by: Charlie Kuss <chaskuss@bellsouth.net>
Troy
Greenlee makes a 60601 punch. The old model number was a 732 radio chassis punch.
This is the purpose built punch for toggle switches. Look on page 33 of the
catalog on the web page listed below. Look for the heading KEY PUNCHES.
http://198.247.193.8/wwwroot/greenlee/holemaking.pdf
Charlie Kuss
RV-8A wiring
Boca Raton, Fl.
>--> AeroElectric-List message posted by: "Troy Scott" <tscott1217@bellsouth.net>
>
>Gentlemen,
>
>I'm thinking there must be a better way to mount the Carling switches than
>drilling two holes in the panel. I don't want the extra "position locking"
>hole. Is there a punch that cuts the hole and leaves the key that keeps the
>switch from rotating?
>
>Regards,
>Troy Scott
>tscott1217@bellsouth.net
>
>
Message 18
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| Subject: | ?punch for Carling? |
--> AeroElectric-List message posted by: "Bruce Gray" <Bruce@glasair.org>
Insert tab washer from the back of the panel with the tab facing the
panel back. Pull the switch forward to set and hold the tab against the
panel back. Rotate the switch +/- 90 degrees. You have now made a scribe
mark on the panel back with the tab. Drill hole halfway through the
panel, from the back, on the scribe line. Done.
Or you can buy a key punch. Expensive $100 +.
Bruce
www.glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Alex
Peterson
Subject: RE: AeroElectric-List: ?punch for Carling?
--> AeroElectric-List message posted by: "Alex Peterson"
<alexpeterson@earthlink.net>
> Gentlemen,
>
> I'm thinking there must be a better way to mount the Carling
> switches than drilling two holes in the panel. I don't want
> the extra "position locking" hole. Is there a punch that
> cuts the hole and leaves the key that keeps the switch from rotating?
>
> Regards,
> Troy Scott
> tscott1217@bellsouth.net
Troy, another option is to drill the locking hole only about half the
depth of the panel, from the back (foreward in plane) side. You might
be able to put a threaded drill bit into a microstop to limit the depth.
It would not be hard to make a little jig to locate the locking hole.
Then, bend the locking tab enough so that it can be used on the switch
side of the panel.
Alex Peterson
Maple Grove, MN
RV6-A N66AP 443 hours
http://www.home.earthlink.net/~alexpeterson/
Message 19
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| Subject: | Runaway stab trim prevention |
--> AeroElectric-List message posted by: Tammy and Mike Salzman <arrow54t@yahoo.com>
Bryan,
I went ahead and installed a "TRIM REVERSE" switch, along with "TRIM
MASTER" and "TRIM COMMAND" switches on my panel. I'm building a
Lancair ES and have lots of room for these switches. The trim reverse
switch is a DPDT (ON-0N) switch that just has jumpers soldered across
the NC of one pole to the NO of the other.(2 jumpers total) Power gets
wired to the NC or NO of respective poles and output to your trim
relays/servos comes off the COM terminals.
The plan is to be able to reverse any runaway condition, then shut off
the trim system at the TRIM MASTER.
Mike Salzman
Fairfield, CA
LNCE
Message 20
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| Subject: | ?punch for Carling? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:09 PM 3/1/2004 -0500, you wrote:
>--> AeroElectric-List message posted by: "Bruce Gray" <Bruce@glasair.org>
>
>Insert tab washer from the back of the panel with the tab facing the
>panel back. Pull the switch forward to set and hold the tab against the
>panel back. Rotate the switch +/- 90 degrees. You have now made a scribe
>mark on the panel back with the tab. Drill hole halfway through the
>panel, from the back, on the scribe line. Done.
>
>Or you can buy a key punch. Expensive $100 +.
>
>Bruce
>www.glasair.org
Another technique I've used is to cut the peripheral
tab completely off the keying washer. Coat one side
with thin coat of E6000 or ShoeGoo cement. Assemble
switch on panel with keying washer on back side, glued
face to the panel. Wait 24 hours before disassembly.
This genre' of cements does a good job of bonding
the keying washer to an aluminum panel. There is
slight risk of some squish-out glue getting into
switch mounting threads. It's only a slight impediment
to future disassembly and may be easily trimmed away
with an Xacto knife later.
Bob . . .
Message 21
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| Subject: | ?punch for Carling? |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 06:44 PM 3/1/2004 -0600, you wrote:
>--> AeroElectric-List message posted by: "Alex Peterson"
><alexpeterson@earthlink.net>
>
>
> > Gentlemen,
> >
> > I'm thinking there must be a better way to mount the Carling
> > switches than drilling two holes in the panel. I don't want
> > the extra "position locking" hole. Is there a punch that
> > cuts the hole and leaves the key that keeps the switch from rotating?
> >
> > Regards,
> > Troy Scott
> > tscott1217@bellsouth.net
>
>Troy, another option is to drill the locking hole only about half the
>depth of the panel, from the back (foreward in plane) side. You might
>be able to put a threaded drill bit into a microstop to limit the depth.
>It would not be hard to make a little jig to locate the locking hole.
>Then, bend the locking tab enough so that it can be used on the switch
>side of the panel.
I did a little piece on this a few years ago and posted it
to
http://www.aeroelectric.com/articles/switchmounting/switchmounting.html
A unibit works as good or better than a spotfacer.
Bob . . .
Message 22
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| Subject: | Runaway stab trim prevention |
--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
You can't put a limit switch on each end of the trim control so that the
motor can only run to the limit and then only a reversal can back it out
again? That's the way I'm doing all my trim servos. Very simple.
Dave Morris
At 08:24 PM 3/1/2004, you wrote:
>--> AeroElectric-List message posted by: Tammy and Mike Salzman
><arrow54t@yahoo.com>
>
>Bryan,
>
>I went ahead and installed a "TRIM REVERSE" switch, along with "TRIM
>MASTER" and "TRIM COMMAND" switches on my panel. I'm building a
>Lancair ES and have lots of room for these switches. The trim reverse
>switch is a DPDT (ON-0N) switch that just has jumpers soldered across
>the NC of one pole to the NO of the other.(2 jumpers total) Power gets
>wired to the NC or NO of respective poles and output to your trim
>relays/servos comes off the COM terminals.
>
>The plan is to be able to reverse any runaway condition, then shut off
>the trim system at the TRIM MASTER.
>
>Mike Salzman
>Fairfield, CA
>LNCE
>
>
Message 23
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| Subject: | Re: batteries and diode isolation |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 02:13 PM 3/1/2004 -0600, you wrote:
>--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
>
>Well, the circuit I'm referring to is here:
>http://sharkey.servebeer.com/~michael/christavia/electrics/batt_schematic_rev3.jpg
>
>It would seem to have all the features we want.
I'm a bit mystified by the schematic. It appears that the designer
was worried about battery failure . . . two batteries are diode
or'ed to feed the bus and ignition with the ignition system bypassing
a "master switch" which I presume is the battery contactor. Then
there are three more diodes on the alternator output. . . one each
to charge batteries and a third to bypass the batteries and drive
system loads whether or not the batteries are "good" . . .
The drawing also calls for a two-pole starter contactor. Since
we don't have two-pole devices in low cost versions, I suspect
we'd end up with two separate contactors to implement the two
pole function. By my count, we have three contactors and five
power diode assemblies. Further, since cranking current doesn't
come through the battery master contactor, we cannot make the
starter feed cable do dual duty service for tying the batteries
to the rest of the system. In this case, the starter contactor(s)
would have to be mounted right at the battery. Single, intermittant
duty starter contactor draws about 5A, so a pair would draw 10A.
Figure Z-11 with a Z-30 aux battery option, we STILL have three
contactors and only one relatively small diode to implement a
relatively independent 4-bus system where busses may be assigned
to mutually exclusive tasks. What operational failure can you
deduce where the Z-11/Z-30 falls short of what the 3-contactor/5-diode
arrangement provides?
Bob . . .
Message 24
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| Subject: | Re: Help with Diagnosis |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
> I am always concerned about reports of "sparks" wherein their
> source is not researched and identified. See chapter 17 of
> the 'Connection for another sparks-outta-nowhere story.
>
>SPARKs came from my clumsy attempt to attach positive of jumper cable to
>amp-meter (load meter?) shunt. Cable not attached to source nor to ground
>side of planes battery. Sparks melted insulation on wires to voltmeter and
>amp-meter. Taped the melted sections. Took battery out of plane and
>charged it on the ground. LR 3C-14 is vintage 1994. Plane has been flying
>since 1995. Put in new battery last month--B&C 25 amp hour. Last 2 trips
>were with new battery in place.
Aha! A much clearer picture.
>
>
>When I did an archive search, I read many posts about nuisance trips and I
>inferred they could be caused by a significant load increase.
Actually, the two most significant sources for nuisance tripping
the LR-3 crowbar ov protection system are: (1) Noises (very short duration
spikes) generated by closing a switch to a heavy load
or opening a switch to un-clamped contactor or relay coil
and (2)longer duration bumps in bus voltage caused by instability
of regulator due to wiring resistance increases coupled with load
changes (usually switch openings) combined with high resistance
wiring between bus and the regulator that severely destabilizes it.
The condition can be exacerbated by a soggy battery.
> Therefore I
>am concerned that I need to be looking for an intermittent short in
>something other than field wire or an intermittent load increase in
>something like my noisy RC Allen electrical Attitude Indicator. But no
>other fuses blow and and every thing works. Could sparks have caused
>degraded insulation more than a few inches from their location?
Probably not. First, your LR-3 is old enough to NOT have received
the modification added a few years back to offset conditions cited
in (1) above. We had some Bonanzas with some gawd-awful mil-spec
switches in the landing and taxi light circuits that bounced REALLY
bad. Turning taxi and landing lights on at the same time would trip
the OV circuit when in fact no OV condition was present.
This is an easy mod to add. I can do it for you if you want to
send me your regulator.
Having said that, I'm wondering why this is a new condition.
How old is the battery? What kind of battery? If it were
my airplane and the battery was more than a year old, I'd
put in a new RG battery and re-wire the regulator to have
the recommended breaker. Then fly the airplane and see if
the breaker trips. If so, does it do it randomly or in response
to some action or activity in the electrical system.
The reason you found quite a few articles on nuisance tripping
is because that's the majority of ALL articles concerning the
LR-3 series regulators. Out of thousands in service, nuisance
tripping has been a problem in a small percentage of the total
and for the most part, the only problem we've encountered. It's
usually easy to track down and fix root cause. Let's get the
system updated a bit and research it from there.
Bob . . .
Message 25
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--> AeroElectric-List message posted by: "Ted Lemen" <tedlem@ecentral.com>
We purchased several crimpers from B&C and included was the RCT-3. It is
supposed to be for the D sub pins but when you sart clamping down on the
pin, you can't release it until you have squeezed all of the way down
and that just about ruins the pin. By the time you can release it the
opening is really small I have used the hex crimper using the .043 slot
which seems to work alright.
Message 26
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--> AeroElectric-List message posted by: "Ted Lemen" <tedlem@ecentral.com>
I thought I asked this question before but Bob, can you use the "hex
BNC" crimper that B&C sells on the amp round BNC connectors? I tried one
and it looked OK.
Message 27
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--> AeroElectric-List message posted by: "Ted Lemen" <tedlem@ecentral.com>
Is it acceptable to use the "hex" crimper that B&C sells with the amp
round BNC connectors? I tried one and it seemed OK.
Message 28
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| Subject: | Re: Runaway stab trim prevention |
--> AeroElectric-List message posted by: Fiveonepw@aol.com
In a message dated 03/01/2004 7:03:07 PM Central Standard Time,
hook3607@bellsouth.net writes:
I would still advocate having a CB or a fuse, but an automatic cut-out
switch that stopped it at say, 2 seconds of continual trim, would stop
it before it ever became an issue. There would be no need to find a CB
while flying an out of trim airplane in the weather, etc...
This would be neat, but more stuff may not always be the best way to tackle
this kind of problem. I want anything electrically controlling a flight
surface as dead-simple as possible. If you NEEDED more than 2 seconds of trim
motion could you do without it if automatically disconnected? Would you recognize
a runaway trim event within 2 seconds? How's your reaction time? (How long
would it take to hit the master switch?) This is one reason my trim and wing
leveler are fed from the Main bus and another justification for the E-bus...
Mark
Message 29
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| Subject: | Re: Runaway stab trim prevention |
--> AeroElectric-List message posted by: Fiveonepw@aol.com
In a message dated 03/01/2004 7:03:07 PM Central Standard Time,
hook3607@bellsouth.net writes:
I would still advocate having a CB or a fuse, but an automatic cut-out
switch that stopped it at say, 2 seconds of continual trim, would stop
it before it ever became an issue. There would be no need to find a CB
while flying an out of trim airplane in the weather, etc...
This would be neat, but more stuff may not always be the best way to tackle
this kind of problem. I want anything electrically controlling a flight
surface as dead-simple as possible. If you NEEDED more than 2 seconds of trim
motion could you do without it if automatically disconnected? Would you recognize
a runaway trim event within 2 seconds? How's your reaction time? (How long
would it take to hit the master switch?) This is one reason my trim and wing
leveler are fed from the Main bus and another justification for the E-bus...
Mark
Message 30
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| Subject: | Re: batteries and diode isolation |
--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
At 09:39 PM 3/1/2004, you wrote:
> >
> >Well, the circuit I'm referring to is here:
> >http://sharkey.servebeer.com/~michael/christavia/electrics/batt_schematic
> _rev3.jpg
> >
> >It would seem to have all the features we want.
>
>
> Figure Z-11 with a Z-30 aux battery option, we STILL have three
> contactors and only one relatively small diode to implement a
> relatively independent 4-bus system where busses may be assigned
> to mutually exclusive tasks. What operational failure can you
> deduce where the Z-11/Z-30 falls short of what the 3-contactor/5-diode
> arrangement provides?
>
Well, for one thing, I think the requirement to separate out loads into 4
different busses, not knowing which of those busses might be the one that
fails, is a liability that this schematic avoids. You don't have to play
Sophie's choice with your electrical loads. I personally find it difficult
to decide which of my loads are "non-essential" (with the obvious exception
of the CD player!). Doesn't this circuit allow you to turn your entire
electrical system into one giant "essential bus" and an "always hot bus"
(i.e. ignition in this diagram), avoid the constant drain of multiple
battery contactors, and eliminate the pilot from the equation totally by
handling all the source switching automatically with solid state components
that have no moving parts?
Dave Morris
Message 31
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| Subject: | Runaway stab trim prevention |
--> AeroElectric-List message posted by: "Jeffrey W. Skiba" <jskiba@icosa.net>
I am a little confused or I guess I have a question as to how this would
operate,
I understand that if the trim ran for more than the X time say 2 seconds
that it would automatically shut OFF, would this also include intentional
operation (I would think so) so what happens if you were actually trimming
and needed more than the two seconds worth ? Would you have to press a reset
button or something??
I guess my next question is to the entire group ?
HOW LONG should the auto-time out be 2 seconds 3 seconds or what ??
Just some thoughts
Jeff.
hook3607@bellsouth.net writes:
I would still advocate having a CB or a fuse, but an automatic cut-out
switch that stopped it at say, 2 seconds of continual trim, would stop it
before it ever became an issue. There would be no need to find a CB while
flying an out of trim airplane in the weather, etc... This would be neat,
but more stuff may not always be the best way to tackle
this kind of problem. I want anything electrically controlling a flight
surface as dead-simple as possible. If you NEEDED more than 2 seconds of
trim
motion could you do without it if automatically disconnected? Would you
recognize
a runaway trim event within 2 seconds? How's your reaction time? (How long
would it take to hit the master switch?) This is one reason my trim and
wing
leveler are fed from the Main bus and another justification for the E-bus...
Mark
Message 32
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| Subject: | Re: Harmonic Balancer |
--> AeroElectric-List message posted by: "Dale Martin" <niceez@cableone.net>
I'm digging around looking for my 22AWG Tefzel wire and what do I find?
A Mark Landoll Harmonic Dampener!
Still shines like new. New was $375 + shipping ....
Save $100 -
Sell for $275 plus shipping from 83501 zip code.
All hardware to mount to Lycoming flywheel and mounting instructions
included.
Pictures on request. Really smooths out a two blade prop.
Dale Martin
Lewiston, ID
LEZ-235
Message 33
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| Subject: | Re: RCT-3 crimper |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:00 PM 3/1/2004 -0700, you wrote:
>--> AeroElectric-List message posted by: "Ted Lemen" <tedlem@ecentral.com>
>
>We purchased several crimpers from B&C and included was the RCT-3. It is
>supposed to be for the D sub pins but when you start clamping down on the
>pin, you can't release it until you have squeezed all of the way down
>and that just about ruins the pin. By the time you can release it the
>opening is really small I have used the hex crimper using the .043 slot
>which seems to work alright.
I am mystified by your comments. The RCT-3 tool IS for machined
D-sub pins and we've sold hundreds of these tools. I give away
a half dozen or so at each weekend seminar. I've not seen or
heard of the problem you describe.
Here's a d-sub pin I just installed with an RCT-3 from my
own toolbox:
http://www.aeroelectric.com/Pictures/RCT-3_Male.jpg
How does this picture differ from the results you're getting?
The tool is designed for a complete, controlled stroke for crimping
the pins. I suppose the tool you have may be defective. You can
send it to me at 6936 Bainbridge Road, Wichita, KS 67226 for
an inspection. I'll have B&C replace it if necessary.
Bob . . .
Message 34
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--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 09:00 PM 3/1/2004 -0700, you wrote:
>--> AeroElectric-List message posted by: "Ted Lemen" <tedlem@ecentral.com>
>
>Is it acceptable to use the "hex" crimper that B&C sells with the amp
>round BNC connectors? I tried one and it seemed OK.
Don't know from first hand experience. If B&C is still selling
the same connectors and tools I used to sell, I can say that
the tool works well with the connectors we supplied for RG-58,
RG-400 and RG-142.
If it looked okay and passed a reasonable pull test (10 pounds)
then it's probably alright.
Bob . . .
-----------------------------------------
( Experience and common sense cannot be )
( replaced with policy and procedures. )
( R. L. Nuckolls III )
-----------------------------------------
Message 35
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| Subject: | Re: Runaway stab trim prevention |
--> AeroElectric-List message posted by: Mickey Coggins <mick-matronics@rv8.ch>
Has this actually happened to someone? What would cause it?
Is there a way to avoid the problem? Sounds kind of nasty.
>Saw a post today on one of the other email groups about the effects of
>runaway stab trim on an RV. ....
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
Message 36
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| Subject: | Re: batteries and diode isolation |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 11:05 PM 3/1/2004 -0600, you wrote:
>--> AeroElectric-List message posted by: Dave Morris <dave@davemorris.com>
>
>At 09:39 PM 3/1/2004, you wrote:
>
> > >
> > >Well, the circuit I'm referring to is here:
> > >http://sharkey.servebeer.com/~michael/christavia/electrics/batt_schematic
> > _rev3.jpg
> > >
> > >It would seem to have all the features we want.
> >
> >
> > Figure Z-11 with a Z-30 aux battery option, we STILL have three
> > contactors and only one relatively small diode to implement a
> > relatively independent 4-bus system where busses may be assigned
> > to mutually exclusive tasks. What operational failure can you
> > deduce where the Z-11/Z-30 falls short of what the 3-contactor/5-diode
> > arrangement provides?
> >
>
>Well, for one thing, I think the requirement to separate out loads into 4
>different busses, not knowing which of those busses might be the one that
>fails, is a liability that this schematic avoids. You don't have to play
>Sophie's choice with your electrical loads. I personally find it difficult
>to decide which of my loads are "non-essential" (with the obvious exception
>of the CD player!). Doesn't this circuit allow you to turn your entire
>electrical system into one giant "essential bus" and an "always hot bus"
>(i.e. ignition in this diagram), avoid the constant drain of multiple
>battery contactors,
It doesn't eliminate battery contactors. I presume the master
switch was a contactor . . . if it's a real switch, keep in mind
that it needs to mount close to the battery. Like 6" wires between
battery and siwtch.
> . . . and eliminate the pilot from the equation totally by
>handling all the source switching automatically with solid state components
>that have no moving parts?
First, the essential bus is not really for ESSENTIAL equipment.
Reread chapter 17 and think in terms of ENDURANCE instead of
ESSENTIAL. The stuff that goes on this bus are items you need for
continued flight in cruise configuration to airport of intended
destination. Battery bus is for things the engine needs to keep
running that require DC power. There should be no truly essential
items in your airplane that are not backed up. Essential things
are those that make the airplane come down or increase your risk
of hitting something hard. They generally do no include exterior
lights, engine instrumentation, supper-whippy panel lighting,
etc. If you have any one thing wherein failure causes you to
break a sweat, then you better have a backup for it. So, the
philosophy is that when everything essential is backed up,
there are no single failures that put the outcome of the flight
in doubt . . . i.e. no single thing is essential to flight.
This is a VERY short list of things. Further, we're assuming you'll
not treat your airplane like a C-172 and will do preventative
maintenance on the battery or batteries. You are not going to
experience an electrical emergency if you've planned your system
with reasonable care and understand how it operates.
Post your list of goodies and get some suggestions as to
how they can be powered from the various busses to provide
failure tolerance. What makes you think you need two batteries?
Do you plan to have a vacuum system?
This is a simpler task that you realize . . . that maze
of diodes to relieve you of having to make design decisions
creates more hazards than it eliminates.
Bob . . .
Message 37
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| Subject: | Re: Battery dumps |
--> AeroElectric-List message posted by: "Paul Messinger" <paulm@olypen.com>
Thanks for your support. I am fine, just see no need to spend thousands on
brand name equipment that may/may not meet DO-160. Also ever try to find out
just what the equipment really was tested to; say from King etc etc. Best
of luck truing to get that info from most any mfgr. Statements meeting
DO-160 or other \specs seldom are informative as which parts etc were met
and which parts were not tested or was it all engineering and no testing.
I fall back on common sense engineering as learned in aerospace where lots
of discussions with EMC group and lab drove what worked and what did not
work..
I have a auto engine conversion and find that requires a somewhat different
design approach. Also most automotive design standards appear to greatly
exceed what I can learn about DO-160 (which is darn little).
As far as DO-160 I do not know if it covers the load dump of the current
discussion and I am waiting for Bob to extract what HV pulse it tests to. As
an unprotected spike can exceed 50V the test of 20v or 30 v is not adequate
in my opinion and seems to be related to OVP not load dump protection.
I am working with another person off line that perhaps has a solution that
will be simple and keep the peak voltage under 20V, At least the potential
is that good. When the development is done He will be the one to announce as
its based on his input to the problem.
Expect it to take a month however to complete.
At this point I am waiting for info from Bob on what DO-160 tests to with
regard to spikes. Also perhaps the test circuit used.
We have what the auto industry tests to for load dump.
I wonder if DO-160 even addresses load dump effects on the equipment??
Who can tell, I sure cannot as Buying a copy is not in my budget.
This is a common problem where Standards are not public and one has to buy
the standard at manufacturers high prices.
Paul
----- Original Message -----
From: "David Carter" <dcarter@datarecall.net>
Subject: Re: AeroElectric-List: Re: Battery dumps
> --> AeroElectric-List message posted by: "David Carter"
<dcarter@datarecall.net>
>
> Bob & Paul,
>
> Thank you for the continuing excellent analysis and discussion - I feel
sure
> that "at the end of the tunnel" of this "thread", we are going to 1) have
> another innovative, well-peer-reviewed addition to our OBAM bus
> architecture - to deal with this "battery dump/surge" phenomenon, or, 2)
> have some really clear understanding of some "required" "pilot operating
> procedures to avoid 'economically un-fixable' bus architecture
limitations",
> and, maybe, 3) an optional 'economically stressful fix' to the problem
> (e.g., "power conditioner" that Bob mentioned - many of us are using
engine
> monitors and electronic fuel injection and electronic ignition controllers
> with computer boards and some are likely NOT DO-160 qual'd - stuff that we
> need to protect in order to stay airborne, as well as MicroEncoders and
> other NON-essential gadgets that we'd like to keep out of the "frying pan"
> so as to save our wallets.)
>
>
Message 38
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| Subject: | Official Usage Guideline [Please Read] [Monthly Posting] |
DNA: do not archive
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