AeroElectric-Archive.digest.vol-mf
January 13, 2014 - February 07, 2014
Legacy, 680 hours
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Z-12 Essential Bus Questions |
At 11:39 AM 1/11/2014, you wrote:
Thanks Bob. I read your recent, excellent
article on DO-160 testing. With EAB airplanes,
can we count on all the devices installed having
seen the same testing? Im planning on a bunch
of Garmins experimental avionics offerings and
Im not sure those boxes see the same testing as
their certified hardware. Ive Googled it a few
times but cant find anything. I need to ask
Garmins Team X about it. So thats why Im a
bit shy to risk putting all the avionics through engine start power cycling.
DO-160 isn't something that people shy away from
to be complied with only when mandated by the
customer . . . or the government.
It's design guidance that says, "If you want your
product to perform as advertised in the proposed
application (in this case, airplanes) then expect
to experience the following kinds of stresses.
The prudent designer of electro-whizzies for
any market has an intense interest in KNOWING
the nature source and magnitude of upsetting
stresses to their product . . . putting
an admonition into the operating manual to
"turn off during engine cranking" is a sad
anomaly that grew out of a knee-jerk reaction
to a spate of failures in solid state avionics
about 50 years ago. It went uncorrected for
decades after the lights of understanding came
on.
Garmin, nor anyone else I know, has a dual-path
development philosophy that says, "Do all the
good testing on products for TC aircraft and
we can let the OBAM market slide."
Good point about the every flight usefulness of
at least getting a radio up without bring all
your avionics up so yes, why not add a few
other essentials and provide a path around the battery contactor as well...
Sorry about my pictogram schematics sometimes
requiring more study than a basic schematic. The
power grid is a bad example of the benefits in my
wiring drawings. I have about 10 drawing layers
covering the various systems where the wiring
schematic is laid out in a kind of topology of
the airplane a top down view of the airplane in
cartoon form. It helps me visualize where
components and wires need to be within the
airplane and where connectors might be most
useful. On these drawings are also included the
basic wiring schematic and other key info related
to that system like pin outs for connectors, part
numbers, etc.. The power grid example in my
email was an excerpt from its overall page and
didnt include the ancillary stuff. Working them
up helps me get my novice head around the
problems involved and collect a lot of key related data in one place.
Understand. It's a powerful visualization tool for
assisting in your understanding and planning. But
its a variant on the language common to the
vast majority of practitioners which impedes
the rapid and accurate transfer of functional
understanding to others.
Bob . . .
________________________________________________________________________________
| Subject: | Re: How to Toggle Speed Brakes with Momentary On Switch? |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Switch Design 101:
Each switch is to be labled describing its function. The condition of the switch
must be apparent from its mechanical position, whether or not power is applied.
Airplanes have no momentary bi-stable switches.
--------
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=416870#416870
________________________________________________________________________________
| Subject: | Re: How to Toggle Speed Brakes with Momentary On |
Switch?
| From: | Eric Page <edpav8r(at)yahoo.com> |
On Jan 13, 2014, at 5:48 PM, "Eric M. Jones" wrote:
> Switch Design 101:
>
> Each switch is to be labled describing its function. The condition of the switch
must be apparent from its mechanical position, whether or not power is applied.
>
> Airplanes have no momentary bi-stable switches.
>
> Eric M. Jones
The overhead panel of the airplane I fly at work is littered with both momentary
contact and bi-stable latching switchlights. These devices have legends that
are illuminated from behind, and which present a flat black face when not illuminated.
Unless the illumination is on, the position of these switches is not
immediately apparent (even the latching variety, as their "on" state is only
~1/8 inch different than "off" and they don't all stick out the same amount).
For some of them, even legend illumination doesn't necessarily match switch position,
as some aircraft systems activate and deactivate automatically (i.e. fuel
boost pumps).
When the aircraft is running, all switchlights dark is considered normal operation.
Abnormal conditions illuminate switch legends. If the aircraft were powered
down, you would have to examine each switchlight closely to be sure of its
position, at least one of them would be impossible, and several would require
lifting a plastic guard to see clearly.
This type of switchlight is common to every large turbine aircraft with which I'm
familiar.
Eric
________________________________________________________________________________
| Subject: | How to Toggle Speed Brakes with Momentary On Switch? |
| From: | GLEN MATEJCEK <fly4grins(at)gmail.com> |
****SNIP****
From: Eric Page <edpav8r(at)yahoo.com>
..... Airplanes have no momentary bi-stable switches.
>
> Eric M. Jones
The overhead panel of the airplane I fly at work is littered with both
momentary
contact and bi-stable latching switchlights. ...
****SNIP****
Same for me and several A/C types I've flown.
________________________________________________________________________________
| Subject: | Re: How to Toggle Speed Brakes with Momentary On Switch? |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Bi-stable switches?
That isn't to say it's a good design. I suppose some allowances can be made, but
the basic principle applies:
Switch Design 101:
"Each switch is to be labled describing its function. The condition of the switch
must be apparent from its mechanical position, whether or not power is applied."
One could allow ignoring this principle for switches that:
a) Don't matter if the power is out and then present no surprises if the power
is turned on.
b) Don't affect safety.
c) Etc.
--------
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=416889#416889
________________________________________________________________________________
| From: | Roger Evenson <revenson(at)comcast.net> |
| Subject: | Change to Shottky? |
I wired Z11 with the earlier recommended endurance bus diode w/15 watt heatsink.
My loads are 11.5 amps intermittent maximum, 6.1a. typical, and if alternator
quits, I could shut things off to get to about 3.3 amps for comfortable endurance
use. I see 13.1-13.3 volts on this bus during flight. I have had no issues
in 350 hours.
Since completing my RV in 2010, I have been absent from the aeroelectric list.
I have noticed that the Shottky diode is now recommended.
Did a search to attempt to 'catch up' with the discussion and have tentatively
concluded that this change would be purely optional, and not 'highly recommended'
for some electrical reason.
I'm on a weight reduction kick, so my only objective to change to the Shottky would
only be to eliminate the 1/2 lb. of the heatsink.
Bob, et al: I'm looking for some assurance. Have I missed something pertinent to
this decision or am I on track?
Roger
"For I know the plans I have for you," declares the Lord, "plans to prosper you
and not to harm you, plans to give you hope and a future." Jeremiah 29:11
________________________________________________________________________________
| Subject: | Re: How to Toggle Speed Brakes with Momentary On Switch? |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
A good example of where you can use a bi-stable switch is on NAV COM frequency
flip-flops.
Logic: If power is out to the radio, then the switch doesn't matter. If power is
restored, then no hazard occurs.
--------
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=416904#416904
________________________________________________________________________________
| From: | Jeff Luckey <jluckey(at)pacbell.net> |
| Subject: | Re: Change to Shottky? |
Roger,=0A=0AThe advantage of Schottky diodes is that they have less voltage
drop than silicon diodes. Silicon is approx 0.7 volts and Schottky about 0
.5 volts. The advantage being that Schottkys dissipate a little less energy
.=0A=0AUsing your numbers for typical load:=0AExisting diode:=0AP = IE=0A
6 * .7 = 4.2W=0A=0ASchottky diode:=0A6 * .5 = 3.0W=0A=0AI agree w/ your
conclusion, probably not worth changing anything for a delta of 1.2W.=0A
=0A-Jeff=0A=0A=0A=0A________________________________=0A From: Roger Evenson
=0ATo: AeroElectric-List(at)matronics.com =0ASent: Tues
day, January 14, 2014 7:19 AM=0ASubject: AeroElectric-List: Change to Shott
ky?=0A =0A=0A=0AI wired Z11 with the earlier recommended endurance bus diod
e w/15 watt heatsink.- My loads are 11.5 amps intermittent maximum, 6.1a.
typical, and if alternator quits, I could shut things off to get to about
3.3 amps for comfortable endurance use.- I see 13.1-13.3 volts on this bu
s during flight.- I have had no issues in 350 hours.=0A=0ASince completin
g my RV in 2010, I have been absent from the aeroelectric list.- I have n
oticed that the Shottky diode is now recommended.=0ADid a search to attempt
to 'catch up' with the discussion and have tentatively concluded that this
change would be purely optional, and not 'highly recommended' for some ele
ctrical reason.=0A=0AI'm on a weight reduction kick, so my only objective t
o change to the Shottky would only be to eliminate the 1/2 lb. of the heats
ink.=0A=0ABob, et al:- I'm looking for some assurance.- Have I missed s
omething pertinent to this decision or am I on track?=0A=0A=0ARoger=0A=0A
=0A"For I know the plans I have for you," declares the Lord, "plans to pros
per you and not to harm you, plans to give you hope and a future."- Jerem
=========================0A
________________________________________________________________________________
| From: | Thomas Blejwas <tomblejwas(at)yahoo.com> |
| Subject: | Re: Change to Shottky? |
-At Bob's suggestion, I've been looking at double anode --single cathod
e arrangements in a TO-247 case, wired so that current goes through both di
odes.-- My average amperage will be 6-7-amps (12 to-14 total)-and
I can find packages that will have voltage drops of 0.3 volts or less.-
The tradeoff is higher leakage, but I don't see how a few tens of-mA will
cause problems.- With only 4 watts or so, Bob suggested using the alumin
um already behind the panel.- Even if you don't have enough sheet aluminu
m, there are light-weight heat sinks for the TO-247 package that only cost
a couple of bucks and weigh-an ounce or so.- The TO-247-does have to
be solder connected and mounted with an electrically resistive-pad, which
adds-little to cost or weight.=0A=0ATom=0A=0A=0A=0A=0A>_________________
_______________=0A> From: Jeff Luckey <jluckey(at)pacbell.net>=0A>To: "aeroele
ctric-list(at)matronics.com" =0A>Sent: Tuesd
ay, January 14, 2014 9:49 AM=0A>Subject: Re: AeroElectric-List: Change to S
hottky?=0A> =0A>=0A>=0A>Roger,=0A>=0A>=0A>The advantage of Schottky diodes
is that they have less voltage drop than silicon diodes. Silicon is approx
0.7 volts and Schottky about 0.5 volts. The advantage being that Schottkys
dissipate a little less energy.=0A>=0A>=0A>Using your numbers for typical
load:=0A>Existing diode:=0A>P = IE=0A>6 * .7 = 4.2W=0A>=0A>=0A>Schottky
diode:=0A>6 * .5 = 3.0W=0A>=0A>=0A>I agree w/ your conclusion, probably
not worth changing anything for a delta of 1.2W.=0A>=0A>=0A>-Jeff=0A>=0A>
=0A> =0A>=0A>________________________________=0A> From: Roger Evenson <reve
nson(at)comcast.net>=0A>To: AeroElectric-List(at)matronics.com =0A>Sent: Tuesday,
January 14, 2014 7:19 AM=0A>Subject: AeroElectric-List: Change to Shottky?
=0A> =0A>=0A>=0A>I wired Z11 with the earlier recommended endurance bus di
ode w/15 watt heatsink.- My loads are 11.5 amps intermittent maximum, 6.1
a. typical, and if alternator quits, I could shut things off to get to abou
t 3.3 amps for comfortable endurance use.- I see 13.1-13.3 volts on this
bus during flight.- I have had no issues in 350 hours.=0A>=0A>Since compl
eting my RV in 2010, I have been absent from the aeroelectric list.- I ha
ve noticed that the Shottky diode is now recommended.=0A>Did a search to at
tempt to 'catch up' with the discussion and have tentatively concluded that
this change would be purely optional, and not 'highly recommended' for som
e electrical reason.=0A>=0A>I'm on a weight=0A reduction kick, so my only o
bjective to change to the Shottky would only be to eliminate the 1/2 lb. of
the heatsink.=0A>=0A>Bob, et al:- I'm looking for some assurance.- Hav
e I missed something pertinent to this decision or am I on track?=0A>=0A>
=0A>Roger=0A>=0A>=0A>"For I know the plans I have for you," declares the Lo
rd, "plans to prosper you and not to harm you, plans to give you hope and a
-========================
=========== =0A>=0A>
________________________________________________________________________________
| From: | "msmeredith" <msmeredith(at)comcast.net> |
Hi - I'm installing a Kannad Integra 406AF ELT with built in GPS. The cheapest
antenna for this ELT is the whip, which is what I bought with it. The blade/vane
for this unit are hundreds/thousands more expensive. But now I'm trying
to figure out where to put the whip! It's a monstrosity.
Aircraft is a Super Chipmunk which I'm totally rebuilding. (Google "Super Chipmunk
Restoration".) I successfully completed a new electrical system using the
Z-11 architecture and knowledge gained from the Aeroelectric Connection and this
list. (Thanks!!) The ELT is the last thing on the to-do list before I secure
all the wire bundles.
This is an unusual Chippy - it's single seat open cockpit, and I installed an 8
foot long turtleback/headrest to conceal a rollover bar behind the rear seat.
It's .025 alum, about a foot high/wide at the cockpit then tapering to about
4 inches at the fin. I'd like to mount the antenna 2 feet back on the top of
the main fuselage structure, so the rubber part is inside the turtleback, then
poke the steel whip out the top through a small hole/grommet. That approach
would be unobtrusive, avoid an ugly 2 foot tall antenna with fat black base,
and avoid beefing up the turtleback top to support it. My question: would the
ELT still be heard with the bottom 8 inches or so of base hidden under .025
alum?
Thanks!
--------
Mark Meredith
Super Chipmunk N7DW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416915#416915
________________________________________________________________________________
| From: | "The Kuffels" <kuffel(at)cyberport.net> |
Mark,
<< would the ELT still be heard with the bottom 8 inches or so of base
hidden under .025 alum? >>
Yes.
You are much more likely to not be heard by having the external part of the
whip sheared off in the crash.
The longer answer involves not only the shielding effect caused by the
aluminum but also the feed mismatch, both of which will reduce signal
output. But the application is so direct there is no doubt you could be
heard by a satellite. If you wish to be sure, build a mock up with foil
over cardboard and scrap tubing. See how it works with and without the
foil. Don't forget the rules about when and how to test ELTs.
Tom Kuffel
________________________________________________________________________________
| From: | "Stuart Hutchison" <stuart(at)stuarthutchison.com.au> |
The Kannad whip antenna is base-loaded, so the ugly first 6" black base is
part of the radiating element that needs to be exposed. I'll be making an
angled mount with fibreglass fairing like a COM antenna for the underside of
my Rocket, since I also have a manual 406 GPS PLB. I figure any automatic
activation of the ELT will be because of a sudden stop, so I'll probably be
upside down about then. My life may depend on the automatic system pointing
skywards from the underbelly.
Kind regards, Stu
F1 Rocket VH-FLY http://www.mykitlog.com/RockFLY
www.teamrocketaircraft.com
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
msmeredith
Sent: Wednesday, January 15, 2014 2:04 PM
Subject: AeroElectric-List: ELT Antenna
-->
Hi - I'm installing a Kannad Integra 406AF ELT with built in GPS. The
cheapest antenna for this ELT is the whip, which is what I bought with it.
The blade/vane for this unit are hundreds/thousands more expensive. But now
I'm trying to figure out where to put the whip! It's a monstrosity.
Aircraft is a Super Chipmunk which I'm totally rebuilding. (Google "Super
Chipmunk Restoration".) I successfully completed a new electrical system
using the Z-11 architecture and knowledge gained from the Aeroelectric
Connection and this list. (Thanks!!) The ELT is the last thing on the
to-do list before I secure all the wire bundles.
This is an unusual Chippy - it's single seat open cockpit, and I installed
an 8 foot long turtleback/headrest to conceal a rollover bar behind the rear
seat. It's .025 alum, about a foot high/wide at the cockpit then tapering
to about 4 inches at the fin. I'd like to mount the antenna 2 feet back on
the top of the main fuselage structure, so the rubber part is inside the
turtleback, then poke the steel whip out the top through a small
hole/grommet. That approach would be unobtrusive, avoid an ugly 2 foot tall
antenna with fat black base, and avoid beefing up the turtleback top to
support it. My question: would the ELT still be heard with the bottom 8
inches or so of base hidden under .025 alum?
Thanks!
--------
Mark Meredith
Super Chipmunk N7DW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416915#416915
________________________________________________________________________________
| From: | "msmeredith" <msmeredith(at)comcast.net> |
The longer answer involves not only the shielding effect caused by the
aluminum but also the feed mismatch, both of which will reduce signal
output. But the application is so direct there is no doubt you could be
heard by a satellite. If you wish to be sure, build a mock up with foil
over cardboard and scrap tubing. See how it works with and without the
foil. Don't forget the rules about when and how to test ELTs.
Tom Kuffel[/quote]
Tom,
Good idea. What do I need to measure the output with this mockup?
--------
Mark Meredith
Super Chipmunk N7DW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416930#416930
________________________________________________________________________________
| From: | "msmeredith" <msmeredith(at)comcast.net> |
stuart(at)stuarthutchison wrote:
> I'll be making an
> angled mount with fibreglass fairing like a COM antenna for the underside of
> my Rocket, since I also have a manual 406 GPS PLB.
> Kind regards, Stu
>
> F1 Rocket VH-FLY http://www.mykitlog.com/RockFLY
> www.teamrocketaircraft.com
> --
Stu,
I've thought about the "impact" of a rollover which is why I added the rollbar.
But think I'll stick with an assumption the airplane is still airborne or upright
in big pieces if the ELT is ever activated!
I have a very small cockpit and don't plan to carry a PLB. There are very few
places to put even a portable GPS for trips, so I went with the installed ELT
(best I can tell, aircraft has never had one since it was built in 1951). Kannad
has an internal antenna also so works without the whip in a handheld mode,
though I'd need a screwdriver and a good hand to access it...
--------
Mark Meredith
Super Chipmunk N7DW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416931#416931
________________________________________________________________________________
| From: | "The Kuffels" <kuffel(at)cyberport.net> |
Mark,
<< works with and without the foil. .... Good idea. What do I need
to measure the output with this mockup? >>
The ELT still transmits on 121.5 so any aircraft band hand held will do
the job. Most hand helds have a signal strength indicator but a better
way (although tedious) is to see how far away (over flat ground) you can
hear it without the foil/cardboard. Then try it with the shield. No
guarantee it will be just as good at 406MHz but the odds are likely.
Or contact a local amateur radio club (find at arrl.org). Many ham UHF
hand helds can receive 406MHz. You will easily find a ham who would
enjoy helping with your experiment.
<< But think I'll stick with an assumption the airplane is still
airborne or upright in big pieces if the ELT is ever activated! >>
My experience suggests this is not a valid assumption. When this is
true, the people are ambulatory, can remove the ELT from its mount,
attach the portable antenna, or just talk on the aircraft radio. But in
most crashes I have seen, if the occupants are badly injured (and so
really need an ELT) then most external antennas are no longer working.
Carrying a PRB in your pocket might be a good Plan B.
If you do run the test, let us know the results.
Tom Kuffel
________________________________________________________________________________
| From: | "msmeredith" <msmeredith(at)comcast.net> |
[quote="kuffel(at)cyberport.net"]Mark,
The ELT still transmits on 121.5 so any aircraft band hand held will do the job.
Most hand helds have a signal strength indicator but a better way (although
tedious) is to see how far away (over flat ground) you can hear it without
the foil/cardboard. Then try it with the shield. No guarantee it will be
just as good at 406MHz but the odds are likely.
Or contact a local amateur radio club (find at arrl.org). Many ham UHF hand
helds can receive 406MHz. You will easily find a ham who would enjoy helping
with your experiment.
>
My experience suggests this is not a valid assumption. When this is true, the
people are ambulatory, can remove the ELT from its mount, attach the portable
antenna, or just talk on the aircraft radio. But in most crashes I have seen,
if the occupants are badly injured (and so really need an ELT) then most
external antennas are no longer working. Carrying a PRB in your pocket might
be a good Plan B.
If you do run the test, let us know the results.
Tom Kuffel
> [b]
Tom,
Thanks. I'll run the test and let you know. I have some extra .025 alum so will
use that for the mockup.
--------
Mark Meredith
Super Chipmunk N7DW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416949#416949
________________________________________________________________________________
| From: | "msmeredith" <msmeredith(at)comcast.net> |
kuffel(at)cyberport.net wrote:
> Mark,
>
>
>
> The ELT still transmits on 121.5 so any aircraft band hand held will do the
job. Most hand helds have a signal strength indicator but a better way (although
tedious) is to see how far away (over flat ground) you can hear it without
the foil/cardboard. Then try it with the shield. No guarantee it will be
just as good at 406MHz but the odds are likely.
>
> Or contact a local amateur radio club (find at arrl.org). Many ham UHF hand
helds can receive 406MHz. You will easily find a ham who would enjoy helping
with your experiment.
>
> >
>
> My experience suggests this is not a valid assumption. When this is true,
the people are ambulatory, can remove the ELT from its mount, attach the portable
antenna, or just talk on the aircraft radio. But in most crashes I have
seen, if the occupants are badly injured (and so really need an ELT) then most
external antennas are no longer working. Carrying a PRB in your pocket might
be a good Plan B.
>
> If you do run the test, let us know the results.
>
> Tom Kuffel
Tom and other listers,
Second thoughts. My bent comm and blade transponder antennas are under the belly
amidships behind the wing, close to the ELT transmitter's position above them.
If I mount the ELT whip antenna underneath also, can I bend the steel rod
beyond the black base so it's shaped similar to my comm antenna? Would I need
a large bend radius to prevent it from breaking, and would this affect the transmit
functionality? I could move it forward a foot or so (just aft the flaps)
to separate it from the comm antennas. I just need to be careful not to
tune my radio to 121.5 when testing the ELT.
Of course that round antenna base will be a big source of drag, but mounting it
underneath would solve the rollover and aesthetic issues. Though now the assumption
is the landing gear stay with the airplane!
--------
Mark Meredith
Super Chipmunk N7DW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=416954#416954
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Change to Shottky? |
At 01:20 PM 1/14/2014, you wrote:
At Bob's suggestion, I've been looking at double anode - single
cathode arrangements in a TO-247 case, wired so that current goes
through both diodes. My average amperage will be 6-7 amps (12 to 14
total) and I can find packages that will have voltage drops of 0.3
volts or less. The tradeoff is higher leakage, but I don't see how a
few tens of mA will cause problems. With only 4 watts or so, Bob
suggested using the aluminum already behind the panel. Even if you
don't have enough sheet aluminum, there are light-weight heat sinks
for the TO-247 package that only cost a couple of bucks and weigh an
ounce or so. The TO-247 does have to be solder connected and mounted
with an electrically resistive pad, which adds little to cost or weight.
You're not going to find Schottky devices with rated
for such low voltage drops at their rated current.
To push the drop down, you use oversized to grossly
oversized diodes lightly loaded and yes, your
drop will go down a tad.
The advantage of Schottky diodes is that they have less voltage drop
than silicon diodes. Silicon is approx 0.7 volts and Schottky about
0.5 volts. The advantage being that Schottkys dissipate a little less energy.
Using your numbers for typical load:
Existing diode:
P = IE
6 * .7 = 4.2W
Schottky diode:
6 * .5 = 3.0W
I agree w/ your conclusion, probably not worth changing anything for
a delta of 1.2W.'
Agreed . . . The only time the diode is 'wasting'
energy is when the alternator is running and if you're
running a 40A+ alternator, the energy 'savings'
is trivial.
I wired Z11 with the earlier recommended endurance bus diode w/15
watt heatsink. My loads are 11.5 amps intermittent maximum, 6.1a.
typical, and if alternator quits, I could shut things off to get to
about 3.3 amps for comfortable endurance use. I see 13.1-13.3 volts
on this bus during flight. I have had no issues in 350 hours.
That heatsink is WAaayyyy bigger than you need for this
application.
Since completing my RV in 2010, I have been absent from the
aeroelectric list. I have noticed that the Shottky diode is now recommended.
It's an OPTION . . . one of several.
Did a search to attempt to 'catch up' with the discussion and have
tentatively concluded that this change would be purely optional, and
not 'highly recommended' for some electrical reason.
EXACTLY. I would not recommend anyone swap out
an existing rectifier installation. The Schotty devices
are attractive for new construction. My product uses
the airframe for heat management . . . a bit more compact
than the rectifier . . .
There are VERY few incarnations of the e-bus that
demands a finned heat-sink for the rectifier. Either
the silicon junction rectifier -OR- the Schottky
device should exist quite happily simply sinked
to the airplane.
Products like this
http://tinyurl.com/mfp9k7a
probably make sense in a composite airplane but I
suspect that few installations in metal airplanes
need the extra heat-sink.
I'm on a weight reduction kick, so my only objective to change to the
Shottky would only be to eliminate the 1/2 lb. of the heat-sink.
1/2 pound? Which heat-sink are you using?
Bob, et al: I'm looking for some assurance. Have I missed something
pertinent to this decision or am I on track?
Is this a metal airplane? Have you looked at simply
bolting the diode to local sheet metal?
Bob . . .
________________________________________________________________________________
| From: | Roger Evenson <revenson(at)comcast.net> |
| Subject: | Re: Change to Shottky? |
Bob: To answer your questions, this is an RV7, all metal airplane. The heat sink
I used was the 15 watt one, the larger of the two offered at B&C. It weighs
7 oz.
I will remove it and install directly to the aluminum subpanel.
Would you change your recommendation if you knew I was in Arizona, occasionally
flying in 100+ temperatures?
Thanks. Roger
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Sent: Wednesday, January 15, 2014 1:43:39 PM
Subject: Re: AeroElectric-List: Change to Shottky?
At 01:20 PM 1/14/2014, you wrote:
At Bob's suggestion, I've been looking at double anode - single
cathode arrangements in a TO-247 case, wired so that current goes
through both diodes. My average amperage will be 6-7 amps (12 to 14
total) and I can find packages that will have voltage drops of 0.3
volts or less. The tradeoff is higher leakage, but I don't see how a
few tens of mA will cause problems. With only 4 watts or so, Bob
suggested using the aluminum already behind the panel. Even if you
don't have enough sheet aluminum, there are light-weight heat sinks
for the TO-247 package that only cost a couple of bucks and weigh an
ounce or so. The TO-247 does have to be solder connected and mounted
with an electrically resistive pad, which adds little to cost or weight.
You're not going to find Schottky devices with rated
for such low voltage drops at their rated current.
To push the drop down, you use oversized to grossly
oversized diodes lightly loaded and yes, your
drop will go down a tad.
The advantage of Schottky diodes is that they have less voltage drop
than silicon diodes. Silicon is approx 0.7 volts and Schottky about
0.5 volts. The advantage being that Schottkys dissipate a little less energy.
Using your numbers for typical load:
Existing diode:
P = IE
6 * .7 = 4.2W
Schottky diode:
6 * .5 = 3.0W
I agree w/ your conclusion, probably not worth changing anything for
a delta of 1.2W.'
Agreed . . . The only time the diode is 'wasting'
energy is when the alternator is running and if you're
running a 40A+ alternator, the energy 'savings'
is trivial.
I wired Z11 with the earlier recommended endurance bus diode w/15
watt heatsink. My loads are 11.5 amps intermittent maximum, 6.1a.
typical, and if alternator quits, I could shut things off to get to
about 3.3 amps for comfortable endurance use. I see 13.1-13.3 volts
on this bus during flight. I have had no issues in 350 hours.
That heatsink is WAaayyyy bigger than you need for this
application.
Since completing my RV in 2010, I have been absent from the
aeroelectric list. I have noticed that the Shottky diode is now recommended.
It's an OPTION . . . one of several.
Did a search to attempt to 'catch up' with the discussion and have
tentatively concluded that this change would be purely optional, and
not 'highly recommended' for some electrical reason.
EXACTLY. I would not recommend anyone swap out
an existing rectifier installation. The Schotty devices
are attractive for new construction. My product uses
the airframe for heat management . . . a bit more compact
than the rectifier . . .
There are VERY few incarnations of the e-bus that
demands a finned heat-sink for the rectifier. Either
the silicon junction rectifier -OR- the Schottky
device should exist quite happily simply sinked
to the airplane.
Products like this
http://tinyurl.com/mfp9k7a
probably make sense in a composite airplane but I
suspect that few installations in metal airplanes
need the extra heat-sink.
I'm on a weight reduction kick, so my only objective to change to the
Shottky would only be to eliminate the 1/2 lb. of the heat-sink.
1/2 pound? Which heat-sink are you using?
Bob, et al: I'm looking for some assurance. Have I missed something
pertinent to this decision or am I on track?
Is this a metal airplane? Have you looked at simply
bolting the diode to local sheet metal?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 09:04 PM 1/14/2014, you wrote:
Hi - I'm installing a Kannad Integra 406AF ELT with built in
GPS. The cheapest antenna for this ELT is the whip, which is what I
bought with it. The blade/vane for this unit are hundreds/thousands
more expensive. But now I'm trying to figure out where to put the
whip! It's a monstrosity.
I presume you're talking about the AV-200 described in
Kannad's manual . . . .
http://tinyurl.com/olaccxt
This is an unusual Chippy - it's single seat open cockpit, and I
installed an 8 foot long turtleback/headrest to conceal a rollover
bar behind the rear seat. It's .025 alum, about a foot high/wide at
the cockpit then tapering to about 4 inches at the fin. I'd like to
mount the antenna 2 feet back on the top of the main fuselage
structure, so the rubber part is inside the turtleback, then poke the
steel whip out the top through a small hole/grommet. That approach
would be unobtrusive, avoid an ugly 2 foot tall antenna with fat
black base, and avoid beefing up the turtleback top to support
it. My question: would the ELT still be heard with the bottom 8
inches or so of base hidden under .025 alum?
Probably not. That "bottom 8" is probably the 406 mHz
part of the antenna. Further, given that this product
doesn't have a separate GPS antenna, I'm assuming that
the single antenna assembly serves the GPS receiver
as well.
I think you should take pains to install per the
manufacturer's recommendations.
Bob . . .
________________________________________________________________________________
| From: | "The Kuffels" <kuffel(at)cyberport.net> |
Mark,
<< If I mount the ELT whip antenna underneath also >>
This is probably the worst location for an ELT antenna. Any kind of brush
at an off-airport landing will wipe it off the fuselage.
<< can I bend the steel rod beyond the black base so it's shaped similar to
my comm antenna? >>
Don't know why not.
<< Would I need a large bend radius to prevent it from breaking, >>
No idea. If the antenna there is just a steel rod as you say, then bending
it around a 1" pipe or so should work. But once again, this is a very bad
location.
<< would this affect the transmit functionality? I could move it forward a
foot or so (just aft the flaps) to separate it from the comm antennas. >>
The nearness of other VHF antennas will affect performance more than a bend.
The above fuselage location has two ground planes of isolation from your Com
antenna.
Is it time yet to consider making the cover out of fiberglass instead of
aluminum?
Tom Kuffel
________________________________________________________________________________
| From: | "Stuart Hutchison" <stuart(at)stuarthutchison.com.au> |
The ELT antenna is almost never radiating and when it is activated, COM
radio performance is unlikely to be relevant. Bob may be able to confirm,
but I believe the ELT antenna proximity to VHF COM antennas can be
problematic because radio transmissions have been known to activate the ELT.
I acknowledge Mark's comment about the possibility of an underbelly antenna
being wiped off, which is why the base of mine will be firmly mounted
(midships) angled aft at about 45 deg (rather than bend the whip element)
and the fat part faired with fibreglass to minimise/absorb antenna impact
damage and or carve a path through the brush/grass. Perhaps different with
a tricycle undercarriage, but I can expect the taildragger to be upside down
if I land in scrub (with the main wheels so far forward and a heavy engine),
so my priority is to have the antenna less shielded by the aircraft when
inverted. If it were mounted on top, then it may also wiped off as the
aircraft comes to rest inverted or be pinned flat against the ally skin.
Preserving the coax link between the transmitter and antenna is a known
problem in major crashes, so keep the coax run short, protected and flexible
too if possible.
Kind regards, Stu
F1 Rocket VH-FLY http://www.mykitlog.com/RockFLY
www.teamrocketaircraft.com
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of The
Kuffels
Sent: Thursday, January 16, 2014 12:32 PM
Subject: Re: AeroElectric-List: Re: ELT Antenna
-->
Mark,
<< If I mount the ELT whip antenna underneath also >>
This is probably the worst location for an ELT antenna. Any kind of brush
at an off-airport landing will wipe it off the fuselage.
<< can I bend the steel rod beyond the black base so it's shaped similar to
my comm antenna? >>
Don't know why not.
<< Would I need a large bend radius to prevent it from breaking, >>
No idea. If the antenna there is just a steel rod as you say, then bending
it around a 1" pipe or so should work. But once again, this is a very bad
location.
<< would this affect the transmit functionality? I could move it forward a
foot or so (just aft the flaps) to separate it from the comm antennas. >>
The nearness of other VHF antennas will affect performance more than a bend.
The above fuselage location has two ground planes of isolation from your Com
antenna.
Is it time yet to consider making the cover out of fiberglass instead of
aluminum?
Tom Kuffel
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
Almost all ELTs, especially the older ones do in fact radiate anytime
they are near high powered VHF transmitters in the FM, TV, etc bands.
That radiation will in fact severely affect Com radio reception.
The antenna for ELT is integral to its TSO so no home brew antennas
fullfill the TSO. While I think most DAR's are somewhat tolerant as to
antenna placement, most install instructions do call for installation on
top of the fuselage, and the install instructions are also part of the
TSO approval.
So while you may have valid points about final resting of a crash being
upside down, during the touchdown, prior to rollout odds are very high
that any belly antenna will be wiped off the airframe. IMHO, with about
equal experience between tail wheel(mostly off pavement in Alaska) and
nose dragging aircraft, in off field landing situations of soft surface,
nose wheel is far more likely to cause flipping than tail wheel.
Non-compliance with TSO is between you and your DAR, but most discussed
here will be at least technical non-compliance.
Kelly
On 1/15/2014 7:47 PM, Stuart Hutchison wrote:
>
> The ELT antenna is almost never radiating and when it is activated, COM
> radio performance is unlikely to be relevant. Bob may be able to confirm,
> but I believe the ELT antenna proximity to VHF COM antennas can be
> problematic because radio transmissions have been known to activate the ELT.
>
> I acknowledge Mark's comment about the possibility of an underbelly antenna
> being wiped off, which is why the base of mine will be firmly mounted
> (midships) angled aft at about 45 deg (rather than bend the whip element)
> and the fat part faired with fibreglass to minimise/absorb antenna impact
> damage and or carve a path through the brush/grass. Perhaps different with
> a tricycle undercarriage, but I can expect the taildragger to be upside down
> if I land in scrub (with the main wheels so far forward and a heavy engine),
> so my priority is to have the antenna less shielded by the aircraft when
> inverted. If it were mounted on top, then it may also wiped off as the
> aircraft comes to rest inverted or be pinned flat against the ally skin.
> Preserving the coax link between the transmitter and antenna is a known
> problem in major crashes, so keep the coax run short, protected and flexible
> too if possible.
>
> Kind regards, Stu
>
> F1 Rocket VH-FLY http://www.mykitlog.com/RockFLY
> www.teamrocketaircraft.com
>
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of The
> Kuffels
> Sent: Thursday, January 16, 2014 12:32 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Re: ELT Antenna
>
> -->
>
> Mark,
>
> << If I mount the ELT whip antenna underneath also >>
>
> This is probably the worst location for an ELT antenna. Any kind of brush
> at an off-airport landing will wipe it off the fuselage.
>
> << can I bend the steel rod beyond the black base so it's shaped similar to
> my comm antenna? >>
>
> Don't know why not.
>
> << Would I need a large bend radius to prevent it from breaking, >>
>
> No idea. If the antenna there is just a steel rod as you say, then bending
> it around a 1" pipe or so should work. But once again, this is a very bad
> location.
>
> << would this affect the transmit functionality? I could move it forward a
>
> foot or so (just aft the flaps) to separate it from the comm antennas. >>
>
> The nearness of other VHF antennas will affect performance more than a bend.
>
> The above fuselage location has two ground planes of isolation from your Com
> antenna.
>
> Is it time yet to consider making the cover out of fiberglass instead of
> aluminum?
>
> Tom Kuffel
>
>
________________________________________________________________________________
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
DAR approval not needed as the ELT is not even required unless there are 2 or more
seats, or for phase 1 testing. Not saying its wise or will work, but it will
not be required to be present for airworthiness.
Tim
> On Jan 15, 2014, at 7:16 PM, Kelly McMullen wrote:
>
>
> Almost all ELTs, especially the older ones do in fact radiate anytime they are
near high powered VHF transmitters in the FM, TV, etc bands.
> That radiation will in fact severely affect Com radio reception.
> The antenna for ELT is integral to its TSO so no home brew antennas fullfill
the TSO. While I think most DAR's are somewhat tolerant as to antenna placement,
most install instructions do call for installation on top of the fuselage,
and the install instructions are also part of the TSO approval.
> So while you may have valid points about final resting of a crash being upside
down, during the touchdown, prior to rollout odds are very high that any belly
antenna will be wiped off the airframe. IMHO, with about equal experience between
tail wheel(mostly off pavement in Alaska) and nose dragging aircraft, in
off field landing situations of soft surface, nose wheel is far more likely
to cause flipping than tail wheel.
> Non-compliance with TSO is between you and your DAR, but most discussed here
will be at least technical non-compliance.
> Kelly
>> On 1/15/2014 7:47 PM, Stuart Hutchison wrote:
>>
>> The ELT antenna is almost never radiating and when it is activated, COM
>> radio performance is unlikely to be relevant. Bob may be able to confirm,
>> but I believe the ELT antenna proximity to VHF COM antennas can be
>> problematic because radio transmissions have been known to activate the ELT.
>>
>> I acknowledge Mark's comment about the possibility of an underbelly antenna
>> being wiped off, which is why the base of mine will be firmly mounted
>> (midships) angled aft at about 45 deg (rather than bend the whip element)
>> and the fat part faired with fibreglass to minimise/absorb antenna impact
>> damage and or carve a path through the brush/grass. Perhaps different with
>> a tricycle undercarriage, but I can expect the taildragger to be upside down
>> if I land in scrub (with the main wheels so far forward and a heavy engine),
>> so my priority is to have the antenna less shielded by the aircraft when
>> inverted. If it were mounted on top, then it may also wiped off as the
>> aircraft comes to rest inverted or be pinned flat against the ally skin.
>> Preserving the coax link between the transmitter and antenna is a known
>> problem in major crashes, so keep the coax run short, protected and flexible
>> too if possible.
>>
>> Kind regards, Stu
>>
>> F1 Rocket VH-FLY http://www.mykitlog.com/RockFLY
>> www.teamrocketaircraft.com
>>
>>
>>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server(at)matronics.com
>> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of The
>> Kuffels
>> Sent: Thursday, January 16, 2014 12:32 PM
>> To: aeroelectric-list(at)matronics.com
>> Subject: Re: AeroElectric-List: Re: ELT Antenna
>>
>> -->
>>
>> Mark,
>>
>> << If I mount the ELT whip antenna underneath also >>
>>
>> This is probably the worst location for an ELT antenna. Any kind of brush
>> at an off-airport landing will wipe it off the fuselage.
>>
>> << can I bend the steel rod beyond the black base so it's shaped similar to
>> my comm antenna? >>
>>
>> Don't know why not.
>>
>> << Would I need a large bend radius to prevent it from breaking, >>
>>
>> No idea. If the antenna there is just a steel rod as you say, then bending
>> it around a 1" pipe or so should work. But once again, this is a very bad
>> location.
>>
>> << would this affect the transmit functionality? I could move it forward a
>>
>> foot or so (just aft the flaps) to separate it from the comm antennas. >>
>>
>> The nearness of other VHF antennas will affect performance more than a bend.
>>
>> The above fuselage location has two ground planes of isolation from your Com
>> antenna.
>>
>> Is it time yet to consider making the cover out of fiberglass instead of
>> aluminum?
>>
>> Tom Kuffel
>
>
>
>
>
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
Agreed if a single seater is all that is involved.
On 1/15/2014 8:47 PM, Tim Andres wrote:
>
> DAR approval not needed as the ELT is not even required unless there are 2 or
more seats, or for phase 1 testing. Not saying its wise or will work, but it
will not be required to be present for airworthiness.
>
> Tim
>
>> On Jan 15, 2014, at 7:16 PM, Kelly McMullen wrote:
>>
>>
>> Almost all ELTs, especially the older ones do in fact radiate anytime they are
near high powered VHF transmitters in the FM, TV, etc bands.
>> That radiation will in fact severely affect Com radio reception.
>> The antenna for ELT is integral to its TSO so no home brew antennas fullfill
the TSO. While I think most DAR's are somewhat tolerant as to antenna placement,
most install instructions do call for installation on top of the fuselage,
and the install instructions are also part of the TSO approval.
>> So while you may have valid points about final resting of a crash being upside
down, during the touchdown, prior to rollout odds are very high that any belly
antenna will be wiped off the airframe. IMHO, with about equal experience
between tail wheel(mostly off pavement in Alaska) and nose dragging aircraft,
in off field landing situations of soft surface, nose wheel is far more likely
to cause flipping than tail wheel.
>> Non-compliance with TSO is between you and your DAR, but most discussed here
will be at least technical non-compliance.
>> Kelly
>>> On 1/15/2014 7:47 PM, Stuart Hutchison wrote:
>>>
>>> The ELT antenna is almost never radiating and when it is activated, COM
>>> radio performance is unlikely to be relevant. Bob may be able to confirm,
>>> but I believe the ELT antenna proximity to VHF COM antennas can be
>>> problematic because radio transmissions have been known to activate the ELT.
>>>
>>> I acknowledge Mark's comment about the possibility of an underbelly antenna
>>> being wiped off, which is why the base of mine will be firmly mounted
>>> (midships) angled aft at about 45 deg (rather than bend the whip element)
>>> and the fat part faired with fibreglass to minimise/absorb antenna impact
>>> damage and or carve a path through the brush/grass. Perhaps different with
>>> a tricycle undercarriage, but I can expect the taildragger to be upside down
>>> if I land in scrub (with the main wheels so far forward and a heavy engine),
>>> so my priority is to have the antenna less shielded by the aircraft when
>>> inverted. If it were mounted on top, then it may also wiped off as the
>>> aircraft comes to rest inverted or be pinned flat against the ally skin.
>>> Preserving the coax link between the transmitter and antenna is a known
>>> problem in major crashes, so keep the coax run short, protected and flexible
>>> too if possible.
>>>
>>> Kind regards, Stu
>>>
>>> F1 Rocket VH-FLY http://www.mykitlog.com/RockFLY
>>> www.teamrocketaircraft.com
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: owner-aeroelectric-list-server(at)matronics.com
>>> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of The
>>> Kuffels
>>> Sent: Thursday, January 16, 2014 12:32 PM
>>> To: aeroelectric-list(at)matronics.com
>>> Subject: Re: AeroElectric-List: Re: ELT Antenna
>>>
>>> -->
>>>
>>> Mark,
>>>
>>> << If I mount the ELT whip antenna underneath also >>
>>>
>>> This is probably the worst location for an ELT antenna. Any kind of brush
>>> at an off-airport landing will wipe it off the fuselage.
>>>
>>> << can I bend the steel rod beyond the black base so it's shaped similar to
>>> my comm antenna? >>
>>>
>>> Don't know why not.
>>>
>>> << Would I need a large bend radius to prevent it from breaking, >>
>>>
>>> No idea. If the antenna there is just a steel rod as you say, then bending
>>> it around a 1" pipe or so should work. But once again, this is a very bad
>>> location.
>>>
>>> << would this affect the transmit functionality? I could move it forward
a
>>>
>>> foot or so (just aft the flaps) to separate it from the comm antennas. >>
>>>
>>> The nearness of other VHF antennas will affect performance more than a bend.
>>>
>>> The above fuselage location has two ground planes of isolation from your Com
>>> antenna.
>>>
>>> Is it time yet to consider making the cover out of fiberglass instead of
>>> aluminum?
>>>
>>> Tom Kuffel
>>
>>
>>
>>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 09:16 PM 1/15/2014, you wrote:
>
>Almost all ELTs, especially the older ones do in fact radiate
>anytime they are near high powered VHF transmitters in the FM, TV, etc bands.
This phenomenon IS demonstrable . . . and rare. The
ELT isn't actually producing any output power unique
to its function. Very strong sources of local radiation
(typically FM stations and the old analog TV stations)
would find its way backwards into the output stage of
the ELT's transmitter (constantly hooked to the antenna -
receiver circuits are not so prone to exhibit this
behavior). If there are two or more strong sources,
then they can MIX or heterodyne against each other
and produce a variety of spurious signals on lots
of frequencies.
Analog TV is gone and about the only source of such
coherent energy would be an FM transmitter but you are unlikely
to spend much time flying around in the FM station's
radiation pattern and in close proximity . . . within
a mile or two.
One might hypothesize that the modern ELT's with
TWO transmitters attached to the antenna are even
more likely to exhibit the behavior . . . but you
still need to be poking around the vicinity of the
strong transmitter at altitudes generally 1000'
AGL or less.
I've heard the rumor that some ELT's were triggered
by local radiation from a comm transmitter . . . but
I've not seen any documentation or FMEA that supported
the assertion. Certainly, modern ELTs are subjected
to the standard DO-160 radiated susceptibility testing
and perhaps even HIRF (high intensity RF) testing.
None of this testing will concern itself with the
intermodulation phenomenon cited above but it would
watch for damage to the ELT and/or false triggering.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
>
>So while you may have valid points about final resting of a crash
>being upside down, during the touchdown, prior to rollout odds are
>very high that any belly antenna will be wiped off the airframe.
>IMHO, with about equal experience between tail wheel(mostly off
>pavement in Alaska) and nose dragging aircraft, in off field landing
>situations of soft surface, nose wheel is far more likely to cause
>flipping than tail wheel.
I don't recall the source now . . . it was many
moons ago . . . but the common wisdom circulated
on the TC side of the house was that on top of
the fuselage, just ahead of the vertical fin, was
the best location for ELT antennas.
If the wreckage did flip over, this location offered
the highest probability for protection by vertical
fin structure.
The 406 mHz signal will be heard nicely even if
the airplane is upside down . . . as long as the
antenna isn't broken off.
Given the magic multi-frequency design of modern
ELTs and their antennas, I suggest the installer
would do well to bite the bullet and strive for
as pristine an installation as possible per the
manufacturer's recommendations.
Hence, bottom side location or bending of the antenna
is discouraged.
Bob . . .
________________________________________________________________________________
| From: | "Gerry van Dyk" <gerry.vandyk(at)shaw.ca> |
At 09:16 PM 1/15/2014, you wrote:
>
>Almost all ELTs, especially the older ones do in fact radiate
>anytime they are near high powered VHF transmitters in the FM, TV, etc
bands.
Analog TV is gone and about the only source of such
coherent energy would be an FM transmitter but you are unlikely
to spend much time flying around in the FM station's
radiation pattern and in close proximity . . . within
a mile or two.
Bob . . .
Just to throw out a thought...
Yesterday the Canadian government opened the bidding to the 700 Mhz spectrum
to cell phone companies. The departure of analog television to digital
freed up the 700 Mhz band. At some point in the future at least in Canada a
smart phone in a pilot's pocket will be communicating on the former analog
TV band. Is this something we should be worrying about this side of the
border? Any thoughts about mitigating such risks?
Gerry van Dyk
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Change to Shottky? |
At 03:29 PM 1/15/2014, you wrote:
>Bob: To answer your questions, this is an RV7, all metal
>airplane. The heat sink I used was the 15 watt one, the larger of
>the two offered at B&C. It weighs 7 oz.
>
>I will remove it and install directly to the aluminum subpanel.
>
>Would you change your recommendation if you knew I was in Arizona,
>occasionally flying in 100+ temperatures?
Nope. 100+ isn't 'hot' for a semiconductor.
The it's only 30F or 16C hotter than what
people like to exist in. Most semiconductor
devices are rated to operate up to 175C
AT THE JUNCTIONS . . . that is hot.
The only time your 100F hypothesis would put
a device at risk is if the heat sink were
marginal in the first place. After operating
your system loads for say 30 minutes or so
(time for temps to stabilize) put your fingers
on the device . . . you may find it 'toasty' but
it probably wouldn't 'sizzle spit' . . . most
of the time you'll find it warm but not dangerous
for the epidermis.
If you're really curious, you can put a temp
sensor on the bolt that mounts the device and get
some real numbers . . . good thing to know
and share.
If you don't have a capable remote temperature
measuring instrument, you might consider this
one . . .
http://tinyurl.com/lomcyp3
Comes with two probes and is shipped from US
location . . . fast.
No matter how convincing I might be by offering
advice from experience, there's nothing better
than to go measure it for yourself and then
report the results.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Wiring Verification |
At 10:19 PM 1/14/2014, you wrote:
Hello again, Bob,
Forgive me for not replying timely; I have had some computer problems
recently and unable to reply. I have stablized my system now so I am
replying before it sleeps again. Hopefully, it won't again soon.
No big deal . . . this IS a hobby . . . other
matters will often prove more pressing . . .
My Luscombe is indeed an all metal airplane. So, the distant grounds
will all be attached at the device location, on the airframe.
Looking over my supply of wire, I find that I have a sufficient
amount of 18 AWG for the power supplies and position lights but no 20
AWG on hand. As I recall from your previous narrative, other than
weight, there is no sin with utilizing a larger wire for this
duty. Since I have the 18 AWG already on hand, I'm theorizing that
would be satisfactory. However, I do have the 16 AWG wire for the
landing lights so that's a no brainer.
I wanted to thank you once again for your assistance. I am moving forward.
Very good. Pleased to hear it. Yes, there's nothing
'wrong' with having wire 'too large' or circuit protection
'too small'. Neither instance elevates risks to the airframe.
Keep us apprised of your progress!
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
Just to throw out a thought...
Yesterday the Canadian government opened the bidding to the 700 Mhz spectrum
to cell phone companies. The departure of analog television to digital
freed up the 700 Mhz band. At some point in the future at least in Canada a
smart phone in a pilot's pocket will be communicating on the former analog
TV band. Is this something we should be worrying about this side of the
border? Any thoughts about mitigating such risks?
Good question . . . and far outside my personal
experience history. But then, that's what all this
DO-160/254/178 etc. etc is suppose to explore, identify
and fix. That doesn't mean the occasional 'gotcha' won't
surface in spite of best efforts . . . recent lithium
battery issues are a good example. But that's part
and parcel of any evolving technology.
I'm working on an article for Kitplanes that will attempt
to put some perspective on the lithium battery market as
it relates to our airplanes. I'm not going to suggest
that everybody pry the lead out of their airplanes
and plunk lithium down in the hole . . . but lithium
IS a rising star on the horizon . . . and there are
ways to minimize risks while exploring POTENTIALLY
attractive returns on investment.
There was a similarly bumpy start up for ni-cad batteries
on airplanes too . . . Wwwaaaayyyy back when. They offered
some spectacular performance . . . but we set a few airplanes
on fire with those batteries too. Today, the ni-cad is
still attractive for some operators but it has not displaced
the lead-acid products. Perhaps lithium will evolve to the
same kind of market position . . . perhaps not . . .
I'd say that the risks from the new phones are VERY low.
Consider the actual radiate power of any hand held device,
particularly a telephone. Digital communications technologies
work very hard to maximize performance while minimizing
energy consumption. This tends to make radiators less
hazardous and receivers more resistant to co-located
interference.
Bob . . .
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
Hmm, I don't know why the switch to digital TV will make much
difference. They are still broadcasting in my area on VHF RF channels 7
and 8 through 13 in my local area. I used to have an antenna
configuration on my Mooney that consisted of VHF com in front of
windshield, top of fuselage behind baggage compartment, Loran about 18
in. behind that, followed by ELT antenna right in front of vertical
stab. When flying VFR transition over Phoenix Sky Harbor I would get bad
squelch break anywhere within 10 nm of the antenna farm located on South
Mountain, approx 8 mi south of Sky Harbor. Made hearing controllers very
difficult.
I isolated it to the ELT by doing a flight with external ELT antenna
disconnected, which completely eliminated problem even within a mile of
the transmitters. This was a 1st generation ELT. Moving 1st com antenna
from in front of windshield to the belly virtually eliminated the
interference. Removing Loran antenna (custom version of Comant CI121)
helped as well.
I understand later versions of ELTs have somewhat better isolation of
the transmit oscillator, but doesn't completely eliminate. Good
separation between ELT and com antennas is probably best defense.
Kelly
On 1/16/2014 6:01 AM, Robert L. Nuckolls, III wrote:
>
>
> At 09:16 PM 1/15/2014, you wrote:
>>
>>
>> Almost all ELTs, especially the older ones do in fact radiate anytime
>> they are near high powered VHF transmitters in the FM, TV, etc bands.
>
> This phenomenon IS demonstrable . . . and rare. The
> ELT isn't actually producing any output power unique
> to its function. Very strong sources of local radiation
> (typically FM stations and the old analog TV stations)
> would find its way backwards into the output stage of
> the ELT's transmitter (constantly hooked to the antenna -
> receiver circuits are not so prone to exhibit this
> behavior). If there are two or more strong sources,
> then they can MIX or heterodyne against each other
> and produce a variety of spurious signals on lots
> of frequencies.
>
> Analog TV is gone and about the only source of such
> coherent energy would be an FM transmitter but you are unlikely
> to spend much time flying around in the FM station's
> radiation pattern and in close proximity . . . within
> a mile or two.
>
> One might hypothesize that the modern ELT's with
> TWO transmitters attached to the antenna are even
> more likely to exhibit the behavior . . . but you
> still need to be poking around the vicinity of the
> strong transmitter at altitudes generally 1000'
> AGL or less.
>
> I've heard the rumor that some ELT's were triggered
> by local radiation from a comm transmitter . . . but
> I've not seen any documentation or FMEA that supported
> the assertion. Certainly, modern ELTs are subjected
> to the standard DO-160 radiated susceptibility testing
> and perhaps even HIRF (high intensity RF) testing.
> None of this testing will concern itself with the
> intermodulation phenomenon cited above but it would
> watch for damage to the ELT and/or false triggering.
>
>
> Bob . . .
>
>
________________________________________________________________________________
| Subject: | Re: Change to Shottky? |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
The calculation here on the dissipation and voltage drops of Schottkys and P/N
diodes are simply being pulled out of the air. What diodes are you referring to?
You show me yours and I'll show you mine.
A "standard" 15A 50V P/N diode is 1.5 Volts Vf like 1N3208. So at 13V you get
11.5V out.
I use and sell IXYS DSSX61-0045A. Power_Deuce_Schottkys. At 15A they are 0.45Volts
Vf. So at 13VDC you get 12.55VDC out.
I supply these on heatsink. They are isolated and paired so they can be used in
Y-configurations or separate or paired.
I've looked and don't see any better diodes for general aircraft purposes. If the
difference was as small as some here have erroneously stated, we wouldn't be
having this conversation. Most modern battery operated equipment have no p/n
diodes. They waste too much power.
Remember: With diodes the measurements are often at 50% duty cycle. Also remember
that Vf is not reduced when diodes are in placed parallel (unlike R for resistors).
--------
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=417007#417007
Attachments:
http://forums.matronics.com//files/power_deuce_schottky_manual_109.pdf
________________________________________________________________________________
| From: | Thomas Blejwas <tomblejwas(at)yahoo.com> |
| Subject: | Re: Change to Shottky? |
-Eric,=0A=0AI think that I misinterpreted the use of the word "average."
- (My-aero, mechanical, and civil engineering degrees were not big on d
iodes.) -Say, for the specific diode STPS60L30CW: http://www.st.com/en/re
sources/technical/document/cd00001857.pdf- ,=0AFig. 1 provides "average f
orward power dissipation versus average forward current (per diode)."- I
now understand that the term "average" is the average for-the cycle (not
the average between the two diodes), i.e., the average amperage for a squar
e-wave cycle with a delta of 0.5 would be half the peak to peak amperage.
- So, if I understand you correctly, the voltage drop with both diodes co
nnected to the same source-should be calculated using the total current,
as if there were only one diode connected. For this particular diode assemb
ly-and my system (14A max.-at 13V), the voltage drop from Fig. 9 at a T
j of 125 degC is 0.31 to 0.32, for a power dissipation of-slightly more t
han 4W.- I would only use this diode if I were confident that I could kee
p the Tj low, because it has high leakage at high temperature and because t
his diode is only rated to 150 degC.- But the leakage versus voltage drop
is the tradeoff I see in the selection process.-
Not clear to me that we need extremely low leakage.=0A=0AI don't understan
d-why the voltage drop should be calculated as if all the current goes th
rough only one diode.- This implies that the current doesn't substantivel
y split, because if it did, the voltage drop in each diode would be lower.
- If there is a good authoritative-reference that you can suggest, I wo
uld appreciate it.- I've Googled and found different views and opinions.
=0A=0AThanks.=0A=0ATom=0A=0A=0A=0A-=0A=0A=0A>____________________________
____=0A> From: Eric M. Jones <emjones(at)charter.net>=0A>To: aeroelectric-list
@matronics.com =0A>Sent: Thursday, January 16, 2014 8:14 AM=0A>Subject: Aer
oElectric-List: Re: Change to Shottky?=0A> =0A>=0A>--> AeroElectric-List m
essage posted by: "Eric M. Jones" =0A>=0A>The calculat
ion here on the dissipation and voltage drops of Schottkys and P/N diodes a
re simply being pulled out of the air. What diodes are you referring to? Yo
u show me yours and I'll show you mine.=0A>=0A>A "standard" 15A 50V P/N dio
de is- 1.5 Volts Vf like 1N3208. So at 13V you get 11.5V out.=0A>=0A>I us
e and sell IXYS- DSSX61-0045A. Power_Deuce_Schottkys. At 15A they are 0.4
5Volts Vf. So at 13VDC you get 12.55VDC out.=0A>=0A>I supply these on heats
ink. They are isolated and paired so they can be used in Y-configurations o
r separate or paired. =0A>=0A>I've looked and don't see any better diodes f
or general aircraft purposes. If the difference was as small as some here h
ave erroneously stated, we wouldn't be having this conversation. Most moder
n battery operated equipment have no p/n diodes. They waste too much power.
=0A>=0A>Remember: With diodes the measurements are often at 50% duty cycle.
Also remember that Vf is not reduced when diodes are in placed parallel (u
nlike R for resistors).=0A>=0A>--------=0A>Eric M. Jones=0A>http://www.peri
heliondesign.com/=0A>113 Brentwood Drive=0A>Southbridge, MA 01550=0A>(508)
764-2072=0A>emjones(at)charter.net=0A>=0A>=0A>=0A>=0A>Read this topic onlin
e here:=0A>=0A>http://forums.matronics.com/viewtopic.php?p=417007#417007
=0A>=0A>=0A>=0A>=0A>Attachments: =0A>=0A>http://forums.matronics.com//files
======================0A>=0A>=0A>
=0A>=0A>=0A>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Z-12 Essential Bus Questions |
At 11:39 AM 1/11/2014, you wrote:
>Thanks Bob. I read your recent, excellent article on DO-160
>testing. With EAB airplanes, can we count on all the devices
>installed having seen the same testing? I'm planning on a bunch of
>Garmin's experimental avionics offerings and I'm not sure those
>boxes see the same testing as their certified hardware. I've
>Googled it a few times but can't find anything. I need to ask
>Garmin's Team X about it. So that's why I'm a bit shy to risk
>putting all the avionics through engine start power cycling.
Garmin doesn't have a dual-path set of products.
Everything they build for the panel has roots
in TC aircraft. DO-160 has become the 'design
bible' for any/all devices attached to a vehicular
DC power system. Except for issues of lightning
strike, gizmos that go into cars and trucks are
just as vulnerable to 'gremlins' as the
stuff that goes onto airplanes.
Garmin's "experimental specific" products are
essentially identical to their TC counterparts.
Bob . . .
________________________________________________________________________________
| From: | "msmeredith" <msmeredith(at)comcast.net> |
All,
After digesting everyone's points, I decided I better pay attention to function
over beauty...I'm going to mount the ELT antenna on top of the turtleback. It'll
be a foot or so forward of the fin - can't reach inside much farther than
that anyway to beef it up and install hardware. Ordered a longer coax today.
Thanks much for all your inputs and ideas!
--------
Mark Meredith
Super Chipmunk N7DW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=417043#417043
________________________________________________________________________________
| From: | "Owen Baker " <bakerocb(at)cox.net> |
1/17/2014
Hello Bob Nuckolls, You wrote: =9CI've heard the rumor that some
ELT's were triggered by local radiation from a comm transmitter . . .
but
I've not seen any documentation or FMEA that supported the
assertion.=9D
Please let me give you one factual data point on that issue. I was
unable to launch on the first attempted test flight of my experimental
amateur built KIS TR-1 airplane because every time I keyed the VHF comm
transmitter to talk to either ground or tower the ACK ELT-01 began to
transmit.
The solution was to move the ELT antenna further away from the VHF comm
antenna and to reorient the ELT antenna from its original location and
orientation. Both antennas were originally, and remained after
relocation of the ELT antenna, inside the fiberglass fuselage.
Kelly McMullen wrote: =9CGood separation between ELT and com
antennas is probably best defense.=9D
That is what worked for me.
=98OC=99
'O C' Baker says "The best investment you can make is the effort to
gather and understand information."
=========
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Subject: Re: AeroElectric-List: Re: ELT Antenna
At 09:16 PM 1/15/2014, you wrote:
>
>Almost all ELTs, especially the older ones do in fact radiate
>anytime they are near high powered VHF transmitters in the FM, TV, etc
bands.
This phenomenon IS demonstrable . . . and rare. The
ELT isn't actually producing any output power unique
to its function. Very strong sources of local radiation
(typically FM stations and the old analog TV stations)
would find its way backwards into the output stage of
the ELT's transmitter (constantly hooked to the antenna -
receiver circuits are not so prone to exhibit this
behavior). If there are two or more strong sources,
then they can MIX or heterodyne against each other
and produce a variety of spurious signals on lots
of frequencies.
Analog TV is gone and about the only source of such
coherent energy would be an FM transmitter but you are unlikely
to spend much time flying around in the FM station's
radiation pattern and in close proximity . . . within
a mile or two.
One might hypothesize that the modern ELT's with
TWO transmitters attached to the antenna are even
more likely to exhibit the behavior . . . but you
still need to be poking around the vicinity of the
strong transmitter at altitudes generally 1000'
AGL or less.
I've heard the rumor that some ELT's were triggered
by local radiation from a comm transmitter . . . but
I've not seen any documentation or FMEA that supported
the assertion. Certainly, modern ELTs are subjected
to the standard DO-160 radiated susceptibility testing
and perhaps even HIRF (high intensity RF) testing.
None of this testing will concern itself with the
intermodulation phenomenon cited above but it would
watch for damage to the ELT and/or false triggering.
Bob . . .
=
From: Kelly McMullen <kellym(at)aviating.com>
Subject: Re: AeroElectric-List: Re: ELT Antenna
Hmm, I don't know why the switch to digital TV will make much
difference. They are still broadcasting in my area on VHF RF channels 7
and 8 through 13 in my local area. I used to have an antenna
configuration on my Mooney that consisted of VHF com in front of
windshield, top of fuselage behind baggage compartment, Loran about 18
in. behind that, followed by ELT antenna right in front of vertical
stab. When flying VFR transition over Phoenix Sky Harbor I would get bad
squelch break anywhere within 10 nm of the antenna farm located on South
Mountain, approx 8 mi south of Sky Harbor. Made hearing controllers very
difficult.
I isolated it to the ELT by doing a flight with external ELT antenna
disconnected, which completely eliminated problem even within a mile of
the transmitters. This was a 1st generation ELT. Moving 1st com antenna
from in front of windshield to the belly virtually eliminated the
interference. Removing Loran antenna (custom version of Comant CI121)
helped as well.
I understand later versions of ELTs have somewhat better isolation of
the transmit oscillator, but doesn't completely eliminate. Good
separation between ELT and com antennas is probably best defense.
Kelly
________________________________________________________________________________
| From: | "Bill S" <docyukon(at)ptcnet.net> |
| Subject: | parelling two rp3 indicators |
Message for Bob, Ref. this email you sent to me Dec. 22 2011
Conserning the capasitor on the attached drawing. What should the
specs. be? I'm not up on electronic ckts. Thanks Bill S.
At 10:59 AM 12/22/2011, you wrote:
>I am wanting to parllel two Ray Allen RP3 led position indicators
>useing only one POS5 position sensor. RAC said that thay wont work
>just parelling them and that I need to add another position sensor
>or a switch which I would rather not do. Can anyone sudjest an
>electrical ckt. that would work for this? Thanks Bill S.
>
You need a 'buffer-amplifier' between the position
feedback potentiometer and ONE of the two indicators.
The problem with paralleling the two indicators arises
from the fact that they're not a 'high impedance' voltmeter.
The system is calibrated for one pot driving one indicator.
Adding a second indicator doubles the load on the position
signal from the potentiometer.
The 'fix' is to convert one of the indicators into a
high-impedance voltmeter. You need an operational
amplifier with rail-to-rail inputs and outputs. A device
like the LM7321 would probably work.
http://search.digikey.com/us/en/products/LM7321MF%2FNOPB/LM7321MFCT-ND/18
78646
Adding this device to the second indicator prevents
it from loading the potentiometer. You need to
fabricate something like this . . .
http://aeroelectric.com/Pictures/Schematics/Ray-Allen_Dual_Indicators.pdf
It could be fabricated on an etched circuit board
that would fit inside a d-sub connector back shell.
Bob . . .
22 2011
________________________________________________________________________________
| Subject: | Re: Change to Shottky? |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
When using diodes in parallel, the Vf drop will stay the same as the lowest diodes
Vf but reverse leakage Ir (and capacitance) will add. But it is often cited
as a bad idea because as one diode heats up, its Vf will decreaseand it will
draw more current, etc. This is called a thermal runaway failure. You can avoid
this by placing the diodes in tight thermal contact with each other, or using
a small resistor in series with each, or making certain the Vfs start and thermally
track each other as closely as possible (and the diodes were made at
the same time, same batch, etc.).
Schottky diodes especially trade off forward Vf with reverse leakage. So always
look for this when trying to get a very low forward Vf. I cant say reverse leakage
is always a bad thing; it depends on the use. The spec sheet for STPS60L30
states:
Dual center tap Schottky rectifier suited for Switch Mode Power Supply and high
frequency DC to DC converters. Packaged in TO247, this device is intended for
use in low voltage, high frequency inverters, free-wheeling and polarity protection
applications.
This statement by STM is a good indication that this part has a huge reverse leakage
Ir, since HF inverter transformers in power supplies can allow for that
reverse DC leakage easily while they benefit from the very low Vf. And it does.
Ir(max) Tj=125C, 500 mA! Can your application accept that?
The spec sheet for IXYS DSSX61-0045A Ir (max) is 20 mA.
I dont want to specify or analyze specific diode choices, but I think IXYS DSSX61-0045A
represents a good compromise for power blocking diodes in price/performance
/Vf/Ir mostly because it is packaged in an isolated SOT-227 package. There
are lower Vf diodes, and lower Ir diodes, and diodes that are far pricier.
But this is a great compromise and very versatile diode. Remember, Schottkys
dissipate less and often require no heatsink compared to a similarly-rated P/N
diode.
> >>From: Thomas Blejwas
> Subject: Re: AeroElectric-List: Re: Change to Schottky?
>
> -Eric, I think that I misinterpreted the use of the word "average."
> - (My-aero, mechanical, and civil engineering degrees were not big on diodes.) -Say, for the specific diode STPS60L30CW: http://www.st.com/en/resources/technical/document/cd00001857.pdf- , Fig. 1 provides "average forward power dissipation versus average forward current (per diode)."- I
> now understand that the term "average" is the average for-the cycle (not
> the average between the two diodes), i.e., the average amperage for a square-wave
cycle with a delta of 0.5 would be half the peak to peak amperage.
>
>
> >>- So, if I understand you correctly, the voltage drop with both diodes connected
to the same source-should be calculated using the total current, as if there
were only one diode connected.
Right, if I get what you're saying. Think of Vf standing for Vertical fall (waterfall).
Adding waterfalls in parallel, doesnt make each Vf waterfall taller.
You can get more current, but you cant reduce the Vf potential loss. It is what
it is. At the top of the waterfall you have a potential; at the bottom you have
lower potential.
> >>For this particular diode assembly-and my system (14A max.-at 13V), the voltage
drop from Fig. 9 at a Tj of 125 degC is 0.31 to 0.32, for a power dissipation
of-slightly more than 4W.- I would only use this diode if I were confident
that I could keep the Tj low, because it has high leakage at high temperature
and because this diode is only rated to 150 degC.- But the leakage versus voltage
drop is the tradeoff I see in the selection process.-
>
True. But even at a Tj of 125 degC, used as an isolation diode, Id be careful because
it doesnt isolate much. This might matter.
> >>Not clear to me that we need extremely low leakage. I don't understand-why
the voltage drop should be calculated as if all the current goes through only
one diode.- This implies that the current doesn't substantively split, because
if it did, the voltage drop in each diode would be lower.- If there is a good
authoritative-reference that you can suggest, I would appreciate it.- I've Googled
and found different views and opinions.
There is a substantial body of work on using Schottkys. Try: http://www.onsemi.com/pub_link/Collateral/AND9038-D.PDF or other application notes from major manufacturers.
Builders new to electronics often wonder if there is a particular best component.
There usually isnt Furthermore sometimes (amazingly!) the manufacturer hides
certain factslike price, which is a really important characteristic unless you
work for the military, or the 56-week lead-time, (happened to me!) or the fact
that the parts are counterfeit. (I will send you some fake MC33030P parts
if interestedstraight from 4-Star Electronicswho wouldnt return my money because
it took me 32 days to come to the hard-to-believe conclusion that their parts
were fakes.)
--------
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=417097#417097
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Change to Shottky? |
At 09:14 AM 1/16/2014, you wrote:
>
>The calculation here on the dissipation and voltage drops of
>Schottkys and P/N diodes are simply being pulled out of the air.
>What diodes are you referring to? You show me yours and I'll show you mine.
Okay, our MBR4060 mounted for convenient installation
heat-sinked to the airframe and provided with terminals
for attachment of wires.
With the pair carrying 10A I measure a drop of 0.45
volts, 20A drops 0.68 volts.
While one cannot expect two diodes to accurately
parallel and share a load, the fact that the voltage
drops at all when the second diode is added demonstrates that
SOME load sharing takes place. This offers a benefit,
(perhaps tiny but quantifiable) for spreading the thermal
stresses over the device's heat-sink surface combined
with a small drop in voltage. In no way is the practice of
paralleling expected to offer a critical performance
jump . . . the second diode was there in the package
. . . might as well do something useful with it . . .
>
>A "standard" 15A 50V P/N diode is 1.5 Volts Vf like 1N3208.
>So at 13V you get 11.5V out.
I just measured one of the RS 25A bridge diodes
at 10A and got 0.84 volts, 20A gave me 0.93 volts
>I use and sell IXYS DSSX61-0045A. Power_Deuce_Schottkys. At 15A
>they are 0.45Volts Vf. So at 13VDC you get 12.55VDC out.
Don't know where the 13v comes from. The normal feedpath
diode takes a feed from the main bus which also drives
the voltage sense pin of the regulator. Hence, this bus
is expected to be at 14.2 +/0 0.2 volts any time the
alternator is operating normally. If the alternator is
running, the bus is >14v . . . if the alternator is
not running the system voltage is <12.5
>I supply these on heatsink. They are isolated and paired so they can
>be used in Y-configurations or separate or paired.
>
>I've looked and don't see any better diodes for general aircraft
>purposes. If the difference was as small as some here have
>erroneously stated, we wouldn't be having this conversation. Most
>modern battery operated equipment have no p/n diodes. They waste too
>much power.
Kumquats and watermelons. Diodes used inside
a piece of electronics have little in common
with design goals for steering diodes in
power distribution systems. There are some really
fat P/N diodes used throughout the Lear, Cessna
and Beech fleets (and no doubt others) that cannot
be Shottky due to requirements for lightning and abnormal
surge voltage requirements. Requirements that
are not levied onto the internal workings of an
appliance.
I think the Hawker 4000 had some Shottky power
steering in their DC system (Low current stuff
driven by TR-sets off wild frequency 208, 3-
phase) and they had to add a lot of monkey-
motion in the form of Transorbs, etc. to make
it through lightning testing.
We're discussing the return on investment in
light airplanes for saving a watt or two in
a system powered with a 500+ watt engine driven
power source is not quantifiable. Energy 'squandered'
is a fraction of a percent of the whole energy
bucket no matter what kind of diode you use.
At the same time, the 'rule of thumb' for selection
of wires says 5% voltage drop is an acceptable
compromise between loss of electrical performance
and unnecessary addition to aircraft empty weight.
That figures out to 0.7 volts per power feeder;
but that too is a 'rule of thumb' . . . were it
twice that amount, no airplane is going to fall
out of the sky and no pilots are going to be
squinting out into the dark because 'violation'
of rule by a factor of 2 or even 3 has dimmed
the lights. No dollars will be saved. So the choice
of components is driven by FMEA and human
factors for reducing risk.
For example, we could replace the normal feedpath
diode with a relay that is controlled by an
aux battery management module . . . relay closed
only when the bus voltage exceeds 13.0 volts.
Hard contacts, lower voltage drop, more complexity.
Or put a switch in. But then, the whole purposed
for the diode was to prevent inadvertent back-feeding
the main bus from the e-bus due to improper operation
of switches.
I've looked and don't see any better diodes for general aircraft
purposes. If the difference was as small as some here have
erroneously stated, we wouldn't be having this conversation. Most
modern battery operated equipment have no p/n diodes. They waste too
much power.
It's easy to avoid getting wrapped around
the weight/energy-savings axles in this application.
Energy savings is trivial . . . weight savings can
be as much as 1/2 pound if the builder discovers
that THEIR implementation of the e-bus normal feed
diode doesn't really need that big heat sink.
If some diode is dropping enough BTU's to require
a hefty heat-sink, then it's not driving an e-bus.
The Endurance Bus was conceived to offer a
narrowly defined benefit . . . electrical endurance
that exceeded fuel endurance. With the electrically
dependent engine needing something on the order
of 100W power for operation, the concept of an
E=Bus is no longer useful. It's unlikely that
anyone will opt to carry enough battery to run
an engine for 3 hours. At the same time,
diodes used to steer power can STILL be sized
in the 8-12 amp range without extra-ordinary
heat-sinking in an all metal airplane.
But in any case, there's no substitute for
confirmation of one's decisions by direct
measurement of effects and benefits. Toward that
end, I supported an RS bridge in air with no heat-sink
and loaded it to 10A. After 20 minutes, the mounting
surface stabilized out at just over 100C. Given
the very limited ability of this surface to reject
heat, the stress across the internal thermal resistance
would be low the diode junction was probably not much
hotter . . . perhaps 110-120C.
But the thing didn't self-destruct. Then I bolted
it to an airplane . . . well . . . a part of
an airplane .040 x 5 x 5 inches. Didn't use
heat-sink grease under the part but I did
put a fender-washer on the back side to stiffen
the aluminum around the mounting hole with
a notion of bringing the rectifier into better
contact with the aluminum sheet.
If one intends to run loads in the 10A class
through a device like this, some heat-sink grease
or Sil-Pad underneath plus a backside 'stiffener'
is probably a good thing to do.
The second experiment was rather profound.
After 20 minutes, the metal around the
rectifier was running 40C. 15C over ambient
for a rise of about 2C/watt. Assuming I had
a lousy thermal interface of . . . say
1.5C/W. These devices will typically
offer a to case resistance 1.5C/W. So the
8w dissipated in the diode was taking
the junction to 8 x 3 or 24C hotter
than the 'airplane' at 40C. This minimalist
approach to heat-sink gave us a junction
temperature about 40C over ambient or 65C
. . . . . .WAaaay less than the rated
150C maximum.
If your airplane isn't metal, then you can
use the same part-of-an-airplane that I just
demonstrated. 25 square inches of aluminum
goes a long way toward cooling things off.
If that were a Schottky running 5 watts
of loss, then the temperature of the junction
can be expected to drop into the neighborhood
of 25C over ambient . . . and a 'savings'
of 3 watts.
The point of this discussion is to put the
worries to bed for application of any diode
technology for steering power to either an
E-bus or M-P bus of the variety we're
discussing today.
Further, note that 'losses' associated with
these diodes can be eliminated from the
concerns for battery-only operations. That's
what the Z-07 discussion is all about.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 07:01 AM 1/16/2014, you wrote:
I wrote: I've heard the rumor that some ELT's were triggered
by local radiation from a comm transmitter . . . but
I've not seen any documentation or FMEA that supported
the assertion.
----------------------
I was informed by an astute reader that the ACK E-01
series ELTs were demonstrably plagued with a tendency
to trigger in response to on-board COMM transmissions.
This fact (and perhaps others like it) may have been the
foundation for advising installers to add separation
between the ELT and ship's COMM antennas.
While the 'fix' is valid, the premise under which
the fix is exercised assumes that the ELT was
properly qualified to be on the airplane in the
first place. Any ELT that goes through the lab
where I work would have demonstrated immunity to
RF interference many times stronger than the ship's
transceivers.
The consumer has every reason to expect certain
levels of performance in their ELT for it has
been decreed and . . . it's a matter of practical
utility.
With better information, a retraction is in order
for my assertion that the RF triggering event
was a 'rumor'. At the same time I would advise
that compromising the installation of your
own 'antenna farm' in recognition of the
historical fact is unnecessary. If the ELT you
have demonstrates such sensitivity, then
there is good reason to suspect a defect in
design and/or manufacturing that needs attended
to . . . defects that may go beyond the sensitivity
to RF.
If the ELT is the last bastion of defense for
your survival, then offer no quarter in
your expectations for its performance.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: parelling two rp3 indicators |
At 02:27 PM 1/17/2014, you wrote:
>Message for Bob, Ref. this email you sent to me Dec. 22
>2011 Conserning the capasitor on the attached drawing. What
>should the specs. be? I'm not up on electronic
>ckts. Thanks Bill S.
>
>
A 10uf/16v would be fine . . . it's exceedinly
un-critical.
http://tinyurl.com/mee3oal
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 07:56 AM 1/17/2014, you wrote:
>1/17/2014
>
>Hello Bob Nuckolls, You wrote: =9CI've heard the
>rumor that some ELT's were triggered by local
>radiation from a comm transmitter . . . but
>I've not seen any documentation or FMEA that supported the assertion.
=9D
>
>Please let me give you one factual data point on
>that issue. I was unable to launch on the first
>attempted test flight of my experimental amateur
>built KIS TR-1 airplane because every time I
>keyed the VHF comm transmitter to talk to either
>ground or tower the ACK ELT-01 began to transmit.
Thanks for the heads-up! I've found a number
of service bulletins against the ELT-01 over
it's market life . . . one involved replacement
of the g-switch. I'd like to know what the
technology is for that switch. Dug around in
the patents a bit but didn't find anything.
Bob . . .
________________________________________________________________________________
| Subject: | Batteries: Pb Acid -vs- Pb Crystal -vs- LiFePO |
| From: | Eric Page <edpav8r(at)yahoo.com> |
I follow an electronics-related YouTube channel by a South African (recently emigrated
to Ohio) gent named Martin Lorton. He posted a video recently in which
he talks about some comparison tests he's done of three different battery chemistries.
His goal is to identify the best for use as a storage bank for a home
solar installation, but I thought his results might be of general interest,
particularly given the recent discussions here WRT lightweight LiFePO batteries.
The battery discussion runs from 16:55 to 24:50 in the video.
http://y2u.be/eQ6m1EVwOAw
Eric
________________________________________________________________________________
| From: | "William Schertz" <wschertz(at)comcast.net> |
My experience indicates that it is not a rumor. When I started testing I
found the ELT being triggered by one of my COM's, and solved that by moving
the position of the ELT itself, not the ELT antenna.
Since repositioning, it has not been a problem
Bill Schertz
-----Original Message-----
From: Robert L. Nuckolls, III
Sent: Saturday, January 18, 2014 10:23 AM
Subject: Re: AeroElectric-List: Re: ELT Antenna
At 07:01 AM 1/16/2014, you wrote:
I wrote: I've heard the rumor that some ELT's were triggered
by local radiation from a comm transmitter . . . but
I've not seen any documentation or FMEA that supported
the assertion.
----------------------
I was informed by an astute reader that the ACK E-01
series ELTs were demonstrably plagued with a tendency
to trigger in response to on-board COMM transmissions.
This fact (and perhaps others like it) may have been the
foundation for advising installers to add separation
between the ELT and ship's COMM antennas.
While the 'fix' is valid, the premise under which
the fix is exercised assumes that the ELT was
properly qualified to be on the airplane in the
first place. Any ELT that goes through the lab
where I work would have demonstrated immunity to
RF interference many times stronger than the ship's
transceivers.
The consumer has every reason to expect certain
levels of performance in their ELT for it has
been decreed and . . . it's a matter of practical
utility.
With better information, a retraction is in order
for my assertion that the RF triggering event
was a 'rumor'. At the same time I would advise
that compromising the installation of your
own 'antenna farm' in recognition of the
historical fact is unnecessary. If the ELT you
have demonstrates such sensitivity, then
there is good reason to suspect a defect in
design and/or manufacturing that needs attended
to . . . defects that may go beyond the sensitivity
to RF.
If the ELT is the last bastion of defense for
your survival, then offer no quarter in
your expectations for its performance.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 06:10 AM 1/19/2014, you wrote:
>
>
>My experience indicates that it is not a rumor. When I started
>testing I found the ELT being triggered by one of my COM's, and
>solved that by moving the position of the ELT itself, not the ELT antenna.
>
>Since repositioning, it has not been a problem
What make and model of ELT was this?
Bob . . .
________________________________________________________________________________
| Subject: | Lancair 235 Accident |
| From: | "user9253" <fransew(at)gmail.com> |
In the January 2014 issue of Sport Aviation is an article, "What Went Wrong", about an accident involving N235MW, a Lancair 235. http://tinyurl.com/myzgxkv
The NTSB probable cause is , "The pilot's decision to operate the airplane with known electrical system problems . . ." Even more significant, in my view, is that the pilot took off without first filling the 11 gallon header tank. The pilot did not build the aircraft. A builder would have known how to repair the electrical system and would have been more familiar with fuel management. There is a more detailed report here: http://tinyurl.com/krf4dk9
It says, " . . .fuel pumps which received their electrical power from the main
electrical bus." Since the fuel system was electrically dependent, it would have
been prudent to power the fuel pumps directly from the battery or from an
E-Bus. Or the main bus should have had two supply paths as in Z-0 (attached).
The accident report mentions a corroded wire between the battery and master contactor.
But that does not explain why there was power to the starter but not
to the main bus. I think there must have been a bad connection between the
master contactor and the main bus.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=417180#417180
Attachments:
http://forums.matronics.com//files/simple_elect_system_106.pdf
________________________________________________________________________________
| From: | <berkut13(at)berkut13.com> |
I had the same problem with a client's composite aircraft, it was the
Ameri-King AK-450 ELT unit that was susceptible to com RF triggering. It
could have also been the un-shielded RJ-11 style phone cable used for the
remote display.
-James
-----Original Message-----
From: Robert L. Nuckolls, III
Sent: Sunday, January 19, 2014 8:42 AM
Subject: Re: AeroElectric-List: Re: ELT Antenna
At 06:10 AM 1/19/2014, you wrote:
>
>
>My experience indicates that it is not a rumor. When I started testing I
>found the ELT being triggered by one of my COM's, and solved that by moving
>the position of the ELT itself, not the ELT antenna.
>
>Since repositioning, it has not been a problem
What make and model of ELT was this?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Lancair 235 Accident |
| From: | "mmayfield" <mmayfield(at)ozemail.com.au> |
The fact that the pilot was not the builder should not be used as an excuse for
anything at all. I haven't built any of the aircraft I've flown during 30 years
of professional aviation, but I still always knew how their fuel system worked
and what their system serviceability status was!
--------
Mike
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=417241#417241
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 03:03 PM 1/19/2014, you wrote:
>
>I had the same problem with a client's composite aircraft, it was
>the Ameri-King AK-450 ELT unit that was susceptible to com RF
>triggering. It could have also been the un-shielded RJ-11 style
>phone cable used for the remote display.
>
>-James
Interesting! . . . and no AD's against these
products? Defending a device from the ravages
of external radio frequency energy sources
is virtual child's play in engineering circles.
If I were directing the activities of a engineering
design and development group, EVERBODY . . . but
particularly the rookies . . . would spend some
time in the qual-test facilities followed by
a stint in the packaging design group. Shielding
the i/o wires is not acceptable practice for
the purpose of passing qual-tests.
No matter what you're going to design or program,
it first has to perform and survive in the
intended environment and be packaged in a way
that fits into the end-use while not driving
up cost and MTBF risk.
Too many of our contemporaries have evolved
their careers with little appreciation for where
and how their work-product has to perform only
to find out that 'little problems' surface after
a few thousand units are in the field.
The folks-who-know-more-about-airplanes-than-we-do
have assured us that this isn't supposed to happen . . .
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Lancair 235 Accident |
At 09:48 AM 1/19/2014, you wrote:
>
>In the January 2014 issue of Sport Aviation is an article, "What
>Went Wrong", about an accident involving N235MW, a Lancair 235.
>http://tinyurl.com/myzgxkv
>The NTSB probable cause is , "The pilot's decision to operate the
>airplane with known electrical system problems . . ."
This is the same incident on which I published
these documents some months ago
http://tinyurl.com/mwo3f4x
Unfortunately, the SA article is typical of many
that I have dubbed "dark-n-stormy night' stories . . .
narratives long story-value, short on understanding.
If one suffers loss of oil because the drain
plug fell out, it's not an "engine problem".
If the elevator becomes disconnected from
the stick, it's not a "controls problem".
The fact that this guy diddled around on numerous
flights to craft a work-around for operating
the landing gear did not make it a "landing gear
problem" . . . or even an "electrical problem."
The issues with the 235 had foundation
in a lack of demonstrated understanding for the
physics of how things work and appreciation for the
performance limits of the components involved.
The guy was flown to another location to get
a couple of freshly charged batteries . . . say
what? The FAA probable cause narrative speaks
to the pilot willingness to initiate flight under battery-
only conditions . . . and do what? Swap
'em out in flight if the first one didn't
get him home? I'd bet he had not a clue as
to the capacity of either "freshly charged
battery."
The same conditions were evident in
the Lancair IV-P accident I cited; I.e.
not one single component of the accident
airframe was defective. Every component
performed in a manner predicted by study
of limits in design and maintenance.
Both of these incidents were "due diligence
problems" waiting to masquerade as an "accident".
You can't do an FMEA without understanding
limits to performance. Rudimentary skills
go a long way toward keeping useful components
attached to each other and performing as
intended. Preventative maintenance
rotates worn-out or abused parts before they
fail. These are but two of many examples of why
we strive for low-risk FMEA combined with
good craftsmanship and responsible operation/
ownership.
Bob . . .
________________________________________________________________________________
| From: | Charles Brame <chasb(at)satx.rr.com> |
Bob, et.al.,
I just replaced my fourth S700-1(or equivalent) strobe switch in about 200 hours
of flying time. Both fast on terminals were badly burned as was about an inch
of the 18ga. wire attached to the fast on. My first two switches were Carlings
from B&C. Based on AeroElectric recommendations made some years back, I ordered
a S700-1 equivalent switch from Honeywell - same result. Then I tried a switch
from DigiKey, same result. I'm back to a Carling, at least for the short
term. I have Carlings for the Nav lights, Landing and Wig Wag lights and instrument
lights, and I have had no problem with any of them. The strobe switch is
backed up by a 7 amp fuse which is recommended for the strobe system (Whelen)
and it has never popped. The run of 18 ga. wire is about ten feet. Of all the
switches, only the strobe switch gets real hot after only a few minutes of use.
I was searching B&C for a relay I could use to reroute the strobe heavy current
wire, and discovered that B&C now advertises a MilSpec single pole switch (MS35058-22)
that is the equivalent of the S700-1. The dimensions appear the same,
with screw type connections rather than fast ons. It ain't cheap, but it would
be worth it to avoid having to frequently replace a burnt out standard switch.
Would this MilSpec switch be a viable solution to the strobe switch problem?
Charlie Brame
RV-6A, N11CB
San Antonio
________________________________________________________________________________
| From: | "B Tomm" <fvalarm(at)rapidnet.net> |
What about using a relay to switch the strobe current? Use the carling
switch to control the relay.
Bevan
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Charles
Brame
Sent: Monday, January 20, 2014 9:33 PM
Subject: AeroElectric-List: Strobe switches
-->
Bob, et.al.,
I just replaced my fourth S700-1(or equivalent) strobe switch in about 200
hours of flying time. Both fast on terminals were badly burned as was about
an inch of the 18ga. wire attached to the fast on. My first two switches
were Carlings from B&C. Based on AeroElectric recommendations made some
years back, I ordered a S700-1 equivalent switch from Honeywell - same
result. Then I tried a switch from DigiKey, same result. I'm back to a
Carling, at least for the short term. I have Carlings for the Nav lights,
Landing and Wig Wag lights and instrument lights, and I have had no problem
with any of them. The strobe switch is backed up by a 7 amp fuse which is
recommended for the strobe system (Whelen) and it has never popped. The run
of 18 ga. wire is about ten feet. Of all the switches, only the strobe
switch gets real hot after only a few minutes of use.
I was searching B&C for a relay I could use to reroute the strobe heavy
current wire, and discovered that B&C now advertises a MilSpec single pole
switch (MS35058-22) that is the equivalent of the S700-1. The dimensions
appear the same, with screw type connections rather than fast ons. It ain't
cheap, but it would be worth it to avoid having to frequently replace a
burnt out standard switch. Would this MilSpec switch be a viable solution to
the strobe switch problem?
Charlie Brame
RV-6A, N11CB
San Antonio
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe switches |
> The strobe switch is backed up by a 7 amp fuse which is
> recommended for the strobe system (Whelen) and it has never popped.
> The run of 18 ga. wire is about ten feet. Of all the switches, only
> the strobe switch gets real hot after only a few minutes of use.
Can you tell where it's getting hot? We've
had this (and similar) discussions on strobe
controls over the years. I am mystified as
to how the burning of switches and terminal
crimps seems to be concentrated on the strobe
systems . . . driven by relatively light
protection (7A fuse).
>I was searching B&C for a relay I could use to reroute the strobe
>heavy current wire, and discovered that B&C now advertises a MilSpec
>single pole switch (MS35058-22) that is the equivalent of the
>S700-1. The dimensions appear the same, with screw type connections
>rather than fast ons. It ain't cheap, but it would be worth it to
>avoid having to frequently replace a burnt out standard switch.
>Would this MilSpec switch be a viable solution to the strobe switch problem?
Your question raises some interesting points.
There seems to be something 'different' about
the strobe system current draw profile that
stresses the centers of highest-resistance
in the power path. In the past, we've seen
failures at the rivet joints on the switches,
contacts within the switches, switch rockers,
and less-than-idea crimps on terminals, etc.
Yet the RMS or average current remains so
low that a relatively fast protective device
like a fuse doesn't complain. I would REALLY
like to see the current profile on a strobe
system that has repeatedly damaged its switch.
There's got to be a characteristic unique to
strobe supplies (perhaps just this model
of supply) that's especially antagonistic
to components in the power feeder.
Getting to your specific questions. A
relay would certainly transfer the stresses
away from the switch . . . but any connecting
devices in the power path (like crimps)
would still see the 'abuse'.
It might well be that a switch with molded
terminal supports . . .
Emacs!
. . . would not offer the weaknesses of
riveted joints . . . but crimps, threaded
fasteners and internal contacts of the
switch would still be getting 'hammered'.
I do have a proof-of-concept, solid state
relay that I'd be pleased to send you. I've
like to get it into service on an often-flown
airplane and perhaps yours is the best
candidate. It appears that the strobes feeder
in your airplane would be a good location to
try the relay while potentially addressing
your specific failure mode.
Do you have access to any test equipment
that might measure and record the current
waveform impressed on the strobe switch
in your airplane?
I'm mulling over ideas for getting data
of your airplane and then perhaps expanding
the investigation to other airplanes to
see if we can identify the controlling
physics.
There are tens of thousands of airplanes
flying Carling switches in the strobe
power feed path . . . the fact that a
few folks here on the List have experienced
serial failures of these switches is
curious to say the least.
Bob . . .
________________________________________________________________________________
| From: | "Dr. Andrew Elliott" <a.s.elliott(at)cox.net> |
| Subject: | Strobe switches? |
Following some FMEA principles might be valuable here, yes? First,
you have some evidence that it is *not* a switch problem, since various
switch replacements have done nothing to alleviate the issue. Second,
many thousands of builders have strobes in their aircraft which have no
problems with switches and fast-on wires burning up. Together, these
would tell me to look elsewhere for the root cause.
Do you have a non-standard strobe power supply? Can you swap it with
a friends to see if that makes any difference? Can you bench test it
using ground power?
Are you using unusual strobe bulbs? Are they the correct bulbs
specified for the power supply and fixtures? Are you using an unusual
flash pattern? Perhaps with a high duty cycle?
Is there any other evidence of higher than expected current flow
behind the switch panel? Other switches or wires? Voltage regulator?
Is the ground for the strobe circuit solid?
FWIW,
Andy
------------------------
Andy Elliott, CL:480-695-9568
N601GE/Z601XL/TD/Corvair
555 hrs since 11/08
<http://servi-aero.com/n601ge/4sale/> Web Site Link
________________________________________________________________________________
| From: | Bill Watson <Mauledriver(at)nc.rr.com> |
| Subject: | Re: Strobe switches |
I experienced a burned out fast-on connector at my fuse panel on the
16AWG strobe power lead between the fuse panel and the switch. My
strobe unit was a CreativAir Avi-Pak 60 watt, 4 outlet strobe power
suppy intended for experimental aircraft use. Three strobes were
connected. There was a 15amp fuse on the unit and a 15amp fuse on the
fuse panel. This was on an RV10 and there was somewhere between 10 and
20 feet of 16AWG wire in the switched power circuit.
I had difficulty identifying the burned out fast-on connector. The
circuit remained intact despite it's inability to carry the required
load. In the course of problem determination, I decided to replace the
unit. (I later determined that the unit works just fine)
The CreativAir units are no longer available so I installed a unit from
Nova Electronics - XPAK604X 60 watt, 4 outlet strobe power suppy. It is
also referred to as a SUPERPAK604X. This unit seems to be intended for
emergency vehicle use but is very similar to the CreativAir product, it
looks like it is from the same manufacturer with the same dimensions and
mounting hardware.
However, it can be powered by an unswitched line directly from the power
circuit. It is operated thru a separate control circuit. In the RV10
this allowed me to reduce the power circuit from over 10 feet to less
than 3 feet. Where the old circuit was warm/hot to the touch,
everything is now cool.
The XPAK604X was cheaper, had more strobe pattern options and used a
control circuit which would seem to accomplish what a relay would do.
On 1/21/2014 2:19 AM, B Tomm wrote:
>
> What about using a relay to switch the strobe current? Use the carling
> switch to control the relay.
>
> Bevan
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Charles
> Brame
> Sent: Monday, January 20, 2014 9:33 PM
> To: List AeroElectric
> Subject: AeroElectric-List: Strobe switches
>
> -->
>
> Bob, et.al.,
>
> I just replaced my fourth S700-1(or equivalent) strobe switch in about 200
> hours of flying time. Both fast on terminals were badly burned as was about
> an inch of the 18ga. wire attached to the fast on. My first two switches
> were Carlings from B&C. Based on AeroElectric recommendations made some
> years back, I ordered a S700-1 equivalent switch from Honeywell - same
> result. Then I tried a switch from DigiKey, same result. I'm back to a
> Carling, at least for the short term. I have Carlings for the Nav lights,
> Landing and Wig Wag lights and instrument lights, and I have had no problem
> with any of them. The strobe switch is backed up by a 7 amp fuse which is
> recommended for the strobe system (Whelen) and it has never popped. The run
> of 18 ga. wire is about ten feet. Of all the switches, only the strobe
> switch gets real hot after only a few minutes of use.
>
> I was searching B&C for a relay I could use to reroute the strobe heavy
> current wire, and discovered that B&C now advertises a MilSpec single pole
> switch (MS35058-22) that is the equivalent of the S700-1. The dimensions
> appear the same, with screw type connections rather than fast ons. It ain't
> cheap, but it would be worth it to avoid having to frequently replace a
> burnt out standard switch. Would this MilSpec switch be a viable solution to
> the strobe switch problem?
>
> Charlie Brame
> RV-6A, N11CB
> San Antonio
>
>
________________________________________________________________________________
| Subject: | Re: Digital Industrial Scales Outlets |
| From: | "Andrew29" <kenwayproperties(at)yahoo.com> |
I also buy different products from Ebay and Amazon .But almost all the scale companuy
directly offer a range of scale on their website. And you can easily buy
scale form their online store at really cheap price. Because in this way you
can save the middle man cost.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=417393#417393
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe switches |
At 11:27 AM 1/21/2014, you wrote:
I experienced a burned out fast-on connector at my fuse panel on the
16AWG strobe power lead between the fuse panel and the switch. My
strobe unit was a CreativAir Avi-Pak 60 watt, 4 outlet strobe power
suppy intended for experimental aircraft use. Three strobes were
connected. There was a 15amp fuse on the unit and a 15amp fuse on
the fuse panel. This was on an RV10 and there was somewhere between
10 and 20 feet of 16AWG wire in the switched power circuit.
I had difficulty identifying the burned out fast-on connector. The
circuit remained intact despite it's inability to carry the required
load. In the course of problem determination, I decided to replace
the unit. (I later determined that the unit works just fine)
Do you still have this 'problem' system?
The XPAK604X was cheaper, had more strobe pattern options and used a
control circuit which would seem to accomplish what a relay would do.
Interesting. I wonder if they 'discovered' the
features in their power demands that were so
abusive of otherwise perfectly good switches . . .
I'm gathering the hardware together to craft a
mailable data acquisition system together that
I can ship to a willing List member to gather
some definitive data on their strobe systems.
I'd like to acquire a library of data both
from systems that have suffered failures in
the power wiring . . . and some that didn't.
"When you can measure what you are speaking about,
and express it in numbers, you know something about
it, when you cannot express it in numbers, your knowledge
is of a meager and unsatisfactory kind; it may be
the beginning of knowledge, but you have scarcely,
in your thoughts advanced to the stage of science."
---- Lord Kelvin ----
We've been watching these rare but significant
events for some years . . . ignorant of the
root cause. I'm thinking it's time to get some
good numbers.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe switches |
At 11:32 PM 1/20/2014, you wrote:
Bob, et.al.,
I just replaced my fourth S700-1(or equivalent) strobe switch in
about 200 hours of flying time. Both fast on terminals were badly
burned as was about an inch of the 18ga. wire attached to the fast on.
Charlie, do you want to try the solid state
relay? If you do install this relay . . .
Emacs!
. . . it will offer a plug-n-play port through which
we can gather some good numbers when the DAS system
goodies I've ordered get here . . .
Bob . . .
________________________________________________________________________________
| From: | Charles Brame <chasb(at)satx.rr.com> |
| Subject: | Re: Strobe switches |
Bob,
Thanks for the response. See my answers to your questions in red below.
Charlie Brame
RV-6A N11CB
San Antonio
------------------------------------------------------------------
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Subject: Re: AeroElectric-List: Strobe switches
> The strobe switch is backed up by a 7 amp fuse which is
> recommended for the strobe system (Whelen) and it has never popped.
> The run of 18 ga. wire is about ten feet. Of all the switches, only
> the strobe switch gets real hot after only a few minutes of use.
Can you tell where it's getting hot?
With this latest switch failure the hot spots were the fast on
connectors at the switch, and I did not notice the switch itself getting
hot. The switch fast on tabs are externally riveted and became very
loose. There is no signs of burning of the switch itself, though
something caused the fast on tabs to become loose on the switch body.
And both of the connectors (power in and power out) were burned. In one
of the previous Carling failures, the switch was fried on the inside,
and the switch itself got hot, including the bat handle. The power
connector at the power pack is a Molex type pin plug and does not show
any heat related distress. The power supply fast on at the fuse panel
has also never shown any signs of heating. With a new switch installed,
there is no evidence of any hot spots. However, after a period of time,
the problem reoccurs.
We've had this (and similar) discussions on strobe
controls over the years. I am mystified as
to how the burning of switches and terminal
crimps seems to be concentrated on the strobe
systems . . . driven by relatively light
protection (7A fuse).
> I discovered that B&C now advertises a MilSpec
> single pole switch (MS35058-22) that is the equivalent of the
> S700-1. Would this MilSpec switch be a viable solution to the strobe
switch problem?
Your question raises some interesting points.
There seems to be something 'different' about
the strobe system current draw profile that
stresses the centers of highest-resistance
in the power path. In the past, we've seen
failures at the rivet joints on the switches,
contacts within the switches, switch rockers,
and less-than-idea crimps on terminals, etc.
Yet the RMS or average current remains so
low that a relatively fast protective device
like a fuse doesn't complain. I would REALLY
like to see the current profile on a strobe
system that has repeatedly damaged its switch.
There's got to be a characteristic unique to
strobe supplies (perhaps just this model
of supply) that's especially antagonistic
to components in the power feeder.
Getting to your specific questions. A
relay would certainly transfer the stresses
away from the switch . . . but any connecting
devices in the power path (like crimps)
would still see the 'abuse'.
It might well be that a switch with molded
terminal supports . . .
Emacs!
. . . would not offer the weaknesses of
riveted joints . . . but crimps, threaded
fasteners and internal contacts of the
switch would still be getting 'hammered'.
I do have a proof-of-concept, solid state
relay that I'd be pleased to send you. I've
like to get it into service on an often-flown
airplane and perhaps yours is the best
candidate. It appears that the strobes feeder
in your airplane would be a good location to
try the relay while potentially addressing
your specific failure mode.
I would be pleased to try your new solid state relay. However, I don't
have any test equipment and am not sure I'm smart enough to use it if I
had access. But I am open to ideas and suggestions.
Do you have access to any test equipment
that might measure and record the current
waveform impressed on the strobe switch
in your airplane?
I'm mulling over ideas for getting data
of your airplane and then perhaps expanding
the investigation to other airplanes to
see if we can identify the controlling
physics.
There are tens of thousands of airplanes
flying Carling switches in the strobe
power feed path . . . the fact that a
few folks here on the List have experienced
serial failures of these switches is
curious to say the least.
In reading some of the other responses, I'd like to clarify the
following: My system is a Whelen three light system with a single power
pack. There have been no changes or additions to the system as it was
received from the manufacturer. All bulbs and flash sequences were
factory set and the cables from the power pack to the lights are factory
supplied. The system is grounded at the power pack and the ground
appears secure. I have seen no evidence of any other over voltage, over
amperage damage to any other switches or devices. The regulator (a
generic Ford regulator) seems to work as advertised. The strobe system
is left on at all times and begins to operate when the master switch is
turned on. In other words, the switch is rarely cycled on or off.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe switches |
At 10:55 AM 1/22/2014, you wrote:
Bob,
Thanks for the response. See my answers to your questions in red below.
Charlie Brame
RV-6A N11CB
San Antonio
------------------------------------------------------------------
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com>
Subject: Re: AeroElectric-List: Strobe switches
The strobe switch is backed up by a 7 amp fuse which is
recommended for the strobe system (Whelen) and it has never popped.
The run of 18 ga. wire is about ten feet. Of all the switches, only
the strobe switch gets real hot after only a few minutes of use.
Can you tell where it's getting hot?
With this latest switch failure the hot spots were the fast on
connectors at the switch, and I did not notice the switch itself
getting hot. The switch fast on tabs are externally riveted and
became very loose. There is no signs of burning of the switch itself,
though something caused the fast on tabs to become loose on the
switch body. And both of the connectors (power in and power out) were
burned. In one of the previous Carling failures, the switch was fried
on the inside, and the switch itself got hot, including the bat
handle. The power connector at the power pack is a Molex type pin
plug and does not show any heat related distress. The power supply
fast on at the fuse panel has also never shown any signs of heating.
With a new switch installed, there is no evidence of any hot spots.
However, after a period of time, the problem reoccurs.
Good data. Thanks.
I would be pleased to try your new solid state relay. However, I
don't have any test equipment and am not sure I'm smart enough to use
it if I had access. But I am open to ideas and suggestions.
Understand. Were your airplane sitting at Medicine Lodge
Intergalactic Airport, there are a number of whippy
tools on my shelf that would get us the data. I've
been considering ways to craft a DAS that could be
mailed at cheap priority mail rates and be relatively
simple to operate. I think I'm close to realizing
that goal . . . you can be the first 'victim' . . .
It will let us get data from YOUR installation,
on the ground and in just a few seconds. It's
basically a 1000 samples/second storage
'oscilloscope' that records to a hard drive.
In reading some of the other responses, I'd like to clarify the
following: My system is a Whelen three light system with a single
power pack. There have been no changes or additions to the system as
it was received from the manufacturer. All bulbs and flash sequences
were factory set and the cables from the power pack to the lights are
factory supplied. The system is grounded at the power pack and the
ground appears secure. I have seen no evidence of any other over
voltage, over amperage damage to any other switches or devices. The
regulator (a generic Ford regulator) seems to work as advertised. The
strobe system is left on at all times and begins to operate when the
master switch is turned on. In other words, the switch is rarely
cycled on or off.
Also excellent data points.
We'll move ahead as if we know what we're
doing. Some of the goodies are coming from
overseas but I can get the relay out to
you this weekend. Shoot me your mailing
address.
As soon as you and I figure that we're doing
a good thing, we'll bicycle the rig around
and get data from as many other airplanes
as we have willing participants.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe switches |
Speaking of strobe switch failures, there was
a series of exchanges here on the list a few
years back where the Lister had experienced
a rash of failures . . . which produced an
understandable bad taste in his mouth for the
Carling switches.
Is that individual still on the List or does
anyone recall who it was? I would be interesting
to know how the problem resolved.
Bob . . .
________________________________________________________________________________
| From: | Bill Watson <Mauledriver(at)nc.rr.com> |
| Subject: | Re: Strobe switches |
Yes I still have the problem system and would be happy to send to you.
Just let me know the address and it's on it's way. No return required.
Thanks
On 1/22/2014 10:10 AM, Robert L. Nuckolls, III wrote:
>
>
> At 11:27 AM 1/21/2014, you wrote:
>
>
> I experienced a burned out fast-on connector at my fuse panel on the
> 16AWG strobe power lead between the fuse panel and the switch. My
> strobe unit was a CreativAir Avi-Pak 60 watt, 4 outlet strobe power
> suppy intended for experimental aircraft use. Three strobes were
> connected. There was a 15amp fuse on the unit and a 15amp fuse on the
> fuse panel. This was on an RV10 and there was somewhere between 10 and
> 20 feet of 16AWG wire in the switched power circuit.
>
> I had difficulty identifying the burned out fast-on connector. The
> circuit remained intact despite it's inability to carry the required
> load. In the course of problem determination, I decided to replace
> the unit. (I later determined that the unit works just fine)
>
> Do you still have this 'problem' system?
>
> The XPAK604X was cheaper, had more strobe pattern options and used a
> control circuit which would seem to accomplish what a relay would do.
>
> Interesting. I wonder if they 'discovered' the
> features in their power demands that were so
> abusive of otherwise perfectly good switches . . .
>
> I'm gathering the hardware together to craft a
> mailable data acquisition system together that
> I can ship to a willing List member to gather
> some definitive data on their strobe systems.
>
> I'd like to acquire a library of data both
> from systems that have suffered failures in
> the power wiring . . . and some that didn't.
>
>
> "When you can measure what you are speaking about,
> and express it in numbers, you know something about
> it, when you cannot express it in numbers, your knowledge
> is of a meager and unsatisfactory kind; it may be
> the beginning of knowledge, but you have scarcely,
> in your thoughts advanced to the stage of science."
>
> ---- Lord Kelvin ----
>
> We've been watching these rare but significant
> events for some years . . . ignorant of the
> root cause. I'm thinking it's time to get some
> good numbers.
>
>
> Bob . . .
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
>
>
________________________________________________________________________________
| Subject: | Re: Strobe switches |
| From: | "racerjerry" <gki(at)suffolk.lib.ny.us> |
I am very reluctant to throw in my two cents here, as there are much greater minds
than mine on this list. I figger that strobe power pack current characteristics
may be causing switch arcing; slowly damaging the switch contact material,
increasing contact resistance to the point where local heating and a snowball
type failure occurs. There are quite a few different materials used for switch
contacts. Depending on switch requirements and UL ratings; all contacts
have their own characteristics and ability survive differing harsh environments.
Ol tungsten lamps are similarly known for their high initial current inrush
characteristics and switches require a T rating from UL, but these are AC
switches and any arc is self extinguishing at the zero crossing point of the AC
wave. DC switches are a different animal. DC switches require a quick snap
action which is independent of operator manipulation.
One trick for switch survival in such instances is to use a double pole switch
with both sets of contacts wired in series to double arc distance and contact
separation speed. (Thank you Mr. Tibolla, wherever you are).
Again, if I were to guess, I would first suspect the initial current draw of the
large strobe capacitor would be the cause. Any contact bounce on switch closing
would definitely aggravate things and hasten failure. I too would want to
check the current / voltage profile of that strobe. Carling generally makes
darned good switches.
--------
Jerry King
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=417461#417461
________________________________________________________________________________
| Subject: | Re: Strobe switches |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
Here's my guess:
The only key difference in strobe supplies is their really big capacitors. When
caps are flat (perhaps after long storage), their current demand is gigantic
for a short time. Good design would put a peak current limiter like a CL-11 surge
suppressor in the input circuit.
An O-scope would show this, but maybe only on the first start after long storage.
Furthermore the test design for this is tricky because the current you are
trying to capture is very high and very short.
A solid state relay, or any other relay, probably isn't the solution to the problem.
--------
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=417468#417468
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe switches |
At 07:57 AM 1/23/2014, you wrote:
I am very reluctant to throw in my two cents
here, as there are much greater minds than mine
on this list. I figger that strobe power pack
current characteristics may be causing switch
arcing; slowly damaging the switch contact
material, increasing contact resistance to the
point where local heating and a snowball type failure occurs.
I agree that some stress of this nature is in
play. A stress that seems to be unique to a
sub-set of the family of strobe products. I can't
speak to the contact style of switches pre-Carling-
rockers on the Cessnas. Without a doubt,
the mechanical features of these switches went
un-changed for decades and, perhaps, persist
to this day. Here's a breakdown of the electron-
pathway through a fast-on-tabbed Carling switch . . .
http://tinyurl.com/qcmyt4e
There are quite a few different materials used
for switch contacts. Depending on switch
requirements and UL ratings; all contacts have
their own characteristics and ability survive
differing harsh environments. Ol tungsten
lamps are similarly known for their high initial
current inrush characteristics and switches
require a T rating from UL, but these are
AC switches and any arc is self extinguishing at
the zero crossing point of the AC wave. DC
switches are a different animal. DC switches
require a quick snap action which is independent of operator manipulation.
One trick for switch survival in such instances
is to use a double pole switch with both sets of
contacts wired in series to double arc distance
and contact separation speed. (Thank you Mr. Tibolla, wherever you are).
Keep in mind that we've seen failures across
the entire spectrum of metal-to-metal interfaces.
http://tinyurl.com/96yqmg
http://tinyurl.com/8zzkfbb
Failures of terminals are almost always a
failure to achieve gas-tight joining. Failure
of the rivet joints are probably precipitated by
degradation of the plastic housing material that
relieves mate-up pressures between the tab and
the contact-rivet. Degradation rooted in elevated
temperatures at a slowly failing junction.
Again, if I were to guess, I would first suspect
the initial current draw of the large strobe
capacitor would be the cause. Any contact
bounce on switch closing would definitely
aggravate things and hasten failure. I too would
want to check the current / voltage profile of
that strobe. Carling generally makes darned good switches.
Carling's demonstrated service history has
offered no incentives for folks in the airplane
business to boot them off the airplanes. At
the same time, tens of thousands of these
same switches have endured the test of time
as controls for strobe lighting systems.
Some years ago, a company that employed
my services banned a particular brand of
relay from the fleet of products . . . they
purged stock and replaced with Brand-M
based on anecdotal information that Brand-M
demonstrated a 'longer service life' in the
same abusive slot on the airplane. Brand-M
STILL stuck but only 1/3rd as often.
It took several years of P&P (play and ponder)
to finally deduce root cause . . . an effect
that was not covered in any of the relay engineering
manuals but repeated demonstrated on my workbench.
The 'fixes' I recommended based on findings
were never implemented. The failure rate had
dropped down enough to fall off the ten-worst-
problems list and the bean-counters lost
interest.
Observations of anecdotes here on the List
suggest that what ever differences
exist across the family of strobe
lighting systems, there IS a
characteristic that will bring out the
worst joint in any bus-voltage pathway to the
strobe supply. The 'worst' has manifested
mostly in failures in and around the strobe
switch. But Listers have told us that the
fast-on terminal to their fuse-block has
proven to be the weak-link that succumbed
to the ravages of whatever weapon their
strobe brought to the fight.
I think we've observed and analyzed enough
history to suggest that an investigation
into weaponry is in order. Hence my decision
to acquire tools of investigation which,
with the help of others here on the List,
may peel back the layers of the onion
and make all secrets known.
Our work here on the strobe switch failure
mystery has little to zero chance
of causing anyone to change their designs.
The best we can hope for is to identify
root cause and craft tools to identify its
recurrence so that some brands of strobes
can be avoided.
Ever hear of "too-little, too-late"? By the
time we figure this out, xenon strobes may
be on their way out of the marketplace and
the 'problem' will simply go away. But there
are simple-ideas and science to be identified
that will give foundation for any future investigation
into mysterious failures of perfectly good
switches and terminals.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe switches |
At 07:38 PM 1/22/2014, you wrote:
>
>Yes I still have the problem system and would be happy to send to you.
>Just let me know the address and it's on it's way. No return required.
Sure.
P.O. Box 130, Medicine Lodge, Ks, 67104-0130
Thanks!
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe switches |
At 09:07 AM 1/23/2014, you wrote:
Here's my guess:
The only key difference in strobe supplies is their really big
capacitors. When caps are flat (perhaps after long storage), their
current demand is gigantic for a short time. Good design would put a
peak current limiter like a CL-11 surge suppressor in the input circuit.
But we've seen failures in switches that are
always left on. Initial inrush events, while
most severe, occur only at turn-on . . . what
we're seeing appears to be a manifestation of
persistent RMS heating . . . i.e. a recurring
condition during operation.
An O-scope would show this, but maybe only on the first start after
long storage. Furthermore the test design for this is tricky because
the current you are trying to capture is very high and very short.
Actually, no worse that for getting
a 100w landing light lit up from a cold
start. Such inrush currents are generally
limited by ship's wiring. Here's an exemplar
plot for starting a 55W lamp.
http://tinyurl.com/mvugala
Cold resistance of the lamp was measured
at 150 mOhm, wiring added another 165
mOhm for a total of 315 mOhm and a predictable
inrush on the order of 14/.315 or 44A. If
the bulb had a monster capacitor across it
then the absolute max inrush would still
be limited by a/c wiring to 14/.165 or
84A.
This is in the ballpark for expected tungsten
lamp inrush values cited when switches are
rated in the lab. Ratings that assume the
system integrator expects a service life in
the thousands of cycles.
We're witnessing failures in under 1000
cycles . . . perhaps as few as 200 cycles.
The failures include devices that don't have
to switch . . . only carry the load.
It may be that initial inrush is a factor
but I'm guessing it's not the dominate
effect. The fact that many strobe systems
do not exhibit the problem while one
system can duplicate the problem several
times suggests that root cause can be
chased down by comparing problem children
with well behaved children . . .
A solid state relay, or any other relay, probably isn't the solution
to the problem.
A solid state relay will eliminate the failures
with roots in contact resistance . . . but there
are other metal-to-metal joints at risk. You're right,
there's more going on here than can be explained
by failure to observe switch ratings from the
catalogs.
Bob . . .
________________________________________________________________________________
| From: | "John Brick" <jebrick(at)comcast.net> |
RV-4 For Sale (N474JB)
Located on Pierce County Airport Thun Field (KPLU)
TT A&E 1340 hours.
Aero Sport Power, IO-360-B1B with 9.2 compression.
Airflow Performance fuel injection with purge valve.
B&C Starter and Alternator.
Lightspeed Plasma III electronic ignition in place of right mag.
Whirl Wind 200RV constant speed prop.
Full IFR panel. GPS, VOR, ILS
IFR approach certified KLN-94 GPS
Mid Continent MD-200-306 CDI/Glideslope
Dynon D6 EFIS
TruTrak ADI
SL70 Transponder
Radios:
Audio Panel: PS Engineering Inc, PMA6000M-IRS
SL30 Nav/Com
ICOM A200
Antenna switchbox to permit use of bottom whip with ICOM handheld (3rd
radio).
Dual axis TruTrak autopilot with automatic pitch trim.
Infinity stick grip with aileron and elevator trim on hat switch.
Dual USB ports.
Mountain High O2D2 Oxygen system.
Bose headsets front and back.
Fuel capacity: 53 gallons in normal leading edge (extended) wing tanks.
RV-7 Wing Tips
Tall main gear legs.
Andair gascolator in each wing root.
Custom built alternate air door.
Performance:
175 knot cruise on 8 gph or less.
Seattle to Oshkosh with one stop, each way.
Absolute ceiling: FL280. Yes been there, May 29th, 2008. Normally
aspirated.
Normal cruising altitudes are 11.5 or 12.5 but cruises nicely at FL210 too.
Aerobatic: absolutely its an RV.
Construction:
Two part epoxy primer throughout.
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Attractive paint and upholstery.
Reason for sale: Medical. Asking $75K.
Questions? 253-230-8516
---
This email is free from viruses and malware because avast! Antivirus protection
is active.
http://www.avast.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Fuse holders |
At 02:32 PM 1/25/2014, you wrote:
>Hi Bob. I found out about you through an EAA article I read. I have
>a question to ask if I may. I have a 69 Cherokee that I'm installing
>a timer, and some lighting in. I wanted to put in 2 1A c/bs, but I
>couldn't find any dimensionally to fit (I guess they don't make my
>size c/b anymore) so I thought maybe I could put in fuse holders. My
>airplane didn't come with fuse holders to get a part #, so I looked
>through 43-13, and the mechanic's handbook, but can find no mention
>of when you can, or can't use a fuse holder, or what the specs. need
>to be. Can I legally install a panel-mount, or in-line (aircraft
>wiring?) fuse holder such as from Spruce in a certified airplane?
>Thank You for your time.
First, this is between you and your IA. It's a
'modification' but can probably be considered
minor . . . perhaps needing nothing more than
a log-book entry and update to the weight and
balance. On the other hand, an IA that knows
a great deal about the need for balanced flight
control surfaces MIGHT elevate the task to
something akin to an STC for JATO assist
take-off bottles.
Do some IA shopping FIRST.
There is no reason in physics, legacy practices
nor past examples of type certificated aircraft
stating that you cannot use fuse-holders. The FARs
require only that feeders from the bus be protected from
conflagration due to faults . . . they speak to
'circuit protective' devices which has included
fuses, circuit breakers and (for the currents
you're talking about) PTC self resetting fuses.
First, are you sure you NEED to add any circuit
protection? It's entirely 'kosher' to run multiple
appliances from a single fuse/breaker as long as
loss of all appliances on the circuit does not
offer more than a maintenance event.
These things sound like they're rather innocuous
with respect to aircraft operation . . . can
you power them from an existing breaker powering
an equally innocuous appliance?
If you decide to add fuses, make them panel
mounted and accessible to crew is probably
unnecessary too. Consider in-line fuse holders
tied into wire bundles close to where they tap
the bus structure.
This style of fuse holder was used on many
of your airplane's ancestors . . .
[]
An if you have both space and desire to panel
mount some fuse holders, these are one option
of several . . .
You can acquire the holder above or the one below
from a local car-parts store. The one below uses
the plastic ATC style fuse and would tie into the
wire bundles behind the panel.
Emacs!
You probably wont find an ATC1 fuse in the
car parts store but an ATC3 or 5 is fine.
Bottom line is that there are no practical
restrictions in physics for adding these
devices to your airplane . . . it's more a
matter to be decided between you and whoever
is going to sign off your paperwork.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | . . . If you have enough horsepower . . . |
See:
http://www.youtube.com/watch?feature=player_embedded&v=NK7ulDQ5h8Y
Bob . . .
________________________________________________________________________________
| From: | <berkut13(at)berkut13.com> |
| Subject: | Re: . . . If you have enough horsepower . . . |
...or are made out of balsa wood like these models. ;-)
-----Original Message-----
From: Robert L. Nuckolls, III
Sent: Saturday, January 25, 2014 5:45 PM
Subject: AeroElectric-List: . . . If you have enough horsepower . . .
See:
http://www.youtube.com/watch?feature=player_embedded&v=NK7ulDQ5h8Y
Bob . . .
________________________________________________________________________________
| From: | <berkut13(at)berkut13.com> |
| Subject: | Re: . . . If you have enough horsepower . . . |
(first two anyway)
-----Original Message-----
From: berkut13(at)berkut13.com
Sent: Saturday, January 25, 2014 7:40 PM
Subject: Re: AeroElectric-List: . . . If you have enough horsepower . . .
...or are made out of balsa wood like these models. ;-)
-----Original Message-----
From: Robert L. Nuckolls, III
Sent: Saturday, January 25, 2014 5:45 PM
Subject: AeroElectric-List: . . . If you have enough horsepower . . .
See:
http://www.youtube.com/watch?feature=player_embedded&v=NK7ulDQ5h8Y
Bob . . .
________________________________________________________________________________
| Subject: | Re: Spoilers vs. Speed Brakes |
| From: | "gotgold5" <pokemonjxc1(at)gmail.com> |
with all the variety of completely different aspects individuals should certainly
see for ones performance might be fantastic
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=417648#417648
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Strobe switches |
At 09:44 AM 1/23/2014, you wrote:
>
>
>At 07:38 PM 1/22/2014, you wrote:
>>
>>Yes I still have the problem system and would be happy to send to you.
>>Just let me know the address and it's on it's way. No return required.
>
> Sure.
>
> P.O. Box 130, Medicine Lodge, Ks, 67104-0130
I received Bill's strobe supply and began
to research its pedigree. Seems to be a custom
device designed for Creativair (now defunct)
and manufactured by Nova.
The nameplate says 10-30 volts input
which speaks to a modern, switchmode
power supply topology. It also says
70 watts in, 60 watts out and input
current of 5.5A.
Of course, that 5.5A figure is accurate
only at the bus voltage where 70 watts
of demand is satisfied or 70/5.5=12.7
volts. At a bus voltage of 14 volts or
more, input current would be expected to
fall to about 5A. IN a 28v airplane, the
current would be about half that.
Bill says he supplied this device through
a 7A fuse which held solid while other
devices in the supply line were less
happy about the nature of demands on
their capabilities.
We would probably do well to compile
a listing of switch/terminal failures
in strobe systems.
Bill, would you repeat your narrative
of what items in your strobe supply path
failed . . . along with your best guess
as to the epicenter of the failures?
How many instances did you experience
before you replaced the power supply?
Bob . . .
________________________________________________________________________________
| From: | "Fisher Paul A." <FisherPaulA(at)johndeere.com> |
If this is the "AVI-PAK" sold by CreativAir, then I have one too. Mine has been
in service for about 3.5 years (300+ flight hours) and I haven't noticed any
problems... so far! Last inspection was in July, and as soon as it warms up
a little, I'll inspect all of the connections again just to be sure nothing is
sneaking up on me.
I'd be very interested in any analysis of this device and what, if anything, we
can do to prevent re-occurrence of this issue.
Paul A. Fisher
RV-7A N18PF
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Robert L. Nuckolls, III
Sent: Tuesday, January 28, 2014 7:01 AM
Subject: Re: AeroElectric-List: Strobe switches
...snip...
I received Bill's strobe supply and began
to research its pedigree. Seems to be a custom
device designed for Creativair (now defunct)
and manufactured by Nova.
...snip
________________________________________________________________________________
| From: | JOHN TIPTON <jmtipton(at)btopenworld.com> |
Hi Guys=0A=0AIs this suitable for the Contactor connections, ANL fuse link
etc, or is 3mm thickness too much=0A=0Ahttp://www.ebay.co.uk/itm/3906923406
35?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649=0A=0A=0ABest r
egards=0A=0AJohn (RV9a - work in progress)=0A
________________________________________________________________________________
| From: | Ron Burnett <ronburnett(at)charter.net> |
As suggested once by Mr. Bob, you can put a piece of copper pipe in a vise.
Works great.
Ron Burnett
RV-6A
Sent from my iPad
May you have the blessings of the Lord today.
> On Jan 28, 2014, at 9:40 AM, JOHN TIPTON wrote:
>
> Hi Guys
>
> Is this suitable for the Contactor connections, ANL fuse link etc, or is 3
mm thickness too much
>
> http://www.ebay.co.uk/itm/390692340635?ssPageName=STRK:MESINDXX:IT&_trks
id=p3984.m1436.l2649
>
> Best regards
>
> John (RV9a - work in progress)
>
>
>
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 07:58 AM 1/28/2014, you wrote:
>
>
>If this is the "AVI-PAK" sold by CreativAir, then I have one
>too. Mine has been in service for about 3.5 years (300+ flight
>hours) and I haven't noticed any problems... so far! Last
>inspection was in July, and as soon as it warms up a little, I'll
>inspect all of the connections again just to be sure nothing is
>sneaking up on me.
>
>I'd be very interested in any analysis of this device and what, if
>anything, we can do to prevent re-occurrence of this issue.
Good idea. I'd also like to 'bicycle' the DAS
system to you and get some data off your
as-installed system.
Bob . . .
________________________________________________________________________________
| From: | Jeff Luckey <jluckey(at)pacbell.net> |
John,=0A=0A3mm is about 1/8 of an inch (if my math is correct) and that thi
ckness is more than enough to handle starter current - if you bussing does
not need to handle that much current then you could go w/ thinner material.
- =0A=0AAnother consideration is that copper oxidizes very quickly so you
need to make sure that the connections are very clean when you assemble.
- In industry, copper bussbars are commonly plated w/ either silver or ti
n to protect against poor connection quality due to oxidation.=0A=0ABrass i
s another material commonly used in electrical busses & devices and it does
not oxidize as quickly and is less expensive.- I just made some bussbars
from .050 brass (they were not in the starter circuit) and the brass was e
asy to work with & cheaper than the equivalent copper.=0A=0A=0A-Jeff=0A=0A
=0A________________________________=0A From: JOHN TIPTON <jmtipton@btopenwo
rld.com>=0ATo: "aeroelectric-list(at)matronics.com" =0ASent: Tuesday, January 28, 2014 7:40 AM=0ASubject: AeroElectric-
List: Copper Bar=0A =0A=0A=0AHi Guys=0A=0AIs this suitable for the Contacto
r connections, ANL fuse link etc, or is 3mm thickness too much=0A=0Ahttp://
www.ebay.co.uk/itm/390692340635?ssPageName=STRK:MESINDXX:IT&_trksid=p39
84.m1436.l2649=0A=0A=0ABest regards=0A=0AJohn (RV9a - work in progress)=0A
====================
________________________________________________________________________________
| Subject: | Re: Strobe switches |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
Creative-air/Avi-pak here also, 240 hrs, two years, no issues. However, it's been
on a Bosch cube relay since day one.
Tim
> On Jan 28, 2014, at 8:34 AM, "Robert L. Nuckolls, III"
wrote:
>
>
> At 07:58 AM 1/28/2014, you wrote:
>>
>> If this is the "AVI-PAK" sold by CreativAir, then I have one too. Mine has
been in service for about 3.5 years (300+ flight hours) and I haven't noticed
any problems... so far! Last inspection was in July, and as soon as it warms
up a little, I'll inspect all of the connections again just to be sure nothing
is sneaking up on me.
>>
>> I'd be very interested in any analysis of this device and what, if anything,
we can do to prevent re-occurrence of this issue.
>
> Good idea. I'd also like to 'bicycle' the DAS
> system to you and get some data off your
> as-installed system.
>
>
>
> Bob . . .
>
>
>
>
________________________________________________________________________________
| Subject: | Schumacher 1562 and PC 680 |
| From: | "JohnInReno" <john(at)morgensen.com> |
I posted the following comment at Enersys.
> I am having very bad luck with PC-680 batteries for use in a Vans Aircraft RV9A.
> Purchased a PC-680 on 9/18/12 from Vans Aircraft.
> Purchased a PC-680 on 9/13/13 from Aircraft Spruce.
> Purchased a PC-680 on 1/22/14 from Batteries Plus in Chandler, AZ.
> The airworthiness certificate was issued July 3, 2013 and I have about 75 hours
on the plane. The latest failure left me stranded at the Chandler, AZ airport
far from home. Is there any warranty on this?
>
>
Batteries #1 and #2 were religiously maintained on a Schumacher 1562A. The Odyssey
Battery Approved 12V Charger List has this:
SC-2500A (no longer in production)
"No other Schumacher branded chargers are approved by ODYSSEY"
Battery #2 would not turn the starter but did operate the panel and fuel pump.
After charging at the local FBO, it showed 12.5+ volts but dropped to 8v in 3
seconds under load. This symptom was confirmed when I purchased #3 at Batteries
Plus.
I believe that Odyssey is saying that the Schumacher killed the battery after only
3 months.
This is the response from Odyssey:
Hello John,
Thank you for contacting EnerSys/ODYSSEY.
Unfortunately, due to the multiple consistent failures, this would indicate that
the PC680 battery is not suited for your application or that it is not being
properly maintained or charged. Charging and maintenance information has been
provided below.
The PC680 powersports battery has a two year warranty (attached) for manufacturing
defects. The warranty procedure requires that the battery be returned to the
point of purchase (preferred) or to a participating ODYSSEY dealer or distributor
for warranty support. No ODYSSEY dealer is required to offer assistance.
It is not what we want to see but it is a fact. Batteries Plus, for example,
has a policy of not warranting product not sold form one of their locations.
Once received at a location, the battery voltage has to be a minimum of at least
8.0V, have a purchase date based on a receipt or ship date code date within
the warranty period, and fails attempted recovery. If the battery is at least
8.0V, is returned within the warranty period, is not recoverable, and shows no
signs of abuse or neglect such as bulging from overheating, overcharging or
damage due to mishandling, the battery can be warranted. If the location will
the warranty the battery then the battery can be warranted by the factory based
on the information provided by the supporting location.
Charge maintenance is critical to maximizing the life and performance of any battery
including the ODYSSEY battery. Here is a little ODYSSEY Battery 101
Most batteries including AGMs are considered fully charged at 12.6-12.7V. This
is not so for the TPPL AGM ODYSSEY battery. The usable energy of the ODYSSEY battery
is from 11.2V (0% state of charge) OCV to 12.84V OCV (Open Circuit Voltage
should be checked after a minimum of 6-8 hours rest period with no loads)
or higher. When the battery goes below 10.0V OCV, you are getting into the chemical
part of the battery and can cause permanent damage. At less than 8.0V the
ODYSSEY limited warranty deems the battery over-discharged due to abuse or neglect,
usually unintentional. At less than 6.0V the battery can develop reversed
cells and once reversed, the cells cannot be reversed back. If the battery
becomes over-discharged (below 11.0V OCV), then the sooner the battery can be
fully charged properly, the better. If the battery remains connected to the
application during storage for extended periods of non-use, an ODYSSEY program
approved 12V maintainer can be used to prevent over-discharge and maintain the
battery at a full state of charge and counteract the parasitic loads of the
application. There is a link to a list of ODYSSEY program approved 12V chargers
(and maintainers) linked on the ODYSSEY website Product Support page for your
reference.
The list of approved 12V chargers is provided due to the many chargers that are
programmed for the vast majority of batteries on the market that prefer low amp
charging and lower float voltages that do not fully charge or maintain the
ODYSSEY battery properly. The recommended charging current for an ODYSSEY battery
is 40% of the 10 hour amp hour rating of the battery for cyclic or deep discharge
applications (about 6A for a single 16Ah PC680), a constant float voltage
of 13.5-13.8V (printed on the top label of the battery) and no constant voltages
exceeding 15.0V in any kind of de-sulfation/reconditioning/equalize mode.
At greater than 15.0V the battery can overcharge, overheat, and/or go into
thermal runaway. Maintaining the battery at less than 13.5V will bring the battery
down and maintain it in an undercharged condition causing premature sulfation
and premature failure.
For seasonal applications (non-daily use applications that set for more than 3
days in a row frequently) regular use of an approved maintainer that meets the
charge voltage requirements noted in the previous paragraph is highly recommended
during the season. The preferred storage method is to fully charge the battery
before storing and disconnect the battery from the application (shelf storage
mode). Stored in or out of the application fully charged, with no loads,
the battery would not require charging for up to 2 years at 77F or until it reaches
12.0V, whichever comes first. The self discharge rate increases significantly
for temperatures above 25C (77F) and for every 10C (18F) temperature increase
the storage time to recharge is decreased by half. Charge maintenance is
critical to maximizing the life and performance of the battery. Freezing will
not harm the battery and self discharge rates reduce significantly at colder
temperatures.
It is recommended that the ODYSSEY battery be charged if it is less than 12.65V
when put into use per the ODYSSEY Owners Manual (link provided on website Literature
page for your reference). Most standard alternators/stators are not meant
to be deep discharge recovery chargers and can damage the alternator/stator
as well as not fully charging the battery with limited use. The Cyclic Charge
Voltage range printed on the top label of the battery is the recommended voltage
at the battery from the applications charging system (alternator or stator).
At less than 14.1V the battery may not be getting fully charged for infrequently
used applications. You can verify the battery voltage by checking the
voltage at the battery at least 8 hours after application use (or off charge)
and if the battery voltage is not at least 12.84V then the battery is not considered
fully charged. Voltage readings taken right off charge or after use (alternator/stator
charging) will be inflated and inaccurate so for a true OCV reading,
you should wait at least 8 hours before checking the voltage (OCV) with
24 hour rest period being preferred.
Simply put, if you have a maintainer that has a high enough charging current to
counteract any parasitic loads of the application and maintain the battery between
13.5-13.8V at the battery and does not exceed 15.0V in any kind of automatic
reconditioning/equalize/de-sulfation mode, it can be used to maintain the
battery indefinitely without harming the ODYSSEY battery. If you do not have
an acceptable maintainer or you have not been using and acceptable maintainer
consistently enough, then that may be your primary issue.
I hope this information gives you an understanding of the product. Please contact
me if you have any questions, concerns or need further assistance.
Sincerely,
cid:image003.jpg(at)01CE6B76.5D725510
Kathy Mitchell
ODYSSEY Sales/Support Representative
Phone: 660-429-7551
Toll Free: 888-422-0317
Fax: 660-429-1758
Email: kathy.mitchell(at)enersys.com
Web site: www.odysseybattery.com
Corp site: www.enersys.com
--------
John Morgensen
RV-9A - Born on July 3, 2013
RV4 - for sale
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=417784#417784
Attachments:
http://forums.matronics.com//files/odysseyapproved12vchargersoct2013_172.pdf
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Schumacher 1562 and PC 680 |
At 12:56 PM 1/28/2014, you wrote:
>
>I posted the following comment at Enersys.
>
>
> > I am having very bad luck with PC-680 batteries for use in a Vans
> Aircraft RV9A.
> > Purchased a PC-680 on 9/18/12 from Vans Aircraft.
> > Purchased a PC-680 on 9/13/13 from Aircraft Spruce.
> > Purchased a PC-680 on 1/22/14 from Batteries Plus in Chandler, AZ.
> > The airworthiness certificate was issued July 3, 2013 and I have
> about 75 hours on the plane. The latest failure left me stranded at
> the Chandler, AZ airport far from home. Is there any warranty on this?
Thank you for posting this John. There's a LOT of
words here . . . some of which are conflicting.
It's going to take awhile to do an analysis.
In he mean time, tell us about your airplane. Is
it wired per any of the z-figures? What's your
bus voltage run in flight? Your failure rate
is too high to blame on a working maintainer
of any brand. Have you measured the maintenance
voltage of your maintainer?
As often as you appear to be flying, there's no
driving concerns for using a maintainer at
all. I'm thinking something else is going on
with your system that's generating these battery
failures. Check that regulator setpoint.
Bob . . .
________________________________________________________________________________
| From: | John Morgensen <john(at)morgensen.com> |
| Subject: | Re: Schumacher 1562 and PC 680 |
On 1/29/2014 2:31 PM, Robert L. Nuckolls, III wrote:
>
> In he mean time, tell us about your airplane. Is
> it wired per any of the z-figures? What's your
> bus voltage run in flight? Your failure rate
> is too high to blame on a working maintainer
> of any brand. Have you measured the maintenance
> voltage of your maintainer?
>
The airplane is an RV9A using Z13/8 and dual P-Mags. In flight voltage
is 14.1 to 14.2 and I have not measured the maintenance voltage of the
maintainer.
> As often as you appear to be flying, there's no
> driving concerns for using a maintainer at
> all. I'm thinking something else is going on
> with your system that's generating these battery
> failures. Check that regulator setpoint.
>
>
> Bob . . .
At this point, I plan to not use the maintainer and fly often enough to
keep the system going. I will test the maintainer on an old battery and
see what voltages I get.
john
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
>Another consideration is that copper oxidizes very quickly so you
>need to make sure that the connections are very clean when you
>assemble. In industry, copper bussbars are commonly plated w/
>either silver or tin to protect against poor connection quality due
>to oxidation.
If the joined materials are in good contact with
each other and made up with sufficient force, joint
integrity is assured in spite of any corrosion visible
outside the joint. So FLAT, clean parts bolted together
with non-trivial force is the key . . .
This is one of the reasons why I have not been a
strong proponent of mashing copper round things
into copper flat things for use as bus bars . . .
it's hard to get them really flat around the bolt
holes.
If you can start with sheet materials, then you are
75% of the way along the path to gas-tight Nirvana.
>Brass is another material commonly used in electrical busses &
>devices and it does not oxidize as quickly and is less expensive. I
>just made some bussbars from .050 brass (they were not in the
>starter circuit) and the brass was easy to work with & cheaper than
>the equivalent copper.
A reader pointed out here on the List that brass
(depending on alloy) has a resistance 2 to 3x
that of copper. So to get the same temperature
rise on a brass bar, it needs to be at least 2x
more 'meat' between the studs.
Just to put it into perspective, a 4AWG
wire is 250 micro-ohms per foot. 200A
would give us a voltage drop on the order
of 50mV/foot. A 4" length of 4AWG
between studs would drop 1/3 that or 16
mV.
In this experiment I conducted on the bench
a few years back
http://tinyurl.com/k9v6mnt
a strip of brass shim stock .75" wide and
.005" thick offered a 40F rise at 20A of
current flow and a 58mV drop. Consider a
brass bar .75 x .05 (10x thicker) at 200A
would offer about the same performance.
We'd have to be 3 times thicker yet or .15"
to bring voltage drop into the same neighborhood
as 4AWG copper.
A copper bar could be 1/2 that thickness
and offer the about the same performance.
4awg has a cross section of 0.03 square
inches. So a copper strip .062 thick
needs to be 0.03/0.63 or about 0.50"
wide. You can't drill 0.32 holes in
strip that narrow so a 0.75" wide x
0.062" copper is a good choice for
this application.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Schumacher 1562 and PC 680 |
>
>At this point, I plan to not use the maintainer and fly often enough
>to keep the system going. I will test the maintainer on an old
>battery and see what voltages I get.
>
>john
Good. The self-discharge rate on RG batteries
is very low . . . there's probably no value in
hooking an airplane to the wall outlet as long as
it's flown every month . . . or more often.
There's something going on with your airplane
at appears abusive to the battery. What kind
of starter? Are your starting events expeditious?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 09:40 AM 1/28/2014, you wrote:
>Hi Guys
>
>Is this suitable for the Contactor connections, ANL fuse link etc,
>or is 3mm thickness too much
>
>http://www.ebay.co.uk/itm/390692340635?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649
>
>Best regards
>
>John (RV9a - work in progress)
It would work nicely. It's a bit thick so you
won't be able to put many more terminals on the
same studs . . . but it's certainly capable
electrically as described in my post of a few
minutes ago.
Bob . . .
________________________________________________________________________________
| From: | Charlie England <ceengland7(at)gmail.com> |
| Subject: | Re: Copper Bar (Heresy Alert!) |
On 1/30/2014 10:32 AM, Robert L. Nuckolls, III wrote:
>
>
>
>> Another consideration is that copper oxidizes very quickly so you
>> need to make sure that the connections are very clean when you
>> assemble. In industry, copper bussbars are commonly plated w/ either
>> silver or tin to protect against poor connection quality due to
>> oxidation.
>
> If the joined materials are in good contact with
> each other and made up with sufficient force, joint
> integrity is assured in spite of any corrosion visible
> outside the joint. So FLAT, clean parts bolted together
> with non-trivial force is the key . . .
>
> This is one of the reasons why I have not been a
> strong proponent of mashing copper round things
> into copper flat things for use as bus bars . . .
> it's hard to get them really flat around the bolt
> holes.
>
> If you can start with sheet materials, then you are
> 75% of the way along the path to gas-tight Nirvana.
>
>
>> Brass is another material commonly used in electrical busses &
>> devices and it does not oxidize as quickly and is less expensive. I
>> just made some bussbars from .050 brass (they were not in the starter
>> circuit) and the brass was easy to work with & cheaper than the
>> equivalent copper.
>
> A reader pointed out here on the List that brass
> (depending on alloy) has a resistance 2 to 3x
> that of copper. So to get the same temperature
> rise on a brass bar, it needs to be at least 2x
> more 'meat' between the studs.
>
> Just to put it into perspective, a 4AWG
> wire is 250 micro-ohms per foot. 200A
> would give us a voltage drop on the order
> of 50mV/foot. A 4" length of 4AWG
> between studs would drop 1/3 that or 16
> mV.
>
> In this experiment I conducted on the bench
> a few years back
>
> http://tinyurl.com/k9v6mnt
>
> a strip of brass shim stock .75" wide and
> .005" thick offered a 40F rise at 20A of
> current flow and a 58mV drop. Consider a
> brass bar .75 x .05 (10x thicker) at 200A
> would offer about the same performance.
> We'd have to be 3 times thicker yet or .15"
> to bring voltage drop into the same neighborhood
> as 4AWG copper.
>
> A copper bar could be 1/2 that thickness
> and offer the about the same performance.
>
> 4awg has a cross section of 0.03 square
> inches. So a copper strip .062 thick
> needs to be 0.03/0.63 or about 0.50"
> wide. You can't drill 0.32 holes in
> strip that narrow so a 0.75" wide x
> 0.062" copper is a good choice for
> this application.
>
>
> Bob . . .
You know, aluminum is only slightly less conductive than gold; certainly
as good as or better than brass. Anyone building an aluminum aircraft
will likely have quite a bit of 6061 alloy scrap & 'cutoffs' lying
around. If the same care in prep & installation is taken with an
aluminum bus bar that is taken with wing ribs, skins, etc, there's no
reason for fatigue to be an issue. A little dielectric compound on the
joint (I'm talking about a screwed/bolted joint, not a spring tab in an
electrical outlet), and it's no more likely to corrode than a wing rib.
As a point of reference, if you live in a house in the USA, your
electrical service wire (street to meter to mains breaker) is almost
certainly aluminum.
Flame suit ready,
Charlie
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Copper Bar (Heresy Alert!) |
You know, aluminum is only slightly less conductive than gold;
certainly as good as or better than brass. Anyone building an
aluminum aircraft will likely have quite a bit of 6061 alloy scrap &
'cutoffs' lying around.
True. 6061 is on the same order of resistivity
as brass . . . so an 0.13 or thicker aluminum
sheet or bar stock would offer an electrically
equivalent bus bar.
If the same care in prep & installation is taken with an aluminum
bus bar that is taken with wing ribs, skins, etc, there's no reason
for fatigue to be an issue. A little dielectric compound on the joint
(I'm talking about a screwed/bolted joint, not a spring tab in an
electrical outlet), and it's no more likely to corrode than a wing rib.
The aluminums found in most shops tend to be
harder than the copper. It's the malleable nature
of copper than makes it more 'terminal friendly'
for achieving gas-tight joints under the make-up
forces of threaded fasteners.
As a point of reference, if you live in a house in the USA, your
electrical service wire (street to meter to mains breaker) is almost
certainly aluminum.
I think the alloy of those wires moves toward
the dead-soft spectrum of alloys with a volume
resistivity on the order of 2.6x10^-8 as opposed to
4.2 to 5.8x10^-8 for the structural alloys.
I'm not aware of any parts on a metal project
that would call for 0.125" material . . . but
you're absolutely correct. There's no
electrical reason to prefer brass over
aluminum . . . but I'll suggest there
are reasons both electrical and mechanical
to prefer copper over both.
If I were fabricating an aluminum bus bar,
I think I would cut and drill in the 'hard'
state for easy machining then anneal the
finished part with techniques described
all over the 'nets metal fabrication forums.
Seal clean joints as you've suggested. Works
good and lasts a long time.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Aviation archaeology |
From all of my personal recollections, the facility on
the northeast corner of Kellogg and Webb was always Beech Plant II.
It's the building where many Bonanzas and Barons were built.
I only recently became aware of it's history. Uncle Walter
didn't built the original structure. The building has been
there for more than 85 years and dates back to a time when
Wichita had 20+ manufacturers of airplanes.
http://tinyurl.com/lgjgnb2
One such company was the Knoll Aircraft Corporation
http://tinyurl.com/lf363n5
http://tinyurl.com/ksxrx2v
In operation barely one year they started out on
West 1st street (right next to Cessna!) before
they built the 'largest building in Kansas devoted
to the manufacturing of airplanes.
They closed the doors in 1929.
Yellow Air Cab company occupied it for about 4 years
http://tinyurl.com/ksxrx2v
Followed by Straughn Aircraft
http://tinyurl.com/kpnnsky
Not until 1940, 21 years after its construction did
it become Beechcraft Plant II.
Vestiges of the original Knoll facility
were visible from outside the additions
constructed over the years by Beech.
Many pages of aviation history were written in
and around that building. They're starting
to tear it down . . . should be level ground
in a few weeks. Ground that hasn't seen the
light of day for over 85 years.
Bob . . .
________________________________________________________________________________
| From: | John Morgensen <john(at)morgensen.com> |
| Subject: | Re: Schumacher 1562 and PC 680 |
The starter is a sky tech lightweight on an IO-320. Cold starts are one
or two blades. Hot starts are still a learning process and the starter
can occasionally get a work-out.
When I was stranded in Chandler, the airplane had flown 3 hours cross
country day vfr and then parked for 2 weeks. The battery should have
been fully charged.
There should not be any drain on the battery with the master off. P-mags
are wired to the main bus. The only thing on the battery bus is the
cigarette lighter and the switch to the essential bus.
When I get to the hanger, I will test for any current flow on the
battery. Is there any thing else I can measure/test that might shed some
light on the problem?
john
On 1/30/2014 8:36 AM, Robert L. Nuckolls, III wrote:
>
> Good. The self-discharge rate on RG batteries
> is very low . . . there's probably no value in
> hooking an airplane to the wall outlet as long as
> it's flown every month . . . or more often.
>
> There's something going on with your airplane
> at appears abusive to the battery. What kind
> of starter? Are your starting events expeditious?
>
>
> Bob . . .
________________________________________________________________________________
| Subject: | Re: Schumacher 1562 and PC 680 |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
Fuel injected? If so PM me, it would be off topic here.
I just learned a slick trick for hot start on a FI engine.
Tim
> On Jan 30, 2014, at 2:01 PM, John Morgensen wrote:
>
>
> The starter is a sky tech lightweight on an IO-320. Cold starts are one or two
blades. Hot starts are still a learning process and the starter can occasionally
get a work-out.
>
> When I was stranded in Chandler, the airplane had flown 3 hours cross country
day vfr and then parked for 2 weeks. The battery should have been fully charged.
>
> There should not be any drain on the battery with the master off. P-mags are
wired to the main bus. The only thing on the battery bus is the cigarette lighter
and the switch to the essential bus.
>
> When I get to the hanger, I will test for any current flow on the battery. Is
there any thing else I can measure/test that might shed some light on the problem?
>
> john
>
>> On 1/30/2014 8:36 AM, Robert L. Nuckolls, III wrote:
>>
>> Good. The self-discharge rate on RG batteries
>> is very low . . . there's probably no value in
>> hooking an airplane to the wall outlet as long as
>> it's flown every month . . . or more often.
>>
>> There's something going on with your airplane
>> at appears abusive to the battery. What kind
>> of starter? Are your starting events expeditious?
>>
>>
>> Bob . . .
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Schumacher 1562 and PC 680 |
| From: | Charles Plumery <barber_seville(at)msn.com> |
Tim,
Send me your trick for a hot start on FI engine. I have a friend that is alw
ays having problems with his setup.
Thanks,
Sent from my iPad,
Chuck
=9CA nation can survive its fools, and even the ambitious. But it cann
ot survive treason from within. An enemy at the gates is less formidable, fo
r he is known and carries his banner openly. But the traitor moves amongst t
hose within the gate freely, his sly whispers rustling through all the alley
s, heard in the very halls of government itself. For the traitor appears not
a traitor; he speaks in accents familiar to his victims, and he wears their
face and their arguments, he appeals to the baseness that lies deep in the h
earts of all men. He rots the soul of a nation, he works secretly and unknow
n in the night to undermine the pillars of the city, he infects the body pol
itic so that it can no longer resist. A murderer is less to fear.=9D
> On Jan 30, 2014, at 5:53 PM, Tim Andres wrote:
>
>
>
> Fuel injected? If so PM me, it would be off topic here.
> I just learned a slick trick for hot start on a FI engine.
> Tim
>
>> On Jan 30, 2014, at 2:01 PM, John Morgensen wrote:
>>
om>
>>
>> The starter is a sky tech lightweight on an IO-320. Cold starts are one o
r two blades. Hot starts are still a learning process and the starter can oc
casionally get a work-out.
>>
>> When I was stranded in Chandler, the airplane had flown 3 hours cross cou
ntry day vfr and then parked for 2 weeks. The battery should have been fully
charged.
>>
>> There should not be any drain on the battery with the master off. P-mags a
re wired to the main bus. The only thing on the battery bus is the cigarette
lighter and the switch to the essential bus.
>>
>> When I get to the hanger, I will test for any current flow on the battery
. Is there any thing else I can measure/test that might shed some light on t
he problem?
>>
>> john
>>
>>> On 1/30/2014 8:36 AM, Robert L. Nuckolls, III wrote:
>>>
>>> Good. The self-discharge rate on RG batteries
>>> is very low . . . there's probably no value in
>>> hooking an airplane to the wall outlet as long as
>>> it's flown every month . . . or more often.
>>>
>>> There's something going on with your airplane
>>> at appears abusive to the battery. What kind
>>> of starter? Are your starting events expeditious?
>>>
>>>
>>> Bob . . .
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Schumacher 1562 and PC 680 |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
This came from Russel Mahlon, I had the email from him but lost it. I had be
en hot starting by:
No boost
Idle cut off
Throttle cracked
Crank and go rich when it catches.
It works ok but on occasion, well you know.
So his procedure is:
No Boost
Both levers forward and then back to idle
Mixture idle cutoff
Throttle half
Crank
When it catches move throttle slowly back to idle
Then mixture forward to about where you normally taxi.
His method is much more reliable than my other, it seems to work every time.
If I'm uncertain about whether to use cold or hot, like after an hour lunch
stop, I'll hit the boost for just a second first.
Hope it works for you.
Tim
> On Jan 30, 2014, at 3:42 PM, Charles Plumery wrot
e:
>
> Tim,
> Send me your trick for a hot start on FI engine. I have a friend that is a
lways having problems with his setup.
> Thanks,
>
> Sent from my iPad,
> Chuck
> =9CA nation can survive its fools, and even the ambitious. But it ca
nnot survive treason from within. An enemy at the gates is less formidable, f
or he is known and carries his banner openly. But the traitor moves amongst t
hose within the gate freely, his sly whispers rustling through all the alley
s, heard in the very halls of government itself. For the traitor appears not
a traitor; he speaks in accents familiar to his victims, and he wears their
face and their arguments, he appeals to the baseness that lies deep in the h
earts of all men. He rots the soul of a nation, he works secretly and unknow
n in the night to undermine the pillars of the city, he infects the body pol
itic so that it can no longer resist. A murderer is less to fear.=9D
>
>> On Jan 30, 2014, at 5:53 PM, Tim Andres wrote:
>>
t>
>>
>> Fuel injected? If so PM me, it would be off topic here.
>> I just learned a slick trick for hot start on a FI engine.
>> Tim
>>
>>> On Jan 30, 2014, at 2:01 PM, John Morgensen wrote:
>>>
com>
>>>
>>> The starter is a sky tech lightweight on an IO-320. Cold starts are one o
r two blades. Hot starts are still a learning process and the starter can oc
casionally get a work-out.
>>>
>>> When I was stranded in Chandler, the airplane had flown 3 hours cross co
untry day vfr and then parked for 2 weeks. The battery should have been full
y charged.
>>>
>>> There should not be any drain on the battery with the master off. P-mags
are wired to the main bus. The only thing on the battery bus is the cigaret
te lighter and the switch to the essential bus.
>>>
>>> When I get to the hanger, I will test for any current flow on the batter
y. Is there any thing else I can measure/test that might shed some light on t
he problem?
>>>
>>> john
>>>
>>>> On 1/30/2014 8:36 AM, Robert L. Nuckolls, III wrote:
>>>>
>>>> Good. The self-discharge rate on RG batteries
>>>> is very low . . . there's probably no value in
>>>> hooking an airplane to the wall outlet as long as
>>>> it's flown every month . . . or more often.
>>>>
>>>> There's something going on with your airplane
>>>> at appears abusive to the battery. What kind
>>>> of starter? Are your starting events expeditious?
>>>>
>>>>
>>>> Bob . . .
>>
>> http://www.matronics.==================
==========================
========; - MATRONICS WEB FORUM"http://forums.matron
ics.com">http://forums.matronics.com
>> http://www.matronics.com/contribution
>> <========================
============
>
>
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
________________________________________________________________________________
| Subject: | Re: Schumacher 1562 and PC 680 |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
Sorry guys, didn't intend to broadcast that.
Tim
> On Jan 30, 2014, at 7:54 PM, Tim Andres wrote:
>
> This came from Russel Mahlon, I had the email from him but lost it. I had b
een hot starting by:
> No boost
> Idle cut off
> Throttle cracked
> Crank and go rich when it catches.
> It works ok but on occasion, well you know.
>
> So his procedure is:
> No Boost
> Both levers forward and then back to idle
> Mixture idle cutoff
> Throttle half
> Crank
> When it catches move throttle slowly back to idle
> Then mixture forward to about where you normally taxi.
> His method is much more reliable than my other, it seems to work every tim
e. If I'm uncertain about whether to use cold or hot, like after an hour lun
ch stop, I'll hit the boost for just a second first.
> Hope it works for you.
> Tim
>
>
>> On Jan 30, 2014, at 3:42 PM, Charles Plumery wro
te:
>>
>> Tim,
>> Send me your trick for a hot start on FI engine. I have a friend that is a
lways having problems with his setup.
>> Thanks,
>>
>> Sent from my iPad,
>> Chuck
>> =9CA nation can survive its fools, and even the ambitious. But it c
annot survive treason from within. An enemy at the gates is less formidable,
for he is known and carries his banner openly. But the traitor moves amongs
t those within the gate freely, his sly whispers rustling through all the al
leys, heard in the very halls of government itself. For the traitor appears n
ot a traitor; he speaks in accents familiar to his victims, and he wears the
ir face and their arguments, he appeals to the baseness that lies deep in th
e hearts of all men. He rots the soul of a nation, he works secretly and unk
nown in the night to undermine the pillars of the city, he infects the body p
olitic so that it can no longer resist. A murderer is less to fear.=9D
>>
>>> On Jan 30, 2014, at 5:53 PM, Tim Andres wrote:
>>>
et>
>>>
>>> Fuel injected? If so PM me, it would be off topic here.
>>> I just learned a slick trick for hot start on a FI engine.
>>> Tim
>>>
>>>> On Jan 30, 2014, at 2:01 PM, John Morgensen wrote:
>>>>
.com>
>>>>
>>>> The starter is a sky tech lightweight on an IO-320. Cold starts are one
or two blades. Hot starts are still a learning process and the starter can o
ccasionally get a work-out.
>>>>
>>>> When I was stranded in Chandler, the airplane had flown 3 hours cross c
ountry day vfr and then parked for 2 weeks. The battery should have been ful
ly charged.
>>>>
>>>> There should not be any drain on the battery with the master off. P-mag
s are wired to the main bus. The only thing on the battery bus is the cigare
tte lighter and the switch to the essential bus.
>>>>
>>>> When I get to the hanger, I will test for any current flow on the batte
ry. Is there any thing else I can measure/test that might shed some light on
the problem?
>>>>
>>>> john
>>>>
>>>>> On 1/30/2014 8:36 AM, Robert L. Nuckolls, III wrote:
>>>>>
>>>>> Good. The self-discharge rate on RG batteries
>>>>> is very low . . . there's probably no value in
>>>>> hooking an airplane to the wall outlet as long as
>>>>> it's flown every month . . . or more often.
>>>>>
>>>>> There's something going on with your airplane
>>>>> at appears abusive to the battery. What kind
>>>>> of starter? Are your starting events expeditious?
>>>>>
>>>>>
>>>>> Bob . . .
>>>
>>> http://www.matronics.=================
==========================
=========; - MATRONICS WEB FORUM"http://forums.mat
ronics.com">http://forums.matronics.com
>>> http://www.matronics.com/contribution
>>> <========================
============
>>
>>
>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> lectric-List"">http://www.matronics.com/Navigator?AeroElectric-List
>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> //forums.matronics.com
>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>> ot;">http://www.matronics.com/contribution
>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>>
>
>
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
________________________________________________________________________________
| From: | "Jay Hyde" <jay(at)horriblehyde.com> |
| Subject: | Schumacher 1562 and PC 680 |
I don=99t think that it was bad to send it out to the list; its
aircraft related, if not electrical. Any extra bit of information like
that is almost always useful
Jay
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Tim
Andres
Sent: 31 January 2014 06:30 AM
Subject: Re: AeroElectric-List: Schumacher 1562 and PC 680
Sorry guys, didn't intend to broadcast that.
Tim
On Jan 30, 2014, at 7:54 PM, Tim Andres wrote:
This came from Russel Mahlon, I had the email from him but lost it. I
had been hot starting by:
No boost
Idle cut off
Throttle cracked
Crank and go rich when it catches.
It works ok but on occasion, well you know.
So his procedure is:
No Boost
Both levers forward and then back to idle
Mixture idle cutoff
Throttle half
Crank
When it catches move throttle slowly back to idle
Then mixture forward to about where you normally taxi.
His method is much more reliable than my other, it seems to work every
time. If I'm uncertain about whether to use cold or hot, like after an
hour lunch stop, I'll hit the boost for just a second first.
Hope it works for you.
Tim
On Jan 30, 2014, at 3:42 PM, Charles Plumery
wrote:
Tim,
Send me your trick for a hot start on FI engine. I have a friend that is
always having problems with his setup.
Thanks,
Sent from my iPad,
Chuck
=9CA nation can survive its fools, and even the ambitious. But it
cannot survive treason from within. An enemy at the gates is less
formidable, for he is known and carries his banner openly. But the
traitor moves amongst those within the gate freely, his sly whispers
rustling through all the alleys, heard in the very halls of government
itself. For the traitor appears not a traitor; he speaks in accents
familiar to his victims, and he wears their face and their arguments, he
appeals to the baseness that lies deep in the hearts of all men. He rots
the soul of a nation, he works secretly and unknown in the night to
undermine the pillars of the city, he infects the body politic so that
it can no longer resist. A murderer is less to fear.=9D
On Jan 30, 2014, at 5:53 PM, Tim Andres wrote:
Fuel injected? If so PM me, it would be off topic here.
I just learned a slick trick for hot start on a FI engine.
Tim
On Jan 30, 2014, at 2:01 PM, John Morgensen wrote:
The starter is a sky tech lightweight on an IO-320. Cold starts are one
or two blades. Hot starts are still a learning process and the starter
can occasionally get a work-out.
When I was stranded in Chandler, the airplane had flown 3 hours cross
country day vfr and then parked for 2 weeks. The battery should have
been fully charged.
There should not be any drain on the battery with the master off. P-mags
are wired to the main bus. The only thing on the battery bus is the
cigarette lighter and the switch to the essential bus.
When I get to the hanger, I will test for any current flow on the
battery. Is there any thing else I can measure/test that might shed some
light on the problem?
john
On 1/30/2014 8:36 AM, Robert L. Nuckolls, III wrote:
Good. The self-discharge rate on RG batteries
is very low . . . there's probably no value in
hooking an airplane to the wall outlet as long as
it's flown every month . . . or more often.
There's something going on with your airplane
at appears abusive to the battery. What kind
of starter? Are your starting events expeditious?
Bob . . .
< span="">
http://www.matronics.==================
=========; - MATRONICS WEB
FORUM"http://forums.matronics.com">http://forums.matronics.com
<>
D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
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lectric-List"">http://www.matronics.com/Navigator?AeroElectric-List
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lectric-List"">http://www.matronics.com/Navigator?AeroElectric-List
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________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
The optimal way to make bus bars is to use Copper-Clad Aluminum. I have tried to
get these add to my product line, but complications regarding size and quantity
have delayed the deal.
Still, there's some out there someplace. Weighs about half what copper weighs.
--------
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=417943#417943
________________________________________________________________________________
| Subject: | Re: Schumacher 1562 and PC 680 |
| From: | Charles Plumery <barber_seville(at)msn.com> |
Thanks Tim,
I will pass it on.
Sent from my iPad,
Chuck
=9CA nation can survive its fools, and even the ambitious. But it cann
ot survive treason from within. An enemy at the gates is less formidable, fo
r he is known and carries his banner openly. But the traitor moves amongst t
hose within the gate freely, his sly whispers rustling through all the alley
s, heard in the very halls of government itself. For the traitor appears not
a traitor; he speaks in accents familiar to his victims, and he wears their
face and their arguments, he appeals to the baseness that lies deep in the h
earts of all men. He rots the soul of a nation, he works secretly and unknow
n in the night to undermine the pillars of the city, he infects the body pol
itic so that it can no longer resist. A murderer is less to fear.=9D
> On Jan 30, 2014, at 11:30 PM, Tim Andres wrote:
>
> Sorry guys, didn't intend to broadcast that.
> Tim
>
>> On Jan 30, 2014, at 7:54 PM, Tim Andres wrote:
>>
>> This came from Russel Mahlon, I had the email from him but lost it. I had
been hot starting by:
>> No boost
>> Idle cut off
>> Throttle cracked
>> Crank and go rich when it catches.
>> It works ok but on occasion, well you know.
>>
>> So his procedure is:
>> No Boost
>> Both levers forward and then back to idle
>> Mixture idle cutoff
>> Throttle half
>> Crank
>> When it catches move throttle slowly back to idle
>> Then mixture forward to about where you normally taxi.
>> His method is much more reliable than my other, it seems to work every ti
me. If I'm uncertain about whether to use cold or hot, like after an hour lu
nch stop, I'll hit the boost for just a second first.
>> Hope it works for you.
>> Tim
>>
>>
>>> On Jan 30, 2014, at 3:42 PM, Charles Plumery wr
ote:
>>>
>>> Tim,
>>> Send me your trick for a hot start on FI engine. I have a friend that is
always having problems with his setup.
>>> Thanks,
>>>
>>> Sent from my iPad,
>>> Chuck
>>> =9CA nation can survive its fools, and even the ambitious. But it c
annot survive treason from within. An enemy at the gates is less formidable,
for he is known and carries his banner openly. But the traitor moves amongs
t those within the gate freely, his sly whispers rustling through all the al
leys, heard in the very halls of government itself. For the traitor appears n
ot a traitor; he speaks in accents familiar to his victims, and he wears the
ir face and their arguments, he appeals to the baseness that lies deep in th
e hearts of all men. He rots the soul of a nation, he works secretly and unk
nown in the night to undermine the pillars of the city, he infects the body p
olitic so that it can no longer resist. A murderer is less to fear.=9D
>>>
>>>> On Jan 30, 2014, at 5:53 PM, Tim Andres wrote:
>>>>
net>
>>>>
>>>> Fuel injected? If so PM me, it would be off topic here.
>>>> I just learned a slick trick for hot start on a FI engine.
>>>> Tim
>>>>
>>>>> On Jan 30, 2014, at 2:01 PM, John Morgensen wrote
:
>>>>>
n.com>
>>>>>
>>>>> The starter is a sky tech lightweight on an IO-320. Cold starts are on
e or two blades. Hot starts are still a learning process and the starter can
occasionally get a work-out.
>>>>>
>>>>> When I was stranded in Chandler, the airplane had flown 3 hours cross c
ountry day vfr and then parked for 2 weeks. The battery should have been ful
ly charged.
>>>>>
>>>>> There should not be any drain on the battery with the master off. P-ma
gs are wired to the main bus. The only thing on the battery bus is the cigar
ette lighter and the switch to the essential bus.
>>>>>
>>>>> When I get to the hanger, I will test for any current flow on the batt
ery. Is there any thing else I can measure/test that might shed some light o
n the problem?
>>>>>
>>>>> john
>>>>>
>>>>>> On 1/30/2014 8:36 AM, Robert L. Nuckolls, III wrote:
>>>>>>
>>>>>> Good. The self-discharge rate on RG batteries
>>>>>> is very low . . . there's probably no value in
>>>>>> hooking an airplane to the wall outlet as long as
>>>>>> it's flown every month . . . or more often.
>>>>>>
>>>>>> There's something going on with your airplane
>>>>>> at appears abusive to the battery. What kind
>>>>>> of starter? Are your starting events expeditious?
>>>>>>
>>>>>>
>>>>>> Bob . . .
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>> http://www.matronics.=================
==========================
=========; - MATRONICS WEB FORUM"http://forums.mat
ronics.com">http://forums.matronics.com
>>>> http://www.matronics.com/contribution
>>>> <========================
============
>>>>
>>>>
>>>>
>>>>
>>>
>>>
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>>> lectric-List"">http://www.matronics.com/Navigator?AeroElectric-List
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>>
>>
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>> lectric-List"">http://www.matronics.com/Navigator?AeroElectric-List
>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
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>> //forums.matronics.com
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>> ot;">http://www.matronics.com/contribution
>> D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
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>>
>
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>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
At 07:33 AM 1/31/2014, you wrote:
>
>The optimal way to make bus bars is to use Copper-Clad Aluminum. I
>have tried to get these add to my product line, but complications
>regarding size and quantity have delayed the deal.
>
>Still, there's some out there someplace. Weighs about half what copper weighs.
But how would that work? What thickness
of cladding are you looking for? Same
question goes to the advantages offered
by copper clad aluminum wire.
Copper and aluminum are not that far
separated for resistance so for the addition
of copper to reduce cross section of aluminum
for purposes of conserving energy is minimal . . .
the copper is not likely to be more than a few
mils thick.
On the other hand, that thin layer of copper
greatly benefits the installer's ability to
secure a high quality, gas-tight connection with
the aluminum either by crimping or soldering.
A short-fall that has plagued the use of
aluminum wiring for decades.
Are you asserting that a copper clad, aluminum
bus material will weigh half that of an
equivalency in copper because cladding
has improved on conductivity . . . our just
connectivity . . . or both? And what is the
expected weight savings for having substituted
aluminum for copper in a piece that is
3-4 inches long?
A copper bus 4 x .75 x .062 inches is about
0.2 cu inch (3.2 cu-cm) of copper for a
weight on the order of 30 grams. What is
the return on investment for saving less than
15 grams of weight with the application of a
sophisticated bus-bar material?
The copper clad wires of significant length
can have some savings of scale that are
attractive . . . savings that don't seem
to repeat with bus-bar material.
Bob . . .
________________________________________________________________________________
| From: | Dave Saylor <dave.saylor.aircrafters(at)gmail.com> |
I've used 1100 aluminum sheet for several bus bars on various airplanes.
My own plane has been flying for 7 years and 1300 hrs with 0 bus issues.
I put a drop of CorrosionX on each screw hoping it will help prevent any
corrosion taking root at the connection. I found the ratio for resistance
for alum/copper and sized it accordingly. Cheap, light, great conductor.
Dave Saylor
831-750-0284 CL
On Fri, Jan 31, 2014 at 9:38 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com>
>
>
> At 07:33 AM 1/31/2014, you wrote:
>
>> emjones(at)charter.net>
>>
>> The optimal way to make bus bars is to use Copper-Clad Aluminum. I have
>> tried to get these add to my product line, but complications regarding size
>> and quantity have delayed the deal.
>>
>> Still, there's some out there someplace. Weighs about half what copper
>> weighs.
>>
>
> But how would that work? What thickness
> of cladding are you looking for? Same
> question goes to the advantages offered
> by copper clad aluminum wire.
>
> Copper and aluminum are not that far
> separated for resistance so for the addition
> of copper to reduce cross section of aluminum
> for purposes of conserving energy is minimal . . .
> the copper is not likely to be more than a few
> mils thick.
>
> On the other hand, that thin layer of copper
> greatly benefits the installer's ability to
> secure a high quality, gas-tight connection with
> the aluminum either by crimping or soldering.
> A short-fall that has plagued the use of
> aluminum wiring for decades.
>
> Are you asserting that a copper clad, aluminum
> bus material will weigh half that of an
> equivalency in copper because cladding
> has improved on conductivity . . . our just
> connectivity . . . or both? And what is the
> expected weight savings for having substituted
> aluminum for copper in a piece that is
> 3-4 inches long?
>
> A copper bus 4 x .75 x .062 inches is about
> 0.2 cu inch (3.2 cu-cm) of copper for a
> weight on the order of 30 grams. What is
> the return on investment for saving less than
> 15 grams of weight with the application of a
> sophisticated bus-bar material?
>
> The copper clad wires of significant length
> can have some savings of scale that are
> attractive . . . savings that don't seem
> to repeat with bus-bar material.
>
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
> Copper and aluminum are not that far
> separated for resistance...Bob N.)
Bob, There are many ways to measure conductivity. But when you care about weight:
The Figure of Merit is Conductivity per unit mass (x 1000)
Aluminum =137
Copper = 66
So Aluminum is more than twice as conductive per unit mass as Copper. And it would
be a whole lot cheaper too, except that every piece of Copper-Clad Aluminum
is custom built. The CCA I use to make battery cables is 10% (by diameter) Copper
and 90% Aluminum. The electric company just uses plain aluminum and employs
special mean to terminate the wires.
One big advantage of CCA is that it has very low scrap value (thus no theft). Furthermore
the price can be set and guaranteed going into the future because Aluminum's
price is very stable.
--------
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=417952#417952
Attachments:
http://forums.matronics.com//files/copper_cables_aluminum_cables_656.pdf
________________________________________________________________________________
| Subject: | Essential Bus question |
| From: | "rkharr" <rkharr(at)gmail.com> |
My RV-6 has been flying 12 years now with an electrical system based on the Z diagrams.
Now I am assisting my wife complete her RV-7 electrical system. She
has chosen to use the VPX Pro unit and wants to incorporate a "backup" source
of power for clearances, engine start, and "endurance" (if the VPX box were to
quit).
The circuit that we are considering uses a bridge diode that would allow the main
battery to supplement the "backup" battery for increased endurance. Since
I have not seen this variation before, there must be a "gotcha" that I haven't
found. Attached is a picture of the basic circuit. Any suggestions and/or
comments would be appreciated.
--------
Ken
RV-6
South Carolina
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=417953#417953
Attachments:
http://forums.matronics.com//files/essential_bus_237.jpg
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
| Subject: | Re: Essential Bus question |
My first question would be why add the complexity of a second electrical
system, when virtually all situations can be handled by either backup
battery for EFIS, ship's battery or just plain old magnetos.
On 1/31/2014 12:53 PM, rkharr wrote:
>
> My RV-6 has been flying 12 years now with an electrical system based on the Z
diagrams. Now I am assisting my wife complete her RV-7 electrical system. She
has chosen to use the VPX Pro unit and wants to incorporate a "backup" source
of power for clearances, engine start, and "endurance" (if the VPX box were
to quit).
> The circuit that we are considering uses a bridge diode that would allow the
main battery to supplement the "backup" battery for increased endurance. Since
I have not seen this variation before, there must be a "gotcha" that I haven't
found. Attached is a picture of the basic circuit. Any suggestions and/or
comments would be appreciated.
>
> --------
> Ken
> RV-6
> South Carolina
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=417953#417953
>
>
> Attachments:
>
> http://forums.matronics.com//files/essential_bus_237.jpg
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Essential Bus question |
At 08:25 PM 1/31/2014, you wrote:
My first question would be why add the complexity of a second
electrical system, when virtually all situations . . .
Define "all situations" . . . the term is non-
quantified/qualified. When we're designing a
TC aircraft, EVERY situation needs to be articulated
in the design documents along with the plan-B, C, . . .
or Z that mitigates that situation. Then we have
to go TEST every one of those plans to demonstrate
compliance with design goals.
. . . can be handled by either backup battery for EFIS, ship's
battery or just plain old magnetos.
For OBAM aircraft it's a function of design goals built upon
the pilot's skills, maintenance protocols, airplane capabilities
and anticipated missions. Obviously, the manner in which
one might outfit a Kitfox can depart greatly from the
way you would craft an LAIV-P. At the same time, the
builder of an RV-6 in the Pacific NW (Lots of clouds
all the time) who travels a lot might have a more
sophisticated system than another builder who intends
to use is LAIV only in day VMC but wants the
speed, ability to hop the occasional mountain range
and air conditioning.
This litany of potential "situations" offers
a brief peek into the value of having design
goals synchronized to the end-use.
Production aircraft tend to have cookie-cutter
approaches to system architecture . . . because
the designers can only hypothesize greatest risk
situations for the targeted customer then address
those hypotheses within the framework of the
impediments to creativity imposed by the FARS.
We on the List have a clean sheet of paper
for the beginning of every project. The Z-figures
are intended to offer a sort of "Cliff's Notes"
on architectures that span the spectrum of
possibilities. Some builders have put Z-14
into their 2 place RV's at no small penalty
for cost and weight . . . but find comfort
in not having to go through the very non-
trivial exercise of optimizing their decision.
There ARE LAIV-P aircraft flying with one
battery, one alternator, and backup batteries
sprinkled over the panel and perhaps some
more in the flight bag.
Its unlikely that either builder has tested
available failure response plans against his/her
perceptions of capability in the Plan-B
hardware.
Given the decreasing failure rates of modern
electro-whizzies, it's unlikely that either
of the pilots in the last two examples will
have a 'dark-n-stormy night' story to write
up for Flying Magazine.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Essential Bus question |
At 01:53 PM 1/31/2014, you wrote:
>
>My RV-6 has been flying 12 years now with an electrical system based
>on the Z diagrams. Now I am assisting my wife complete her RV-7
>electrical system. She has chosen to use the VPX Pro unit and wants
>to incorporate a "backup" source of power for clearances, engine
>start, and "endurance" (if the VPX box were to quit).
Okay, you're plagued with the same litany of concerns
that arise from lack of confidence in your present
'vision' for how this system should evolve.
>
>The circuit that we are considering uses a bridge diode that would
>allow the main battery to supplement the "backup" battery for
>increased endurance. Since I have not seen this variation before,
>there must be a "gotcha" that I haven't found. Attached is a
>picture of the basic circuit. Any suggestions and/or comments would
>be appreciated.
Read through the posting I made a few minutes ago
and then consider a list of design goals that are
based on . . .
(1) How will this airplane be used? Do you
anticipate long legs of travel at night over
unfriendly terrain?
(2) Are you anticipating more than a tiny
percentage of approaches to landing to be
in IMC?
(3) Do you plan to carry the ultimate in
backup reliability in your flight bag?
http://tinyurl.com/d5mrjgh
This is the stuff I recommend for folks like
me who only rent airplanes . . . but if
it were my airplane, those items would still
be with me. In fact, I've not turned on a
VOR or ADF in 15 years . . . nor have I used
a panel mounted GPS . . . but that's another
story.
(4) Are your skill sets going to be honed
to the levels necessary for low risk
implementation of the hardware you plan to install?
It's entirely possible to have an airplane
decked out to the window-sills with goodies
only to have A pilot become the weak link
in the chain.
http://tinyurl.com/kb2zr8m
I've flown with pilots who were quite proud
of all those dials, switches and knobs on
the panel who never flew more IFR than to
keep their ticket current. The greatest
risk for bending their airplane was not
rooted failure of hardware.
Keep in mind that 2x the hardware is 2x
the probability of failure. Got some more
batteries scattered around the airplane
. . . guess what . . . now you're running
a clinic for batteries upon which you believe
you're building a 'dependable' system.
Commodity items like batteries are like house plants.
Just because you have two of them does not mitigate
the need for knowledgeable preventative
maintenance but it DOES double the maintenance
$time$.
So before we spend a lot of time refining
the work-arounds for hypothesized failures,
let's look at the big picture and size the
solutions to realistic risks having the
greatest probability of presentation.
Then you're ready to sift solutions for those
having the lowest cost of ownership, weight
penalties on the aircraft and taxation of
your skill sets.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: 12V to 9V converter |
>Bob, I have an old (30+ years) Hall variometer that I want to put in
>my trike. It's powered by 9V batteries so it seems an easy enough
>project to use a converter to power it off the dynamo on the HKS
>engine. 2 amps should be more than enough output. There are quite a
>few vendors on eBay that offer them for $2 or so. Do you have any
>favorite vendors for this kind of thing?
>
>Rick Girard
What kind of 9v batteries? These things?
Emacs!
More than one? How many and do you KNOW
they are in parallel and not series for
+/- supply to the electronics?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Essential Bus question |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
I would just add a simple Brown out 7ah Alarm battery/Aux bus charged thru a Schottky
diode and maybe a resistor is very simple & cheap to do. A lot of equipment
now comes with multiple diode isolated power inputs making it easy.
This allows flight plan entry and clearance requests before start up without draining
the main battery, keeps the GPS/NAV/COM and EFIS from rebooting when cranking
the engine, and provides maybe 20-30 minutes of extra time to get back
on the ground.
Weight/cost is about $35 and 5 lbs. cheaper than a factory backup, which only powers
one item.
Tim
> On Feb 2, 2014, at 8:39 AM, "Robert L. Nuckolls, III"
wrote:
>
>
> At 01:53 PM 1/31/2014, you wrote:
>>
>> My RV-6 has been flying 12 years now with an electrical system based on the
Z diagrams. Now I am assisting my wife complete her RV-7 electrical system.
She has chosen to use the VPX Pro unit and wants to incorporate a "backup" source
of power for clearances, engine start, and "endurance" (if the VPX box were
to quit).
>
> Okay, you're plagued with the same litany of concerns
> that arise from lack of confidence in your present
> 'vision' for how this system should evolve.
>>
>> The circuit that we are considering uses a bridge diode that would allow the
main battery to supplement the "backup" battery for increased endurance. Since
I have not seen this variation before, there must be a "gotcha" that I haven't
found. Attached is a picture of the basic circuit. Any suggestions and/or
comments would be appreciated.
>
> Read through the posting I made a few minutes ago
> and then consider a list of design goals that are
> based on . . .
>
> (1) How will this airplane be used? Do you
> anticipate long legs of travel at night over
> unfriendly terrain?
>
> (2) Are you anticipating more than a tiny
> percentage of approaches to landing to be
> in IMC?
>
> (3) Do you plan to carry the ultimate in
> backup reliability in your flight bag?
>
> http://tinyurl.com/d5mrjgh
>
> This is the stuff I recommend for folks like
> me who only rent airplanes . . . but if
> it were my airplane, those items would still
> be with me. In fact, I've not turned on a
> VOR or ADF in 15 years . . . nor have I used
> a panel mounted GPS . . . but that's another
> story.
>
> (4) Are your skill sets going to be honed
> to the levels necessary for low risk
> implementation of the hardware you plan to install?
> It's entirely possible to have an airplane
> decked out to the window-sills with goodies
> only to have A pilot become the weak link
> in the chain.
>
> http://tinyurl.com/kb2zr8m
>
> I've flown with pilots who were quite proud
> of all those dials, switches and knobs on
> the panel who never flew more IFR than to
> keep their ticket current. The greatest
> risk for bending their airplane was not
> rooted failure of hardware.
>
> Keep in mind that 2x the hardware is 2x
> the probability of failure. Got some more
> batteries scattered around the airplane
> . . . guess what . . . now you're running
> a clinic for batteries upon which you believe
> you're building a 'dependable' system.
>
> Commodity items like batteries are like house plants.
> Just because you have two of them does not mitigate
> the need for knowledgeable preventative
> maintenance but it DOES double the maintenance
> $time$.
>
> So before we spend a lot of time refining
> the work-arounds for hypothesized failures,
> let's look at the big picture and size the
> solutions to realistic risks having the
> greatest probability of presentation.
>
> Then you're ready to sift solutions for those
> having the lowest cost of ownership, weight
> penalties on the aircraft and taxation of
> your skill sets.
>
>
> Bob . . .
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Essential Bus question |
At 11:31 AM 2/2/2014, you wrote:
>
>I would just add a simple Brown out 7ah Alarm battery/Aux bus
>charged thru a Schottky diode and maybe a resistor is very simple &
>cheap to do. A lot of equipment now comes with multiple diode
>isolated power inputs making it easy.
>This allows flight plan entry and clearance requests before start up
>without draining the main battery, keeps the GPS/NAV/COM and EFIS
>from rebooting when cranking the engine, and provides maybe 20-30
>minutes of extra time to get back on the ground.
>Weight/cost is about $35 and 5 lbs. cheaper than a factory backup,
>which only powers one item.
>
>Tim
Good data points. Let us consider the premises
underlying the evolution of Figure Z-07
http://tinyurl.com/my9u3ud
this shows a two battery/single alternator system
for an electrically dependent engine. This
exercise in 'electron gazing' grew out of Fred's
project already fitted with a EXP-Bus. I could
see a way to accommodate Fred's initial design
goals for two batteries with a simple mod to
the EXP-Bus . . . but I could see an alternative
to Z-19 evolving from the deliberations . . .
hence Z-07.
Off in the distance, I think I see a single-battery
variant of this architecture but that's possible
only after we get real energy requirements data
. . . and further refine the operating philosophy
for the system. Tim's words raise useful questions
that go directly to deliberations for sizing risks
in a single-battery design.
Where is it written or demonstrated that having
the ship's processors 'reboot' is a bad thing?
Under what operating scenarios is it useful/necessary
minimize the time between the glass being awake
and reaching the end of the runway just prior
to engine run-up?
I recall some stories about the Blue-Mountain
systems (hard drives?) taking perhaps 90
seconds to wake up . . . but when was the
last time you were ready to check mags less
than, say 3-4 minutes after engine startup?
I've reviewed as many of the airports I've
visited that I can remember. I cannot recall
any departure where engine run-up was accomplished
for before the oil was warmed up a bit and I
had taxied from parking to the run-up stand,
certainly 4 minutes, sometimes 10. I think
it took 15 minutes to get out of KCI once.
. . . the check list belongs to YOU . . . you
can adjust sequences of events to fit hardware.
Let us consider "draining the main battery"
for the purposes of gathering the ATIS data
and getting a clearance delivery. Suppose the
e-bus runs 5A and the exercise takes 3 minutes.
12v x 5a x 60s x 3m = 10,800 watt-seconds.
Cranking the engine 12v x 200a x 10s = 24,000
watt-seconds. What does the battery hold?
12v x 5a x 60s x 120m = 432,000 watt-seconds.
Okay, you used up 34,800 watt-seconds before
the engine was lit for 35K/432K or 8 percent
of the battery's capacity. If you're targeting
80% of new capacity for banishing your battery
to kiddie-car duty, then the last flight
will tax the battery to 10% of available
capacity.
The above analysis is a first order estimate
and does not take into account vagaries of
temperature and internal impedances of the
battery but it's in the right church if not
in the right pew.
Whats is the return on investment for 5 more
pounds of battery and two batteries to maintain
instead of one?
The value of this . . . or even more detailed
analysis presumes that you KNOW what the
drains are and what the battery's capabilities
are after accounting for aforementioned
vagaries AND targeted end of life decisions.
Bob . . .
________________________________________________________________________________
| From: | Jeff Luckey <jluckey(at)pacbell.net> |
| Subject: | Re: Essential Bus question |
my comments in larger font...=0A=0A-Jeff=0A=0A=0A=0A_______________________
_________=0A From: "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com
>=0ATo: aeroelectric-list(at)matronics.com =0ASent: Sunday, February 2, 2014 1
0:47 AM=0ASubject: Re: AeroElectric-List: Essential Bus question=0A =0A=0A-
.bob(at)aeroelectric.com>=0A=0AAt 11:31 AM 2/2/2014, you wrote:=0A> --> AeroEl
ectric-List message posted by: Tim Andres =0A> =0A>
I would just add a simple Brown out 7ah Alarm battery/Aux bus charged thru
a Schottky diode and maybe a resistor is very simple & cheap to do. A lot o
f equipment now comes with multiple diode isolated power inputs making it e
asy.=0A> This allows flight plan entry and clearance requests before start
up without draining the main battery,- keeps the GPS/NAV/COM and EFIS fro
m rebooting when cranking the engine, and provides maybe 20-30 minutes of e
xtra time to get back on the ground.=0A> Weight/cost is about $35 and 5 lbs
. cheaper than a factory backup, which only powers one item.=0A> =0A> Tim
=0A=0A- Good data points. Let us consider the premises=0A- underlying
the evolution of Figure Z-07=0A=0Ahttp://tinyurl.com/my9u3ud=0A=0A- thi
s shows a two battery/single alternator system=0A- for an electrically d
ependent engine. This=0A- exercise in 'electron gazing' grew out of Fred
's=0A- project already fitted with a EXP-Bus. I could=0A- see a way t
o accommodate Fred's initial design=0A- goals for two batteries with a s
imple mod to=0A- the EXP-Bus . . . but I could see an alternative=0A-
to Z-19 evolving from the deliberations . . .=0A- hence Z-07.=0A=0A-
Off in the distance, I think I see a single-battery=0A- variant of this
architecture but that's possible=0A- only after we get real energy requ
irements data=0A- . . . and further refine the operating philosophy=0A
- for the system. Tim's words raise useful questions=0A- that go dire
ctly to deliberations for sizing risks=0A- in a single-battery design.
=0A=0A- Where is it written or demonstrated that having=0A- the ship'
s processors 'reboot' is a bad thing?=0A=0AOK, let me write it here:=0AWatc
hing the Garmin 430 in my Cherokee re-boot after engine start is very incon
venient. Is it catastrophic? No.- Are there work-arounds? Certainly.- I
t's just a pain in the @ss.- In an experimental w/ all glass, it would be
even more annoying.=0A=0ANow that I'm designing the electrical system for
my RV-7A, I'm certainly want a design where that does not happen.- This i
s one of the reasons people like us build our own airplanes - we get to eng
ineer-out those little annoyances that we just have to put up with in certi
fied airplanes.=0A=0A=0A- Under what operating scenarios is it useful/ne
cessary=0A- minimize the time between the glass being awake=0A- and r
eaching the end of the runway just prior=0A- to engine run-up?=0A=0A-
I recall some stories about the Blue-Mountain=0A- systems (hard drives?
) taking perhaps 90=0A- seconds to wake up . . . but when was the=0A-
last time you were ready to check mags less=0A- than, say 3-4 minutes a
fter engine startup?=0A=0A- I've reviewed as many of the airports I've
=0A- visited that I can remember. I cannot recall=0A- any departure w
here engine run-up was accomplished=0A- for before the oil was warmed up
a bit and I=0A- had taxied from parking to the run-up stand,=0A- cer
tainly 4 minutes, sometimes 10. I think=0A- it took 15 minutes to get ou
t of KCI once.=0A=0AAll true but, there are also thousands of quiet little
airports where you can depart as quickly as you want to=0A=0A- . . . the
check list belongs to YOU . . . you=0A- can adjust sequences of events
to fit hardware.=0A=0A- Let us consider "draining the main battery"=0A
- for the purposes of gathering the ATIS data=0A- and getting a clear
ance delivery. Suppose the=0A- e-bus runs 5A and the exercise takes 3 mi
nutes.=0A- 12v x 5a x 60s x 3m = 10,800 watt-seconds.=0A- Cranking
the engine 12v x 200a x 10s = 24,000=0A- watt-seconds. What does the b
attery hold?=0A- 12v x 5a x 60s x 120m = 432,000 watt-seconds.=0A=0A
- Okay, you used up 34,800 watt-seconds before=0A- the engine was lit
for 35K/432K or 8 percent=0A- of the battery's capacity. If you're targ
eting=0A- 80% of new capacity for banishing your battery=0A- to kiddi
e-car duty, then the last flight=0A- will tax the battery to 10% of avai
lable=0A- capacity.=0A=0A- The above analysis is a first order estima
te=0A- and does not take into account vagaries of=0A- temperature and
internal impedances of the=0A- battery but it's in the right church if
not=0A- in the right pew.=0A=0A- Whats is the return on investment fo
r 5 more=0A- pounds of battery and two batteries to maintain=0A- inst
ead of one?=0A=0A- The value of this . . . or even more detailed=0A-
analysis presumes that you KNOW what the=0A- drains are and what the bat
tery's capabilities=0A- are after accounting for aforementioned=0A- v
=================
________________________________________________________________________________
| From: | Jeff Luckey <jluckey(at)pacbell.net> |
Listers,=0A=0AAttached find a schematic (some people call them ladder diagr
ams) of a design for the electrical system for my RV-7A.- Below is a list
of design goals, pros and cons. Please take a look and provide engineering
feedback.=0A=0ATIA=0A=0A=0AElectrical Systems Design Goals:=0A1. fault tol
erant - able to tolerate failure of any single component and fly for 45 min
.=0A2. easy to operate=0A3. no avionics brown-out on engine start=0A4. easy
to repair=0A5. comprised of standard, readily-available components =0A6. c
ost effective=0A=0A=0APros:=0A1. simplified operation - only 2 master switc
hes=0A2. simplified design - single buss=0A=0A3. no brown-out on engine sta
rt=0A4. automatic fail-over - no pilot interaction required; avionics won't
reset=0A=0A--- In the event a battery system suffers a failure, eith
er an open circuit or a ground fault, the faulty=0A--- system simply
stops providing power to the buss and the remaining good system continues t
o =0A=0A--- provide electricity without interruption.=0A=0A=0ACons:
=0A1. buss-isolation power diodes may require heat sinks=0A2. some energy w
asted as heat thru power diodes
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Essential Bus question |
OK, let me write it here:
Watching the Garmin 430 in my Cherokee re-boot after engine start is
very inconvenient.
Stop-watch that for me some time. I'd really
like to have a number on this widely discussed
but never quantified driver of design goals.
Is it catastrophic? No. Are there work-arounds? Certainly. It's
just a pain in the @ss.
In an experimental w/all glass, it would be even more annoying.
Now that I'm designing the electrical system for my RV-7A, I'm
certainly want a design
where that does not happen. This is one of the reasons people like
us build our own
airplanes - we get to engineer-out those little annoyances that we just have to
put up with in certified airplanes.
Then by all means do so. It's your airplane and your
design goals. The question wasn't whether or not you
wanted to do a particular thing, it was an invitation
explore why you wanted to do it . . . hopefully for reasons
firmly of your own choosing and not 'just because'
hangar lore and legacy traditions dictated it.
Brownout batteries have been discussed her on the list often
for several years an even illustrated one approach
in Z-10/8
http://tinyurl.com/7ro5yuc
All true but, there are also thousands of quiet little airports where you can
depart as quickly as you want to
Yup . . . there are. If a significant percentage
of your departures are so expeditious that
boot time on the glass becomes an impediment,
then you have an element of fact that drives
a different design goal.
I'm trying head off any notions that just because
one is considering a glass cockpit that a brownout
battery is recommended . . . it comes with a price in
weight and costs of ownership that may add little
or no value.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Essential Bus question |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
Not to argue your points Bob, and I agree simple is often better, but I would just
add that I don't want to wait 20 seconds for the screens to reboot after engine
start as my engine data is there also and I want see oil pressure etc right
away.
And I much prefer to enter a lengthy flight plan with the prop off as my attention
will be focused inside the plane, I'll admit on occasion I've looked up from
the panel and discovered the plane moving. My flight plan will then be lost
when I then crank the engine, unless I save it to memory, which I won't unless
I'm using it again.
And sometimes I take off with a hot engine, I'd rather not sit with the already
hot engine running in the summer heat while I enter several waypoints in the
Garmin.
To me it's worth the 5lbs for the convenience, and the cost is easily overcome
in fuel not burned.
The beauty of EAB, built what you want, then live with your decisions.
Tim
> On Feb 2, 2014, at 10:47 AM, "Robert L. Nuckolls, III"
wrote:
>
>
> At 11:31 AM 2/2/2014, you wrote:
>>
>> I would just add a simple Brown out 7ah Alarm battery/Aux bus charged thru a
Schottky diode and maybe a resistor is very simple & cheap to do. A lot of equipment
now comes with multiple diode isolated power inputs making it easy.
>> This allows flight plan entry and clearance requests before start up without
draining the main battery, keeps the GPS/NAV/COM and EFIS from rebooting when
cranking the engine, and provides maybe 20-30 minutes of extra time to get back
on the ground.
>> Weight/cost is about $35 and 5 lbs. cheaper than a factory backup, which only
powers one item.
>>
>> Tim
>
> Good data points. Let us consider the premises
> underlying the evolution of Figure Z-07
>
> http://tinyurl.com/my9u3ud
>
> this shows a two battery/single alternator system
> for an electrically dependent engine. This
> exercise in 'electron gazing' grew out of Fred's
> project already fitted with a EXP-Bus. I could
> see a way to accommodate Fred's initial design
> goals for two batteries with a simple mod to
> the EXP-Bus . . . but I could see an alternative
> to Z-19 evolving from the deliberations . . .
> hence Z-07.
>
> Off in the distance, I think I see a single-battery
> variant of this architecture but that's possible
> only after we get real energy requirements data
> . . . and further refine the operating philosophy
> for the system. Tim's words raise useful questions
> that go directly to deliberations for sizing risks
> in a single-battery design.
>
> Where is it written or demonstrated that having
> the ship's processors 'reboot' is a bad thing?
> Under what operating scenarios is it useful/necessary
> minimize the time between the glass being awake
> and reaching the end of the runway just prior
> to engine run-up?
>
> I recall some stories about the Blue-Mountain
> systems (hard drives?) taking perhaps 90
> seconds to wake up . . . but when was the
> last time you were ready to check mags less
> than, say 3-4 minutes after engine startup?
>
> I've reviewed as many of the airports I've
> visited that I can remember. I cannot recall
> any departure where engine run-up was accomplished
> for before the oil was warmed up a bit and I
> had taxied from parking to the run-up stand,
> certainly 4 minutes, sometimes 10. I think
> it took 15 minutes to get out of KCI once.
>
> . . . the check list belongs to YOU . . . you
> can adjust sequences of events to fit hardware.
>
> Let us consider "draining the main battery"
> for the purposes of gathering the ATIS data
> and getting a clearance delivery. Suppose the
> e-bus runs 5A and the exercise takes 3 minutes.
> 12v x 5a x 60s x 3m = 10,800 watt-seconds.
> Cranking the engine 12v x 200a x 10s = 24,000
> watt-seconds. What does the battery hold?
> 12v x 5a x 60s x 120m = 432,000 watt-seconds.
>
> Okay, you used up 34,800 watt-seconds before
> the engine was lit for 35K/432K or 8 percent
> of the battery's capacity. If you're targeting
> 80% of new capacity for banishing your battery
> to kiddie-car duty, then the last flight
> will tax the battery to 10% of available
> capacity.
>
> The above analysis is a first order estimate
> and does not take into account vagaries of
> temperature and internal impedances of the
> battery but it's in the right church if not
> in the right pew.
>
> Whats is the return on investment for 5 more
> pounds of battery and two batteries to maintain
> instead of one?
>
> The value of this . . . or even more detailed
> analysis presumes that you KNOW what the
> drains are and what the battery's capabilities
> are after accounting for aforementioned
> vagaries AND targeted end of life decisions.
>
>
> Bob . . .
>
>
>
>
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
| Subject: | Re: Essential Bus question |
Virtually all glass have their own light weight backup batteries so do
not have startup brown out issues unless no backup battery is installed.
I see very little value in being able to turn on GPS prior to start.
While one needs engine instrumentation prior to and during start, one
does not need avionics on.
Of course newer avionics that allow faster input of flight plans than
the 430 help, if that is the reason for turning on 430 before start.
On 2/2/2014 4:39 PM, Robert L. Nuckolls, III wrote:
>
>
> Brownout batteries have been discussed her on the list often
> for several years an even illustrated one approach
> in Z-10/8
>
> http://tinyurl.com/7ro5yuc
>
>
> All true but, there are also thousands of quiet little airports where
> you can
> depart as quickly as you want to
>
> Yup . . . there are. If a significant percentage
> of your departures are so expeditious that
> boot time on the glass becomes an impediment,
> then you have an element of fact that drives
> a different design goal.
>
> I'm trying head off any notions that just because
> one is considering a glass cockpit that a brownout
> battery is recommended . . . it comes with a price in
> weight and costs of ownership that may add little
> or no value.
>
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Essential Bus question |
At 06:14 PM 2/2/2014, you wrote:
>
>Not to argue your points Bob, and I agree simple is often better,
>but I would just add that I don't want to wait 20 seconds for the
>screens to reboot after engine start as my engine data is there also
>and I want see oil pressure etc right away.
Yeah . . . that's an old saw that has been around
since the Curtis Jenny . . . when sheared oil pump
shafts were relatively common . . . along with a
host of other ills associated with vintage engines.
I've never encountered a pilot who's oil pump died
at startup. I've flown lots of airplanes in cold
weather that didn't show any pressure for 30-45
seconds after start.
>And I much prefer to enter a lengthy flight plan with the prop off
>as my attention will be focused inside the plane, I'll admit on
>occasion I've looked up from the panel and discovered the plane
>moving. My flight plan will then be lost when I then crank the
>engine, unless I save it to memory, which I won't unless I'm using it again.
>And sometimes I take off with a hot engine, I'd rather not sit with
>the already hot engine running in the summer heat while I enter
>several waypoints in the Garmin.
You mean its stored waypoints go away during
reboot?
>
>To me it's worth the 5lbs for the convenience, and the cost is
>easily overcome in fuel not burned.
>The beauty of EAB, built what you want, then live with your decisions.
Absolutely. But why 5#? What did Eric decide about
his brown-out eliminator? Perhaps we still need
to refine the electronic bus-booster idea . . . it
weights a few ounces and has no periodic maintenance
requirements. Of course, a battery used only for
brownout protection can be run until it dies . . .
as long as the pilot doesn't included it in his/her
calculations for battery only endurance.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Analyze This |
At 05:38 PM 2/2/2014, you wrote:
>Listers,
>
>Attached find a schematic (some people call them ladder diagrams) of
>a design for the electrical system for my RV-7A. Below is a list of
>design goals, pros and cons. Please take a look and provide
>engineering feedback.
The alternator's b-lead is two diode-drops
removed from the regulator bus sense lead so
expect the b-lead to run 2-drops higher voltage
than the regulator's set-point. With the battery
tapped in between the two diodes, you'll want to
adjust the regulator for a BATTERY voltage of
14.2V
This will peg the b-lead at 14.2+diodeV and
the bus at 14.2-diodeV.
Current limiters are not generally recommended
or demonstrated as useful in battery feeders.
Bob . . .
________________________________________________________________________________
| From: | Jeff Luckey <jluckey(at)pacbell.net> |
| Subject: | Re: Analyze This |
=0A=0A=0A=0A________________________________=0A From: "Robert L. Nuckolls,
III" =0ATo: aeroelectric-list(at)matronics.com
=0ASent: Sunday, February 2, 2014 5:56 PM=0ASubject: Re: AeroElectric-List:
Nuckolls, III" =0A=0AAt 05:38 PM 2/2/2014, y
ou wrote:=0A> Listers,=0A> =0A> Attached find a schematic (some people call
them ladder diagrams) of a design for the electrical system for my RV-7A.
- Below is a list of design goals, pros and cons. Please take a look and
provide engineering feedback.=0A=0A- The alternator's b-lead is two diode
-drops=0A- removed from the regulator bus sense lead so=0A- expect the
b-lead to run 2-drops higher voltage=0A- than the regulator's set-point.
With the battery=0A- tapped in between the two diodes, you'll want to=0A
- adjust the regulator for a BATTERY voltage of=0A- 14.2V=0A=0A- This
will peg the b-lead at 14.2+diodeV and=0A- the bus at 14.2-diodeV.=0A=0A
Roger that=0A=0A- Current limiters are not generally recommended=0A- or
demonstrated as useful in battery feeders.=0A=0AIf the prove to be problem
atic, it is very easy to bypass them=0A=0Athanks bob=0A=0A=0A- Bob . . .
=========================0A
===================
________________________________________________________________________________
| Subject: | Re: 12V to 9V converter |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Bob, Yes, they are the standard 9V battery as you pictured. The vario has
two, but they are switched so that only one is used at a time. Not much
worse, at least in a hang glider, than being 40 miles out on a cross
country flight and having your vario go down for a depleted battery.
Rick
On Sun, Feb 2, 2014 at 10:49 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
>
> Bob, I have an old (30+ years) Hall variometer that I want to put in my
> trike. It's powered by 9V batteries so it seems an easy enough project to
> use a converter to power it off the dynamo on the HKS engine. 2 amps should
> be more than enough output. There are quite a few vendors on eBay that
> offer them for $2 or so. Do you have any favorite vendors for this kind of
> thing?
>
> Rick Girard
>
>
> What kind of 9v batteries? These things?
>
> [image: Emacs!]
>
> More than one? How many and do you KNOW
> they are in parallel and not series for
> +/- supply to the electronics?
>
>
> Bob . . .
>
--
Zulu Delta
Mk IIIC
Thanks, Homer GBYM
It isn't necessary to have relatives in Kansas City in order to be unhappy.
- Groucho Marx
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: 12V to 9V converter |
At 07:07 AM 2/3/2014, you wrote:
>Bob, Yes, they are the standard 9V battery as you pictured. The
>vario has two, but they are switched so that only one is used at a
>time. Not much worse than being 40 miles out on a cross country
>flight and having your vario go down for a depleted battery.
Okay. Devices that operate from this style of battery
don't take much current. Suggest you cobble this circuit
up on a piece of perf-board . . .
[]
For 9v out, make R1 a FIXED 1500 ohm resistor. You won't
even need to heat sink the regulator. Both resistors can
be 1/4 watt or larger. Capacitors rated for 15v or more.
Radio Shack probably has all the parts you need . . .or I
can drop you a care-package . . .
Bob . . .
________________________________________________________________________________
| Subject: | Re: Essential Bus question |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Bob, There is more than inconvenience to not having engine instruments if
you fly with a Rotax. Unlike the LyConosaurs, these engines are so tight,
the wear limit on a piston is only .0015" and a standard new fit is .0000"
to .0009", that to lose oil pressure is catastrophic within seconds. The
example that I saw in school was an engine that the owner had hooked the
oil hoses up backward. On first start up the engine ran for less than 10
seconds before it threw a rod and blew a big hole in the engine case.
Rick Girard
On Sun, Feb 2, 2014 at 7:10 PM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com>
>
> At 06:14 PM 2/2/2014, you wrote:
>
>> tim2542(at)sbcglobal.net>
>>
>> Not to argue your points Bob, and I agree simple is often better, but I
>> would just add that I don't want to wait 20 seconds for the screens to
>> reboot after engine start as my engine data is there also and I want see
>> oil pressure etc right away.
>>
>
> Yeah . . . that's an old saw that has been around
> since the Curtis Jenny . . . when sheared oil pump
> shafts were relatively common . . . along with a
> host of other ills associated with vintage engines.
>
> I've never encountered a pilot who's oil pump died
> at startup. I've flown lots of airplanes in cold
> weather that didn't show any pressure for 30-45
> seconds after start.
>
>
> And I much prefer to enter a lengthy flight plan with the prop off as my
>> attention will be focused inside the plane, I'll admit on occasion I've
>> looked up from the panel and discovered the plane moving. My flight plan
>> will then be lost when I then crank the engine, unless I save it to memory,
>> which I won't unless I'm using it again.
>>
>
> And sometimes I take off with a hot engine, I'd rather not sit with the
>> already hot engine running in the summer heat while I enter several
>> waypoints in the Garmin.
>>
>
> You mean its stored waypoints go away during
> reboot?
>
>
>> To me it's worth the 5lbs for the convenience, and the cost is easily
>> overcome in fuel not burned.
>> The beauty of EAB, built what you want, then live with your decisions.
>>
>
> Absolutely. But why 5#? What did Eric decide about
> his brown-out eliminator? Perhaps we still need
> to refine the electronic bus-booster idea . . . it
> weights a few ounces and has no periodic maintenance
> requirements. Of course, a battery used only for
> brownout protection can be run until it dies . . .
> as long as the pilot doesn't included it in his/her
> calculations for battery only endurance.
>
>
> Bob . . .
>
>
--
Zulu Delta
Mk IIIC
Thanks, Homer GBYM
It isn't necessary to have relatives in Kansas City in order to be unhappy.
- Groucho Marx
________________________________________________________________________________
| Subject: | Re: 12V to 9V converter |
| From: | Etienne Phillips <etienne.phillips(at)gmail.com> |
Hi Bob
You could also use an LM7809... It's the same as the LM317, but already set
to 9V, and doesn't require the external resistor divider. Although I have
used it fairly reliably without the input and output smoothing capacitors,
I would still recommend putting them in to assure stability.
Thanks
Etienne
On 3 February 2014 15:22, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> At 07:07 AM 2/3/2014, you wrote:
>
> Bob, Yes, they are the standard 9V battery as you pictured. The vario has
> two, but they are switched so that only one is used at a time. Not much
> worse than being 40 miles out on a cross country flight and having your
> vario go down for a depleted battery.
>
>
> Okay. Devices that operate from this style of battery
> don't take much current. Suggest you cobble this circuit
> up on a piece of perf-board . . .
>
> [image: []]
>
> For 9v out, make R1 a FIXED 1500 ohm resistor. You won't
> even need to heat sink the regulator. Both resistors can
> be 1/4 watt or larger. Capacitors rated for 15v or more.
> Radio Shack probably has all the parts you need . . .or I
> can drop you a care-package . . .
>
>
> Bob . . .
>
> *
>
>
> *
>
>
________________________________________________________________________________
| Subject: | Re: Analyze This |
| From: | "user9253" <fransew(at)gmail.com> |
The 60 amp fuse protects battery A from an alternator short circuit, but there
is no fuse to protect battery B. Either relocate the 60 amp fuse to the alternator
side of the diodes or else add a second 60 amp fuse.
A single shunt could be located in the alternator B lead and eliminate the ammeter
selector switch. Or a 3 position selector switch and a third shunt could
measure alternator output. Battery current shunts will carry very little current
most of the time except after engine start. There have been lots of discussions
about the best location for a shunt or if it is actually needed. It
is a matter of personal preference.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418032#418032
________________________________________________________________________________
| Subject: | Re: Analyze This |
| From: | "user9253" <fransew(at)gmail.com> |
When the alternator fails, there should be a way to shut off the alternator field
to conserve battery energy. Either a pullable circuit breaker or an independent
switch.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418036#418036
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Essential Bus question |
At 07:27 AM 2/3/2014, you wrote:
>Bob, There is more than inconvenience to not having engine
>instruments if you fly with a Rotax. Unlike the LyConosaurs, these
>engines are so tight, the wear limit on a piston is only .0015" and
>a standard new fit is .0000" to .0009", that to lose oil pressure is
>catastrophic within seconds. The example that I saw in school was an
>engine that the owner had hooked the oil hoses up backward. On first
>start up the engine ran for less than 10 seconds before it threw a
>rod and blew a big hole in the engine case.
Back in the day, the oil pressure gage was the same
device on grandpa's Ferguson tractor . . . a pressure
gage plumbed to the engine with a small diameter
tube.
In cold weather, the 50W oil would turn to road
tar in the tubing and delay accurate readings of
the gage by many seconds.
If I had an engine so critically vulnerable to
low oil pressure, then I'd add a pressure switch
as close as practical to the engine plumbed in
with any transducer intended to drive electronics.
10 seconds to destruct because the oil pressure
was absent on THAT start? Broke a rod because the
piston fits got tight? I'm skeptical. Pistons
seizing up progressively in the bores will
load up the engine until it stalls.
I worked a Rotax 912 accident that the owner tried to
blame on an electrical issue with ignition. I proved
the ignition system to be intact . . . but in the
accident narrative, the owner had taxied around for
30+ minutes 'getting the feel of the airplane' before
he decided to take off. On climb out the engine
slowly lost power . . . as if somebody was closing
the throttle. He descended into the trees, destroyed
the airplane and received a back injury. I told my
client attorney that they should do a teardown
of the engine and inspect cylinders for signs of
seizing due to overheat. Whether engine seizes
due to poor oil, air or water flow, the behavior is
the same.
I'll bet that engine had been in trouble for some
time and only decided to give up the ghost on that start-
event. It probably would have shelled out pretty
soon whether it had oil pressure or not.
Bob . . .
________________________________________________________________________________
| From: | Jeff Luckey <jluckey(at)pacbell.net> |
| Subject: | Re: Analyze This |
both of those things are on the drawing...=0A=0AThx for reviewing,=0A=0A-Je
ff=0A=0A=0A=0A=0A________________________________=0A From: user9253 <franse
w(at)gmail.com>=0ATo: aeroelectric-list(at)matronics.com =0ASent: Monday, Februar
y 3, 2014 10:41 AM=0ASubject: AeroElectric-List: Re: Analyze This=0A =0A=0A
=0AWhen the alternator fails, there should be a way to shut off the alterna
tor field to conserve battery energy.- Either a pullable circuit breaker
or an independent switch.=0AJoe=0A=0A--------=0AJoe Gores=0A=0A=0A=0A=0ARea
d this topic online here:=0A=0Ahttp://forums.matronics.com/viewtopic.php?p
=========================0A
- - - - - - - - - - - - - -Matt Dralle, List Adm
=====
________________________________________________________________________________
| Subject: | Re: Analyze This |
| From: | "user9253" <fransew(at)gmail.com> |
Suppose the alternator shorts to ground and the 60 amp fuse blows. Is there a
chance that a 100 amp current limiter will also blow?
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418042#418042
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Essential Bus question |
At 02:57 PM 2/3/2014, you wrote:
>Bob, As one Rotax mechanic I know put it quite succinctly, "The
>worst enemy of the Rotax 912 is their owners".
>As for the blown up engine I saw, the school I attended was taught
>by the owner of the Rotax North American distributorship. I cannot
>fathom why he would make up such a story. If the owner had followed
>the manual, prelubed the engine, and then burped the oil system (the
>912 has a dry sump oiling system that has no scavenge pump but
>instead relies upon blow by to pressurize the crankcase and push the
>oil out) he'd never have had a problem.
But a broken rod in 10 seconds? Rod failures
tend to be the byproduct of hammering of the
end cap after the bearing is worn . . . a process
that takes hours. To break the rod with the
torque offered by a seized bearing that
lacked lubrication for 10 seconds doesn't
fit with the physics. You cited tight fits
for the pistons and segued to a broken
rod.
To be sure, we don't have the benefit of
failure analysis on the subject engine
but using what appears to be capitalization
of outlier event to re-enforce a perfectly
reasonable caution to be certain of engine
lubrication smells of "teaching by
sensationalism." This sort of teaching is core
to many the useless if not expensive
ol' mechanic's tales that plague our
community.
I'm not calling him a liar . . . but I am
skeptical based on the cause/effect cited.
Bob . . .
________________________________________________________________________________
| From: | Jeff Luckey <jluckey(at)pacbell.net> |
| Subject: | Re: Analyze This |
I would say it's highly unlikely. The 100 amp might warm up but the 60 shou
ld hit its melting point before the 100.- I don't know how the resistance
of a fuse that's in the process of blowing changes.- If its resistance g
oes up, it would begin to limit the current for a few milliseconds until it
clears.=0A=0A-Jeff=0A=0A=0A=0A=0A________________________________=0A From:
user9253 =0ATo: aeroelectric-list(at)matronics.com =0ASent
: Monday, February 3, 2014 4:02 PM=0ASubject: AeroElectric-List: Re: Analyz
w(at)gmail.com>=0A=0ASuppose the alternator shorts to ground and the 60 amp fu
se blows.- Is there a chance that a 100 amp current limiter will also blo
w?=0AJoe=0A=0A--------=0AJoe Gores=0A=0A=0A=0A=0ARead this topic online her
e:=0A=0Ahttp://forums.matronics.com/viewtopic.php?p=418042#418042=0A=0A
=
________________________________________________________________________________
| From: | "R. curtis" <mrspudandcompany(at)verizon.net> |
| Subject: | Re: Essential Bus question |
You also have to take into account that unlike the LyCo's, the Rotax has a
five piece crank that is pressed together with nothing but the pressure of
the fit to keep it together and aligned. I would imagine the trail of tear
s would include a piston seizure that causes the crank to come out of align
ment which not only destroys a bearing or two, but gives the various crank
sections a chance to beat upon each other. The reason for the multipiece cr
ank is so that it can be made shorter by reducing the clearance between the
side of the rod, see picture. With so little clearance between the rod and
the adjacent crank web the twisted, misaligned crank now has a chance to r
eally start beating on the rods, the piston skirts, and any pieces that hav
e come loose. Of course the Rotax engineers have reduced clearances between
the rotating assembly and the case halves to shave off more weight and by
now the bearings are not only being twisted out of their seats but the case
webs are being hammered, too.
I find this scenerio to be highly unlikely! If this were the case, t
hen I would wager that there would be cases of this type of failure during
normal operation, due to the stress and vibration created during high power
running.
Roger
--
Do you have a slow PC=3F Try a Free scan http://www.spamfighter.com/SLOW-PCfi
ghter=3Fcid=sigen
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Teaching vs. Propagandizing |
At 08:23 PM 2/3/2014, you wrote:
>Bob, You also have to take into account that unlike the LyCo's, the
>Rotax has a five piece crank that is pressed together with nothing
>but the pressure of the fit to keep it together and aligned.
>Rotax engines are just a different animal.
Understand. This isn't a study in design
philosophies. It's a sifting of the simple
ideas in work -> heat -> loss of finish ->
more heat -> destruction over time.
Temperature rise in mass is a time dependent
phenomenon. The parts at risk of failure
need to take on energy that begins with a
very low value (new, slick surfaces) and builds
as the level of destruction advances.
Most engines run minutes producing a high
percentage of rated power with no more oil
on moving parts than that which was used to
assemble it. Then there's the notion that
destruction of cylinder walls (of significant
mass with water on the other side) had
anything to do with rod failure that went
from start to completion in 10 seconds.
I've spend a lot of my career sifting
through narratives for the purpose of
assembling data bits into a coherent picture
of cause and effect. "No piston
lube resulted in breaking a rod and
pushing the end through the crankcase
at 1000 rpm" does not paint a coherent
picture.
There is MUCH that is not said/known
and as such is a poor tool for educating
the listener with any better understanding
than they get from watching a Hollywood
portrayal of fantastic physics. Memorable
perhaps but it's akin to telling our
kids they'd better behave or the "boggy
man is going to get you." We've conducted
similar exercises here on the List with
close examination of narratives in the
flying rags that I've dubbed "dark-
n-stormy-night" stories. In this case:
"Better not have your EFIS system rebooting
right after start up lest the engine put
a rod through the crankcase."
The difference between teacher and propagandist
is the ability to bring all the simple-ideas
in a narrative together for that coherent
picture. The puzzle may be ten pieces or
1000 pieces but until they've been
fitted into place, the integrity of the
narrative is suspect.
Remember that math teacher who insisted
you write down all the steps for solving
a problem? The goal WAS NOT to get to the
right answer on one problem . . . the goal
WAS to understand HOW to get to the right
answer on all problems.
Bob . . .
________________________________________________________________________________
| Subject: | Batteries and step down converters |
Two totally unrelated questions...
1) To keep my primary EFIS up during engine start, I'm thinking of using a small
battery (I will need two since I've got a 24v system). I've seen mention of
people using 7ah batteries for this. What manufacture/model battery people are
using?
2) I've got one device that is only available in a 12v version. I was going to
get this step down converter from Lone Star.
http://www.lonestaraviation.com/Step-Down-Conveter-24V-to-13.8-Volts.html
Then I ran across this one at 1/5th the cost.
http://www.pyleaudio.com/sku/PSWNV480/24V-DC-to-12V-DC-Power-Step-Down-480-Watt--Converter-W-PMW-Technology
I'm wondering if it's likely that there is a fundamental difference between the
two beyond one of them being for the aviation market.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418075#418075
________________________________________________________________________________
| Subject: | Re: Batteries and step down converters |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
I think most any of them will run on 12 volts just fine. If so no need to convert
it. Here's what I use:
http://www.batteriesplus.com/product/46043-WKA12--7F-12V-7Ah-AGM-Battery/566-0/8183-Emergency-Light-Security-Battery/655122-Moose/Z1100-Security-Alarm.aspx
Tim
> On Feb 4, 2014, at 8:34 AM, "donjohnston" <don@velocity-xl.com> wrote:
>
>
> Two totally unrelated questions...
>
> 1) To keep my primary EFIS up during engine start, I'm thinking of using a small
battery (I will need two since I've got a 24v system). I've seen mention of
people using 7ah batteries for this. What manufacture/model battery people are
using?
>
> 2) I've got one device that is only available in a 12v version. I was going to
get this step down converter from Lone Star.
> http://www.lonestaraviation.com/Step-Down-Conveter-24V-to-13.8-Volts.html
>
> Then I ran across this one at 1/5th the cost.
> http://www.pyleaudio.com/sku/PSWNV480/24V-DC-to-12V-DC-Power-Step-Down-480-Watt--Converter-W-PMW-Technology
>
> I'm wondering if it's likely that there is a fundamental difference between the
two beyond one of them being for the aviation market.
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=418075#418075
>
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Batteries and step down converters |
| From: | Eric Page <edpav8r(at)yahoo.com> |
What device are you planning to power from such a DC/DC converter that needs a
supply capable of 10-20 amps?
Lone Star's prices reflect the high cost of TSO compliance testing and, as you
suggested, application of the word "aviation" to their products. That said, I'll
bet they're high quality. The Pyle... who knows?
As long as in-flight failure of the connected device would have no safety implications,
I wouldn't hesitate to use the Pyle converter, or indeed any you might
find on eBay for even less $, smaller size and lower weight.
Perhaps this: http://bit.ly/1frGS3M -or this- http://bit.ly/1eQFmXj -or this- http://bit.ly/LM7x2A
Or, if 5A current capacity is enough, this: http://bit.ly/1n8N17Y
Search eBay for "DC buck" and you'll get endless hits.
I would figure out the peak current draw of your device, double it, and buy a converter
with that capability to assure adequate supply without high operating
temps. I wouldn't lose much sleep about reliability; if a converter functions
out of the box, it's probably unlikely to fail later, assuming it's not driven
to absurd temperatures or subjected to mechanical abuse.
Eric
On Feb 4, 2014, at 9:34 AM, "donjohnston" <don@velocity-xl.com> wrote:
>
> Two totally unrelated questions...
>
> 1) To keep my primary EFIS up during engine start, I'm thinking of using a small
battery (I will need two since I've got a 24v system). I've seen mention of
people using 7ah batteries for this. What manufacture/model battery people are
using?
>
> 2) I've got one device that is only available in a 12v version. I was going to
get this step down converter from Lone Star.
> http://www.lonestaraviation.com/Step-Down-Conveter-24V-to-13.8-Volts.html
>
> Then I ran across this one at 1/5th the cost.
> http://www.pyleaudio.com/sku/PSWNV480/24V-DC-to-12V-DC-Power-Step-Down-480-Watt--Converter-W-PMW-Technology
>
> I'm wondering if it's likely that there is a fundamental difference between the
two beyond one of them being for the aviation market.
________________________________________________________________________________
| Subject: | Small Connector for Ray Allen Trim Servo Cables? |
| From: | "Valin" <thorn(at)starflight.aero> |
Hello,
Can anyone recommend a good, small, preferably environmentally sealed connector
to use on the five conductor cable of 22 AWG wires that run to each of the Ray
Allen trim servos? If I werent going to be flying in primer first Id probably
just splice the wires together for the entire run. But with paint and control
surface removal in the known future Id like to make removal of the control
surfaces easier with connectors on these cables. They need to be low volume
connectors to fit in the space where theyll be.
Thanks,
Valin Thorn
Lancair Legacy Project
Boulder, Colorado
BTW, when I try to email in questions to the list nothing comes through for me.
So posting directly to the AeroElectric List Forum.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418080#418080
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Small Connector for Ray Allen Trim Servo Cables? |
At 12:38 PM 2/4/2014, you wrote:
Hello,
Can anyone recommend a good, small, preferably
environmentally sealed connector to use on the
five conductor cable of 22 AWG wires that run to
each of the Ray Allen trim servos? If I
werent going to be flying in primer first
Id probably just splice the wires together for
the entire run. But with paint and control
surface removal in the known future Id like to
make removal of the control surfaces easier with
connectors on these cables. They need to be low
volume connectors to fit in the space where theyll be.
Thanks,
Valin Thorn
Lancair Legacy Project
Boulder, Colorado
BTW, when I try to email in questions to the list
nothing comes through for me. So posting
directly to the AeroElectric List Forum.
Not sure what you mean by 'email to the list'
Using aeroelectric-list(at)matronics.com in your address
is the only way to post to the list server and in this
case, it seems to have worked for you.
Why 'environmentally sealed' . . . that opens
a huge catalog of choices few of which offer
a good return on investment.
Consider this:
http://tinyurl.com/cmq7epd
. . . for reducing the profile on a d-sub
to allow threading through the lightening
holes on an RV . . . not sure what your
cable routing constraints are . . . perhaps
a stock pair of D-Sub9 connectors would
fit.
If you're committed to the environmentally
sealed variety heres an exemplar selection
http://tinyurl.com/n3auqc4
http://tinyurl.com/k883l97
I think you'll find the rudimentary D-Subs
adequate to the task.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Small Connector for Ray Allen Trim Servo Cables? |
| From: | Eric Page <edpav8r(at)yahoo.com> |
Weather Pack connectors should do the trick, assuming they fit your space co
nstraints. The 5-pin is a bit bulky, but a 2-pin and a 3-pin offset from on
e another might work. They're even available as pigtails so you don't need t
he crimp tool.
http://www.whiteproducts.com/weather_pack.shtml
Eric
On Feb 4, 2014, at 11:38 AM, "Valin" wrote:
> Hello,
>
> Can anyone recommend a good, small, preferably environmentally sealed conn
ector to use on the five conductor cable of 22 AWG wires that run to each of
the Ray Allen trim servos? If I weren=99t going to be flying in prim
er first I=99d probably just splice the wires together for the entire r
un. But with paint and control surface removal in the known future I=99
d like to make removal of the control surfaces easier with connectors on the
se cables. They need to be low volume connectors to fit in the space where t
hey=99ll be.
>
> Thanks,
>
> Valin Thorn
> Lancair Legacy Project
> Boulder, Colorado
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Batteries and step down converters |
At 10:34 AM 2/4/2014, you wrote:
Two totally unrelated questions...
1) To keep my primary EFIS up during engine start, I'm thinking of
using a small battery (I will need two since I've got a 24v system).
I've seen mention of people using 7ah batteries for this. What
manufacture/model battery people are using?
What is the input voltage requirement for your
electro-whizzies. Many contemporary products now
use switch-mode power supplies with a wide range
of acceptable inputs . . . typically 0-32 volts.
If your devices are of this generation, then you
don't need brownout protection in a 28v system . . .
starter inrush drain won't pull your bus below
10 volts and the glass will stay powered up.
The problem arises when a device with a 10v minimum
input voltage sees a drop to 7-8 volts during starter
inrush events.
2) I've got one device that is only available in a 12v version. I was
going to get this step down converter from Lone Star.
http://www.lonestaraviation.com/Step-Down-Conveter-24V-to-13.8-Volts.html
Then I ran across this one at 1/5th the cost.
http://www.pyleaudio.com/sku/PSWNV480/24V-DC-to-12V-DC-Power-Step-Down-480-Watt--Converter-W-PMW-Technology
I'm wondering if it's likely that there is a fundamental difference
between the two beyond one of them being for the aviation market.
What is the device you're fitting with the down-converter
and what are its input demands?
Bob . . .
________________________________________________________________________________
| Subject: | Re: Small Connector for Ray Allen Trim Servo Cables? |
| From: | rparigor(at)suffolk.lib.ny.us |
Hi Valin
We were going to use D-sub connector with no shell, use Goop to hold
wires to connector and heat shrink together (this was one of Bobs ideas,
I am pretty sure he has instructions for this).
Since we have an inspection cover close to the servo, insteads of using a
connector we just stagger soldered wires and heat shrunk, leaving a
service loop to allow us to unsolder if servo ever needed replacement or
removal.
In addition we marked on a white piece of heat shrink which wires you
would want to connect to a 9 volt battery to jog to a somewhat neutral
position to get you home in the event the pitch circuit failed.
Details:
http://www.europaowners.org/main.php?g2_itemId=30484
Ron Parigoris
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Small Connector for Ray Allen Trim Servo Cables? |
>They need to be low volume connectors to fit in the space where theyll be.
>
>Thanks,
If you've got a really tight size restriction, then
there are some pretty compact but still well enclosed
connectors from Lemo
http://tinyurl.com/p4ycw9p
I used these on a couple of programs at Beech . . . but
they come in so many assembly options that nobody stocks
many ready-to-install combinations. Both times I needed
4 and 5 wire connectors, they were ordered in from a
Lemo distribution facility that custom assembled to the
desired option. Cost about $40 each half plus back
shells and 6 week lead time.
Nice connectors tho . . .
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Off the shelf product update |
A few weeks ago we were discussing several design
goals that would benefit from the incorporation
of solid state relays. At that time I cruised the
offerings on eBay and purchased this item
http://tinyurl.com/l2v72uf
Emacs!
This is a DC/DC solid state relay rated for switching
up to 60 volts at 100 amps. I selected the 100 amp
rated device based on the notion that mos-fet transistors
rated for the greatest currents tend to have the lowest
On-Resistance ratings. I've used many 'oversized'
transistors in a task not because I needed some
'headroom' for reliability . . . but because I wanted
the lowest practical on-resistance which in turn
produces the simplest heat rejection problem.
When the first relay arrived, I biased the critter
up on a 20A constant current supply and it exhibited
a voltage drop on the order of 5 volts . . . obviously
unsuited to the task at any current level.
Wrote to the seller who was wanting to see
schematics on how I had wired it up . . . but who
didn't have a clue as to how it was supposed to
work. I finally lodged a complaint with eBay for
merchandise not as advertised.
The seller responded with an offer to replace it
and I received the second part directly from the
factory yesterday. This part does perform much
better . . . only 0.5 volts drop at 20A and probably
less than the advertised 1.0 volt drop at 100A.
I closed the 'gripe' with the eBay seller.
This discovery demonstrates the designers unwillingness
to 'bootstrap' the gate supplies to his power
FETs for the purpose of achieving the lowest possible
on-resistance . . . hence the lowest possible heat
dissipation.
This product is offered by many eBay sellers and
I've found a few bad-reviews . . . but for the
most part, these critters seem to operate as
advertised.
But we can do better . . .
I've got a 20A package I'm working with that is
in a plastic enclosure and requires NO heat-sink.
But it wont sell for $13 either.
I can recommend the product offered on eBay for
situations where the MINIMUM drop on the order
of 0.5 volts is not a stumbling point. At $13, its
a good value. I would not operate it at much more
than 20A for the same heat-rejection issues
we've been deliberating here on the list for
bus power steering diodes.
I'm going to throw the SSR in the goodies-bin
and move on . . . might have a place I can use
it on my truck someday.
Bob . . .
________________________________________________________________________________
| Subject: | Relay for OV Protection |
| From: | Thomas E Blejwas <tomblejwas(at)yahoo.com> |
In modifying Z-07 or Z-19 for my Viking engine, I will add over-voltage protection
for the Viking-supplied, internally regulated, 40A alternator by ND. Based
in part on Bob's demonstration in the literature of a type 70 contactor opening
under simulated o.v. conditions, I'd started to plan on such a relay/contactor
instead of spending over $200 on an EV200 or similar. But since the relay
is not in the starting loop, could I use a stout auto relay instead? I recently
became aware of the Picker 7150 (now sold by Waytek) that has ratings of
75V switching voltage and 150A for continuous load and breaking. It has 3/8"
quick tabs for the load, but connectors for #8 wire are available from Digikey.
Advantages would be weight (2.1 oz.) and electrical draw (2.9W). Are there
potential problems? Btw, I'm not concerned with it surviving an o.v. event,
since it would cost $20 or so to replace. Thanks in advance for any feedback.
Tom
Sent from my iPad
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Relay for OV Protection |
At 02:12 PM 2/4/2014, you wrote:
In modifying Z-07 or Z-19 for my Viking engine, I will add
over-voltage protection for the Viking-supplied, internally
regulated, 40A alternator by ND. Based in part on Bob's
demonstration in the literature of a type 70 contactor opening under
simulated o.v. conditions, I'd started to plan on such a
relay/contactor instead of spending over $200 on an EV200 or
similar. But since the relay is not in the starting loop, could I
use a stout auto relay instead? I recently became aware of the
Picker 7150 (now sold by Waytek) that has ratings of 75V switching
voltage and 150A for continuous load and breaking. It has 3/8" quick
tabs for the load, but connectors for #8 wire are available from
Digikey. Advantages would be weight (2.1 oz.) and electrical draw
(2.9W). Are there potential problems? Btw, I'm not concerned with
it surviving an o.v. event, since it would cost $20 or so to
replace. Thanks in advance for any feedback.
Tom
Give it a try! The ratings are good.
http://tinyurl.com/kwlvfj2
I note that they come with built in coil
suppression that appears to be a plain vanilla
diode.
Your "high-risk" features are centered more on
the connectors and crimps than on the relay.
Of all the S700-3 switches 'smoked' by strobe systems,
I don't think we've seen any evidence of contact's
ill suited to the task. We've seen terminals overheat
and do the precipitous slide to smoke and fire, also
compression joints across plastic housings (tabs
held by rivets) and even some 'teeter totters' that
annealed and deformed . . . but the contacts looked
fine.
What we're learning here is the value of gas-tight
integrity for made up joints . . . they appear
far more vulnerable to abusive electron flows than
the actual controlling contacts.
With 3/8" fast-on tabs, you might consider drilling
them for #6 screw and using ring terminals to attach.
I think I'd go for a soldered-on non insulated
ring terminal too. With due diligence to your made
up joints, odds for success are quite good.
Now for the caveats . . . this is a plastic enclosure
and a runaway IR alternator ALWAYS goes into self
destruct by putting something on the order of 200 volts
on its own field winding - and nearly as much on the
b-lead disconnect relay. The only concern I have is
for the possibility of internal-eternal fire getting
outside the housing . . . this was not a concern with
the metal housed Model 70.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Teaching vs. Propagandizing |
| From: | Richard Girard <aslsa.rng(at)gmail.com> |
Bob et al, It's been seven years since I saw that engine at Lockwoods. At
the time I didn't think to take pictures, however I have a request in to
Dean Vogel, there, to see if I can get one or two pictures of it.
I've had the misfortune to blow up an engine or two over the last 50 years.
The first was an Alfa Romeo four cylinder that blew a head gasket. I had
just had the engine rebuilt after I over revved it and spun a rod bearing.
The book said to re-torque the head every 1300 miles. I had a date and
thought I could get it the next morning. Sure enough, white steam began
pouring out of the exhaust a block from her house. The trip odometer said
the engine had 1317 miles on it. The fellow I sold the car to did the same
thing. Dave, as I recall, got a little over that but did not reach 1400
miles. Alfa was quite serious about the 1300 mile re-torquing. I was 19 and
it made an impression on me that the manufacturer generally knows his
product.
Back to the Rotax. First, your assumption that it would idle at 1000 rpm.
It's a geared engine that idles at 1800 to 2200. Kinetic energy increases
at the square of the speed, does it not? So we have around 4 times the
energy from the idle speed you used as an example.
Rotax piston fits. As I said, somewhere back, the allowable piston to
cylinder fit for a 912 is .0000 to .0009". It is perfectly acceptable to
have a size on size fit up. Even at .0009" it does not take much to seize a
piston.
When I examined the damage, one of the things that impressed me was the
absence of metal discoloration or burned oil on the parts, in this case
break in lube. This is why my recreation of events concentrated on the
failure of the built up crank. I just didn't see the damage signature that
I've seen in a typical rod failure event. What there was, was a lot of
impact damage.
If I'm lucky enough to get a picture or two, I'll pass them along.
Rick
On Tue, Feb 4, 2014 at 10:08 AM, Robert L. Nuckolls, III <
nuckolls.bob(at)aeroelectric.com> wrote:
> nuckolls.bob(at)aeroelectric.com>
>
> At 08:23 PM 2/3/2014, you wrote:
>
>> Bob, You also have to take into account that unlike the LyCo's, the Rotax
>> has a five piece crank that is pressed together with nothing but the
>> pressure of the fit to keep it together and aligned. Rotax engines
>> are just a different animal.
>>
>
> Understand. This isn't a study in design
> philosophies. It's a sifting of the simple
> ideas in work -> heat -> loss of finish ->
> more heat -> destruction over time.
>
> Temperature rise in mass is a time dependent
> phenomenon. The parts at risk of failure
> need to take on energy that begins with a
> very low value (new, slick surfaces) and builds
> as the level of destruction advances.
>
> Most engines run minutes producing a high
> percentage of rated power with no more oil
> on moving parts than that which was used to
> assemble it. Then there's the notion that
> destruction of cylinder walls (of significant
> mass with water on the other side) had
> anything to do with rod failure that went
> from start to completion in 10 seconds.
>
> I've spend a lot of my career sifting
> through narratives for the purpose of
> assembling data bits into a coherent picture
> of cause and effect. "No piston
> lube resulted in breaking a rod and
> pushing the end through the crankcase
> at 1000 rpm" does not paint a coherent
> picture.
>
> There is MUCH that is not said/known
> and as such is a poor tool for educating
> the listener with any better understanding
> than they get from watching a Hollywood
> portrayal of fantastic physics. Memorable
> perhaps but it's akin to telling our
> kids they'd better behave or the "boggy
> man is going to get you." We've conducted
> similar exercises here on the List with
> close examination of narratives in the
> flying rags that I've dubbed "dark-
> n-stormy-night" stories. In this case:
> "Better not have your EFIS system rebooting
> right after start up lest the engine put
> a rod through the crankcase."
>
> The difference between teacher and propagandist
> is the ability to bring all the simple-ideas
> in a narrative together for that coherent
> picture. The puzzle may be ten pieces or
> 1000 pieces but until they've been
> fitted into place, the integrity of the
> narrative is suspect.
>
> Remember that math teacher who insisted
> you write down all the steps for solving
> a problem? The goal WAS NOT to get to the
> right answer on one problem . . . the goal
> WAS to understand HOW to get to the right
> answer on all problems.
>
>
> Bob . . .
>
>
--
Zulu Delta
Mk IIIC
Thanks, Homer GBYM
It isn't necessary to have relatives in Kansas City in order to be unhappy.
- Groucho Marx
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Teaching vs. Propagandizing |
At 03:40 PM 2/4/2014, you wrote:
>Bob et al, It's been seven years since I saw that engine at
>Lockwoods. At the time I didn't think to take pictures, however I
>have a request in to Dean Vogel, there, to see if I can get one or
>two pictures of it.
>If I'm lucky enough to get a picture or two, I'll pass them along.
Great. If he could also expand the narrative to
explain the sequence of events along with photos
of the participating features . . .
Bob . . .
________________________________________________________________________________
| Subject: | Re: Teaching vs. Propagandizing |
| From: | Robert Borger <rlborger(at)mac.com> |
Gents,
This thread should probably be on the Rotax list, but sometimes we take what we
can get where we can get it.
I too have attended Lockwoods 91X class and have seen the engine and heard the
story from Dean. There was also a second story related which involved loss of
oil due to vibrational damage to an extended fitting to mount the oil pressure
sensor. A fitting was inserted between the oil pressure sender and the engine
case. The fitting was put in place to add a pressure switch to illuminate
a light should the oil pressure drop below the switch pressure set point. Now
you have a classic mass on a spring with the sender hanging out on that extension.
I dont remember how long that arrangement held up but I dont believe it
was very long before the extension piece broke, the gentlemans low oil pressure
lamp illuminated and the contents of the oil sump were dumped overboard. Again,
the report was that the engine probably didnt run longer than 10-20 second
before it seized once the oil was gone. I cant speak to the accuracy of the
10-20 seconds without oil before seizure not having been there in either case.
But the takeaway point was that the Rotax 91X engine requires continuous lubrication
and that any interruption in that lubrication would be detrimental
to your engine.
BTW, I have moved my oil pressure sender off the engine and onto the firewall using
a length of SS braided pressure line. Saves vibrational stresses on the
sender and the fitting to the engine.
One of the many things I like about my Grand Rapids EIS 4000 is that it stays up
during engine start and the default page shows oil pressure so I know immediately
upon engine start if theres oil pressure.
Just my 2 and worth at least half that.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs).
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger(at)mac.com
On Feb 4, 2014, at 3:40 PM, Richard Girard wrote:
Bob et al, It's been seven years since I saw that engine at Lockwoods. At the time
I didn't think to take pictures, however I have a request in to Dean Vogel,
there, to see if I can get one or two pictures of it.
I've had the misfortune to blow up an engine or two over the last 50 years. The
first was an Alfa Romeo four cylinder that blew a head gasket. I had just had
the engine rebuilt after I over revved it and spun a rod bearing. The book said
to re-torque the head every 1300 miles. I had a date and thought I could get
it the next morning. Sure enough, white steam began pouring out of the exhaust
a block from her house. The trip odometer said the engine had 1317 miles on
it. The fellow I sold the car to did the same thing. Dave, as I recall, got a
little over that but did not reach 1400 miles. Alfa was quite serious about the
1300 mile re-torquing. I was 19 and it made an impression on me that the manufacturer
generally knows his product.
Back to the Rotax. First, your assumption that it would idle at 1000 rpm. It's
a geared engine that idles at 1800 to 2200. Kinetic energy increases at the square
of the speed, does it not? So we have around 4 times the energy from the
idle speed you used as an example.
Rotax piston fits. As I said, somewhere back, the allowable piston to cylinder
fit for a 912 is .0000 to .0009". It is perfectly acceptable to have a size on
size fit up. Even at .0009" it does not take much to seize a piston.
When I examined the damage, one of the things that impressed me was the absence
of metal discoloration or burned oil on the parts, in this case break in lube.
This is why my recreation of events concentrated on the failure of the built
up crank. I just didn't see the damage signature that I've seen in a typical
rod failure event. What there was, was a lot of impact damage.
If I'm lucky enough to get a picture or two, I'll pass them along.
Rick
________________________________________________________________________________
| Subject: | Re: Analyze This |
| From: | "user9253" <fransew(at)gmail.com> |
Most aircraft are wired so that starter motor current comes from the battery, through
the master contactor, then through the starter contactor to the starter
motor. Then if the starter contactor sticks closed, the pilot can break the
circuit by shutting off the master switch. I modified Jeff's circuit (attached).
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418101#418101
Attachments:
http://forums.matronics.com//files/starter_circuit_194.pdf
________________________________________________________________________________
| Subject: | Re: Relay for OV Protection |
| From: | Thomas E Blejwas <tomblejwas(at)yahoo.com> |
Thanks Bob. I particularly appreciate the caveat. If the runaway can really get
to 200V in 5 ms, then I will have a hard time evaluating the potential risk.
Tom
Sent from my iPad
> On Feb 4, 2014, at 2:42 PM, "Robert L. Nuckolls, III"
wrote:
>
>
> At 02:12 PM 2/4/2014, you wrote:
>
> In modifying Z-07 or Z-19 for my Viking engine, I will add over-voltage protection
for the Viking-supplied, internally regulated, 40A alternator by ND. Based
in part on Bob's demonstration in the literature of a type 70 contactor opening
under simulated o.v. conditions, I'd started to plan on such a relay/contactor
instead of spending over $200 on an EV200 or similar. But since the relay
is not in the starting loop, could I use a stout auto relay instead? I recently
became aware of the Picker 7150 (now sold by Waytek) that has ratings
of 75V switching voltage and 150A for continuous load and breaking. It has 3/8"
quick tabs for the load, but connectors for #8 wire are available from Digikey.
Advantages would be weight (2.1 oz.) and electrical draw (2.9W). Are there
potential problems? Btw, I'm not concerned with it surviving an o.v. event,
since it would cost $20 or so to replace. Thanks in advance for any feedback.
>
> Tom
>
> Give it a try! The ratings are good.
>
> http://tinyurl.com/kwlvfj2
>
> I note that they come with built in coil
> suppression that appears to be a plain vanilla
> diode.
>
> Your "high-risk" features are centered more on
> the connectors and crimps than on the relay.
>
> Of all the S700-3 switches 'smoked' by strobe systems,
> I don't think we've seen any evidence of contact's
> ill suited to the task. We've seen terminals overheat
> and do the precipitous slide to smoke and fire, also
> compression joints across plastic housings (tabs
> held by rivets) and even some 'teeter totters' that
> annealed and deformed . . . but the contacts looked
> fine.
>
> What we're learning here is the value of gas-tight
> integrity for made up joints . . . they appear
> far more vulnerable to abusive electron flows than
> the actual controlling contacts.
>
> With 3/8" fast-on tabs, you might consider drilling
> them for #6 screw and using ring terminals to attach.
> I think I'd go for a soldered-on non insulated
> ring terminal too. With due diligence to your made
> up joints, odds for success are quite good.
>
> Now for the caveats . . . this is a plastic enclosure
> and a runaway IR alternator ALWAYS goes into self
> destruct by putting something on the order of 200 volts
> on its own field winding - and nearly as much on the
> b-lead disconnect relay. The only concern I have is
> for the possibility of internal-eternal fire getting
> outside the housing . . . this was not a concern with
> the metal housed Model 70.
>
>
>
> Bob . . .
>
>
>
>
________________________________________________________________________________
| From: | Jeff Luckey <jluckey(at)pacbell.net> |
| Subject: | Re: Analyze This |
I chose the "non-traditional" approach because:=0A1. Contactor sticking is
exceedingly rare=0A2. I did not want cranking to be dependent on 2 contacto
rs=0A3. It allows for more choices when selection a master relay=0A=0A=0A
=0A=0A________________________________=0A From: user9253 <fransew(at)gmail.com
>=0ATo: aeroelectric-list(at)matronics.com =0ASent: Tuesday, February 4, 2014
6:31 PM=0ASubject: AeroElectric-List: Re: Analyze This=0A =0A=0A--> AeroEle
ctric-List message posted by: "user9253" =0A=0AMost airc
raft are wired so that starter motor current comes from the battery, throug
h the master contactor, then through the starter contactor to the starter m
otor.- Then if the starter contactor sticks closed, the pilot can break t
he circuit by shutting off the master switch.- I modified Jeff's circuit
(attached).=0AJoe=0A=0A--------=0AJoe Gores=0A=0A=0A=0A=0ARead this topic o
nline here:=0A=0Ahttp://forums.matronics.com/viewtopic.php?p=418101#41810
1=0A=0A=0A=0A=0AAttachments: =0A=0Ahttp://forums.matronics.com//files/start
- - - - - - - - - - - - -Matt Dralle, List Admin.
====
________________________________________________________________________________
| Subject: | Re: Small Connector for Ray Allen Trim Servo Cables? |
| From: | "hooverra" <hooverra(at)comcast.net> |
http://www.digikey.com/catalog/en/partgroup/en3-series/2186
switchcraft en series is sealed, small and works well for trim cables. It takes
reasonable soldering skill but not bad.
Ralph
--------
Ralph & Laura Hoover
RV7A N527LR
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418113#418113
________________________________________________________________________________
| From: | "Dennis Johnson" <pinetownd(at)volcano.net> |
| Subject: | Small Connector for Ray Allen Trim Servo Cables? |
Hi Valin,
I used mini S-VHS connectors for my Ray Allen trim servos. That is what
the company recommends and S-VHS connectors are round and have the
benefit of passing through existing round holes, unlike D-Sub
connectors. Mini S-VHS connectors from DigiKey are available with
different numbers of wire connections, depending on which servo you're
connecting them to. I don't see any need for environmentally sealed
connectors in my Legacy.
If I had it to do again, I'd go with Ron's suggestion of soldering the
wires together, with a generous service loop. Since you're flying
before final painting, that might be emotionally difficult because
you'll have to cut the wires to remove the rudder and elevator when you
paint, but it's not that big of a deal. I think soldering the wires
together for first flight, cutting them apart for painting, and then
soldering them back together is going to be less trouble and more
reliable than finding and using connectors.
If I absolutely had to have connectors instead of soldering the wires
together, I'd use Bob's method of D-Sub connectors without the shell,
covered by heat shrink. You might have to slightly enlarge some of the
pass through holes to get the connector through, but that's not a
problem.
I also recommend buying the wire from Ray Allen to connect to the
servos. I know it's tiny 28 gauge, but it comes in a very durable
sheath and will be much neater than making your own bundle from manually
twisting 22 gauge wires together.
Best,
Dennis
Lancair Legacy, 680 hours
________________________________________________________________________________
| From: | "Owen Baker " <bakerocb(at)cox.net> |
| Subject: | Small Connector for Ray Allen Trim Servo Cables? |
2/5/2014
Hello Valin, Why not purchase several male and female machined D sub
pins? Here is just one example:
http://www.newark.com/cinch/030-1952-000/d-sub-contact-pin-24-20awg-crimp
/dp/12M3924?mckv=sShye0Dzw|pcrid|33869844621|plid|&CMP=KNC-GPLA
(You may prefer the high density version.)
Then you just crimp the appropriate gender pin on each of the 10 Ray
Allen bare wire ends and stick the pins together. Some tips and
comments:
a) Be sure to put the appropriate sized heat shrink over the wires
before crimping the pins onto the wires so that you can slide the heat
shrink over the joined pins before heat shrinking. The heat shrink will
help keep the pins together when joined and provide some environmental
protection.
b) If you desire additional environmental protection some goop can be
applied to the ends of the heat shrink.
http://eclecticproducts.com/e6000_retail.htm
c) If you are not satisfied with how firmly the pins connect together
put a very slight bend in the male pin before inserting it into the
female pin to assure a better connection.
d) You can stagger the ends of the cut wires so that all of the pins do
not remain in one large clump when the job is finished.
e) These connections can be separated (for later reconnection) by
carefully using a razor blade or Xacto knife to split the heat shrink.
OC
=============
Subject: AeroElectric-List: Small Connector for Ray Allen Trim Servo
Cables?
From: "Valin" <thorn(at)starflight.aero>
Hello,
Can anyone recommend a good, small, preferably environmentally sealed
connector
to use on the five conductor cable of 22 AWG wires that run to each of
the Ray
Allen trim servos? If I werent going to be flying in primer first Id
probably
just splice the wires together for the entire run. But with paint and
control
surface removal in the known future Id like to make removal of the
control
surfaces easier with connectors on these cables. They need to be low
volume
connectors to fit in the space where theyll be.
Thanks,
Valin Thorn
Lancair Legacy Project
Boulder, Colorado
________________________________________________________________________________
| Subject: | Re: Small Connector for Ray Allen Trim Servo Cables? |
| From: | "user9253" <fransew(at)gmail.com> |
I think this was Bob's idea but I could not find it on his website. Use 5 sets
of male-female D-Sub pins without any shell at all. Cover each mated pair with
heat-shrink. If the joints have to be weather proof, use adhesive lined heat-shrink.
The heat shrink will have to be cut to separate the connections, not
a big deal.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418118#418118
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Small Connector for Ray Allen Trim Servo |
Cables?
At 06:21 AM 2/5/2014, you wrote:
>
>http://www.digikey.com/catalog/en/partgroup/en3-series/2186
>
>switchcraft en series is sealed, small and works well for trim
>cables. It takes reasonable soldering skill but not bad.
Interesting find! Thank you. According to the
data sheet
http://tinyurl.com/le3gwtp
these are available in 20AWG crimp pins. There's
a 95% chance that the el-cheepo (and platinum
plated) 4-quadrant tools will install these
pins. Unfortunately, Digikey doesn't stock the
crimp versions yet but they will do special orders
of 10 or more connectors. I'll put these on
my list of "things to go buy and evaluate" and
may add them to the AeroElectric Catalog. But
if they're popular, Digikey will eventually
stock them.
Switchcraft is a staid, old-line supplier of
electronic components . . . low risk.
Bob . . .
________________________________________________________________________________
| Subject: | Electrical architecture with aux battery |
| From: | "user9253" <fransew(at)gmail.com> |
Attached is a circuit with a brownout battery (non cranking). It will be kept
charged through a diode when the E-Bus alternate feed is off. The aux battery
will be connected in parallel with the main battery when both aux battery switch
and the E-Bus switch are turned on (expected normal operation after engine
start). This circuit is not for my plane. I offer it for discussion and comments.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418123#418123
Attachments:
http://forums.matronics.com//files/z_11_modified_2_971.pdf
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Teaching vs. Propagandizing |
At 05:01 PM 2/4/2014, you wrote:
Gents,
This thread should probably be on the Rotax list,
but sometimes we take what we can get where we can get it.
I will suggest this is an appropriate discussion
for the purpose of honing our critical analysis
tools. Most of the 'tiger teams' on which I served
at Beech were not wrestling with electrons . . .
but they were grounded in the same physics that drives
everything made up of matter and driven by energy.
I too have attended Lockwood=92s 91X class and have
seen the engine and heard the story from
Dean. There was also a second story related
which involved loss of oil due to vibrational
damage to an extended fitting to mount the oil
pressure sensor. A fitting was inserted between
the oil pressure sender and the engine case. The
fitting was put in place to add a pressure switch
to illuminate a light should the oil pressure
drop below the switch pressure set point. Now
you have a classic mass on a spring with the
sender hanging out on that extension. I don=92t
remember how long that arrangement held up but I
don=92t believe it was very long before the
extension piece broke, the gentleman=92s low oil
pressure lamp illuminated and the contents of the
oil sump were dumped overboard. Again, the
report was that the engine probably didn=92t run
longer than 10-20 second before it seized once
the oil was gone. I can=92t speak to the accuracy
of the 10-20 seconds without oil before seizure
not having been there in either case. But the
takeaway point was that the Rotax 91X engine
requires continuous lubrication and that any
interruption in that lubrication would be detrimental to your engine.
Great example!
BTW, I have moved my oil pressure sender off the
engine and onto the firewall using a length of SS
braided pressure line. Saves vibrational
stresses on the sender and the fitting to the engine.
There you go . . . this is a demonstrable example
of fitting all the puzzle pieces together. I'm
betting that the fittings which broke were brass . . .
a non-ferrous material of which all such materials
have a service life.
There's a feature in the study of strengths of
materials called the S/N to Failure. Stress
levels/Number of cycles to failure curve for
steel becomes flat at some value of S/N
below N of 10M. The rule of thumb for testing
steel parts is, "If you can't break it in
10,000,000 cycles, you aren't going to break it."
On the other hand, non-steel parts have a service
life at ANY stress level. It's just parts like
wings, struts and tail feathers are so lightly
stressed that their service lives far exceed the
expected life of an airplane. But poor attention
to details of design, operation and maintenance
have proven spectacularly catastrophic.
[]
It's that sneaky old s/n ratio thingy that makes
us attentive to adding wire support immediately
adjacent to a crimped or soldered bundle of wire
strands.
Having a rudimentary understanding of s/n ratio
is useful for stringing wires, installing rivets,
building support brackets . . . and yes . . .
evaluating cause-effect for connecting rods coming
through the crankcase. It'a all the same physics.
One of the many things I like about my Grand
Rapids EIS 4000 is that it stays up during engine
start and the default page shows oil pressure so
I know immediately upon engine start if there=92s oil pressure.
Just my 2=A2 and worth at least half that.
Undoubtedly . . .
Blue skies & tailwinds,
Bob Borger
Bob . . .
________________________________________________________________________________
| Subject: | Re: Teaching vs. Propagandizing |
| From: | Robert Borger <rlborger(at)mac.com> |
On Feb 5, 2014, at 11:46 AM, Robert L. Nuckolls, III
wrote:
At 05:01 PM 2/4/2014, you wrote:
Gents,
There you go . . . this is a demonstrable example
of fitting all the puzzle pieces together. I'm
betting that the fittings which broke were brass . . .
a non-ferrous material of which all such materials
have a service life.
Robert, If I remember correctly, the fitting was brass. Broke off just about flush
with the oil pump housing. Which is right where the maximum vibrational
stress would have been applied.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs).
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger(at)mac.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Small Connector for Ray Allen Trim Servo |
Cables?
At 09:30 AM 2/5/2014, you wrote:
>
>I think this was Bob's idea but I could not find it on his
>website. Use 5 sets of male-female D-Sub pins without any shell at
>all. Cover each mated pair with heat-shrink. If the joints have to
>be weather proof, use adhesive lined heat-shrink. The heat shrink
>will have to be cut to separate the connections, not a big deal.
Last panel on this comic book . . .
http://tinyurl.com/c5v2xvm
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Teaching vs. Propagandizing |
>Robert, If I remember correctly, the fitting was brass. Broke off
>just about flush with the oil pump housing. Which is right where
>the maximum vibrational stress would have been applied.
Bingo . . .
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Electrical architecture with aux battery |
At 11:43 AM 2/5/2014, you wrote:
>
>Attached is a circuit with a brownout battery (non cranking). It
>will be kept charged through a diode when the E-Bus alternate feed
>is off. The aux battery will be connected in parallel with the main
>battery when both aux battery switch and the E-Bus switch are turned
>on (expected normal operation after engine start). This circuit is
>not for my plane. I offer it for discussion and comments.
There is a way to avoid charging the aux
battery through a diode and eliminate one
switch.
http://tinyurl.com/7ro5yuc
Bob . . .
________________________________________________________________________________
| Subject: | Re: Teaching vs. Propagandizing |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
Most of us probably know this, but cantilever mounted engine pressure senders is
bad practice, steel or brass. I have personally seen steel ones break.
Tim
> On Feb 5, 2014, at 12:25 PM, "Robert L. Nuckolls, III"
wrote:
>
>
>
>> Robert, If I remember correctly, the fitting was brass. Broke off just about
flush with the oil pump housing. Which is right where the maximum vibrational
stress would have been applied.
>
> Bingo . . .
>
>
> Bob . . .
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Electrical architecture with aux battery |
| From: | "user9253" <fransew(at)gmail.com> |
Bob,
I had looked at Z-10/8 but neglected to notice that your circuit uses one less
switch than mine. I should have known better than to try and improve on your
architecture. :D
Thanks for the reply.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418143#418143
________________________________________________________________________________
| Subject: | Re: Electrical architecture with aux battery |
| From: | "user9253" <fransew(at)gmail.com> |
When the alternator is off or has failed, the extra switch in my circuit would
allow powering the E-bus by only one battery at a time. I do not know if that
is an advantage or not. The more complicated a system is, the greater the chance
for pilot error.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418144#418144
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Teaching vs. Propagandizing |
At 03:04 PM 2/5/2014, you wrote:
>
>Most of us probably know this, but cantilever mounted engine
>pressure senders is bad practice, steel or brass. I have personally
>seen steel ones break.
>Tim
Yeah, those threads do offer a powerful stress
riser. Coming off a crankcase with a low mass,
soft overhang is probably never wrong.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Electrical architecture with aux battery |
At 04:17 PM 2/5/2014, you wrote:
>
>Bob,
> I had looked at Z-10/8 but neglected to notice that your circuit
> uses one less switch than mine. I should have known better than to
> try and improve on your architecture.
Don't know that it won't happen yet . . .
but had you not exercised the idea it's
comparative value would never have been
tested. Good job.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Electrical architecture with aux battery |
At 04:44 PM 2/5/2014, you wrote:
>
>When the alternator is off or has failed, the extra switch in my
>circuit would allow powering the E-bus by only one battery at a
>time. I do not know if that is an advantage or not. The more
>complicated a system is, the greater the chance for pilot error.
>Joe
That's a point to ponder . . . I'm still mulling
over light weight, no maintenance 'band aids'
to manage the brown-out, reboot problem.
Bob . . .
________________________________________________________________________________
| From: | Robert Borger <rlborger(at)mac.com> |
| Subject: | Some data points and pictures from my Rotax 91X School |
Bob & others out there in aeroelectric land,
I have some pictures from the Rotax 91X school I attended back in 2006. They are posted on my Europa build web site. You can go directly to the school pictures with this URL: http://www.europaowners.org/main.php?g2_itemId=64472
The first set of pictures of a piston/con-rod are from that engine in which the
gentleman reversed the in/out fittings to the oil reservoir.
The next set of pictures are of the engine which had the oil pressure sender mounted
out on the extension to allow for a pressure switch. You can see the broken
brass fitting in the housing of the oil pump, a couple pictures of the holes
in the crankcase that the thrown rods made and an overview of the engine.
Which is now the demo engine used in the course.
As I said, I dont know if the engine seized in 10 seconds or 10 minutes, but Dean
said that if you interrupt the lubrication of the Rotax 91X engine it will
usually seize like that in 10 to 30 seconds. It does not tolerate loss of lube
at all well. And Im not going to test it on my engine. You can have a total
loss of the coolant and the engine will continue to run and will usually get
you to a safe landing at a reasonably close airstrip. It may never run again
after it gets you there, but it will get you there. You loose oil pressure and
you better find a flat spot quick because the engine is going to stop very
soon.
The Rotax 91X engine has much more in common with motor cycle engines than it does
with your normal Lycoming or Continental. The 914 turbo is 74 cu.in. and
produces 115 HP @ 5800 rpm. It is recommended that you limit this power setting
to 5 minutes max on take off. It uses a gearbox with a 2.43:1 gear ratio to
drive the propeller. The gearbox has a slipper clutch to protect the engine
in case of a prop strike. Because the engine and gearbox share the lube system
special oil is required. Most of the recommended oils are motorcycle oils.
But Shell does make an oil specifically for the Rotax 91X engine. The engine
has a dual Capacitive Discharge ignition, no mags. Normal operating range of
the engine is 5000 to 5500 rpm and you must keep the idle above 1400 rpm, preferably
above 1800 if you can. This saves wear on the gearbox. It has air cooled
cylinders and liquid cooled heads. It is a dry sump engine with separate
oil reservoir and oil cooler. Oil is returned from the engine directly to the
reservoir. From the reservoir it goes through the cooler on its way to the
oil pump. Purge the oil system after every oil/filter change. Never turn the
prop backward more than half a turn or you stand a chance of ingesting air into
the oil system and into the hydraulic valve lifts. This could trash your
valves. Always burp the engine before starting. (Open the oil reservoir, turn
the prop forward slowly to get compression on each cylinder, continue till all
the residual oil has been forced from the crank case into the reservoir. You
will get a distinct gurgle or burp when all the oil is back in the reservoir.)
This allows an accurate determination of the actual oil in the system and provides
some oil into the engine so you dont get a dry start. It has dual carburetors
which must be balanced for the engine to run smoothly. When the carbs
are properly balanced, the engine is extremely smooth with almost no vibration.
Almost like an electric motor.
All in all, it is a very good little engine. Lots of power for the size and weight
of the engine. I dont think anything out there can match the power to installed
weight ratio. A very efficient engine with a fuel consumption of about
4.5 gph at a 130 kt cruise in my Europa tri-gear. 5.0 gph will get you to 140
kts. You just can not treat it like your daddys Ly/Co. If you do, you will
probably hurt it.
I HIGHLY-HIGHLY recommend anyone flying behind a Rotax 91X engine attend one of
the Rotax operators schools. They are available from several Rotax shops in
the US and Canada.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs).
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger(at)mac.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Change of business model . . . |
I was running short on several commodities and
checked back on how long the last replenishments
took to clear the shelves. It appears that I
could really use that cash and shelf space to
better advantage.
Back when Dr. Dee and I started merchandising
our work product and that of others, 50% of
our inventory rolled over about every 90 days.
90% in 180 days or less.
Now the roll-over is 3 to 4 times longer.
For low volume manufacturing to work at all,
it needs to be part of a larger stable of
activities that rolls inventory faster.
Before Dr. Dee finished her graduate work and got
a better job than I had . . . she took care
of most of the day-to-day activities on the
merchandising side. But she's busy with a
new job and my 'retirement' has been less than
free of opportunities to do what I do best.
As of this evening, I've closed the manufacturing
operations for the AeroElectric Connection. Return
on investment for the hammer-n-tongs operation is
poor compared to the writing/teaching/consulting
activities that have little overhead.
I'll continue to do the fun stuff (AeroElectric
List and seminars), get back on Revision 13
to the book, write for Kitplanes and exploit
some opportunities on the TC side of the house
as well.
I'm looking for a manufacturing operation that
would like to add current AEC original
designs to their stable along with a half dozen in
the wings that are stagnant simply because I
don't own/run a factory.
After current commitments are fulfilled, the
mechanism by which future product developments
are actualized will have to happen in somebody
else's shops.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Change of business model . . . |
| From: | "jhausch" <jimhausch(at)gmail.com> |
Bob,
This is a very interesting development. I expect this thread to go on for a while....
I work in distribution/sales for industrial automation. Occasionally we find ourselves
in a situation where a standard product does not fit the customer need,
so we'll design a little kit or combine some products and accessories together
to meet the customers' needs. Usually those are one-off events; however,
we sometimes find ourselves in non-ideal situations. Example 1: the customer
either buys one or two every year for many years; small batch builds not being
very profitable. Example 2: the customer buys many 10s or 100s and we find ourselves
building kits more than selling new stuff.
Your situation in some ways reminds me of those challenges.
I just visited aeroelectric.com and could not find a listing of these items. I
thought it might be under "Catalog of Products and Services", but I only see
your publications there along with another note about the sale of the business.
Is there a list / catalog of your many "solutions"?
Regarding the business sale.... do you want to sell the designs as a "lot", license
the designs to a third party, license some designs and still manufacture
some designs and only outsource distribution, etc, etc?
Perhaps you're waiting to see what the post/pronouncement brings...
I don't think I am the right man for the job, but I though fleshing out the discussion
a bit would be beneficial for all.
Regards,
Jim
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418178#418178
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | engine pressure senders installation |
Tim
So, what is the way to mount engine pressure senders not cantilevered?
Carlos
At 03:04 PM 2/5/2014, you wrote:
Most of us probably know this, but cantilever mounted engine pressure
senders is bad practice, steel or brass. I have personally seen steel
ones break.
Tim
________________________________________________________________________________
| From: | Werner Schneider <glastar(at)gmx.net> |
| Subject: | Re: engine pressure senders installation |
via a flexible hose and the pressure sensors on he FW ( I use the T bar
from Van's to mount them, advantage is I can have a pressure sensor plus
a switch on the same hose for oil pressure. SHould have somewhere some
pictures from my Glastar
On 06.02.2014 16:45, Carlos Trigo wrote:
>
> Tim
>
> So, what is the way to mount engine pressure senders not cantilevered?
>
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | engine pressure senders installation |
Hi Werner
Well, that one I know, I've used it in the RV-9A and also the -10, but the
senders are also cantilever mounted in the T bar ... I know that the T bar
will not shake as the engine itself, but there are also cantilevered, and
can break as well
Carlos
-----Mensagem original-----
De: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] Em nome de Werner
Schneider
Enviada: 6 de fevereiro de 2014 16:00
Para: aeroelectric-list(at)matronics.com
Assunto: Re: AeroElectric-List: engine pressure senders installation
-->
via a flexible hose and the pressure sensors on he FW ( I use the T bar from
Van's to mount them, advantage is I can have a pressure sensor plus a switch
on the same hose for oil pressure. SHould have somewhere some pictures from
my Glastar
On 06.02.2014 16:45, Carlos Trigo wrote:
> -->
>
> Tim
>
> So, what is the way to mount engine pressure senders not cantilevered?
>
________________________________________________________________________________
| Subject: | Re: engine pressure senders installation |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
Hi Carlos
Obviously they have to be installed cantilevered, just don't mount them to t
he vibrating engine.
Remote mount them with a block like this Aircraft spruce part, 04-00318, mou
nted on the firewall, run -3 hose to it with a restrictor fitting at the eng
ine to restrict flow if there is a hose failure or fire. This for oil and fu
el pressure.
Tim
> On Feb 6, 2014, at 7:45 AM, "Carlos Trigo" wrote:
>
c.pt>
>
> Tim
>
> So, what is the way to mount engine pressure senders not cantilevered?
>
> Carlos
>
>
> At 03:04 PM 2/5/2014, you wrote:
>
>
> Most of us probably know this, but cantilever mounted engine pressure
> senders is bad practice, steel or brass. I have personally seen steel
> ones break.
> Tim
>
>
>
>
>
>
>
>
==========================
=========
==========================
=========
==========================
=========
==========================
=========
>
>
>
________________________________________________________________________________
| From: | Werner Schneider <glastar(at)gmx.net> |
| Subject: | Re: engine pressure senders installation |
Carlos, mine are vertical so much different scenario, and the vibration
level is magnitudes less then directly on the engine housing. You could
mount it on the hose only and then fix the sensor by a clamp around the
sensor housing that is the least stress on them.
Cheers Werner
On 06.02.2014 17:23, Carlos Trigo wrote:
>
> Hi Werner
>
> Well, that one I know, I've used it in the RV-9A and also the -10, but the
> senders are also cantilever mounted
________________________________________________________________________________
| Subject: | Re: engine pressure senders installation |
| From: | Jared Yates <email(at)jaredyates.com> |
I put a large adel clamp around my oil pressure sender, actually two of
them. Then those adel clamps are bolted to smaller clamps that go around
two nearby engine mount tubes. As I understand the term cantilevered, I
would say that mine is not.
On Thu, Feb 6, 2014 at 1:08 PM, Werner Schneider wrote:
> >
>
> Carlos, mine are vertical so much different scenario, and the vibration
> level is magnitudes less then directly on the engine housing. You could
> mount it on the hose only and then fix the sensor by a clamp around the
> sensor housing that is the least stress on them.
>
> Cheers Werner
>
>
> On 06.02.2014 17:23, Carlos Trigo wrote:
>
>> trigo(at)mail.telepac.pt>
>>
>> Hi Werner
>>
>> Well, that one I know, I've used it in the RV-9A and also the -10, but the
>> senders are also cantilever mounted
>>
>
>
________________________________________________________________________________
| Subject: | Re: engine pressure senders installation |
| From: | Robert Borger <rlborger(at)mac.com> |
Carlos,
You can see how I did it at: http://www.europaowners.org/main.php?g2_itemId=67636
The first 11 pictures show how I did a remote mount of the oil pressure sender.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs).
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
3705 Lynchburg Dr.
Corinth, TX 76208-5331
Cel: 817-992-1117
rlborger(at)mac.com
On Feb 6, 2014, at 9:45 AM, Carlos Trigo wrote:
Tim
So, what is the way to mount engine pressure senders not cantilevered?
Carlos
________________________________________________________________________________
| Subject: | Re: IVO Prop current limiter |
| From: | "kfav8r" <kfav8r(at)outlook.com> |
Hey guys,
I built Bob's current limiter for my IVO prop. My first attempt at it did not
work. It seemed to have an issue similar to that reported by Mike Welch some
time ago. As soon as I hit the switch in either direction, the motor would
turn very briefly, then the yellow light would come on.
I could not figure out where I'd gone wrong, so I built a new circuit from scratch.
My second attempt seems to work properly, although I'm still building and
my prop is not assembled. With the second circuit, the motor turns normally
in both directions. To test the cut-off, I shorted the leads that would normally
go to the motor. In that configuration, the yellow LED immediately turns
on, and the breaker does not trip.
It will be a little while before I can test it with the propeller assembled.
Bob, this is such a terrific addition to the IVO IFA prop. I greatly appreciate
you designing this and making it available. Thanks also to Dennis for his
involvement in making it happen.
Doug Garland
Norman, OK
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418213#418213
________________________________________________________________________________
| Subject: | Re: engine pressure senders installation |
| From: | Tim Andres <tim2542(at)sbcglobal.net> |
Hi Werner, with respect, it is NOT a much different scenario. Its orientatio
n makes no difference, it's a cantilevered mounted sensor no matter where or
how you mount it. It's the mass vibrating on the end of the threaded fittin
g that may cause the failure.
If you support it like suggested with an Adel clamp that may work, but the c
orrect fix (and good practice) is to remote mount it somewhere other than on
the engine.
Tim
>> Werner Schneider>
>>
>> Carlos, mine are vertical so much different scenario, and the vibration l
evel is magnitudes less then directly on the engine housing. You could mount
it on the hose only and then fix the sensor by a clamp around the sensor ho
using that is the least stress on them.
>>
>> Cheers Werner
>>
>>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: IVO Prop current limiter |
At 03:12 PM 2/6/2014, you wrote:
>
>Hey guys,
>
>I built Bob's current limiter for my IVO prop. My first attempt at
>it did not work. It seemed to have an issue similar to that
>reported by Mike Welch some time ago. As soon as I hit the switch
>in either direction, the motor would turn very briefly, then the
>yellow light would come on.
>
>I could not figure out where I'd gone wrong, so I built a new
>circuit from scratch. My second attempt seems to work properly,
>although I'm still building and my prop is not assembled. With the
>second circuit, the motor turns normally in both directions. To
>test the cut-off, I shorted the leads that would normally go to the
>motor. In that configuration, the yellow LED immediately turns on,
>and the breaker does not trip.
>
>It will be a little while before I can test it with the propeller assembled.
>
>Bob, this is such a terrific addition to the IVO IFA prop. I
>greatly appreciate you designing this and making it
>available. Thanks also to Dennis for his involvement in making it happen.
Send me your assembly and let me stroke it
on the bench with a 'scope attached. This
is one of several products I'm hoping will
come to the market after the new AeroElectric
'team' is assembled. I've had offers to
discuss options from several people. In
the mean time, we need to see if a fine-tuning
of circuit constants is called for.
Bob . . .
________________________________________________________________________________
| From: | dlj04 <dlj04(at)josephson.com> |
| Subject: | Connectors and factories |
Bob,
As someone who runs a small electronics factory I can sympathize with
your decision not to continue doing that. There are a thousand trivial
things you have to do every day that impact your bottom line, your
ability to sleep well, and in the OBAM business, more serious consequences.
I'm building a CH750 and just this week have been pondering the problem
mentioned with the Ray Allen trim servo wires. There are other
disassembly points too like lights and gauge senders in the wing, so I
would like to choose one type and stick to it. Maybe we can kick this
around for a bit.
While I would like to use a standard connector, preferably mil standard
like the old MIL-DTL-5015 ("MS connector") they are just too bulky and
heavy. I really would rather not use a proprietary sole-source connector
like the Switchcraft EN but if I'm going to choose something sole source
I would want one that's in common use.
I'm considering two connector families. One is weatherproof automotive
connectors like the Delphi Weather Pack. The other is a lightweight
plastic variant of a military round connector, like the AMP CPC series.
Weather Pack is available in 1 to 6 and 22 contacts, and seems to be a
well proven system, but seems a little bulky.
Comments?
________________________________________________________________________________
| From: | Werner Schneider <glastar(at)gmx.net> |
| Subject: | Re: engine pressure senders installation |
Tim,
mine are mounted remote on the Firewall (which indirectly is written in
my posting (vibration level.....)), directly on the engine IS a bad idea.
Werner
On 06.02.2014 23:06, Tim Andres wrote:
> Hi Werner, with respect, it is NOT a much different scenario. Its
> orientation makes no difference, it's a cantilevered mounted sensor no
> matter where or how you mount it. It's the mass vibrating on the end of
> the threaded fitting that may cause the failure.
> If you support it like suggested with an Adel clamp that may work, but
> the correct fix (and good practice) is to remote mount it somewhere
> other than on the engine.
>
> Tim
>
>
>> Werner Schneider>
>>
>>
>> Carlos, mine are vertical so much different scenario, and the
>> vibration level is magnitudes less then directly on the engine
>> housing. You could mount it on the hose only and then fix the
>> sensor by a clamp around the sensor housing that is the least
>> stress on them.
>>
>> Cheers Werner
>>
>>
>> *
>> *
> *
>
>
> *
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: Connectors and factories |
At 07:39 PM 2/6/2014, you wrote:
Bob,
As someone who runs a small electronics factory I can sympathize with
your decision not to continue doing that. There are a thousand
trivial things you have to do every day that impact your bottom line,
your ability to sleep well, and in the OBAM business, more serious
consequences.
Agreed . . . but it's not that the production tasks were
demeaning or debilitating. It wasn't even a decision
driven so much by economics . . . had my product flow
been say 100x larger and I was running a profitable
factory, it still wouldn't have made much sense.
I've been reviewing the ideas offered by the likes of
Adam Smith who spoke of the value and 'rightness' of
division of labor and spontaneous organization. An
economist Leonard Read spoke to these ideas most
elegantly in his essay "I Pencil" about 60 years
ago:
http://tinyurl.com/me3q3hj
http://tinyurl.com/mmlbv8p
The point I have belatedly acknowledged that in spite
of all the hats I can wear, it makes best sense
to take on those efforts where my time and talents
move the project along most efficiently. I.e. it
makes no sense for the cobbler to raise corn,
feed cattle, butcher them for hides and tan the
leather to make shoes. There are people who
do these ancillary tasks better than he can
and he doesn't even need to supervise them!
So my quest is to seek out a combination of
wearers of hats that compliment each other.
I'm building a CH750 and just this week have been pondering the
problem mentioned with the Ray Allen trim servo wires. There are
other disassembly points too like lights and gauge senders in the
wing, so I would like to choose one type and stick to it. Maybe we
can kick this around for a bit.
While I would like to use a standard connector, preferably mil
standard like the old MIL-DTL-5015 ("MS connector") they are just too
bulky and heavy. I really would rather not use a proprietary
sole-source connector like the Switchcraft EN but if I'm going to
choose something sole source I would want one that's in common use.
I'm considering two connector families. One is weatherproof
automotive connectors like the Delphi Weather Pack. The other is a
lightweight plastic variant of a military round connector, like the
AMP CPC series. Weather Pack is available in 1 to 6 and 22 contacts,
and seems to be a well proven system, but seems a little bulky
Your perceptions are correct but lets consider
the return on investment for the 'ideal solution'.
There are some folks who make very rugged yet
tiny connectors suited to the task. One in
particular is LEMO
[]
who joins up bundles of wires in a rugged,
water tight connector about 1/2" in diameter.
I've seen these in the catalogs for years but
didn't cross swords with one until a couple
years ago when a device I had to talk to
came already fitted with a LEMO connector.
We had to come up with a mate and get it
installed on the end of a 4-wire bundle. By
the time we tracked down sources for and
purchased the mating connector and tools,
we probably had 2,000 dollars of labor
and purchases invested in the task. Too
late in a meeting weeks before first flight
I blurted out, "Lets cut the damned thing
off, go to the warehouse and get $50 worth
of connectors out of stock that install with
tools we already have!"
Everybody smiled and nodded except the program
manager who had already expended the $2K
and wasn't willing to pitch it in favor of
moving the project forward by about a week.
This is a prime example for loss of spontaneous
organization and focus on design goals.
What are your concerns for mating those itty-
bitty actuator wires to the ship's systems?
What are the consequences for say, inadvertent
disconnect on a dark-n-stormy night flight
over Mount Doom?
Is the airplane likely to be stuck in a condition
so far out of trim that it's un-manageable with
elevated risks to aluminum and bone?
How many times over the lifetime of the airplane
do you expect to open this connection for maintenance
or replacement of the actuator? By what
percentage of total task would labor go up if
those wires were simply soldered together and
heat-shrinked?
I think well considered answers to those
questions will form the basis for a practical
selection of a connector for the task.
I used to commiserated with my chief scientist
at Beech about 'thousand dollar meetings' . . .
10 people sitting around a table for an hour
to arrive at some decision . . . and then
walking out of the meeting no closer to a
solution than when we walked in . . . or
perhaps having burdened our work order with
a $1000 decision on a $50 part.
How can we free up some hours for our readers
to go buck a few more rivets as opposed to
getting wrapped around the decision axle on
the particular harness connector?
Adam Smith would approve . . .
Bob . . .
________________________________________________________________________________
| From: | Emil Sr <papa11(at)centurylink.net> |
| Subject: | Re: IVO Prop current limiter |
On 2/6/2014 4:12 PM, kfav8r wrote:
>
> Hey guys,
>
> I built Bob's current limiter for my IVO prop. My first attempt at it did not
work. It seemed to have an issue similar to that reported by Mike Welch some
time ago. As soon as I hit the switch in either direction, the motor would
turn very briefly, then the yellow light would come on.
>
> I could not figure out where I'd gone wrong, so I built a new circuit from scratch.
My second attempt seems to work properly, although I'm still building
and my prop is not assembled. With the second circuit, the motor turns normally
in both directions. To test the cut-off, I shorted the leads that would
normally go to the motor. In that configuration, the yellow LED immediately
turns on, and the breaker does not trip.
>
> It will be a little while before I can test it with the propeller assembled.
>
> Bob, this is such a terrific addition to the IVO IFA prop. I greatly appreciate
you designing this and making it available. Thanks also to Dennis for his
involvement in making it happen.
>
> Doug Garland
> Norman, OK
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=418213#418213
>
> Hi Bob if you still have any of the limiter kits available I would like to have
one thanks Emil Radtke
>
>
________________________________________________________________________________
| Subject: | Re: Change of business model . . . |
| From: | "eschlanser" <eschlanser(at)yahoo.com> |
Too bad for me. I had been pondering which size and style of avionics ground bus
to order. Hopefully, another manufacturer will soon provide the AEC parts. If
there is going to be a delay before those parts become available, will you provide
some guidance on a bill of materials and directions on a way to DIY? As
a workaround, would the connections to the avionics bus be able to go straight
to the instrument panel ground bus or would there be a problem with it? 12 V
system, Z-13/8, GNS430W, GTX327, PM3000, GRT HXr efis, EIS 4000, dual magnetos.
Regards, Eric
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418284#418284
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)aeroelectric.com> |
| Subject: | Re: IVO Prop current limiter |
>>Hi Bob if you still have any of the limiter kits available I would
>>like to have one thanks Emil Radtke
it was never 'kitted' . . . only a schematic offered.
several have been built and a few folks have experienced
difficulties. We'll track down the 'glitches' and
apply any necessary/useful refinements.
I have a board laid out from which this device can
be fabricated and a housing to enclose it. It will
be one of several products to spin up from the
selected manufacturing partner for the AeroElectric
Connection brand . . .
But in the mean time, see
http://tinyurl.com/ny5jhgr
Bob . . .
________________________________________________________________________________
| Subject: | Mac's theory defies the laws a physics |
| From: | "user9253" <fransew(at)gmail.com> |
Mac McClellan's theory seems to defy the laws a physics: http://goo.gl/VaZ4MS
I think that he is wrong. Of course an airplane will lose airspeed in a level
turn unless power is added, because part of the lift that was used to maintain
altitude must be used to "lift" the airplane around a turn, overcoming inertia.
I think that the only force the earth exerts on an airplane is gravity, no
matter its relative motion.
This is not electrically related. But there are some pretty smart people who lurk
on the AeroElectric List. It will be interesting to read their opinions.
Joe
--------
Joe Gores
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=418301#418301
________________________________________________________________________________
| From: | Bill Watson <Mauledriver(at)nc.rr.com> |
| Subject: | Re: Essential Bus question |
Sorry about adding to this rather old discussion but I've been away for
awhile.
I finished my RV10 in 2011 which means that I designed my electrical
system and panel around 2008 for a 2009-2010 build.
I have 3 GRT HX EFISs - 2 aimed at the pilot, 1 at the passenger. They
supply synthetic vision, moving map, weather, traffic and a complete
suite of engine stats. No light weight backup batteries can be
configured at the factory with these systems. These screens have no
integral on/off switch. I chose not to add any switches or operable
CBs. They come on with the master and will usually reboot when my IO540
cold starts with a single, fresh PC 680 battery.
The GPS WAAS smarts for this system are supplied by a G430W.
I am a serious traveler with this machine and practically all flight are
on IFR plans. My normal routine for all flights is to file my plan
using Foreflight on an iPad. Whenever at an airport with clearance
delivery, or when departing into IMC conditions, I obtain my clearance
on the ground, before engine start, and enter it into my iPad and then
into my G430. Many times in congested areas, this entry is followed by
no small amount of study. As my aging mind continues to fog over, I'm
finding that the study time grows.
Here's the challenge on G430 based panels; it loses any entered flight
plan when powered off. An engine start that reboots my GRTs, reboots my
G430.
An acute challenge on 430 based panels when used for flights around the
Wash DC area or for flights along Florida's Atlantic coast is that the
G430 does not know what a Victor airway is. These are flights I make
regularly and clearances in these areas typically still include Victor
airways. So in the routine described above, entry into the iPad
generates the necessary waypoints to any Victor airways. Accurate entry
of these waypoints into the G430 is important and there's no way I want
to redo the work.
As Bob would put it, this is the 'kitchen sink' I choose to fly with. I
think it's fantastic and works very very well for me. It's now a well
grooved swing. The inability of some (e.g. Bob, not necessarily you
Kelly but I did choose to respond to your post) to 'get' this
requirement for this pilot, seems to me is just an inability to see past
old school experience or perhaps your current pleasure flying routines.
I have a Z-14 with 2 batts, 2 alts, and 2 buses and I REALLY like it. I
bring up the 'kitchen sink' on one battery, get my clearances, enter
them into my systems, study my departure plan when doing complicated
airspace or low IMC departures and then bring up the 2nd battery bus,
cross link them and start my engine. Everything stays up. Before
takeoff I've learned, per Bob, to de-link the buses and off I go.
Per Bob, I've eliminated any semblance of an avionics bus, extra
switches or CBs. After a few operational adjustments and refinements
(Thanks Bob!), the 'overkill' of a Z-14 has given me exactly what I
think I need.
I need my avionics on before start and I have a big kitchen sink that
takes care of the dishes just like I want them done. So can we please
stop dismissing this approach to equipping and traveling in our very
fine OBAM aircraft within the user fee free ATC system we have? Some
of us do it every day because that's the way we choose to roll.
PS: I've been out of the loop island hopping the Bahamas. Recommend it
highly. What an adjustment flying VFR from place to place! However, I
still used the same procedures because that's what standard procedures
are for.
Bill "It's pretty darn good in the Bahamas" Watson
N215TG
On 2/2/2014 7:14 PM, Kelly McMullen wrote:
>
>
> Virtually all glass have their own light weight backup batteries so do
> not have startup brown out issues unless no backup battery is installed.
> I see very little value in being able to turn on GPS prior to start.
> While one needs engine instrumentation prior to and during start, one
> does not need avionics on.
> Of course newer avionics that allow faster input of flight plans than
> the 430 help, if that is the reason for turning on 430 before start.
>
________________________________________________________________________________
| Subject: | Re: Mac's theory defies the laws a physics |
| From: | Robert Borger <rlborger(at)mac.com> |
Gents,
I like Mac most of the time, but here I believe hes all wet.
First, he bases his premise on a false assumption; that ground speed affects air
speed. Wrong. Ground speed has zero effect on airspeed. Its just the opposite.
Airspeed is the operative mechanism and ground speed just follows.
>From then on he wades into the age old down wind turn and I dont even want to
go there.
Blue skies & tailwinds,
Bob Borger
Europa XS Tri, Rotax 914, Airmaster C/S Prop (50 hrs).
Little Toot Sport Biplane, Lycoming Thunderbolt AEIO-320 EXP
January 13, 2014 - February 07, 2014
AeroElectric-Archive.digest.vol-mf