AeroElectric-Archive.digest.vol-hr
March 04, 2008 - March 23, 2008
On all other drawings it appears the E-BUS normal feed is directly off the
Main PWR Dist Block binding post (not a breaker) thru a diode.
Is there a reason for the different setup on the Z-19 series?
Regards,
Mark Sletten
________________________________________________________________________________
| Subject: | New EMAG and PMAG Wiring question |
| From: | "Matt Prather" <mprather(at)spro.net> |
This idea may have been hashed/rehashed enough, but I can't resist putting
in my two cents..
Bob has said (and others have agreed) that it makes sense to design system
architecture to comfortably deal with single failures gracefully. The
odds of having multiple component failures on a single flight is
comfortably unlikely, given good component selection and best practices
installation/implementation methods. This is how to have low cost fault
tolerance.
In my opinion, the P-mags are best powered from the main bus. Their
operation on internal power can be checked regularly (once per flying
day?). If an in-flight situation develops that warrants shutting down the
main bus (electrical fire, main alternator failure, etc.), I think you
can be confident that both p-mags will continue to function on internal
power. No sweat. This is one of the beauties of the P-mags - they allow
for more easy fault tolerance. I believe this is part of the rationale of
the recommended wiring configuration.
You say, "you like the idea of running them (the P-mags) from the always
hot battery bus." Can you explain why you like the idea of this?
Regards,
Matt-
>
>
>
>>
>>Thanks Bob. I forgot to mention that I have 2 PMAGS and like the idea of
>>running them from the always hot battery bus.
>
> It's your airplane. I'm only echoing a design philosophy
> that's recommended by the manufacturer supported by
> a elegant assemblage of simple-ideas. You'll need to
> do something different with respect to the switching.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | <dsvs(at)ca.rr.com> |
| Subject: | New EMAG and PMAG Wiring question |
Matt and Bob. Thanks for the replies. I guess this was just a left over idea
from Bob's original design. Both of my PMAGs will be powered from the main bus.
Don
---- Matt Prather wrote:
>
> This idea may have been hashed/rehashed enough, but I can't resist putting
> in my two cents..
>
> Bob has said (and others have agreed) that it makes sense to design system
> architecture to comfortably deal with single failures gracefully. The
> odds of having multiple component failures on a single flight is
> comfortably unlikely, given good component selection and best practices
> installation/implementation methods. This is how to have low cost fault
> tolerance.
>
> In my opinion, the P-mags are best powered from the main bus. Their
> operation on internal power can be checked regularly (once per flying
> day?). If an in-flight situation develops that warrants shutting down the
> main bus (electrical fire, main alternator failure, etc.), I think you
> can be confident that both p-mags will continue to function on internal
> power. No sweat. This is one of the beauties of the P-mags - they allow
> for more easy fault tolerance. I believe this is part of the rationale of
> the recommended wiring configuration.
>
> You say, "you like the idea of running them (the P-mags) from the always
> hot battery bus." Can you explain why you like the idea of this?
>
>
> Regards,
>
> Matt-
>
>
> >
> >
> >
> >>
> >>Thanks Bob. I forgot to mention that I have 2 PMAGS and like the idea of
> >>running them from the always hot battery bus.
> >
> > It's your airplane. I'm only echoing a design philosophy
> > that's recommended by the manufacturer supported by
> > a elegant assemblage of simple-ideas. You'll need to
> > do something different with respect to the switching.
> >
> > Bob . . .
> >
> >
> >
> >
> >
> >
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Peter Pengilly" <peter(at)sportingaero.com> |
I am changing the engine on my One Design. I am removing an O-320-E3D
and fitting an IO-360-B1B (180 hp regular compression). I will be
fitting an Odyssey 17ah battery. The 320 has a B&C starter that has been
used for around 100 hours, it also has 122 teeth on the starter ring.
The 360 has a Sky-tec PM starter (and is brand new and is painted bright
red) and a 149 tooth starter ring. The airplane is fitted with a B&C
SD-8 generator so cannot guarantee a fully charged battery every time.
I have heard stories that permanent magnet starters and Odyssey
batteries do not get on, and that starting is often slow, especially the
first couple of blades. All things being equal I would swap the starter
and the starter ring, but that's not possible as the part numbers of the
starter rings between the two engines are different - I don't know the
precise differences, and I would have to paint the old starter ring. To
be able to use the B&C starter on the new engine B&C recommend I change
out the ring gear, or return the starter for overhaul ($310 plus
shipping from Europe). And will have to change something on the old
engine.
So my questions is, am I right to be concerned about the long term
abilities of a Skytec PM starter and the Odyssey battery to provide
reliable starting? Does anyone have any experience with this
combination?
Regards, Peter
________________________________________________________________________________
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
there are many Io360's and Skytec PM starters used mainly on Vans aircraft.
..In fact the Odyssy is that standard supplied battery...Never heard of any
one having an issue...Mine works just fine.
Now, Skytecs will break if they suffer kickback, My emags avoid this by all
owing three blades to pass through before firing...This can be over ridden
if you ever had to hand prop.
But generally the odyssy/Skytech combo has a long relaible track record.
Frank
RV7a Io360
________________________________
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectr
ic-list-server(at)matronics.com] On Behalf Of Peter Pengilly
Sent: Tuesday, March 04, 2008 2:20 PM
Subject: AeroElectric-List: Starter Choice
I am changing the engine on my One Design. I am removing an O-320-E3D and f
itting an IO-360-B1B (180 hp regular compression). I will be fitting an Ody
ssey 17ah battery. The 320 has a B&C starter that has been used for around
100 hours, it also has 122 teeth on the starter ring. The 360 has a Sky-tec
PM starter (and is brand new and is painted bright red) and a 149 tooth st
arter ring. The airplane is fitted with a B&C SD-8 generator so cannot guar
antee a fully charged battery every time.
I have heard stories that permanent magnet starters and Odyssey batteries d
o not get on, and that starting is often slow, especially the first couple
of blades. All things being equal I would swap the starter and the starter
ring, but that's not possible as the part numbers of the starter rings betw
een the two engines are different - I don't know the precise differences, a
nd I would have to paint the old starter ring. To be able to use the B&C st
arter on the new engine B&C recommend I change out the ring gear, or return
the starter for overhaul ($310 plus shipping from Europe). And will have t
o change something on the old engine.
So my questions is, am I right to be concerned about the long term abilitie
s of a Skytec PM starter and the Odyssey battery to provide reliable starti
ng? Does anyone have any experience with this combination?
Regards, Peter
________________________________________________________________________________
| From: | "J. Mcculley" <mcculleyja(at)starpower.net> |
| Subject: | Re: Starter Choice |
Peter,
I have over 500 flight hours on my O-360 with a skytec permanent magnet
starter and not one moment of problem with just an Odyssey 17 AH battery
and a B&C SD-8 permanent magnet alternator.
Jim
----------------------------------------------------------------------------------
Peter Pengilly wrote:
I am changing the engine on my One Design. I am removing an O-320-E3D and
fitting an IO-360-B1B (180 hp regular compression). I will be fitting an
Odyssey 17ah battery. The 320 has a B&C starter that has been used for
around
100 hours, it also has 122 teeth on the starter ring. The 360 has a Sky-tec
PM starter (and is brand new and is painted bright red) and a 149 tooth
starter
ring. The airplane is fitted with a B&C SD-8 generator so cannot
guarantee a
fully charged battery every time.
I have heard stories that permanent magnet starters and Odyssey batteries
do not get on, and that starting is often slow, especially the first couple
of blades. All things being equal I would swap the starter and the starter
ring, but thats not possible as the part numbers of the starter rings
between
the two engines are different I dont know the precise differences, and I
would have to paint the old starter ring. To be able to use the B&C
starter on
the new engine B&C recommend I change out the ring gear, or return the
starter
for overhaul ($310 plus shipping from Europe ). And will have to
change
something on the old engine.
So my questions is, am I right to be concerned about the long term abilities
of a Skytec PM starter and the Odyssey battery to provide reliable
starting?
Does anyone have any experience with this combination?
Regards, Peter
----------------------------------------------------------------------------------
________________________________________________________________________________
| From: | "Steve Sampson" <ssamps(at)gmail.com> |
| Subject: | Re: New EMAG and PMAG Wiring question |
Don _ I have wired my 2 p-mags as follows.
Both are connected via a fuse to the main bus. I have then used two 2-50
switches, one for each mag.
- in the bottom position with the master on, the P-mag was powered, but the
P-lead off.
- in the middle position (and this is the normal flying position) the power
and P-lead is on.
- in the top, momentary position, the power is cut. (To test the self
generation.) The P-lead remains on.
Operating this way the P-mag would see power once the master is on. It would
only loose power from the battery when the engine is running and you switch
to the self generation test. P-mag condone that.
So to test say the RH mag before takeoff, you turn the LH mag's plugs off,
by pushing the switch down from the middle position. It remains powered but
the p-lead is off. You then lift the RH switch. It should keep running if it
is self generating.
It is very close to the e-mag wiring but permits just two switches.
It makes sense to me. Steve.
________________________________________________________________________________
| From: | "Terry Frazier" <fraziernv(at)earthlink.net> |
I'm building an RV7A with one SL-30 radio and inside the wingtip antennae.
I'll probably use the Sport Aircraft design for the antennae. Question is,
can I use a diplexer "backwards" to feed the one VOR with two antenna feeds
to both boost signal and reduce shadowing effects? Would a standard
diplexer work, or would I need something special?
Thanks in advance,
Terry
7A Panel Wiring
________________________________________________________________________________
| From: | "Dr. Andrew Elliott" <a.s.elliott(at)cox.net> |
| Subject: | RG-400 vs. RG-142? |
I know that has been discussed before, but I want to be sure. Are there
any significant downsides to using RG-142 for aircraft antenna
applications where the cable will not be regularly flexed (except for
normal vibration)? I am somewhat leery of using a solid core coax.
Andy Elliott, Mesa, AZ
N601GE (reserved)
601XL/TD, Corvair, building...
________________________________________________________________________________
| From: | "Dawson, Bill" <Bill.Dawson(at)pepperdine.edu> |
You are talking about diversity reception. Google that term and lot's of
things pop up.
I use it a great deal with wireless mics. Go to this website for
starters...
http://www.lectrosonics.com/WPapers-Magazines/ReceptionTechniques/Recepti
onTechniques.htm
The problem is, the antennas can not be tied together as the signal one
picks up will not
be in phase with the other antenna. The result is a reduced signal and
in some cases complete
cancel of the signal.
So how do the dual antenna receivers do it? They constantly sample the
antennas and
*switch* to the antenna with the most signal.
Bill
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com on behalf of Terry
Frazier
Sent: Wed 3/5/2008 7:51 AM
Subject: AeroElectric-List: VOR Diplexer
I'm building an RV7A with one SL-30 radio and inside the wingtip
antennae.
I'll probably use the Sport Aircraft design for the antennae. Question
is,
can I use a diplexer "backwards" to feed the one VOR with two antenna
feeds
to both boost signal and reduce shadowing effects? Would a standard
diplexer work, or would I need something special?
Thanks in advance,
Terry
7A Panel Wiring
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | static system leak check procedure |
I started to do a preliminary static system leak check and noticed that
it only takes about 500 feet of static vacuum to make the ASI read about
100 knots. 10 or 20 thousand feet would peg the ASI pretty firmly. Is
the pitot side subjected to the same vacuum as the static side of the
system to prevent altimeter damage or is that not a concern? It seems
prudent to check for obvious leaks before taking the plane to the radio
shop.
thank you
Ken
________________________________________________________________________________
| From: | "Ralph E. Capen" <recapen(at)earthlink.net> |
| Subject: | Re: static system leak check procedure |
I did a similar test with the ASI removed and its fittings plugged to verify the
integrity of the rest of the system up to 20000ft. Then I put it all back together
and verified the leakdown integrity.
-----Original Message-----
>From: Ken <klehman(at)albedo.net>
>Sent: Mar 5, 2008 2:02 PM
>To: aeroelectric-list(at)matronics.com
>Subject: AeroElectric-List: static system leak check procedure
>
>
>I started to do a preliminary static system leak check and noticed that
>it only takes about 500 feet of static vacuum to make the ASI read about
>100 knots. 10 or 20 thousand feet would peg the ASI pretty firmly. Is
>the pitot side subjected to the same vacuum as the static side of the
>system to prevent altimeter damage or is that not a concern? It seems
>prudent to check for obvious leaks before taking the plane to the radio
>shop.
>thank you
>Ken
>
>
________________________________________________________________________________
| From: | "Peter Pengilly" <peter(at)sportingaero.com> |
Frank & Jim,
Thanks for your advice - do nothing is an option!
Peter
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of J.
Mcculley
Sent: 04 March 2008 23:47
Subject: Re: AeroElectric-List: Starter Choice
Peter,
I have over 500 flight hours on my O-360 with a skytec permanent magnet
starter and not one moment of problem with just an Odyssey 17 AH battery
and a B&C SD-8 permanent magnet alternator.
Jim
------------------------------------------------------------------------
----------
Peter Pengilly wrote:
I am changing the engine on my One Design. I am removing an O-320-E3D
and
fitting an IO-360-B1B (180 hp regular compression). I will be fitting an
Odyssey 17ah battery. The 320 has a B&C starter that has been used for
around
100 hours, it also has 122 teeth on the starter ring. The 360 has a
Sky-tec
PM starter (and is brand new and is painted bright red) and a 149 tooth
starter
ring. The airplane is fitted with a B&C SD-8 generator so cannot
guarantee a
fully charged battery every time.
I have heard stories that permanent magnet starters and Odyssey
batteries
do not get on, and that starting is often slow, especially the first
couple
of blades. All things being equal I would swap the starter and the
starter
ring, but that's not possible as the part numbers of the starter rings
between
the two engines are different - I don't know the precise differences,
and I
would have to paint the old starter ring. To be able to use the B&C
starter on
the new engine B&C recommend I change out the ring gear, or return the
starter
for overhaul ($310 plus shipping from Europe ). And will have to
change
something on the old engine.
So my questions is, am I right to be concerned about the long term
abilities
of a Skytec PM starter and the Odyssey battery to provide reliable
starting?
Does anyone have any experience with this combination?
Regards, Peter
------------------------------------------------------------------------
----------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: RG-400 vs. RG-142? |
>I know that has been discussed before, but I want to be sure. Are there
>any significant downsides to using RG-142 for aircraft antenna
>applications where the cable will not be regularly flexed (except for
>normal vibration)? I am somewhat leery of using a solid core coax.
Then use the stranded version, RG-400.
RG-58 in the lengths we common use for small
airplanes does not present a significant
performance impact. However, the materials
from which RG-58 is made and the technology
behind the design of the coax is now over 60
years old.
See:
http://www.aeroelectric.com/Pictures/Curves/coaxloss1.pdf
Consider a 10' run of coax from GPS receiver
to antenna. RG58 offers an attenuation of about
35db/100'; RG-400/142 is about 24db/100'.
10' runs reduce to 3.5 and 2.4 db for a difference
of 1.3 db . . . delta that is impossible to
observe and difficult to measure at that frequency.
With respect to materials, RG-400/142 are double-
layer, silver-plated shield and fabricated from
modern cousins to Teflon. It's the best we know how
to do . . . today.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Starter Choice |
>I am changing the engine on my One Design. I am removing an O-320-E3D and
>fitting an IO-360-B1B (180 hp regular compression). I will be fitting an
>Odyssey 17ah battery. The 320 has a B&C starter that has been used for
>around 100 hours, it also has 122 teeth on the starter ring. The 360 has a
>Sky-tec PM starter (and is brand new and is painted bright red) and a 149
>tooth starter ring. The airplane is fitted with a B&C SD-8 generator so
>cannot guarantee a fully charged battery every time.
Size of the alternator certainly influences how
well your battery is charged at shutdown. But judicious
stewardship of stored energy from the battery after
to back off the throttle for approach to landing can
go a long way toward mitigating the effects.
From an energy perspective, cranking an engine takes
perhaps 5% of the total energy stored on your battery.
If you use say 20% off the top during descent and
taxi to parking, cranking performance from 100% charge
versus 80% charge would not be terribly noticable.
>
>
>I have heard stories that permanent magnet starters and Odyssey batteries
>do not get on, and that starting is often slow, especially the first
>couple of blades. All things being equal I would swap the starter and the
>starter ring, but that s not possible as the part numbers of the starter
>rings between the two engines are different I don t know the precise
>differences, and I would have to paint the old starter ring. To be able to
>use the B&C starter on the new engine B&C recommend I change out the ring
>gear, or return the starter for overhaul ($310 plus shipping from Europe).
>And will have to change something on the old engine.
>So my questions is, am I right to be concerned about the long term
>abilities of a Skytec PM starter and the Odyssey battery to provide
>reliable starting? Does anyone have any experience with this combination?
This question stands on a whole lot of variables
both in the observed performance of your as-installed
starter/proposed battery -AND- the as-installed/
demonstrated battery of those who would hope to
advise you.
Let's consider another approach that takes advantage
of a demonstrated experiment using your equipment.
What are the risks of leaving the present starter in
place and going ahead with the installation?
EVERY starter system benefits from wound-field
starter motors in terms of cranking under worst
case conditions. However, there are thousands of
PM starters in service where users report satisfactory
performance to their needs.
I'll suggest that if time and costs to get
your new engine installed are to be minimized, there's
little risk in leaving the system configured as you've
described. In fact, I'll suggest there is an advantage
for leaving the configuration alone. You have a
significant task for changing out the engine and getting
everything tight and tuned up. Why not get these tasks
done while being sensitive to starter performance
for the purpose of answering your own question . . .
and then having some experimental data to share
with the rest of us?
Bob . . .
________________________________________________________________________________
| From: | "Bill and Marsha" <docyukon(at)ptcnet.net> |
Question for Bob. I am doing my final wiring checkout on my soon to be
complete Pulsar lll Rotax 912 project. I came across a revision L to
Z16. Question, Was their a specific problem for the change to the
alternator disconnect ckt? and would you recommend changing from version
k to rev. L and why. Thanks Bill
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | static system leak check procedure |
By the way, can somebody explain how is a static leak check performed?
Carlos
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-
> server(at)matronics.com] On Behalf Of Ken
> Sent: quarta-feira, 5 de Maro de 2008 19:02
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: static system leak check procedure
>
>
> I started to do a preliminary static system leak check and noticed that
> it only takes about 500 feet of static vacuum to make the ASI read about
> 100 knots. 10 or 20 thousand feet would peg the ASI pretty firmly. Is
> the pitot side subjected to the same vacuum as the static side of the
> system to prevent altimeter damage or is that not a concern? It seems
> prudent to check for obvious leaks before taking the plane to the radio
> shop.
> thank you
> Ken
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Status of the small strobe wiring experiment. |
Neal's strobe parts have arrived. I've decided to shift
the emphasis to a lab experiment. My good ol' Luna Pro-F
flash light meter died years ago and I've had no good
reason to replace it until now. Just picked up a much
younger replacement off of Ebay.
We'll wire one tube with 15' of 20AWG Beldfoil and the
other with 22AWG twisted trio and see what the difference
is between light output of the two tubes. I'll also get some
waveforms for both the flash-tubes and the 14V DC input
power. We can convert these measurement to total energy
numbers.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
> Question for Bob. I am doing my final wiring checkout on my soon to be
> complete Pulsar lll Rotax 912 project. I came across a revision L to
> Z16. Question, Was their a specific problem for the change to the
> alternator disconnect ckt? and would you recommend changing from version
> k to rev. L and why. Thanks Bill
It's a cleaner way to do it. The previous configuration
will function as advertised but it's better to interrupt
the energy flow as close to the source as possible.
Bob . . .
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
| Subject: | static system leak check procedure |
Carlos, check out the following website...
http://www.kilohotel.com/rv8/rvlinks/ssec.html
Bill B
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Carlos
Trigo
Sent: Wednesday, March 05, 2008 7:16 PM
Subject: RE: AeroElectric-List: static system leak check procedure
-->
By the way, can somebody explain how is a static leak check performed?
Carlos
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-
> server(at)matronics.com] On Behalf Of Ken
> Sent: quarta-feira, 5 de Maro de 2008 19:02
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: static system leak check procedure
>
>
> I started to do a preliminary static system leak check and noticed
> that it only takes about 500 feet of static vacuum to make the ASI
> read about 100 knots. 10 or 20 thousand feet would peg the ASI pretty
> firmly. Is the pitot side subjected to the same vacuum as the static
> side of the system to prevent altimeter damage or is that not a
> concern? It seems prudent to check for obvious leaks before taking the
> plane to the radio shop.
> thank you
> Ken
________________________________________________________________________________
| From: | Rodney Dunham <rdunhamtn(at)hotmail.com> |
| Subject: | RE: "Poor Man's" coax termination with RG-400 |
Since RG-400 has a doulble braid shield, how do I do the "Poor Man's" coax
termination with it?
Braid the two shields as one and crimp on the lug OR ....
Rodney in Tennessee
_________________________________________________________________
Need to know the score, the latest news, or you need your Hotmail=AE-get yo
ur "fix".
http://www.msnmobilefix.com/Default.aspx
________________________________________________________________________________
| From: | "Ralph E. Capen" <recapen(at)earthlink.net> |
| Subject: | static system leak check procedure |
Here's how I did it:
I got a vacuum brake bleeding kit (JC Whitney IIRC) - it has a guage that will
allow you to see an evacuation level and watch it change.
I disconnected my ASI, VSI, and capped off the rest of the static system. The
VSI has a built in leak and the ASI limits your altitude as the airspeed is artificially
induced by the differential pressure.
I plugged one static port and attached the brake bleeder to the other port.
Pump the handle and watch the dial as you pull a vacuum. (I did mine all the way
to 20,000').
Start a stop watch and look for the dial to rotate downward indicating leakdown.
Swap static ports and start over.
I added the ASI and did another test with lower altitude levels to ensure the integrity
of the ASI. Swap static ports and start over.
You're allowed 100'/min IIRC from the regs - I ended up with 150'/hr so I think
I'm OK......
Someone may convince me of the error of my ways and I'll re-do it differently -
but noone's tried yet.
-----Original Message-----
>From: Carlos Trigo <trigo(at)mail.telepac.pt>
>Sent: Mar 5, 2008 7:16 PM
>To: aeroelectric-list(at)matronics.com
>Subject: RE: AeroElectric-List: static system leak check procedure
>
>
>By the way, can somebody explain how is a static leak check performed?
>
>Carlos
>
>
>> -----Original Message-----
>> From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-
>> server(at)matronics.com] On Behalf Of Ken
>> Sent: quarta-feira, 5 de Maro de 2008 19:02
>> To: aeroelectric-list(at)matronics.com
>> Subject: AeroElectric-List: static system leak check procedure
>>
>>
>> I started to do a preliminary static system leak check and noticed that
>> it only takes about 500 feet of static vacuum to make the ASI read about
>> 100 knots. 10 or 20 thousand feet would peg the ASI pretty firmly. Is
>> the pitot side subjected to the same vacuum as the static side of the
>> system to prevent altimeter damage or is that not a concern? It seems
>> prudent to check for obvious leaks before taking the plane to the radio
>> shop.
>> thank you
>> Ken
>
>
________________________________________________________________________________
| From: | "Kevin Horton" <khorton01(at)rogers.com> |
| Subject: | Re: static system leak check procedure |
You can do an acceptable test much more simply than this. The standard (as
described in FAR 23.1325(b)(2)(i)) only calls for enough vacuum to raise th
e
indicated altitude 1000 ft above the altitude of the test site. On my RV-8
,
I put a piece of tape over one static port, and held a piece of rubber hose
against the other static port. I put the other end of the hose in my mouth
,
and sucked until I had increased the altitude more than 1000 ft. I put my
tongue over the end of hose to trap the pressure, and made sure to keep
pushing the other end hard against the static port so no air leaked out
there. The altimeter dropped much less than 100 ft in a minute (the
pass/fail criteria from FAR 23.1325), so my system was OK.
There is no need to disconnect ASI or VSI (assuming you don't introduce
excessive vacuum, which could damage an ASI). In fact, doing it with
instruments removed invalidates the test, as you might introduce a leak whe
n
you put those instruments back into the static system. You really need to
do an end-to-end leak check with the whole static system in the state it
would be when you fly the airplane.
Kevin Horton
On Thu, Mar 6, 2008 at 8:27 AM, Ralph E. Capen
wrote:
> recapen(at)earthlink.net>
>
> Here's how I did it:
>
> I got a vacuum brake bleeding kit (JC Whitney IIRC) - it has a guage that
> will allow you to see an evacuation level and watch it change.
>
> I disconnected my ASI, VSI, and capped off the rest of the static system.
> The VSI has a built in leak and the ASI limits your altitude as the
> airspeed is artificially induced by the differential pressure.
>
> I plugged one static port and attached the brake bleeder to the other
> port.
>
> Pump the handle and watch the dial as you pull a vacuum. (I did mine all
> the way to 20,000').
>
> Start a stop watch and look for the dial to rotate downward indicating
> leakdown. Swap static ports and start over.
>
> I added the ASI and did another test with lower altitude levels to ensure
> the integrity of the ASI. Swap static ports and start over.
>
> You're allowed 100'/min IIRC from the regs - I ended up with 150'/hr so I
> think I'm OK......
>
> Someone may convince me of the error of my ways and I'll re-do it
> differently - but noone's tried yet.
>
> -----Original Message-----
> >From: Carlos Trigo <trigo(at)mail.telepac.pt>
> >Sent: Mar 5, 2008 7:16 PM
> >To: aeroelectric-list(at)matronics.com
> >Subject: RE: AeroElectric-List: static system leak check procedure
> >
> trigo(at)mail.telepac.pt>
> >
> >By the way, can somebody explain how is a static leak check performed?
> >
> >Carlos
> >
> >
> >> -----Original Message-----
> >> From: owner-aeroelectric-list-server(at)matronics.com
> >[mailto:owner-aeroelectric-list-
> >> server(at)matronics.com] On Behalf Of Ken
> >> Sent: quarta-feira, 5 de Mar=E7o de 2008 19:02
> >> To: aeroelectric-list(at)matronics.com
> >> Subject: AeroElectric-List: static system leak check procedure
> >>
> >>
> >> I started to do a preliminary static system leak check and noticed tha
t
> >> it only takes about 500 feet of static vacuum to make the ASI read
> about
> >> 100 knots. 10 or 20 thousand feet would peg the ASI pretty firmly. Is
> >> the pitot side subjected to the same vacuum as the static side of the
> >> system to prevent altimeter damage or is that not a concern? It seems
> >> prudent to check for obvious leaks before taking the plane to the radi
o
> >> shop.
> >> thank you
> >> Ken
> >
> >
> >
> >
> >
> >
________________________________________________________________________________
| From: | "mike humphrey" <mike109g6(at)insideconnect.net> |
| Subject: | Re: RE: "Poor Man's" coax termination with RG-400 |
Rodney,
Bob shows an excellent way to attach BNC connectors on the RG-400. Just
archive aeroelectric.
Mike H 9A/8A
----- Original Message -----
From: Rodney Dunham
To: aeroelectric-list(at)matronics.com
Sent: Thursday, March 06, 2008 7:34 AM
Subject: AeroElectric-List: RE: "Poor Man's" coax termination with
RG-400
Since RG-400 has a doulble braid shield, how do I do the "Poor Man's"
coax termination with it?
Braid the two shields as one and crimp on the lug OR ....
Rodney in Tennessee
-------------------------------------------------------------------------
-----
Need to know the score, the latest news, or you need your
Hotmail=AE-get your "fix". Check it out.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: RE: "Poor Man's" coax termination with RG-400 |
>Since RG-400 has a doulble braid shield, how do I do the "Poor Man's" coax
>termination with it?
>
>Braid the two shields as one and crimp on the lug OR ....
What are you wanting to attach it to? I presume that
since you're talking about "crimp" that you don't
want to install the usual connector.
Here's a technique I've used on all manner of shielded
wires for 50 years. See how this works for you.
http://aeroelectric.com/articles/shldwire/shldwire.html
Bob . . .
________________________________________________________________________________
| From: | Jeff Page <jpx(at)Qenesis.com> |
| Subject: | Re: RG-400 vs. RG-142 |
From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
Consider a 10' run of coax from GPS receiver
to antenna. RG58 offers an attenuation of about
35db/100'; RG-400/142 is about 24db/100'.
10' runs reduce to 3.5 and 2.4 db for a difference
of 1.3 db . . . delta that is impossible to
observe and difficult to measure at that frequency.
With respect to materials, RG-400/142 are double-
layer, silver-plated shield and fabricated from
modern cousins to Teflon. It's the best we know how
to do . . . today.
What do you think about Andrew FSJ1RN-50B Heliax Cable ?
At 150MHz the attenuation is only 2.2 dB/100'
The minimum bend radius is only 1" and it doesn't try to unbend itself
due to the corrugated shield.
It is more expensive of course, plus you need their expensive BNC connectors.
http://www.andrew.com/catalog/product_details.aspx?id=1343
Jeff Page
Dream Aircraft Tundra #10
________________________________________________________________________________
| From: | Rodney Dunham <rdunhamtn(at)hotmail.com> |
| Subject: | RE: "Poor Man's" coax termination with RG-400 |
Bob,
Sorry I didn't explain it very well.
My buddy wants to use RG-400 for his VHF COMM. He has one of those antennas
that has only a Delrin insulator and the end of the antenna is threaded. H
e currently has some old RG-58 which is installed according to the 'Connect
ion, Chapter 13, The "Poor Man's" coax termination in lieu of a BNC connect
or, which is not an option with this antenna.
He was wondering if he should just twist the two layers of (RG-400) braid i
nto one "wire" and crimp on a lug like the previous (RG-58) install. I was
wondering if the outer (RG-400) braid should be trimmed short and only the
inner braid teased out for crimping onto the ground lug. Or does it even ma
tter?
Sorry for the misdirect.
Rodney in Tennessee
_________________________________________________________________
Climb to the top of the charts!-Play the word scramble challenge with sta
r power.
http://club.live.com/star_shuffle.aspx?icid=starshuffle_wlmailtextlink_ja
n
________________________________________________________________________________
| From: | John Morgensen <john(at)morgensen.com> |
| Subject: | Re: Low voltage indicator for LR3 |
My "spam can" doesn't have much in the way of a low voltage warning but
the Garmin x96 does! I found a data field that displays volts and an
alarm that allows you to set the voltage threshold.
johninreno
Jeff Page wrote:
>
>> Failure of the main alternator is not an emergency. It's
>> an emergency only if you have no alternatives i.e, you
>> have no back up engine driven power source and you haven't
>> the foggiest notion of how long your battery will run goodies
>> in the endurance mode.
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | RE: "Poor Man's" coax termination with RG-400 |
>Bob,
>
>Sorry I didn't explain it very well.
>
>My buddy wants to use RG-400 for his VHF COMM. He has one of those
>antennas that has only a Delrin insulator and the end of the antenna is
>threaded. He currently has some old RG-58 which is installed according to
>the 'Connection, Chapter 13, The "Poor Man's" coax termination in lieu of
>a BNC connector, which is not an option with this antenna.
>
>He was wondering if he should just twist the two layers of (RG-400) braid
>into one "wire" and crimp on a lug like the previous (RG-58) install. I
>was wondering if the outer (RG-400) braid should be trimmed short and only
>the inner braid teased out for crimping onto the ground lug. Or does it
>even matter?
>
>Sorry for the misdirect.
That's what I thought . . . and the technique described
in the link I provided at:
http://aeroelectric.com/articles/shldwire/shldwire.html
is what I would suggest. If you pull the center conductor
through the side of BOTH shields, then there's no "twisting"
necessary. The braid conductors are already grouped together
in a manner that's conducive to installation of a terminal.
The rule of thumb is to keep the coax pigtails as short
as practical and know that the short length of exposed
center conductor will cause an electrical "lengthening"
of the antenna. This will shift the antenna's center-frequency
down a Mhz or so . . . not generally a big deal.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: RG-400 vs. RG-142 |
>
>From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
> Consider a 10' run of coax from GPS receiver
> to antenna. RG58 offers an attenuation of about
> 35db/100'; RG-400/142 is about 24db/100'.
> 10' runs reduce to 3.5 and 2.4 db for a difference
> of 1.3 db . . . delta that is impossible to
> observe and difficult to measure at that frequency.
>
> With respect to materials, RG-400/142 are double-
> layer, silver-plated shield and fabricated from
> modern cousins to Teflon. It's the best we know how
> to do . . . today.
>
>What do you think about Andrew FSJ1RN-50B Heliax Cable ?
>
>At 150MHz the attenuation is only 2.2 dB/100'
>The minimum bend radius is only 1" and it doesn't try to unbend itself
>due to the corrugated shield.
>It is more expensive of course, plus you need their expensive BNC connectors.
>
>http://www.andrew.com/catalog/product_details.aspx?id=1343
There are MANY alternative coax products that
would reduce losses in the antenna's feedline.
But what's the return on investment? The as-installed
performance differences for having utilized some form
of super-coax would be difficult to measure, much less
observe.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: RG-400 vs. RG-142? |
>From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
>Subject: Re: AeroElectric-List: RG-400 vs. RG-142?
>>any significant downsides to using RG-142 for aircraft antenna
>>applications where the cable will not be regularly flexed (except
>> for normal vibration)? I am somewhat leery of using a solid core
>>coax.
>Then use the stranded version, RG-400.
Bob is right but you can get stranded versions of many coxial
cables if you know where to look. The best thing recommending
RG-58 (which can be had stranded) is its easier to find. Cost?
RG-400 is spendy but when you look at cost of plane and avionics
it's nickles and dimes. I still would not criticize you for using RG-58
but at least look for stranded.
RG-400 prices have come down to $1.85/ft. cost difference small.
SCORE! http://www.steinair.com/wire.htm has RG-400 for $1.85/ft.
B&C also has a the same price.
I know you don't need 500ft of RG-58 stranded but this is $0.23/ft
http://www.pacificcable.com/Picture_Page.asp?DataName=RG58AU
It does show RG-58 comes in stranded.
There are many RG-58 equiv on the market but RG-400 is king,
but be careful RG-400 comes in solid and stranded as well. Get
stranded; why not? Not sure RG-142 comes in stranded?
G
---------------------------------
Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.
________________________________________________________________________________
| Subject: | Re: RG-400 vs. RG-142 |
| From: | "jetboy" <sanson.r(at)xtra.co.nz> |
I'm up to my elbows on a daily basis in FSJ1-50 and the larger family of heliax
up to 3" dia.
They are unsuitable for aircraft use due to weight and flexibility. Especially
the end connections which do not tolerate much post - install stress.
The cables Bob has replied are the best for the purpose, besides, transponders
and radios are designed to operate with some cable loss and in fact you will
have a harder time getting a satisfactory match over the VHF band if your cable
is too good. Then you have to start re-engineering and / or ferrite loading
the antenna system.
Be sure to use good connectors, not the computer - grade variety. Connectors improperly
installed cause more problems than the cable.
Ralph
--------
Ralph - CH701 / 2200a
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=168096#168096
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
| Subject: | Re: RG-400 vs. RG-142 |
I installed my transponder antenna about 6 months ago in the rear of my
plane. Now I am getting ready to install the transponder itself. While
reading the instructions, I discovered that the max distance for RG400 is
8.8 feet. My installation is probably 10 feet. Do I need to move the
antenna? If I don't move it, what will be the down side? It is a Garmin
GTX327 if that matters..
Bill B
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of jetboy
Sent: Thursday, March 06, 2008 4:11 PM
Subject: AeroElectric-List: Re: RG-400 vs. RG-142
I'm up to my elbows on a daily basis in FSJ1-50 and the larger family of
heliax up to 3" dia.
They are unsuitable for aircraft use due to weight and flexibility.
Especially the end connections which do not tolerate much post - install
stress.
The cables Bob has replied are the best for the purpose, besides,
transponders and radios are designed to operate with some cable loss and in
fact you will have a harder time getting a satisfactory match over the VHF
band if your cable is too good. Then you have to start re-engineering and /
or ferrite loading the antenna system.
Be sure to use good connectors, not the computer - grade variety. Connectors
improperly installed cause more problems than the cable.
Ralph
--------
Ralph - CH701 / 2200a
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=168096#168096
________________________________________________________________________________
| From: | "Ralph Finch" <rgf(at)dcn.davis.ca.us> |
| Subject: | RE: "Poor Man's" coax termination with RG-400 |
While we're on the topic of coax and RG-400....what would you guys recommend
as to a wire stripper tool? I got the Ideal Stripmaster for stripping
regular wire but need something for coax.
And while we're on wire...what would you recommend for a crimper?
Thanks,
Ralph Finch
Davis CA
________________________________________________________________________________
| From: | Ralph Hoover <hooverra(at)verizon.net> |
| Subject: | RE: "Poor Man's" coax termination with RG-400(coax |
stripper)
Ralph,
A single edge razor blade or small knife used with care works fine.
Score the jacket and pull it off with a small diagonal cutter. Do the
same for the center conductor. Any nicks to the conductors start over!!
You can master this in several practice attempts and when done properly
there is no difference in results. Any time you may save with the
expensive tool you will probably loose looking for the too :) The
diagonal cutter can be used to trim the braid. I have used the expensive
tools, a razor blade and a swiss army knife over the course of years and
many hundreds of connectors, The knife is always in my pocket and the
final result is the same.
Whatever tool you use slide the ferrule on first and then prep the cable.
Here is another option but your wallet will be $50 lighter.
http://www.specialized.net/ecommerce/shop/layout.asp?product%5Fid=108X956
--
Ralph C. Hoover
RV7A
hooverra at verizon dot net
________________________________________________________________________________
| From: | Ralph Hoover <hooverra(at)verizon.net> |
| Subject: | RE: "Poor Man's" coax termination with RG-400 |
Go here and then to the product drawing for cable strip details.
http://catalog.tycoelectronics.com/TE/bin/TE.Connect?C=1&M=BYPN&TCPN=5225395-6&RQPN=5225395-6
--
Ralph C. Hoover
RV7A
hooverra at verizon dot net
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: static system leak check procedure |
I'm still wondering how the radio shop does a transponder check?
I'm guessing they connect their vacuum source to the static port AND the
pitot port?? If so, I'm going to need to check the pitot side of things
for leakage as well I think.
thank you
Ken
Kevin Horton wrote:
> You can do an acceptable test much more simply than this. The standard
> (as described in FAR 23.1325(b)(2)(i)) only calls for enough vacuum to
> raise the indicated altitude 1000 ft above the altitude of the test
> site. On my RV-8, I put a piece of tape over one static port, and held
> a piece of rubber hose against the other static port. I put the other
> end of the hose in my mouth, and sucked until I had increased the
> altitude more than 1000 ft. I put my tongue over the end of hose to
> trap the pressure, and made sure to keep pushing the other end hard
> against the static port so no air leaked out there. The altimeter
> dropped much less than 100 ft in a minute (the pass/fail criteria from
> FAR 23.1325), so my system was OK.
>
> There is no need to disconnect ASI or VSI (assuming you don't introduce
> excessive vacuum, which could damage an ASI). In fact, doing it with
> instruments removed invalidates the test, as you might introduce a leak
> when you put those instruments back into the static system. You really
> need to do an end-to-end leak check with the whole static system in the
> state it would be when you fly the airplane.
>
> Kevin Horton
>
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: RG-400 vs. RG-142 |
I think I asked the same question awhile ago Bill but 11 feet seems to
work fine on a GTX320 despite the 8.8 foot caution.
Ken
Bill Bradburry wrote:
>
> I installed my transponder antenna about 6 months ago in the rear of my
> plane. Now I am getting ready to install the transponder itself. While
> reading the instructions, I discovered that the max distance for RG400 is
> 8.8 feet. My installation is probably 10 feet. Do I need to move the
> antenna? If I don't move it, what will be the down side? It is a Garmin
> GTX327 if that matters..
>
> Bill B
>
________________________________________________________________________________
| Subject: | Coax termination and electrical theory explained. |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
I have been dabbling with the physics of current moving along a wire. One of the
remarkable things about physics that I have to keep re-learning is that seemingly
simple phenomena have wildly complicated reasons for working as they do.
But understanding these reasons keep us on track .
You would think that the theory of electricity has been well worked out by now.
But heres your test:
1)What carries the energy in a simple electrical circuit?
a-Electrons,
b-Holes,
c-God knows!
2)What returns on the ground or return wire?
a-Electrons,
b-Holes,
c-God knows!
3)In a coaxial cable, exactly where is the energy carried?
a-In the center conductor,
b-In the shield,
c-God knows!
If you answered c for the three questions, you are close to correct but we can
shed considerable light on the subject and only a few miracles will be invoked.
Lets start with some simple truths:
1) You can't expect electrons to carry energy to the load because a coulomb (a
miniscule amount of electrons), a meter from another coulomb electrostatically
repel each other with about a million tons of force. (So there's probably some
kind of taxpayer-funded DARPA electronic weapon based on this fact in our future....).
2) Electrons dont carry signals or information either because they are far too
slow. It takes days for an electron to go a mile. Electromagnetic fields do the
job.
3) The notion of ground current as used-up tired electrons slowly returning home
to battery rehabilitation is wrong. BOTH the high potential and ground return
conductors do identical things, but with opposite polaritieseven in DC circuits.
4) Electrons dont carry energy to the load because they usually dont get there
anyway. Most circuits just dont connect power and load in any contiguous way.
5) Coaxial cables are waveguides because the energy transmitted is almost entirely
within the inner insulation. An amazing proof of this is that the wave velocity
is almost exactly the speed of the electromagnetic wave in the particular
material out of which the insulation is made. The importance of this is directly
proportional to frequency. For audio purposes it matters little.
Skin Effect is a 1957 tribute to Bridgette Bardot, and also what happens to electrons
that increasingly drift towards the surface of a conductor at high frequencies.
Why do we care about this when electrons dont do much anyway? This is
interesting only because the center of conductors at high frequencies have no
function. This is easily seen in HF induction coils made of hollow tubing instead
of solid.
The "pigtails" where the coax shield is twisted into a lead and both the inner
conductor and twisted up shield lead are treated as separate wires is deadly to
high frequency signals >Megahertz. The shield should be terminated by any method
that does not decrease the impedance of the shield or the inner conductor.
There are many ways to do this, but they all use some collar arrangement to
terminate the messy coax shield. Any coax catalog has lots of solutions. Remember
that above a megaHertz, the inner INSULATION carries the bulk of the energy!
(As an aside--50 Ohms and 75 Ohms are the impedance of vacuum and air respectively.
Early coaxial cables were one or the other.)
Bob, in my humble opinion, needs a little nudge on this. Here's how NOT to terminate
coaxial cable--
http://aeroelectric.com/articles/shldwire/shldwire.html
But yikes....! So it turns out that the simplest DC circuit operation is wildly
difficult to explain, but basically the electromagnetic fields carry the energy,
not the electrons. They are just there to move and cause the magnetic field.
The electrons have only an electric field, and it is only the electrons movement
through space that generates a magnetic field. If you followed alongside
an electron, you wouldnt see ANY magnetic field. This is the difference between
static electricity and the regular stuff. Static electricity has no magnetic
field because the electrons arent moving with respect to the observer.
http://science.uniserve.edu.au/school/curric/stage6/phys/stw2002/sefton.pdf and if this (excellent!) paper doesn't blow your mind, try--
http://sites.huji.ac.il/science/stc/staff_h/Igal/Research%20Articles/Pointing-AJP.pdf
http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/audio/part6/page3.html
Textbook, Electromagnetics Explained: Part of the EDN Series for Design Engineers
by Ron Schmidt
--------
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=168228#168228
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Grounding shielded wires |
I know - the subject's been covered before. And yes, I know - it's in the
archives.
But, I can't find it in the archives and I'd appreciate some help.
I'm getting conflicting advice from the radio harness maker and from the
intercom maker regarding the grounding of shielded wires. One tells me to
ground the shield on only one end while the other says to ground both ends. Who
to believe?
My situation: SL30 with professionally wired harness. Shields are all
grounded on the radio chassis.
I'm building the harness for the intercom. The intercom instructions show
shielding grounded at both ends only on the audio wires. However, email from
intercom maker says to ground both ends of all shielded wire.
1. Should shielded wires from SL30 to intercom be grounded at both ends?
2. Should those grounds be ganged together to connect to the single ground
pin on the intercom?
3. Should mic phone plug wire shields be grounded at both ends?
4. Should headphone plug wire shields be grounded at both ends?
5. Should all shields be ganged together to connect to the single ground pin
on the intercom?
Stumped,
Stan Sutterfield
**************It's Tax Time! Get tips, forms, and advice on AOL Money &
Finance. (http://money.aol.com/tax?NCID=aolprf00030000000001)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | RE: "Poor Man's" coax termination with RG-400 |
>
>While we're on the topic of coax and RG-400....what would you guys recommend
>as to a wire stripper tool? I got the Ideal Stripmaster for stripping
>regular wire but need something for coax.
>
>And while we're on wire...what would you recommend for a crimper?
My personal favorite stripper is offered by Gilchrist Electric at:
http://www.gilchrist-electric.com/3-blade-coax-cable-strip.php
They used to have an Ebay store but seem to have split
the sheets with Ebay. The link above goes directly to
their website. This is a 3-blade tool that comes with
the appropriate sized allen wrench to effect adjustment
of cutting depth for each blade. See the 3-Blade Stripper
pictures at:
http://www.aeroelectric.com/Pictures/Tools/Wire_Strippers/
I presume you're asking about coax crimpers . . . for
BNC connectors, you need a high-leverage, hard-die tool
with 0.068" and 0.213" pockets. This tool offered by
Radio Shack is one option:
http://tinyurl.com/ys7oed
as is the RCT-2 offered by http://bandc.biz
For the pre-insulated ring terminals, consider this
tool:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93977
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: RG-400 vs. RG-142 |
>
>I think I asked the same question awhile ago Bill but 11 feet seems to
>work fine on a GTX320 despite the 8.8 foot caution.
>Ken
>
>Bill Bradburry wrote:
>>
>>I installed my transponder antenna about 6 months ago in the rear of my
>>plane. Now I am getting ready to install the transponder itself. While
>>reading the instructions, I discovered that the max distance for RG400 is
>>8.8 feet. My installation is probably 10 feet. Do I need to move the
>>antenna? If I don't move it, what will be the down side? It is a Garmin
>>GTX327 if that matters..
>>Bill B
When a manufacturer publishes performance specifications
for a product, they need to state the boundaries on installation
variables that influence the numbers.
In the case of 8.8' max length, they're only saying that
performance will be degraded from the published specifications
if that length is exceeded. What is not so apparent is
whether or not a user/observer would be aware of the
degradation . . . and in this case, the answer is no.
There's enough head-room in the receiver's capability to
deliver useful performance in spite of an additional 0.1
Db or so of feedline losses.
Now, if you were installing this radio in a 787 and needed
to put the antenna out on a wing tip, a higher performance
coax cable would be a really good idea.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | Ernest Christley <echristley(at)nc.rr.com> |
| Subject: | Re: Coax termination and electrical theory explained. |
Eric M. Jones wrote:
> Bob, in my humble opinion, needs a little nudge on this. Here's how NOT to terminate
coaxial cable--
>
> http://aeroelectric.com/articles/shldwire/shldwire.html
>
The difference between theory and practice is that in theory they are
the same.
You have two copper strips to form an antennae. One must be connected
to the center conductor, the other to the shield. Whether you terminate
the coax with some fancy, expensive solution from an electronics
catalogue or Bob's method, at some point the center conductor has to
split out from the shield. The difference in actual performance in the
flying airplane will be lost in the noise (pun intended). In theory,
there is an advantage in the expensive, complicated solution. In
practice, the advantage ain't worth the headache.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Grounding shielded wires |
>I know - the subject's been covered before. And yes, I know - it's in the
>archives.
>But, I can't find it in the archives and I'd appreciate some help.
>I'm getting conflicting advice from the radio harness maker and from the
>intercom maker regarding the grounding of shielded wires. One tells me to
>ground the shield on only one end while the other says to ground both
>ends. Who to believe?
>My situation: SL30 with professionally wired harness. Shields are all
>grounded on the radio chassis.
>I'm building the harness for the intercom. The intercom instructions show
>shielding grounded at both ends only on the audio wires. However, email
>from intercom maker says to ground both ends of all shielded wire.
>
>1. Should shielded wires from SL30 to intercom be grounded at both ends?
>2. Should those grounds be ganged together to connect to the single ground
>pin on the intercom?
>3. Should mic phone plug wire shields be grounded at both ends?
>4. Should headphone plug wire shields be grounded at both ends?
>5. Should all shields be ganged together to connect to the single ground
>pin on the intercom?
Follow the instructions. If the wiring diagram
provided by the manufacturer SHOWS a ground connection
at both ends, then there's a reason for it an
the designer's intentions should be observed.
However, the general rule of thumb is that shields
are to be GROUNDED at one end only . . . that doesn't
mean that the shield is not CONNECTED at both ends . . .
the shield may have an important role to play with
respect to signal or power return paths.
A very common double-grounding error in aircraft
audio systems occurs when headset and microphone
jacks are allowed to find local ground at the
point of attachment to the airframe. This is why
insulating washers . . .
http://www.aeroelectric.com/Pictures/Connectors/Audio/Jack_Insulation_Washers.jpg
are recommended where the jacks are to me mounted
to a conductive location on structure.
The schematic for wiring the product should be
quite explicit as to where the shields are connected.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Coax termination and electrical theory explained. |
>
>I have been dabbling with the physics of current moving along a wire. One
>of the remarkable things about physics that I have to keep re-learning is
>that seemingly simple phenomena have wildly complicated reasons for
>working as they do. But understanding these reasons keep us on track .
>You would think that the theory of electricity has been well worked
>out by now. But heres your test:
>
> 1)What carries the energy in a simple electrical circuit?
> a-Electrons,
> b-Holes,
> c-God knows!
>Bob, in my humble opinion, needs a little nudge on this. Here's how NOT to
>terminate coaxial cable--
>
>http://aeroelectric.com/articles/shldwire/shldwire.html
>
>But yikes....! So it turns out that the simplest DC circuit operation is
>wildly difficult to explain, but basically the electromagnetic fields
>carry the energy, not the electrons. They are just there to move and cause
>the magnetic field. The electrons have only an electric field, and it is
>only the electrons movement through space that generates a magnetic field.
>If you followed alongside an electron, you wouldnt see ANY magnetic
>field. This is the difference between static electricity and the regular
>stuff. Static electricity has no magnetic field because the electrons
>arent moving with respect to the observer.
Eric my friend . . . you're making this far more complex
than it needs to be. Yes, the physics of conducting electrical
energy from one place to another have been studied, quantified and
explained for a century or so. However, there ARE practical
departures from "ideal" that do not materially affect performance.
Super-simple VHF COMM antennas were installed by the tens of
thousands in light aircraft using the technique illustrated.
Yes, the effects on SWR, radiation patterns, and radiation
efficiency were degraded from ideal . . . but the the
ideal was never perfect either.
For the frequencies of interest (118 - 135 Mhz), effects
of the 1" or so of non-coaxial conductor that results from the
use of terminals on pigtails was barely noticeable in the
lab and never noticed by a pilot in an airplane. Now, the
effects of this technique at transponder frequencies is
much larger . . . easily measured in the lab. But with
some judicious refinement of fabrication technique to
get the shortest possible leads (below 1/2") the
effects on real time performance were not observable.
When we go to the lab to make calibrated measurements
of performance, the obvious goal is to minimize the
effects of test-setup error. In this environment we
strive for the-best-we-know-how-to-do with the goal of
suppressing sum of all test errors to less than 1/4
that of the phenomenon being measured. But in the real
world of talking to Flight Watch from an RV, well considered
departures from the best-we-know-how-to-do don't reflect badly
upon our craftsmanship.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Coax termination and electrical theory explained. |
| From: | "Eric M. Jones" <emjones(at)charter.net> |
> The difference in actual performance in the
> flying airplane will be lost in the noise (pun intended). In theory,
> there is an advantage in the expensive, complicated solution. In
> practice, the advantage ain't worth the headache.
Maybe, maybe not. It depends on the details. But you have not tested it, (nor has
Bob). I submit that when the HANDY SHORT-CUT solution is proposed as the GENERAL
solution, the best interests are not well served.
The coax terminations in electronics catalogs are neither difficult nor complicated.
Furthermore you can make you own in a pinch. So there are two choices:
1) The right way.
2) The other way.
--------
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=168247#168247
________________________________________________________________________________
| From: | Kevin Klinefelter <kevann(at)gotsky.com> |
| Subject: | Ignition/Starter switch wiring |
Bob and all,
I have a couple questions.
I am wiring a Rotax 914 in my Europa per Z-16(sort of). I want to use a
switch for each "mag" that will be down-off, middle-on, momentary-up of
both to start. Is there a drawing somewhere on the site that shows how
to wire this?
I also want to wire a switch to control two alternators, the rotax built
dynamo and a Denso IR alternator mounted on the vac pad. I would like to
use one switch; down-dynamo middle-off and up-main alternator(denso).Is
there a drawing showing how to wire that?
Thanks, Kevin
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Coax termination and electrical theory explained. |
>
>
> > The difference in actual performance in the
> > flying airplane will be lost in the noise (pun intended). In theory,
> > there is an advantage in the expensive, complicated solution. In
> > practice, the advantage ain't worth the headache.
>
>
>Maybe, maybe not. It depends on the details. But you have not tested it,
>(nor has Bob).
???? I've made a good living for over 40 years delivering
products to a customer's needs and in many cases, verifying
performance both in the lab and in the customer's application.
For you to make ANY assertions about what I have or have not
learned by experiment, or success of myself and colleagues
in the field is specious and without foundation.
> I submit that when the HANDY SHORT-CUT solution is proposed as the
> GENERAL solution, the best interests are not well served.
You extrapolate much floobydust from the original question.
The goal was to make an electrically adequate connection between
a coax feedline and the classic stone-simple, rod-on-a-feedthru comm
antenna.
This style antenna is still offered by many suppliers not the
least of which is . . .
http://www.chiefaircraft.com/Aircraft/Antennas/Images/AS_AV534.jpg
and yields 76 hits on a Google search. So, returning to the
original question, what are your recommendations for attaching
a coax to this product? Further, if your recommendations involve
extensive $time$ to satisfy some goals for transmission line
matching or keeping the holes separated from the electrons, what's
the expected return on investment for making that effort?
You should know that the last time I designed one of these antennas
into an installation, I discarded the large ring-terminal intended for
shield braid connection to airframe (large area, low pressure) in
favor of the PIDG ring terminal (small area, high pressure) connection
of the shield to the airframe.
What we were discussing was NOT a SHORT-CUT as a GENERAL solution
but a well considered, time tested, current marketplace practice
to a very SPECIFIC application.
>The coax terminations in electronics catalogs are neither difficult nor
>complicated. Furthermore you can make you own in a pinch. So there are two
>choices:
>
>1) The right way.
>2) The other way.
There are MANY ways to work toward design goals. Some perform better,
some most more, some are not possible to implement in the present
situation. The hallmark of craftsmanship is achieving the best
solution to the task of the moment with resources at hand.
Bob . . .
________________________________________________________________________________
| From: | CardinalNSB(at)aol.com |
| Subject: | Coax termination, theory, and..do I balun? |
I'm using a King KNS-80 and Narco 12D, and replacing the rg-58 in my spam
can with rg400 for my vor/glideslope catwhisker antenna,
Should I replicate the 40 year old balun where it mates with antenna? or
does the termination issue outweigh the benefits of the balun? Thanks Skip
**************It's Tax Time! Get tips, forms, and advice on AOL Money &
Finance. (http://money.aol.com/tax?NCID=aolprf00030000000001)
________________________________________________________________________________
| Subject: | Re: Z-19 Series Architecture |
| From: | "Mark Sletten" <marknlisa(at)hometel.com> |
Bob,
I was wondering if you had a chance to take a look at the Z-19 drawings in response
to my inquiry.
Specifically, the latest revs of the Z-19 drawings on your website show the E-bus
normal feed on a fused connection from the primary bus. Is there a reason for
supplying the E-bus on the Z-19 drawings this way?
Regards,
Mark
--------
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=168391#168391
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Re: static system leak check procedure |
Yes, if they do the transponder check on the aircraft, they would
have to also connect to the pitot to put vacuum there, or they could
damage the ASI.
But, you really should do a pitot leak check anyway, as a leak in the
pitot side could affect ASI accuracy. Be aware that some pitot ports
have a water drain on the tube, which introduces a very small at the
tube. This doesn't affect ASI accuracy as it is so close to the
pitot tube, that any air that leaks out is quickly replaced without
affecting the pressure in the pitot line. But it does affect leak
checks - you need to block the water drain during the leak check, or
you'll end up looking for a phantom leak.
Kevin
On 6 Mar 2008, at 22:06, Ken wrote:
>
> I'm still wondering how the radio shop does a transponder check?
> I'm guessing they connect their vacuum source to the static port
> AND the pitot port?? If so, I'm going to need to check the pitot
> side of things for leakage as well I think.
> thank you
> Ken
>
> Kevin Horton wrote:
>> You can do an acceptable test much more simply than this. The
>> standard (as described in FAR 23.1325(b)(2)(i)) only calls for
>> enough vacuum to raise the indicated altitude 1000 ft above the
>> altitude of the test site. On my RV-8, I put a piece of tape over
>> one static port, and held a piece of rubber hose against the other
>> static port. I put the other end of the hose in my mouth, and
>> sucked until I had increased the altitude more than 1000 ft. I
>> put my tongue over the end of hose to trap the pressure, and made
>> sure to keep pushing the other end hard against the static port so
>> no air leaked out there. The altimeter dropped much less than 100
>> ft in a minute (the pass/fail criteria from FAR 23.1325), so my
>> system was OK.
>> There is no need to disconnect ASI or VSI (assuming you don't
>> introduce excessive vacuum, which could damage an ASI). In fact,
>> doing it with instruments removed invalidates the test, as you
>> might introduce a leak when you put those instruments back into
>> the static system. You really need to do an end-to-end leak check
>> with the whole static system in the state it would be when you fly
>> the airplane.
>> Kevin Horton
>
>
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: Cheap "Coat Hanger" antenna (was Coax termination |
elect theory)
No offense to Ernest or Bob, the old coat hanger
antennas that you terminated the coax with crimp on
lugs has not been used in production airplanes since
the 50's or early 60's.
Coat hanger antenna
http://www.aircraftspruce.com/catalog/avpages/av534.php
What Eric says about "EM field energy", which I recall
bits from physics and armature radio, the coax,
BNC connector is way more efficient. That inch of
exposed shield/core & important lost insulation does
count. The "coat hanger antenna connections are
subject to corrosion and fatigue way more than a BNC
connector. Just my opinion.
No one is seriously using the coat hanger wire antenna
on new OEM aircraft any more.
"Testimonials" that they work in the plane or bench are
great, but unless you do a test on the airframe in an
antenna test chamber (EMF / RF anechoic chamber),
we are guessing. Besides performance there is the
reliability of the installation.
Just from an installation standpoint, spend the $124
for the real antenna and leave the $50 coat hanger
antenna for the closet. Antenna energy, non-ionizing
radiation is EMF energy at high frequencies. It needs
"ducting" to be most effective.
Does the "strip-it crimp-it" antenna connection work?
Yes it "works", but gosh ughaaa, ugly.
We're talking about 5-8 watts of energy and communications
of 5 to 50 mile, line of sight, listening for even more powerful
transmitters, usually without obstacles. We can get away
with a weak antenna.
The coat hanger works, but its not ideal. We have better
ways. If I was restoring a classic Beech or something, yea
I'd keep the coat hanger antenna. Other wise coat hangers
are for the closet (pun intended).
$110-$150 for newer antenna design
http://www.aircraftspruce.com/catalog/avpages/av17.php
PS: Some have experienced RFI with unshielded antenna
connections thru gauges and avionics.
>From: Ernest Christley <echristley(at)nc.rr.com>
>Subject: Re: Coax termination and electrical theory
>explained.
>Eric M. Jones wrote:
>> Bob, in my humble opinion, needs a little nudge
>> on this. Here's how NOT to terminate coaxial
>> cable--
http://aeroelectric.com/articles/shldwire/shldwire.html
>The difference between theory and practice is that in
>theory they are the same.
> You have two copper strips to form an
>antennae. One must be connected to the center
>conductor, the other to the shield. Whether you
>terminate the coax with some fancy, expensive
>solution from an electronics catalogue or Bob's
>method, at some point the center conductor has to
>split out from the shield. The difference in actual
>performance in the flying airplane will be lost in
>the noise (pun intended). In theory, there is an
>advantage in the expensive, complicated solution.
>In practice, the advantage ain't worth the
>headache.
---------------------------------
Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.
________________________________________________________________________________
| From: | "Richard Girard" <jindoguy(at)gmail.com> |
| Subject: | The difference between theory and practice |
All this discussion about antenna connections brings to mind an old story
about a mathematician, a theoretical physicist, and an engineer. They began
pondering a thought experiment about a man and a beautiful naked red head
standing six feet apart. The question was this; if the man halves the
distance between himself and the red head each second, how long will it take
before he reaches her?
The mathematician and the physicist both immediately answered that of course
the man would never reach her.
The engineer calculated that in four seconds he'd be close enough for all
practical purposes.
This is what comes from listening to the annual "Prairie Home Companion"
joke show this evening.
Ya'll take it easy and have a nice Sunday.
Rick
________________________________________________________________________________
| From: | Ed Holyoke <bicyclop(at)pacbell.net> |
| Subject: | High density D-sub crimper |
Howdy,
I've got to crimp about 30 machined high density d-sub pins on an ACU
install and I don't think my standard density crimper (B&C) is gonna
work. I'd hate to spend $800 on a Daniels and postitioners for one
little deed. Any ideas?
I thought about getting a $30 crimper and some of the fold over pins.
Are those pins as reliable as the machined ones? Will the crimper (fold
over style, also B&C) do those little pins in one of it's slots?
Pax,
Ed Holyoke
________________________________________________________________________________
| Subject: | B&C S895-1 as start button for 20A/14VDC ciruit? |
| From: | "n707sm" <mobrien02(at)comcast.net> |
Hi Bob,
Hope all is well with you :)
I have a B&C S895-1 push button originally intended as a start buton; however,
the Eggenfellner recommendation for the starter circuit is for a switch or push
button capable of 20A/14VDC (switch will be connected to the internal contactor
on the Subaru H6 starter solenoid).
I have been reviewing both your Switch_Rating.pdf and the chapter in the Connection,
and I'm coming to the conclusion that this switch is probably too light
for this application. Would it work? Sure. For how long? Who knows... But
what would be the risk that I could fuse this switch closed or just plain heat
it up too much? Also, the connection leads on this switch seem a bit small/light
for 12AWG wire...
Please advise when you have a moment.
Thanks in advance!
Michael O'Brien
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=168543#168543
________________________________________________________________________________
| Subject: | Re: High density D-sub crimper |
| From: | "N395V" <Bearcat(at)bearcataviation.com> |
My UMA instruments came with the overfold sub D pins. Crimps looked good and they
have worked fine for a long time.
--------
Milt
2003 F1 Rocket
2006 Radial Rocket
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=168553#168553
________________________________________________________________________________
| Subject: | Re: High density D-sub crimper |
| From: | "rampil" <ira.rampil(at)gmail.com> |
If you crimp connectors without the specific dies, you would
be well served by soldering the wire strands to the crimps as
well or the wires might just fall out!
I have an AMP ProCrimp II with all the dies for the CPC
Series I connectors, and they still sometimes fail the tug test when I
don't oversolder them!
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=168557#168557
________________________________________________________________________________
| From: | PJ Seipel <seipel(at)seznam.cz> |
| Subject: | Re: High density D-sub crimper |
If you have the standard density crimper (the red one that puts the 4
little indents into the pin), you can use it on the high density
machined pins if you're careful. What I did was cut a short piece of
wire (like 1/8" or so) and put it into the hole first as a spacer to
position the pin in the right spot. Then you can crimp like normal.
You may have to play around a bit to adjust the length of the spacer to
get the pin in the right spot. If you're only doing a few pins you
shouldn't have any issues. Mine passed a 15lb pull test and that's good
enough for me.
PJ Seipel
RV-10 #40032
Ed Holyoke wrote:
>
>
> Howdy,
>
> I've got to crimp about 30 machined high density d-sub pins on an ACU
> install and I don't think my standard density crimper (B&C) is gonna
> work. I'd hate to spend $800 on a Daniels and postitioners for one
> little deed. Any ideas?
>
> I thought about getting a $30 crimper and some of the fold over pins.
> Are those pins as reliable as the machined ones? Will the crimper
> (fold over style, also B&C) do those little pins in one of it's slots?
>
> Pax,
>
> Ed Holyoke
>
>
________________________________________________________________________________
| From: | "Bill Schlatterer" <billschlatterer(at)sbcglobal.net> |
| Subject: | Diodes versus switches 101 ? |
There was some discussion about Z19 using diodes in a critical ECU circuit
and the question arose as to what kind of failure modes apply to diodes and
their reliability as compared to switches. I think the trust of that thread
(sub list) and post below is that diodes might be "automatic" but switches
are safer and less likely to fail? ( I have no opinion but would like to
understand the rationale ) This was posted and I was just wondering what
the thought might be on the AE list since most of Bobs diagrams "suggest" a
diode in the E-Bus circuit as opposed to a switch. That might not be AS
critical as the ECU/EFI circuit on an all electric engine but the same
concerns still apply?
Posted to the Sub list:
"After 30 years in the industrial electrical construction and maintenance
field I can say without equivocation that a robust switch is much less
likely to fail than a robust diode. The science of the switch is much
simpler - use a lot of good conducting material that is not likely to
corrode and support it with stout mechanical parts that hold tightly.
Now, by contrast, the science of the diode starts with getting good silicon
material and contaminating it in just the right proportion with just the
right material at just the right temperature for just the right time. THEN
you can start on building the junctions onto some sort of heat dissipating
holder. I have replaced dozens of solid state devices that failed (always
failed open) and I never found the root cause of failure. I put in an exact
replacement and the circuit worked just fine for years. The trade off you
get for the "automatic" switching of a diode vs. the manual switch is in the
area of RELIABILITY. I'll be using manual switches for all critical loads."
Not wanting to stir anything up, just want to understand the thinking and
factual matter in the post above?
Thanks Bill S
7a Z13/8 Z32(HD E-Bus) Z35(7ah)
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
| Subject: | Re: Diodes versus switches 101 ? |
Here is an excerpt of something I posted on the Sub list which relates
to this email:
Regarding the reliability of switches and diodes... According to Mil handbook
217F - the "bible" of reliability prediction - a Schottky power diode (which is
the only type anyone should be using in any power circuit in an airplane) has
a predicted failure rate of 0.0028 failures per million hours. A mil rated
toggle switch has a predicted failure rate of 0.1 failures per million hours.
Now, realistically, this prediction for a switch is partially related to the
toggle mechanics and partially related to the individual contacts. The mil handbook
relates to a single set of contacts while the specified switch has four
sets of contacts so the switch in question is probably less reliable that the
handbook predicts for a simple toggle switch. But even if we ignore that detail,
for what it is worth, a diode of the type that should be used is 35 times
more reliable than the type switch specified. So much for the superiority reliability
of a switch that some have been bandying ab
out...
A properly designed diode circuit provides automatic, uninterrupted power transfer
in the event of the loss of the main supply. A switched circuit requires
the pilot to notice the problem and take some action (toggle the switch to the
other position).
A diode circuit has not been specified (in the Subaru application), so one is on
their own if that were to be the choice of a user. While this is not an insurmountable
problem, the diode circuit is more susceptible to a poor design.
One must choose a diode with sufficient current and voltage ratings for the desired
circuit conditions. Additionally, since there can be considerable heat
generated in a power diode, proper heat sinking must be provided (not particularly
hard to do as long as you know how to calculate what is needed).
So... If you are electrically challenged use the factory recommended circuit design
- good or bad as it may be, it has full factory support.
If you really know what you are doing, a diode circuit has certain advantages.
However, if you choose to depart from the factory design, do not expect any assistance
or support from the factory for your design and if you have a problem
it is your problem.
I have already wired my RV9A (long before this discussion and long before "diode"
became a dirty word) and I am using two very beefy Schottky diodes to connect
both battery buses to the engine bus. If either bus goes down for whatever
reason, the engine keeps on running and an annunciator tells me which bus is
down. Additionally, a voltmeter on each bus keeps me informed of its health continuously.
It should also be noted that in the instance in question that the ECU was provided
power from a, probably, inadequately heat sinked bridge that was, possibly,
underrated for the application.
For what Bob recommends the bridge - the Ebus - it is an excellent solution for
the typical experimental plane builder.
Dick Tasker
Bill Schlatterer wrote:
>
> There was some discussion about Z19 using diodes in a critical ECU
> circuit and the question arose as to what kind of failure modes apply
> to diodes and their reliability as compared to switches. I think the
> trust of that thread (sub list) and post below is that diodes might be
> "automatic" but switches are safer and less likely to fail? ( I have
> no opinion but would like to understand the rationale ) This was
> posted and I was just wondering what the thought might be on the AE
> list since most of Bobs diagrams "suggest" a diode in the E-Bus
> circuit as opposed to a switch. That might not be AS critical as the
> ECU/EFI circuit on an all electric engine but the same concerns still
> apply?
>
> Posted to the Sub list:
>
> "After 30 years in the industrial electrical construction and
> maintenance field I can say without equivocation that a robust switch
> is much less likely to fail than a robust diode. The science of the
> switch is much simpler - use a lot of good conducting material that is
> not likely to corrode and support it with stout mechanical parts that
> hold tightly.
>
> Now, by contrast, the science of the diode starts with getting good
> silicon material and contaminating it in just the right proportion
> with just the right material at just the right temperature for just
> the right time. THEN you can start on building the junctions onto some
> sort of heat dissipating holder. I have replaced dozens of solid state
> devices that failed (always failed open) and I never found the root
> cause of failure. I put in an exact replacement and the circuit worked
> just fine for years. The trade off you get for the "automatic"
> switching of a diode vs. the manual switch is in the area of
> RELIABILITY. I'll be using manual switches for all critical loads."
>
> Not wanting to stir anything up, just want to understand the thinking
> and factual matter in the post above?
> Thanks Bill S
> 7a Z13/8 Z32(HD E-Bus) Z35(7ah)
>
--
Please Note:
No trees were destroyed in the sending of this message. We do concede, however,
that a significant number of electrons may have been temporarily inconvenienced.
--
________________________________________________________________________________
| From: | "Rob Turk" <matronics(at)rtist.nl> |
| Subject: | Re: Diodes versus switches 101 ? |
I think it's important to take into account what the purpose of the switch
and/or diode is, and more important, what the failure modes of the circuits
around it is. A diode may be much more reliable when used within it's
designed specs, but if you overload it, it will fail much quicker than a
switch. Compare a diode and a switch, both rated at 25A. A short-circuit
current of 100A through the diode for a few seconds will make it fail, most
likely open circuit. The same current through a switch may heat it up and
damage the contacts, even cause some sparks, but it may still limp along.
Rob
----- Original Message -----
From: "Richard E. Tasker" <retasker(at)optonline.net>
Sent: Sunday, March 09, 2008 8:42 PM
Subject: Re: AeroElectric-List: Diodes versus switches 101 ?
>
>
> Here is an excerpt of something I posted on the Sub list which relates to
> this email:
>
> Regarding the reliability of switches and diodes... According to Mil
> handbook 217F - the "bible" of reliability prediction - a Schottky power
> diode (which is the only type anyone should be using in any power circuit
> in an airplane) has a predicted failure rate of 0.0028 failures per
> million hours. A mil rated toggle switch has a predicted failure rate of
> 0.1 failures per million hours. Now, realistically, this prediction for a
> switch is partially related to the toggle mechanics and partially related
> to the individual contacts. The mil handbook relates to a single set of
> contacts while the specified switch has four sets of contacts so the
> switch in question is probably less reliable that the handbook predicts
> for a simple toggle switch. But even if we ignore that detail, for what
> it is worth, a diode of the type that should be used is 35 times more
> reliable than the type switch specified. So much for the superiority
> reliability of a switch that some have been bandying ab
> out...
________________________________________________________________________________
| From: | "" <wlively(at)gvtc.com> |
| Subject: | ANL/ANN current limiter |
Hello
I have a relatively long run (10+ ft) of 1/0 CCA main battery power wire in
my -8 I am building from the rear baggage all the way to the front firewall. I
would like to install an current limiter on the output of the battery as an added
layer of protection for my long wire run. I know Mr. Nuckolls has not advocated
that on small aircraft, but I want to do it anyway as peace of mind since
the wire passes thru quite few bulkheads and want to have something which will
trip alot faster than I can act. So, which is the better choice, ANN or ANL
and what current rating would be best, I have a 200 hp angle valve to start?
Thank you,
Wade Lively
N100WL, reserved
________________________________________________________________________________
| From: | Kevin Klinefelter <kevann(at)gotsky.com> |
Bob and all,
I have a couple questions.
I am wiring a Rotax 914 in my Europa per Z-16(sort of). I want to use a
switch for each "mag" that will be down-off, middle-on, momentary-up of
both to start. Is there a drawing somewhere on the site that shows how
to wire this?
I also want to wire a switch to control two alternators, the rotax built
indynamo and a Denso IR alternator mounted on the vac pad. I would like
to use one switch; down-dynamo middle-off and up-main
alternator(denso).Is there a drawing showing how to wire that?
Thanks, Kevin
________________________________________________________________________________
| From: | Ed Holyoke <bicyclop(at)pacbell.net> |
| Subject: | Re: High density D-sub crimper |
Hmmmm, I was worried about the diameter difference and hadn't addressed
the depth. You're saying that the red handle crimper worked on the
skinny pins. I haven't counted the pins that came with the install kit,
but I'd be surprised if there are extras to burn so I've been a little
leery of trying tests.
Pax,
Ed Holyoke
PJ Seipel wrote:
>
> If you have the standard density crimper (the red one that puts the 4
> little indents into the pin), you can use it on the high density
> machined pins if you're careful. What I did was cut a short piece of
> wire (like 1/8" or so) and put it into the hole first as a spacer to
> position the pin in the right spot. Then you can crimp like normal.
> You may have to play around a bit to adjust the length of the spacer
> to get the pin in the right spot. If you're only doing a few pins you
> shouldn't have any issues. Mine passed a 15lb pull test and that's
> good enough for me.
>
> PJ Seipel
> RV-10 #40032
>
> Ed Holyoke wrote:
>>
>>
>> Howdy,
>>
>> I've got to crimp about 30 machined high density d-sub pins on an ACU
>> install and I don't think my standard density crimper (B&C) is gonna
>> work. I'd hate to spend $800 on a Daniels and postitioners for one
>> little deed. Any ideas?
>>
>> I thought about getting a $30 crimper and some of the fold over pins.
>> Are those pins as reliable as the machined ones? Will the crimper
>> (fold over style, also B&C) do those little pins in one of it's slots?
>>
>> Pax,
>>
>> Ed Holyoke
>>
>>
>>
>>
>>
>>
>
>
________________________________________________________________________________
| From: | PJ Seipel <seipel(at)seznam.cz> |
| Subject: | Re: High density D-sub crimper |
I bought some from Mouser, so I had some to practice on. If they have
the little hole in them then you could also put some solder in there and
that would probably work as well. If you don't have any extras, I'd be
leery of trying the crimper as well, because it took me a few tries to
find the right depth.
PJ Seipel
RV-10 #40032
Ed Holyoke wrote:
>
>
> Hmmmm, I was worried about the diameter difference and hadn't
> addressed the depth. You're saying that the red handle crimper worked
> on the skinny pins. I haven't counted the pins that came with the
> install kit, but I'd be surprised if there are extras to burn so I've
> been a little leery of trying tests.
>
> Pax,
>
> Ed Holyoke
>
> PJ Seipel wrote:
>>
>> If you have the standard density crimper (the red one that puts the 4
>> little indents into the pin), you can use it on the high density
>> machined pins if you're careful. What I did was cut a short piece of
>> wire (like 1/8" or so) and put it into the hole first as a spacer to
>> position the pin in the right spot. Then you can crimp like normal.
>> You may have to play around a bit to adjust the length of the spacer
>> to get the pin in the right spot. If you're only doing a few pins
>> you shouldn't have any issues. Mine passed a 15lb pull test and
>> that's good enough for me.
>>
>> PJ Seipel
>> RV-10 #40032
>>
>> Ed Holyoke wrote:
>>>
>>>
>>> Howdy,
>>>
>>> I've got to crimp about 30 machined high density d-sub pins on an
>>> ACU install and I don't think my standard density crimper (B&C) is
>>> gonna work. I'd hate to spend $800 on a Daniels and postitioners for
>>> one little deed. Any ideas?
>>>
>>> I thought about getting a $30 crimper and some of the fold over
>>> pins. Are those pins as reliable as the machined ones? Will the
>>> crimper (fold over style, also B&C) do those little pins in one of
>>> it's slots?
>>>
>>> Pax,
>>>
>>> Ed Holyoke
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>
>
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
| Subject: | Re: Diodes versus switches 101 ? |
True, but it is easy to get a diode that is rated for far over the
normal operating current. In fact, doing so costs very little extra and
has other advantages.
Additionally, while your example as started is true, hopefully no one on
this forum would end up with a design where it is possible to draw 100A
on a 25A circuit without some sort of protective device interrupting the
current before "a few seconds" are up...
Rob Turk wrote:
>
>
> I think it's important to take into account what the purpose of the
> switch and/or diode is, and more important, what the failure modes of
> the circuits around it is. A diode may be much more reliable when used
> within it's designed specs, but if you overload it, it will fail much
> quicker than a switch. Compare a diode and a switch, both rated at
> 25A. A short-circuit current of 100A through the diode for a few
> seconds will make it fail, most likely open circuit. The same current
> through a switch may heat it up and damage the contacts, even cause
> some sparks, but it may still limp along.
>
> Rob
>
> ----- Original Message ----- From: "Richard E. Tasker"
>
> To:
> Sent: Sunday, March 09, 2008 8:42 PM
> Subject: Re: AeroElectric-List: Diodes versus switches 101 ?
>
>
>>
>>
>> Here is an excerpt of something I posted on the Sub list which
>> relates to this email:
>>
>> Regarding the reliability of switches and diodes... According to Mil
>> handbook 217F - the "bible" of reliability prediction - a Schottky
>> power diode (which is the only type anyone should be using in any
>> power circuit in an airplane) has a predicted failure rate of 0.0028
>> failures per million hours. A mil rated toggle switch has a
>> predicted failure rate of 0.1 failures per million hours. Now,
>> realistically, this prediction for a switch is partially related to
>> the toggle mechanics and partially related to the individual
>> contacts. The mil handbook relates to a single set of contacts while
>> the specified switch has four sets of contacts so the switch in
>> question is probably less reliable that the handbook predicts for a
>> simple toggle switch. But even if we ignore that detail, for what it
>> is worth, a diode of the type that should be used is 35 times more
>> reliable than the type switch specified. So much for the superiority
>> reliability of a switch that some have been bandying ab
>> out...
>
>
--
Please Note:
No trees were destroyed in the sending of this message. We do concede, however,
that a significant number of electrons may have been temporarily inconvenienced.
--
________________________________________________________________________________
| From: | Brian Cross <bcross2160(at)rogers.com> |
| Subject: | Diode from the Main Bus to the Endurance Bus |
Hi Folks
I have already one airplane flying using Bob's Z-11 architecture with
absolutely no issues. It has been great & really appreciated all the
info provided by Bob & the forum.
I do have one question. I am not questioning the wisdom of the
design but merely wondering why a diode is placed between the main
bus & the endurance bus. I realize that it is there to prevent
backfeeding from the E bus to the main bus when the master is turned
off in the case of an alternator failure etc.
However, you can easily install a 2-10 switch that could be used to set to
1/ Both buses off
2/ E bus only on, master off & all other buses turned off
3/ Main bus & E bus on with the E bus being fed through the main bus & master
Is the considered opinion of the group that a diode is more reliable
than a switch & therefore used, or, to simplify the whole design or what?
Just curious as there is a slight power loss across the diode of
course which is the only negative and think of at this point.
Thanks very much
Brian Cross
RV-8 #81844
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Coax termination |
>
>Holy cow, I just want to talk on the radio. I've got a plastic airplane so
>I just snip off the ends and throw them away.
"snip of the ends"??? Are you talking about coax connectors?
On your plastic airplane, have you fabricated some form of
ground plane under the antennas?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Coax termination, theory, and..do I balun? |
>I'm using a King KNS-80 and Narco 12D, and replacing the rg-58 in my spam
>can with rg400 for my vor/glideslope catwhisker antenna,
>
>Should I replicate the 40 year old balun where it mates with antenna? or
>does the termination issue outweigh the benefits of the balun? Thanks Skip
Not easy to measure, and almost impossible to tell a difference
by observation from the pilot's seat. We built thousands
of Cessnas with split conductors of a coax simply
attached to the cat-whiskers. Then somebody got religion
and for a time we built a bunch of baluns. Some time later,
we were having too much trouble with process . . . seems
the PVC and Polyethelyene insulations got somewhat gooey
at solder temperatures and unless the fabricator was
particularly careful, poor craftsmanship caused field
failures later. So we became heathens again and dumped
the balun.
Today, one may return to the old faiths with greater
probability of success . . . seems the insulations
used on RG400/142 withstand soldering temperatures
very handily. So if you feel the urge, you can craft
a balun as shown in:
http://www.aeroelectric.com/articles/BALUN/Balun_Fabrication.html
May your radios navigate on stations nobody else even
hears and may your antenna patterns be exemplary.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Diode from the Main Bus to the Endurance Bus |
>
>Hi Folks
>
>I have already one airplane flying using Bob's Z-11 architecture with
>absolutely no issues. It has been great & really appreciated all the info
>provided by Bob & the forum.
>
>I do have one question. I am not questioning the wisdom of the design but
>merely wondering why a diode is placed between the main bus & the
>endurance bus. I realize that it is there to prevent backfeeding from the
>E bus to the main bus when the master is turned off in the case of an
>alternator failure etc.
>
>However, you can easily install a 2-10 switch that could be used to set to
>1/ Both buses off
>2/ E bus only on, master off & all other buses turned off
>3/ Main bus & E bus on with the E bus being fed through the main bus & master
>
>Is the considered opinion of the group that a diode is more reliable than
>a switch & therefore used, or, to simplify the whole design or what?
>
>Just curious as there is a slight power loss across the diode of course
>which is the only negative and think of at this point.
The design goal is to have TWO INDEPENDENT paths of
power to the e-bus, ONE of which is battery direct so
that one can operate e-bus loads with the battery
master switch off.
If you use a single switch in the mode you've described,
there is a single point of failure in the switch.
Voltage drop in the diode is not significant. Consider
the fact that when power is expected to come through the
diode, the alternator is operating. This raises the main
bus to 14.2 to 14.6 volts. A typical 0.7 volt drop in the
diode offers an e-bus supply of 13.5 to 13.9 volts . . .
entirely satisfactory supply levels.
Contrast normal operating conditions with battery-only
operations where the e-bus will start out at 12.5 and
drop to 11.0 by the time the battery is used up.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Diodes versus switches 101 ? |
>
>
>I think it's important to take into account what the purpose of the switch
>and/or diode is, and more important, what the failure modes of the
>circuits around it is. A diode may be much more reliable when used within
>it's designed specs, but if you overload it, it will fail much quicker
>than a switch. Compare a diode and a switch, both rated at 25A. A
>short-circuit current of 100A through the diode for a few seconds will
>make it fail, most likely open circuit. The same current through a switch
>may heat it up and damage the contacts, even cause some sparks, but it may
>still limp along.
I've never replaced a diode that failed open. I don't
mean to imply that they NEVER fail open but in what must
be dozens of personal observations, I've never seen one
open. Oh yeah, take that back. I did have a plastic 1A
device that blew up such that the stuff between the wires
just disappeared. I guess that could be classified as
an "open".
Diodes are generally pretty robust. Exemplar devices
might include the diminutive 1A, plastic 1N4001 described
here . . .
http://www.aeroelectric.com/Mfgr_Data/Semiconductors/1N4001.pdf
and his big brother 25A bridge rectifier . . .
http://www.aeroelectric.com/Mfgr_Data/Semiconductors/gbpc12.pdf
Note that the single cycle surge (approx 8 milliseconds) for
the 1A device is 30A. The 25A device will stand off 300A
for 8 mS.
Power diodes for steering energy amongst the busses in
the heavy iron birds have been used for 50+ years. Their
failure rates have been exceedingly low.
Diodes also have an exceedingly long service life. I've
never seen one 'wear out'. On the other hand, switches do
have a service life . . . one that is profoundly affected
by numbers of operations per year and under what electrical
load and environmental conditions. I've seen switches open
up with very few cycles on them after ten+ years of sitting
in an airplane.
99.9% of observed diode failures in light aircraft were
in alternators where the designers of the installation
did not exercise due diligence with respect to cooling.
Concerns for a 25A diode used as the e-bus normal feedpath
management are not well founded.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: ANL/ANN current limiter |
>
>Hello
>
> I have a relatively long run (10+ ft) of 1/0 CCA main battery power
> wire in my -8 I am building from the rear baggage all the way to the
> front firewall. I would like to install an current limiter on the output
> of the battery as an added layer of protection for my long wire run. I
> know Mr. Nuckolls has not advocated that on small aircraft, but I want to
> do it anyway as peace of mind since the wire passes thru quite few
> bulkheads and want to have something which will trip alot faster than I
> can act. So, which is the better choice, ANN or ANL and what current
> rating would be best, I have a 200 hp angle valve to start?
An ANL200 will carry 300A continuously. See:
http://www.aeroelectric.com/Mfgr_Data/Fuses_and_Current_Limiters/Bussman/ANL_Specs.pdf
This device can practically be expected to carry
worst case cranking currents without nuisance tripping.
At the same time, if you did fault that cable to
the edge of a lightening hole, the same ANL will
probably not trip while the wire burns its way
clear at the edge of the hole.
This is why these circuits have not been "protected"
in TC aircraft. Protection robust enough to stay
connected for worst case cranking will also carry
more than enough current in a 'soft fault' condition
to burn away the offending aluminum with little or
no damage to the copper.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: "Coat Hanger" antenna |
>No offense to Ernest or Bob, the old coat hanger
>antennas that you terminated the coax with crimp on
>lugs has not been used in production airplanes since
>the 50's or early 60's.
>
>Coat hanger antenna
><http://www.aircraftspruce.com/catalog/avpages/av534.php>http://www.aircraftspruce.com/catalog/avpages/av534.php
>
>What Eric says about "EM field energy", which I recall
>bits from physics and armature radio, the coax,
>BNC connector is way more efficient. That inch of
>exposed shield/core & important lost insulation does
>count. The "coat hanger antenna connections are
>subject to corrosion and fatigue way more than a BNC
>connector. Just my opinion.
But without quantification. The advantages of the
modern antennas are mainly mechanical. They don't
twist in the insulator. In high-dollar models there
are p-static immunities due to the DC grounded
fabrication . . . and they look sexier and have lower
maintenance costs.
>
>No one is seriously using the coat hanger wire antenna
>on new OEM aircraft any more.
. . . for the reasons stated plus some others but
none related to observable performance.
>"Testimonials" that they work in the plane or bench are
>great, but unless you do a test on the airframe in an
>antenna test chamber (EMF / RF anechoic chamber),
>we are guessing. Besides performance there is the
>reliability of the installation.
>
>Just from an installation standpoint, spend the $124
>for the real antenna and leave the $50 coat hanger
>antenna for the closet. Antenna energy, non-ionizing
>radiation is EMF energy at high frequencies. It needs
>"ducting" to be most effective.
???? don't know what this "ducting" stuff is.
>
>Does the "strip-it crimp-it" antenna connection work?
>Yes it "works", but gosh ughaaa, ugly.
>
>We're talking about 5-8 watts of energy and communications
>of 5 to 50 mile, line of sight, listening for even more powerful
>transmitters, usually without obstacles. We can get away
>with a weak antenna.
"Weak" is un-quantified. However, just like concerns about
"iron poor blood" it may help sell alternative antennas.
>
>The coat hanger works, but its not ideal. We have better
>ways. If I was restoring a classic Beech or something, yea
>I'd keep the coat hanger antenna. Other wise coat hangers
>are for the closet (pun intended).
>
>$110-$150 for newer antenna design
>
><http://www.aircraftspruce.com/catalog/avpages/av17.php>http://www.aircraftspruce.com/catalog/avpages/av17.php
>
>PS: Some have experienced RFI with unshielded antenna
>connections thru gauges and avionics.
Now this IS a potential effect because the little
chunk of antenna inside the aircraft is indeed a
radiator.
However, in the age of plastic airplanes (both experimental
and T/C) and reasonable adherence to DO-160 radiated
and conducted susceptibility issues, potential victims
are not going to go T/U due to the small increase in
energy at the panel due to errant radiation. Field
strengths for your VHF comm while transmitting are really
strong in the cockpit (tens of volts per meter) even
with idealized antenna installations.
Bottom line is that we're fabricating OBAM aircraft.
Yes, there are sexier, more convenient and probably
more 'efficient' antennas to be considered over the
stone-simple, rod and feed-thru insulator antennas
that were quite popular 40 years ago. It all comes
down to the builder's preferences for trading his/her
personal expenditure of $time$ versus purchasing
the product of someone else's $time$ for a more
sophisticated design.
Performance risks for going the low-dollar, DIY
route are low and easily managed.
Bob . . .
________________________________________________________________________________
| From: | "Dave Saylor" <Dave(at)AirCraftersLLC.com> |
| Subject: | Plane Power's Friendly Warning Light |
B&C's flashing warning light is pretty annoying, so I was glad to see Plane
Power's light is a steady, happy glow.
Trouble is, it turns out, that the annoying flash is pretty handy when you
really need to see it...no equipment failures to report, just didn't use the
checklist...twice >:-(
So, does anyone have a suggestion as to how to wire a flasher into the PP
light? Can I just use a simple automotive flasher, or do I need something
designed for less current? I want a fairly high (annoying) flash rate.
Hope I don't need a horn.
Thanks,
Dave Saylor
AirCrafters LLC
140 Aviation Way
Watsonville, CA
831-722-9141
831-750-0284 CL
www.AirCraftersLLC.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Plane Power's Friendly Warning Light |
>B&C's flashing warning light is pretty annoying, so I was glad to see
>Plane Power's light is a steady, happy glow.
If I recall correctly, the Plane Power warning
light drives from the alternator fail output of
the built-in regulator. While certainly better than
no light, it's not an independent monitor of
alternator/regulator performance.
You might consider a separate LV Warning
system that flashes the light.
>
>Trouble is, it turns out, that the annoying flash is pretty handy when you
>really need to see it...no equipment failures to report, just didn't use
>the checklist...twice >:-(
Yup, when we crafted that system the flash rate
was set at approx 3 flashes per second. Supposedly
this is the rate most 'irritating', i.e. attention
getting for cockpit warning lamps.
Bill also supplied a 6v lamp for the 14V regulators
to increase intensity of the lamp for sunlight viewability.
>
>So, does anyone have a suggestion as to how to wire a flasher into the PP
>light? Can I just use a simple automotive flasher, or do I need something
>designed for less current? I want a fairly high (annoying) flash rate.
The simplest method for adding flashing to
an existing lamp circuit is by means of a "two-wire
lamp flasher". There are a number of variations
on the theme. One such circuit is illustrated here:
http://www.aeroelectric.com/Pictures/Schematics/Lamp_Flasher_1.pdf
This circuit should be assembled with a C-Mos
version of the ubiquitous 555 timer. In this
case, the Intersil ICM7555 is called out.
This flasher will deliver a symmetrical ON-OFF
flash pattern at approx 3Hz.
An alternative is shown at:
http://www.aeroelectric.com/Pictures/Schematics/Lamp_Flasher_2.pdf
This is built from more generic discrete parts
and can probably be made to do what you want to
accomplish although its not likely to be a
symmetrical pattern.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "John Cleary" <john_rv10(at)yahoo.com> |
| Subject: | Critique please Bob and other learned members |
Bob,
First, thank you for your outstanding contribution to the OBAM
community,
especially for the AeroElectric Connection, this email list, and the
sample
wire book which we have used to craft our design. We are building an all
electric panel, IFR RV-10, and in the development of our thoughts and
knowledge about and around our electrical design, your input, and that
of
the other learned people on this email list, have been invaluable. You
have
all helped us move from a position of zero knowledge to a position where
we
now have some idea of what questions to ask.
We struggled around Z-14, Z-13/8 and finally Z-12 to settle on our
current
design, and we would welcome comments from you and others on any aspect
of
our design, but especially on the specific question areas noted below.
Our mission is cross country flight with IFR capability, mostly with two
POB
and the ability to take large amounts of luggage as we tour Australia.
We concluded that the alternator was the unit with the highest
probability
of failure in service and decided early on that we would go with 2
alternators.
We have calculated that we have added about 55 lb to the basic VANs
design
empty weight, primarily in the panel, console, overhead console, second
alternator and second battery. We have elected to maintain design gross
weight which limits baggage in the baggage compartment to 45lb
95% of the time my wife and I will fly in the front seats. We are both
light
by VANs standards, and that combination plus the added weight indicated
a
need to move some weight forward. We have decided to go with 2 PC680
batteries instead of the standard battery, and the W & B works out
theoretically perfect with the second battery relocated forward in the
centre console. The console battery, power buss and power switches are
all
co-located in the centre console with a spark isolation barrier between
the
electrical switches and the fuel system.
This is a long introduction, but necessary I think for you to understand
why
we have gone the way we have.
We began by trying to fit Z14 to our perceived needs, then Z13/8. The
electrical load analysis shows that in IFR conditions with the pitot
heater
on, we will draw about 17 amps continuous on the power circuit and also
on
the combined endurance and avionics circuits. The max/intermittent draw
on
each circuit is about 37 amps. We weren=92t happy with either of these
being
loaded onto the 20 amp system as part of normal operations, especially
if
that system was to be our endurance circuit. Z14 and Z13/8 also both
required that we run an extra fat wire back to one of the batteries.
Our decision finally was that we should concentrate on designing the
system
for robust normal operations with the minimum parts count for
reliability,
weight and cost reasons, and make the back up systems as simple as
possible.
We decided to go with a modified Z12 design because it keeps the noisy
wires
firewall forward and away from the panel, it uses one less contactor to
use
both batteries to crank the engine, the day to day loads are left with
the
larger alternator, and there is one less fat wire needed when the
batteries
are down the back. Normal operations will be to run with both battery
contactors energised, the main alt on, the endurance and avionics busses
fed
from the main buss, and the aux alt resting on standby.
Failure modes would be treated as follows:-
Main alt failure - turn off main alt, turn on aux alt and
adjust
loads to suit
Much less likely failures:-
Main battery contactor fails closed in flight ' no action
needed
till landed
Main battery contactor fails open in flight ' The alternator
load
is balanced by the aux battery which needs to be always on in flight.
The
main battery relay can be opened to bring the main battery back on line
Aux battery contactor fails closed in flight ' no action
needed
till landed
Aux battery contactor fails open in flight ' No action
necessary,
but aux relay can be opened if desired
Both alts fail ' Open main or aux battery relay to run min
endurance load approx 3.5A. Close main and aux batt contactors to
conserve
power for landing phase
Fuse link between power buss and endurance buss blows ' Open
main
or aux batt relay to feed endurance and avionics busses
Alternators:- We plan to go with the Plane Power 60A alternator for the
main
alt, primarily because of its inherent simplicity from an installation
and
operations perspective. We plan to leave the aux alt turned off unless
the
main alt fails, which means it should rarely get used. The SD 8 seems
perfectly designed for this task and there is about a 3 lb penalty with
the
SD 20, but the SD 20 will give better peace of mind should the main alt
fail
in IMC. So, we plan to go with the SD-20 subject to your critique, and
this
leads us to our first question:- Is it OK to leave the SD 20 installed
but
not running? Will this cause any problems with the SD 20? Are the
generic
ford regulator and OVM adequate and appropriate to this task with the SD
20?
Power supply to the alternator fields:- Do you have any concerns with
the
alt fields supplied as depicted ' ie main alt field via 22AWG fuseable
link
through 18AWG wire to the 5A CB, then 20AWG to switch and the main alt
field. Does it matter which side of the switch the CB goes in this case?
Would a 5A SCB be better?
Ground system:- We plan to use your forest of tabs either side of the
firewall for everything on the panel and firewall forward, with the
engine
crankcase grounded to the through firewall stud. We have nominated local
grounds for items such as landing lights, pitot heater, etc. We think we
should ground both batteries locally. Is this correct, or should we
handle
battery grounds some other way with this design?
Fuse tray:- Are there any risks in placing the endurance buss, avionics
buss, regulator and OVM in close proximity to each other on a hinged
fuse
tray under the panel? Is there a preferred way to connect the two busses
together when in such close proximity?
We currently plan not to fit the diode between the main buss and the
endurance buss because the SD 20 gives us the time needed to
systematically
reduce loads as needed should the main alt fail. Do we create any
problems
for ourselves not having an isolation relay or diode between the main
buss
and the endurance buss?
Bob, in appendix Z you comment that the ACS-OFF-L-R-BOTH-START keyswitch
is
not suitable for electronic ignition. I have also read somewhere that if
you
use this switch with an electronic ignition you disconnect the ground at
the
back of the switch. We are confused on this matter, so would you please
explain whether you can use this switch or not with a future electronic
ignition, and what you have to do to make it work properly? If it
can=92t be
used, would you please explain what problem it causes? Do the same
issues
apply with the potential future installation of a Pmag?
Bob and others, we thank you for the time you take to look at our
design,
which is a works in progress. We will value any comments you care to
make.
John and Jenny Cleary and Peter Bowman,
Australia
Canopy and doors 90% done and 90% to go
Trying to finalise the wiring plan so we can drill the holes and fit the
cable attachments prior to painting inside
Checked by AVG.
10/03/2008
11:07 AM
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Plane Power's Friendly Warning Light (Corrected |
Link)
B&C's flashing warning light is pretty annoying, so I was glad to see Plane
Power's light is a steady, happy glow.
If I recall correctly, the Plane Power warning
light drives from the alternator fail output of
the built-in regulator. While certainly better than
no light, it's not an independent monitor of
alternator/regulator performance.
You might consider a separate LV Warning
system that flashes the light.
Trouble is, it turns out, that the annoying flash is pretty handy when you
really need to see it...no equipment failures to report, just didn't use
the checklist...twice >:-(
Yup, when we crafted that system the flash rate
was set at approx 3 flashes per second. Supposedly
this is the rate most 'irritating', i.e. attention
getting for cockpit warning lamps.
Bill also supplied a 6v lamp for the 14V regulators
to increase intensity of the lamp for sunlight viewability.
So, does anyone have a suggestion as to how to wire a flasher into the PP
light? Can I just use a simple automotive flasher, or do I need something
designed for less current? I want a fairly high (annoying) flash rate.
The simplest method for adding flashing to
an existing lamp circuit is by means of a "two-wire
lamp flasher". There are a number of variations
on the theme. One such circuit is illustrated here:
http://www.aeroelectric.com/Pictures/Schematics/Lamp_Flasher_1.pdf
This circuit should be assembled with a C-Mos
version of the ubiquitous 555 timer. In this
case, the Intersil ICM7555 is called out.
This flasher will deliver a symmetrical ON-OFF
flash pattern at approx 3Hz.
An alternative is shown at:
http://www.aeroelectric.com/Pictures/Schematics/Lamp_Flasher_2.jpg
(was .pdf)
This is built from more generic discrete parts
and can probably be made to do what you want to
accomplish although its not likely to be a
symmetrical pattern.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: "Coat Hanger" antenna |
>From: "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net>
>Subject: Re: "Coat Hanger" antenna
>>No offense to Ernest or Bob, the old coat hanger
>>antennas that you terminated the coax with crimp on
>>lugs has not been used in production airplanes since
>>the 50's or early 60's.
>>
>>Coat hanger antenna
>><http://www.aircraftspruce.com/catalog/avpages/av534.php">http://www.aircraftspruce.com/catalog/avpages/av534.php>http://www.aircraftspruce.com/catalog/avpages/av534.php
>>
>>What Eric says about "EM field energy", which I recall
>>bits from physics and armature radio, the coax,
>>BNC connector is way more efficient. That inch of
>>exposed shield/core & important lost insulation does
>>count. The "coat hanger antenna connections are
>>subject to corrosion and fatigue way more than a BNC
>>connector. Just my opinion.
>But without quantification. The advantages of the
>modern antennas are mainly mechanical. They don't
>twist in the insulator. In high-dollar models there
>are p-static immunities due to the DC grounded
>fabrication . . . and they look sexier and have lower
>maintenance costs.
Bob its more than sexy it is indeed that last inch of exposed
dielectric, often close to some conductive material, even
in a composite plane (don't they need a ground plane for a 1/4
wave dipole?) that is the issue, at least to me.
>>No one is seriously using the coat hanger wire antenna
>>on new OEM aircraft any more.
>for the reasons stated plus some others but
>none related to observable performance.
Bob I have to take your word for it. However in my experience
I have seen these antennas SRW go up and up and up with time
because of dissimilar metal corrosion and bad crimps. Like I
said most pilots only demand short range line-O-sight
communication, not DX comm. The term observable
performance should include maintenance and durability in
my humble opinion.
>>"Testimonials" that they work in the plane or bench are
>>great, but unless you do a test on the airframe in an
>>antenna test chamber (EMF / RF anechoic chamber),
>>we are guessing. Besides performance there is the
>>reliability of the installation.
>>
>>Just from an installation standpoint, spend the $124
>>for the real antenna and leave the $50 coat hanger
>>antenna for the closet. Antenna energy, non-ionizing
>>radiation is EMF energy at high frequencies. It needs
>>"ducting" to be most effective.
>>
>>???? don't know what this "ducting" stuff is.
Well Wikipedia to the rescue:
http://en.wikipedia.org/wiki/Coaxial_cable
I use the word "ducting" in an informal way to describe how
a coaxial cable propagates elect mag wave energy.
"Coaxial lines solve this problem by confining the
electromagnetic wave to the area inside the cable,
between the center conductor and the shield. The
transmission of energy in the line occurs totally through
the dielectric inside the cable between the conductors."
"ducting" - was a casual my way of describing how coaxial
propagates EMW. Where open wire transmission lines, like
you have that inch before the "coat hanger" antenna, two
parallel wires, have the property where the electromagnetic
wave propagating down the line, extends into the space
surrounding it, an undesirable characteristic. You say the
loss is small? OK I guess, sure but every little bit helps
or hurts. The fact is radios are so good with filters and
excellent sensitivity and stability, a less than optimal
antenna can be some what tollerated.
>>Does the "strip-it crimp-it" antenna connection work?
>>Yes it "works", but gosh ughaaa, ugly.
>>
>>We're talking about 5-8 watts of energy and communications
>>of 5 to 50 mile, line of sight, listening for even more powerful
>>transmitters, usually without obstacles. We can get away
>>with a weak antenna.
>"Weak" is un-quantified. However, just like concerns about
>"iron poor blood" it may help sell alternative antennas.
True it is unqualified, but we could get into dB or signal strength,
but all I am saying is in Aviation we are talking about strong
signals at short distances, most of the time, period. However if
you want real long range communications at distance than it
does matter. Yes "matter" is an unqualified term as well.
>>The coat hanger works, but its not ideal. We have better
>>ways. If I was restoring a classic Beech or something, yea
>>I'd keep the coat hanger antenna. Other wise coat hangers
>>are for the closet (pun intended).
>>
>>$110-$150 for newer antenna design
>><http://www.aircraftspruce.com/catalog/avpages/av17.php">http://www.aircraftspruce.com/catalog/avpages/av17.php>http://www.aircraftspruce.com/catalog/avpages/av17.php
>>
>>PS: Some have experienced RFI with unshielded antenna
>>connections thru gauges and avionics.
>Now this IS a potential effect because the little
>chunk of antenna inside the aircraft is indeed a
>radiator.
So true Bob.
>However, in the age of plastic airplanes (both experimental
>and T/C) and reasonable adherence to DO-160 radiated
>and conducted susceptibility issues, potential victims
>are not going to go T/U due to the small increase in
>energy at the panel due to errant radiation. Field
>strengths for your VHF comm. while transmitting are really
>strong in the cockpit (tens of volts per meter) even
>with idealized antenna installations.
>
>Bottom line is that we're fabricating OBAM aircraft.
>Yes, there are sexier, more convenient and probably
>more 'efficient' antennas to be considered over the
>stone-simple, rod and feed-thru insulator antennas
>that were quite popular 40 years ago. It all comes
>down to the builder's preferences for trading his/her
>personal expenditure of $time$ versus purchasing
>the product of someone else's $time$ for a more
>sophisticated design.
Well sexier I guess, but cost is only times 2 and when you
have a $1000 or $3000 radio, $60 more is a drop in da bucket.
>Performance risks for going the low-dollar, DIY
>route are low and easily managed.
>
>Bob
Well I guess we disagree with the last part, but I agree
making antennas and testing them is FUN! VHF on a plane
is pretty easy, and I have no problem with a DIY, however
as I said in my opinion, if you are going to buy an antenna,
like most builders, get a $120 antenna with a BNC connector.
My focus is all towards metal planes, composites have more
flexibility to experiment with internal antennas.
A BNC will be more secure & robust. You can have BNC
problems and other issues, but keeping the coaxial cable
intact to the last inch, is not totally trivial.
With a composite plane the connection will be on the "back
side of the ground plane? Right? There will be signal loss and
reflected RF into the airplane, IMHO.
Good discussion. The proof is in the eating of the pudding.
Fly a plane with both antennas and test them against a
ground station for both TX and RX. I think you will see a
difference in one antenna getting a weak incoming signal
and getting out a stronger signal. Of course bent whips
are a compromise. The radiating element should be as
perpendicular to the ground plane as possible but most
pilots like the looks and lower drag of the bent whip for a
little more SRW. Also the "Blade" high speed antennas
have "wider" band width. There are good enough antennas
and better, best antennas. It is definitely esoteric but for
just secure connection the BNC has it over the crimp
and screw exposed twin lead approach, at least in the
VHF band of freq's, in my opinion. Old ways are still
good but there is a reason new methods & connections
where developed. It may take more sensitive lab equip
to notice but I can't believe it makes NO difference, but
than you say you tested it, and I have not. All I can go
by is when trouble shooting poor radio performance on
old planes, the first place I look is at those old corroded
connections on the "coat hanger".
Cheers George
---------------------------------
Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.
________________________________________________________________________________
| From: | "nauga(at)brick.net" <dhyde01(at)earthlink.net> |
| Subject: | Request for Bob N. |
Bob, I have not been able to reach you through direct e-mail or the message area
of your website (multiple attempts both ways) - can you check on the status
of an order for me?
Dave 'Nauga' Hyde
________________________________________________________________________________
| From: | "Bill Settle" <billsettle(at)bellsouth.net> |
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: "Coat Hanger" antenna |
> >From: "Robert L. Nuckolls, III"
> <nuckolls.bob(at)cox.net>
> >Subject: Re: "Coat Hanger" antenna
>
>
> >>No offense to Ernest or Bob, the old coat hanger
> >>antennas that you terminated the coax with crimp on
> >>lugs has not been used in production airplanes since
> >>the 50's or early 60's.
> >>
> >>Coat hanger antenna
>
>
> >><<http://www.aircraftspruce.com/catalog/avpages/av534.php>http://www.aircraftspruce.com/catalog/avpages/av534.php>http://www.aircraftspruce.com/catalog/avpages/av534.php>http://www.aircraftspruce.com/catalog/avpages/av534.php
> >>
> >>What Eric says about "EM field energy", which I recall
> >>bits from physics and armature radio, the coax,
> >>BNC connector is way more efficient. That inch of
> >>exposed shield/core & important lost insulation does
> >>count. The "coat hanger antenna connections are
> >>subject to corrosion and fatigue way more than a BNC
> >>connector. Just my opinion.
>
> >But without quantification. The advantages of the
> >modern antennas are mainly mechanical. They don't
> >twist in the insulator. In high-dollar models there
> >are p-static immunities due to the DC grounded
> >fabrication . . . and they look sexier and have lower
> >maintenance costs.
>
>Bob its more than sexy it is indeed that last inch of exposed
>dielectric, often close to some conductive material, even
>in a composite plane (don't they need a ground plane for a 1/4
>wave dipole?) that is the issue, at least to me.
Sure. But let's consider the "loaded" antenna. An antenna that's
physically too short for efficient operation at the desired frequency.
The ideal, full sized quarter-wave mobile antennas operating at say 14 Mhz
would LIKE to have about 17.5 feet of antenna on the bumper. See:
http://tinyurl.com/2dyfss
This is not practical on a moving vehicle so some means of electrically
lengthening a "too short" antenna is called for. This is done in a variety
of ways but all involve adding some reactive component (inductive or
capacitive)
to the antenna.
My last HF mobile installation featured a 4' stub mast, an adjustable
center loading coil and an 8' whip antenna above all this. Here's
a modern example of this style of artificial antenna lengthening:
http://www.hiqantennas.com/images/MVC-462.jpg
Let's examine a practical example where there's value
in making an antenna shorter while minimizing effects on
performance. A few years ago I got a call from the production
line on some new ELT transmitters that were shutting down
with a high SWR fault. Here's the antennas in question:
http://tinyurl.com/2u5c8u
The original system integrator installed dual antennas
(125.5 and 406 Mhz) under the fiberglas 'instep cap'
of the vertical fin. There were some composite
air ducts with metallic components also located
in the fin cap. These not only made it necessary to
fold the longer antenna over, proximity of the metal
further de-tuned it. See:
http://tinyurl.com/38symp
Older versions of the ELT transmitter would tolerate
this degradation of antenna performance, the new ones would
not.
I wrote a white paper suggesting a variety of options.
The elegant solution was a top-loaded antenna physically
short enough to mount under the fin cap and avoid
close proximity to the duct-metal.
http://tinyurl.com/2vv5e4
I crafted an exemplar antenna that was only 9" tall
and took it to the lab for comparison with a full
sized 24" antenna. It's radiation angle was higher
and maximum radiation levels were down by less than
2 dB from the full sized quarter wave. Entirely
satisfactory for this installation.
We could have considered some other scenarios. See:
http://tinyurl.com/3aaocs
There are an infinite number of combinations of
top, center and base loading that would minimize
SWR at the frequency of interest. However, all versions
other than top-loading increased fabrication labor
and produced a lower performance.
Let's take the ideas illustrated above and consider
when one chooses to use the stone-simple, rod and
feed-thru antenna.
Open conductors have inductance. As a rule of thumb,
we ball-park an open wire (and in this case, an extension
of the antenna base below the ground plane) at 20 nH/inch.
Assuming 1.5" of bare conductors total, we can expect
something on the order of 30nH of series inductance at
the base of the antenna. This works out to about 25 ohms
of reactance at 130 Mhz. A full length, 24" antenna's
center frequency would shift downward due to this loading
inductance.
A purest would get out the antenna analyzer and trim
the antenna's physical length (shift toward capacitive
reactance) to balance reactive effects of the base loading
inductance.
The next time I have occasion to get the test ground
plane out, I'll take a look at the effects of exposed
conductors at the base of the stone-simple antenna
and report the amount of shortening required to shift
the antenna's center frequency back to the design
optimum.
These exposed conductors ARE at the base of the
antenna where the highest currents are encountered
which go hand-in-hand with the highest radiation.
So indeed, we are squirting some RF into the aircraft's
interior spaces that would not be present with other
antennas . . . but in practice this is seldom a problem
either for EMC issues or overall performance.
>
> >>No one is seriously using the coat hanger wire antenna
> >>on new OEM aircraft any more.
>
> >for the reasons stated plus some others but
> >none related to observable performance.
>
>Bob I have to take your word for it. However in my experience
>I have seen these antennas SRW go up and up and up with time
>because of dissimilar metal corrosion and bad crimps.
Absolutely! But connectors corrode too . . . and
suffer from bad craftsmanship at assembly. I tossed
out the large-area, low-pressure ground terminal supplied
with the stone-simple antenna and substituted a PIDG
terminal properly bonded to the skin with a 10-32 screw
torqued up tight. Similarly, I made sure that the
PIDG terminal at the base of the antenna had the
super-mash on it between two nuts. If you don't
have gas-tight joints, they will degrade with time.
> Like I
>said most pilots only demand short range line-O-sight
>communication, not DX comm. The term observable
>performance should include maintenance and durability in
>my humble opinion.
To be sure. The DIY antennas do have cost of ownership issues
that are strongly affected by craftsmanship of the original
installation. But if one understands the potential 'gotchas'
with ANY antenna and exercises due diligence for craftsmanship,
there's good value to be realized from either of these
antennas.
't know what this "ducting" stuff is.
>
>Well Wikipedia to the rescue:
><http://en.wikipedia.org/wiki/Coaxial_cable>http://en.wikipedia.org/wiki/Coaxial_cable
>
>I use the word "ducting" in an informal way to describe how
>a coaxial cable propagates elect mag wave energy.
>
> "Coaxial lines solve this problem by confining the
> electromagnetic wave to the area inside the cable,
> between the center conductor and the shield. The
> transmission of energy in the line occurs totally through
> the dielectric inside the cable between the conductors."
>
>"ducting" - was a casual my way of describing how coaxial
>propagates EMW. Where open wire transmission lines, like
>you have that inch before the "coat hanger" antenna, two
>parallel wires, have the property where the electromagnetic
>wave propagating down the line, extends into the space
>surrounding it, an undesirable characteristic. You say the
>loss is small? OK I guess, sure but every little bit helps
>or hurts. The fact is radios are so good with filters and
>excellent sensitivity and stability, a less than optimal
>antenna can be some what tollerated.
Understand.
>
>
> >"Weak" is un-quantified. However, just like concerns about
> >"iron poor blood" it may help sell alternative antennas.
>
>True it is unqualified, but we could get into dB or signal strength,
>but all I am saying is in Aviation we are talking about strong
>signals at short distances, most of the time, period. However if
>you want real long range communications at distance than it
>does matter. Yes "matter" is an unqualified term as well.
Wouldn't argue that the stone-simple antenna does not
represent the best-we-know-how-to-do. But neither is
a Toyota starter bolted to a Lycoming on an adapter
plate carved out on a bandsaw.
I would recommend that any builder take advantage of
the convenience of pre-fabricated, optimized antennas.
But I think we would be remiss as teachers if we did not
define the simple-ideas that control performance
and service life of the DIY approaches. I would not
discourage anyone from doing the best they can with
what they have to work with . . . whether by choice or
circumstance.
>
> >Bottom line is that we're fabricating OBAM aircraft.
> >Yes, there are sexier, more convenient and probably
> >more 'efficient' antennas to be considered over the
> >stone-simple, rod and feed-thru insulator antennas
> >that were quite popular 40 years ago. It all comes
> >down to the builder's preferences for trading his/her
> >personal expenditure of $time$ versus purchasing
> >the product of someone else's $time$ for a more
> >sophisticated design.
>
>Well sexier I guess, but cost is only times 2 and when you
>have a $1000 or $3000 radio, $60 more is a drop in da bucket.
Agreed. But one can do the stone-simple antenna with
self procured components for much less than the $60
sale price . . . and there are very few builders who
have $3000 tied up in a radio.
>
> >Performance risks for going the low-dollar, DIY
> >route are low and easily managed.
> >
> >Bob
>
>Well I guess we disagree with the last part, but I agree
>making antennas and testing them is FUN! VHF on a plane
>is pretty easy, and I have no problem with a DIY, however
>as I said in my opinion, if you are going to buy an antenna,
>like most builders, get a $120 antenna with a BNC connector.
>My focus is all towards metal planes, composites have more
>flexibility to experiment with internal antennas.
>
>A BNC will be more secure & robust. You can have BNC
>problems and other issues, but keeping the coaxial cable
>intact to the last inch, is not totally trivial.
True. We could build a bracket to mount the connector
but it needs to be attached to the airframe with rivets,
not by assembly forces of the ceramic feed-thru insulator.
The problems of establishing gas-tight joints at both
the ground plane and at the antenna feed-point are the
same for both metal and plastic airplanes. See:
http://tinyurl.com/yu38rz
I would hope that the efforts I made toward that goal
over 35 years ago paid off in trouble-free performance
over the lifetime of the installation. The last time
I had occasion to install a rod-n-cone antenna was
on a wrecked straight-tail, C182 during the rebuild.
It was a belly mounted antenna for a #2 nav/com.
The antenna survived the accident but the belly skin
was wrinkled and got replaced.
>
>With a composite plane the connection will be on the "back
>side of the ground plane? Right? There will be signal loss and
>reflected RF into the airplane, IMHO.
True. The effects are non-zero but for most users
are not operationally significant.
>
>Good discussion. The proof is in the eating of the pudding.
>Fly a plane with both antennas and test them against a
>ground station for both TX and RX. I think you will see a
>difference in one antenna getting a weak incoming signal
>and getting out a stronger signal. Of course bent whips
>are a compromise. The radiating element should be as
>perpendicular to the ground plane as possible but most
>pilots like the looks and lower drag of the bent whip for a
>little more SRW. Also the "Blade" high speed antennas
>have "wider" band width. There are good enough antennas
>and better, best antennas. It is definitely esoteric but for
>just secure connection the BNC has it over the crimp
>and screw exposed twin lead approach, at least in the
>VHF band of freq's, in my opinion. Old ways are still
>good but there is a reason new methods & connections
>where developed. It may take more sensitive lab equip
>to notice but I can't believe it makes NO difference,
. . . no perceivable difference from the pilot's
seat. We often get wrapped around a performance axle
trying to tweak things based on test measurements
that return no operational benefits. I had one
instructor tell me there was benefit after a
balked landing to turn off the alternator so that we
could get more horsepower to the prop! Intuitively
we know there's a measurable difference but
the practical benefits are someplace between zero and not
much.
> . . . but than you say you tested it, and I have not.
All of the testing has been in the lab were we
do indeed see quantifiable differences. But in
practice, tens of thousands of these antennas have
flown and offered the user good return on investment
too.
> All I can go
>by is when trouble shooting poor radio performance on
>old planes, the first place I look is at those old corroded
>connections on the "coat hanger".
All very much on point . . . and I would suggest that
any readers of this List make note of the fact that
some installations are more deserving of preventative
maintenance than others. Use of good assembly practice
when making up the joints will forestall if not eliminate
future maintenance events.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Z-19 Series Architecture |
| From: | "Mark Sletten" <marknlisa(at)hometel.com> |
Listers,
I've posted this question a couple of times via the Matronics Forum interface,
but I've not gotten a response.
My posts are coming back to me via the daily list digest, but I'm not sure Bob
is getting them. Should I email directly to the Matronics list instead of posting
via the Forum?
Regards,
Mark
Mark Sletten wrote:
> Bob,
>
> On the Z-19 rev M and Z-19/RB rev A drawings the E-BUS normal feed is from
> the Main PWR Dist block thru a 7A breaker and diode.
>
> On all other drawings it appears the E-BUS normal feed is directly off the
> Main PWR Dist Block binding post (not a breaker) thru a diode.
>
> Is there a reason for the different setup on the Z-19 series?
>
>
> Regards,
>
> Mark Sletten
--------
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=169244#169244
________________________________________________________________________________
| Subject: | Re: Z-19 Series Architecture |
| From: | "mikef" <mikefapex(at)gmail.com> |
Mark,
Your posts are getting through, I've not seen any replies to your question either.
There was a related Z19 question a few weeks before xmas about updating the Z19
to reflect separate power feeds for coils (and possibly injectors). No further
replies seen on that either.
Mike
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=169263#169263
________________________________________________________________________________
| Subject: | Re: Z-19 Series Architecture |
Mark,
I questioned that too. Not sure I ever got a strait answer. As far as I
am concerned that constitutes the weakest link for what is supposed to
be an essential bus system.
I did see something Bob mentioned about the feed coming from both ends.
One side is fed from the 7A fuse, and the other from the switch which is
powered via the backup battery via its contactor switch. I believe Bob's
logic is that one will backup the other. If you turn the switch off, the
e-bus still has 7A and if you lose the 7A job, the switch will power the
e-bus through via the backup battery contactor. The diode keeps the
juice from going back other way (through the fuse) when powered by the
switch.
Earlier I questioned the 7A limit, but if you start breaking down the
load, that can support a lot of today's panel. A Dynon and an sl30 are
still within values. That's all I need to get down. The fuel pumps,
ignition and engine stuff would all feed off of the secondary power
switch not the e-bus.
To hell with idealism - for my Sub, the e-bus will work both ways based
on the intended design or an improvement in it. 7A is not going to make
anything glow. In an emergency we'll be glad for the 7A.
What I think is missing or confusing is the process (a standard issue
for technos). Be sure you have a sound practice for throwing switches
and knowing what is working etc. I may even include a warning light
which closes if that ole 7A takes a pill.
How'z that project going?
Glenn
http://n661gl.blogspot.com
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mark
Sletten
Sent: Wednesday, March 12, 2008 11:06 AM
Subject: AeroElectric-List: Re: Z-19 Series Architecture
-->
Listers,
I've posted this question a couple of times via the Matronics Forum
interface, but I've not gotten a response.
My posts are coming back to me via the daily list digest, but I'm not
sure Bob is getting them. Should I email directly to the Matronics list
instead of posting via the Forum?
Regards,
Mark
Mark Sletten wrote:
> Bob,
>
> On the Z-19 rev M and Z-19/RB rev A drawings the E-BUS normal feed is
> from the Main PWR Dist block thru a 7A breaker and diode.
>
> On all other drawings it appears the E-BUS normal feed is directly off
> the Main PWR Dist Block binding post (not a breaker) thru a diode.
>
> Is there a reason for the different setup on the Z-19 series?
>
>
> Regards,
>
> Mark Sletten
--------
Mark Sletten
Legacy FG N828LM
http://www.legacyfgbuilder.com
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=169244#169244
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Z-19 Series Architecture |
>Mark Sletten wrote:
> > Bob,
> >
> > On the Z-19 rev M and Z-19/RB rev A drawings the E-BUS normal feed is from
> > the Main PWR Dist block thru a 7A breaker and diode.
> >
> > On all other drawings it appears the E-BUS normal feed is directly off the
> > Main PWR Dist Block binding post (not a breaker) thru a diode.
> >
> > Is there a reason for the different setup on the Z-19 series?
No reason other than observance practice for protecting
any small wire feeder of 6" or more in length. If the e-bus
is located right next to the main bus fuse block, then you
can make direct connections through the diode without
fuses or breakers to protect the wires.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Z-19 Series Architecture |
>
>Mark,
>
>Your posts are getting through, I've not seen any replies to your question
>either.
>
>There was a related Z19 question a few weeks before xmas about updating
>the Z19 to reflect separate power feeds for coils (and possibly
>injectors). No further replies seen on that either.
I'm not in a position at present to modify the
Z-figures for the purpose of customizing. Remember,
these are intended to illustrate architectures that
offer attractive failure modes effects analysis,
I.e, failure tolerance.
Exactly what loads are tied to what busses by what
sizes of wire/fuse is up to the builder to work out
as appropriate to their particular engine and
suite of appliances.
Bob . . .
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: Diodes versus switches 101 ? |
>
> Bill Schlatterer wrote:
>>
>> There was some discussion about Z19 using diodes in a critical ECU
>> circuit and the question arose as to what kind of failure modes apply
>> to diodes and their reliability as compared to switches. I think the
>> trust of that thread (sub list) and post below is that diodes might
>> be "automatic" but switches are safer and less likely to fail? ( I
>> have no opinion but would like to understand the rationale ) This
>> was posted and I was just wondering what the thought might be on the
>> AE list since most of Bobs diagrams "suggest" a diode in the E-Bus
>> circuit as opposed to a switch. That might not be AS critical as the
>> ECU/EFI circuit on an all electric engine but the same concerns still
>> apply?
>>
>> Posted to the Sub list:
>>
>> "After 30 years in the industrial electrical construction and
>> maintenance field I can say without equivocation that a robust switch
>> is much less likely to fail than a robust diode. The science of the
>> switch is much simpler - use a lot of good conducting material that
>> is not likely to corrode and support it with stout mechanical parts
>> that hold tightly.
>>
>> Now, by contrast, the science of the diode starts with getting good
>> silicon material and contaminating it in just the right proportion
>> with just the right material at just the right temperature for just
>> the right time. THEN you can start on building the junctions onto
>> some sort of heat dissipating holder. I have replaced dozens of solid
>> state devices that failed (always failed open) and I never found the
>> root cause of failure. I put in an exact replacement and the circuit
>> worked just fine for years. The trade off you get for the "automatic"
>> switching of a diode vs. the manual switch is in the area of
>> RELIABILITY. I'll be using manual switches for all critical loads."
>>
>> Not wanting to stir anything up, just want to understand the thinking
>> and factual matter in the post above?
>> Thanks Bill S
>> 7a Z13/8 Z32(HD E-Bus) Z35(7ah)
>>
>
Not a direct answer to the question of whether a diode is more likely to
fail than a switch, but a response to the method used to reach his answer.
Old pre-1970's era point-type ignitions are based around switches (the
points). Just about every production car since then has used variations
on diodes (doped semiconductor junctions) in all the various components
of modern solid state ignitions (transistors, FETs, photocells, etc).
Using his analysis technique, it's obvious that point-type ignitions are
the way to go, since they are in fact cheaper & *much* simpler. Yet we
don't see them in new cars.
The real question is, which is more reliable in real world applications?
Charlie
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: switch wiring |
Kevin
You may need a starter contactor or relay but an ON-OFF-momentary ON
switch can probably be wired to do the mags like that. I don't know if
you will find such a ready made diagram though (or anyone to recommend
it), as I think such a scheme would greatly increase the risk of injury
from a live mag. I can understand an OFF-Batt-Alt switch but generally I
try to avoid those 3 position switches as I find them awkward,
especially at night.
Also it may be more common to use a separate switch for each alternator.
That way one failed switch can't disable both alternators.
Ken
Kevin Klinefelter wrote:
>
>
> Bob and all,
>
> I have a couple questions.
>
> I am wiring a Rotax 914 in my Europa per Z-16(sort of). I want to use a
> switch for each "mag" that will be down-off, middle-on, momentary-up of
> both to start. Is there a drawing somewhere on the site that shows how
> to wire this?
>
> I also want to wire a switch to control two alternators, the rotax built
> indynamo and a Denso IR alternator mounted on the vac pad. I would like
> to use one switch; down-dynamo middle-off and up-main
> alternator(denso).Is there a drawing showing how to wire that?
>
> Thanks, Kevin
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: switch wiring |
Kevin Klinefelter wrote:
Bob and all,
I have a couple questions.
I am wiring a Rotax 914 in my Europa per Z-16(sort of). I want to use a
switch for each "mag" that will be down-off, middle-on, momentary-up of
both to start. Is there a drawing somewhere on the site that shows how to
wire this?
I also want to wire a switch to control two alternators, the rotax built
indynamo and a Denso IR alternator mounted on the vac pad. I would like to
use one switch; down-dynamo middle-off and up-main alternator(denso).Is
there a drawing showing how to wire that?
Thanks, Kevin
For the ignition switches you need two, two-pole,
three position, center off, one side momentary
devices.
Another way to describe this switch is 2P3T on-off-(on).
This would be a B&C S700-2-5 switch. See:
http://www.bandc.biz
Wire one side of each switch to their respective ignition
modules such that the switch is closed in the down position
and shorts the ignition module to an OFF condition.
Wire the other sides of the two switches in series such
that both have to be lifted to the START position to
engage the starter contactor.
Recommend you keep the two alternator switches separate.
You don't want failure of one switch to cause both alternators
to become unavailable to you.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Diodes versus switches 101 ? |
There was some discussion about Z19 using diodes in a critical ECU circuit
and the question arose as to what kind of failure modes apply to diodes and
their reliability as compared to switches. I think the trust of that
thread (sub list) and post below is that diodes might be "automatic" but
switches are safer and less likely to fail? ( I have no opinion but would
like to understand the rationale ) This was posted and I was just
wondering what the thought might be on the AE list since most of Bobs
diagrams "suggest" a diode in the E-Bus circuit as opposed to a
switch. That might not be AS critical as the ECU/EFI circuit on an all
electric engine but the same concerns still apply?
Posted to the Sub list:
"After 30 years in the industrial electrical construction and maintenance
field I can say without equivocation that a robust switch is much less
likely to fail than a robust diode. The science of the switch is much
simpler - use a lot of good conducting material that is not likely to
corrode and support it with stout mechanical parts that hold tightly.
Now, by contrast, the science of the diode starts with getting good silicon
material and contaminating it in just the right proportion with just the
right material at just the right temperature for just the right time. THEN
you can start on building the junctions onto some sort of heat dissipating
holder. I have replaced dozens of solid state devices that failed (always
failed open)
Interesting! Most solid state failures I've observed were
shorted devices (overheated and or voltage spiked). The
devices that did go OPEN were transistors that shorted first
and then opened their emitter bond-wires due to over current.
. . . and I never found the root cause of failure. I put in an exact
replacement and the circuit worked just fine for years. The trade off you
get for the "automatic" switching of a diode vs. the manual switch is in
the area of RELIABILITY. I'll be using manual switches for all critical loads."
Not wanting to stir anything up, just want to understand the thinking and
factual matter in the post above?
About 1980 I was designing a new solid state speed
controller and runaway monitor system for the Lear 55
and ultimately the entire fleet of 30 series aircraft.
It was the first time I was tasked with doing a formal
failure mode effects analysis and mean-time-between-failures
(MTBF) study on a new product.
I dug out Mil-HDK-217 and began slogging through the
part-by-part service life prediction algorithms.
By the time some 200+ items of solder joints, transistors,
resistors, capacitors, etc were all accounted for, I was
pleased to turn the crank and a really nice MTBF number
on the order of 10,000 hours fell out. But wait, there
was this really expensive, mil-spec, hermetically sealed
25A power relay used as a last-ditch backup disconnect.
After factoring this device into the grand scheme
of things, my shinning MTBF number fell to something
on the order of 900 hours!
Several times over the last 25 years I've asked the
guys at Electromech's field service shop how the Lear
trim controllers are holding up. The failure items
they have to report were surprising. MOST of the field
failures were in mass-terminated ribbon cable connectors
followed by loss of ground through the mounting hardware
that held the two boards together. Seems this was before
I learned about having solid, on-purpose wiring grounds
and NOT to depend on mountings that loosen and/or corrode.
Electronically, most failures were the usual gang of
jelly bean components, solder joints, etc. Most failures
were in the monitor boards that had 3x the parts count
of a controller board. There were NO failures of the
controller that caused a runaway and a tiny fraction
of the failures incapacitated the system. There had
been no failures for that piece-o-#@@$, high-dollar
relay that crashed my MTBF study.
Bottom line: Was this relay badly misjudged? No,
I had a pretty good understanding of contact physics
and designed the electronics such that relay contacts
were closed before electronics actually caused the motor
to run. Similarly, electronics shut the motor down and
waited some tens of milliseconds before opening the
relay. Hence, the relay was never required to actually
switch any power. No current was flowing when the relay
contacts opened or closed and current was not allowed to
flow until contacts stopped bouncing on closure.
This is why Lear bought my design with the somewhat
distorted MTBF numbers because in thousands of hours
of flight, the relay never really saw any switching
service. Nowadays, there are more accurate considerations
of how a part is used that will provide a more realistic
prediction of failure rates.
Does this mean that the very robust, mil-spec relay
is the golden child of the design and the electronics
were left holding the bag for all the failures?
No, most failures were due to bonding/connection
issues. This controller resides in the vertical fin,
just under the leading edge of the stabilizer. This
has to be the worst environment in the airplane for
environmental extremes. For the most part, the electronics
seem to be living up to predictions for a long and
quite satisfactory service life in thousands of hours.
My personal experience since supports an assertion
that the silicon rectifier diode has an expected
service life that will far outpace any electro-mechanical
device (relay or switch) that is tasked with controlling
current flow.
Some of my most vexing field failures problems to solve
involve relays or switches. I've never had to chase down
root cause for failures of energy steering diodes
in an airplane.
Now, let us consider the gentleman's contrary assertion.
No doubt he has replaced blown diodes and perceives them
to be less robust than a switch. I cannot help but wonder
if his problem children were not subject to overheating
and or over-voltage due to industrial line transients
or local lightning. Whatever the root cause of his
observed failures, there is nothing in my experience
or that of my colleagues in the aircraft industry that
parallels his experience. I'm not suggesting that he is
being untruthful; only that we're probably observing
an apples/oranges situation. The environments
in which our diodes live and the manner in which they
are applied in airplanes are sufficiently different
from his industrial environment to prevent a useful
comparison.
So please folks, don't rip out your diodes and put
in switches. There are two reasons to support this
suggestion:
First, we design for failure tolerance.
What are the risks if a diode DOES fail? How will
the pilot know it? Is it pre-flight detectable? Will
the failure cripple the system such that it becomes
a hazard? If the answers to any of these questions
give you cause for concern about comfortable termination
of flight, then redesign the system to eliminate
the potential for stress. Consider his statement:
"I'll be using manual switches for all critical loads."
Our common usage of steering diodes for power is
one of TWO power paths to an e-bus. So even if it
does fail open, it has backup. If it fails shorted,
we can detect this during pre-flight.
Second, there is nothing in the service history of
diodes (or any other solid state device) to suggest
they are recognized problem children waiting for a
chance to ruin your day or drive up your cost of
ownership.
Bob . . .
________________________________________________________________________________
| From: | "Bill Schlatterer" <billschlatterer(at)sbcglobal.net> |
| Subject: | Diodes versus switches 101 ? |
Thanks Bob, that tells me what I need to know. Wasn't planning on taking
the diode out anyway but it's good to understand the why and why not? My
only regret about my building process is that once I'm done, I won't have
much use for the things I have come to understand from this list. Education
is a good thing but practical use makes it excellent. In my case, I have
learned just enough from this list to recognize what I don't know yet? That
may be the reason I become a repeat builder ;-)
Thanks Bill S
-----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: Wednesday, March 12, 2008 9:41 PM
Subject: Re: AeroElectric-List: Diodes versus switches 101 ?
-->
There was some discussion about Z19 using diodes in a critical ECU circuit
and the question arose as to what kind of failure modes apply to diodes and
their reliability as compared to switches. I think the trust of that thread
(sub list) and post below is that diodes might be "automatic" but switches
are safer and less likely to fail? ( I have no opinion but would like to
understand the rationale ) This was posted and I was just wondering what
the thought might be on the AE list since most of Bobs diagrams "suggest" a
diode in the E-Bus circuit as opposed to a switch. That might not be AS
critical as the ECU/EFI circuit on an all electric engine but the same
concerns still apply?
Posted to the Sub list:
"After 30 years in the industrial electrical construction and maintenance
field I can say without equivocation that a robust switch is much less
likely to fail than a robust diode. The science of the switch is much
simpler - use a lot of good conducting material that is not likely to
corrode and support it with stout mechanical parts that hold tightly.
Now, by contrast, the science of the diode starts with getting good silicon
material and contaminating it in just the right proportion with just the
right material at just the right temperature for just the right time. THEN
you can start on building the junctions onto some sort of heat dissipating
holder. I have replaced dozens of solid state devices that failed (always
failed open)
Interesting! Most solid state failures I've observed were
shorted devices (overheated and or voltage spiked). The
devices that did go OPEN were transistors that shorted first
and then opened their emitter bond-wires due to over current.
. . . and I never found the root cause of failure. I put in an exact
replacement and the circuit worked just fine for years. The trade off you
get for the "automatic" switching of a diode vs. the manual switch is in the
area of RELIABILITY. I'll be using manual switches for all critical loads."
Not wanting to stir anything up, just want to understand the thinking and
factual matter in the post above?
About 1980 I was designing a new solid state speed
controller and runaway monitor system for the Lear 55
and ultimately the entire fleet of 30 series aircraft.
It was the first time I was tasked with doing a formal
failure mode effects analysis and mean-time-between-failures
(MTBF) study on a new product.
I dug out Mil-HDK-217 and began slogging through the
part-by-part service life prediction algorithms.
By the time some 200+ items of solder joints, transistors,
resistors, capacitors, etc were all accounted for, I was
pleased to turn the crank and a really nice MTBF number
on the order of 10,000 hours fell out. But wait, there
was this really expensive, mil-spec, hermetically sealed
25A power relay used as a last-ditch backup disconnect.
After factoring this device into the grand scheme
of things, my shinning MTBF number fell to something
on the order of 900 hours!
Several times over the last 25 years I've asked the
guys at Electromech's field service shop how the Lear
trim controllers are holding up. The failure items
they have to report were surprising. MOST of the field
failures were in mass-terminated ribbon cable connectors
followed by loss of ground through the mounting hardware
that held the two boards together. Seems this was before
I learned about having solid, on-purpose wiring grounds
and NOT to depend on mountings that loosen and/or corrode.
Electronically, most failures were the usual gang of
jelly bean components, solder joints, etc. Most failures
were in the monitor boards that had 3x the parts count
of a controller board. There were NO failures of the
controller that caused a runaway and a tiny fraction
of the failures incapacitated the system. There had
been no failures for that piece-o-#@@$, high-dollar
relay that crashed my MTBF study.
Bottom line: Was this relay badly misjudged? No,
I had a pretty good understanding of contact physics
and designed the electronics such that relay contacts
were closed before electronics actually caused the motor
to run. Similarly, electronics shut the motor down and
waited some tens of milliseconds before opening the
relay. Hence, the relay was never required to actually
switch any power. No current was flowing when the relay
contacts opened or closed and current was not allowed to
flow until contacts stopped bouncing on closure.
This is why Lear bought my design with the somewhat
distorted MTBF numbers because in thousands of hours
of flight, the relay never really saw any switching
service. Nowadays, there are more accurate considerations
of how a part is used that will provide a more realistic
prediction of failure rates.
Does this mean that the very robust, mil-spec relay
is the golden child of the design and the electronics
were left holding the bag for all the failures?
No, most failures were due to bonding/connection
issues. This controller resides in the vertical fin,
just under the leading edge of the stabilizer. This
has to be the worst environment in the airplane for
environmental extremes. For the most part, the electronics
seem to be living up to predictions for a long and
quite satisfactory service life in thousands of hours.
My personal experience since supports an assertion
that the silicon rectifier diode has an expected
service life that will far outpace any electro-mechanical
device (relay or switch) that is tasked with controlling
current flow.
Some of my most vexing field failures problems to solve
involve relays or switches. I've never had to chase down
root cause for failures of energy steering diodes
in an airplane.
Now, let us consider the gentleman's contrary assertion.
No doubt he has replaced blown diodes and perceives them
to be less robust than a switch. I cannot help but wonder
if his problem children were not subject to overheating
and or over-voltage due to industrial line transients
or local lightning. Whatever the root cause of his
observed failures, there is nothing in my experience
or that of my colleagues in the aircraft industry that
parallels his experience. I'm not suggesting that he is
being untruthful; only that we're probably observing
an apples/oranges situation. The environments
in which our diodes live and the manner in which they
are applied in airplanes are sufficiently different
from his industrial environment to prevent a useful
comparison.
So please folks, don't rip out your diodes and put
in switches. There are two reasons to support this
suggestion:
First, we design for failure tolerance.
What are the risks if a diode DOES fail? How will
the pilot know it? Is it pre-flight detectable? Will
the failure cripple the system such that it becomes
a hazard? If the answers to any of these questions
give you cause for concern about comfortable termination
of flight, then redesign the system to eliminate
the potential for stress. Consider his statement:
"I'll be using manual switches for all critical loads."
Our common usage of steering diodes for power is
one of TWO power paths to an e-bus. So even if it
does fail open, it has backup. If it fails shorted,
we can detect this during pre-flight.
Second, there is nothing in the service history of
diodes (or any other solid state device) to suggest
they are recognized problem children waiting for a
chance to ruin your day or drive up your cost of
ownership.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Diodes versus switches 101 ? |
| From: | "ZuluZephyr" <zuluzephyr(at)yahoo.com> |
I have followed the switch vs diode controversy on a number of forums with interest
since I am building a Sportsman with a Subaru H6 Engine. I am aware of crash
involving a failed diode. I believe the diode was not rated for the actual
amp load which was the most likely reason for the diode failure and the ensuing
controversy.
There is another design recommending the elimination of the diodes and using one
switch to supply the fuel pumps, ECU and EFI. This provides a single point
of failure which I think violates the design goals of the Z19 drawing of providing
redundant paths, components and circuits.
Being a committed party ( I have the engine) and wanting the simplest most reliable
electrical system possible, I have designed a variation of the Z19 drawing
using the same parts count with diodes (rated for the load) than includes a
bypass circuit in case of diode failure (unlikely).
Please see attached drawing. I welcome all comments and suggestions.
Rocky Morrison
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=169493#169493
Attachments:
http://forums.matronics.com//files/proposed_fuel_pump_eci_efi_circuit_for_eggenfellner_subaru_h6_233.pdf
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Diodes versus switches 101 ? |
>
>
>Thanks Bob, that tells me what I need to know. Wasn't planning on taking
>the diode out anyway but it's good to understand the why and why not? My
>only regret about my building process is that once I'm done, I won't have
>much use for the things I have come to understand from this list. Education
>is a good thing but practical use makes it excellent. In my case, I have
>learned just enough from this list to recognize what I don't know yet? That
>may be the reason I become a repeat builder ;-)
Correct . . . presuming that you do not take what
you've learned and share it with others. Knowledge and
understanding are commodities that grow in value the more they
are given away. We all benefit every day from associations
with individuals who are willing to share what they've learned.
After your airplane is finished, you can satisfy your debt
to all the teachers who participated in your success by
"paying it forward". See:
http://en.wikipedia.org/wiki/Pay_it_forward
http://tinyurl.com/32cfym
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Diodes versus switches 101 ? |
>
>I have followed the switch vs diode controversy on a number of forums with
>interest since I am building a Sportsman with a Subaru H6 Engine. I am
>aware of crash involving a failed diode. I believe the diode was not
>rated for the actual amp load which was the most likely reason for the
>diode failure and the ensuing controversy.
Due diligence in design cannot be discounted. It
could just as easily have been a failure due to an
improperly tightened nut. Had it been a fastener failure,
is there value in responding to that knowledge by
replacing all the fasteners in our machines with
grade 8 hardware and metal locknuts?
The real issue is to understand what suite of
components are available to arrive at at an elegant
solution and then properly apply those components
to the task.
>There is another design recommending the elimination of the diodes and
>using one switch to supply the fuel pumps, ECU and EFI. This provides a
>single point of failure which I think violates the design goals of the Z19
>drawing of providing redundant paths, components and circuits.
Consideration of design goals and failure mode
effects are important components of the process . . .
>Being a committed party ( I have the engine) and wanting the simplest most
>reliable electrical system possible, I have designed a variation of the
>Z19 drawing using the same parts count with diodes (rated for the load)
>than includes a bypass circuit in case of diode failure (unlikely).
It's unfortunate that your lack of confidence leads
you to conclude that there is value in "backing
up" a diode. On the other hand, it's far better that
you fly this airplane free of worry about it. Worries
do not enhance your piloting skills and should be
assuaged irrespective of the physics and/or probabilities.
Bob . . .
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Electrical Question |
3/12/2008
Hello Tom, You wrote:
1) "For clarification, the NC switch means that I press the button to
actually cut the power. Why would this be used on an old military
helicopter stick? What is the reason for cutting the power on a switch?"
We used to say that having helicopter time in your logbook was like having
an STD entry (Sexually Transmitted Disease -- it was called venereal
disease back then) in your health record.
So I will reluctantly admit that I did fly a helicopter (CH-46) for a year
in Viet Nam. The cyclic grip had a button on it that when pressed would
disconnect the electronic flight stability / attitude positioning system so
that one could manually reposition the stick and the helicopter's attitude
then releasing the button would reengage the electronic attitude positioning
system.
Maybe you have a control stick grip that does something similar.
2) "Again, is there any way I can wire it to work with my remote ident
operation?"
I am not the right guy to answer that question, but I am sure that by using
two of the small "ice cube" type relays that ident operation could be
accomplished. It might be a pretty awkward way of doing it though from an
electrical viewpoint.
I'll forward your question to the Matronic's aeroelectric-list and maybe one
of the electrical experts there (even the great guru Bob Nuckolls) would
take a shot at it.
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
PS: You can subscribe to this list here -- the daily digest is a great deal.
One email inbound each day puts you in contact with the living beating heart
of the homebuilder's electrical world.
http://www.matronics.com/Navigator/?AeroElectric-List
--------------------------------------------------------
----- Original Message -----
From: "Tom Gibbons" <TomisFlyingby(at)comcast.net>
Sent: Wednesday, March 12, 2008 12:25 AM
Subject: Electrical question
On my military surplus control stick I have 4 push buttons, 2 wired normally
opened (NO) and 2 wired normally closed (NC). I really do not have access
to these switches so I have to make due but can I use the NC switches
somehow?
I have plans for comm flip/flop, nav flip/flop, and Ident for my
transponder. I actually have a "hattie" switch in the middle for trim which
is not hooked up. The stick is installed with the ptt and intercom trigger
switches working good. All kinds of switches on this guy. Was not going to
use it but hey, it felt so comfortable, why not.
For clarification, the NC switch means that I press the button to actually
cut the power. Why would this be used on an old military helicopter stick?
What is the reason for cutting the power on a switch? Again, is there any
way I can wire it to work with my remote ident operation?
Tom
Paint this summer???
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: B&C S895-1 as start button for 20A/14VDC ciruit? |
>
>Hi Bob,
>
>Hope all is well with you :)
>
>I have a B&C S895-1 push button originally intended as a start buton;
>however, the Eggenfellner recommendation for the starter circuit is for a
>switch or push button capable of 20A/14VDC (switch will be connected to
>the internal contactor on the Subaru H6 starter solenoid).
>
>I have been reviewing both your Switch_Rating.pdf and the chapter in the
>Connection, and I'm coming to the conclusion that this switch is probably
>too light for this application. Would it work? Sure. For how long? Who
>knows... But what would be the risk that I could fuse this switch closed
>or just plain heat it up too much? Also, the connection leads on this
>switch seem a bit small/light for 12AWG wire...
>
>Please advise when you have a moment.
The S895-1 switch would probably give a good service
life in this application. See:
http://www.aeroelectric.com/articles/Switch_Ratings.pdf
the REAL stress on this device will be the arcing
that takes place during release -AND- the openings
that occur during contact bounce at closure. Make
sure there's a diode from contactor (+) to ground.
I think B&C is supplying that switch with an MOV
already mounted. I recommended that about 10 years
ago during my brief love affair with MOVs . . .
turns out the diode is a MUCH more effective
solution to inductive energy management.
I'm wondering if the starter solenoid supplied
is the two-stage configuration described in
http://www.aeroelectric.com/articles/strtctr.pdf
If so, the 20A rating request by Eggenfellner
is probably an acknowledgement of the short term
energizing inrush unique to this design. The
wires supplied on that switch were tailored
to the starter contactor supplied in tht B&C
starter installation kit. Your application
would be better served with 16AWG wire and
a 15A fuse.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: High density D-sub crimper |
>
>If you crimp connectors without the specific dies, you would
>be well served by soldering the wire strands to the crimps as
>well or the wires might just fall out!
>I have an AMP ProCrimp II with all the dies for the CPC
>Series I connectors, and they still sometimes fail the tug test when I
>don't oversolder them!
Your talking about the open-barrel, sheet metal pins.
I just went to the shop and pulled three 24AWG wires
from pins installed with my generic open-barrel crimp
tool. I got pullout forces that ran from 8 to 11 pounds.
If your pulling these off with your fingers you may have
the wrong tool or are not closing it hard enough.
I put some high density machined pins on with the $low$
d-sub crimp tool and produced crimps that I could not
pull off with the fingers. I don't have any of these
pins on hand right now but as soon as I can, I'll do
a calibrated pull-test and look at the cross sectioned
wire grips under the microscope. But I'm betting that
we'll find the crimps to be satisfactory on the HD
pins too.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: High density D-sub crimper |
>
>Howdy,
>
>I've got to crimp about 30 machined high density d-sub pins on an ACU
>install and I don't think my standard density crimper (B&C) is gonna work.
>I'd hate to spend $800 on a Daniels and postitioners for one little deed.
>Any ideas?
>
>I thought about getting a $30 crimper and some of the fold over pins. Are
>those pins as reliable as the machined ones? Will the crimper (fold over
>style, also B&C) do those little pins in one of it's slots?
Your risks for process error are lower with the machined
pins. I thick Steinair can sell you some. I also believe
the 20AWG crimper from B&C will properly install the
22AWG pins. I'll see if I can get a considered confirmation
in the next few days. I have come connectors on order with
my favorite local connector guy but he's a 15 mile drive from
here. When my order comes in, I'll pick up some 22AWG HD
pins for the experiment.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Diodes versus switches 101 ? |
| From: | "ZuluZephyr" <zuluzephyr(at)yahoo.com> |
Bob,
I appreciate your comments, thoughts and efforts in helping all the builders develop
more reliable and better electrical systems. A worrier I am not, but a
simple change to the design that provides backup to a potential component failure
makes logical sense to me. I plan on flying in remote places and reliability
is high on my list of design goals. That is why I am here to learn and listen,
ask questions and share if I think something is worthy of the groups time.
Keep up the great work. Your work has been invaluable to me in the building process.
Bob, Thanks!!
Rocky Morrison
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=169589#169589
________________________________________________________________________________
| Subject: | Diodes versus switches 101 ? |
Bob,
Thanks for the background and scope of the diode. That said and given
the intended reliability of the diode, I would hope my e-bus capacity
remains below 20A in my Z19 setup. Assuming the use of the B & C cooled
diode setup, should I fear any continuous load up to the 25A suggested
rating?
Thanks too for the tips on switching. I can see a few 2-10's in my
future for saving valuable panel space. Some great examples through 8-9x
in your book.
Glenn
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Bill
Schlatterer
Sent: Wednesday, March 12, 2008 11:57 PM
Subject: RE: AeroElectric-List: Diodes versus switches 101 ?
-->
Thanks Bob, that tells me what I need to know. Wasn't planning on
taking the diode out anyway but it's good to understand the why and why
not? My only regret about my building process is that once I'm done, I
won't have much use for the things I have come to understand from this
list. Education is a good thing but practical use makes it excellent.
In my case, I have learned just enough from this list to recognize what
I don't know yet? That may be the reason I become a repeat builder ;-)
Thanks Bill S
-----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: Wednesday, March 12, 2008 9:41 PM
Subject: Re: AeroElectric-List: Diodes versus switches 101 ?
-->
There was some discussion about Z19 using diodes in a critical ECU
circuit and the question arose as to what kind of failure modes apply to
diodes and their reliability as compared to switches. I think the trust
of that thread (sub list) and post below is that diodes might be
"automatic" but switches are safer and less likely to fail? ( I have no
opinion but would like to understand the rationale ) This was posted
and I was just wondering what the thought might be on the AE list since
most of Bobs diagrams "suggest" a diode in the E-Bus circuit as opposed
to a switch. That might not be AS critical as the ECU/EFI circuit on an
all electric engine but the same concerns still apply?
Posted to the Sub list:
"After 30 years in the industrial electrical construction and
maintenance field I can say without equivocation that a robust switch is
much less likely to fail than a robust diode. The science of the switch
is much simpler - use a lot of good conducting material that is not
likely to corrode and support it with stout mechanical parts that hold
tightly.
Now, by contrast, the science of the diode starts with getting good
silicon material and contaminating it in just the right proportion with
just the right material at just the right temperature for just the right
time. THEN you can start on building the junctions onto some sort of
heat dissipating holder. I have replaced dozens of solid state devices
that failed (always failed open)
Interesting! Most solid state failures I've observed were
shorted devices (overheated and or voltage spiked). The
devices that did go OPEN were transistors that shorted first
and then opened their emitter bond-wires due to over current.
. . . and I never found the root cause of failure. I put in an exact
replacement and the circuit worked just fine for years. The trade off
you get for the "automatic" switching of a diode vs. the manual switch
is in the area of RELIABILITY. I'll be using manual switches for all
critical loads."
Not wanting to stir anything up, just want to understand the thinking
and factual matter in the post above?
About 1980 I was designing a new solid state speed
controller and runaway monitor system for the Lear 55
and ultimately the entire fleet of 30 series aircraft.
It was the first time I was tasked with doing a formal
failure mode effects analysis and mean-time-between-failures
(MTBF) study on a new product.
I dug out Mil-HDK-217 and began slogging through the
part-by-part service life prediction algorithms.
By the time some 200+ items of solder joints, transistors,
resistors, capacitors, etc were all accounted for, I was
pleased to turn the crank and a really nice MTBF number
on the order of 10,000 hours fell out. But wait, there
was this really expensive, mil-spec, hermetically sealed
25A power relay used as a last-ditch backup disconnect.
After factoring this device into the grand scheme
of things, my shinning MTBF number fell to something
on the order of 900 hours!
Several times over the last 25 years I've asked the
guys at Electromech's field service shop how the Lear
trim controllers are holding up. The failure items
they have to report were surprising. MOST of the field
failures were in mass-terminated ribbon cable connectors
followed by loss of ground through the mounting hardware
that held the two boards together. Seems this was before
I learned about having solid, on-purpose wiring grounds
and NOT to depend on mountings that loosen and/or corrode.
Electronically, most failures were the usual gang of
jelly bean components, solder joints, etc. Most failures
were in the monitor boards that had 3x the parts count
of a controller board. There were NO failures of the
controller that caused a runaway and a tiny fraction
of the failures incapacitated the system. There had
been no failures for that piece-o-#@@$, high-dollar
relay that crashed my MTBF study.
Bottom line: Was this relay badly misjudged? No,
I had a pretty good understanding of contact physics
and designed the electronics such that relay contacts
were closed before electronics actually caused the motor
to run. Similarly, electronics shut the motor down and
waited some tens of milliseconds before opening the
relay. Hence, the relay was never required to actually
switch any power. No current was flowing when the relay
contacts opened or closed and current was not allowed to
flow until contacts stopped bouncing on closure.
This is why Lear bought my design with the somewhat
distorted MTBF numbers because in thousands of hours
of flight, the relay never really saw any switching
service. Nowadays, there are more accurate considerations
of how a part is used that will provide a more realistic
prediction of failure rates.
Does this mean that the very robust, mil-spec relay
is the golden child of the design and the electronics
were left holding the bag for all the failures?
No, most failures were due to bonding/connection
issues. This controller resides in the vertical fin,
just under the leading edge of the stabilizer. This
has to be the worst environment in the airplane for
environmental extremes. For the most part, the electronics
seem to be living up to predictions for a long and
quite satisfactory service life in thousands of hours.
My personal experience since supports an assertion
that the silicon rectifier diode has an expected
service life that will far outpace any electro-mechanical
device (relay or switch) that is tasked with controlling
current flow.
Some of my most vexing field failures problems to solve
involve relays or switches. I've never had to chase down
root cause for failures of energy steering diodes
in an airplane.
Now, let us consider the gentleman's contrary assertion.
No doubt he has replaced blown diodes and perceives them
to be less robust than a switch. I cannot help but wonder
if his problem children were not subject to overheating
and or over-voltage due to industrial line transients
or local lightning. Whatever the root cause of his
observed failures, there is nothing in my experience
or that of my colleagues in the aircraft industry that
parallels his experience. I'm not suggesting that he is
being untruthful; only that we're probably observing
an apples/oranges situation. The environments
in which our diodes live and the manner in which they
are applied in airplanes are sufficiently different
from his industrial environment to prevent a useful
comparison.
So please folks, don't rip out your diodes and put
in switches. There are two reasons to support this
suggestion:
First, we design for failure tolerance.
What are the risks if a diode DOES fail? How will
the pilot know it? Is it pre-flight detectable? Will
the failure cripple the system such that it becomes
a hazard? If the answers to any of these questions
give you cause for concern about comfortable termination
of flight, then redesign the system to eliminate
the potential for stress. Consider his statement:
"I'll be using manual switches for all critical loads."
Our common usage of steering diodes for power is
one of TWO power paths to an e-bus. So even if it
does fail open, it has backup. If it fails shorted,
we can detect this during pre-flight.
Second, there is nothing in the service history of
diodes (or any other solid state device) to suggest
they are recognized problem children waiting for a
chance to ruin your day or drive up your cost of
ownership.
Bob . . .
________________________________________________________________________________
| Subject: | Re: High density D-sub crimper |
| From: | "rampil" <ira.rampil(at)gmail.com> |
Hi Bob,
I was responding to Ed's comment that he might get some stamped
pins. I still think soldering crimped open barrels is the way to go.
The reason is that to meet specs on the pull test you must have
a connector pin specific to both the wire size and insulation along with
accompanying crimp dies. Since available wire may have unpredictable
insulation thickness in a homebuilder's shop, soldering is just extra assurance.
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=169619#169619
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Diodes versus switches 101 ? |
>
>Bob,
>Thanks for the background and scope of the diode. That said and given
>the intended reliability of the diode, I would hope my e-bus capacity
>remains below 20A in my Z19 setup. Assuming the use of the B & C cooled
>diode setup, should I fear any continuous load up to the 25A suggested
>rating?
>
>Thanks too for the tips on switching. I can see a few 2-10's in my
>future for saving valuable panel space. Some great examples through 8-9x
>in your book.
You're welcome. I would hope your endurance bus is below
20A too. I get about 2 or 3 drawings a month from builders
who are asking for a review of their particular implementation
of a Z-figure. The majority of these drawings have too much
stuff on the e-bus.
A review of the endurance bus philosophy might be useful here.
If one is flying one alternator and one battery, the e-bus is
intended to offer a minimum power load on a battery of known
capacity for the purpose of NOT turning an alternator failure
into an emergency. How much 'stuff' is necessary to stay on-course
for say 1 to 2 hours with the airplane configured for en route
phase of flight?
This list boils down to one nav receiver, transponder, minimal
panel lighting, etc. The nicely crafted e-bus for a one-alternator
airplane should be reduced to 4A or less total load. Now, other
things can drive from the e-bus but should be capable of being
switched off during alternator out operations.
If you have an auxiliary 8A alternator then the e-bus loads can
be elevated to 8A total. Likewise, a 20A aux alternator would
support a 20A e-bus . . . and perhaps there's little if any value
in even having an e-bus.
The 25A diode bridge recommended since day-one for the e-bus
normal feedpath diode was selected for its MECHANICAL convenience
of mounting and making connections via fast-on terminals. In
no way was it intended to imply that e-bus loads could total up
to that value. Anything over 10A should prompt a review of the
diode installation for the purpose of deducing thermal adequacy
of the mounting in carrying away heat.
Most of my fused feeders to the e-bus in the Z-figures are protected
at 7A. If you have an SD-8 second alternator, perhaps that fuse
should go up to 10A. But if your suite of proposed equipment
combined with an evaluation of how you plan to fly causes you
to pile everything but the kitchen sink on the e-bus, then
we need to talk.
If your e-bus loads are more than 10x the battery contactor
load then the advantages of shedding the contactor as a
battery only load are diminished considerably.
If most of the stuff you really need to run exceeds 8A then
you need an SD20 aux alternator and Figure Z-12 is probably
your minimum parts count approach to managing alternator
out conditions. Z-12 cannot fully exploit the design goals
for an e-bus so it would not be unreasonable to eliminate
it entirely and run the whole airplane from the main bus
with the SD-20 backing up the main alternator.
That takes care of the worries about diodes and e-bus
switches and makes the airplane simpler to operate.
Bob . . .
________________________________________________________________________________
| Subject: | Diodes versus switches 101 ? |
| From: | "Matt Prather" <mprather(at)spro.net> |
snip
> A review of the endurance bus philosophy might be useful here.
> If one is flying one alternator and one battery, the e-bus is
> intended to offer a minimum power load on a battery of known
> capacity for the purpose of NOT turning an alternator failure
> into an emergency. How much 'stuff' is necessary to stay on-course
> for say 1 to 2 hours with the airplane configured for en route
> phase of flight?
>
> This list boils down to one nav receiver, transponder, minimal
> panel lighting, etc. The nicely crafted e-bus for a one-alternator
Plus any devices required to remain upright (in an all-electric airplane)
- aviate, then navigate? An EFIS (or an electric attitude indicator).
>
> Bob . . .
>
Regards,
Matt-
________________________________________________________________________________
| From: | "Lee Logan" <leeloganster(at)gmail.com> |
| Subject: | Re: AeroElectric-List Digest: 13 Msgs - 03/12/08 |
Does anyone know where I can download the installation manuals for the
Garmin GNC300, SL-30, and a PS Engineering PMA6000MC?
Thanks for the help!
Lee...
________________________________________________________________________________
| From: | Ed Holyoke <bicyclop(at)pacbell.net> |
| Subject: | Re: High density D-sub crimper |
Thanks Bob,
I'm interested in how the experiment comes out.
Ed Holyoke
Robert L. Nuckolls, III wrote:
>
>
>
>>
>>
>> Howdy,
>>
>> I've got to crimp about 30 machined high density d-sub pins on an ACU
>> install and I don't think my standard density crimper (B&C) is gonna
>> work. I'd hate to spend $800 on a Daniels and postitioners for one
>> little deed. Any ideas?
>>
>> I thought about getting a $30 crimper and some of the fold over pins.
>> Are those pins as reliable as the machined ones? Will the crimper
>> (fold over style, also B&C) do those little pins in one of it's slots?
>
> Your risks for process error are lower with the machined
> pins. I thick Steinair can sell you some. I also believe
> the 20AWG crimper from B&C will properly install the
> 22AWG pins. I'll see if I can get a considered confirmation
> in the next few days. I have come connectors on order with
> my favorite local connector guy but he's a 15 mile drive from
> here. When my order comes in, I'll pick up some 22AWG HD
> pins for the experiment.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | "Andrew Butler" <andrewbutler(at)ireland.com> |
| Subject: | Keyed Master Switch? |
All,
I plan on a PUSH Button Start and Dual Electonic Ignition. Can anyone
help with a method of enabling "key start" access to ignition/power?
I have dual paths to each ignition, so need four switches (to enable
pre-flight checks of each path), so the documented adapted mag key start
switch option won't work.
I can't get fully comfortable with a fully live system being just a flip
of a switch away....... See attached to get the idea.
Best regards,
Andrew Butler
RV 71700 - West of Ireland.
Fueslage (right way up!)
________________________________________________________________________________
| Subject: | Keyed Master Switch? |
| From: | "Glaeser, Dennis A" <dennis.glaeser(at)eds.com> |
Consider putting a keyed switch in the Push Button Start circuit. If
the key isn't on, the start button doesn't work! One switch does the
trick and it doesn't put another switch (point of failure) in any of
your other critical circuits.
Your ignition systems may be live if their switches are flipped, but
nothing happens without the starter.
Dennis Glaeser
RV7A - Subaru H6 - DAR inspection next week!
-----------------------------------------
I plan on a PUSH Button Start and Dual Electonic Ignition. Can anyone
help with a method of enabling "key start" access to ignition/power?
I have dual paths to each ignition, so need four switches (to enable
pre-flight checks of each path), so the documented adapted mag key start
switch option won't work.
I can't get fully comfortable with a fully live system being just a flip
of a switch away....... See attached to get the idea.
Best regards,
Andrew Butler
RV 71700 - West of Ireland.
Fueslage (right way up!)
________________________________________________________________________________
| From: | "Dave Saylor" <Dave(at)AirCraftersLLC.com> |
Here is a picture of a current limiter from a recent job. It had been
replaced for unknown reasons over a year ago. The installer didn't use a
washer between the limiter terminal tab and the nut. The nut grabbed and
torqued the tab, deformed the ears that are supported by the rivets, and
partially tore the base of the filiment (right word?) After many months the
filiment finally broke. I don't think it was experienceing any particularly
high current load, but from the looks of the mounting terminal, it did see
some pretty rough handling.
Dave Saylor
AirCrafters LLC
140 Aviation Way
Watsonville, CA
831-722-9141
831-750-0284 CL
www.AirCraftersLLC.com
________________________________________________________________________________
| From: | "CHARLES T BECKER" <ctbecker(at)atlanticbb.net> |
| Subject: | Re: Keyed Master Switch? |
Dennis has the right idea, especially in light of all the
emphasis on '2 locks'. My 8A will have a key switch
between the battery and the starter switch. The actual
starter switch will be on the stick, controlling a relay
in the starter circuit.
Charlie Becker
N464CB(r) 8A(e)
Finishing
"Glaeser, Dennis A" wrote:
>Dennis A"
>
> Consider putting a keyed switch in the Push Button Start
>circuit. If
> the key isn't on, the start button doesn't work! One
>switch does the
> trick and it doesn't put another switch (point of
>failure) in any of
> your other critical circuits.
> Your ignition systems may be live if their switches are
>flipped, but
> nothing happens without the starter.
>
> Dennis Glaeser
> RV7A - Subaru H6 - DAR inspection next week!
>
> -----------------------------------------
> I plan on a PUSH Button Start and Dual Electonic
>Ignition. Can anyone
> help with a method of enabling "key start" access to
>ignition/power?
>
> I have dual paths to each ignition, so need four
>switches (to enable
> pre-flight checks of each path), so the documented
>adapted mag key start
> switch option won't work.
>
> I can't get fully comfortable with a fully live system
>being just a flip
> of a switch away....... See attached to get the idea.
>
> Best regards,
>
> Andrew Butler
> RV 71700 - West of Ireland.
>Fueslage (right way up!)
>
>
>
>Un/Subscription,
>http://www.matronics.com/Navigator?AeroElectric-List
>Forums!
>Admin.
>
>
>
________________________________________________________________________________
| From: | "Terry Watson" <terry(at)tcwatson.com> |
| Subject: | Keyed Master Switch? |
My plan has been to put a simple toggle switch in the baggage compartment
that disconnects the starter switch. Hopefully this plus a canopy lock will
meet the 2 lock requirement. The baggage compartment will also have a lock.
I wonder how many times I will get all strapped in before I realize I
haven't enabled the starter switch.
Terry
RV-8A wiring
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of CHARLES T
BECKER
Sent: Friday, March 14, 2008 12:09 PM
Subject: Re: AeroElectric-List: Keyed Master Switch?
Dennis has the right idea, especially in light of all the
emphasis on '2 locks'. My 8A will have a key switch
between the battery and the starter switch. The actual
starter switch will be on the stick, controlling a relay
in the starter circuit.
Charlie Becker
N464CB(r) 8A(e)
Finishing
"Glaeser, Dennis A" wrote:
>Dennis A"
>
> Consider putting a keyed switch in the Push Button Start
>circuit. If
> the key isn't on, the start button doesn't work! One
>switch does the
> trick and it doesn't put another switch (point of
>failure) in any of
> your other critical circuits.
> Your ignition systems may be live if their switches are
>flipped, but
> nothing happens without the starter.
>
> Dennis Glaeser
> RV7A - Subaru H6 - DAR inspection next week!
>
> -----------------------------------------
> I plan on a PUSH Button Start and Dual Electonic
>Ignition. Can anyone
> help with a method of enabling "key start" access to
>ignition/power?
>
> I have dual paths to each ignition, so need four
>switches (to enable
> pre-flight checks of each path), so the documented
>adapted mag key start
> switch option won't work.
>
> I can't get fully comfortable with a fully live system
>being just a flip
> of a switch away....... See attached to get the idea.
>
> Best regards,
>
> Andrew Butler
> RV 71700 - West of Ireland.
>Fueslage (right way up!)
>
>
>
>Un/Subscription,
>http://www.matronics.com/Navigator?AeroElectric-List
>Forums!
>Admin.
>
>
>
________________________________________________________________________________
| Subject: | Keyed Master Switch? |
| From: | "Matt Prather" <mprather(at)spro.net> |
Do you plan to put a guard on the switch (or cover) to keep loose items in
the baggage compartment from bumping it? I suppose that in flight you
probably won't have to engage the starter ever should that happen. If you
fly the plane long enough without a guard on that switch, you'll
eventually be in a situation where you can't figure out why you can't
engage the starter - after giving somebody a ride maybe, or trying to
restart after a fuel stop..
Will the switch be in a place where it interferes with loading things into
the baggage compartment? Will you have to unload anything form the
compartment in order to gain access to the switch?
Matt-
>
>
> My plan has been to put a simple toggle switch in the baggage compartment
> that disconnects the starter switch. Hopefully this plus a canopy lock
> will
> meet the 2 lock requirement. The baggage compartment will also have a
> lock.
> I wonder how many times I will get all strapped in before I realize I
> haven't enabled the starter switch.
>
> Terry
> RV-8A wiring
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of CHARLES
> T
> BECKER
> Sent: Friday, March 14, 2008 12:09 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Keyed Master Switch?
>
>
>
> Dennis has the right idea, especially in light of all the
> emphasis on '2 locks'. My 8A will have a key switch
> between the battery and the starter switch. The actual
> starter switch will be on the stick, controlling a relay
> in the starter circuit.
>
> Charlie Becker
> N464CB(r) 8A(e)
> Finishing
>
>
> "Glaeser, Dennis A" wrote:
>>Dennis A"
>>
>> Consider putting a keyed switch in the Push Button Start
>>circuit. If
>> the key isn't on, the start button doesn't work! One
>>switch does the
>> trick and it doesn't put another switch (point of
>>failure) in any of
>> your other critical circuits.
>> Your ignition systems may be live if their switches are
>>flipped, but
>> nothing happens without the starter.
>>
>> Dennis Glaeser
>> RV7A - Subaru H6 - DAR inspection next week!
>>
>> -----------------------------------------
>> I plan on a PUSH Button Start and Dual Electonic
>>Ignition. Can anyone
>> help with a method of enabling "key start" access to
>>ignition/power?
>>
>> I have dual paths to each ignition, so need four
>>switches (to enable
>> pre-flight checks of each path), so the documented
>>adapted mag key start
>> switch option won't work.
>>
>> I can't get fully comfortable with a fully live system
>>being just a flip
>> of a switch away....... See attached to get the idea.
>>
>> Best regards,
>>
>> Andrew Butler
>> RV 71700 - West of Ireland.
>>Fueslage (right way up!)
>>
>>
>>
>>Un/Subscription,
>>http://www.matronics.com/Navigator?AeroElectric-List
>>Forums!
>>Admin.
>>
>>
>>
>
>
________________________________________________________________________________
| From: | "Terry Watson" <terry(at)tcwatson.com> |
| Subject: | Keyed Master Switch? |
Those are all good considerations, but having it on the starter circuit
rather than ignition makes them a little less critical. The switch guard is
probably pretty important. I would not expect to always use the switch to
disconnect the starter when leaving the airplane, but more for away from
home, overnight -- just one more safeguard, and of course one more point of
possible failure.
I am willing to be convinced that it is not a good idea.
Terry
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Matt
Prather
Sent: Friday, March 14, 2008 2:40 PM
Subject: RE: AeroElectric-List: Keyed Master Switch?
Do you plan to put a guard on the switch (or cover) to keep loose items in
the baggage compartment from bumping it? I suppose that in flight you
probably won't have to engage the starter ever should that happen. If you
fly the plane long enough without a guard on that switch, you'll
eventually be in a situation where you can't figure out why you can't
engage the starter - after giving somebody a ride maybe, or trying to
restart after a fuel stop..
Will the switch be in a place where it interferes with loading things into
the baggage compartment? Will you have to unload anything form the
compartment in order to gain access to the switch?
Matt-
>
>
> My plan has been to put a simple toggle switch in the baggage compartment
> that disconnects the starter switch. Hopefully this plus a canopy lock
> will
> meet the 2 lock requirement. The baggage compartment will also have a
> lock.
> I wonder how many times I will get all strapped in before I realize I
> haven't enabled the starter switch.
>
> Terry
> RV-8A wiring
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of CHARLES
> T
> BECKER
> Sent: Friday, March 14, 2008 12:09 PM
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Keyed Master Switch?
>
>
>
> Dennis has the right idea, especially in light of all the
> emphasis on '2 locks'. My 8A will have a key switch
> between the battery and the starter switch. The actual
> starter switch will be on the stick, controlling a relay
> in the starter circuit.
>
> Charlie Becker
> N464CB(r) 8A(e)
> Finishing
>
>
> "Glaeser, Dennis A" wrote:
>>Dennis A"
>>
>> Consider putting a keyed switch in the Push Button Start
>>circuit. If
>> the key isn't on, the start button doesn't work! One
>>switch does the
>> trick and it doesn't put another switch (point of
>>failure) in any of
>> your other critical circuits.
>> Your ignition systems may be live if their switches are
>>flipped, but
>> nothing happens without the starter.
>>
>> Dennis Glaeser
>> RV7A - Subaru H6 - DAR inspection next week!
>>
>> -----------------------------------------
>> I plan on a PUSH Button Start and Dual Electonic
>>Ignition. Can anyone
>> help with a method of enabling "key start" access to
>>ignition/power?
>>
>> I have dual paths to each ignition, so need four
>>switches (to enable
>> pre-flight checks of each path), so the documented
>>adapted mag key start
>> switch option won't work.
>>
>> I can't get fully comfortable with a fully live system
>>being just a flip
>> of a switch away....... See attached to get the idea.
>>
>> Best regards,
>>
>> Andrew Butler
>> RV 71700 - West of Ireland.
>>Fueslage (right way up!)
>>
>>
>>
>>Un/Subscription,
>>http://www.matronics.com/Navigator?AeroElectric-List
>>Forums!
>>Admin.
>>
>>
>>
>
>
________________________________________________________________________________
| From: | "Bill Schoen" <flybill2usa(at)msn.com> |
| Subject: | Re: ANL 50 Failure |
Thank you Dave for sharing that critical information. I will be very
careful when installing the 3 ANLs in my RV-7,
project.
Bill Schoen
N727BN res
South Fork, Co.
----- Original Message -----
From: Dave Saylor<mailto:Dave(at)AirCraftersLLC.com>
To:
aeroelectric-list(at)matronics.com
Sent: Friday, March 14, 2008 12:49 PM
Subject: AeroElectric-List: ANL 50 Failure
Here is a picture of a current limiter from a recent job. It had been
replaced for unknown reasons over a year ago. The installer didn't use
a washer between the limiter terminal tab and the nut. The nut grabbed
and torqued the tab, deformed the ears that are supported by the rivets,
and partially tore the base of the filiment (right word?) After many
months the filiment finally broke. I don't think it was experienceing
any particularly high current load, but from the looks of the mounting
terminal, it did see some pretty rough handling.
Dave Saylor
AirCrafters LLC
140 Aviation Way
Watsonville, CA
831-722-9141
831-750-0284 CL
www.AirCraftersLLC.com
________________________________________________________________________________
| From: | "Dennis & Anne Glaeser" <glaesers(at)wideopenwest.com> |
| Subject: | RE: Keyed Master Switch? |
Why not a key switch in a more convenient (in the cockpit somewhere)
location? It doesn't have to be on the panel, maybe tucked away somewhere,
but reasonably easy to access. Then no post strap-in remorse, and if you use
the baggage compartment much at all, I predict you'll be removing or
relocating that switch before long.
If you are in a locked hangar, you probably won't use it unless you're away
from home.
Believe me, you're convenience and ease of use is most important.
Dennis
---------------------------------------------------------------------------
My plan has been to put a simple toggle switch in the baggage compartment
that disconnects the starter switch. Hopefully this plus a canopy lock will
meet the 2 lock requirement. The baggage compartment will also have a lock.
I wonder how many times I will get all strapped in before I realize I
haven't enabled the starter switch.
Terry
RV-8A wiring
________________________________________________________________________________
| From: | "Andrew Butler" <andrewbutler(at)ireland.com> |
| Subject: | Re: Keyed Master Switch? |
Hi Charlie,
What type of switch are you using and where did you source it?
Cheers, Andrew.
----- Original Message -----
From: "CHARLES T BECKER"
To: aeroelectric-list(at)matronics.com
Subject: Re: AeroElectric-List: Keyed Master Switch?
Date: Fri, 14 Mar 2008 15:09:25 -0400
Dennis has the right idea, especially in light of all the emphasis on
'2 locks'. My 8A will
have a key switch between the battery and the starter switch. The
actual starter switch will be
on the stick, controlling a relay in the starter circuit.
Charlie Becker
N464CB(r) 8A(e)
Finishing
"Glaeser, Dennis A" wrote:
>
> Consider putting a keyed switch in the Push Button Start circuit.
If
> the key isn't on, the start button doesn't work! One switch does
the
> trick and it doesn't put another switch (point of failure) in any
of
> your other critical circuits.
> Your ignition systems may be live if their switches are flipped,
but
> nothing happens without the starter.
>
> Dennis Glaeser
> RV7A - Subaru H6 - DAR inspection next week!
>
> -----------------------------------------
> I plan on a PUSH Button Start and Dual Electonic Ignition. Can
anyone
> help with a method of enabling "key start" access to
ignition/power?
>
> I have dual paths to each ignition, so need four switches (to
enable
> pre-flight checks of each path), so the documented adapted mag key
start
> switch option won't work.
>
> I can't get fully comfortable with a fully live system being just a
flip
> of a switch away....... See attached to get the idea.
>
> Best regards,
>
> Andrew Butler
> RV 71700 - West of Ireland.
> Fueslage (right way up!)
>
>
>
> Un/Subscription,
> http://www.matronics.com/Navigator?AeroElectric-List
> Forums!
> Admin.
>
>
>
===========
===========
===========
===========
________________________________________________________________________________
| From: | "Mark Sletten" <marknlisa(at)hometel.com> |
| Subject: | Re: Keyed Master Switch? |
Why not just use a standard keyed starter switch? Get rid of all the other
push button/toggle switches in the circuit. Power your electrical system
thru a standard toggle if you like and just use the starter side of the
keyed switch in the starter circuit.
Regards,
Mark
________________________________________________________________________________
| From: | "ROGER & JEAN CURTIS" <mrspudandcompany(at)verizon.net> |
| Subject: | Keyed Master Switch?Keyed Master Switch? |
Terry,
I would put, on the instrument panel, a simple key switch, (on-off) no
other
contacts, between the 12V supply and the start button. This has several
advantages, convenience, ease of use, and due to the convenience and
ease of
use it will get used regularly to help protect your aircraft from theft.
These switches are available from electronic supply houses, cheap.
Roger
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Keyed Master Switch? |
Automotive and farm suppliers sell good key switches for around $12 and
marine suppliers (at about twice the price) as well. Typically rated for
a 25 amp starter solenoid load. I use one for the battery master and the
spring loaded position cranks the engine. I like the fact that with the
key in my pocket nobody can crank the engine accidentally, and that from
cars we subconsciously associate keys with cranking. Also I think there
is very little chance of the circuit staying energized after cranking
since my fingers can force it back from the crank position even if the
spring fails or the contacts try to weld. Of course my starter solenoid
can still physically stick, but not the switch I hope.
Ken
Mark Sletten wrote:
>
> Why not just use a standard keyed starter switch? Get rid of all the other
> push button/toggle switches in the circuit. Power your electrical system
> thru a standard toggle if you like and just use the starter side of the
> keyed switch in the starter circuit.
>
> Regards,
>
> Mark
________________________________________________________________________________
| From: | "Terry Watson" <terry(at)tcwatson.com> |
| Subject: | Re: Keyed Master Switch? |
Think of it this way: I prefer combination locks to keyed locks because the
latter requires that I have the proper physical key with me while a
combination lock requires only that I know how to open it. What I am
proposing amounts to a combination lock on the ignition: you just have to
know where the switches are. Locking the baggage compartment where the
disconnect switch is located is that additional security feature that we are
now required to have.
When I was in college I bought a sad looking '50 Chevy sedan for $60. It
turned out to be a great car until I ran it low on oil and threw a rod, but
one of the great features was the ignition switch. Key use was optional. You
could turn it to the left with the key in it and remove the key and it was
locked, or you could just remove the key without turning it to the left and
it was still an ignition switch but didn't require a key.
Yes, canopy and baggage compartments will still require a key. My current
Mazda MX-5 only requires that I have the key in my pocket and it
"recognizes" me and allows me to open the doors or trunk and start the
engine. But that's way more complex than I want to go with my airplane.
Terry
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mark
Sletten
Sent: Saturday, March 15, 2008 6:47 AM
Subject: AeroElectric-List: Re: Keyed Master Switch?
Why not just use a standard keyed starter switch? Get rid of all the other
push button/toggle switches in the circuit. Power your electrical system
thru a standard toggle if you like and just use the starter side of the
keyed switch in the starter circuit.
Regards,
Mark
________________________________________________________________________________
| From: | Steven Eberhart <steve(at)newtech.com> |
| Subject: | Re: Keyed Master Switch? |
I like the idea of a shorting plug that will short the mag p leads to
ground. Insert the plug to disable the airplane. Remove the plug to
fly. You really are not adding anything to fail in flight. I will only
be using it when away from my home field. Simple, cheap and relatively
free from unintended consequences (I think).
Steve Eberhart
RV-7A, Wiring up everything so I can finally fly this thing.
Andrew Butler wrote:
> All,
>
> I plan on a PUSH Button Start and Dual Electonic Ignition. Can anyone
> help with a method of enabling "key start" access to ignition/power?
>
> I have dual paths to each ignition, so need four switches (to enable
> pre-flight checks of each path), so the documented adapted mag key
> start switch option won't work.
>
> I can't get fully comfortable with a fully live system being just a
> flip of a switch away....... See attached to get the idea.
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Ground Start enunciator light |
Listers
I installed a Piper-type male socket to my airplane, to have the possibility
of a ground start in case of a low battery cranking difficulty.
As recommended by this List experts, I connected the socket to the battery
through a continuous duty contactor (aka Master Relay or Battery solenoid),
the S701-1 from B&C, controlled by a SPST switch, which grounds the
contactor when thrown to ON.
Now what I want to do is to put a green enunciator light in my panel, which
illuminates when that switch is ON and the contactor is closed to allow the
ground start procedure, to remind me to switch it Off after finishing that
procedure.
I have tried some wiring of the warning light to the switch, but I cannot
make it work properly. Can somebody please enlighten me how to wire it?
TIA
Carlos
________________________________________________________________________________
| From: | "Ron Shannon" <rshannon(at)CRUZCOM.COM> |
| Subject: | Re: Ground Start enunciator light |
I assume you want this to be on whenever the ground switch (relay) is ON,
whether external power is connected or not. If so, use a DPDT switch for the
relay instead of an SPST, and use the extra pair of contacts to switch the
light to run from your main battery bus.
Ron
On 3/15/08, Carlos Trigo wrote:
>
> trigo(at)mail.telepac.pt>
>
> Listers
>
> I installed a Piper-type male socket to my airplane, to have the
> possibility
> of a ground start in case of a low battery cranking difficulty.
> As recommended by this List experts, I connected the socket to the battery
> through a continuous duty contactor (aka Master Relay or Battery
> solenoid),
> the S701-1 from B&C, controlled by a SPST switch, which grounds the
> contactor when thrown to ON.
>
> Now what I want to do is to put a green enunciator light in my panel,
> which
> illuminates when that switch is ON and the contactor is closed to allow
> the
> ground start procedure, to remind me to switch it Off after finishing that
> procedure.
>
> I have tried some wiring of the warning light to the switch, but I cannot
> make it work properly. Can somebody please enlighten me how to wire it?
>
> TIA
> Carlos
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: ANL 50 Failure |
>Here is a picture of a current limiter from a recent job. It had been
>replaced for unknown reasons over a year ago. The installer didn't use a
>washer between the limiter terminal tab and the nut. The nut grabbed and
>torqued the tab, deformed the ears that are supported by the rivets, and
>partially tore the base of the filiment (right word?).
Looks like it was probably stress cracked, there's
no evidence of a melt-open event.
> After many months the filiment finally broke. I don't think it was
> experienceing any particularly high current load, but from the looks of
> the mounting terminal, it did see some pretty rough handling.
Thanks for sharing this with us. This is
an excellent reminder of the need to think about
where reaction torques are going when we cinch things
down tight. Another at-risk-joint is on the fat-wire
main terminals of these contactors:
http://www.aeroelectric.com/Pictures/Contactors/s701-2.jpg
It's a good idea to put a wrench on the nut adjacent
to the case and put some counter-acting torque while
tightening the nut that holds wires.
Take a look at:
http://www.aeroelectric.com/Pictures/Fuses/Fuse_Holders/ANN-ANL_Base.jpg
If you look real closely under the washers, you'll see the
bottom nut in the stack for each terminal. The things that
should on top of the first nut are terminals on ends of wires
and/or straps. Next is the second, thin,-jam nut, preferably
brass torqued to 80% of ultimate for brass. The ANL limiter goes next
followed by the washer and finally, the third locking nut shown.
This order of assembly allows replacing of the ANL without
opening the joints for conductors.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Ground Start enunciator light |
>
>
>Listers
>
>I installed a Piper-type male socket to my airplane, to have the possibility
>of a ground start in case of a low battery cranking difficulty.
>As recommended by this List experts, I connected the socket to the battery
>through a continuous duty contactor (aka Master Relay or Battery solenoid),
>the S701-1 from B&C, controlled by a SPST switch, which grounds the
>contactor when thrown to ON.
>
>Now what I want to do is to put a green enunciator light in my panel, which
>illuminates when that switch is ON and the contactor is closed to allow the
>ground start procedure, to remind me to switch it Off after finishing that
>procedure.
>
>I have tried some wiring of the warning light to the switch, but I cannot
>make it work properly. Can somebody please enlighten me how to wire it?
The schematic is shown at:
http://www.aeroelectric.com/articles/grndpwr.pdf
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| Subject: | Ground Start enunciator light |
You might also want to power the relay from the external power with a diode
to verify that the external power is of the right polarity.
r.t.s.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Carlos
Trigo
Sent: Saturday, March 15, 2008 8:54 PM
Subject: AeroElectric-List: Ground Start enunciator light
Listers
I installed a Piper-type male socket to my airplane, to have the possibility
of a ground start in case of a low battery cranking difficulty.
As recommended by this List experts, I connected the socket to the battery
through a continuous duty contactor (aka Master Relay or Battery solenoid),
the S701-1 from B&C, controlled by a SPST switch, which grounds the
contactor when thrown to ON.
Now what I want to do is to put a green enunciator light in my panel, which
illuminates when that switch is ON and the contactor is closed to allow the
ground start procedure, to remind me to switch it Off after finishing that
procedure.
I have tried some wiring of the warning light to the switch, but I cannot
make it work properly. Can somebody please enlighten me how to wire it?
TIA
Carlos
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Ground Start enunciator light |
Bob
Thanks for pointing me to this schematic.
I have 2 questions about this schematic:
- shouldn't the "Ground Power" contactor p/n be S701-1 instead of
S702-1?
- regarding the lamp, if I want to put a simple 2 terminal lamp,
instead
of a ptt lamp, is the wiring the same?
Carlos
> -----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: domingo, 16 de Mar=E7o de 2008 3:08
> To: aeroelectric-list(at)matronics.com
> Subject: Re: AeroElectric-List: Ground Start enunciator light
>
>
>
>
> >
> >
> >Listers
> >
> >I installed a Piper-type male socket to my airplane, to have the
possibility
> >of a ground start in case of a low battery cranking difficulty.
> >As recommended by this List experts, I connected the socket to the
battery
> >through a continuous duty contactor (aka Master Relay or Battery
solenoid),
> >the S701-1 from B&C, controlled by a SPST switch, which grounds the
> >contactor when thrown to ON.
> >
> >Now what I want to do is to put a green enunciator light in my panel,
which
> >illuminates when that switch is ON and the contactor is closed to
allow
the
> >ground start procedure, to remind me to switch it Off after finishing
that
> >procedure.
> >
> >I have tried some wiring of the warning light to the switch, but I
cannot
> >make it work properly. Can somebody please enlighten me how to wire
it?
>
> The schematic is shown at:
>
> http://www.aeroelectric.com/articles/grndpwr.pdf
>
>
>
> Bob . . .
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Electrical question |
3/12/2008
Hello Tom, You wrote:
1) "For clarification, the NC switch means that I press the button to
actually cut the power. Why would this be used on an old military
helicopter stick? What is the reason for cutting the power on a switch?"
We used to say that having helicopter time in your pilot's logbook was like
having
an STD entry (it was called venereal disease back then) in your health
record.
So I will reluctantly admit that I did fly a helicopter (CH-46) for a year
in Viet Nam. The cyclic grip had a button on it that when pressed would
disconnect the electronic flight stability / attitude positioning system so
that one could manually reposition the stick and the helicopter's attitude
then releasing the button would reengage the electronic attitude positioning
system.
Maybe you have a control stick grip that does something similar.
2) "Again, is there any way I can wire it to work with my remote ident
operation?"
I am not the right guy to answer that question, but I am sure that by using
two of the small "ice cube" type relays that ident operation could be
accomplished. It might be a pretty awkward way of doing it though from an
electrical viewpoint.
I'll forward your question to the Matronic's aeroelectric-list and maybe one
of the electrical experts there (even the great guru Bob Nuckolls) would
take a shot at it.
'OC' Says: "The best investment we can make is the effort to gather and
understand knowledge."
--------------------------------------------------------
----- Original Message -----
From: "Tom Gibbons" <TomisFlyingby(at)comcast.net>
Sent: Wednesday, March 12, 2008 12:25 AM
Subject: Electrical question
On my military surplus control stick I have 4 push buttons, 2 wired normally
opened (NO) and 2 wired normally closed (NC). I really do not have access
to these switches so I have to make due but can I use the NC switches
somehow?
I have plans for comm flip/flop, nav flip/flop, and Ident for my
transponder. I actually have a "hattie" switch in the middle for trim which
is not hooked up. The stick is installed with the ptt and intercom trigger
switches working good. All kinds of switches on this guy. Was not going to
use it but hey, it felt so comfortable, why not.
For clarification, the NC switch means that I press the button to actually
cut the power. Why would this be used on an old military helicopter stick?
What is the reason for cutting the power on a switch? Again, is there any
way I can wire it to work with my remote ident operation?
Tom
________________________________________________________________________________
| Subject: | Van's Ammeter Question |
| From: | "rampil" <ira.rampil(at)gmail.com> |
Anyone know why Van's Ammeter gauge requires a +12V source
(independent of lighting)?
My hangar neighbor is building a -7 and noticed that when he keys
his ICOM his ammeter goes to 20-30 Amps on some frequencies but
only 2-3 Amps on others.
Externally, the ammeter looks like a standard analog mechanical
gauge using an external shunt and with no technical docs provided
by Vans.
My buddy also has RFI on his trim servo indicator (apparently quite
common) and on his Van's Manifold Pressure gauge.
Shielded cable apparently does the trick for the servo, but I'd like
to understand the Ammeter a bit better before throwing bypass
caps and ferrites at it.
Thanks!
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=170155#170155
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Ground Start enunciator light (Addendum) |
>
>
>Listers
>
>I installed a Piper-type male socket to my airplane, to have the possibility
>of a ground start in case of a low battery cranking difficulty.
>As recommended by this List experts, I connected the socket to the battery
>through a continuous duty contactor (aka Master Relay or Battery solenoid),
>the S701-1 from B&C, controlled by a SPST switch, which grounds the
>contactor when thrown to ON.
>
>Now what I want to do is to put a green enunciator light in my panel, which
>illuminates when that switch is ON and the contactor is closed to allow the
>ground start procedure, to remind me to switch it Off after finishing that
>procedure.
>
>I have tried some wiring of the warning light to the switch, but I cannot
>make it work properly. Can somebody please enlighten me how to wire it?
Carlos,
A couple of hours after I replied to this it occurred to me that
you probably were not incorporating a press-to-test light fixture
nor did you mention crowbar ov protection. I've updated the
schematics in the article to include "Ground Power Lite" without
OV protection and using a plain vanilla lamp fixture. See the
last page of:
http://www.aeroelectric.com/articles/grndpwr.pdf
Is this more like what you needed?
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Jim McBurney" <jmcburney(at)pobox.com> |
| Subject: | DPDT high-current contactor needed |
Hi, Listers,
I need a manually operated double pole double throw contactor that will
carry (not make or break) up to 400 amps. I'm building a 14v system, but my
engine requires 24v to spin the starter. My plan is to install 2 batteries.
Normal configuration will be parallel for charging and normal running, but
switching one battery into a series configuration for starting. Actual
starting will be with a starter contactor, so the dpdt contactor won't make
or break the starting current. Any thoughts on where I could find such a
contactor?
Blue skies and tailwinds
Jim
CH-801
DeltaHawk diesel
Augusta GA
90% done, 90% left
________________________________________________________________________________
| From: | "nauga(at)brick.net" <dhyde01(at)earthlink.net> |
| Subject: | Audio iso amp ordered, never received |
First, to all, Bob Nuckolls included, I apologize for bringing this up here, but
I don't see any alternative.
Bob, I ordered an audio isolation amp board from you in December and paid using
Paypal. You said you were
planning on updating the board but would pull one and send it to me. I've sent
messages through the message
area, e-mails using the address in your responses to my questions before ordering,
and a request for info on the
Aeroelectric list. I've gotten no response or recognition that you've received
any of my attempts at communication.
So: Can you let me know what's going on with my order? I wouldn't mind the wait
if I knew something was happening
at your end but that just hasn't been the case.
Please respond here or contact me by e-mail. You have my address.
Dave Hyde
________________________________________________________________________________
| From: | "William Slaughter" <willslau(at)comcast.net> |
| Subject: | Ground Start enunciator light (Addendum) |
On a related note:
The instructions for modifying the receptacle call for a propane torch or
"large soldering iron". How large an iron? I ask because I incinerated the
phenolic insulator when I tried to solder it with my propane torch, and have
just ordered a replacement receptacle to try again. If I preheat the bolt in
the oven, would a Weller 100/140 soldering gun have enough oomph? If not,
????.
William Slaughter
-----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: Sunday, March 16, 2008 9:01 PM
Subject: AeroElectric-List: Ground Start enunciator light (Addendum)
>
>
>Listers
>
>I installed a Piper-type male socket to my airplane, to have the
possibility
>of a ground start in case of a low battery cranking difficulty.
>As recommended by this List experts, I connected the socket to the battery
>through a continuous duty contactor (aka Master Relay or Battery solenoid),
>the S701-1 from B&C, controlled by a SPST switch, which grounds the
>contactor when thrown to ON.
>
>Now what I want to do is to put a green enunciator light in my panel, which
>illuminates when that switch is ON and the contactor is closed to allow the
>ground start procedure, to remind me to switch it Off after finishing that
>procedure.
>
>I have tried some wiring of the warning light to the switch, but I cannot
>make it work properly. Can somebody please enlighten me how to wire it?
Carlos,
A couple of hours after I replied to this it occurred to me that
you probably were not incorporating a press-to-test light fixture
nor did you mention crowbar ov protection. I've updated the
schematics in the article to include "Ground Power Lite" without
OV protection and using a plain vanilla lamp fixture. See the
last page of:
http://www.aeroelectric.com/articles/grndpwr.pdf
Is this more like what you needed?
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Audio iso amp ordered, never received |
>
>
>First, to all, Bob Nuckolls included, I apologize for bringing this up
>here, but I don't see any alternative.
>Bob, I ordered an audio isolation amp board from you in December and paid
>using Paypal. You said you were
>planning on updating the board but would pull one and send it to me. I've
>sent messages through the message
>area, e-mails using the address in your responses to my questions before
>ordering, and a request for info on the
>Aeroelectric list. I've gotten no response or recognition that you've
>received any of my attempts at communication.
>
>So: Can you let me know what's going on with my order? I wouldn't mind
>the wait if I knew something was happening
>at your end but that just hasn't been the case.
My apologies. I HAVE 20 some boards around here somewhere. After
your request came in I modified the artwork to include some
later enhancements and ordered boards. They came in with
some other boards and I've misplaced them.
I've had so many irons in the fire the past few months that
my shop is presently in a stage II train wreck. They're
not lost, I just don't know where I "filed" them.
I've just ordered another batch. They should be here
Wednesday morning. I'll get your board out Wednesday
afternoon via priority mail.
I wasn't planning on resurrecting this product but
when I find the first batch, I'll have "plenty" on hand.
I guess I'll have to put it back up on the website!
In the mean time, things re starting to spool down
a bit on the 20hr/wk (yeah right!) consulting job.
Weather is getting warmer and I'd really like to get
the alternator drive stand in the garage running as
well as cleanup/organize the shop!
Bob . . .
________________________________________________________________________________
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Ground Start enunciator light (Addendum) |
> -----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: segunda-feira, 17 de Mar=E7o de 2008 2:01
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: Ground Start enunciator light (Addendum)
>
>
> A couple of hours after I replied to this it occurred to me that
> you probably were not incorporating a press-to-test light fixture
> nor did you mention crowbar ov protection. I've updated the
> schematics in the article to include "Ground Power Lite" without
> OV protection and using a plain vanilla lamp fixture. See the
> last page of:
>
> http://www.aeroelectric.com/articles/grndpwr.pdf
>
> Is this more like what you needed?
>
> Bob . . .
You=92re right on target, Bob. Thanks again
(Having a good teacher and being a good pupil ' forgive my immodesty
' I had
already wired it yesterday like you now designed, and it worked!!)
Carlos
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Van's Ammeter Question |
>
>Anyone know why Van's Ammeter gauge requires a +12V source
>(independent of lighting)?
Don't know for sure. I've ordered one to find out.
>My hangar neighbor is building a -7 and noticed that when he keys
>his ICOM his ammeter goes to 20-30 Amps on some frequencies but
>only 2-3 Amps on others.
>
>Externally, the ammeter looks like a standard analog mechanical
>gauge using an external shunt and with no technical docs provided
>by Vans.
>
>My buddy also has RFI on his trim servo indicator (apparently quite
>common) and on his Van's Manifold Pressure gauge.
>
>Shielded cable apparently does the trick for the servo, but I'd like
>to understand the Ammeter a bit better before throwing bypass
>caps and ferrites at it.
Van's ammeter appears to be enhanced with internal
electronics. The rudimentary meter movement is not
sensitive to radio frequency interference.
It's unfortunate that suppliers to the OBAM aircraft
industry are so slow on the uptake for rudimentary
design skills. It should NEVER be the responsibility
of the installer to RFI-proof the system.
On the TC side of the house, all accessories are
tested in the lab and the designer is only rarely
allowed to take credit for external shielding and/or
filters on the interconnect cables.
We see this a lot in consumer electronics where
video, data and some audio cables come with
some form of RFI mitigation enhancement on them.
In each of these cases, the cables are pre-assembled
and the end user is never expected to fabricate one
that is longer or has different connectors on it.
In aircraft, the installers are always expected to
fabricate cables and install connectors. Installations
of a product over time and many different airframes
can experience a wide variety of assaults from
EMC/RFI issues.
As I write these words, I'm assisting an OEM with
a random nuisance tripping of the fault detection
system in a product that is over 20 years old and
installed by the thousands in aircraft where this
phenomenon has never manifested itself. However,
in this new installation, a device that has been
traditionally installed in the nose has been moved
to the top of the vertical fin on a large a/c. This
is the first time (anyone knows of) that the harness
became so long and traversed so many EMC gauntlets
on its way through the a/c.
A review of schematics for the product revealed some
ill-conceived filtering on i/o pins . . . that PASSED
DO-160 conducted and radiated susceptibility tests
20+ years ago.
When root cause of this problem is deduced, I'm
betting that a few changes to components inside
the product will fix it. But changing anything
inside will raise re-certification flags with
those-who-know-more-about-airplanes-than-we-do.
We may well have to fabricate a filtered
connector to go on the end of our interface
harness. Seems the installer controls harnesses
and are not part of the cert basis for the appliance.
We can fix the problem with an external band-aid
without having to re-qualify the appliance.
The bureaucratic Catch 22 causes us to do really
dumb things to work around the do-gooders. On
the OBAM aircraft side of the house, suppliers
of devices like trim indicators and ammeters
can make indicated improvements to their products
in a heartbeat without seeking anyone's permission.
Problem is getting them to recognize shortcomings
of their design and fix them. The TC guys will go
to great lengths to avoid significant changes to
the certification effort. I've seen changes to
a 10-cent resistor generate thousands of dollars
in re-qualification testing!
(sigh)
As soon as the Van's ammeter gets here, I'll see
what makes it tick and report back to the group.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
Wondering if the server is asleep . . .
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Ground Start enunciator light (Addendum) |
>
>
>Listers
>
>I installed a Piper-type male socket to my airplane, to have the possibility
>of a ground start in case of a low battery cranking difficulty.
>As recommended by this List experts, I connected the socket to the battery
>through a continuous duty contactor (aka Master Relay or Battery solenoid),
>the S701-1 from B&C, controlled by a SPST switch, which grounds the
>contactor when thrown to ON.
>
>Now what I want to do is to put a green enunciator light in my panel, which
>illuminates when that switch is ON and the contactor is closed to allow the
>ground start procedure, to remind me to switch it Off after finishing that
>procedure.
>
>I have tried some wiring of the warning light to the switch, but I cannot
>make it work properly. Can somebody please enlighten me how to wire it?
Carlos,
A couple of hours after I replied to this it occurred to me that
you probably were not incorporating a press-to-test light fixture
nor did you mention crowbar ov protection. I've updated the
schematics in the article to include "Ground Power Lite" without
OV protection and using a plain vanilla lamp fixture. See the
last page of:
http://www.aeroelectric.com/articles/grndpwr.pdf
Is this more like what you needed?
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Audio iso amp ordered, never received |
>
>
>First, to all, Bob Nuckolls included, I apologize for bringing this up
>here, but I don't see any alternative.
>Bob, I ordered an audio isolation amp board from you in December and paid
>using Paypal. You said you were
>planning on updating the board but would pull one and send it to me. I've
>sent messages through the message
>area, e-mails using the address in your responses to my questions before
>ordering, and a request for info on the
>Aeroelectric list. I've gotten no response or recognition that you've
>received any of my attempts at communication.
>
>So: Can you let me know what's going on with my order? I wouldn't mind
>the wait if I knew something was happening
>at your end but that just hasn't been the case.
My apologies. I HAVE 20 some boards around here somewhere. After
your request came in I modified the artwork to include some
later enhancements and ordered boards. They came in with
some other boards and I've misplaced them.
I've had so many irons in the fire the past few months that
my shop is presently in a stage II train wreck. They're
not lost, I just don't know where I "filed" them.
I've just ordered another batch. They should be here
Wednesday morning. I'll get your board out Wednesday
afternoon via priority mail.
I wasn't planning on resurrecting this product but
when I find the first batch, I'll have "plenty" on hand.
I guess I'll have to put it back up on the website!
In the mean time, things re starting to spool down
a bit on the 20hr/wk (yeah right!) consulting job.
Weather is getting warmer and I'd really like to get
the alternator drive stand in the garage running as
well as cleanup/organize the shop!
Bob . . .
________________________________________________________________________________
| From: | "John McMahon" <blackoaks(at)gmail.com> |
| Subject: | Z-19 with Z-30 and Z-31B |
I connected my Piper style socket to a brass bus bar which will connect my
two 12 v. batteries on the aircraft side of the contactors. I was doing
this to keep the batteries isolated from each other unless both battery
contactors were closed. This would allow charging either or both batteries
or only powering aircraft systems from the ground power plug. If I
understand correctly, that would not be a good idea because powering
aircraft systems without a battery on line is a bad idea. Any pros or cons
to this?
On Sun, Mar 16, 2008 at 7:00 PM, Robert L. Nuckolls, III <
nuckolls.bob(at)cox.net> wrote:
> nuckolls.bob(at)cox.net>
>
>
> >
> >
> >Listers
> >
> >I installed a Piper-type male socket to my airplane, to have the
> possibility
> >of a ground start in case of a low battery cranking difficulty.
> >As recommended by this List experts, I connected the socket to the
> battery
> >through a continuous duty contactor (aka Master Relay or Battery
> solenoid),
> >the S701-1 from B&C, controlled by a SPST switch, which grounds the
> >contactor when thrown to ON.
> >
> >Now what I want to do is to put a green enunciator light in my panel,
> which
> >illuminates when that switch is ON and the contactor is closed to allow
> the
> >ground start procedure, to remind me to switch it Off after finishing
> that
> >procedure.
> >
> >I have tried some wiring of the warning light to the switch, but I cannot
> >make it work properly. Can somebody please enlighten me how to wire it?
>
>
> Carlos,
>
> A couple of hours after I replied to this it occurred to me that
> you probably were not incorporating a press-to-test light fixture
> nor did you mention crowbar ov protection. I've updated the
> schematics in the article to include "Ground Power Lite" without
> OV protection and using a plain vanilla lamp fixture. See the
> last page of:
>
> http://www.aeroelectric.com/articles/grndpwr.pdf
>
> Is this more like what you needed?
>
>
> Bob . . .
>
> ----------------------------------------)
> ( . . . a long habit of not thinking )
> ( a thing wrong, gives it a superficial )
> ( appearance of being right . . . )
> ( )
> ( -Thomas Paine 1776- )
> ----------------------------------------
>
>
--
John McMahon
Lancair Super ES, S/N 170, N9637M (Reserved)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
>Hi Bob,
>
>I have sort of an electrical problem/issue and I was wondering if you
>could give me some guidance. I have a pristine Bendix King KLX 100 GPS
>Portable Nav Com that I want to use primarily to listen to air traffic
>while in my hangar. It runs fine on the eight AA batteries required but I
>want to use AC in the hangar and/or DC in my car to power it. It doesn't
>have the factory cords. So I called Bendix King and they want 350 for the
>AC cord and 150 for the DC cord the total of which is more than the unit
>itself is worth. I was wondering if there was some way for me to figure
>out which type of AC and DC cords I could use say from Radio Shack or some
>other supplier to get the job done.
>
>As I'm sure you know some AC cords are 9v some 12v with different outputs
>from 500millamps on up. The DC cords also come in varieties. My owner's
>manual doesn't say much on what is required for AC or DC power. Is there
>any way for me to figure this out based on the batteries used to power the
>unit, (8 AA's) or is there some other resource that could assist me?
What does the external power connector look
like on the radio? Does it look like the
external power jacks found on most consumer
electronics? See:
http://www.aeroelectric.com/Pictures/Connectors/Power/Coaxial_DC_Power.jpg
If so, it's only necessary to find the appropriate
"wall wart" power supply and mating connector.
If not this form factor, take a picture of the
external power port on your radio and send it to
me.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Z-19 with Z-30 and Z-31B |
>
> I connected my Piper style socket to a brass bus bar which will connect
> my two 12 v. batteries on the aircraft side of the contactors. I was
> doing this to keep the batteries isolated from each other unless both
> battery contactors were closed. This would allow charging either or both
> batteries or only powering aircraft systems from the ground power plug.
> If I understand correctly, that would not be a good idea because powering
> aircraft systems without a battery on line is a bad idea. Any pros or
> cons to this?
There's been much discussion on this over the years. Generally
speaking in the TC world, ground power is not considered a battery
charging tool. In fact, it's not recommended that the pilot use
ground power to get an engine started with a dead battery . . .
ground power is to ASSIST the battery for difficult starts, i.e.
cold weather or long cranking cycles for turbine engines, and
ground maintenance.
You can use what ever philosophy you're comfortable with.
My reason for the architecture shown is that first, a pilot
has absolute control over incoming power. Second, ground
power can be applied, turned on and verified for polarity
and proper voltage before the battery master is closed
thus connecting the ground power/battery combination to
the aircraft's systems.
For your situation, being able to charge only one of
the two batteries should not be a problem very often
during your ownership of the airplane. On the other hand,
when that kid standing out in the cold wind, back to
you is flipping switches on that WWII surplus gasoline
driven generator, it would be nice if YOU were the
final arbiter of when ground power is actually applied
to your airplane's electrical system.
Bob . . .
________________________________________________________________________________
| Subject: | Re: Van's Ammeter Question |
| From: | "rampil" <ira.rampil(at)gmail.com> |
Thanks Bob,
It's hard to imagine why they would need an "enhancement"
to the rudimentary meter movement since they are so widely
used in this shunt current (voltage) range without.
Also, the price of the meter from Van's suggests they are just custom
labeling a automotive movement.
Well, we will see thanks to Bob's generosity!
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=170457#170457
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Ground Start enunciator light (Addendum) |
>
>
>On a related note:
>The instructions for modifying the receptacle call for a propane torch or
>"large soldering iron". How large an iron? I ask because I incinerated the
>phenolic insulator when I tried to solder it with my propane torch, and have
>just ordered a replacement receptacle to try again. If I preheat the bolt in
>the oven, would a Weller 100/140 soldering gun have enough oomph? If not,
>????.
No. Go to Home Depot or Lowes and see if you can find a
Bernzomatic ST100T micro torch. This is my all time favorite
although I don't find it described on the Bernszomatic website.
It may be discontinued. In any case, you need a micro-torch not
unlike those shown at:
http://www.aeroelectric.com/Pictures/Tools/Soldering/Gas_Tools/
Harbor Freight has some butane micro-torches as do many
hardware stores. I think Walmart stocks one too. Ace Hardware
stores have:
http://tinyurl.com/2tgatp
Also, use 63/37 alloy solder. This stuff melts at 361F and
flows nicely below 400. There's a rubber-bumper on the
end of the receptacle center-pin. Pull this off for soldering
operations and replace it after the pin cools.
Bob . . .
________________________________________________________________________________
| From: | ECLarsen81(at)aol.com |
| Subject: | Re: Van's Ammeter Question |
The instruments themselves are manufactured by ISS for Van's, and now Cheif
and Aircraft Spruce both sell the same item with different faceplates.
I did open the case to take a peek and it had a small circuit board with SM
parts all over it. You'll have fun with it Bob.
I gleaned all this when I ordered one from spruce for a customer of mine,
it didn't come with instructions but had 4 pins on the back, so I called
spruce. The saleperson there gave me the number to an engineer at ISS who was
very
unhappy I interupted his day. I did get the instructions from van's site and
a few weeks later a friend ordered one for his homebuilt from spruce. This
time it came with the Van's instructions. so the engineer must have got it
resolved in that direction.
So far as I know, niether installation has had problems so I'd be curious
as well.
Ed Larsen
(43G) Larsen Airpark
**************It's Tax Time! Get tips, forms, and advice on AOL Money &
Finance. (http://money.aol.com/tax?NCID=aolprf00030000000001)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Van's Ammeter Question |
> The instruments themselves are manufactured by ISS for Van's, and now
> Cheif and Aircraft Spruce both sell the same item with different faceplates.
> I did open the case to take a peek and it had a small circuit board with
> SM parts all over it. You'll have fun with it Bob.
> I gleaned all this when I ordered one from spruce for a customer of
> mine, it didn't come with instructions but had 4 pins on the back, so I
> called spruce. The saleperson there gave me the number to an engineer at
> ISS who was very unhappy I interupted his day. I did get the instructions
> from van's site and a few weeks later a friend ordered one for his
> homebuilt from spruce. This time it came with the Van's instructions. so
> the engineer must have got it resolved in that direction.
> So far as I know, niether installation has had problems so I'd be
> curious as well.
> Ed Larsen
> (43G) Larsen Airpark
Thank you for sharing this. It's what I would have
guessed that it has some form of electronics. When
you have an instrument with this mechanical span
(approx 270 degrees) you either use a stepper motor
or a moving magnet suspended in quadrature coils.
You can buy a motor driven instrument for $40 so
it must be a moving magnet device.
There are a number of integrated circuits designed
to drive a 2-coil instrument motor . . . many transistors
capable of responding to VHF radios. Do you have
a name and phone number for the engineer at ISS?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: DPDT high-current contactor needed |
>
>Hi, Listers,
>
>I need a manually operated double pole double throw contactor that will
>carry (not make or break) up to 400 amps. I'm building a 14v system, but my
>engine requires 24v to spin the starter. My plan is to install 2 batteries.
>Normal configuration will be parallel for charging and normal running, but
>switching one battery into a series configuration for starting. Actual
>starting will be with a starter contactor, so the dpdt contactor won't make
>or break the starting current. Any thoughts on where I could find such a
>contactor?
The last time I saw a series-parallel battery controller
it was a about half the size of a breadbox, weighed about
10 pounds and cost a couple of grand. Of course, this was
an electrically engaged/disengaged device. It was a WWII
era design. I think a Hartman product. Not part of their
current bag of tricks that I could see . . .
http://relays.tycoelectronics.com/hartman.asp
I'm unaware of any manually operated device for this
purpose. On the TC side of the house, we go to a LOT
of effort to avoid a need for such agility in battery
management.
Here's a drawing I did for a client some years ago
to address a similar requirement. He didn't need 400A
so the Stancore/White-Rogers contactors would suffice.
If this approach works for you, you'll need to consider
some heavier devices. Perhaps Type 124?
http://www.stancor.com/wrdstc/pdfs/Catalog_2006/Pg_054_55.pdf
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | Keith Rhea <krhea(at)sktc.net> |
| Subject: | AeroElectric Manual |
Bob: any chance of getting an manual? I have tried to order online.
Thanks
Keith Rhea
N52VP
________________________________________________________________________________
| From: | "David Dalton" <ddalton536(at)gmail.com> |
| Subject: | Re: AeroElectric Manual |
I placed an order a couple weeks back also, and am still anxiously waiting
for delivery.
David Dalton
On Tue, Mar 18, 2008 at 5:11 AM, Keith Rhea wrote:
>
> Bob: any chance of getting an manual? I have tried to order online.
>
> Thanks
>
> Keith Rhea
> N52VP
>
>
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: AeroElectric Manual |
My wife ordered one for my B-day about 8 days ago, & it came in 4 days
later.
Charlie
David Dalton wrote:
> I placed an order a couple weeks back also, and am still anxiously
> waiting for delivery.
>
> David Dalton
>
> On Tue, Mar 18, 2008 at 5:11 AM, Keith Rhea > wrote:
>
> >
>
> Bob: any chance of getting an manual? I have tried to order online.
>
> Thanks
>
> Keith Rhea
> N52VP
>
________________________________________________________________________________
| From: | jim-bean(at)ATT.NET |
________________________________________________________________________________
| From: | <frank.phyllis(at)mindspring.com> |
Last evening I experienced smoke in the cockpit of my Kitfox--912S.
First, I want to thank Bob N for convincing me of the importance of
using Z16, incorporating an E-Bus circuit. Worked great and reduced the
load on my "little" motorcycle battery so that I maintained > 11.5 v for
the 15 min duration of my flt.
It was twilight & I had Whelan strobe & nav lights on, near max elec
capacity for the 912 generator. I threw on the landing lt to see what
the added load would do to the system. (Probably not a smart move)
Immediately the system voltage, normally runs 13v, began dropping, so I
turned the landing lt off after a few seconds.
I then began doing a series of steep climbs at slow airspeed. After
about five min I noticed a burning odder, thinking to myself "someone
must be burning trash and I'm in the trail of smoke." After about 30
seconds I noticed smoke coming from under the instrument panel and a
much stronger burning odder. I dropped the nose of the airplane--no
more smoke.
At that moment my GRT EIS warning lt flashed and I noticed the system
voltage below 11 v. I turned on the E Bus switch and off on the main.
Voltage came up--12 v I think. No odder or smoke or falling voltage.
After a few minutes I decided to try the main switch again, pulling in
the battery relay and alternator. Voltage began to climb above 12 v to
about 12.5 v. I added strobe & nav lt again causing an immediate
reversal in voltage trend and warning lt came on again as it plunged
below 11 v. Again I went to E Bus an off main. I landed uneventfully.
My guess is the relay over heated with the momentary excessive
electrical draw (does that happen?) causing the smoke. Any Ideas? I
assume I need to replace the regulator??? What would you recommend as a
replacement regulator/source. Anything else??????
Thanks
Frank
N5929
________________________________________________________________________________
| From: | "Sam Hoskins" <shoskins(at)MCHSI.COM> |
*Positive ground depends upon proper circuit functioning, the
transmission of negative ions by retention of the visible spectral
manifestation known as "smoke". Smoke is the thing that makes electrical
circuits work; we know this to be true because every time one lets the
smoke out of the electrical system, it stops working. This can be
verified repeatedly through empirical testing.
When, for example, the smoke escapes from an electrical component (i.e.,
say, a Lucas voltage regulator), it will be observed that the component
stops working. The function of the wire harness is to carry the smoke
from one device to another; when the wire harness "springs a leak", and
lets all the smoke out of the system, nothing works afterwards. Starter
motors were frowned upon in British Automobiles for some time, largely
because they consume large quantities of smoke, requiring very large
wires.
It has been noted that Lucas components are possibly more prone to
electrical leakage than Bosch or generic Japanese electrics. Experts
point out that this is because Lucas is British and all things British
leak. British engines leak oil, shock absorbers, hydraulic forks and
disk brakes leak fluid, British tires leak air and the British defense
establishment leaks secrets...so, naturally, British electronics leak
smoke.
The Theory Explained through Discussion.
When wires smoke, how come the smoke is not the same color as the wire?
This is not completely true. When the smoke is in the wire, it is under
pressure (called voltage). The pressure difference causes the color to
change from the normal color we are used to. Not unlike the blood in our
veins and arteries changing color due to the oxygen content. When the
smoke escapes the wire and is exposed to air, the pressure is released,
and the color reverts back to what we commonly recognize as smoke. The
wire then changes to the color of the smoke that escaped.
I hope this helps you understand.
I would only question the last sentence of that description. It has been
my experience that the wire turns a color directly opposite of the
smoke.
Not always true, I think it must depend on the composition of the smoke
in question.
I should have made it a little clearer; the color the wire becomes, is
directly proportional to the escape velocity of the smoke. Higher
velocities generate higher heat. This heat tends to burn the wire and
affect the coloring. The statement was meant to be a generalization,
indicating the fact that the color of the wire does in fact change.
Sorry for the miscommu nication.
I was speaking of electrical smoke which is generally white. The spent
smoke casing generally assumes a color somewhat near black after the
smoke leaves.
I can't stand it anymore! If, as you say, light bulbs suck up darkness
and convert it to smoke which is transmitted (via wire) to a power
source for recycling...why do car batteries go dead when lights are left
on? Do car batteries (and flashlight batteries for that matter) have a
limited amount of storage capability? Is it like a hard drive that gets
so full that you have to double-space and then lose all data?
Now you're getting it.......
I thought you guys were smarter than this. Of course the battery stores
the smoke. In fact it can store so much smoke that if you open the top
and light a match, the resulting explosion can do serious damage. I'm
sure you are aware that usually where there's smoke there's fire. If you
connect the battery to a charger, the smoke is then returned to the wire
(Remember, a light bulb wont work unless it is connected to a wire
system) for the utility companies to use. Your hard drive analogy is a
very good example.
Our hardware guys might be onto something in their quest for superior
wiring. I have noticed the unique method of series/parallel wiring the
power strips on our systems seems to prevent the smoke from getting out
of the wires. A "Smoke Loop" of sorts. In the case of the "smoked"
workstation recently, you should notice that this was a conventional
single power strip installation.
Since color is perceived by the cone shaped receptors in our eyes, and
cones require more light that their rod shaped counterparts. Is the sky
blue at night?
At night the process including contraction of the pupil is visual purple
by which the eye adapts to conditions of increased illumination when
facing 300 candle power redeflecting devices.
Since there is a spectrum of light that we as humans cannot see, I
support the theory that everything is going up in smoke, we just can't
see it. This may explain why the neighbors dog barks for no apparent
reason.
I think your basic understanding of smoke systems is remarkable. However
I find a flaw with your theory. The battery is a reusable storage device
for smoke. therefore, one would assume that some sort of one way valve
(we can call it a diode) should be needed to prevent pressure flooding
back into the system while at rest. Unlike the A/C system, the smoke
system is collecting darkness at the headlights and converting it to
smoke. This causes the system to fill up. The battery can contain much
higher pressures and volumes than the wires. If this pressure exceeds
the capacity of the wire, it will cause a rupture as you described. The
rupture can be controlled by a sacrificial device known as a fuse. Bu t
this still doesn't eliminate the problem. Perhaps a two way valve (zener
diode) is used to allow a small amount of pressure to return to the
system, and partially equalize. I find this theory unlikely though, due
to the increase in the force required to start the pump (which is now
under pressure) working again...
The smoke continues circulating through the system, due to the pressure
differential in the battery (smoke pressure/vacuum reservoir). When the
reservoir becomes depleted, the pressure simply equalizes everywhere in
the system (similar to an A/C system when it's turned off) and stuff
just wont work. Notice the relations: Work (W) = Force (F) x Distance
(D); Force (F) = total difference in pressure (Dp) x Area (A).
Therefore, the work done in a pressure system is: Dp x A x D. If the
pressure differential (Dp) is reduced to zero then W = 0 x A x D = 0.
The smoke only escapes the wires when a path is created b etween the
pressure differential areas (@ either the reservoir or the pump) that
has too little restriction. When this happens, the smoke travels through
the wires so fast that the friction between the smoke and the outer
walls of the wiring heats the wires until they rupture. The smoke
continues to escape until its pressure is equalized with the atmosphere,
or until the conduit that provides the path between pressure areas is
severed. When this happens, the sudden drop in pressure allows the wires
to "collapse" slightly and, being soo hot, as the edges of the ruptures
and severed ends touch, the material becomes fused, sealing the system
and retaining the remaining smoke.
Don't forget, when the system is at rest, all the valves, (switches and
relays) are closed, keeping the pressure areas separated. When
restarting the pump, as long as everything is OK, the smoke pressure is
equal on both sides of the pump and there is no net force on the pump
when it begins operating again. Also, within the pump there are
pressure/volume actuated one-way valves with restrictors built in,
arranged in such a way that they keep excess smoke volume recirculating
through an integral smoke loop, which maintains the pressure within
manageable limits.
The excess smoke, created by the light/smoke converters (headlights and
other darkness absorbing devices), is changed back to darkness and
dissipated in small unit concentrations so its dark effect is not
locally observed. The smoke pump impeller (stator), converts smoke into
magnetic flux which does work on the engine. Some of the excess work
energy is dissipated through the cooling system and exhaust in the form
of heat, while the remaining work energy is converted back to smoke and
distributed evenly in small concentrations as you drive. This maintains
the total quantity of smoke in the system at an average that does not
change over time.*
On Tue, Mar 18, 2008 at 7:43 PM, wrote:
>
> Last evening I experienced smoke in the cockpit of my Kitfox--912S.
>
> First, I want to thank Bob N for convincing me of the importance of
> using Z16, incorporating an E-Bus circuit. Worked great and reduced the
> load on my "little" motorcycle battery so that I maintained > 11.5 v for
> the 15 min duration of my flt.
>
> It was twilight & I had Whelan strobe & nav lights on, near max elec
> capacity for the 912 generator. I threw on the landing lt to see what
> the added load would do to the system. (Probably not a smart move)
> Immediately the system voltage, normally runs 13v, began dropping, so I
> turned the landing lt off after a few seconds.
>
> I then began doing a series of steep climbs at slow airspeed. After
> about five min I noticed a burning odder, thinking to myself "someone
> must be burning trash and I'm in the trail of smoke." After about 30
> seconds I noticed smoke coming from under the instrument panel and a
> much stronger burning odder. I dropped the nose of the airplane--no
> more smoke.
>
> At that moment my GRT EIS warning lt flashed and I noticed the system
> voltage below 11 v. I turned on the E Bus switch and off on the main.
> Voltage came up--12 v I think. No odder or smoke or falling voltage.
>
> After a few minutes I decided to try the main switch again, pulling in
> the battery relay and alternator. Voltage began to climb above 12 v to
> about 12.5 v. I added strobe & nav lt again causing an immediate
> reversal in voltage trend and warning lt came on again as it plunged
> below 11 v. Again I went to E Bus an off main. I landed uneventfully.
>
> My guess is the relay over heated with the momentary excessive
> electrical draw (does that happen?) causing the smoke. Any Ideas? I
> assume I need to replace the regulator??? What would you recommend as a
> replacement regulator/source. Anything else??????
>
> Thanks
>
> Frank
> N5929
>
>
________________________________________________________________________________
| From: | "Dale Alexander" <dalexan48(at)dslextreme.com> |
For those of you out there that own, have owned, may own or have worked on
anything British:
What are the three positions of a Lucas headlight switch?
1) Dim
2) Flicker
3) and Smoke
Now let's not mention Lucas in a aviation newsgroup again...or Microsoft.
The blue screen of death takes on a WHOLE new meaning when you MS powered
glass screen goes belly-up in the scud.
Dale Alexander
Trying to build something, probably never finish it...
________________________________ Message 8
_____________________________________
>
>
> From: "Sam Hoskins" <shoskins(at)MCHSI.COM>
> Subject: Re: AeroElectric-List: Smoke
>
> *Positive ground depends upon proper circuit functioning, the
> transmission of negative ions by retention of the visible spectral
> manifestation known as "smoke". Smoke is the thing that makes electrical
> circuits work; we know this to be true because every time one lets the
> smoke out of the electrical system, it stops working. This can be
> verified repeatedly through empirical testing.
________________________________________________________________________________
| From: | jon(at)finleyweb.net |
=0AYeah, no doubt. While we're at it:=0A=0A =0A=0A1. NEVER fly behind a Ly
coming (or pick your most hated brand). They are the most dangerous engine
ever built. I had one die on me in 1961 and have never flown one since.=0A
=0A2. NEVER purchase a Ford (or pick your most hated brand). I owned a 195
2 that got horrible mileage and always needed work. They are terrible produ
cts.=0A=0A3. DO NOT operate a computer. I tried to use one once but didn't
know what I was doing. It got is so screwed up that it wouldn't work - OBV
IOUSLY someone else's fault (pick your most hated vendor).=0A=0A4. ABSOLUTE
LY NEVER EVER use a calculator. I had one once that pinched my index finde
r between the keys - horribly dangerous machines!!=0A=0A5. STAY AWAY from t
elephones. Someone called me once trying to sell me something. They are wo
rks of Satan and huge time wasters.=0A=0A =0A=0AJon=0A=0APLEASE do not arch
ive=0A=0A =0A=0A=0A=0A=0A-----Original Message-----=0AFrom: Dale Alexander
=0ASent: Wednesday, March 19, 2008 10:04am=0ATo:
aeroelectric-list(at)matronics.com=0ASubject: AeroElectric-List: Re:Smoke=0A
e of you out there that own, have owned, may own or have worked on =0Aanyth
ing British:=0A=0AWhat are the three positions of a Lucas headlight switch?
=0A1) Dim=0A2) Flicker=0A3) and Smoke=0A=0ANow let's not mention Lucas in a
aviation newsgroup again...or Microsoft. =0AThe blue screen of death takes
on a WHOLE new meaning when you MS powered =0Aglass screen goes belly-up i
n the scud.=0A=0ADale Alexander=0ATrying to build something, probably never
finish it...=0A
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
>
>Last evening I experienced smoke in the cockpit of my Kitfox--912S.
>
>First, I want to thank Bob N for convincing me of the importance of
>using Z16, incorporating an E-Bus circuit. Worked great and reduced the
>load on my "little" motorcycle battery so that I maintained > 11.5 v for
>the 15 min duration of my flt.
>
>It was twilight & I had Whelan strobe & nav lights on, near max elec
>capacity for the 912 generator. I threw on the landing lt to see what
>the added load would do to the system. (Probably not a smart move)
>Immediately the system voltage, normally runs 13v, began dropping, so I
>turned the landing lt off after a few seconds.
>
>I then began doing a series of steep climbs at slow airspeed. After
>about five min I noticed a burning odder, thinking to myself "someone
>must be burning trash and I'm in the trail of smoke." After about 30
>seconds I noticed smoke coming from under the instrument panel and a
>much stronger burning odder. I dropped the nose of the airplane--no
>more smoke.
>
>At that moment my GRT EIS warning lt flashed and I noticed the system
>voltage below 11 v. I turned on the E Bus switch and off on the main.
>Voltage came up--12 v I think. No odder or smoke or falling voltage.
>
>After a few minutes I decided to try the main switch again, pulling in
>the battery relay and alternator. Voltage began to climb above 12 v to
>about 12.5 v. I added strobe & nav lt again causing an immediate
>reversal in voltage trend and warning lt came on again as it plunged
>below 11 v. Again I went to E Bus an off main. I landed uneventfully.
>
>My guess is the relay over heated with the momentary excessive
>electrical draw (does that happen?) causing the smoke. Any Ideas? I
>assume I need to replace the regulator??? What would you recommend as a
>replacement regulator/source. Anything else??????
Do we know exactly where the smoke was coming from?
Is the relay visibly damaged or the regulator?
The fact that your voltage started to come up when
you re-energized the alternator suggests that the
rectifier-regulator was not killed. Try making a
hard connection to bypass the control relay and
do a ground run to see if the bus voltage comes
up . . . do this with a fully charged battery
so that you don't have to wait for the alternator
to top off the battery.
If I'm understanding your words, the relay is what
failed. I'd like to get my hands on it for examination.
I'd be pleased to send you a replacement but I suspect
you can find one much faster locally.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Jim Baker" <jlbaker(at)msbit.net> |
| Subject: | KLN-35(A) pinout.... |
X-mailer: Pegasus Mail for Windows (4.41)
X-SpamReason %%SpamReason%%:
Had a gentleman ask me about a pinout for the above after seeing a reference in
this list and a posting I'd made. It's not in the AeroElectric archives. Should
be a 15 pin card edge connector.
Thanks!
Jim Baker
580.788.2779
Elmore City, OK
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
| Subject: | ELT antenna requirements |
I will be installing the Artex ME406 w/110-773 whip antenna. It broadcasts
on 121.5 and 406 Mhz.
I am installing it in an E-glass plane. What is the mimimum ground plane
that will work. The instructions are suggesting that the ground plane
radius should be 24" in all directions! The plane is not 4' wide at any
point in the fuselage!!?
I really don't have much room for this install since I am trying to keep all
the antennas inside the plane.
Does anyone have a suggestion as to how I can install this antenna or make a
half wave that doesn't require a ground plane?
Bill B
________________________________________________________________________________
| From: | "Tim Andres" <tim2542(at)sbcglobal.net> |
Lucas was the first to invent intermittent wipers....I'm told
Tim Andres
For those of you out there that own, have owned, may own or have worked on
anything British:
What are the three positions of a Lucas headlight switch?
1) Dim
2) Flicker
3) and Smoke
Now let's not mention Lucas in a aviation newsgroup again...or Microsoft.
The blue screen of death takes on a WHOLE new meaning when you MS powered
glass screen goes belly-up in the scud.
Dale Alexander
Trying to build something, probably never finish it...
________________________________ Message 8
_____________________________________
>
>
> From: "Sam Hoskins" <shoskins(at)MCHSI.COM>
> Subject: Re: AeroElectric-List: Smoke
>
> *Positive ground depends upon proper circuit functioning, the
> transmission of negative ions by retention of the visible spectral
> manifestation known as "smoke". Smoke is the thing that makes electrical
> circuits work; we know this to be true because every time one lets the
> smoke out of the electrical system, it stops working. This can be
> verified repeatedly through empirical testing.
________________________________________________________________________________
| Subject: | Re: ELT antenna requirements |
| From: | "Matt Prather" <mprather(at)spro.net> |
The ground plane can curve - to some extent following the contour of the
fuse. I imagine that if the radiator is in the middle of the fuse and the
ground plane wraps very far up the sides, performance will suffer to some
extent, though performance may still be acceptable to you.
What type of antenna have other builders used? External?
Is it possible to install the antenna in the fin? Is it e-glass also?
You may be able to install an antenna that looks electrically like a 1/4
wave dipole, but is more physically compact in length (height). How tall
is the fin?
Regards,
Matt-
>
>
> I will be installing the Artex ME406 w/110-773 whip antenna. It
> broadcasts
> on 121.5 and 406 Mhz.
> I am installing it in an E-glass plane. What is the mimimum ground plane
> that will work. The instructions are suggesting that the ground plane
> radius should be 24" in all directions! The plane is not 4' wide at any
> point in the fuselage!!?
> I really don't have much room for this install since I am trying to keep
> all
> the antennas inside the plane.
> Does anyone have a suggestion as to how I can install this antenna or make
> a
> half wave that doesn't require a ground plane?
>
> Bill B
>
>
________________________________________________________________________________
| Subject: | "Shuntless" Ammeter in Diagram Z-16 |
| From: | "txpilot" <djg7(at)comcast.net> |
Hello,
I am building a Zenith CH701 with a Rotax 912ULS engine. I am using the Z-16 diagram as reference for my electrical system. I purchased a VDO ammeter (no shunt required) from Aircraft Spruce: http://www.aircraftspruce.com/catalog/inpages/vdoammeter.php
I am wondering how I can incorporate this into the electrical system to monitor
battery output/discharge. Can the ammeter simply be put in between the battery
and battery contactor?
Thanks,
Dan Ginty
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=171146#171146
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: ELT antenna requirements |
>
>
> I will be installing the Artex ME406 w/110-773 whip antenna. It broadcasts
>on 121.5 and 406 Mhz.
>I am installing it in an E-glass plane. What is the mimimum ground plane
>that will work. The instructions are suggesting that the ground plane
>radius should be 24" in all directions! The plane is not 4' wide at any
>point in the fuselage!!?
>I really don't have much room for this install since I am trying to keep all
>the antennas inside the plane.
>Does anyone have a suggestion as to how I can install this antenna or make a
>half wave that doesn't require a ground plane?
The ground plane radials need to be 24" long but not necessarily
flat. The easiest way to make this happen is to mount a "patch"
of brass sheet (shim stock, sheet stock from hobby shop) about
3" diameter on the inside surface of the skin centered on your
antenna location. Copper foil is nice stuff to make radials out
of but copper wire will work too. Further, it's easier to find
(a 6 foot piece of 12x2 Romex with ground will yield 18' total
of 12AWG solid wire). Solder as many 23" pieces of 12AWG
wire as you are willing to mess with to the edge of your
brass grounding pad at the base of the antenna. Route radials
away from antenna following inside contours of skin. Stick each
radial to the skin with patches of BID glass and 5 minute epoxy.
4 radials is about the minimum, return on investment of time
beyond 8 radials is poor.
Recommend you stay with the supplied antenna . . . it may have
features that enhance its two-frequency performance.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: KLN-35(A) pinout.... |
>
>X-SpamReason %%SpamReason%%:
>
>Had a gentleman ask me about a pinout for the above after seeing a
>reference in
>this list and a posting I'd made. It's not in the AeroElectric archives.
>Should
>be a 15 pin card edge connector.
I found it in 'the book' and I've posted it at:
http://www.aeroelectric.com/Installation_Data/KLN-35A.pdf
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| Subject: | Re: "Shuntless" Ammeter in Diagram Z-16 |
| From: | "txpilot" <djg7(at)comcast.net> |
Never mind. I just reviewed Section 7 and found what I was looking for. I'll try
and rearrange the system to the 'classic battery ammeter wiring' shown in Figure
7-11. Thanks anyway.
Dan Ginty
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=171156#171156
________________________________________________________________________________
| From: | "Richard Girard" <jindoguy(at)gmail.com> |
Tim, How can you have a discussion of electricity without paying homage to
Joseph Lucas, the discoverer of the short circuit? :-)
Rick
On Wed, Mar 19, 2008 at 7:38 PM, Tim Andres wrote:
> tim2542(at)sbcglobal.net>
>
> Lucas was the first to invent intermittent wipers....I'm told
> Tim Andres
>
> For those of you out there that own, have owned, may own or have worked on
> anything British:
>
> What are the three positions of a Lucas headlight switch?
> 1) Dim
> 2) Flicker
> 3) and Smoke
>
> Now let's not mention Lucas in a aviation newsgroup again...or Microsoft.
> The blue screen of death takes on a WHOLE new meaning when you MS powered
> glass screen goes belly-up in the scud.
>
> Dale Alexander
> Trying to build something, probably never finish it...
>
> ________________________________ Message 8
> _____________________________________
> >
> >
> > From: "Sam Hoskins" <shoskins(at)MCHSI.COM>
> > Subject: Re: AeroElectric-List: Smoke
> >
> > *Positive ground depends upon proper circuit functioning, the
> > transmission of negative ions by retention of the visible spectral
> > manifestation known as "smoke". Smoke is the thing that makes electrical
> > circuits work; we know this to be true because every time one lets the
> > smoke out of the electrical system, it stops working. This can be
> > verified repeatedly through empirical testing.
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: "Shuntless" Ammeter in Diagram Z-16 |
>
>Never mind. I just reviewed Section 7 and found what I was looking
>for. I'll try and rearrange the system to the 'classic battery ammeter
>wiring' shown in Figure 7-11. Thanks anyway.
>
>Dan Ginty
Dan, do you have a scanner? I'm not familiar with this
ammeter and I'd like to have a copy of the installation
instructions for it for my library.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: "Shuntless" Ammeter in Diagram Z-16 |
>
>Never mind. I just reviewed Section 7 and found what I was looking
>for. I'll try and rearrange the system to the 'classic battery ammeter
>wiring' shown in Figure 7-11. Thanks anyway.
>
>Dan Ginty
Dan, do you have a scanner? I'm not familiar with this
ammeter and I'd like to have a copy of the installation
instructions for it for my library.
Scratch that request, I found it on the Internet!
Bob . . .
________________________________________________________________________________
| From: | "Palvary" <paula.alvary(at)verizon.net> |
| Subject: | Re: ELT antenna requirements |
I have an Ameriking AK450 ELT (121.5/243.0MHz) also in a plastic plane. The
ELT antenna was broken when I got the plane so I calculated the optimal
length and made a whip antenna out of welding rod. I simply soldered the rod
to the center BNC conductor and insulated the section coming out of the BNC
shell area. To fit the approx. 23" antenna in the space I had to bend it 90
degrees over a 2" radius, about 5" from the BNC. My biggest concern was lack
of ground plane, but I was hoping the ELT itself acted as a ground plane.
Even I know this is not optimal, but is it "workable"?
--Jose
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: ELT antenna requirements |
>
>I have an Ameriking AK450 ELT (121.5/243.0MHz) also in a plastic plane. The
>ELT antenna was broken when I got the plane so I calculated the optimal
>length and made a whip antenna out of welding rod. I simply soldered the rod
>to the center BNC conductor and insulated the section coming out of the BNC
>shell area. To fit the approx. 23" antenna in the space I had to bend it 90
>degrees over a 2" radius, about 5" from the BNC. My biggest concern was lack
>of ground plane, but I was hoping the ELT itself acted as a ground plane.
>Even I know this is not optimal, but is it "workable"?
Depends on what how we define "workable". The task of getting some
manifestation of energy stored on the ELT's batteries to an overhead
satellite is burdened with many losses and pitfalls in the conversion
and conduction of energy. The batteries will deliver at 10-14 volts,
the satellite will hear your ELT if the signal arrives at the
1 to 10 MICROvolt level.
The weakest link in the energy conduction process is the antenna.
It has no way of knowing where the satellite is so it spreads
your signal all over the sky . . . and ground too. Everything
you do that departs from the best-we-know-how-to-do adds another
degree of uncertainty to the probability that the satellite gets
a useful signal.
On the other side of the coin, the probability that this piece
of equipment will be a major contributor to your surviving the
unplanned arrival with the earth is low. An article published
in one of the journals a couple of years ago cited something
much less than 10% of recovery situations where the ELT figured
strongly in the success of the operation.
The departures you've described from "ideal" will no doubt
degrade the benchmark performance of the system. Will it
make the difference between your pile of bent aluminum being
found or not found? Probably not. Your failure to make good
on a flight plan followed by a decision by someone to go
looking for you is more likely to initiate any sort of
rescue action. Then, if search aircraft also happen to carry
receivers and direction finding equipment for ELT frequencies,
then even your degraded performance MIGHT be of some assistance
in finding you sooner . . . if ever.
If you're putting much faith in the utility of this device
to make the difference between surviving or not, then one
of the more sophisticated devices is called for. One that
transmits your last known GPS position. You can also consider
an internal antenna like this:
http://www.aircraftspruce.com/catalog/avpages/antennasystems.php
At the very least, put a ground plane under the antenna you described
above. I posted a recommended process on adding ground planes
to plastic antennas to the List yesterday.
Alternatively, making your ELT a hand-held device with
a full length, telescoping antenna gets around a lot of
installation hassles.
Bob . . .
________________________________________________________________________________
| From: | John Markey <markeypilot(at)yahoo.com> |
| Subject: | Re: AeroElectric-List Digest: 8 Msgs - 03/18/08 |
Sam,
I think I am beginning to understand how airplanes work.
If I extrapolate [dangerous, I know, but humor me], then
gasoline must be a natural storage device of wind energy,
and the engines on our planes simply liberate the wind
stored in the gasoline.
Is this correct? If so, does it then follow that the reason
some of us need bigger engines is because we naturally
have more stored wind which the larger engine is more
able to convert?
Your views are appreciated in advance,
John Markey
Glasair II-FT
_____________________________________
From: "Sam Hoskins" <shoskins(at)MCHSI.COM>
Subject: Re: AeroElectric-List: Smoke
*Positive ground depends upon proper circuit
functioning, the
transmission of negative ions by retention of the
visible spectral
manifestation known as "smoke". Smoke is the thing
that makes electrical
circuits work; we know this to be true because every
time one lets the
smoke out of the electrical system, it stops working.
This can be
verified repeatedly through empirical testing.
"I have sworn upon the altar of God, eternal hostility against every form of tyranny
over the mind of man."
-- Thomas Jefferson
---------------------------------
Be a better friend, newshound, and know-it-all with Yahoo! Mobile. Try it now.
________________________________________________________________________________
| From: | Ron Shannon <rshannon(at)CRUZCOM.COM> |
| Subject: | alternator field current |
I'm building a dual alternator, single battery Z-12 and am trying to
figure out the running current loads of the alternator field circuits.
Of course, I see that a 5A fuse is recommended, however, I'd like to
know what is the normal current on this circuit.
Ron
________________________________________________________________________________
| From: | Ron Shannon <rshannon(at)CRUZCOM.COM> |
| Subject: | alternator field current |
I'm building a dual alternator, single battery Z-12 and am trying to
figure out the running current loads of the alternator field circuits.
Of course, I see that a 5A fuse is recommended, however, what is the
normal current on this circuit?
Ron
________________________________________________________________________________
| From: | James H Nelson <rv9jim(at)juno.com> |
Ah yes, Lucas, the folks who invented darkness
Jim
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: alternator field current |
>
>I'm building a dual alternator, single battery Z-12 and am trying to
>figure out the running current loads of the alternator field circuits.
>Of course, I see that a 5A fuse is recommended, however, what is the
>normal current on this circuit?
These are not normally considered to be part of the ship's running
loads. It's assumed that an alternator will be required to carry
its own excitation requirements. Therefore, an alternator rated
for say 60A is really expected to supply 60 amps IN ADDITION
to energy needed to excite the field. So use 3A as a max,
1A as average and then don't add it into your load analysis.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Vernon Little" <rv-9a-online(at)telus.net> |
| Subject: | Plane Power Alternator Failure (brand new) |
A friend had a Plane Power alternator fail after his first flight.
Apparently, he left the Master "on" (in ALT position) for 30-40 minutes
while he was working on the plane, and after that he noticed that his ALT
Field enable fuse was blown. It happened to a replacement fuse as well.
I checked the wiring right to the alternator-- no fault with it unplugged.
I can't measure any shorts to ground on the Alternator pins.
My theory is the the internal voltage regulator overheated and failed short.
My theory is that it would overheat because there was no airflow and was
providing maximum field current for a long time.
Has anyone else experienced this or have an alternate diagnosis?
Thanks, Vern Little
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Audio iso amp ordered, never received |
>
>
>
>So: Can you let me know what's going on with my order? I wouldn't mind
>the wait if I knew something was happening
>at your end but that just hasn't been the case.
Dave, the boards just arrived. I'm putting your board
first class mail. I've also refunded your money for
the board. You've suffered enough over this project!
There are some changes to the board that don't affect
the parts you'll need to install. There are some extra
holes for speaker-out load resistors (not often needed)
that you won't use. I'll try to get the data package
updated to the new board and put the DIY project back
up on the website!
Bob . . .
________________________________________________________________________________
| From: | Tim Olson <Tim(at)MyRV10.com> |
| Subject: | Re: Plane Power Alternator Failure (brand new) |
I'm not sure if the theory is good or bad, but I can say that I've left
my master on for a very very long time before....many hours, as opposed
to those 30-40 minutes, and I've never seen anything like that. I
suppose the regulator or something could have gone bad, but I'd also
check real well for any wiring errors. First off though, I'd call them
and see what they say...they'll know better than most people, and I
bet they take care of it right away.
Tim Olson - RV-10 N104CD - Flying
Vernon Little wrote:
>
> A friend had a Plane Power alternator fail after his first flight.
>
> Apparently, he left the Master "on" (in ALT position) for 30-40 minutes
> while he was working on the plane, and after that he noticed that his ALT
> Field enable fuse was blown. It happened to a replacement fuse as well.
>
> I checked the wiring right to the alternator-- no fault with it unplugged.
> I can't measure any shorts to ground on the Alternator pins.
>
> My theory is the the internal voltage regulator overheated and failed short.
> My theory is that it would overheat because there was no airflow and was
> providing maximum field current for a long time.
>
> Has anyone else experienced this or have an alternate diagnosis?
>
> Thanks, Vern Little
>
>
________________________________________________________________________________
| From: | "Harold Lanfear" <hlanfear(at)verizon.net> |
| Subject: | Tool to crimp a 90 degree Faston terminal? |
I have a need to use a few 90 degree 1/4" Faston Terminal ( I believe
they are also called "Flags") but can't figure out what tool is used to
crimp the wires. It doesn't appear there is any way to use the standard
dies for other insulated crimp terminals. Anybody know what works?
Thanks much,
Harold Lanfear
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Plane Power Alternator Failure (brand new) |
>
>
>A friend had a Plane Power alternator fail after his first flight.
>
>Apparently, he left the Master "on" (in ALT position) for 30-40 minutes
>while he was working on the plane, and after that he noticed that his ALT
>Field enable fuse was blown. It happened to a replacement fuse as well.
>
>I checked the wiring right to the alternator-- no fault with it unplugged.
>I can't measure any shorts to ground on the Alternator pins.
>
>My theory is the the internal voltage regulator overheated and failed short.
>My theory is that it would overheat because there was no airflow and was
>providing maximum field current for a long time.
>
>Has anyone else experienced this or have an alternate diagnosis?
It's a plausible theory. The only schematics for regulators
I've been able to study take a sample of the AC from the
alternator's stator windings and won't turn the field on unless
there is a detected motion of the rotor. But I don't know that
all regulators do that . . . in particular, those used in
Plane Power's products. A phone call to them should reinforce
or wash out your hypothesis. They've been courteous and quite
forthcoming with useful information when I've had occasion
to communicate with them.
If the regulator doesn't shut down during engine-off
ops, then it full-fields the alternator. I wouldn't
expect this to overheat the regulator . . . but it
might have cooked insulation in the field windings
and cause a short there.
This is one of several reasons why the Z-figures are
configured to allow pilot/mechanic control of field
excitation both in flight and on the ground. Separate
but interlocked Battery and Alternator switches configured
to emulate the infamous split-rocker switch.
Give PlanePower a call and let us know what they have
to say.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Tool to crimp a 90 degree Faston terminal? |
>I have a need to use a few 90 degree 1/4" Faston Terminal ( I believe
>they are also called "Flags") but can't figure out what tool is used to
>crimp the wires. It doesn't appear there is any way to use the standard
>dies for other insulated crimp terminals. Anybody know what works?
Push comes to shove, use the hardware store crimp tool
for insulated terminals. Put the super mash on the wire
grip, be more gentle on the insulation grip.
See:
http://www.aeroelectric.com/Pictures/Tools/Crimp_Tools/Two_Shot_Crimp_Tool.jpg
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | Ernest Christley <echristley(at)nc.rr.com> |
| Subject: | Re: Tool to crimp a 90 degree Faston terminal? |
Harold Lanfear wrote:
> I have a need to use a few 90 degree 1/4" Faston Terminal ( I believe they are
also called "Flags") but can't figure out what tool is used to crimp the wires.
It doesn't appear there is any way to use the standard dies for other insulated
crimp terminals. Anybody know what works?
>
> Thanks much,
> Harold Lanfear
>
I used a standard B crimper.
--
http://www.ronpaultimeline.com
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Plane Power Alternator Failure (brand new) |
Would not surprise me Vern. My wee ND IR alternator draws a couple of
amps and heats up quite noticeably with the engine off and the IGN
terminal (and B+ lead) connected to the battery. Fortunately the OV
relay lets me disconnect it by opening the alternator control switch.
Ken
Vernon Little wrote:
>
> A friend had a Plane Power alternator fail after his first flight.
>
> Apparently, he left the Master "on" (in ALT position) for 30-40 minutes
> while he was working on the plane, and after that he noticed that his ALT
> Field enable fuse was blown. It happened to a replacement fuse as well.
>
> I checked the wiring right to the alternator-- no fault with it unplugged.
> I can't measure any shorts to ground on the Alternator pins.
>
> My theory is the the internal voltage regulator overheated and failed short.
> My theory is that it would overheat because there was no airflow and was
> providing maximum field current for a long time.
>
> Has anyone else experienced this or have an alternate diagnosis?
>
> Thanks, Vern Little
>
________________________________________________________________________________
| From: | "Dawson-Townsend,Timothy" <tdawson-townsend(at)aurora.aero> |
Jose wrote:
"I have an Ameriking AK450 ELT (121.5/243.0MHz)"
After next January, the satellites are going to stop listening for 121.5
MHz (too many false alerts), and instead only listen for 406 MHz. So
you best bet is to buy a new ELT next year.
Bob wrote:
"On the other side of the coin, the probability that this piece
of equipment will be a major contributor to your surviving the
unplanned arrival with the earth is low. An article published
in one of the journals a couple of years ago cited something
much less than 10% of recovery situations where the ELT figured
strongly in the success of the operation."
The poor performance of 121.5 MHz probably contributes to that. The 406
MHz signal will offer better accuracy at determining your position, and
do it faster, too. Remember the accident that spurred closing a
loophole that allowed business jets to fly without ELTs: A Learjet with
no ELT went down within 30 miles or so of taking off of Lebanon, NH, but
due to snow cover and then dense forest, they didn't find it for over a
year . . .
TDT
Tim Dawson-Townsend
RV-10 N52KS
tdt(at)aurora.aero
617-500-4812 (office)
617-905-4800 (mobile)
________________________________________________________________________________
| Subject: | Re: Plane Power Alternator Failure (brand new) |
| From: | "tomvelvick" <tomvelvick(at)cox.net> |
Hi Vern,
When my battery is low the Plane Power Alt pulls over 4 amps with the master on.
I have had it pop my 5amp field breaker. I increased my C/B to 7 amps and
haven't had any more problems. Once the engine is running, the currents drops
down to less than 1/2 amp on the field line.
Regards,
Tom Velvick
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=171476#171476
________________________________________________________________________________
| From: | "Vernon Little" <rv-9a-online(at)telus.net> |
| Subject: | Re: Plane Power Alternator Failure (brand new) |
We checked this, and blew 10A fuse immediately. Alternator is kaput.
V
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
tomvelvick
Sent: March 21, 2008 7:34 AM
Subject: AeroElectric-List: Re: Plane Power Alternator Failure (brand new)
-->
Hi Vern,
When my battery is low the Plane Power Alt pulls over 4 amps with the master
on. I have had it pop my 5amp field breaker. I increased my C/B to 7 amps
and haven't had any more problems. Once the engine is running, the currents
drops down to less than 1/2 amp on the field line. Regards, Tom Velvick
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=171476#171476
________________________________________________________________________________
| From: | "Palvary" <paula.alvary(at)verizon.net> |
Admittedly, my 121.5/243.0MHz ELT offers little insurance in case of a
crash. Not only is it old technology, but in the best scenario it will
probably go undetected for the various reasons that Bob stated. (Case in
point, who knows what direction the antenna will wind up in after a
crash?) That is why I did not go to the extent of doing the antenna in
the best fashion that we know how to do. However, even after emergency
services stop listening, it still meets the FAA requirement for an ELT
as detailed in the recent EAA Sport Aviation article. My question was
simply trying to determine if what I did was next to useless or had a
reasonable chance of radiating some RF energy.
--Jose
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
Good Afternoon Jose,
Please understand that I am not an expert on the FARs and I have very little
electronic knowledge, but I do have a question concerning your antenna
installation.
Is it not true that the ELT is a required piece of requirement?
Because of that, is it not true that the emission from the ELT must meet
some certain standard?
The last one that I installed did have specifications concerning the
available signal emission. It said the antenna that came with the set OR an antennae
that met specified standards must be used before the ELT met the regulatory
standards.
I realize that many regulations do not apply to OBAM aircraft, but I would
not be surprised if the regulations concerning the ELT must be followed.
Any thoughts thereon?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
628 West 86th Street
Downers Grove, IL 60516
630 985-8502
Stearman N3977A
Brookeridge Air Park LL22
In a message dated 3/21/2008 2:59:52 P.M. Central Daylight Time,
paula.alvary(at)verizon.net writes:
Admittedly, my 121.5/243.0MHz ELT offers little insurance in case of a
crash. Not only is it old technology, but in the best scenario it will probably
go
undetected for the various reasons that Bob stated. (Case in point, who
knows what direction the antenna will wind up in after a crash?) That is why I
did not go to the extent of doing the antenna in the best fashion that we know
how to do. However, even after emergency services stop listening, it still
meets the FAA requirement for an ELT as detailed in the recent EAA Sport
Aviation article. My question was simply trying to determine if what I did was
next
to useless or had a reasonable chance of radiating some RF energy.
--Jose
**************Create a Home Theater Like the Pros. Watch the video on AOL
Home.
(http://home.aol.com/diy/home-improvement-eric-stromer?video=15?ncid=aolhom00030000000001)
________________________________________________________________________________
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Answer Steve Fossett!
Just the chance of the g switch not working, the antenna being ripped off i
s enough to push me to the PLB...Ya sure its another chore to set it off...
buts its #2 on my emergency list.
I also make sure I am talking to ATC when going across the rocks..I just fi
le an IFR flight plan because I can, but VFR flight following is as good as
long as they will do it for you.
I migth also look into an APHRS datalogger at some point.
Frank
________________________________
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectr
ic-list-server(at)matronics.com] On Behalf Of Palvary
Sent: Friday, March 21, 2008 1:54 PM
Subject: Re: AeroElectric-List: ELTs
Admittedly, my 121.5/243.0MHz ELT offers little insurance in case of a cras
h. Not only is it old technology, but in the best scenario it will probably
go undetected for the various reasons that Bob stated. (Case in point, who
knows what direction the antenna will wind up in after a crash?) That is w
hy I did not go to the extent of doing the antenna in the best fashion that
we know how to do. However, even after emergency services stop listening,
it still meets the FAA requirement for an ELT as detailed in the recent EAA
Sport Aviation article. My question was simply trying to determine if what
I did was next to useless or had a reasonable chance of radiating some RF
energy.
--Jose
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
>Admittedly, my 121.5/243.0MHz ELT offers little insurance in case of a
>crash. Not only is it old technology, but in the best scenario it will
>probably go undetected for the various reasons that Bob stated. (Case in
>point, who knows what direction the antenna will wind up in after a
>crash?) That is why I did not go to the extent of doing the antenna in the
>best fashion that we know how to do. However, even after emergency
>services stop listening, it still meets the FAA requirement for an ELT as
>detailed in the recent EAA Sport Aviation article. My question was simply
>trying to determine if what I did was next to useless or had a reasonable
>chance of radiating some RF energy.
Sounds like you have a realistic understanding of the
capabilities/limitations for the system. The simple answer
is, "yes, the thing will radiate . . . and probably no worse
than some less-than-ideal installations found on some certified
aircraft." Best yet, it keeps those-who-know-more-about-airplanes-
than-we-do at arms length . . . for awhile.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Oh yes, the 125.5 ELT has to have an RF power output of just 100mW...PLB's
(or 406MHz ELTS) have an output of 5W...I.e a 50 times stronger signal...Ap
parently the signal even punches through tree cover.
Its the emergency equivilent of a big battery drill compared to a screwdriv
er...:)
frank
________________________________
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectr
ic-list-server(at)matronics.com] On Behalf Of Hinde, Frank George (Corvallis)
Sent: Friday, March 21, 2008 1:16 PM
Subject: RE: AeroElectric-List: ELTs
Answer Steve Fossett!
Just the chance of the g switch not working, the antenna being ripped off i
s enough to push me to the PLB...Ya sure its another chore to set it off...
buts its #2 on my emergency list.
I also make sure I am talking to ATC when going across the rocks..I just fi
le an IFR flight plan because I can, but VFR flight following is as good as
long as they will do it for you.
I migth also look into an APHRS datalogger at some point.
Frank
________________________________
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectr
ic-list-server(at)matronics.com] On Behalf Of Palvary
Sent: Friday, March 21, 2008 1:54 PM
Subject: Re: AeroElectric-List: ELTs
Admittedly, my 121.5/243.0MHz ELT offers little insurance in case of a cras
h. Not only is it old technology, but in the best scenario it will probably
go undetected for the various reasons that Bob stated. (Case in point, who
knows what direction the antenna will wind up in after a crash?) That is w
hy I did not go to the extent of doing the antenna in the best fashion that
we know how to do. However, even after emergency services stop listening,
it still meets the FAA requirement for an ELT as detailed in the recent EAA
Sport Aviation article. My question was simply trying to determine if what
I did was next to useless or had a reasonable chance of radiating some RF
energy.
--Jose
ist">http://www.matronics.com/Navigator?AeroElectric-List
ics.com
.matronics.com/contribution
________________________________________________________________________________
| From: | "Bill Denton" <bdenton(at)bdenton.com> |
I'm not 100% sure, but if you are talking about an Artex ELT, I believe that
the TSO covers the unit AND the antenna. If you don't install the correct
antenna properly, you won't meet the TSO. And that could lead to an
inspection problem.
You might want to check the manufacturer's website.
Thanks!
Bill Denton
bdenton(at)bdenton.com
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Palvary
Sent: Friday, March 21, 2008 3:54 PM
Subject: Re: AeroElectric-List: ELTs
Admittedly, my 121.5/243.0MHz ELT offers little insurance in case of a
crash. Not only is it old technology, but in the best scenario it will
probably go undetected for the various reasons that Bob stated. (Case in
point, who knows what direction the antenna will wind up in after a crash?)
That is why I did not go to the extent of doing the antenna in the best
fashion that we know how to do. However, even after emergency services stop
listening, it still meets the FAA requirement for an ELT as detailed in the
recent EAA Sport Aviation article. My question was simply trying to
determine if what I did was next to useless or had a reasonable chance of
radiating some RF energy.
--Jose
________________________________________________________________________________
| From: | "Matt Prather" <mprather(at)spro.net> |
What was the question??
> Answer Steve Fossett!
>
> Just the chance of the g switch not working, the antenna being ripped off
> is enough to push me to the PLB...Ya sure its another chore to set it
> off...buts its #2 on my emergency list.
>
> I also make sure I am talking to ATC when going across the rocks..I just
> file an IFR flight plan because I can, but VFR flight following is as good
> as long as they will do it for you.
There's a good amount of the western US over which I have flown where the
minimum radar altitude is above 11000MSL. The MEA on the route between
BOI and TWF is 10000MSL and there aren't any passes to cross; the route
can be comfortably flown at 5500 - and not be even slightly close to
terrain. Having to climb to 10000 on such a short trip isn't particularly
efficient... I agree with the philosophy you are proposing however.
>
> I migth also look into an APHRS datalogger at some point.
>
> Frank
>
Matt-
________________________________________________________________________________
| From: | "Palvary" <paula.alvary(at)verizon.net> |
Hi Bob S.,
Because of that, is it not true that the emission from the ELT must
meet some certain standard?
------A good point worth considering. I do not have an anwer nor meter
to check the output. Best I can do for now is just do a tower check on
the hour. I do know that my ELT came with a simple (non-loaded)
telescoping antenna (which had broken and dissappeared) and I think the
solid wire antenna I made is hopefully as good as that one.
Eventually, 406MHz and/or APRS is the way to go.
--Jose
PS-This is the best list ever. Thanks everyone.
________________________________________________________________________________
| From: | "Bill Bradburry" <bbradburry(at)bellsouth.net> |
I am looking for an install manual for the GNS430W. Didn't I see where
someone had these manuals on a website somewhere?
Thanks,
Bill B
________________________________________________________________________________
| Subject: | Re: Install Manuals |
Bill Bradburry a crit :
>
> I am looking for an install manual for the GNS430W. Didnt I see where
> someone had these manuals on a website somewhere?
>
Bill,
At one time, those manuals were concealed on the Garmin website, but
they seem to be unavailable now.
The revision M is downloadable from my website :
http://contrails.free.fr/download.php
Scroll down to "Avionique" then "GPS Garmin series 400"
Hope this helps,
Best regards,
--
Gilles
http://contrails.free.fr
________________________________________________________________________________
| From: | "William Slaughter" <willslau(at)comcast.net> |
Try
http://www.mstewart.net/Downloads/howtogetagarminmanual.htm
William
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Bill
Bradburry
Sent: Friday, March 21, 2008 5:50 PM
Subject: AeroElectric-List: Install Manuals
I am looking for an install manual for the GNS430W. Didn't I see where
someone had these manuals on a website somewhere?
Thanks,
Bill B
________________________________________________________________________________
| Subject: | Re: Install Manuals |
William Slaughter a crit :
>
> Try
>
> http://www.mstewart.net/Downloads/howtogetagarminmanual.htm
>
William and all,
Unfortunately Garmin changed their website in order to make their
installation manuals no longer readily available to the layman.
Best regards,
--
Gilles
http://contrails.free.fr
________________________________________________________________________________
| From: | "William Slaughter" <willslau(at)comcast.net> |
That's not very neighborly.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Gilles
Thesee
Sent: Friday, March 21, 2008 6:29 PM
Subject: Re: AeroElectric-List: Install Manuals
<Gilles.Thesee@ac-grenoble.fr>
William Slaughter a crit :
>
> Try
>
> http://www.mstewart.net/Downloads/howtogetagarminmanual.htm
>
William and all,
Unfortunately Garmin changed their website in order to make their
installation manuals no longer readily available to the layman.
Best regards,
--
Gilles
http://contrails.free.fr
________________________________________________________________________________
| From: | Kelly McMullen <kellym(at)aviating.com> |
You are correct. All ELTs must meet TSO, and TSO includes antenna spec.
Even a different brand antenna for ELT does not meet letter of the law.
And yes, it doesn't matter whether experimental or type certified, both
are required by reg to have TSOd ELT.
Bill Denton wrote:
>
> Im not 100% sure, but if you are talking about an Artex ELT, I
> believe that the TSO covers the unit AND the antenna. If you dont
> install the correct antenna properly, you wont meet the TSO. And that
> could lead to an inspection problem.
>
> You might want to check the manufacturers website
>
> Thanks!
>
> Bill Denton
>
> bdenton(at)bdenton.com
>
> *
>
> *
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: Plane Power Alternator Failure (brand new) |
Gentlemen all, you are gussing.
Call PP & send it back. Get the real reason. PP does modify the
regulator & therefore he's the source of creditable facts. I can say
a stock ND should not get hot with BAT/ALT on, but I stand to
be corrected. I never tried it. However............
For a regular internally regulated ND alternator, if it uses more than
50 millivolts, with the engine shut down you have voltage regulator or
diode issue. Internally regulated alternators do not have a FIELD
WIRE of course.
>From: Ken <klehman(at)albedo.net>
>Subject: Re: Plane Power Alternator Failure (brand
new)
>Would not surprise me Vern. My wee ND IR alternator draws a couple of
>amps and heats up quite noticeably with the engine off and the IGN
>terminal (and B+ lead) connected to the battery. Fortunately the OV
>relay lets me disconnect it by opening the alternator control switch.
>Ken
Ken is it possible you are reading more than the alternator? Master contactor?
---------------------------------
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Plane Power Alternator Failure (brand new) |
gmcjetpilot(at)yahoo.com wrote:
> Gentlemen all, you are gussing.
>
> Call PP & send it back. Get the real reason. PP does modify the
> regulator & therefore he's the source of creditable facts. I can say
> a stock ND should not get hot with BAT/ALT on, but I stand to
> be corrected. I never tried it. However............
>
> For a regular internally regulated ND alternator, if it uses more than
> 50 millivolts, with the engine shut down you have voltage regulator or
> diode issue. Internally regulated alternators do not have a FIELD
> WIRE of course.
>
>
> >From: Ken <klehman(at)albedo.net <mailto:klehman(at)albedo.net>>
> >Subject: Re: Plane Power Alternator Failure (brand
> new)
> >Would not surprise me Vern. My wee ND IR alternator draws a couple of
> >amps and heats up quite noticeably with the engine off and the IGN
> >terminal (and B+ lead) connected to the battery. Fortunately the OV
> >relay lets me disconnect it by opening the alternator control switch.
> >Ken
>
> Ken is it possible you are reading more than the alternator? Master
> contactor?
>
No
It was purchased new about 5 years ago and it always did this. Of course
in a car the Ign terminal would not be powered with the key in the off
or accessory position. Newer models might sense rotation before they
power the field. But apparently this 40 amp unit that often is found on
small industrial equipment is not that sophisticated.
Ken
ps. I assume you meant to type 50 milliamps above. I've never seen
anything near that high (yet) but standby parasitic current "leakage" is
getting ridiculous on cars these days.
________________________________________________________________________________
| From: | "Jim McBurney" <jmcburney(at)pobox.com> |
I know that at this time personal locator beacons aren't legal to be used as
ELTs. If someone designed an automatic activation system for a PLB, I
wonder if a case could be made to
"the-guys-who-know-airplanes-better-than-we-do" to use such in lieu of a
TSOd ELT in OBAM aircraft? Just thinking (oops, not supposed to do that).
Blue skies and tailwinds
Jim
CH-801
DeltaHawk diesel
Augusta GA
90% done, 90% left
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckolls.bob(at)cox.net> |
| Subject: | Re: Plane Power Alternator Failure (brand new) |
INnn
>Gentlemen all, you are gussing.
>
>Call PP & send it back. Get the real reason. PP does modify the
>regulator & therefore he's the source of creditable facts. I can say
>a stock ND should not get hot with BAT/ALT on, but I stand to
>be corrected. I never tried it. However............
>
I can't imagine that ND would not take advantage of the
practice for monitoring rotor motion and shutting down
field current if the engine is stopped.
>For a regular internally regulated ND alternator, if it uses more than
>50 millivolts, with the engine shut down you have voltage regulator or
>diode issue. Internally regulated alternators do not have a FIELD
>WIRE of course.
Plane-Power's offerings that include the externally mounted
crowbar ov protection have been modified to bring the
internal regulator's b-lead feed out side so that one may
effectively shut down the alternator from outside. Normally,
this does not require modification of the regulator itself
(difficult to do . . . it's a hybrid device and usually sealed
up). It does require that you open the b-lead feeder to the
regulator and bring it outside (relatively easy). We were
offered this information by Mr. Steve Klodd at Plain-Power
just over a year ago. See:
http://www.aeroelectric.com/Mfgr_Data/Alternators/Plane_Power/70129A_Plane-Power_SKlodd.pdf
>
>
> >From: Ken <<mailto:klehman(at)albedo.net>klehman(at)albedo.net>
> >Subject: Re: Plane Power Alternator Failure (brand
> new)
> >Would not surprise me Vern. My wee ND IR alternator draws a couple of
> >amps and heats up quite noticeably with the engine off and the IGN
> >terminal (and B+ lead) connected to the battery. Fortunately the OV
> >relay lets me disconnect it by opening the alternator control switch.
> >Ken
>
>Ken is it possible you are reading more than the alternator? Master contactor?
I presume that the internal regulator would still be expected
to shut the field down if no rotation were sensed. I'll drop
a note to Steve requesting clarification.
Bob . . .
-----------------------------------------
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | <frank.phyllis(at)mindspring.com> |
Bob,
Today I ran the engine. I was not sure how to make a "hard connection
to bypass the control relay" as you suggested. So I just operated the
system normally. Minimal load the voltage was initially 11.8 and then
went to 11.9 with the master on "alternator". No further change after
about three minutes. Looks like I may not be getting alternator input??
As I said, normally I get 13 v.
I did not charge the battery before hand.
I pulled the covers off (cowling, etc). The relay appears to be
undamaged. I don't see any signs that would indicate it was "fried".
During the even I was unable to tell exactly where the smoke was
actually coming from--just from under the panel.
I've ordered another relay. I'll plug it in and see what happens. Any
other suggestions?
If it's the relay, I'd be happy to send you the old one.
Thanks for your help.
Frank
N5929
-----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: Wednesday, March 19, 2008 11:42 AM
Subject: Re: AeroElectric-List: Smoke
>
>Last evening I experienced smoke in the cockpit of my Kitfox--912S.
>
>First, I want to thank Bob N for convincing me of the importance of
>using Z16, incorporating an E-Bus circuit. Worked great and reduced
the
>load on my "little" motorcycle battery so that I maintained > 11.5 v
for
>the 15 min duration of my flt.
>
>It was twilight & I had Whelan strobe & nav lights on, near max elec
>capacity for the 912 generator. I threw on the landing lt to see what
>the added load would do to the system. (Probably not a smart move)
>Immediately the system voltage, normally runs 13v, began dropping, so I
>turned the landing lt off after a few seconds.
>
>I then began doing a series of steep climbs at slow airspeed. After
>about five min I noticed a burning odder, thinking to myself "someone
>must be burning trash and I'm in the trail of smoke." After about 30
>seconds I noticed smoke coming from under the instrument panel and a
>much stronger burning odder. I dropped the nose of the airplane--no
>more smoke.
>
>At that moment my GRT EIS warning lt flashed and I noticed the system
>voltage below 11 v. I turned on the E Bus switch and off on the main.
>Voltage came up--12 v I think. No odder or smoke or falling voltage.
>
>After a few minutes I decided to try the main switch again, pulling in
>the battery relay and alternator. Voltage began to climb above 12 v to
>about 12.5 v. I added strobe & nav lt again causing an immediate
>reversal in voltage trend and warning lt came on again as it plunged
>below 11 v. Again I went to E Bus an off main. I landed uneventfully.
>
>My guess is the relay over heated with the momentary excessive
>electrical draw (does that happen?) causing the smoke. Any Ideas? I
>assume I need to replace the regulator??? What would you recommend as
a
>replacement regulator/source. Anything else??????
Do we know exactly where the smoke was coming from?
Is the relay visibly damaged or the regulator?
The fact that your voltage started to come up when
you re-energized the alternator suggests that the
rectifier-regulator was not killed. Try making a
hard connection to bypass the control relay and
do a ground run to see if the bus voltage comes
up . . . do this with a fully charged battery
so that you don't have to wait for the alternator
to top off the battery.
If I'm understanding your words, the relay is what
failed. I'd like to get my hands on it for examination.
I'd be pleased to send you a replacement but I suspect
you can find one much faster locally.
Bob . . .
----------------------------------------)
( . . . a long habit of not thinking )
( a thing wrong, gives it a superficial )
( appearance of being right . . . )
( )
( -Thomas Paine 1776- )
----------------------------------------
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: Plane Power Alternator Failure (brand new) |
Yes I meant 50 milliamps and you are right with all the
memory keep alive, the parasitic drain is high. I travel
and have to sometimes disconnect the battery. I have
one of those battery disconnect terminals. It's an old car
1990 but it still has a computer, so I lose the codes and
fuel injection mapping. But its better than jumping the
the thing.
I have some small industrial ND's, new genuine
March 04, 2008 - March 23, 2008
AeroElectric-Archive.digest.vol-hr