AeroElectric-Archive.digest.vol-ep
July 06, 2005 - July 19, 2005
-->
Working on the wiring diagram for a subaru powered Zodiac with 2 fuel
pumps and 2 electronic ignitions and 2 batteries.
I would like a switch that would allow me to run each ignition and each
fuel pump of either of my
2 battery busses. This would be 4 switches.
Also the best setup for this would be down position of the switch is
off. Middle would be left battery and all the way up would be other
battery.
I looked at quite allot of switches last night and they all seemed to
have the middle position as on.
thanks for any pointers
Jim Pollard
Merlin Ont
Zenair ch601hds
ea81
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: Need a switch |
Just to say I agree with Frank's comments, and I'm doing it
the same way he is. Individual switches for each function,
simple, cheap, and reliable.
Best regards,
Mickey
>
> Anyway. I like to avoid any single point of failure...A changeover
> switch like this is a single point of failure...if the switch burns up
> down you go!
>
> I set mine up with a single on/off switch for each fuel pump and each
> ignition. Batt #1 runs the left fuel pump and Ign #1. Batt #2 runs the
> right Fp and Ignition #2.
>
> The benefit with this system is no interconnection and very very simple.
> The second batt is on 3AH but should be good for at least an hour of
> flying on the right tank. Depending on current draw you can size your
> batteries to suit your needs.
>
> The single alt charges both batteries, but use a diode between Bat #1
> and Batt#2 to prevent backflow in the event of a major short.
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
________________________________________________________________________________
| From: | Jim and Lucy <jpollard(at)ciaccess.com> |
| Subject: | Re: Need a switch |
At 11:09 AM 7/6/2005, you wrote:
>Just to say I agree with Frank's comments, and I'm doing it
>the same way he is. Individual switches for each function,
>simple, cheap, and reliable.
>
>Best regards,
>Mickey
The system I am working on does have a single switch for each
fuel pump and each electronic ignition.
The reason for the special switch is so I can choose which
battery to run them off in case one of the batteries fails.
I want to be able to run with all on or one of each on.
The diode setup of z19 has some problems if you hook more
than a single pump and ignition up to it.
Jim Pollard
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
7/6/2005
Hello Experts, I have an ICOM IC-A4 hand held radio that I carry in my
airplane as a communications back up. I also have the ICOM OPC-752 Headset
Adapter cable accessory, but I do not have the separate ICOM 3.5 mm diameter
PTT switch accessory for keying the transmitter while using the radio with
that adapter and a headset. The manual says that the transmitter keying
button on the side of the radio will not work when the headset adapter is
plugged in.
According to a diagram in the ICOM IC-A4 manual the ICOM PTT switch simply
connects the tip of the microphone plug to the shank of the microphone plug
in order to key the IC-A4 transmitter.
My question is: Can I instead use my standard push-to-talk switch, with the
larger diameter sized microphone receptacle and plug such as David Clark and
Telex sell, in line with the microphone plug from the headset to the OPC-752
Adapter to key the IC-A4 transmitter?
ICOM refuses to answer this question for me by saying they won't comment on
any one else's equipment. Thanks.
OC
PS: I suppose that there is no substitute for an actual trial test, but I
haven't been able to get two people and another radio together to run such a
test.
________________________________________________________________________________
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Not familiar with Z19.
Yes but the problem of course is what happens if the switch itself
fails?
I thought the power schotty diode (sp) had a pretty big load
rating?....Are you running fuel injected pumps?...The Facets only run
about 1.8Amps and the ignition about another 1.5...From memeory....Whats
the nature of the problem?
You could have a double end fed buss with a separate switch to each
battery...I think in Bob's setup he uses a the diode to replace one of
those switches.
Frank
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Jim
and Lucy
Subject: Re: AeroElectric-List: Need a switch
-->
At 11:09 AM 7/6/2005, you wrote:
>Just to say I agree with Frank's comments, and I'm doing it the same
>way he is. Individual switches for each function, simple, cheap, and
>reliable.
>
>Best regards,
>Mickey
The system I am working on does have a single switch for each fuel pump
and each electronic ignition.
The reason for the special switch is so I can choose which battery to
run them off in case one of the batteries fails.
I want to be able to run with all on or one of each on.
The diode setup of z19 has some problems if you hook more than a single
pump and ignition up to it.
Jim Pollard
________________________________________________________________________________
| From: | Cameron Kurth <cameronkurth(at)yahoo.com> |
| Subject: | Re: Garmin 196 interferes with com radio |
Bob
When I pulled the fuse to the Garmin 196 it was then
running off the internal batteries in the 196 and the
noise went away. It's quite repeatable, when I put
the 196 back on the plane's power buss the noise
returns. So maybe an inline filter will help?
Cam
--- "Robert L. Nuckolls, III"
wrote:
> Nuckolls, III"
>
>
> Kurth
> >
> >
> >I have a Garmin 196 that is wired into the plane's
> >power buss. I get interference at a small range of
> >frequencies on my com radio from the Garmin (just
> >happens to be Detroit approach). If I pull the
> fuse
> >to the Garmin so it runs off the battery the
> >interference goes away. It's a similar
> interference
> >that the Dynon D10's had when they first came out.
> >
> >So, what kind of filter should I use? Will the
> Radio
> >Shack 270-055 work in this situation? I called
> Garmin
> >about it. They said that the 196 was a handheld so
> it
> >has to meet the same specs as a toaster. They were
> >very nice about it but quite clear that it's only a
> >handheld so it was not designed for airplane use
> and
> >I'm on my own.
>
> This is NOT going to be easy. The symptoms you
> describe
> walk, talk and smell like radiated noise from
> the radio
> itself. Try operating the Garmin from a separate
> portable
> battery (does it have internal batteries?). If
> the noise
> goes away, a filter in the wires may help. If
> the noise
> is still there, then relocating the Garmin is
> the only
> thing left . . . it's unlikely that you want to
> build
> a shielded enclosure for the Garmin.
>
> This is an example of what DO-160 does for us in
> the certified world. These issues are best
> addressed
> in the design lab as opposed to your cockpit.
>
> Bob . . .
>
>
>
> browse
> Subscriptions page,
> FAQ,
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Lloyd, Daniel R." <LloydDR(at)wernerco.com> |
Can you put your primary radio on speaker and stand outside the plane
and talk into the handheld and see if the plane receives it?
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
bakerocb(at)cox.net
Subject: AeroElectric-List: ICOM PTT
7/6/2005
Hello Experts, I have an ICOM IC-A4 hand held radio that I carry in my
airplane as a communications back up. I also have the ICOM OPC-752
Headset
Adapter cable accessory, but I do not have the separate ICOM 3.5 mm
diameter
PTT switch accessory for keying the transmitter while using the radio
with
that adapter and a headset. The manual says that the transmitter keying
button on the side of the radio will not work when the headset adapter
is
plugged in.
According to a diagram in the ICOM IC-A4 manual the ICOM PTT switch
simply
connects the tip of the microphone plug to the shank of the microphone
plug
in order to key the IC-A4 transmitter.
My question is: Can I instead use my standard push-to-talk switch, with
the
larger diameter sized microphone receptacle and plug such as David Clark
and
Telex sell, in line with the microphone plug from the headset to the
OPC-752
Adapter to key the IC-A4 transmitter?
ICOM refuses to answer this question for me by saying they won't comment
on
any one else's equipment. Thanks.
OC
PS: I suppose that there is no substitute for an actual trial test, but
I
haven't been able to get two people and another radio together to run
such a
test.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Garmin 196 interferes with com radio |
>
>
>Bob
>
>When I pulled the fuse to the Garmin 196 it was then
>running off the internal batteries in the 196 and the
>noise went away. It's quite repeatable, when I put
>the 196 back on the plane's power buss the noise
>returns. So maybe an inline filter will help?
Good news. Yes, an inline filter will probably
help. It doesn't have to be big . . . that radio
can't draw much current. Do you know exactly how
much?
Bob . . .
________________________________________________________________________________
| Subject: | Garmin 196 interferes with com radio |
| From: | "Lloyd, Daniel R." <LloydDR(at)wernerco.com> |
DO you get the same interference when you use the cigarette plug
adapter? If not then I would take a guess it is your wiring that you
installed and you can get a shielded cable to replace the el cheapo one
they send you for the combo plug on the back. I had the same issue when
I tried to split out the pins for power and data, that cable they
send/sell is crap, so I made my own, and it solved the issue.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Cameron Kurth
Subject: Re: AeroElectric-List: Garmin 196 interferes with com radio
Bob
When I pulled the fuse to the Garmin 196 it was then
running off the internal batteries in the 196 and the
noise went away. It's quite repeatable, when I put
the 196 back on the plane's power buss the noise
returns. So maybe an inline filter will help?
Cam
--- "Robert L. Nuckolls, III"
wrote:
> Nuckolls, III"
>
>
> Kurth
> >
> >
> >I have a Garmin 196 that is wired into the plane's
> >power buss. I get interference at a small range of
> >frequencies on my com radio from the Garmin (just
> >happens to be Detroit approach). If I pull the
> fuse
> >to the Garmin so it runs off the battery the
> >interference goes away. It's a similar
> interference
> >that the Dynon D10's had when they first came out.
> >
> >So, what kind of filter should I use? Will the
> Radio
> >Shack 270-055 work in this situation? I called
> Garmin
> >about it. They said that the 196 was a handheld so
> it
> >has to meet the same specs as a toaster. They were
> >very nice about it but quite clear that it's only a
> >handheld so it was not designed for airplane use
> and
> >I'm on my own.
>
> This is NOT going to be easy. The symptoms you
> describe
> walk, talk and smell like radiated noise from
> the radio
> itself. Try operating the Garmin from a separate
> portable
> battery (does it have internal batteries?). If
> the noise
> goes away, a filter in the wires may help. If
> the noise
> is still there, then relocating the Garmin is
> the only
> thing left . . . it's unlikely that you want to
> build
> a shielded enclosure for the Garmin.
>
> This is an example of what DO-160 does for us in
> the certified world. These issues are best
> addressed
> in the design lab as opposed to your cockpit.
>
> Bob . . .
>
>
>
> browse
> Subscriptions page,
> FAQ,
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Need a switch |
| From: | "Glaeser, Dennis A" <dennis.glaeser(at)eds.com> |
If you subscribe to the 'single failure' philosophy for one flight, then
the batteries are only in the equation if the alternator has failed!
But ignoring that detail, and assuming battery only operation...
Powering each ignition and pump from a separate battery (as in Z-19)
provides redundancy. Whatever single item fails (battery, or ignition,
or pump, or switch), you complete the flight with the other one.
Allowing each pump and ignition to be powered by either battery does
allow for certain multiple failures (2 failures of different
components), but not all: failure of both batteries, or pumps, or
ignitions, or both switches to either the pumps or ignitions). Is the
added cost and complexity really value added? A test: write the
procedure for properly positioning the switches for your flight manual.
If (after the alternator fails) a battery fails, do you really want (or
need) to run both ignitions? You could fly longer by only using one.
A previous version of my electrical system had a 3 way switch to allow
my E-Bus to be powered from either battery. Bob Nuckolls pointed out
that all it did was provide an opportunity to make a bad decision, so I
simplified back to a 2 way switch. A simple system for my simple mind
:-)
Dennis Glaeser
RV-7A Empennage
>
Working on the wiring diagram for a subaru
powered Zodiac with 2 fuel pumps and 2 electronic
ignitions and 2 batteries.
I would like a switch that would allow me to run
each ignition and each fuel pump of either of my
2 battery busses. This would be 4 switches.
Also the best setup for this would be down position
of the switch is off. Middle would be left battery
and all the way up would be other battery.
I looked at quite allot of switches last night and
they all seemed to have the middle position as on.
thanks for any pointers
Jim Pollard
Merlin Ont
Zenair ch601hds
ea81
________________________________________________________________________________
Received-SPF: softfail (mta6: domain of transitioning trigo(at)mail.telepac.pt does
not designate 85.138.30.109 as permitted sender) receiver=mta6; client_ip=85.138.30.109;
envelope-from=trigo(at)mail.telepac.pt;
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
| Subject: | Re: Need a switch |
Mickey
Does that mean that you are not using the ExpBus?
Carlos
Just to say I agree with Frank's comments, and I'm doing it
the same way he is. Individual switches for each function,
simple, cheap, and reliable.
Best regards,
Mickey
________________________________________________________________________________
| From: | Cameron Kurth <cameronkurth(at)yahoo.com> |
| Subject: | Re: Garmin 196 interferes with com radio |
Bob
Do I filter the power supply to the com radio or the
GPS? I think the com radio pulls about 5-7 amps.
It's a King KX125.
Lloyd
I have the stock data/power cable. I was looking at
the lack of shielding and thought I might try using
shielded wire on the power side. I don't have a way
of hooking up the cigar lighter plug in the plane.
It's either to the power buss or internal batteries.
Cam
--- "Robert L. Nuckolls, III"
wrote:
> Nuckolls, III"
>
>
> Kurth
> >
> >
> >Bob
> >
> >When I pulled the fuse to the Garmin 196 it was
> then
> >running off the internal batteries in the 196 and
> the
> >noise went away. It's quite repeatable, when I put
> >the 196 back on the plane's power buss the noise
> >returns. So maybe an inline filter will help?
>
> Good news. Yes, an inline filter will probably
> help. It doesn't have to be big . . . that radio
> can't draw much current. Do you know exactly how
> much?
>
> Bob . . .
>
>
>
> browse
> Subscriptions page,
> FAQ,
>
>
>
>
>
>
________________________________________________________________________________
| From: | Joe Dubner <jdubner(at)yahoo.com> |
| Subject: | Re: Garmin 196 interferes with com radio |
Cam,
I have a Garmin GPS 196 wired to the bus in my Long-EZ and have
experienced no problems (that I know of). In addition, my installation
uses the RS-232 data in/data out wires with 4800 baud NMEA data pulsing
continuously. Of course, there are real differences in our
installations (e.g. antenna locations) but I would be interested in the
specific VHF frequencies so I can test my setup.
My cable came from http://pfranc.com/, more specifically the pDP0 cable
($9.99 on the right side of http://pfranc.com/cables/index.mhtml). It
seems well constructed and contains a molded-in ferrite choke. I
ordered two of them from Frank McJunkin, fmcjunki(at)comcast.net and paid
$10 each postpaid. (I use the second one on my bench for the occasions
when I bring the GPS home to program for a complex route, learn to use
all the features, upgrade the firmware, upgrade the databases, or
download the logbook. Come to think of it, that second cable gets used
more than the first )
--
Joe
Joe Dubner, K7JD
523 Cedar Avenue
Lewiston, ID 83501
cell: (208) 305-2688
http://www.nicon.org/chapter328/jd/
On 06-Jul-05 14:33 Cameron Kurth wrote:
>
> Bob
> Do I filter the power supply to the com radio or the
> GPS? I think the com radio pulls about 5-7 amps.
> It's a King KX125.
>
> Lloyd
> I have the stock data/power cable. I was looking at
> the lack of shielding and thought I might try using
> shielded wire on the power side. I don't have a way
> of hooking up the cigar lighter plug in the plane.
> It's either to the power buss or internal batteries.
>
> Cam
>
>
> --- "Robert L. Nuckolls, III"
> wrote:
>
>> Nuckolls, III"
>>
>>
>> Kurth
>> >
>> >
>> >Bob
>> >
>> >When I pulled the fuse to the Garmin 196 it was
>> then
>> >running off the internal batteries in the 196 and
>> the
>> >noise went away. It's quite repeatable, when I put
>> >the 196 back on the plane's power buss the noise
>> >returns. So maybe an inline filter will help?
>>
>> Good news. Yes, an inline filter will probably
>> help. It doesn't have to be big . . . that radio
>> can't draw much current. Do you know exactly how
>> much?
>>
>> Bob . . .
>>
>>
>>
>> browse
>> Subscriptions page,
>> FAQ,
>>
>>
>>
>>
>>
>>
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | Jim and Lucy <jpollard(at)ciaccess.com> |
| Subject: | Re: Need a switch |
At 04:11 PM 7/6/2005, you wrote:
>
>
>If you subscribe to the 'single failure' philosophy for one flight, then
>the batteries are only in the equation if the alternator has failed!
I think I have the single point of failures all addressed as
much as possible.
If either battery or its wiring fails. I have another battery
also hooked to the alternator.
If the alternator fails, I have 2 batteries to run on.
If a fuel pump fails, I run on the other at the other wing tank.
IF an ignition fails, I run on the other one.
Both ignitions are not on together except for takeoff and landing.
If any one of the two switches fails for the 2 pumps and any one of the
two switches fails for the 2 ignitions, I will run on the other pump or
ignition.
By using this special switch Bob mentioned earlier I can choose which
battery is powering either pump and ignition. Otherwise keeping one ignition
and pump dedicated to one battery could cause a case where I have
a full tank but that pump is hooked to a dead battery during an electrical
failure.
During normal operations it would not matter which on position the
switch was in. IE hooked to left battery buss or right battery bus.
If the alternator quits, I will open all contactors to save power.
The pumps and ignition are hooked to the always live battery buses
so the engine will not quit when the contactors are opened.
The eis is hooked to the battery buses and it will warm me for
overvoltage or under voltage. There is a switch to
power the EIS from either of the battery busses. This way
the voltage can be checked on each one separately.
Overvoltage is taken care of automatically by Bobs crowbar gizmo
on my externally regulated ND alternator.
thanks for all the replys guys
Jim Pollard
Merlin Ont
Zenair ch601hds
subaru ea81
________________________________________________________________________________
| From: | Cameron Kurth <cameronkurth(at)yahoo.com> |
| Subject: | Re: Garmin 196 interferes with com radio |
>I would be interested in the specific VHF frequencies
so I can test my setup.
>
The only frequency that has any interference is
118.95. That just happens to be Detroit Approach. I
live under Detroit's class B airspace so it's an
important frequency for me. Also I'm working on my
instrument ticket so I talk to approach quite abit and
a channel full of static just doesn't help in my
learnings :)
Cam
________________________________________________________________________________
| From: | "Jim Stone" <jsto1(at)tampabay.rr.com> |
| Subject: | RE: Help - low voltage - update |
I was running some current calibration tests this weekend and measured
the following values for Nav lights (9 Amps average) and Aeroquip
Strobes (7 Amps average). However the strobes are a pulsed load so
current peaks are much higher. Voltage drops, imply that the alternator
and/or battery cannot meet the peak power needs so the voltage drops.
The starting voltage indicates the battery isn't fully charged to begin
with.
If you were pulling 20 Amps and added another 7 Amps average, and the
voltage dropped as noted, I'd suspect that the alternator may be
undersized, or have a regulator/diode problem. Checking with an
osilloscope and currnt probe could define the peak current surge but
most people don't have access to that equipment. You might check the
Wheelin data sheets to see if they list peak currents.
The EI monitor will probably work down to around 10V.
Jim Stone
Jabiru J450
Clearwater FL.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mike
& Lee Anne Wiebe
Subject: AeroElectric-List: Help - low voltage - update
-->
Well all, sorry for the slow response. But is seems that the need to
make money to buy avgas got in the way of consuming it for the last week
or so.
Thx for the advice on my low voltage situation (Falco, with EI
instrumentation). I tested various conditions in a 'safe flight'
environment and found the following, using the on board EI
instrumentation. I seem to have isolated it to a strobe issue, but
would appreciate any insights.
Battery voltage before start 12.2 (it had run a little, cycling gear
etc. for some other tests recently). After start, charging 25A at 13.9V
at 1100rpm. Within 30 seconds, it was 15A, same other readings.
I loaded it up to a 20 amp draw in runup (1700 rpm) in various
configurations and saw between 13.8 and 14.0 volts. The only exception
was with the strobe on and it was bouncing between 12.1 and 12.9 volts,
and between 12-14 amps draw. In flight (anywhere between 2300 and
2700 rpm), with loads of up to 20 Amps saw voltages of 14.2 virtually
rock solid. Again however, with the strobe on, voltage varied between
12.9-14.1 volts, and 11-13 amps draw.
All other readings in the cockpit (egt, cht, oil temps/pressures, etc.)
which are also all monitored through EI instrumentation were rock solid
during strobe operation. So I don't think it's strobe noise issue. The
strobes work (Whelan, big multiple flash unit). So the simple answer
appears to be to leave the strobes off. However, if any genius out
there can describe a failure mode from this data, I'd sure appreciate
the insights.
Thx
Mike
________________________________________________________________________________
Bob: On your Z-14 diagram you show a primary fuel pump on the main
battery bus and a secondary fuel pump on the auxiliary battery bus. Is this two
sources of power to the same fuel pump? If yes this solves my problem.
Tonight I went out to start my plane and I had left the main master on over
night. main battery dead of course. Aux battery fine but right now I only have
the electric fuel pump wired to the main battery buss so no fuel pump and
crossfeed doesn't help. Engine would crank but without fuel pump no start.
Two
solutions I considered 1. two battery sources to fuel pump, therefore my
question above or 2. move the fuel pump wire to Main or Aux bus. Thanks
Tim Rhodenbaugh
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Re: Need a switch |
On 6 Jul 2005, at 19:44, Jim and Lucy wrote:
> I think I have the single point of failures all addressed as
> much as possible.
>
...
> IF an ignition fails, I run on the other one.
>
> Both ignitions are not on together except for takeoff and landing.
>
> If any one of the two switches fails for the 2 pumps and any one of
> the
> two switches fails for the 2 ignitions, I will run on the other
> pump or
> ignition.
>
Something to think about - if one ignition fails, and you then select
the other ignition on, the engine will have been pushing unburnt fuel
into the exhaust. There is a good chance you will have a very large
backfire, which could possibly break an exhaust stack off. A broken
exhaust stack could lead to a fire.
Possible solutions:
1. an exhaust system robust enough to handle massive backfires
without failure (= heavy), or
2. Run both ignitions all the time, or
3. Convince yourself that you will be smart enough to pull the
throttle to idle before selecting the other ignition to ON.
Personally, I've made enough screwups in my time that I would be very
cautious about assuming I wouldn't screw this one up.
If you believe the exhaust system is robust enough to handle
backfires, I would want to demonstrate this capability in controlled
conditions during the flight test program. Go over head the
airfield, with one ignition ON, and the other OFF. Select the first
ignition OFF, don't move the throttle, wait several seconds, then
select the second ignition ON. Pull the throttle to idle and do an
immediate approach and landing, using as little power as possible.
Inspect the exhaust system and repeat. Start the tests with low
power, working up in power for subsequent tests until you have done
one at full power. I'd rather discover a problem during this kind of
testing, than have an ignition fail when I am a long way from the
airfield and have to spend a long time with power on, and a possible
broken exhaust stack.
Good luck,
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: Need a switch |
In a message dated 7/6/2005 9:10:30 P.M. Central Standard Time,
khorton01(at)rogers.com writes:
3. Convince yourself that you will be smart enough to pull the
throttle to idle before selecting the other ignition to ON.
Personally, I've made enough screw ups in my time that I would be very
cautious about assuming I wouldn't screw this one up.
Good Evening Kevin,
If you are going to go with this one, I would strongly suggest that you
place the mixture in idle cutoff instead of closing the throttle. Pushing the
mixture slowly in after the ignition is on and with the throttle full open will
be a lot easier on the engine and it will also start a lot easier with full
throttle than it will with the throttle closed.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
bakerocb(at)cox.net wrote:
>
>7/6/2005
>
>Hello Experts, I have an ICOM IC-A4 hand held radio that I carry in my
>airplane as a communications back up. I also have the ICOM OPC-752 Headset
>Adapter cable accessory, but I do not have the separate ICOM 3.5 mm diameter
>PTT switch accessory for keying the transmitter while using the radio with
>that adapter and a headset. The manual says that the transmitter keying
>button on the side of the radio will not work when the headset adapter is
>plugged in.
>
>According to a diagram in the ICOM IC-A4 manual the ICOM PTT switch simply
>connects the tip of the microphone plug to the shank of the microphone plug
>in order to key the IC-A4 transmitter.
>
>My question is: Can I instead use my standard push-to-talk switch, with the
>larger diameter sized microphone receptacle and plug such as David Clark and
>Telex sell, in line with the microphone plug from the headset to the OPC-752
>Adapter to key the IC-A4 transmitter?
>
>ICOM refuses to answer this question for me by saying they won't comment on
>any one else's equipment. Thanks.
>
>OC
>
>PS: I suppose that there is no substitute for an actual trial test, but I
>haven't been able to get two people and another radio together to run such a
>test.
>
Plug in the headset adaptor, turn on the radio & push the side mounted
xmit button. Does the xmit led light up?
My IC-A4 works fine using the adaptor & the regular xmit button.
My manual says the radio won't work while on the external charge jack
(exactly opposite what the ICOM rep promised me before I bought it).
Charlie
________________________________________________________________________________
| From: | Jim and Lucy <jpollard(at)ciaccess.com> |
| Subject: | Re: Need a switch |
At 10:08 PM 7/6/2005, you wrote:
>Something to think about - if one ignition fails, and you then select
>the other ignition on, the engine will have been pushing unburnt fuel
>into the exhaust. There is a good chance you will have a very large
>backfire,
That is a good thing to think about that I had not got to yet.
For the first few hours my exhaust system will be as it is now
with just 2 straight 19 inch straight pipes coming off the heads
and exiting the cowl to a few inches behind the firewall.
Some mufflers will be added later.
I have been told that the belt drive subaru does not spin
very long in the air after the engine shuts down and getting
an airstart will be way over vne. So that may help some.
I once shut of the ignition on a pickup while at highway speed
to try to hear a distant CB radio transmission that was
being overpowered by the ignition noise. When I turned it
back on one of the mufflers ripped itself to shreds. Did
not no any better at 18 years old.
Jim Pollard
Merlin Ont
________________________________________________________________________________
| From: | owner-aeroelectric-list-server(at)matronics.com |
| Subject: | Warning lights fro day VFR |
Folks,
Could some of you guys recommend warning lights to put on the panel? My
objective is to have bright lights therefore visible in direct sunlight.
LEDs could probably do it better than incandescent bulbs. Since I shall not
be doing night VFR or IFR as most of Europe does not allow it with
experimentals (unless the engine and avionics are certified and maintained
as a certified), I would not need a dimmer circuit.
Thanks,
Mich=E8le Delsol
RV8 Fuselage (working on first assembly of the dreaded gear boxes).
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Re: Warning lights fro day VFR |
On 7 Jul 2005, at 02:36, Michle Delsol wrote:
>
> Folks,
>
>
> Could some of you guys recommend warning lights to put on the
> panel? My
> objective is to have bright lights therefore visible in direct
> sunlight.
> LEDs could probably do it better than incandescent bulbs. Since I
> shall not
> be doing night VFR or IFR as most of Europe does not allow it with
> experimentals (unless the engine and avionics are certified and
> maintained
> as a certified), I would not need a dimmer circuit.
>
>
Michle,
The large red LED that comes with the Grand Rapids EIS is very
bright, and quite visible in sunlight. The same lamp comes in green,
available at Newark Electronics, part numbers:
52F9235 Green LED http://www.newark.com/NewarkWebCommerce/newark/
en_US/endecaSearch/partDetail.jsp?SKU=52F9235&N=0
52F9237 Red LED http://www.newark.com/NewarkWebCommerce/newark/en_US/
endecaSearch/partDetail.jsp?SKU=52F9237&N=0
Newark also used to carry the amber version, part number 52F9239, but
their web site no longer admits any knowledge of this one.
These red LEDs are quite bright. The amber and green are a bit less
bright. I originally planned to use them, but eventually found a
good price on used Vivisun annunciators.
You can get an idea of what these LEDs look like from the picture of
when I had them in my panel:
http://www.kilohotel.com/rv8/article.php?story=20040418195119749
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| From: | rveighta <rveighta(at)earthlink.net> |
| Subject: | Re: Warning lights fro day VFR |
Michele, I agree with Kevin Horton regarding the Grand Rapids engine monitor.
I might add that the warning light blinks on and off until you acknowledge the
problem by pushing the "ack" button, whereupon it displays a steady red.
I have been flying an RV-8A for two years with this set-up and highly recommend
it. I have also installed Van's hour meter in my new RV-8 which has a red light
which comes on when you activate the master switch until it senses oil pressure
from engine start. This serves a a good reminder to turn the master off after a
flight.
Walt Shipley
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
Subject: AeroElectric-List: Warning lights fro day VFR
Folks,
Could some of you guys recommend warning lights to put on the panel? My
objective is to have bright lights therefore visible in direct sunlight.
LEDs could probably do it better than incandescent bulbs. Since I shall not
be doing night VFR or IFR as most of Europe does not allow it with
experimentals (unless the engine and avionics are certified and maintained
as a certified), I would not need a dimmer circuit.
Thanks,
Mich=E8le Delsol
RV8 Fuselage (working on first assembly of the dreaded gear boxes).
________________________________________________________________________________
| From: | "Dave Morris \"BigD\"" <BigD(at)DaveMorris.com> |
| Subject: | Re: Warning lights fro day VFR |
There's always this: http://www.aircraftsimulators.com/f18cautlts.html
They will create a custom panel for you, pretty cheap. Add a warning tone
for maximum alert.
Dave Morris
At 01:36 AM 7/7/2005, you wrote:
>
>Folks,
>
>
>Could some of you guys recommend warning lights to put on the panel? My
>objective is to have bright lights therefore visible in direct sunlight.
>LEDs could probably do it better than incandescent bulbs. Since I shall not
>be doing night VFR or IFR as most of Europe does not allow it with
>experimentals (unless the engine and avionics are certified and maintained
>as a certified), I would not need a dimmer circuit.
>
>
>Thanks,
>
>Mich=E8le Delsol
>
>RV8 Fuselage (working on first assembly of the dreaded gear boxes).
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Warning lights fro day VFR |
>
>I have been flying an RV-8A for two years with this set-up and highly
>recommend
>it. I have also installed Van's hour meter in my new RV-8 which has a red
>light
>which comes on when you activate the master switch until it senses oil
>pressure
>from engine start. This serves a a good reminder to turn the master off
>after a
>flight.
Active notification of low bus voltage will also help
you forget to turn of the battery master.
Bob . . .
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Warning lights fro day VFR |
FWIW the indicator that came with my EIS was incandescent not an LED
although it looks identical externally. I agree with soldering wires to
it rather than using the supplied push on PIDG terminals. The bulb is
potted in epoxy and connected with solid wires which means that after a
couple of wiggles the wire to the terminal breaks. Mine also drew about
100 ma at 12 volts rather than the 35 shown at
http://www.imlec.com/indicators/model1501.pdf Might have been a custom
extra bright indicator...
For one of my indicators I potted a large 10mm 12volt red and green
alternating flashing LED in a round aluminum bezel. It's an attention
getter...
Ken
Kevin Horton wrote:
>
>On 7 Jul 2005, at 02:36, Michle Delsol wrote:
>
>
>
>>
>>Folks,
>>
>>
>>Could some of you guys recommend warning lights to put on the
>>panel? My
>>objective is to have bright lights therefore visible in direct
>>sunlight.
>>LEDs could probably do it better than incandescent bulbs. Since I
>>shall not
>>be doing night VFR or IFR as most of Europe does not allow it with
>>experimentals (unless the engine and avionics are certified and
>>maintained
>>as a certified), I would not need a dimmer circuit.
>>
>>
>>
>>
>
>Michle,
>
>The large red LED that comes with the Grand Rapids EIS is very
>bright, and quite visible in sunlight. The same lamp comes in green,
>available at Newark Electronics, part numbers:
>
>52F9235 Green LED http://www.newark.com/NewarkWebCommerce/newark/
>en_US/endecaSearch/partDetail.jsp?SKU=52F9235&N=0
>52F9237 Red LED http://www.newark.com/NewarkWebCommerce/newark/en_US/
>endecaSearch/partDetail.jsp?SKU=52F9237&N=0
>
>Newark also used to carry the amber version, part number 52F9239, but
>their web site no longer admits any knowledge of this one.
>
>These red LEDs are quite bright. The amber and green are a bit less
>bright. I originally planned to use them, but eventually found a
>good price on used Vivisun annunciators.
>
>You can get an idea of what these LEDs look like from the picture of
>when I had them in my panel:
>
>http://www.kilohotel.com/rv8/article.php?story=20040418195119749
>
>Kevin Horton RV-8 (finishing kit)
>Ottawa, Canada
>http://www.kilohotel.com/rv8
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Warning lights fro day VFR (need another cup of coffee!) |
>
>
>
> >
> >I have been flying an RV-8A for two years with this set-up and highly
> >recommend
> >it. I have also installed Van's hour meter in my new RV-8 which has a red
> >light
> >which comes on when you activate the master switch until it senses oil
> >pressure
> >from engine start. This serves a a good reminder to turn the master off
> >after a
> >flight.
>
> Active notification of low bus voltage will also help
> you forget to turn of the battery master.
. . . of course this should read "help you AVOID forgetting
to turn off the battery master."
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
>
>Bob: On your Z-14 diagram you show a primary fuel pump on the main
>battery bus and a secondary fuel pump on the auxiliary battery bus. Is
>this two
>sources of power to the same fuel pump? If yes this solves my problem.
>Tonight I went out to start my plane and I had left the main master on over
>night. main battery dead of course. Aux battery fine but right now I
>only have
>the electric fuel pump wired to the main battery buss so no fuel pump and
>crossfeed doesn't help. Engine would crank but without fuel pump no
>start. Two
>solutions I considered 1. two battery sources to fuel pump, therefore my
>question above or 2. move the fuel pump wire to Main or
>Aux bus. Thanks
>Tim Rhodenbaugh
>
>
>--
>
>
>-- incoming mail is certified Virus Free.
Bob . . .
--------------------------------------------------------
< Throughout history, poverty is the normal condition >
< of man. Advances which permit this norm to be >
< exceeded -- here and there, now and then -- are the >
< work of an extremely small minority, frequently >
< despised, often condemned, and almost always opposed >
< by all right-thinking people. Whenever this tiny >
< minority is kept from creating, or (as sometimes >
< happens) is driven out of a society, the people >
< then slip back into abject poverty. >
< >
< This is known as "bad luck". >
< -Lazarus Long- >
<------------------------------------------------------>
http://www.aeroelectric.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
>
>Bob: On your Z-14 diagram you show a primary fuel pump on the main
>battery bus and a secondary fuel pump on the auxiliary battery bus. Is
>this two
>sources of power to the same fuel pump?
It's what ever you need it to be. Z-14 and its brothers are
simply examples of architecturs where you can mix/match features
between them. If you have two fuel pumps, then running each from
opposite sides of Z-14 makes sense. If you have one fuel pump,
then perhaps diode isolated feeds from both sides to the same pump
makes sense.
> If yes this solves my problem.
>Tonight I went out to start my plane and I had left the main master on over
>night. main battery dead of course. Aux battery fine but right now I
>only have
>the electric fuel pump wired to the main battery buss so no fuel pump and
>crossfeed doesn't help. Engine would crank but without fuel pump no
>start. Two
>solutions I considered 1. two battery sources to fuel pump, therefore my
>question above or 2. move the fuel pump wire to Main or Aux bus.
Your note illuminates what we might call a "problem" area
with Z-14 or ANY two-battery system. If the battery has been
depleted to dead-Dead-DEAD then you cannot use it to get
it's own contactor closed even if the other battery will still
get the airplane started . . . and everything on the DEAD battery
bus remains un-powered and the dead battery cannot be recharged
from the ship's alternator.
One might consider using the S701-2 CROSSFEED contactor arrangement
as a battery contactor. The two-diode feed to the top of the
coil would allow the contactor to close using energy
from EITHER the battery or bus side of contactor. Assuming
the charged battery is capable of cranking the engine, then
this re-wiring of the contactor will prevent a reoccurrence
of the scenario you've described.
Bob . . .
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | DC fans problem. |
A customer of mine bought a solid state relay from me but it failed when driving
a small DC fan. This certainly does not speak well of the ruggedness of the
solid state device. It is based on the International Rectifier IPS5551T with a
few added features and additional EMI protection. I test these things at 60 Amps.
Examining the SSR didn't help much except to show that the chip was toast and that
it probably didn't fail from current (usually current failures show cracked
cases). Besides the thing has overcurrent and overtemp protection. This was
a mystery that took far too long to solve...but finally I checked the whole circuit
and found that when a DC fan is turned off, it becomes a power generator
for at least a few seconds, and the voltage output (no load!) can easily exceed
the specs of the SSR.
So I offer this interesting information. Lots of devices have DC fans and solid
state parts. The devil is in the details. Make sure you put a Transient Voltage
Suppressor across every DC fan and every relay and coil and motor unless an
oscilloscope says you don't need to.
By the way--The output voltage transient in this case was in the same polarity
as the applied voltage--so a diode wouldn't do anything. The peak voltage spikes
exceeded 30V on a very small 2.6W 12V DC fan.
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
When trouble arises and things look bad,
there is always one individual who perceives
a solution and is willing to take command.
Very often, that individual is crazy.
--Dave Barry
________________________________________________________________________________
| Subject: | Re: Need a switch |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Or just run both ignitions all the time...I hear lot of debabte about
whether this is a good idea or not but I never saw a coil joiner or
other component that failed due to running like this.
Frank
HDS Subaru
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Jim
and Lucy
Subject: Re: AeroElectric-List: Re: Need a switch
-->
At 10:08 PM 7/6/2005, you wrote:
>Something to think about - if one ignition fails, and you then select
>the other ignition on, the engine will have been pushing unburnt fuel
>into the exhaust. There is a good chance you will have a very large
>backfire,
That is a good thing to think about that I had not got to yet.
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
AeroElectric-List message previously posted by: Charlie England
ceengland(at)bellsouth.net
>AeroElectric-List message posted by: bakerocb(at)cox.net
>.....skip.......My question is: Can I instead use my standard push-to-talk
>switch, with the
>larger diameter sized microphone receptacle and plug such as David Clark
>and
>Telex sell, in line with the microphone plug from the headset to the
>OPC-752
>Adapter to key the IC-A4 transmitter?......skip
Plug in the headset adaptor, turn on the radio & push the side mounted
xmit button. Does the xmit led light up? My IC-A4 works fine using the
adaptor & the regular xmit button. My manual says the radio won't work while
on the external charge jack
(exactly opposite what the ICOM rep promised me before I bought it). Charlie
7/7/2005
Hello Charlie, Thanks for your input and suggestion -- I will try that. But
lighting up a light is no absolute guarantee that you are transmitting a
signal. Only using a separate receiver and receiving a signal would
guarantee that -- I am a skeptical type.
I agree that there are some misleading / incorrect statements in the manual,
but I think some caution is in order in interpreting or rejecting them.
Here are two extracts from my manual:
"EXTERNAL DC POWER JACK [CHARGE]Connect a 12 to 16 V DC power source using
the optional
cables, CP-12L or OPC-254L, to charge the attached battery pack; or connect
the BC-110V wall charger for charging. CAUTION:This connection is for
charging ONLY. Power to the transceiver must be turned OFF during charging."
..... "CP-12L CIGARETTE LIGHTER CABLE WITH NOISE FILTER
Allows you to charge a battery pack connected to the transceiver via a DC
power source (12-16 V DC) For charging ONLY-the transceiver cannot be
simultaneously operated."
I was researching something on the IC-A4 earlier and was told by some
authoritative source (can't recall who now) that: Yes, the radio would work
when you are providing DC power to the external DC power jack, but the radio
is designed to operate on 9.6 volts DC -- the output from a normal battery
pack. If instead you try to operate the radio when some higher DC voltage is
being applied to the external DC power jack you run the risk of damaging the
radio.
No specific information on just how high that higher DC voltage has to be
coming into the external DC power jack in order to damage the radio while
attemping to operate it, but caution would be in order.
OC
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
AeroElectric-List message previouslyposted by: "Lloyd, Daniel R."
Can you put your primary radio on speaker and stand outside the plane
and talk into the handheld and see if the plane receives it?
7/7/2005
Hello Lloyd, Thanks for your suggestion, but I built my KIS TR-1 with no
speaker. I have headset operations only.
I did try something similar by attempting to transmit with my IC-A4 to my
Sporty's Air Scan V radio, but only generated a squeal. I assumed that I was
too close and over powering the Sporty's radio receiver. This left me still
uncertain of my IC-A4's capability in regard to using a standard push to
talk button.
OC
________________________________________________________________________________
| From: | "Leo Corbalis" <leocorbalis(at)sbcglobal.net> |
| Subject: | Re: Warning lights fro day VFR |
I thought that the light was enough too. I had to wait a week for my second
flight. I didn't see the red light ON with the sun in my face and ran the
battery FLAT over the weekend. (wife comes first) and I had get a new one. I
added a simple piezo beeper in paralell with the light. Get one that is on
continueously when the power is on, you don't want two differient timers
trying to control the beep. Haven't forgotten the master sw. since then.
Leo Corbalis
----- Original Message -----
From: "rveighta" <rveighta(at)earthlink.net>
Subject: Re: AeroElectric-List: Warning lights fro day VFR
>
>
> Michele, I agree with Kevin Horton regarding the Grand Rapids engine
> monitor.
> I might add that the warning light blinks on and off until you acknowledge
> the
> problem by pushing the "ack" button, whereupon it displays a steady red.
>
> I have been flying an RV-8A for two years with this set-up and highly
> recommend
> it. I have also installed Van's hour meter in my new RV-8 which has a red
> light
> which comes on when you activate the master switch until it senses oil
> pressure
> from engine start. This serves a a good reminder to turn the master off
> after a
> flight.
>
> Walt Shipley
>
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> To: aeroelectric-list(at)matronics.com
> Subject: AeroElectric-List: Warning lights fro day VFR
>
>
> Folks,
>
>
> Could some of you guys recommend warning lights to put on the panel? My
> objective is to have bright lights therefore visible in direct sunlight.
> LEDs could probably do it better than incandescent bulbs. Since I shall
> not
> be doing night VFR or IFR as most of Europe does not allow it with
> experimentals (unless the engine and avionics are certified and maintained
> as a certified), I would not need a dimmer circuit.
>
>
> Thanks,
>
> Mich=E8le Delsol
>
> RV8 Fuselage (working on first assembly of the dreaded gear boxes).
>
>
>
________________________________________________________________________________
| Subject: | DC fans problem. |
| From: | "George Braly" <gwbraly(at)gami.com> |
Was it wired up as a high side or a low side switch to the DC Fan motor ?
George
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com [mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Eric M. Jones
Subject: AeroElectric-List: DC fans problem.
A customer of mine bought a solid state relay from me but it failed when driving
a small DC fan. This certainly does not speak well of the ruggedness of the
solid state device. It is based on the International Rectifier IPS5551T with a
few added features and additional EMI protection. I test these things at 60 Amps.
Examining the SSR didn't help much except to show that the chip was toast and that
it probably didn't fail from current (usually current failures show cracked
cases). Besides the thing has overcurrent and overtemp protection. This was
a mystery that took far too long to solve...but finally I checked the whole circuit
and found that when a DC fan is turned off, it becomes a power generator
for at least a few seconds, and the voltage output (no load!) can easily exceed
the specs of the SSR.
So I offer this interesting information. Lots of devices have DC fans and solid
state parts. The devil is in the details. Make sure you put a Transient Voltage
Suppressor across every DC fan and every relay and coil and motor unless an
oscilloscope says you don't need to.
By the way--The output voltage transient in this case was in the same polarity
as the applied voltage--so a diode wouldn't do anything. The peak voltage spikes
exceeded 30V on a very small 2.6W 12V DC fan.
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
When trouble arises and things look bad,
there is always one individual who perceives
a solution and is willing to take command.
Very often, that individual is crazy.
--Dave Barry
---
---
________________________________________________________________________________
| From: | Charlie Brame <chasb(at)satx.rr.com> |
| Subject: | Regulator output |
Bob, et. al.,
The electrical system in my RV-6A is configured very close to Bob's
Z-13, All Electric on a Budget. I have a B&C alternator and a Ford
equivalent regulator which is adjustable and bench set to 13.8 volts.
With the main contactor off and using the essential bus only, I show
about 13.5 volts at the bus. However, when using the normal system with
the essential bus powered through a diode, the essential bus only shows
12.8 volts. This is understandable considering the loss through the
contactor and the diode.
My avionics and my gyros (ADI and DG) are connected via the essential
bus and I wonder if a higher voltage would improve both radio and gyro
perfomance somewhat.
My question is: should I up the regulator voltage in order to get close
to 13.8 volts at the essential bus when using the main or normal system?
This would result in 14+ volts on the main bus, but that shouldn't
adversely affect anything, IMHO.
Charlie
RV-6A N11CB
San Antonio
________________________________________________________________________________
| From: | Charlie Brame <chasb(at)satx.rr.com> |
I can't speak to the ICOM IC-A4. I have an ICOM IC-A23 which I also use
as a comm backup. With my headset plugged into the A23, the side button
PTT works as advertised - i.e., it transmits with a good side tone. I
can also plug in a separate PTT switch which works just as well. My
headset adapter is an ICOM product, but the separate PTT switch is an
off brand item.
Charlie
RV-6A N11CB
San Antonio
------------------------------
> From:
> Subject: AeroElectric-List: ICOM PTT
>
>
> 7/6/2005
>
> Hello Experts, I have an ICOM IC-A4 hand held radio that I carry in my
> airplane as a communications back up. I also have the ICOM OPC-752 Headset
> Adapter cable accessory, but I do not have the separate ICOM 3.5 mm diameter
> PTT switch accessory for keying the transmitter while using the radio with
> that adapter and a headset. The manual says that the transmitter keying
> button on the side of the radio will not work when the headset adapter is
> plugged in.
>
> According to a diagram in the ICOM IC-A4 manual the ICOM PTT switch simply
> connects the tip of the microphone plug to the shank of the microphone plug
> in order to key the IC-A4 transmitter.
>
> My question is: Can I instead use my standard push-to-talk switch, with the
> larger diameter sized microphone receptacle and plug such as David Clark and
> Telex sell, in line with the microphone plug from the headset to the OPC-752
> Adapter to key the IC-A4 transmitter?
>
> ICOM refuses to answer this question for me by saying they won't comment on
> any one else's equipment. Thanks.
>
> OC
>
>
________________________________________________________________________________
| From: | Charlie Brame <chasb(at)satx.rr.com> |
| Subject: | Regulator output |
Bob, et. al.,
The electrical system in my RV-6A is configured very close to Bob's
Z-13, All Electric on a Budget. I have a B&C alternator and a Ford
equivalent regulator which is adjustable and bench set to 13.8 volts.
With the main contactor off and using the essential bus only, I show
about 13.5 volts at the bus. However, when using the normal system with
the essential bus powered through a diode, the essential bus only shows
12.8 volts. This is understandable considering the loss through the
contactor and the diode.
My avionics and my gyros (ADI and DG) are connected via the essential
bus and I wonder if a higher voltage would improve both radio and gyro
perfomance somewhat.
My question is: should I up the regulator voltage in order to get close
to 13.8 volts at the essential bus when using the main or normal system?
This would result in 14+ volts on the main bus, but that shouldn't
adversely affect anything, IMHO.
Charlie
RV-6A N11CB
San Antonio
________________________________________________________________________________
| From: | Paul Wilson <pwilson(at)climber.org> |
| Subject: | Multimeter problem |
I have 3 digital multimeters that do not agree at all. Unfortunately I
posted some battery voltages on a large automotive AGM Optima battery that
are now highly suspect.
On the battery which was freshly charged:
1) GB Instruments GDT-11 bought at Home Depot about 2 months ago
12.80v, same with new 9v battery
2) Radio Shack Auto ranging # 22-163, about 2 years old
12.55v same with new AA cells
3) Radio Shack # 22-191, 8-10 years old
12.69v same with new AA cells.
Way to much difference to tell the state of charge of this relatively new
battery.
How can I tell which units are reading correct voltages? Is there a test
I can perform?
Thanks, Paul
________________________________________________________________________________
| Subject: | Alternator output |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
So my all elctric IFR plane (no mech fuel pump) will have main alt and
an SD-8 for backup.
My question is around failure detection.
It seems to me NOT to be a good idea to rely on voltage reduction to
detect an alternator failure, because it may take a while for the volts
to dip if at all.
A much better way would appear to be to use the Dynon engine management
system to measure current from the alternator and to set an alarm below
the minimum day VFR loads...This alarm would send an audio tone thru my
headset...
This method should work fine if I only had one alternator...with the
SD-8 I have 2 and the current may not drop that low because the min day
VFR could be a s low as 7 to 8 amps, depending on voltage the Main alt
may only be generating a couple of amps and a failure difficult to
detect.
An alternative would be not to run the SD-8 unless I had to...I.e keep
it switched off...if the main alt dies or trips on OV I get a low
current alarm...Then bang on the SD-8 and start load managing.
Any flaw in the logic here?...Can I switch an SD-8 like this?
Thanks
Frank
________________________________________________________________________________
| Subject: | Re: Regulator output |
| From: | "Craig P. Steffen" <craig(at)craigsteffen.net> |
First of all: I HAVE NO KNOWLEDGE OF THE SAFETY, PRACTICALITY OR
LEGALITY OF ISOLATOR DIODES IN AIRCRAFT. That having been said,
> The electrical system in my RV-6A is configured very close to Bob's
> Z-13, All Electric on a Budget. I have a B&C alternator and a Ford
> equivalent regulator which is adjustable and bench set to 13.8 volts.
> With the main contactor off and using the essential bus only, I show
> about 13.5 volts at the bus. However, when using the normal system with
> the essential bus powered through a diode, the essential bus only shows
> 12.8 volts. This is understandable considering the loss through the
> contactor and the diode.
If memory of my electronics course serves, a silicon diode has a
forward voltage drop of between .6 and .7 V, which accounts for the
voltage on your essential bus. Also if memory serves, the forward
voltage drop of a germanium diode is .3V. The DISadvantage of
germanium diodes is that they have a reverse leakage current much
higher than silicon diodes, in the milliamp range vs. the micro-amp
range for silicon.
I don't know how hard germanium diodes are to get, or if you could get
one of the proper rating at all. Remember, it has to be large enough to
dissipate the current powering the essential bus when the
alternator is working properly ( .3V * max_essential_bus_current ).
Just a thought, from the electronics side of things.
Craig Steffen
--
craig(at)craigsteffen.net
public key available at http://www.craigsteffen.net/GPG/
current goal: use a CueCat scanner to inventory my books
career goal: be the first Vorlon Time Lord
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | RE: DC fans problem. |
Subject: From: George Braly (gwbraly(at)gami.com)
>Was it wired up as a high side or a low side switch to the DC Fan motor?
>George
George,
It was configured as a high side switch. See
http://www.irf.com/product-info/datasheets/data/ips5551t.pdf
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
Teamwork: " A lot of people doing exactly what I say."
(Marketing exec., Citrix Corp.)
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: DC fans problem. |
> ... Make sure you put
> a Transient Voltage Suppressor across every DC fan and every relay
> and coil and motor unless an oscilloscope says you don't need to.
Hi Eric,
What would be the part number for that Transient Voltage Suppressor?
Do you sell them with a pretty picture like you have for the rest
of your stuff?
Thanks,
Mickey
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
________________________________________________________________________________
| Subject: | Alternator output |
| From: | "RV Builder (Michael Sausen)" <rvbuilder(at)sausen.net> |
I believe B&C sells a regulator specifically to keep the backup alternator offline
until the bus voltage drops below a specific point. This is probably what
you want. Someone else can chime in with the part specifics.
Michael Sausen
-10 #352 Tailcone
________________________________
From: owner-aeroelectric-list-server(at)matronics.com on behalf of Hinde, Frank George
(Corvallis)
Subject: AeroElectric-List: Alternator output
So my all elctric IFR plane (no mech fuel pump) will have main alt and
an SD-8 for backup.
My question is around failure detection.
It seems to me NOT to be a good idea to rely on voltage reduction to
detect an alternator failure, because it may take a while for the volts
to dip if at all.
A much better way would appear to be to use the Dynon engine management
system to measure current from the alternator and to set an alarm below
the minimum day VFR loads...This alarm would send an audio tone thru my
headset...
This method should work fine if I only had one alternator...with the
SD-8 I have 2 and the current may not drop that low because the min day
VFR could be a s low as 7 to 8 amps, depending on voltage the Main alt
may only be generating a couple of amps and a failure difficult to
detect.
An alternative would be not to run the SD-8 unless I had to...I.e keep
it switched off...if the main alt dies or trips on OV I get a low
current alarm...Then bang on the SD-8 and start load managing.
Any flaw in the logic here?...Can I switch an SD-8 like this?
Thanks
Frank
________________________________________________________________________________
| From: | <gmcjetpilot(at)yahoo.com> |
| Subject: | Re: Garmin 196 interferes with com radio |
You might consider the power wire to the 196 is producing EMF or RF at that one
freq. A power filter may help but suggest you may consider trying the below:
I agree the stock cable is not shielded but the one suggested by Joe I don't think
will work for the 196 (which does not have a round receptacle).
You could take the stock harness and cut the wires off near the plug and splice
in a shielded cable for the stock wires, or you could reroute the power cable
away from coax or other wires to the radio.
Before you do anything I wounder if you can borrow another 196 and plug it in
to see if it is the unit itself.
Sounds like a very specific freq. I was thinking it could be also picked up by
the intercom but because it is on one freq it seems to me it is RF interference
at that one freq.
A shielded or rerouted cable might help? EMF or IF problems have been solved by
just physically moving or separating the wires.
A testimonial will not help but my 196 mounted in the panel above my KX155 never
had any interference. You already confirmed that is is coming thru the power
line.
Good Luck George
From: Cameron Kurth <cameronkurth(at)yahoo.com>
Subject: Garmin 196 interferes with com radio
I have a Garmin 196 that is wired into the plane's
power buss. I get interference at a small range of
frequencies on my com radio from the Garmin (just
happens to be Detroit approach). If I pull the fuse
to the Garmin so it runs off the battery the
interference goes away. It's a similar interference
that the Dynon D10's had when they first came out.
So, what kind of filter should I use? Will the Radio
Shack 270-055 work in this situation? I called Garmin
about it. They said that the 196 was a handheld so it
has to meet the same specs as a toaster. They were
very nice about it but quite clear that it's only a
handheld so it was not designed for airplane use and
I'm on my own.
Thanks
Cam
________________________________________________________________________________
| From: | chad-c_sip(at)stanfordalumni.org |
| Subject: | Re: Multimeter problem |
Z-USANET-MsgId: XID379JggTiP0479X38
Do you have a resistor lying around that you could use to do a current test?
You'll probably want to solder the ends of the resistor to some wire so you
have a nice solid contact. Then use your various multimeters to measure the
current flow across the terminals. If all 3 multimeters think the resistance
of the resistor is the same and they all measure the same current then you
know the voltage of the battery: V = I * R
Use a large-ish resistor and you won't drain your batteryat all in the
process. 10 kOhms should be a nice small current to look at. And your
multimeters shouldn't have any trouble with that.
If the multimeters disagree on the resistance of the resistor or measure the
currents differently then your meters aren't accurate enough for this
measurement. If you've got an 8-bit A to D in those meters on a -20 to 20V
range you're looking at 156 mV as the least significant bit. That's not going
to be enough. I honestly don't know if those various multimeters are 8, 10, or
12 bit devices.
Good luck.
Chad
Chad Sipperley
Lancair IVP-turbine (under construction)
Phoenix, AZ
------ Original Message ------
From: Paul Wilson <pwilson(at)climber.org>
Subject: AeroElectric-List: Multimeter problem
>
> I have 3 digital multimeters that do not agree at all. Unfortunately I
> posted some battery voltages on a large automotive AGM Optima battery that
> are now highly suspect.
> On the battery which was freshly charged:
> 1) GB Instruments GDT-11 bought at Home Depot about 2 months ago
> 12.80v, same with new 9v battery
> 2) Radio Shack Auto ranging # 22-163, about 2 years old
> 12.55v same with new AA cells
> 3) Radio Shack # 22-191, 8-10 years old
> 12.69v same with new AA cells.
>
> Way to much difference to tell the state of charge of this relatively new
> battery.
> How can I tell which units are reading correct voltages? Is there a test
> I can perform?
>
> Thanks, Paul
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: DC fans problem. |
> ... Make sure you put a Transient Voltage Suppressor across every DC fan
> and every relay
> and coil and motor unless an oscilloscope says you don't need to.
>What would be the part number for that Transient Voltage Suppressor?
>Do you sell them with a pretty picture like you have for the rest
>of your stuff? Thanks, Mickey
Mickey,
Bidirectional transorb P6KE18CA will do the job and Digikey has them. I do
sell these in a 12-pack as "SnapJacks"
including shrink tubing and connector lugs and mysterious details sufficient
to outfit a typical small airplane.
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge
MA 01550-2705
(508) 764-2072
"Democracy is the theory that the common people know what they want and
deserve to get it good and hard." -- H. L. Mencken
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Regulator output |
>
>Bob, et. al.,
>
>The electrical system in my RV-6A is configured very close to Bob's
>Z-13, All Electric on a Budget. I have a B&C alternator and a Ford
>equivalent regulator which is adjustable and bench set to 13.8 volts.
>With the main contactor off and using the essential bus only, I show
>about 13.5 volts at the bus. However, when using the normal system with
>the essential bus powered through a diode, the essential bus only shows
>12.8 volts. This is understandable considering the loss through the
>contactor and the diode.
>
>My avionics and my gyros (ADI and DG) are connected via the essential
>bus and I wonder if a higher voltage would improve both radio and gyro
>perfomance somewhat.
>
>My question is: should I up the regulator voltage in order to get close
>to 13.8 volts at the essential bus when using the main or normal system?
>This would result in 14+ volts on the main bus, but that shouldn't
>adversely affect anything, IMHO.
No. When the alternator is running, it's set for 13.8 plus which puts
13.0 plus on the e-bus. When when the alternator stops, you move the
e-bus feed directly to the battery which delivers it's capacity over
the range of 12.5 down to about 11.0 volts.
Assuming you've chosen instruments that are designed to operate
over the range of battery supply voltages, then I'll suggest that
an alternator-ON operating voltage of 13.0 to 13.8 is superior
to the still satisfactory alternator-OFF operating voltage of
11.0 to 12.5.
The diode drop is, therefore insignificant. Further, the energy
dissipation
differences between the various technologies are also insignificant
while the alternator is operating because you have a 500+ watt,
unlimited duration energy source supplying all the BTUs. When you're
down to battery-only ops, then energy expenditure needs to be considered
more closely . . . This is why you seldom see a diode of any kind
downstream of a battery feed in my drawings.
Bob . . .
________________________________________________________________________________
| From: | Cameron Kurth <cameronkurth(at)yahoo.com> |
| Subject: | Re: Garmin 196 interferes with com radio |
Looks like shielding the wires is my best first try.
>
> A testimonial will not help but my 196 mounted in
> the panel above my KX155 never had any interference.
> You already confirmed that is is coming thru the
> power line.
It took me almost 130 hours of flying to find the
problem. It's only one frequency and it's only when
I'm quite a distance away from the source. When I'm
close to Detroit there is no problem. I have to be at
least 30 miles out before the interefence becomes a
problem. I assume that the interfernce is quite minor
so a small improvement is all I may need.
Thanks for the input.
Cam
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: Multimeter problem |
Paul,
Proper ventillation when doing fiberglass work is essential to avoid
becoming distracted on small problems like this.
Let's say the average of the three meters is 12.68 volts. Then the worst
case is that the meters have an error of:
GB Instruments GDT-11 12.80v........................+0.95%.......Under 1%
error. Very good
Radio Shack Auto ranging # 22-163 12.55v....... -1.03%.......Over 1% error.
Obviously Radio Shack junk
Radio Shack # 22-191 12.69v..........................+0.08%........Under
1/10 %. Well...even a blind pig finds an acorn sometimes.
Now, measuring battery voltages separately with meters is fraught with error
because of the small differences in meter impedance. To get numbers that are
meaningful you need to measure the same battery at the same time with all
the meters simultaneously.
Final word: Build the airplane.......
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
"Everything you've learned in school as "obvious" becomes
less and less obvious as you begin to study the universe.
For example, there are no solids in the universe. There's
not even a suggestion of a solid. There are no absolute con-
tinuums. There are no surfaces. There are no straight lines."
- R. Buckminster Fuller
------ Original Message ------
From: Paul Wilson <pwilson(at)climber.org>
Subject: Multimeter problem
>
> I have 3 digital multimeters that do not agree at all. Unfortunately I
> posted some battery voltages on a large automotive AGM Optima battery that
> are now highly suspect.
> On the battery which was freshly charged:
> 1) GB Instruments GDT-11 bought at Home Depot about 2 months ago
> 12.80v, same with new 9v battery
> 2) Radio Shack Auto ranging # 22-163, about 2 years old
> 12.55v same with new AA cells
> 3) Radio Shack # 22-191, 8-10 years old
> 12.69v same with new AA cells.
>
> Way to much difference to tell the state of charge of this relatively
> new
> battery.
> How can I tell which units are reading correct voltages? Is there a test
> I can perform?
>
> Thanks, Paul
________________________________________________________________________________
| From: | Dave Morris <BigD(at)DaveMorris.com> |
| Subject: | Re: Multimeter problem |
Stick a 7812 voltage regulator on it, and see what the 3 meters read. The
one that reads 12.0V is the winner.
Dave Morris
At 12:05 PM 7/7/2005, you wrote:
>
>I have 3 digital multimeters that do not agree at all. Unfortunately I
>posted some battery voltages on a large automotive AGM Optima battery that
>are now highly suspect.
> On the battery which was freshly charged:
>1) GB Instruments GDT-11 bought at Home Depot about 2 months ago
>12.80v, same with new 9v battery
>2) Radio Shack Auto ranging # 22-163, about 2 years old
>12.55v same with new AA cells
>3) Radio Shack # 22-191, 8-10 years old
>12.69v same with new AA cells.
>
> Way to much difference to tell the state of charge of this relatively new
>battery.
> How can I tell which units are reading correct voltages? Is there a test
>I can perform?
>
>Thanks, Paul
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | DC fans problem. |
>
>A customer of mine bought a solid state relay from me but it failed when
>driving a small DC fan. This certainly does not speak well of the
>ruggedness of the solid state device. It is based on the International
>Rectifier IPS5551T with a few added features and additional EMI
>protection. I test these things at 60 Amps.
>
>Examining the SSR didn't help much except to show that the chip was toast
>and that it probably didn't fail from current (usually current failures
>show cracked cases). Besides the thing has overcurrent and overtemp
>protection. This was a mystery that took far too long to solve...but
>finally I checked the whole circuit and found that when a DC fan is turned
>off, it becomes a power generator for at least a few seconds, and the
>voltage output (no load!) can easily exceed the specs of the SSR.
I went to the bench and ran some brushless fans. One was
a 1.8W, 12V motor, the other was an 8W, 12V device.
I was curious as to the form and energy content of any
transients I could see. Using the "Nuckolls, super-fast,
arc-less test switch" I was able to capture some 60v, positive
going transients on the little 1.8W motor. These were about
1 sec wide at the base, 60V tall and dropped to 40V when loaded
with 1K. This suggests the source impedance of the spike generator
is about 500 ohms since 2/3 of the spike would remain across
the 1K load. Since we're working back to a 15 volt (round numbers)
bus, we could extrapolate 45 volts being available to
"spike" the solid state relay with a current delivery (60-15)/500
= .09 amps.
This translates to an energy content for each spike of
about 45(volts) x 1.0(assume area under curve is square . . .
which it cannot be) x .09(amps) x 1(uSec) or
about 27 microJoules per spike. I always got 4 in a row
for each fan disconnect (4-pole motor?) for a total energy
dump of 108 microJoules.
FETs have an inherent 'body diode' that will go into
conduction if you try to carry the source more positive
than the drain. So in this case, all the energy feeding
back from the motor gets sinked off to the bus and resultant
reverse stress on the FET is under 1 volt.
The specs for handling inductive load energy dumps for the
switch (See
http://www.irf.com/product-info/datasheets/data/ips5551t.pdf
Figures 10 and 19) cites inductive load handling abilities
fare in excess of the 100+ microJoules calculated above by
several orders of magnitude.
Are you sure the mechanism by which the switch failed has
been properly illuminated? I'm having trouble believing
these itty-bitty spikes are hazardous to a IPS5551 high
side switch. I noted further that these spikes could
not have been related to a counter-emf spin-down. The
observable CEMF output dropped to 50% applied voltage
at switch opening and took about 3 seconds to drop to
5% of applied voltage.
Bob . . .
________________________________________________________________________________
| From: | Paul Wilson <pwilson(at)climber.org> |
| Subject: | Re: Multimeter problem |
Thanks Eric,
I had been using the bad meter and was trying to figure why the batt
always read low suspected it needed charging. Yes it was a distraction. I
am off this issue and will find a better meter to use in the shop and call
the question resolved. The GB meter is one I leave at home for messing with
AA powered gadgets. It only cost around $10 compared to the RS ones which
were much more expensive.
BTW I did try Chad's suggestion and the numbers were all over the place
because the meters wont read amps that are accurate enough.
Hey guys, suggest a cost effective meter that I can rely on.
Thanks, Paul
=====================
At 03:20 PM 7/7/2005, you wrote:
>
>Paul,
>
>Proper ventillation when doing fiberglass work is essential to avoid
>becoming distracted on small problems like this.
>
>Let's say the average of the three meters is 12.68 volts. Then the worst
>case is that the meters have an error of:
>
> GB Instruments GDT-11 12.80v........................+0.95%.......Under 1%
>error. Very good
> Radio Shack Auto ranging # 22-163 12.55v....... -1.03%.......Over 1% error.
>Obviously Radio Shack junk
> Radio Shack # 22-191 12.69v..........................+0.08%........Under
>1/10 %. Well...even a blind pig finds an acorn sometimes.
>
>Now, measuring battery voltages separately with meters is fraught with error
>because of the small differences in meter impedance. To get numbers that are
>meaningful you need to measure the same battery at the same time with all
>the meters simultaneously.
>
>Final word: Build the airplane.......
>
>Eric M. Jones
>www.PerihelionDesign.com
>113 Brentwood Drive
>Southbridge MA 01550-2705
>(508) 764-2072
>
>"Everything you've learned in school as "obvious" becomes
>less and less obvious as you begin to study the universe.
>For example, there are no solids in the universe. There's
>not even a suggestion of a solid. There are no absolute con-
>tinuums. There are no surfaces. There are no straight lines."
>
> - R. Buckminster Fuller
>
>------ Original Message ------
>From: Paul Wilson <pwilson(at)climber.org>
>To: aeroelectric-list(at)matronics.com
>Subject: Multimeter problem
>
> >
> > I have 3 digital multimeters that do not agree at all. Unfortunately I
> > posted some battery voltages on a large automotive AGM Optima battery that
> > are now highly suspect.
> > On the battery which was freshly charged:
> > 1) GB Instruments GDT-11 bought at Home Depot about 2 months ago
> > 12.80v, same with new 9v battery
> > 2) Radio Shack Auto ranging # 22-163, about 2 years old
> > 12.55v same with new AA cells
> > 3) Radio Shack # 22-191, 8-10 years old
> > 12.69v same with new AA cells.
> >
> > Way to much difference to tell the state of charge of this relatively
> > new
>
> > battery.
> > How can I tell which units are reading correct voltages? Is there a test
> > I can perform?
> >
> > Thanks, Paul
>
>
________________________________________________________________________________
| From: | chad-c_sip(at)stanfordalumni.org |
| Subject: | Re: Multimeter problem |
Z-USANET-MsgId: XID494JggXvP0235X30
I don't know about cost-effective in the short run. But in the lab for my
graduate work we only used Flukes. All the other el-cheapo meters died within
a year and were totally unreliable for anything critical. I've had the same
Fluke multimeter for about 6 years now going on it's 10th or more set of
batteries and third set of probes.
Chad
Chad Sipperley
Lancair IVP-turbine (under construction)
Phoenix, AZ
------ Original Message ------
From: Paul Wilson <pwilson(at)climber.org>
Subject: Re: AeroElectric-List: Re: Multimeter problem
>
> Thanks Eric,
> I had been using the bad meter and was trying to figure why the batt
> always read low suspected it needed charging. Yes it was a distraction. I
> am off this issue and will find a better meter to use in the shop and call
> the question resolved. The GB meter is one I leave at home for messing with
> AA powered gadgets. It only cost around $10 compared to the RS ones which
> were much more expensive.
> BTW I did try Chad's suggestion and the numbers were all over the place
> because the meters wont read amps that are accurate enough.
>
> Hey guys, suggest a cost effective meter that I can rely on.
>
> Thanks, Paul
> =====================
>
> At 03:20 PM 7/7/2005, you wrote:
> >
> >Paul,
> >
> >Proper ventillation when doing fiberglass work is essential to avoid
> >becoming distracted on small problems like this.
> >
> >Let's say the average of the three meters is 12.68 volts. Then the worst
> >case is that the meters have an error of:
> >
> > GB Instruments GDT-11 12.80v........................+0.95%.......Under
1%
> >error. Very good
> > Radio Shack Auto ranging # 22-163 12.55v....... -1.03%.......Over 1%
error.
> >Obviously Radio Shack junk
> > Radio Shack # 22-191
12.69v..........................+0.08%........Under
> >1/10 %. Well...even a blind pig finds an acorn sometimes.
> >
> >Now, measuring battery voltages separately with meters is fraught with
error
> >because of the small differences in meter impedance. To get numbers that
are
> >meaningful you need to measure the same battery at the same time with all
> >the meters simultaneously.
> >
> >Final word: Build the airplane.......
> >
> >Eric M. Jones
> >www.PerihelionDesign.com
> >113 Brentwood Drive
> >Southbridge MA 01550-2705
> >(508) 764-2072
> >
> >"Everything you've learned in school as "obvious" becomes
> >less and less obvious as you begin to study the universe.
> >For example, there are no solids in the universe. There's
> >not even a suggestion of a solid. There are no absolute con-
> >tinuums. There are no surfaces. There are no straight lines."
> >
> > - R. Buckminster Fuller
> >
> >------ Original Message ------
> >From: Paul Wilson <pwilson(at)climber.org>
> >To: aeroelectric-list(at)matronics.com
> >Subject: Multimeter problem
> >
> > >
> > > I have 3 digital multimeters that do not agree at all. Unfortunately I
> > > posted some battery voltages on a large automotive AGM Optima battery
that
> > > are now highly suspect.
> > > On the battery which was freshly charged:
> > > 1) GB Instruments GDT-11 bought at Home Depot about 2 months ago
> > > 12.80v, same with new 9v battery
> > > 2) Radio Shack Auto ranging # 22-163, about 2 years old
> > > 12.55v same with new AA cells
> > > 3) Radio Shack # 22-191, 8-10 years old
> > > 12.69v same with new AA cells.
> > >
> > > Way to much difference to tell the state of charge of this relatively
> > > new
> >
> > > battery.
> > > How can I tell which units are reading correct voltages? Is there a
test
> > > I can perform?
> > >
> > > Thanks, Paul
> >
> >
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Alternator output |
So my all electric IFR plane (no mech fuel pump) will have main alt and
an SD-8 for backup.
My question is around failure detection.
It seems to me NOT to be a good idea to rely on voltage reduction to
detect an alternator failure, because it may take a while for the volts
to dip if at all.
Absolutely not true. Batteries charge, and alternators are set
down. A low voltage light set for 13.0 volts comes on in seconds
after
the alternator quits.
A much better way would appear to be to use the Dynon engine management
system to measure current from the alternator and to set an alarm below
the minimum day VFR loads...This alarm would send an audio tone thru my
headset...
This method should work fine if I only had one alternator...with the
SD-8 I have 2 and the current may not drop that low because the min day
VFR could be a s low as 7 to 8 amps, depending on voltage the Main alt
may only be generating a couple of amps and a failure difficult to
detect.
An alternative would be not to run the SD-8 unless I had to...I.e keep
it switched off...if the main alt dies or trips on OV I get a low
current alarm...Then bang on the SD-8 and start load managing.
That's the recommended operating procedure. SD-8
stays off until after you get a low-volts light
to show that main alternator is off. Then turn
SD-8 ON, Main battery master OFF. Continue in en route
endurance mode until airport in sight. Close battery
master contactor to bring main bus up to use any
equipment you like for approach to landing.
Bob . . .
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
bakerocb(at)cox.net wrote:
>
>AeroElectric-List message previously posted by: Charlie England
>ceengland(at)bellsouth.net
>
>
>
>
>>AeroElectric-List message posted by: bakerocb(at)cox.net
>>
>>
>
>
>
>>.....skip.......My question is: Can I instead use my standard push-to-talk
>>switch, with the
>>larger diameter sized microphone receptacle and plug such as David Clark
>>and
>>Telex sell, in line with the microphone plug from the headset to the
>>OPC-752
>>Adapter to key the IC-A4 transmitter?......skip
>>
>>
>
>
>Plug in the headset adaptor, turn on the radio & push the side mounted
>xmit button. Does the xmit led light up? My IC-A4 works fine using the
>adaptor & the regular xmit button. My manual says the radio won't work while
>on the external charge jack
>(exactly opposite what the ICOM rep promised me before I bought it). Charlie
>
>7/7/2005
>
>Hello Charlie, Thanks for your input and suggestion -- I will try that. But
>lighting up a light is no absolute guarantee that you are transmitting a
>signal. Only using a separate receiver and receiving a signal would
>guarantee that -- I am a skeptical type.
>
>I agree that there are some misleading / incorrect statements in the manual,
>but I think some caution is in order in interpreting or rejecting them.
>
>Here are two extracts from my manual:
>
>"EXTERNAL DC POWER JACK [CHARGE]Connect a 12 to 16 V DC power source using
>the optional
>cables, CP-12L or OPC-254L, to charge the attached battery pack; or connect
>the BC-110V wall charger for charging. CAUTION:This connection is for
>charging ONLY. Power to the transceiver must be turned OFF during charging."
>..... "CP-12L CIGARETTE LIGHTER CABLE WITH NOISE FILTER
>Allows you to charge a battery pack connected to the transceiver via a DC
>power source (12-16 V DC) For charging ONLY-the transceiver cannot be
>simultaneously operated."
>
>I was researching something on the IC-A4 earlier and was told by some
>authoritative source (can't recall who now) that: Yes, the radio would work
>when you are providing DC power to the external DC power jack, but the radio
>is designed to operate on 9.6 volts DC -- the output from a normal battery
>pack. If instead you try to operate the radio when some higher DC voltage is
>being applied to the external DC power jack you run the risk of damaging the
>radio.
>
>No specific information on just how high that higher DC voltage has to be
>coming into the external DC power jack in order to damage the radio while
>attemping to operate it, but caution would be in order.
>
>OC
>
My reply was rather poorly worded. I should have said that mine actually
works fine in both xmit & rcv using the headset adaptor & the builtin
PTT. I assumed that you had no 2nd radio to test with, & the led is a
pretty strong indicator that the button is doing what it claims to do.
Consider the extra design/circuit work involved in making it light under
both conditions of transmit & no-transmit.
from another post:
>>>I did try something similar by attempting to transmit with my IC-A4 to my
Sporty's Air Scan V radio, but only generated a squeal. I assumed that I was
too close and over powering the Sporty's radio receiver. This left me still
uncertain of my IC-A4's capability in regard to using a standard push to
talk button.
>>>
Repeat the test with the scanner in an adjacent room or walk outside & let someone
else listen to the scanner. Odds are, the squeal was actually feedback caused
by the mic on the ICOM picking up its own audio from the scanner, amplifying,
retransmitting, etc.
RE:operation while charging issues, if the radio would be damaged by external charge
voltage due to operating on 9.6 V, the battery would also be damaged rather
quickly from the same overvoltage. It is so simple to design this feature
into the radio that it never occurred to me to question the rep's word about it.
I was shocked & disgusted when I discovered that he lied about it & that I
couldn't use ship's power, even with a purpose built adapter, to both keep the
battery topped off & operate the radio. (Ahh well... rants about ICOM's ?integrity?
are best left for another post.)
Good luck with your testing,
Charlie
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
snip
>RE:operation while charging issues, if the radio would be damaged by external
charge voltage due to operating on 9.6 V, the battery would also be damaged rather
quickly from the same overvoltage. It is so simple to design this feature
into the radio that it never occurred to me to question the rep's word about
it. I was shocked & disgusted when I discovered that he lied about it & that I
couldn't use ship's power, even with a purpose built adapter, to both keep the
battery topped off & operate the radio. (Ahh well... rants about ICOM's ?integrity?
are best left for another post.)
>
>Good luck with your testing,
>
>Charlie
>
>
Do we know that it won't transmit reliably while charging or that damage
occurs? I certainly listen to my A4 while it is charging. I don't think
I've transmitted for more than a few seconds while charging though. The
marketing types who write icom manuals can't or don't talk to the
engineers IMO. I suspect the engineers wouldn't let it turn on while
charging if damage was likely. The rep may know more than the manual...
Ken
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Alternator output |
>
>
>I believe B&C sells a regulator specifically to keep the backup alternator
>offline until the bus voltage drops below a specific point. This is
>probably what you want. Someone else can chime in with the part specifics.
This is the SB-1 regulator crafted for certified installations
similar to Z-12 where both alternators share a common main bus.
This is not recommended for new design but that doesn't mean
it won't work. But it was intended for UPGRADING a certified
ship where the standby alternator was added to an existing
architecture that was difficult to change.
ANY adjustable regulator can be set up for autoswitching.
Run both altenrnators all the time. Set the standby regulator
for 1 volt or so BELOW the normal bus voltage. When the main
alternator comes up, the standby regulator simply relaxes
believing that it has control of the bus and that the bus
voltage is presently too high . . . the standby alternator
shuts down.
If the main alternator quits, the bus voltage sags and the
standby alternator comes on line to pick up whatever slack
it is capable of handling. The low voltage warning circuitry
in the regulator was not useful so we converted it to a
"alternator active" detection circuit. When the main alternator
goes down and the standby switches automatically, we wanted
a light to indicate the event.
Nothing magic or very special and easy to accomplish with
generic hardware if Figure Z-12 rings your chimes. This mode
of operation MIHGT work with an SD-8 . . . it would have to
be tested. The SD-8's regulator does not operate with
the same precision as the wound-field alternators.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Multimeter problem |
>
>Thanks Eric,
> I had been using the bad meter and was trying to figure why the batt
>always read low suspected it needed charging. Yes it was a distraction. I
>am off this issue and will find a better meter to use in the shop and call
>the question resolved. The GB meter is one I leave at home for messing with
>AA powered gadgets. It only cost around $10 compared to the RS ones which
>were much more expensive.
> BTW I did try Chad's suggestion and the numbers were all over the place
>because the meters wont read amps that are accurate enough.
>
> Hey guys, suggest a cost effective meter that I can rely on.
I have a half dozen multimeters of various manufacture and
yes, some are from Radio Shack. Two are from Fluke with one
of them being over 30 years old. The to Flukes agree with
each other to 2 parts per thousand (0.2%), all others agree
with the Flukes to within 5 parts per thousand (0.5%). One
of the el-cheeso instruments came from Sears with Craftsman's
brand on it for $19.95 . . . it agreed to 0.3%
I used to give away a multimeter as part of the door prizes
for my weekend seminars. I purchased a dozen devices from my
supplier for under $5 each and they all tracked the Flukes
to better than 1.0%.
Modern technology offers the ability to craft a lot 0f accuracy
into a measurement system to the extent that price of the
instrument is driven more by mechanical features (ruggedness)
and marketing (Fluke buys full page ads in journals circulated
world wide).
If one desires off-the-shelf, no doubts assurances of quality
and accuracy, anything with John Fluke's name on it can be
relied upon to meet advertised performance for decades of
reasonable use (I dropped a Fluke from a tower once . . .
it didn't survive).
However, it's not useful to sniff at anything less just
because it doesn't have a brand or history to support it.
When I buy a new instrument, I check it against the Flukes
and make note of it's shortfall should it be more than
1.0% in error. There are some excellent buys out there
but you have to "trust but verify".
I was saddened when they outlawed mercury cells. The RM
series cells at room temperature were VERY accurate
sources of 1.345 volts that could be used to check voltmeters.
Nowadays, you can buy an off-the-shelf, precision
voltage reference factory trimmed to better than 1 part
in 4000 for an accuracy of 0.025% for a few dollars and
build your own voltmeter checker.
There is no value in making simultaneous battery readings
with these modern instruments. All have input impedances of
10 megohms or more and variability of independent versus
simultaneous readings is down in the nanovolt region.
Finally, the voltmeter is a rough check of battery capacity
due to a number of variables. It anyone has concerns about
whether a battery is fully charged. Put a 14.2 volt power
supply on it and wait until recharge current drops below
0.2A or so (Concord uses 0.5A). Then you KNOW the battery
is topped off. Similarly, keeping a battery stored on
a talented maintainer is another sure bet for knowing that
the battery is charged to it's FULL CAPACITY, whatever
it happens to be. This does not mean that the battery is
still capable of factory-new capacity, that's a different
test.
The short answer to the question is check at sears for
a little blister-packed multimeter like the one you see
illustrated in:
http://www.aeroelectric.com/articles/LowOhmsAdapter_3.pdf
I found this particular device to be a very good value
at $20. If you know someone with a Fluke or other laboratory
grade instrument, it wouldn't hurt to check any multimeter
you have against it. But most manufacturers only offer
1.0% accuracy with a handful going to 0.5% or below. Just
because the critter displays 4 digits should not imply
accuracy that may not be there.
Bob . . .
________________________________________________________________________________
| Subject: | Regulator output |
| From: | "Doerr, Ray R [NTK]" <Ray.R.Doerr(at)mail.sprint.com> |
Could you not also run with the Essential Buss Bypass switch on.
This would allow the current to flow through the switch and not the
diode, whereby eliminating the voltage drop across the diode. The down
side with this is that if you don't get an early indication that your
alternator failed, you would have used up some of your reverse battery
power while the master was still on. On the plus side, there is no
voltage drop on the essential bus and no high current via the diode.
The diode would simply ensure that if the master is off and the
essential bus bypass is no, then current will not flow from the
essential buss to the main buss.
Thank You
Ray Doerr
-----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
Subject: Re: AeroElectric-List: Regulator output
>
>Bob, et. al.,
>
>The electrical system in my RV-6A is configured very close to Bob's
>Z-13, All Electric on a Budget. I have a B&C alternator and a Ford
>equivalent regulator which is adjustable and bench set to 13.8 volts.
>With the main contactor off and using the essential bus only, I show
>about 13.5 volts at the bus. However, when using the normal system with
>the essential bus powered through a diode, the essential bus only shows
>12.8 volts. This is understandable considering the loss through the
>contactor and the diode.
>
>My avionics and my gyros (ADI and DG) are connected via the essential
>bus and I wonder if a higher voltage would improve both radio and gyro
>perfomance somewhat.
>
>My question is: should I up the regulator voltage in order to get close
>to 13.8 volts at the essential bus when using the main or normal
system?
>This would result in 14+ volts on the main bus, but that shouldn't
>adversely affect anything, IMHO.
No. When the alternator is running, it's set for 13.8 plus which
puts
13.0 plus on the e-bus. When when the alternator stops, you move the
e-bus feed directly to the battery which delivers it's capacity over
the range of 12.5 down to about 11.0 volts.
Assuming you've chosen instruments that are designed to operate
over the range of battery supply voltages, then I'll suggest that
an alternator-ON operating voltage of 13.0 to 13.8 is superior
to the still satisfactory alternator-OFF operating voltage of
11.0 to 12.5.
The diode drop is, therefore insignificant. Further, the energy
dissipation
differences between the various technologies are also insignificant
while the alternator is operating because you have a 500+ watt,
unlimited duration energy source supplying all the BTUs. When you're
down to battery-only ops, then energy expenditure needs to be
considered
more closely . . . This is why you seldom see a diode of any kind
downstream of a battery feed in my drawings.
Bob . . .
________________________________________________________________________________
| From: | "Vern W." <vernw(at)ev1.net> |
| Subject: | Re: Alternator output |
I'd like to ask a simple follow-up question here, Bob.
In a scenario of Z13/8 with only the one main battery existing in the
system, if (for example) a lug breaks on the battery and it's taken out of
the system, will the main alternator continue to power the system? Or
without the battery in the system, would there be a voltage runaway and the
main alternator would have to be taken offline? ... (If that were the case,
then the SD8 would have no chance of coming alive by itself).
If the main alternator WOULD continue to power the system within the
proper voltage range (due to it's regulator controlling the voltage?), and
the SD8 is then switched on, would the SD8 come alive using the voltage from
the main alternator as the exciter? And then would the SD8 continue to power
the system on it's own without a battery in the system?
What I'm trying to get straight in my head is the various failure
scenarios possible and how the "surviving" components are expected to react.
Vern
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: AeroElectric-List: Alternator output
>
>
> So my all electric IFR plane (no mech fuel pump) will have main alt and
> an SD-8 for backup.
>
> My question is around failure detection.
>
> It seems to me NOT to be a good idea to rely on voltage reduction to
> detect an alternator failure, because it may take a while for the volts
> to dip if at all.
>
> Absolutely not true. Batteries charge, and alternators are set
> down. A low voltage light set for 13.0 volts comes on in seconds
> after
> the alternator quits.
>
> A much better way would appear to be to use the Dynon engine management
> system to measure current from the alternator and to set an alarm below
> the minimum day VFR loads...This alarm would send an audio tone thru my
> headset...
>
> This method should work fine if I only had one alternator...with the
> SD-8 I have 2 and the current may not drop that low because the min day
> VFR could be a s low as 7 to 8 amps, depending on voltage the Main alt
> may only be generating a couple of amps and a failure difficult to
> detect.
>
> An alternative would be not to run the SD-8 unless I had to...I.e keep
> it switched off...if the main alt dies or trips on OV I get a low
> current alarm...Then bang on the SD-8 and start load managing.
>
> That's the recommended operating procedure. SD-8
> stays off until after you get a low-volts light
> to show that main alternator is off. Then turn
> SD-8 ON, Main battery master OFF. Continue in en route
> endurance mode until airport in sight. Close battery
> master contactor to bring main bus up to use any
> equipment you like for approach to landing.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
AeroElectric-List message previously posted by: Charlie Brame
<>
7/8/2005
Hello Charlie Brame, Does the off brand PTT switch that you use have the
normal standard sized (larger) PTT switch plug or the small 3.5mm size plug?
Each switch would get plugged into the headset adapter in a different place
/ manner.
Thanks, OC
PS: One of the more aggravating aspects of trying to sort through what
should be a rather simple problem is that some of ICOM's PTT switches are
identified as being used with only certain of their radio models when I
think that there is really only one ICOM 3.5mm PTT switch for use with all
of their radios when using a headset adapter.
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
AeroElectric-List message previously posted by: Charlie England
<>
from another post:
<<....skip....RE:operation while charging issues, if the radio would be
damaged by external charge
voltage due to operating on 9.6 V, the battery would also be damaged rather
quickly from the same overvoltage. It is so simple to design this feature
into the radio that it never occurred to me to question the rep's word about
it.
I was shocked & disgusted when I discovered that he lied about it & that I
couldn't use ship's power, even with a purpose built adapter, to both keep
the
battery topped off & operate the radio. (Ahh well... rants about ICOM's
?integrity?
are best left for another post.) Good luck with your testing, Charlie>>
7/8/2005
Hello Charlie England, I don't know why one would assume that the 9.6 volt
battery would be damaged when exposed to a DC charging source of greater
than 9.6 volts. I am under the impression that to charge a battery one must
apply more than its nominal voltage output. And the ICOM charger that I have
says it puts out 12 volts DC. The ICOM IC-A4 manual says 12-16 charging
volts is OK.
Obviously there is some voltage level above which the battery would be
damaged just as there some applied voltage level above 9.6 volts by which
the radio itself would be damaged if turned on or transmitted from. ICOM
apparently is sensitive to the issue of damage to their radios from too high
a voltage source applied through the battery charging port so they mislead
you in their manuals to stop you from operating and possibly damaging your
radio while charging.
But I don't know why they would mislead us about the non functioning of the
IC-A4 on set transmitter button while the headset adapter is installed if
the button and the radio works OK just like Charlie Brame says it does for
the IC-A23.
ICOM Tech Support, do you wish to comment?
OC
________________________________________________________________________________
| From: | Paul Wilson <pwilson(at)climber.org> |
| Subject: | Re: Multimeter problem |
Bob, Sorry to belabor this issue, but two more questions please:
I just want a meter that tells me the battery status. Then I can put on the
charger as needed. I thought that the table published in the Battery tender
flyer was good enough. It says a fully changed batt (after a 12 hr rest)
would have 12.6-12.8v and one with 12.2-12.4v would be charged at 50-75%
based on the chemistry of the battery. Thus that 3+% is a big deal to me
and my meters showed a spread of more than 1% and therefore I am being
misled about my battery condition.
I suspect my newest ~$10 GB meter is accurate, but I would like to know.
1) Bob can you make available the gadget to test the meter discussed in
your link below?
I hate to throw away a meter/s until I know how they test. I have zero
confidence that I can build your gadget. lots easier to test the MM than to
drive to town and use the battery guys Fluke.
Related question to bolster my confidence.
2) Am I correct that the Schumacher WM1562A charger/maintainer meets the
criteria for a properly charging these RG batteries?
I like your method of just putting a smart charger on the batt an then one
knows it is charged fully.
Thanks for your wisdom, Paul
=====================
At 07:07 AM 7/8/2005, you wrote:
>
>
>
> >
> >Thanks Eric,
> > I had been using the bad meter and was trying to figure why the batt
> >always read low suspected it needed charging. Yes it was a distraction. I
> >am off this issue and will find a better meter to use in the shop and call
> >the question resolved. The GB meter is one I leave at home for messing with
> >AA powered gadgets. It only cost around $10 compared to the RS ones which
> >were much more expensive.
> > BTW I did try Chad's suggestion and the numbers were all over the place
> >because the meters wont read amps that are accurate enough.
> >
> > Hey guys, suggest a cost effective meter that I can rely on.
>
>
> I have a half dozen multimeters of various manufacture and
> yes, some are from Radio Shack. Two are from Fluke with one
> of them being over 30 years old. The to Flukes agree with
> each other to 2 parts per thousand (0.2%), all others agree
> with the Flukes to within 5 parts per thousand (0.5%). One
> of the el-cheeso instruments came from Sears with Craftsman's
> brand on it for $19.95 . . . it agreed to 0.3%
>
> I used to give away a multimeter as part of the door prizes
> for my weekend seminars. I purchased a dozen devices from my
> supplier for under $5 each and they all tracked the Flukes
> to better than 1.0%.
>
> Modern technology offers the ability to craft a lot 0f accuracy
> into a measurement system to the extent that price of the
> instrument is driven more by mechanical features (ruggedness)
> and marketing (Fluke buys full page ads in journals circulated
> world wide).
>
> If one desires off-the-shelf, no doubts assurances of quality
> and accuracy, anything with John Fluke's name on it can be
> relied upon to meet advertised performance for decades of
> reasonable use (I dropped a Fluke from a tower once . . .
> it didn't survive).
>
> However, it's not useful to sniff at anything less just
> because it doesn't have a brand or history to support it.
> When I buy a new instrument, I check it against the Flukes
> and make note of it's shortfall should it be more than
> 1.0% in error. There are some excellent buys out there
> but you have to "trust but verify".
>
> I was saddened when they outlawed mercury cells. The RM
> series cells at room temperature were VERY accurate
> sources of 1.345 volts that could be used to check voltmeters.
> Nowadays, you can buy an off-the-shelf, precision
> voltage reference factory trimmed to better than 1 part
> in 4000 for an accuracy of 0.025% for a few dollars and
> build your own voltmeter checker.
>
> There is no value in making simultaneous battery readings
> with these modern instruments. All have input impedances of
> 10 megohms or more and variability of independent versus
> simultaneous readings is down in the nanovolt region.
>
> Finally, the voltmeter is a rough check of battery capacity
> due to a number of variables. It anyone has concerns about
> whether a battery is fully charged. Put a 14.2 volt power
> supply on it and wait until recharge current drops below
> 0.2A or so (Concord uses 0.5A). Then you KNOW the battery
> is topped off. Similarly, keeping a battery stored on
> a talented maintainer is another sure bet for knowing that
> the battery is charged to it's FULL CAPACITY, whatever
> it happens to be. This does not mean that the battery is
> still capable of factory-new capacity, that's a different
> test.
>
> The short answer to the question is check at sears for
> a little blister-packed multimeter like the one you see
> illustrated in:
>
>http://www.aeroelectric.com/articles/LowOhmsAdapter_3.pdf
>
> I found this particular device to be a very good value
> at $20. If you know someone with a Fluke or other laboratory
> grade instrument, it wouldn't hurt to check any multimeter
> you have against it. But most manufacturers only offer
> 1.0% accuracy with a handful going to 0.5% or below. Just
> because the critter displays 4 digits should not imply
> accuracy that may not be there.
>
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | joelrhaynes(at)AOL.COM |
| Subject: | Re: AeroElectric-List Digest: 33 Msgs - 07/06/05 |
I have an IC-A22 that works just fine with a large plug headset adapter and a
non-Icom PTT switch used as you suggest.
Joel Haynes
Bozeman, MT
RV-7a canopy
bakerocb(at)cox.net wrote:
>
>7/6/2005
>
>Hello Experts, I have an ICOM IC-A4 hand held radio that I carry in my
>airplane as a communications back up. I also have the ICOM OPC-752 Headset
>Adapter cable accessory, but I do not have the separate ICOM 3.5 mm diameter
>PTT switch accessory for keying the transmitter while using the radio with
>that adapter and a headset. The manual says that the transmitter keying
>button on the side of the radio will not work when the headset adapter is
>plugged in.
>
>According to a diagram in the ICOM IC-A4 manual the ICOM PTT switch simply
>connects the tip of the microphone plug to the shank of the microphone plug
>in order to key the IC-A4 transmitter.
>
>My question is: Can I instead use my standard push-to-talk switch, with the
>larger diameter sized microphone receptacle and plug such as David Clark and
>Telex sell, in line with the microphone plug from the headset to the OPC-752
>Adapter to key the IC-A4 transmitter?
>
>ICOM refuses to answer this question for me by saying they won't comment on
>any one else's equipment. Thanks.
>
>OC
>
>PS: I suppose that there is no substitute for an actual trial test, but I
>haven't been able to get two people and another radio together to run such a
>test.
>
________________________________________________________________________________
| From: | BobsV35B(at)AOL.COM |
| Subject: | Battery Isolation. |
Would Anyone On The AeroElectric-List care to comment on this dissertation?
Happy Skies,
Old Bob
"Fred,
The make-before-break switch and two-switch approaches would work, but a
third possibility, which intrigues me the most, is to use no switches at all.
I
suspect that the backup/redundancy capability you are looking for could be
accomplished automatically by the appropriate use of isolation diodes.
Consider this approach:
- Alternator output is connected to main bus and battery #1 as usual.
- Main bus also charges battery #2 through an isolation diode which
prevents battery #2 from discharging onto main bus.
- Battery #2 and main bus both feed power to an essential power bus
through isolation diodes, so that the essential power bus is powered by
whichever of those two have the higher voltage.
Under normal circumstances, the essential power bus is powered from the main
bus (alternator and Battery #1). If the main bus voltage drops below the
voltage of Battery #2, then the essential power bus is powered by Battery #2.
Hook essential items (#1 gps/nav/com, audio panel, transponder, electric
gyros, cockpit lighting, etc.) to essential power bus. Hook everything else
(especially anything with a motor or heating element) to main bus.
Look ma, no switches!
Whatcha think?
Best...Mike
P.S. I'd probably use 100-amp silicon rectifiers for the isolation
diodes. They should be heat-sinked, since they could dissipate up to 70
watts of heat at their maximum 100-amp current capacity.
At 03:17 AM 7/8/2005, Fred Scott, Jr wrote:
How can two batteries be selected so as to switch from BATT1 to BATT2
without losing voltage (for a few milliseconds) to the load as the selection occurs?
>
Some of our Beech aircraft (P-Barons, 58TC, etc.) have Alternate
Battery busses..these come alive only with MASTER OFF and AVIONICS OFF.
Turning power OFF, even for an instant, and then back ON will re-boot most
electronic devices.
>
If you are switching to an alternate buss, that=B9s the wrong time to be
rebooting anything.
>
To explain. Let=B9s say we add a second ship=B9s battery, for backup. One of my
thoughts would be to have a [ Batt1<--> Batt2 ] selector that can ONLY be
physically released to detents as BATT1 or BATT2, yet must slide through and
maintain an electrical BOTH ON (internally, not as a detent, and only as the
selection occurs) as the Battery source is selected from 1 to 2 or vice versa.
When the new position is achieved, the switch would then disconnect
>from the previous source.
>
Is this nuts? Anyone in the electrical world know how to do this? Are such=20
selectors available? ..... or:.. How to insert a non-interrupt delay of some
sort? My KLN-94 has that internally. One assumes: for the purpose of
avoiding re-boots.
>--
>Fred W. Scott, Jr. _fscott(at)bundoranfarm.com_
(http://b3.mail.yahoo.com/ym/beechowners.com/Compose?
Tofscott(at)bundoranfarm.com&YY2888&orderdown&sortdate&pos0)
>BUNDORAN FARM please visit us at... _http://www.bundoranfarm.com_
(http://www.bundoranfarm.com/)
>1801 Bundoran Drive
>North Garden, VA 22959
>
>Office 434-295-4188 ; fax 977-2552
>Home 434-293-9221 ; fax 963-4888
Michael D. Busch, A&P/IA
SAVVY AVIATOR, INC.
URL: _http://www.savvyaviator.com/_ (http://www.savvyaviator.com/)
Email: _mike.busch(at)savvyaviator.com_
(http://b3.mail.yahoo.com/ym/beechowners.com/Compose?Tomike.busch@savvyaviator.com&YY2888&orderdown&sortdate&pos0)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Battery Isolation. |
Not sure I deduce the rational but the core seems to be
avoid having any glitches cause the pilot to do
anything . . . but I wonder if the writer would be fond
of moving map displays, engine analyzers and any number
of goodies on the panel that require much more NON-PILOTING
thought and attention than it takes to observe a low voltage
warning light and flip a few switches.
Interesting thing about this thinking is that the writer
may be putting a lot of effort into mitigating workload
for an event that may NEVER happen while plenty of
other electro-whizzies guaranteed to be distractions
are also a part of his "complete" design.
If it's not a 'sin' to expect a pilot to operate
engine, flight and nav-aid controls as a normal course
of aviating from A -> B then it seems that the effort
to eliminate one or two switches that may never have to
be operated under duress is not a good return on investment
of design time.
Without seeing schematics of what's being proposed, I
cannot comment on the how well the system being described
meets the writer's design goals. The more interesting
question might be to deduce exactly what the design goals
are.
Bob . . .
>
>Would Anyone On The AeroElectric-List care to comment on this dissertation?
>
>Happy Skies,
>
>Old Bob
>
>"Fred,
>
>The make-before-break switch and two-switch approaches would work, but a
>third possibility, which intrigues me the most, is to use no switches at
>all. I
>suspect that the backup/redundancy capability you are looking for could be
>accomplished automatically by the appropriate use of isolation diodes.
>Consider this approach:
>
>- Alternator output is connected to main bus and battery #1 as usual.
>
>- Main bus also charges battery #2 through an isolation diode which
>prevents battery #2 from discharging onto main bus.
>
>- Battery #2 and main bus both feed power to an essential power bus
>through isolation diodes, so that the essential power bus is powered by
>whichever of those two have the higher voltage.
>
>Under normal circumstances, the essential power bus is powered from the main
>bus (alternator and Battery #1). If the main bus voltage drops below the
>voltage of Battery #2, then the essential power bus is powered by Battery #2.
>
>Hook essential items (#1 gps/nav/com, audio panel, transponder, electric
>gyros, cockpit lighting, etc.) to essential power bus. Hook everything else
>(especially anything with a motor or heating element) to main bus.
>
>Look ma, no switches!
>
>Whatcha think?
>
>Best...Mike
>
>P.S. I'd probably use 100-amp silicon rectifiers for the isolation
>diodes. They should be heat-sinked, since they could dissipate up to 70
>watts of heat at their maximum 100-amp current capacity.
>
>At 03:17 AM 7/8/2005, Fred Scott, Jr wrote:
>How can two batteries be selected so as to switch from BATT1 to BATT2
>without losing voltage (for a few milliseconds) to the load as the
>selection occurs?
> >
>Some of our Beech aircraft (P-Barons, 58TC, etc.) have Alternate
>Battery busses..these come alive only with MASTER OFF and AVIONICS OFF.
>Turning power OFF, even for an instant, and then back ON will re-boot most
>electronic devices.
> >
>If you are switching to an alternate buss, that=B9s the wrong time to be
>rebooting anything.
> >
>To explain. Let=B9s say we add a second ship=B9s battery, for backup. One
>of my
>thoughts would be to have a [ Batt1<--> Batt2 ] selector that can ONLY be
>physically released to detents as BATT1 or BATT2, yet must slide through and
>maintain an electrical BOTH ON (internally, not as a detent, and only as the
>selection occurs) as the Battery source is selected from 1 to 2 or vice
>versa.
>When the new position is achieved, the switch would then disconnect
> >from the previous source.
> >
>Is this nuts? Anyone in the electrical world know how to do this? Are such
>selectors available? ..... or:.. How to insert a non-interrupt delay of some
>sort? My KLN-94 has that internally. One assumes: for the purpose of
>avoiding re-boots.
________________________________________________________________________________
| From: | Doug Gray <dgra1233(at)bigpond.net.au> |
| Subject: | Re: alternator testing |
Bob,
Re: http://www.aeroelectric.com/articles/Alternators/Alternator_Test.pdf
The paper suggests (to me anyway) that the alternator field plus regulator current
load alone
exceeds 2 Amps. I am a little surprised that this is so high and I had not factored
it in to my
load analysis.
Is this a typical load, and if so for what sized alternator?
How does this current vary with alternator load?
Is the rating of an Alternator inclusive of this load? That is, does an alternater
rating of say 30
Amps mean the Alternator 'system' can suppply 30Amps or only 28Amps if we assume
the regulator and
field are drawing 2 Amps.
Doug Gray
________________________________________________________________________________
| From: | "Mike & Lee Anne Wiebe" <mwiebe(at)sympatico.ca> |
| Subject: | Re: Help - low voltage - update |
Thx Jim - that makes some sense. I think it's time to pull the
alternator and check the diode bridge.
You raise another interesting idea. What do you think of this scenario?
I recently changed the battery to a smaller one (had the Odessey 680
ready to go for the new aircraft, so when it came time for a
"Knuckoll's change-out" I replaced the large B&C with the Odessey). The
alternator is the larger B&C, so alternator load shouldn't be the
problem (presuming the diodes are OK). Do you think a change to a
smaller battery might have changed the ability of the system to "sink"
the pulsing load of the strobes, and make voltage vary more?
I guess it's also possible that its done this since new, and I've just
never noticed. Though somehow I think I would have before now.
Mike
________________________________________________________________________________
| From: | "Mark & Lisa" <marknlisa(at)hometel.com> |
| Subject: | 24V Starter & 12V System |
Bob (&/or other expert),
In your last msg on this subject you told us how you'd added a "Starter
Fault" circuit (a set of resistors and LEDs) to your drawing as a means of
ensuring all contactors are correctly configured prior to engaging the
starter.
http://www.aeroelectric.com/PPS/Engine/Starter/24V_Starter_14V_System.pdf
Since you show several resistors installed in the circuit, I wondered if
LEDs designed to run from 12V (they already have resistors installed) like
these would work?
http://rocky.digikey.com/WebLib/Chicago%20Miniature/Web%20Data/5110F%20Serie
s.pdf
If not, would you please provide specs on the proper LEDs?
Would you please provide a little more depth on your "Starter Fault"
circuit? I was able to follow the schematic for the rest of the system, but
you lost me on this circuit. I can see how power gets back to the LEDs if
K2, K3, K4 or K5 are stuck, but I don't understand what happens in the
"Starter Fault" circuit itself. It seems that power can go either direction
thru there, but that's as far as I get.
BTW, you labeled both 150ohm 1w resistors connected to post 1 of S1 as "R1".
________________________________________________________________________________
| From: | "F. ILMAIN" <f_ilmain(at)hotmail.com> |
| Subject: | IC A23 external antenna adapter |
Anyone knows what cable is need to connect an Icom A23 handheld (BNC) to an
external Antenna (BK external antenna adapter plug)
Thanks
________________________________________________________________________________
| From: | "Jim Stone" <jsto1(at)tampabay.rr.com> |
| Subject: | Re: Help - low voltage - update |
My opinion would be that the smaller Odessey could contribute the
problem, but the alternator is more likely. Older batteries are known
to have increased internal resistance which limit their capacity to
provide current. If yours is new, that shouldn't be a problem.
The battery "sources" at least a hundred amps of current during an
engine start. The strobe power supply has several capacitors that are
re-charging and thus represent a low resistance needing an in-rush of
current. If the current isn't available the voltage drops. The current
can come from the alternator or the battery. Battery and alternator
internal resistance limits the surge current capability.
Jim Stone
Jabiru J450
Clearwater FL.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Mike
& Lee Anne Wiebe
Subject: AeroElectric-List: Re: Help - low voltage - update
-->
Thx Jim - that makes some sense. I think it's time to pull the
alternator and check the diode bridge.
You raise another interesting idea. What do you think of this scenario?
I recently changed the battery to a smaller one (had the Odessey 680
ready to go for the new aircraft, so when it came time for a
"Knuckoll's change-out" I replaced the large B&C with the Odessey). The
alternator is the larger B&C, so alternator load shouldn't be the
problem (presuming the diodes are OK). Do you think a change to a
smaller battery might have changed the ability of the system to "sink"
the pulsing load of the strobes, and make voltage vary more?
I guess it's also possible that its done this since new, and I've just
never noticed. Though somehow I think I would have before now.
Mike
________________________________________________________________________________
| From: | rv-9a-online <rv-9a-online(at)telus.net> |
| Subject: | Re: Warning lights fro day VFR |
I have four lamps:
Stall warning (red)
Engine warning (yellow) (driven from the alarm output of the Rocky
Mountain engine monitor and or-tied with an oil pressure switch)
Flap operation (blue). Indicates when the flap motor is running (using
an ON-OFF-(ON) flap switch)).
Fuel pump operation (green).
I use the B&C lamps and the Vx Aviation lamp controller.
http://www.bandc.biz/parts.html
http://www3.telus.net/aviation/vx
A note on the flap operation and boost pump lights:
Rather than using a flap position switch which requires position sensors
and relays, (money, install time, another point of failure), I use a B&C
S700-2-5 switch. To position the flaps, I look out the window. To
extend the flaps, this switch must be held down. To retract the flaps,
the switch is flipped up and left up. In a go-around or touch&go, this
frees up your hand for other important tasks.
The lamp is there to 'remind you' that you may have left the flap switch
up and should neutralize it to save wear and tear on the flap motor.
Since this lamp is in parallel with the flap motor (or controlled with
the Vx Aviation device), a failure in the lamp circuit will not likely
affect flap operation.
Similarly, the boost pump light is there to 'remind you' that the pump
is on.
I like the idea that the pilot is in control, not some fancy electronics
stuck in the middle that positions the flaps or turns the boost pump off
automatically.
Thanks,
Vern Little
RV-9A
>
>Could some of you guys recommend warning lights to put on the panel? My
>objective is to have bright lights therefore visible in direct sunlight.
>LEDs could probably do it better than incandescent bulbs. Since I shall not
>be doing night VFR or IFR as most of Europe does not allow it with
>experimentals (unless the engine and avionics are certified and maintained
>as a certified), I would not need a dimmer circuit.
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: B: Avoiding power interrupts |
>Good morning Mr. Nuckolls
>Thank you for a very helpful note
>
>GIVEN THAT: We are wiring our aircraft in a way that will allow both
>batteries to be in parallel simply by turning them both on. We will also
>have the option to take either off line in case of failure ....they
>sometimes fail by shorting internally resulting in a load to the system
Define "sometimes" . . .
Shorted cells in a flooded battery were fairly common in the
1950s . . . flooded cells typical in automobiles had 'bilges'
below the stack of plates in each cell. These were collection
spaces for active material flaking off the plates of an aging
battery. This always happens well into the service life of
the battery. There are two things that make this a non-issue
today and particularly in airplanes:
(1) VRSLA batteries of today stack the plates together
very tightly in a sandwich of lead grids and fiberglas sheets.
Some designs (like Concord) ADD a porous plastic bag over the
negative plate IN addition to the fiberglas mats which hold
the electrolyte. Cells in these batteries don't short.
(2) Airplane batteries should be monitored for useful capacity
and replaced when they fall below some value as determined by
(a) your endurance mode load analysis and (b) design goals for
ultimate endurance in the battery only mode. Unless you're
willing to settle for a relatively SHORT endurance mode like
30 minutes (I hope most of my OBAM aircraft builders are
planning for duration that equals or exceeds that of fuel
aboard), then your battery(ies) will be replaced LONG before
they quit cranking the engines and long before they would
have been subject to the wear and tear that promotes shorted
cells.
>. It will also allow us to run power with the engine not running and then
>to isolate the depleted battery during start so it will not drag down the
>other one. We will be able to deplete it completely and still have enough
>juice for three starts with no charging required.
Dead batteries do not materially "drag a charged battery
down". It takes a bus voltage substantially in excess of
the battery's open circuit terminal voltage to put a charge
into the dead battery. A battery delivers energy at 12.5 volts
and DOWN. A battery needs to see 13.5 volts and HIGHER to
accept meaningful amounts of energy. If you connect a fully
charged battery to a dead battery, there will be a substantial
but very short lived current flow from the charged battery
into the dead battery. But the ENERGY transferred in this
event is a small percentage of the charged battery's total
capacity. Given that a typical engine cranking scenario
taps less than 10% of a battery's total capacity, the concerns
for loading effects of a dead battery in the system are
not supported by the physics.
It's not clear from our discussion thus far how just ONE of
TWO batteries becomes depleted. It seems that this happens
only because of inadvertent positioning of switches when
parking the airplane. If ONE battery can be run down by not
positioning all switches in accordance with the shutdown
checklist, then it seems that TWO batteries are at equal
risk.
It is my suggestion that if one plans to add a second battery
to a light twin, then it would be wise to go all the way
and craft a FULLY redundant architecture offered by
independent systems as shown in Z-14.
Sticking another battery onto the certified, stock single
engine electrical system with two alternators does not
take advantage of all the features a twin engine system
could have. Even our big biz jets drive a single battery
with two generators . . . the word "twin" has been mistaken
to imply "redundancy". I'll suggest that current certified
designs fall far short of what COULD be achieved by the
simple implementation of a Z-14 style architecture.
In the mean time, your concerns about battery depletion,
and battery shorts are not well supported by facts in
evidence or by the state of current technologies. In the
case of P-barons (or similar light twins) inadvertent
switch positioning is easily offset by judicious use
of checklists propped up with ACTIVE notification of low
voltage (flashing light on panel that says battery is ON
but alternators are OFF). Once you've taken care of the
battery depletion problem, then service life of the battery
is a simple matter of a well considered preventative
maintenance program that will pull a flooded battery from service
long before it will suffer intra-cell shorts. Better yet
put a VSLA battery in and the shorted cells issue goes
away completely.
>Maybe there will be no need to switch the ESSENTIALS BUSS to the second
>battery at all.
>
>(would you be kind enough to show me how can I find a Figure Z-30 or Z-12?)
Sure, you can find the z-figures along with a host useful materials
at:
http://aeroelectric.com/articles.html
The Z-figures are contained in the assortment of power distribution
diagrams published as an update to the AeroElectric Connection.
Folks who have revision 10 books can get the latest updates which
includes Appendix Z at:
http://aeroelectric.com/articles/Rev11/AppZ_R11C.pdf
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: 24V Starter & 12V System |
>
>Bob (&/or other expert),
>
>In your last msg on this subject you told us how you'd added a "Starter
>Fault" circuit (a set of resistors and LEDs) to your drawing as a means of
>ensuring all contactors are correctly configured prior to engaging the
>starter.
>
>http://www.aeroelectric.com/PPS/Engine/Starter/24V_Starter_14V_System.pdf
>
>
>Since you show several resistors installed in the circuit, I wondered if
>LEDs designed to run from 12V (they already have resistors installed) like
>these would work?
Not without some re-design . . . and even then the performance
degrdes.
>http://rocky.digikey.com/WebLib/Chicago%20Miniature/Web%20Data/5110F%20Serie
>s.pdf
>
>If not, would you please provide specs on the proper LEDs?
ANY red led NOT fitted with a resistor. The circuit's operating
parameters are predicated on the 1.7v average operating voltage
of the "barefoot" LED.
>Would you please provide a little more depth on your "Starter Fault"
>circuit? I was able to follow the schematic for the rest of the system, but
>you lost me on this circuit. I can see how power gets back to the LEDs if
>K2, K3, K4 or K5 are stuck, but I don't understand what happens in the
>"Starter Fault" circuit itself. It seems that power can go either direction
>thru there, but that's as far as I get.
When you place the switch in the START position and before you
push the button, you want to know that ALL relays are OPEN. We
do this by placing a 1/2 of battery bias voltage on a junction
common to all four relays. The 1/2 battery voltage bias comes
from the divider R1/R2. If no relays are closed, then putting a
voltmeter on any part of the monitored circuitry would show
about 6v. If any one of the relays is closed, current through
the relay will either pull the 6V bias toward ground or toward
battery voltage. This causes a 'fault detection' current to flow
into or out of the voltage divider which causes one of the LEDs
to illuminate.
If there are no relays closed, the LEDs are dark and you know
that it's okay to press the button. An LED will light while
you're cranking but should go out when your finished showing
that the system is ready to switch to the parallel battery
NORMAL mode.
>BTW, you labeled both 150ohm 1w resistors connected to post 1 of S1 as "R1".
Rev E has been uploaded to:
http://www.aeroelectric.com/PPS/Engine/Starter/24V_Starter_14V_System.pdf
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: alternator testing |
>
>Bob,
>
>Re: http://www.aeroelectric.com/articles/Alternators/Alternator_Test.pdf
>
>The paper suggests (to me anyway) that the alternator field plus regulator
>current load alone
>exceeds 2 Amps. I am a little surprised that this is so high and I had
>not factored it in to my
>load analysis.
You don't need to. An alternator is rated for USEFUL output which
already accounts for energy used to excite its own field.
>Is this a typical load, and if so for what sized alternator?
>
>How does this current vary with alternator load?
>
>Is the rating of an Alternator inclusive of this load? That is, does an
>alternater rating of say 30
>Amps mean the Alternator 'system' can suppply 30Amps or only 28Amps if we
>assume the regulator and
>field are drawing 2 Amps.
Check out chapter 3 and then see if you have any
questions.
Bob . . .
________________________________________________________________________________
| From: | Charlie Brame <chasb(at)satx.rr.com> |
| Subject: | IC A23 external antenna adapter |
I used a length of RG-58 cable from Radio Shack and installed female BNC
connectors on both ends. The RG-58 is more flexible than RG-400 and
rolls up easily for storage. It connects my A23 to a panel mounted male
bulkhead BNC which is permanently connected to an external antenna using
RG-400 cable. Works great.
Charlie Brame
RV-6A N11CB
San Antonio
> From: "F. ILMAIN"
> Subject: AeroElectric-List: IC A23 external antenna adapter
>
>
> Anyone knows what cable is need to connect an Icom A23 handheld (BNC) to an
> external Antenna (BK external antenna adapter plug)
> Thanks
>
>
________________________________________________________________________________
| From: | Jim and Lucy <jpollard(at)ciaccess.com> |
| Subject: | Re: 24V Starter & 12V System |
I have a European built combine harvester that has a
12-volt electrical system with a 24 volt starter.
The contactor setup on it
uses one big contactor assembly where all the insides
are locked together so it all has to switch when engaged.
No real chance of part of it not switching unless
the inside brakes somehow. There are fuseable link strips
across terminals under the wire access cover in case
somthing somewhere gets shorted.
It is made by bosche.
Yikes I just looked up the price and it is 500 dollars.
Ill hope it lasts a verylong time.
This probably wont help but there may be other switches
in big truck stores like this you could look at. Bobs
diagram looks much easier to fix out in the field.
Jim Pollard
Merlin Ont.
________________________________________________________________________________
| From: | "Bill Schlatterer" <billschlatterer(at)sbcglobal.net> |
| Subject: | Z13 with B&C Alt/Reg combination ? |
Bob, am I missing something? I was looking for the Z13 diagram with the B&C
alt/reg combination and can't seem to find it. Would be great to see with
P-mag but assume you can just add in the R11C Z13 w/P-Mags.
Bill S
RV7a Arkansas
>
>(would you be kind enough to show me how can I find a Figure Z-30 or Z-12?)
Sure, you can find the z-figures along with a host useful materials
at:
http://aeroelectric.com/articles.html
The Z-figures are contained in the assortment of power distribution
diagrams published as an update to the AeroElectric Connection.
Folks who have revision 10 books can get the latest updates which
includes Appendix Z at:
http://aeroelectric.com/articles/Rev11/AppZ_R11C.pdf
Bob . . .
________________________________________________________________________________
| From: | "Lui Esc" <f1rocketbuilder(at)hotmail.com> |
Does anyone knows if there is any document that covers Diodes by themselves?
I have a few gray areas understanding which diode to use, identify, rating,
etc.
There are several diodes shown on the Aeroelectric diagrams but I can't see
part numbers to reference. Ex. a diode between the essential bus and the
primary bus, also, diode on the starter seleniod.
I need to use some diodes in other areas but, I am still learning and want
to be sure I use/order the correct stuff.
I sent an email to Bob via his web site, but I did not hear back from him.
I just learned about this forum, so I subscribed to the Digest.
Thanks,
LE
Comments/Questions: Building a F-1 Rocket. Love your publications, learned
a lot thanks to you. But continue trying to learn and understand the
electric side as much as I can since I am doing the wiring by myself. Do
you have a document that covers Diodes by themselves? I have a gray area
trying to identify part number or diode required on certain areas mentioned
in your publications. Ex. a diode between the essential bus and the primary
bus and others. Thanks. Luis
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Re: Split Pin Connectors? |
Aeroelectric-list message previously posted by Bob Nuckolls
<<....skip....What's the brand and model number of the autopilot?
One can often deduce the connector technology by knowing
who made the system. Manufacturers often have a stable
of connectors-of-choice. Getting a peek at the installation/
maintenance manual for the autopilot may help. Was the
autopilot installed as a Beechcraft option? If so, I
may have access to data in the company archives that
would help. Bob . . .>>
7/1/2005
Hello Bob Nuckolls, I am the owner of the Beechcraft Sierra with autopilot
problems that OC Baker referred to . In answer to your response I can
provide the following additional data, and any help/suggestions you provide
would be greatly appreciated.
The POH for the Beechcraft Sierra C24R depicts an autopilot in the
instrument panes for all a/c after serial no. MC 571. My a/c, serial no. is
MC 778 mfg'd in 1982. However, the POH does not provide any information on
the autopilot itself. Neither the logs nor the weight and balance sheets
mention an autopilot add-on. I therefore am led to believe that it was a
factory install at time of delivery. The autopilot itself is a Century IIB
mfg'd by Flight Systems, Inc. PO Box 610, Mineral Wells, TX 76067. As to
"split pin connectors", another Sierra owner offers that the techie was
referring to the "Little Blue Plugs used by Century for many of their
autopilot connections. They have stamped receptor pins rather than solid
ones."
Does any of this additional info help shed some light on the problem? Thanks
for you help. George Philipps
________________________________________________________________________________
| From: | chad-c_sip(at)stanfordalumni.org |
Z-USANET-MsgId: XID223JgkoNs0424X37
A good ol' Google Search on "diode tutorial" brought up this link:
http://www.americanmicrosemi.com/tutorials/diode.htm
It seemed like a good introduction. At least from that you know the
terminology used when describing a diode. And now you can compare the
performance of different beasties. The only other thing I'd add is that "full
wave rectifiers" are really just 4 diodes laid out nose-to-tail in a diamond
pattern. We tend to talk about rectifiers as power diodes are they already
come in larger power packages ready to be attached to a heat sink. And there's
no reason you can't simply use only one of the 4 diodes in the package.
Good luck.
Chad
Chad Sipperley
Lancair IV-P turbine (under construction)
Phoenix, AZ
------ Original Message ------
From: "Lui Esc" <f1rocketbuilder(at)hotmail.com>
Subject: AeroElectric-List: Diodes 101
>
> Does anyone knows if there is any document that covers Diodes by
themselves?
> I have a few gray areas understanding which diode to use, identify, rating,
> etc.
>
> There are several diodes shown on the Aeroelectric diagrams but I can't see
> part numbers to reference. Ex. a diode between the essential bus and the
> primary bus, also, diode on the starter seleniod.
>
> I need to use some diodes in other areas but, I am still learning and want
> to be sure I use/order the correct stuff.
>
> I sent an email to Bob via his web site, but I did not hear back from him.
> I just learned about this forum, so I subscribed to the Digest.
>
> Thanks,
> LE
>
>
> Comments/Questions: Building a F-1 Rocket. Love your publications, learned
> a lot thanks to you. But continue trying to learn and understand the
> electric side as much as I can since I am doing the wiring by myself. Do
> you have a document that covers Diodes by themselves? I have a gray area
> trying to identify part number or diode required on certain areas mentioned
> in your publications. Ex. a diode between the essential bus and the primary
> bus and others. Thanks. Luis
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
>
>
>Does anyone knows if there is any document that covers Diodes by themselves?
>I have a few gray areas understanding which diode to use, identify, rating,
>etc.
>
>There are several diodes shown on the Aeroelectric diagrams but I can't see
>part numbers to reference. Ex. a diode between the essential bus and the
>primary bus, also, diode on the starter seleniod.
>
>I need to use some diodes in other areas but, I am still learning and want
>to be sure I use/order the correct stuff.
>
>I sent an email to Bob via his web site, but I did not hear back from him.
>I just learned about this forum, so I subscribed to the Digest.
ANY rectifier diode that LOOKs like this will do:
http://www.aeroelectric.com/Pictures/s401-25.jpg
Here's an excerpt from the Radio Shack catalog:
http://www.aeroelectric.com/Pictures/RS_Diodes.jpg
Note that it offers an 276-1185 full wave bridge rectifier
which is suited for use as the e-bus normal feed diode illustrated
above
It also offers the 1N540X series diodes which
are my favorites for use on contactors. These are
mechanically more robust and easy to work with.
See:
http://www.aeroelectric.com/Pictures/s701-1l.jpg
http://www.aeroelectric.com/Pictures/s701-2.jpg
If the 5400 series are too heavy mechanically
for your application, consider the 1N400x series
on the same page.
A typical useage for the 4000 series is shown
here:
http://www.aeroelectric.com/Pictures/s704inst.jpg
Ratings for diodes used as spike catchers is
not critical. Only the e-bus normal feed diode
needs to have some electrical heftiness and
the 276-1185 or any of its siblings will be fine.
If it comes in this package, then it's big enough.
See note 12 of
http://aeroelectric.com/articles/Rev11/AppZ_R11C.pdf
and
http://aeroelectric.com/articles/spikecatcher.pdf
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Z13 with B&C Alt/Reg combination ? |
>
>
>
>Bob, am I missing something? I was looking for the Z13 diagram with the B&C
>alt/reg combination and can't seem to find it. Would be great to see with
>P-mag but assume you can just add in the R11C Z13 w/P-Mags.
>
>Bill S
>RV7a Arkansas
The z-figures are crafted to illustrate architectures, not to make
specific recommendations for use of parts. I COULD craft a dozen
z-13's, each depicting a different regulator, alternator, etc.
Usage of the LR-3 series devices is illustrated in several
other z-figures . . . if that's your regulator of choice for
Z-13, then you'll need to draw out your own power distribution
diagram modified to include your features of choice.
EVERYONE should do their own power distribution diagrams to
exactly match their project. The Z-figures are only a guide to
get you started.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Help - low voltage - update |
Before you pull anything off the airplane, let's do a good job of
diagnosis to KNOW which part needs attention. I've got a piece nearly
finished on alternator system troubleshooting that I'll publish on
the website in next day or so along with links from this list.
Bob . . .
>
>
>Thx Jim - that makes some sense. I think it's time to pull the
>alternator and check the diode bridge.
>
>You raise another interesting idea. What do you think of this scenario?
>I recently changed the battery to a smaller one (had the Odessey 680
>ready to go for the new aircraft, so when it came time for a
>"Knuckoll's change-out" I replaced the large B&C with the Odessey). The
>alternator is the larger B&C, so alternator load shouldn't be the
>problem (presuming the diodes are OK). Do you think a change to a
>smaller battery might have changed the ability of the system to "sink"
>the pulsing load of the strobes, and make voltage vary more?
>
>I guess it's also possible that its done this since new, and I've just
>never noticed. Though somehow I think I would have before now.
>
>Mike
>
>
>--
>
>
>-- incoming mail is certified Virus Free.
Bob . . .
--------------------------------------------------------
< Throughout history, poverty is the normal condition >
< of man. Advances which permit this norm to be >
< exceeded -- here and there, now and then -- are the >
< work of an extremely small minority, frequently >
< despised, often condemned, and almost always opposed >
< by all right-thinking people. Whenever this tiny >
< minority is kept from creating, or (as sometimes >
< happens) is driven out of a society, the people >
< then slip back into abject poverty. >
< >
< This is known as "bad luck". >
< -Lazarus Long- >
<------------------------------------------------------>
http://www.aeroelectric.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Help - low voltage - update (P.S.) |
PS have you conducted the tests described in:
http://www.aeroelectric.com/articles/Alternators/Alternator_Test.pdf
This is the best way to isolate the problem with respect to
regulation or alternator issues . . .
B-
Before you pull anything off the airplane, let's do a good job of
diagnosis to KNOW which part needs attention. I've got a piece nearly
finished on alternator system troubleshooting that I'll publish on
the website in next day or so along with links from this list.
Bob . . .
________________________________________________________________________________
| From: | Jon Goguen <jon.goguen(at)umassmed.edu> |
| Subject: | Overvoltage and PM alternators |
Hi All,
My first post to the list. I'm co-builder of the Kitfox described in
the signature along with my uncle Nelson Goguen. Most of what remains
to get the ship finished is electrical so here I am. I've read Bob's
Aeroeletric Connection and found it very informative, and very much
like his design philosophy and the principle that we should build
better than certified. I've had a lifelong interest in electronics
and instrumentation, and hope I might be able to make some useful
contributions to the community. Thanks in advance for all your relies.
Now down to business. I'm wondering about the importance of
overvoltage protection on PM alternators. Without a field coil,
extreme voltage runaway shouldn't be possible with these machines.
They do produce 30 volts or so, which could certainly be damaging if it
passed through the regulator, but I believe the regulators use a phase
control shunt-based design. If so, the shunting SCRs would virtually
always fail in the conducting mode, which would give low rather than
high voltage output. Does anyone know of a documented case of
overvoltage problems with a properly installed PM alternator?
Given the simplicity and reliability of PM alternators, it would seem
that the regulator is by far the weakest link in the charging system.
This would argue for a dual regulator design. I don't know enough
about the regulator innards to know if paralleling two of them would
result in undesirable interactions, but I suspect that it might. This
could be avoided by simply providing means to switch between the two
regulators.
So:
Does OV protection really make sense for a PM alternator system?
Would a dual-regulator design provide a worthwhile enhancement in
reliability?
Thanks!
Jon
Jon Goguen
jon.goguen(at)umassmed.edu
Central Massachusetts
Kitfox Series V Rotax 912S / N456JG (reserved)
Complete except for electrics and avionics
________________________________________________________________________________
| From: | "Rick Fogerson" <rickf(at)cableone.net> |
| Subject: | Fw: Diagnostic voltages for Alternator |
Hi Bob,
If you answered this already I must have missed it. Would appreciate some numbers
as I don't have a clue what a high field voltage would be, etc.
Rick
----- Original Message -----
From: Rick Fogerson
Subject: Diagnostic voltages for Alternator
Hi Bob,
I put a jack in my airplane a la Page Z-6 for alternator diagnostics. I have B&C's
alternator and voltage regulator. Could I get some numbers/ranges to the
voltages for the descriptive words in the following paragraphs:
Paragraph (a) alt output is zero when the bus voltage is ______?
Paragraph (e) If the field voltage is high_____? and does not drop significantly_____?
when engine rpm increases but bus voltage seems normal under light load
and sags under heavy loads....
What would be the voltage regulators normal set point____?
Thanks Bob and have a great 4th of July,
Rick Fogerson
RV3 done, making POH
Boise, ID
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator output |
>
> I'd like to ask a simple follow-up question here, Bob.
> In a scenario of Z13/8 with only the one main battery existing in the
>system, if (for example) a lug breaks on the battery and it's taken out of
>the system, will the main alternator continue to power the system? Or
>without the battery in the system, would there be a voltage runaway and the
>main alternator would have to be taken offline? ... (If that were the case,
>then the SD8 would have no chance of coming alive by itself).
> If the main alternator WOULD continue to power the system within the
>proper voltage range (due to it's regulator controlling the voltage?), and
>the SD8 is then switched on, would the SD8 come alive using the voltage from
>the main alternator as the exciter? And then would the SD8 continue to power
>the system on it's own without a battery in the system?
> What I'm trying to get straight in my head is the various failure
>scenarios possible and how the "surviving" components are expected to react.
A worthwhile endeavor. Most alternators will continue to produce
power with a disconnected battery as long as they don't get "stalled".
A wound field alternator needs a sample of it's own output to produce
power . . . load it severely (in excess of it's ratings) just for
a few milliseconds and it may quit and stay dead.
Battery terminal breakage (or battery contactor failure) is
relatively rare. I've never encountered one personally or known
one who has. I've replaced dozens of contactors that failed in
pre-flight but never one that failed in flight.
Is the risk zero? No, just small. If this worries you, then
perhaps a dual battery installation is in order either in the
form of Z-30 implementation or perhaps Z-14. Keep in mind that
hundreds of thousands of spam cans have flown for nearly
a century with electrical systems being WAAAAYYYY down on the
list of contributing events for the entire constellation of
accident scenarios.
When I walk up to a rental airplane and make ready to launch,
I don't care if ANYTHING on the panel is getting power. I have
tools in my flight back and the mindset that I intend to arrive
at the airport of original destination with the airplane in
a "J-3 Mode" of operation if necessary.
I'll suggest it's much easier to prepare yourself for the
worst kinds of electrical failure than it is to design a system that
will NEVER fail. The worst case is that your "bullet proof"
system will fail you anyhow and you'll find yourself ill-prepared
to cope with it.
What kind of airplane are you building? How is it electrically
dependent? How do you plan to use the airplane? How much are
YOU electrically dependent? The road to comfortable flight
is lined with answers to these questions even if some answers
do not offer 99.999999 or even 90.0 percent reliability.
Bob . . .
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Internal regulation |
On 12 Jul 2005, at 10:06, Dave Harmon wrote:
>
>
> Can we go over again why it's not rec. to use internal regulation on
> alternators.
> Dave
Dave,
The first big question is whether you want to have over voltage
protection or not. Some folks who have never heard of any over
voltage cases on cars, figure that an automotive alternator with
internal regulation is reliable enough that they don't worry about an
over voltage. But, there was a message on this list a while back
from a guy who had an automotive alternator on his aircraft that
would go into an over voltage condition as soon as he selected it
on. So, over voltages do happen.
If your avionics are cheap, or you have enough money that you are
prepared to risk them, you could go without over voltage protection.
If you want over voltage protection, and you use an externally
regulated alternator, the over voltage protection device can simply
cut the power between the voltage regulator and the alternator
field. This line only has small current in it, so there is no
problem to chop the power if an over voltage ever occurs.
But, if you have an internally regulated alternator, the wire from
the voltage regulator to the field is buried inside the alternator -
you can't get at it. So, the only way to deal with an over voltage
is to have a contactor in the alternator output that is opened
automatically if the alternator runs away. This contactor will have
to open when the alternator is supplying as much current as it can
possibly do, and there is some question about whether the contactor
will actually reliably cut the alternator output, or whether it might
arc internally and weld closed.
There have also been a few unexplained problems with internally
regulated alternators sold by Van's aircraft if they are installed
with the over voltage protection sold by B&C Specialties. There have
been several events where something happened that fried the internal
regulator, but no one has been able to figure out the cause, so we
have no fix yet.
If you use an externally regulated alternator, you can use the over
voltage protection sold by B&C Specialties (and designed by Bob
Nuckolls). A small number of people have a philosophical problem
with the way it shorts out the field line to cause the field CB to
pop open, but no one has been able to demonstrate a real problem with
the design. It is simple, and it works.
So, my advice: if you want over voltage protection, go with an
externally regulated alternator. If you judge the cost and hassle of
replacing avionics to be less important than the cost and hassle of
an installing an externally regulated alternator + over voltage
protection, then go with an internally regulated alternator and skip
the over voltage protection.
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| Subject: | Internal regulation |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Interesting thoughts Kevin...And a nice web site too!
Of course I've already got my internally regulated alt and my avionics
will cost a fortune..rather like yours in fact..:)
I went with one of those kilovolt contators driven by an OV module and
although I can't remember the numbers the break current was monstrously
huge from my recollection.
In short I have a hard time believing it will not break in a OV
event...At least I hope it will..:)
Frank
RV-7A..airframe complete, need to paint cockpit.
Dave,
The first big question is whether you want to have over voltage
protection or not. Some folks who have never heard of any over voltage
cases on cars, figure that an automotive alternator with internal
regulation is reliable enough that they don't worry about an over
voltage. But, there was a message on this list a while back from a guy
who had an automotive alternator on his aircraft that would go into an
over voltage condition as soon as he selected it on. So, over voltages
do happen.
If your avionics are cheap, or you have enough money that you are
prepared to risk them, you could go without over voltage protection.
________________________________________________________________________________
| Subject: | Re: AeroElectric-List Digest: 11 Msgs - 07/11/05 |
| From: | "Glaeser, Dennis A" <dennis.glaeser(at)eds.com> |
>Subject: Re: AeroElectric-List Digest: 11 Msgs - 07/11/05
>From: Dave Harmon (vagabondpa15(at)verizon.net
>Date: Tue Jul 12 - 7:07 AM
Can we go over again why it's not rec. to use internal regulation on
alternators.
>Dave
------------------------------------------------------
Bottom line: inability control the field current (elegantly
enable/disable the Alternator output), and unknown OV protection.
With most IR's, once the field is energized, it 'latches on' and there
is no external way to turn it off - so there is no external way to
disable the alternator in case of OV except by disconnecting the B lead
(which also can cause problems - search the archives for 'load dump').
Many modern automotive IR's have built-in OV protection, and may be just
fine - but it is next to impossible to get technical info on them in
order to make an educated decision. And even if you do, it would be for
that specific (make, model) regulator, not IR's in general. Bob won't
recommend something he can't verify (a reasonable position IMHO).
Dennis Glaeser
RV7A Empennage
________________________________________________________________________________
| From: | Phil Birkelbach <phil(at)petrasoft.net> |
| Subject: | Re: Internal regulation |
Excellent reply Kevin,
I went with the internal regulated alternator with a contactor on the
'B' lead (B for Big right :-) ) and the B&C crowbar overvoltage device.
I suspect that some day in the future the regulator inside the
alternator will shed all of it's smoke at which time I'll have it
overhauled and turned into an externally regulated type and buy a
regulator. It'll be a simple change.
The questions about the voltage spike killing the alternator, center
around disconnecting the alternator 'B' lead while the alternator is
producing current. My checklists are set up so that once I turn the
alternator on it stays on until the engine isn't turning anymore. If I
get the overvoltage event and the contactor opens it up then the
assumption is that the regulator is fried anyway.
Godspeed,
Phil Birkelbach - Houston Texas
RV-7 N727WB - Finishing Up
http://www.myrv7.com
Kevin Horton wrote:
>
>On 12 Jul 2005, at 10:06, Dave Harmon wrote:
>
>
>
>>
>>
>>Can we go over again why it's not rec. to use internal regulation on
>>alternators.
>>Dave
>>
>>
>
>
>Dave,
>
>The first big question is whether you want to have over voltage
>protection or not. Some folks who have never heard of any over
>voltage cases on cars, figure that an automotive alternator with
>internal regulation is reliable enough that they don't worry about an
>over voltage. But, there was a message on this list a while back
>from a guy who had an automotive alternator on his aircraft that
>would go into an over voltage condition as soon as he selected it
>on. So, over voltages do happen.
>
>If your avionics are cheap, or you have enough money that you are
>prepared to risk them, you could go without over voltage protection.
>
>If you want over voltage protection, and you use an externally
>regulated alternator, the over voltage protection device can simply
>cut the power between the voltage regulator and the alternator
>field. This line only has small current in it, so there is no
>problem to chop the power if an over voltage ever occurs.
>
>But, if you have an internally regulated alternator, the wire from
>the voltage regulator to the field is buried inside the alternator -
>you can't get at it. So, the only way to deal with an over voltage
>is to have a contactor in the alternator output that is opened
>automatically if the alternator runs away. This contactor will have
>to open when the alternator is supplying as much current as it can
>possibly do, and there is some question about whether the contactor
>will actually reliably cut the alternator output, or whether it might
>arc internally and weld closed.
>
>There have also been a few unexplained problems with internally
>regulated alternators sold by Van's aircraft if they are installed
>with the over voltage protection sold by B&C Specialties. There have
>been several events where something happened that fried the internal
>regulator, but no one has been able to figure out the cause, so we
>have no fix yet.
>
>If you use an externally regulated alternator, you can use the over
>voltage protection sold by B&C Specialties (and designed by Bob
>Nuckolls). A small number of people have a philosophical problem
>with the way it shorts out the field line to cause the field CB to
>pop open, but no one has been able to demonstrate a real problem with
>the design. It is simple, and it works.
>
>So, my advice: if you want over voltage protection, go with an
>externally regulated alternator. If you judge the cost and hassle of
>replacing avionics to be less important than the cost and hassle of
>an installing an externally regulated alternator + over voltage
>protection, then go with an internally regulated alternator and skip
>the over voltage protection.
>
>
>Kevin Horton RV-8 (finishing kit)
>Ottawa, Canada
>http://www.kilohotel.com/rv8
>
>
>
>
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | split pin connectors |
7/12/2005
OC, please pass on to Bob Nuckolls.
A total of seven "split pin connectors" emanating from the autopilot, all
blue in color were found behind the instrument panel of the Beech Sierra,
Each one was first disconnected and then reconnected. No further trouble
shooting took place before an operational test was conducted on the Century
IIB autopilot. The test on the ground was successful, A subsequent airborne
operational test also proved the autopilot to be fully operational.
Thank you again for any time, effort and thought that went into this trouble
shooting. George Philipps
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
AeroElectric-List message previously posted by: OC Baker
> ....skip......But I don't know why they would mislead us about the non
> functioning of the IC-A4 on set transmitter button while the headset
> adapter is installed if the button and the radio works OK just like
> Charlie Brame says it does for the IC-A23.
>
> ICOM Tech Support, do you wish to comment?
>
> OC
7/12/2005
I went flying yesterday with a friend and conducted some ground tests with
my ICOM IC-A4 hand held radio. Here is what I observed:
1) With the headset adapter plugged in and a headset connected to the
adapter, the PTT button on the side of the radio activated the transmitter
and normal transmissions could be made with the microphone built into the
radio. Transmissions could be heard by the head set wearer (side tone) and a
separate receiving radio.
2) With the headset adapter plugged in and a headset connected to the
adapter with a standard large size PTT adapter cord (not 3.5mm) in line with
the microphone plug the transmitter could be activated by pushing the PTT
button on the adapter cord. Transmissions could be made with the headset
microphone and could be heard by sidetone in the headset and at a receiving
radio.
Why the IC-A4 manual states or implies that the two operations above cannot
be conducted is beyond me. Both of these modes of operation would be
considered normal and advantageous by any one considering buying or owning a
hand held radio.
ICOM Tech Support, do you wish to comment?
OC
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Fw: Diagnostic voltages for Alternator |
>
>Hi Bob,
>If you answered this already I must have missed it. Would appreciate some
>numbers as I don't have a clue what a high field voltage would be, etc.
>Rick
>----- Original Message -----
>From: Rick Fogerson
>To: aeroelectric-list(at)matronics.com
>Subject: Diagnostic voltages for Alternator
>
>
>Hi Bob,
>I put a jack in my airplane a la Page Z-6 for alternator diagnostics. I
>have B&C's alternator and voltage regulator. Could I get some
>numbers/ranges to the voltages for the descriptive words in the following
>paragraphs:
>
>Paragraph (a) alt output is zero when the bus voltage is ______?
Paragraph (a) says:
"(a) If the alternator field voltage is zero when the output is
zero, then the regulator or associated wiring has failed."
It's speaks simply to the fact that if you don't apply SOME
voltage to the alternator's field, then it's reasonable to
expect that even a GOOD alternator's output will be zero
because it has been commanded to shut down completely.
>Paragraph (e) If the field voltage is high_____? and does not drop
>significantly_____? when engine rpm increases but bus voltage seems
>normal under light load and sags under heavy loads....
Paragrahp (e) says:
(e) If field voltage is high, does not drop significantly when
engine RPM increases but bus voltage seems normal under
light load and sags under heavy loads, then the alternator
may have one or more diodes open/shorted.
This speaks to the situation where the alternator appears
to be operating normally some times . . . I.e. low voltage
light goes out under light loads but comes on under heavy
loads at engine RPMs sufficient for full alternator output,
then a strong field excitation voltage (close to or equal
to PRESENT bus voltage) combined with a manifestation
of inadequate alternator output (bus voltage less than
regulator setpoint and not under control of alternator) then
there is reason to suspect the alternator is crippled. The
only way you can have an alternator put out set-point
voltage under light loads but fail to support rated loads
is problems with a portion of the diode array or perhaps
one stator lead is open.
I related a first-hand experience with this phenomenon in section
3 under ALTERNATOR FAULT ISOLATION.
>What would be the voltage regulators normal set point____?
Where ever you put it or wherever it was set when you
received it. 13.8 is adequate for hi-temperature climates
while folks in Alaska might want to run it at 14.6. I believe
B&C ships them set for 14.2, most automotive products are
set at 14.2
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Multimeter problem |
>
>Bob, Sorry to belabor this issue, but two more questions please:
>I just want a meter that tells me the battery status. Then I can put on the
>charger as needed. I thought that the table published in the Battery tender
>flyer was good enough. It says a fully changed batt (after a 12 hr rest)
>would have 12.6-12.8v and one with 12.2-12.4v would be charged at 50-75%
>based on the chemistry of the battery. Thus that 3+% is a big deal to me
>and my meters showed a spread of more than 1% and therefore I am being
>misled about my battery condition.
> I suspect my newest ~$10 GB meter is accurate, but I would like to know.
>1) Bob can you make available the gadget to test the meter discussed in
>your link below?
Sure. Check out specs on LM4040AIZ-10.0 precision regulator
at:
http://www.national.com/ds/LM/LM4040.pdf
This is a 10.000 volt zener accurate to within 10 millivolts that
sells from Digikey and others for about $2.50 See:
http://dkc3.digikey.com/PDF/T052/0592.pdf
Assemble in small box with a push-button, two 9v batteries,
a 4.7K, 1/2w resistor like shown in:
http://www.aeroelectric.com/articles/VM_Calibrator_Schm.pdf
Hook this puppy to your voltmeter to be tested
and push the button. The voltmeter should read 10.000
volts PLUS or MINUS the total error budget for the
combination of components.
For example, we know that our calibrator is off-the-shelf
rated for 10.000 plus or minus 0.01 volts. The instrument
your checking may have a specification like "plus or minus
0.5% of reading + one count". Okay lets assume a display
that shows xx.xx volts. 0.5% of 10 volts is 50 millivolts.
If we stack all errors up for a max deviation from true,
we get 10 millivolts for the calibrator, 50 millivolts for
the instrument plus another 10 millivolts for the display
error for a total uncertainty of 60 millivolts IN EITHER
DIRECTION.
Probability is that it's less . . . with most instruments
having less than 1/2 the maximum error . . . but one
cannot DEPEND on it for all cases.
So, any reading between 10.06 and 9.94 volts says that
none of the pieces of equipment (calibrator, voltmeter
or display) are suspected of being out of stated
tolerance.
Now, you can use a calibrator to wash out some
instrument error. Suppose we got a reading of 10.04
volts. We can attribute a maximum of 0.01 volts to
calibrator error and another 0.01 volts to display
error which says are degree of uncertainty for the
reading is reduced to 0.02 volts. Therefore, the
REAL voltage reading is somewhere between 10.02 and
10.06 volts.
This resolves to an error of 0.2% of reading so
your observations of battery voltage in the 12.5
volt have a degree of uncertainty around plus or
minus 0.025 volts.
Many 5 digit displays have a tighter tolerance in
voltmeter readings but higher display errors. For
example, one of my 5 digit instruments is 0.1% plus
or minus 5 counts.
In this case the error for this instrument to read
my 10.000 calibrator would be 10.000 plus or minus
.025 volts (10 mv for calibrator, 10 mv for voltmeter,
and 5 counts for display).
You can wash out error in your calibrator by having
it checked against an instrument of still greater
accuracy. For example, if you know that the calibrator
puts out 10.008 volts (at room temperature) you can
account for this in your new error budget for
deducing the accuracy of your own instruments.
Do not assume that putting your own portable instrument
on a super accurate source can wash out more than
voltmeter error. The "counts" error in the display
is a digital quantizing error that may or may not
be fixed. In the case of my xx.xxx reading instrument,
I'll ALWAYS have a degree of uncertainty of plus or
minus 0.005 volts irrespective of other factors.
Bob . . .
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
| Subject: | Contactor Failures? |
Bob,
In yesterdays post, you said;
Battery terminal breakage (or battery contactor failure) is
relatively rare. I've never encountered one personally or known
one who has. I've replaced dozens of contactors that failed in
pre-flight but never one that failed in flight.
What kinds of failures have you seen? Failure due to heat? manufacturing
defects? external damage? internal failure?
Is it worthwhile to replace contactors periodically similar to your battery
replacement concept? If so, how often?
Stan Sutterfield
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: split pin connectors |
>
>7/12/2005
>
>OC, please pass on to Bob Nuckolls.
>
>A total of seven "split pin connectors" emanating from the autopilot, all
>blue in color were found behind the instrument panel of the Beech Sierra,
>Each one was first disconnected and then reconnected. No further trouble
>shooting took place before an operational test was conducted on the Century
>IIB autopilot. The test on the ground was successful, A subsequent airborne
>operational test also proved the autopilot to be fully operational.
>
>Thank you again for any time, effort and thought that went into this trouble
>shooting. George Philipps
I'll call the service reps in piston props and see if I
can get a better reading on what these connectors are.
Bob . . .
________________________________________________________________________________
| From: | revenson(at)comcast.net |
| Subject: | EXPBUS OV Protection |
1.25 RCVD_NUMERIC_HELO Received: contains an IP address used for HELO
Haven't found any comments in the archives on the alternator OV Protection feature
built into the EXPBUS. Has any review been done here?
Haven't found any comments in the archiveson thealternator OV Protection feature
built into the EXPBUS. Has any review been done here?
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: EXPBUS OV Protection |
>
>Haven't found any comments in the archives on the alternator OV Protection
>feature built into the EXPBUS. Has any review been done here?
>
>Haven't found any comments in the archiveson thealternator OV Protection
>feature built into the EXPBUS. Has any review been done here?
>
An accurate review requires detailed schematics and parts
lists of the proffered system. I've not seen the necessary
documentation . . . is it posted on the 'net?
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Contactor Failures? |
>
>Bob,
>In yesterdays post, you said;
> Battery terminal breakage (or battery contactor failure) is
> relatively rare. I've never encountered one personally or known
> one who has. I've replaced dozens of contactors that failed in
> pre-flight but never one that failed in flight.
>What kinds of failures have you seen? Failure due to heat? manufacturing
>defects? external damage? internal failure?
Internal failure usually attributable to wear out.
Corroded/burned contacts resulting in high resistance
across the closed contacts.
>Is it worthwhile to replace contactors periodically similar to your battery
>replacement concept? If so, how often?
Depends on what you consider to be a reasonable insurance
premium. If you don't mind a $25 "investment" every
1, 2, 3 years or 200, 500, 1000 hours, then pick your numbers
and fly with whatever degree of comfort this activity
affords you. I try to design so that contactor failure does
not force an uncomfortable in-flight scenario. Under this
design philosophy, it seems to me that the "insurance" premium
is a poor value and the contactor(s) can be operated to
wear-out.
Bob . . .
________________________________________________________________________________
| Subject: | Re: EXPBUS OV Protection |
Bob Hi!
Some information that may or may not allow you to make comment on EXP Bus OV
Protection.
http://support.anywheremap.com/pdfs/expbus_overvolt.pdf
http://support.anywheremap.com/pdfs/exp2vsch.PDF
Regards
Gerry
How much free photo storage do you get? Store your holiday
________________________________________________________________________________
| From: | "Bret Smith" <smithhb(at)tds.net> |
| Subject: | Re: EXPBUS OV Protection |
Bob, you might get what you need here...
http://support.anywheremap.com/idx/0/020/article/Avionics_Documentation_and_Reference_Materials.html
Bret Smith
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: AeroElectric-List: EXPBUS OV Protection
>
>
> >
> >Haven't found any comments in the archives on the alternator OV
Protection
> >feature built into the EXPBUS. Has any review been done here?
> >
> >Haven't found any comments in the archiveson thealternator OV Protection
> >feature built into the EXPBUS. Has any review been done here?
> >
>
> An accurate review requires detailed schematics and parts
> lists of the proffered system. I've not seen the necessary
> documentation . . . is it posted on the 'net?
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | Roy Wheaton <roy_wheaton(at)yahoo.com> |
| Subject: | Re: PM Alternator / Regulator failure modes |
Many motorcycle manufacturers (Harley, Indian, etc.) still use PM-type of
alternators and 2 or 3 phase regulators. The failures are most often an open or
shorted rectifier diode, or a shorted SCR. There are usually two SCR's in
parallel, and it's rare for both to fail.
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: Multimeter problem |
Various meter concerns continue to pop up here, but I would like to advise
that these are unjustified.
In the days of analog meters people never worried because the resolution was
so poor. Now that you can see the last digit, one is inclined to worry. Of
course, we worry about the easy stuff--nobody worries about the strength of
their weld joints or fiberglass structure.
By the Way--holding as some sort of "standards" the venerable Simpson 260
(Simpson still makes these!) or the Weston Master II light meter, or your HP
200AB Oscillator---Well, my grandmother (who had not one nostalgic bone in
her body) would say bad things in Finnish at you. We never knew what she was
saying but when she said them, spit would fly all the animals would scatter
.
It's pretty easy to set up your own tests to determine if your meter is
accurate...then you will discover that there are no calibration adjustments
anyway! You can eliminate most consideration by looking and smelling
carefully for burned resistors in the meter.
Heck, I suggest if you are unhappy with the accuracy of your meters--donate
them to me!
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
"Everything you've learned in school as "obvious" becomes
less and less obvious as you begin to study the universe.
For example, there are no solids in the universe. There's
not even a suggestion of a solid. There are no absolute con-
tinuums. There are no surfaces. There are no straight lines."
- R. Buckminster Fuller
________________________________________________________________________________
| Subject: | Alternator questions? |
| From: | "Paul Weismann" <pw(at)weismannassociates.com> |
Apologies if this topic has been covered but I searched and could not
find...
2 alternator questions:
1. I am using a Denso automotive alternator in my turbine Rotorway
helicopter. The generally used diagram for the alternator is to have
TWO AWG12 b-leads running each to its own 30amp CB, and then TWO AWG12
leads to a junction post linking the battery and starter. I was going
to use the post on the starter for this.
What is the benefit, if any, to using 2 wires - is it only
redundancy, and if so, how much incremental protection would such a
design offer?
2. In some of Bingelis' writings, he recommends having the alternator
b-leads shielded. I do not see shielding in Bob's schematics (apologies
if I am reading them incorrectly). Is it necessary?
Thanks, very informative resource.
Paul
________________________________________________________________________________
| From: | Jon Goguen <jon.goguen(at)umassmed.edu> |
| Subject: | Re: PM Alternator / Regulator failure modes |
On Jul 13, 2005, at 1:57 PM, Roy Wheaton wrote:
> The failures are most often an open or
> shorted rectifier diode, or a shorted SCR. There are usually two SCR's
> in
> parallel, and it's rare for both to fail.
Am I correct in thinking that none of these failure modes would result
in an over voltage condition?
Thanks!
Jon
Jon Goguen
jon.goguen(at)umassmed.edu
Central Massachusetts
Kitfox Series V Rotax 912S / N456JG (reserved)
Complete except for electrics and avionics
________________________________________________________________________________
| From: | Charlie England <ceengland(at)bellsouth.net> |
| Subject: | Re: AeroElectric-List Digest: 8 Msgs - 07/12/05 |
Dave Harmon wrote:
>
>Thanks every body I now have a better understanding on internal voltage
>regulation. Do you think a dry contactor on the B+ terminal will act fast
>enough? What's your thoughts on a fusible link on the output (B+) lead and
>go directly to the battery. PS I don't have a lot of money in the radios but
>every nickel counts to me. I think that's what got me into this problem I
>bought a 90.00 denso 40 amp. min. Now I don't want to use it. Maybe I can
>takeout the reg. and go external.
>Dave
>
(digest snipped)
There are more opinions about this than the primer wars over on the RV
list & picking your favorite might not be easy, but here's mine.
It's much more likely to *cause* a problem than to protect yourself from
one by disassembling & modifying a Denso alternator.
My personal preference is to use an internally regulated alternator with
overvoltage detection to disconnect the B lead in the unlikely event of
overvoltage. The battery will absorb a *lot* of current & hold the
voltage to a reasonable level for the short time it takes the contactor
to open. I trust Denso's internal design & physical/electrical
integrity more than I trust running several extra wires & connections
around the engine compartment to make an external regulator talk to an
alternator. Just personal preference.
The fusible link isn't likely to prevent frying electronics; if the
battery is near full charge the voltage will likely rise high enough to
damage electronics before over-current would blow a high current fuse
link (assuming that there's no OV protection relay).
Charlie
________________________________________________________________________________
| From: | "Bruce Gray" <Bruce(at)glasair.org> |
| Subject: | Re: AeroElectric-List Digest: 8 Msgs - 07/12/05 |
The fusible link is to protect the wiring from a high amperage event
(Short). OV protection is to protect the electronics from a high voltage
event. Apples and oranges.
Bruce
www.glasair.org
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Charlie
England
Subject: Re: AeroElectric-List: Re: AeroElectric-List Digest: 8 Msgs -
07/12/05
Dave Harmon wrote:
>
>Thanks every body I now have a better understanding on internal voltage
>regulation. Do you think a dry contactor on the B+ terminal will act fast
>enough? What's your thoughts on a fusible link on the output (B+) lead and
>go directly to the battery. PS I don't have a lot of money in the radios
but
>every nickel counts to me. I think that's what got me into this problem I
>bought a 90.00 denso 40 amp. min. Now I don't want to use it. Maybe I can
>takeout the reg. and go external.
>Dave
>
(digest snipped)
There are more opinions about this than the primer wars over on the RV
list & picking your favorite might not be easy, but here's mine.
It's much more likely to *cause* a problem than to protect yourself from
one by disassembling & modifying a Denso alternator.
My personal preference is to use an internally regulated alternator with
overvoltage detection to disconnect the B lead in the unlikely event of
overvoltage. The battery will absorb a *lot* of current & hold the
voltage to a reasonable level for the short time it takes the contactor
to open. I trust Denso's internal design & physical/electrical
integrity more than I trust running several extra wires & connections
around the engine compartment to make an external regulator talk to an
alternator. Just personal preference.
The fusible link isn't likely to prevent frying electronics; if the
battery is near full charge the voltage will likely rise high enough to
damage electronics before over-current would blow a high current fuse
link (assuming that there's no OV protection relay).
Charlie
________________________________________________________________________________
| Subject: | Power buss alt field breaker |
Bob,
and others-
In figure Z-14 you show the typical 5A breaker architecture from the bus to term
6 (bus) of the LR-3
controller.
In Z13, you placed a fuselink between the bus and the 5A breaker.
Would you explain?
Thanks
Peter
________________________________________________________________________________
| From: | "Travis Hamblen" <TravisHamblen(at)cox.net> |
| Subject: | CESSNA SPLIT MASTER SWITCH |
0.03 HTML_TEXT_AFTER_HTML BODY: HTML contains text after HTML close tag
0.06 HTML_TEXT_AFTER_BODY BODY: HTML contains text after BODY close tag
I have the CESSNA SPLIT MASTER SWITCH which came with nothing in the way of
wiring diagrams or schematics. Does anyone have a schematic or wiring
diagram for this thing?? I know it is stone simple, as I know where the
wires route to and basically how it works, but I don=92t know which wire goes
onto which terminal. If you want you can e-mail me directly.
Travis
TravisHamblen(at)cox.net
--
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: EXPBUS OV Protection |
>
>Bob, you might get what you need here...
>http://support.anywheremap.com/idx/0/020/article/Avionics_Documentation_and_Reference_Materials.html
>
>Bret Smith
Checked it out but no joy. I need detailed schematics and bills
of materials to deduce OVP performance.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: EXPBUS OV Protection |
><gholland@gemini-resourcing.com>
>
>Bob Hi!
>
>Some information that may or may not allow you to make comment on EXP Bus OV
>Protection.
>
>http://support.anywheremap.com/pdfs/expbus_overvolt.pdf
>
>http://support.anywheremap.com/pdfs/exp2vsch.PDF
Found these from links folks have sent but they only
show block diagrams and speak of functionality. Without
detailed schematics and parts values, I can't see
how well they did the job.
Note further that EXPBus ov protection assumes an
alternator that can ALWAYS be controlled from the
"field supply" wire which does not include most
internally regulated alternators.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Alternator questions? |
>
>
>Apologies if this topic has been covered but I searched and could not
>find...
>
>2 alternator questions:
>1. I am using a Denso automotive alternator in my turbine Rotorway
>helicopter. The generally used diagram for the alternator is to have
>TWO AWG12 b-leads running each to its own 30amp CB, and then TWO AWG12
>leads to a junction post linking the battery and starter. I was going
>to use the post on the starter for this.
> What is the benefit, if any, to using 2 wires - is it only
>redundancy, and if so, how much incremental protection would such a
>design offer?
None that I can deduce.
>2. In some of Bingelis' writings, he recommends having the alternator
>b-leads shielded. I do not see shielding in Bob's schematics (apologies
>if I am reading them incorrectly). Is it necessary?
No
Bob . . .
--------------------------------------------------------
< Throughout history, poverty is the normal condition >
< of man. Advances which permit this norm to be >
< exceeded -- here and there, now and then -- are the >
< work of an extremely small minority, frequently >
< despised, often condemned, and almost always opposed >
< by all right-thinking people. Whenever this tiny >
< minority is kept from creating, or (as sometimes >
< happens) is driven out of a society, the people >
< then slip back into abject poverty. >
< >
< This is known as "bad luck". >
< -Lazarus Long- >
<------------------------------------------------------>
http://www.aeroelectric.com
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> modes |
| Subject: | Re: PM Alternator / Regulator failure |
modes
>
>
>On Jul 13, 2005, at 1:57 PM, Roy Wheaton wrote:
>
> > The failures are most often an open or
> > shorted rectifier diode, or a shorted SCR. There are usually two SCR's
> > in
> > parallel, and it's rare for both to fail.
>
>Am I correct in thinking that none of these failure modes would result
>in an over voltage condition?
No . . . but ANY alternator that needs a REGULATOR can REGULATE
at the desired voltage or, depending on what part has failed,
can depart greatly from the design voltage.
Given that most PM alternators are relatively low current sources,
a GOOD svla battery (recombinant gas) will keep a runaway alternator
from driving the bus to the moon for several seconds. Perhaps 10-20
or more. One could CONSIDER an OV warning and a manual reaction to said
warning. However one chooses to go, manual or automatic, ANY alternator
of ANY size is capable of driving the bus voltage up to unhealthy
levels. It's just a matter of time.
However with the smaller alternators, this isn't a really fast
race. See last figure on the 8th page of
http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_C.pdf
where we see that a 30A runaway alternator may not raise bus
voltage high enough to trip an ov sensor set for 16.2 to 16.5
volts for quite awhile . . . perhaps minutes. Smaller alternators
take even longer. This presumes you've got a good battery that
will do its best to soak up all the excess electrons pumped out
by a runaway alternator.
For 40A machines an larger, I'd recommend fully automatic
ov protection.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Power buss alt field breaker |
>
>
>Bob,
>and others-
>
>In figure Z-14 you show the typical 5A breaker architecture from the bus
>to term 6 (bus) of the LR-3
>controller.
>In Z13, you placed a fuselink between the bus and the 5A breaker.
>Would you explain?
Z-14 depicts a breaker panel where the breaker feeding
field power to the LR-3 comes from bus adjacent to the
breaker.
Z-13 illustrates a fuse block were we're EXTENDING the
bus to a remote breaker for crowbar ov protection. That
piece of wire from the bus to the breaker would benefit
from some degree of SLOW protection, like a fusible link.
This is one of a FEW places where the fusible link is
a recommended wire protection device.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> 07/12/05 |
| Subject: | Re: AeroElectric-List Digest: 8 Msgs - |
07/12/05
>
>
>Dave Harmon wrote:
>
>
> >
> >Thanks every body I now have a better understanding on internal voltage
> >regulation. Do you think a dry contactor on the B+ terminal will act fast
> >enough? What's your thoughts on a fusible link on the output (B+) lead and
> >go directly to the battery. PS I don't have a lot of money in the radios
> but
> >every nickel counts to me. I think that's what got me into this problem I
> >bought a 90.00 denso 40 amp. min. Now I don't want to use it. Maybe I can
> >takeout the reg. and go external.
> >Dave
> >
>(digest snipped)
>
>There are more opinions about this than the primer wars over on the RV
>list & picking your favorite might not be easy, but here's mine.
>
>It's much more likely to *cause* a problem than to protect yourself from
>one by disassembling & modifying a Denso alternator.
>
>My personal preference is to use an internally regulated alternator with
>overvoltage detection to disconnect the B lead in the unlikely event of
>overvoltage. The battery will absorb a *lot* of current & hold the
>voltage to a reasonable level for the short time it takes the contactor
>to open. I trust Denso's internal design & physical/electrical
>integrity more than I trust running several extra wires & connections
>around the engine compartment to make an external regulator talk to an
>alternator. Just personal preference.
>
>The fusible link isn't likely to prevent frying electronics; if the
>battery is near full charge the voltage will likely rise high enough to
>damage electronics before over-current would blow a high current fuse
>link (assuming that there's no OV protection relay).
Correct.
Fusible links, fuses, breakers, etc are for WIRE PROTECTION ONLY
and have no useful functionality for mitigating an over-voltage
condition. These circuit protective devices are recommended in
a variety of locations as shown in the Z-figures but none of
these devices is intended to be primary sensing/protection for
an ov condition. A crowbar OV protection module takes advantage
of a fuse or circuit breaker's willingness to protect the field
supply wire AFTER the crowbar module trips . . . but operation
of circuit protection is PAIRED with the ov protection module.
Neither device by itself offers any form of ov protection.
Bob . . .
________________________________________________________________________________
| From: | "Kingsley Hurst" <khurst(at)taroom.qld.gov.au> |
| Subject: | Power buss alt field breaker |
Bob,
You said :-
> Z-13 illustrates a fuse block were we're EXTENDING the
bus to a remote breaker for crowbar ov protection. That
piece of wire from the bus to the breaker would benefit
from some degree of SLOW protection, like a fusible link.
This is one of a FEW places where the fusible link is
a recommended wire protection device.
Would it be okay to omit the fusible link if the OV CB is within 4" of
the BUS and say a 10 or 12awg wire is used to join the BUS to the CB or
should I make a 4" fusible link ?
In my case, the BUS is an integral part of the Bussman Fuse Block.
Thank you in advance.
Regards
Kingsley in Oz.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Power buss alt field breaker |
>
>
>Bob,
>
>You said :-
>
> > Z-13 illustrates a fuse block were we're EXTENDING the
> bus to a remote breaker for crowbar ov protection. That
> piece of wire from the bus to the breaker would benefit
> from some degree of SLOW protection, like a fusible link.
> This is one of a FEW places where the fusible link is
> a recommended wire protection device.
>
>Would it be okay to omit the fusible link if the OV CB is within 4" of
>the BUS and say a 10 or 12awg wire is used to join the BUS to the CB or
>should I make a 4" fusible link ?
>
>In my case, the BUS is an integral part of the Bussman Fuse Block.
The FAA's pulled-out-of-thin-air rule of thumb for
unprotected wire segments is 6" . . . so your 4" proposal
wouldn't raise any eyebrows in the certified world and
it's certainly acceptable here.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: CESSNA SPLIT MASTER SWITCH |
>
>
>I have the CESSNA SPLIT MASTER SWITCH which came with nothing in the way of
>wiring diagrams or schematics. Does anyone have a schematic or wiring
>diagram for this thing?? I know it is stone simple, as I know where the
>wires route to and basically how it works, but I don=92t know which wire goes
>onto which terminal. If you want you can e-mail me directly.
I used to have one of those things laying around here but can't
put my hands on it.
Use your ohmmeter to determine sequence of operation between
the two sides. While holding the switch in an "operating" position,
the contacts which close first and in response to operating the left
side only is your battery master switch. The other set of contacts
should close in response to operating the right side, those are
your alternator control.
If the desired switching sequences don't seem be evident, you
may have the switch upside down.
Bob . . .
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: OVP, Alternators, and stuff |
0.60 COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
I've been considering posting a list of 95 Theses and nailing them to the
hangar door....Disputations on the Power and Efficiacy of Electrons, etc. It
is difficult to ascertain the best state of knowledge of how to build an
aircraft electrical system when so much seems up in the air. Here's my
biased summary of the recent discussion:
1) Internally vs. Externally Regulated Alternators: There are advantages and
disadvantages to both. I suspect the externally regulated alternator will
become less common and is probably a bit less reliable. In the rare OV event
in and externally regulated system, the external regulator is probably the
faulty part. For internally regulated alternators especially, a B-lead
contactor of the B&C Stancor type has not been shown to be capable of
interrupting the B-lead circuit. The documentation regarding its breaking
performance against high voltages possible in a runaway does not exist--(I
checked into this thoroughly.) However, the Kilovac Czonka III P/N
EV200AAANA will do the job easily--200A Interrupt at 320V. As a bonus its
coil draws only 100 milliamps.
2) Crowbars--The Z-figure crowbar is a poor way to do the job. The circuit
breaker cannot be show to open against the current induced by the crowbar.
Crowbars have no place in battery systems. How do you think the modern
alternator regulator IC's terminate the field?---They simply latch off the
field with a mosfet. No crowbars Bubela.
3) E-bus Diodes--Use a big fat Schottky for bus isolation. The arguments
against not doing this trigger my Attention Deficit Disorder--knocking me
into the ozone. What were we discussing....?
4) LEDs--Automakers are planning to introduce LED headlights in the 2008
model year. Then the efficacy will be 100 lumens-per-watt (as good as
fluorescents). Bet on it.
More later, only 91 more theses to go....
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
Teamwork: "A lot of people doing exactly what I say."
(Marketing exec., Citrix Corp.)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: battery maintenance |
>
>Related question to bolster my confidence.
>2) Am I correct that the Schumacher WM1562A charger/maintainer meets the
>criteria for a properly charging these RG batteries?
Yes. ALL the Schumacher products I've looked at have
well designed charge/maintenance modes of operation.
The Harbor Freight device I looked at a few months ago
did not.
Another manufacturer of charger/maintainer/desulphator
products is sending me some samples. I suspect I'll
find that the charger/maintainer functions are adequate.
I'm not convinced that the desulphating technology is
useful (or even effective). There are several approaches
to "desulphating" batteries.
Watch this space. In the mean time, I've tested and
routinely use Battery Tenders . . .
http://www.batterytender.com/
and Schumacher products (some models offered by Walmart)
http://www.batterychargers.com/chargers.cfm
have proven quite satisfactory. I'll report on others
as time and opportunity permit.
>I like your method of just putting a smart charger on the batt an then one
>knows it is charged fully.
We have $many thousands$ worth of batteries in storage
and an unreasonably high rates of loss in storage due
to variability in manufacturer's and local handling rules
and tools. I've suggested that we can save $bundles$ by
tossing all the current rules and tools and install
maintenance racks with battery maintainers and mating
connectors for all stocked batteries.
A new battery can be placed on the shelf and IGNORED
for years if 100% supported by active maintainer
as opposed to being handled every 90 days for a "boost
charge" . . . the labor to maintain a battery under
the old rules is high. Risks to batteries is also high.
100% solution is to plug-em-in and forget them until
time to ship to a customer.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Regulator output |
> Could you not also run with the Essential Buss Bypass switch on.
>This would allow the current to flow through the switch and not the
>diode, whereby eliminating the voltage drop across the diode. The down
>side with this is that if you don't get an early indication that your
>alternator failed, you would have used up some of your reverse battery
>power while the master was still on.
??? Not so. If you have ACTIVE NOTIFICATION of low voltage,
alternator failure is annunciated immediately irrespective
of the position of any switches.
> On the plus side, there is no
>voltage drop on the essential bus and no high current via the diode.
>The diode would simply ensure that if the master is off and the
>essential bus bypass is no, then current will not flow from the
>essential buss to the main buss.
What are the concerns about "voltage drop"? This issue gets
elevated to discussion status and prayed over several times
a year but without putting any numbers on when "voltage drop"
becomes a real concern. We don't install silver wire to reduce
voltage drop because our design goals and the underlying physics
says there's no return on investment for doing so. If
"voltage drop" across the e-bus diode IS a real operational
concern, then it should be an easy sell with NUMBERS.
The design goals that include a normal feedpath diode to the
e-bus show that .8 volts of drop in an operating system with
a 14.2 volt (or greater) bus is no big deal. When the alternator
quits and the ENDURANCE-bus is running barefoot through battery
land, the diode is not in the loop.
If one is going to hypothesize about the merits of one operating
mode over another, then it's necessary to consider the ramifications
with numbers. One of my heros once noted:
"When you can measure what you are speaking about, and
express it in numbers, you know something about it; but
when you cannot measure it, when you cannot express it in
numbers, your knowledge of it is of a meager and
unsatisfactory kind; it may be the beginning of knowledge,
but you have scarcely, in your thoughts, advanced it to the
stage of science."
Sir William Thompson, Lord Kelvin (1824-1907)
Bob . . .
________________________________________________________________________________
| From: | Dave Morris <BigD(at)DaveMorris.com> |
| Subject: | Regulator output |
That's a pretty cool statement, since I presume the number ZERO was named
in his honor on the temperature scale.
Dave Morris
At 09:50 AM 7/14/2005, you wrote:
>
>
> "When you can measure what you are speaking about, and
> express it in numbers, you know something about it; but
> when you cannot measure it, when you cannot express it in
> numbers, your knowledge of it is of a meager and
> unsatisfactory kind; it may be the beginning of knowledge,
> but you have scarcely, in your thoughts, advanced it to the
> stage of science."
>
> Sir William Thompson, Lord Kelvin (1824-1907)
________________________________________________________________________________
| From: | Paul Wilson <pwilson(at)climber.org> |
| Subject: | Re: battery maintenance |
Bob, Thanks for the info.
Input My WalMart now carries Black & Decker charger/maintainers:
Black & Decker VEC 0808D $17.44, Vector #VEC 10863 $24.83, & others which
cost much more.
Paul
===============
At 08:39 AM 7/14/2005, you wrote:
>
>
>
> >
> >Related question to bolster my confidence.
> >2) Am I correct that the Schumacher WM1562A charger/maintainer meets the
> >criteria for a properly charging these RG batteries?
>
> Yes. ALL the Schumacher products I've looked at have
> well designed charge/maintenance modes of operation.
> The Harbor Freight device I looked at a few months ago
> did not.
>
> Another manufacturer of charger/maintainer/desulphator
> products is sending me some samples. I suspect I'll
> find that the charger/maintainer functions are adequate.
> I'm not convinced that the desulphating technology is
> useful (or even effective). There are several approaches
> to "desulphating" batteries.
>
> Watch this space. In the mean time, I've tested and
> routinely use Battery Tenders . . .
>
>http://www.batterytender.com/
>
> and Schumacher products (some models offered by Walmart)
>
>http://www.batterychargers.com/chargers.cfm
>
> have proven quite satisfactory. I'll report on others
> as time and opportunity permit.
>
>
> >I like your method of just putting a smart charger on the batt an then one
> >knows it is charged fully.
>
> We have $many thousands$ worth of batteries in storage
> and an unreasonably high rates of loss in storage due
> to variability in manufacturer's and local handling rules
> and tools. I've suggested that we can save $bundles$ by
> tossing all the current rules and tools and install
> maintenance racks with battery maintainers and mating
> connectors for all stocked batteries.
>
> A new battery can be placed on the shelf and IGNORED
> for years if 100% supported by active maintainer
> as opposed to being handled every 90 days for a "boost
> charge" . . . the labor to maintain a battery under
> the old rules is high. Risks to batteries is also high.
> 100% solution is to plug-em-in and forget them until
> time to ship to a customer.
>
> Bob . . .
>
>
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: OVP, Alternators, and stuff |
> ... The documentation regarding its breaking
> performance against high voltages possible in a runaway does not exist--(I
> checked into this thoroughly.) However, the Kilovac Czonka III P/N
> EV200AAANA will do the job easily--200A Interrupt at 320V. As a bonus its
> coil draws only 100 milliamps.
Eric, are you saying this is the relay you recommend in this
diagram: http://www.periheliondesign.com/OVP/OVschems.gif
(Sorry, don't know where to put the ? in that kind of sentence.)
I found one at http://www.onlinecomponents.com/tyco.cfm and they
want over 111 USD for it in quantities of one. They drop
all the way to 68 USD for quantities of 500.
--
Mickey Coggins
http://www.rv8.ch/
#82007 finishing
________________________________________________________________________________
| From: | Matt Dralle <dralle(at)matronics.com> |
| Subject: | List Digest Truncation Fixed!! |
Dear Listers,
I finally figured out today what was causing the occasional
truncation of the daily List Digest emails. Seems that every once in
a while a message would contain a single "." (period) on line all by
itself. The mailers would see this and assume that this was the
universal emailer signal for "end of message", and consequently
wouldn't process any of the rest of the Digest message.
I've put in a filter today to remove any of these sequences so we
should be back in business on the Digests.
Best regards,
Matt Dralle
Matronics Email List Admin.
Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551
925-606-1001 V | 925-606-6281 F | dralle(at)matronics.com Email
http://www.matronics.com/ WWW | Featuring Products For Aircraft
________________________________________________________________________________
| Subject: | Re: battery maintenance |
| From: | "Hinde, Frank George (Corvallis)" <frank.hinde(at)hp.com> |
Out of interest (cus I have 4 of them) what was wrong with the HF
device?
I assume you are talking about the little black trickle charger the
transformer is on the plug with a 1" square box on the supply line.
Frank
-----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
Subject: AeroElectric-List: Re: battery maintenance
-->
>
>Related question to bolster my confidence.
>2) Am I correct that the Schumacher WM1562A charger/maintainer meets
>the criteria for a properly charging these RG batteries?
Yes. ALL the Schumacher products I've looked at have
well designed charge/maintenance modes of operation.
The Harbor Freight device I looked at a few months ago
did not.
Another manufacturer of charger/maintainer/desulphator
products is sending me some samples. I suspect I'll
find that the charger/maintainer functions are adequate.
I'm not convinced that the desulphating technology is
useful (or even effective). There are several approaches
to "desulphating" batteries.
Watch this space. In the mean time, I've tested and
routinely use Battery Tenders . . .
http://www.batterytender.com/
and Schumacher products (some models offered by Walmart)
http://www.batterychargers.com/chargers.cfm
have proven quite satisfactory. I'll report on others
as time and opportunity permit.
>I like your method of just putting a smart charger on the batt an then
>one knows it is charged fully.
We have $many thousands$ worth of batteries in storage
and an unreasonably high rates of loss in storage due
to variability in manufacturer's and local handling rules
and tools. I've suggested that we can save $bundles$ by
tossing all the current rules and tools and install
maintenance racks with battery maintainers and mating
connectors for all stocked batteries.
A new battery can be placed on the shelf and IGNORED
for years if 100% supported by active maintainer
as opposed to being handled every 90 days for a "boost
charge" . . . the labor to maintain a battery under
the old rules is high. Risks to batteries is also high.
100% solution is to plug-em-in and forget them until
time to ship to a customer.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: OVP, Alternators, and stuff |
0.60 COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
>
>I've been considering posting a list of 95 Theses and nailing them to the
>hangar door....Disputations on the Power and Efficiacy of Electrons, etc. It
>is difficult to ascertain the best state of knowledge of how to build an
>aircraft electrical system when so much seems up in the air. Here's my
>biased summary of the recent discussion:
>
>1) Internally vs. Externally Regulated Alternators: There are advantages and
>disadvantages to both. I suspect the externally regulated alternator will
>become less common and is probably a bit less reliable. In the rare OV event
>in and externally regulated system, the external regulator is probably the
>faulty part. For internally regulated alternators especially, a B-lead
>contactor of the B&C Stancor type has not been shown to be capable of
>interrupting the B-lead circuit. The documentation regarding its breaking
>performance against high voltages possible in a runaway does not exist--(I
>checked into this thoroughly.) However, the Kilovac Czonka III P/N
>EV200AAANA will do the job easily--200A Interrupt at 320V. As a bonus its
>coil draws only 100 milliamps.
Agreed.
>2) Crowbars--The Z-figure crowbar is a poor way to do the job. The circuit
>breaker cannot be show to open against the current induced by the crowbar.
Paul's assertions that the I-T operating curves for response
times should also be interpreted as limits was in error.
All breakers produced under mil-spec (and by inference, any
identical, commercial breaker produced on the same line)
a qualified by demonstrating an ability to interrupt a fault
current many times higher than the limits Paul inferred.
See http://www.aeroelectric.com/Reference_Docs/Circuit_Breaker/Mil-C-5806G.pdf
After being subjected to the high fault current interrupt, the breaker
must still meet all other performance requirements.
I've discussed Paul's inference with two experienced and
learned engineer/reps for circuit breaker manufacturers and
they've never even heard of any fault limits that put
a breaker at-risk when used in the crowbar ov protection system.
Paul's assertions were without foundation in fact and easily
discounted by researching the test specifications and consulting
the people who BUILD circuit breakers.
>Crowbars have no place in battery systems.
How so? Paul tossed out lots of hyperbole to support
the same hypothesis and then picked up his marbles and
left when I began to explore the real numbers in . . .
http://www.aeroelectric.com/articles/Crowbar_OV_Protection/DC_Power_System_Dynamics_C.pdf
If crowbar ov protection is such an evil concept,
then I'll ask you the same question. Show the numbers
from a repeatable experiment that support the
premise. There are plenty of folks flying thousands of regulators
fitted with crowbar ovp systems (some certified) who
are as interested as I am in any illumination you have
to offer. I'll pick up on the next revision to the document
cited above if you'll describe the setup that will prove/
disprove any premise you wish to discuss.
> How do you think the modern
>alternator regulator IC's terminate the field?---They simply latch off the
>field with a mosfet. No crowbars Bubela.
There are plenty of alternative philosophies, any or all
of which will be acceptable under some design. These
may be perfectly acceptable competing philosophies and
products. It depends on the system design goals.
Paul suggested a new paradigm that offered 18v upper bounds
for DC power system transients. If we had enjoyed the
benefit of that limit in 1980, we would have offered
pure series, solid state ov protection too . . . but our
paradigm of the time called for an 80v/40v limit and
crowbar made more sense. Until we can demonstrate the
physics that support your proposed prohibition, I'll suggest
that the crowbar ovp module offers a useful alternative
yet today.
>3) E-bus Diodes--Use a big fat Schottky for bus isolation. The arguments
>against not doing this trigger my Attention Deficit Disorder--knocking me
>into the ozone. What were we discussing....?
Who is arguing AGAINST? I am suggesting that the
argument FOR has no foundation under the design goals
under which the Z-figures and specifically the e-bus
were created. There's nothing WRONG with a Schottky
device but there's no compelling RIGHT either.
I've never suggested that builders should not consider
using your (or anyone else's) Schottky product . . .
however, there are no compelling reasons they shouldn't
consider an equally suitable device from Radio Shack.
Bob . . .
________________________________________________________________________________
| From: | <chaztuna(at)adelphia.net> |
| Subject: | Auto Pilot Servo Ground wire |
Bob & Listers,
Should the servo ground wires for the Trutrak (or other) auto pilot servos & control
boxs be grounded locally or should they be run up to the common ground
point?
I have a rear mounted battery on my RV-8A project. The pitch servo & controller
are only 6 - 8" from my battery. Should I ground them directly to the battery?
Charlie Kuss
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Regulator output |
>
>That's a pretty cool statement, since I presume the number ZERO was named
>in his honor on the temperature scale.
Correct. Kelvin was a big energy guy and temperature
is one of the most rudimentary manifestations of energy.
See http://inventors.about.com/library/inventors/blthermometer.htm
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: A question on my crossbar overvoltage protection |
>Hi Bob,
>
>Thanks to your fine book and mailing list I wired up my RV-7A and
>everything works swimmingly. In theory I'm an EE, but in practice I'm
>more of a software guy/ASIC/Verilog sort of EE. ;-)
Understand! But I'm confident that we can do some good
science together . . .
>I did notice one problem:
>
>I have the little two wire OV protection circuit wired per your "OV
>protection for an internally regulated alternator". During early testing
>I noticed that the OV protection component was pulling the circuit down to
>ground and thus popping the field breaker. This makes me think the OV
>circuit thought there was an OV condition. These events seemed to occur
>when switching on different components - i.e. the primer solenoid, flaps
>or strobes.
>
>My GRT EIS alarm for over voltage did not trigger. When I hooked up my
>DVM, I didn't see any high voltage when the occasional events would occur.
>
>I've temporarily disconnected the OVP circuit to allow other flight
>testing to continue.
>What do you recommend? Ideas that occur to me:
>1) Could this be a one-off problem with my OV circuit and I should just
>call B&C and get another one?
Possibly but I kind of doubt it. The fact that the system
is stable until triggered by a switching event is interesting.
In ten years or so of building these things, I've seen a hand-full
of special cases where un-anticipated characteristics in
the ship's electrical system would nuisance trip the SCR in
the ov module.
In fact, I have an OVM-14 on my bench right now that's shown
some tendency to nuisance trip. It's very early serial number.
By the way, how long have you had yours and what color are the
leads?
>2) If necessary, I can borrow a digital scope from work and see if the bus
>really is going over voltage briefly? How long of an over voltage
>condition should be required before the OV circuit pulls things to ground.
That wouldn't hurt but the event we're looking for is not
a "OV" event. I.e., it's not being triggered through the
OV detection circuit which has tens of milliseconds time
constant. It's probably a dv/dt sensitivity.
Let's try an experiment or two. Don't worry about
things we do to the module because I'm going to replace the
one you have.
Get a low ESR 0.1 uf capacitor and tie it across the
OVM's leadwires with shortest practical capacitor leads.
A Radio Shack 272-109 is suitable. See if the tripping
stops with this capacitor in place. If not, try a 1.0 uF
(RS 272-1055).
>Thank you for any ideas. Feel free to forward this to the list - I wasn't
>sure if you prefer these sorts of queries via the list or directly.
Thanks for bringing this up and I don't mind
carrying this out on the list. I'll carbon-copy this reply
to the list and we can continue the investigation where
others may benefit also. We're not going to do a thing
we wouldn't want others to know about.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: battery maintenance |
>
>Bob, Thanks for the info.
> Input My WalMart now carries Black & Decker charger/maintainers:
>Black & Decker VEC 0808D $17.44, Vector #VEC 10863 $24.83, & others which
>cost much more.
I went to Wallyworld to see if I could buy one. My local store
is still stocked with the Schumacher WM1562 (still at $18 too).
I'll watch for the Black & Decker products and snap one up for
examination under the microscope when and if they appear on
the shelves.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: battery maintenance |
>
>
>Out of interest (cus I have 4 of them) what was wrong with the HF
>device?
>
>I assume you are talking about the little black trickle charger the
>transformer is on the plug with a 1" square box on the supply line.
No. I purchased a #33895 . . .
http://www.aeroelectric.com/Pictures/HF_Battery_Maintainer.jpg
and it performed badly. I don't recall right now in exactly what
way. Further, this MIGHT be a one-of-a-kind event. I opened the
thing up and it has enough 'stuff' inside to do a good job. This
one may simply be broke.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Auto Pilot Servo Ground wire |
>
>Bob & Listers,
> Should the servo ground wires for the Trutrak (or other) auto pilot
> servos & control boxs be grounded locally or should they be run up to the
> common ground point?
> I have a rear mounted battery on my RV-8A project. The pitch servo &
> controller are only 6 - 8" from my battery. Should I ground them directly
> to the battery?
What do the instructions say? Posting a question
like that on the List is fraught with risk. You need
to do it only when the instructions are not clear -AND-
attempts to clarify ambiguous instructions with
the manufacturer has failed or is impossible.
Then your ONLY recourse is to seek learned advice.
However, unless the responding individuals have first hand
knowledge unique to the product, then the best you
can hope for is an educated guess.
I'll suggest it's FAR better to exhaust all opportunities
for the "good" advice before you resort to "best guess"
advice.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Auto Pilot Servo Ground wire |
P.S. if you get a good answer from Trutrak, please
share it with us on the list so that it gets stashed
in the archives. Let us know who you talked, their
phone number and what was advised along with any
explanations they may have to offer.
Bob . . .
>
>Bob & Listers,
> Should the servo ground wires for the Trutrak (or other) auto pilot
> servos & control boxs be grounded locally or should they be run up to the
> common ground point?
> I have a rear mounted battery on my RV-8A project. The pitch servo &
> controller are only 6 - 8" from my battery. Should I ground them directly
> to the battery?
What do the instructions say? Posting a question
like that on the List is fraught with risk. You need
to do it only when the instructions are not clear -AND-
attempts to clarify ambiguous instructions with
the manufacturer has failed or is impossible.
Then your ONLY recourse is to seek learned advice.
However, unless the responding individuals have first hand
knowledge unique to the product, then the best you
can hope for is an educated guess.
I'll suggest it's FAR better to exhaust all opportunities
for the "good" advice before you resort to "best guess"
advice.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Spam Can Architecture |
>
>Bob et al;
>
>Firstly, thanks to all Aeroelectric digest contributors for advancing
>our knowledge base. I'm continually humbled and indebted. Electron
>wrangling is a mighty task.
>
>Next, I like to ask about spam can electrical architecture, specifically
>the Cessna stuff from the late 60's early 70's. My aircraft is a '68 177
> 150hp fixed gear and prop. It's a simple 4 place cruiser.
>
>Now as it's age is creeping up to 40 years old, I have doubts about the
>integrity of the electrical system. Putting obvious certification issues
>aside and looking at just flight safety and reliability, what
>technologies could be considered to advance the integrity of the
>electrical system? Maintenance of items like batteries, switches and
>breakers, contactors and wiring seemed to be addressed in the certified
>world on a breakdown basis rather than predictive maintenance.
You haven't got many choices. If it were MY airplane and I
was allowed to DE-certify it (like you can on some airplanes
in Canada) then I would consider the following:
First, an RG battery would go in. Probably a big Panasonic (cheep)
so I could replace it every year or so without bashing the checkbook.
There are no options for a better alternator but I'd certainly
change the avionics bus to an e-bus and move a few selected items
from the main bus to the e-bus. The old avionics master becomes
an e-bus alternate feed switch.
For alternator regulation stability, I'd probably replace all wiring,
components and connectors between the bus and the alternator with
new including breaker, split rocker, and all connections/connectors.
You can keep the regulator and ov module.
Having done that, there's not much to really be worried about.
I'd certainly keep an eye on condition of insulation on wires,
particularly under the cowl.
There's a boat-load of hand-ringers writing articles about
ageing aircraft . . . Sport Aviation is right up there with
the big guys for circulating the Chicken-Little stories. See:
http://www.aeroelectric.com/articles/Wired_for_Disaster.pdf
Your biggest hedge against an unhappy day is to posture yourself
for failure tolerance. I approach every rental airplane with the
mindset that it doesn't matter what is or is not working on
the panel . . . I have enough stuff in my flight bag to get
to airport of intended destination with the panel completely
dark if necessary.
I recall a flight instructor who used to sing the "go-around
waltz" every time we sailed down the glideslope. His point was
virtually every pilot approaches the missed approach point with
a gonna-put-the-wheels-on-the-ground mindset. Pilots don't
practice go-arounds, they don't like go-arounds, they don't
expect or want a go-around so when a real one is force upon
them, they're a mixture of surprised/disappointed. His philosophy
was to slide down the chute PRAYING for the opportunity to do
a go-around and being primed to do all the right things when
it happened.
I'll suggest a corollary approach to owning and operating
an aged airplane. In this case, you can even practice operating
your airplane in the "J-3 mode" under benign conditions just
to be sure you're outfitted and mentally prepared to get
the job done with confidence and competence. This will be
a lot safer and less expensive than anything you can legally
do to your airplane.
If you smell something bad, shut it ALL off and get where you
intended to go (or back to the home field) and fix it there . . .
not on some grass strip in Podunk. If you manage to get an
e-bus installation on your airplane, so much the better but
it should not be a show stopper.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> location |
| Subject: | flight over Wichita/battery,contactor |
location
>. .
>
>
>Bob: Cruised by Wichita Monday last. We left Tucson at 06:20MST and
>landed at Adrian, MI (ADG)at 18:10EST with two stops. Most of the trip
>was at 9500'. The air was surprisingly smooth at altitude but there was
>significant turbulence on landing in Missouri and Michigan.
>
>Questions: If I place the battery (RV-8)aft of the baggage compartment
>along with the contacter are there reasons other than weight (and
>work)not to put the starter contacter there as well? It would mean
>bringing a buss lead forward and if I decide to add electric heating
>(garments or seats) a 60A alternator and probably a 6AWG buss lead would
>be required. If this is done, how best to provide protection for the
>buss lead? Should a temperature sensor be used with the LR-3?
Sorry for the delayed response.
If you put the starter contactor back there, then you need TWO
fat wires forward . . one for the bus and one for the starter.
It's much better to put the starter contactor on the firewall
and use it as a tie-point for the fat wire to the bus.
6AWG would be adequate for a 60A bus but I'd rather see it
come off the firewall than of the battery contactors in the tail.
"Protection" for fat wires is usually purely mechanical. I.e.,
like all big cranking and battery wires from rear mounted
batteries, we take extra precautions to support these wires
and provide separation from moving parts. Experience has shown
little value in doing more on small airplanes.
I wouldn't recommend temperature compensating the LR-3 unless
your battery gets REALLY cold on long cruising flight. You might
put a thermocouple on it and see how cold it gets. The problem comes
from second segment of a trip where the battery is too cold to
take a charge after long soak on first segment. It's pretty
rare that this becomes an issue.
Next time I let you drop into a black hole, drop me a direct
email or give me a call.
>Hope to see you at Oshkosh.
Can't make it this year.
Bob . . .
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: A question on my crossbar overvoltage |
protection
I wonder if this is related to what I reported a month or so ago?
"While tracking down a electrical problem ( haven't run the engine yet)
I was sidetracked for awhile by the circuit breaker that feeds a 40 amp
OV relay on my permanent magnet alternator popping. It seems that
wiggling a loose connection between the breaker and the relay will trip
the OVP and open the breaker. The crowbar OVP is constructed from the
new design. It tests OK and it doesn't trip if the alternator switch is
operated. It does trip if I intentionally rapidly connect and disconnect
the wire to the relay. The relay coil draws about 130 mA. If I
disconnect the OVP I am unable to make the C/B trip so it would seem
that the OVP is activating. It doesn't seem to make any difference
whether a diode is across the relay coil.
I'm guessing this is normal and I'm making voltage spikes at a faster
rate than the OVP time delay resets but I would have expected negative
spikes rather than positive spikes. "
At that time I also said that "temporarilly adding a unidirectional
transorb across it makes it more resistant to tripping which seems to
confirm that I am generating positive spikes" but in retrospect I'm not
certain that the transorb made much difference. Since I can't cycle the
switch fast enough to cause a problem and nobody commented, I tightened
my loose connection and did not persue this further.
Ken
>>I did notice one problem:
>>
>>I have the little two wire OV protection circuit wired per your "OV
>>protection for an internally regulated alternator". During early testing
>>I noticed that the OV protection component was pulling the circuit down to
>>ground and thus popping the field breaker. This makes me think the OV
>>circuit thought there was an OV condition. These events seemed to occur
>>when switching on different components - i.e. the primer solenoid, flaps
>>or strobes.
>>
>>
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Narco 122D mounting? |
I just received a Narco 122D, and am struggling to get the thing in
the panel. I want to mount it on the aft side (front side?, engine
side?, you know what I mean) of the panel, rather than cut an ATI
shaped hole and slip it in from the cockpit side of the panel. I've
cut the hole and its various cutouts, as shown in the install
manual. But I can't get the darned thing in the hole - the knobs are
in the way. It is like a Chinese puzzle. As near as I can figure, I
need to remove every knob to get it to slip into the hole. It seems
like the long shaft at the top right has to slip into its hole first,
and that limits how much you can jockey the unit around to get the
knobs into the cutouts.
I've managed to remove the Power/Volume knob, and the Course Select
knob, but, I can't get the frequency changing knobs off. One set
screw doesn't seem to fit anything I've got to turn it with. It is
so deep in the hole that I can't see what it looks like
What is the trick? Is there a set screw in every hole in the
frequency knobs? Are they all Torx T-5, or is one of something else
like a tiny Allen headed screw?
Thanks for any information.
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| From: | Kevin Horton <khorton01(at)rogers.com> |
| Subject: | Re: Narco 122D mounting? |
On 14 Jul 2005, at 19:10, Kevin Horton wrote:
> I just received a Narco 122D, and am struggling to get the thing in
> the panel. I want to mount it on the aft side (front side?, engine
> side?, you know what I mean) of the panel, rather than cut an ATI
> shaped hole and slip it in from the cockpit side of the panel.
> I've cut the hole and its various cutouts, as shown in the install
> manual. But I can't get the darned thing in the hole - the knobs
> are in the way. It is like a Chinese puzzle. As near as I can
> figure, I need to remove every knob to get it to slip into the
> hole. It seems like the long shaft at the top right has to slip
> into its hole first, and that limits how much you can jockey the
> unit around to get the knobs into the cutouts.
>
> I've managed to remove the Power/Volume knob, and the Course Select
> knob, but, I can't get the frequency changing knobs off. One set
> screw doesn't seem to fit anything I've got to turn it with. It is
> so deep in the hole that I can't see what it looks like
>
> What is the trick? Is there a set screw in every hole in the
> frequency knobs? Are they all Torx T-5, or is one of something
> else like a tiny Allen headed screw?
>
> Thanks for any information.
>
> Kevin
I knew I would figure this out as soon as I sent the e-mail.
I had messed around with that blasted thing for 30 minutes, and
couldn't do it. But I just went back out in the garage for one more
try, and I found the solution. I swear I tried this before, and it
wouldn't work, but it does now.
Solution - remove the Power/Volume and Course Select knobs. Insert
the long Power/Volume shaft in its hole, and slid the unit towards
the panel, so it is at an angle, touching the panel on the right
edge. You should be able to twist it just so to rotate the lower
right portion into place, with the shaft below the frequency changing
knobs slipping into its cutout. Then you can slip the Course Select
knob shaft into its hole. Insert the screws, then replace all the
knobs. Piece of cake :)
Problem solved.
Kevin Horton RV-8 (finishing kit)
Ottawa, Canada
http://www.kilohotel.com/rv8
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: OVP, Alternators, and stuff |
BOB.
I was not INFERRING anything I was QUOTING DIRECTLY FROM A MANUFACTURERS
DATA SHEET and using the INDUSTRY STANDARD definitions for the terms used
therein. No inference, no opinion, no weasel wording etc. Just simple facts.
I have seen CB specifications that do allow one time extremely high current
breaking but the subject specification does not address any such terms.
Also, in general, this hi current is one time only sacrificial use.
If the data sheet is in error it needs to be corrected. OPINION from
engineers who build the devices (as you say "they've never even heard of any
fault limits") do not trump the engineering REQUIREMENTS that we have in the
aerospace industry that PREVENTS ANY violation of the manufacturers data
sheet. Also the CB you used in your tests is not normally available to the
general builders of OBAM aircraft. Clearly the Mil spec specifies fault
limits but as below I cannot read what they are.
I downloaded the mil spec data sheet and regardless of image processing its
not possible for me to read any info relating to the test hi current trip
currents but it appears to start with a 1xx current, clearly not hundreds of
amps but that is a guess as its truly useless to read the specific page in
the spec relating to this subject that you provided for our reading.
I guess we need to check our sources as when I called a CB mfgr the engineer
I talked to said they would not recommend exceeding the limits on the spec
sheet. Perhaps it's being conservative but as there is absolutely no reason
for the hi current WHY?? have it?
I would like to hear from engineers that Designed the original breakers.
From what I can find, none are still around and the current crop of
engineers and reps lack of knowledge is understandable but clearly not a
fact to rely on. Not useful to rely on "lack of info" as info in a
discussion of FACTS. Consider this "latest version of the Mil spec is dated
1967!"
I believe we should NEVER design by inference, opinion etc.. My aerospace
experience says that parts are not necessarily the same quality. Many times
the coml testing is less and or the mil spec failed parts are redefined as
commercial.
I am not aware of any requirements from you that specify the exact circuit
breaker brand and style that also has an identical mil spec equivalent. Its
extremely common for production lines to select parts for mil spec quality
and the rest go to commercial usage (if there is a mil spec and commercial
identical CB which is not always true.
So, if your Crow Bar design depends on a specific mil spec equivalent CB you
should so state that requirement. But WHY? as its so simple to limit the
current with ONE low cost part and the debate and potential problem is
history.
Finally I posted how I got 400 amps thru your crow bar using normal wiring
practices but different from your sample of one test that only shows one
possible short current and ignores worst case possible design currents. You
have apparently ignored the details of my 400 amp circuit that you can
easily duplicate for your own edification.
MY circuit was not a wild example but an exact replica of what is in my
aircraft. I did pick the CB for lowest resistance but the rest is a real
duplicate with the actual batteries etc.
Finally there is absolutely no reason for such a hi short current thru the
crow bar when the addition of a simple resistor can correct this (to many of
us, a glaring design fault) extremely hi current short.
I guess we need to check our sources as when I called a CB mfgr, the
engineer I talked to said they would not recommend exceeding the limits on
the spec sheet. Perhaps it's just being conservative ( I think its simply
there is no testing to document out of spec conditions so its UNK as to the
resulting conditions) but as there is clearly no reason for the hi current
WHY have it?
Please consider being accurate when quoting me. Its fine to disagree but as
you often suggest just the facts so I resent being accused of false or
misleading statements.
Please consider running the test that I detailed to you (in a post to this
list some months ago) that consistently produced 400 amp crow bar currents
when 50 amps is an overkill to open the CB. These currents and the setup was
done under lab conditions (and measured with quality lab calibrated
equipment and while 400 amps was measured there was no worst case analysis
to see what the real max current might be. I saw no reason to do further
analysis as the basic design of the crow bar was unacceptable in my opinion
and has a propensity to false trip (again in a repeatable lab environment,
and You did agree with this in one of our past exchanges) and is another
simple crow bar circuit design error that seldom is seen as its triggered by
a uncommon set of circumstances but still should be corrected. I suspect
this may be one source for the dozens of reported trips that have resulted
in off this list removal of the device from aircraft. Both Eric and I have
had many reports of this.
Regardless I continue to be astounded that you have failed to simply add a
simple resistor and limit the current to a reasonable value.
NO this not mean a return to posting but I will respond to what I feel are
mistatements of my words.
Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: AeroElectric-List: Re: OVP, Alternators, and stuff 0.60
COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
>
> Paul's assertions that the I-T operating curves for response
> times should also be interpreted as limits was in error.
> All breakers produced under mil-spec (and by inference, any
> identical, commercial breaker produced on the same line)
> a qualified by demonstrating an ability to interrupt a fault
> current many times higher than the limits Paul inferred.
>
> See
> http://www.aeroelectric.com/Reference_Docs/Circuit_Breaker/Mil-C-5806G.pdf
>
> After being subjected to the high fault current interrupt, the breaker
> must still meet all other performance requirements.
>
> I've discussed Paul's inference with two experienced and
> learned engineer/reps for circuit breaker manufacturers and
> they've never even heard of any fault limits that put
> a breaker at-risk when used in the crowbar ov protection system.
> Paul's assertions were without foundation in fact and easily
> discounted by researching the test specifications and consulting
> the people who BUILD circuit breakers.
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: OVP, Alternators, and stuff |
0.60 COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
>> However, the Kilovac Czonka III P/N
>> EV200AAANA will do the job easily--200A Interrupt at 320V. As a bonus its
>> coil draws only 100 milliamps.
>Eric, are you saying this is the relay you recommend in this
>diagram: http://www.periheliondesign.com/OVP/OVschems.gif
>Mickey Coggins
Hi Mickey,
That's affirmative. I have a load of these for sale at $80 each (I
think...email me offlist). Nothing else I know is sure to do the job. My
approach is to eliminate all the other contactors anyway so this one is the
only one you need. When you consider it, the race car battery switches are
better than battery contactor; the starter contactor is only used to allow
the use of a wimpy ignition keyswitch; the ground power contactor is
unnecessary, and the crossfeed contactor can easily be eliminated (but I
have too much yardwork to do to describe the details....).
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
When choosing between two evils, I always like to try the one I've never
tried before.
--Mae West
________________________________________________________________________________
| From: | "Thomas Johnson" <trj01(at)comcast.net> |
| Subject: | OVP crowbar false triggering |
I would like to relate my experience with false triggering of the AEC OVP module.
When I started to check out my electrical system (prior to first engine start)
back in 2001, I saw a lot of false triggering. Many switches could invoke
this: fuel pump, flaps, wig-wag, strobes; sometimes switching on, other times
switching off, and there seemed to be a randomness to it.
The schematic for the AeroElectric OVP module has changed slightly over the years,
and I have built several versions. Each one displayed a unique personality
but all of them would false triggered under some condition. I experimented
a bit and eventually thought I "had it whipped" with an array of decoupling capacitors.
Once I moved on to engine start and flight testing I found that I still had a problem.
Engaging the starter almost always triggered the OVP, and in-flight flap
motor engagement sometimes did. For a while I just removed the OVP module
to get on with flight testing.
At some point I came across an AeroElectric-list post reporting a problem similar
to mine. E.Bob responded with a comment about the dv/dt condition that can
effect SCR devices and mentioned that he had considered re-designing the OVP
module using a MOS-FET instead of the SCR. I am an amateur EE and far more comfortable
with digital stuff than analog but I thought I would take a shot at
this.
I built an OVP module based on the IRL3803 and unfortunately the LTC1696. I say
unfortunate not because it is a bad part but that it made a bad experiment (changing
two things at once). I have been flying with this module for about a
year now and have not seen one false trigger. My guess is that there was nothing
wrong with the AEC OVP trigger and that this dv/dt thing was the heart of
my problems.
E.Bob has commented on several occasions is that he has seen this kind of nuisance
trip behavior before but that it is rare. Is there a way we can measure this
condition? I have it, but I have no idea what caused it.
Tom Johnson
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: OVP, Alternators, and stuff |
0.60 COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
>
>BOB.
>
>I was not INFERRING anything I was QUOTING DIRECTLY FROM A MANUFACTURERS
>DATA SHEET and using the INDUSTRY STANDARD definitions for the terms used
>therein. No inference, no opinion, no weasel wording etc. Just simple facts.
My apologies. Can you give me a link to the specifications
for the parts you were investigating? Can you share your
thoughts for selecting those parts for consideration in the
study?
>I have seen CB specifications that do allow one time extremely high current
>breaking but the subject specification does not address any such terms.
>Also, in general, this hi current is one time only sacrificial use.
I'd be pleased to know what devices are so restricted and how
they might find their way into a builder's design.
>If the data sheet is in error it needs to be corrected. OPINION from
>engineers who build the devices (as you say "they've never even heard of any
>fault limits") do not trump the engineering REQUIREMENTS that we have in the
>aerospace industry that PREVENTS ANY violation of the manufacturers data
>sheet. Also the CB you used in your tests is not normally available to the
>general builders of OBAM aircraft. Clearly the Mil spec specifies fault
>limits but as below I cannot read what they are.
>
>I downloaded the mil spec data sheet and regardless of image processing its
>not possible for me to read any info relating to the test hi current trip
>currents but it appears to start with a 1xx current, clearly not hundreds of
>amps but that is a guess as its truly useless to read the specific page in
>the spec relating to this subject that you provided for our reading.
Oops. Stubbed my toe. The TESTS are described in 5806
but test LEVELS are called out in a detail spec for each part.
I've uploaded a typical detail spec for breakers used in Beechcraft
and RAC products for many decades past. See:
http://www.aeroelectric.com/Reference_Docs/Circuit_Breaker/MS3320.pdf
. . . specifically Table three where fault interruption test currents
in the thousands of amps are called out.
These qualification tests are described in the 5806 paragraph 4.7.14
Interrupting Capacity which you'll note was formerly called Rupture
Capacity. See also Figure 3 and Table VII. My gurus suggested that
the term "rupture" was abandoned because it conjured up visions of
an alternative meaning that implied explosion . . . which did happen
sometimes on high voltage, terrestrial power distribution systems
but never in vehicular systems. The term "interrupt" was thought more
appropriate. They didn't recall when this change was made but thought
it was more than 30 years ago. I could go dig the old specs out of the
microfilm and see but I'm not sure it's important.
>I guess we need to check our sources as when I called a CB mfgr the engineer
>I talked to said they would not recommend exceeding the limits on the spec
>sheet. Perhaps it's being conservative but as there is absolutely no reason
>for the hi current WHY?? have it?
But there IS/WAS a reason. When the crowbar ovp system was evolved, the
technology of choice was the relay . . . probably the poorest form of
mechanical
switch for interrupting a highly inductive circuit during an alternator
runaway event. I'll grant you that the crowbar technology is quite
dated . . . a malady that carries over from the certified world. When
we find something that works, it tends to be carved in stone in the
certified world. The LR series regulators are now over 20 years old
and some of those are certified too. I'm not arguing against new and
better ways to do things with today's parts. What I do object to
is general lambasting of an older technology as somehow evil, dangerous,
or lacking in good engineering consideration as a means for selling
the latest-and-greatest . . .
>I would like to hear from engineers that Designed the original breakers.
> From what I can find, none are still around and the current crop of
>engineers and reps lack of knowledge is understandable but clearly not a
>fact to rely on. Not useful to rely on "lack of info" as info in a
>discussion of FACTS. Consider this "latest version of the Mil spec is dated
>1967!"
Actually, that "1967" is "1987" for revision G which replaces revision
"F" dated 1972. But what does the date have to do with it? It's THE
specification to which every breaker we use in our aircraft is tested.
It wouldn't matter if it were crafted in 1940.
This includes all of the push-pull, miniature breakers offered by
Klixon, Cutler-Hammer, Mechanical Products, etc. I'll suggest the
real significance of the date shows the concept of high current
interruption capability is quite mature.
>I believe we should NEVER design by inference, opinion etc.. My aerospace
>experience says that parts are not necessarily the same quality.
My apologies again. I was looking at data sheets for the line
of breakers cited above where I could find NO prohibition for
expecting the breaker to perform as intended in the crowbar
OVP system. If data sheets you were referring to carried such
prohibitions . . . I'd be pleased to know which parts these are.
>Many times the coml testing is less and or the mil spec failed parts
>are redefined as commercial.
Except that there's no economic value in separate production
facilities for "commercial" and "military" components. Once the
design has been proven to be "qualifiable" into a military requirement,
then there's no economic advantage to build a lesser designed part
that's same as the military part except that it won't pass the tests.
Any of the manufacturers above will tell you that all parts of
a particular function and form factor are built on the same production
lines . . . just as the mil-spec integrated circuits were built on
the same lines as commercial parts. The only difference being the
screening and certification processes that required individual handling
of parts . . . the price of mil-spec parts has more to do with labor
intensive hoop jumping and paper shuffling than with any incremental
improvement in quality over it's commercial siblings.
The vast majority of suppliers to the mil-spec market have stopped
offering the screening services. If we want devices screened to
the mil-spec levels, we have to do it ourselves. Manufacturers
got tired of shuffling paper to "prove" that certain of their
every-day run of parts were suited to some customer's extra-ordinary
desires.
The manufacturers wanted to concentrate on building good parts
and get out of the paper business. We're more that welcome to
buy a bunch of their parts and generate a pile of paper to go
with them but we have to do that on our own.
>I am not aware of any requirements from you that specify the exact circuit
>breaker brand and style that also has an identical mil spec equivalent. Its
>extremely common for production lines to select parts for mil spec quality
>and the rest go to commercial usage (if there is a mil spec and commercial
>identical CB which is not always true.
Yes, when the manufacturer's were asked to produce mil-spec parts,
they would screen the output of a production line for parts that
were at the top of the bell curve for characteristics unique to
the military environment, usually things like operating temperature,
leakages, switching speeds, etc. When they found enough parts to
fill the mil-spec order, then parts that didn't meet the mil-specs
were probably sent through the commercial pipe. But a lot of parts
that WOULD meet mil-spec screening went through the commercial pipe
too.
>So, if your Crow Bar design depends on a specific mil spec equivalent CB you
>should so state that requirement. But WHY? as its so simple to limit the
>current with ONE low cost part and the debate and potential problem is
>history.
Because sir, if I capitulate to your suggestion in the spirit
of compromise and good will, then it's a tacit if not overt
acknowledgement of a design deficiency in thousands of delivered
systems. I belive that the "potential problem" does not exist
for reasons cited and DETAILED. If I believed that a critical
design deficiency exists, then I would be obligated to inform a lot of
customers about it and take remedial action.
The breakers we've always sold, recommended and supplied in our
kits have been the miniature, push-pull breakers from the
constellation of products offered by suppliers cited. I would
not expect other styles to be so different but if you can
cite them, I'll stand corrected as to interpretation of the
specs you examined. I'll acquire exemplar parts for examination
as to risks and go from there. Just tell me where to find them.
>Finally I posted how I got 400 amps thru your crow bar using normal wiring
>practices but different from your sample of one test that only shows one
>possible short current and ignores worst case possible design currents. You
>have apparently ignored the details of my 400 amp circuit that you can
>easily duplicate for your own edification.
I'll have to go back an look but I seem to recall we started
with a 700 amp value. The point of my bench experiments was to
put some more reasonable upper bound on expected fault currents.
Given that MY breakers of choice are all I-Squared*R devices and
have series heaters with resistances on the order of 40 milliohms
then the maximum zero-wire length fault current to be expected
is 500 amps. Add in some minimal wire lengths and add the 2v drop
across the triggered SCR and we get currents MUCH less than 500
amps; a small fraction of that to which MY choice of breakers was
qualified.
>MY circuit was not a wild example but an exact replica of what is in my
>aircraft. I did pick the CB for lowest resistance but the rest is a real
>duplicate with the actual batteries etc.
Which breaker? What wire lengths? Were these conditions chosen
as an optimization of a design or an investigation of the worst
possible case imaginable?
>Finally there is absolutely no reason for such a hi short current thru the
>crow bar when the addition of a simple resistor can correct this (to many of
>us, a glaring design fault) extremely hi current short.
100-200 amps for tens of milliseconds is a sneeze compared
to 200+ amps for seconds when cranking an engine. If we're
expecting electro-whizzies to operate in a graceful manner
during a 12,000 watt-second cranking event that happens
once-per-flight-cycle, then there's no reason I can deduce
to fear or demonize the 50 watt-second crowbar OV event that may never
happen over the lifetime of the airplane.
>I guess we need to check our sources as when I called a CB mfgr, the
>engineer I talked to said they would not recommend exceeding the limits on
>the spec sheet. Perhaps it's just being conservative ( I think its simply
>there is no testing to document out of spec conditions so its UNK as to the
>resulting conditions) but as there is clearly no reason for the hi current
>WHY have it?
>
>Please consider being accurate when quoting me. Its fine to disagree but as
>you often suggest just the facts so I resent being accused of false or
>misleading statements.
I presumed you were referring to the same data sheets I was
that described the style and quality of breakers common to
the certified aircraft industry. I'd be pleased to know what
breakers YOU were using and your rational for selecting those
devices to use in your tests. The interruption current limits
you cited must be INFERRED from the data sheets I was looking
at . . . please accept my apology and enlighten me as to the
data upon which you relied.
>Please consider running the test that I detailed to you (in a post to this
>list some months ago) that consistently produced 400 amp crow bar currents
>when 50 amps is an overkill to open the CB. These currents and the setup was
>done under lab conditions (and measured with quality lab calibrated
>equipment and while 400 amps was measured there was no worst case analysis
>to see what the real max current might be. I saw no reason to do further
>analysis as the basic design of the crow bar was unacceptable in my opinion
>and has a propensity to false trip (again in a repeatable lab environment,
>and You did agree with this in one of our past exchanges) and is another
>simple crow bar circuit design error that seldom is seen as its triggered by
>a uncommon set of circumstances but still should be corrected. I suspect
>this may be one source for the dozens of reported trips that have resulted
>in off this list removal of the device from aircraft. Both Eric and I have
>had many reports of this.
Yup, the SCR has sensitivities to dv/dt effects that must be
accommodated in the design of any product that uses them. First
crack at the design was compliant with everything MIL-Std-704
and DO-160 told us to expect. Experience from the field has
shown that there are unanticipated effects that dictated
refinement of the design. So what's new? The stand-by alternator
on the Bonanzas is a good example (Landing and taxi lights inrush
+ bounce of the breaker-switch would trip the system). That
system has been in successful service now for over 5 years and
has proven to been 1000% better than the system it replaced.
Overall, the system has enjoyed a good run in the marketplace
of better than 20 years. Problems have been identified and worked out
as soon as they were identified and are still being worked in
small numbers today. I hand-delivered a crowbar ovm to a customer
last night who is experiencing nuisance trips after add a new
transponder! We'll see if we can get an opportunity to deduce
root cause of this new phenomenon.
>Regardless I continue to be astounded that you have failed to simply add a
>simple resistor and limit the current to a reasonable value.
In our first designs (LR-1) there WAS a current limiting
resistor. It was a fabricated device that was labor intensive,
added to parts count and reduced reliability. Further testing
and investigation proved that it was UNNECESSARY and it was
removed in the LR-2 and subsequent designs.
>NO this not mean a return to posting but I will respond to what I feel are
>mistatements of my words.
Perhaps no mistakes at all. What we may be finally zeroing in on
is (1) an open exchange of all data upon which our designs and
assertions are based and and (2) a sifting design features for which you
say "Plan K" is "better" than "Plan F".
I have NEVER produced words intended to attack a new idea
or product. From my perspective, 100% of my efforts in this discussion
have been to defend the conception, design, fabrication, marketing,
refinement, and customer service for a product that has performed
as intended and without undue side-effects for about 30 years.
If you have a modern alternative to offer, nobody will be more
supportive than I . . . but as I write these words, we have
yet to benefit from any DATA supporting either (1) your demonization
of the crowbar ovp system in its present form or (2) demonstrations
of the next greatest thing offered to move our art and science
forward.
I feel like a guy selling vacuum tube radios that has somebody
standing on the sidewalk outside holding up a little black box
which just MIGHT be a transistor radio who is telling folks not
to buy my radios because they give you warts or trash your
brain cells. No, the little black box is not for sale, but that
will all happen "in due course." But in the mean time, if I
could be persuaded to change the color of the radio's case,
it would stop trashing brain cells and only cause warts.
Every endeavor starts out with what one hopes is an accurate
recipe for success. The recipe gets tweaked for improvements as
the market life of the product evolves. Any successful entrepreneur
welcomes suggestions for improvement. I have no illusions as to
the marketplace longevity of the crowbar ovp system. In fact,
I may even replace it myself. But please, let us evolve market
offerings based on shared information and science; not as
prophylactics against warts. I've laid out my recipe in detail
and offered DATA, repeatable experiments and marketplace history
to support that data. Any errors of inference on my part should
be easy to set aside and I'd be delighted to know the facts.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> overvoltage protection |
| Subject: | Re: A question on my crossbar |
overvoltage protection
>
>I wonder if this is related to what I reported a month or so ago?
>
>"While tracking down a electrical problem ( haven't run the engine yet)
>I was sidetracked for awhile by the circuit breaker that feeds a 40 amp
>OV relay on my permanent magnet alternator popping.
???? 40A breaker ???? What power distribution diagram are
you using?
> It seems that
>wiggling a loose connection between the breaker and the relay will trip
>the OVP and open the breaker. The crowbar OVP is constructed from the
>new design. It tests OK and it doesn't trip if the alternator switch is
>operated. It does trip if I intentionally rapidly connect and disconnect
>the wire to the relay. The relay coil draws about 130 mA. If I
>disconnect the OVP I am unable to make the C/B trip so it would seem
>that the OVP is activating. It doesn't seem to make any difference
>whether a diode is across the relay coil.
Hmmm . . .
>I'm guessing this is normal and I'm making voltage spikes at a faster
>rate than the OVP time delay resets but I would have expected negative
>spikes rather than positive spikes. "
It might be "normal" but not expected. I can deduce no
feature of the design that would "pump up" the ov protection
to some trip level based on the intermittent connection
you describe.
>At that time I also said that "temporarilly adding a unidirectional
>transorb across it makes it more resistant to tripping which seems to
>confirm that I am generating positive spikes" but in retrospect I'm not
>certain that the transorb made much difference. Since I can't cycle the
>switch fast enough to cause a problem and nobody commented, I tightened
>my loose connection and did not persue this further.
Interesting. I'm sorry I missed the original discussion. I presume
your talking about an OVM-14 from B&C. I've not had any activity
with that product for several years. I'd like to get yours back
to see if I can duplicate your experience on the bench. Shoot
me your address and I'll send you a new one and a return envelope
for the old one.
I'll remind everyone that I'm intently interested in pursuing
this kind of investigation on products of any manufacture and
if I don't pick up on the conversation from a routine List
posting, send me a direct e-mail through the website at:
http://www.aeroelectric.com/bob.nuckolls/ (I'm use this to
avoid posting the "real" address for 'bots' to find.)
I've got a lot of balls in the air at once and I don't
want folks to believe my inattention is an overt avoidance of
the issue.
Bob. . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: OVP crowbar false triggering |
>
>I would like to relate my experience with false triggering of the AEC OVP
>module. When I started to check out my electrical system (prior to first
>engine start) back in 2001, I saw a lot of false triggering. Many
>switches could invoke this: fuel pump, flaps, wig-wag, strobes; sometimes
>switching on, other times switching off, and there seemed to be a
>randomness to it.
>
>The schematic for the AeroElectric OVP module has changed slightly over
>the years, and I have built several versions. Each one displayed a unique
>personality but all of them would false triggered under some condition. I
>experimented a bit and eventually thought I "had it whipped" with an array
>of decoupling capacitors.
>
>Once I moved on to engine start and flight testing I found that I still
>had a problem. Engaging the starter almost always triggered the OVP, and
>in-flight flap motor engagement sometimes did. For a while I just removed
>the OVP module to get on with flight testing.
>
>At some point I came across an AeroElectric-list post reporting a problem
>similar to mine. E.Bob responded with a comment about the dv/dt condition
>that can effect SCR devices and mentioned that he had considered
>re-designing the OVP module using a MOS-FET instead of the SCR. I am an
>amateur EE and far more comfortable with digital stuff than analog but I
>thought I would take a shot at this.
>
>I built an OVP module based on the IRL3803 and unfortunately the
>LTC1696. I say unfortunate not because it is a bad part but that it made
>a bad experiment (changing two things at once). I have been flying with
>this module for about a year now and have not seen one false trigger. My
>guess is that there was nothing wrong with the AEC OVP trigger and that
>this dv/dt thing was the heart of my problems.
>
>E.Bob has commented on several occasions is that he has seen this kind of
>nuisance trip behavior before but that it is rare. Is there a way we can
>measure this condition? I have it, but I have no idea what caused it.
Great question and thanks for the post. Yes, the current
production ovp modules have been tweaked to accommodate
situations such as you've described. I would be delighted
to put my hands on your airplane with some test equipment
to see if we can understand why it's so different . . . or
whether the crowbar module has a manufacturing or design
problem.
Do you still have the old module? If so, you can send it
back to me for a no-charge upgrade. I'd be grateful to
hear of your experiences with the "upgraded" module. In
fact, since you have a "problem" airplane, it might
be interesting to send you several modules with various
evolutionary steps installed to see which one is the
"rose wood stake". If you're willing to participate
in the experiment, I think we could do some good science
here.
Bob . . .
________________________________________________________________________________
| From: | <chaztuna(at)adelphia.net> |
| Subject: | Re: Auto Pilot Servo Ground wire |
---- "Robert L. Nuckolls wrote:
>
>
> P.S. if you get a good answer from Trutrak, please
> share it with us on the list so that it gets stashed
> in the archives. Let us know who you talked, their
> phone number and what was advised along with any
> explanations they may have to offer.
>
> Bob . . .
Bob,
I spoke to tech support at Trutrak this morning. They told me to make all the
grounds at a single point.
Charlie Kuss
>
> >
> >Bob & Listers,
> > Should the servo ground wires for the Trutrak (or other) auto pilot
> > servos & control boxs be grounded locally or should they be run up to the
> > common ground point?
> > I have a rear mounted battery on my RV-8A project. The pitch servo &
> > controller are only 6 - 8" from my battery. Should I ground them directly
> > to the battery?
>
> What do the instructions say? Posting a question
> like that on the List is fraught with risk. You need
> to do it only when the instructions are not clear -AND-
> attempts to clarify ambiguous instructions with
> the manufacturer has failed or is impossible.
>
> Then your ONLY recourse is to seek learned advice.
> However, unless the responding individuals have first hand
> knowledge unique to the product, then the best you
> can hope for is an educated guess.
>
> I'll suggest it's FAR better to exhaust all opportunities
> for the "good" advice before you resort to "best guess"
> advice.
>
> Bob . . .
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Auto Pilot Servo Ground wire |
>
>
>---- "Robert L. Nuckolls wrote:
>
> >
> >
> > P.S. if you get a good answer from Trutrak, please
> > share it with us on the list so that it gets stashed
> > in the archives. Let us know who you talked, their
> > phone number and what was advised along with any
> > explanations they may have to offer.
> >
> > Bob . . .
>
>Bob,
> I spoke to tech support at Trutrak this morning. They told me to make
> all the grounds at a single point.
>Charlie Kuss
Good data. Thanks. I might have guessed that but
now we can ALL speak to the question with a higher
degree of certainty. As a rule-of-thumb, one is almost
never wrong grounding all components of a single system
at the same place. When that system shares data or control
lines with a second system, then it's good that both of those
systems ground at the same place too.
In terms of your original question I'll suggest it
doesn't matter in terms of system performance whether
you ground all stuff at the battery or at the firewall
ground bus . . . they're best grounded TOGETHER.
Bob . . .
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: A question on my crossbar overvoltage |
protection
Hi Bob
It's obvious that you are a busy man and I thank you for your
observations. No this is not a 40amp breaker. It's a small automotive
relay with 40 amp rated contacts. It provides an OV disconnect for a 20
amp PM alternator. The relay coil draws about 130 ma. The circuit
breaker that feeds this relay coil, and that the Crowbar OVP trips, is
a 2 1/2 amp (two and a half amp) breaker.
The OVP is not from B&C. It is homemade according to the revision dated
4/16/2 and constructed with the recommended Digi-key parts. Since you
have confirmed that this is unexpected behaviour, I will do some more
investigation and let you know what I find.
This is on a modified Z-14 and it is not even on the battery that feeds
the primary systems of my electrically dependant engine. This battery
and PM alternator feeds the backup engine systems. I'll start by
investigating whether the OVP for the other alternator behaves similarly
and perhaps put a scope on the 22 uF capacitor and the SCR. If I don't
learn anything useful and it is still exhibiting this behaviour, I'll be
happy to donate it to the cause if you still want to see it but it is
just a homemade unit.
thanks
Ken
Robert L. Nuckolls, III overvoltage protection wrote:
>
>
>
>
>>
>>I wonder if this is related to what I reported a month or so ago?
>>
>>"While tracking down a electrical problem ( haven't run the engine yet)
>>I was sidetracked for awhile by the circuit breaker that feeds a 40 amp
>>OV relay on my permanent magnet alternator popping.
>>
>>
>
> ???? 40A breaker ???? What power distribution diagram are
> you using?
>
>
>> It seems that
>>wiggling a loose connection between the breaker and the relay will trip
>>the OVP and open the breaker. The crowbar OVP is constructed from the
>>new design. It tests OK and it doesn't trip if the alternator switch is
>>operated. It does trip if I intentionally rapidly connect and disconnect
>>the wire to the relay. The relay coil draws about 130 mA. If I
>>disconnect the OVP I am unable to make the C/B trip so it would seem
>>that the OVP is activating. It doesn't seem to make any difference
>>whether a diode is across the relay coil.
>>
>>
>
> Hmmm . . .
>
>
>
>>I'm guessing this is normal and I'm making voltage spikes at a faster
>>rate than the OVP time delay resets but I would have expected negative
>>spikes rather than positive spikes. "
>>
>>
>
> It might be "normal" but not expected. I can deduce no
> feature of the design that would "pump up" the ov protection
> to some trip level based on the intermittent connection
> you describe.
>
>
>
>
>>At that time I also said that "temporarilly adding a unidirectional
>>transorb across it makes it more resistant to tripping which seems to
>>confirm that I am generating positive spikes" but in retrospect I'm not
>>certain that the transorb made much difference. Since I can't cycle the
>>switch fast enough to cause a problem and nobody commented, I tightened
>>my loose connection and did not persue this further.
>>
>>
>
> Interesting. I'm sorry I missed the original discussion. I presume
> your talking about an OVM-14 from B&C. I've not had any activity
> with that product for several years. I'd like to get yours back
> to see if I can duplicate your experience on the bench. Shoot
> me your address and I'll send you a new one and a return envelope
> for the old one.
>
> I'll remind everyone that I'm intently interested in pursuing
> this kind of investigation on products of any manufacture and
> if I don't pick up on the conversation from a routine List
> posting, send me a direct e-mail through the website at:
>
> http://www.aeroelectric.com/bob.nuckolls/ (I'm use this to
> avoid posting the "real" address for 'bots' to find.)
>
> I've got a lot of balls in the air at once and I don't
> want folks to believe my inattention is an overt avoidance of
> the issue.
>
> Bob. . .
>
>
________________________________________________________________________________
| Subject: | Re: OVP, Alternators, and stuff |
On 15 Jul 2005 at 10:34, Eric M. Jones wrote:
>
>
>
>
>> one is the only one you need. When you consider it, the race car
> battery switches are better than battery contactor; the starter
> contactor is only used to allow the use of a wimpy ignition keyswitch;
> the ground power contactor is unnecessary, and the crossfeed contactor
> can easily be eliminated (but I have too much yardwork to do to
> describe the details....).
>
Eric
What manly keyswitch would use for the starter? Also, I believe the contactor is
used so that in case the
solenoid sticks and the ring gear remains engaged, there is no power to the starter.
Peter
________________________________________________________________________________
| From: | "Thomas Johnson" <trj01(at)comcast.net> |
| Subject: | Re: OVP crowbar false triggering |
Bob N,
I would be delighted to put my hands on your airplane with some test equipment
to see if we can understand why it's so different.
I would like that too but I am in SoCal and you are not (COME ON OUT! I'll buy
lunch!). What do you think is the minimum requirement for test equipment to
get some useful data on this? I think the answer will be "more than I can afford"
but it does not hurt to ask.
Do you still have the old module? If so, you can send it back to me for a no-charge
upgrade.
Yes, I have all of them. I built four but it was really 2 X 2 versions. I will
round them up and send them to the address on your web site if I don't hear
otherwise. I do not need you to send replacements for my sake, I am quite happy
with the "MOS-FET miracle" I am flying now. I would be willing try out new
versions in my airplane and report the results.
to see which one is the "rose wood stake".
Please forgive my ignorance. I know what a "rosetta stone" is, but I do not know
what "rose wood stake" means. It always hurts to ask this kind of question
but if I don't ask I will never know.
Tom Johnson
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: OVP, Alternators, and stuff |
0.60 COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
>>
>>
>>
>>
>> one is the only one you need. When you consider it, the race car
>> battery switches are better than battery contactor; the starter
>> contactor is only used to allow the use of a wimpy ignition
>> keyswitch;...........Eric
>What manly keyswitch would use for the starter?
I don't know of a 300A keyswitch either. I meant to imply that using a
separate manual switch for starting might be better.
>Also, I believe the contactor is used so that in case the solenoid sticks
>and the ring gear remains engaged, there is no power to the starter...Peter
In that case powering down the whole system might be better. Many starters
use a built-in solenoid, and I'd go with one of those. Again a stuck starter
would mean powering down.
>> approach is to eliminate all the other contactors anyway so this one is
>> the
>> only one you need. When you consider it, the race car battery switches
>> are
>> better than battery contactor; ...Eric
>Sounds interesting. Do you have one you recommend, and will they
>work for rear mounted batteries? I've already got mine hooked up
>with standard contactors, but it's always fun to learn something
>new.
I don't know the best one. Perhaps the Aeroelectric minions can find the
best one. But start with the battery disconnects from Flaming-River.com (
http://www.flamingriver.com/index.cfm/page/ptype=results/Category_ID=133/home_id=76/mode=cat/cat133.htm )
would probably work. I am still in search mode on this.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
"Nothing is too wonderful to be true."
James Clerk Maxwell, discoverer of electromagnetism
"Too much of a good thing can be wonderful."
Mae West, discoverer of personal magnetism
________________________________________________________________________________
| From: | "John Burnaby" <jonlaury(at)impulse.net> |
| Subject: | Dual Fuel Pumps and EFI |
I want to wire 2 fuel pumps, for an EFI system, into AEC schematic Z-14 so that
when fuel pressure drops below a preset psi, the secondary pump turns on and
locks on ,and I want to have manual overides.
I was told pressure switches are not that accurate re repeatability and that I
would be better off with a pressure transducer. I'm not sure what a transducer
is and how it would be integrated into a switch that would control the pumps,
but I'm guessing that the pressure sensing device (transducer?) would be wired
into some sort of locking relay.
I welcome any ideas.
Thanks,
John
________________________________________________________________________________
| From: | "John Burnaby" <jonlaury(at)impulse.net> |
| Subject: | Dual Fuel Pumps and EFI |
I want to wire 2 fuel pumps, for an EFI system, into AEC schematic Z-14 so that
when fuel pressure drops below a preset psi, the secondary pump turns on and
locks on ,and I want to have manual overides.
I was told pressure switches are not that accurate re repeatability and that I
would be better off with a pressure transducer. I'm not sure what a transducer
is and how it would be integrated into a switch that would control the pumps,
but I'm guessing that the pressure sensing device (transducer?) would be wired
into some sort of locking relay.
I welcome any ideas.
Thanks,
John
________________________________________________________________________________
| From: | "Greg Puckett" <rv8er(at)myawai.com> |
| Subject: | KMA20 installation manual or ?? |
Hello,
I'm installing a KMA20 and while I have the pin-out from
aeroelectric.com I need a couple of questions answered.
It appears that the KMA20 has a speaker input and a phone level input
from each Comm. The TKM radio has a speaker output and a Comm. output.
I'm assuming that I should not be connecting both of these, but I'm not
sure.
Does the KMA20 have a speaker level and a phone level input available
just so you can connect a navcom that may only have one or the other.
I'm worried that both of these inputs will be summed if I connect them
both and the overall volume will be twice as loud as it should.
Does anyone have a KMA20 install manual handy that may have the answer
to this?
Thanks,
Greg
________________________________________________________________________________
| From: | "r falstad" <bobair8(at)msn.com> |
| Subject: | CESSNA SPLIT MASTER SWITCH: Something's Backwards |
I'm going to use a Cessna split master switch in my GlaStar. But something is
backwards (either the switch or my head).
When the switch assembly is oriented so that rocking the switches "UP" is "ON",
the left-hand switch will not switch "ON" without engaging and forcing the right-hand
switch "ON", as well. I can switch the right-hand switch "ON" while
leaving the left-hand switch "OFF".
My sense of ergonomics and recollection from flying Cessnas years ago tell me that
the Battery Master switch should be on the left and the Alt. Field switch
on the right. It also seems to me that the interlocking feature of the two switches
is there to make sure that the Alt. Field switch can't be turned on without
the Battery Master switch also being on, but that the Battery Master switch
can be on without having the Alt. Field switch on also.
If my thinking is correct, then the left-hand switch will have to be my Alt. Field
switch and the right-hand switch will have to be the Battery Master.
Is the switch backwards or am I? (I bought the switch from Aircraft Spruce several
years ago but (so far) it is new and unused.)
Best regards,
Bob
________________________________________________________________________________
| From: | "Alan Adamson" <aadamson(at)highrf.com> |
| Subject: | CESSNA SPLIT MASTER SWITCH: Something's Backwards |
It's actually backwards from that.
http://www.highrf.com/gallery/38AL-Panel/DSCN0418
Is the picture of my 2004 Cessna 182 with G1000. You'll see the "red"
rocker switch with Batt on the right and Alt on the left. There is a
lockout, If you press the left switch up, it causes both to go on, if you
press the right switch to on, it will only cause the Batt to turn on, and
the Alt will stay off.
Alan
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of r falstad
Subject: AeroElectric-List: CESSNA SPLIT MASTER SWITCH: Something's
Backwards
I'm going to use a Cessna split master switch in my GlaStar. But something
is backwards (either the switch or my head).
When the switch assembly is oriented so that rocking the switches "UP" is
"ON", the left-hand switch will not switch "ON" without engaging and forcing
the right-hand switch "ON", as well. I can switch the right-hand switch
"ON" while leaving the left-hand switch "OFF".
My sense of ergonomics and recollection from flying Cessnas years ago tell
me that the Battery Master switch should be on the left and the Alt. Field
switch on the right. It also seems to me that the interlocking feature of
the two switches is there to make sure that the Alt. Field switch can't be
turned on without the Battery Master switch also being on, but that the
Battery Master switch can be on without having the Alt. Field switch on
also.
If my thinking is correct, then the left-hand switch will have to be my Alt.
Field switch and the right-hand switch will have to be the Battery Master.
Is the switch backwards or am I? (I bought the switch from Aircraft Spruce
several years ago but (so far) it is new and unused.)
Best regards,
Bob
________________________________________________________________________________
| From: | "John Swartout" <jgswartout(at)earthlink.net> |
| Subject: | Wiring a stick-grip PTT? |
I'm ready to wire my RAC stick grip PTT for pilot headset COM radio
transmission. No co-pilot PTT (My Zenith CH-801 has a center
"Y"-stick.) I'm using an ICOM A200 radio and a PS Engineering PM
1000-II intercom. No audio panel. I don't understand the section of
the intercom installation manual dealing with the PTT switch.
Three possible scenarios are given:
1. The PTT is built into the pilot and copilot yokes....
This would not apply because nothing is "built in" yet, and there will
be only one PTT.
2. Built in PTT only on the pilot side only [sic]. This
configuration requires a modified external PTT switch plugged into the
copilot's mic jack. (See Appendix A) When the copilot's PTT is
depressed, this activiates an internal relay that switches the mic audio
to the aircraft radio from the pilot to the copilot.
3. No built in PTT switch at all. Two built-in PTT must be installed
or two external, modified PTT switches will be required for both the
pilot and copilot. Modifications to the PTT may be required. See
Appendix A.
# 3 seems closest to where I'm starting, but it seems to suggest that I
MUST have a PTT for the copilot. This makes no sense to me because if I
did install a PTT switch for the copilot and then never used it, it
would just be a forever-open circuit that wouldn't affect the operation
of the intercom in any way I can deduce.
(There will be a microphone on the panel that anybody in the airplane
could use if the pilot slumped over on his milk crate.)
Here's Appendix A:
PTT Modifications
When received from the manufacturer, an after-market PTT switch opens
the mic audio path to the "ring" connection of the PTT mic plug. When
the PTT is between the intercom and the headset, the intercom function
will not work until the PTT switch is depressed. A simple modification
can be performed to allow proper intercom operation. NOTE: This mod
does not alter normal operations. The following are sample procedures
for common PTT switches. Contact the PTT manufacturer if you require
more information.
Then modification procedures are given for David Clark, Telex
PT-200, and Telex PT-300 PTT switches. None of them make any sense to
me because they all seem to have, as near as I can tell, three wires in
them, whereas the RAC has only a high and a low and a push button to
connect them. There is no wiring diagram to show what these
modifications accomplish.
On the PS Engineering website, the wiring diagram for the PM1000II
(11902) does not show the complication indicated in the text above. It
simply shows the PTT switch making contact between pin 24 (Pilot Mic
PTT) and pin 11 (Pilot Mic Audio Lo), and, for the copilot, making
contact between pin 22 (Copilot Mic PTT) and pin 10 (Copilot Mic Audio
Lo).
So can't I just run the two wires from the PTT switch to Pins 24
and 11 and be done with it? Or would I have to add a third wire
someplace in the PTT switch so the intercom function will work?
Or, could I avoid the problem described in Appendix A by wiring
the PTT switch someplace NOT between the intercom and the headset?
Any help is appreciated in advance.
John
________________________________________________________________________________
| From: | "glaesers" <glaesers(at)wideopenwest.com> |
| Subject: | Re: Dual Fuel Pumps and EFI |
See the Aux Fuel Pump circuit on the Engine Electrical Architecure diagram
on this page:
http://www.wideopenwest.com/~glaesers/RV7A/RV7A_Electrical.htm
It does exactly what you want - see the explanation in the OPERATION box.
This is an adaptation of the electrical system architecture from the
Eggenfeller Subaru installation manual. Their design uses a single 4PDT
switch to control the power to the engine. I want switch reduncancy, so I
use more (and less expensive) switches.
Eggenfeller supplies the fuel pressure sensor switch. I don't have one yet
so I don't know what kind of sensor it is (mechanical or electronic), but
I've been on their Yahoo list for over a year, and no one has ever reported
problems. I'm sure you could contact Jan Eggenfeller to get the part number
if you are interested.
A transducer is a generic term for converting one form of energy to another
(in this case pressure to electrical). So any pressure switch is a
transducer, but I suspect the comment was about the type of transducer (ie.
mechanical vs. electronic sensor). Dick Tasker (who participates on this
list) would be a good source for info - his company makes sensors.
Dennis Glaeser
RV7A Empennage
I want to wire 2 fuel pumps, for an EFI system, into AEC schematic Z-14 so
that
when fuel pressure drops below a preset psi, the secondary pump turns on and
locks on ,and I want to have manual overides.
I was told pressure switches are not that accurate re repeatability and that
I
would be better off with a pressure transducer. I'm not sure what a
transducer
is and how it would be integrated into a switch that would control the
pumps,
but I'm guessing that the pressure sensing device (transducer?) would be
wired
into some sort of locking relay.
I welcome any ideas.
Thanks,
John
________________________________________________________________________________
| From: | "John Swartout" <jgswartout(at)earthlink.net> |
| Subject: | Re: DC fans problem. |
Eric, would you recommend one of these Transient Voltage Suppressors for
a Commercial Aviation Products 12VDC flap actuator (Model D145-00-36-3)?
John
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Eric
M. Jones
Subject: AeroElectric-List: Re: DC fans problem.
> ... Make sure you put a Transient Voltage Suppressor across every DC
fan
> and every relay
> and coil and motor unless an oscilloscope says you don't need to.
>What would be the part number for that Transient Voltage Suppressor?
>Do you sell them with a pretty picture like you have for the rest
>of your stuff? Thanks, Mickey
Mickey,
Bidirectional transorb P6KE18CA will do the job and Digikey has them. I
do
sell these in a 12-pack as "SnapJacks"
including shrink tubing and connector lugs and mysterious details
sufficient
to outfit a typical small airplane.
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge
MA 01550-2705
(508) 764-2072
"Democracy is the theory that the common people know what they want and
deserve to get it good and hard." -- H. L. Mencken
________________________________________________________________________________
| From: | "Mike Larkin" <mlas(at)cox.net> |
| Subject: | Wiring a stick-grip PTT? |
All you would have to do is run one side of the pilots PTT switch to pin
11 (pilot audio ground) and the other side of the PTT switch to pin 24
(pilot mic). This will give you transmit function for the pilot's mic
and normal VOX intercom function. The drawing give an option for a loud
cockpit setup that enables you to turn off the vox, this will not be
used in your case. If you should decide to put a PTT on the co-pilot
side then the PTT switch would go from pin 10 (co-pilot audio ground) to
pin 22 (co-pilot mic). That's it...
Mike Larkin
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of John
Swartout
Subject: AeroElectric-List: Wiring a stick-grip PTT?
I'm ready to wire my RAC stick grip PTT for pilot headset COM radio
transmission. No co-pilot PTT (My Zenith CH-801 has a center
"Y"-stick.) I'm using an ICOM A200 radio and a PS Engineering PM
1000-II intercom. No audio panel. I don't understand the section of
the intercom installation manual dealing with the PTT switch.
Three possible scenarios are given:
1. The PTT is built into the pilot and copilot yokes....
This would not apply because nothing is "built in" yet, and there will
be only one PTT.
2. Built in PTT only on the pilot side only [sic]. This
configuration requires a modified external PTT switch plugged into the
copilot's mic jack. (See Appendix A) When the copilot's PTT is
depressed, this activiates an internal relay that switches the mic audio
to the aircraft radio from the pilot to the copilot.
3. No built in PTT switch at all. Two built-in PTT must be installed
or two external, modified PTT switches will be required for both the
pilot and copilot. Modifications to the PTT may be required. See
Appendix A.
# 3 seems closest to where I'm starting, but it seems to suggest that I
MUST have a PTT for the copilot. This makes no sense to me because if I
did install a PTT switch for the copilot and then never used it, it
would just be a forever-open circuit that wouldn't affect the operation
of the intercom in any way I can deduce.
(There will be a microphone on the panel that anybody in the airplane
could use if the pilot slumped over on his milk crate.)
Here's Appendix A:
PTT Modifications
When received from the manufacturer, an after-market PTT switch opens
the mic audio path to the "ring" connection of the PTT mic plug. When
the PTT is between the intercom and the headset, the intercom function
will not work until the PTT switch is depressed. A simple modification
can be performed to allow proper intercom operation. NOTE: This mod
does not alter normal operations. The following are sample procedures
for common PTT switches. Contact the PTT manufacturer if you require
more information.
Then modification procedures are given for David Clark, Telex
PT-200, and Telex PT-300 PTT switches. None of them make any sense to
me because they all seem to have, as near as I can tell, three wires in
them, whereas the RAC has only a high and a low and a push button to
connect them. There is no wiring diagram to show what these
modifications accomplish.
On the PS Engineering website, the wiring diagram for the PM1000II
(11902) does not show the complication indicated in the text above. It
simply shows the PTT switch making contact between pin 24 (Pilot Mic
PTT) and pin 11 (Pilot Mic Audio Lo), and, for the copilot, making
contact between pin 22 (Copilot Mic PTT) and pin 10 (Copilot Mic Audio
Lo).
So can't I just run the two wires from the PTT switch to Pins 24
and 11 and be done with it? Or would I have to add a third wire
someplace in the PTT switch so the intercom function will work?
Or, could I avoid the problem described in Appendix A by wiring
the PTT switch someplace NOT between the intercom and the headset?
Any help is appreciated in advance.
John
--
--
________________________________________________________________________________
| From: | "Mike Larkin" <mlas(at)cox.net> |
| Subject: | CESSNA SPLIT MASTER SWITCH: Something's Backwards |
That is normal.....
Mike Larkin
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of r
falstad
Subject: AeroElectric-List: CESSNA SPLIT MASTER SWITCH: Something's
Backwards
I'm going to use a Cessna split master switch in my GlaStar. But
something is backwards (either the switch or my head).
When the switch assembly is oriented so that rocking the switches "UP"
is "ON", the left-hand switch will not switch "ON" without engaging and
forcing the right-hand switch "ON", as well. I can switch the
right-hand switch "ON" while leaving the left-hand switch "OFF".
My sense of ergonomics and recollection from flying Cessnas years ago
tell me that the Battery Master switch should be on the left and the
Alt. Field switch on the right. It also seems to me that the
interlocking feature of the two switches is there to make sure that the
Alt. Field switch can't be turned on without the Battery Master switch
also being on, but that the Battery Master switch can be on without
having the Alt. Field switch on also.
If my thinking is correct, then the left-hand switch will have to be my
Alt. Field switch and the right-hand switch will have to be the Battery
Master.
Is the switch backwards or am I? (I bought the switch from Aircraft
Spruce several years ago but (so far) it is new and unused.)
Best regards,
Bob
--
--
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Dual Fuel Pumps and EFI |
>
>I want to wire 2 fuel pumps, for an EFI system, into AEC schematic Z-14 so
>that when fuel pressure drops below a preset psi, the secondary pump turns
>on and locks on ,and I want to have manual overides.
How does your engine behave under in-flight fuel starvation? Does it
present a situation that is difficult or dangerous to recover from?
The reason I ask is because systems with automatic features generally
have parts counts several times that of a simple manual system. In
all of the airplanes I fly, fuel starvation due to a misplacement of
fuel selector valve or failure of primary pump will recover in seconds
after corrective action on the part of the pilot with very little loss
of altitude.
>I was told pressure switches are not that accurate re repeatability and
>that I would be better off with a pressure transducer. I'm not sure what a
>transducer is and how it would be integrated into a switch that would
>control the pumps, but I'm guessing that the pressure sensing device
>(transducer?) would be wired into some sort of locking relay.
I'll suggest a careful consideration of added value for installing
this kind of system. Automatic or "smart" systems can have a way
of lulling a pilot into ill-placed confidence or worse, complacency.
They certainly add to cost of ownership in that there's just that
much "stuff" to buy, install, maintain, and break.
Bob . . .
________________________________________________________________________________
| From: | "Ed Anderson" <eanderson(at)carolina.rr.com> |
| Subject: | Re: Dual Fuel Pumps and EFI |
I agree with Bob regarding the advisability of adding "Smart" fuel pump
control, additional parts = more chances for a malfunction/failure. I have
flown 6 years with an all electrical set up. I have two high pressure fuel
pumps for my EFI fuel system. Both are on for take off and landings (as
well as a boost pump). At altitude I turn one of the EFI pumps off - should
it fail, it would take no more than a couple of seconds to switch the back
up on and at altitude that should pose little problem. During take off and
landing would be the phase when a fraction of a second could make a
difference - that of course is why both are on during those phases of
operation. Don't complicate your fuel system, keep it simple. FWIW
Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
eanderson(at)carolina.rr.com
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckollsr(at)cox.net>
Subject: Re: AeroElectric-List: Dual Fuel Pumps and EFI
>
>
>
>>
>>
>>I want to wire 2 fuel pumps, for an EFI system, into AEC schematic Z-14 so
>>that when fuel pressure drops below a preset psi, the secondary pump turns
>>on and locks on ,and I want to have manual overides.
>
> How does your engine behave under in-flight fuel starvation? Does it
> present a situation that is difficult or dangerous to recover from?
> The reason I ask is because systems with automatic features generally
> have parts counts several times that of a simple manual system. In
> all of the airplanes I fly, fuel starvation due to a misplacement of
> fuel selector valve or failure of primary pump will recover in seconds
> after corrective action on the part of the pilot with very little loss
> of altitude.
>
>
>>I was told pressure switches are not that accurate re repeatability and
>>that I would be better off with a pressure transducer. I'm not sure what a
>>transducer is and how it would be integrated into a switch that would
>>control the pumps, but I'm guessing that the pressure sensing device
>>(transducer?) would be wired into some sort of locking relay.
>
> I'll suggest a careful consideration of added value for installing
> this kind of system. Automatic or "smart" systems can have a way
> of lulling a pilot into ill-placed confidence or worse, complacency.
> They certainly add to cost of ownership in that there's just that
> much "stuff" to buy, install, maintain, and break.
>
> Bob . . .
>
>
>
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Dual Fuel Pumps and EFI |
I don't follow Eggenfellner info but I have heard that their early
pressure switches were not very compatible with gasoline and had to be
replaced due to leakage. Injected engines with a fuel return should
recover power very quickly anyway so I've kept my installation simple. I
may run both pumps when close to the ground if that proves feasible. The
pump output is regulated at 38 psi above manifold pressure as I recall
so I can see the temptation to use a dual port sensor.
A dual port sensor would be nice for the fuel pressure gauge but I'm not
aware of an affordable fuel compatible unit. A dual port sensor has the
additional failure mode of leaking fuel into the intake manifold as
well though. What sensors are the oem car manufacturers using for the
systems that use pcm fuel pump control for returnless pressure regulation.?
.
However I'd also think that a one port sensor/switch would be fine if it
triggered at something like 20 psi with +/- 5 or 10psi accuracy. I don't
see why you'd need accurate repeatability?? The manifold can't draw much
more than about 13 psi vacuum below ambient. Presumably you'd feed the
sensor with a small orifice to help dampen fluctuations.
I dunno, if the engine isn't running correctly I'd imagine you are going
to turn that second pump on manually anyway...
Ken
glaesers wrote:
>
>See the Aux Fuel Pump circuit on the Engine Electrical Architecure diagram
>on this page:
>http://www.wideopenwest.com/~glaesers/RV7A/RV7A_Electrical.htm
>It does exactly what you want - see the explanation in the OPERATION box.
>
>This is an adaptation of the electrical system architecture from the
>Eggenfeller Subaru installation manual. Their design uses a single 4PDT
>switch to control the power to the engine. I want switch reduncancy, so I
>use more (and less expensive) switches.
>
>Eggenfeller supplies the fuel pressure sensor switch. I don't have one yet
>so I don't know what kind of sensor it is (mechanical or electronic), but
>I've been on their Yahoo list for over a year, and no one has ever reported
>problems. I'm sure you could contact Jan Eggenfeller to get the part number
>if you are interested.
>
>A transducer is a generic term for converting one form of energy to another
>(in this case pressure to electrical). So any pressure switch is a
>transducer, but I suspect the comment was about the type of transducer (ie.
>mechanical vs. electronic sensor). Dick Tasker (who participates on this
>list) would be a good source for info - his company makes sensors.
>
>Dennis Glaeser
>RV7A Empennage
>
>
>
>
>I want to wire 2 fuel pumps, for an EFI system, into AEC schematic Z-14 so
>that
>when fuel pressure drops below a preset psi, the secondary pump turns on and
>locks on ,and I want to have manual overides.
>
>I was told pressure switches are not that accurate re repeatability and that
>I
>would be better off with a pressure transducer. I'm not sure what a
>transducer
>is and how it would be integrated into a switch that would control the
>pumps,
>but I'm guessing that the pressure sensing device (transducer?) would be
>wired
>into some sort of locking relay.
>
>I welcome any ideas.
>
>Thanks,
>John
>
>
>
>
________________________________________________________________________________
| From: | Richard Tasker <retasker(at)optonline.net> |
| Subject: | Re: Dual Fuel Pumps and EFI |
The pressure switch Jan supplies is a mechanical sensor (I know because
I have an Eggenfellner Subaru engine). For most applications, including
this one, a mechanical sensor is more than adequate. The only real
reason to use an electronic sensor in a switch would be if you are
trying to control or monitor something to a very high degree of accuracy
- such as on a process control application, etc.
Another email in this thread mentioned that Eggenfellner had problems
with this switch. That is not quite true. The first switch supplied
had problems with gasoline (an internal o-ring failed) but the new
switch now supplied is designed to work with hydrocarbons and works fine
(all previous switches were replaced by Jan with the new one well over a
year or two ago).
Dick Tasker
glaesers wrote:
>
>See the Aux Fuel Pump circuit on the Engine Electrical Architecure diagram
>on this page:
>http://www.wideopenwest.com/~glaesers/RV7A/RV7A_Electrical.htm
>It does exactly what you want - see the explanation in the OPERATION box.
>
>This is an adaptation of the electrical system architecture from the
>Eggenfeller Subaru installation manual. Their design uses a single 4PDT
>switch to control the power to the engine. I want switch reduncancy, so I
>use more (and less expensive) switches.
>
>Eggenfeller supplies the fuel pressure sensor switch. I don't have one yet
>so I don't know what kind of sensor it is (mechanical or electronic), but
>I've been on their Yahoo list for over a year, and no one has ever reported
>problems. I'm sure you could contact Jan Eggenfeller to get the part number
>if you are interested.
>
>A transducer is a generic term for converting one form of energy to another
>(in this case pressure to electrical). So any pressure switch is a
>transducer, but I suspect the comment was about the type of transducer (ie.
>mechanical vs. electronic sensor). Dick Tasker (who participates on this
>list) would be a good source for info - his company makes sensors.
>
>Dennis Glaeser
>RV7A Empennage
>
>
>
>
>I want to wire 2 fuel pumps, for an EFI system, into AEC schematic Z-14 so
>that
>when fuel pressure drops below a preset psi, the secondary pump turns on and
>locks on ,and I want to have manual overides.
>
>I was told pressure switches are not that accurate re repeatability and that
>I
>would be better off with a pressure transducer. I'm not sure what a
>transducer
>is and how it would be integrated into a switch that would control the
>pumps,
>but I'm guessing that the pressure sensing device (transducer?) would be
>wired
>into some sort of locking relay.
>
>I welcome any ideas.
>
>Thanks,
>John
>
>
>
>
________________________________________________________________________________
| From: | Eric Ruttan <ericruttan(at)chartermi.net> |
| Subject: | Re: OVP, Alternators, and stuff |
>3) E-bus Diodes--Use a big fat Schottky for bus isolation. The arguments
>against not doing this trigger my Attention Deficit Disorder--knocking me
>into the ozone. What were we discussing....?
>
>
Are you admitting you have no technical reasons to drive this
implementation? And it has not been tested? And it belongs on an
airplane why?
>4) LEDs--Automakers are planning to introduce LED headlights in the 2008
>model year. Then the efficacy will be 100 lumens-per-watt (as good as
>fluorescents). Bet on it.
>
>More later, only 91 more theses to go....
>
>Eric M. Jones
>
Eric;
Can you post a source for your LED proclamations? In all my
conversations (monthly) with lighting engineers at Visteon, Delphi and
Siemens (all located right here) White LEDs are failing badly in all
areas that drive implementation.
But perhaps you have data from a better source than I?
________________________________________________________________________________
| Subject: | battery contactor alternative |
| From: | ray.stlaurent(at)vsea.com |
0.12 MISSING_HEADERS Missing To: header
If the purpose of the battery contactor is to isolate the electrical
system from a large current source, the battery, what if instead a high
current solid state relay such as one of Erics Powerlinks connected the
battery to the electrical system. Since the Powerlink is unidirectional, a
power shottky diode could used to handle the much lower current return
flow requirements to the battery.
Or have I missed something fundamental?
-- Ray
________________________________________________________________________________
| From: | david caswell <davidbcaswell(at)yahoo.com> |
| Subject: | EI V/A Discharge light |
Hi Bob,
I have a new L-40 Alternator and a new LR3C-14 regulator. Architecture is basically
Z-11. With engine running and no loads, voltage on EI volt/amp instrument
is 13.3V (approx) As loads are added the EI volt/amp instrument shows the
Volts (bus voltage) reducing as I increase loads until at 12.5 V the EI instrument
discharge light comes on (it is set to come on when bus voltage is below
12.6 volts) The low voltage warning light hooked to the LR3C regulator does not
come on when the EI light comes on, but does come on when engine is not running
and Alternator switch is ON. The external shunt is hooked up on the alternator
lead.
Any suggestions as to what I may have done wrong?
Is this an EI problem?
Thank you, in advance.
David Caswell
RV7 805 DJ 1st flight 7/17/05
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: DC fans problem. |
>Eric, would you recommend one of these Transient Voltage Suppressors
>[Bidirectional transorb P6KE18CA] for
>a Commercial Aviation Products 12VDC flap actuator (Model D145-00-36-3)?
>John
John,
Yes, I would.... Although Bob N. objects to sprinking these things around,
he comes from a large family of muggles who don't believe in wizardry at
all..
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge
MA 01550-2705
(508) 764-2072
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: OVP crowbar false triggering |
>
>Bob N,
>
>I would be delighted to put my hands on your airplane with some test
>equipment to see if we can understand why it's so different.
>
>I would like that too but I am in SoCal and you are not (COME ON
>OUT! I'll buy lunch!). What do you think is the minimum requirement for
>test equipment to get some useful data on this? I think the answer will
>be "more than I can afford" but it does not hurt to ask.
my all time favorite investigative tool is the Tektronix
TDS210/220 series digital 'scopes. They're small, light,
very fast and will dump a screen to a printer. I have
a portable battery/inverter pak that will support the
scope and an inkjet printer for use in the field.
>Do you still have the old module? If so, you can send it back to me for a
>no-charge upgrade.
>
>Yes, I have all of them. I built four but it was really 2 X 2
>versions. I will round them up and send them to the address on your web
>site if I don't hear otherwise. I do not need you to send replacements
>for my sake, I am quite happy with the "MOS-FET miracle" I am flying
>now. I would be willing try out new versions in my airplane and report
>the results.
Your experience has never included an OVM-14 from myself or
B&C? Can you send me a schematic of the mos-fet version?
> to see which one is the "rose wood stake".
>
>Please forgive my ignorance. I know what a "rosetta stone" is, but I do
>not know what "rose wood stake" means. It always hurts to ask this kind
>of question but if I don't ask I will never know.
A rose wood stake through the heart is the sure fire
way to dispatch a vampire. Crosses and garlic may
chase them away but a rose wood stake is the ultimate
cure. This depends on what part of the world your vampire
lore is crafted . . . some say ash is the best material,
others call for any ol' wood stake. "Rose wood" has a
better 'ring' to it . . .
Bob . . .
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: EI V/A Discharge light |
>
>
>Hi Bob,
>
>I have a new L-40 Alternator and a new LR3C-14 regulator. Architecture
>is basically Z-11. With engine running and no loads, voltage on EI
>volt/amp instrument is 13.3V (approx) As loads are added the EI volt/amp
>instrument shows the Volts (bus voltage) reducing as I increase loads
>until at 12.5 V the EI instrument discharge light comes on (it is set to
>come on when bus voltage is below 12.6 volts) The low voltage warning
>light hooked to the LR3C regulator does not come on when the EI light
>comes on, but does come on when engine is not running and Alternator
>switch is ON. The external shunt is hooked up on the alternator lead.
The EI reading for alternator output is also probably zero.
>Any suggestions as to what I may have done wrong?
The alternator is not producing any output. I suggest you
troubleshoot per B&C instructions, per note 8 of Appendix-Z.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | How to test the OV? |
>
>
>Mike,
>
>I tested mine with a variable power supply. I put the OVP is series with a
>current limiting resistor and the power supply. I put a voltmeter across
>the resitor and slowly increased the voltage until the SCR tripped and the
>voltage across the resistor jumped up. I believe that it tripped at 16.5
>volts. This was tested on the bench before I ever installed in on the
>plane.
That's what it's supposed to do. Suggest you do this every
annual on ANY form of ov protection. I worked a case of smoked
electronics many moons ago where the ov relay failed to catch
a runaway alternator. A lead wire had broken off inside the
relay at some undertmined time in the past rendering the
ov protection inoperative.
Bob . . .
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: OVP, Alternators, and stuff |
0.60 COMMA_SUBJECT Subject is like 'Re: FDSDS, this is a subject'
ericruttan(at)chartermi.net
Hi Eric
>>3) E-bus Diodes--Use a big fat Schottky for bus isolation. The arguments
>>against not doing this trigger my Attention Deficit Disorder--knocking me
>>into the ozone. What were we discussing....?
>>
>>
>Are you admitting you have no technical reasons to drive this
>implementation? And it has not been tested? And it belongs on an
>airplane why?
No. When I admit something, my lower lip starts to tremble and my palms
sweat. I was refering to the fact that the Schottky subject has been argued
out. I sell PowerSchottkies by the truckload.
>4) LEDs--Automakers are planning to introduce LED headlights in the 2008
>model year. Then the efficacy will be 100 lumens-per-watt (as good as
>fluorescents). Bet on it.
>Eric M. Jones
>Eric;
>Can you post a source for your LED proclamations? In all my
>conversations (monthly) with lighting engineers at Visteon, Delphi and
>Siemens (all located right here) White LEDs are failing badly in all
>areas that drive implementation.But perhaps you have data from a better
>source than I?
Proclamation? No, that was an "Optimistic Futurist Pronunciamento". Check
out Lamina, Lumileds (of course), Nichia, Cree, and LEDs magazine (online).
The big guys generally move too slowly. The problem with white phosphors is
real but is being addressed in a variety of ways. Very technical
publications are online but they usually charge for them. The future in LEDs
is almost guaranteed because the theoretical efficiency is better than
almost any other light source. Expect LEDs to double in efficiency for each
of the next three years.
But as they say--your mileage may vary....
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
(508) 764-2072
When trouble arises and things look bad,
there is always one individual who perceives
a solution and is willing to take command.
Very often, that individual is crazy.
--Dave Barry
________________________________________________________________________________
| From: | david caswell <davidbcaswell(at)yahoo.com> |
| Subject: | Re: EI V/A Discharge light |
Bob,
Thanks for input. I will perform diagnostic test per note 8 when I get back to
plane. But I'm somewhat baffled by why the "low voltage warning light" from
the LR3C regulator doesn't come on if there is zero output from the alternator....I
thought that was the purpose of the "warning light"?
"Robert L. Nuckolls, III" wrote:
>
>
>Hi Bob,
>
>I have a new L-40 Alternator and a new LR3C-14 regulator. Architecture
>is basically Z-11. With engine running and no loads, voltage on EI
>volt/amp instrument is 13.3V (approx) As loads are added the EI volt/amp
>instrument shows the Volts (bus voltage) reducing as I increase loads
>until at 12.5 V the EI instrument discharge light comes on (it is set to
>come on when bus voltage is below 12.6 volts) The low voltage warning
>light hooked to the LR3C regulator does not come on when the EI light
>comes on, but does come on when engine is not running and Alternator
>switch is ON. The external shunt is hooked up on the alternator lead.
The EI reading for alternator output is also probably zero.
>Any suggestions as to what I may have done wrong?
The alternator is not producing any output. I suggest you
troubleshoot per B&C instructions, per note 8 of Appendix-Z.
Bob . . .
________________________________________________________________________________
Bob N. ,
Do you have a source for an Alternator loadmeter?
I believe you once carried this product.
Peter Laurence
________________________________________________________________________________
| From: | "William" <wschertz(at)ispwest.com> |
| Subject: | Re: EI V/A Discharge light |
In a test I did, when the freshly charged battery is connected to the LR-3,
and only the battery solenoid was being drawn from the battery, it took a
couple of minutes for the voltage to drop enough for the LV light to start
flashing. If there is any load on the system, I expect that it would come on
faster.
Bill Schertz
KIS Cruiser # 4045
----- Original Message -----
From: "david caswell" <davidbcaswell(at)yahoo.com>
Subject: Re: AeroElectric-List: EI V/A Discharge light
>
>
> Bob,
>
> Thanks for input. I will perform diagnostic test per note 8 when I get
> back to plane. But I'm somewhat baffled by why the "low voltage warning
> light" from the LR3C regulator doesn't come on if there is zero output
> from the alternator....I thought that was the purpose of the "warning
> light"?
>
> "Robert L. Nuckolls, III" wrote:
>
>
>>
>>
>>Hi Bob,
>>
>>I have a new L-40 Alternator and a new LR3C-14 regulator. Architecture
>>is basically Z-11. With engine running and no loads, voltage on EI
>>volt/amp instrument is 13.3V (approx) As loads are added the EI volt/amp
>>instrument shows the Volts (bus voltage) reducing as I increase loads
>>until at 12.5 V the EI instrument discharge light comes on (it is set to
>>come on when bus voltage is below 12.6 volts) The low voltage warning
>>light hooked to the LR3C regulator does not come on when the EI light
>>comes on, but does come on when engine is not running and Alternator
>>switch is ON. The external shunt is hooked up on the alternator lead.
>
> The EI reading for alternator output is also probably zero.
>
>
>>Any suggestions as to what I may have done wrong?
>
> The alternator is not producing any output. I suggest you
> troubleshoot per B&C instructions, per note 8 of Appendix-Z.
>
> Bob . . .
>
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: EI V/A Discharge light |
>
>
>Bob,
>
>Thanks for input. I will perform diagnostic test per note 8 when I get
>back to plane. But I'm somewhat baffled by why the "low voltage warning
>light" from the LR3C regulator doesn't come on if there is zero output
>from the alternator....I thought that was the purpose of the "warning light"?
Yes . . . but if there are very light loads on the battery, the battery
might support the bus above the low voltage light trip point. Nominally
they're set for 13.0 volts. Easy to check on the bench with a power
supply and good meter. Further, do not assume that because all the
various voltmeters are hooked to "the system" that they're all going
to read the same voltage for a variety of reasons that include votlage
drop in system conductors and instrument accuracy.
The best check is to measure the trip points and calibration of each
instrument independently before you start chasing down other variables
in the system. The LR-3 trip point is set up by precision resistors and
a precision reference device. It MIGHT be that one of the resistors is
a wrong value but I would be skeptical . . . the 13.0 plus or minus 0.2
volt is an acceptance test parameter at B&C.
Bob . . .
________________________________________________________________________________
| From: | "John Burnaby" <jonlaury(at)impulse.net> |
| Subject: | Re: Re: Dual Fuel Pumps and EFI |
Thanks to all for your suggestions.
After reading them all, I realize the pedestrian idea of having one SPST per pump
is the simplest, least expensive, and least maintenance option. And I forget
who said it, but when the fire goes out and my "on" indicator light for pump
# 2 is lit, I'm still going to hit its manual over ride to "on".
Now, can anyone tell me how to respond to a thread on the list without having to
copy the Subject line and paste it into a new message? I couldn't find a "Post
reply" button and I tried clicking the Re: (subject) line with no joy.
Thanks,
John
________________________________________________________________________________
Received-SPF: softfail (mta2: domain of transitioning trigo(at)mail.telepac.pt does
not designate 85.138.30.109 as permitted sender) receiver=mta2; client_ip=85.138.30.109;
envelope-from=trigo(at)mail.telepac.pt;
| From: | "Carlos Trigo" <trigo(at)mail.telepac.pt> |
I am bulding an all electric RV-9A with an electrically dependent Subaru engine.
It has 2 batteries and the Subaru internal regulated alternator, and will
be using the ExpBus.
I am intending to measure Volts and Amps where needed to always monitor, at land
(before leaving it) and in flight (to know if I have to land ASAP), if there
are enough electrons to keep me out of a gliding experience.
Regarding Amps, I am thinking to measure them in 3 places, the alternator output
and the 2 batteries, in order to know "who" is charging and discharging and
"how much" each. By an arithmetic sum, this will even give me the total current
being used by the plane.
Is this a good design? Where exactly should I hook the ammeter wires? Should I
use shunts or Hall effect sensors? And to work as I want, I suspect I will have
to put 3 separate indicators in my pannel, right?
Regarding Volts, I believe I should measure them in 2 places, which are the 2
batteries. Is this right? And again, where exactly should I hook the voltmeter
wires? And should I use 2 voltmeters or only one with a comuting switch?
At thousands of miles of phisical distance from you guys, this list has been my
DC electric university, therefore:
Answers and other comments from Bob and the usual suspects are most wellcome, even
required... :
)
Thanks
Carlos Trigo
Portugal
________________________________________________________________________________
| Subject: | Re: EI V/A Discharge light |
Bob,
Tim at B&C told me that the LR3 trips at approx 12.5 to
12.7 V. The SB1A-14 trips at 13V.
Peter
>>Bob,
>>
>>Thanks for input. I will perform diagnostic test per
>>note 8 when I get
>>back to plane. But I'm somewhat baffled by why the "low
>>voltage warning
>>light" from the LR3C regulator doesn't come on if there
>>is zero output
>>from the alternator....I thought that was the purpose of
>>the "warning light"?
>
> Yes . . . but if there are very light loads on the
>battery, the battery
> might support the bus above the low voltage light
>trip point. Nominally
> they're set for 13.0 volts. Easy to check on the
>bench with a power
> supply and good meter. Further, do not assume that
>because all the
> various voltmeters are hooked to "the system" that
>they're all going
> to read the same voltage for a variety of reasons
>that include votlage
> drop in system conductors and instrument accuracy.
>
> The best check is to measure the trip points and
>calibration of each
> instrument independently before you start chasing
>down other variables
> in the system. The LR-3 trip point is set up by
>precision resistors and
> a precision reference device. It MIGHT be that one of
>the resistors is
> a wrong value but I would be skeptical . . . the 13.0
>plus or minus 0.2
> volt is an acceptance test parameter at B&C.
>
> Bob . . .
>
>
>page,
>
>
>
>
________________________________________________________________________________
| From: | Gary Casey <glcasey(at)adelphia.net> |
| Subject: | Re: Dual Fuel Pumps and EF |
I basically agree with Bob, but the operative condition is that with
a manual system safety in the case of a pump failure to totally
dependent on the operator doing the right thing at the right time. I
have a system designed, not yet installed, that uses a pressure
switch and a relay wired to turn the pump on an hold it on in case of
a pressure loss. It is accompanied by a "pump on" warning. I expect
that a pump failure will result in no event except the light coming
on and that I propose is better than a silent engine followed by a
pilot trying to figure out what to do next. The extra complexity
will never result in the pump not coming on as there is a manual "on"
position as well. Also, I see no reason to install a "transducer" as
someone suggested because the exact value of the switchpoint isn't
important. (I assume he is referring to an analog pressure sensor,
the output of which would have to be measured by some electronics and
compared to a reference switchpoint voltage)
Gary Casey
>
> I want to wire 2 fuel pumps, for an EFI system, into AEC schematic
> Z-14 so
> that when fuel pressure drops below a preset psi, the secondary
> pump turns
> on and locks on ,and I want to have manual overides.
>
How does your engine behave under in-flight fuel starvation? Does it
present a situation that is difficult or dangerous to recover from?
The reason I ask is because systems with automatic features
generally
have parts counts several times that of a simple manual system. In
all of the airplanes I fly, fuel starvation due to a misplacement of
fuel selector valve or failure of primary pump will recover in
seconds
after corrective action on the part of the pilot with very little
loss
of altitude.
> I was told pressure switches are not that accurate re repeatability
> and
> that I would be better off with a pressure transducer. I'm not sure
> what a
> transducer is and how it would be integrated into a switch that would
> control the pumps, but I'm guessing that the pressure sensing device
> (transducer?) would be wired into some sort of locking relay.
>
I'll suggest a careful consideration of added value for installing
this kind of system. Automatic or "smart" systems can have a way
of lulling a pilot into ill-placed confidence or worse, complacency.
They certainly add to cost of ownership in that there's just that
much "stuff" to buy, install, maintain, and break.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Volts and Amps |
>
>
> I am bulding an all electric RV-9A with an electrically dependent
> Subaru engine. It has 2 batteries and the Subaru internal regulated
> alternator, and will be using the ExpBus.
> I am intending to measure Volts and Amps where needed to always
> monitor, at land (before leaving it) and in flight (to know if I have to
> land ASAP), if there are enough electrons to keep me out of a gliding
> experience.
> Regarding Amps, I am thinking to measure them in 3 places, the
> alternator output and the 2 batteries, in order to know "who" is charging
> and discharging and "how much" each. By an arithmetic sum, this will even
> give me the total current being used by the plane.
>Is this a good design? Where exactly should I hook the ammeter wires?
>Should I use shunts or Hall effect sensors? And to work as I want, I
>suspect I will have to put 3 separate indicators in my pannel, right?
> Regarding Volts, I believe I should measure them in 2 places, which are
> the 2 batteries. Is this right? And again, where exactly should I hook
> the voltmeter wires? And should I use 2 voltmeters or only one with a
> comuting switch?
Voltmeters and ammeters have minimal if any useful value for
flight operations. Your #1 concern as PILOT is: Are alternator(s)
supporting all of ship's loads and (2) are battery(ies) all on
line and being charged by the alternator?
The very best WARNING tools for telling a PILOT that one of these
conditions is not being met is the low voltage warning light.
In your case (1 alt/dual bat) a low voltage warning fed from each
of the two battery busses would be useful. If either battery contactor
was open, the battery on that circuit would fall below the trip
point on the low voltage warning.
If any one of those lights comes on, it's time to switch to a carefully
crafted, well maintained PLAN-B wherein you KNOW what endurance is
available to you for comfortable termination of flight.
As a MECHANIC, it may be useful to know voltages and currents in
lots of places about the airplane and it's doubtful that any combination
of panel mounted devices and selector switches is going to tell you
everything you need to know to chase a rat out of the woodpile. So,
if probability is high that you'll need to get out the multimeter
to troubleshoot the airplane, then the decision as to how many places
you choose to monitor with your panel mounted instruments becomes
a toss-up.
My suggestion is to MINIMIZE complexity, parts count, weight, and
cost of ownership of your airplane. A part that's NOT installed is
not a part that will need to be fixed later. A system that's not
installed is not going to be a distraction to you when you should
be concentrating on comfortable termination of flight.
If it were my airplane, install the AMPs function as an alternator
loadmeter and provide some means by which each battery can be
probed independently - preferably with ACTIVE warning devices.
Everything else has an increasingly poor return on investment.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: EI V/A Discharge light |
>
>In a test I did, when the freshly charged battery is connected to the LR-3,
>and only the battery solenoid was being drawn from the battery, it took a
>couple of minutes for the voltage to drop enough for the LV light to start
>flashing. If there is any load on the system, I expect that it would come on
>faster.
Correct. It's been some years since I messed with the LR-3 so I
checked the B&C website for data. The LR-3 installation instructions
at:
http://bandc.biz/LR3INSTRUCT.pdf
Says the low voltage light operating range is 12.5 to 13.0 volts. In
another place, the statement is made that the low voltage light should
be flashing by the time bus voltage drops to 12.5 volts.
I set my LVWarn modules at 13.0 plus or minus about 0.1 volts
which might make them come on a little earlier than the warning
in an LR-3 but under normal operating conditions the differences
are insignificant.
A fully charged RG battery will present an open circuit voltage
greater than 12.5 volts. Actually, it's almost 13.0 volts. So it's
not unreasonable to expect the LR-3 to delay a period of time after
the battery master is turned on before the light flashes.
Bob . . .
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Volts and Amps |
I understand - except that once the low voltage light comes on - will
one have the discipline to act? I think a lot of the folks on this list
would then want to see what the voltage is so that they believe the
light. There is a human tendancy to not believe one indication and think
that it must be the low voltage detector that has failed. In addition
I'd find it comforting to be able to confirm proper voltage before
takeoff with an electrically dependant engine as I have seen voltage
regulators drift out of spec and cook batteries. I've also seen it where
the airplane was able to be repaired on the ground with screwdriver,
pliers, AND that panel mounted voltmeter because nothing else was
available. So... rather than a loadmeter, I'd opt for a voltmeter
capable of reading both battery voltages in addition to the low voltage
warning devices ;) A load meter seems less useful to me and if I really
really wanted one I'd rather use a hall sensor to avoid additional
connections for a shunt. If there are no voltmeters then I see the value
in a loadmeter to confirm low alternator output.
Ken
Robert L. Nuckolls, III wrote:
>
>
>
>
>>
>>
>> I am bulding an all electric RV-9A with an electrically dependent
>>Subaru engine. It has 2 batteries and the Subaru internal regulated
>>alternator, and will be using the ExpBus.
>> I am intending to measure Volts and Amps where needed to always
>>monitor, at land (before leaving it) and in flight (to know if I have to
>>land ASAP), if there are enough electrons to keep me out of a gliding
>>experience.
>> Regarding Amps, I am thinking to measure them in 3 places, the
>>alternator output and the 2 batteries, in order to know "who" is charging
>>and discharging and "how much" each. By an arithmetic sum, this will even
>>give me the total current being used by the plane.
>>Is this a good design? Where exactly should I hook the ammeter wires?
>>Should I use shunts or Hall effect sensors? And to work as I want, I
>>suspect I will have to put 3 separate indicators in my pannel, right?
>> Regarding Volts, I believe I should measure them in 2 places, which are
>>the 2 batteries. Is this right? And again, where exactly should I hook
>>the voltmeter wires? And should I use 2 voltmeters or only one with a
>>comuting switch?
>>
>>
>
> Voltmeters and ammeters have minimal if any useful value for
> flight operations. Your #1 concern as PILOT is: Are alternator(s)
> supporting all of ship's loads and (2) are battery(ies) all on
> line and being charged by the alternator?
>
> The very best WARNING tools for telling a PILOT that one of these
> conditions is not being met is the low voltage warning light.
> In your case (1 alt/dual bat) a low voltage warning fed from each
> of the two battery busses would be useful. If either battery contactor
> was open, the battery on that circuit would fall below the trip
> point on the low voltage warning.
>
> If any one of those lights comes on, it's time to switch to a carefully
> crafted, well maintained PLAN-B wherein you KNOW what endurance is
> available to you for comfortable termination of flight.
>
> As a MECHANIC, it may be useful to know voltages and currents in
> lots of places about the airplane and it's doubtful that any combination
> of panel mounted devices and selector switches is going to tell you
> everything you need to know to chase a rat out of the woodpile. So,
> if probability is high that you'll need to get out the multimeter
> to troubleshoot the airplane, then the decision as to how many places
> you choose to monitor with your panel mounted instruments becomes
> a toss-up.
>
> My suggestion is to MINIMIZE complexity, parts count, weight, and
> cost of ownership of your airplane. A part that's NOT installed is
> not a part that will need to be fixed later. A system that's not
> installed is not going to be a distraction to you when you should
> be concentrating on comfortable termination of flight.
>
> If it were my airplane, install the AMPs function as an alternator
> loadmeter and provide some means by which each battery can be
> probed independently - preferably with ACTIVE warning devices.
> Everything else has an increasingly poor return on investment.
>
> Bob . . .
>
>
>
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: OVP crowbar false triggering |
Good Morning Bob,
I looked on their website and see that those units have been disconnected.
Do you have a recommendation for a replacement?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
In a message dated 7/19/2005 8:29:21 A.M. Central Standard Time,
nuckollsr(at)cox.net writes:
my all time favorite investigative tool is the Tektronix
TDS210/220 series digital 'scopes. They're small, light,
very fast and will dump a screen to a printer. I have
a portable battery/inverter pak that will support the
scope and an inkjet printer for use in the field.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: DC fans problem. |
>
>
>
> >Eric, would you recommend one of these Transient Voltage Suppressors
> >[Bidirectional transorb P6KE18CA] for
> >a Commercial Aviation Products 12VDC flap actuator (Model D145-00-36-3)?
> >John
>
>John,
>
>Yes, I would.... Although Bob N. objects to sprinking these things around,
>he comes from a large family of muggles who don't believe in wizardry at
>all..
Nope, I prefer confidence in my instruments and the repeatable
experiment. Haven't found a "glitch" with enough energy in it to
wake up a snoozing mosquito much less justify extra-ordinary
prophylaxis. (See my post on the DC fan "problem" of last week).
If one has concerns for the nano-transient, certainly a single
trap device at the bus would be sufficient. The best trap
is the ship's battery. Very narrow, fast rise time events
have a difficult time getting past a capacitor too.
I'm still waiting for details of a bench test that demonstrates
the value of adding one of these things ANYWHERE much less
all over the airplane. Thus far all I've noticed are quotations
from the manuals (produced by folks who sell Transorbs) that
highly recommend a multi-junction vaccination of every electrical
system. In light of those recommendations, I'm still marveling
at how we managed to get along without them for nearly 90 years
of sticking DC powered electro-whizzies in airplanes.
It's only recently that our systems have become sprinkled with
such devices . . . in the latest and greatest of composite
airplanes. Sadly, the threat is of our own design. We built a machine
from materials having 1000 times the resistance of aluminum and
found that the energy in a lightning strike will wake deaf dogs
from a mile away. I didn't find a use for Transorbs in over 20 years
of aviation systems design until DO-160 added a new section on
indirect lightning effects where the energies applied to my
electro-whizzy were on the order of 600v with a 2 ohm source
impedance (300 amps)!
Now, if anyone anticipates close encounters with strikes of the
worst kind, all bets are off . . . I don't care how many Transorbs
you sprinkle around the airplane if you haven't tested effectiveness
in the lab. But for everything else, show me the schematic, parts
list and measurements of the energies observed. I keep getting
assurances that the evils exist but to date, not a single repeatable
experiment to support the hypothesis.
Bob . . .
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Volts and Amps |
>
>I understand - except that once the low voltage light comes on - will
>one have the discipline to act? I think a lot of the folks on this list
>would then want to see what the voltage is so that they believe the
>light. There is a human tendancy to not believe one indication and think
>that it must be the low voltage detector that has failed.
Does one have the discipline to keep that nose DOWN and airspeed
UP even if it means landing short of the end of the runway? It's
damned
> In addition
>I'd find it comforting to be able to confirm proper voltage before
>takeoff with an electrically dependant engine as I have seen voltage
>regulators drift out of spec and cook batteries.
I'm not suggesting that one shouldn't consider leaving them
off the airplane. They have some utility (especially in
pre-flight BEFORE you become a pilot) but they poor in-flight
warning devices and possibly more distraction than assistance
when you KNOW that PLAN-B, PLAN-C . . . etc is the next sure
step to a happy end on the day.
> I've also seen it where
>the airplane was able to be repaired on the ground with screwdriver,
>pliers, AND that panel mounted voltmeter because nothing else was
>available. So... rather than a loadmeter, I'd opt for a voltmeter
>capable of reading both battery voltages in addition to the low voltage
>warning devices ;) A load meter seems less useful to me and if I really
>really wanted one I'd rather use a hall sensor to avoid additional
>connections for a shunt. If there are no voltmeters then I see the value
>in a loadmeter to confirm low alternator output.
Sounds like a plan . . .
Bob . . .
________________________________________________________________________________
| From: | BobsV35B(at)aol.com |
| Subject: | Re: OVP crowbar false triggering |
In a message dated 7/19/2005 9:12:59 A.M. Central Standard Time, Bobs V35B
writes:
I looked on their website and see that those units have been disconnected.
Do you have a recommendation for a replacement?
Obviously, should have said discontinued rather than disconnected!
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
| Subject: | Re: Diagnostic Scope |
>
>
>Good Morning Bob,
>
>I looked on their website and see that those units have been disconnected.
>Do you have a recommendation for a replacement?
There are 7 of the 210/220 series scopes on ebay right now.
Given the inherent robustness of Tektronix products, any
offering that's not covered in mud dobber nests and bird
poop is a low-risk buy. Try to find one with the printer
port adapter included (this will boost the price by $150
to $200).
There's a newer version available from the factory but
they'll cost you about 2x a used one . . . something
on the order of $1300.
Bob . . .
>In a message dated 7/19/2005 8:29:21 A.M. Central Standard Time,
>nuckollsr(at)cox.net writes:
>
>my all time favorite investigative tool is the Tektronix
>TDS210/220 series digital 'scopes. They're small, light,
>very fast and will dump a screen to a printer. I have
>a portable battery/inverter pak that will support the
>scope and an inkjet printer for use in the field.
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <nuckollsr(at)cox.net> |
>
>Bob N. ,
>
>Do you have a source for an Alternator loadmeter?
>
>I believe you once carried this product.
Yeah, I've got a box of 100 cores on my shop floor
right now waiting for the time to re-scale them
into http://www.aeroelectric.com/Pictures/Loadmeter_2.jpg
These are 10x the instrument that Westach builds.
Won't mind putting my brand on these movements by
Triplett.
I'm also working on a process where I MIGHT be able
to offer white lettering on a black face. No
promises for when but these will eventually find
their way onto my website.
Bob . . .
________________________________________________________________________________
| From: | Phil Birkelbach <phil(at)petrasoft.net> |
| Subject: | Re: Volts and Amps |
I wound up with three volt meters by accident. The Dynon D-10 measures
the voltage on the main power feed and the backup feed. This gives me
July 06, 2005 - July 19, 2005
AeroElectric-Archive.digest.vol-ep