AeroElectric-Archive.digest.vol-dl
August 25, 2004 - September 07, 2004
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Re: 220 Ohm Resistors? |
>
>
>I believe I have seen that two 220 ohm resistors can be used in
>conjunction with an LED to act as a OV light on the B&C LR3s. Can
>someone help me with how 220 ohm was determined and why two of them?
>Normally, I use a 600 ohm resistor in series with an LED to operate at
>13.8V. (drop 12V at 20ma). What am I missing here?
To replace an incandescent lamp on the LR-3 Alternator Controller
with and LED, one has to account for a built-in leakage current
for the LR-3's lamp driver picked so that the lamp will illuminate
even when ALL power is removed from the LR-3 as long as the warning
lamp has + power.
This allows the LR-3 to be used with incandescent annunciator
panels that get power from a third source and still annunciate
regulator failure if all power is removed from the regulator.
This leakage is too small to cause an incandescent lamp to glow
but it will cause an LED to glow even when it's supposed to be
dark. Hence, the resistor around the lamp to drive up it's minimum
illumination current to something on the order of 7-8 mA.
So taking the 220 ohm resistors as recommended, let's figure
2v across the illuminated lamp which means we have about 9 mA
used up in the parallel resistor. Figure 12.5v for the bus voltage
while flashing which leaves 10.5 volts across the series resistor
and 47 mA total through it. With 8 mA being sucked off by
the parallel resistor, this leaves 39 mA or so for the LED.
A bit more than its "rated" current but by no means overly
stressful.
The 10.5 volt drop on series resistor at 47 mA suggests
that a 490 milliwatt resistor is called for . . . except
that this is used in a flashing light system with about 50%
duty cycle which cuts dissipation in half. So the 1/2
watt callouts on the drawing at
http://www.aeroelectric.com/temp/LV_Led.jpg
are plenty conservative.
Why 220 ohm resistors? That was a size stocked by
Radio Shack (stock #271-1111) in packages of
5 for about a dollar. Other resistors could have
worked just as well for the parallel value . . . but
then one would have to buy two 5-paks and throw
away 8 resistors. The design offered gets the job
done with one 5-pak of resistors and only 3 surplus
devices.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Re: Dual VOR/GS Comant Splitter... |
>
>
>I have a Garmin 430 and an SL30 Radio. The 430 has coax inputs for NAV
>and G/S. The SL30 has one input for NAV and splits off the G/S signal
>internally to the radio. My question is it OK to use a dual NAV, G/S
>splitter (Comant CI 1125) that has two NAV and two G/S outputs? My
>intent is to run one NAV and one G/S to the 430 and then run the second
>NAV to the SL30. This will leave one G/S output of the splitter
>attached to nothing, also will the NAV signal still have the G/S signal
>in it after it has passed through the splitter/diplexer?
What you propose will work fin . . . and there's no
big need to do anything with the open GS port.
Bob . . .
---
________________________________________________________________________________
| From: | "Malcolm Thomson" <mdthomson(at)attglobal.net> |
| Subject: | Dual VOR/GS Comant Splitter... |
Thanks Bob for this and the other reply about 220 ohms resistors!
Malcolm.
-----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: Dual VOR/GS Comant Splitter...
-->
>
>
>I have a Garmin 430 and an SL30 Radio. The 430 has coax inputs for NAV
>and G/S. The SL30 has one input for NAV and splits off the G/S signal
>internally to the radio. My question is it OK to use a dual NAV, G/S
>splitter (Comant CI 1125) that has two NAV and two G/S outputs? My
>intent is to run one NAV and one G/S to the 430 and then run the second
>NAV to the SL30. This will leave one G/S output of the splitter
>attached to nothing, also will the NAV signal still have the G/S signal
>in it after it has passed through the splitter/diplexer?
What you propose will work fin . . . and there's no
big need to do anything with the open GS port.
Bob . . .
---
==
direct advertising on the Matronics Forums.
==
==
==
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: DC-DC converter |
On Aug 23, 2004, at 1:04 PM, Ken Rice wrote:
>
> I have a magnetic clutch rated at 24 V and about 2-4 amps that I want
> to operate in my 14 V system. Is there a simple way to step-up the
> voltage?
http://www.surepower.com/pdf/ebr_dcdc.pdf
See the 41201 12V-to-24V upconverter rated at 5A.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Dual VOR/GS Comant Splitter... |
On Aug 23, 2004, at 8:57 PM, Malcolm Thomson wrote:
>
>
> I have a Garmin 430 and an SL30 Radio. The 430 has coax inputs for NAV
> and G/S. The SL30 has one input for NAV and splits off the G/S signal
> internally to the radio. My question is it OK to use a dual NAV, G/S
> splitter (Comant CI 1125) that has two NAV and two G/S outputs? My
> intent is to run one NAV and one G/S to the 430 and then run the second
> NAV to the SL30. This will leave one G/S output of the splitter
> attached to nothing, also will the NAV signal still have the G/S signal
> in it after it has passed through the splitter/diplexer?
No, that will not work. If you do that you will have no GS signal to
your SL-30
You need a broadband splitter such as a Mini-Circuits ZFSC-2-1 after
the antenna to split the signal between the SL-30 and the nav splitter
feeding the Garmin 430 like this:
---
\|/ ,------------>[SL-30]
| |
`-------[ZFSC-2-1]
|
|
`--------[nav/gs splitter]
| | ,-----------.
| `--------->| GS |
| | Garmin 430|
`-------------->| nav |
`-----------'
The ZFSC-2-1 splits the whole signal, both nav and GS, and routes it to
the SL-30 and the nav/gs splitter. The nav/gs splitter then divides
the nav and GS signals and routes them to the appropriate input to the
Garmin 430.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Re: Simplification |
>
>There were a number of very good comments received - I appreciate them all:
> Manual master switch -
>
> <<(from Bob) How many parts are anticipated for the mechanical linkage to
> the battery switch. Are these more (less) likely to fail than a
>contactor?>>
>I would hope it would be less likely to fail as the contactor requires a
>continuous current to work - any open in coil will render it inoperative.
>The manual switch could fail, probably by the linkage falling off - but the
>failure mode is to stay where it was, not fail open. Then there is the
>continuous current draw of the contactor, but who's counting milliamps?
But with failure tolerant design, we are PLANNING on having
it fail and making sure it's no big deal. In actuality these
little critters are rather robust and don't need much attention
over the lifetime of the airplane. They're a common fixture in
any airplanes more complex than an ultra-light for convenience,
commonality with other airplanes that virtually all pilots are
familiar with and the weight/power penalties are tolerable.
> <<(From Bob) Do you plan to have an alternate power path
> to and endurance bus? How would failure of a battery contactor
> affect the outcome of any particular mode of flight?>>
>Yes, there will be a direct path from the battery through a switch to the
>endurance bus as well as a diode feed from the main bus. I expect that an
>IFR flight will be inconvenienced from a master failure, but I don't expect
>a higher heart rate. Besides the primary Chelton PFD there will be a
>complete vacuum-powered "6-pack" on the right side of the panel in addition
>to the endurance bus.
Okay . . .
> "contactor-less" starter. There was another comment on this subject by a
>builder and basically, his comments were correct. The main starter power
>will be connected at the bus-side of the master switch. The solenoid power
>will be fed through the main bus and a momentary-contact switch.
There's no such thing as a contactor-less starter. What you describe
is using the contactor BUILT IN to modern starters. A version
of what you describe is illustrated in Figure Z-22 where I show
a "boost relay" mounted next to the starter to take care of inrush
currents, mitigate the need for fat wire and robust starter switch.
However you choose to use this feature on the starter, as long as
you've accounted for its unique characteristics, you're okay without
adding the external contactor recommended by B&C and others.
> Eliminate the alternator switch entirely. There was a suggestion to mount
>the breaker close to the master to make it intuitive. It brings up a good
>question: With the alternator field power directly connected to the main
>bus the alternator would be self-exited with the master off IF the stator
>were connected to the main bus side of the master. So the no-switch idea
>would only work if the alternator stator were wired to the BATTERY side of
>the master. that's not such a good idea because if the stator developed a
>short it could discharge the battery (BTDT). hmm. Considering Bob's
>reminder of resale value, it just might push me back to a conventional
>contactor and sequential master switch.
That's the thrust of my questions. Keep in mind that the Z-figures
evolved over the past 15 years of discussions with the OBAM aircraft
community. If we went back to Revision 4 or 5 to the 'Connection, you'd
find some suggestions that are no longer published because we discovered
their down-sides or lack of value. Unlike C-172s that are wired like
they were in 1968, the Z-figures have and will continue to evolve
through the filter of field experience and critical review by lots
of folks.
This is why I'm a little miffed when a newby writes to say, "I'm using
Figure Z-xx but I've incorporated a few ideas of my own." He then
lists all the things he plans to do and wants on-the-spot critical
review. I have to explain that the best thing to do is pick a figure
as published and then let's discuss any perceived shortcomings one
at a time. If there is merit to alternative architectures, we'll
publish it and get feedback from the rest of the community. That's
how Appendix Z has grown and will continue to grow.
> Assuming the direct connection of
>the stator through a fuse to the main bus side of the master contactor
>what's to prevent that from pulling the system down (assuming the short
>isn't enough to blow the fuse)?
How do you get a low current short "short" in the diode stack
of an alternator? It's so rare that automobiles don't even bother
to fuse the b-lead.
> There is no way to manually disconnect the
>stator from the main bus. Add a 60-amp pullable breaker? But that would
>add several feet of thick wire and several electrical connections.
Yup, and then you're beginning to look like at C-172 again.
Bob . . .
---
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
Extract from a previous posting by David Carter
<<2. Starter: I assume you are proposing not to have "main starter cranking current"
go through a high current capacity "starter relay" - rather, have the starter
motor hard wired to the battery and only have the pilot
actuate a lower current switch to energize the relay coil of the relay on the starter
that engages the Bendix and also closes the "high current" circuit to the
motor from the "hard wired" wire. Do I have that wiring and
terminology correct? Then, if the starter ever fails and continues to crank when
the starter switch is released, then the Manual Battery Master can be used to
kill power to the starter motor.>>
8/25/2004
Hello David, some terminology clarification if I may. A Bendix in starter terminology
is a mechanical spiral geared device used to move and engage the starter
motor pinion gear with the teeth on the fly wheel as a result of the initial
rotation of the starter motor.
Many modern starters use an on-starter solenoid to both complete electrical contact
to the starter motor and move a pinion gear into and out of mesh with the
teeth on the fly wheel or a gear in the engine accessory section.
Therefore such starters do not incorporate a Bendix.
OC
________________________________________________________________________________
| From: | "Malcolm Thomson" <mdthomson(at)attglobal.net> |
| Subject: | Dual VOR/GS Comant Splitter... |
I managed to get my hands on some test equipment this evening and found
out your are exactly correct.
The CI 1125 does in fact strip off the G/S from both the NAV outputs and
hence I will have to use the approach you suggest.
Thanks
Malcolm.
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Brian
Lloyd
Subject: Re: AeroElectric-List: Dual VOR/GS Comant Splitter...
On Aug 23, 2004, at 8:57 PM, Malcolm Thomson wrote:
>
>
> I have a Garmin 430 and an SL30 Radio. The 430 has coax inputs for
> NAV and G/S. The SL30 has one input for NAV and splits off the G/S
> signal internally to the radio. My question is it OK to use a dual
> NAV, G/S splitter (Comant CI 1125) that has two NAV and two G/S
> outputs? My intent is to run one NAV and one G/S to the 430 and then
> run the second NAV to the SL30. This will leave one G/S output of the
> splitter attached to nothing, also will the NAV signal still have the
> G/S signal in it after it has passed through the splitter/diplexer?
No, that will not work. If you do that you will have no GS signal to
your SL-30
You need a broadband splitter such as a Mini-Circuits ZFSC-2-1 after
the antenna to split the signal between the SL-30 and the nav splitter
feeding the Garmin 430 like this:
---
\|/ ,------------>[SL-30]
| |
`-------[ZFSC-2-1]
|
|
`--------[nav/gs splitter]
| | ,-----------.
| `--------->| GS |
| | Garmin 430|
`-------------->| nav |
`-----------'
The ZFSC-2-1 splits the whole signal, both nav and GS, and routes it to
the SL-30 and the nav/gs splitter. The nav/gs splitter then divides
the nav and GS signals and routes them to the appropriate input to the
Garmin 430.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
==
direct advertising on the Matronics Forums.
==
==
==
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
AeroElectric-List message previously posted by: "Mark Banus" >
8/25/2004
Hello Mark, Just go to the google search window and type in avikrimp. Many sources
will show up including Mouser, Digikey, Newark, etc.
Avikrimp is a Molex trade name and these are the high quality PIDG type terminals
with a metal area to crimp around the wire insulation for strain relief. The
Avikrimp terminals come in a wide variety of sizes and types, including fully
insulated, so you may want to pick around a bit to find the exact ones that
you want.
OC
________________________________________________________________________________
| From: | "Dr. Andrew Elliott" <a.s.elliott(at)cox.net> |
| Subject: | Which diode to use? |
Folks:
I have discovered that the aux power outlet (i.e. cigarette lighter
socket) in my non-ABAM plane is wired without any protection against
back-feeding the bus. That is, if I plug in my 17-79 headset to
recharge the internal battery, and forget that I did so, then when I
shut down the plane the 9V headset battery provides at least enough
power to light up the "alternator off" warning light.
I would like to add a diode to the system to prevent this. In the
forward direction, the socket is protected by a 5A fuse. What would be
the appropriate size/rating of a diode to add to the line? And what
would be the best way to wire it in?
Andy Elliott
N481HY/AA-1(TD,160)/KFFZ
________________________________________________________________________________
| From: | "Dr. Andrew Elliott" <a.s.elliott(at)cox.net> |
| Subject: | Crimper selection? |
Will a ratcheting crimper designed for Sta-Kon terminals also properly
crimp standard PIDG hardware? Is there any significant difference
between Sta-Kon and other spec hardware?
Andy Elliott
N481HY/AA-1(TD,160)/KFFZ
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Locking female fast-ons |
AeroElectric-List message previously posted by: Charlie Kuss
Listers, I recently purchased several Bosch (automotive style) relays and the
related sockets for my RV-8A flap circuit. I purchased these items from
Waytek Wire. Nice folks with brand name stuff at good prices. The
sockets for these relays use a variant of the common 1/4" female fast ons.
These are open barrel, rather than PIDG items. They also have a locking tang,
to secure the connector into the socket body. Anyone familiar with
automotive connectors has seen these.My question is, I need to find a part number
and source for these connectors designed for 22/18 AWG wire. Waytek has these
connectors
for 16/14 AWG, but not for the 22/18 AWG. I know that these things are
actually quite common. I've tried finding them in Allied Electronics
paper catalog and their web site. However, I don't know the manufacturer or
the proper terminology these items are known by. Because of this, I have
not been able to locate what I need. Can anyone help?
The relay sockets and connectors can be seen here:
http://order.waytekwire.com/IMAGES/M37/catalog/216_54
I'm using the #75280 style sockets. These are modular. You can stack
them together. The connectors are part # 31073, also seen on the above web
page. Charlie Kuss RV-8A cockpit wiring & systems>>
8/25/2004
Hello Charlie, Why wouldnt an Avikrimp female .250 push on terminal work? You can
get them in either insulated (AA-8140) or uninsulated (AA-1140F) configuration.
(Also fully insulated, but you dont want that here).Just do a google search.
Yes they are the high quality complete surround PIDG crimp on type terminals, not
open barrel, and the lock on feature may not be a perfect match with the lock
on built into the socket body, but Ill bet they wouldnt come loose from the
male terminal inside the socket body.
I use the Avikrimp fully insulated male and female terminals as in-line connectors
in much of my wiring. One draw back is that when I want to separate them it
takes holding the inner shell with a pliers and twisting a broad blade screwdriver
between the side of the pliers and the end of the outer shell to separate
them. The make positive connection.
OC
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Locking female fast on source needed |
>
>
>This is not a knock on the relay pigtail or similar connectors, but they
>are not a required part. Let's not lose sight of the fact that you can
>simply attach regular female fast-ons to the male lugs on the relays.
>Just a thought....
That's what I've always recommended. I KNOW the quality of a PIDG
fast-on female connector. I don't know the quality of the connectors
supplied with the pre-wired sockets or socket kits. One should
not need to replace these relays very often . . . not having them
on a socket is a minor risk/inconvenience.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Re: Crimper selection? |
>
>
>Will a ratcheting crimper designed for Sta-Kon terminals also properly
>crimp standard PIDG hardware? Is there any significant difference
>between Sta-Kon and other spec hardware?
Don't know. You need to install some terminals and then
cut them apart. See:
http://www.aeroelectric.com/articles/CrimpTools/crimptools.html
It wouldn't hurt if you had access to a 40x microscope to check
the wire grip for complete closure as described in the
article.
Someone else on the list might have some experience with this
tool. If your tool looks like this one:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=303&item=4320192350&rd=1
. . . odds are that it's okay with PIDG harware.
If it looks more like this one:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=20767&item=4320748635&rd=1
I wouldn't use it on my lawnmower.
Problem is that "Sta-Kon" covers a wide range of products that
makes it difficult to judge suitability of your tool without
having more data.
Bob . . .
---
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: Simplification |
OC,
Thanks for the clarification. I'm assuming that aircraft starters don't use
the Bendix engagement system - too old and clunky? The Z-diagrams show a
starter "solenoid" - so that gadget is going to do the two things - provide
current to motor and move the pinion gear to engage the flywheel.
So, looks like us two proponents of "simplification" are suggesting use of a
manual battery switch which then allows the elimination of the "starter
contactor" in the Z- drawings, i.e., #2awg fat wire goes from downstream
side of manual batt sw to fat wire terminal on starter solenoid (instead of
to upstream side of a starter contactor) and the push-to-start wire goes to
the starter solenoid coils instead of the "eliminated starter contactor
coils".
Sound reasonable and without some bad operational quirk I've not thought of?
David
----- Original Message -----
From: <bakerocb(at)cox.net>
Subject: AeroElectric-List: Simplification
>
> Extract from a previous posting by David Carter
>
> <<2. Starter: I assume you are proposing not to have "main starter
cranking current" go through a high current capacity "starter relay" -
rather, have the starter motor hard wired to the battery and only have the
pilot
> actuate a lower current switch to energize the relay coil of the relay on
the starter that engages the Bendix and also closes the "high current"
circuit to the motor from the "hard wired" wire. Do I have that wiring and
> terminology correct? Then, if the starter ever fails and continues to
crank when the starter switch is released, then the Manual Battery Master
can be used to kill power to the starter motor.>>
>
> 8/25/2004
>
> Hello David, some terminology clarification if I may. A Bendix in starter
terminology is a mechanical spiral geared device used to move and engage the
starter motor pinion gear with the teeth on the fly wheel as a result of the
initial rotation of the starter motor.
>
> Many modern starters use an on-starter solenoid to both complete
electrical contact to the starter motor and move a pinion gear into and out
of mesh with the teeth on the fly wheel or a gear in the engine accessory
section.
>
> Therefore such starters do not incorporate a Bendix.
>
> OC
________________________________________________________________________________
| From: | Geoff Evans <hellothaimassage(at)yahoo.com> |
I recently bought a couple of the Vans dimmers for cockpit lighting. They
come with a miniature (1/4" mount, 1/8" shaft) 1K pot.
The suggested wiring diagram shows getting 12V from the nav light switch --
i.e. when the nav lights are on, the cockpit lights are on. However, it seems
to me that the cockpit lights should have a separate fuse. Why lose the
cockpit lighting if you happen to blow the fuse for the nav lights?
So, since I don't want to install a separate toggle switch, I'm looking for a
1K miniature pot that has a switch at the fully counter-clockwise position.
I'd like one with the same exterior parameters as the original pot -- namely,
a 1/4" mounting hole, a 1/8" shaft, and solder terminals on the back (as
opposed to on the side).
The Digikey catalog has a bazillion different variants of these things, and
I'm not sure which one to order. Can someone point me in the right direction,
preferably with an exact part number or the like?
Thanks.
-Geoff
RV-8
_______________________________
________________________________________________________________________________
| From: | "jcrain2(at)juno.com" <jcrain2(at)juno.com> |
I am hearing slight alternator noise in my headsets. Sometimes they are garbled
plus transp. doesn't always get through. I feel I need to separate my
com/intercom from the master solenoid and feed off the battery. I have already
installed the noise filter after the master solenoid.
Also the mic key makes the wing leveler turn plus the fuel gauge pegs out. Is
there an extra shielded coax that works with the B and C connectors or should I
pull some off of an other larger coax to double shield?
I have just a "whip antenna" with a metal screen ground plane. Would
the aluminum "Flying W" be better than a dipole flat metal ribbon that
"Spruce" advertises?
Is there an archive in Kit planes or could you FAX me a schematic showing parts
and hook ups for a fix?
Bruce Crain
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Re: Simplification |
>
>
>OC,
>
>Thanks for the clarification. I'm assuming that aircraft starters don't use
>the Bendix engagement system - too old and clunky?
Some modern products do use the Bendix style pinion engagement
mechanism. It's relatively simple and works well as long as it's
not badly worn or insufficiently lubricated. But like batteries
in most airplanes, they don't get attention until they have been
misbehaving for some time.
B&C chose not to go the Bendix route in a quest for the most
trouble free design with the longest service life we could deduce
at the time.
> The Z-diagrams show a
>starter "solenoid" - so that gadget is going to do the two things - provide
>current to motor and move the pinion gear to engage the flywheel.
If you're talking about the circle perched right on top of the
"STARTER" symbol, yes. That is a combination electrical control
contactor and pinion gear engagement solenoid. See:
http://www.aeroelectric.com/articles/strtctr.pdf
Some of the earliest revisions to the Z-figures were driven by
a late discovery of the very high inrush currents demanded by
this style of starter contactor/solenoid mechanism. When installing
this starter on an airplane with a keyswitch, the solenoid would
be VERY hard on the starter contacts of the switch.
Had a guy working for me about 15 years ago that had some brand
of small Japanese car. It wouldn't start one afternoon in the
parking lot of my business. We got out the meter and trouble shot
the system to discover that the starter switch in the key lock
was not closing. Upon disassembly of the switch, we found the
brass contacts of the starter circuit blackened and burned away.
He noted that the starter had been flaky for several months before
it quit. A new switch "fixed" it . . . an external contactor added
on as suggested in the Z-figures would have made the problem
go away for the lifetime of the car.
This is what drove the recommendation for an external contactor
as shown in Figure 6 of the article and explained in the last
few paragraphs.
>So, looks like us two proponents of "simplification" are suggesting use of a
>manual battery switch which then allows the elimination of the "starter
>contactor" in the Z- drawings, i.e., #2awg fat wire goes from downstream
>side of manual batt sw to fat wire terminal on starter solenoid (instead of
>to upstream side of a starter contactor) and the push-to-start wire goes to
>the starter solenoid coils instead of the "eliminated starter contactor
>coils".
You have unrelated things tied together. The use of a manual battery
switch has no bearing on your style of starter or even if you have
a starter. Many aircraft have used manual switches in years past.
The Tri-Pacer in which I took dual instruction in 1961 had the battery
mounted under the right seat. The battery master was a fat toggle
under the front edge of the seat. You can have a mechanical switch
for ANY battery installation on any airplane whether or not it has
a starter.
You can use the starter's built in contactor/solenoid as shown
in Figure 6 of the article . . . just be aware of the special
stresses on what ever switch you use to energize the contactor/solenoid.
There are heavy duty push-buttons offered by many industrial
and heavy automotive supply houses that would be fine. I've not
conducted any tests on driving this bad-mamma contactor through
a fuse. You may find it necessary to use a 15A fuse and 14AWG
wire for your push-button circuit so that the inrush current doesn't
nuisance-trip the fuse.
Parts count reduction is a good thing generally. Just be aware
that not all parts shown in the Z-figures were added purely for
the sake of some convenience. We've been trading off service life,
reliability, installed weight, wire routing and convenience
issues for decades. I'd like to think that the Z-figures
represent a distilled approach that has a considered
purpose for each component. Compared to the way we
can hose up the electrical system architecture in a biz jet,
the z-figures are stone simple. Efforts toward further
simplification should be supported by a through understanding
of the thought processes by which proposed "excess parts" were
included.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Re: Switched Pot |
>
>
>I recently bought a couple of the Vans dimmers for cockpit lighting. They
>come with a miniature (1/4" mount, 1/8" shaft) 1K pot.
>
>The suggested wiring diagram shows getting 12V from the nav light switch --
>i.e. when the nav lights are on, the cockpit lights are on. However, it seems
>to me that the cockpit lights should have a separate fuse. Why lose the
>cockpit lighting if you happen to blow the fuse for the nav lights?
Minimal cockpit lighting should be on its own fuse off the e-bus.
How much current does your lighting system draw in the minimum light
mode for flight in full darkness. I would have two lighting systems.
A panel flood that runs from the e-bus that draws perhaps 100 mA max.
The big-kahuna lighting system would fuse from the main bus and have
a dimmer control set up for min-max voltage tailored for how the lights
operate. OFF is at about 4 volts for an incandescent lamp. Our dimmers
are set up for 4-max volts over the full rotation of the pot. No
toggle switch is recommended. It only adds to parts count, takes up
panel space and offers no operational advantages. Don't want lights?
Turn them down to min output of 4v and call them "off" . . . lamp life
at this voltage level is somewhere between a very long time and forever.
Current draw under this condition is insignificant.
>So, since I don't want to install a separate toggle switch, I'm looking for a
>1K miniature pot that has a switch at the fully counter-clockwise position.
>I'd like one with the same exterior parameters as the original pot -- namely,
>a 1/4" mounting hole, a 1/8" shaft, and solder terminals on the back (as
>opposed to on the side).
>
>The Digikey catalog has a bazillion different variants of these things, and
>I'm not sure which one to order. Can someone point me in the right direction,
>preferably with an exact part number or the like?
Pots with switches are now almost totally non-existent. They were
popular when volume controls were also tasked with turning power
on and off for a radio. This technique is seldom used for anything
other than $4 pocket radios. I'd suggest you set up your dimming
for the voltage control range cited above, have perhaps two lighting
systems independently fused and split between the two busses and
include NO toggle switches.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Re: Which diode to use? |
>
>
>Folks:
>
>I have discovered that the aux power outlet (i.e. cigarette lighter
>socket) in my non-ABAM plane is wired without any protection against
>back-feeding the bus. That is, if I plug in my 17-79 headset to
>recharge the internal battery, and forget that I did so, then when I
>shut down the plane the 9V headset battery provides at least enough
>power to light up the "alternator off" warning light.
>
>I would like to add a diode to the system to prevent this. In the
>forward direction, the socket is protected by a 5A fuse. What would be
>the appropriate size/rating of a diode to add to the line? And what
>would be the best way to wire it in?
I'd add this diode to the power cable for the headset. The
power needed by this system is quite small. A 1-amp rated diode
from radio shack would suffice. See the 1N400x series diodes
at:
http://www.radioshack.com/search.asp?cookie%5Ftest=1&find=diode&hp=search&image1.x=0&image1.y=0&image1=submit&SRC=1
Wire one into the + power lead for the headset with the banded
end of the diode facing the headset.
Bob . . .
---
________________________________________________________________________________
| Subject: | Re: Switched Pot |
| From: | "Matt Prather" <mprather(at)spro.net> |
Hi Geoff,
Bob already sent a good reply to this. However, if your heart is set
on having a switch control the panel lights, a double pole switch might
be the way to go. Such a switch has two power inputs as well as two
switched outputs - isolated. I propose that you use 2 seperately fused
inputs to the switch - one for the nav, one for the panel.
Regards,
Matt-
>
>
> I recently bought a couple of the Vans dimmers for cockpit lighting.
> They come with a miniature (1/4" mount, 1/8" shaft) 1K pot.
>
> The suggested wiring diagram shows getting 12V from the nav light switch
> -- i.e. when the nav lights are on, the cockpit lights are on. However,
> it seems to me that the cockpit lights should have a separate fuse. Why
> lose the cockpit lighting if you happen to blow the fuse for the nav
> lights?
>
> So, since I don't want to install a separate toggle switch, I'm looking
> for a 1K miniature pot that has a switch at the fully counter-clockwise
> position. I'd like one with the same exterior parameters as the original
> pot -- namely, a 1/4" mounting hole, a 1/8" shaft, and solder terminals
> on the back (as opposed to on the side).
>
> The Digikey catalog has a bazillion different variants of these things,
> and I'm not sure which one to order. Can someone point me in the right
> direction, preferably with an exact part number or the like?
>
> Thanks.
> -Geoff
> RV-8
>
>
> _______________________________
>
>
________________________________________________________________________________
aeroelectric-list(at)matronics.com
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Warning light on Main and Aux Alternator installation |
lus.com>
>Bob, I posted (thought I posted) this question to the aeroelectric list, but
>got no responses. Can a single LO/OV module work with a 2 alternator, Main
>and EBuss system as I envision? If not, is there a way?
>Thx
>Randy
Not real sure what the question is. What Z-figure are we talking
about? You talke about a "504-1 module" is this the S704-1
disconnect relay combined with an OVM-14 crowbar OV module?
I'm not visualizing how you would wire all this stuff together.
Let's pick a z-figure and then describe how it's modified.
>
>
>Could we not feed the 504-1 module with power from both the Main and
>Essential busses? When the Main Alternator failed the light would come on
>because the E Buss switch would be open so power would be lost to both
>busses momentarily,
When an alternator quits, NO busses loose power. The voltage
simple falls from 13.8 to 14.6 volts down to 12.6 or below.
Everything continues to function and the low voltage warning
light begins to flash.
> and then go off when the E Buss switch is closed
>providing 12v again to the 504 module?
>Randy
I think your mixing up the functionality of two separate systems.
The S704-1/OVM-14 combination is for control of the SD-8 and OV protection.
This task is separate and independent of altenrator failure warning
by some active form of low voltage warning . . . either by our
LVW/ABMM module, -OR- the low volts warning built into a B&C LR-3, -OR-
any other form of LV WARN you plan to incorporate to watch the main
bus voltage.
I presume you're talking about Figure Z-13. What changes would
you perceive to be useful?
Bob . . .
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Locking female fast on source needed |
Bob
I'm not going to use a "pre wired" socket. I don't like the PVC insulated
wire on them.
Charlie
>
>
>
> >
> >
> >This is not a knock on the relay pigtail or similar connectors, but they
> >are not a required part. Let's not lose sight of the fact that you can
> >simply attach regular female fast-ons to the male lugs on the relays.
> >Just a thought....
>
> That's what I've always recommended. I KNOW the quality of a PIDG
> fast-on female connector. I don't know the quality of the connectors
> supplied with the pre-wired sockets or socket kits. One should
> not need to replace these relays very often . . . not having them
> on a socket is a minor risk/inconvenience.
>
> Bob . . .
>
>
>---
>
>
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
8/26/2004
Hello David, I will respond in pieces below:
AeroElectric-List message posted by: "David Carter"
<< OC, Thanks for the clarification. I'm assuming that aircraft starters
don't use the Bendix engagement system - too old and clunky? >>
That statement is a little too sweeping. I think it would be more accurate to say
that many recent modern design aircraft starters do not use the Bendix spiral
gear mechanism, but instead use a solenoid to engage and disengage the starter
pinion gear. Until the fairly recent arrival of the aviation engine light
weight starters installation of the heavy, clunky, and maintenance needy Bendix
mechanism was widespread and thousands of airplanes are still flying with it
today.
<>
Yes. On those Z diagrams with the little circle with the letters SOL inside drawn
next to the STARTER circle that is what is being portrayed. But notice on Z-18
for the LOM engine there is no SOL next to the starter. Presumably the LOM
engine uses a starter with a Bendix or some other method of starting.
<>
I dont see that installation of a manual battery switch is a mandatory precedence
to eliminating the starter contactor. Either one should be able to be implemented
independent of each other. I have not arrived at the design point of abandoning
the battery contactor. My KIS TR-1 is completed (they never are really)
and flying and my next project (bigger and faster) is still in the wife convincing
stage.
<>
What you describe is exactly how I understand it. Obviously some modification of
the starter wiring is going to be required because as designed the electricity
going to the input fat wire terminal on the starter solenoid also goes at the
same time to the coil on the solenoid. The result is movement of the solenoid
slug which completes the electrical circuit to the starter motor and moves
the pinion gear into contact. Since your plan calls for activation of the solenoid
coil independently after the fact that electricity is already at the starter
input point means some starter wiring modification is required.
Now two caveats both from Bob Nuckolls in passing in the 8/24/04 aeroelectric-list:
1) Bob mentions some sort of relay near the starter to handle in rush current in
the above scenario. This is a mystery to me. You might want to seek clarification
from him.
2) Bob mentions the separate starter contactor as recommended by B&C. I intend
to contact them and ask why. I will report back.
OC
________________________________________________________________________________
| From: | "DAVID REEL" <dreel(at)cox.net> |
| Subject: | Crimping 22AWG PIDG terminals |
Has anyone had problems getting a good crimp with Cleveland Tools WTC380 ratchet
terminal crimper? I cannot get the 18-22 AWG terminals to firmly grab 22AWG
wire. Even doubling the wire doesn't make a firm connection. So far I'm 0 out
of 4 tries. The crimper otherwise seems good on the other sizes but the 18-22
size is out on the far end of the tool & I'm suspecting some flexing. Though
I'm not an experienced crimper, the whole thing seems pretty idiot proof so
I can't imagine what else might be wrong. The PIDG terminals came from B&C.
Dave Reel - RV8A
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: Simplification |
Bob & OC,
Thanks for the nice replies. Bob, your article on starters and circuit
evolution is great.
The only reason I "linked" manual batt sw and elim of starter contactor was
the issue of "killing the fat wire to the starter" - i.e., if the starter
contactor is eliminated, and the fat wire is hot all the time the battery sw
is "on", and then, someday, the starter "runs on" after I release the start
button - some other way of killing that wire is needed - the manual battery
sw does that. Oh, so does a normal battery contactor. Oh, so, there is no
linkage. Either one works the same. Boy, I'm slow.
I appreciate the issue of "stress" on the starter switch, i.e., it ought not
be subjected to current (inrush) that adversely shortens its life. The
starter contactor is a good solution. But, with respect to that
"evolutionary or evolved" refinement of the starter circuits - and I don't
mean any disrespect for something that works and is in general practice -
but adding a contactor to protect a switch from premature death is a
work-around or substitute for getting a better switch. Now, as I say that,
I know that cars and non-OBAM aircraft operators aren't and can't,
respectively, going to go put in a better switch, so the starter contactor
becomes the elegantly simple and reasonable solution.
- However, for us OBAMers, I'd rather get one of those heavy duty
industrial grade "push to start" switches Bob mentioned in his reply. Fits
in with the idea of parts simplification and using better stuff than
non-OBAM are permitted to use.
I'll have to pick a starter that can be readily modified to unhook (or cut)
the solenoid coil's power lead from the "fat wire terminal" and have it get
its power from my industrial grade push button (Hey!! If all else fails I
could use a knife switch & watch the big blue spark when I disconnect the
starter - wouldn't that look cool? (or kooky?)
Thanks, again for the great info and help "understanding the physics
involved".
David
----- Original Message -----
From: "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com>
Subject: Re: AeroElectric-List: Simplification
>
>
> >
> >
> >OC,
> >
> >Thanks for the clarification. I'm assuming that aircraft starters don't
use
> >the Bendix engagement system - too old and clunky?
>
> Some modern products do use the Bendix style pinion engagement
> mechanism. It's relatively simple and works well as long as it's
> not badly worn or insufficiently lubricated. But like batteries
> in most airplanes, they don't get attention until they have been
> misbehaving for some time.
>
> B&C chose not to go the Bendix route in a quest for the most
> trouble free design with the longest service life we could deduce
> at the time.
>
>
> > The Z-diagrams show a
> >starter "solenoid" - so that gadget is going to do the two things -
provide
> >current to motor and move the pinion gear to engage the flywheel.
>
> If you're talking about the circle perched right on top of the
> "STARTER" symbol, yes. That is a combination electrical control
> contactor and pinion gear engagement solenoid. See:
>
> http://www.aeroelectric.com/articles/strtctr.pdf
>
> Some of the earliest revisions to the Z-figures were driven by
> a late discovery of the very high inrush currents demanded by
> this style of starter contactor/solenoid mechanism. When installing
> this starter on an airplane with a keyswitch, the solenoid would
> be VERY hard on the starter contacts of the switch.
>
> Had a guy working for me about 15 years ago that had some brand
> of small Japanese car. It wouldn't start one afternoon in the
> parking lot of my business. We got out the meter and trouble shot
> the system to discover that the starter switch in the key lock
> was not closing. Upon disassembly of the switch, we found the
> brass contacts of the starter circuit blackened and burned away.
> He noted that the starter had been flaky for several months before
> it quit. A new switch "fixed" it . . . an external contactor added
> on as suggested in the Z-figures would have made the problem
> go away for the lifetime of the car.
>
> This is what drove the recommendation for an external contactor
> as shown in Figure 6 of the article and explained in the last
> few paragraphs.
>
>
> >So, looks like us two proponents of "simplification" are suggesting use
of a
> >manual battery switch which then allows the elimination of the "starter
> >contactor" in the Z- drawings, i.e., #2awg fat wire goes from downstream
> >side of manual batt sw to fat wire terminal on starter solenoid (instead
of
> >to upstream side of a starter contactor) and the push-to-start wire goes
to
> >the starter solenoid coils instead of the "eliminated starter contactor
> >coils".
>
> You have unrelated things tied together. The use of a manual battery
> switch has no bearing on your style of starter or even if you have
> a starter. Many aircraft have used manual switches in years past.
> The Tri-Pacer in which I took dual instruction in 1961 had the battery
> mounted under the right seat. The battery master was a fat toggle
> under the front edge of the seat. You can have a mechanical switch
> for ANY battery installation on any airplane whether or not it has
> a starter.
>
> You can use the starter's built in contactor/solenoid as shown
> in Figure 6 of the article . . . just be aware of the special
> stresses on what ever switch you use to energize the
contactor/solenoid.
> There are heavy duty push-buttons offered by many industrial
> and heavy automotive supply houses that would be fine. I've not
> conducted any tests on driving this bad-mamma contactor through
> a fuse. You may find it necessary to use a 15A fuse and 14AWG
> wire for your push-button circuit so that the inrush current doesn't
> nuisance-trip the fuse.
>
> Parts count reduction is a good thing generally. Just be aware
> that not all parts shown in the Z-figures were added purely for
> the sake of some convenience. We've been trading off service life,
> reliability, installed weight, wire routing and convenience
> issues for decades. I'd like to think that the Z-figures
> represent a distilled approach that has a considered
> purpose for each component. Compared to the way we
> can hose up the electrical system architecture in a biz jet,
> the z-figures are stone simple. Efforts toward further
> simplification should be supported by a through understanding
> of the thought processes by which proposed "excess parts" were
> included.
>
> Bob . . .
________________________________________________________________________________
| From: | echristley(at)nc.rr.com |
| Subject: | Re: Simplification |
>
> This is why I'm a little miffed when a newby
writes to say,
> "I'm using
> Figure Z-xx but I've incorporated a few ideas
of my own." He then
> lists all the things he plans to do and wants
on-the-spot critical
> review. I have to explain that the best thing
to do is pick a
> figure as published and then let's discuss any
perceived
> shortcomings one
> at a time. If there is merit to alternative
architectures, we'll
> publish it and get feedback from the rest of
the community. That's
> how Appendix Z has grown and will continue to grow.
>
>
Bob, I haven't purchased the book...yet. I have to
many task with the requisite purchases and education
in the way before I get down to designing the
electrical system. I figure by the time I purchase
the book, it'll have evolved another generation or two.
That being said, how are changes tracked in the
book. Are the changes listed with a short paragraph
as to why? I often ask naive question when I can't
understand the 'why' of a particular technique that
is not used. Once I find out what the 'why' is, the
answer is often more illuminating than the 'why's
dealing with what IS used.
Again, I don't have the book, but if this is done
then newbie questions of this type should get a curt
RTFM.
________________________________________________________________________________
| From: | "LarryRobertHelming" <lhelming(at)sigecom.net> |
| Subject: | Re: Simplification |
David, the primary concern I have with running the big-o-boy start
button/switch is that heavy and high amp wire runs all the way from its
power source (the battery) to your panel switch and then on to the starter
motor. That is a lot of big wire. Starters draw a lot of amps.
Unfortunately, Bob's wiring diagrams do not show how long all the runs are.
With my battery contactor, I do not have any big wires on the pilot's side
of the firewall. That is lighter and safer.
Indiana Larry, RV7 TipUp "SunSeeker"
The sincerest satisfactions in life come in doing and not dodging duty; in
meeting and solving problems, in facing facts, in being a dependable person.
- Richard L. Evans
----- Original Message -----
From: "David Carter" <dcarter(at)datarecall.net>
Subject: Re: AeroElectric-List: Simplification
>
> Bob & OC,
>
> Thanks for the nice replies. Bob, your article on starters and circuit
> evolution is great.
>
> The only reason I "linked" manual batt sw and elim of starter contactor
was
> the issue of "killing the fat wire to the starter" - i.e., if the starter
> contactor is eliminated, and the fat wire is hot all the time the battery
sw
> is "on", and then, someday, the starter "runs on" after I release the
start
> button - some other way of killing that wire is needed - the manual
battery
> sw does that. Oh, so does a normal battery contactor. Oh, so, there is
no
> linkage. Either one works the same. Boy, I'm slow.
>
> I appreciate the issue of "stress" on the starter switch, i.e., it ought
not
> be subjected to current (inrush) that adversely shortens its life. The
> starter contactor is a good solution. But, with respect to that
> "evolutionary or evolved" refinement of the starter circuits - and I don't
> mean any disrespect for something that works and is in general practice -
> but adding a contactor to protect a switch from premature death is a
> work-around or substitute for getting a better switch. Now, as I say
that,
> I know that cars and non-OBAM aircraft operators aren't and can't,
> respectively, going to go put in a better switch, so the starter contactor
> becomes the elegantly simple and reasonable solution.
> - However, for us OBAMers, I'd rather get one of those heavy duty
> industrial grade "push to start" switches Bob mentioned in his reply.
Fits
> in with the idea of parts simplification and using better stuff than
> non-OBAM are permitted to use.
>
> I'll have to pick a starter that can be readily modified to unhook (or
cut)
> the solenoid coil's power lead from the "fat wire terminal" and have it
get
> its power from my industrial grade push button (Hey!! If all else fails I
> could use a knife switch & watch the big blue spark when I disconnect the
> starter - wouldn't that look cool? (or kooky?)
>
> Thanks, again for the great info and help "understanding the physics
> involved".
>
> David
>
> ----- Original Message -----
> From: "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com>
> To:
> Subject: Re: AeroElectric-List: Simplification
>
>
>
> >
> >
> > >
> > >
> > >OC,
> > >
> > >Thanks for the clarification. I'm assuming that aircraft starters
don't
> use
> > >the Bendix engagement system - too old and clunky?
> >
> > Some modern products do use the Bendix style pinion engagement
> > mechanism. It's relatively simple and works well as long as it's
> > not badly worn or insufficiently lubricated. But like batteries
> > in most airplanes, they don't get attention until they have been
> > misbehaving for some time.
> >
> > B&C chose not to go the Bendix route in a quest for the most
> > trouble free design with the longest service life we could deduce
> > at the time.
> >
> >
> > > The Z-diagrams show a
> > >starter "solenoid" - so that gadget is going to do the two things -
> provide
> > >current to motor and move the pinion gear to engage the flywheel.
> >
> > If you're talking about the circle perched right on top of the
> > "STARTER" symbol, yes. That is a combination electrical control
> > contactor and pinion gear engagement solenoid. See:
> >
> > http://www.aeroelectric.com/articles/strtctr.pdf
> >
> > Some of the earliest revisions to the Z-figures were driven by
> > a late discovery of the very high inrush currents demanded by
> > this style of starter contactor/solenoid mechanism. When installing
> > this starter on an airplane with a keyswitch, the solenoid would
> > be VERY hard on the starter contacts of the switch.
> >
> > Had a guy working for me about 15 years ago that had some brand
> > of small Japanese car. It wouldn't start one afternoon in the
> > parking lot of my business. We got out the meter and trouble shot
> > the system to discover that the starter switch in the key lock
> > was not closing. Upon disassembly of the switch, we found the
> > brass contacts of the starter circuit blackened and burned away.
> > He noted that the starter had been flaky for several months before
> > it quit. A new switch "fixed" it . . . an external contactor added
> > on as suggested in the Z-figures would have made the problem
> > go away for the lifetime of the car.
> >
> > This is what drove the recommendation for an external contactor
> > as shown in Figure 6 of the article and explained in the last
> > few paragraphs.
> >
> >
> > >So, looks like us two proponents of "simplification" are suggesting use
> of a
> > >manual battery switch which then allows the elimination of the "starter
> > >contactor" in the Z- drawings, i.e., #2awg fat wire goes from
downstream
> > >side of manual batt sw to fat wire terminal on starter solenoid
(instead
> of
> > >to upstream side of a starter contactor) and the push-to-start wire
goes
> to
> > >the starter solenoid coils instead of the "eliminated starter contactor
> > >coils".
> >
> > You have unrelated things tied together. The use of a manual battery
> > switch has no bearing on your style of starter or even if you have
> > a starter. Many aircraft have used manual switches in years past.
> > The Tri-Pacer in which I took dual instruction in 1961 had the
battery
> > mounted under the right seat. The battery master was a fat toggle
> > under the front edge of the seat. You can have a mechanical switch
> > for ANY battery installation on any airplane whether or not it has
> > a starter.
> >
> > You can use the starter's built in contactor/solenoid as shown
> > in Figure 6 of the article . . . just be aware of the special
> > stresses on what ever switch you use to energize the
> contactor/solenoid.
> > There are heavy duty push-buttons offered by many industrial
> > and heavy automotive supply houses that would be fine. I've not
> > conducted any tests on driving this bad-mamma contactor through
> > a fuse. You may find it necessary to use a 15A fuse and 14AWG
> > wire for your push-button circuit so that the inrush current doesn't
> > nuisance-trip the fuse.
> >
> > Parts count reduction is a good thing generally. Just be aware
> > that not all parts shown in the Z-figures were added purely for
> > the sake of some convenience. We've been trading off service life,
> > reliability, installed weight, wire routing and convenience
> > issues for decades. I'd like to think that the Z-figures
> > represent a distilled approach that has a considered
> > purpose for each component. Compared to the way we
> > can hose up the electrical system architecture in a biz jet,
> > the z-figures are stone simple. Efforts toward further
> > simplification should be supported by a through understanding
> > of the thought processes by which proposed "excess parts" were
> > included.
> >
> > Bob . . .
>
>
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | starter circuit simplification |
8/26/2004
Hello Dave Carter and Other Builders, I queried Tim Hedding of B&C regarding eliminating
the independent starter contactor in the starting circuit and using
just the solenoid on the starter itself to complete the electrical circuit and
move the pinion gear into and out of engagement. Below is Tims reply. I know
the attachments will not come through on the aeroelectric list, but if anyone
wants the attachments just email me and I will get them to you direct.
OC
-----------------------RESPONSE FROM TIM HEDDING FOLLOWS-------------
Owen, Let me offer the following points for consideration (these are specifically
with reference to our starters):
1) The starter solenoid houses two coils. They are common at the push-on tab on
the rear of the solenoid. The other end of one is grounded inside the solenoid
body. The other end of the second is tied to the starter motor output post and,
therefore, is grounded through the low resistance motor windings. When power
is applied to the push-on blade, the coils are both energized and both act
to extend the starter pinion. Once the starter pinion is extended fully, the motor
contacts in the base of the solenoid are closed, bypassing one of the coils
and energizing the starter motor. The remaining coil continues to keep the
pinion extended.
The "in-rush" current of the two parallel coils is about 30 amps. The residual
current during the start is about 10 amps. Most starter switches would be toast
very quickly if assigned to close on this much current. In fact, we have had
some who "knew better" and tried this only to buy a new starter because their
start switch welded closed. This is one reason why we wire the push-on tab permanently
to the starter input post and use a starter relay ("contactor") to complete
the circuit.
2) It is possible for either a starter solenoid to stick or a starter relay ("contactor")
to stick. Either, installed by itself could leave the starter running
until it is destroyed. This possibility is reduced when the relay and solenoid
are both used. In this case, the slowest contacts will be the ones stuck closed
and the other set will still be functional. If both are used and the relay
sticks, the master relay may be de-energized to kill the starter. If there
is no master relay (such as in our wiring diagram for aerobatic airplanes attached)
we provide a starter kill switch in the starter solenoid control circuit
to allow the pilot to interrupt the runaway starter. These normally-closed contacts
will not be damaged by the momentary 30 Amp in-rush but are capable of
interrupting the 10 Amp residual current.
While we're discussing this point, let me say that it is a good idea to install
a "Starter On Light" (drawing attached) that receives its power from the output
side of the starter relay. We've had some pilots who couldn't tell that the
starter was still running and did nothing to disengage the starter even when
they could have. These little devices are required by some foreign aviation authorities.
3) Though not practical in all airplanes, the best starter circuit wiring is usually
to place the master relay and starter relay close to the battery. The wiring
associated with these high current switches is large and not protected by
over-current devices. So, the wires are kept short and dressed carefully to prevent
uncontrollable fault currents. In this case, the wire from the starter
relay to the starter is not "hot" except when cranking. A short to an engine mount
or firewall at a penetration point during flight is inconsequential because
the wire is inert. If a starter relay is not used and the starter solenoid
is used as the controlling relay, this wire is hot continually and poses some
additional hazard or at least deserves extra attention to wire dress and pinion
points. A large hot cable such as this could also present an extra accident
hazard. Hopefully, we'll never have a bad landing incident that can violate the
engine compartment structure. In the unlikely event
that our "precious" goes cartwheeling down the runway, crushed or bent structures
could leave a very good ignition source in the engine compartment to set
off oil or fuel fumes.
Now, I know that different airframe construction materials, methods and architectures
affect the statements I've made above, but what would you recommend in
general concerning starter wiring, not knowing the intimate construction details
of each project that we deal with.
Tim Hedding,
E.E. at B&C
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: Simplification |
Larry,
Larry, the starter wiring thing we are talking is to run the "fat wire" 2awg
for starter motor current from downstream side of battery switch (manual) or
battery contactor (standard practice) to the "fat" terminal on the starter,
then mod the starter to feed the starter solenoid from a "heavy duty starter
switch" instead of staying tied to the post the fat wire goes on. Then run
a smaller wire that will handle 30 amps momentary, 10 amps continuous just
to power the starter solenoid coils (2 windings, as explained in Bob's
article & B&C's discussion in next e-mail). "Lectric Bob" made a
recommendation for size of such a wire to stand the inrush and short
duration steady state 10 amps - would not be the "motor current", just the
"solenoid current" - Bob's recent comment during this discussion was, "15A
fuse and 14AWG wire for your push-button circuit so that the inrush current
doesn't nuisance-trip the fuse."
David
----- Original Message -----
From: "LarryRobertHelming" <lhelming(at)sigecom.net>
Subject: Re: AeroElectric-List: Simplification
>
> David, the primary concern I have with running the big-o-boy start
> button/switch is that heavy and high amp wire runs all the way from its
> power source (the battery) to your panel switch and then on to the starter
> motor. That is a lot of big wire. Starters draw a lot of amps.
> Unfortunately, Bob's wiring diagrams do not show how long all the runs
are.
> With my battery contactor, I do not have any big wires on the pilot's side
> of the firewall. That is lighter and safer.
>
> Indiana Larry, RV7 TipUp "SunSeeker"
________________________________________________________________________________
| Subject: | ELT antenna replacement |
My AK-450 ELT antenna just broke off in the slip stream. Question I have is
can I successfully use an antenna from an old STS Loran for this service?
Looking at them, they seem to be about the same size.
Pat Long
PGLong(at)aol.com
N120PL
RV4
Bay City, Michigan
3CM
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: ELT antenna replacement |
>> My AK-450 ELT antenna just broke off in the slip stream. Question I
>> have is can I successfully use an antenna from an old STS Loran for
>> this
>> service?
>
> Probably not. The LORAN antenna is not tuned to the aviation band. It
> operates at a frequency about 1000 times lower than the band in which
> your ELT operates. The LORAN antenna may also have a built-in
> preamplifier which will block any VHF signal from getting in or out.
>
> Play it safe and install a proper antenna.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | Benford2(at)aol.com |
| Subject: | Re: ELT antenna replacement |
In a message dated 8/27/2004 5:10:59 AM Mountain Daylight Time,
PGLong(at)aol.com writes:
>
>
> My AK-450 ELT antenna just broke off in the slip stream. Question I have is
>
> can I successfully use an antenna from an old STS Loran for this service?
> Looking at them, they seem to be about the same size.
>
> Pat Long
> PGLong(at)aol.com
> N120PL
> RV4
> Bay City, Michigan
>
Funny you should post this. My AK450 antenna fell off on my first flight. I
bet it happens more often then we think. Anybody else have this same thing
happen too??
Ben Haas N801BH
________________________________________________________________________________
| From: | "Trampas" <tstern(at)nc.rr.com> |
| Subject: | Transponder Converter from Serial to Gray code |
I am thinking about making a simple converter which converts a serial data
stream like from the Dynon to a gray code output. However I do not have a
gray code encoder handy to figure out what the output voltages are, does
anyone know?
Regards,
Trampas
www.sterntech.com
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Brian
Lloyd
Subject: Re: AeroElectric-List: ELT antenna replacement
>> My AK-450 ELT antenna just broke off in the slip stream. Question I
>> have is can I successfully use an antenna from an old STS Loran for
>> this
>> service?
>
> Probably not. The LORAN antenna is not tuned to the aviation band. It
> operates at a frequency about 1000 times lower than the band in which
> your ELT operates. The LORAN antenna may also have a built-in
> preamplifier which will block any VHF signal from getting in or out.
>
> Play it safe and install a proper antenna.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | Matt Jurotich <mjurotich(at)hst.nasa.gov> |
| Subject: | MicroAir 760 Radio |
I am redoing the panel on already built RV 6A, there is 8 3/4 in depth
behind the main panel to the structural sub-panel. Would the MicroAir 760
radio fit without penetration of the sub-panel? Would this radio work well
in a system with a GNX80 NavCom and a PS engineering PS 6000 mono audio
intercom?
Thanks
Matthew M. Jurotich
e-mail mail to:
phone : 301-286-5919
________________________________________________________________________________
| From: | "Lonnie Benson" <lonben(at)erols.com> |
| Subject: | Re: Crimping 22AWG PIDG terminals |
Dave,
I have and AMP crimper you can borrow.
----- Original Message -----
From: "DAVID REEL" <dreel(at)cox.net>
Subject: AeroElectric-List: Crimping 22AWG PIDG terminals
>
> Has anyone had problems getting a good crimp with Cleveland Tools WTC380
ratchet terminal crimper? I cannot get the 18-22 AWG terminals to firmly
grab 22AWG wire. Even doubling the wire doesn't make a firm connection. So
far I'm 0 out of 4 tries. The crimper otherwise seems good on the other
sizes but the 18-22 size is out on the far end of the tool & I'm suspecting
some flexing. Though I'm not an experienced crimper, the whole thing seems
pretty idiot proof so I can't imagine what else might be wrong. The PIDG
terminals came from B&C.
>
> Dave Reel - RV8A
>
>
________________________________________________________________________________
| From: | "Fergus Kyle" <VE3LVO(at)rac.ca> |
| Subject: | Nuckolls' article |
Bob,
I must tell you I've been collecting and saving your articles for
many years now, and am approaching the time when they are coming into use.
One such was the "Little Connector" article. It took me several hours to
complete ONE connector (of course I'm doing it at the tail of the aircraft
with five inches of pigtail) but I want to thank you for having taken the
trouble to publish it.
I know that next time I will be able to do it in jig time AND how
much skill you used to produce it. I had no idea the darn things were so
small!
Again many thanks and best regards,
Ferg
Europa A064
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Crimping 22AWG PIDG terminals |
This question illustrates the fact that there are crimp
tools and then there are MORE crimp tools. This is why
the article at:
http://www.aeroelectric.com/articles/CrimpTools/crimptools.html
. . . was generated. Unless you purchase terminals and tools
from the same manufacturer which are stated to be compatible
with each other, then you have some investigative work to
do before you start mashing terminals onto wires for your
airplanes.
Dave's tool/terminal combination doesn't pass a rudimentary
pull test. I'd say this is very strong data suggesting that
the tool and terminals are not compatible with each other.
The Cleveland listing for this tool at:
http://cleavelandtool.com/catalog/amp.html
Says:
# Best we've ever seen.
# Easy to squeeze ratcheting crimper sets a crimp that really holds.
# Crimps 22-28, 16-18, 10-12 gauge terminals in three separate
crimping nests.
# Will not split, cut, crack the terminals.
# Makes perfect crimps every time.
# Crimps terminal and strain relief the correct amount.
# Great for aircraft electrical wiring.
The Cleveland folks didn't fall off the turnip truck yesterday.
I have to believe they've done some reasonable research into
suitability to the task. If the terminals are PIDG from
a reliable source, I'm mystified.
I'd really like to put my hands on that tool. If
you'd mail it to me I'll send it back post-hasty and
cover your outbound mailing costs.
Bob Nuckolls
6936 Bainbridge Road
Wichita, KS 67226-1008
>
> Has anyone had problems getting a good crimp with Cleveland Tools WTC380
ratchet terminal crimper? I cannot get the 18-22 AWG terminals to firmly
grab 22AWG wire. Even doubling the wire doesn't make a firm connection. So
far I'm 0 out of 4 tries. The crimper otherwise seems good on the other
sizes but the 18-22 size is out on the far end of the tool & I'm suspecting
some flexing. Though I'm not an experienced crimper, the whole thing seems
pretty idiot proof so I can't imagine what else might be wrong. The PIDG
terminals came from B&C.
>
> Dave Reel - RV8A
>
________________________________________________________________________________
| From: | Fiveonepw(at)aol.com |
| Subject: | Re: MicroAir 760 Radio |
In a message dated 8/27/04 8:12:00 AM Central Daylight Time,
mjurotich(at)hst.nasa.gov writes:
> Would the MicroAir 760
> radio fit without penetration of the sub-panel?
>>>>>>>>>>
The 760 is less than 5&1/2" front to rear, plus the D-sub connector you use.
Shells can be purchased with angled harness exits if you need to, or you can
just be cheap like me and cut a hole in the side of a standard straight one
for the wires to exit. The antenna coax may have a pretty good bend in it, but
a small hole in the sub-panel could be used or 90 deg adapters are available
from DigiKey if necessary. Shouldn't have any trouble squeezing it in........
Mark
________________________________________________________________________________
| From: | Joe Dubner <jdubner(at)yahoo.com> |
| Subject: | Re: Transponder Converter from Serial to Gray code |
Trampas,
Funny you should mention it -- I just built such a converter.
http://home.velocitus.net/jdubner/EncoderPCB.jpg
The outputs are TTL open collector (i.e. 7407 buffer). In fact, 7407s
were used in an ancient TCI blind encoder I dissected a while back.
--
Joe
Long-EZ 821RP
Clarkston, WA
--- Trampas wrote:
>
> I am thinking about making a simple converter which converts a serial
> data
> stream like from the Dynon to a gray code output. However I do not
> have a
> gray code encoder handy to figure out what the output voltages are,
> does
> anyone know?
>
> Regards,
> Trampas
> www.sterntech.com
__________________________________
________________________________________________________________________________
| From: | Geoff Evans <hellothaimassage(at)yahoo.com> |
| Subject: | Re: Switched Pot |
Bob.
Thanks for the response.
>>
Don't want lights? Turn them down to min output of 4v and call them "off"
<<
Regarding that.. Does the LM-317 put out more heat at at low voltage output
(dim) settings or high voltage output (bright) settings?
If it makes more heat at high settings, then no problem. If it makes more
heat at low settings, then will having the LM-317 and heatsink setting there
cooking 75% of the time result in any problems?
Thanks.
-Geoff
_______________________________
________________________________________________________________________________
| From: | PeterHunt1(at)aol.com |
| Subject: | Shielded magneto wires - Z Figures |
Bob:
I need a little help understanding if I should be utilizing shielded magneto
wires in some fashion. I am wiring the LASAR ignition which Lycoming
installed on my O-360 engine. The LASAR control box has two separate unshielded
wires
(part of the LASAR low voltage control harness) which come into the cockpit
and are marked "Left magneto P lead" and "Right magneto P lead." I am
installing two 1-3 switches which will take each of these two wires to ground when
the
engine is off. During start up and engine running these two switches (left
magneto and right magneto) will be open.
I know there are fancier ways to utilize magneto switches to include the
starting circuit, etc., but that would complicate my question. So, assuming I
have the above arrangement, should I be using shielded wires in some manner?
What is the electrostatic coupling of magneto noise you speak of in Note 3 of
your book? Am I OK just running the two LASAR magneto P leads through two
switches to ground and doing so without any shielded wires? If not, please give
me
a little guidance.
Thanks for the help.
Pete Hunt
Clearwater, FL
RV-6, engine finished, wiring just about done.
________________________________________________________________________________
| From: | "Werner Schneider" <wernerschneider(at)compuserve.com> |
| Subject: | Re: Shielded magneto wires - Z Figures |
Peter,
the high voltage (noise producing wires) are shielded on the Lasar and
running between the box and the magnetos, the wires running from the box to
the switches are low voltage and NOT suspect to produce any voice, mine are
running fine without any problem inside the cockpit (only noise comes from
alternator.
Werner
----- Original Message -----
From: <PeterHunt1(at)aol.com>
Subject: AeroElectric-List: Shielded magneto wires - Z Figures
>
> Bob:
>
> I need a little help understanding if I should be utilizing shielded
magneto
> wires in some fashion. I am wiring the LASAR ignition which Lycoming
> installed on my O-360 engine. The LASAR control box has two separate
unshielded wires
> (part of the LASAR low voltage control harness) which come into the
cockpit
> and are marked "Left magneto P lead" and "Right magneto P lead." I am
> installing two 1-3 switches which will take each of these two wires to
ground when the
> engine is off. During start up and engine running these two switches
(left
> magneto and right magneto) will be open.
>
> I know there are fancier ways to utilize magneto switches to include the
> starting circuit, etc., but that would complicate my question. So,
assuming I
> have the above arrangement, should I be using shielded wires in some
manner?
> What is the electrostatic coupling of magneto noise you speak of in Note 3
of
> your book? Am I OK just running the two LASAR magneto P leads through two
> switches to ground and doing so without any shielded wires? If not,
please give me
> a little guidance.
>
> Thanks for the help.
>
> Pete Hunt
> Clearwater, FL
> RV-6, engine finished, wiring just about done.
>
>
________________________________________________________________________________
| Subject: | ELT antenna replacement |
OK, so I won't use my old STS Loran antenna on my ELT. Looking in catalogs,
I must have missed replacements to use on my AK-450 ELT. Can anyone recommend
a replacement for me to use and where I can purchase one? Thanks for the
help.
Pat Long
PGLong(at)aol.com
N120PL
RV4
Bay City, Michigan
3CM
Do Not Archive
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Transponder Converter from Serial to Gray code |
I also have a need for such a device.
Care to share details or sell a copy.
Paul
----- Original Message -----
From: "Joe Dubner" <jdubner(at)yahoo.com>
Subject: Re: AeroElectric-List: Transponder Converter from Serial to Gray
code
>
> Trampas,
>
> Funny you should mention it -- I just built such a converter.
> http://home.velocitus.net/jdubner/EncoderPCB.jpg
>
> The outputs are TTL open collector (i.e. 7407 buffer). In fact, 7407s
> were used in an ancient TCI blind encoder I dissected a while back.
>
> --
> Joe
> Long-EZ 821RP
> Clarkston, WA
>
>
> --- Trampas wrote:
>
> >
> > I am thinking about making a simple converter which converts a serial
> > data
> > stream like from the Dynon to a gray code output. However I do not
> > have a
> > gray code encoder handy to figure out what the output voltages are,
> > does
> > anyone know?
> >
> > Regards,
> > Trampas
> > www.sterntech.com
>
>
> __________________________________
>
>
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: OV protection for PM alternators |
on juliet
Hi David
The PM alternators have two wires coming out because they output AC to
the regulator. (The regulator contains a full wave rectifier to change
it to DC). The two wires go to a coil that is not connected to ground
inside the alternator.
Maybe it is overkill but I was presuming that a two pole relay would be
preferable to disconnect both AC wires. That would allow total isolation
even if one side of the alternator shorted to ground internally but that
is a different failure and probably quite unlikely compared to a
regulator failure.
Ken
David Carter wrote:
>
>Ken,
>
>To do what you suggest, looks feasible to "transplant" the OVM relay,
>module, and CB system from its current position in Z-13 to be between one
>of the two wires showing between the SD-8 (John Deere in your case and
mine)
>and the VR. Seems like a fairly simple mod. Or, at least a fusible link
>ought to be in that output line between PM Alt & VR so the "always
spinning,
>always outputting" PM alternator would have no place to "output" to.
>
>A question: Why does it show two wires between the SD-8 and its VR? Will
>the John Deere also have two wires, or just one? I think you and I have
>Deere schematics but I can't lay my hand on mine (office is packed up for
>painting walls).
>
>David Carter
>
>----- Original Message -----
>From: "Ken" <klehman(at)albedo.net>
>To:
>Subject: AeroElectric-List: OV protection for PM alternators on juliet
>
>
>
>
>>
>>All the Z diagrams show the overvoltage disconnect relay wired to the
>>output of the voltage regulator on permanent magnet alternators. Given
>>that the most likely cause of an over voltage is probably a regulator
>>failure, wouldn't it make more sense to disconnect the input to the VR
>>just in case the VR decided to overheat and make smoke? This would
>>require a two pole relay to disconnect the AC input but that should not
>>be a major problem since I was going to use a "40" amp rated automotive
>>relay with my 20 amp John Deere VR and alternator. I'm assuming that the
>>fusible link (actually a circuit breaker on my machine) would disconnect
>>the VR from battery current in case the VR shorted - but that might be a
>>bad assumption???
>>Ken
>>
________________________________________________________________________________
| From: | "Trampas" <tstern(at)nc.rr.com> |
| Subject: | OV protection for PM alternators on juliet |
Would it not be simpler to place some fuses in the wires from the alternator
if a short in the regulator is a concern to you?
Regards,
Trampas
www.sterntech.com
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of Ken
Subject: Re: AeroElectric-List: OV protection for PM alternators on juliet
Hi David
The PM alternators have two wires coming out because they output AC to
the regulator. (The regulator contains a full wave rectifier to change
it to DC). The two wires go to a coil that is not connected to ground
inside the alternator.
Maybe it is overkill but I was presuming that a two pole relay would be
preferable to disconnect both AC wires. That would allow total isolation
even if one side of the alternator shorted to ground internally but that
is a different failure and probably quite unlikely compared to a
regulator failure.
Ken
David Carter wrote:
>
>Ken,
>
>To do what you suggest, looks feasible to "transplant" the OVM relay,
>module, and CB system from its current position in Z-13 to be between one
>of the two wires showing between the SD-8 (John Deere in your case and
mine)
>and the VR. Seems like a fairly simple mod. Or, at least a fusible link
>ought to be in that output line between PM Alt & VR so the "always
spinning,
>always outputting" PM alternator would have no place to "output" to.
>
>A question: Why does it show two wires between the SD-8 and its VR? Will
>the John Deere also have two wires, or just one? I think you and I have
>Deere schematics but I can't lay my hand on mine (office is packed up for
>painting walls).
>
>David Carter
>
>----- Original Message -----
>From: "Ken" <klehman(at)albedo.net>
>To:
>Subject: AeroElectric-List: OV protection for PM alternators on juliet
>
>
>
>
>>
>>All the Z diagrams show the overvoltage disconnect relay wired to the
>>output of the voltage regulator on permanent magnet alternators. Given
>>that the most likely cause of an over voltage is probably a regulator
>>failure, wouldn't it make more sense to disconnect the input to the VR
>>just in case the VR decided to overheat and make smoke? This would
>>require a two pole relay to disconnect the AC input but that should not
>>be a major problem since I was going to use a "40" amp rated automotive
>>relay with my 20 amp John Deere VR and alternator. I'm assuming that the
>>fusible link (actually a circuit breaker on my machine) would disconnect
>>the VR from battery current in case the VR shorted - but that might be a
>>bad assumption???
>>Ken
>>
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: OV protection for PM alternators |
Ken,
I was up past midnight last night (this morning) modifying my Z-13.
Elimintated the starter contactor and removed jumper between top of solenoid
& side and ran wire from starter switch to side of solenoid. Eliminated PM
Alternator Sw (just grounded bottom of 5 amp CB associated with OVM). Then
I started working on the PM alternator circuitry - spent lot of time moving
the OVM stuff way off to right of diagram to make room to shift other stuff
left. Was planning to insert the OVM in between the PM Alt and the VR -
then realized - "That stuff coming out of the alternator is not regulated -
so why would I put an OVM in there!!??" My mental "what if'ing" and
"analysis" still lacks something - I hope it is ONLY lack of experience with
this electrical stuff and that I'll get better. I then clicked "Undo" a LOT
to return the OVM to original place in Z-13 and quit for the night.
Someone else suggested fusing the 2 AC wires between the PM alternator & its
VR - sounds OK to me as long as we don't introduce a corrosion, high
resistance, failure point. Solder in a "fusable link" or "fusable wire" or
connect in an ANL limiter or some such - I need to re-read the Aeroelectric
Connection about those things.
David
----- Original Message -----
From: "Ken" <klehman(at)albedo.net>
Subject: Re: AeroElectric-List: OV protection for PM alternators on juliet
>
> Hi David
>
> The PM alternators have two wires coming out because they output AC to
> the regulator. (The regulator contains a full wave rectifier to change
> it to DC). The two wires go to a coil that is not connected to ground
> inside the alternator.
>
> Maybe it is overkill but I was presuming that a two pole relay would be
> preferable to disconnect both AC wires. That would allow total isolation
> even if one side of the alternator shorted to ground internally but that
> is a different failure and probably quite unlikely compared to a
> regulator failure.
>
> Ken
>
> David Carter wrote:
>
>
> >
> >Ken,
> >
> >To do what you suggest, looks feasible to "transplant" the OVM relay,
> >module, and CB system from its current position in Z-13 to be between
one
> >of the two wires showing between the SD-8 (John Deere in your case and
> mine)
> >and the VR. Seems like a fairly simple mod. Or, at least a fusible
link
> >ought to be in that output line between PM Alt & VR so the "always
> spinning,
> >always outputting" PM alternator would have no place to "output" to.
> >
> >A question: Why does it show two wires between the SD-8 and its VR?
Will
> >the John Deere also have two wires, or just one? I think you and I have
> >Deere schematics but I can't lay my hand on mine (office is packed up
for
> >painting walls).
> >
> >David Carter
> >
> >----- Original Message -----
> >From: "Ken" <klehman(at)albedo.net>
> >To:
> >Subject: AeroElectric-List: OV protection for PM alternators on juliet
> >
> >
> >
> >
> >>
> >>All the Z diagrams show the overvoltage disconnect relay wired to the
> >>output of the voltage regulator on permanent magnet alternators. Given
> >>that the most likely cause of an over voltage is probably a regulator
> >>failure, wouldn't it make more sense to disconnect the input to the VR
> >>just in case the VR decided to overheat and make smoke? This would
> >>require a two pole relay to disconnect the AC input but that should not
> >>be a major problem since I was going to use a "40" amp rated automotive
> >>relay with my 20 amp John Deere VR and alternator. I'm assuming that
the
> >>fusible link (actually a circuit breaker on my machine) would
disconnect
> >>the VR from battery current in case the VR shorted - but that might be
a
> >>bad assumption???
> >>Ken
> >>
>
>
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: OV protection for PM alternators |
Ken, forgot to mention in my summary of "simplification mods" to Z-13 that,
in the OVM wiring, I took the short jumper from red wire of OVM that
originally went left to bottom of main contacts and disconnected from bottom
of main contact and reattached to top of filter capacitor to right of OVM -
so coils to contactor get power when alternator starts turning on start-up
of engine. No alternator switch - always on unless OVM blows the CB or I
pull the CB to de-energize its contactor.
- If get electrical fire/smoke, I'll first turn off the battery switch.
Can also immediately pull the alternator cb - or wait to see if turning off
the battery switch is adequate. In either case, my electrically dependent
rotary engine will continue to get juice from an "always hot" battery bus,
with individual items on that bus having on-off switches.
David
----- Original Message -----
From: "David Carter" <dcarter(at)datarecall.net>
Subject: Re: AeroElectric-List: OV protection for PM alternators
>
> Ken,
>
> I was up past midnight last night (this morning) modifying my Z-13.
> Elimintated the starter contactor and removed jumper between top of
solenoid
> & side and ran wire from starter switch to side of solenoid. Eliminated
PM
> Alternator Sw (just grounded bottom of 5 amp CB associated with OVM).
Then
> I started working on the PM alternator circuitry - spent lot of time
moving
> the OVM stuff way off to right of diagram to make room to shift other
stuff
> left. Was planning to insert the OVM in between the PM Alt and the VR -
> then realized - "That stuff coming out of the alternator is not
regulated -
> so why would I put an OVM in there!!??" My mental "what if'ing" and
> "analysis" still lacks something - I hope it is ONLY lack of experience
with
> this electrical stuff and that I'll get better. I then clicked "Undo" a
LOT
> to return the OVM to original place in Z-13 and quit for the night.
>
> Someone else suggested fusing the 2 AC wires between the PM alternator &
its
> VR - sounds OK to me as long as we don't introduce a corrosion, high
> resistance, failure point. Solder in a "fusable link" or "fusable wire"
or
> connect in an ANL limiter or some such - I need to re-read the
Aeroelectric
> Connection about those things.
>
> David
>
> ----- Original Message -----
> From: "Ken" <klehman(at)albedo.net>
> To:
> Subject: Re: AeroElectric-List: OV protection for PM alternators on juliet
>
>
> >
> > Hi David
> >
> > The PM alternators have two wires coming out because they output AC to
> > the regulator. (The regulator contains a full wave rectifier to change
> > it to DC). The two wires go to a coil that is not connected to ground
> > inside the alternator.
> >
> > Maybe it is overkill but I was presuming that a two pole relay would be
> > preferable to disconnect both AC wires. That would allow total isolation
> > even if one side of the alternator shorted to ground internally but that
> > is a different failure and probably quite unlikely compared to a
> > regulator failure.
> >
> > Ken
> >
> > David Carter wrote:
> >
> >
> > >
> > >Ken,
> > >
> > >To do what you suggest, looks feasible to "transplant" the OVM relay,
> > >module, and CB system from its current position in Z-13 to be between
> one
> > >of the two wires showing between the SD-8 (John Deere in your case and
> > mine)
> > >and the VR. Seems like a fairly simple mod. Or, at least a fusible
> link
> > >ought to be in that output line between PM Alt & VR so the "always
> > spinning,
> > >always outputting" PM alternator would have no place to "output" to.
> > >
> > >A question: Why does it show two wires between the SD-8 and its VR?
> Will
> > >the John Deere also have two wires, or just one? I think you and I
have
> > >Deere schematics but I can't lay my hand on mine (office is packed up
> for
> > >painting walls).
> > >
> > >David Carter
> > >
> > >----- Original Message -----
> > >From: "Ken" <klehman(at)albedo.net>
> > >To:
> > >Subject: AeroElectric-List: OV protection for PM alternators on juliet
> > >
> > >
> > >
> > >
> > >>
> > >>All the Z diagrams show the overvoltage disconnect relay wired to the
> > >>output of the voltage regulator on permanent magnet alternators.
Given
> > >>that the most likely cause of an over voltage is probably a regulator
> > >>failure, wouldn't it make more sense to disconnect the input to the
VR
> > >>just in case the VR decided to overheat and make smoke? This would
> > >>require a two pole relay to disconnect the AC input but that should
not
> > >>be a major problem since I was going to use a "40" amp rated
automotive
> > >>relay with my 20 amp John Deere VR and alternator. I'm assuming that
> the
> > >>fusible link (actually a circuit breaker on my machine) would
> disconnect
> > >>the VR from battery current in case the VR shorted - but that might
be
> a
> > >>bad assumption???
> > >>Ken
> > >>
> >
> >
>
>
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Off Topic....Quo Vadis? |
Life's vicissitudes have marooned me in Massachusetts. (Wife left, cat went
feral, got fired).
New England is a good place to raise children, and it has good schools,
lobsters, oaks, proximity to NYC, and a short flight to Europe.
None of these really suit my needs anymore. I am 57 and single again; have
been running a small business on the internet, and can locate anywhere I
want. Financially I am okay.
I prefer the West. I have lived in Los Angeles. I love Tucson, but no longer
know anyone there. I have a sister in Portland Oregon, but they are moving
in a few years. I have a scattering of friends all over the place. I have
looked at Prescott, Tucson, LA, San Luis Obispo, Cambria, Eureka, Portland,
Seattle, Victoria BC. Small towns are better, with some access to big cities
if necessary.
I dont need much square footage. I need a place to build my Glastar and run
my little internet business. I would like a very friendly community as well
as proximity to an active homebuilder group.
QUESTION: Where should I go? Where is the ideal place and why?
Please contact me offline:
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
________________________________________________________________________________
| From: | Jim and Lucy Pollard <jpollard(at)ciaccess.com> |
| Subject: | Re: ELT antenna replacement |
>Funny you should post this. My AK450 antenna fell off on my first flight. I
>bet it happens more often then we think. Anybody else have this same thing
>happen too??
Mine fell apart while I was installing it. The wire droped out of the
bulkhead connector it is made from. It was just a piece of hose pushed
through a reamed out bulkhead connector. The wire with a soldered on
fitting for the coax was pressed through this piece of hose. I super
glued the thing back together but I thought it sure looked junky.
Another thing is this ELT came with the batterys in it and when
I opened the box the thing was armed and the transmition light
was showing that it was set off. There is not much use giving
you free batteries if they are going to be mostly dead when you
get the thing. I called the sar guys and they did not pick it up
in Trenton. Possibly because by the time it got into Canada from
California the batteries were so dead that it was not putting out
much signal. He said they have seen this a few times where the signal
is traveling down the freeway and into a city where tracking it down is very
hard to do.Maybe these boneheads should pay for the sar guys following
mail trucks because they are not smart enough to leave the batteries
out of the things when the mail them.
Jim Pollard
Merlin Ont
________________________________________________________________________________
| From: | Walter Tondu <walter(at)tondu.com> |
| Subject: | Re: Off Topic....Quo Vadis? |
On 08/28 7:24, Eric M. Jones wrote:
>
>
> Life's vicissitudes have marooned me in Massachusetts. (Wife left, cat went
> feral, got fired).
>
> New England is a good place to raise children, and it has good schools,
> lobsters, oaks, proximity to NYC, and a short flight to Europe.
>
> None of these really suit my needs anymore. I am 57 and single again; have
> been running a small business on the internet, and can locate anywhere I
> want. Financially I am okay.
>
> I prefer the West. I have lived in Los Angeles. I love Tucson, but no longer
> know anyone there. I have a sister in Portland Oregon, but they are moving
> in a few years. I have a scattering of friends all over the place. I have
> looked at Prescott, Tucson, LA, San Luis Obispo, Cambria, Eureka, Portland,
> Seattle, Victoria BC. Small towns are better, with some access to big cities
> if necessary.
>
> I dont need much square footage. I need a place to build my Glastar and run
> my little internet business. I would like a very friendly community as well
> as proximity to an active homebuilder group.
>
> QUESTION: Where should I go? Where is the ideal place and why?
North Dallas. Cheap living. Airparks all around. Friendly people.
Close proximity to the big city should you require that. Tons of RVs
too. Not sure about Glastars. See you there in a couple of years.
Oh, you have to like heat, thunderstorms and the occasional hail storm.
> Please contact me offline:
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge MA 01550-2705
> Phone (508) 764-2072
> Email: emjones(at)charter.net
>
>
>
>
>
--
Walter Tondu
http://www.rv7-a.com
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
AeroElectric-List message previously posted by: "jcrain2(at)juno.com"
<<.skip..Also the mic key makes the wing leveler turn plus the fuel gauge pegs
out. Is there an extra shielded coax that works with the B and C connectors or
should I pull some off of an other larger coax to double shield?.....skip.>>
8/28/2004
Hello Bruce, That connector is called a BNC connector. BNC stands for Bayonet Neil
Councilman.
B=Bayonet for the way it connects together sort of like sticking a bayonet on
the end of a rifle.
N=Neil for the last name of one of the inventors.
C=Councilman for the last name of the other inventor.
There is also a connector called a TNC connector. It will be left as an exercise
for the student to determine what TNC stands for.
OC
PS: Both RG 142 and RG 400 are double shielded.
PPS: Extra credit goes to the first student who posts what the letters RG stand
for on the coax cable used with these connectors.
________________________________________________________________________________
| From: | "davercook" <davercook(at)Prodigy.net> |
| Subject: | Re: Wire Stripper |
Radio Shack has a new one out that works very well. It has no dies and no
holes. It automatically adjusts to the wire size. Cost about $19 I could
not get the one from B&C to work for me at all.
Dave Cook RV-6 Wiring
----- Original Message -----
From: "Steve Collins" <steveco(at)houston.rr.com>
Subject: AeroElectric-List: Wire Stripper
>
> I need to get a wire stripper. Anyone found one that works well with
Tefzel
> wire (I understand a lot of common strippers don't work well on it, but I
> don't have personal experience)? With all the wiring I'll eventually be
> doing, I don't mind paying a little extra for a good tool.
>
>
> -Steve Collins
>
> -RV-7A, wings
>
>
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: OV protection for PM alternators |
on juliet
Hi David
While it seemed like a good idea to fuse the wires from the PM
alternator I don't think that accomplishes anything. If the fuse(s) can
handle max alternator output then they likely won't pop if the regulator
develops a short. A fuse on the output of the VR would protect the VR
from excessive battery sourced current though in the event of a VR
short. That is why I was musing that it might be better to put the OV
disconnect relay on the alternator output wires. I still don't know if a
VR short is in fact a significant risk on a John Deere VR though...
For what it's worth I'm finding that the architecture diagrams have to
considered together with component placement. ie. Which side of the
firewall is the component and how long will the wires be. That largely
made the decision for me whether to use manual or electric contactors
for instance. And the components don't always seem to fit where I
planned them either ;)
Ken
David Carter wrote:
>
>Ken,
>
>I was up past midnight last night (this morning) modifying my Z-13.
>Elimintated the starter contactor and removed jumper between top of
solenoid
>& side and ran wire from starter switch to side of solenoid.
Eliminated PM
>Alternator Sw (just grounded bottom of 5 amp CB associated with OVM).
Then
>I started working on the PM alternator circuitry - spent lot of time
moving
>the OVM stuff way off to right of diagram to make room to shift other
stuff
>left. Was planning to insert the OVM in between the PM Alt and the VR -
>then realized - "That stuff coming out of the alternator is not
regulated -
>so why would I put an OVM in there!!??" My mental "what if'ing" and
>"analysis" still lacks something - I hope it is ONLY lack of
experience with
>this electrical stuff and that I'll get better. I then clicked "Undo"
a LOT
>to return the OVM to original place in Z-13 and quit for the night.
>
>Someone else suggested fusing the 2 AC wires between the PM alternator
& its
>VR - sounds OK to me as long as we don't introduce a corrosion, high
>resistance, failure point. Solder in a "fusable link" or "fusable
wire" or
>connect in an ANL limiter or some such - I need to re-read the
Aeroelectric
>Connection about those things.
>
>
________________________________________________________________________________
| From: | beecho(at)beecho.org |
| Subject: | Re: Off Topic....Quo Vadis? |
Hi Eric
I see you have considered San Luis Obispo. Great place, a truly wonderful climate
and two home building groups. The one in Paso Robles a bit North is much more
active and on a great non towered airport. (PRB) As in most of Southern
CA, home prices are excessive. We can use your expertise!!
Tom Friedland, Atascadero CA Europa mono/Jabiru N96V
----- Original Message -----
From: Walter Tondu <walter(at)tondu.com>
Date: Sat, 28 Aug 2004 21:00:16 -0400
Subject: Re: AeroElectric-List: Off Topic....Quo Vadis?
On 08/28 7:24, Eric M. Jones wrote:
>
>
> Life's vicissitudes have marooned me in Massachusetts. (Wife left, cat went
> feral, got fired).
>
> New England is a good place to raise children, and it has good schools,
> lobsters, oaks, proximity to NYC, and a short flight to Europe.
>
> None of these really suit my needs anymore. I am 57 and single again; have
> been running a small business on the internet, and can locate anywhere I
> want. Financially I am okay.
>
> I prefer the West. I have lived in Los Angeles. I love Tucson, but no longer
> know anyone there. I have a sister in Portland Oregon, but they are moving
> in a few years. I have a scattering of friends all over the place. I have
> looked at Prescott, Tucson, LA, San Luis Obispo, Cambria, Eureka, Portland,
> Seattle, Victoria BC. Small towns are better, with some access to big cities
> if necessary.
>
> I dont need much square footage. I need a place to build my Glastar and run
> my little internet business. I would like a very friendly community as well
> as proximity to an active homebuilder group.
>
> QUESTION: Where should I go? Where is the ideal place and why?
North Dallas. Cheap living. Airparks all around. Friendly people.
Close proximity to the big city should you require that. Tons of RVs
too. Not sure about Glastars. See you there in a couple of years.
Oh, you have to like heat, thunderstorms and the occasional hail storm.
> Please contact me offline:
> Eric M. Jones
> www.PerihelionDesign.com
> 113 Brentwood Drive
> Southbridge MA 01550-2705
> Phone (508) 764-2072
> Email: emjones(at)charter.net
>
>
>
>
>
--
Walter Tondu
http://www.rv7-a.com
________________________________________________________________________________
| From: | "Mickey Billings" <mbilli(at)cox.net> |
Hey guys, does anyone know what the dots represent on a schematic
representing a audio transformer? The transformer is a 8 ohm to 500 ohm at
center taps. Therefore the Secondary has connections 1 2 & 3 with a DOT at
1 & 2 on the schematic. The Primary connections are 4 5 & 6 with a DOT on 4
& 5......I don't know what the dots represent! Can anyone help! The
application is to convert the output on the CD player (8) ohms to the input
on the Flightcom 403 (600) ohms in order to use headphones.
Thanks in advance
Mickey Billings RV7
N445BH
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
The dots mark the phasing of the windings. That is, they mark the
direction of the windings. Or, from an electrical point of view: If
you apply a sine wave to the primary, when the signal waveform is rising
at the dotted end of the primary, it will also be rising at the dotted
end of the secondary.
Assuming you are connecting a CD output to a monaural headphone the dots
make no difference..
However, if you have a stereo CD output you want to connect to stereo
headphones, you will need two transformers and then it makes a
difference. Both transformers should be wired so the dots are
consistent. Connect the transformers so all the dots are connected to
common (or all the opposite). If you connect them differently from each
other your stereo music will sound a little strange - sort of more
spread out.
Dick Tasker
Mickey Billings wrote:
>
>Hey guys, does anyone know what the dots represent on a schematic
>representing a audio transformer? The transformer is a 8 ohm to 500 ohm at
>center taps. Therefore the Secondary has connections 1 2 & 3 with a DOT at
>1 & 2 on the schematic. The Primary connections are 4 5 & 6 with a DOT on 4
>& 5......I don't know what the dots represent! Can anyone help! The
>application is to convert the output on the CD player (8) ohms to the input
>on the Flightcom 403 (600) ohms in order to use headphones.
>
>Thanks in advance
>Mickey Billings RV7
>N445BH
>
>
________________________________________________________________________________
| From: | "Mickey Billings" <mbilli(at)cox.net> |
Dick, thank you for the quick response. I do have 2 transformers and I am
using it for stereo. So are you saying the dots do not matter as long as I
keep both transformers wired exactly the same?
Mickey Billings
RV7 N45BH
----- Original Message -----
From: "Richard E. Tasker" <retasker(at)optonline.net>
Subject: Re: AeroElectric-List: Transformer
>
> The dots mark the phasing of the windings. That is, they mark the
> direction of the windings. Or, from an electrical point of view: If
> you apply a sine wave to the primary, when the signal waveform is rising
> at the dotted end of the primary, it will also be rising at the dotted
> end of the secondary.
>
> Assuming you are connecting a CD output to a monaural headphone the dots
> make no difference..
>
> However, if you have a stereo CD output you want to connect to stereo
> headphones, you will need two transformers and then it makes a
> difference. Both transformers should be wired so the dots are
> consistent. Connect the transformers so all the dots are connected to
> common (or all the opposite). If you connect them differently from each
> other your stereo music will sound a little strange - sort of more
> spread out.
>
> Dick Tasker
>
> Mickey Billings wrote:
>
> >
> >Hey guys, does anyone know what the dots represent on a schematic
> >representing a audio transformer? The transformer is a 8 ohm to 500 ohm
at
> >center taps. Therefore the Secondary has connections 1 2 & 3 with a DOT
at
> >1 & 2 on the schematic. The Primary connections are 4 5 & 6 with a DOT
on 4
> >& 5......I don't know what the dots represent! Can anyone help! The
> >application is to convert the output on the CD player (8) ohms to the
input
> >on the Flightcom 403 (600) ohms in order to use headphones.
> >
> >Thanks in advance
> >Mickey Billings RV7
> >N445BH
> >
> >
>
>
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: OV protection for PM alternators |
Ken, comments and agreement embedded below.
David
----- Original Message -----
From: "Ken" <klehman(at)albedo.net>
Subject: Re: AeroElectric-List: OV protection for PM alternators on juliet
>
> Hi David
>
> While it seemed like a good idea to fuse the wires from the PM
> alternator I don't think that accomplishes anything. If the fuse(s) can
> handle max alternator output then they likely won't pop if the regulator
> develops a short.
........Agree
> A fuse on the output of the VR would protect the VR
> from excessive battery sourced current though in the event of a VR
> short.
.........Z-13 already has a fuselink (16awg wire in a 12 awg main
alternator-to-battery circuit) that does what you want - no need to add
anything, i.e., if VR fried and shorted, and there was no longer any output
from "main output" terminal of VR, and output from PM alternator could not
get out of the VR box, and if the postulated short existed in the VR box,
then there would be a massive short from the battery to that new "unplanned"
ground - & the fuselink would do its job and melt.
> That is why I was musing that it might be better to put the OV
> disconnect relay on the alternator output wires.
........I think we agree that we can't see a need for putting anything,
especially the OV system, between PM alternator & regulator.
> I still don't know if a
> VR short is in fact a significant risk on a John Deere VR though...
...........as noted above, we are covered, regardless of risk.
> Ken
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Re: Switched Pot |
>
>
>Bob.
>
>Thanks for the response.
>
> >>
>Don't want lights? Turn them down to min output of 4v and call them "off"
><<
>
>Regarding that.. Does the LM-317 put out more heat at at low voltage output
>(dim) settings or high voltage output (bright) settings?
>
>If it makes more heat at high settings, then no problem. If it makes more
>heat at low settings, then will having the LM-317 and heatsink setting there
>cooking 75% of the time result in any problems?
Not if the heatsink is adequate.
If an adjustable regulator like the LM317 were driving a purely
resistive load, then output current is directly proportional to
output voltage. In this case, power dissipated in the LM317
peaks and is equal to power in load when output voltage
is 1/2 the supply voltage.
Since the lamp's voltage resistance characteristics are
not linear, then driving a bank of lamps with a linear
regulator has a characteristic something like this:
Volts Volts Amps Watts Watts
In Lamp Total Reg Lamp
14.0 1.0 .14 1.82 .14
14.0 2.0 .17 2.04 .34
14.0 3.0 .19 2.09 .57
14.0 4.0 .21 2.10 .84
14.0 5.0 .24 2.16 1.2
14.0 6.0 .26 2.08 1.7
14.0 7.0 .28 1.96 1.96
14.0 8.0 .29 1.74 2.32
14.0 9.0 .31 1.55 2.79
14.0 10.0 .33 1.32 3.30
14.0 11.0 .34 1.02 3.74
14.0 12.0 .36 0.72 4.32
14.0 13.0 .37 0.37 4.81
14.0 14.0 .39 0.0 5.46
With this particular lamp load, it's easy to see that
power dissipated in the regulator peaks at something
on the order of 35% of full output due effects of
lamp's strong positive temperature coefficient of
resistance. This exercise also demonstrates
the fact that peak power dissipated in the regulator
is less than 1/2 total power for the lamps.
So, a lamp load of say 1.5 amps (21 watts) would
be expected to produce a maximum power dissipation
in the controller of less than 10 watts. This value
is what sizes the heat sink.
Bob . . .
---
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Posting dwg drawings or pdf images to a website for |
other builders to view
I have an unsophisticated website and am trying to learn how to add stuff to
it. I can post .jpg stuff OK. Today, I tried posting a .dwg file (my mod
to Z-13) - it wouldn't open with Autocad (actually, Intellicad clone of
Autocad). Converted to .pdf and uploaded - still won't display. I think I
don't have the source coding for that image correct in my "Builder's Log".
My website url for that page is
http://www.datarecall.net/~dcarter/Builder's%20Log.html
- Anyone have either of these type images posted - I'd like to go to
your site and "copy source" and see how you do it.
David
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
Yes, that is correct!
Dick
Mickey Billings wrote:
>
>Dick, thank you for the quick response. I do have 2 transformers and I am
>using it for stereo. So are you saying the dots do not matter as long as I
>keep both transformers wired exactly the same?
>
>Mickey Billings
>RV7 N45BH
>
>----- Original Message -----
>From: "Richard E. Tasker" <retasker(at)optonline.net>
>To:
>Subject: Re: AeroElectric-List: Transformer
>
>
>
>
>>
>>
>
>
>
>>The dots mark the phasing of the windings. That is, they mark the
>>direction of the windings. Or, from an electrical point of view: If
>>you apply a sine wave to the primary, when the signal waveform is rising
>>at the dotted end of the primary, it will also be rising at the dotted
>>end of the secondary.
>>
>>Assuming you are connecting a CD output to a monaural headphone the dots
>>make no difference..
>>
>>However, if you have a stereo CD output you want to connect to stereo
>>headphones, you will need two transformers and then it makes a
>>difference. Both transformers should be wired so the dots are
>>consistent. Connect the transformers so all the dots are connected to
>>common (or all the opposite). If you connect them differently from each
>>other your stereo music will sound a little strange - sort of more
>>spread out.
>>
>>Dick Tasker
>>
>>Mickey Billings wrote:
>>
>>
>>
>>>
>>>
>
>
>
>>>Hey guys, does anyone know what the dots represent on a schematic
>>>representing a audio transformer? The transformer is a 8 ohm to 500 ohm
>>>
>>>
>at
>
>
>>>center taps. Therefore the Secondary has connections 1 2 & 3 with a DOT
>>>
>>>
>at
>
>
>>>1 & 2 on the schematic. The Primary connections are 4 5 & 6 with a DOT
>>>
>>>
>on 4
>
>
>>>& 5......I don't know what the dots represent! Can anyone help! The
>>>application is to convert the output on the CD player (8) ohms to the
>>>
>>>
>input
>
>
>>>on the Flightcom 403 (600) ohms in order to use headphones.
>>>
>>>Thanks in advance
>>>Mickey Billings RV7
>>>N445BH
>>>
>>>
>>>
>>>
>>
>>
>
>
>
>
________________________________________________________________________________
| From: | "Jon Finley" <jon(at)finleyweb.net> |
| Subject: | Posting dwg drawings or pdf images to a website |
for other builders to view
Hi David,
Lots of good HTML help online but to get you started:
The images that you have on your page are "shown" thru the use of an IMG
(image tag). One of your links is:
Typical image type (jpg, bmp, gif, etc...) links work as browsers know
how to display these file types. A browser does not know how to display
an ACAD drawing. So, you generally have to display a link to these files
using a hyperlink tag (A :
Q2 Front Hinged Canopy
Most browsers figure out that they don't know how to display this file
so they ask if you would like to open or save the file (if open, what
program to use).
There are a millions of things that can be done via HTML, the key is
finding the thing that works! :-)
Jon Finley
N90MG Q2 - Subaru EJ-22 DD - 461 Hrs. TT
Apple Valley, Minnesota
http://www.FinleyWeb.net/Q2Subaru
> -----Original Message-----
> From: owner-aeroelectric-list-server(at)matronics.com
> [mailto:owner-aeroelectric-list-server(at)matronics.com] On
> Behalf Of David Carter
> Sent: Sunday, August 29, 2004 7:22 PM
> To: aeroelectric-list
> Subject: AeroElectric-List: Posting dwg drawings or pdf
> images to a website for other builders to view
>
>
> -->
>
> I have an unsophisticated website and am trying to learn how
> to add stuff to it. I can post .jpg stuff OK. Today, I
> tried posting a .dwg file (my mod to Z-13) - it wouldn't open
> with Autocad (actually, Intellicad clone of Autocad).
> Converted to .pdf and uploaded - still won't display. I
> think I don't have the source coding for that image correct
> in my "Builder's Log". My website url for that page is
> http://www.datarecall.net/~dcarter/Builder's%20Log.html
> - Anyone have either of these type images posted - I'd
> like to go to your site and "copy source" and see how you do it.
>
> David
________________________________________________________________________________
| From: | "Ron Koyich" <Ron(at)Koyich.com> |
I just have to ask: why are folks are still using transformers for audio
distribution in aircraft (or ??)
________________________________________________________________________________
| Subject: | SCR for a Hobbs meter |
| From: | Tom Brusehaver <cozytom(at)mn.rr.com> |
I'm finishing a canard aircraft, and am about to hook up
the hobbs meter. Electric tach, so I don't have another
hour meter.
I don't like the extra oil pressure lines, Tee's and
wiring. Seems like one more place to have a leak
and more stuff to put in the back of the plane.
I am thinking of using an SCR to trigger the start of
the Hobbs meter. The trigger would be the starter switch.
Simple, light weight, and relable.
It does risk leaving the master switch on, and having
a few extra hours added to the time. Hopefully I'll
actually use a shutdown checklist everytime, and that
won't happen.
________________________________________________________________________________
| From: | "cgalley" <cgalley(at)qcbc.org> |
| Subject: | Re: Posting dwg drawings or pdf images to a website |
for other builders to view
I use PDFs all the time for forms on www.qcbc.org. Click on the left hand
Heartland Century link. You do have to have adobe Acrobat reader installed
to see a PDF. The newsletter link has a link to Adobe's site to get the free
reader.
As the reader has to load before display of the PDF, it takes a while and
sometime you might think it isn't working because ot the time lag.
Cy Galley - Webmaster www.qcbc.org
----- Original Message -----
From: "David Carter" <dcarter(at)datarecall.net>
Subject: AeroElectric-List: Posting dwg drawings or pdf images to a website
for other builders to view
>
> I have an unsophisticated website and am trying to learn how to add stuff
to
> it. I can post .jpg stuff OK. Today, I tried posting a .dwg file (my mod
> to Z-13) - it wouldn't open with Autocad (actually, Intellicad clone of
> Autocad). Converted to .pdf and uploaded - still won't display. I think
I
> don't have the source coding for that image correct in my "Builder's Log".
> My website url for that page is
> http://www.datarecall.net/~dcarter/Builder's%20Log.html
> - Anyone have either of these type images posted - I'd like to go to
> your site and "copy source" and see how you do it.
>
> David
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: OV protection for PM alternators |
>
>
>Ken, comments and agreement embedded below.
>
>David
>
>----- Original Message -----
>From: "Ken" <klehman(at)albedo.net>
>To:
>Subject: Re: AeroElectric-List: OV protection for PM alternators on juliet
>
>
> >
> > Hi David
> >
> > While it seemed like a good idea to fuse the wires from the PM
> > alternator I don't think that accomplishes anything. If the fuse(s) can
> > handle max alternator output then they likely won't pop if the regulator
> > develops a short.
>
>........Agree
Alternators never pop their own fuses. Note that the fusible link
is at the BUS END of the feeder. The fusible link protects the
feeder from current that comes from the BATTERY . . . not the alternator.
> > A fuse on the output of the VR would protect the VR
> > from excessive battery sourced current though in the event of a VR
> > short.
>
>.........Z-13 already has a fuselink (16awg wire in a 12 awg main
>alternator-to-battery circuit) that does what you want - no need to add
>anything, i.e., if VR fried and shorted, and there was no longer any output
>from "main output" terminal of VR, and output from PM alternator could not
>get out of the VR box, and if the postulated short existed in the VR box,
>then there would be a massive short from the battery to that new "unplanned"
>ground - & the fuselink would do its job and melt.
>
> > That is why I was musing that it might be better to put the OV
> > disconnect relay on the alternator output wires.
This would work fine too . . .
>........I think we agree that we can't see a need for putting anything,
>especially the OV system, between PM alternator & regulator.
>
> > I still don't know if a
> > VR short is in fact a significant risk on a John Deere VR though...
>
>...........as noted above, we are covered, regardless of risk.
Put the relay where ever it suits you to disconnect the alternator
in the event of regulator failure.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: SCR for a Hobbs meter |
>
>
>I'm finishing a canard aircraft, and am about to hook up
>the hobbs meter. Electric tach, so I don't have another
>hour meter.
>
>I don't like the extra oil pressure lines, Tee's and
>wiring. Seems like one more place to have a leak
>and more stuff to put in the back of the plane.
These have been pretty trouble free and the price
is right.
>I am thinking of using an SCR to trigger the start of
>the Hobbs meter. The trigger would be the starter switch.
>Simple, light weight, and relable.
>
>It does risk leaving the master switch on, and having
>a few extra hours added to the time. Hopefully I'll
>actually use a shutdown checklist everytime, and that
>won't happen.
It's pretty easy to build an "engine running" detector
for your tach signal line that will run the Hobbs only
while the engine is rotating above a certain speed.
Bob . . .
---
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: OV protection for PM alternators |
on juliet
David
Actually I don't think we are seeing the same thing here.
Unless someone sees a problem with it, I am indeed going to put the OV
relay disconnect contacts between the alternator and the regulator. That
would enable me to manually stop the current flow from the alternator to
the Regulator if I should notice that the John Deere regulator above my
right foot is smoking. The Z-13 fuselink might already be melted at that
point due to a VR problem and I'm postulating that it makes sense to
insure that the alternator can't still feed 20 amps into the failed and
smoking regulator.
In fact with our discussion I now realize that since I've use a circuit
breaker instead of the Z-13 fuselink I can also pull that to manually
disconnect the battery from the VR if it doesn't pop by itself so I
think this is an improvement.
Ken
>.........Z-13 already has a fuselink (16awg wire in a 12 awg main
>alternator-to-battery circuit) that does what you want - no need to add
>anything, i.e., if VR fried and shorted, and there was no longer any output
>from "main output" terminal of VR, and output from PM alternator could not
>get out of the VR box, and if the postulated short existed in the VR box,
>then there would be a massive short from the battery to that new "unplanned"
>ground - & the fuselink would do its job and melt.
>
>
>
>> That is why I was musing that it might be better to put the OV
>>disconnect relay on the alternator output wires.
>>
>>
>
>........I think we agree that we can't see a need for putting anything,
>especially the OV system, between PM alternator & regulator.
>
>
>
>>I still don't know if a
>>VR short is in fact a significant risk on a John Deere VR though...
>>
>>
>
>...........as noted above, we are covered, regardless of risk.
>
>
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: Posting dwg drawings or pdf images to a website |
for other builders to view
Jon Finley & Cy Galley,
Thanks for the excellent tips. Just what I needed. I'll digest this stuff
tomorrow and mod my website until it works.
David
----- Original Message -----
From: "cgalley" <cgalley(at)qcbc.org>
Subject: Re: AeroElectric-List: Posting dwg drawings or pdf images to a
website for other builders to view
>
> I use PDFs all the time for forms on www.qcbc.org. Click on the left hand
> Heartland Century link. You do have to have adobe Acrobat reader
installed
> to see a PDF. The newsletter link has a link to Adobe's site to get the
free
> reader.
>
> As the reader has to load before display of the PDF, it takes a while and
> sometime you might think it isn't working because ot the time lag.
>
> Cy Galley - Webmaster www.qcbc.org
>
> ----- Original Message -----
> From: "David Carter" <dcarter(at)datarecall.net>
> To: "aeroelectric-list"
> Subject: AeroElectric-List: Posting dwg drawings or pdf images to a
website
> for other builders to view
>
>
>
> >
> > I have an unsophisticated website and am trying to learn how to add
stuff
> to
> > it. I can post .jpg stuff OK. Today, I tried posting a .dwg file (my
mod
> > to Z-13) - it wouldn't open with Autocad (actually, Intellicad clone of
> > Autocad). Converted to .pdf and uploaded - still won't display. I
think
> I
> > don't have the source coding for that image correct in my "Builder's
Log".
> > My website url for that page is
> > http://www.datarecall.net/~dcarter/Builder's%20Log.html
> > - Anyone have either of these type images posted - I'd like to go
to
> > your site and "copy source" and see how you do it.
> >
> > David
> >
> >
>
>
________________________________________________________________________________
| From: | "Glaeser, Dennis A" <dennis.glaeser(at)eds.com> |
"'aeroelectric-list(at)matronics.com'"
e for other builders to view
| Subject: | Posting dwg drawings or pdf images to a websit |
e for other builders to view
David
When I went to your website and viewed the source, everything looked OK, but
nothing came up when I viewed the page. This typically means it couldn't
find the file.
The path to your file (/%7Edcarter/z13%20David%27s%20RV-6%2029Aug04.pdf) has
special characters and spaces (the %7 and %20). I suggest removing those -
either run the name together without spaces or use an underscore to make it
more readable. The "/%7Edcarter" as a subdirectory name is very suspicious
(to me) - verify that as well.
Feel free to contact me off-list if you need more help.
Dennis Glaeser
dennis.glaeser(at)eds.com
From: "David Carter" <dcarter(at)datarecall.net>
Subject: AeroElectric-List: Posting dwg drawings or pdf images to a website
for other builders to view
-->
I have an unsophisticated website and am trying to learn how to add stuff to
it. I can post .jpg stuff OK. Today, I tried posting a .dwg file (my mod
to Z-13) - it wouldn't open with Autocad (actually, Intellicad clone of
Autocad). Converted to .pdf and uploaded - still won't display. I think I
don't have the source coding for that image correct in my "Builder's Log".
My website url for that page is
http://www.datarecall.net/~dcarter/Builder's%20Log.html
<http://www.datarecall.net/~dcarter/Builder's%20Log.html>
- Anyone have either of these type images posted - I'd like to go to
your site and "copy source" and see how you do it.
David
------------------------------------
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: e-bus alternate feed sizing |
>Comments/Questions: Hello Bob,
>
> I have read the AeroElectric Connection and started the electrical
> system on my RV-7A. I am a neophyte when it comes to this stuff but I
> think its starting to sink in. I am following your Z-11 diagram and was
> curious why the fuse that is protecting the E-buss alternate feed is only
> 7A while the wire is 16AWG.
Keep in mind that the Z-figures are ARCHITECTURAL examples, not wiring
diagrams.
You need to select from all of the simple ideas offered in the rest of
the book
to fine-tune and adjust to fit your mission and equipment compliment.
You have demonstrated a good beginning by raising a question to clarify
fuse and wire selection for a particular circuit . . . simple ideas
from the fuse and wire sections of the book don't seem to fit together
in the Z-figure. Let's consider the following:
The e-bus alternate feed path is a major power pathway that should be
sized for robust performance (tolerate of abuse from downstream
faults) and low voltage drop. The 16AWG feeder and 7A fuse might be
selected for an e-bus load of 2A average, 5A peak and 16AWG was
selected to minimize voltage drop on a 10' long feedline.
You need to do a load analysis for how things on your e-bus will
load the alternate feed path. Consider also how far it is from
battery to e-bus. Of course, you could take the broad brush
approach and make the feeder from say 12AWG wire and protect it
with a 20AWG fusible link. VERY low voltage drop, VERY robust
fault protection. It's perhaps a bit 'oversized' but the weight
and cost penalties are measured in ounces and pennies.
Your e-bus feeder might be best configured with 16AWG and
a 10A fuse . . . don't know and you won't know until you
run the numbers.
> I belive 16AWG can handle more than 7 amps and I would think that you
> would not want the fuse to blow unnecessary while using the E-buss in an
> emergency situation. Can you set me straight on this issue? Thanks for
> your time. John
You're installing an e-bus so that you DON'T HAVE an
emergency situation. Had our hero Gomez in chapter 17
of the 'Connection enjoyed the benefits of an e-bus
in his airplane, the story he shared with us would never
have been written.
We're not just building electrical systems here . . .
ANYBODY can build and electrical system. The certified
side of GA has been demonstrating how to do it for
decades. We're building failure tolerant, emergency
free electrical systems.
Suggest you join us on the AeroElectric List described
at http://www.aeroelectric.com/consulting.html
I am certain you'll find it very worthy of your time.
Bob . . .
-----------------------------------------
( Experience and common sense cannot be )
( replaced with policy and procedures. )
( R. L. Nuckolls III )
-----------------------------------------
________________________________________________________________________________
| From: | "DAVID REEL" <dreel(at)cox.net> |
| Subject: | Re: Crimping 22AWG PIDG terminals |
Everybody should try the following experiment in crimping. It's a great confidence
builder, only takes 15 minutes, and removes any uncertainty over the compatibility
of crimp tool and terminal.
After my failure with Cleveland's WTC380 tool, I borrowed an Ideal crimper with
a 30-579 die for PIDG terminals from OC Baker and crimped a 22 awg wire onto
one of the red terminals. Then I clipped the wire off where it exited the terminal,
removed the red plastic from the barrel & started grinding away the barrel
using my belt sander. Examining the ground end periodically, I could see
how the die had reformed the barrel gripping the insulation tighter and tighter
until I reached the wire only part of the joint. The small gap previously occupied
by insulation gradually disappeared until the whole thing looked like
one solid piece of metal as I neared the point of maximum crimp. Bob's article
on crimping shows pictures of this but because of variations in crimpers and
terminals, one doesn't really know if a crimper will do the job on the terminals
in one's parts bin until they try it.
Dave Reel - RV8A
________________________________________________________________________________
| From: | George Neal E Capt AU/PC <Neal.George(at)maxwell.af.mil> |
| Subject: | SCR for a Hobbs meter |
Tom -
Wag Aero has a self-contained Hobbs meter that is activated by the vibration
of the engine. Powered by a lithium battery, so no wires, no switches, no
oil... Wag Aero SKU/Item#: A-255-000, Price: $34.00.
Neal
________________________________________________________________________________
| From: | PeterHunt1(at)aol.com |
| Subject: | Shielded magneto wires - Z Figures |
Bob:
I didn't get an answer on this so, if I may, I am asking again. I need a
little help understanding if I should be using shielded magneto wires in some
fashion. My LASAR control box which sits forward of the firewall has two low
voltage unshielded wires marked "left magneto P lead" and "right magneto P lead."
I have brought these non shielded wires into the cabin to my left magneto
switch and my right magneto switch which ground these wires when the engine is
shut down. No shielded wires in the circuit. Unison (the LASAR people) could
not tell me if I needed shielded wires anywhere, but did say there is voltage
in my two P lead wires even though there is no current flowing while my
switches are open in the engine running position.
I want the best possible installation.
Questions: Should I run shielded wire from my switches through the firewall
and splice them to the P leads on my LASAR control box? If this would be a
better instillation, should I ground the shield at both ends or just one end?
Question: What is the electrostatic coupling of magneto noise you speak of
in Note 3 of your book?
I did get one response to my original post from a guy who did not use
shielded wires with his LASAR, but he had the conventional start switch and claims
to
have "alternator" noise.
A little help would be appreciated, thanks.
Pete Hunt
Clearwater, FL
RV-6, finishing wiring
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Simplification |
on juliet
I found a cheap marine key switch with a 30 amp solenoid start circuit
rating that I'm going to try for this. My own preference is for a key
switch for cranking only because then I know someone can't accidently
crank it if the key is in my pocket.
Princess Auto is also selling surplus 200 amp starter push buttons for
cdn$20. which would likely stand up fairly well ;)
Ken
>>2. "contactor-less" starter. By using one of the lightweight
>>solenoid-engaged starters I can energize the solenoid with a simple
>>momentary-contact switch rated at the appropriate current (I figure a
50-amp
>>rating is adequate). It reduces the number of wires and connections,
>>eliminates one of the contactors and should improve reliability while
>>reducing weight. The system is identical in concept to all automotive
>>starts, but a redundant way to shut off the starter is still there
with the
>>master switch.
>>
>>
>
> Lots of builders have gone this route. There are no down-sides
> that I can deduce.
>
>
________________________________________________________________________________
| From: | Matt Jurotich <mjurotich(at)hst.nasa.gov> |
| Subject: | Re: SCR for a Hobbs meter |
Bob
I infer from Pretty easy that means pretty easy for you. How about a "how
to" for those of us more challanged?
Thanks
Matthew M. Jurotich
e-mail mail to:
phone : 301-286-5919
________________________________________________________________________________
| From: | "Glen Matejcek" <aerobubba(at)earthlink.net> |
| Subject: | RE: AeroElectric-List Digest: 12 Msgs - 08/28/04 |
Hmmm... I was taught that "B" stands for "baby" and that "T" stands for
"Tiny".
Glen Matejcek
aerobubba(at)earthlink.net
> Hello Bruce, That connector is called a BNC connector. BNC stands for
Bayonet Neil
> Councilman.
>
> B=Bayonet for the way it connects together sort of like sticking a
bayonet on
> the end of a rifle.
>
> N=Neil for the last name of one of the inventors.
>
> C=Councilman for the last name of the other inventor.
>
> There is also a connector called a TNC connector. It will be left as an
exercise
> for the student to determine what TNC stands for.
>
> OC
>
> PS: Both RG 142 and RG 400 are double shielded.
>
> PPS: Extra credit goes to the first student who posts what the letters RG
stand
> for on the coax cable used with these connectors.
>
>
________________________________________________________________________________
| From: | SportAV8R(at)aol.com |
| Subject: | Solid state contactors, OVP |
'Lectric Bob-
I'm wondering if a few details of your design philosophy will necessarily shift
when builders begin adopting Eric Jones's not-yet-available solid state large-current
(1280 amp)contactors (or similar) in their designs, as regards the need
to shed the one-amp battery contactor load during an alternator failure. Seems
like in addition to a weight savings versus electromagnetic contactors and
relays, there might be a reduction in parts count for the essentials bus supply
routing.
I'm also curious to hear your "take" on PerihelionDesign's non-crowbar approach
to alternator regulation and OVP.
Bill B
--studying and planning the electrical system changes to my RV that I would have
incorporated 8 years ago if I had read the 'Connection back then :-)
________________________________________________________________________________
| From: | rd2(at)evenlink.com |
| Subject: | SCR for a Hobbs meter |
Actually the same item can be found even cheaper; if interested drop me an
email, I'll try to dig out the source in the pyle here. I got one to test
it: worked well in the aircraft. The display is LCD so it is expected to be
"lazy" when it's cold (testing was done in summer). Also LCD displays
aren't best if you use polarized sunglasses. Problem with this meter was it
reacted to other vibrations; we used it successfully as walking/jogging
timer; tested it also in 2 vehicles on 2 different roads - if ride is very
smooth, it could read just partial time. Probably not bad, but I decided to
stick with the good old hobbs w/pressure switch (or whatever means of
activation is used).
Rumen
_____________________Original message __________________________
(received from George Neal E Capt AU/PC; Date: 08:38 AM
Tom -
Wag Aero has a self-contained Hobbs meter that is activated by the vibration
of the engine. Powered by a lithium battery, so no wires, no switches, no
oil... Wag Aero SKU/Item#: A-255-000, Price: $34.00.
Neal
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: OVM disconnect relay 'tween alternator & VR |
Ken (and rest of list, especially "Lectric Bob" for any comments),
I'll be using the 35 (or 40) amp John Deere alternator. Wonder if your idea
of an auto relay rated at around 20 amps is enough of a rating.
20 amp rating will probably will be OK, since the (OV disconnect) relay
contacts will close during engine start as soon as there is enough voltage
for relay coils to close the relay - no heavy electrical load at that moment
(almost no load - battery is supplying all the juice for engine ignition &
fuel inj) so not going to be any "stressing" arcs when contacts close. On
shut down, with most/all items turned off (except engine stuff on battery
bus), and with the engine and alternator at idle rpm & dropping during
shutdown, not going to be much output and therefore, again, not much arcing
when relay drops off-line as voltage drops during engine wind-down and relay
coils let go the "Normally Open" contacts.
I just got my pdf version of my modified Z-13 to show up on my web site
"Builder's Log" at
http://www.datarecall.net/~dcarter/Builder's%20Log.html
Tomorrow I hope to mod Z-13 to show the 2 contact relay between the PM
alternator & the VR, etc. I haven't yet learned how to insert the
electrical symbols in the "blocks" section of Autocad "Explorer" - will
study "Help" and figure it out.
David
----- Original Message -----
From: "Ken" <klehman(at)albedo.net>
Subject: Re: OVM disconnect relay 'tween alternator & VR
> Hi David
> I was just going to use a double pole (two sets of contacts) automotive
> relay with push on connectors. Should be good for 20 amps. Bob didn't
> object to wiring it this way but he didn't seem to get excited about it
> either so I guess it's not a big deal one way or the other. Sometimes
> ideas like this attract more comment when they come up the second time
> in a couple of months... I now think a single set of contacts is
> probably also acceptable since it would take a double failure to really
> need the double contacts.
> Ken
>
> David Carter wrote:
>
> >Ken, I just did a pencil drawing rearranging the "Dynamo", VR, & OVM &
it's
> >relay. Having to learn new things about Autocad and will have Z-13
modified
> >soon. When I add it to my website (both as .dwg and also as .pdf), I'll
put
> >a notice on the Aeroelectric List. I'm assuming there is a suitable
> >disconnect contactor that has two contacts, 1 for each of the alternating
> >current wires between the PM Alternator and it's VR. That will certainly
> >"kill that snake" (the alternator) if electrons start running amok
anywhere
> >downstream of there.
> >
> >David
> >
> >
> >
> >
> >
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Crimping 22AWG PIDG terminals |
>
>Everybody should try the following experiment in crimping. It's a great
>confidence builder, only takes 15 minutes, and removes any uncertainty
>over the compatibility of crimp tool and terminal.
>
>After my failure with Cleveland's WTC380 tool, I borrowed an Ideal crimper
>with a 30-579 die for PIDG terminals from OC Baker and crimped a 22 awg
>wire onto one of the red terminals. Then I clipped the wire off where it
>exited the terminal, removed the red plastic from the barrel & started
>grinding away the barrel using my belt sander. Examining the ground end
>periodically, I could see how the die had reformed the barrel gripping the
>insulation tighter and tighter until I reached the wire only part of the
>joint. The small gap previously occupied by insulation gradually
>disappeared until the whole thing looked like one solid piece of metal as
>I neared the point of maximum crimp. Bob's article on crimping shows
>pictures of this but because of variations in crimpers and terminals, one
>doesn't really know if a crimper will do the job on the terminals in one's
>parts bin until they try it.
>
>Dave Reel - RV8A
Let's hear it for the repeatable experiment . . .
I'd still like to get my hands on and example of the WTC380 . . .
if those folks are selling a poorly performing tool, they
need to know about it.
Bob . . .
---
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Locking female fast-ons |
>
>AeroElectric-List message previously posted by: Charlie Kuss
>
>
>Listers, I recently purchased several Bosch (automotive style) relays and the
>related sockets for my RV-8A flap circuit. I purchased these items from
>Waytek Wire. Nice folks with brand name stuff at good prices. The
>sockets for these relays use a variant of the common 1/4" female fast ons.
>These are open barrel, rather than PIDG items. They also have a locking tang,
>to secure the connector into the socket body. Anyone familiar with
>automotive connectors has seen these.My question is, I need to find a part
>number and source for these connectors designed for 22/18 AWG wire. Waytek
>has these connectors
>for 16/14 AWG, but not for the 22/18 AWG. I know that these things are
>actually quite common. I've tried finding them in Allied Electronics
>paper catalog and their web site. However, I don't know the manufacturer or
>the proper terminology these items are known by. Because of this, I have
>not been able to locate what I need. Can anyone help?
>The relay sockets and connectors can be seen here:
>http://order.waytekwire.com/IMAGES/M37/catalog/216_54
>I'm using the #75280 style sockets. These are modular. You can stack
>them together. The connectors are part # 31073, also seen on the above web
>page. Charlie Kuss RV-8A cockpit wiring & systems>>
>
>8/25/2004
>
>Hello Charlie, Why wouldnt an Avikrimp female .250 push on terminal work?
>You can get them in either insulated (AA-8140) or uninsulated (AA-1140F)
>configuration. (Also fully insulated, but you dont want that here).Just do
>a google search.
>
>Yes they are the high quality complete surround PIDG crimp on type
>terminals, not open barrel, and the lock on feature may not be a perfect
>match with the lock on built into the socket body, but Ill bet they
>wouldnt come loose from the male terminal inside the socket body.
>
>I use the Avikrimp fully insulated male and female terminals as in-line
>connectors in much of my wiring. One draw back is that when I want to
>separate them it takes holding the inner shell with a pliers and twisting
>a broad blade screwdriver between the side of the pliers and the end of
>the outer shell to separate them. The make positive connection.
>
>OC
OC
Yes, they will work, but it would defeat part of the reason for using the
sockets in the first place. (Retaining all the terminals in place in the
socket) If I could find PIDG fast ons with the locking tab, they would
work great. It's no big deal. I was just hoping someone on the list might
know where to find what I was looking for.
Charlie
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
>
>I just have to ask: why are folks are still using transformers for audio
>distribution in aircraft (or ??)
They're simple. Don't require power supplies. I one of the
design goals is to break every potential "ground loop", a
transformer's input-to-output isolation is unequaled.
Bob . . .
---
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: OVM disconnect relay 'tween alternator |
& VR
on juliet
David
Your pdf displayed just fine for me after I patched the link in your e-mail.
I didn't know there was a 40amp JD alternator. While
there are automotive relays supposedly rated at 40 amp they usually have
push on connectors and in the past Bob has recommended not exceeding 20
amps for push on connectors. I ended up purchasing a battery master
contactor for the ov circuit on my main 40 amp ND alternator. I couldn't
find anything else that was affordable, rated for continuous duty, and
had bolt on connections.
FWIW I elected to try a smaller than 5 amp breaker to feed the ov relay.
Ken
David Carter wrote:
>
>Ken (and rest of list, especially "Lectric Bob" for any comments),
>
>I'll be using the 35 (or 40) amp John Deere alternator. Wonder if
your idea
>of an auto relay rated at around 20 amps is enough of a rating.
>
>20 amp rating will probably will be OK, since the (OV disconnect) relay
>contacts will close during engine start as soon as there is enough
voltage
>for relay coils to close the relay - no heavy electrical load at that
moment
>(almost no load - battery is supplying all the juice for engine
ignition &
>fuel inj) so not going to be any "stressing" arcs when contacts
close. On
>shut down, with most/all items turned off (except engine stuff on battery
>bus), and with the engine and alternator at idle rpm & dropping during
>shutdown, not going to be much output and therefore, again, not much
arcing
>when relay drops off-line as voltage drops during engine wind-down and
relay
>coils let go the "Normally Open" contacts.
>
>I just got my pdf version of my modified Z-13 to show up on my web site
>"Builder's Log" at
>http://www.datarecall.net/~dcarter/Builder's%20Log.html
>
>Tomorrow I hope to mod Z-13 to show the 2 contact relay between the PM
>alternator & the VR, etc. I haven't yet learned how to insert the
>electrical symbols in the "blocks" section of Autocad "Explorer" - will
>study "Help" and figure it out.
>
>David
________________________________________________________________________________
AeroElectric List
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Locking female fast-ons |
David
Thanks for your efforts on my behalf. However, push ons are not what I'm
looking for. What I WANT, is called "push to lock". These are a variant of
the more common "push ons" you refer to below. The "push to lock" females
have a U shaped area cut from the back (flat) side of the terminal's
contact area. This area is bent out. When pushed into a matching socket,
the terminal is trapped in the socket by this tab. See
http://order.waytekwire.com/IMAGES/M37/catalog/216_54
Look carefully at terminal 31073 & you can see the "cut out" I'm referring
to. You may have to "zoom in" to see this. If I can't find the 18/22 AWG
size terminals, I'll just double the wire back and use the 16/14 AWG terminals.
Thanks for trying
Charlie
>
>
>The link didn't work. I went to www.waytekwire.com , clicked top left
>"Products" link, scrolled way down to "Select a catagory", scrolled down to
>"Terminals, push on", got listing of 6 items and clicked first item, "Fully
>Insulated Female", scrolled to bottom and clicked the red text "22-18 GA
>FEMALE PUSH-ON RED NYLON INS W/EXTRA SLEEVE" and got info but no size, and
>looked at lower rt corner and clicked "...view the catalog" and got the full
>info on full range of selections, including 1/4" insulated and non-insulated
>pushons. The fully insultated should be good for use with the male blades
>on the auto relays.
>
>I called - they are coated with bright tin. The option of "extra sleeve" is
>for strain relief to grip the insulation - you crimp them twice, once for
>electrical connection on bare end of wire, 2nd on insulated wire, just like
>we like. The 1/4" female fully insulated with extra sleeve for 22-18ga was
>p/n 30713.
>
>Min order is about 50 he said. Sounds like we need to get A/C Spruce and
>Wicks to stock these beauties.
>
>David
>snipped
________________________________________________________________________________
| From: | "Malcolm Thomson" <mdthomson(at)attglobal.net> |
| Subject: | Dual Alternator/Bat Crossfeed? |
Is there any reason to not leave the Crossfeed switch in the ON position
all the time? I know it is used for starting power and for "backup"
power but would it be OK to leave on during normal operations. What
would be the pro/cons for doing so?
Thanks
Malcolm.
________________________________________________________________________________
| From: | "Ron Koyich" <Ron(at)Koyich.com> |
>> Don't require power supplies. I one of the design goals is to break
every potential "ground loop", a transformer's input-to-output isolation
is unequaled.<<
No arguments with either of those statements, Bob.
But a simple pad will match a 23 Watt car stereo amplifier to an intercom
music input better than a 500 mW 8 ohm to 500 ohm transformer, without
danger of smoking the little transformer. If a bigger transformer were
used, I believe it would weigh more than the attenuator.
Ron
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: Locking female fast-ons |
Charlie,
You are right - I overlooked the essential thing you were looking for - the
"lock in connector shell" tab. I got to play with those things when
extending my Whelen tail/strobe light harness.
Well, if "the industry" simply doesn't punch any of the 1/4" push-ons for
22-18awg, then I'll bet it wouldn't be too hard to make a little punch that
would do the job in your shop. Trace the shape of the U tab, then use small
file and/or rotary tool with cutting wheel and shape the end of a 1/8" dia
steel rod or big nail. Maybe make a matching female "die" with sloped
depression to punch the back of push-on down into with the rod-tool.
Then you could rent out the new tools!
David
----- Original Message -----
From: "Charlie Kuss" <chaztuna(at)adelphia.net>
Subject: Re: AeroElectric-List: Locking female fast-ons
>
> David
> Thanks for your efforts on my behalf. However, push ons are not what I'm
> looking for. What I WANT, is called "push to lock". These are a variant of
> the more common "push ons" you refer to below. The "push to lock" females
> have a U shaped area cut from the back (flat) side of the terminal's
> contact area. This area is bent out. When pushed into a matching socket,
> the terminal is trapped in the socket by this tab. See
>
> http://order.waytekwire.com/IMAGES/M37/catalog/216_54
>
> Look carefully at terminal 31073 & you can see the "cut out" I'm referring
> to. You may have to "zoom in" to see this. If I can't find the 18/22 AWG
> size terminals, I'll just double the wire back and use the 16/14 AWG
terminals.
> Thanks for trying
> Charlie
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | tion-reducing elec load so can use 35amp PM alternator [ was |
Re: AeroElectric-List: Re: OVM disconnect relay 'tween alternator & VR ]
Ken, I reviewed my info sheet on Deere alternators. There is a 35 amp that
is light weight, which I consider usable. There is also a 40/50 that is
much heavier. I knew there was one of them that I had conflicting info on -
was the 40/50, not a "35/40".
As noted, one could use 2 of the 20 amp alterntors to have a 40 amp
capacity. Would be appealing if had a pulley at each end of engine so each
alternator had its own belt - true redundancy and separation in case 1 belt
broke it wouldn't take out the other. I don't plan on trying this.
That 35amp "limit" is the reason I am interested the "Simplification"
architecture - eliminating the 1amp current draw of a "battery contactor"
(or 2) - and am interested in using LED lights to the max instead of
incandescant bulbs - to keep night IFR load below 35 amps.
David
----- Original Message -----
From: "Ken" <klehman(at)albedo.net>
Subject: Re: AeroElectric-List: Re: OVM disconnect relay 'tween alternator &
VR on juliet
>
> David
>
> Your pdf displayed just fine for me after I patched the link in your
e-mail.
>
> I didn't know there was a 40amp JD alternator. While
> there are automotive relays supposedly rated at 40 amp they usually have
> push on connectors and in the past Bob has recommended not exceeding 20
> amps for push on connectors. I ended up purchasing a battery master
> contactor for the ov circuit on my main 40 amp ND alternator. I couldn't
> find anything else that was affordable, rated for continuous duty, and
> had bolt on connections.
>
> FWIW I elected to try a smaller than 5 amp breaker to feed the ov relay.
>
> Ken
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
On Aug 31, 2004, at 10:14 AM, Ron Koyich wrote:
> But a simple pad will match a 23 Watt car stereo amplifier to an
> intercom
> music input better than a 500 mW 8 ohm to 500 ohm transformer, without
> danger of smoking the little transformer. If a bigger transformer were
> used, I believe it would weigh more than the attenuator.
But most automobile stereo system outputs are bridged rather than
referenced to ground. Basically you have a balanced output. The
transformer is nice to solve the balanced-to-unbalanced output problem.
And since the output of the car stereo is something like 24V-pp maximum
output you don't really need a step-up transformer. You probably want
a step down transformer with a relatively high impedance input.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | "Glaeser, Dennis A" <dennis.glaeser(at)eds.com> |
"'aeroelectric-list(at)matronics.com'"
| Subject: | RE: [subaruaircraft] Digest Number 1262 |
OK, the batteries are both getting charged AND buffering the alternator - a
valid and important point. Is there an advantage to switching back and
forth between 2 batteries, vs. just leaving both connected all the time?
Regarding the VR: My understanding is: if it sensed a fully charged battery,
to prevent overcharging it would reduce the voltage from the 'charging'
level to the 'maintenance' level. I forget the values, but it is something
like 13.8 charging and 13.2 maintenance. The alternator still takes the
whole electrical load, but now the battery is being treated 'better'.
Now the question is: Will the added complexity of treating the battery
'better' truly add reliability to the system? In our case, we're not talking
about reducing battery failure (I just don't see that as a problem), we're
looking for maximum battery capacity - making it last the longest time
possible if the alternator fails. Does anyone have statistics on the
degradation of batteries constantly charged at 13.8V (for 1 to 4 hours -
then sit for a few days) versus those where the voltage is reduced once
fully charged? My guess is that the difference would be measurable but not
dramatic. In the end, replacing oldest the battery every annual probably
mitigates the whole thing. If treating the battery 'better' demonstrates
that keeping a battery longer could be justified, that might justify the
cost/complexity of such a system.
I'm going to post this on the AeroElectric list also, to get that group's
input. Might as well stir two pots with one spoon!
Dennis Glaeser
=============================================================
Date: Mon, 30 Aug 2004 22:40:01 -0500
From: "Jim Skala" <wa8vwy2(at)bellsouth.net>
Subject: Re: Re: Alternative Electrical System
Not true -- battery needs to be connected while alternator is running to
keep the AC components to a minimum. If you run the alternator without the
battery, you will have about 2 volts peak-to-peak of AC on the DC bus.
Date: Mon, 30 Aug 2004 23:02:22 -0500
From: "Jim Skala" <wa8vwy2(at)bellsouth.net>
Subject: Re: Re: Alternative electrical system
Lets say a VR could sense a fully charged battery. What then? If the
airplane took absolutely no current to run anything, and the only purpose of
the alternator was to charge the battery, then no problem with reducing the
alternator field current to zero. But because the alternator must supply
the power load of the airplane, any drop in voltage would cause the battery
to begin to discharge because the battery is a critical part of the circuit,
and current is constantly shuffling in and out of the battery to keep the
alternator's natural AC components off the DC bus.
----- Original Message -----
From: Glaeser, Dennis A
To: 'subaruaircraft(at)yahoogroups.com'
Sent: Thursday, August 26, 2004 1:39 PM
Subject: [subaruaircraft] Re: Alternative Electrical System
While the alternator is working, the batteries aren't doing anything
except
getting charged, so what does the switching back and forth accomplish? In
battery-only operation such a device will be using precious electrons
(maybe
not many, but not zero) which should be running the engine and other
essential devices. It is also another failure point.
Batteries are one of the most reliable items in the system, there are 2 of
them, and they should be checked before flight and monitored in-flight.
Is
there a problem I'm missing that needs to be solved?
Dennis Glaeser
Future RV7A builder...
==============================================
Date: Mon, 30 Aug 2004 23:02:22 -0500
From: "Jim Skala" <wa8vwy2(at)bellsouth.net>
Subject: Re: Re: Alternative electrical system
Lets say a VR could sense a fully charged battery. What then? If the
airplane took absolutely no current to run anything, and the only purpose of
the alternator was to charge the battery, then no problem with reducing the
alternator field current to zero. But because the alternator must supply
the power load of the airplane, any drop in voltage would cause the battery
to begin to discharge because the battery is a critical part of the circuit,
and current is constantly shuffling in and out of the battery to keep the
alternator's natural AC components off the DC bus.
> Date: Thu, 26 Aug 2004 22:40:09 EDT
> From: eaainc(at)aol.com
>Subject: Re: Alternative electrical system
>
>
>In a message dated 8/26/2004 10:08:18 PM Eastern Standard Time,
>jean_don(at)msn.com writes:
>
>I see great advantage to putting both batteries into the circuit
>until there some need to separate them - failed alternator. This
>can be done manually or automatically. Doing this will allow both
>batteries to be recharged together after the start and you could
>alternate which battery was used for the start or use both. I would
>also recommend getting into a routine of changing out one of the
>batteries each year. A very small cost for very good insurance.
>
>Don Russell
--------------------------------
>I am also thinking along these lines. I am instantly warned if the
>alternator is out of the loop and fuses handle any kind of short. Each
battery could
>even be fused separately to the bus with 100A or so fuses. This
approach
>would make things simple. There could be an engine BUS from each
battery
for
>emergency use when not running on dual?
>
>This discussion is no longer about replacing the existing system but
rather
>an alternative system. I believe the alternative should be a simpler
system.
>
>Jan
------------------
Date: Wed, 25 Aug 2004 22:04:11 EDT
From: eaainc(at)aol.com
Subject: Re: Alternative Electrical System
I have been reading the posts regarding the alternative electrical system.
What are the implications of having a single battery bus system, then
alternating the feed to it from 2 separate batteries on a time schedule?
Good and bad?
Jan
============================================================================
===
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: RE: [subaruaircraft] Digest Number 1262 |
On Aug 31, 2004, at 11:16 AM, Glaeser, Dennis A wrote:
> Now the question is: Will the added complexity of treating the battery
> 'better' truly add reliability to the system? In our case, we're not
> talking
> about reducing battery failure (I just don't see that as a problem),
> we're
> looking for maximum battery capacity - making it last the longest time
> possible if the alternator fails. Does anyone have statistics on the
> degradation of batteries constantly charged at 13.8V (for 1 to 4 hours
> -
> then sit for a few days) versus those where the voltage is reduced once
> fully charged? My guess is that the difference would be measurable
> but not
> dramatic. In the end, replacing oldest the battery every annual
> probably
> mitigates the whole thing. If treating the battery 'better'
> demonstrates
> that keeping a battery longer could be justified, that might justify
> the
> cost/complexity of such a system.
We had a big discussion on this a while back so you might want to
peruse the archives.
The issue of reducing the voltage from "charge" to "float" is one of
increasing battery life, not increasing battery capacity (well, perhaps
that too if you count how the life is limited by lost capacity). If
you live in a warm climate (I do) battery life is greatly extended by
adjusting the charge voltage for temperature and not overcharging the
battery. Batteries rarely last two years down here where temps are
typically over 80F year-round unless you have compensated the charging
voltage for temperature.
If you want a two or three stage charge regulator with temperature
compensation for your battery such things are available from marine
supply places since that charging regimen is becoming the rule on boats
that use their battery banks to provide power when the engine is not
running.
The other thing to look at is what the charge and float voltages should
be for flooded-cell, AGM, and gel-cell batteries. AGM and flooded-cell
are pretty close but AGMs do not tolerate overcharge as well as
flooded-cell batteries do. Gel-cell batteries have charge and float
voltages relatively near to each other so it is possible to set your
regulator to a single voltage and stay within both the change and float
voltage ranges. If you set the charge voltage to the low end of the
acceptable range you are probably at the upper end of the acceptable
float voltage range. This means you can get away with a regulator with
a single setpoint. Temperature compensation is important in that case.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Locking female fast-ons |
on juliet
Charlie
I haven't followed this thread but I have in my hand what sounds like
what you might be after.
Digikey A27927CT for 14-18ga
Digikey A27930CT for 12-16ga
They are tin plated 1/4" female pushons that lock into digikey PB16
sockets for 5 pin VF4 series relays among others.
Ken
Charlie Kuss wrote:
>
>David
> Thanks for your efforts on my behalf. However, push ons are not what I'm
>looking for. What I WANT, is called "push to lock". These are a variant of
>the more common "push ons" you refer to below. The "push to lock" females
>have a U shaped area cut from the back (flat) side of the terminal's
>contact area. This area is bent out. When pushed into a matching socket,
>the terminal is trapped in the socket by this tab. See
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Locking female fast-ons on juliet |
I've run numerous tests and demonstrations for resistance
to vibration and the "non locking" variety fast-on terminals
are entirely adequate for our applications. All of the PIDG
fast-on females feature a locking pip that will increase
retention force on male terminals that also feature the right
detent . . . yeah, it's pretty good idea but the difference
is not worth worrying about.
Bob . . .
>
>Charlie
>I haven't followed this thread but I have in my hand what sounds like
>what you might be after.
>Digikey A27927CT for 14-18ga
>Digikey A27930CT for 12-16ga
>They are tin plated 1/4" female pushons that lock into digikey PB16
>sockets for 5 pin VF4 series relays among others.
>Ken
>
>Charlie Kuss wrote:
>
>
> >
> >David
> > Thanks for your efforts on my behalf. However, push ons are not what I'm
> >looking for. What I WANT, is called "push to lock". These are a variant of
> >the more common "push ons" you refer to below. The "push to lock" females
> >have a U shaped area cut from the back (flat) side of the terminal's
> >contact area. This area is bent out. When pushed into a matching socket,
> >the terminal is trapped in the socket by this tab. See
> >
> >
>
>
>---
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" <b.nuckolls(at)cox.net> |
| Subject: | Re: 35amp PM alternator |
>
>
>Ken, I reviewed my info sheet on Deere alternators. There is a 35 amp that
>is light weight, which I consider usable. There is also a 40/50 that is
>much heavier. I knew there was one of them that I had conflicting info on -
>was the 40/50, not a "35/40".
>
>As noted, one could use 2 of the 20 amp alterntors to have a 40 amp
>capacity. Would be appealing if had a pulley at each end of engine so each
>alternator had its own belt - true redundancy and separation in case 1 belt
>broke it wouldn't take out the other. I don't plan on trying this.
>
>That 35amp "limit" is the reason I am interested the "Simplification"
>architecture - eliminating the 1amp current draw of a "battery contactor"
>(or 2) - and am interested in using LED lights to the max instead of
>incandescant bulbs - to keep night IFR load below 35 amps.
>
>David
I'd like to see your final load analysis. The largest full-up
IFR load I've run to date on a 14v system is 27A.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Dual Alternator/Bat Crossfeed? |
>
>
>Is there any reason to not leave the Crossfeed switch in the ON position
>all the time? I know it is used for starting power and for "backup"
>power but would it be OK to leave on during normal operations. What
>would be the pro/cons for doing so?
Z-14's major advantage is totally independent electrical systems
that back each other up . . . not work in tandem. If you want a
system like a 1970's Baron or a Twin Comanche then you can simply
leave the contactor out and tie the two systems together. If you
fly with the contactor closed, you can have failure of one alternator
go un-annunciated if the working alternator is capable of carrying
the full system load.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Locking female fast-ons on juliet |
>
>
>
> I've run numerous tests and demonstrations for resistance
> to vibration and the "non locking" variety fast-on terminals
> are entirely adequate for our applications. All of the PIDG
> fast-on females feature a locking pip that will increase
> retention force on male terminals that also feature the right
> detent . . . yeah, it's pretty good idea but the difference
> is not worth worrying about.
>
> Bob . . .
Hmmmm . . . I guess I was thinking of the wrong 'locking' feature.
I understand now that the question was about a the retaining barb
that holds an installed terminal captive to the molded housing.
The Digikey parts look like
http://rocky.digikey.com/WebLib/Amp/Web%20Data/42281.pdf
Looks like the minimum buy is 100 pieces.
These terminals can be installed using tools like B&Cs
BCT-1 which you can see at:
http://bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?9X358218#BCT-
Bob . . .
> >
> >Charlie
> >I haven't followed this thread but I have in my hand what sounds like
> >what you might be after.
> >Digikey A27927CT for 14-18ga
> >Digikey A27930CT for 12-16ga
> >They are tin plated 1/4" female pushons that lock into digikey PB16
> >sockets for 5 pin VF4 series relays among others.
> >Ken
> >
> >Charlie Kuss wrote:
> >
> >
> > >
> > >David
> > > Thanks for your efforts on my behalf. However, push ons are not what I'm
> > >looking for. What I WANT, is called "push to lock". These are a variant of
> > >the more common "push ons" you refer to below. The "push to lock" females
> > >have a U shaped area cut from the back (flat) side of the terminal's
> > >contact area. This area is bent out. When pushed into a matching socket,
> > >the terminal is trapped in the socket by this tab. See
> > >
> > >
> >
> >
> >---
>
>
> 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
>
>
>---
>
>
>---
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" <b.nuckolls(at)cox.net> |
>
> >> Don't require power supplies. I one of the design goals is to break
>every potential "ground loop", a transformer's input-to-output isolation
>is unequaled.<<
>
>No arguments with either of those statements, Bob.
>
>But a simple pad will match a 23 Watt car stereo amplifier to an intercom
>music input better than a 500 mW 8 ohm to 500 ohm transformer, without
>danger of smoking the little transformer. If a bigger transformer were
>used, I believe it would weigh more than the attenuator.
Oh certainly, I'd put a pad ahead of a small transformer so its
size can remain low. But if a pad-only installation has any extraneous
noises audible during quiet passages of the music, I'd sure try
adding transformers to see if breaking ground loops helps.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Solid state contactors, OVP |
>
>'Lectric Bob-
>
>I'm wondering if a few details of your design philosophy will necessarily
>shift when builders begin adopting Eric Jones's not-yet-available solid
>state large-current (1280 amp)contactors (or similar) in their designs, as
>regards the need to shed the one-amp battery contactor load during an
>alternator failure. Seems like in addition to a weight savings versus
>electromagnetic contactors and relays, there might be a reduction in parts
>count for the essentials bus supply routing.
I've not had occasion to try one. I had a sample a year or so
ago and had intentions of testing it but lost access to my
high current test stand. I've not built one for my shop yet.
I returned the parts to Eric.
>I'm also curious to hear your "take" on PerihelionDesign's non-crowbar
>approach to alternator regulation and OVP.
That will work too . . . especially after we slay the "battery-dump"
dragon. The same ceiling on battery-dump excursions will protect
the series pass components of a solid state ov disconnect "relay".
Bob . . .
---
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: 35amp PM alternator |
----- Original Message -----
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: AeroElectric-List: Re: 35amp PM alternator
>
>
> >
> >
> >Ken, I reviewed my info sheet on Deere alternators. There is a 35 amp
that
> >is light weight, which I consider usable. There is also a 40/50 that is
> >much heavier. I knew there was one of them that I had conflicting info
on -
> >was the 40/50, not a "35/40".
> >
> >As noted, one could use 2 of the 20 amp alterntors to have a 40 amp
> >capacity. Would be appealing if had a pulley at each end of engine so
each
> >alternator had its own belt - true redundancy and separation in case 1
belt
> >broke it wouldn't take out the other. I don't plan on trying this.
> >
> >That 35amp "limit" is the reason I am interested the "Simplification"
> >architecture - eliminating the 1amp current draw of a "battery contactor"
> >(or 2) - and am interested in using LED lights to the max instead of
> >incandescant bulbs - to keep night IFR load below 35 amps.
> >
> >David
>
> I'd like to see your final load analysis. The largest full-up
> IFR load I've run to date on a 14v system is 27A.
>
> Bob . . .
My spreadsheet currently shows 28A "night cruise" and 30.4 "night descent" -
with mech switches for Batt 1 & 2. With a few engine computer items not yet
included because I haven't found out the current draw, yet. Also based on
incandescent lighting - haven't calculated led systems, yet. I'll be
running 30 to 35A with incandescent exterior lights,with a 35 amp
alternator. Hope to be down to 30 or so amps with LED ext lites - for more
"headroom".
David
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: Solid state contactors, OVP |
----- Original Message -----
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: Re: AeroElectric-List: Solid state contactors, OVP
>
>
> >
> >'Lectric Bob-
> >
> >I'm wondering if a few details of your design philosophy will necessarily
> >shift when builders begin adopting Eric Jones's not-yet-available solid
> >state large-current (1280 amp)contactors (or similar) in their designs,
as
> >regards the need to shed the one-amp battery contactor load during an
> >alternator failure. Seems like in addition to a weight savings versus
> >electromagnetic contactors and relays, there might be a reduction in
parts
> >count for the essentials bus supply routing.
>
> I've not had occasion to try one. I had a sample a year or so
> ago and had intentions of testing it but lost access to my
> high current test stand. I've not built one for my shop yet.
> I returned the parts to Eric.
>
>
> >I'm also curious to hear your "take" on PerihelionDesign's non-crowbar
> >approach to alternator regulation and OVP.
>
> That will work too . . . especially after we slay the "battery-dump"
> dragon. The same ceiling on battery-dump excursions will protect
> the series pass components of a solid state ov disconnect "relay".
>
> Bob . . .
Where's the info on PerihelionDesign's non-crowbar approach to regulation
and OVP? Website? Word of mouth so far? If the "current technology" relay
shown with the Crowbar OVM in the Z-drawings could be replaced with "solid
state", that would be another .8 or 1.0 amp reduction in load for my 35 amp
alternator.
David
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
| Subject: | Re: Alternator shaft thread? |
>Comments/Questions: What is the diameter of the shaft( where the pulley is
>mounted) and the thread pitch for a delco-remy generator on a Piper
>Apache? I agreed to loan my pulley to another pilot-friend and his
>mechanic ( more like grease-monkey) did not use a pulley-puller, instead
>he used a hammer and mushroomed the end of my generator shaft and I need
>to order a dye so I can reinstall the pulley and nut. These generators
>have a tag that says "Aero elct, Wichita, KS"
>Thanks
>Gerry
If the shaft has been hammered, then the bearings are suspect.
If that mechanic has an a/p ticket, it ought to be pulled.
You need to talk to what's left of the Aeroelectric Incorporated
which is now owned by Kelly Aerospace, 316-943-6100.
Bob . . .
-----------------------------------------
( Experience and common sense cannot be )
( replaced with policy and procedures. )
( R. L. Nuckolls III )
-----------------------------------------
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: Solid state contactors, OVP |
>Where's the info on PerihelionDesign's non-crowbar approach to regulation
>and OVP? Website? Word of mouth so far? If the "current technology"
relay
>shown with the Crowbar OVM in the Z-drawings could be replaced with "solid
>state", that would be another .8 or 1.0 amp reduction in load for my 35 amp
>alternator.
>David
David,
The "non-crowbar" OVP, which I prefer to call an "in-line" or "linear" OVP
is on my website. I have shipped a couple but now am waiting for two parts.
One due next week late and one on Digikey's backorder list with no delivery
date. I am no longer selling "crowbar" OVPs, since I have become a believer
in the linear approach. Call me a flip-flopper....
I have also redesigned the Powerlink Jr 35/50A to use IR's new IPS chips.
This lowers parts counts and is easier to build and provides additional
features.
The big PowerLink is a curious beast. I have several flying in airplanes and
have sent out several more. All with no reports of problems. On the other
hand, all with no data other than that.... So I am faced with (maybe) making
and selling a semi-critical device that has almost squat for test data.
Hmmmmm....
Will it start your airplane engine reliably? I don't know.
Will it work as a crossfeed/ground power contactor in your Lancair? I don't
know.
Will it work for 10,000 hours? I don't know.
Will it start your IO-550 at zero degC and 50 degC. I don't know.
What is the maximum time it can withstand 200A cranking at 50 degC? I don't
have a clue.
What happens if the ground guy uses two series batteries to start you cold
engine? I don't know.
Will it pass DO-160? Probably; but there are many unanswered questions.
Some things I know:
Weight: about one ounce. (The B&C S701-1 weighs 13 ounces).
Contact bounce none.
On current 30 milliamps or less.
Minimum operating (hold-on) voltage 6VDC appx.
Feedback is invited. I am easy to reach. And please check my website.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
Teamwork: "A lot of people doing exactly what I say."
(Marketing exec., Citrix Corp.)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Shielded magneto wires - Z Figures |
>
>Bob:
>
>I didn't get an answer on this so, if I may, I am asking again. I need a
>little help understanding if I should be using shielded magneto wires in some
>fashion. My LASAR control box which sits forward of the firewall has two low
>voltage unshielded wires marked "left magneto P lead" and "right magneto P
>lead."
>I have brought these non shielded wires into the cabin to my left magneto
>switch and my right magneto switch which ground these wires when the
>engine is
>shut down. No shielded wires in the circuit. Unison (the LASAR people)
>could
>not tell me if I needed shielded wires anywhere, but did say there is voltage
>in my two P lead wires even though there is no current flowing while my
>switches are open in the engine running position.
>
>I want the best possible installation.
>
>Questions: Should I run shielded wire from my switches through the firewall
>and splice them to the P leads on my LASAR control box? If this would be a
>better instillation, should I ground the shield at both ends or just one end?
What do the LASAR drawings show? Where there are installation instructions
for the system, those should be your first source of installation
data.
>Question: What is the electrostatic coupling of magneto noise you speak of
>in Note 3 of your book?
There are three coupling modes to get noise energy into our out of a wire.
Electrostatic - where the noise conductor and victim conductor are in close
proximity and insulation acts as the dielectric of a capacitor.
Electro-static
coupling is most conducive to the propagation of fast rising voltages like
those found on magneto p-leads. Shielding breaks this coupling mode.
Electro-magnetic coupling works on external magnetic fields that surround
a current carrying wire and therefor work on current magnitude, not
voltage. Electro-magnetic coupling is broken with techniques like twisted
pair outbound and return path sharing or concentric conductors (center
conductor
outbound, shield return) or by gross separation of potential
victim/antagonist
wires.
Radiated is another ball game entirely where wires serve as antennas
for both transmission and reception of noise energy. This propagation mode
rarely prevails in a small aircraft noise problem. Spark plug wires are the
most noteworthy radiators and are easily tamed by shielding or judicious
use of resistance/inductance/capacitors (filters) to damp the radiation
efficiency of the wire.
>I did get one response to my original post from a guy who did not use
>shielded wires with his LASAR, but he had the conventional start switch
>and claims to
>have "alternator" noise.
>
>A little help would be appreciated, thanks.
>
>Pete Hunt
>Clearwater, FL
>RV-6, finishing wiring
Good to hear from you my friend. I'd be skeptical of the other anecdotal
response. If there are errors of installation for the ignition system
that cause you problems, the problems will have nothing to do with the
alternator. I'd do exactly what the installation instructions tell you
to do with a 95% confidence that it's going to be okay as installed.
By the way, I'm thinking about offering a seminar in Clearwater again
perhaps next spring. I want to bring Dee with me this time. Are we going
to get a ride in your RV-6?
Bob . . .
---
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Locking female fast-ons |
on juliet
Those do look like the part numbers that I mentioned; which were
available from the Digi-key web site in lots of 10 a few months ago,
despite what the catalog may say. I can't vouch either way for the
quality - think they were Potter & Brumfield parts.
Ken
>snip
> Hmmmm . . . I guess I was thinking of the wrong 'locking' feature.
> I understand now that the question was about a the retaining barb
> that holds an installed terminal captive to the molded housing.
> The Digikey parts look like
>
> http://rocky.digikey.com/WebLib/Amp/Web%20Data/42281.pdf
>
>
> Looks like the minimum buy is 100 pieces.
> These terminals can be installed using tools like B&Cs
> BCT-1 which you can see at:
>
>http://bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?9X358218#BCT-
>
> Bob . . .
>
>
>
>
>>>
>>>Charlie
>>>I haven't followed this thread but I have in my hand what sounds like
>>>what you might be after.
>>>Digikey A27927CT for 14-18ga
>>>Digikey A27930CT for 12-16ga
>>>They are tin plated 1/4" female pushons that lock into digikey PB16
>>>sockets for 5 pin VF4 series relays among others.
>>>Ken
>>>
>>>
>
>
________________________________________________________________________________
| From: | "Werner Schneider" <wernerschneider(at)compuserve.com> |
| Subject: | Re: Shielded magneto wires - Z Figures |
> >I did get one response to my original post from a guy who did not use
> >shielded wires with his LASAR, but he had the conventional start switch
> >and claims to
> >have "alternator" noise.
>
> Good to hear from you my friend. I'd be skeptical of the other
anecdotal
> response. If there are errors of installation for the ignition system
> that cause you problems, the problems will have nothing to do with the
> alternator. I'd do exactly what the installation instructions tell you
> to do with a 95% confidence that it's going to be okay as installed.
>
Hi Bob and Peter,
I have some Alternator whining but is nearly not remarkable at all and I do
not blame it on the wiring of the ignition. The original installation
instruction
of the Lasar does show it as a twisted wire which I did.
Werner
________________________________________________________________________________
| From: | "Werner Schneider" <wernerschneider(at)compuserve.com> |
| Subject: | Re: Shielded magneto wires - Z Figures |
> Hi Bob and Peter,
>
> I have some Alternator whining but is nearly not remarkable at all and I
do
> not blame it on the wiring of the ignition. The original installation
> instruction
> of the Lasar does show it as a twisted wire which I did.
>
> Werner
>
Forgot to mention, I believe it is the alternator as when I increase load
(switch things on) the sound changes.
Werner
________________________________________________________________________________
| From: | "James Foerster" <jmfpublic(at)comcast.net> |
| Subject: | Re: Simplification-reducing elec load so can use 35amp |
PM alternator [ was
David,
I've been following this thread, and it occurs to me that you could go to the standard
Z-14 architecture by using low-current versions of the standard contactor.
I have one of these, and I measured 125 ma current draw, with an in-rush
of about 2 amps. These are extensively specified because they are used for electric
vehicles, and if I recall, can pass 600 amps for 30 sec, and 200 amps
long term. This has been mentioned on the list before: Oct 2002.
"...the source of the low power contactor. It
is made by Kilovac, which was bought by Tyco-and thus the site is harder to navigate.
The model that you would want is the EV200AAANA. This is $67.61 from
onlinecomponents.com , which is one of the distributors."
By using the Z-14 diagram, you would have the benefit of using something examined
by many people and refined to its present state. Also, construction and maintainance
would be easier.
Jim Foerster, J400, Z14 user(modified for one field alternator and one PM type.)
________________________________________________________________________________
| From: | "James Foerster" <jmfpublic(at)comcast.net> |
| Subject: | Re: Simplification-reducing elec load so can use 35amp |
PM alternator [ was
David,
Here is the link to the spec sheet.
http://relays.tycoelectronics.com/datasheets/ev200.pdf
If this does not work, use 'kilovac' on the tyco website, or 'ev200' to get to
the data. The links in the 2002 post were out of date.
Jim Foerster
________________________________________________________________________________
| From: | SportAV8R(at)aol.com |
| Subject: | Re: Solid state contactors, OVP |
Where's the info on PerihelionDesign's non-crowbar approach to regulation
and OVP? Website?
That's where I got it... www.periheliondesign.com
I'm planning to contact Eric directly and ask the state of his hi-current solid
state relay developments. Website says they're in testing at 6 sites.
-Bill
________________________________________________________________________________
| From: | SportAV8R(at)aol.com |
| Subject: | Re: Solid state contactors, OVP |
Eric: is the powerlink technology bidirectional, as in non-polarized for cross-feed?
Cost for the big one?
Thanks,
-Bill B
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: Solid state contactors, OVP |
>Eric: is the powerlink technology bidirectional, as in non-polarized for
cross-feed?
>Cost for the big one?
>Thanks,-Bill B
The stock item is one-direction. Custom order can be bidirectional. Hell,
since they don't yet really exist, custom item can be thermo-nuclear
powered. Or is that thermu-nuculur?
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
"You can't have a new boomerang until you throw your old one away."
--Bernie
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Solid state contactors, OVP |
>
>Eric: is the powerlink technology bidirectional, as in non-polarized for
>cross-feed? Cost for the big one?
>
>Thanks,
>
>-Bill B
battery contactors need to be bi-directional too . . . ya gotta
charge and discharge the battery through the same device.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Shielded magneto wires - Z Figures |
>
>
> > Hi Bob and Peter,
> >
> > I have some Alternator whining but is nearly not remarkable at all and I
>do
> > not blame it on the wiring of the ignition. The original installation
> > instruction
> > of the Lasar does show it as a twisted wire which I did.
> >
> > Werner
> >
>Forgot to mention, I believe it is the alternator as when I increase load
>(switch things on) the sound changes.
aha! excellent data point. This almost always points to
a ground loop. You have more than one ground for avionics/audio
equipment that's reading high current ground returns for high
current equipment like landing lights, pitot heat, etc.
Bob . . .
---
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Z-13 - latest version of 'simplification' |
I've learned some more about Autocad (Intellicad actually) and figured out
how to use the symbol "blocks", etc.
- Wasn't able to eliminate the "alternator switch" and only use the CB.
Reason: The OVM's relay coils are hooked up to the batt bus so it would
suck the battery dry unless there's a switch to disconnect the coil after
engine shutdown/overnight, etc. I don't want to use the CB after every
shutdown - rather "use a switch for a switch - not a CB".
I printed my dwg file as pdf and re-posted to my website. Hope to get some
feedback form 'Lectric Bob and others.
- Especially what I did to the Endurance Bus circuit. I don't like
diodes - they fail, even though they are said to be "solid state, highly
reliable". My experience is otherwise. Rather use a simple switch to
select how the E-bus gets fed when the electrons hit the fan.
http://www.datarecall.net/~dcarter/Builder's%20Log.html
David
________________________________________________________________________________
| From: | "Werner Schneider" <wernerschneider(at)compuserve.com> |
| Subject: | Re: Shielded magneto wires - Z Figures |
> > >
> >Forgot to mention, I believe it is the alternator as when I increase load
> >(switch things on) the sound changes.
>
> aha! excellent data point. This almost always points to
> a ground loop. You have more than one ground for avionics/audio
> equipment that's reading high current ground returns for high
> current equipment like landing lights, pitot heat, etc.
>
Hello Bob,
interesting, I followed the recommendation and grounded each and every
equipment to the single 48-tab ground block from B&C, but my panel is metal
and the avionics rack are directly screwed onto the aluminum as well as the
whole panel is hinged on the metal cage, I added a separate ground from the
tab block to the panel but no change. The Battery is connected with a 2AWG
cable to the ground tab, on the other side of the firewall a braided cable
is going to the engine crankcase.
As told the noise is very low and maybe only audible to me because of the
ANR headset.
What is the best way to tackle this? Should I build the milliohmmeter from
Figure 5-3 to investigate and where to lock first, what about if the noise
is not there with stopped engine (have to listen next time).
Thanks Werner
________________________________________________________________________________
| From: | Walter Tondu <walter(at)tondu.com> |
| Subject: | Re: Shielded magneto wires - Z Figures |
On 09/01 11:19, Werner Schneider wrote:
>
> > > >
> > >Forgot to mention, I believe it is the alternator as when I increase load
> > >(switch things on) the sound changes.
> >
> > aha! excellent data point. This almost always points to
> > a ground loop. You have more than one ground for avionics/audio
> > equipment that's reading high current ground returns for high
> > current equipment like landing lights, pitot heat, etc.
> >
> Hello Bob,
>
> interesting, I followed the recommendation and grounded each and every
> equipment to the single 48-tab ground block from B&C, but my panel is metal
> and the avionics rack are directly screwed onto the aluminum as well as the
> whole panel is hinged on the metal cage, I added a separate ground from the
> tab block to the panel but no change. The Battery is connected with a 2AWG
> cable to the ground tab, on the other side of the firewall a braided cable
> is going to the engine crankcase.
>
> As told the noise is very low and maybe only audible to me because of the
> ANR headset.
>
> What is the best way to tackle this? Should I build the milliohmmeter from
> Figure 5-3 to investigate and where to lock first, what about if the noise
> is not there with stopped engine (have to listen next time).
Are both Mags grounded to the ground block as well?
--
Walter Tondu
http://www.rv7-a.com
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Locking female fast-ons |
Ken
Eureka! You've found it. Now that I know that the correct terminology is
"fast-in, fast-on", I'll have no trouble finding these. Thanks. I was
actually looking for the females for 22/18 AWG, which are on the same page
as the terminals you mention.
22/18 AWG Digikey # A27933CT AMP # 60295-2
It's nice to know that they even make these to handle up to 12 AWG. I had
already located the larger gauge terminals at www.waytekwire.com
Thanks again
Charlie Kuss
Now if Hurricane Francine leaves me and my RV-8A project intact, I might
just get this thing wired!
Boca Raton, Florida
>
>Charlie
>I haven't followed this thread but I have in my hand what sounds like
>what you might be after.
>Digikey A27927CT for 14-18ga
>Digikey A27930CT for 12-16ga
>They are tin plated 1/4" female pushons that lock into digikey PB16
>sockets for 5 pin VF4 series relays among others.
>Ken
>
>Charlie Kuss wrote:
>
>
> >
> >David
> > Thanks for your efforts on my behalf. However, push ons are not what I'm
> >looking for. What I WANT, is called "push to lock". These are a variant of
> >the more common "push ons" you refer to below. The "push to lock" females
> >have a U shaped area cut from the back (flat) side of the terminal's
> >contact area. This area is bent out. When pushed into a matching socket,
> >the terminal is trapped in the socket by this tab. See
> >
> >
>
>
________________________________________________________________________________
| From: | Charlie Kuss <chaztuna(at)adelphia.net> |
| Subject: | Re: Locking female fast-ons |
Bob,
The problem is not knowing the proper terminology for a product. Looking
in DigiKey, Mouser or Allied's catalogs when you don't know what the item
is called, is daunting. Thanks for everyone's patient help. Color me a
"happy camper" :-)
Charlie Kuss
>
>
>
> >
> >
> >
> > I've run numerous tests and demonstrations for resistance
> > to vibration and the "non locking" variety fast-on terminals
> > are entirely adequate for our applications. All of the PIDG
> > fast-on females feature a locking pip that will increase
> > retention force on male terminals that also feature the right
> > detent . . . yeah, it's pretty good idea but the difference
> > is not worth worrying about.
> >
> > Bob . . .
>
> Hmmmm . . . I guess I was thinking of the wrong 'locking' feature.
> I understand now that the question was about a the retaining barb
> that holds an installed terminal captive to the molded housing.
> The Digikey parts look like
>
> http://rocky.digikey.com/WebLib/Amp/Web%20Data/42281.pdf
>
>
> Looks like the minimum buy is 100 pieces.
> These terminals can be installed using tools like B&Cs
> BCT-1 which you can see at:
>
>http://bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?9X358218#BCT-
>
> Bob . . .
>
>
> > >
> > >Charlie
> > >I haven't followed this thread but I have in my hand what sounds like
> > >what you might be after.
> > >Digikey A27927CT for 14-18ga
> > >Digikey A27930CT for 12-16ga
> > >They are tin plated 1/4" female pushons that lock into digikey PB16
> > >sockets for 5 pin VF4 series relays among others.
> > >Ken
> > >
> > >Charlie Kuss wrote:
> > >
> > >
> > > >
> > > >David
> > > > Thanks for your efforts on my behalf. However, push ons are not
> what I'm
> > > >looking for. What I WANT, is called "push to lock". These are a
> variant of
> > > >the more common "push ons" you refer to below. The "push to lock"
> females
> > > >have a U shaped area cut from the back (flat) side of the terminal's
> > > >contact area. This area is bent out. When pushed into a matching socket,
> > > >the terminal is trapped in the socket by this tab. See
> > > >
> > > >
> > >
> > >
> > >---
> >
> >
> > 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
> >
> >
> >---
> >
> >
> >---
>
>
> 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: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: Simplification-reducing elec load so can use |
35amp PM alternator [ was
James, that little beauty costs $167.61, not $67... used in hi pwr mil apps
(according to Tycoelectronics website). Like someone else said recently and
it applies to me: "You didn't specify cost as a factor"! But it really is.
Thanks for the other feedback. I'll check it out.
David
----- Original Message -----
From: "James Foerster" <jmfpublic(at)comcast.net>
Subject: AeroElectric-List: Re: Simplification-reducing elec load so can use
35amp PM alternator [ was
>
> David,
>
> I've been following this thread, and it occurs to me that you could go to
the standard Z-14 architecture by using low-current versions of the standard
contactor. I have one of these, and I measured 125 ma current draw, with an
in-rush of about 2 amps. These are extensively specified because they are
used for electric vehicles, and if I recall, can pass 600 amps for 30 sec,
and 200 amps long term. This has been mentioned on the list before: Oct
2002.
>
> "...the source of the low power contactor. It
> is made by Kilovac, which was bought by Tyco-and thus the site is harder
to navigate.
> The model that you would want is the EV200AAANA. This is $67.61 from
> onlinecomponents.com , which is one of the distributors."
> Jim Foerster, J400, Z14 user(modified for one field alternator and one PM
type.)
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> . . . |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved |
. . .
. . .
>
>Interesting.
>
>ALL the tools I have seen designed for the Tefzel wire and the associated
>PIDG terminals, have different dies for the wire crimp VS the insulation
>crimp. Also PIDG terminals typically have different insulation allowances
>(typically two or more commonally available allowances for the same terminal
>style and wire size) in any wire AWG size.
>In any event always test any different terminal to wire combo and do a pull
>test (to wire failure).
>
>Paul
Paul is correct in that you cannot rely on the statements
of tool and terminal manufacturers to insure compatibility
of products - ESPECIALLY when the tool manufacturer and
terminal manufacturer are different folks. These pictures
illustrate one example of what might be called a fairly
universal tool.
http://www.aeroelectric.com/Pictures/67A.jpg
http://www.aeroelectric.com/Pictures/68A.jpg
These pictures are the business end of a t-head AMP tool
I bought almost exactly 40 years ago. It features an adjustable
wire-grip die set. Most of my AMP tools have adjustable
wire-grip dies although the t-head has the widest range.
Lot cost tools like the one that started this thread
never have adjustable insulation grip dies . . . so one
needs to be more selective.
When I offered the low cost tool for the first time about
6 years ago, I tested the tool with AMP PIDG terminals
on tefzel wire and found the combination adequate. About
a year ago, I got some samples of terminals from JST in
Japan. These are mil-qualified but when tested with the
tool I sold, produced results I didn't want to sell.
See:
http://www.aeroelectric.com/Pictures/JST_Samples.jpg
The upper terminal was a JST, the lower is AMP PIDG.
I was disappointed because the JST terminals were about
half the cost of PIDG . . .
The idea behind the shop notes at:
http://www.aeroelectric.com/articles/CrimpTools/crimptools.html
was to reinforce the simple ideas about successful
terminal installation. Unless you're using tools mated
to terminal by the same manufacturer, it's a good idea to
be treat the combination with suspicion until you confirm
that the terminals, tool and wire are suited for the
task. It's not difficult if you take time to understand
what's needed.
Bob . . .
---
________________________________________________________________________________
| From: | "Werner Schneider" <wernerschneider(at)compuserve.com> |
| Subject: | Re: Shielded magneto wires - Z Figures |
> > > aha! excellent data point. This almost always points to
> > > a ground loop. You have more than one ground for avionics/audio
> > > equipment that's reading high current ground returns for high
> > > current equipment like landing lights, pitot heat, etc.
> > >
> > Hello Bob,
> >
> > interesting, I followed the recommendation and grounded each and every
> > equipment to the single 48-tab ground block from B&C, but my panel is
metal
> > and the avionics rack are directly screwed onto the aluminum as well as
the
> > whole panel is hinged on the metal cage, I added a separate ground from
the
> > tab block to the panel but no change. The Battery is connected with a
2AWG
> > cable to the ground tab, on the other side of the firewall a braided
cable
> > is going to the engine crankcase.
> >
> > As told the noise is very low and maybe only audible to me because of
the
> > ANR headset.
> >
>
> Are both Mags grounded to the ground block as well?
Hello Walter,
as I'm using a Lasar Ignition the game is a tad different, the Ignition Box
is grounded to the block as well as the magneto wires coming from the box
via the magneto/starter switch.
Werner
________________________________________________________________________________
| From: | N1deltawhiskey(at)aol.com |
> ... a simple pad ...
For the benefit of the clueless (me), what are we talking about here?
Thanks,
Doug Windhorn
________________________________________________________________________________
| From: | "Ron Koyich" <Ron(at)Koyich.com> |
>>> ... a simple pad ...<<
A resistive attenuator which 'pads down' the signal.
See: http://www.mcsquared.com/dbframe.htm for instance.
REK
________________________________________________________________________________
| From: | "James Foerster" <jmfpublic(at)comcast.net> |
| Subject: | Aircraft receivers |
Does anyone have any experience with the XCOM 760, available from
Aircraft Spruce? It is made by Micheal Coates out of Australia, and
seems to be loosely based on the Micro Air 760. It seems to have
advantages, in that it has a VOX circuit rather than 'hot mike' that
Micro Air uses. It is priced just under $1000 now, as is the iCom
ic-A200. The iCom looks nice, but I recall at least one negative
comment about ignition noise--which may be very antenna and plane
specific. Any comments?
The web page comparing the XCOM to others is
http://www.mcp.com.au/xcom760/comparison/comparison.html
________________________________________________________________________________
| From: | Mickey Coggins <mick-matronics(at)rv8.ch> |
| Subject: | Re: Aircraft receivers |
Hi,
I have read at least one positive PIREP on the "RVs_in_Aus"
yahoo group.
Mickey
>Does anyone have any experience with the XCOM 760, available from
>Aircraft Spruce? It is made by Micheal Coates out of Australia, and
>seems to be loosely based on the Micro Air 760. It seems to have
>advantages, in that it has a VOX circuit rather than 'hot mike' that
>Micro Air uses. It is priced just under $1000 now, as is the iCom
>ic-A200. The iCom looks nice, but I recall at least one negative
>comment about ignition noise--which may be very antenna and plane
>specific. Any comments?
--
Mickey Coggins
http://www.rv8.ch/
#82007 QB Wings/Fuselage
________________________________________________________________________________
| From: | Walter Tondu <walter(at)tondu.com> |
| Subject: | Re: Shielded magneto wires - Z Figures |
On 09/02 6:49, Werner Schneider wrote:
>
> > > > aha! excellent data point. This almost always points to
> > > > a ground loop. You have more than one ground for avionics/audio
> > > > equipment that's reading high current ground returns for high
> > > > current equipment like landing lights, pitot heat, etc.
> > > >
> > > Hello Bob,
> > >
> > > interesting, I followed the recommendation and grounded each and every
> > > equipment to the single 48-tab ground block from B&C, but my panel is
> metal
> > > and the avionics rack are directly screwed onto the aluminum as well as
> the
> > > whole panel is hinged on the metal cage, I added a separate ground from
> the
> > > tab block to the panel but no change. The Battery is connected with a
> 2AWG
> > > cable to the ground tab, on the other side of the firewall a braided
> cable
> > > is going to the engine crankcase.
> > >
> > > As told the noise is very low and maybe only audible to me because of
> the
> > > ANR headset.
> > >
> >
> > Are both Mags grounded to the ground block as well?
>
> Hello Walter,
>
> as I'm using a Lasar Ignition the game is a tad different, the Ignition Box
> is grounded to the block as well as the magneto wires coming from the box
> via the magneto/starter switch.
I have the LASAR ignition as well and each magneto has a grounding
strap. Doesn't yours?
--
Walter Tondu
http://www.rv7-a.com
________________________________________________________________________________
| From: | Harley <harley(at)AgelessWings.com> |
| Subject: | Re: Aircraft receivers |
I had considered that model...but just received my Microair M760 yesterday!
The Xcom does look like it has some better features, but I was as much
concerned with price...and Microair had the best deal (IMHO) with their
combo package that included everything including the transponder,
transceiver, VOX intercom, encoder and cables and antenna for $2700 US.
That's a considerable discount from Micrtoir's individual prices, with
an additional 5% from OxAero in Mississippi where I bought it.
http://www.oxaero.com/Microair-ComboKits.asp
And with the fine reputation that Microair has acheived in the field, I
didn't want to take a chance with the new kid on the block...it may be
better, but I didn't want to be the one to find out that it isn't.
Harley Dixon
www.agelesswings.com
James Foerster wrote:
>
>Does anyone have any experience with the XCOM 760, available from
>Aircraft Spruce? It is made by Micheal Coates out of Australia, and
>seems to be loosely based on the Micro Air 760. It seems to have
>advantages, in that it has a VOX circuit rather than 'hot mike' that
>Micro Air uses. It is priced just under $1000 now, as is the iCom
>ic-A200. The iCom looks nice, but I recall at least one negative
>comment about ignition noise--which may be very antenna and plane
>specific. Any comments?
>
>The web page comparing the XCOM to others is
>http://www.mcp.com.au/xcom760/comparison/comparison.html
>
>
>
>
________________________________________________________________________________
| From: | "Werner Schneider" <wernerschneider(at)compuserve.com> |
| Subject: | Re: Shielded magneto wires - Z Figures |
> > Hello Walter,
> >
> > as I'm using a Lasar Ignition the game is a tad different, the Ignition
Box
> > is grounded to the block as well as the magneto wires coming from the
box
> > via the magneto/starter switch.
>
> I have the LASAR ignition as well and each magneto has a grounding
> strap. Doesn't yours?
>
Hello Walter,
yes, every magneto has a bonding strap to the crankcase housing.
Werner
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
On Sep 2, 2004, at 1:15 AM, N1deltawhiskey(at)aol.com wrote:
>
>
>> ... a simple pad ...
>
> For the benefit of the clueless (me), what are we talking about here?
The signal as it comes from the car stereo is much too high for the
music input of the audio panel so it must be reduced. A 'pad' is a
combination of resistors that reduces the signal by a set amount while
still maintaining the proper resistances that the two devices expect to
see. The output of the car stereo is probably on the order of 24V
peak-to-peak at full output and the maximum input to the audio panel is
probably on the order of 2V peak-to-peak. Something needs to cut the
signal voltage down by a factor of 10 or so (20dB).
But there is a second problem that renders the pad undesirable in this
application and makes the transformer more desirable. The speaker
outputs of most car stereos are balanced (bridged actually). The
outputs at the speaker leads are equal and opposite in phase so you
don't have one lead at ground. Both leads are above ground but
opposite in polarity, i.e. when the signal on one speaker lead is
momentarily at +10V the other lead is at -10V leaving you with 20V
between the two leads. There is no ground reference. They do this
because you can get four times the power, approximately 20W, from a 12V
supply when you do this.
Unlike the pad, the transformer works regardless of the ground
reference. Both sides of the transformer may have different ground
references and still work just fine. Since there is no common ground
to both sides the transformer may also be used to break a ground-loop.
In this application the original poster (sorry, I forget who posted the
original question) had purchased 500 ohm to 8 ohm coupling transformers
from Radio Shack. The problem here is, if they hook the 8 ohm side to
the car stereo the output voltage at the 500 ohm side will be *way* too
high. The trick is to connect the transformer "backwards", i.e.
connect the 500 ohm side to the car stereo speaker leads and the 8 ohm
side to the audio panel music input. Now the transformer becomes a
step-down transformer.
The voltage ratio of the transformer is the ratio of the square roots
of the impedances or about 8:1 in the case of a 500 ohm to 8 ohm
transformer [ sqrt(500)/sqrt(8) ]. That is about the right ratio of
signal output at the speaker lead of the car stereo to signal input to
the audio panel. The amplifiers in car stereos are basically power
op-amps and are stable without a load so you don't need to put an 8-ohm
load on the amplifier to make it work properly.
As Bob suggested, the transformers are quite simple and solve the
problem nicely. This solution will probably horrify any tweak
audiophile worth his or her salt but given the low-fidelity nature of
most aviation headphones and the low-fidelity nature of automobile
audio electronics, the quality of the transformers is probably not
really an issue.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | Gerry Holland <gnholland(at)onetel.com> |
Brian Hi!
> For the benefit of the clueless (me), what are we talking about here?
Great explanation on Audio. Many Thanks
Gerry
Europa 384 G-FIZY
Trigear with Rotax 912 and Arplast CS Prop.
Engine very near to starting.
Painting completed. Vinyl design scheme to be added.
Completing Wiring to Panel.
Dynon EFIS, KMD 150, Icom A-200 and SL70 Transponder. AoA Fitted.
Shoulder Width Mod. Heater Unit constructed and fitted.
http://www.g-fizy.com
+44 7808 402404
gnholland(at)onetel.com
________________________________________________________________________________
| From: | PeterHunt1(at)aol.com |
| Subject: | Shielded magneto wires - Z Figures |
Bob and others:
I still need some help. Concerning my question as to how/if to use shielded
wires on my magneto P leads coming from my LASAR control box, Bob N. responds
"What do the LASAR drawings show? Where there are illustration instructions
for the system, those should be your first source of installation data."
The drawings show the LASAR control box mounted in the engine compartment
with the blue left magneto P lead and green right magneto P lead coming into the
cockpit. A "dot" at the end of each of these lines suggests termination
points which I can only assume is a switch. The drawing does not suggest shielded
wires. Now, on the next page are the written instructions which imply the use
of a conventional (all in one) start switch, not left and right magneto
switches like I have. The instructions read as follows:
"Attach the left P-lead switch wire to the blue wire in the LASAR low
voltage control harness. NOTE: Ensure shielding on P-lead does not ground P-lead
at splice. Attach the right P-lead switch to the green wire in the LASAR low
voltage control harness. NOTE: Ensure shielding on P-lead switch wire does
not ground P-lead at splice."
Now to me that suggests there are shielded wires in use. My question
remains. Do I need shielded wire through the cockpit all the way to the LASAR
control box to the two p-leads out of the box or may I run the two unshielded LASAR
P-lead out to my switches? So I called Unison Industries (makers of LASAR).
After a long discussion their answer was "we don't know." They did point out
that even with my magneto switches open during engine running there is voltage
in the P-leads, just no current flowing. That is when I called for help on
this list.
Thanks again Werner for your response. Wener didn't shield his LASAR wires.
How about the others of you who have LASAR systems???? What did you do?
Yes, Bob, you are always welcome here in Clearwater. Stay with me as before
and do bring Dee with you. My RV-6 may be flying by late spring and if I have
flown my test time off you are welcome to a ride. If not, we can do some
sailing.
Pete Hunt
Clearwater, FL
RV-6 close to finished
________________________________________________________________________________
| From: | f1rocket(at)comcast.net |
| Subject: | Re: Shielded magneto wires - Z Figures |
I did not use shielded wire to connect up my LASAR system in my RV-6. I used the
wire loom provided in the kit and wired directly to my keyed ignition switch.
I did not have any problem with noise in my audio system. The airplane was
wired per Bob's suggestions in the Connection.
Go ahead and wire them up to your separate toggle switches and forget about it.
Randy
F1 Rocket
http://f1rocket.home.comcast.net/
-------------- Original message --------------
>
> Bob and others:
>
> I still need some help. Concerning my question as to how/if to use shielded
> wires on my magneto P leads coming from my LASAR control box, Bob N. responds
> "What do the LASAR drawings show? Where there are illustration instructions
> for the system, those should be your first source of installation data."
>
> The drawings show the LASAR control box mounted in the engine compartment
> with the blue left magneto P lead and green right magneto P lead coming into
the
> cockpit. A "dot" at the end of each of these lines suggests termination
> points which I can only assume is a switch. The drawing does not suggest
> shielded
> wires. Now, on the next page are the written instructions which imply the use
> of a conventional (all in one) start switch, not left and right magneto
> switches like I have. The instructions read as follows:
>
> "Attach the left P-lead switch wire to the blue wire in the LASAR low
> voltage control harness. NOTE: Ensure shielding on P-lead does not ground
> P-lead
> at splice. Attach the right P-lead switch to the green wire in the LASAR low
> voltage control harness. NOTE: Ensure shielding on P-lead switch wire does
> not ground P-lead at splice."
>
> Now to me that suggests there are shielded wires in use. My question
> remains. Do I need shielded wire through the cockpit all the way to the LASAR
> control box to the two p-leads out of the box or may I run the two unshielded
> LASAR
> P-lead out to my switches? So I called Unison Industries (makers of LASAR).
> After a long discussion their answer was "we don't know." They did point out
> that even with my magneto switches open during engine running there is voltage
> in the P-leads, just no current flowing. That is when I called for help on
> this list.
>
> Thanks again Werner for your response. Wener didn't shield his LASAR wires.
> How about the others of you who have LASAR systems???? What did you do?
>
> Yes, Bob, you are always welcome here in Clearwater. Stay with me as before
> and do bring Dee with you. My RV-6 may be flying by late spring and if I have
> flown my test time off you are welcome to a ride. If not, we can do some
> sailing.
>
> Pete Hunt
> Clearwater, FL
> RV-6 close to finished
>
>
>
>
>
>
I did not use shielded wire to connect up my LASAR system in my RV-6. I used the
wire loom provided in the kit and wired directly to my keyed ignition switch.
I did not have any problem with noise in my audio system. The airplane was wired
per Bob's suggestions in the Connection.
Go ahead and wire them up to your separate toggle switches and forget about it.
Randy
F1 Rocket
http://f1rocket.home.comcast.net/
-------------- Original message --------------
-- AeroElectric-List message posted by: PeterHunt1(at)aol.com
Bob and others:
I still need some help. Concerning my question as to how/if to use shielded
wires on my magneto P leads coming from my LASAR control box, Bob N. responds
"What do the LASAR drawings show? Where there are illustration instructions
for the system, those should be your first source of installation data."
The drawings show the LASAR control box mounted in the engine compartment
with the blue left magneto P lead and green right magneto P lead coming into the
cockpit. A "dot" at the end of each of these lines suggests termination
points which I can only assume is a switch. The drawing does not suggest
shielded
wires. Now, on the next p
age are the written instructions which imply the use
of a conventional (all in one) start switch, not left and right magneto
switches like I have. The instructions read as follows:
"Attach the left P-lead switch wire to the blue wire in the LASAR low
voltage control harness. NOTE: Ensure shielding on P-lead does not ground
P-lead
at splice. Attach the right P-lead switch to the green wire in the LASAR low
voltage control harness. NOTE: Ensure shielding on P-lead switch wire does
not ground P-lead at splice."
Now to me that suggests there are shielded wires in use. My question
remains. Do I need shielded wire through the cockpit all the way to the LASAR
control box to the two p-leads out of the box or may I run the two unshielded
LASAR
P-lead out to my switches? So I called Unison Industries (makers of LASAR).
After a long discussion
their answer was "we don't know." They did point out
that even with my magneto switches open during engine running there is voltage
in the P-leads, just no current flowing. That is when I called for help on
this list.
Thanks again Werner for your response. Wener didn't shield his LASAR wires.
How about the others of you who have LASAR systems???? What did you do?
Yes, Bob, you are always welcome here in Clearwater. Stay with me as before
and do bring Dee with you. My RV-6 may be flying by late spring and if I have
flown my test time off you are welcome to a ride. If not, we can do some
sailing.
Pete Hunt
Clearwater, FL
RV-6 close to finished
gh the Contributions
_
-= Photo Share: http://www.matronics.com/photoshare
________________________________________________________________________________
| From: | "DAVID REEL" <dreel(at)cox.net> |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved . . . |
Mystery not solved! I certainly did not put the terminals in the tool backwards.
Buzz returned the terminal with the bad crimp that I sent him & I'm sending
it to you. You will note that the deep crimp is where it should be on the terminal
side of the barrel. I'm also sending a crimp Buzz sent me along with
a replacement tool. I figure he thought the problem was having a bad example
of the tool. Just feeling the two crimps shows how much deeper the indentations
in Buzz's good crimp are compared to mine. Now if you got a good crimp using
my tool, that leaves only the terminal as suspect. I look forward to hearing
what you think when you get the terminal. Buzz's crimp also captures the tefzel
much better than mine.
Dave Reel - RV8A
________________________________________________________________________________
| From: | Phil Birkelbach <phil(at)petrasoft.net> |
| Subject: | Re: Z-13 - latest version of 'simplification' |
The thing that jumps out at me on your modification is that you have
created a single point of failure for your endurance buss with the
switch. A better solution would be two switches. One for the main feed
and the other for the battery buss feed. Actually a better solution
would be the diode. I agree that diodes do fail, but in my experience
switches fail more often than diodes. I would be curious what your
experience with diodes is that causes you to believe that a switch is
more reliable.
Another problem with the single switch is that you will have a
millisecond or two where there is no voltage. I imagine that this
probably won't cause any grief.
There is also an unprotected wire between the main buss and your e-buss
switch. This wire is unprotected in the original architecture as well
but it is assumed that the diode is physically close to both busses.
You will most likely mount that switch on the panel, which will make the
wire longer than 6" and therefore it will need to be protected. If you
replace the single switch with two switches you will also have to
protect both wires from both ends of both switches because they will all
be too long and will have the potential to be powered from both ends.
It seems to me the parts count is increasing at an alarming rate and
this decreases reliablity in any system.
Godspeed,
Phil Birkelbach - Houston Texas
RV-7 N727WB (Reserved) - Panel
http://www.myrv7.com
David Carter wrote:
>
>I've learned some more about Autocad (Intellicad actually) and figured out
>how to use the symbol "blocks", etc.
> - Wasn't able to eliminate the "alternator switch" and only use the CB.
>Reason: The OVM's relay coils are hooked up to the batt bus so it would
>suck the battery dry unless there's a switch to disconnect the coil after
>engine shutdown/overnight, etc. I don't want to use the CB after every
>shutdown - rather "use a switch for a switch - not a CB".
>
>I printed my dwg file as pdf and re-posted to my website. Hope to get some
>feedback form 'Lectric Bob and others.
> - Especially what I did to the Endurance Bus circuit. I don't like
>diodes - they fail, even though they are said to be "solid state, highly
>reliable". My experience is otherwise. Rather use a simple switch to
>select how the E-bus gets fed when the electrons hit the fan.
>
>http://www.datarecall.net/~dcarter/Builder's%20Log.html
>
>David
>
>
>
>
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: Z-13 - latest version of 'simplification' |
Phil,
Good & helpful observations.
OK, perhaps someone can help me "increase my confidence in diodes". Before
that, I figure the switch in my current Z-13 will only be used once or twice
in my lifetime and its lifetime. So I don't think "reliability of switches"
is even an issue. I'm surely not worried about it "shorting" across any of
its terminals in normal use (unactuated, just a static failure).
But parts count is a good issue. So, what "range of options" do I have on
the diode, installed as per original Z-13? I know that resistors have
"watts" ratings. How about diodes? What would be a good diode to use?
Would like to see its specs on a supplier's web site or some such.
David
----- Original Message -----
From: "Phil Birkelbach" <phil(at)petrasoft.net>
Subject: Re: AeroElectric-List: Z-13 - latest version of 'simplification'
>
> The thing that jumps out at me on your modification is that you have
> created a single point of failure for your endurance buss with the
> switch. A better solution would be two switches. One for the main feed
> and the other for the battery buss feed. Actually a better solution
> would be the diode. I agree that diodes do fail, but in my experience
> switches fail more often than diodes. I would be curious what your
> experience with diodes is that causes you to believe that a switch is
> more reliable.
>
> Another problem with the single switch is that you will have a
> millisecond or two where there is no voltage. I imagine that this
> probably won't cause any grief.
>
> There is also an unprotected wire between the main buss and your e-buss
> switch. This wire is unprotected in the original architecture as well
> but it is assumed that the diode is physically close to both busses.
> You will most likely mount that switch on the panel, which will make the
> wire longer than 6" and therefore it will need to be protected. If you
> replace the single switch with two switches you will also have to
> protect both wires from both ends of both switches because they will all
> be too long and will have the potential to be powered from both ends.
> It seems to me the parts count is increasing at an alarming rate and
> this decreases reliablity in any system.
>
> Godspeed,
>
> Phil Birkelbach - Houston Texas
> RV-7 N727WB (Reserved) - Panel
> http://www.myrv7.com
>
>
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Z-13 - latest version of 'simplification' |
On Sep 2, 2004, at 12:19 PM, David Carter wrote:
> OK, perhaps someone can help me "increase my confidence in diodes".
> Before
> that, I figure the switch in my current Z-13 will only be used once or
> twice
> in my lifetime and its lifetime. So I don't think "reliability of
> switches"
> is even an issue. I'm surely not worried about it "shorting" across
> any of
> its terminals in normal use (unactuated, just a static failure).
Switches need to switch on a regular basis to keep the contacts clean
and reliable. A switch that sits in one position is asking for a
failure.
A diode has no moving parts and no place for potential oxidation (if
installed properly). It will just last a lot longer.
> I know that resistors have "watts" ratings. How about diodes?
They have a watts rating too but because their voltage drop is
relatively constant they are rated in amps. Schottky type diodes have
a lower forward voltage drop so they can handle more current in the
same package before dissipating the same amount or power.
> What would be a good diode to use?
I prefer Schottky power rectifier diodes. Bob likes the old
tried-n-true silicon rectifiers. I prefer the 0.3V drop to the 0.7+V
drop of the plain silicon rectifier. You pays yer money and you takes
yer choice.
> Would like to see its specs on a supplier's web site or some such.
It depends on your load in amps. How much is your e-buss going to draw
when it is fully loaded?
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Z-13 - latest version of 'simplification' |
On Sep 2, 2004, at 12:19 PM, David Carter wrote:
> OK, perhaps someone can help me "increase my confidence in diodes".
> Before
> that, I figure the switch in my current Z-13 will only be used once or
> twice
> in my lifetime and its lifetime. So I don't think "reliability of
> switches"
> is even an issue. I'm surely not worried about it "shorting" across
> any of
> its terminals in normal use (unactuated, just a static failure).
Switches need to switch on a regular basis to keep the contacts clean
and reliable. A switch that sits in one position is asking for a
failure.
A diode has no moving parts and no place for potential oxidation (if
installed properly). It will just last a lot longer.
> I know that resistors have "watts" ratings. How about diodes?
They have a watts rating too but because their voltage drop is
relatively constant they are rated in amps. Schottky type diodes have
a lower forward voltage drop so they can handle more current in the
same package before dissipating the same amount or power.
> What would be a good diode to use?
I prefer Schottky power rectifier diodes. Bob likes the old
tried-n-true silicon rectifiers. I prefer the 0.3V drop to the 0.7+V
drop of the plain silicon rectifier. You pays yer money and you takes
yer choice.
> Would like to see its specs on a supplier's web site or some such.
It depends on your load in amps. How much is your e-buss going to draw
when it is fully loaded?
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Electrical current load spreadsheet |
Mike,
I'm replying both to the list (no attachments) and to you (so I can attach a
sophisticated spreadsheet Shannon Knoepfliein posted a year or so ago).
I'll also attach my mod of that spreadsheet showing my lower budget loads,
as far as I know it right now, and arranged a little different, with some
sub-totals and "accumulated sub-totals" after "Batt Bus", "Enduance Bus",
"Main Bus"; also some additional columns for "additional phases of flight".
Stuff I don't plan to use was cut and moved down below that, so it is still
there for reference.
Also attached Richard Reynold's BusLoad.xls - another perspective and "data
point"
David
________________________________________________________________________________
| From: | Ken <klehman(at)albedo.net> |
| Subject: | Re: Z-13 - latest version of 'simplification' |
on juliet
Well David, seeing as how you are talking about switches, that last
diagram also shows your 40 amp alternator current going through a
switch. Most of the switches that I see can't really handle that
especially with push on connectors. Just because you are not planning to
move the switch when loads are high does not mean that internal (or
external) connections won't heat up and fail in service. In the original
Z-13 all the high currents are switched by the relay and as I mentioned
before, I ended up using a hefty battery contactor for that with a 40
amp alternator. I prefer the original AEC Z-13 architecture. There is
lots of diode discussion in the archives.
Ken
David Carter wrote:
>
>Phil,
>
>Good & helpful observations.
>
>OK, perhaps someone can help me "increase my confidence in diodes". Before
>that, I figure the switch in my current Z-13 will only be used once or twice
>in my lifetime and its lifetime. So I don't think "reliability of switches"
>is even an issue. I'm surely not worried about it "shorting" across any of
>its terminals in normal use (unactuated, just a static failure).
>
>But parts count is a good issue. So, what "range of options" do I have on
>the diode, installed as per original Z-13? I know that resistors have
>"watts" ratings. How about diodes? What would be a good diode to use?
>Would like to see its specs on a supplier's web site or some such.
>
>David
>
>----- Original Message -----
>From: "Phil Birkelbach" <phil(at)petrasoft.net>
>To:
>Subject: Re: AeroElectric-List: Z-13 - latest version of 'simplification'
>
>
>
>
>>
>>
>
>
>
>>The thing that jumps out at me on your modification is that you have
>>created a single point of failure for your endurance buss with the
>>switch. A better solution would be two switches. One for the main feed
>>and the other for the battery buss feed. Actually a better solution
>>would be the diode. I agree that diodes do fail, but in my experience
>>switches fail more often than diodes. I would be curious what your
>>experience with diodes is that causes you to believe that a switch is
>>more reliable.
>>
>>Another problem with the single switch is that you will have a
>>millisecond or two where there is no voltage. I imagine that this
>>probably won't cause any grief.
>>
>>There is also an unprotected wire between the main buss and your e-buss
>>switch. This wire is unprotected in the original architecture as well
>>but it is assumed that the diode is physically close to both busses.
>>You will most likely mount that switch on the panel, which will make the
>>wire longer than 6" and therefore it will need to be protected. If you
>>replace the single switch with two switches you will also have to
>>protect both wires from both ends of both switches because they will all
>>be too long and will have the potential to be powered from both ends.
>>It seems to me the parts count is increasing at an alarming rate and
>>this decreases reliablity in any system.
>>
>>Godspeed,
>>
>>Phil Birkelbach - Houston Texas
>>RV-7 N727WB (Reserved) - Panel
>>http://www.myrv7.com
>>
>>
________________________________________________________________________________
| From: | Phil Birkelbach <phil(at)petrasoft.net> |
| Subject: | Re: Z-13 - latest version of 'simplification' |
I hope you plan to use that switch every time you start the airplane.
You always check your backups during pre-flight. Besides whether or not
you use it still doesn't change the fact it is still a single point of
failure and I would contend that not using the switch will actually hurt
it's reliablity, due to corrosion and other factors. It is a mechanical
device after all. And it's not just the switch that is the single point
of failure it is also two terminals and a piece of wire any one of which
will cause your endurance buss to go cold.
Diodes are generally rated in Amps. The diode that is sold by B & C
Specialty (and that Bob recomends) is actually a full wave rectifier. I
think that it is rated at 25Amps or so. The reasoning for the FWR is
simply that it is easy to physically mount and since it has 1/4" fast on
tabs it is easy to wire to. It will also dissipate it's heat well since
it's heat sink will most likely be bolted to some metal on most planes.
If you are worried then a proper heat sink for the package can be had at
Radio Shack for a couple of bucks.
The only time I have ever seen diodes fail is when they were subjected
to too much heat (or allowed to generate too much heat of their own).
Most alternator diodes fail this way. That is why I asked you about
your experience with diodes. I suspect that your bad luck with diodes
had to do with too much heat, probably in alternators. They do need to
dissipate some energy but the one that we are discussing will be as
happy as it can be for years running well below it's maximum current
rating and properly heat sunk. Also we are only dumping the heat from
one of the four diodes in the package. You can estimate the power that
you'll need to dissipate by multiplying the current through the device
by 0.7, which is the forward voltage drop of the typical silicon diode.
At 10 amps you're looking at around 7 watts. That'll barely get warm.
Here is a Mouser link...
http://checkoway.com/url/?s=49833a03
Now where are all those Schottky diode guys??? :-)
Godspeed,
Phil Birkelbach - Houston Texas
RV-7 N727WB (Reserved) - Panel
http://www.myrv7.com
David Carter wrote:
>
>Phil,
>
>Good & helpful observations.
>
>OK, perhaps someone can help me "increase my confidence in diodes". Before
>that, I figure the switch in my current Z-13 will only be used once or twice
>in my lifetime and its lifetime. So I don't think "reliability of switches"
>is even an issue. I'm surely not worried about it "shorting" across any of
>its terminals in normal use (unactuated, just a static failure).
>
>But parts count is a good issue. So, what "range of options" do I have on
>the diode, installed as per original Z-13? I know that resistors have
>"watts" ratings. How about diodes? What would be a good diode to use?
>Would like to see its specs on a supplier's web site or some such.
>
>David
>
>----- Original Message -----
>From: "Phil Birkelbach" <phil(at)petrasoft.net>
>To:
>Subject: Re: AeroElectric-List: Z-13 - latest version of 'simplification'
>
>
>
>
>>
>>
>
>
>
>>The thing that jumps out at me on your modification is that you have
>>created a single point of failure for your endurance buss with the
>>switch. A better solution would be two switches. One for the main feed
>>and the other for the battery buss feed. Actually a better solution
>>would be the diode. I agree that diodes do fail, but in my experience
>>switches fail more often than diodes. I would be curious what your
>>experience with diodes is that causes you to believe that a switch is
>>more reliable.
>>
>>Another problem with the single switch is that you will have a
>>millisecond or two where there is no voltage. I imagine that this
>>probably won't cause any grief.
>>
>>There is also an unprotected wire between the main buss and your e-buss
>>switch. This wire is unprotected in the original architecture as well
>>but it is assumed that the diode is physically close to both busses.
>>You will most likely mount that switch on the panel, which will make the
>>wire longer than 6" and therefore it will need to be protected. If you
>>replace the single switch with two switches you will also have to
>>protect both wires from both ends of both switches because they will all
>>be too long and will have the potential to be powered from both ends.
>>It seems to me the parts count is increasing at an alarming rate and
>>this decreases reliablity in any system.
>>
>>Godspeed,
>>
>>Phil Birkelbach - Houston Texas
>>RV-7 N727WB (Reserved) - Panel
>>http://www.myrv7.com
>>
>>
>>
>>
>
>
>
>
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Z-13 - latest version of 'simplification' |
On Sep 2, 2004, at 3:58 PM, David Carter wrote:
>
>
> Thanks, Brian - good words. 'Lectric Bob likes to use a certain
> "Bridge
> Rectifier"? (bridge something) that is in a good package for mounting
> and
> you don't have to use all the leads and parts inside. I think the
> guts are
> probably just plain silicon diodes, though - not Schottky.
That is 100% correct. I prefer to use the schottky diodes in the
TO-220 package. They are more difficult to mount but then, if that is
too difficult you probably shouldn't be building an airplane anyway.
;-)
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Re: Z-13 - latest version of 'simplification' |
Ken & Phil,
How I love this list. A guy can "try out his budding knowledge" and get
good technical "educational feedback". Thanks for taking the time to
explain this stuff beyond my fledgling knowledge.
About the alternator switch - that was a late at night, hastily added item -
zero thought about anything except running down my battery without a switch
there. I'll add (re-insert) a standard contactor (as in original Z-13!! or
lower holding current EV200 by Kilovac mentioned by James Foerster - if
price can be "refined") or solid state device that can handle the current
(Eric Jones's)
About the E-bus switch instead of a diode - Yep, my experience is automotive
alternator diodes. Plus one that shorted on a ckt board in an A-7 "Big
Eight" test station ($1 million for each of the 8 test stations) - cost
about $100,000 in parts after the unprotected failure cascaded throughout
the test station and took out about all of its electrical guts.
- The point about heat affecting the auto alternator diodes - vs very
benign environment for the E-bus diode - is well taken. I'll go with the
diode (and maybe put a "knife blade" switch in parallel in case the diode
shorts or opens - no, just kidding).
Thanks again for the help
David
----- Original Message -----
From: "Ken" <klehman(at)albedo.net>
Subject: Re: AeroElectric-List: Z-13 - latest version of 'simplification' on
juliet
>
> Well David, seeing as how you are talking about switches, that last
> diagram also shows your 40 amp alternator current going through a
> switch. Most of the switches that I see can't really handle that
> especially with push on connectors. Just because you are not planning to
> move the switch when loads are high does not mean that internal (or
> external) connections won't heat up and fail in service. In the original
> Z-13 all the high currents are switched by the relay and as I mentioned
> before, I ended up using a hefty battery contactor for that with a 40
> amp alternator. I prefer the original AEC Z-13 architecture. There is
> lots of diode discussion in the archives.
> Ken
>
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Wire size calculator help |
Mike, here's two spreadsheets (attached to the e-mail to your address, won't
be on the Aeroel List).
- The one with color "wiresize.xls" is sophisticated from someone else.
I think I added the right columns to figure voltage drop - because I believe
Bob suggested in the Aeroelectric Conn to use bigger wires for longer runs
so as to not drop more than 5% of voltage - it isn't even an issue of
heating the wire. I added that to the traditional "don't fry the wire"
calcs.
- The other, "David's wire size...", is a simple sample that I did on my
own - it illustrates the voltage drop thing - I added 3 lines for your 7amp
load with different lengths of 22 awg and a line for 18 awg (didn't know
what length you were looking at so just picked something like back in the
tail or to a wingtip).
David
________________________________________________________________________________
| From: | Tracy <tracyinva(at)gmail.com> |
please take me off this list!!
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> . |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved . . |
.
.
>
>Mystery not solved! I certainly did not put the terminals in the tool
>backwards. Buzz returned the terminal with the bad crimp that I sent him
>& I'm sending it to you. You will note that the deep crimp is where it
>should be on the terminal side of the barrel. I'm also sending a crimp
>Buzz sent me along with a replacement tool. I figure he thought the
>problem was having a bad example of the tool. Just feeling the two crimps
>shows how much deeper the indentations in Buzz's good crimp are compared
>to mine. Now if you got a good crimp using my tool, that leaves only the
>terminal as suspect. I look forward to hearing what you think when you
>get the terminal. Buzz's crimp also captures the tefzel much better than mine.
Without a doubt, there may be terminals that will work with
this tool. I used AMP PIDG terminals and got a good wire grip
but poor insulation grip on tefzel. So we had half-of-a-good
crimp. I didn't try a Plasti-Grip terminal . . . I'm not sure
I have any around here. These have a bit more massive insulators
and may well close down on the wire a bit better.
Bob . . .
---
________________________________________________________________________________
| Subject: | Re: Z-13 - latest version of 'simplification' |
| From: | "Matt Prather" <mprather(at)spro.net> |
Hi David,
>
>
> Ken & Phil,
>
> How I love this list. A guy can "try out his budding knowledge" and get
> good technical "educational feedback". Thanks for taking the time to
> explain this stuff beyond my fledgling knowledge.
This list is a fantastic resource. I continue to learn a bunch of stuff.
snip
> About the E-bus switch instead of a diode - Yep, my experience is
> automotive alternator diodes. Plus one that shorted on a ckt board in
> an A-7 "Big Eight" test station ($1 million for each of the 8 test
> stations) - cost about $100,000 in parts after the unprotected failure
> cascaded throughout the test station and took out about all of its
> electrical guts.
One thing to consider about diodes... If you are planning to have an
alternator at all... you have to have a rectifier of some sort, and those
are most often implemented using... diodes. So you're stuck.
Another thing to consider about diodes... I wonder if the diodes on
the A-7 (Corsair?) test station were solid state or tube. Further, I could
imagine that they likely were fab'ed using an ancient process, much
more prone to failure. Any ideas?
> - The point about heat affecting the auto alternator diodes - vs
> very
> benign environment for the E-bus diode - is well taken. I'll go with
> the diode (and maybe put a "knife blade" switch in parallel in case the
> diode shorts or opens - no, just kidding).
>
> Thanks again for the help
>
> David
>
snip
Back to work!
MAP
________________________________________________________________________________
| From: | Chris Krieg <rv6a(at)mac.com> |
Please look a few lines down in all emails. There is an "unsubscribe"
link.
On Sep 2, 2004, at 2:31 PM, Tracy wrote:
>
> please take me off this list!!
>
>
> _-
> =======================================================================
> _-
> =======================================================================
> _-
> =======================================================================
> _-
> =======================================================================
> >
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> 'simplification' |
| Subject: | Re: Z-13 - latest version of |
'simplification'
'simplification'
>
>
>Ken & Phil,
>
>How I love this list. A guy can "try out his budding knowledge" and get
>good technical "educational feedback". Thanks for taking the time to
>explain this stuff beyond my fledgling knowledge.
>
>About the alternator switch - that was a late at night, hastily added item -
>zero thought about anything except running down my battery without a switch
>there. I'll add (re-insert) a standard contactor (as in original Z-13!! or
>lower holding current EV200 by Kilovac mentioned by James Foerster - if
>price can be "refined") or solid state device that can handle the current
>(Eric Jones's)
>
>About the E-bus switch instead of a diode - Yep, my experience is automotive
>alternator diodes. Plus one that shorted on a ckt board in an A-7 "Big
>Eight" test station ($1 million for each of the 8 test stations) - cost
>about $100,000 in parts after the unprotected failure cascaded throughout
>the test station and took out about all of its electrical guts.
> - The point about heat affecting the auto alternator diodes - vs very
>benign environment for the E-bus diode - is well taken. I'll go with the
>diode (and maybe put a "knife blade" switch in parallel in case the diode
>shorts or opens - no, just kidding).
Diodes have been used for major power distribution tasks between
busses on bizjets for 40 years. I remember seeing them on some
20 series Lears. They're the oldest power semiconductor device
in our arsenal of parts . . . quite mature, quite robust when
operated within limits. Alternator rectifier stacks are not good
examples of situations that guarantee operation in-limits 100% of
the time . . .
Numerous folks have suggested a switch to replace the diode . . . seems
they still buy into the "avionics master switch" concept. I've suggested
that they put a switch in series with the diode and leave the diode in
place . . . this prevents one from blowing the e-bus alternate feed
path due to inappropriate placement of switches.
Bob . . .
---
________________________________________________________________________________
| From: | "Tony Babb" <tonybabb(at)alejandra.net> |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved . . . |
Bob et al,
> . It's not difficult if you take time to understand
> what's needed.
>
> Bob . . .
>
Is there a list of known good tool/terminal/wire combinations based on the
'lectric listers experience? Not that I'm looking for guarantees ... but
would save me and others following from reinventing the same wheel you all
invented before. For example if I bought the B&C ratchet crimpers - all
three - are there known terminals/wire types they work well with/ or not so
well with.
Of course we're always looking for good deals but in this case I don't mind
paying extra for a tool that will likely produce better connections for the
'lectrically challenged such as me.
.Thanks as always.
Tony
________________________________________________________________________________
| From: | "Werner Schneider" <wernerschneider(at)compuserve.com> |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved . . . |
Hello Tony,
I have also the B&C crimpers worked fine with their fastons, I used several
kind of d-sub pins and had also excellent results (all crimps still ok) and
did replace all my soldered d-subs with crimped (had a broken wire on the
encoder).
Werner
----- Original Message -----
From: "Tony Babb" <tonybabb(at)alejandra.net>
Subject: Re: AeroElectric-List: Re: Cleveland Crimp Tool Mystery Solved . .
.
>
> Bob et al,
>
>
> > . It's not difficult if you take time to understand
> > what's needed.
> >
> > Bob . . .
> >
> Is there a list of known good tool/terminal/wire combinations based on
the
> 'lectric listers experience? Not that I'm looking for guarantees ... but
> would save me and others following from reinventing the same wheel you all
> invented before. For example if I bought the B&C ratchet crimpers - all
> three - are there known terminals/wire types they work well with/ or not
so
> well with.
>
> Of course we're always looking for good deals but in this case I don't
mind
> paying extra for a tool that will likely produce better connections for
the
> 'lectrically challenged such as me.
>
> .Thanks as always.
>
> Tony
>
>
________________________________________________________________________________
| From: | "Paul McAllister" <paul.mcallister(at)qia.net> |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved . . . |
Tony,
I purchased my crimper and fastons from B&C and they worked perfectly
together. The same for the D sub pins and tool they sell.
I did purchase a cheaper tool from Radio Shack to do the BNC's ($15.00) and
it worked fine with the BNCs I purchased from B&C as well
Paul
________________________________________________________________________________
| From: | "Wayne Williams" <rwayne(at)gamewood.net> |
| Subject: | Resistor values for LEDs |
Can someone tell me how to calculate the resistor value to go in series with
an LED in my 12VDC system.
Thanks!
Wayne
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> . . . |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved |
. . .
. . .
>
>Bob et al,
>
>
> > . It's not difficult if you take time to understand
> > what's needed.
> >
> > Bob . . .
> >
> Is there a list of known good tool/terminal/wire combinations based on the
>'lectric listers experience? Not that I'm looking for guarantees ... but
>would save me and others following from reinventing the same wheel you all
>invented before. For example if I bought the B&C ratchet crimpers - all
>three - are there known terminals/wire types they work well with/ or not so
>well with.
Sure . . . the one's that B&C sells. The tool and terminal
inventory is (or at least was when I sold them the business)
based on my selection of tools and terminals that I tested to
prove compatibility with the tools. I would hope that ALL
merchants who offer interdependent products would be similarly
diligent in testing their compatibility.
As for any "list" . . . not that I know of. For the most part if
you purchase tools and materials from common sources like AMP,
Waldom/Molex, etc. you are assured of compatibility.
>Of course we're always looking for good deals but in this case I don't mind
>paying extra for a tool that will likely produce better connections for the
>'lectrically challenged such as me.
No need to pay "extra" . . . the combination of tools and components
I compiled, sold and ultimately transferred to B&C were selected
for their value and low price attractiveness. However, there's no
substitute
for getting educated enough to do your own evaluations for
compatibility . . . there's probably a half dozen articles
on tools and terminals on my website alone. If you have the time and
inclination to save money by doing a lot of research on the lower cost
offerings, that's great. However, I'll suggest that the best values are
those
where the research has been done by one to the benefit of many as
opposed to lots of folks doing their own research to the same end.
It seems that we're still not fully informed as to the compatibility
of the Cleveland tool . . . I tested it with AMP PIDG terminals and
found it incompatible. I guess there are samples of other terminals
coming that purport to fill in the gaps. We'll see and report
findings here. There's nothing that outperforms the repeatable
experiment for clearing away the fog.
In the mean time, if you need to purchase tools and materials at
attractive prices to move YOUR project along, I can vouch for the
collection offered by htp://bandc.biz Perhaps in a week or
so we can offer similar confirmation for Cleveland's offerings.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> . . . |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved |
. . .
. . .
>
>
>Hello Tony,
>
>I have also the B&C crimpers worked fine with their fastons, I used several
>kind of d-sub pins and had also excellent results (all crimps still ok) and
>did replace all my soldered d-subs with crimped (had a broken wire on the
>encoder).
>
>Werner
Most people are not aware of it . . . but the d-sub crimp tool
they offer is available from lots of other sources in the wild . . .
but I determined early-on that the tool places the crimp in the
wrong place on the pin. All the tools we sold and now sold at
B&C have the pin-positioners cut down on a lathe to correct this
deficiency. This is an example of the efforts put forth (by
some suppliers least) to elevate the value of products and
services offered. Most folks who sell that tool don't have
a clue.
Bob . . .
---
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Resistor values for LEDs |
On Sep 3, 2004, at 9:08 AM, Wayne Williams wrote:
>
>
> Can someone tell me how to calculate the resistor value to go in
> series with
> an LED in my 12VDC system.
First you need to know three things:
1. the voltage drop across the LED at your operating current (I will
call this Vdl);
2. the operating current for the LED (I will call this Il);
3. the source voltage (Vs).
The high-brightness LEDs have different voltage drops depending on the
color of the LED. Red LEDs usually have a drop of about 1.5V. For the
sake of argument I will pick 20mA as the proper operating current.
Resistance = Volts/Amps (good old ohms law).
So the formula you want is:
R = (Vs - Vdl) / Il
For your example and using the values above, the calculation is:
R = (14V - 1.5V) / .020 A
R = 625 ohms.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Resistor values for LEDs |
On Sep 3, 2004, at 9:08 AM, Wayne Williams wrote:
>
>
> Can someone tell me how to calculate the resistor value to go in
> series with
> an LED in my 12VDC system.
First you need to know three things:
1. the voltage drop across the LED at your operating current (I will
call this Vdl);
2. the operating current for the LED (I will call this Il);
3. the source voltage (Vs).
The high-brightness LEDs have different voltage drops depending on the
color of the LED. Red LEDs usually have a drop of about 1.5V. For the
sake of argument I will pick 20mA as the proper operating current.
Resistance = Volts/Amps (good old ohms law).
So the formula you want is:
R = (Vs - Vdl) / Il
For your example and using the values above, the calculation is:
R = (14V - 1.5V) / .020 A
R = 625 ohms.
> Thanks!
>
> Wayne
>
>
> _-
> =======================================================================
> _-
> =======================================================================
> _-
> =======================================================================
> _-
> =======================================================================
> >
>
>
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved .//NOT |
.
----- Original Message -----
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: AeroElectric-List: Re: Cleveland Crimp Tool Mystery Solved . . .
snip>>Unlike the tools B&C sells with symmetrical dies, >>>>
Bob, I simply do not understand how the above symetrical die tool will
properly crimp a terminal.
Sure it can crimp the conductor to the needed gas tight crimp.
However the insulation grip REQUIRES a different shape die to properly crimp
the insulation with the metal sleeve that is a part of the PIDG terminal.
The need is to crimp the sleeve on both sides of the wire with minimal
crimping on top of the wire.
After this thread started I went and looked again at my various crimpers. I
have crimpers designed for the vinyl insulation terminals commonly sold in
auto stores as well as AMP crimpers designed for PIDG terminals. Both types
work well on the terminals they were designed for. ALL have different die
shapes for the two parts of the crimp.
Insulation support is part of the terminal design and a proper insulation
crimp is needed in my opinion (as well as the industry it seems). Simply
looking at the result of a proper crimp shows the inner metal sleeve of the
terminal nicely shaped around the wire insulation without insulation
distortion and nearly 360 degree support. The excess material results in a
end view much like a round fush acft with mid stubby wings =O=.
Proper insulation support on the wire side of the crimp is critical to wire
to terminal long term resistance to failure.
Paul
________________________________________________________________________________
| From: | SportAV8R(at)aol.com |
| Subject: | Re: Resistor values for LEDs |
Wayne, there's also the empiric method, wher you connect a power supply or battery
in series with a sample LED and digital multimeter, and place various resistors
in series, starting with about 1k ohm and going lower in steps: 750, 680,
560, 470, 330, 220 until you achieve the brightness you want, or the listed
maximum current, or (for fun and education) until the LED gets real bright and
then pops. This will satisfy you that the LED is of a comfortable, useful brightness
and also (hopefully) within its rated current specs. I suggest this
experiment be done in a darkened workshop as well as in daylight, to see how you
like it in both conditions. You may want to include a dimmer, which is a whole
other subject...
-Stormy
________________________________________________________________________________
| Subject: | Re: Cleveland Crimp Tool Mystery Solved . . . |
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Tony -
We haven't even started to wire the airplane yet, but here is my
experience on tools and wiring thus far.
I finally bought the Ideal Stripmaster with the dies that Bob recommends.
A guy on the Lancair list bought several sets for a very good price and
passed the savings on to those of us lucky enough to catch his email and
react!! Two previous strippers are nowhere near it in quality and ease of
use. It is easily worth the money to get consistent, fast strips on
tefzel. If it does tefzel, it can do anything!
I bought the DSub crimper for machined pins from B&C. It works beautifully.
I bought a frame and dies (4100 series) for PIDG terminals & RG58 coax
from Sargent. They were on a closeout sale at RC and are very good.
However, when I ordered a set of dies from them, via Mouser, for open
barrel terminals, the order was so goofed up that I cancelled and bought a
Palladin frame (Series 1300) and two sets of dies for open barrels. The
order was in March and delivery had still not occurred as of August
15th!!! From what I can see, the PIDG and RG58 dies from Palladin would be
just as good as the Sargents. They certainly are much easier to swap dies
in the frame. They also use the same dies for more than one series of
frames.
After lots of practice with all of the tools - including open barrel
crimps on Molex Mini Fit Jr. pins to that miserable AWG 26 wire used on RC
Allen trim servos, I concluded that open barrels are by far the most
difficult. Bob's (B&C) tool and comic book piece on how to use it is a
good way to go. It is time consuming, but making two separate crimps saves
you crimps that are not placed in the dies correctly or wire inserted
improperly because you cannot see where it is in the terminal. The dies
tend to cover up the area. To do the Molex terminals, I literally had to
use a jewellers loop to set the pin in the tool, to strip the wire and
insert it into the pin for crimping. Furthermore, I had to cut off part
of the insulation "ears" to keep the crimper from mashing the insulation
into the wire and cutting it!
By comparison, the machined pins/Dsub combo is vastly easier to do. I hope
to standardize on Dsubs as much as I can and also on AMP CPC Type II's
because they use the machined pins. Unfortunately, Dsubs don't come in any
decent array of sizes and the CPC's do, but they are a lot more expensive
and a bit long. To fill the gap, we will use the Molex Minifit Jr's for
the remainder of the connectors. The pins can carry up to 9 amps and that
covers 90 percent of the requirements. They also have locking tabs that
are good to have. The older .062 and .093 molex connectors are ubiquitous
and cheap, but this newer line is better (IMHO). I'll practice a bit more
with the Palladin frame and dies. It looks like life will be a lot easier
with them when we can get to the AWG 22 wire down stream of the trim of
the RC Allen servos, indicators and switches! AWG 22 really should be the
absolute minimum size for wiring.
We keep learning over and over that life is too short, aggravating and
senseless to spend it trying to make cheap tools or the wrong type tool
work on something in the airplane.
BTW, buy at least a dozen extra pins of each size for practice and a
jewellers loop with a good bench light to examine your work.
Bob - How's this for a good ad for your long experience and advice?
Cheers,
John
________________________________________________________________________________
| Subject: | Re: Resistor values for LEDs |
| From: | Kent Ashton <kjashton(at)vnet.net> |
Radio Shack has a little booklet on Opto-Electronics with an explanation of
LEDs and the resistor formulas. Good simple reference book.
--Kent
> From: "Wayne Williams" <rwayne(at)gamewood.net>
> Reply-To: aeroelectric-list(at)matronics.com
> Date: Fri, 3 Sep 2004 09:08:47 -0400
> To:
> Subject: AeroElectric-List: Resistor values for LEDs
>
>
>
> Can someone tell me how to calculate the resistor value to go in series with
> an LED in my 12VDC system.
> Thanks!
>
> Wayne
>
>
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Resistor values for LEDs |
| From: | "John Schroeder" <jschroeder(at)perigee.net> |
Try this web site. It is a tutorial and calculator!
http://ourworld.compuserve.com/homepages/Bill_Bowden/led.htm
John
>> Can someone tell me how to calculate the resistor value to go in series
>> with an LED in my 12VDC system.
>> Thanks!
>>
>> Wayne
________________________________________________________________________________
| From: | echristley(at)nc.rr.com |
| Subject: | Re: Resistor values for LEDs |
----- Original Message -----
From: SportAV8R(at)aol.com
Date: Friday, September 3, 2004 10:29 am
Subject: Re: AeroElectric-List: Resistor values for LEDs
SportAV8R(at)aol.com
>
> Wayne, there's also the empiric method, wher you
connect a power
> supply or battery in series with a sample LED and
digital
> multimeter, and place various resistors in series,
starting with
> about 1k ohm and going lower in steps: 750, 680,
560, 470, 330, 220
> until you achieve the brightness you want, or the
listed maximum
> current, or (for fun and education) until the LED
gets real bright
> and then pops. This will satisfy you that the LED
is of a
> comfortable, useful brightness and also
(hopefully) within its
> rated current specs. I suggest this experiment be
done in a
> darkened workshop as well as in daylight, to see
how you like it in
> both conditions. You may want to include a
dimmer, which is a
> whole other subject...
>
> -Stormy
>
You'll also want to know that the LED will be
somewhat useful when the electron pump goes away on
you're on the tail end of battery operation. Either
use Brian's method to calculate that the current can
turn the LED on with the chosen resistor and only 11
volts,
OR
turn the power supply down to get down to 11 volts.
Most spec sheets will give a max, min and typical
current rating. Keeping the current just below the
typical current rating of a half decent LED will
almost guarantee that it will last longer than your
airframe.
________________________________________________________________________________
| From: | "DAVID REEL" <dreel(at)cox.net> |
| Subject: | Crimping 22awg PIDG Terminal Mystery |
I got the Cleveland WTC380 crimper back from Bob today & used a dial caliper to
measure the minimum separation of the dies used for 22-18awg terminals. .097
inches. Then I measured the replacement from Cleveland. .088 inches. So I
think Buzz at Cleveland was right & my problem was just an out-of-spec variation
in the tool. I still can't figure out how Bob got a good crimp out of the
.097 inch tool though. By the way, Ideal's 30-579 die separaton measured ,088.
Still waiting to hear what Bob thinks of the grip on the insulation end from
the sample I sent him though.
Dave Reel - RV8A
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Resistor values for LEDs |
>
>
>Can someone tell me how to calculate the resistor value to go in series with
>an LED in my 12VDC system.
>Thanks!
>
>Wayne
See:
http://www.aeroelectric.com/articles/leds3.pdf
Bob . . .
---
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
I'm considering using a 28 volt electrical system in my RV-8 with one
alternator and two batteries. What are your thoughts on that? Are there drawbacks
to using 28 volt?
Stan Sutterfield
Tampa
RV-8A 25%
________________________________________________________________________________
| From: | Speedy11(at)aol.com |
Forget my question. I should have researched the archives before asking.
Stan Sutterfield
Tampa
RV-8A
________________________________________________________________________________
| From: | david caswell <davidbcaswell(at)yahoo.com> |
I am in process of installing International Electronics iInstruments and am connecting
wiring to the panel mounted warning lights (B&C) from the instruments
(EGT/CHT and Fuel). The installation instructions specify that current be no
higher that 1/10 amp on the FUEL, and 2/10 amp on the EGT. The signal from both
instruments creates a ground. What is the best way to limit the current from
the buss to these lights? A resistor in series? And is the R=E/I the way to
calculate the size of this resistor? (14/.020=700) ? 700 ohm resistor? I am also
wiring a "starter engaged" warning light from the starter "I" terminal. Does
this lead need a resistor before it gets to the warning light?
Any help would be greatly appreciated. Thank you.
David
________________________________________________________________________________
| From: | david caswell <davidbcaswell(at)yahoo.com> |
I am looking for a grip mounted "slide switch" for my flaps. The only one I've located is Otto Controls http://ottoeng.com/control/slideswitch.htm. The price is $180. I think I remember reading about one that was priced more reasonably. Does anyone have a source for this item?
THANK YOU
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | current limiting warning lights for EI instruments |
>
>
> I am in process of installing International Electronics iInstruments
> and am connecting wiring to the panel mounted warning lights (B&C)
> from the instruments (EGT/CHT and Fuel). The installation
> instructions specify that current be no higher that 1/10 amp on the
> FUEL, and 2/10 amp on the EGT. The signal from both instruments
> creates a ground. What is the best way to limit the current from the
> buss to these lights? A resistor in series?
Yes.
> And is the R=E/I the way to calculate the size of this resistor?
> (14/.020=700) ? 700 ohm resistor?
You are correct in how you calculate the resistance but you neglected
to account for the resistance in the bulb itself. You also didn't
indicate whether you plan to use incandescent light indicators or LED
indicators.
Also, 2/10 amp is 0.2A, not 0.020A. The latter is 20mA, just about
right for an LED.
If the indicator is an incandescent bulb you just select the bulb to
have the proper current draw. If it is a low-voltage bulb, perhaps
6.3V, then you need a dropping resistor in series to put the proper
voltage drop across the bulb. Likewise for an LED.
> I am also wiring a "starter engaged" warning light from the starter
> "I" terminal. Does this lead need a resistor before it gets to the
> warning light?
It depends on the type of bulb you are using. Can you provide more
detail?
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | david caswell <davidbcaswell(at)yahoo.com> |
| Subject: | Re: current limiting warning lights for EI instruments |
Brian Lloyd wrote:
>
>
> I am in process of installing International Electronics iInstruments
> and am connecting wiring to the panel mounted warning lights (B&C)
> from the instruments (EGT/CHT and Fuel). The installation
> instructions specify that current be no higher that 1/10 amp on the
> FUEL, and 2/10 amp on the EGT. The signal from both instruments
> creates a ground. What is the best way to limit the current from the
> buss to these lights? A resistor in series?
Yes.
> And is the R=E/I the way to calculate the size of this resistor?
> (14/.020=700) ? 700 ohm resistor?
You are correct in how you calculate the resistance but you neglected
to account for the resistance in the bulb itself. You also didn't
indicate whether you plan to use incandescent light indicators or LED
indicators.
Also, 2/10 amp is 0.2A, not 0.020A. The latter is 20mA, just about
right for an LED.
If the indicator is an incandescent bulb you just select the bulb to
have the proper current draw. If it is a low-voltage bulb, perhaps
6.3V, then you need a dropping resistor in series to put the proper
voltage drop across the bulb. Likewise for an LED.
> I am also wiring a "starter engaged" warning light from the starter
> "I" terminal. Does this lead need a resistor before it gets to the
> warning light?
It depends on the type of bulb you are using. Can you provide more
detail?
The warning lights are from the B & C Specialties http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?10X358218#s888-1-2. I really didn't look at the bulbs, or even if they had bulbs. I assume they are incandescent. I will look tomorrow. Thanks for direction.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | "David Carter" <dcarter(at)datarecall.net> |
| Subject: | Z-13 modifications for 35 amp PM Alternator |
After the recent exchange of ideas on "simplification", and an examination
of relays and contactors available for use to shutdown the PM alternator,
and because of a concern expressed by one fellow of a short in the voltage
regulator and nothing between the alternator and the VR to protect the wires
or the VR, here are two things I think I need to do to in adapting Z-13 to
my specific system:
1. Relay to connect/disconnect the alternator & VR from the aircraft
electrical busses (as shown in ORIGINAL - unmodified - Z-13, not the stuff I
put on my website the other night):
- Since the SD-8 (8 amp device) is being replaced with a 35 amp John
Deere PM alternator as my only alternator, the S-704-1 relay, being good for
only 20 amps continuous, will be replaced by, for example, a Bosch High
Capacity (50 amps) relay, WayTek p/n 75002, Bosch p/n 0 332 019 110, 12v,
SPST, 50 amps Normally Open, four terminals (2 for coil, 2 for power) ,
bracket mount $3.53 + $0.27 for 75281 connector shell (vs $10 for S-704-1
from B and C).
- Does it look like I have a reasonable amount of "head room" (if that
is the correct term) for the relay, it being rated at 50 amps (DC) and my
alternator being rated at 35 amps ( but putting out who-knows-what into the
regulator, which has to suck up and dissipate all the unused electrons)?
2. Protect the wires between "dynamo" and VR with in-line fuses of ______
amp capacity:
- Since the "dynamo" is putting out unregulated voltage and alternating
current which is directly proportional to rpm of alternator, and independent
of what my aircraft systems (other than the VR) are consuming, and given
that the alternator is "rated at" 35 amps and I won't have any more than
that "on-line" at any time, then how do I design appropriate protection for
the 2 wires going to the VR?
- What is the nature of the current flow in the 2 wires when the
airplane is actually consuming 35 amps?
. . . -- I.e., at a given engine and alternator rpm at cruise, and
actual electrical consumption by stuff in the airplane actually turned on
and consuming 35 amps of electricity, what kind and rating of fuse do I need
in each of the 2 wires between the alternator and VR? 17.5 amps in each
wire, or 35 amps in each wire?
... -- Whichever, then how much "head room" should I allow for, i.e.,
if each wire is going to be designed for a normal current of 35 amps, then
revised Fig 8-4 says I might consider, for 35 deg C/63 deg F rise, using
"13.5 awg" (pick next larger, 12 awg, which is what Z-13 shows for use with
the 8 amp dynamo). If max current is only 17.5 amps, then could use 18 or
16 awg for 35 deg C rise. Z-13 shows using 12 awg.
...-- If want to allow only a 10 deg C rise (18 deg F) in the already
warm engine compartment, then Fig 8-4 suggests 8 awg for 35 amps each wire
or 14 awg for 17.5 amps in each wire.
- The bigger question - peculiar to PM alternators (dynamos) - is this:
If alternator output is proportional to rpm, only, not to what the aircraft
(other than the VR) is consuming, it looks like 1) I need a graph (or need
to make my own) of "current vs rpm" and 2) if I size my pulleys for the
alternator so I get enough current to run my "night IFR, descent to landing
phase of flight" load at some reduced descent power, then when I am cruising
at higher rpm, or taking off and climbing (or racing?) at full throttle,
then what is the current output of the PM alternator?
Whatever I'm not consuming out of the VR is going to be consumed by the VR
itself to generate heat - correct?
If so, then I need to size my wires from alternator to VR and fuse them to
protect against my "max engine/alternator rpm" condition. I don't yet know
what that is. How can I estimate it?
Looks like I need an AC ammeter in my aircraft so I'll know what the
alternator is doing. Is there such a device available to adapt to my OBAM
aircraft? I assume it will be different from the DC loadmeters and ammeters
we normally discuss on this list.
David
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: current limiting warning lights for EI instruments |
>
>
> The warning lights are from the B & C Specialties
> http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?
> 10X358218#s888-1-2. I really didn't look at the bulbs, or even if
> they had bulbs. I assume they are incandescent. I will look
> tomorrow. Thanks for direction.
I am familiar with the assembly as the same one came with my LR-3
regulator. I don't remember the current drain either but I suspect it
would work fine directly with the EI instruments without any extra
hardware.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Cleveland Crimp Tool Mystery Solved .NOT . |
>
>
>----- Original Message -----
>From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
>To:
>Subject: AeroElectric-List: Re: Cleveland Crimp Tool Mystery Solved . . .
>
>snip>>Unlike the tools B&C sells with symmetrical dies, >>>>
>
>Bob, I simply do not understand how the above symetrical die tool will
>properly crimp a terminal.
>
>Sure it can crimp the conductor to the needed gas tight crimp.
>
>However the insulation grip REQUIRES a different shape die to properly crimp
>the insulation with the metal sleeve that is a part of the PIDG terminal.
>The need is to crimp the sleeve on both sides of the wire with minimal
>crimping on top of the wire.
>
>After this thread started I went and looked again at my various crimpers. I
>have crimpers designed for the vinyl insulation terminals commonly sold in
>auto stores as well as AMP crimpers designed for PIDG terminals. Both types
>work well on the terminals they were designed for. ALL have different die
>shapes for the two parts of the crimp.
>
>Insulation support is part of the terminal design and a proper insulation
>crimp is needed in my opinion (as well as the industry it seems). Simply
>looking at the result of a proper crimp shows the inner metal sleeve of the
>terminal nicely shaped around the wire insulation without insulation
>distortion and nearly 360 degree support. The excess material results in a
>end view much like a round fush acft with mid stubby wings =O=.
>
>Proper insulation support on the wire side of the crimp is critical to wire
>to terminal long term resistance to failure.
I was skeptical too when I evaluated the sample of the low-cost
tool that lunched my parts/tools business a few years ago. Up to that
time, I'd used nothing but the $high$ professional tools from AMP and
installed the occasional terminal with the hardware store, stamped
sheet metal tools.
Crimps produced by the $40 tool were, as you've noted, decidedly
different that the "pro" tools. See:
http://www.aeroelectric.com/articles/CrimpTools/H.jpg
This picture shows a 22-18 PIDG closed down on a 22AWG
Tefzel wire (22759/16-22) with the "pro" tool and the "el-cheapo"
tool. Yup, the one on the right is more purty . . . but is
it all that different in performance? If we're trying to
relieve stress on the transition from stranded to solid
conductors at the crimp, all that's required is some support
of the wire. As it was explained to me some years ago, support
means anything from just shy of actually touching the insulation
(meaning that a couple thousanths gap is not evil) to actually
putting some crush on the insulation. Recall that we're crushing
the bejabbers out of the stands to get gas tight conduction - there's
no prohibition for putting some crush on the insulation
in the support grip as well. The symmetrical die tool puts
considerable mash on an 18AWG insulation in the red
PIDG terminal. While the well-molded insulation grip produced
by the $high$ is pleasing to look at, there's no foundation
in physics that says it outperforms its ugly cousins.
The wire grip produced by the Cleveland tool in
http://www.aeroelectric.com/Pictures/CLEVELAND66A.jpg
just barely contacts the insulation . . . since this is
the smallest PVC wire that would be used with that terminal,
I'll suggest the insulation grip will be adequate for
22-18 AWG PVC. On the other hand, the grip shown in
http://www.aeroelectric.com/Pictures/CLEVELAND65A.jpg
is WAAAaaayyyy too loose. Dave tells us that a replacement for
this tool measures about 0.010" smaller in the wire grip
opening . . . given the breezeway I observe in the picture
above, I am skeptical that 0.010" more closure on the die
will close sufficiently on 22769/16-22 Tefzel.
If I had my druthers, everyone building their own airplane
would have AMP tools to install AMP terminals throughout.
However, that's not possible so our goal as advisors is to
gage the impact of various compromises. I judge that the Cleveland
tool I tested is NOT a compromise but completely off the
mark for installing PIDG on 22759/16 wire. However, the
$low$, symmetrical die tool as tested several years ago
produces consistent, and adequate if somewhat ugly crimps
that will perform well.
Just for grins, I went to the bench and put a red PIDG
on Tefzel wire with a hardware store crimp tool. This tool
produced the predictably funky results illustrated in
http://www.aeroelectric.com/Pictures/90.jpg
and
http://www.aeroelectric.com/Pictures/92.jpg
Ugly? Yes.
Cross section through the wire grip?
Gas tight.
Pull test? Over 30 pounds . . . wire failed
leaving strands captured in wire grip of
terminal.
Insulation grip? Again, not very pretty
but I see no reason in physics to suspect
it's any less adequate to the task than
other tools I have ranging from $40 to $600.
Bob . . .
---
________________________________________________________________________________
| From: | "jacklockamy" <jacklockamy(at)verizon.net> |
| Subject: | Pitot Heat wiring question.... |
Here's one that has me 'stumped'......
Building an RV-7A. Wings are on... I'm at the airport wiring the wings/wingtips.
I hook up the Pitot (Gretz) Heat wire, turn ON the battery side of the Cessna
type Split Master switch I have installed... no heat. Check to make sure
I'm getting 12v to the pitot mast +wiring... yep. Then I turn the ALTERNATOR
side of the split master ON in conjunction with the Battery side of the switch...
then I get heat at the Pitot mast. And when I say "heat".. I mean "HEAT!!!".
My Gretz heated pitot tube gets so hot it will burn you if you aren't careful.
What is going on here? I have a master bus (where the pitot + is connected) in
addition to an Avionics bus. Everthing else is working 'normally'..... Just
can't figure out why the pitot mast doesn't get hot until the Alternator side
of the split master is turned ON with the Battery side turned ON. All other items
on the Master bus get "hot' when I turn the battery side of the split switch
ON. Does this make sense? Why doesn't the mast get hot with just the Battery
side of the switch on? I don't have an engine mounted (still at the re-builders)
thus I have no alternator hooked up either.......
It works, but I just don't understand what is going on....
Thanks in advance,
Jack Lockamy
Camarillo, CA
BTW.... I was lucky enough to purchase my chromed Gretz heated Pitot tube, mounting
bracket, etc. for $50! Another fellow was parting out his RV and I snagged
it!
________________________________________________________________________________
| From: | David Nelson <david.nelson(at)pobox.com> |
| Subject: | Re: Pitot Heat wiring question.... |
Hi Jack,
Is the ground wire at the pitot _really_ attached to ground and verified with a
multi-meter?
Regards,
/\/elson
Austin, TX
Left wing/tank
On Sat, 4 Sep 2004, jacklockamy wrote:
>
>
> Here's one that has me 'stumped'......
>
> Building an RV-7A. Wings are on... I'm at the airport wiring the
> wings/wingtips. I hook up the Pitot (Gretz) Heat wire, turn ON the battery
> side of the Cessna type Split Master switch I have installed... no heat.
> Check to make sure I'm getting 12v to the pitot mast +wiring... yep. Then I
> turn the ALTERNATOR side of the split master ON in conjunction with the
> Battery side of the switch... then I get heat at the Pitot mast. And when I
> say "heat".. I mean "HEAT!!!". My Gretz heated pitot tube gets so hot it
> will burn you if you aren't careful.
>
> What is going on here? I have a master bus (where the pitot + is connected)
> in addition to an Avionics bus. Everthing else is working 'normally'.....
> Just can't figure out why the pitot mast doesn't get hot until the Alternator
> side of the split master is turned ON with the Battery side turned ON. All
> other items on the Master bus get "hot' when I turn the battery side of the
> split switch ON. Does this make sense? Why doesn't the mast get hot with
> just the Battery side of the switch on? I don't have an engine mounted
> (still at the re-builders) thus I have no alternator hooked up either.......
>
> It works, but I just don't understand what is going on....
>
> Thanks in advance,
>
> Jack Lockamy Camarillo, CA
>
> BTW.... I was lucky enough to purchase my chromed Gretz heated Pitot tube,
> mounting bracket, etc. for $50! Another fellow was parting out his RV and I
> snagged it!
>
>
>
>
>
>
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved .NOT . |
Thanks for your very complete reply.
Paul
----- Original Message -----
From: "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net>
Subject: AeroElectric-List: Cleveland Crimp Tool Mystery Solved .NOT .
> >snip>>Unlike the tools B&C sells with symmetrical dies, >>>>
> >
> >Bob, I simply do not understand how the above symetrical die tool will
> >properly crimp a terminal.
> >
>snipped
> Insulation grip? Again, not very pretty
> but I see no reason in physics to suspect
> it's any less adequate to the task than
> other tools I have ranging from $40 to $600.
>
> Bob . . .
________________________________________________________________________________
| From: | <bakerocb(at)cox.net> |
| Subject: | Electrical Education |
9/5/2004
Hello Bob Nuckolls, The slide switch at this URL
<<http://ottoeng.com/control/slideswitch.htm>> has these listed electrical ratings at 28 V DC:
Resistive: 5 Amp. Inductive: 3 Amp. Lamp: 1 Amp. Low level: 10 mAmp @30 mv.
Can you please help me better understand the significance of these ratings? The
following questions come to my mind:
1) Wouldnt an incandescent lamp (assumed) be a resistive load and have the same
rating as given for the resistive circuit load?
2) I understand the concept of higher initial inrush current affecting the lamp
current rating, but wouldnt that apply to any resistive load and not just the
lamp?
3) Why would the switch need a low level rating? If it can handle the larger current
loads couldnt it easily handle any small current load?
4) Is the inductive circuit current rating lower than the resistive circuit rating
because of the voltage spike caused by opening the switch?
5) Couldnt that inductive circuit current rating for the switch be higher if one
used a diode connected to ground across the inductive coil in the circuit?
6) Would those current load ratings improve, be less, or the same if the switch
were used in a 12 V DC circuit instead of a 28 V DC circuit?
Many thanks for your help from an electrical neophyte.
OC
________________________________________________________________________________
| From: | "Wayne Williams" <rwayne(at)gamewood.net> |
| Subject: | RE:Resistor values for LEDs |
Thanks, everyone, for the excellent ideas on LEDs. I learned a lot!
Wayne
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re; Electrical Education |
>Resistive: 5 Amp. Inductive: 3 Amp. Lamp: 1 Amp. Low level: 10 mAmp @30 mv.
These describe how the switch handles various types of DC switch loads.
What seems like a simple contact closure is in fact a complicated piece of
work when you look at the details. A hundred more operating modes could be
called out. The devil is in the details.
>1) Wouldnt an incandescent lamp (assumed) be a resistive load and have the
same
>rating as given for the resistive circuit load?
A resistive load behaves like Ohm's law. But a lamp usually has a
cold-filament current many times the hot filament current. It does not obey
Ohm's law very well.
>2) I understand the concept of higher initial inrush current affecting the
lamp
>current rating, but wouldnt that apply to any resistive load and not just
the
>lamp?
Load resistors are made to exhibit low surge currents. (They are often
crafted for other characteristics too).
>3) Why would the switch need a low level rating? If it can handle the
larger current
>loads couldnt it easily handle any small current load?
Many switches have poor or intermittent contact in what are called "dry"
loads--low volts. The material, shape and pressure of the contacts
determines this. Low voltages at higher currents are less of a problem
because the contacts weld a bit.. Gold does especially well for dry loads
like logic circuits.
>4) Is the inductive circuit current rating lower than the resistive circuit
rating
>because of the voltage spike caused by opening the switch?
Like the lamp load, the initial inductive circuit current can be arbitrarily
high, but the real issue is that the inductive load arcs when the switch
tries to open. This erodes the contacts.
>5) Couldnt that inductive circuit current rating for the switch be higher
if one
>used a diode connected to ground across the inductive coil in the circuit?
It turns out that it helps but doesn't cure the problem. A capacitor across
the contacts helps more. Then you throw a bunch of EMI parts into the mess.
>6) Would those current load ratings improve, be less, or the same if the
switch
>were used in a 12 V DC circuit instead of a 28 V DC circuit?
Great question! Switch contacts carry current when closed. When open they
withstand voltage. Sometimes the transition is difficult.
So the simple answer is that the current capacities stay roughly the same
regardless of voltage. The complicated answer is that everything changes.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
"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
________________________________________________________________________________
| From: | "Jon Finley" <jon(at)finleyweb.net> |
| Subject: | Watts conversion |
Hi all,
I have purchased a really slick little wireless color video camera. I
intend to mount this camera on my airframe in various places for both
enjoyment and drag reduction efforts (I have found it REALLY hard to see
the belly of the airplane while flying!). I need to carry a little 13"
tv/vcr combo in the airplane to record the video. So, the question:
The tv/vcr unit states that it consumes 65 watts at 13.2 volts. If I
understand this correctly, the unit will be consuming about 6.5 amps (at
13.2 volts). Is this correct?
Just wanted to confirm before I plug it into my plane and smoke the
electrical system....
Thanks much!
Jon Finley
N90MG Q2 - Subaru EJ-22 DD - 465 Hrs. TT
Apple Valley, Minnesota
http://www.FinleyWeb.net/Q2Subaru
________________________________________________________________________________
| From: | "Ron Koyich" <Ron(at)Koyich.com> |
| Subject: | Watts conversion |
How about 4A, Jon.
For DC, resistive circuits:
Power = Voltage x Current (P=EI)
Therefore,
Current = Power/Voltage (I=P/E)
65/13.2 = 4.0123456....etc Amperes
________________________________________________________________________________
| Subject: | Re: Watts conversion |
| From: | Steven Fingerhut <beechboy(at)nctv.com> |
Hello Jon. I see nobody has answered your question yet and i know when i ask
a question sometimes I really wanna know NOW. So since it is a simple
question here's the simple answer. Watts are volts X amps. So if they said
it was 65 watts at 13.2 volts it would be right at 5 amps. Make sure that it
said "65 watts at 13.2 volts.
Steve
> From: "Jon Finley" <jon(at)finleyweb.net>
> Reply-To: aeroelectric-list(at)matronics.com
> Date: Sun, 5 Sep 2004 19:31:40 -0500
> To:
> Subject: AeroElectric-List: Watts conversion
>
>
> Hi all,
>
> I have purchased a really slick little wireless color video camera. I
> intend to mount this camera on my airframe in various places for both
> enjoyment and drag reduction efforts (I have found it REALLY hard to see
> the belly of the airplane while flying!). I need to carry a little 13"
> tv/vcr combo in the airplane to record the video. So, the question:
>
> The tv/vcr unit states that it consumes 65 watts at 13.2 volts. If I
> understand this correctly, the unit will be consuming about 6.5 amps (at
> 13.2 volts). Is this correct?
>
> Just wanted to confirm before I plug it into my plane and smoke the
> electrical system....
>
> Thanks much!
>
> Jon Finley
> N90MG Q2 - Subaru EJ-22 DD - 465 Hrs. TT
> Apple Valley, Minnesota
> http://www.FinleyWeb.net/Q2Subaru
>
>
>
>
>
>
>
________________________________________________________________________________
| From: | "DAVID REEL" <dreel(at)cox.net> |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved .NOT . |
Concerning the insulation grip of the asymetrical die tools, I went back to the
dial caliper and measured the minimum die opening on the insulation grip side.
Here's the results:
Loose grip Cleveland tool: .159
Replacement tight grip tool: .149
Ideal crimper with 30-579 die .125
Looks like the Cleveland tool's insulation grip on the 22awg wire is somewhat loose
compared to the ideal dies. I'm real curious what the minimum gaps are on
your $600 AMP crimper Bob.
Dave Reel
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Watts conversion |
On Sep 5, 2004, at 8:31 PM, Jon Finley wrote:
>
> The tv/vcr unit states that it consumes 65 watts at 13.2 volts. If I
> understand this correctly, the unit will be consuming about 6.5 amps
> (at
> 13.2 volts). Is this correct?
Yes.
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | Brian Lloyd <brianl(at)lloyd.com> |
| Subject: | Re: Watts conversion |
On Sep 6, 2004, at 1:28 AM, Brian Lloyd wrote:
>
> On Sep 5, 2004, at 8:31 PM, Jon Finley wrote:
>
>>
>> The tv/vcr unit states that it consumes 65 watts at 13.2 volts. If I
>> understand this correctly, the unit will be consuming about 6.5 amps
>> (at
>> 13.2 volts). Is this correct?
>
> Yes.
No, and I don't know what I was thinking. P = I * E. I = P/E. P =
65W, E = 13.2V I = 65W/13.2V = 4.9A
Brian Lloyd 6501 Red Hook Plaza
brianl(at)lloyd.com Suite 201
+1.340.998.9447 St. Thomas, VI 00802
________________________________________________________________________________
| From: | "jacklockamy" <jacklockamy(at)verizon.net> |
| Subject: | Re: Pitot Heat wiring question.... |
The pitot heat ground IS located near the mast.... however.... I have NOT ohm'd
it out. I will give that a try along with the other suggestions I received off-list....
Thanks,
Jack Lockamy
Camarillo, CA
________________________________________________________________________________
| From: | "Paul Messinger" <paulm(at)olypen.com> |
| Subject: | Re: Cleveland Crimp Tool Mystery Solved .NOT . |
On the insulation grip side of the AMP tool its not the one dimension its
the overall shape of the die.
You get =O= vs around the insulation.
On the wire side of the crimper, Dies that are designed for the common vinyl
insulated terminals have a larger min die opening vs the Nylon PIDG terminal
tools as the Nylon insulation is thinner. (not the only difference but one
that is simple to see just by looking). The copper part of the terminal is
very different between the common and the PIDG types.
Also the AMP tools hold the terminal on all 4 sides so not only is there a
top to bottom clamping but the sides are supported (to prevent the otherwise
resulting increase in width) so you get copper compression all around. This
is a feature not found on any of the lower cost Tools I have seen. This
results in a very controlled squeeze that insures a HI quality result. Just
what you could expect from a $500 to $600 tool.
As Bob has suggested its possible for a reliable result from a much lower
cost tool.
I will look next time I am in my hanger and provide the AMP part numbers for
the tools I have. The AMP web site has the specs on these tools. Each Tool
has the applicable PIDG terminal sizes the dies were designed for so its
easy to get the right tool.
Paul
----- Original Message -----
From: "DAVID REEL" <dreel(at)cox.net>
Subject: Re: AeroElectric-List: Cleveland Crimp Tool Mystery Solved .NOT .
>
> Concerning the insulation grip of the asymetrical die tools, I went back
to the dial caliper and measured the minimum die opening on the insulation
grip side. Here's the results:
>
> Loose grip Cleveland tool: .159
> Replacement tight grip tool: .149
> Ideal crimper with 30-579 die .125
>
> Looks like the Cleveland tool's insulation grip on the 22awg wire is
somewhat loose compared to the ideal dies. I'm real curious what the minimu
m gaps are on your $600 AMP crimper Bob.
>
> Dave Reel
>
>
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <bob.nuckolls(at)cox.net> |
> Hi Bob
>
>I have 2 questions
>1. where do I order a circuitboard for the isolation amplifier
>(AEC9009-301-1)??
http://www.aeroelectric.com/Catalog/AECcatalog.html
>2. thinking out loud here, wondering where to run all the
>wiring....building an RV8 battery in the back, running a #2 to the
>firewall. the #2 passes by the fuseblock(s), is there a way to cut the
>insulation off locally and making a tap point for a #4 or so? I do realize
>that the 2 foot from the fire wall back to the fuseblocks in #4 or
>whatever the size is, won't kill me.
Some builders have successfully "tapped" a 2AWG or larger
pass-by either a soldered tap wire to the pass-by or
using a split-bolt tap . . . See:
http://www.goodmart.com/products/84477.htm
You can get these at Home Depot and most real hardware
stores. Electrical integrity is assured with these products
but you want to be sure you've mechanically protected the
joint with moisture barrier and insulation. A non-hardening
moldable sealant covered with heat shrink. All this
is pretty labor intensive . . . The only airplane on which
I found this to be really practical was a seaplane where
batteries were about 8' of wire forward of the instrument
panel. Here we decided that tapping the wire had a lower
parts count and higher longevity than putting terminals on
all the wires and bringing them together on an insulated,
threaded post.
In your case, I think I'd bring a small feeder back through
the firewall from the starter contactor to the fuseblocks.
You can use feed-through insulated posts . . . but they
increase parts count and raise questions about firewall
integrity. See:
http://www.aeroelectric.com/articles/Firewall_Penetration/firewall.html
> what about using a bulkhead pass-tru in the form of an 3/8 copper bolt
> in an insulator??
If you can find a threaded fastener feedthru with really
fire proof or fire resistant insulator, okay. The ones
I've seen offered by automotive speed shops are NOT suitable.
>Well, thanks for your time..
You're welcome . . .
Bob . . .
-----------------------------------------
( Experience and common sense cannot be )
( replaced with policy and procedures. )
( R. L. Nuckolls III )
-----------------------------------------
________________________________________________________________________________
| From: | "DAVID REEL" <dreel(at)cox.net> |
| Subject: | Re: Re; Electrical Education |
>1) Wouldnt an incandescent lamp (assumed) be a resistive load and have the
same
>rating as given for the resistive circuit load?
A resistive load behaves like Ohm's law. But a lamp usually has a
cold-filament current many times the hot filament current. It does not obey
Ohm's law very well.
An incandescent lamp filament is a resistive load that obeys Ohm's law. What happens
is the resistance of the filament increases a lot as it heats up. If you
measure the resistance of a cold filament you get a value that will give you
the initial inrush current. The rating on the bulb can be used to calculate
the resistance of a hot filament. AC43.13-1B paragraph 11-53 has good info on
the switch issue. It states that you can expect an inrush current 15 times
larger than the hot filament steady state current rating on the lamp. The book
suggests using a switch with 5 times the current capacity of the lamp.
Dave Reel - RV8A
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <rnuckolls(at)aeroelectric.com> |
| Subject: | Re: Wire Stripper |
>
>Radio Shack has a new one out that works very well. It has no dies and no
>holes. It automatically adjusts to the wire size. Cost about $19 I could
>not get the one from B&C to work for me at all.
What stripper did you buy from B&C? I don't see one on their
website and was unaware of any strippers they were offering.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> instruments |
| Subject: | Re: current limiting warning lights for EI |
instruments
instruments
>
> >
> >
> > The warning lights are from the B & C Specialties
> > http://www.bandc.biz/cgi-bin/ez-catalog/cat_display.cgi?
> > 10X358218#s888-1-2. I really didn't look at the bulbs, or even if
> > they had bulbs. I assume they are incandescent. I will look
> > tomorrow. Thanks for direction.
>
>I am familiar with the assembly as the same one came with my LR-3
>regulator. I don't remember the current drain either but I suspect it
>would work fine directly with the EI instruments without any extra
>hardware.
The lamp assemblies from B&C are incandescent. For a time,
B&C offered 6v lamps in their 14 volt regulator kits . . . made
for a really bright warning light.
These fixtures accept the T1-3/4 midge flanged base bulbs which
are available in a variety of voltage, service life ratings
and intensities. See:
http://www.chml.com/aviation/avia_incan3.cfm?type=T-1%203/4&crit=t134
Get the part number off the lamp and check its ratings against
the catalog page.
Bob . . .
---
________________________________________________________________________________
| From: | "Dan Checkoway" <dan(at)rvproject.com> |
| Subject: | Fw: Alternator Failure |
Ed says his email is being rejected from this list for some reason. Figured
I'd post it here for him.
----- Original Message -----
From: <edmondperry(at)sbcglobal.net>
Subject: Alternator Failure
> I tried sending this through the Aeroelectric list but it kept getting
returned. No responses from The VAF, So now it's out to you all...Anybody
know about Alternators and voltage regulators?
>
> What is the failure mode of an alternator? Here's the scenario, 35amp
alternator (from Van's)and the following equipment running. MicroAir 760
radio, EIS-4000, u-encoder, Garmin GTX320A- Transponder, LED cockpit
lighting, Taxi Light (Duckworth 55w) and then when I turned on the landing
light(Duckworth 55w) for takeoff the EIS-4000 gives an alarm for
12.2V(meaning I lost the alternator), and I start to smell burning
electrical. I immediately pull the CB for the alternator, but it is too
late. The alternator is toast. How does an alternator fail like this and
was it due to the increased current requirements with the second landing
light? I ran the figures and it seems like I was below the 35Amps that the
alternator was rated for. Even so if I was drawing more than 35Amps
wouldn't that just mean that the alternator would not be replacing the
current to the battery as fast as I was using it? Any ideas? Could it have
just been coincdence, and induced by the additional load?
>
> I'm confused....
>
> Ed Perry
> RV-8
> 190 hours
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: Re: Re; Electrical Education |
>>1) Wouldnt an incandescent lamp (assumed) be a resistive load and have
the
same
>rating as given for the resistive circuit load?
A resistive load behaves like Ohm's law. But a lamp usually has a
cold-filament current many times the hot filament current. It does not
obey
Ohm's law very well.
>An incandescent lamp filament is a resistive load that obeys Ohm's law.
What happens
>is the resistance of the filament increases a lot as it heats up. If you
>measure the resistance of a cold filament you get a value that will give
you
>the initial inrush current.
I stand by my wild blathering. For filament lamps, voltage and current do
not follow the simple equation "I=E/R" because the lamp's filament
resistance does not remain stable for different currents. Ohm's law
expresses a linear relationship that filament lamps do not follow very well.
Is Ohm's law true for filament lamps as "t goes to zero"?.....Yes, but
that's not the issue here.
Regards,
Eric M. Jones
www.PerihelionDesign.com
113 Brentwood Drive
Southbridge MA 01550-2705
Phone (508) 764-2072
Email: emjones(at)charter.net
Some days you get the food pellet; some days you get the electric shock."
---Rat
________________________________________________________________________________
| From: | Paul <pwilson(at)climber.org> |
Just had to do some wiring and tap into a 200a system for a new building. The
latest NEC required insulated cable blocks as split bolts are now forbidden. Turns
out that the local electrical supply house has most sizes in stock. They
have blocks for wires from 14 to 750 and all kinds of taps are available.
A simple one will slip over an existing wire and allow a tap. No cutting is required. When the assembly is complete it is fully insulated. Test the plastic to see if it meets airplane standards. The brand I used is shown at www.nsipolaris.com. To tap welding wire one would have to prep the joint by filling the wires with solder so the bolt would not damage the fine wires.
The way the block work is just like the blocks in a commercial breaker panel
which is a set screw crunches the wire in an AL/CU block. The insulated device
has plastic plugs to seal the holes.
Tell you one thing for sure - the split bolts are a lot easier to install and
they cost much less.
Paul
==========
>
>
>> Hi Bob
>>
> >I have 2 questions
>---- snip ------
>
>>2. thinking out loud here, wondering where to run all the
>>wiring....building an RV8 battery in the back, running a #2 to the
>>firewall. the #2 passes by the fuseblock(s), is there a way to cut the
>>insulation off locally and making a tap point for a #4 or so? I do realize
>>that the 2 foot from the fire wall back to the fuseblocks in #4 or
>>whatever the size is, won't kill me.
>
>
> Some builders have successfully "tapped" a 2AWG or larger
> pass-by either a soldered tap wire to the pass-by or
> using a split-bolt tap . . . See:
>
> http://www.goodmart.com/products/84477.htm
>
> You can get these at Home Depot and most real hardware
> stores. Electrical integrity is assured with these products
> but you want to be sure you've mechanically protected the
> joint with moisture barrier and insulation. A non-hardening
> moldable sealant covered with heat shrink. All this
> is pretty labor intensive . . . The only airplane on which
> I found this to be really practical was a seaplane where
> batteries were about 8' of wire forward of the instrument
> panel. Here we decided that tapping the wire had a lower
> parts count and higher longevity than putting terminals on
> all the wires and bringing them together on an insulated,
> threaded post.
>
> In your case, I think I'd bring a small feeder back through
> the firewall from the starter contactor to the fuseblocks.
> You can use feed-through insulated posts . . . but they
> increase parts count and raise questions about firewall
> integrity. See:
>
> http://www.aeroelectric.com/articles/Firewall_Penetration/firewall.html
>
>
>> what about using a bulkhead pass-tru in the form of an 3/8 copper bolt
>> in an insulator??
>
> If you can find a threaded fastener feedthru with really
> fire proof or fire resistant insulator, okay. The ones
> I've seen offered by automotive speed shops are NOT suitable.
>
>
>>Well, thanks for your time..
>
> You're welcome . . .
>
> Bob . . .
>
>
> -----------------------------------------
> ( Experience and common sense cannot be )
> ( replaced with policy and procedures. )
> ( R. L. Nuckolls III )
> -----------------------------------------
--
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: SL40 intercom and isolation amp |
>
>I asked a similar question before, but it may have been on a different
>group. I received some good answers, but I would like to be a little more
>specific.
>
>I think everyone that replied said an intercom of some sort was necessary
>in an RV. The question was about using the built-in intercom on some of
>the radios. Most said this wasn't a good idea. I'm wondering specifically
>about the intercom function in the SL40. This radio seems to be well liked
>including the intercom function. I'm wondering if this radio/intercom in
>conjuction with one of Bob's audio isolation amps would be acceptable and
>eliminate the need for a separate intercom.
The audio isolation amplifier has nothing to do with the intercom.
An iso amp provides a way to mix multiple received signal sources
with and optional entertainment source. If you have more than
one receiver and/or you wish to add a music source (stereo or
monophonic) to your equipment list, then some form of audio
mixer is called for.
There are some perfectly good intercom systems built into radios.
If the intercom is fitted with either adjustable vox controls
or autovox like the PS Engineering products, there's no reason
why it should not perform adequately. I can't think of any
reason that using an intercom built into a radio is a "bad"
idea.
Bob . . .
---
________________________________________________________________________________
| From: | "Robert L. Nuckolls, III" <b.nuckolls(at)cox.net> |
| Subject: | Re: Fw: Alternator Failure |
>
>Ed says his email is being rejected from this list for some reason. Figured
>I'd post it here for him.
I got the same query from Ed direct to my personal e-mail box. I've
attached my reply to him below. . .
By the way, had a nice visit with Cheryl and Tim Hedding
at their half done new house (3 years gone, 3 years to go)
east of Newton this afternoon. They work at B&C. See:
http://www.bandcspecialty.com/Staff.html
Cheryl told me of an L-60 alternator returned for zero-time
overhaul last week. The alternator had over 2000 hours on it
and the owner was overhauling the engine. She said she was
amazed at the condition of the alternator. She thought it would
have run another 2K as is. The bearings were great. Brush lengths
were good to go, slip rings were smooth and bright.
>----- Original Message -----
>From: <edmondperry(at)sbcglobal.net>
>Subject: Alternator Failure
>
>
> > I tried sending this through the Aeroelectric list but it kept getting
>returned. No responses from The VAF, So now it's out to you all...Anybody
>know about Alternators and voltage regulators?
> >
> > What is the failure mode of an alternator? Here's the scenario, 35amp
>alternator (from Van's)and the following equipment running. MicroAir 760
>radio, EIS-4000, u-encoder, Garmin GTX320A- Transponder, LED cockpit
>lighting, Taxi Light (Duckworth 55w) and then when I turned on the landing
>light(Duckworth 55w) for takeoff the EIS-4000 gives an alarm for
>12.2V(meaning I lost the alternator), and I start to smell burning
>electrical. I immediately pull the CB for the alternator, but it is too
>late. The alternator is toast. How does an alternator fail like this and
>was it due to the increased current requirements with the second landing
>light? I ran the figures and it seems like I was below the 35Amps that the
>alternator was rated for. Even so if I was drawing more than 35Amps
>wouldn't that just mean that the alternator would not be replacing the
>current to the battery as fast as I was using it? Any ideas? Could it have
>just been coincdence, and induced by the additional load?
> >
> > I'm confused...
The failure probably had nothing to do with load. They can
fail for several reasons that have nothing to do with
electrical stresses. Last I heard, Vans sells rebuilt
alternators. My personal choice for an aircraft alternator
would be the B&C L-40. Return rate on these machines has
been under 1% . . . for the entire fleet for the market
lifetime of nearly 15 years and several thousand units
sold.
It is quite likely that the L-40 is the last alternator
you'll have to buy.
BTW, you don't HAVE to use an LR-3 regulator with an L-40
although it too is an excellent performer. You can use a
generic Ford regulator and add your own ov protection.
I take if from your original query that you already have
active notification of low voltage so an LR-3 is overkill.
I will invite you to join us on the AeroElectric List
to continue this and similar discussions. It's useful to
share the information with as many folks as possible.
A further benefit can be realized with membership on
the list. There are lots of technically capable folks
on the list who can offer suggestions too. You can
join at . . .
http://www.matronics.com/subscribe/
Bob . . .
---
________________________________________________________________________________
| From: | "Franz Fux" <franz(at)lastfrontierheli.com> |
| Subject: | Aircraft receivers |
Hi Harley,
could you tell me what kind of intercom is included in the package,
Franz
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Harley
Subject: Re: AeroElectric-List: Aircraft receivers
I had considered that model...but just received my Microair M760 yesterday!
The Xcom does look like it has some better features, but I was as much
concerned with price...and Microair had the best deal (IMHO) with their
combo package that included everything including the transponder,
transceiver, VOX intercom, encoder and cables and antenna for $2700 US.
That's a considerable discount from Micrtoir's individual prices, with
an additional 5% from OxAero in Mississippi where I bought it.
http://www.oxaero.com/Microair-ComboKits.asp
And with the fine reputation that Microair has acheived in the field, I
didn't want to take a chance with the new kid on the block...it may be
better, but I didn't want to be the one to find out that it isn't.
Harley Dixon
www.agelesswings.com
James Foerster wrote:
>
>Does anyone have any experience with the XCOM 760, available from
>Aircraft Spruce? It is made by Micheal Coates out of Australia, and
>seems to be loosely based on the Micro Air 760. It seems to have
>advantages, in that it has a VOX circuit rather than 'hot mike' that
>Micro Air uses. It is priced just under $1000 now, as is the iCom
>ic-A200. The iCom looks nice, but I recall at least one negative
>comment about ignition noise--which may be very antenna and plane
>specific. Any comments?
>
>The web page comparing the XCOM to others is
>http://www.mcp.com.au/xcom760/comparison/comparison.html
>
>
---
---
________________________________________________________________________________
| From: | "Richard E. Tasker" <retasker(at)optonline.net> |
| Subject: | Re: Re: Re; Electrical Education |
Sorry, Eric, but David is correct on this one.
An incandescent light does indeed follow Ohm's law. What it doesn't do
is remain the same resistance as it heats up - but that doesn't mean
that ohms law doesn't hold at any given resistance. Ohm's law doesn't
say anything about linearity of a load - only that at any particular set
of R, I and E they will follow the equation.
Dick Tasker
Eric M. Jones wrote:
>
>
> >>1) Wouldnt an incandescent lamp (assumed) be a resistive load and have
>the
> same
> >rating as given for the resistive circuit load?
>
> A resistive load behaves like Ohm's law. But a lamp usually has a
> cold-filament current many times the hot filament current. It does not
>obey
> Ohm's law very well.
>
>
>
>>An incandescent lamp filament is a resistive load that obeys Ohm's law.
>>
>>
>What happens
>
>
>>is the resistance of the filament increases a lot as it heats up. If you
>>measure the resistance of a cold filament you get a value that will give
>>
>>
>you
>
>
>>the initial inrush current.
>>
>>
>
>I stand by my wild blathering. For filament lamps, voltage and current do
>not follow the simple equation "I=E/R" because the lamp's filament
>resistance does not remain stable for different currents. Ohm's law
>expresses a linear relationship that filament lamps do not follow very well.
>
>Is Ohm's law true for filament lamps as "t goes to zero"?.....Yes, but
>that's not the issue here.
>
>Regards,
>Eric M. Jones
>www.PerihelionDesign.com
>113 Brentwood Drive
>Southbridge MA 01550-2705
>Phone (508) 764-2072
>Email: emjones(at)charter.net
>
>Some days you get the food pellet; some days you get the electric shock."
> ---Rat
>
>
>
>
________________________________________________________________________________
| Subject: | Re: Re: Re; Electrical Education |
| From: | "John Loram" <johnl(at)loram.org> |
This is one of those wonderful philosophical questions that divides the
real world from the simple/ideal world. Ohm's law tell us that if you
double the voltage the current will double. But ohm's law is a simple
equation that is only correct in the simple/ideal world where loads are
simple/ideal and do not respond to the current flowing through them. In
the real world, like light bulbs, loads are affected by the current
flowing through them. The tungsten lamp filament like many materials has
a positive temperature coefficient. As it gets hot it's resistance
increases. Ohm's law does not take that into account. There are other
formulations that do.
So, is Ohm's law broken????? Well, perhaps not. It's just not up to the
task of describing a light bulb. You have to make sure that the science
you are using is up to describing the world your investigating. E.g.
classical physics bombs out at the quantum level.
Regards, -john-
-----Original Message-----
From: owner-aeroelectric-list-server(at)matronics.com
[mailto:owner-aeroelectric-list-server(at)matronics.com] On Behalf Of
Richard E. Tasker
Subject: Re: AeroElectric-List: Re: Re: Re; Electrical Education
-->
Sorry, Eric, but David is correct on this one.
An incandescent light does indeed follow Ohm's law. What it doesn't do
is remain the same resistance as it heats up - but that doesn't mean
that ohms law doesn't hold at any given resistance. Ohm's law doesn't
say anything about linearity of a load - only that at any particular set
of R, I and E they will follow the equation.
Dick Tasker
________________________________________________________________________________
| From: | Harley <harley(at)AgelessWings.com> |
| Subject: | Re: Aircraft receivers |
Morning, Franz...
They didn't have much information on the intercom on the Microair
website, but I found this page at another distributor...it's a PS
engineering Intercom...here's the manual in pdf format:
http://www.ps-engineering.com/docs/PM501PilotGuide.pdf
Harley
Franz Fux wrote:
>
>Hi Harley,
>could you tell me what kind of intercom is included in the package,
>Franz
>
>-----Original Message-----
>From: owner-aeroelectric-list-server(at)matronics.com
>[mailto:owner-aeroelectric-list-server(at)matronics.com]On Behalf Of Harley
>To: aeroelectric-list(at)matronics.com
>Subject: Re: AeroElectric-List: Aircraft receivers
>
>
>I had considered that model...but just received my Microair M760 yesterday!
>
>The Xcom does look like it has some better features, but I was as much
>concerned with price...and Microair had the best deal (IMHO) with their
>combo package that included everything including the transponder,
>transceiver, VOX intercom, encoder and cables and antenna for $2700 US.
>That's a considerable discount from Micrtoir's individual prices, with
>an additional 5% from OxAero in Mississippi where I bought it.
>
>http://www.oxaero.com/Microair-ComboKits.asp
>
>And with the fine reputation that Microair has acheived in the field, I
>didn't want to take a chance with the new kid on the block...it may be
>better, but I didn't want to be the one to find out that it isn't.
>
>Harley Dixon
>
>www.agelesswings.com
>
>
>James Foerster wrote:
>
>
>
>>
>>
>
>
>
>>Does anyone have any experience with the XCOM 760, available from
>>Aircraft Spruce? It is made by Micheal Coates out of Australia, and
>>seems to be loosely based on the Micro Air 760. It seems to have
>>advantages, in that it has a VOX circuit rather than 'hot mike' that
>>Micro Air uses. It is priced just under $1000 now, as is the iCom
>>ic-A200. The iCom looks nice, but I recall at least one negative
>>comment about ignition noise--which may be very antenna and plane
>>specific. Any comments?
>>
>>The web page comparing the XCOM to others is
>>http://www.mcp.com.au/xcom760/comparison/comparison.html
>>
>>
>>
>>
>
>
>---
>
>---
>
>
>
>
________________________________________________________________________________
| From: | "Eric M. Jones" <emjones(at)charter.net> |
| Subject: | Re: Re: Re: Re; Electrical Education |
>Sorry, Eric, but David is correct on this one.
Richard, I stick with my wild blathering....
>An incandescent light does indeed follow Ohm's law.
Only if you use Brian's busted calculator....
>What it doesn't do is remain the same resistance as it heats up -
Then it does not follow Ohm's Law.
>but that doesn't mean that ohms law doesn't hold at any given resistance.
Yes it does.
>Ohm's law doesn't say anything about linearity of a load -
Ohm's Law is a "Linear" equation in a non-linear problem.
>only that at any particular set of R, I and E they will follow the
equation.
As I mentioned.....perhaps at an instant in time (derivative t of a more
complex equation.)
Here are three aids to explain what is happening:
1) Physics is not math. This usually takes some kind of undergraduate Zen
epiphany to understand. If you think that the process of doing algebra and
balancing the equation on a particular set of E, I, and R means
something...then you do not yet understand grasshopper.
2) The Stephan-Boltzmann law "Radiation is proportional to the forth power
of temperature", correctly describes the E/I characteristics of filament
lamps. Google this stuff if you dare. So do the S-B Law and Ohm's Law
describe the same Physics?
3) A real-world approach---Imagine having a filament lamp on your experiment
bench. Can you set the power supply voltage, measure the cold lamp
resistance, and use Ohm's Law to calculate the current you will get when you
turn on the light? Try it--if you succeed then Ohms' Law might apply to the
situation.
Some will say, "...Yes, but Ohm's Law states that the current through the
circuit is directly proportional to the applied voltage and inversely
August 25, 2004 - September 07, 2004
AeroElectric-Archive.digest.vol-dl