Today's Message Index:
----------------------
1. 04:15 AM - Re: Pitot Current Draw (Rodney Dunham)
2. 04:50 AM - Re: Re: Pitot Current Draw (raymondj)
3. 05:20 AM - Re: AEC9005-301-1A Module (Robert L. Nuckolls, III)
4. 05:22 AM - Re: Re: Pitot Current Draw (Robert L. Nuckolls, III)
5. 05:26 AM - Re: GPS Antenna (Robert L. Nuckolls, III)
6. 05:27 AM - Re: Re: Pitot Current Draw (Chuck Jensen)
7. 05:36 AM - Re: Re: Pitot Current Draw (Chuck Jensen)
8. 06:58 AM - Re: GPS Antenna (Dale Ensing)
9. 07:01 AM - : Rotax Aux Altenator switching. (James H Nelson)
10. 07:03 AM - Need engine rpm pickup for Lycoming 360 (Jay Herron)
11. 07:24 AM - Re: Re: Pitot Current Draw (Bob White)
12. 07:32 AM - Landing Radar....! (Fergus Kyle)
13. 07:55 AM - Re: Re: Pitot Current Draw (Chuck Jensen)
14. 08:22 AM - LED backlit rocker switches (Chris Johnston)
15. 08:55 AM - Re: LED backlit rocker switches (6440 Auto Parts)
16. 09:38 AM - Re: : Rotax Aux Altenator switching. ()
17. 09:40 AM - Re: Re: Pitot Current Draw (Ernest Christley)
18. 09:45 AM - Re: Re: Pitot Current Draw (Fiveonepw@aol.com)
19. 09:55 AM - Re: Re: Pitot Current Draw (Matt Prather)
20. 10:16 AM - Re: LED backlit rocker switches (Ernest Christley)
21. 11:40 AM - Re: LED backlit rocker switches (Fiveonepw@aol.com)
22. 12:53 PM - Re: LED backlit rocker switches (Matt Prather)
23. 02:26 PM - Re: LED backlit rocker switches (John Bolding)
24. 03:02 PM - Re: Re: Pitot Current Draw (C Smith)
25. 04:16 PM - Re: : Rotax Aux Altenator switching. (h&jeuropa)
26. 04:21 PM - Aluminum Bus question for Bob (Dave Saylor)
27. 04:32 PM - Re: Re: Pitot Current Draw (Matt Prather)
28. 05:35 PM - Re: Need engine rpm pickup for Lycoming 360 (Robert L. Nuckolls, III)
29. 05:49 PM - Re: Re: Pitot Current Draw (Robert L. Nuckolls, III)
30. 05:53 PM - Re: Re: Pitot Current Draw (Robert L. Nuckolls, III)
31. 07:10 PM - Re: Pitot Current Draw (Duty Cycle Control Case) (Robert L. Nuckolls, III)
32. 07:51 PM - Re: Re: Pitot Current Draw (Mike)
33. 07:52 PM - Re: Re: Pitot Current Draw (Bob White)
34. 08:33 PM - Re: Re: Pitot Current Draw (SteinAir, Inc.)
35. 08:40 PM - Re: Need engine rpm pickup for Lycoming 360 ()
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| Subject: | RE: Pitot Current Draw |
Grasshopper,
When I was in the Navy, practicing emergency medicine at NAS JAX Hospital, a
corpsman came to me and in the course of conversation brought up the idea of
vapor locking the heart. We had been
having a conversation about how the human body handles gases and he asked me
how much air one could inject into a vein in order to vapor lock the heart
and kill the person. Well, I was training these guys to be ready for
anything in combat so I didn't think anything about the question. I shot out
a WAG number of cc's and the conversation drifted on to other topics.
A few days later he didn't show up for work. One of his buddies informed me
that he had tried to commit suicide by injecting air into his veins! Nobody
else overheard our "vapor lock" conversation
and nobody knew I had advised him on the "proper" technic for vapor locking
the heart. Not even me!
Well, that young and foolish sailor lived through his crisis and I was
relieved. And since that day, I am reluctant to give "answers" just because
inquiring minds want to know. You see, I believe I have some measure of
culpability for the actions of others if I have enabled them in some way to
DO something bad with the information they're gathering. And, I believe the
listers here believe that too!
We listers want everyone here to play safe! Play yes, absolutely! BUT, play
safe! And if you ask questions that raise suspicion that you're not going to
play safe, don't expect your buddies here on the list to simply not notice!
You're asking them for advice precisely because they have expertise greater
than your own! Think about it. Sometimes the teacher has to backtrack the
pupil's training a step or two and illustrate why their [the student's]
thinking is wrong. Don't get your panties in a wad when that happens. The
enlightened student GETS the light bulb phenomenon and realizes that he did,
in fact, "get an acceptable answer."
Rodney in Tennessee
DO NOT ARCHIVE
>From: Speedy11@aol.com
>To: aeroelectric-list@matronics.com
>Subject: AeroElectric-List: Re: Pitot Current Draw
>Date: Wed, 6 Dec 2006 20:56:45 EST
>
>Chuck,
>You have just experienced the main thing I dislike about this forum. When
>you ask for advice or assistance, you will commonly get critique on why you
>should not do what it is you want to do. It takes several attempts at
>explaining
>that you don't care about opinions - you simply want assistance. For
>example,
>I've asked how to sample volts and amps in multiple places in my electrical
>system. I got "you don't need to know that info while you're flying."
>Regardless, I want to be able to do that so how can I do it? Answer: since
>I don't
>think you should do that I'm not going to tell you how to do it.
>As you've discovered, getting an answer can be very frustrating.
>Still, I've learned a lot about electrical stuff here and I continue to
>learn. So, I still find the forum of value.
>I wish I had the answer for you - I would provide it. But, I don't.
>Hopefully, you will get an acceptable answer.
>Stan Sutterfield
>
>Okay, I appreciate everyone holding forth that it's stupid to fly in
>ice....I'm not that dumb, I only look it. However, the question stands,
>how does one knock down the heat and current draw. Richard mentioned a
>'strut switch'....whoever that is. Can someone enlighten us
>non-electrical types. What I'm concerned about is being in the clouds,
>close to freezing and loose electrical--I'd just as soon not have to
>turn off the pitot heat because it's sucking the battery dry in short
>order; I'd rather it be in long order.
>
>Chuck Jensen
_________________________________________________________________
Get free, personalized commercial-free online radio with MSN Radio powered
by Pandora http://radio.msn.com/?icid=T002MSN03A07001
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| Subject: | RE: Pitot Current Draw |
Rodney (O Wise Master),
Pretty arrogant of you to think that you have control of or responsibility
for another's actions and to think that you have any right to try to impose
your values on another by attempting to control their actions.
Raymond Julian
Kettle River, MN.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Rodney
Dunham
Sent: Thursday, December 07, 2006 6:14 AM
Subject: AeroElectric-List: RE: Pitot Current Draw
<rdunhamtn@hotmail.com>
Grasshopper,
When I was in the Navy, practicing emergency medicine at NAS JAX Hospital, a
corpsman came to me and in the course of conversation brought up the idea of
vapor locking the heart. We had been
having a conversation about how the human body handles gases and he asked me
how much air one could inject into a vein in order to vapor lock the heart
and kill the person. Well, I was training these guys to be ready for
anything in combat so I didn't think anything about the question. I shot out
a WAG number of cc's and the conversation drifted on to other topics.
A few days later he didn't show up for work. One of his buddies informed me
that he had tried to commit suicide by injecting air into his veins! Nobody
else overheard our "vapor lock" conversation
and nobody knew I had advised him on the "proper" technic for vapor locking
the heart. Not even me!
Well, that young and foolish sailor lived through his crisis and I was
relieved. And since that day, I am reluctant to give "answers" just because
inquiring minds want to know. You see, I believe I have some measure of
culpability for the actions of others if I have enabled them in some way to
DO something bad with the information they're gathering. And, I believe the
listers here believe that too!
We listers want everyone here to play safe! Play yes, absolutely! BUT, play
safe! And if you ask questions that raise suspicion that you're not going to
play safe, don't expect your buddies here on the list to simply not notice!
You're asking them for advice precisely because they have expertise greater
than your own! Think about it. Sometimes the teacher has to backtrack the
pupil's training a step or two and illustrate why their [the student's]
thinking is wrong. Don't get your panties in a wad when that happens. The
enlightened student GETS the light bulb phenomenon and realizes that he did,
in fact, "get an acceptable answer."
Rodney in Tennessee
DO NOT ARCHIVE
>From: Speedy11@aol.com
>To: aeroelectric-list@matronics.com
>Subject: AeroElectric-List: Re: Pitot Current Draw
>Date: Wed, 6 Dec 2006 20:56:45 EST
>
>Chuck,
>You have just experienced the main thing I dislike about this forum. When
>you ask for advice or assistance, you will commonly get critique on why you
>should not do what it is you want to do. It takes several attempts at
>explaining
>that you don't care about opinions - you simply want assistance. For
>example,
>I've asked how to sample volts and amps in multiple places in my electrical
>system. I got "you don't need to know that info while you're flying."
>Regardless, I want to be able to do that so how can I do it? Answer: since
>I don't
>think you should do that I'm not going to tell you how to do it.
>As you've discovered, getting an answer can be very frustrating.
>Still, I've learned a lot about electrical stuff here and I continue to
>learn. So, I still find the forum of value.
>I wish I had the answer for you - I would provide it. But, I don't.
>Hopefully, you will get an acceptable answer.
>Stan Sutterfield
>
>Okay, I appreciate everyone holding forth that it's stupid to fly in
>ice....I'm not that dumb, I only look it. However, the question stands,
>how does one knock down the heat and current draw. Richard mentioned a
>'strut switch'....whoever that is. Can someone enlighten us
>non-electrical types. What I'm concerned about is being in the clouds,
>close to freezing and loose electrical--I'd just as soon not have to
>turn off the pitot heat because it's sucking the battery dry in short
>order; I'd rather it be in long order.
>
>Chuck Jensen
_________________________________________________________________
Get free, personalized commercial-free online radio with MSN Radio powered
by Pandora http://radio.msn.com/?icid=T002MSN03A07001
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| Subject: | Re: AEC9005-301-1A Module |
At 02:45 PM 12/6/2006 -0500, you wrote:
><bbradburry@allvantage.com>
>
>Bob,
>I intended to set my plane up following the Z-19 drawing. It appears that
>the Over/under voltage monitor module is no longer available. I can find
>no link to the instructions for building one?? Are the boards you were
>selling still available or are they gone?
>How should I reconfigure the Aux battery switch if the "auto" capability
>is no longer available?
I'm replacing the 9005 series products with a new
technology. You can get a pre-view at:
http://www.aeroelectric.com/Catalog/AEC/9011/9011-700-1C.pdf
There will be a version that offers the same functionality
as the old 9005-301-1 ECB from which the LVW/ABMM product was
assembled. However . . .
The 9011 as depicted offers TWO independent LV warning channels
that offers the same functionality as the 9005, just not
automatic. One LV channel is used to watch the main bus, the
other watches the aux battery bus. If the pilot fails to close
the aux battery switch after starting the engine, then only the
main bus warning light goes out.
The ADVANTAGE of this architecture and operating philosophy
is that a failed aux battery contactor can be spotted with the 9011
installed where it will go un-annunciated with the 9005.
The third output channel drives a latching relay suitable for
shutting down PM alternators, and older generators in an OV
condition. It can also be used on wound-field alternators.
I really didn't want to "step back" to the relay technology
but it's appeal is universal applicability to virtually
all engine driven power sources.
>Thanks for your excellent support and assistance for the OBAM group.
>
>I notice that most of your daily responses start at around 3:00-3:30
>AM!!! When,(if??) do you sleep??!!
You're welcome. The times posted for List messages is Pacific
time were the server is located. I'm generally up about 6
and check the e-mail first thing. I'm usually in bed by
midnight.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
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| Subject: | Re: Pitot Current Draw |
At 09:14 PM 12/6/2006 -0500, you wrote:
>Ernest,
>Please explain what you mean by a cockpit referenced backup altimeter. I
>don't think I've ever heard of any thing like that. And how would it help
>keep you from hitting the ground?
>Maybe you're referring to alternate static air. But the question wasn't
>on heating the static port - it was on losing pitot ram air to ice.
"Cockpit referenced" is a specific term for "vented to
cockpit atmosphere" . . . which is what the vast majority
of alternate static sources do.
The piper Pacer and Tri-Pacer didn't have static systems.
The altimeter was simply mounted to the panel and vented
to cockpit as was any VSI and/or altitude encoders added
at later dates.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
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At 07:04 PM 12/6/2006 -0800, you wrote:
>Are GPS antennas generic so they can be hooked up to any receiver? A
>friend of mine has a L1/L2 antenna manufactured by Sensor Systems and
>wants to hook it up to a handheld Lowrance.
>
>
If it's an un-amplified antenna, it's interchangeable.
If an "active" antenna, there are no industry wide standards
for such antennas and there is risk that an antenna not
specifically designed to service your receiver will
work. That doesn't mean that there aren't a whole lot
of active antennas that will nicely interchange . . . only
that folks who build receivers would dearly love for
you to use their antenna and are not likely to give you
a list of other, equally suitable antennas.
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
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| Subject: | Re: Pitot Current Draw |
Mike,
If I was able to draw the sarcasm out of you, I'd had to see what a pro
could do! (:-)). Actually, I've done the calculations and am satisfied
of the results, even if not confirmed by empirical data. The current
pitot draws about 15 amps. By comparison, my older, but very adequate
(as in--never iced up) pitot drew 7 amps. While not on a first name
basis with any electrons, I assume that an amp is an amp and is
generally going to produce a certain amount of heat, which is apparently
adequate, based on empirical experience. So, if 7 amps was good enough
in the old pitot, I was thinkin' that 7 amps was probably good enough
for this pitot. I could hire a thermodynamist to confirm all this, but
I'll go out on a limb and employ common sense instead--it's cheaper and
often, just as accurate.
As to your suggestion of simply using a bigger battery, I didn't notice
any calculations showing how big and how many batteries I should have.
However, if by limiting heat output in the pitot, I cut my amperage in
half, I can calculate that the draw from my current battery will be 1/2
as much and last twice as long (but not for the full load, since the
pitot is only a fraction of the total load; unfortunately, a high
fraction). As to the suggestion to just turn it off.....duh, the reason
we have a heated pitot is--never mind, it makes my head hurt.
Sorry for my poor response and sarcasm, but I think you brought it out
of me.
All the forgoing is just kidding. Not many people intentionly flying
their GA craft into icing and not many lose electrical power generation,
but when the two are combined, even though the odds are it happening are
small, the odds of ending up dead are quite large. So, if there was a
reasonably simple mechanical/electrical means of reducing the current
draw of the pitot, I wanted to do it. Kind of like flying an
airplane--not many of us have real good reasons for doing it, but we
just want to do it.
Chuck Jensen
Mike wrote....
The only way I can answer this question is to tell a story. First,
flying in the ice is something many pilot do every year and sometimes
often. If you know what you're doing and are prepared then the risks
are minimal. I have been flying in ice with airplanes that are able to
handle it for better then 20 years. It's not like flying on a sunny
day. But once you get use to it and prepare for it, it's not that big
of a deal. A few words of advice, no two icing days are the same. Only
experience will help you here. My personal feeling on ice in piston
powered planes, you don't have many out when the weather gets bad. When
in ice greater then light find a place to land ASAP.
As for you electric question; First the easy answer is to put a bigger
battery in the airplane. Second, why would you think that using less
power for pitot heat is going to be any better then turning the pitot
heat off all together? Unless you run a thermal equation on the speed,
temperature, and heat (layman's terms) required to guarantee the
anti-ice properties needed, then everything your doing is just a big
guess anyway. And I guessing that since I have to go to the book to do
said equation thoroughly, I would guess the electrical formula by
comparison would be a piece of cake. I know this is not what you want
to hear but the facts are the facts. The reason that the pitot uses so
much power (in general) is that is what it takes to keep ice off the
probe in 100% humidity at temperatures < 10dec C.
Sorry for the poor and somewhat sarcastic answer, but I think Chuck
brought it out in me.
Regards,
Mike Larkin
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Speedy11@aol.com
Sent: Wednesday, December 06, 2006 6:57 PM
Subject: AeroElectric-List: Re: Pitot Current Draw
Chuck,
You have just experienced the main thing I dislike about this forum.
When you ask for advice or assistance, you will commonly get critique on
why you should not do what it is you want to do. It takes several
attempts at explaining that you don't care about opinions - you simply
want assistance. For example, I've asked how to sample volts and amps
in multiple places in my electrical system. I got "you don't need to
know that info while you're flying." Regardless, I want to be able to
do that so how can I do it? Answer: since I don't think you should do
that I'm not going to tell you how to do it.
As you've discovered, getting an answer can be very frustrating.
Still, I've learned a lot about electrical stuff here and I continue to
learn. So, I still find the forum of value.
I wish I had the answer for you - I would provide it. But, I don't.
Hopefully, you will get an acceptable answer.
Stan Sutterfield
Okay, I appreciate everyone holding forth that it's stupid to
fly in
ice....I'm not that dumb, I only look it. However, the question
stands,
how does one knock down the heat and current draw. Richard
mentioned a
'strut switch'....whoever that is. Can someone enlighten us
non-electrical types. What I'm concerned about is being in the
clouds,
close to freezing and loose electrical--I'd just as soon not
have to
turn off the pitot heat because it's sucking the battery dry in
short
order; I'd rather it be in long order.
Chuck Jensen
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Message 7
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| Subject: | RE: Pitot Current Draw |
Wow, this thread is about everything except how to reduce the pitot
current draw, though I'll follow up on the Gretz pitot heat control
idea.
I don't think Rodney was arrogant in thinking he had control or
responsibility for another's actions...though he might be mistaken.
Information and knowledge is a tool, how it is used is generally not
under the control and responsibility of the teacher. If that were the
case, Driver Eds teachers would be a horribly conflicted, guilt-ridden
bunch.
Chuck Jensen
Do Not Archive
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
raymondj
Sent: Thursday, December 07, 2006 7:49 AM
Subject: RE: AeroElectric-List: RE: Pitot Current Draw
--> <raymondj@frontiernet.net>
Rodney (O Wise Master),
Pretty arrogant of you to think that you have control of or
responsibility for another's actions and to think that you have any
right to try to impose your values on another by attempting to control
their actions.
Raymond Julian
Kettle River, MN.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Rodney
Dunham
Sent: Thursday, December 07, 2006 6:14 AM
Subject: AeroElectric-List: RE: Pitot Current Draw
<rdunhamtn@hotmail.com>
Grasshopper,
When I was in the Navy, practicing emergency medicine at NAS JAX
Hospital, a corpsman came to me and in the course of conversation
brought up the idea of vapor locking the heart. We had been having a
conversation about how the human body handles gases and he asked me how
much air one could inject into a vein in order to vapor lock the heart
and kill the person. Well, I was training these guys to be ready for
anything in combat so I didn't think anything about the question. I shot
out a WAG number of cc's and the conversation drifted on to other
topics.
A few days later he didn't show up for work. One of his buddies informed
me that he had tried to commit suicide by injecting air into his veins!
Nobody else overheard our "vapor lock" conversation and nobody knew I
had advised him on the "proper" technic for vapor locking the heart. Not
even me!
Well, that young and foolish sailor lived through his crisis and I was
relieved. And since that day, I am reluctant to give "answers" just
because inquiring minds want to know. You see, I believe I have some
measure of culpability for the actions of others if I have enabled them
in some way to DO something bad with the information they're gathering.
And, I believe the listers here believe that too!
We listers want everyone here to play safe! Play yes, absolutely! BUT,
play safe! And if you ask questions that raise suspicion that you're not
going to play safe, don't expect your buddies here on the list to simply
not notice! You're asking them for advice precisely because they have
expertise greater than your own! Think about it. Sometimes the teacher
has to backtrack the pupil's training a step or two and illustrate why
their [the student's] thinking is wrong. Don't get your panties in a wad
when that happens. The enlightened student GETS the light bulb
phenomenon and realizes that he did, in fact, "get an acceptable
answer."
Rodney in Tennessee
DO NOT ARCHIVE
>From: Speedy11@aol.com
>To: aeroelectric-list@matronics.com
>Subject: AeroElectric-List: Re: Pitot Current Draw
>Date: Wed, 6 Dec 2006 20:56:45 EST
>
>Chuck,
>You have just experienced the main thing I dislike about this forum.
>When you ask for advice or assistance, you will commonly get critique
>on why you should not do what it is you want to do. It takes several
>attempts at explaining that you don't care about opinions - you simply
>want assistance. For example,
>I've asked how to sample volts and amps in multiple places in my
electrical
>system. I got "you don't need to know that info while you're flying."
>Regardless, I want to be able to do that so how can I do it? Answer:
since
>I don't
>think you should do that I'm not going to tell you how to do it.
>As you've discovered, getting an answer can be very frustrating.
>Still, I've learned a lot about electrical stuff here and I continue to
>learn. So, I still find the forum of value.
>I wish I had the answer for you - I would provide it. But, I don't.
>Hopefully, you will get an acceptable answer.
>Stan Sutterfield
>
>Okay, I appreciate everyone holding forth that it's stupid to fly in
>ice....I'm not that dumb, I only look it. However, the question stands,
>how does one knock down the heat and current draw. Richard mentioned a
>'strut switch'....whoever that is. Can someone enlighten us
>non-electrical types. What I'm concerned about is being in the clouds,
>close to freezing and loose electrical--I'd just as soon not have to
>turn off the pitot heat because it's sucking the battery dry in short
>order; I'd rather it be in long order.
>
>Chuck Jensen
_________________________________________________________________
Get free, personalized commercial-free online radio with MSN Radio
powered by Pandora http://radio.msn.com/?icid=T002MSN03A07001
Message 8
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Maybe these people http://gilsson.stores.yahoo.net/ can tell you if
the Sensor Systems antenna works with the Lowrance handheld GPS.
Dale Ensing
----- Original Message -----
From: "Robert L. Nuckolls, III" <nuckollsr@cox.net>
Sent: Thursday, December 07, 2006 8:24 AM
Subject: Re: AeroElectric-List: GPS Antenna
> <nuckollsr@cox.net>
>
> At 07:04 PM 12/6/2006 -0800, you wrote:
>
>>Are GPS antennas generic so they can be hooked up to any receiver? A
>>friend of mine has a L1/L2 antenna manufactured by Sensor Systems and
>>wants to hook it up to a handheld Lowrance.
>>
>>
>
> If it's an un-amplified antenna, it's interchangeable.
> If an "active" antenna, there are no industry wide standards
> for such antennas and there is risk that an antenna not
> specifically designed to service your receiver will
> work. That doesn't mean that there aren't a whole lot
> of active antennas that will nicely interchange . . . only
> that folks who build receivers would dearly love for
> you to use their antenna and are not likely to give you
> a list of other, equally suitable antennas.
>
> Bob . . .
>
>
> ---------------------------------------------------------
> < What is so wonderful about scientific truth...is that >
> < the authority which determines whether there can be >
> < debate or not does not reside in some fraternity of >
> < scientists; nor is it divine. The authority rests >
> < with experiment. >
> < --Lawrence M. Krauss >
> ---------------------------------------------------------
>
>
>
Message 9
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| Subject: | : Rotax Aux Altenator switching. |
That sounds really nice. Where did you find them?
Jim
Message 10
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| Subject: | Need engine rpm pickup for Lycoming 360 |
I am finally ready to start hooking up wires on my Zenith 801 with Lycoming O-360a1a.
I have a Aveo E-1 and MaxFlight on my panel and need an electronic RPM
pickup for the Lycoming. My ultralight (Quicksilver GT400) was very simple to
wire up as it had a pulse wire from the electronic ignition already. No electronic
ignition on this old Lycoming (Bendix mags). Any suggestions?
Jay Herron
CH801 95% complete
Salem, OH
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=79835#79835
Message 11
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| Subject: | Re: Pitot Current Draw |
On Thu, 7 Dec 2006 08:27:22 -0500
"Chuck Jensen" <cjensen@dts9000.com> wrote:
><snip> The current
> pitot draws about 15 amps. By comparison, my older, but very adequate
> (as in--never iced up) pitot drew 7 amps. While not on a first name
> basis with any electrons, I assume that an amp is an amp and is
> generally going to produce a certain amount of heat, which is apparently
> adequate, based on empirical experience. So, if 7 amps was good enough
> in the old pitot, I was thinkin' that 7 amps was probably good enough
> for this pitot. I could hire a thermodynamist to confirm all this, but
> I'll go out on a limb and employ common sense instead--it's cheaper and
> often, just as accurate.
>
<snip>
Not quite true Chuck. Your old pitot tube was about 2 ohms. You were
drawing 7 amps from around 14 volts. Power is I^2 * R = 98 W. Now
you have a pitot that's about 1 ohm drawing 15 amps from 14 volts (0.933
ohms but who's counting). Drop the current in this pitot to 7 amps and
power is only 49 W. It was suggested by someone that the dropping
resistor could be mounted on the pitot also which would help, but still
not be equivalent.
Bob W. (Not a thermodynamist but I learned ohms law at an early age.)
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
First Flight: 11/23/2006 7:50AM - 0.7 Hours Total Time
Cables for your rotary installation - http://www.roblinphoto.com/shop/
Message 12
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| Subject: | Landing Radar....! |
Well, no, it isn't, BUT it works the same way.......
The basis is a back-up sensor which warns you when backing, that you are
approaching ( a pre-set distance from) a reflected object with a 'beep'.
Mine works with 42 kHz out and 24kHz in, I think. (sub-audible frequencies).
These are common in the auto shops now. I revised mine (according to a great
friend and mentor, Graham Clark) to give a sliding tone (in the earphones)
from a high at 5 feet to a low at 5 inches. This I believe will be most
useful over smooth ground (of course) for monowheel or conventional
tailwheel drivers, airframe. Trigear drivers just have to feel their way
down.
However I am told that the newer versions of the 'backup' sensor now
incorporate this feature. The Lockheed TriStar carried a descent radar which
produced a 'pip' of increasing frequency from 250' AGL to 50' then stopped,
just as it got interesting......
With all these solid state devises, I'm getting close to a 1/7 scale
L-1011........!
Ferg Kyle
Europa A064 914 Classic
Message 13
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| Subject: | Re: Pitot Current Draw |
Bob,
Thanks for the (correct) information. As a child, I lead a sheltered
existance and wasn't allow to play with Ohms, Amps and other foreigners,
so this is new to me. There's a whole new, big, world out there to
learn about. P.S., I still want to reduce my current draw!
Chuck Jensen
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob
White
Sent: Thursday, December 07, 2006 10:23 AM
Subject: Re: AeroElectric-List: Re: Pitot Current Draw
On Thu, 7 Dec 2006 08:27:22 -0500
"Chuck Jensen" <cjensen@dts9000.com> wrote:
><snip> The current
> pitot draws about 15 amps. By comparison, my older, but very adequate
>(as in--never iced up) pitot drew 7 amps. While not on a first name
>basis with any electrons, I assume that an amp is an amp and is
>generally going to produce a certain amount of heat, which is
>apparently adequate, based on empirical experience. So, if 7 amps was
>good enough in the old pitot, I was thinkin' that 7 amps was probably
>good enough for this pitot. I could hire a thermodynamist to confirm
>all this, but I'll go out on a limb and employ common sense
>instead--it's cheaper and often, just as accurate.
>
<snip>
Not quite true Chuck. Your old pitot tube was about 2 ohms. You were
drawing 7 amps from around 14 volts. Power is I^2 * R = 98 W. Now you
have a pitot that's about 1 ohm drawing 15 amps from 14 volts (0.933
ohms but who's counting). Drop the current in this pitot to 7 amps and
power is only 49 W. It was suggested by someone that the dropping
resistor could be mounted on the pitot also which would help, but still
not be equivalent.
Bob W. (Not a thermodynamist but I learned ohms law at an early age.)
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
First Flight: 11/23/2006 7:50AM - 0.7 Hours Total Time
Cables for your rotary installation - http://www.roblinphoto.com/shop/
Message 14
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| Subject: | LED backlit rocker switches |
Hey all -
I've been monitoring this list for awhile now - I'm building an RV-10 -
and I wondered if any of the electron whizzes could help me. I'm trying
to find a good source for custom legend LED backlit rocker switches for
my project.
I've historically done quite a bit of night flying, and after I got my
instrument rating, which I did 100% at night (with the one exception of
the checkride!) I vowed that I would not accept anything less than
complete readability of all controls and switches at night in the
cockpit. It just seemed so crazy that I had to juggle 3 flashlights in
the cockpit - one red led flash attached to my headset, a small red
maglite for cocpit instruments farther away from the pilot position, and
one more large one to look for ice on the airframe (yikes!). then I'd
get into my car after a long night of flying, turn on the lights, and
have no trouble reading any of the controls or switches. This is how I
want my aircraft to be! All controls self illuminating, and a
flashlight for emergency use only! Seems so simple, but I've been
confounded at every turn. Anyone have any suggestions?
Thanks in advance!
cj
#40410
fuse
www.perfectlygoodairplane.net
Message 15
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| Subject: | Re: LED backlit rocker switches |
I agree looking for a switch that is always lit and readable not just
when in the on position is like looking for a needle in a haystack. I
fianally decided to go with the cheap EL light strips under the panel. But I
don't do much night flying anyway.
Randy
----- Original Message -----
From: "Chris Johnston" <CJohnston@popsound.com>
Sent: Thursday, December 07, 2006 10:20 AM
Subject: AeroElectric-List: LED backlit rocker switches
> <CJohnston@popsound.com>
>
> Hey all -
>
> I've been monitoring this list for awhile now - I'm building an RV-10 -
> and I wondered if any of the electron whizzes could help me. I'm trying
> to find a good source for custom legend LED backlit rocker switches for
> my project.
>
> I've historically done quite a bit of night flying, and after I got my
> instrument rating, which I did 100% at night (with the one exception of
> the checkride!) I vowed that I would not accept anything less than
> complete readability of all controls and switches at night in the
> cockpit. It just seemed so crazy that I had to juggle 3 flashlights in
> the cockpit - one red led flash attached to my headset, a small red
> maglite for cocpit instruments farther away from the pilot position, and
> one more large one to look for ice on the airframe (yikes!). then I'd
> get into my car after a long night of flying, turn on the lights, and
> have no trouble reading any of the controls or switches. This is how I
> want my aircraft to be! All controls self illuminating, and a
> flashlight for emergency use only! Seems so simple, but I've been
> confounded at every turn. Anyone have any suggestions?
>
> Thanks in advance!
>
> cj
> #40410
> fuse
> www.perfectlygoodairplane.net
>
>
>
Message 16
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| Subject: | Re: : Rotax Aux Altenator switching. |
Hello Jim
As far as Kuntzleman combo LED position and strobe
"That sounds really nice. Where did you find them?"
Home:
http://www.kestrobes.com/
Combo Head:
http://www.kestrobes.com/our_strobe_hds.html
Double Dual Magnum:
http://www.kestrobes.com/ddm_models.html
Dual Magnum strobe under 2 amps, and for both starboard and port, red,
green and both sides aft white 2/3 of an amp total!
The lens cover is I think vacuum formed?? It is OK in clarity, not superb,
overall price is low.
Unit is not certified, and to be honest I don't care all that much if I am
absolute legal to the absolute letter of the law, paramount to me is that
my strobe and position LEDs allow me to be seen.
In my case with a Rotax 914, if you overburden the electrical system with
an approved strobe / position light system, fail your generator and kill
your battery, without electrical power to at least 1 fuel pump, well
"Silent Night" will begin to play.
Absolute/official checking to make sure position lights meet specs is not
an easy and cheap thing. I am more worried that certified planes with
approved position lights and strobes don't have the inside of lenses
dirty, high resistance wiring or less than new output bulbs.
He sells to military I think for Helicopters, and think he says they will
meet specs, but too costly to test.
I tried out my position LEDs, and for certain comparing right next to
local Beechcraft/Piper and Cessnas they work very well. The size of the
LED illumination is a bit smaller than the traditional, not much, but it
is more intense, overall very visable. Coverage as far as area of
visibility is very good with 2 wingtip Combo heads compared to Cessna and
Piper 2 wingtip strobes and 2 tip position lights and tail white from
observing on ground and from top obf building, I didn't test inflight from
below, but extrapulating from test, I am easily happy to trust my life and
all others on the ability for me to be seen.
On my Europa XS Monowheel I am going low draw strobes/position, SD20S with
LR3C main and internal generator as backup / help out with temp high loads
or low RPM, and a total loss 2200mA 13 cell NiMh backup battery in
starboard headrest. Backup battery (under 2 pounds) can run 1 pump with
autonomous wiring in seconds, even start the motor! Or for absolute
certain run the prop for an airstart. After soaring, it is true you should
consider yourself a glider once you shut down motor and treat as you can
not restart, when I do try a inflight restart and my battery that just
passed a load test the week before "opened", in seconds the NiMh can
effortless help out when in 1500 FPM sink! Can also run Main or E-Bus.
Ron Parigoris
Message 17
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| Subject: | Re: RE: Pitot Current Draw |
raymondj wrote:
>
>Rodney (O Wise Master),
>
> Pretty arrogant of you to think that you have control of or responsibility
>for another's actions and to think that you have any right to try to impose
>your values on another by attempting to control their actions.
>
>
>
Oh, get over yourself already. Until you start forking over some cash,
you have no right to demand that anyone answer your questions at all,
let alone in any particular fashion. Many of us sign in here because it
is a good place to mull over and exchange ideas. That includes not only
how to do things, but why to do things. This list, like most, is a
conversation, not just an answering service. I get to choose how I
share what I know. That's MY right. It's pretty arrogant of you to
think that you have control of how another person shares his own
knowledge, and to think that you have any right to try to impose your
values on another by attempting to control their actions.
That said, the original poster was provided with several avenues to
pursue: a power cycler, a series resistor, and Eric's thermal gradient
resistors (sorry, Eric, can't remember the proper name). The merits and
drawbacks of each were discussed. So you he had to spend a few days
watching the ideas bounce around a bit. How much more did that cost vs.
paying a consultant? Was anything learned in the interim that is
probably useless right now, but was free to you none the less, and
possibly useful in the future? I reached deep and gave what little
knowledge I had. Others did the same, teaching me some stuff which I
consider more than adequate payment for my efforts. I controlled no
one, and no one controlled me.
--
,|"|"|, Ernest Christley |
----===<{{(oQo)}}>===---- Dyke Delta Builder |
o| d |o http://ernest.isa-geek.org |
Message 18
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| Subject: | Re: Pitot Current Draw |
In a message dated 12/07/2006 7:31:48 AM Central Standard Time,
cjensen@dts9000.com writes:
So, if there was a reasonably simple mechanical/electrical means of reducing
the current draw of the pitot, I wanted to do it.
>>>
Not sure if this would work for you- just a possible solution:
http://mpja.com/productview.asp?product=4057+MD
It is a pulse-width modulation speed control for DC motors. I used one for
dimming my panel LEDs. It is rated for 10 amps, so if the pitot heater drew
more, you "might" have to add an appropriate resistor between the board output
and the pitot, but not sure about this. You could use a DPDT switch on the
panel for Pitot Heat with "Full" in one position, wired direct to the the heater,
and the other side "Adj" (or something appropriate) that would supply power
to the speed controller. This would also require adding the control pot to the
panel to adjust the controller, or you could just set it to an acceptable
partial setting and do without the adjustability.
DISCLAIMER: lest somebody take this suggestion and go out and kill
themselves, don't blame me! No sarcasm at all here, and please remember this is
a
venue for advancing the art of experimental aviation electrical systems, not
commentary on opinions of personal philosophy- let's stay on mission, folks...
>From The PosumWorks in TN
Mark Phillips
Message 19
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| Subject: | Re: Pitot Current Draw |
Hey Chuck,
Putting a resistor in series does reduce your current draw.. Are you
happy with how much so? Has your question been answered? Your original
question didn't quantify your goal. As has been mentioned, there are
solutions to this problem which can deliver more power to the pitot tube
for less total current expended, but they require more circuitry/figetry
to accomplish.
Matt-
> <cjensen@dts9000.com>
>
> Bob,
>
> Thanks for the (correct) information. As a child, I lead a sheltered
> existance and wasn't allow to play with Ohms, Amps and other foreigners,
> so this is new to me. There's a whole new, big, world out there to
> learn about. P.S., I still want to reduce my current draw!
>
> Chuck Jensen
>
>
> -----Original Message-----
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob
> White
> Sent: Thursday, December 07, 2006 10:23 AM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Re: Pitot Current Draw
>
>
>
> On Thu, 7 Dec 2006 08:27:22 -0500
> "Chuck Jensen" <cjensen@dts9000.com> wrote:
>
>><snip> The current
>> pitot draws about 15 amps. By comparison, my older, but very adequate
>
>>(as in--never iced up) pitot drew 7 amps. While not on a first name
>>basis with any electrons, I assume that an amp is an amp and is
>>generally going to produce a certain amount of heat, which is
>>apparently adequate, based on empirical experience. So, if 7 amps was
>
>>good enough in the old pitot, I was thinkin' that 7 amps was probably
>>good enough for this pitot. I could hire a thermodynamist to confirm
>>all this, but I'll go out on a limb and employ common sense
>>instead--it's cheaper and often, just as accurate.
>>
> <snip>
>
> Not quite true Chuck. Your old pitot tube was about 2 ohms. You were
> drawing 7 amps from around 14 volts. Power is I^2 * R = 98 W. Now you
> have a pitot that's about 1 ohm drawing 15 amps from 14 volts (0.933
> ohms but who's counting). Drop the current in this pitot to 7 amps and
> power is only 49 W. It was suggested by someone that the dropping
> resistor could be mounted on the pitot also which would help, but still
> not be equivalent.
>
> Bob W. (Not a thermodynamist but I learned ohms law at an early age.)
>
>
> --
> N93BD - Rotary Powered BD-4 - http://www.bob-white.com
> First Flight: 11/23/2006 7:50AM - 0.7 Hours Total Time
> Cables for your rotary installation - http://www.roblinphoto.com/shop/
>
>
Message 20
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| Subject: | Re: LED backlit rocker switches |
Chris Johnston wrote:
>
>Hey all -
>
>I've been monitoring this list for awhile now - I'm building an RV-10 -
>and I wondered if any of the electron whizzes could help me. I'm trying
>to find a good source for custom legend LED backlit rocker switches for
>my project.
>
>I've historically done quite a bit of night flying, and after I got my
>instrument rating, which I did 100% at night (with the one exception of
>the checkride!) I vowed that I would not accept anything less than
>complete readability of all controls and switches at night in the
>cockpit. It just seemed so crazy that I had to juggle 3 flashlights in
>the cockpit - one red led flash attached to my headset, a small red
>maglite for cocpit instruments farther away from the pilot position, and
>one more large one to look for ice on the airframe (yikes!). then I'd
>get into my car after a long night of flying, turn on the lights, and
>have no trouble reading any of the controls or switches. This is how I
>want my aircraft to be! All controls self illuminating, and a
>flashlight for emergency use only! Seems so simple, but I've been
>confounded at every turn. Anyone have any suggestions?
>
>Thanks in advance!
>
>
I compromised. Digikey has toggle switches with LEDs in the handles. I
used different colors for various items. Water pumps are blue. Fuel
pumps are red. Engine controls are green. All lighting is yellow.
They're all rated at 30A 12VDC, and cost right at $5 each...except for
the blue which I was surprised to find cost $9. (I didn't look that
closely until after I had the order placed).
I daisey chained them all the LED ground tabs together and brought a
single wire to an MPJA motor controller for dimming. They do dim, but I
would like quite a bit more range. I don't think I have the controller
calibrated correctly. The blues are harshly bright, but everything else
glows nice and softly.
This doesn't completely solve what you're looking for, but with an
intimate knowledge of the switch placement and color patterns, I think
it is an improvement.
--
,|"|"|, Ernest Christley |
----===<{{(oQo)}}>===---- Dyke Delta Builder |
o| d |o http://ernest.isa-geek.org |
Message 21
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| Subject: | Re: LED backlit rocker switches |
In a message dated 12/07/2006 12:21:33 PM Central Standard Time,
echristley@nc.rr.com writes:
The blues are harshly bright, but everything else
glows nice and softly.
HI Ed-
Used the same dimmer with similar rockers and had to add about 1000 ohm
resistors (maybe 2000, IIRC) to choke down the blue LEDS. Resistors were added
to
the ground faston tabs on the switch for the LED ground.
Now back to the original question, which was WHERE TO GET LED BACKLIT ROCKER
SWITCHES:
I have also spent much time looking for same. Best I've come up with so far
are not LED, but found these from Aerocraft:
http://www.aerocraftparts.com/Categories.aspx?Category=38940ec0-b260-4e9f-a23c
-b80ff8e89c67 (or go to www.aerocraftparts.com/ and look for
Electrical\Switches\Rocker Switches). These are incandescent.
I ordered a sample, but they are a bit bigger than I'd like, so I am now
looking at these:
http://www.engravers.net/aircraft/rocker_switches.htm which are available
with neon or incandescent bulbs. Will order a sample and see how they look. If
anyone DOES know of some alternatives, particularly with LEDs I'd love to hear
about them!
>From The PossumWorks
Mark
Message 22
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| Subject: | Re: LED backlit rocker switches |
Carling 632 series switches seem like they might fill the bill:
http://rocker-switches.carlingtech.com/illuminated-rocker-switch__37.asp#elibrary
Link to a descriptive pdf file:
http://www.carlingtech.com/pdf/CarlingSW_622_632.pdf
Then get them custom engraved.. Or engrave them yourself.. I suspect it
wouldn't be too difficult.
Matt-
> <CJohnston@popsound.com>
>
> Hey all -
>
> I've been monitoring this list for awhile now - I'm building an RV-10 -
> and I wondered if any of the electron whizzes could help me. I'm trying
> to find a good source for custom legend LED backlit rocker switches for
> my project.
>
> I've historically done quite a bit of night flying, and after I got my
> instrument rating, which I did 100% at night (with the one exception of
> the checkride!) I vowed that I would not accept anything less than
> complete readability of all controls and switches at night in the
> cockpit. It just seemed so crazy that I had to juggle 3 flashlights in
> the cockpit - one red led flash attached to my headset, a small red
> maglite for cocpit instruments farther away from the pilot position, and
> one more large one to look for ice on the airframe (yikes!). then I'd
> get into my car after a long night of flying, turn on the lights, and
> have no trouble reading any of the controls or switches. This is how I
> want my aircraft to be! All controls self illuminating, and a
> flashlight for emergency use only! Seems so simple, but I've been
> confounded at every turn. Anyone have any suggestions?
>
> Thanks in advance!
>
> cj
> #40410
> fuse
> www.perfectlygoodairplane.net
>
>
Message 23
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| Subject: | Re: LED backlit rocker switches |
If memory serves, Airpax.net has switch/breaker assys that have the
lever illuminated, used them on my RV3 30 yrs ago. John
----- Original Message -----
From: Matt Prather
To: aeroelectric-list@matronics.com
Sent: Thursday, December 07, 2006 2:52 PM
Subject: Re: AeroElectric-List: LED backlit rocker switches
<mprather@spro.net>
Carling 632 series switches seem like they might fill the bill:
http://rocker-switches.carlingtech.com/illuminated-rocker-switch__37.asp#
elibrary
Link to a descriptive pdf file:
http://www.carlingtech.com/pdf/CarlingSW_622_632.pdf
Then get them custom engraved.. Or engrave them yourself.. I suspect
it
wouldn't be too difficult.
Matt-
> <CJohnston@popsound.com>
>
> Hey all -
>
> I've been monitoring this list for awhile now - I'm building an
RV-10 -
> and I wondered if any of the electron whizzes could help me. I'm
trying
> to find a good source for custom legend LED backlit rocker switches
for
> my project.
>
> I've historically done quite a bit of night flying, and after I got
my
> instrument rating, which I did 100% at night (with the one exception
of
> the checkride!) I vowed that I would not accept anything less than
> complete readability of all controls and switches at night in the
> cockpit. It just seemed so crazy that I had to juggle 3 flashlights
in
> the cockpit - one red led flash attached to my headset, a small red
> maglite for cocpit instruments farther away from the pilot position,
and
> one more large one to look for ice on the airframe (yikes!). then
I'd
> get into my car after a long night of flying, turn on the lights,
and
> have no trouble reading any of the controls or switches. This is
how I
> want my aircraft to be! All controls self illuminating, and a
> flashlight for emergency use only! Seems so simple, but I've been
> confounded at every turn. Anyone have any suggestions?
>
> Thanks in advance!
>
> cj
> #40410
> fuse
> www.perfectlygoodairplane.net
>
>
>
>
>
>
>
Message 24
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| Subject: | Re: Pitot Current Draw |
Hello people, new to list here, and just thinking about the RV-10. I
have a
bit of experience in electronics and things electrical. While I don=92t
have a
circuit right now to show you for the desired purpose of regulating
current
to the pitot (I=92ll need a bit of time to look up a good one) things to
keep
in mind are:
Just a power resister to drop the current will waste =BD the power in
the
limiting resister.
Use the PWM with caution, as it may produce noise in the electrical
system
(depending on the frequency of the oscillations) that may affect your
other
systems, and be a cause for great frustration in locating the
interference.
Give me a few days to do some looking, and maybe I can find a better
solution. Lower frequency is better, go for something that cycles in
seconds, not milliseconds.
Craig Smith.
_____
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Fiveonepw@aol.com
Sent: Thursday, December 07, 2006 12:42 PM
Subject: Re: AeroElectric-List: Re: Pitot Current Draw
In a message dated 12/07/2006 7:31:48 AM Central Standard Time,
cjensen@dts9000.com writes:
So, if there was a reasonably simple mechanical/electrical means of
reducing
the current draw of the pitot, I wanted to do it.
>>>
Not sure if this would work for you- just a possible solution:
http://mpja.com/productview.asp?product=4057+MD
It is a pulse-width modulation speed control for DC motors. I used one
for
dimming my panel LEDs. It is rated for 10 amps, so if the pitot heater
drew
more, you "might" have to add an appropriate resistor between the board
output and the pitot, but not sure about this. You could use a DPDT
switch
on the panel for Pitot Heat with "Full" in one position, wired direct to
the
the heater, and the other side "Adj" (or something appropriate) that
would
supply power to the speed controller. This would also require adding
the
control pot to the panel to adjust the controller, or you could just set
it
to an acceptable partial setting and do without the adjustability.
DISCLAIMER: lest somebody take this suggestion and go out and kill
themselves, don't blame me! No sarcasm at all here, and please remember
this is a venue for advancing the art of experimental aviation
electrical
systems, not commentary on opinions of personal philosophy- let's stay
on
mission, folks...
>From The PosumWorks in TN
Mark Phillips
Message 25
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| Subject: | Re: : Rotax Aux Altenator switching. |
We also are using Jim Nelson's crankshaft driven alternator on our Europa Rotax
914. It works very well!! I have also supplied all the necessary parts to others
- my local machine shop does a great job. We don't attempt to run both
the B&C alt and the Rotax simultaneously. During pretakeoff checks, we verify
the Rotax system is operational for use as a backup, but we use the B&C.
Note that if you use the vacuum pump drive on 912 / 914 Rotax, it rotates at a
slower speed than Lyc / Cont so B&C SD 8 and SD 20 put out less current than rated.
Also, a Rotax crank shaft driven alternator runs at 5000 rpm, much less
than the rpm that the manufacturer rates the alternator at. B&C L60 at 5000
rpm is 46 A; L40 at 5000 rpm is 33A. We've supplied kits for both. We have L60
on our 914 - fills in the space in the engine mount pretty well.
Also note that FAR 91 requires "approved position and collision lights". In this
case FAR 23 applies to experimental. Last I checked, the Kuzlemann lights
do not meet the spec. But then your inspector probably won't notice or question
them. We fitted Whelen lights to our Europa.
Jim & Heather Butcher
Europa N241BW
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=79961#79961
Message 26
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| Subject: | Aluminum Bus question for Bob |
Bob,
How can I calculate the current carrying capacity of aluminum for sizing of
aluminum bus bars? Can I convert copper AWG to square inches then apply a
factor for aluminum? Any idea what the factor would be? I want to jump 3-4
inches from a GPU plug to the main bus. #4 copper should be adequate but
what size aluminum bar would be equivalent?
Dave Saylor
AirCrafters LLC
140 Aviation Way
Watsonville, CA
831-722-9141
www.AirCraftersLLC.com
Message 27
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| Subject: | Re: Pitot Current Draw |
Mmm sort of.. I've seen the details of this topic danced around a bit so
far..
First, let's assume that it's not practically possible to mount the
dropping resistor in such a way that it dissipates it's heat into the
pitot tube. Best case scenario mounts the resistor to the same fasteners
that attach the heater to the wing. Many inches from the place that needs
to get hot.
Point: Let's assume the old, adequate heater used 100Watts when wired to
the bus. Let's further assume the new one uses 200Watts when wired to the
bus. That the old heater was adequate says that 100Watts is enough power
(the right amount) for what Chuck wants to do. The challenge is to get
the new heater to only use 100Watts. The way pick a dropping resistor
which will do that is slightly complex.
First, find the equivalent resistance of the new heater. That can be
found by noting R=V^2/P = 14V*14V/200W = 0.98ohm. Great.
Now we need to look at how much current needs to be shoved through the
0.98ohm resistor to get 100W. That can be found by using I = sqrt(P/R)
sqrt(100/0.98) = 10.101A. Need to pass 10A through a 1ohm resistor to
burn 100Watts. Good, passes the bs check.
Now, let's look at what the total series resistance needs to be in order
to get 10.1A through the circuit. That is R= V/I = 14V/10.1A = 1.386ohm.
So, the total loop resistance needs to be 1.386ohm. 0.98ohm of that is
coming from the pitot tube, and the other 0.41ohm comes from the dropping
resistor.
The power lost in the resistor can be found a couple of ways; I'll show
one... P= (I^2)*R = 41Watts.
The current without the dropping resistor is I = P/V = 200W/14V = 14.3A.
Summary:
To use a dropping resistor to get the equivalent amount of heat from the
pitot tube (goal) reduces the current from 14.3A to 10.1A, and wastes
41Watts on the resistor.
As has been mentioned, picking a resistor value equal to the equivalent
resistance of the heater divides the current consumed by the circuit by
two, but the power delivered to the tube itself by four. Maybe that's not
an adequate amount of power for the tube to function. Certainly it
wouldn't perform as well as the old pitot tube.
Regards,
Matt-
snip
>
> Just a power resister to drop the current will waste the power in the
> limiting resister.
>
snip
> Craig Smith.
>
>
> _____
>
> From: owner-aeroelectric-list-server@matronics.com
> [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
> Fiveonepw@aol.com
> Sent: Thursday, December 07, 2006 12:42 PM
> To: aeroelectric-list@matronics.com
> Subject: Re: AeroElectric-List: Re: Pitot Current Draw
>
>
> In a message dated 12/07/2006 7:31:48 AM Central Standard Time,
> cjensen@dts9000.com writes:
>
> So, if there was a reasonably simple mechanical/electrical means of
> reducing
> the current draw of the pitot, I wanted to do it.
>
>>>>
>
>
> Not sure if this would work for you- just a possible solution:
>
>
> http://mpja.com/productview.asp?product=4057+MD
>
>
> It is a pulse-width modulation speed control for DC motors. I used one
> for
> dimming my panel LEDs. It is rated for 10 amps, so if the pitot heater
> drew
> more, you "might" have to add an appropriate resistor between the board
> output and the pitot, but not sure about this. You could use a DPDT
> switch
> on the panel for Pitot Heat with "Full" in one position, wired direct to
> the
> the heater, and the other side "Adj" (or something appropriate) that would
> supply power to the speed controller. This would also require adding the
> control pot to the panel to adjust the controller, or you could just set
> it
> to an acceptable partial setting and do without the adjustability.
>
>
> DISCLAIMER: lest somebody take this suggestion and go out and kill
> themselves, don't blame me! No sarcasm at all here, and please remember
> this is a venue for advancing the art of experimental aviation electrical
> systems, not commentary on opinions of personal philosophy- let's stay on
> mission, folks...
>
>
>>From The PosumWorks in TN
>
> Mark Phillips
>
>
Message 28
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| Subject: | Re: Need engine rpm pickup for Lycoming 360 |
At 07:01 AM 12/7/2006 -0800, you wrote:
>
>I am finally ready to start hooking up wires on my Zenith 801 with
>Lycoming O-360a1a. I have a Aveo E-1 and MaxFlight on my panel and need
>an electronic RPM pickup for the Lycoming. My ultralight (Quicksilver
>GT400) was very simple to wire up as it had a pulse wire from the
>electronic ignition already. No electronic ignition on this old Lycoming
>(Bendix mags). Any suggestions?
You can read rpm from across the p-lead connections of an
operating magneto. When you say 'electronic RPM pickup' I
would hope that your instrument defines what that means.
Many electronic tachs have been built and marketed that
will read RPM from a magneto. Others depend on "real"
5 or 12v square waves from a hall effect device (some will
read the spinning magneto magnet right through the housing).
Still others may be unique pick-up technologies that expected
something way out of the mainstream.
What do the instructions for your instrument say?
Bob . . .
---------------------------------------------------------
< What is so wonderful about scientific truth...is that >
< the authority which determines whether there can be >
< debate or not does not reside in some fraternity of >
< scientists; nor is it divine. The authority rests >
< with experiment. >
< --Lawrence M. Krauss >
---------------------------------------------------------
Message 29
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| Subject: | Re: Pitot Current Draw |
At 08:22 AM 12/7/2006 -0700, you wrote:
>
>On Thu, 7 Dec 2006 08:27:22 -0500
>"Chuck Jensen" <cjensen@dts9000.com> wrote:
>
> ><snip> The current
> > pitot draws about 15 amps. By comparison, my older, but very adequate
> > (as in--never iced up) pitot drew 7 amps. While not on a first name
> > basis with any electrons, I assume that an amp is an amp and is
> > generally going to produce a certain amount of heat, which is apparently
> > adequate, based on empirical experience. So, if 7 amps was good enough
> > in the old pitot, I was thinkin' that 7 amps was probably good enough
> > for this pitot. I could hire a thermodynamist to confirm all this, but
> > I'll go out on a limb and employ common sense instead--it's cheaper and
> > often, just as accurate.
> >
><snip>
>
>Not quite true Chuck. Your old pitot tube was about 2 ohms. You were
>drawing 7 amps from around 14 volts. Power is I^2 * R = 98 W. Now
>you have a pitot that's about 1 ohm drawing 15 amps from 14 volts (0.933
>ohms but who's counting). Drop the current in this pitot to 7 amps and
>power is only 49 W. It was suggested by someone that the dropping
>resistor could be mounted on the pitot also which would help, but still
>not be equivalent.
>
>Bob W. (Not a thermodynamist but I learned ohms law at an early age.)
We touched on this in an earlier post. Recall that while you're reducing
the current through the heater by 1/2, this drops the voltage across it
by 1/2 also for a new dissipation value of 1/4 the original which comes
to 29.5 watts for the tube and 29.5 watts dropped across the companion
resistor for a system total of 49 watts.
If one is applying a rule of thumb that "7 amps was adequate" then the
goal is to drop the 15A tube (14 x 15 = 210 watts) down to what the
original tube ran (7 x 14 = 98 watts). Obviously this is not a drop
to 1/4 power but 1/2 power. So to get 98 watts dissipated in
the new tube at 1 ohm resistance then I(squared) x 1 = 98.
The new value for current drops NOT to 7A but to 10 amps. Given
14 volts applied and 10 volts needed for the new pitot heater then
we need to drop 4 volts at 10 amps in the power reduction resistor.
This calculates out to 4/10 or 0.4 ohms. The resistor will dissipate
4v x 10A or 40 watts.
So, to keep the same heat delivered to the pitot tube we can only
drop the current from 15A down to 10A. Total system draw will be
140 watts instead of the original 210 watts with 100 watts in the
tube and 40 watts in the resistor.
The foregoing assumption of equivalency holds only if the two
tubes distribute their energy over the same number of square inches
of tube surface. Equivalency for ice-melting abilities is measured
in watts per square inch of power density.
Bob . . .
Message 30
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| Subject: | Re: Pitot Current Draw |
At 05:32 PM 12/7/2006 -0700, you wrote:
>
>Mmm sort of.. I've seen the details of this topic danced around a bit so
>far..
<snip>
Good job Matt. You picked it right up and beat me to it!
Bob . . .
Message 31
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| Subject: | Re: Pitot Current Draw (Duty Cycle Control Case) |
>
>
> So, to keep the same heat delivered to the pitot tube (USING A RESISTOR)
> we can only drop the current from 15A down to 10A. Total system draw
> will be
> 140 watts instead of the original 210 watts with 100 watts in the
> tube and 40 watts in the resistor.
>
> The foregoing assumption of equivalency holds only if the two
> tubes distribute their energy over the same number of square inches
> of tube surface. Equivalency for ice-melting abilities is measured
> in watts per square inch of power density.
Let us consider the duty cycle controller. If you put a transistor
in series with the pitot tube heater and drive it with a 50% duty
cycle square wave, an interesting thing happens . . .
The PEAK power is still 14v x 15A or 210 watts. But since
the heater is operating only 1/2 the time, the AVERAGE power
is now down to 1/2 of peak or 105 watts. Interestingly enough,
the AVERAGE current will also be down to 7A. The conservation
of energy rules are not violated. In the resistor case, there
are LOSSES in the current dropping device while a duty-cycle
driven transistor has minimal losses (as low as 1 watt!).
As others have mentioned, the down side of this scheme is that
your bus gets whacked with a 15A pulse for each operating cycle
of the heater system. One can explore relatively high frequency
switching to avoid seeing the panel lights flicker (and believe
me, they WILL) but this might cause audible noises elsewhere.
Suggest about 30 Hz for minimum observability and below the
audio frequencies of interest in the rest of your electro-whizzies.
Bob . . .
Message 32
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| Subject: | Re: Pitot Current Draw |
Chuck,
I like you! Few people are able to understand my sarcasm and read
between the line when I hammer on the keys=85. I response to what you
just wrote, if in fact 7amps will do and your sure of that. Then what
you are saying is the current (no pun) version of pitot tube is over
kill (also no pun intended). All these assumptions being true then all
you would have to do is reduce the voltage until the current is at 7.
Have fun,
Mike
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Chuck
Jensen
Sent: Thursday, December 07, 2006 6:27 AM
Subject: RE: AeroElectric-List: Re: Pitot Current Draw
Mike,
If I was able to draw the sarcasm out of you, I'd had to see what a pro
could do! (:-)). Actually, I've done the calculations and am satisfied
of the results, even if not confirmed by empirical data. The current
pitot draws about 15 amps. By comparison, my older, but very adequate
(as in--never iced up) pitot drew 7 amps. While not on a first name
basis with any electrons, I assume that an amp is an amp and is
generally going to produce a certain amount of heat, which is apparently
adequate, based on empirical experience. So, if 7 amps was good enough
in the old pitot, I was thinkin' that 7 amps was probably good enough
for this pitot. I could hire a thermodynamist to confirm all this, but
I'll go out on a limb and employ common sense instead--it's cheaper and
often, just as accurate.
As to your suggestion of simply using a bigger battery, I didn't notice
any calculations showing how big and how many batteries I should have.
However, if by limiting heat output in the pitot, I cut my amperage in
half, I can calculate that the draw from my current battery will be 1/2
as much and last twice as long (but not for the full load, since the
pitot is only a fraction of the total load; unfortunately, a high
fraction). As to the suggestion to just turn it off.....duh, the reason
we have a heated pitot is--never mind, it makes my head hurt.
Sorry for my poor response and sarcasm, but I think you brought it out
of me.
All the forgoing is just kidding. Not many people intentionly flying
their GA craft into icing and not many lose electrical power generation,
but when the two are combined, even though the odds are it happening are
small, the odds of ending up dead are quite large. So, if there was a
reasonably simple mechanical/electrical means of reducing the current
draw of the pitot, I wanted to do it. Kind of like flying an
airplane--not many of us have real good reasons for doing it, but we
just want to do it.
Chuck Jensen
Mike wrote....
The only way I can answer this question is to tell a story. First,
flying in the ice is something many pilot do every year and sometimes
often. If you know what you=92re doing and are prepared then the risks
are minimal. I have been flying in ice with airplanes that are able to
handle it for better then 20 years. It=92s not like flying on a sunny
day. But once you get use to it and prepare for it, it=92s not that big
of a deal. A few words of advice, no two icing days are the same. Only
experience will help you here. My personal feeling on ice in piston
powered planes, you don=92t have many out when the weather gets bad.
When
in ice greater then light find a place to land ASAP.
As for you electric question; First the easy answer is to put a bigger
battery in the airplane. Second, why would you think that using less
power for pitot heat is going to be any better then turning the pitot
heat off all together? Unless you run a thermal equation on the speed,
temperature, and heat (layman=92s terms) required to guarantee the
anti-ice properties needed, then everything your doing is just a big
guess anyway. And I guessing that since I have to go to the book to do
said equation thoroughly, I would guess the electrical formula by
comparison would be a piece of cake. I know this is not what you want
to hear but the facts are the facts. The reason that the pitot uses so
much power (in general) is that is what it takes to keep ice off the
probe in 100% humidity at temperatures < 10dec C.
Sorry for the poor and somewhat sarcastic answer, but I think Chuck
brought it out in me.
Regards,
Mike Larkin
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of
Speedy11@aol.com
Sent: Wednesday, December 06, 2006 6:57 PM
Subject: AeroElectric-List: Re: Pitot Current Draw
Chuck,
You have just experienced the main thing I dislike about this forum.
When you ask for advice or assistance, you will commonly get critique on
why you should not do what it is you want to do. It takes several
attempts at explaining that you don't care about opinions - you simply
want assistance. For example, I've asked how to sample volts and amps
in multiple places in my electrical system. I got "you don't need to
know that info while you're flying." Regardless, I want to be able to
do that so how can I do it? Answer: since I don't think you should do
that I'm not going to tell you how to do it.
As you've discovered, getting an answer can be very frustrating.
Still, I've learned a lot about electrical stuff here and I continue to
learn. So, I still find the forum of value.
I wish I had the answer for you - I would provide it. But, I don't.
Hopefully, you will get an acceptable answer.
Stan Sutterfield
Okay, I appreciate everyone holding forth that it's stupid to fly in
ice....I'm not that dumb, I only look it. However, the question stands,
how does one knock down the heat and current draw. Richard mentioned a
'strut switch'....whoever that is. Can someone enlighten us
non-electrical types. What I'm concerned about is being in the clouds,
close to freezing and loose electrical--I'd just as soon not have to
turn off the pitot heat because it's sucking the battery dry in short
order; I'd rather it be in long order.
Chuck Jensen
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Message 33
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| Subject: | Re: Pitot Current Draw |
On Thu, 07 Dec 2006 19:48:32 -0600
"Robert L. Nuckolls, III" <nuckollsr@cox.net> wrote:
>
> At 08:22 AM 12/7/2006 -0700, you wrote:
>
> >
> >On Thu, 7 Dec 2006 08:27:22 -0500
> >"Chuck Jensen" <cjensen@dts9000.com> wrote:
> >
> > ><snip> The current
> > > pitot draws about 15 amps. By comparison, my older, but very adequate
> > > (as in--never iced up) pitot drew 7 amps. While not on a first name
> > > basis with any electrons, I assume that an amp is an amp and is
> > > generally going to produce a certain amount of heat, which is apparently
> > > adequate, based on empirical experience. So, if 7 amps was good enough
> > > in the old pitot, I was thinkin' that 7 amps was probably good enough
> > > for this pitot. I could hire a thermodynamist to confirm all this, but
> > > I'll go out on a limb and employ common sense instead--it's cheaper and
> > > often, just as accurate.
> > >
> ><snip>
> >
> >Not quite true Chuck. Your old pitot tube was about 2 ohms. You were
> >drawing 7 amps from around 14 volts. Power is I^2 * R = 98 W. Now
> >you have a pitot that's about 1 ohm drawing 15 amps from 14 volts (0.933
> >ohms but who's counting). Drop the current in this pitot to 7 amps and
> >power is only 49 W. It was suggested by someone that the dropping
> >resistor could be mounted on the pitot also which would help, but still
> >not be equivalent.
> >
> >Bob W. (Not a thermodynamist but I learned ohms law at an early age.)
>
> We touched on this in an earlier post. Recall that while you're reducing
> the current through the heater by 1/2, this drops the voltage across it
> by 1/2 also for a new dissipation value of 1/4 the original which comes
> to 29.5 watts for the tube and 29.5 watts dropped across the companion
> resistor for a system total of 49 watts.
Just a minor point - the 49 W is already 1/4 of the power consumption of
the 'new' pitot tube. The only point I was making was that "I assume
that an amp is an amp and is generally going to produce a certain
amount of heat" was not correct.
Bob W.
>
> If one is applying a rule of thumb that "7 amps was adequate" then the
> goal is to drop the 15A tube (14 x 15 = 210 watts) down to what the
> original tube ran (7 x 14 = 98 watts). Obviously this is not a drop
> to 1/4 power but 1/2 power. So to get 98 watts dissipated in
> the new tube at 1 ohm resistance then I(squared) x 1 = 98.
> The new value for current drops NOT to 7A but to 10 amps. Given
> 14 volts applied and 10 volts needed for the new pitot heater then
> we need to drop 4 volts at 10 amps in the power reduction resistor.
> This calculates out to 4/10 or 0.4 ohms. The resistor will dissipate
> 4v x 10A or 40 watts.
>
> So, to keep the same heat delivered to the pitot tube we can only
> drop the current from 15A down to 10A. Total system draw will be
> 140 watts instead of the original 210 watts with 100 watts in the
> tube and 40 watts in the resistor.
>
> The foregoing assumption of equivalency holds only if the two
> tubes distribute their energy over the same number of square inches
> of tube surface. Equivalency for ice-melting abilities is measured
> in watts per square inch of power density.
>
> Bob . . .
>
>
--
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
First Flight: 11/23/2006 7:50AM - 0.7 Hours Total Time
Cables for your rotary installation - http://www.roblinphoto.com/shop/
Message 34
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| Subject: | RE: Pitot Current Draw |
MessageWow! This discussion has really taken on a mind of it's own....I see
almost 41 posts in this thread! As usual and in my own sarcastic way, I'm
really confused and boggled as to why we're even discussing this (and to the
unbelievably detailed technical minutia that has arisen out of something
like this)....when there is a perfectly good heated pitot on the market that
does EXACTLY what you want it to do....it varies the current to the tube
from .1 Amps to 7 Amps depending on it's own temperature. When it doesn't
need the heat it just idles, when it does it shoves more power out there.
Why re-invent the wheel...someone already has and his name is Warren Gretz!
I swear, just reading all these posts will waste more time than the $400 and
some odd bucks it takes to buy one brand new....no messing around with all
kinds of crazy little electrical components...bolt it on and go!
Just my 2 cents as usual!
Cheers,
Stein.
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com]On Behalf Of Chuck
Jensen
Sent: Tuesday, December 05, 2006 7:18 AM
To: aeroelectric-list@matronics.com
Subject: RE: AeroElectric-List: RE: Pitot Current Draw
Hi, Keith,
That was exactly my thought process also. I didn't want a red hot
branding iron to bore my way through ice cubes...just warm enough to keep
the pitot stuffed full of rain water from freezing. If the icing is bad
enough that it freezes over a warm-to-very warm pitot, I've got bigger
problems that a red hot pitot won't solve.
Since no ideas have been tossed out, I wonder if there is an efficient
means of cycling the pitot heater on/off at some interval, such as on for 30
seconds, off for two minutes. This would reduce the total current draw if a
person was in the soup, lost electrical and needed whatever extra time
available to get to safety but didn't dare to turn off the pitot in marginal
icing conditions.
Chuck Jensen
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Keith
Hallsten
Sent: Monday, December 04, 2006 10:36 PM
To: aeroelectric-list@matronics.com
Subject: AeroElectric-List: RE: Pitot Current Draw
Chuck,
I mounted a 28v Known Ice pitot on the nose of my Velocity. Since I
have a 14 volt electrical system, its power consumption will be reduced by a
factor of 4 (power = V * V / R). I figure that is sufficient for my
purposes, because a Velocity is NOT a Known Ice type of airframe. If I
should find enough ice to overwhelm my lightweight pitot heating system, I
have bigger problems than the pitot. Im not flying yet, but thats my
position for now.
Actually, now that we all have GPS available to us, loss of pitot is not
as critical as it used to be. With a fat margin to allow for wind, flying
by groundspeed is generally a fair approximation.
Regards,
Keith Hallsten
Subject: RE: Pitot Current Draw
From: Chuck Jensen (cjensen@dts9000.com)
Date: Mon Dec 04 - 12:06 PM
Wow, I must be hard-of-speaking (or writing). I concede that flying
into icing when not so equipped is not a good idea, but if a person
flies IFR in the winter most anywhere in the continental US, sooner or
later, they'll pick up some ice. Even if my wings start looking like
something that should be used to cool a gin and tonic, I don't want to
lose air speed indication. Granted, I may not know what my new stall
speed is, but I would like to know WHAT my speed is...and I can't do
that with a pitot full of ice.
So, the question on the table is still the same, is there a way off
'turning down the heat' and reducing current draw?
Chuck Jensen
href="http://www.aeroelectric.com">www.aeroelectric.com
href="http://www.buildersbooks.com">www.buildersbooks.com
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Message 35
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| Subject: | Re: Need engine rpm pickup for Lycoming 360 |
Jay,
Advanced Flight Systems has a tach sensor that screws into the mag. Another way
is to purchase a tach drive sensor that screws into the tach drive on the engine.
Check Aircraft Spruce or Wicks for this. Don
---- Jay Herron <jay@agstore.net> wrote:
>
> I am finally ready to start hooking up wires on my Zenith 801 with Lycoming O-360a1a.
I have a Aveo E-1 and MaxFlight on my panel and need an electronic RPM
pickup for the Lycoming. My ultralight (Quicksilver GT400) was very simple
to wire up as it had a pulse wire from the electronic ignition already. No electronic
ignition on this old Lycoming (Bendix mags). Any suggestions?
>
> Jay Herron
> CH801 95% complete
> Salem, OH
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=79835#79835
>
>
>
>
>
>
>
>
>
>
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