To Jim Weir

[Charlie Smith]

Jim,

From info I have located on the internet, I have cobbled together a
circuit diagram for illuminating my instrument panel using LED's. I was
wondering if I emailed you a copy, would you would be kind enough to
take a peek at the circuit and see if I missed anything? Electronics
isn't my expertise but I enjoy it all the same.

Thanks in advance,
Charlie Smith

[Brian Whatcott]

Charlie Smith wrote:
> Jim,
>
> From info I have located on the internet, I have cobbled together a
> circuit diagram for illuminating my instrument panel using LED's. I was
> wondering if I emailed you a copy, would you would be kind enough to
> take a peek at the circuit and see if I missed anything? Electronics
> isn't my expertise but I enjoy it all the same.
>
> Thanks in advance,
> Charlie Smith

Hi Charles, can I ask you what you do for a living?

I'm sure there's something I could use your expertise for.

If you were a physician, you might be able to tell me if
the lemon juice I'm taking for gall-stones will help.
If you're a plumber, I am sure you could tell me about
the slope I need when laying new sewer lines.

Stuff like that.

I wouldn't ask, But I am pretty sure you are a nice guy.

Regards

Brian W

[Jim Logajan]

brian whatcott > wrote:
> Charlie Smith wrote:
>> Jim,
>>
>> From info I have located on the internet, I have cobbled together a
>> circuit diagram for illuminating my instrument panel using LED's. I
>> was wondering if I emailed you a copy, would you would be kind enough
>> to take a peek at the circuit and see if I missed anything?
>> Electronics isn't my expertise but I enjoy it all the same.
>>
>> Thanks in advance,
>> Charlie Smith
>
> Hi Charles, can I ask you what you do for a living?
>
> I'm sure there's something I could use your expertise for.
>
> If you were a physician, you might be able to tell me if
> the lemon juice I'm taking for gall-stones will help.
> If you're a plumber, I am sure you could tell me about
> the slope I need when laying new sewer lines.
>
> Stuff like that.
>
> I wouldn't ask, But I am pretty sure you are a nice guy.

Brian -

If you're implying Charlie is being presumptuous to ask for help, then I
believe you're out of line with your followup. Not only did he first
politely ask permission, the following author info is posted for Jim Weir
on page 71 of the February 2010 issue of Kitplanes magazine:

"Jim Weir began acquiring Aero'Lectrics expertise in 1959, fixing Narco
Superhomers in exchange for flight hours. A commercial pilot, CFI, and
A&P/IA, Jim has owned and restored four single-engine Cessnas. These
days, he runs RST Engineering and teaches electronics at Sierra College.
Ask him questions at rec.aviation.homebuilt or visit his site at
www.rst-engr.com/kiplanes."

Since there is an open invitation in black on white to ask him questions
on this newsgroup, there doesn't seem to be any merit to your
implication.

NOTE to Charlie: You should also consider directing your question to
sci.electronics.design. I used to read that group a few years ago and at
least back then it was a great resource. Had a few personal exchanges
with one of the authors of the text "Art of Electronics" (which was
required for my experimental physics class about a zillion years ago) who
hung out there; very nice group - and helpful if questions honestly
posed. Hopefully it still is.

[Charlie Smith]

Jim Logajan wrote:
> brian whatcott > wrote:
>> Charlie Smith wrote:
>>> Jim,
>>>
>>> From info I have located on the internet, I have cobbled together a
>>> circuit diagram for illuminating my instrument panel using LED's. I
>>> was wondering if I emailed you a copy, would you would be kind enough
>>> to take a peek at the circuit and see if I missed anything?
>>> Electronics isn't my expertise but I enjoy it all the same.
>>>
>>> Thanks in advance,
>>> Charlie Smith
>> Hi Charles, can I ask you what you do for a living?
>>
>> I'm sure there's something I could use your expertise for.
>>
>> If you were a physician, you might be able to tell me if
>> the lemon juice I'm taking for gall-stones will help.
>> If you're a plumber, I am sure you could tell me about
>> the slope I need when laying new sewer lines.
>>
>> Stuff like that.
>>
>> I wouldn't ask, But I am pretty sure you are a nice guy.
>
> Brian -
>
> If you're implying Charlie is being presumptuous to ask for help, then I
> believe you're out of line with your followup. Not only did he first
> politely ask permission, the following author info is posted for Jim Weir
> on page 71 of the February 2010 issue of Kitplanes magazine:
>
> "Jim Weir began acquiring Aero'Lectrics expertise in 1959, fixing Narco
> Superhomers in exchange for flight hours. A commercial pilot, CFI, and
> A&P/IA, Jim has owned and restored four single-engine Cessnas. These
> days, he runs RST Engineering and teaches electronics at Sierra College.
> Ask him questions at rec.aviation.homebuilt or visit his site at
> www.rst-engr.com/kiplanes."
>
> Since there is an open invitation in black on white to ask him questions
> on this newsgroup, there doesn't seem to be any merit to your
> implication.
>
> NOTE to Charlie: You should also consider directing your question to
> sci.electronics.design. I used to read that group a few years ago and at
> least back then it was a great resource. Had a few personal exchanges
> with one of the authors of the text "Art of Electronics" (which was
> required for my experimental physics class about a zillion years ago) who
> hung out there; very nice group - and helpful if questions honestly
> posed. Hopefully it still is.

Thanks Jim. Your reasoning is quite correct and thanks for the
suggetion. As Jim's articles are the primary reason I have a Kitplane's
subscription and as I have purchased items from RST in the past, I
thought I might ask here. But to be honest, I did have reservations as
one never knows if it would do any good. Jim may get many such requests
and simply cannot answer them. Even though others may be qualified to
answer, there is always the possibility one might encounter the kind of
person you would expect to find living in those sloping sewer lines and
that made me really hesitant. As a rule, I don't find these forums worth
the hassle. Perhaps is would be a more interesting electronics question
to find out how they get internet service down there.

Best regards.

[Brian Whatcott]

Jim Logajan wrote:
>
>>> From info I have located on the internet, I have cobbled together a
>>> circuit diagram for illuminating my instrument panel using LED's. I
>>> was wondering if I emailed you a copy, would you would be kind enough
>>> to take a peek at the circuit and see if I missed anything?
>>> Electronics isn't my expertise but I enjoy it all the same.
>>>
>>> Thanks in advance,
>>> Charlie Smith

>> Hi Charles, can I ask you what you do for a living?
>>
>> I'm sure there's something I could use your expertise for.
>>
>> If you were a physician, you might be able to tell me if
>> the lemon juice I'm taking for gall-stones will help.
>> If you're a plumber, I am sure you could tell me about
>> the slope I need when laying new sewer lines.
>>
>> Stuff like that.
>>
>> I wouldn't ask, But I am pretty sure you are a nice guy.
>
> Brian -
>
> If you're implying Charlie is being presumptuous to ask for help, then I
> believe you're out of line with your followup. Not only did he first
> politely ask permission, the following author info is posted for Jim Weir
> on page 71 of the February 2010 issue of Kitplanes magazine:
>
> "Jim Weir began acquiring Aero'Lectrics expertise in 1959, fixing Narco
> Superhomers in exchange for flight hours. A commercial pilot, CFI, and
> A&P/IA, Jim has owned and restored four single-engine Cessnas. These
> days, he runs RST Engineering and teaches electronics at Sierra College.
> Ask him questions at rec.aviation.homebuilt or visit his site at
> www.rst-engr.com/kiplanes."
>
> Since there is an open invitation in black on white to ask him questions
> on this newsgroup, there doesn't seem to be any merit to your
> implication.
>
> NOTE to Charlie: You should also consider directing your question to
> sci.electronics.design. I used to read that group a few years ago and at
> least back then it was a great resource. Had a few personal exchanges
> with one of the authors of the text "Art of Electronics" (which was
> required for my experimental physics class about a zillion years ago) who
> hung out there; very nice group - and helpful if questions honestly
> posed. Hopefully it still is.

First rule of etiquette on newsgroups: to make a request for help in a
way so that any person who feels he can offer help, is able to do so.
If only one person's reply is to be valued, then it it OBVIOUS that the
email should go to the addressee only. I say it *is* obvious, but it
obviously isn't: still, it SHOULD be obvious, even to folks who have
taken undergraduate physics.

When Jim offers help via a newsgroup, I imagine he does not expect to be
the only responder in general. He would (I can suppose) be happier
offering corrections and enhancement on a selection of replies.
That is how everyone wins.

As it happens, in the long past, I have received kind treatment from
Jim Weir, so that I was able present his materials for setting up copper
tape antennas with ferrite stoppers in glass and fabric homebuilts to a
builder group. I am not amused when I see people sniping at him on
newsgroups, or appearing to take advantage of his goodwill. He has to
make a living, as do we all.

Moreover, since you mention it, I was able to swap Winfield an old
technical book that interested him for an autographed copy of that
splendid electronics reference in 1168 pages, The Art of Electronics, by
Paul Horowitz and Winfield Hill. At that time, the first edition was
still current.
I am pleased to see that Winfield, as generous with his advice as
Jim Weir, who was kind enough to autograph a first Edition for me, now
offers a third edition, no less helpful.


Brian Whatcott.

[Stealth Pilot[_3_]]

On Thu, 07 Jan 2010 15:39:13 -0500, Charlie Smith
> wrote:

>Jim,
>
> From info I have located on the internet, I have cobbled together a
>circuit diagram for illuminating my instrument panel using LED's. I was
>wondering if I emailed you a copy, would you would be kind enough to
>take a peek at the circuit and see if I missed anything? Electronics
>isn't my expertise but I enjoy it all the same.
>
>Thanks in advance,
>Charlie Smith

charlie, assuming that you are using a 12 volt bus, all you need to do
to use an LED is put a 680ohm resistor in series with it.
so if you had an instrument that was lit by a small tungsten globe, in
theory, all you need to do is take out the lamp holder and wire in the
led and the resistor in its place. the led should then work with the
original switching.
you need to have a resistor in series with each LED. so if you use a
number of LED's in the panel each must have a resistor in series with
it.
simple enough isnt it.

Stealth Pilot

[Charlie Smith]

Stealth Pilot wrote:
> On Thu, 07 Jan 2010 15:39:13 -0500, Charlie Smith
> > wrote:
>
>> Jim,
>>
>> From info I have located on the internet, I have cobbled together a
>> circuit diagram for illuminating my instrument panel using LED's. I was
>> wondering if I emailed you a copy, would you would be kind enough to
>> take a peek at the circuit and see if I missed anything? Electronics
>> isn't my expertise but I enjoy it all the same.
>>
>> Thanks in advance,
>> Charlie Smith
>
> charlie, assuming that you are using a 12 volt bus, all you need to do
> to use an LED is put a 680ohm resistor in series with it.
> so if you had an instrument that was lit by a small tungsten globe, in
> theory, all you need to do is take out the lamp holder and wire in the
> led and the resistor in its place. the led should then work with the
> original switching.
> you need to have a resistor in series with each LED. so if you use a
> number of LED's in the panel each must have a resistor in series with
> it.
> simple enough isnt it.
>
> Stealth Pilot

No, its more complicated than that. I'm building the instrument panel
from scratch with 20 LED's. I have put together a PWM dimmer circuit
that has a built in 5V linear regulator. That way, if the battery
starts to die, I have panel lights down to about 7V on the battery. I
just wanted Jim to look it over and make sure I didn't miss something
obvious. I am quite capable of some bone-head mistakes. I've
bread-boarded the circuit and it works fine (with one LED). But that's
different than flying with it.

Thanks,
Charlie

[Bug Dout]

Stealth Pilot > writes:

> charlie, assuming that you are using a 12 volt bus, all you need to do
> to use an LED is put a 680ohm resistor in series with it.

Huh? You can't generalize about LEDs like that! There are many different
LEDs with different electrical characteristics. Given the OP's post,
you can't even state that a simple resistor is what he wants; he may
want variable lighting, in which case a potentiometer is what's needed.

If the OP doesn't get a reply from Weir, I suggest the Matronics
AeroElectric list at http://forums.matronics.com/viewforum.php?f=3

--
Too bad you can't just grab a tree by the very tip-top and bend
it clear over the ground and then let her fly, because I bet
you'd be amazed at all the stuff that comes flying out.
- Jack Handey

[Stealth Pilot[_3_]]

On Fri, 08 Jan 2010 16:54:14 -0800, Bug Dout >
wrote:

>Stealth Pilot > writes:
>
>> charlie, assuming that you are using a 12 volt bus, all you need to do
>> to use an LED is put a 680ohm resistor in series with it.
>
>Huh? You can't generalize about LEDs like that! There are many different
>LEDs with different electrical characteristics. Given the OP's post,
>you can't even state that a simple resistor is what he wants; he may
>want variable lighting, in which case a potentiometer is what's needed.
>

I can state what I like. it is a free society.
what I wrote works for me.
ymmv
Stealth Pilot

[vaughn[_2_]]

"Stealth Pilot" > wrote in message
...
>
> I can state what I like. it is a free society.

Yes you can. Even if it happens to be wrong.

Vaughn

[Brian Whatcott]

Stealth Pilot wrote:
> On Fri, 08 Jan 2010 16:54:14 -0800, Bug Dout >
> wrote:
>
>> Stealth Pilot > writes:
>>
>>> charlie, assuming that you are using a 12 volt bus, all you need to do
>>> to use an LED is put a 680ohm resistor in series with it.

>> Huh? You can't generalize about LEDs like that! There are many different
>> LEDs with different electrical characteristics. Given the OP's post,
>> you can't even state that a simple resistor is what he wants; he may
>> want variable lighting, in which case a potentiometer is what's needed.
>>
>
> I can state what I like. it is a free society.
> what I wrote works for me.
> ymmv
> Stealth Pilot


Quite so. Moreover, the idea of providing an individual series resistor
to pass about 20 mA works for a good variety of LEDs.
Focussing on the desire to dim a LED, there is no reason (that I know)
not to reduce the current. This has the great advantage over pulse width
modulation that it does not kick up radio interference. There are LED
drive chips on offer now that might suit....

Brian W

[Scott[_7_]]

brian whatcott wrote:

>
> Quite so. Moreover, the idea of providing an individual series resistor
> to pass about 20 mA works for a good variety of LEDs.
> Focussing on the desire to dim a LED, there is no reason (that I know)
> not to reduce the current. This has the great advantage over pulse width
> modulation that it does not kick up radio interference. There are LED
> drive chips on offer now that might suit....
>
> Brian W

Maybe this will help the builder. A current source (rather than a
voltage source) will make the LED brightness varaiable. A typical (red)
LED runs at about 20 mA for full brightness, while dropping about 1.7V
across the LED. Lowering this current dims the LED. The shown circuit
can be set to supply up to about 400 mA, enough for about 20 LEDs. Of
course, he will want to use red LEDs in place of the white ones drawn in
the circuit...

http://radiolocation.tripod.com/LEDdimmer/LEDlampDimmer.html

Scott

[Dan[_12_]]

Scott wrote:
> brian whatcott wrote:
>
>>
>> Quite so. Moreover, the idea of providing an individual series
>> resistor to pass about 20 mA works for a good variety of LEDs.
>> Focussing on the desire to dim a LED, there is no reason (that I
>> know) not to reduce the current. This has the great advantage over
>> pulse width modulation that it does not kick up radio interference.
>> There are LED drive chips on offer now that might suit....
>>
>> Brian W
>
> Maybe this will help the builder. A current source (rather than a
> voltage source) will make the LED brightness varaiable. A typical (red)
> LED runs at about 20 mA for full brightness, while dropping about 1.7V
> across the LED. Lowering this current dims the LED. The shown circuit
> can be set to supply up to about 400 mA, enough for about 20 LEDs. Of
> course, he will want to use red LEDs in place of the white ones drawn in
> the circuit...
>
> http://radiolocation.tripod.com/LEDdimmer/LEDlampDimmer.html
>
> Scott


Didn't Weir do an article in "Kit Planes" awhile back on this subject?

Dan, U.S. Air Force, retired

[Brian Whatcott]

Scott wrote:
> brian whatcott wrote:
>
>>
>> Quite so. Moreover, the idea of providing an individual series
>> resistor to pass about 20 mA works for a good variety of LEDs.
>> Focussing on the desire to dim a LED, there is no reason (that I
>> know) not to reduce the current. This has the great advantage over
>> pulse width modulation that it does not kick up radio interference.
>> There are LED drive chips on offer now that might suit....
>>
>> Brian W
>
> Maybe this will help the builder. A current source (rather than a
> voltage source) will make the LED brightness varaiable. A typical (red)
> LED runs at about 20 mA for full brightness, while dropping about 1.7V
> across the LED. Lowering this current dims the LED. The shown circuit
> can be set to supply up to about 400 mA, enough for about 20 LEDs. Of
> course, he will want to use red LEDs in place of the white ones drawn in
> the circuit...
>
> http://radiolocation.tripod.com/LEDdimmer/LEDlampDimmer.html
>
> Scott


Yep.

Here's another idea that sticks with the non pulsed approach.

It uses a variable voltage reg in constant current form - allowing a
string of several LEDS as is:
<http://www.instructables.com/id/Circuits-for-using-High-Power-LED_s/step11/an-even-simpler-current-source/>

...or in TinyURL format:
http://tinyurl.com/yb9kyyr


....this could be massaged to provide the drive for 24 LEDs at rather low
cost and component count.

Brian W

[Scott[_7_]]

> Scott wrote:

>>
>> Maybe this will help the builder. A current source (rather than a
>> voltage source) will make the LED brightness varaiable. A typical
>> (red) LED runs at about 20 mA for full brightness, while dropping
>> about 1.7V across the LED. Lowering this current dims the LED. The
>> shown circuit can be set to supply up to about 400 mA, enough for
>> about 20 LEDs. Of course, he will want to use red LEDs in place of
>> the white ones drawn in the circuit...
>>
>> http://radiolocation.tripod.com/LEDdimmer/LEDlampDimmer.html
>>
>> Scott
>
>
> Didn't Weir do an article in "Kit Planes" awhile back on this subject?
>
> Dan, U.S. Air Force, retired

Dunno. Haven't gotten the rag in a couple years. Price stayed the same
but page count went down, didn't find it cost effective, with all the
magazines I was gettin'. That said, I wouldn't doubt it was covered at
one time or another...

[RST Engineering[_2_]]

Hello, Charlie ...

The main reason I post on this newsgroup is so that my answers are
vetted by the group and we don't cut holes in the airplane when
something obviously isn't going to work.

Tell you what, and with a couple of options:

1. Post on these newsgroups in alt.binaries.scientific.electronics
and attach the schematic with a request to look it over and I (as well
as a dozen other folks whose opinion I value) can massage it for you.

2. Join the newsgroup Pilots Of America and post the schematic in
Maintenance Bay. Again, there are folks in there who will certainly
not let me give you bum information.

Jim




On Thu, 07 Jan 2010 15:39:13 -0500, Charlie Smith
> wrote:

>Jim,
>
> From info I have located on the internet, I have cobbled together a
>circuit diagram for illuminating my instrument panel using LED's. I was
>wondering if I emailed you a copy, would you would be kind enough to
>take a peek at the circuit and see if I missed anything? Electronics
>isn't my expertise but I enjoy it all the same.
>
>Thanks in advance,
>Charlie Smith

[RST Engineering[_2_]]

Make that

alt.binaries.schematics.electronic


Jim


On Thu, 07 Jan 2010 15:39:13 -0500, Charlie Smith
> wrote:

>Jim,
>
> From info I have located on the internet, I have cobbled together a
>circuit diagram for illuminating my instrument panel using LED's. I was
>wondering if I emailed you a copy, would you would be kind enough to
>take a peek at the circuit and see if I missed anything? Electronics
>isn't my expertise but I enjoy it all the same.
>
>Thanks in advance,
>Charlie Smith

[Charlie Smith]

RST Engineering wrote:
> Hello, Charlie ...
>
> The main reason I post on this newsgroup is so that my answers are
> vetted by the group and we don't cut holes in the airplane when
> something obviously isn't going to work.
>
> Tell you what, and with a couple of options:
>
> 1. Post on these newsgroups in alt.binaries.scientific.electronics
> and attach the schematic with a request to look it over and I (as well
> as a dozen other folks whose opinion I value) can massage it for you.
>
> 2. Join the newsgroup Pilots Of America and post the schematic in
> Maintenance Bay. Again, there are folks in there who will certainly
> not let me give you bum information.
>
> Jim
>
>
>
>
> On Thu, 07 Jan 2010 15:39:13 -0500, Charlie Smith
> > wrote:
>
>> Jim,
>>
>> From info I have located on the internet, I have cobbled together a
>> circuit diagram for illuminating my instrument panel using LED's. I was
>> wondering if I emailed you a copy, would you would be kind enough to
>> take a peek at the circuit and see if I missed anything? Electronics
>> isn't my expertise but I enjoy it all the same.
>>
>> Thanks in advance,
>> Charlie Smith
>

Thanks Jim.

I knew of Matronics but not these other places. This all I really need;
some good, trustworthy advice.

Thanks again.


Charlie

[cavelamb[_2_]]

RST Engineering wrote:
> Make that
>
> alt.binaries.schematics.electronic
>
>
> Jim
>
>
> On Thu, 07 Jan 2010 15:39:13 -0500, Charlie Smith
> > wrote:
>
>> Jim,
>>
>> From info I have located on the internet, I have cobbled together a
>> circuit diagram for illuminating my instrument panel using LED's. I was
>> wondering if I emailed you a copy, would you would be kind enough to
>> take a peek at the circuit and see if I missed anything? Electronics
>> isn't my expertise but I enjoy it all the same.
>>
>> Thanks in advance,
>> Charlie Smith
>



Good grief!
I thought rec.crafts.metalworking had a lot of noise...



--

Richard Lamb
http://www.home.earthlink.net/~cavelamb/


"The clock of life is wound but once, and no man has the power
to tell just when the hands will stop, at late or early hour...
Now is the only time you own. Live, love, toil with a will.
Place no faith in time. For the clock may soon be still."