Come see us at Oshkosh

Dean,

Congrats on the new product. Make sure Julie at AOPA and the various mags
get the press release.

My knowledge of LEDs is: pick an LED, add a 1K resistor and a 9V and you're
good to go - back from my hobby electronic days . I had a quick question
about the temperatures. Death Valley gets to 120-130F (I believe). If you
run the LED as an anti-collision system during take/off and landing,
couldn't you get about (or at least close to) the 150F?

Thanks,

Hilton



wrote in message
oups.com...
On Jul 25, 7:14 am, Denny wrote:
Just some general comments - not aimed at Dean's product...

LED has been touted as the end all and be all of lighting, replacing
the incandescent bulb... However, the emperor's new clothes may be a
bit revealing...

First, is that LED lights require substantial heat sinks and adequate
ventilation in order to function... (Dean's product looks competently
designed for this)... Failure to adequately cool the LED will result
in short service life... An adequate heat sink often erases any size
advantage the LED started out with...
Initial installation cost of LED light assembly is markedly higher
than an incandescent... Colreg approved LED running lights for boats
are downright expensive...
Replacement cost of LED lighting that fails in service is vastly
higher than simply replacing a $20 bulb...
By the time the LED assembly is properly cooled with a heatsink the
weight advantage of LED is markedly lessened...
Voltage control is more stringent for proper functioning of LED light
assemblies, as opposed to incandescent filament bulbs..
Dimmers for LED lights are expensive for technical reasons...

In boats/yachts where extended operation from a battery set is a way
of life there has been a rush to replace incandescent with LED due to
it's more efficient use of watt hours... The experience with that has
shown that LED has its place, but it is not a blanket replacement...
For task lighting, such as spot lighting over a galley counter, the
LED is excellent... It is also excellent for lighting of stair steps,
in the head, inside of cabinets, drawers and closets, and night
lights...For general cabin lighting (even lighting of large areas) the
cold cathode and fluorescent lights are still preferred... For high
intensity tasks, such as deck lights, anchor raising lights, and spot
lights, the halogen bulb still reigns supreme... For a reading light,
the jury is still out - and I personally have not found a light my
eyes like better than the incandescent for extended periods of
reading... For mast lights and running lights the LED is making
progress, but initial cost and light output is still an issue...

Things are never as simple as they seem... Now, this is not intended
to begin a debate over Dean's product, it is simply remarks on what I
have found in the 2 years of research for outfitting my boat... What
that means in an aircraft is up to you...

denny

Denny,

You are correct that proper heat sinking is essential to preserving an
LED. Exceeding the rated junction temperature of an LED will result
in it failing long before its rated life. Our design guarantees that
the LEDs will remain at least 40C below their maximum junction
temperature of 150C even on the hottest day at full power. We have
had many people come by our exhibit in the North Aircraft area wanting
to know why the device has such a large heat sink and weighs 0.9
pounds (just under 1 pound).

Most people who experiment with LEDs just hook them up to a current
limiting resistor and call it good. That is really not a good
practice for an airplane. Our product has a switching supply that
regulates the LED current for an input voltage range of 9V to 36V
which guarantees reliable operation. It is also protected against
voltage spikes, ESD, and lightning transients. We have also conducted
DO-160E RFI and conducted emissions tests to ensure that it does not
interfere with radios or anything on the electrical system.

To really appreciate how well our landing light works, you have to see
it at night. We have demoed it to a few people after 9pm. We
generate a lot more light than a 55W halogen at less that 1/2 the
power.

We arrived at Oshkosh at 12:15 on Saturday when the sun was very
bright, and the controller at Fisk called us out as the high wing with
blue stripes on the wings and flashing lights (wig wag mode was on).
We were happy to hear that!

Dean
AeroLEDs LLC
www.aeroleds.com

On Aug 1, 3:27 pm, "Hilton" wrote:
Dean,

Congrats on the new product. Make sure Julie at AOPA and the various mags
get the press release.

My knowledge of LEDs is: pick an LED, add a 1K resistor and a 9V and you're
good to go - back from my hobby electronic days . I had a quick question
about the temperatures. Death Valley gets to 120-130F (I believe). If you
run the LED as an anti-collision system during take/off and landing,
couldn't you get about (or at least close to) the 150F?

Thanks,

Hilton

wrote in message

oups.com...



On Jul 25, 7:14 am, Denny wrote:
Just some general comments - not aimed at Dean's product...

LED has been touted as the end all and be all of lighting, replacing
the incandescent bulb... However, the emperor's new clothes may be a
bit revealing...

First, is that LED lights require substantial heat sinks and adequate
ventilation in order to function... (Dean's product looks competently
designed for this)... Failure to adequately cool the LED will result
in short service life... An adequate heat sink often erases any size
advantage the LED started out with...
Initial installation cost of LED light assembly is markedly higher
than an incandescent... Colreg approved LED running lights for boats
are downright expensive...
Replacement cost of LED lighting that fails in service is vastly
higher than simply replacing a $20 bulb...
By the time the LED assembly is properly cooled with a heatsink the
weight advantage of LED is markedly lessened...
Voltage control is more stringent for proper functioning of LED light
assemblies, as opposed to incandescent filament bulbs..
Dimmers for LED lights are expensive for technical reasons...

In boats/yachts where extended operation from a battery set is a way
of life there has been a rush to replace incandescent with LED due to
it's more efficient use of watt hours... The experience with that has
shown that LED has its place, but it is not a blanket replacement...
For task lighting, such as spot lighting over a galley counter, the
LED is excellent... It is also excellent for lighting of stair steps,
in the head, inside of cabinets, drawers and closets, and night
lights...For general cabin lighting (even lighting of large areas) the
cold cathode and fluorescent lights are still preferred... For high
intensity tasks, such as deck lights, anchor raising lights, and spot
lights, the halogen bulb still reigns supreme... For a reading light,
the jury is still out - and I personally have not found a light my
eyes like better than the incandescent for extended periods of
reading... For mast lights and running lights the LED is making
progress, but initial cost and light output is still an issue...

Things are never as simple as they seem... Now, this is not intended
to begin a debate over Dean's product, it is simply remarks on what I
have found in the 2 years of research for outfitting my boat... What
that means in an aircraft is up to you...

denny

Denny,

You are correct that proper heat sinking is essential to preserving an
LED. Exceeding the rated junction temperature of an LED will result
in it failing long before its rated life. Our design guarantees that
the LEDs will remain at least 40C below their maximum junction
temperature of 150C even on the hottest day at full power. We have
had many people come by our exhibit in the North Aircraft area wanting
to know why the device has such a large heat sink and weighs 0.9
pounds (just under 1 pound).

Most people who experiment with LEDs just hook them up to a current
limiting resistor and call it good. That is really not a good
practice for an airplane. Our product has a switching supply that
regulates the LED current for an input voltage range of 9V to 36V
which guarantees reliable operation. It is also protected against
voltage spikes, ESD, and lightning transients. We have also conducted
DO-160E RFI and conducted emissions tests to ensure that it does not
interfere with radios or anything on the electrical system.

To really appreciate how well our landing light works, you have to see
it at night. We have demoed it to a few people after 9pm. We
generate a lot more light than a 55W halogen at less that 1/2 the
power.

We arrived at Oshkosh at 12:15 on Saturday when the sun was very
bright, and the controller at Fisk called us out as the high wing with
blue stripes on the wings and flashing lights (wig wag mode was on).
We were happy to hear that!

Dean
AeroLEDs LLC
www.aeroleds.com- Hide quoted text -

- Show quoted text -

I have tinkered with high brightness LEDs for some time. My conclusion
was LEDs significantly outperform other sources only in situations
where you need single color, such as nav lights, red cockpit lights,
traffic lights etc... For white light applications their performance
is less impressive. That is reasonable because LEDs inherently produce
single color photons, while incandescent sources produce a broadband
of photons. You lose efficiency converting a broad band to a single
color, and you also lose efficiency converting a single color to a
broad band.

Also, it is not fair to just compare the brightness. You should also
consider the weight of the heat sink and extra circuitry. In addition,
LED lamps are typically thermally bonded to their heat sinks so
individually replacing burnt out LED may be difficult or impossible.
You might have to replace the whole array. They are insensitive to
vibration, but are more sensitive to temperature fluctuations.

On Aug 1, 1:27 pm, "Hilton" wrote:
Dean,

Congrats on the new product. Make sure Julie at AOPA and the various mags
get the press release.

My knowledge of LEDs is: pick an LED, add a 1K resistor and a 9V and you're
good to go - back from my hobby electronic days . I had a quick question
about the temperatures. Death Valley gets to 120-130F (I believe). If you
run the LED as an anti-collision system during take/off and landing,
couldn't you get about (or at least close to) the 150F?

Thanks,

Hilton


Hi Hilton,

At 130F (55C) the heatsink on our unit will be at 90C (194F) which
will not damage the components. If the heat sink gets to about 95C,
the unit will self-protect by automatically entering the flash mode
which cuts the power in half, preventing any further temperature
rise...

Dean

On Aug 1, 2:03 pm, Andrew Sarangan wrote:
On Aug 1, 3:27 pm, "Hilton" wrote:

I have tinkered with high brightness LEDs for some time. My conclusion
was LEDs significantly outperform other sources only in situations
where you need single color, such as nav lights, red cockpit lights,
traffic lights etc... For white light applications their performance
is less impressive. That is reasonable because LEDs inherently produce
single color photons, while incandescent sources produce a broadband
of photons. You lose efficiency converting a broad band to a single
color, and you also lose efficiency converting a single color to a
broad band.


This is not true anymore... the LEDs we are using are now available in
efficiencies as high as 100lumens/Watt. That is better than a compact
fluorescent light bulb. You can not look directly at the LEDs we are
using when they are on. If you do, you will see spots for quite a
while afterwards.

Also, it is not fair to just compare the brightness. You should also
consider the weight of the heat sink and extra circuitry. In addition,
LED lamps are typically thermally bonded to their heat sinks so
individually replacing burnt out LED may be difficult or impossible.
You might have to replace the whole array. They are insensitive to
vibration, but are more sensitive to temperature fluctuations.- Hide quoted text -


Equivalent halogen wing-mounted landing lights are no lighter than our
product, and we are much brighter. Duckworks touts their light-weight
halogen light as being only 15.5 Oz (0.97 lbs) which is about the same
weight as our unit...

Dean
AeroLEDs LLC
www.aeroleds.com

Matt,

IMHO it would be better to have a big notice about the product on the
very first page. It can be a link to the detail page, but it needs to
be on the first page your potential customers see.


Good point, I did that...

The press release should be on the Web page (in HTML) as well as in PDF.
Again, don't make people do extra work to find out about your product.


I will do this...

The photo of the light by itself is natively 587x373, but is being
scaled in the HTML to 587x464, which makes the light appear "stretched"
vertically. It also makes the photo a little more blocky or pixellated
than it otherwise might be. Things with reflectors are somewhat
difficult to take pictures of, but if you reshoot, consider putting the
light on a piece of white paper (to remove all distractions from the
background), lighting it from multiple angles to reduce shadows, and
turning off the camera flash.


We didn't have a lot of time to get professional photos of the product
leading up to Oshkosh. We have more time now to do that, so we will
be putting much better photos on the site soon...

I think the installation instructions for the light would benefit from a
typical wiring diagram for both one and two light installations, and a
view of the connector with pin numbers. You should also give directions
on what to do with the master and slave wires that are unused (tape
off/insulate, most likely). This gets into the specifics of how it
installs on a particular plane, but you may also consider installing the
light half of the Molex connector at the factory, and possibly even
providing the harness half of the connector installed on a 12" or so
pigtail. Otherwise, the purchaser has to deal with crimping Molex pins,
which nobody has the right crimper for. If you are going to supply the
pins loose piece, give 'em six or seven of each, so they can screw up
once or twice.


Good points, and we do provide an extra pin for each connector...

The installation instructions also suffer from typical Microsoft Turd
paragraph indent problems in the ten installation steps and in part
1.0 of the Specifications. Also, part 1.0 should say "LEDs" (plural)
instead of "LED's" (possessive). Should part 3.4 say "Lightning"
instead of "Lighting"?


Thanks, I'll fix that.

I don't quite understand section 3.5 of the specifications. I know what
the difference between positive and negative ground is, but it's not
clear whether the red and yellow wires always have to be more positive
than the black wire, or if it doesn't matter. Put another way, if you
have something like

resistor LED
red wire ---/\/\/------||--- black wire

then the red wire always has to be more positive than the black wire,
whereas if you have something like

bridge resistor LED
red wire ---+---||---+------/\/\/------||---,
| | |
'---||-----, |
| | |
,---||---' | |
| | |
black wire ---+---||-----+---------------------'

then it doesn't matter how the red and black wires are hooked up. (Yes,
I do realize that what's inside your light is a more complicated than a
resistor and an LED!)


The design is reverse polarity protected, but we do require that
ground and power be hooked up correctly to function. A full-wave
bridge adds another diode drop and cost, both of which are not
desireable.

Power to the red wire gives full-on operation. Power to the yellow
wire gives flashing operation, regardless of the state of the red
wire.

I realize the big show is over, but an interesting demo might be to
mount one of your lights and a plain old incandescent lamp on a paint
shaker, or an electric motor with an offset weight on the shaft, or a
lawnmower engine - something that vibrates. Hook both lights to a
battery with very simple and visible wiring, to show that there's
nothing funny going on. Then turn on the shaker and see which one burns
out first. It's not as impressive as seeing it in person, but a
video of such a demo might be useful. Again, this is hard to
photograph, and it's not as good as seeing it in person, but you could
also put one of your lights on one wing, a regular lamp on the other
wing, turn them both on, and take a photo (no flash) from the cockpit
to illustrate the difference. Depending on how the lights are aimed,
it might help to have the plane pointing at the wall of a hangar, or
a known distance from a stripe on the pavement, to illustrate the
difference.


We did have a show-down on Saturday night with an RV-7 that had
Duckworks leading edge halogens with a wig-wag controller. Our
lights were much brighter, lit a much larger area, and we could leave
them on for much much longer than the RV dared.

I like your idea about the paint shaker.

Dean Wilkinson
AeroLEDs LLC
www.aeroleds.com

wrote:

If the heat sink gets to about 95C,
the unit will self-protect by automatically entering the flash mode


THAT would be fun on short final to a dark runway!

--
Dan
T-182T at BFM

On Aug 2, 12:38 pm, "Dan Luke" wrote:
wrote:
If the heat sink gets to about 95C,
the unit will self-protect by automatically entering the flash mode

THAT would be fun on short final to a dark runway!

--
Dan
T-182T at BFM

Dan,

The air temperature inside a wing at night in flight will never get
anywhere close to 140F, so it won't happen on short final at night...
plus, it would take at least 45 minutes to an hour even in a 140F
ambient for the unit to get hot enough to self-protect.

Dean
AeroLEDs LLC
www.aeroleds.com

wrote:
If the heat sink gets to about 95C,
the unit will self-protect by automatically entering the flash mode

THAT would be fun on short final to a dark runway!
Dan
T-182T at BFM

wrote:
Dan,
The air temperature inside a wing at night in flight will never get
anywhere close to 140F, so it won't happen on short final at night...
plus, it would take at least 45 minutes to an hour even in a 140F
ambient for the unit to get hot enough to self-protect.

I can fore-see a mini-draft tube as an optional addition. :-)

On Aug 2, 1:31 pm, john smith wrote:
wrote:
If the heat sink gets to about 95C,
the unit will self-protect by automatically entering the flash mode
THAT would be fun on short final to a dark runway!
Dan
T-182T at BFM
wrote:
Dan,
The air temperature inside a wing at night in flight will never get
anywhere close to 140F, so it won't happen on short final at night...
plus, it would take at least 45 minutes to an hour even in a 140F
ambient for the unit to get hot enough to self-protect.

I can fore-see a mini-draft tube as an optional addition. :-)

John,

Actually that isn't necessary. Wings leak quite a bit of air in
flight, so there is always some airflow inside them. Even if there is
no airflow, our unit will passively cool in stagnant air. The volume
of air inside most wings is perfectly adequate to allow it to remain
at a reasonable temperature even if you are parked on the ground.
Once in flight, there is plenty of cooling so the unit will run even
cooler...

Dean
AeroLEDs LLC
www.aeroleds.com

wrote in message

We didn't have a lot of time to get professional photos of the product
leading up to Oshkosh. We have more time now to do that, so we will
be putting much better photos on the site soon...

I would love for you to have a "show down" on your web page, with
comparisons of your light vs. a couple other lights.

It would be good to see it from two views; from looking into the different
lights, and looking at the light shining onto a wall, or a taxiway.

If I were in the market for such a product, I would be convinced about them
increasing your visibility from other planes looking for you. I would be
skeptical about how well it would throw the light on the ground, for use as
a landing or taxi light. That is the thing I would need to be convinced
about.

You would need to have a picture with both types in the same frame, to make
it less likely to the observer that "tricks" have been used to skew the
results.

Neat product. Keep up the product development!
--
Jim in NC