31 Days till OSH

On Jun 23, 10:00 am, Jay Honeck wrote:
I didn't mean to seem coy, I just wasn't trying to make any sort of
announcement here...

Jeez, Dean -- this newsgroup is read by thousands of pilots --
announce away!

The product sounds absolutely AWESOME. When you certify them, I'll be
in line.

Now, if someone could only replace standard incandescent bulbs with
LEDs, I'd buy 'em tomorrow... To never change another g*($#@@ light
bulb at the inn would be worth a lot of money to me!
--
Jay Honeck
Iowa City, IA
Pathfinder N56993www.AlexisParkInn.com
"Your Aviation Destination"

Jay,

How much would you be willing to pay for an LED light bulb that put
out 800 lumens on 12 Watts of power? (yes, I am considering making
such a beast)

Dean

How much would you be willing to pay for an LED light bulb that put
out 800 lumens on 12 Watts of power? (yes, I am considering making
such a beast)

Um, er, I don't know. Is this for the plane? The hotel? How many
lumens does a (for example) standard 60 watt incandescent bulb kick
out?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

On Jun 25, 10:33 pm, Jay Honeck wrote:
How much would you be willing to pay for an LED light bulb that put
out 800 lumens on 12 Watts of power? (yes, I am considering making
such a beast)

Um, er, I don't know. Is this for the plane? The hotel? How many
lumens does a (for example) standard 60 watt incandescent bulb kick
out?
--
Jay Honeck
Iowa City, IA
Pathfinder N56993www.AlexisParkInn.com
"Your Aviation Destination"

Jay,

This is a lightbulb replacement. A 60 Watt incandescent puts out
about 650 lumens.

Dean

How much would you be willing to pay for an LED light bulb that put
out 800 lumens on 12 Watts of power? (yes, I am considering making
such a beast)

What would the color curve look like?

Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.

Jay (and others of a technical bent)...

Here is a page showing the relative efficiencies of the various forms of
light emitters:

http://members.misty.com/don/lfunfact.html#lw

Note that amongst the "normal" forms of lighting that you can buy over the
counter, the most efficient is the small 1" diameter 32 watt fluorescent in
a 4' tube (F32T8) at about 90 lumens/watt. The best LEDs as of the date
this was written is about 70 lumens/watt.

Dean is proposing an LED (or string of them) that puts out 67 lumens/watt,
but as the page says, this does not include any ballast losses. White LEDs
have a forward voltage drop of about 3 volts/lamp, so to get decent
efficiency you string 4 of them in series to get CLOSE to 12 volts, but you
still wind up fudging around with ballast resistors and/or switching current
regulators to keep the power to the devices constant. And, they are going
to get hotter than billy blue blazes unless you keep airflow over them.

The LED is probably going to be the "light bulb" of the future (see
http://www.superbrightleds.com/ for a smattering of what is on the market)
and notice way down at the bottom of the "LEDS" page that there are some one
watt devices on the market with integral heat sinks. These suckers are
BRIGHT and expensive, but as with all mass marketed devices, once the auto
industry picks up on them, they become dirt cheap.

And, on Don's page (again) you find that a 60 watt incandescent light bulb
puts out about 600 lumens, or a lousy 10 lumens/watt. The sooner we abandon
Edison's invention the better.

Jim



--
"Life is not a journey to the grave with the intention of arriving safely in
a pretty and well preserved body, but rather to skid in broadside,
thoroughly used up, totally worn out, with chocolate in one hand and wine in
the other, loudly proclaiming 'WOO HOO What a Ride!'"
--Unknown
wrote in message
oups.com...



Jay,

How much would you be willing to pay for an LED light bulb that put
out 800 lumens on 12 Watts of power? (yes, I am considering making
such a beast)

Dean

And, [LED lights] are going to get hotter than
billy blue blazes unless you keep airflow over them.

Moreso than the edison invention? If so, where's the efficiency coming
from?

Jose
--
You can choose whom to befriend, but you cannot choose whom to love.
for Email, make the obvious change in the address.

Let's take ten watts from a battery or from the wall plug.

A light bulb (just for illustration sake, don't take the numbers as gospel)
spends 9.9 of those watts generating heat and 0.1 of the watts generating
light.

An LED spends 9 of those watts generating heat and 1 of those watts
generating light. The LED is therefore about ten times as efficient as a
light bulb.

However, the light bulb has about five or six square inches over which to
get rid of the 9.9 watts of heat (although the bulb is still very hot) while
the LED has less than a quarter of a square inch (without a heat sink) to
get rid of the 9 watts. Which one do you think will get hotter?

Jim

--
"Life is not a journey to the grave with the intention of arriving safely in
a pretty and well preserved body, but rather to skid in broadside,
thoroughly used up, totally worn out, with chocolate in one hand and wine in
the other, loudly proclaiming 'WOO HOO What a Ride!'"
--Unknown


"Jose" wrote in message
et...

And, [LED lights] are going to get hotter than
billy blue blazes unless you keep airflow over them.

Moreso than the edison invention? If so, where's the efficiency coming
from?

Jose

On Jun 26, 3:50 pm, "RST Engineering" wrote:
Let's take ten watts from a battery or from the wall plug.

A light bulb (just for illustration sake, don't take the numbers as gospel)
spends 9.9 of those watts generating heat and 0.1 of the watts generating
light.

An LED spends 9 of those watts generating heat and 1 of those watts
generating light. The LED is therefore about ten times as efficient as a
light bulb.

However, the light bulb has about five or six square inches over which to
get rid of the 9.9 watts of heat (although the bulb is still very hot) while
the LED has less than a quarter of a square inch (without a heat sink) to
get rid of the 9 watts. Which one do you think will get hotter?

Jim

--
"Life is not a journey to the grave with the intention of arriving safely in
a pretty and well preserved body, but rather to skid in broadside,
thoroughly used up, totally worn out, with chocolate in one hand and wine in
the other, loudly proclaiming 'WOO HOO What a Ride!'"
--Unknown

"Jose" wrote in message

et...



And, [LED lights] are going to get hotter than
billy blue blazes unless you keep airflow over them.

Moreso than the edison invention? If so, where's the efficiency coming
from?

Jose- Hide quoted text -

- Show quoted text -

Hi Jim,

Actually, the lightbulb dissipates most of its heat as Infra-red
radiation so it dosn't get terribly hot (other than the filament).
Remember that the visible light is only the tail of the black-body
radiation spectrum emitted by the bulb, so from a pure radiation
perspective its fairly efficient, but not from a visible light
perspective.

The LEDs have to dissipate most all of their waste heat via conduction
and convection, and very little by radiation. So they have their own
thermal challenges.

But there are ways to make it work....

Dean