Need a recommendation.


I like the idea of LED but am open to options

would like dimmable.


I looked at one LED setup but it said it takes two minutes to turn
on...not sure if I like that idea...but a slow warm up like CFL is OK

philo wrote:
Need a recommendation.


I like the idea of LED but am open to options

would like dimmable.


I looked at one LED setup but it said it takes two minutes to turn
on...not sure if I like that idea...but a slow warm up like CFL is OK

LED is not heat source. It turns on instant not like CFL. Use LOT less
power, lasts long time, dimmable. Many fixtures to choose from at
lighting store.
We just replaced all incandescent pod flood lights with daylight LEDs.
75W down to 12W each. Wife likes it.

On 08/09/2015 09:02 PM, Tony Hwang wrote:
philo wrote:
Need a recommendation.


I like the idea of LED but am open to options

would like dimmable.


I looked at one LED setup but it said it takes two minutes to turn
on...not sure if I like that idea...but a slow warm up like CFL is OK

LED is not heat source. It turns on instant not like CFL. Use LOT less
power, lasts long time, dimmable. Many fixtures to choose from at
lighting store.
We just replaced all incandescent pod flood lights with daylight LEDs.
75W down to 12W each. Wife likes it.



An LED requires about 2 volts . Though the heat an LED produces is
negligible, the problem is in the self-contained power supply.


That is what produces the heat.


Guess we will just go to the store and have a look, thanks

On 8/10/2015 4:39 AM, philo wrote:
On 08/09/2015 09:02 PM, Tony Hwang wrote:
philo wrote:
Need a recommendation.


I like the idea of LED but am open to options

would like dimmable.


I looked at one LED setup but it said it takes two minutes to turn
on...not sure if I like that idea...but a slow warm up like CFL is OK

LED is not heat source. It turns on instant not like CFL. Use LOT less
power, lasts long time, dimmable. Many fixtures to choose from at
lighting store.
We just replaced all incandescent pod flood lights with daylight LEDs.
75W down to 12W each. Wife likes it.



An LED requires about 2 volts . Though the heat an LED produces is
negligible, the problem is in the self-contained power supply.

Wrong.

The source of the heat is the semiconductor junction of the LED. No heat
to speak of on the surface of the plastic part where the light emits
from, but significant heat from the junction. Look at the heat sink on
an LED bulb. Look at the heat sink on high-power LED flashlights.
Vehicles with LED headlights often use fans for cooling the lamp, or
they need an elaborate passive heatsink.

The reason so many LED lamps use multiple LEDs is that it's so difficult
to bleed off all the heat from a very high power LED. The junction is
very small and you need active cooling for very high power LEDs.

Good article about this he
http://www.ledsmagazine.com/articles/print/volume-8/issue-6/features/active-cooling-can-boost-lumen-output-in-led-lighting-magazine.html.
Read the section "Thermal issues in LED lighting."

On 08/10/2015 09:00 AM, sms wrote:


An LED requires about 2 volts . Though the heat an LED produces is
negligible, the problem is in the self-contained power supply.

Wrong.

The source of the heat is the semiconductor junction of the LED. No heat
to speak of on the surface of the plastic part where the light emits
from, but significant heat from the junction. Look at the heat sink on
an LED bulb. Look at the heat sink on high-power LED flashlights.
Vehicles with LED headlights often use fans for cooling the lamp, or
they need an elaborate passive heatsink.

The reason so many LED lamps use multiple LEDs is that it's so difficult
to bleed off all the heat from a very high power LED. The junction is
very small and you need active cooling for very high power LEDs.

Good article about this he
http://www.ledsmagazine.com/articles/print/volume-8/issue-6/features/active-cooling-can-boost-lumen-output-in-led-lighting-magazine.html.
Read the section "Thermal issues in LED lighting."




My experience with LED's goes as far as pilot lights which produce no
heat...thanks for the correction on those used for lighting.

On 8/10/2015 8:23 AM, philo wrote:
On 08/10/2015 09:00 AM, sms wrote:


An LED requires about 2 volts . Though the heat an LED produces is
negligible, the problem is in the self-contained power supply.

Wrong.

The source of the heat is the semiconductor junction of the LED. No heat
to speak of on the surface of the plastic part where the light emits
from, but significant heat from the junction. Look at the heat sink on
an LED bulb. Look at the heat sink on high-power LED flashlights.
Vehicles with LED headlights often use fans for cooling the lamp, or
they need an elaborate passive heatsink.

The reason so many LED lamps use multiple LEDs is that it's so difficult
to bleed off all the heat from a very high power LED. The junction is
very small and you need active cooling for very high power LEDs.

Good article about this he
http://www.ledsmagazine.com/articles/print/volume-8/issue-6/features/active-cooling-can-boost-lumen-output-in-led-lighting-magazine.html.

Read the section "Thermal issues in LED lighting."




My experience with LED's goes as far as pilot lights which produce no
heat...thanks for the correction on those used for lighting.

Yes, that's where the misconception comes from. Indicator lamp LEDs are
totally different.

I recall in the bicycling Usenet group someone was extolling the
benefits of LED lights and he was thrilled that there was no "white hot
filament." True enough, but that was replaced by a very hot
semiconductor junction which is even harder to cool than a white hot
filament in a hot bulb. Obviously he didn't understand anything about
semiconductor physics and junction current and temperatures (Tj). Sadly,
he claimed to be a physics professor at a university!

There's no free lunch here. There is heat, a lot of heat, to deal with
in both LEDs and incandescent sources. I was just looking at LED car
headlamps afer the last incandescent bulb I put it lasted only six
months. The problem with them is that the rating for hours that they
last is pretty low. Some models have little fans for cooling, some use
metal braiding out the back and explain that you have to be sure that
there is clearance for the heat sinking.

sms writes:
On 8/10/2015 8:23 AM, philo wrote:

My experience with LED's goes as far as pilot lights which produce no
heat...thanks for the correction on those used for lighting.


There's no free lunch here. There is heat, a lot of heat, to deal with
in both LEDs and incandescent sources. I was just looking at LED car

However, the amount of heat possible from an LED is limited
compared to that in an incandescent source, as the dissipated
heat is a function of the VA applied to the device. A 7watt
LED lamp will produce much, much less heat than a 60watt incandescent.

On 08/10/2015 11:52 AM, Scott Lurndal wrote:
sms writes:
On 8/10/2015 8:23 AM, philo wrote:

My experience with LED's goes as far as pilot lights which produce no
heat...thanks for the correction on those used for lighting.


There's no free lunch here. There is heat, a lot of heat, to deal with
in both LEDs and incandescent sources. I was just looking at LED car

However, the amount of heat possible from an LED is limited
compared to that in an incandescent source, as the dissipated
heat is a function of the VA applied to the device. A 7watt
LED lamp will produce much, much less heat than a 60watt incandescent.




Now that's for sure...

philo posted for all of us...



Need a recommendation.


I like the idea of LED but am open to options

would like dimmable.


I looked at one LED setup but it said it takes two minutes to turn
on...not sure if I like that idea...but a slow warm up like CFL is OK

I received a catalog from a co called Econo light or similar. They had it in
and I saw a dusk to dawn light I might get.

--
Tekkie *Please post a follow-up*

On 08/14/2015 03:40 PM, Tekkie® wrote:
philo posted for all of us...



Need a recommendation.


I like the idea of LED but am open to options

would like dimmable.


I looked at one LED setup but it said it takes two minutes to turn
on...not sure if I like that idea...but a slow warm up like CFL is OK

I received a catalog from a co called Econo light or similar. They had it in
and I saw a dusk to dawn light I might get.




Ended up getting halogen, only had time to put one of them up today...\
it's real nice and was not expensive

philo posted for all of us...



On 08/14/2015 03:40 PM, Tekkie® wrote:
philo posted for all of us...



Need a recommendation.


I like the idea of LED but am open to options

would like dimmable.


I looked at one LED setup but it said it takes two minutes to turn
on...not sure if I like that idea...but a slow warm up like CFL is OK

I received a catalog from a co called Econo light or similar. They had it in
and I saw a dusk to dawn light I might get.




Ended up getting halogen, only had time to put one of them up today...\
it's real nice and was not expensive

Good hope you make out well and thanks for the follow up.

--
Tekkie