Strange problem with low energy light bulb

[Mr.T]

I've done a fair number of fairly large (i.e., 8 or more bulbs per room)
incadescent (mostly halogen) to CFL upgrades, with extremely positive
results. In every case the fixtures were previously loaded up with
incadescent bulbs rated at the fixture's maximum power. They were providing
poor to marginal lighting.

No argument from me that most halogens are even bigger crap than most CFL's.
However I had never assumed people do not bother to differentiate standard
filament light bulbs from small halogens.
I'm puzzled why they even bother to differentiate CFL's in that case. Simply
call them lamps

MrT.

 

[Mr.T]

Yes, when "you" make a choice... but this thread is not one comparing
CFL lamps to standard tube-types.

Taken literally THIS thread is NOT about lamps at all then. It is only about
"Stevenson = fucking moron".

However we all get to choose how we respond, you ONLY get to make your
choices NOT mine.
If you don't like it, simply move on to the next post/thread.

You may choose to argue on a
tangent, that is your privilege and absolute right.

Thank you.

MrT.

 

[Mr.T]

LOL !

You need to get out a bit.

Maybe you can tell us exactly which houses have electric lighting and 40degC
temperatures at night.
(or why they choose to run lights during the day in such conditions)
I obviously haven't been "getting out" to those!

MrT.

 

[Arfa Daily]

Don't believe everything you read.

Experience is the best teacher.

In other words, LEDs suck for bright light sources.

However, the hype is good for selling them to fools over the
TV/Internet. Like that one guy selling LED light bulbs on TV (USA). He
doesn't explicitly say that they're bright as a lightbulb, but they
are in a lightbulb package and used in the commercial as if they were
a lightbulb. Some people probably fall for that.


Right, but pointless except for low light applications.

I have a friend who has LED downlighters as the only source of light in his
shop. They are perfectly bright and adequate for the job, if a little 'cold'
in colour temperature. Also, a local photography shop uses similar ones for
its window display, and again, the only comment you would make is that they
are a little cold. The specifications for up to date ones would certainly
suggest that they are on a par in terms of light output and beamwidth, with
comparable fitting halogens. With a bit of work, I'm sure that they will
also get to the point where they can replace a standard filament bulb, in
the same sized package, unlike a CFL which has to accommodate the ballast. I
think it might be a case of 'ya gets wot ya pay fer'

Arfa

 

[Lostgallifreyan]

Don't believe everything you read.

Experience is the best teacher.

In other words, LEDs suck for bright light sources.

However, the hype is good for selling them to fools over the
TV/Internet. Like that one guy selling LED light bulbs on TV (USA). He
doesn't explicitly say that they're bright as a lightbulb, but they
are in a lightbulb package and used in the commercial as if they were
a lightbulb. Some people probably fall for that.

In your infinite wisdom, how do you explain this?

http://www.cree.com/products/xlamp.asp

NIST confim the brightness, so you don't have to believe the 'hype', you
only have to ask a few basic technical questions: How efficient is it?
Is there enough light to fit purpose at given cost?


"LED luminaires can only be considered high efficacy if the LED can be
tested (according to UL) to be at least 40 lm/W on the line voltage input
side of any power supply or other device.” Otherwise the fixture is not
considered high efficacy."
Source: http://www.icfi.com/Markets/Energy/doc_files/led-lighting.pdf


Light Type: lm/WW CRI Life (hrs)
Incandescent 17 100 3k
Halogen 20 100 10k
Cree XLamp 7090 XR 48 80 >50k
T12 flourescent 60 75-85 20k
Metal halide 70 70 20k
Cree XLamp 7090 XR-E 70 80 >50k
T8 flourescent 74 75-85 20k
High-pressure sodium 91 22 20k
Low-pressure sodium 120 5 18k
Source: http://www.cree.com/products/pdf/XLamp7090XR-Esheet.pdf

Even if you lose nearly half the light you can still claim high efficiency
to UL standards given the 95% efficient power converters made to run LED
lamps. It would be a poor luminaire that lost that much.

As for actual light output, newer LED's put out 176 lumens or more. That's
still a tad short of what's wanted in many cases, but not by much. 7 to 10
emitters would match a standard 100W incandescent (7 for the 240V type, 10
for the 110V type). Given that the cost of the first CFL's was around £26
in the UK, maybe £40 in todays money, that puts LED's in a good position,
you can get a lot better device for a lot less than that, even now, and
it's improving fast, a lot faster than the time CFL's took to develop, and
there are probably more ways to cut costs without sacrificing safety.

It would take only a fourfold increase in output from a single emitter at
same cost to make them compete with any other light source for domestic
use, and I think we'll only need to wait a few months for that.

 

[Eeyore]

"Eeyore" wrote


Maybe you can tell us exactly which houses have electric lighting and 40degC
temperatures at night.

I didn't say specifically at night.

There are plenty of tropical places where temps are that high. And there are
planty of ppor perolpe whi can't afford air conditioning in such places too.

Graham

 

[Eeyore]

I have a friend who has LED downlighters as the only source of light in his
shop. They are perfectly bright and adequate for the job, if a little 'cold'
in colour temperature. Also, a local photography shop uses similar ones for
its window display, and again, the only comment you would make is that they
are a little cold. The specifications for up to date ones would certainly
suggest that they are on a par in terms of light output and beamwidth, with
comparable fitting halogens. With a bit of work, I'm sure that they will
also get to the point where they can replace a standard filament bulb, in
the same sized package, unlike a CFL which has to accommodate the ballast. I
think it might be a case of 'ya gets wot ya pay fer'

The brightest LEDs do unfortunately have that cool blue 7000K or so colour temp.
There's a significant trade off in efficiency for the 3000K ones.

Graham

 

[Mr.T]

I didn't say specifically at night.

Then as I said, why do they use the lights during the day, rather than
operate some form of cooling?
IF they don't, your argument is totally irrelevant.

There are plenty of tropical places where temps are that high. And there are
planty of ppor perolpe whi can't afford air conditioning in such places

too.

And plenty who have no electric lighting either, but that has nothing to do
with the claim of 40degC ambient temperature at the light fitting when
operating.
Your whole argument is thus pointless. No real surprise there.

MrT.

 

[Eeyore]

And plenty who have no electric lighting either, but that has nothing to do
with the claim of 40degC ambient temperature at the light fitting when
operating.
Your whole argument is thus pointless.

Not at all. What kind of CFLs do you sell in tropical or desert countries ?

Graham

 

[Albert Manfredi]

Right, but pointless except for low light applications.

Suggest you do some searching here:

http://www.ieee.org/web/publications/xplore/index.html

Bert

 

[default]

Experience is the best teacher.

Yes. Had someone told you there would be pocket sized radio telephone
equipment in the 50's you might not have believed it.

Agreed LEDs aren't quite there yet, but they are almost there, and
that is pretty exciting stuff. (or at least it is compared to the
LEDs we were using in the early 70's)

Experience with electronics suggests things will get smaller lighter
cheaper and work better over time.

You'd condemn the whole industry, and research effort, because some
charlatan wants to make a quick buck on TV?

 

[Kevin McMurtrie]

Don't believe everything you read.

Experience is the best teacher.

In other words, LEDs suck for bright light sources.

However, the hype is good for selling them to fools over the
TV/Internet. Like that one guy selling LED light bulbs on TV (USA). He
doesn't explicitly say that they're bright as a lightbulb, but they
are in a lightbulb package and used in the commercial as if they were
a lightbulb. Some people probably fall for that.


Right, but pointless except for low light applications.

http://www.lumileds.com/products/line.cfm?lineId=19

145 Typical lumens from 700mA @ 3.6V, or 58 lumens per watt. The LED is
a surface mount chip 3.1 x 4.6 x 2.1 millimeters in size. A thin strip
of 12 of these chips puts out light comparable to a 100W tungsten lamp
but only uses 30W.

I'm using 8 of the older Luxeon K2 LEDs in a bicycle light. The output
is nothing short of impressive. It's brilliant at just 5W of input
power. Crank it up to 40W and it puts car headlights to shame.

 

[Eeyore]

http://www.lumileds.com/products/line.cfm?lineId=19

145 Typical lumens

No. NOT TYPICAL. That's the highest output (most expensive) grade.
LXML-PWC1-0080
http://www.lumileds.com/pdfs/DS56.pdf

from 700mA @ 3.6V, or 58 lumens per watt.

In 'cool white' i.e, the very blue light with a 6500K colour temp. Not very
suitable for domestic lighting.

More like 95 lumens for a warm white, which works out as 43 lumens/W
http://www.lumileds.com/pdfs/DS56.pdf

Graham

 

[Eeyore]

http://www.lumileds.com/products/line.cfm?lineId=19

145 Typical lumens from 700mA @ 3.6V, or 58 lumens per watt. The LED is
a surface mount chip 3.1 x 4.6 x 2.1 millimeters in size. A thin strip
of 12 of these chips puts out light comparable to a 100W tungsten lamp
but only uses 30W.

I'm using 8 of the older Luxeon K2 LEDs in a bicycle light. The output
is nothing short of impressive. It's brilliant at just 5W of input
power. Crank it up to 40W and it puts car headlights to shame.

 

[Dave Plowman (News)]

http://www.lumileds.com/products/line.cfm?lineId=19

145 Typical lumens from 700mA @ 3.6V, or 58 lumens per watt. The LED is
a surface mount chip 3.1 x 4.6 x 2.1 millimeters in size. A thin strip
of 12 of these chips puts out light comparable to a 100W tungsten lamp
but only uses 30W.

That's poorer efficiency than a CFL can manage. Chances are the colour
temperature is poor too - if tungsten is your norm.

 

[Eeyore]

http://www.lumileds.com/products/line.cfm?lineId=19

145 Typical lumens from 700mA @ 3.6V, or 58 lumens per watt. The LED is
a surface mount chip 3.1 x 4.6 x 2.1 millimeters in size. A thin strip
of 12 of these chips puts out light comparable to a 100W tungsten lamp
but only uses 30W.

The colour temperature won't be anywhere near comparable.

In any case don't 'white leds' use the same phosphor method of producing light
that CFLs do ?

Graham

 

[Eeyore]

With a bit of work, I'm sure that they [LEDs] will
also get to the point where they can replace a standard filament bulb, in
the same sized package, unlike a CFL which has to accommodate the ballast.

To run LEDs efficiently from 240V AC will also require some active electronics.
I see no-one ever factors in the power losses that'll be associated with that.

Graham

 

[GregS]

With a bit of work, I'm sure that they [LEDs] will
also get to the point where they can replace a standard filament bulb, in
the same sized package, unlike a CFL which has to accommodate the ballast.

To run LEDs efficiently from 240V AC will also require some active electronics.
I see no-one ever factors in the power losses that'll be associated with that.

When you use up the watts, you get heat. The lamp has to efficiently get
rid of it. May even need a fan.

In my experimental 45 watt, 9- 5 watt Luxeon array, I use copper, aluminum, and a fan.
DC drive is nice.

greg

 

[Eeyore]

With a bit of work, I'm sure that they [LEDs] will
also get to the point where they can replace a standard filament bulb, in
the same sized package, unlike a CFL which has to accommodate the ballast.

To run LEDs efficiently from 240V AC will also require some active electronics.
I see no-one ever factors in the power losses that'll be associated with that.

When you use up the watts, you get heat. The lamp has to efficiently get
rid of it. May even need a fan.

Quite possibly so. How many watts does the fan need ?

In my experimental 45 watt, 9- 5 watt Luxeon array, I use copper, aluminum, and a fan.
DC drive is nice.

The normal home doesn't have DC. What do you use for current limiting and how much power does that
dissipate ?

Graham

 

[GregS]

Arfa Daily wrote:

With a bit of work, I'm sure that they [LEDs] will
also get to the point where they can replace a standard filament bulb, in
the same sized package, unlike a CFL which has to accommodate the ballast.

To run LEDs efficiently from 240V AC will also require some active electronics.
I see no-one ever factors in the power losses that'll be associated with

that.

When you use up the watts, you get heat. The lamp has to efficiently get
rid of it. May even need a fan.

Quite possibly so. How many watts does the fan need ?

Just uses a small CPU fan. I'm actually using a CPU sink/fan combo, but the LED's are epoxied to a copper
plate. I even have diamond dust as a buffer/insulator. To close space the LED's
I needed the best thermal transfer. Did I forget to mention the Peltier device.
I am also using unmounted LED's.

The normal home doesn't have DC. What do you use for current limiting and how
much power does that
dissipate ?

Nothing is compact. I use a large variable supply. There is 45 watts going to the LED's.
About 20 [email protected] amps. 3 series sets of LED's. You cannot look at the light.
The device was intended to be flashed in the final form. peaking at about 60 watts.

greg