1W LED's

[Overclocked]

What is meant by 1W LEDs? Do they provide 1W Of light? Or can they dissipate 1W of power?

 

[audioguru]

A 1W LED dissipates 1W of heat and creates a little amount of light.
An ordinary 25mA white LED (3.2V) dissipates 80mW of heat and creates a tiny amount of light.

A 100W incandescent light bulb dissipates about 90W of heat and creates a lot of light.
A 23W compact fluorescent light bulb dissipates about 22W of heat and creates a lot of light.

 

[justDIY]

yea, guru's pretty much spelled it out in examples.

the light output should be stated in lumens or mw, but often, for inferior leds, is measured in (mili)candella as it is easier to generate huge (false) numbers that way.

 

[Overclocked]

**broken link removed**

Is where Im getting it from. Ive gotten LEDs from this person before, and they are OK. it will take about 2 weeks to get here, but by the looks of it they are discontinued Lumileds.

How can I measure the light output of my LEDs? If I recal, there was a circuit in one of my books by Forrest M., III Mims I got from radioshack that had a circuit. I'll check later and post.

 

[audioguru]

Unlike light bulbs, LEDs are focussed into a very bright, very narrow beam.
Cheap ones have an old dim LED with tight focussing and they don't tell you how narrow is their beam.

 

[fingers]

The Luxeon 1 which you are buying is being replaced by the K2 because it can withstand the remperatures of being reflowed through the SMT Oven. Otherwise the Luxeon K2 has pretty much the same spec as its original. To run these high power LEDs anywhere near their ratings requires them to be attached to a larger heatsink.
The angle of these LEDs is 140deg, which isn't a great deal of use without attaching the lens to focus the light. Not bright enough to light a room, not precise enough to use as a torch. Still good fun to play around with so long as you don't look directly at them.

 

[Hero999]

Still, a 1W LED will give as much light as a 3W bulb so it's definately worth using them as a bulb replacement in torches.

 

[Overclocked]

The Luxeon 1 which you are buying is being replaced by the K2 because it can withstand the remperatures of being reflowed through the SMT Oven. Otherwise the Luxeon K2 has pretty much the same spec as its original. To run these high power LEDs anywhere near their ratings requires them to be attached to a larger heatsink.
The angle of these LEDs is 140deg, which isn't a great deal of use without attaching the lens to focus the light. Not bright enough to light a room, not precise enough to use as a torch. Still good fun to play around with so long as you don't look directly at them.

I know hes wholesale, so Im wondering if they are over stock. I was going to use them to light up part of the basement. I was going to attach them to a old florescent hanging thing (what ever you call them, they hold the bulbs and hang from the celing) and use that as the heatsink. The Area Needed to be lighted is small, and Im thinking it would be another good project.

According to the data sheet, they can use up to 1500mA :O! I was hoping they used 350mA Of current, but I guess not! but still, 140 deg is close to 180, which is what "normal" lights output at.

I have found 2 circuits, and I dont know which one to go by. They dont say what units they measure in, they are only light meters. I was thinking I could measure some other way, ie if 1 lumen is 1 candle at 1 foot, lighting up 1 sq ft of surface, then I could draw something up and measure that way. So for example, if at one foot, A LED lights up 2 sq feet, that would be 2 Lumens, Correct? Or would it be 2 lumens at 2 feet lighting an area of 2 sq feet.

I could also build the circuit, and measure 1 candle from 1 foot away and calibrate from there. That would tell how many Candles my LEDs are, but not Lumens or candela.

And whats a "torch" in LED terms?

 

[audioguru]

On our side of the pond a torch has a fire coming out of it. Maybe they still use the fire in torches in Britain. Maybe they use acetylene or kerosene as a fuel.

An LED flashlight has a single LED for a keychain light and many LEDs for a bright flashlight.

 

[Hero999]

I know hes wholesale, so Im wondering if they are over stock. I was going to use them to light up part of the basement. I was going to attach them to a old florescent hanging thing (what ever you call them, they hold the bulbs and hang from the celing) and use that as the heatsink. The Area Needed to be lighted is small, and Im thinking it would be another good project.

Keep the fluroscent, they're much more efficient, unless you require a direct light source of course.

According to the data sheet, they can use up to 1500mA :O! I was hoping they used 350mA Of current, but I guess not! but still, 140 deg is close to 180, which is what "normal" lights output at.

You can power them at 350mA if you want.

Also, I'd recommend a switch mode power supply as resistors waste energy.

And whats a "torch" in LED terms?

https://www.electro-tech-online.com/threads/wind-up-led-torch.30670/?highlight=torch

 

[audioguru]

Back to the "Torch" or 'Flashlight" debate:
1) A flashlight that uses an incandescent light bulb has its lightbulb burn out often enough that you could say it flashes.
Some flashlights carry a spare bulb in their case.
2) A flashlight has a focussed beam of light. When the flashlight is moved then it is very bright when it shines at you and it is dim when it doesn't. So it appears to flash on and off.

Ape-men used torches before electricity was invented.

 

[fingers]

According to the data sheet, they can use up to 1500mA :O! I was hoping they used 350mA Of current, but I guess not! but still, 140 deg is close to 180, which is what "normal" lights output at.

1500mA - no way! Not sure which datasheet you're looking at. 350mA at 2.79V (the minimum voltage specified) is the absolute maximum that you'd want to run it at. The 1W rating is the current x voltage. This is the datasheet for your LED **broken link removed** . It looks to be the lambertain.
I did a test at work to test how well different thermally conducting compounds work. At the end I cranked up the current in stages see how much current these LEDs can draw before blowing up. Around 800mA for a few seconds.

Audioguru - its a torch! The flash light flashes no more than a ceiling light. (Do you call ceilings something different over there too?)

 

[audioguru]

We don't call people "mates" nor "blokes".
We don't call a truck a "lorry".
We don't call the hood (front engine cover) of a car a "I can't remember what you call it".
We don't call the rear trunk of a car the "boot".
We don't have such a strong accent that nobody knows what we are saying.
Brits talk funny.

The bulb in a flashlight has a lifetime of only 5 hours to 20 hours. Incandescent bulbs on the ceiling have a lifetime of 1000 hours to 2000 hours.

 

[Hero999]

We don't call the hood (front engine cover) of a car a "I can't remember what you call it".

We call it the bonnet.

We don't have such a strong accent that nobody knows what we are saying.
Brits talk funny.

That depends on where your from and your upbringing, the pronounciation of some words changes within a few miles in some areas. Some British accents can be hard for me to understand; I can't understand some Scottish, Irish, Welsh and even some Essex accents. There again, they say accents are becomming weaker as time goes by; as communication improves and people move around more.

 

[audioguru]

What do Brits call H2O?
Woe-tahh!
We call it water.

I go to the washroom. Brits go to the Loo. Who is Lou? A pervert?
Funny differences.

 

[Hero999]

Well I call it water, or (to spell it phonetically) worter.

I go to the toilet but lavatory, loo, bog are also common.

 

[audioguru]

Is "worter" Cockney?

 

[justDIY]

I think the long O sound Canadians use in a lot of words is kinda funny. What time is it? it's a-boot 2 o'clock

 

[audioguru]

People from Newfoundland in Canada have an accent. I think they say aboot but I say about. They make their own booze called Moonshine. It makes people talk and act funny.

 

[philba]

Oh, I thought it was a-boat 2 O'clock. And upper midwest USA people say that too - Wisconsin, Minn and UP Michigan. I don't think it's any sillier than other accents of the english language. Though, I have to say I find Scotts-English impenetrable

Moonshine - I thought that was Southern USA slang 'cause it was made at night when the revenuers didn't work.