# Does 5W CREE LED exist?



## pwangdel (Oct 6, 2009)

Greetings:

I see a headlight flashlight specification showing a 5W CREE LED. The google result only shows one at the whole sale headlight web site. Does 5W CREE LED exist? 

Thanks.


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## moviles (Oct 7, 2009)

no.
but XR-E package with ez900 or ez1000 chip can be a little overdrived at 1.4 amp and work at 5w

pin = wats


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## Marduke (Oct 7, 2009)

It's most likely that the package specification is just a fanciful number with no basis in reality.


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## pwangdel (Oct 7, 2009)

Thank you all for the info.

Can the ez900 or 1000 chip be seen easily if the flashlight circuitry is disassembled?


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## LEDninja (Oct 7, 2009)

I bought an LED nitelite bulb at Dollarama yesterday. It has ONE 5MM LED in it.




I have a 5mm LED rated at 7W! :twothumbs :thinking:  :shakehead :sigh: :mecry: :naughty: :laughing: 

I have many guesses as to how the 5W got on the headlamp description.
1)
It uses a 0.5W Cree LED. The decimal point in the .5 somehow got lost in the printing.
2)
The headlamp was a 5W Luxeon (overdriven LuxIII or K2). When they switched to Cree LEDs they just added Cree to the end of the name.
A few years ago the cheap thrower was a 7W LuxeonIII overdriven at 1000mA. I bought a 3AAA SSC-P4 light a couple of years after that. The '7 WATT' was still silkscreened on the body.
3)
The marketing people saw 3W Cree and 4W Cree and decided to play the one-upmanship game.


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## vali (Oct 7, 2009)

Or maybe "5W" is just the model of the light and W doesnt mean Watts.


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## Yoda4561 (Oct 7, 2009)

pwangdel said:


> Thank you all for the info.
> 
> Can the ez900 or 1000 chip be seen easily if the flashlight circuitry is disassembled?



The ezXXXX chips are the LED itself, the actual emitter.


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## pwangdel (Oct 7, 2009)

Thank you all for the additional info.

I e-mail the retailer and they confirm it is a 5W CREE LED. The headlight was purchased directly from the manufacture.

Since there is no way to verify the chip itself, so the oversea manufacture may claim whatever they like.


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## csshih (Oct 7, 2009)

LEDninja said:


> I bought an LED nitelite bulb at Dollarama yesterday. It has ONE 5MM LED in it.
> I have a 5mm LED rated at 7W! :twothumbs :thinking:  :shakehead :sigh: :mecry: :naughty: :laughing:
> I have many guesses as to how the 5W got on the headlamp description.
> 1)
> ...


nope! it doesn't say 7 Watt LED, it says 7 Watt!!
which could mean

7 Watt Circuit

Which makes for a *very *inefficient circuit!
how's that for marketing? :green:


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## Marduke (Oct 7, 2009)

pwangdel said:


> Thank you all for the additional info.
> 
> I e-mail the retailer and they confirm it is a 5W CREE LED. The headlight was purchased directly from the manufacture.
> 
> Since there is no way to verify the chip itself, so the oversea manufacture may claim whatever they like.



Actually you can tell the model simply by looking at the emitter.

The ONLY Cree emitter rated for 5W is the MC-E, and VERY few headlamps use them. In fact I can only think of one, and it is no longer made.


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## fyrstormer (Oct 7, 2009)

I have a bunch of those little LED nightlight bulbs. The wattage rating just means it's as bright as a 7W (or in my case, 4W) incandescent bulb.

Most people don't have a damned clue what the lumen rating is for, so for consumer lightbulbs they just tell you what the wattage would be for an equivalent incandescent -- hell, I had to explain it to my next-door neighbor, and he's an electrical engineer! He was saying how he was going to drop a couple thousand bucks on LED lighting for his whole house, and I told him:

1. The average 60W incandescent outputs ~800 lumens. (this is when he asked what lumens were. :shakehead)

2. The Arc6 I was holding in my hand at that very moment had an LED rated for 250 lumens at 3.7V x 1.5A = 5.6W.

3. That means, to get the same amount of light from an LED bulb, he'd need to run 17.9W through an LED fixture with the same efficiency as my flashlight.

4. A 14W fluorescent will produce the same amount of light for a third of the price.

I know the math isn't perfect, but it's close enough. Poor guy was about to walk into a hardware store and get bent over the checkout counter for all the LEDs he was going to buy, all because he didn't think to check the lumen rating first. We need an ad campaign telling people to look at lumens first, wattage second, and technology last.


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## moviles (Oct 8, 2009)

fyrstormer said:


> I have a bunch of those little LED nightlight bulbs. The wattage rating just means it's as bright as a 7W (or in my case, 4W) incandescent bulb.
> 
> Most people don't have a damned clue what the lumen rating is for, so for consumer lightbulbs they just tell you what the wattage would be for an equivalent incandescent -- hell, I had to explain it to my next-door neighbor, and he's an electrical engineer! He was saying how he was going to drop a couple thousand bucks on LED lighting for his whole house, and I told him:



i think the same thing

Many years ago I buy this bad flashlight luxeon 5w 1xaa : 





we can read 5w and it work at only 0.7w


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## LEDninja (Oct 8, 2009)

LEDninja said:


> I bought an LED nitelite bulb at Dollarama yesterday. It has ONE 5MM LED in it.
> 
> 
> 
> ...





csshih said:


> nope! it doesn't say 7 Watt LED, it says 7 Watt!!
> which could mean
> 7 Watt Circuit
> Which makes for a *very *inefficient circuit!
> how's that for marketing? :green:


It says energy used 7W in the bottom left but the bulb is nowhere near as hot as a 7W incan. Someone just copied all the words of a 7W incan bulb package over and just added 'LED'.

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LEDninja said:


> I have many guesses as to how the 5W got on the headlamp description.
> 1)
> It uses a 0.5W Cree LED. The decimal point in the .5 somehow got lost in the printing.
> 2)
> ...





pwangdel said:


> I e-mail the retailer and they confirm it is a 5W CREE LED. The headlight was purchased directly from the manufacture.


So guess #1 does not pan out.

It has been so long since I saw a torch rated by watts I forgot about guess #4.
4) The old Luxeon torches are rated as follows:
It can be power to the LED or power drain from the batteries (BIG DIFFERENCE)
a) LuxI - 350mA > 1W,
b) LuxIII - 350mA > 3W, (These use a '3W' LED even though the circuit is 1W). This created a problem for the manufacturers of LuxIII/700mA torches so:
c) LuxIII - 700mA > 5W,
d) LuxIII - overdriven at 1000mA 7W, (These are 2*CR123A, LED gets 4W, dropping resistor absorbs 3W)
e) LuxIII - DD by 3AAA > 6W, (These were originally also rated 7W but when that got poo-pooed big time in CPF and other forums got derated to 6W)
f) K2 various drive levels 10W, 12W, 15W.
So the headlamp could be based on c) with a LED swap: Cree - 700mA > 5W or it could be a Cree overdriven at 1400mA (true 5W at the LED).

What batteries do the headlamp need and how many?
This should give us some idea of the power available.


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## TorchBoy (Oct 14, 2009)

pwangdel said:


> I see a headlight flashlight specification showing a 5W CREE LED. ... Does 5W CREE LED exist?


I think LEDninja might be on the right track. Many manufacturers seem to use a convention that comes from Luxeon I and III LEDs where any white LED driven at 350 mA is "1W" and at 700 mA is "3W" even though it's not actually 3 W. By extension, a white LED driven at 1 A would be "5W" even though it's not actually 5 W.

Of course, they might be using that artificial "5W" for what the maximum current the LED is rated for, not what it's being driven at in the headlamp.


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