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: :poke: :shakehead :sigh: :mecry: :naughty: :laughing: :crackup:
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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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.
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.