Hi Guys
I think that should be .001615 W. They stated 1615uW.I have crunched some numbers but they may be wrong as I am tired after a long week. Will not post yet until I go over.
I thought I would share some previous posts from our long lost friends Anachronist and Kozzy who did the calculation back then. You will be able to extrapolate an answer from this. Not sure if we are comparing apples to apples when comparing our p gan to a packaged led ready for sale.
Would be nice to hear what our old friends think of this progress.
Great to hear this step improvement in the last month. Bring on the coming months.
Cheers.
Anachronist from 2012
BLG quoted an output of 1.23mW at 50mA for a frequency of 456nM
Although a UV detector was used in this measurement, it was calibrated to the wavelength of light used in this test ,ie 456 nm, which not UV.
It is the wavelength of Blue LEDs.
At this wavelength typical LED efficacies are around 35 lumens per Watt.
Lumens per Watt is the typical measure for LEDs in the optical spectrum.
So from this perspective BLG's first run output figures need to be recalibrated into lumens.
Lumens is a measure of the total light power calibrated to the spectral sensitivity of the human eye.
At the human eye's peak sensitivity and 100% efficiency, 1 Watt produces 683 lumens.
Therefore BLG's 1.23mW measured light output corresponds to 0.84 lumens from the 0.25W input.
ie 3.36 lumens /Watt. Which is about 10% of typical Blue LEDs.
Agrees with your figures kozzy!
Nothing to crow about, but it is a first run of a new technology.
The higher the frequencies, the more difficult it is to get the efficiencies especially in the UV spectrum.
Figures I found, show that currently the world's best UV LEDs can output powers around 16mW at 50mA drive
It is extremely interesting however that BLG's measurement was done with a UV detector. That's in fact why the output was given in mW as opposed to the usual Lumens used in the LED industry.
Having this measuring kit in place there, hints at the fact that BLG may be working at their tool being optimized to manufacture more efficient UV LEDs.
The UV LED market is a very new and as yet untapped market, due to current technology being unable to manufacture UV LEDs of sufficient efficiency to be useful and commercially viable.
Consequently it is currently an extremely small market, but having huge potential.
Kozzy from 2012
re: Ann: BLG Demonstrates Promising Prelimina...
I'm no LED expert but have a degree in electronic engineering, not exactly sure why they have reported the light output as 270uW and 1.23mW they usually report UV LED output with that measurement (milliwatt), possibly because it's a sample rather than a packaged LED.
Hopefully they report the output as millicandela in the future.
Going by a typical UV LED I think we need the output above 12mW
Found a forum post which has gone through the conversion, it's not exact but at least gives us a ball park value of around 17mW for a typical high output blue LED with a 5000mcd (millicandela) output.
http://www.candlepowerforums.com/vb/showthread.php?176206-Comparing-mW-to-MCD-equivalent
