Impressive! Aliexpress offers over-unity energy.
There's a reason why I've never bought something from there.
About the standard difference between standard W and Chinese W when used for LEDs.
About the standard difference between standard W and Chinese W when used for LEDs.
Hahaha!
Seriously though, perhaps they mean W/sr? But without a radiation pattern, this is useless as well.
My experience with specs on this sort of random Chinese stuff is they just make something up, you really can't rely on any of the data.
I believe it probably means "this is the same substrate that we fill with white LEDs to yield a 20W (?) aggregate part, only stuffed with IR LEDs instead. Max current remains the same (?) and Vf is lower - isn't that great?"
Those watts means:
- this "20W" LED will produce the same amount of light as a 20W incandescent light bulb
- the "20W" is unrelated with how much power the LED requires in order to produce the equivalent light of a "20W classical incandescent light bulb". Usually the LED will require less power than a light bulb.
Later edit:
Sorry, I missed the LEDs here are IR.
That doesn't make any sense for IR LEDs, and even for visible types, I have a lot of 10W and 20W white LEDs that are WAY brighter than 10 or 20W incandescent.
I believe it probably means "this is the same substrate that we fill with white LEDs to yield a 20W (?) aggregate part, only stuffed with IR LEDs instead. Max current remains the same (?) and Vf is lower - isn't that great?"
This looks like a probable answer. Indeed, for their white leds, there is not this inconsistency. I have asked directly to hte store. They answered very rapidly, but not in a very satisfactory manner. I probably did not went beyond the first level of support.
Ccp Chen: Hi,
The current of 600mA is not the max current.But we suggest to use 600mA for 20W led,it can extend the life of led.If you want to use 700mA,it also ok for it.But pls make sure the working temperature less than 60 degree.
You can check IR led from other store.They also suggest to use current 560-700mA.
Even with 700mA, it is only 10W, and not 20W.
Chinese watts. Derate by 50% and a bit more if you want them to last.
(update #1 2019_01_21)
Hi AlcidePiR2
Don't try to rationalize specifications for any commercial component/equipment or you will go insane in the brain, just get to the important characteristics. With IR LEDs, they are:
- input electrical power
- IR output power
- IR frequency
- beam pattern
- life
Don't try to rationalize specifications for any commercial component/equipment or you will go insane in the brain, just get to the important characteristics. With LEDS they are:- input power
- lumens
- colour (temperature)
- beam angle
- life
The second two: lumens and colour temperature are only relevant to visible LEDs. The LED linked to above is infrared so will have a very low output in lumens: near zero.
The colour temperature is only relevant to white LEDs. Colour LEDs are normally specified as the dominant wavelength for monochromatic devices and chromacity coordinates.
Radiant power output, over the desired bandwidth is what's important for IR LEDs and is also used for LEDs at the far ends of the visible spectrum, which are typically used for other applications than direct illumination.
Refer to the papers linked below for more information.
http://depts.washington.edu/mictech/optics/me557/Radiometry.pdfhttps://www.thorlabs.de/catalogPages/506.pdf
Don't try to rationalize specifications for any commercial component/equipment or you will go insane in the brain, just get to the important characteristics. With LEDS they are:- input power
- lumens
- colour (temperature)
- beam angle
- life
The second two: lumens and colour temperature are only relevant to visible LEDs. The LED linked to above is infrared so will have a very low output in lumens: near zero.
The colour temperature is only relevant to white LEDs. Colour LEDs are normally specified as the dominant wavelength for monochromatic devices and chromacity coordinates.
Radiant power output, over the desired bandwidth is what's important for IR LEDs and is also used for LEDs at the far ends of the visible spectrum, which are typically used for other applications than direct illumination.
Refer to the papers linked below for more information.
http://depts.washington.edu/mictech/optics/me557/Radiometry.pdf
https://www.thorlabs.de/catalogPages/506.pdf
You beat me to it. I was thinking about visible LEDs. Above post amended.
All the same, the general message about not trying to rationalize specifications and focusing on the core parameters is the important point.
Whoops, I forgot to say that chomacity coordinates are used for LEDs with a non-spectral colour, such as pink, purple, pale green etc. which are made use a deep blue/violet/UV LED and a phosphor coating. Anyway, that's off-topic, as this thread is about an infrared, not a visible LED.
My experience with specs on this sort of random Chinese stuff is they just make something up, you really can't rely on any of the data.
Reminds me of about 40 years ago when audio systems were all the rage and they would come up with tiny systems claiming to put out hundreds of watts, which was clearly impossible and so they would claim it was not "RMS watts" but "musical watts" which was a totally made-up unit and they could claim whatever they liked.
Maybe these LEDs watts are "visual watts".
Oh they still do that. Somewhere I have a tiny set of amplified PC speakers that proudly proclaim 400 Watts.
"Peak Modulated Power Output" used to be a very common bogus rating too.
PMPO = "Peak Music Power Output"
I've seen both definitions for PMPO. Either way it's a meaningless metric made up by marketers.