In the LED demo box at a local electronic store, their "purple" looked magenta to me, while the violet looked good at burning retinas 😱
Cheers!
I tend to avoid purple / violet led's as most of them seem to put out a reasonable amount of UV.
The real question is which LED makes for better sound. Once it is properly broken in, of course.
This is a good question - and one over which I have had many arguments.
Purple to me is a combination of red and blue light. I.E. a hole in the middle of the spectrum, no green. Violet is a wavelength shorter than blue. Newton called it Indigo. It can be seen below blue on the rainbow, the shortest wavelength we see.
I am not sure, however, how the eye distinguishes it from blue. It seems that the red cones in the eye are also a bit sensitive to blue, so it may be that cross talk that looks blue to us. Some digital cameras and displays have a hard time with true violet, it comes out blue. Violet is often faked with purple (magenta.)
More than you wanted to know, I'm sure.
As for red being a good color for nigh vision, this is quite true. Used in aircraft cockpits, for example. Look up "Rhodopsin" to learn why.
I'm pretty sure that I've read on this forum the LED's sound bad and that light bulbs are preferred. Not inclined to search for the posts though. LED's contaminate the power supply, you see.
Hey what do you call an LED that only has two pins but does two colours?
I want to replace the LED in my Jolida passive but I can't figure out how to find it on digikey. It glows red when off and blue when on. The symbols on the pcb make me think the current is reversed to make it change colour?
I want to replace the LED in my Jolida passive but I can't figure out how to find it on digikey. It glows red when off and blue when on. The symbols on the pcb make me think the current is reversed to make it change colour?
That's a bi-colour LED that has the diodes connected in reverse-parallel.
http://au.farnell.com/multicomp/l24r5005k2p2/led-5mm-he-red-grn/dp/1208859?Ntt=1208859
http://au.farnell.com/multicomp/l24r5005k2p2/led-5mm-he-red-grn/dp/1208859?Ntt=1208859
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There are 7 color names in Russian language: Red, Orange, Yellow, Green, 2 different colors of Blue with different names, and Violet.
By the way, in Eskimo language there are 40 (!) names for the snow, and they can easily tell one from another.
Accommodation after red light happens faster. Astronomers use red flashlights as well.
Thanks G.K.
Is this one of those? None seem to say anything about reverse-parallel... Difficult to source!
Is this one of those? None seem to say anything about reverse-parallel... Difficult to source!
If you're that worried about noise, throw the whole circuit in liquid nitrogen.I'm pretty sure that I've read on this forum the LED's sound bad and that light bulbs are preferred. Not inclined to search for the posts though. LED's contaminate the power supply, you see.
Yes it is. You can see the reverse-parallel diodes in the schematic on the datasheet.
Or just use audiophile-certified light bulbs instead of LEDs.
Also electric vehicles are becoming unsafe (for pedestrians) and an electronic " roar!" is being studied.
Yes, the names your language gives to color influences the way you see them. What are the 2 names for blue in Russian and how would you define them?
Unfortunately, this is an urban myth.
The rainbow colours are conventionally named: Violet, Indigo, Blue, Green, etc.
So the first three are three distinct colors.
People who are aphakic (i.e., have no natural lens in the eye) due to cataract surgery can see further into the violet part of the spectrum. The retina is sensitive to near ultra-violet, but normally the lens filters it out.
(To me, a room 'lit' by ultra-violet black tubes - which apparently appears dark to most people - is as brightly lit as if conventional fluorescent tubes were used.)
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the eye distinguishes it because the red receptors have a small sensitivity peak as well there; thus leading to a purple violet tinge ;p
(yes i know it is going around in circles, because colors are ineffible ;p)
it was found while studying intelligence photos of enemy bases, that having a
colorblind person on the team, leads to a higher detection rate, as some colorblind people often can discern different mixtures of colors which seem equal to regular people. and also often rendering for instance camouflage ineffective
afaik.
*edit: the perception of red, to be precise.
(yes i know it is going around in circles, because colors are ineffible ;p)
it was found while studying intelligence photos of enemy bases, that having a
colorblind person on the team, leads to a higher detection rate, as some colorblind people often can discern different mixtures of colors which seem equal to regular people. and also often rendering for instance camouflage ineffective
afaik.
*edit: the perception of red, to be precise.
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As in English, then? Red, Orange, Yellow, Green, [Blue, Indigo], Violet.
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As usual. 2 different colors, with 2 different frequencies. They are not of the same frequency with different intensities, they are different colors.
In English people confuse Blue, Indigo, and Violet. Some say that Indigo is a dark blue, some say that Indigo is a Violet.
By the way, paints have more of frequency gradations, with own names.
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