SparkFun Electronics Commentsurn:uuid:214d0e4e-f1b1-d287-ce26-ac5b4c9f82492024-03-28T17:11:27-06:00SparkFun ElectronicsPickledDog on COM-12704 - LED - Violet 5mmPickledDogurn:uuid:b3dc9532-80fb-ccb6-9cd6-da5962c7dadd2014-02-06T22:09:45-07:00<p>Just received some. They are... violet! Close to UV - not purple at all. Indeed, they perform identically to the <a href="https://www.sparkfun.com/products/8662" rel="nofollow">Ultra-voilet</a> LED's. Like those, these can (faintly) reveal the security marks on currency. Given their similarities to the aforementioned, I'm guessing they're 400nm - just brushing the edge of UVA.<p>I've been looking for some of the blue + red ones, like the kind you find in christmas light sets. I guess I'll keep looking :)</p></p>
Toni_K on COM-12704 - LED - Violet 5mmToni_Kurn:uuid:8ad05702-e577-d599-395b-be634ea790572014-01-27T12:43:11-07:00<p>We often do not catch all of the new comments that come in, and are not attempting to avoid answering you or simply don't understand. The issue is that for things like this that we do not make in-house, we have to wait until we can get a data sheet from the manufacturer (as several other customers have requested as well), and unfortunately, there is not always a quick turn around time on that.</p>
rylos on COM-12704 - LED - Violet 5mmrylosurn:uuid:4b893ebb-8c7b-5909-3327-2f88eeb7ecda2014-01-25T15:23:29-07:00<p>These are definitely violet, with a good dose of UV thrown in, and not the "purple" you get from a red-blue combination such as with RGB LEDs. I tested a few of these on a breadboard with 5v and a potentiometer, with a few other lights for comparison. At very low intensities these LEDs appear violet to the eye. As the intensity increases with higher current, the color turns pale blue, and does a pretty good job of lighting up various colors of fluorescent paper, which is the UV portion doing its job. See Wikipedia's color swatches for blue, violet and purple for comparison.</p>
tz on COM-12704 - LED - Violet 5mmtzurn:uuid:9edf3360-8cb2-76f1-da57-27543748348b2014-01-24T19:33:58-07:00<p>I must be asking a question too hard for the engineers. Hint: Purple consists of Blue and Red, and usually violet light. Violet only has the top end of the spectrum.</p>
elligl on COM-12704 - LED - Violet 5mmelliglurn:uuid:f18748df-83a8-1022-0a3f-0950467982322014-01-24T08:35:34-07:00<p>I was thinking the same thing. I have my monitors calibrated too. It could be the camera which could not be showing how this really looks.</p>
ratronic on COM-12704 - LED - Violet 5mmratronicurn:uuid:bb796eec-9282-6157-9232-090e350a9e102014-01-24T08:18:12-07:00<p>Is there a datasheet available for this LED? I am interested in it's wavelength and output mcd's.</p>
gagir on COM-12704 - LED - Violet 5mmgagirurn:uuid:cdf3cf85-f75b-2158-dcf7-264244b6578b2014-01-24T08:12:47-07:00<p>SparkFun should make an effort to get the data sheets and specs for LED's and other photonic devices.
UV radiation can be harmful if not careful...
UV radiation can be useful at certain wavelengths....</p>
MostThingsWeb on COM-12704 - LED - Violet 5mmMostThingsWeburn:uuid:98606000-d428-d4c3-d672-99251484124f2014-01-20T13:56:51-07:00<p>There are also 5mm UV LEDs on here</p>
PickledDog on COM-12704 - LED - Violet 5mmPickledDogurn:uuid:410a0c05-f864-65b7-e71f-964c4de835492014-01-19T15:06:06-07:00<p>I wouldn't read too much into these listed forward voltages - the Basic Blue and Super Bright Blue are also listed 3.4V.</p>
Customer #472766 on COM-12704 - LED - Violet 5mmCustomer #472766urn:uuid:9f082023-7fe1-c874-1804-8bf1ded963222014-01-18T13:37:58-07:00<p>According to this photon energy-wavelength calculator
(http://www.pveducation.org/pvcdrom/properties-of-sunlight/energy-of-photon)
if the photon energy is ~3.4 eV (for forward V drop of 3.4 V) then the wavelength would be 365 nm. This is an approximation since I don't know if the forward voltage drop will give the actual eV of the photon. Does anyone on this know for sure? This is a good UV wavelength, about the same as one of the Hg lines (365 nm) used in early photolitho.</p>
bfesser on COM-12704 - LED - Violet 5mmbfesserurn:uuid:d4134e43-1a07-2a88-c769-6182233ae66d2014-01-17T20:18:03-07:00<p>A datasheet would be preferable.</p>
R_Phoenix on COM-12704 - LED - Violet 5mmR_Phoenixurn:uuid:69a37df4-3a7e-c8cc-b9ff-727129cf41722014-01-17T20:01:56-07:00<p>The picture sure does look blue to me</p>
tz on COM-12704 - LED - Violet 5mmtzurn:uuid:305ec9e0-4450-04cf-62cf-a774251f17fb2014-01-17T19:25:32-07:00<p>Is it purple or violet?</p>
PickledDog on COM-12704 - LED - Violet 5mmPickledDogurn:uuid:3a66637e-e1cc-d138-8da0-e3289b2133612014-01-17T10:43:22-07:00<p>Is this a "conventional" LED, or one of those multi-frequency ones (blue with a red phosphor)? If it's conventional, what wavelength is it?</p>