unrise_lyrical Posted May 25, 2008 Report Share Posted May 25, 2008 Planning out the cosmetics of a Midibox64 and Im looking at having a design in the back of it that will glow with UV leds. will the following be suitable to be powered off the voltage inside a midibox? (I dont understand all the nitty gritty yet :) )Specifications:Material: InGaN Emitting Colour: purple/violet Lens Type: water clear Reverse Voltage: 5.0 V [ 1/4W,470ohm resistor is needed ] DC Forward Voltage: Typical: 1.9 V Max: 2.3 V Wave Length: 625-635nm Luminous Intensity MCD: Typ: 3,000 mcd DC Forward Current: 20mA Viewing Angle: 12±5degree Lead Soldering Temp: 260oC for 5 seconds Intensely Bright Im planning to run maybe 50 of them around a piece of frosted perspex and have them shining in from the edges, with a second set only on when a midi signal is detected going in/out. If that doesnt exactly make sense I can explain it a bit more clearly but basically the main thing I want to know is will these work in a midibox? :) Quote Link to comment Share on other sites More sharing options...
stryd_one Posted May 25, 2008 Report Share Posted May 25, 2008 50 of them?! I don't think you'll need that many :) (and if you do, you might need a special PSU just for them hehe) Quote Link to comment Share on other sites More sharing options...
unrise_lyrical Posted May 25, 2008 Author Report Share Posted May 25, 2008 hahaha yea, maybe not 50 :) I'm buying a pack of 200 of them though...so its not like I need to be sparing with them! :) but yea, will they be usable? Quote Link to comment Share on other sites More sharing options...
stryd_one Posted May 25, 2008 Report Share Posted May 25, 2008 its not like I need to be sparing with them! :) but yea, will they be usable?Depends on how sparing you are with them ;) Yes, they'll work, but too many will draw too much juice, and then nothing will work. Quote Link to comment Share on other sites More sharing options...
unrise_lyrical Posted May 25, 2008 Author Report Share Posted May 25, 2008 is it possible to run some form of electrical component in series with their power to limit their supply so they glow less brightly and chew up less power? Is that what perhaps a resistor may do? Id rather have alot of them glowing dull-ly instead of a few glowing brightly..then I can get a more uniform wash of light thru the perspex Quote Link to comment Share on other sites More sharing options...
stryd_one Posted May 25, 2008 Report Share Posted May 25, 2008 I'll let the hardware-savvy guys field that :)(I'll take a guess: the resistor sounds good) heheheh Quote Link to comment Share on other sites More sharing options...
Wilba Posted May 25, 2008 Report Share Posted May 25, 2008 You will need to experiment.But yeah, you could increase the resistor value to 1K, 2K or higher for less brightness and less current per LED.http://www.kpsec.freeuk.com/components/led.htm Quote Link to comment Share on other sites More sharing options...
Pascal Posted May 25, 2008 Report Share Posted May 25, 2008 Wave Length: 625-635nm Purple?This Wavelength was Yellow to bright red! Not Purple! Purple was ca. 380 - 420 nm!Look:http://de.wikipedia.org/wiki/LichtCheck this befor you order ;-) Quote Link to comment Share on other sites More sharing options...
NV Posted May 31, 2008 Report Share Posted May 31, 2008 Depending on the size of your design you will most likely not need nearly as many as 50, particularly with light as noticeable as purple/UV and the 20mA LEDs you specified (water clear, ultra brights). LEDs are cheap, and while you may not need to be sparing with the 200 pack you've purchased you certainly don't need to utilize any more than is necessary.Provided that you use all 50 LEDs without any resistive elements you'll be drawing 1A from your power supply, which is more than an entire Midibox in many cases. Using resistors you will be able to lower the current draw and thus the brightness of the LEDs, although the wiring of 50 LEDs and resistors is nothing to scoff at, particularly if you are trying to outline a display rather than simply grid them in a uniform pattern.I would experiment with a few LEDs at first and see how you like the appearance. Assuming your design isn't enormous (I'm thinking around 6" x 6" as a guess? Using 5mm LEDs?) you could probably use 12 LEDs with resistors and achieve basically the same result as 50, only with less wiring nightmares, less current draw, and less of a headache when it blasts on and illuminates your neighborhood through the window. Positioning the LEDs to accomodate their relatively small viewing angles and providing them with appropriate power and space should be plenty to illuminate your display uniformly without any dead patches. Just to give you an idea of how bright these LEDs can get, I have a flashlight with six 20mA 5mm white LEDs in it, and it can light up an entire room from 20 feet away. Quote Link to comment Share on other sites More sharing options...
SLP Posted May 31, 2008 Report Share Posted May 31, 2008 Purple?This Wavelength was Yellow to bright red! Not Purple! Purple was ca. 380 - 420 nm!that's true,.....and don't change UV with purple! if you want to use uv-reactive-paint, you've gut to use only UV-LEDs, 'cause if you use purple LEDs the purple light will be so bright, and the UV-part will be so small, so you won't recognize your UV-reactive paint glow.And, btw, be sure not to use LEDs with wavelengths below 300nm! those rays are called UV-B radiation and are dangerous for your skin and eyes! Especially when the ambient light is dimmed and your pupils will open to let more light on your retina, there will also be more of the dangerous UV-B light damaging your eyes.It's the same thing with wearing cheap sunglasses with no UV-protection on a sunny day. "Oh my god, you're so tanned! Have you been to a solarium?""No, I had a gig with my midibox yesterday evening" ;) Quote Link to comment Share on other sites More sharing options...
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