I've recently purchased a black and white CM 690II and intend to replace all the led's (inc dvd, hdd, power, card reader and fans) with purple led's and sleeve all the cables with purple paracord as the case is supposed to be a surprise for my daughter when she finishes her gcse's. I purchased some 3000mcd ultra bright led's, 3mm and 5mm and the brightness just isn't there, I inserted one of the 3mm ones into the housing for the hdd activity light and fired it up with a 3v battery and you can barely see it whereas the blue one I removed you can't really look directly at as you end with stars in your eyes. The seller says this is inherent with purple/uv leds. Are there better purple leds out there or would I be better off going with something like led strips or maybe cathodes?
Purple LEDs are tricky. Their spectrum is on the edge of what our eyes can see, so they may appear less bright (but can still mess with your retinas). Cheap ones tend to degrade towards blue over time, like cheap white LEDs do as well. Having said that, I do know that it is possible to get some pretty bright ones. I would check the forward voltage --3V may not be enough. Even a 0.5V increase may ramp up their brightness quite a lot.
When you say mess with your retina do you mean cause damage or just that stars effect? There rated 3.2-3.8v. Not sure what they get fed by the motherboard and fans though.
I mean proper don't-stare-into-the-sun, lasers or strong sources of UV light damage. Although you're probably OK. If they are rated 3.2-3.8V you will absolutely not get a sense of their brightness while running them on 3V. Motherboards supply 5V and throttle the amps to compensate, so you'll be OK there.
So if they can do damage is it safe to use them in a pc long term? Or is it a case of just don't stare directly at them?
Personally I've never used them as a direct light source, but I knew them a long time ago. They may be better and safer now. Some Google-fu suggests that purple LEDs are mainly UVA. Which is a bit like those stoner backlight UV tubes or sunbed tubes, not the harmful UVB or UVC. Just don't stare straight into them very up close because they are brighter than they appear.
These are the ones I have Just read this also. Not sure how accurate that is as I don't know much about this subject.
460nm is believed to be dangerous for children: http://www.luxmagazine.co.uk/news/45/research-on-retina-damage-sparks-fresh-led-health-scare
Well I've decided to use white leds for the HDD activity, power, card reader and optical drive leds. I know these are still UV but would they be okay if fitted to the roof of the case so she wouldn't be looking directly at them at any time? Phobya purple strip or Or these?
After reading up alot about these I think the 395nm are safe, I'm only using them in the fans and the beam is directed to the centre of the fan and defused through the clear fan casing. The case is also on the floor and under a desk so I don't think any led's would be visible directly if you know what I mean.
They are 3000. I was testing them with a 3v battery when they are supposed even though they are rated at 3.2-3.8v and didn't think the extra little bit of voltage would make that much difference. I replaced the four led's in one fan and hooked it up to the proper supply and they are plenty bright enough. Thanks for the links though