Purple LEDs at last ...

[jean-paul]

At last a means to go off the beaten track of blue LEDs. I wasn't aware they existed but they do since 2003 :

http://www.ledsupply.com/l3-0-v5th15-1.html

A better link with technical info:

http://ledmuseum.home.att.net/ledvio.htm

No excuses anymore to use that boring blue LEDs on your amps ! For the brave among you there are also amber and turqoise LEDs, I did not check for pink types but I wouldn't be surprised if they also exist.

[BrianGT]

Originally posted by jean-paul
At last a means to go off the beaten track of blue LEDs. I wasn't aware they existed but they do:

http://www.ledsupply.com/l3-0-v5th15-1.html

I always thought that the wavelength was too small to create with and LED, but I guess I was wrong. Here is a page with all kinds of purple LEDs:
http://ledmuseum.home.att.net/leduv.htm

--
Brian

[tiroth]

These LEDs can look very cool, but can be painful if you are exposed directly to the light. Probably best used with some kind of diffuser.

The wavelength is generally short enough that you get a blacklight-type effect.

[Bricolo]

You're right Jean-Paul, blue leds are so rubbish

I use white leds in my stuff, they look so hype
The violet ones also look great, but be carefull. Some manufacturers sell violet leds that in fact are more UV than violet, and can be dangerous for your eyes

[Bricolo]

An easy test to see if a led emits UV
if you haven't any UV reactive toys, simply put the led over a 500€ some UV reactive ink will appear (it also works with smaller ones )

[Tensop]

i'd of thought the dangerous UV light(a,b or c?) would of been too little.
it's also going through epoxy/something that would block most of it anyway, not to mention the air also..

[Bricolo]

I don't know if epoxy stops UVs, but for sure air doesn't
Except if you have a big plasma tweeter that produces a lot of ozone in your room, then the ozone will block most of the UVs. But then the ozone will be a bigger concern

[groggory]

purple LED in action

[Sch3mat1c]

Originally posted by Bricolo
I don't know if epoxy stops UVs, but for sure air doesn't
Except if you have a big plasma tweeter that produces a lot of ozone in your room, then the ozone will block most of the UVs. But then the ozone will be a bigger concern

http://webpages.charter.net/dawill/t...Elec_SSTC.html

But then that's been beefed up to 1/2" spark now, which makes too much noise to be worth much as a tweeter. Plus I wouldn't leave it on, the transistor gets a bit warm just running it for 10 seconds.

Oh, obviously epoxy can't be too bad for UV since there are UV LEDs on the market.

Tim

[Christer]

Originally posted by jean-paul

A better link with technical info:

http://ledmuseum.home.att.net/ledvio.htm

There seems to be something puzzling here. The wavelengths
stated are really on the borderline of what is visible, and given
the tolerances stated many of the devices wouldn't be visible
at all, if any of them are. It seems one would have to buy a
bunch of LEDs and then select those that happens to be
visible at all.

I question whether a purple LED can be a single-wavelength
device at all. More probably one would have to mix two
wavelenghts, each of them close to either end of the visible
spectrum.


BTW, I have probably told the story before, but when blue LEDs
had just started to appear on the market 20 years ago, a
collegue of mine wanted to use them for a product and phoned
the swedish distributor for prices. The salesman asked what
quantities they were discussing, and my collegues said, well
10k+ quantities. There was a very very long silence at the
other end of the line and then came the response, I am afraid
the yearly production is only about 5000 devices (there was
still only one manufacturer then).