Re: Blue LED with no emission beyond 480 nm

Arnold <aspoor@[EMAIL PROTECTED]
> writes:

< On 14 sep, 01:17, "Bobby" <b...@[EMAIL PROTECTED]
> wrote:
>> "Steve" <st...@[EMAIL PROTECTED]
> wrote in message
>>
>> news:v2clc4tbttcr0rg3h0cp8qpgsit63gr7cv@[EMAIL PROTECTED]
>>
>> > I'm seeking an LED with no emission beyond  (longer than) 480 nm.
>> > It's best if it was eye-safe so as little UV emission as possible is
>> > desired (> 400 nm ?).  The few blue led's I've come across with peak
>> > or dominant wavelengths of 430 nm have very wide spectra extending
>> > beyond 480 nm.
>>
>> Construct a cct that will turn the LED off when a freq > 480nm is
reached ;)
>
< May be you could use ordinary glass as a filter: it partially blocks
< UVA (wavelength 400 and 300 nm) and totally blocks UVC and UVB
< (wavelengths shorter than 300 nm) due to the addition of compounds
< such as sodium carbonate (see wikipedia). Or other UV-filters that
< completely block UVA.

This sounds like an excellent idea - what do you call it...? ``glass''.
Where do you get glass from? It's illegal in my country to purchase/posses
``glass'' (melted silica ~= 3000^\degree{} - (no not allowed to by
phosphorous either)) unless you are not an individual and are trying to
sell
it with a business license.

I actually had some ``glass'', acetate paper, and a ``lens'' and a
``prism''
but they all turned into plastic somehow; right before my oven was stolen.

[ sorry just aggrevated at the moment - my pcb sucks because my printer
fuses at too high a temperature so now I am using a borrowed laserjet 5
(works ok, but not my 4049) ]