by Arnold <aspoor@[EMAIL PROTECTED]
>
Sep 20, 2008 at 11:58 AM
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 =A0(longer than) 480 nm.
> > It's best if it was eye-safe so as little UV emission as possible is
> > desired (> 400 nm ?). =A0The 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.
