[opendtv] Re: LEDs shine as replacement for lightbulb
- From: "John Shutt" <shuttj@xxxxxxxxx>
- To: <opendtv@xxxxxxxxxxxxx>
- Date: Sun, 18 Nov 2007 09:06:49 -0500
Bert,
I sort of "led" (no pun intended) you astray when I said UV photons are
emitted from "white" LEDs. What I should have said was just "photons."
I think your photos are safe from "white" LEDs.
John
From Wiki:
http://en.wikipedia.org/wiki/LED
White LEDs
Blue LEDs can be added to existing red and green LEDs to produce the
impression of white light, though white LEDs today rarely use this
principle. Most "white" LEDs in production today are based on an InGaN-GaN
structure, and emit blue light of wavelengths between 450 nm and 470 nm blue
GaN. These GaN-based, InGaN-active-layer LEDs are covered by a yellowish
phosphor coating usually made of cerium-doped yttrium aluminum garnet
(Ce3+:YAG) crystals which have been powdered and bound in a type of viscous
adhesive. The LED chip emits blue light, part of which is efficiently
converted to a broad spectrum centered at about 580 nm (yellow) by the
Ce3+:YAG. The single crystal form of Ce3+:YAG is actually considered a
scintillator rather than a phosphor. Since yellow light stimulates the red
and green receptors of the eye, the resulting mix of blue and yellow light
gives the appearance of white, the resulting shade often called "lunar
white". This approach was developed by Nichia and was used by them from 1996
for manufacturing of white LEDs.
----- Original Message -----
From: "Albert Manfredi" <bert22306@xxxxxxxxxxx>
Since we have established that the toxicity problem goes away with LEDs,
one remaining problem IMO is that the white ones still emit UV. Whereas
LED bulb replacements consisting of R,G,B LEDs would not. So that's
another reason why I prefer that approach (in addition to being able to
adjust the warmth).
----------------------------------------------------------------------
You can UNSUBSCRIBE from the OpenDTV list in two ways:
- Using the UNSUBSCRIBE command in your user configuration settings at FreeLists.org
- By sending a message to: opendtv-request@xxxxxxxxxxxxx with the word
unsubscribe in the subject line.
Other related posts:
