[opendtv] Re: LEDs shine as replacement for lightbulb
- From: Albert Manfredi <bert22306@xxxxxxxxxxx>
- To: <opendtv@xxxxxxxxxxxxx>
- Date: Sat, 17 Nov 2007 17:46:11 -0500
Tom Barry wrote:
> I've been using spiral florescent bulbs for many years but
> also for 2-3 years have been trying to find LED
> replacements for regular bulbs. I'm not even as picky on
> the color but it is hard to find any giving off more than
> about the equivalent light of a 25 Watt regular bulb.
>
> I remember some other process was supposed to make
> those available by this past summer but never saw them.
I look at the fluorescents as a stop-gap. They have too many problems. Aside
from the toxicity, where you have to worry about something as trivial as
dropping one accidentally, they can't be used in too many cases. They can't be
used in enclosed fixtures or with dimmers. And they emit enough UV that they
cause fading of photos over time. Whereas incandescent bulbs really do not.
From personal experience over decades.
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).
Not sure about the enclosed fixtures restriction. An LED in principle should
require only a diode and a resistor. From what I've seen, the efficiency is
about the same as that of the fluorescents. Which means, a 60W equivalent would
be about 13W. So the series resistor would get warm to the touch. Too warm for
the rectifier diode and LED in an enclosed fixture? Who knows.
Conventional triac light dimmers should work fine, I would think, because in
effect what they do is pulse width modulation. They reduce the duty cycle of
the 120 VAC sinusoid, keeping the same peaks. I think that's the most
consistent way of dimming LEDs, vs. controlling the voltage.
Bert
_________________________________________________________________
Share life as it happens with the new Windows Live.Download today it's FREE!
http://www.windowslive.com/share.html?ocid=TXT_TAGLM_Wave2_sharelife_112007
----------------------------------------------------------------------
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:
