Groups > alt.folklore.computers > #155039

Re: 1957 LED

From	Ahem A Rivet's Shot <steveo@eircom.net>
Newsgroups	alt.folklore.computers
Subject	Re: 1957 LED
Date	2015-12-11 16:37 +0000
Organization	A noiseless patient Spider
Message-ID	<20151211163742.1424c366b440ca4c48b70ce2@eircom.net> (permalink)
References	<aa4ec05a-2408-4323-b7fe-34d6d61651cb@googlegroups.com> <n4cib8$se5$1@dont-email.me> <alpine.LNX.2.02.1512101442480.27427@darkstar.example.org> <27ac7d07-c3cf-4041-b39e-5c2d8f2cafd3@googlegroups.com>

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On Fri, 11 Dec 2015 07:41:09 -0800 (PST)
hancock4@bbs.cpcn.com wrote:

> It's curious in that while LED's may have become cost practical
> in the 1970s for electronic devices, it took until recently for
> them to be cost practical in bright lighting such as streetlights
> and flashlights.

	The use for indicator lamps did not require efficiency, they could
be much less efficient than a small incandescent (quite hard that) and still
be fine if they outlasted the equipment they went in (thus saving holders
and replacement costs). There was also no worry about available colours,
using what was available and cheap was fine - for a long time everything
glowed in little red dots.

	Illumination OTOH is sensitive to efficiency and colour, the latter
may be sacrificed for the former sometimes (sodium street lights for
example) but for most purposes a half decent white light is essential and
it was a long time before LEDs got past green. Getting to blue in the 1990s
netted the inventors a Nobel prize (in 2014).

	White LEDs, like the ones that illuminate my house, are actually
blue LEDs pumping a phosphor that emits a reddish yellow light.

	Then there was the little matter of efficiency - which by the time
we had white LEDs was really important and the bar was way up - as good as
an incandescent was nowhere near good enough, the target was a CFL at four
times the efficiency of an incandescent. That was reached a few years ago,
and now the best LEDs are surpassing even HID for efficiency, while LEDs
better than CFLs are cheap.

	Whatever lighting technology displaces LEDs will have a hard act to
follow, I look foreward to seeing it.

-- 
Steve O'Hara-Smith                          |   Directable Mirror Arrays
C:>WIN                                      | A better way to focus the sun
The computer obeys and wins.                |    licences available see
You lose and Bill collects.                 |    http://www.sohara.org/

Thread

1957 LED hancock4@bbs.cpcn.com - 2015-12-10 11:03 -0800
  Re: 1957 LED Al Kossow <aek@bitsavers.org> - 2015-12-10 11:06 -0800
    Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-10 14:44 -0500
      Re: 1957 LED hancock4@bbs.cpcn.com - 2015-12-11 07:41 -0800
        Re: 1957 LED Ahem A Rivet's Shot <steveo@eircom.net> - 2015-12-11 16:37 +0000
        Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-11 14:42 -0500
    Re: 1957 LED philo <philo@privacy.net> - 2015-12-10 13:56 -0600
      Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-10 22:59 -0500
        Re: 1957 LED "Osmium" <r124c4u102@comcast.net> - 2015-12-11 08:20 -0600
          Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-11 14:33 -0500
      Re: 1957 LED Quadibloc <jsavard@ecn.ab.ca> - 2015-12-13 07:58 -0800
        Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-13 13:00 -0500
      Re: 1957 LED Lon <lon.stowell@comcast.net> - 2015-12-13 12:48 -0700
        Re: 1957 LED Stan Barr <plan.b@bluesomatic.org> - 2015-12-14 09:07 +0000
          Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-14 11:47 -0500
          Re: 1957 LED rpw3@rpw3.org (Rob Warnock) - 2015-12-16 14:55 +0000
            Re: 1957 LED Stan Barr <plan.b@bluesomatic.org> - 2015-12-16 16:32 +0000
              Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-16 14:17 -0500
              Re: 1957 LED "Charles Richmond" <numerist@aquaporin4.com> - 2015-12-16 18:15 -0600
                Re: 1957 LED Stan Barr <plan.b@bluesomatic.org> - 2015-12-17 07:58 +0000
                Re: 1957 LED Andrew Swallow <am.swallow@btinternet.com> - 2015-12-17 13:21 +0000
        Re: 1957 LED Ingo Paschke <ipaschke@lpclabs.de> - 2015-12-14 11:11 +0100
    Re: 1957 LED Stephen Wolstenholme <steve@easynn.com> - 2015-12-11 10:58 +0000
      Re: 1957 LED Lon <lon.stowell@comcast.net> - 2015-12-13 12:50 -0700
        Re: 1957 LED Stephen Wolstenholme <steve@easynn.com> - 2015-12-14 12:57 +0000
          Re: 1957 LED "gareth" <no.spam@thank.you.invalid> - 2015-12-14 14:07 +0000
            Re: 1957 LED Stephen Wolstenholme <steve@easynn.com> - 2015-12-14 14:33 +0000
    Re: 1957 LED hancock4@bbs.cpcn.com - 2015-12-11 07:31 -0800
      Re: 1957 LED Quadibloc <jsavard@ecn.ab.ca> - 2015-12-13 07:42 -0800
        Re: 1957 LED Ahem A Rivet's Shot <steveo@eircom.net> - 2015-12-14 09:39 +0000
        Re: 1957 LED Jon Elson <jmelson@wustl.edu> - 2015-12-14 17:07 -0600
          Re: 1957 LED Alfred Falk <falk@arc.ab.ca> - 2015-12-15 18:53 +0000
            Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-15 15:05 -0500
              Re: 1957 LED hancock4@bbs.cpcn.com - 2015-12-16 07:32 -0800
                Re: 1957 LED Alfred Falk <falk@arc.ab.ca> - 2015-12-16 17:23 +0000
                Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-16 14:23 -0500
                Re: 1957 LED Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-16 20:13 +0000
                Re: 1957 LED hancock4@bbs.cpcn.com - 2015-12-16 13:15 -0800
                Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-17 14:53 -0500
                Re: 1957 LED "Charles Richmond" <numerist@aquaporin4.com> - 2015-12-17 14:17 -0600
                Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-18 19:43 -0500
                Re: 1957 LED "Charles Richmond" <numerist@aquaporin4.com> - 2015-12-20 20:02 -0600
                Re: 1957 LED hancock4@bbs.cpcn.com - 2015-12-21 10:31 -0800
                Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-21 14:53 -0500
                Re: 1957 LED mausg@mail.com - 2015-12-21 20:27 +0000
                Re: 1957 LED Uncle Steve <stevet810@gmail.com> - 2015-12-17 18:48 -0500
          Re: 1957 LED davidmylastname@acm.org (David Griffith) - 2015-12-16 02:43 +0000
          Re: 1957 LED Mike Spencer <mds@bogus.nodomain.nowhere> - 2015-12-16 17:44 -0400
  Re: 1957 LED scott@slp53.sl.home (Scott Lurndal) - 2015-12-10 19:13 +0000
    Re: 1957 LED "gareth" <no.spam@thank.you.invalid> - 2015-12-10 20:17 +0000
      Re: 1957 LED Lawrence Statton <lawrence@sengiuo.mx> - 2015-12-10 17:10 -0600
      Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-10 23:00 -0500
        Re: 1957 LED isw <isw@witzend.com> - 2015-12-10 21:21 -0800
          Re: 1957 LED Stan Barr <plan.b@bluesomatic.org> - 2015-12-11 08:01 +0000
            Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-11 14:30 -0500
            Re: 1957 LED "Charles Richmond" <numerist@aquaporin4.com> - 2015-12-11 15:36 -0600
              Re: 1957 LED Stan Barr <plan.b@bluesomatic.org> - 2015-12-12 07:55 +0000
                Re: 1957 LED mausg@mail.com - 2015-12-12 11:20 +0000
                Re: 1957 LED Stan Barr <plan.b@bluesomatic.org> - 2015-12-12 15:39 +0000
                Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-12 10:50 -0500
                Re: 1957 LED Stan Barr <plan.b@bluesomatic.org> - 2015-12-13 08:00 +0000
                Re: 1957 LED "gareth" <no.spam@thank.you.invalid> - 2015-12-13 11:10 +0000
              Re: 1957 LED Lon <lon.stowell@comcast.net> - 2015-12-13 12:51 -0700
        Re: 1957 LED "gareth" <no.spam@thank.you.invalid> - 2015-12-11 10:59 +0000
          Re: 1957 LED Ahem A Rivet's Shot <steveo@eircom.net> - 2015-12-11 15:46 +0000
            Re: 1957 LED "gareth" <no.spam@thank.you.invalid> - 2015-12-11 17:37 +0000
              Re: 1957 LED Ahem A Rivet's Shot <steveo@eircom.net> - 2015-12-11 18:34 +0000
                Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-11 14:49 -0500
                Re: 1957 LED "Charles Richmond" <numerist@aquaporin4.com> - 2015-12-11 15:39 -0600
                Re: 1957 LED Bob Eager <news0005@eager.cx> - 2015-12-11 22:46 +0000
                Re: 1957 LED Michael Black <et472@ncf.ca> - 2015-12-11 19:07 -0500
                Re: 1957 LED Bob Eager <news0005@eager.cx> - 2015-12-12 01:04 +0000
                Re: 1957 LED Ahem A Rivet's Shot <steveo@eircom.net> - 2015-12-12 08:54 +0000
        Re: 1957 LED hancock4@bbs.cpcn.com - 2015-12-11 11:52 -0800
          Re: 1957 LED "Charles Richmond" <numerist@aquaporin4.com> - 2015-12-11 15:46 -0600
            Re: 1957 LED Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-12-11 22:56 +0000
        Re: 1957 LED "Charles Richmond" <numerist@aquaporin4.com> - 2015-12-11 15:35 -0600
        Re: 1957 LED Quadibloc <jsavard@ecn.ab.ca> - 2015-12-13 07:51 -0800
  Re: 1957 LED Lawrence Statton <lawrence@senguio.mx> - 2015-12-10 17:09 -0600

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