Groups > alt.folklore.computers > #155266

Re: 1957 LED

From	Michael Black <et472@ncf.ca>
Newsgroups	alt.folklore.computers
Subject	Re: 1957 LED
Date	2015-12-16 14:23 -0500
Organization	National Capital Freenet, Ottawa, Ontario, Canada
Message-ID	<alpine.LNX.2.02.1512161417540.7681@darkstar.example.org> (permalink)
References	(3 earlier) <e2d26d9c-7353-4cbb-9c1b-ef85199a2621@googlegroups.com> <sLOdnVJVds5_1_LLnZ2dnUU7-VWdnZ2d@giganews.com> <XnsA5717968B3B92falkarcabca@213.239.209.88> <alpine.LNX.2.02.1512151503510.5698@darkstar.example.org> <04e31e21-cbc6-4c99-9cc0-e6bb37df69e9@googlegroups.com>

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On Wed, 16 Dec 2015, hancock4@bbs.cpcn.com wrote:

> On Tuesday, December 15, 2015 at 3:02:18 PM UTC-5, Michael Black wrote:
>> Since the photocell dropped resistance with light, I initally couldn't
>> figure out how that would work.  When the light wasn't interrupted, the
>> photo cell would let the voltage from the battery to the bell (I was
>> thinking in terms of "burglar alarm"), but it was when the light was
>> interrupted that you needed the bell.
>
> I don't know the specific technology, but in the 1950s-1960s there
> were two types of camera meters.  (Originally the meter was a
> separate device, then later miniaturized to fit into the camera).
>
> Anyway, the earliest meters just measured the light and used it
> to drive the meter scale.  I think it was plain photo cell.
>
An actual "solar cell".  But that would give the same problem, voltage 
only when the light isn't interrupted.

> Later, better meters required a battery and used a different
> photo cell (Cs?).  That measured the difference and was
> supposedly more accurate.
>
Cadmium photocells, or something, they varied resistance with light, 
rather than generating voltage.  That's what I had, and since the 
resistance went up with the beam of light was broken, still not useful.

Like I said, it was early on in my learning about electronics, and at the 
time I couldn't see a solution, though later I could.


> My old Nikon required a tiny battery for the meter; everything
> else was manual.  The meter battery lasted forever.  My
> digital Nikon has a battery the size of the Empire State
> Building and needs regular charging.  A replacement is $50.
>
The only good camera I had had batteries, but that also powered the
built in flash.  I seem to recall it used two "N" cells, half the length 
of an AA, and not so commonly available.  But the batteries did last long.

> (I suspect when that battery no longer holds a charge, a
> replacement won't be available, and I'll have to buy a
> whole new camera.  Admittedly, I do like digital better
> than film, but the rapid obsolescence is a turnoff.)
>
I found a decent Olympus point and shoot, something like 6MP so it was 
fine for most uses.  Even came with a 1gig memory card, useful since it 
used XD cards. But it didn't use standard batteries, and I'm not willing 
to spend the money on a new battery unless I know that the camera works, 
and without the battery, I can't test the camera.

I'd never buy a new camera that didn't use AA batteries, so if I was 
really stuck, I could put in alkaline bought at the corner store.

Of course, most digital cameras also have some button cells, to keep
settings intact, and who knows what else.

   Michael

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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