28 Aug
2008
28 Aug
'08
10:14 p.m.
On Thu, Aug 28, 2008 at 09:12:53PM -0800, Brent Hilpert wrote:
Ethan Dicks wrote:
Indeed - that's how I found that page (googling something like "goldfinger
incandescent digit").
I was recently watching "Goldfinger"
and oggling the countdown timer
on the bomb. I don't think I've ever seen that type of display
technology up close, but in principle, it shouldn't be hard to
replicate.
<http://www.vintagecalculators.com/html/calculator_displays.html#Incandescent>
Ha! .. funny you should notice that (see the comment at
http://www.cs.ubc.ca/~hilpert/eec/calcs/Canon130.html). I suspect (just a
guess) that the counter in the movie is a mocked up General Radio instrument,
as they made counter instruments using their own version of that type of display.
Could be.
Rick Bensene's site has some good pictures of the
internals of the Canon
version (http://www.oldcalculatormuseum.com/canon161.html).
Yep. Saw that, too.
This idea was discussed on the list sometime ago, and
I did a quick experiment
with some plexiglass, forming the digits with a sequence of 'dots' formed by
the end of a drill bit in the plexiglass, and white LEDs, but it was only
moderately successful. I think I was using too-thick plexiglass, and also
concluded that one would need several LEDs per digit, making it quite
expensive, but this was a couple of years ago and white LED's were pricey.
IIRC, the light dispersion of LEDs was part of the problem (that is, they don't
disperse enough compared to incandescents).
I was discussing the technology with our machinist, who was willing to mock up
a prototype digit or two if I'd give him X-Y coords (so he could dial them in
on our non-CNC milling machine), but so far, I haven't found any clear plastic
thin enough to try.
Trying to get all the LEDs arrayed around the
plexiglass edges with appropriate
light shielding may become an issue. Arrays of bare LED die would be nice..
I had thought about SMT LEDs - those should have better dispersion characteristics
than T1-3/4 packaging, I would think.
One of the nice things about using LEDs is heat
dissipation wouldn't be an
issue as it was for the original designs with incandescents (note the aluminum
bulb enclosures).
Sure - one could also use black ABS for a body - easier to work and most likely
cheaper than hunks of aluminum.
A more considered effort than what I attempted may
well be more successful..
Perhaps. Thanks for sharing your experiences.
-ethan
--
Ethan Dicks, A-333-S Current South Pole Weather at 29-Aug-2008 at 05:10 Z
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Ethan.Dicks at usap.gov http://penguincentral.com/penguincentral.html