On 2012-02-22, Michael A. Terrell wrote:
"DoN. Nichols" wrote:
On 2012-02-21, Michael A. Terrell wrote:
Their early models were brass & steel parts, wih a small glass window
over the mechanical displays.
Hmm ... early being when? I first saw them back in 1960/1961
IIRC.
I'm talking about the all mechanical cash registers that were the
main products of NCR. The had several large buildings in the Dayton
area that were machine shops cranking out all the parts to feed their
assembly plants. They started building them over 100 years ago.
O.K. I thought that we were still talking about the NLS digital
voltmeter readouts. :-)
Speaking of "mechanical displays", we had one DVM at a later
date which was a servo driven Veeder-root counter which rotated the
digit drums do display the position of a 10-turn pot. I forget who made
those. Not very impressive, really. :-)
Sounds as bad as the old HP printer with a bunch of rubber wheels and
solenoids to rotate them to the proper number to log a frequency.
How about the line printers (not HP) which had a drum of letter
forms rotating and a solenoid driving a hammer on the other side of the
paper to drive it into the ribbon. Early ones had all the letters lined
up, but tended to fail with the massive current surge when you printed a
line of all '*' or all '_'. The latter, btw, made a nice "tear here"
weakened point. :-)
Yes -- a problem. That's why I wanted one with a built in
bridge rectifier. Are those made now?
O.K. A quick search finds this:
http://www.martekled.com/-strse-173/midget-flange-based-LED/Detail.bok
and they offer your choice of AC, positive center contact, and negative
center contact. (And, your choice of colors, too.) And the price is
down to $4.25 if you buy in sufficient quantities (1000). :-) Unit price
is $8.95 ea, which is better than it once was, at least.
That's a big improvement. The AC version in white would make a nice
universal replacement,
I wonder why they make the polarized DC versions? Perhaps
brighter? I didn't see a clue that the AC ones cost any more -- though
they *should*. :-)
but colored lamps would eliminate the need for
those tiny colored silicone rubber covers.
The ones which tended to tear when you tried to pull them over
the rim of the bulb sleeve, or when you pressed on them to eject a bad
bulb. :-) Who was it -- Honeywell -- who made those switch assemblies.
I know that MicroSwitch made the snap-on switch elements.
I first saw the 327/328 lamps on a tour of the VOA Bethany facility
while it was being upgraded from the original design. It was one tech's
job to wander around the facility to test & replace bad lamps. There
were over 3,000 in use, and they were still installing new equipment.
With a pushbutton on each panel to light all bulbs on that
panel? There were such on the flight simulator instructor's control
panel which a company I worked for for a while made.
Enjoy,
DoN.
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