[sf-lug] SF-LUG meeting notes for Sunday December 3, 2017

Rick Moen rick at linuxmafia.com
Wed Dec 6 21:42:30 PST 2017

Quoting Michael Paoli (Michael.Paoli at cal.berkeley.edu):

> Exercise:  What's the wattage rating of the transformer?
> Can we figure out an approximate impedance/inductance of a 25VAC
> secondary of a 120VAC/25VAC stepdown transformer?

Back when I was an undergrad, the third (top) floor of Princeton
University's Engineering Quad building was completely empty.  It 
used to house massive air conditioning equipment for the vacuum tube
computers downstairs when the building went up in the immediate
post-WWII years, but all of that was long gone, leaving a vast empty
space.  Rather than wall it off or install a big locked door at the top
of each stairwell, but still wanting to discourage, say, roller-skating,
the university looped a chain across the top landing, with a sign
hanging from it:

     No Admittance

Seeing a chance for a harmless gag, I made a nice stencil in the same
typeface and added a clarification:

     No Admittance
  (infinite impedance)

I gather that the EE faculty liked the in-joke
(https://en.wikipedia.org/wiki/Admittance), as it was still there a few
years later.

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