Steve Foley wrote:
I remember a loooooong time ago, I was in a math class. We were being told a
story about some math genius who came up with a better something-or-other.
In the notes was a formula with the notation "Proof is trivial". In the
hundreds of years since, nobody has been able to prove that formula. It
appears to be correct, but it's never been 'proven'.

I believe it was "Interesting proof." And didn't someone finally work
it back out a couple of years ago?

I like the college professor who is lecturing and showing the steps to
solve a problem. Step 1...2...3... then as he writes down step three
he adds "and from there it is obvious that..." and writes down step
four. He backs up a minute, stares at the board, looks puzzled.
Mumbles to himself a bit, and finally wanders out of the classroom.

Students sit there puzzled. Five minutes go by, then ten. Suddenly
the professor reappears, beaming from ear to ear. "I was RIGHT!" he
exclaims. "It *IS* obvious!"

[And we need some more info about your "switch." Above 13 volts, below
13 volts, precisely at 13 volts? How much current?]

jmk