[time-nuts] Clocking a PIC16F628A from a Rubidium Standard

[David VanHorn]

Somewhere or another there should be a compromise that makes you happy...
you will, however, never achieve true safety as long as you are alive.


I am far more aware of this than you might suspect, but I do think that it is a very good idea to know the risks involved.
An optoisolator is vanishingly unlikely to fail shorted, in that they are specifically designed with this failure mode in mind.
A resistor is likely to fail open, but failing shorted isn't unheard of.  See also designs for wrist straps.  

I won't be trusting a single resistor to sit between me and a fire that could kill people.