AVR-Chat

> 
> Since I'm protecting an analog signal line here I assume optos are 
inappropriate
> (at least I've only seen ones suitable for digital, as opposed to 
analog,
> links).  


If you are protecting an analogue line, why not make it into a 
digital signal and then use an opto  or even fiber optic ?

I am working intermitantly  on a sensor for a plasma cutter machine 
and that pulse is in the 300 volt range.  it varies from about 20 to 
220 for it's actual work and when working it should hold very close 
to some setting the operator chooses.   ie: if set for 90 volts, it 
should operate around 90 volts unless things start to change like 
holes in the metal or the gas pressure or the part warps.

converting the raw signal into a digital and then over a fiber optic 
line is the goal.

Dave