[sdiy] input buffer question

[David G. Dixon]

> For a non-inverting op amp voltage follower, the input is high impedance,
> so you don't have to worry about the 10K resistor contributing to the
> input loading.  BUT for the same reason it also won't really offer any
> protection; you'll probably want clamping diodes to the positive and
> negative supply rails.  Maybe Schottky diodes if you want to be really
> cautious.  I don't know why you would put a resistor in the feedback loop,
> I don't think it would do anything.

Brilliant!  Thanks, Scott.  I will leave the 10k resistor on the input, then
put clamping diodes (just plain ol' 1N4148s) between each rail, the
resistor, and the + input of the opamp.  The diodes will protect the opamp,
and the resistor will limit the current through the diodes.  I will also
remove the feedback resistor.