What is a Schmidt Trigger?

[zigmund]

Hello,
What is a Schmidt Trigger? I have a position feedback device on the end of the x axis table on a milling machine that hasn't been accurate for a while. I tried swapping the x and Y axis feedback devices and the problem stays with the x axis so it is not the encoder (or whatever type of feedback this is). The machine is old but it doesn't appear to be this unit.

I spoke with the previous owner of the business and casually mentioned the problem. He said it sounds like I've got a bad Schmidt trigger circuit. Any thoughts on this?

Thanks!

[Cheller]

What is a Schmidt Trigger?

A Schmidt trigger is a squaring circuit where its output is always a square wave regardless of the shape of the input signal (or input waveform). Schmidt triggers are very useful when converting an imperfect analog signal over to a digital 1 or 0.

I think it is actually spelled something like Schmit or Schmitt.