the micro processor control board detects a short circuit and quickly throttole banck the currwent to prevent electronic board damage!
a FET is a field effect transistor is a device used to control voltage and current circuits think of it like a water spout and controls the flow of electrons threw the circuit being used ok!
that's as simple as I can explain it and not loose you or confuse you ok !
hope you understand fet is in effect a valve controlling electron flow!
Alan
