Re: gEDA-user: basic anti-EMI design q

["Phil Taylor" <phil@xxxxxxxxxxxxxxxxxxxxxxxx>]

Looking at the pcb w/ chips, optos and triacs.  It probably be good to get 2"
between the chips and the triacs.  Filtering on the triac power circuits will
help if there are some problems coming from there.  Triacs are always a noise
culprit, distance and buffering are a must.

Also, optoisolators need low impedance drive circuits.  To achieve hi speed
with them they need power.  Even if you don't want them to fire quickly (can't
tell if your software is running them as dimmers) there is a benefit to a
forceful drive.  It's that interference/surges getting onto the lines between
the opto and whatever is driving it (your latch it appears) will get weighted
down by the low impedance at this point ... making it harder for those
surges/emi to swim upstream and latch your logic, or trip your latch.