I have built a digital motor controller for my sync RSG. It is
malfunctioning due to picking up RFI on each firing of the gap. The
circuit is enclosed in an aluminum box. There several wires that go
outside the box, but they are optoisolated and I have ruled out the
possibility of RFI getting in on these. The RFI is definitely passing
through the box and hitting the logic circuitry. I have 0.01 uF caps
next to each chip and the power supply is well-filtered.
I have tried grounding the box and leaving it unconnected to
anything. Could you please give me some suggestions for
blocking this RFI.