Re: RFI isolation


Here are a few possibilities:

  - Conducted RFI through the wires coming into the box, including power

  - Insufficient electrical connection all along the edges of the box

  - Magnetic field coupling from the tank circuit when the gap fires

Move the box so that it's further away from the gap. Go to a steel box
or add mu-metal shielding to the interior of the box. Run continuous
copper foil around the joints of the box. Add additional filtration to
the incoming power, or power the electronics via an internal battery.
These changes should do the trick.

-- Bert --

> Tesla List wrote:
> Original Poster: "Matt Behrend" <electronxlc-at-earthlink-dot-net>
> Hi all,
> 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.
> Matt Behrend