Garage door opener protection

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Steve White by way of Terry Fritz <twftesla-at-qwest-dot-net>" <slwhite-at-zeus.ia-dot-net>

I am in the process of buiding a pole transformer powered coil theoretically
capable of 8 foot arcs. I would like to run this coil at perhaps partial power
in my garage at times. Like many people, I have a garage door opener. Is there
any advice on how to protect the opener from damage? The only idea that I have
is to build a grounded Faraday cage around it and unplug its power cord. The
Faraday cage will take care of the electric field but what about the magnetic
field?