Large Faraday Cage for Electrophysiology

The small faraday cage I built for work last year did the trick, but was too small to stay out of the way when working under it. It's grounding scheme was also far from ideal—with a grounding wire taped to a spot of bare metal on the bench—and needed to be improved upon.

While setting up the last faraday cage, it took us a while to realize that that the microscope's (unlabeled) power adapter generated 12 V 60 Hz AC rather than DC. Consequently, its power cable carried 60 Hz noise into the cage, even when the microscope was turned off (the power is switched at the microscope, not at the adapter). Grounding the cage doesn't do anything to attenuate noise originating inside the cage as you'd expect, but unplugging it at the wall helped.

Rather than continually plugging-and-unplugging the adapter, I bought a switchable single-outlet tap, and wired a non-switched hard ground using the same, solving both problems at once.

hard ground wired into single-outlet switchable tap

As for the cage, this time around, I used a thicker galvanized steel mesh and fastened it together with zip-ties at the seams. Functionally, this one works even better than the last, and is much more roomy.

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