Question

ELECTRIC CAGE PART II

I'm building a cage to safely expose materials to an increasing amount of voltage. I have the 'current regulator' to safely increase the voltage output to the cage. My questions, if I cover a container with copper foil tape and let the tape touch the table will that ground the container and therefore not expose the material to the voltage? If I don't ground it will the container heat up? Any ideas to do this? Remember the purpose is to introduce a material in a cage to a voltage for a prolonged period of time.

I received the following answer

"Yes, silver foil touching the table will ground the cage preventing the material from high voltage. If we don't ground it, the cage will be heated up. But, even if we don't ground it, the material may be exposed to voltage as electric field will not penetrate into the metallic cage due to electrostatic shielding."

I therefore ask, what steps should I take when building this experiment to ensure that the material in the cage is exposed to voltage without the cage heating up?

Answer 1

I suppose in the experiment you apply an external electric field "wirelessly" toward the container.

Cause of heating in a metal under CHANGING MAGNETIC FIELD is due to formation of eddy currents.

therefore under static case there are no eddy currents formed, and are only formed when the field is under change i.e. u changing the applied voltage.

For the arguement of grounding the the container, i dont think it essentially has any effect when the field is static and low. And it might even cause charge leak and joule heating. If the cage is grounded the excess charges will be neutralized as an equipotential bonding between the outside of the cage and the environment is created, but this has no use for us in attenueting the external field inside.

BETTER ALTERNATIVE

To reduce the eddy currents, i suggest u to use MESH pattern cage made of metal to cover the container.

use as ROUND shape for the caging as possible.