It is precisely that. However, depending on the thinkness of the wall of the box, you may want to consider a higher frequency. For a given mechanical size, you get a higher coupling factor when frequency goes higher. That's why avionic AC was traditionally on 400 Hz, to get the transformer-type components smaller. To avoid the annoying whine, you may want to choose a frequency more typical of, say, switch-mode power supplies. That is, supersonic.
(no subject)