adaptor so a 220V Brewzilla gen 4 can plug into 110V wall socket.

[Broken Crow]

It seemed to me that was being used to support where 240V came from, i.e. two 120V 180-deg out summing together.

From a post a bit earlier in the thread -

Yup...I really am clumsy in my wording these days and shouldn't post when drinking! Glad you could join the pedantry!
..If I'd had one more drink I probably would've instead said that the majority of the conitinent runs on 5V-24V DC, since most homes only use a full 120VAC or 240VAC for electric motors and heating elements and even LED lightbulbs have a rectifier built into the base.
It was @Cheshire Cat 's post that compelled me to respond as many of us colonials suffer longer than civilized wait times for an electric tea-kettle to boil owing to our half-phase 120V power outlets.