Switched-mode power supplies, switched-mode power supplies. Gosh they can be difficult to understand. So again I go looking back at Wikipedia, and of course I should have known. The Wikipedia article on switched-mode power supplies is a good table of contents for all variations of the switched-mode power supply design.
20200328/https://en.wikipedia.org/wiki/Switched-mode_power_supply
In particular, I’m using a SEPIC switched-mode power supply design, and this article has really helped me better understand how it works.
20200328/https://en.wikipedia.org/wiki/SEPIC_converter