If you prowl around that site a bit there's example after example of flyback power supplies and how they can be made. I gather that, given their chips, it all boils down to the flyback transformer design and choice of resistors that are used. They even offer a transformer prototyping service that can build a transformer for you based on their application notes. I don't want to build one, I want to use one.
Now, all I have to do is find a tiny, cheap, constant voltage power supply that isn't already stuck inside a wall wart to experiment with.
See, I have this dream of a device that houses an XBee, a minimal arduino and a couple of screw terminals all built inside a wall wart like this: GS-2415 | Wall-plug Electronics Plastic Enclosure . That way I can deploy a sensor and read its data remotely. Things like the inside temperature of the chicken coup, voltage of the generator battery, open-closed state of the North gate, become easily done. Add a few more terminals and a couple of tiny relays and you have a sprinkler system, a remote gate opener for the UPS guy, an auto drain for the horse watering trough (mosquito prevention). With a simple sealed float switch I can remotely tell when the septic tank starts to rise so I can go out and clean the output filter and hose out the input. Yes, the chicken coup has power, this is Arizona, they even have a swamp cooler in the summer.
I have practical uses for this kind of thing.