Tiny, cheap, and dangerous: Inside an iPhone charger. Ken writes -

I opened up a cheap phone charger and examine how the circuit works. In the process, I find that the manufacturer cut a lot of safety corners, and it’s nowhere near US safety standards. There’s a reason that name-brand chargers cost a bit more.

Since you reverse-engineered the protocol for Apple chargers, you will probably be interested in reference #15 from my article… which documents the resistances used by Sony and Apple chargers – their values are
very close to the ones you found.

Here’s Ladyada reverse engineering the iPod/iPhone charger.