Switching power supply circuit diagram

Switching power supply circuit diagram
http://www.siliconray.com/sense-g5-tube-solidstate-hifi-headphone-amplifier.html
The first is that circles low-pass filter (to prevent the high frequency signal into power supply circuit), the second call rectifier bridge (alternating current into the direct current).
The third is high frequency transformers. Circuit is how it works: integrated circuits and transformers group concussion circuit, in integrated circuit 6 foot output pulse signal, for dozens of frequency to hundreds of K, 2 SK2067 is switch tube, when high electric circuit switch tube at ordinary times conduction, electricity flows through the primary transformer to switch tube (conduction) to power negative (return), when square wave low electricity at ordinary times the switch tube, transformer primary didn't current. Don't speak more below, I see it. In fact in the transformer primary added pulse voltage (exchange). Ask the high frequency transformers is that right after the chopper ? coupling ac component