Close the switch to start (And yes, it is in an odd position. Not having the switch near the battery has and advantage. When the simulation is started, the capacitor is already charged - to 8V in this case - and current is already flowing through the inductor. It take a while for the cap to go from 0-8V. )
The output voltage is given by
Vo = 1.04(1+R2/R1)
And like my Buck Converter, the PWM frequency is low (a bit higher this time, but it's still low compared to commercial Boost/Buck Converters, and will result in huge ripples for big loads).
Don't worry about the 300mV battery in the middle of the ckt. I put it there to get the op amp oscillating. There are other ways of doing it. And why 300mV? Long story, don't ask!
