To both 2112 and RadekG
The idea is exactly the opposite - use simple diodes rectifier and transistor current limiter.
I am not a noob and know how the rectifiers work and in the calculations above 220 * 1.4 is simplified for 220 * sqrt(2).
Many people said that it won't work and that's why this (crazy / hobby) project - to prove it does!
I did not think you are noob - I am sure you know how rectifier works. I see PFC ctrl much better idea:
1) PFC means stable op voltage, easy to tune, no efficiency drops
2) with current limiter you will dissipate lot of energy.
3) it is unclear if you want to filter rectified voltage, but from your posts it looks you would like to use unfiltered -> how do you make chips stable at low voltage parts of periods?
4) If you want to limit current at 2A, you will have about 78V@2A RMS at transistor to dissipate.
Still think PFC version is better. But wish you good luck, it would be really nice if you prove it can work.