Switching mode power supply of 120 volt

[M.Imran Ali]

Hi
Friends i want to make an power supply of 120 V . I rectified 220 AC and used a buck converter after it to bring down voltage to 120 V . Now if i put a load on it its voltage come down and can't drive load . Where can be problem ?

 

[D.A.(Tony)Stewart]

Without full design details, One can imagine it must be somewhere in the Buck design and layout.