my input voltage is AC 220V ac. i tried to find inside design of professional firms but i could not find any pcb or any circuit shematic diagram.
Offline LED drivers often don't have schematics on line, I'm not sure why...perhaps its a trade secret.
Since your design implementation concerns AC-DC conversions, I would recommend just buying a prebuilt LED driver.
There are the dedicated drivers [110V, 125V, 220V,
Xitanium], and there are switch modes [100-240V,
Magtech,
lightech]
How many LEDs are you planning to use with your system? the smallest unit I know is the Magtech WH-L03U-350:
Input: 100-240VAC 120ma 50/60Hz
Output: 12VDC Max 350ma
at
$14 its significantly cheaper than most offline LED drivers, CREEs are about 3.3V in at 350ma so its capable of driving up to 3 LEDs.