we r plannin to make a circuit which can work as rectifier, inverter, ac voltage controller and dc chopper. our main principle is to use same SCRs 4 all the modes of operation n for the mode changing, we want to use switches....
so, suggest us wether such circuit can be designed or not n can u xplain hw the ratings of SCRs 4 such a circuit are calculated...

 

Hello,

Please use proper english (do not use half words).
Here is a page on Diac, triac and thyristor applications of the EDUCYPEDIA.
http://www.educypedia.be/electronics/powerelectronicsdiac.htm

There are more of these pages over there :
Power electronics: Diac Triac Thyristor Motor speed control Power supplies SMPS General overview Power control Power supply topics SPWM

Greetings,
Bertus

 

IBM made a power supply like that back in about 1966. It was not reliable. If you can run down the schematics for the 1311 disk drive, you will be able to see what it looked like.