Respected sir,

To proceed the single phase voltage controller, the upper SCR present in the antiparallel connection is conducting but the lower SCR is not conducting..Can you please answer this question ?

note:Eventhough delay angle of 0.015 seconds is provided for the lower SCR of antiparallel connection it is not conducting.During the negative half cycle ouput follows the input .

I provided time delay of 0.005s ,pulse width of 0.01s total time period of 0.02s,but it's not conducting

I replaced different switches instead of SCR.,but no change in the output

thanking you