AKHIL NAIR

I think i got your query.If i not got please let me know.Following writing is about what i understood The 240 v is per phase voltage.The transformer at substation convert 33/11 kv step down to 415v which is 3 phase value and then per phase value is been calculated the 3 phase value divided by sqrt of 3 which is aprox 240v. Moreover our house hold system is now inbound with this value

The SCRS are much common in the use as they can effictively switch the circuit at high frequencies.And what you said above i dun get much but i think u wanna ckt that can switch on and off if some one comes yes thyristor can do that effectively