You're right Ron, this is for commercial application. Ok, I tell you all my project purpose... Ideally, my project is running of the transformer, through the op-amp configuration and the current transformer to the relay ... the whole function is used as stabilizer purpose in order to save the energy.. STABLE the voltage in 220V
I've faced some problems,when my application is loading a small power product which is below 2A (Let's say the electricity product load is not over 2A), my transformer is unable to switch over to bypass.... so at the end the relay unable to switch on to another part as well to function as stabilizer..
I've considerate in many situations, current too small (the transformer I used was large power,heat dissipation and one of the idea is using the comparator to compare the current..
but it seems like not a good idea..
P.S the components I've used ~ LM324. TRIAC OPTO, ULN200A (current gain), transformer, current transformer, relay