I have a refrence single phase voltage of 220VAC.
Now there are three (3) phase supply; a phase to neutral measure average of 220vac plus or minus
At any time I need a single phase output, out of this three phase supply with the nearest voltage value to my refrence voltage of 220VAC to be choosen to operate a 12VDC relay.
Kindly help me out with basic and simple circuit to achieve my aim
If I've understood you correctly any one of the phases should give you 220V AC from phase to neutral. Put that into a 220:9 step-down transformer and rectify and smooth the 9V AC output to give ~ 12V DC to power the relay.
Thanks Alec_t I ned a simple circuit to monitored the three phase and choose for me the phase that have the most colse value to my refrence voltage out of the three phase to supply my relay at any time.
i ned a simple circuit to monitored the three phase and choose for me the phase that have the most colse value to my refrence voltage out of the three phase