hi i made water level controller ckt using 89c51 but it is not working and there is no sign of relay working when the water level decrease wheather it is under ground tank or above tank all led at output indicate indicates except pin no 4(pi.3)does not indicating does it require 3 different power supply and there is voltage at o/p pin no 36(p2.4) can i get solution or any other ckt which works perfectly