I want to build lght based sensor circuit using LM393 ic. The purpose of the circuit is to turn on or off the relay depending upon the intensity of light. I have built this circuit using transistors , which worked well. but now i want to build this circuit using LM393 ic. I am new to this IC . I have tried to build the circuit using only one comparator of this ic, but circuit is not working.LDR is used for light sensing. On pin +3 of this ic i have connected resistive divider of 10k and 0n -2 pin of ic i have connected resistive divider of LDR and variable resistor.ouput is conncted to transistor for relay driving, i dont know whether to pull down or pull up output. plz someone tell.