ON THIS PART LETS SAY I HAVE A SINEWAVE OF 2VP-P ON X1 X2 IS GOING TO GROUND NOW WE HAVE AT THE OUTPUT PIN 14 THE SAME 2VP-P SIGNAL MAYBE A LITTLE MORE ARE LESS OKAY NOW WE HAVE 1.99VP-PON THE NEG PIN Y2 PIN 7 AND PINY1#6 GOING TO GROUND THE OUTPUT IS STILL SHOWING THE APPROX OF 2VP-P NOW AS Y2 STARTS TO GO OVER THE 2VP-P RAIL THE OUPUT PIN 14 STARTS TO DECREASE AS Y2 STARTS TO DECREASE THE OUTPUT STARTS TO GO BACK UP TO THE REF LEVEL THAT IS SET BE X12VP-P SIGNAL OKAY NOW LETS SAY THE THE REF SIGNAL AT X1 AND THE SENSE SIGNAL AT Y2 OF THE SAME AND THERE IS NO CHANGE OF THE OUTPUT, NO IF I APPLY A VOL OF SUCH TO Z1 AND Z2 IS GROUND WOULD THE OUTPUT INSTANTLY DROP T CERTAIN AMOUNT ARE SHOULD IT BE Z1 GROUND AND THE VOLTAGE APPLIED TO Z2 WHAT I NEED TO SEE IS A SHARP DECREASE IN AMPLITUDE AND AS THIS VOLTAGE GO BACK TO ZERO THE OUTPUT STAYS THE SAME UNTIL Y2 CHANGES,X1 WILL ALWAYS BE THE ADJ. REF SIGNAL ONCE SET IT DOSNT CHANGE, WHAT CAUSE CHANGE TO THE OUPUT IS Y2 ANDZ1 ARE Z2 WILL HAVE A NEG CHANGE ON THE OUTPUT LET ME NO AND WHAT PIN SHOULD I USE Z1 ARE Z2 TO GET A NEG CHANGE ON VOUT THANKS, WILLIE