four quadrant multiplier

75 four quadrant multiplier This four quadrant multiplier can be built using just one op-amp and the amplification factor can be preset with a potentiometer. The input signal, U 1, is applied to the inverting input of the (741) op- amp via resistor R 1. As R 1 = R 2, the signal is amplified by a factor 1. However, U1is also applied to the RS ó 15V 0 2 1 01 22 n- ui x 83408 1 VI 83408 2 15V R4 jó v2 U1 10k 15V 55 non inverting input of the op-amp inverting input is determined by via potentiometer Pl and resistor 83, the position of Pl. The resulting therefore the signal level at the non total output voltage is given by 15V 7-79 elektorjuly/august 1983 U2 = (2x — 1)U1 where x rep- resents the position of Pl. For example, with the wiper of Pl fully clockwise ("up" in the circuit diagram) x = 1, in the mid position x = 0.5 and fully anti clockwise x = 0. It should be noted that U1 may be a d.c. or an a.c. signal The input level can then be preset with P2 and the multiplication...