written 8.8 years ago by |
The negative sum is obtained by setting V3 = 0. As shown in Figure 1,
V′O=−RFR1V1−RFR1V2 V′O=−RFR1(V1+V2) Given RF = 100K, R1 = 10K, V1 = 1.5V and V2 = 3V V′O=−100K10K(1.5+3) V′O=−45V..........(1)
Now set V1 = V2 = 0V, in order to find output voltage due V3 ,
Since 10K becomes parallel to 10K as V1 and V2 are grounded hence equivalent resistance R becomes as shown in Figure 2,
R=10K||10K=10KX10K10K+10K=5KΩ......(2) Calculate the output voltage due to V3: V"O=(1+RFR)V′3.........(3)
Where V′3 is the voltage obtained due to Voltage Divider Rule as shown in Figure 3,
V′3=1.5K10K+1.5KV3=0.130X4=0.52V....(4)
Substituting equation (2) and equation (4) in equation (3), V"O=(1+100K5K)X0.52=10.92V V"O=10.92V.......(5)
Adding equation (1) and (5) to obtain total output voltage VO, V0=V′0+V"0 V0=−45+10.92 VO=−34.08V