Question

4.0 First Circuit. The summing junction circuit Figure 2-4 below is the circuit for summing two voltages, V, and V. The required components are an op-amp and resistors. Although the voltage are summed, the final summation is negative (I hope your experiment will prove this). This is what is called inverting op amp configuration. Nonetheless, the circuit sums Iwo voltages and is called summing circuit. 159 Tokom M Olhas -15 -IV ISV TOXO RA w 10km Vout 15V -ISV Figure 2-4: The Summing Circuit Experiment Steps 1. Build the circuit according to the circuit diagram. Notice that the two potentiometer on the left side are 0 - 1 k12 potentiometers. Set and measure the appropriate voltages and fill-up the following table 2. V (volts) V2 (volts) V (volls) 0.5 4.5 1.0 4.0 1.5 3.5 6.0 2.0 -6.0 2.5 -7.0 -3.0 3. Derive an expression that relates V, V, and

Answer 1

Schematic-

R1 RO 500.00mV 305.45uV 11 10k 10k 0.5 OV 15 LM324 R2 W 10k 4.500V Vout -5.000v R3 2 447.59V 3 1 10k U1A V3 15 OV

Expression of output voltage-

Applying KCL to inverting terminal of Op Amp-

$\frac{0-V1}{R}+\frac{0-V2}{R}+\frac{0-Vo}{R}=0$

$Vo=-(V1+V2)$

V1 (V)	V2 (V)	Vout (V)
0.5	4.5	-5
1.0	4.0	-5
1.5	3.5	-5
-2	-4	6
3.5	2.5	-6
4	3	-7
1.5	1.5	-3

Schematic of some readings-

Vo=-3

R1 R6 1.500V 285.13uV V1 10k 10K 1.5 jovi 15 R2 LM324 TH 1.500V 2 10k Vout -3.000V R3 V+ V2 1447.48uvi 3 U1A 1.5 10K 4 + V3 15 OV TH TH

Vo = -6

R1 R6 3.500V 315.610V + V1 10k 10k 3.5 jov 15 R2 LM324 11 [2.500V 2 10k V- Vout |-6.000V R3 V+ V2 + 1447.65uvi 3 01 N 1 U1A V3 10k 15 OV TH

For Vo=-5

R1 R6 1.500V 305.45uV V1 10k 10k 1.5 ovi 15 LM324 HI R2 3.500V 2 10K V- Vout 1-5.000V R3 V2 1447.59uvi 3 10k 4 U1A V3 3.5 + 15 = OV TH