Summer Amplifier (Week 6 - Day 11)

     In this experiment, we analyzed an operational amplifier in order to implement a single mathematical operation: addition. We used this op-amp in order to add voltages from two sources.

     We used both waveform generator channels with v_b set to a constant 1V, and v_a ranging from -4V, -2V, -1V, 0V, 1V, 2V, 3V, 5V. The resistances chosen in this experiment and their measured values are as follows:

R₁ = R₂ = 1kΩ, R₃ = 1.2kΩ
R₁ = 0.995kΩ, R₂ = 0.997kΩ, R₃ = 1.169kΩ

The desired result from this experiment was to measure v_out to be equal to the sum of both voltages.

Complete setup of summing amplifier circuit

Theoretical values using measured resistances along with measured values for v_out:

     There was a discrepancy with some of the theoretical values with the measured ones due to the use of the Digilent product. The Analog Discovery reached saturation at certain input voltages, which we can see from the data collected. Other than that, our actual results came to within about 0.3% - 1.2 % error. This experiment was an overall success. We confirmed that v_out is simply the ratio between the feeder resistor and the other resistors multiplied by their respective voltages.