Operational Amplifiers I

Purpose: To use an inverting amplifier to design a Signal Conditioning circuit that has corresponding output ranges between 0 and -10V when the sensor's output is 0 to +1.

Introduction:
a. using the constraints of the problem we find the value of an acceptable input resistance.

b. In order to acheive the required gain we find the feedback resistance.

c. Determine Rx of the voltage divider

d. Determine the maximum setting of Ry

e. With Ry set to the value from d, determine the thevinin equivalent of the divider circuit.

Experiment:

set up the circuit as so:

Measure voltage across Rf and Ri.

V in (V)	V out (V)	Gain	V Ri (V)	I Ri (mA)	V Rf(V)
0.00	0	N/a	0.00	0	0
0.25	-2.51	-10.04	0.25	0.000256	-2.51
0.50	-5.04	-10.08	0.50	0.000512	-5.04
0.75	-7.56	-10.08	0.75	0.000768	-7.56
1.00	-10.07	-10.07	0.999	0.001024	-10.09

current I_v1= 2.27mA

current I_v2= -1.613mA

Calculations:

Conclusion:

      This shows a gain of -10 from input to output. This is an inverting amplifier.This agrees with the 30mW power constraint for each supply. To reduce the power drawn without changing the amplifier we could reduce the power supply.