Cascaded op amp

We started class with cascaded op amp circuits by drawing ideal op amp .
A cascade connection is a head to tail arrangement of two or more op amp circuits such that the output of one is the input of the next.

We did following problem of cascaded op amp



LAB: Temperature Measurement Design and Appendix A -Wheatstone Bridge Circuits

LAB: Temperature measurement system design

We started this lab with building wheatstone bridge circuit first. Wheatstone bridge circuits are most often used to convert vaiations in resistance to variations in voltages. It is used in measurement system as a number of common sensors provide a resistance variations in response to some external influence.

Thermistors change resistance in response to temperature change. Straing gages change resistance in response to deformations.

Then we balanced our wheatsone bridge circuit so that output voltage is zero when the variable resistance is at its nominal value.

Following is the set up of our wheatstone brdige.

Following is the video showing the bridge working. 

Difference ampliflier design. Difference ampliflier circuit is shown in above picture. The output of the circuit is proportional to the difference between the two inputs Va and Vb.

R1=R2=R3=R4

vout= R2/R1 (Vb-Va)