0.2 Operational amplifiers and signal conditioning  (Page 2/5)

The breadboards are fairly robust; however they are susceptible to damage from wires that are too large. Donot use wires larger than 28 gauge. Components with leads that are too large can damage the breadboard as well.

Procedure

Part 1: set up the power supply

You will use a Tektronix triple-output power supply. The power supplies should be set up when you come to lab.For your reference, set-up instructions are given below. Perform the following steps before you turn the power supply on.

The power supply has three dc-power outputs; one capable of 0-5 V, and two capable of 0-15 V. To power theelectronic components for the lab, we will need a +12 V supply, a–12 V supply, and a ground connection. We will use the two 0-15 V outputs in series and adjust them to output approximately 12 Veach.

• Switch the power supply to“series”.
• Adjust the“A”power to ~ 12 V (the“B”output will match the“A”output).
• Connect a red cable to the“+”terminal for the“A”power output.
• Connect a black cable to the“–“terminal for the“B”power output.

In this configuration, the negative side of the“B”output is a–12 V source. The positive side of the“A”output becomes the +12 V source. The positive side of the“B”output and the negative side of the“A”output are theground.

Incorrectly connecting an op-amp to the power supply will destroy the op-amp. Make sure that the op-amp isconnected with correct polarity.

Part 2: preparing the breadboard

• Connect the +12 V supply to one of the strips in the A region.
• The other strip in the A region should be tied to ground.
• In the D region, one of the strips should be the–12 V bus.
• The other D region strip should be used as a ground bus.

Your breadboard is now configured to power the circuits for this lab.

Part 3: generate a simulated signal

Use the function generator to create a sine wave with the following characteristics:

• 50 Hz
• amplitude of 80 mV
• offset (bias) of approximately 800 mV

For such a small signal, the Attenuator button on the function generator must be depressed. This signal will betreated as the output of a sensor. We will condition this "sensor output" with a signal conditioning circuit.

Part 4: modify existing vi for multiple inputs

In this lab, we will build on the skills that were developed in Introduction to Benchtop Equipment and Data Acquisition and Temperature Measurement and First-Order Dynamic Response . It is assumed that the student understands the concepts of a Front Panel, a Block Diagram, theControl Palette, and the Functions Palette. It is also assumed that the student can search the control and functions palette fornecessary features. The student should be familiar with configuration options for voltage measurements using the DAQAssistant.

The VI that you developed for Temperature Measurement and First-Order Dynamic Response can be easily modified to examine circuit inputs and outputs.

• Open the VI named Lab3 that you saved during Temperature Measurement and First-Order Dynamic Response .
• Open the DAQ Assistant Configuration Box.
  • Delete the Voltage channel.
  • Add a voltage channel for module 1, analog input 0.
  • Add a voltage channel for module 1, analog input 1.
  • For the Terminal Configuration, select Differential.
  • For Acquisition Mode, select Continuous.
• Click File>>Save As…>>Substitute Copy for Original to save your VI with a new name.