Lab 5 - Resistive Sensors

Due Jul 4, 2016 by 12:59am
Points 100
Submitting a file upload

Note: This lab is due at the start of Lab 6.

Lab 5: ECE1250F14_Lab5_RSensors CMF.doc Download ECE1250F14_Lab5_RSensors CMF.doc

OR ECE1250F14_Lab5_RSensors CMF.pdf Download ECE1250F14_Lab5_RSensors CMF.pdf

Background:

In Lab 1 you used the MyDAQ to measure resistance. You will repeat those measurements for several types of resistive sensors, including some you will build.
In Lab 2 you built an LED resistance indicator. In this lab you will build a different kind of circuit – an op amp switch to respond to changes in resistance. You calculated and simulated this in your homework.
In your recent homework, you calculated and simulated an inverting amplifier. In this lab, you will build and test it.

Overview:

In this lab you will:

Test several types of resistive sensors:
- Thermistor (R changes with temperature)
- Photoresistor (R changes with light)
- Graphite resistor (R changes with width, length – use this as a moisture sensor)
Build two types of circuits that respond to changes in resistance:
- Op amp switch (for your thermistor and one other sensor of your choice)
- Op amp inverting amplifier (for your thermistor)

Equipment List:

MyDAQ board with cables. (You can hook them to the lab computers, or bring your laptop.)
Multisim software, running on your computer, or use the lab computers.
Additional parts (See Lab Handout)

Prelab (Do this before you come to lab)

Read through the lab, and (optional, you will be faster) run the Multisim simulations prior to coming to lab.
Print out the Lab Handout
Buy the parts needed from the ECE Stockroom.
Watch this Video Description of Op Amps, How they Work, and how the pins are laid out
http://www.youtube.com/watch?v=5my9_kRYVqc&list=PL170A01159D42313D&index=11&feature=plpp_video

Instructions & Reference Material:

Remember : To get your MyDAQ started, look for the NI Instrument Launcher on your computer (you may want to use the 'search' box to do this easily).
MyDAQ and Multisim resources (see LAB page)
Thermistor RL0503-5820-97-MS

Photoresistor PDV-P8103

What is a photoresistor: http://en.wikipedia.org/wiki/Photoresistor (Links to an external site.)
Data sheet: http://advancedphotonix.com/wp-content/uploads/PDV-P8103.pdf (Links to an external site.)

Op Amp LM324

Data sheet: http://www.ti.com/lit/ds/symlink/lm324.pdf (Links to an external site.)

Light Emitting Diodes (LED)

LED tutorial (especially see the picture of how the diode is built inside the red plastic dome, and what the 'flat edge' means http://en.wikipedia.org/wiki/Led
Data sheet: http://www.electronics-tutorials.ws/diode/diode_8
LED Specs (abbreviated) http://www.electronics-tutorials.ws/diode/diode_8.html (Links to an external site.)

Multisim files

Multisim file for Op Amp Switch Download Multisim file for Op Amp Switch

Multisim file for Thermistor Amplifier Download Multisim file for Thermistor Amplifier

What is Due When? Answer the questions in the handout. This is due at the start of your NEXT lab (Lab 6). OK to hand in either in hardcopy to your TA or homework box or electronically.

For fun, Check this out: Paper & Pencil circuit (like the resistor you created in your lab!)

https://www.youtube.com/watch?v=BwKQ9Idq9FM Links to an external site.