Week #10: Comparators & LM34, Differential & Instrumentation Amplifiers

[rjagodowski]

Comparators & the LM34 Precision Temperature Sensor. The next EET-210L scheduled (11/24 and 12/3) is investigating an LM311 Quad Comparator used in several thermostat applications. The lab can be found here in Week #13 of the lab. Note that we skipped over the Differential and Instrumentation Amplifier experiment for week's #10 & #11.

We'll begin this week with a discussion on Precision Comparators:

Op-Amp Comparators from www.electronics-tutorials.ws
.

This is a great video on Comparator Applications from Texas Instruments.

Before we discuss the Precision Comparators, we need to spend a few minutes introducing Open Collector Outputs, in this case, from EvilMadScientist.com

Comparators: LM-339 Data Sheet or here as a pdf:

LM339 Datasheet.PDF

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This is the website that inspired this week's lab: ermicroblog. There are some typos on the schematics and their description of the circuit operation is misleading, which will be pointed out in class and when we build these circuits in lab. Actually, aside from the circuits, this site isn't so great. LOL

Voltage Comparator Information and Circuits.

A comparator summary from bristolwatch.com.










This week we'll finish the discussion on Op-Amps from Week #9 and then begin to investigate Differential Amplifiers and Instrumentation Amplifiers, including the lab exercise found here.

The Op-Amp Difference Amplifier.


Differential and Instrumentation Amplifiers from Electronics-Tutorials.

The Instrumentation Amplifier The labsheet containing the I.A. can be found here.



For repetition, here is the homework assignment on Gain Calculations.

Gain Calculation Problems v15.1.pdf

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These are two Excel files to help with calculations and a demonstration of Differential Amplifier operation.

This file will perform the calculations for Differential Mode, Common Mode and CMRR for the Differential Amplifier Circuit built in lab.

EET-210 Differential Amplifier Worksheet v18.1.xls

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This file will show how the Differential Amplifier can be used to extract and amplify a low level signal out a field of noise, attenuating the noise.

EET-210 Differential Amplifier Example v19.1.xlsx

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