Transcript Thermocouple Signal Simulator

Thermocouple Signal Simulator
Sponsor: Emerson- Kent Burr, Charles Eastberg
Advisor- Dr. Semih Aslan
Group: NPPH(1.7)
Taylor Nash, Rey Perez, Victor Pinones, and Travis
Howell
Why Emerson Needs A Thermocouple Signal
Simulator
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Emerson has three different test
teams in Round Rock
They do different types of
component testing, maxing out,
and configurations
Thermocouples is a very common
component they test
They want to be able to simulate
thermocouple readings
What does the Thermocouple
Signal Simulator do?
Options
❖ Input
➢ Multiple inputs
➢ Configure thermocouple
types
■ Input on DIP switches
■ Software implemented
❖ Output
➢ Have multiple outputs
➢ Have just one output
Dataflow
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Hardware implemented
➢ Need 8 of each
components, one for each
of the thermocouple types
➢ Too costly for hardware set
up- not enough space, too
many bugs
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Software implemented
➢ Only need one processor
Components
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Hardware
➢ Arduino Mega 2560
➢ DAC, ADC
➢ Electrical Isolator
➢ 5V power supply
➢ 4-20mA input
➢ Power resistors
➢ Op Amp
➢ Printed Circuit Board
(PCB)
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Software
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Program to execute all logic
and arithmetic
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Thermocouple Polynomial
Library
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Thermocouple look-up
tables
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Input
Proposal
➢ 4-20mA, provided by Emerson
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Project: convert the 4-20mA signal into an isolated mV signal
ranging from ±100mV
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Combination of mostly software and some hardware
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Configuration to each type of thermocouple
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8 synchronized output nodes
Demo: Dataflow
Input
4-20mA
Find relative
temp. for
thermocouple
Input range
percentage
conversion
Map to
PWM port
range
Use temp.
for “look-up”
value
Output
Budget
Device
Price
$200/member
Total: $800
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Arduino Mega 2560.……………...$40
5V High/Low Opto-isolator……....$8
PCB by TXST………………...…...$0
24 bit ADC…………………………$11
20 bit DAC ………………………..$20
1-8 demultiplexer………………....$5
Project houseing………………....TBA
Total Estimated Price:
$84
Test Plan
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Overview
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Input 4-20 mA signal
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Convert and isolate the input to eight ±100 mV outputs
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Outputs run to Emerson’s CHARM systems
Constraints
❖ Economical
➢ Hardware implementation
would be costly
➢ Wasteful of resources, i.e.
all hardware would result
in multiple components
➢ Processor/software
implementation was much
more practical
Timeline
Dataflow
Schematic
Output
Isolation
Hardware
Selection
Hardware
Purchase
Hardware
Purchase
Timeline
Write
Program
Progra
Deviation
Handling
m
Debug
Circuit
Circuit
Assem
Assembly
bly
Testing
Testing
Softwar
Software
e
Circuit
Testing
System
Verify
System
Testing
Demo and Progress
❖ Our demo simulates the type T thermocouple
❖ Input from Arduino’s serial interface
❖ Outputs analog signal on PWM port
❖ Similar to our completed system, except no isolation
References
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htatp://community.emerson.com/cfs-file/__key/communityserver-blogscomponents-weblogfiles/00-00-00-0292/3581.emerson_5F00_electric_2D00_logo.jpg
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http://upload.wikimedia.org/wikipedia/en/e/ed/Thermocouple_%28work_dia
gram%29_LMB.png
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http://www.ti.com/graphics/folders/partimages/ADS1675.jpg
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http://www.vetco.net/catalog/images/VET-SP-DIP3-1.jpg
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http://media.digikey.com/Renders/~~Pkg.Case%20or%20Series/DIP16_SO
T38-1%20Pkg.jpg
Questions?