P Po ow we er r C Co on nt tr ro ol l S Sy ys st te em m f fo or r a a C Co on nc cr re et te e D Du ur ra ab bi il li it ty y T Te es st t C Ca ab bi in ne et t

flounderconvoyΗλεκτρονική - Συσκευές

15 Νοε 2013 (πριν από 3 χρόνια και 10 μήνες)

99 εμφανίσεις


1


P
P
o
o
w
w
e
e
r
r


C
C
o
o
n
n
t
t
r
r
o
o
l
l


S
S
y
y
s
s
t
t
e
e
m
m


f
f
o
o
r
r


a
a


C
C
o
o
n
n
c
c
r
r
e
e
t
t
e
e


D
D
u
u
r
r
a
a
b
b
i
i
l
l
i
i
t
t
y
y


T
T
e
e
s
s
t
t


C
C
a
a
b
b
i
i
n
n
e
e
t
t



Project ID: May08
-
34



Gro
up Members:

Matt Griffith
, EE

Lindsay Spring
, EE

Laron Evans
, EE



Client
:

National Concrete Testing Center

Manager: Bob Steffes



Faculty advisor
:

Dr.
Gregory Smith


DISCLAIMER: This document was developed as part of the requirements of an electrical and computer engineering
course at Iowa State University, Ames, Iowa. The document does not constitute a professional engineering design
or a professional land surveying d
ocument. Although the information is intended to be accurate, the associated
students, faculty, and Iowa State University make no claims, promises, or guarantees about the accuracy,
completeness, quality, or adequacy of the information. Document users shal
l ensure that any such use does not
violate any laws with regard to professional licensing and certification requirements. Such use includes any work
resulting from this student
-
prepared document that is required to be under the responsible charge of a lic
ensed
engineer or surveyor. This document is copyrighted by the students who produced the document and the
associated faculty advisors. No part may be reproduced without the written permission of the senior design
course coordinator.


December 5
, 2007





2


Table of Contents

Table
of Content
s


2

Table of Terms


3

Table of Figures


4


Chapter I: Project Plan

Current Situation


5

Problem


5

Customer Need Statement


5

System Block Diagram


6

New System Description


6

Operating Environment


6

Functional Requirements


6

Non
-
functional Requirements


7

Market Research


7

Deliverables


7

Work Breakdown Structure


8

Project Resources


11

Resource Requirements


12

Project Schedule


13

Signature Page


14


Chapter II:
Project
Design



15

Design Method



16

Option 1: Design A


17

Option 1: Design B


21

Option 2: Design A


24

Option 2: Design B


26

System Schematic


29

System

Wiring

Diagram


30

A
dvantages/Disadvantages


31


3


Team Recommendation


32


T
T
a
a
b
b
l
l
e
e


o
o
f
f


t
t
e
e
r
r
m
m
s
s


Term

Description

SPST

Single Pole Single Throw. Like a light switch either open or closed.

IC

Inte
grated circuit. A small chip that

has a complex circuit on it.

RS 485

Is a type of connector like an Ethernet plug or serial port.

RS

232

A common port on most computers.

PID

Proportional integrate and derivative control. A general class describing control circuitry.

DIN

A circular cable end with multiple pins. L
ike a mouse or keyboard connector.

MODBUS

An
industry standard serial communications protocol.

ASCII

American Standard Code for Information Interchange. A way to turn letters and symbols
in to decimal numbers.

PCB

Printed Circuit Board


4


T
T
a
a
b
b
l
l
e
e


o
o
f
f


F
F
i
i
g
g
u
u
r
r
e
e
s
s




Figure

Description

1

Functional block diagram

2

Option 1 Design A system block diagram

3

Option 1 Design A wiring diagram

4

Option 1 Design A wiring diagram exploded view

5

Option 1 Design B scale drawing of temperature probe

6

Option 1 Design A system block diagram

7

Option 1 Design B system block diagram

8

Existing system schematic

9

Existing system wiring diagram

10

Sample computer user interface.






5


Current Situation


The National Concrete Testing Center, located in the Town Engineering building, uses a
Humboldt
H
-
3185

rapid freeze
-
thaw cabinet to perform the ATSM C
-
666 test. It is controlled
by a Johnson Controls A72 temperature controller. The temperature recorder is
a Supco
CR87B. The goal of the current system is to automatically run the C
-
666 test for about 300
cycles without incident.



Problem



The problem is the current system can’t perform the C
-
666 test within specifications
(documentation included p.asdf).
T
he current control and data recording systems
for the test
cabinet are not able to perform
consistently.
Sometimes it isn’t possible to get the concrete
samples down to 0
°F
or up to 40
°F
. If the test can’t be done consistently then the test cabinet
is of l
ittle value.
Without further testing it isn’t possible to determine if the problem is with the
temperature
control or with the data recording system or with both.



Customer Need Statement


A completely new system must be implemented

to control the heat
-
cool cycle, and to record
the resulting temperatures. The specifications are as follows.




The heat
-
cool cycle must be automatically recorded by a computer with the use of
National Instrument's LabVIEW
TM
.



The data must be displayed on
the computer screen as well as recorded to an Excel
spreadsheet.



The user interface must

be digitally controlled via an on
-
site computer.



The heat
-
cool cycle must be constant for days at a time without adjustment.



The system must be scalable to allow the
control of both machines in the lab.





6


System Block Diagram




New System Description



The new system will have a temperature input and a control signal output. The input signal will
be the voltage across a thermocouple placed inside one of the concrete blocks in the cabinet.
The voltage from the thermocouple will be digitized by the NI USB
-
6008. Once the
temperature data is read into the computer we will be able to use a program written with
LabVIEW to decide if the compressor or heating elements should be turned on. For example if
the compressor should be on then the USB
-
6008 will output a
10V signal which will actuate a
relay sending 120 VAC to the compressor turning it on.


Operating E
nvironment


The system will operate in an indoor laboratory. We can assume that the room will be kept at
normal room temperature. The system will have to
operate in dusty and possibly wet
conditions. Optimally the system should be mounted under the cabinet to minimize risk.



Functional Requirements


FR 1.

The freezing
-
thawing apparatus shall have automatic controls which are able to
continuously
reproduce
cycle
s from 0±3°F to 40±3°F.

FR 2.

If the control fails it
sha
ll fail in a frozen condition.

FR 3.

The temperature sensor shall

be able to sample various points within cabinet.

FR 4.

The heat
-
cool cycle shall

take between 2
-
5 hours.

FR 5.

The time between fr
eezing and thawing phas
es shall not

exceed 10 minutes.


7


FR 6.

The new system
shall
operate completely separate from the old system.

FR 7.

All of the
temperature data shall

be recorded to an excel spreadsheet.



Non
-
Functional Requirements


NFR 1.


All of the electrical components shall be
housed in a waterproof enclosure.

NFR 2.


The system shall not cause any fire hazards.

NFR 3.


The system shall not cause any electrical shocks.

NFR 4.


The user interface shall show a temperature vs. time graph that is open at all times
during testing.


Market Research


The company ScienTemp offers a very
similar system. Their system contains the following
features:



Touch
-
screen interface



On/Off/Auto switch



On/Off light indicators



Cycle counter



Safety interlocks and alarms



Dedicated computer


There is also the company H
umboldt who produces rapid freeze
-
thaw cabinets that is the same
as the current system of this project. Humboldt provides freeze
-
thaw cabinets with 115V or
230V power rating, 50Hz or 60Hz frequency, and single phase. They also provide heating
elements, sta
inless steel sample positioning tray, recording thermometer chart paper, and other
accessories necessary and compatible with the system.


The company Veriteq produces a precision temperature data logger, Spectrum 1000, which has
internal sensors, memory an
d a 10
-
year lifetime. It has a software package that enables real
-
time monitoring over an Ethernet network. It is also said to be durable and accurate under cold
conditions; its operating range is
-
40 degrees C to 85 degrees C. It will accept any 100 K ohm

thermistor probe compatible with Betatherm 100K6A1.


There are temperature controllers by Delta and Red Lion that are specifically designed to
control heating and cooling processes. The power supply needed for the temperature
controllers are 100
-
240VAC. I
ts input options are an analog, RTD, or thermocouple input. It
can be designed for 2
-
4 outputs and the options are relay, transistor, pulse voltage, and/or
linear voltage or current. It includes MODBUS communications, PID control programs, and
auto
-
tuning.







8


Deliverables




A

computerized system that
automatically
controls the freeze
-
thaw cycle



A sufficient user
-
interface that allows lab users to input and analyze data



Two system operation; electromechanical or computerized control



More accurate
temperature sensing; two or three temperature sensors



Ability to switch system operation



Automatic system error adjustments



Manual for future reference








9


Work Breakdown Structure





















Task Name

Complete

Incomplete

% Completion

Project Planning

X



Planning Presentation

X



Plan Review

X



Create Website

X



Retrieve LabVIEW

X



Learn LabVIEW

X



Project Design


X

90%

Design LabVIEW User Interface

X



Design/Build System


X

50%

Design Power Supply

X



Design Input Sensing and Controls

X



Design Output Controls

X



Design New Relay Control integration

X



Design Switch Control integration

X



Design Thermocouple Amplifier

X



Design Communications Scheme

X



Design System Location/Mounting


X

70%

Finalize System Design


X

90%

Design
Presentation

X



Design Review


X

90%

Install Relay


X

N/A

Install switch


X

N/A

Integrate New System


X

N/A

Test System Integration


X

N/A


10


The project will have the following work breakdown:




Project Planning



Plan Review



Create
Website



Project Design

o

Design LabVIEW User
-
Interface

o

Design/Build

System



Design
Power Supply



Design Input Sensing and Controls



Design Output Controls



Design
New Relay Control integration



Design Switch Control integration



Design Thermocouple Amplifier



Design Communications Scheme



Design System Location/Mounting

o

Finalize System

o

Design Presentation

o

Design Review



Install Relay



Install Switch



Integrate New System



Test system


Individual
and Dual
Tasks

Lindsay Spring:

Design Input Sensing and Controls

Desig
n System Location/Mounting

Design Switch Control integration

Install Switch

Design Communications Scheme

System test/diagnosis


Laron Evans:


Design Power Supply

Design Output Controls

Design System Location/Mounting

Design New Relay Control integration

System test/diagnosis


Matt Griffith:


Design LabVIEW user
-
interface

Design Input Sensing and Controls

Design New Relay Control integration




Install Relay

Design Thermocouple Amplifier

System test/diagnosis



11


Project Resources


Laron Evans
Project Engineer
Team Lead
Lindsay Spring
Project Engineer
Comm
.
Coor
.
Matt Griffith
Project Engineer
Greg Smith
Project Advisor
Course
Coordinator
Bob Steffes
Client
Project Resources
Diana Gualillo
Management
Consultant

Power Control System for
Concrete Durability Test Cabinet
May
08
-
34









12


Resource Requirements


Resources are engineers Lindsay Spring,

Laron Evans, and Matt Griffith. The
faculty advisor
is
Dr. Greg Smith

and the management consultant is Diana Gualillo
.
The

client resource is Bob
Steffes.
Each engineer

ha
s

been assigned tasks that
will contribute to completing the project on
time. Engineers will roughly work 190 to 200 hours to complete the project. T
he following
calculations are from assigning engineer resources to tasks:



Hours:


Lindsay Spring: 1
92

Laro
n Evans:
206

Matt Griffith: 192


Project Labor Cost

Lindsay Spring:




$
1,920

Laron Evans:





$
2,060

Matt Griffith:





$1,920


Materials Cost

Electromechanical Relay, 30A:


$30

Solid
-
State Relay, 30A




$50

Control Switch:




$5

Power Supply, 15V, 1A:



$15

Thermocouple, K
-
type,
-
330 to 2200 F:

$39.50

Misc.:






$20



Total Costs:





$6059.5

Total Cost minus labor:



$159.50











13





14


P
P
o
o
w
w
e
e
r
r


C
C
o
o
n
n
t
t
r
r
o
o
l
l


S
S
y
y
s
s
t
t
e
e
m
m


f
f
o
o
r
r


a
a


C
C
o
o
n
n
c
c
r
r
e
e
t
t
e
e


D
D
u
u
r
r
a
a
b
b
i
i
l
l
i
i
t
t
y
y


T
T
e
e
s
s
t
t


C
C
a
a
b
b
i
i
n
n
e
e
t
t


P
P
r
r
o
o
j
j
e
e
c
c
t
t
:
:


M
M
a
a
y
y
0
0
8
8
-
-
3
3
4
4



Faculty advisor, client,
and engineers please sign, print and date below indicating that you have
read and approve the project plan


Sign





Print







Date


X
_________________________

X
__________________________

X_______


X
_________________________

X
_________
_________________

X_______


X_________________________

X
__________________________


X_______


X_________________________

X
__________________________
X_______


X_________________________

X
__________________________


X_______









15


P
P
o
o
w
w
e
e
r
r


C
C
o
o
n
n
t
t
r
r
o
o
l
l


S
S
y
y
s
s
t
t
e
e
m
m


f
f
o
o
r
r


a
a


C
C
o
o
n
n
c
c
r
r
e
e
t
t
e
e


D
D
u
u
r
r
a
a
b
b
i
i
l
l
i
i
t
t
y
y


T
T
e
e
s
s
t
t


C
C
a
a
b
b
i
i
n
n
e
e
t
t






F
F
i
i
n
n
a
a
l
l


D
D
e
e
s
s
i
i
g
g
n
n





Project ID: May08
-
34



Gro
up Members:

Matt Griffith
, EE

Lindsay Spring
, EE

Laron Evans
, EE



Client
:

National Concrete Testing Center

Manager: Bob Steffes



Faculty advisor
:

Dr.
Gregory Smith


DISCLAIMER: This document was developed as part of the requirements of an electrical and computer engineering
course at Iowa State University, Ames, Iowa
. The document does not constitute a professional engineering design
or a professional land surveying document. Although the information is intended to be accurate, the associated
students, faculty, and Iowa State University make no claims, promises, or gu
arantees about the accuracy,
completeness, quality, or adequacy of the information. Document users shall ensure that any such use does not
violate any laws with regard to professional licensing and certification requirements. Such use includes any work
res
ulting from this student
-
prepared document that is required to be under the responsible charge of a licensed
engineer or surveyor. This document is copyrighted by the students who produced the document and the
associated faculty advisors. No part may be re
produced without the written permission of the senior design
course coordinator.

December 5
, 2007



16








D
D
e
e
s
s
i
i
g
g
n
n


M
M
e
e
t
t
h
h
o
o
d
d



Functional D
ecomposition






Input Specification

Output Specification


The system ha
s one
temperature input ranging
from 0
o

to 40
o
F.


The design will
have one
SPST

relay output which will control
the heating and cooling elements in the existing system.




D
D
e
e
s
s
i
i
g
g
n
n






Option 1:
NI

6008

Option 2: Delta temp controller

Design A

Thermocouple

RS 485 to RS 232 to computer

Design B

Analog temperature IC

Analog Voltage to
NI

6008 to
computer






Figure 1


17


O
O
p
p
t
t
i
i
o
o
n
n


1
1
:
:




D
D
e
e
s
s
i
i
g
g
n
n


A
A



Design A:


U
se a

thermocouple and thermocouple amplifier

to send an analog voltage to the
NI

6008
.

Use LabVIEW to make the control decisions. Use the digital output
powered by an amplifier to switch a relay connected to the existing system.


If

we choose to implement design A

using a thermocouple as the temperature sensor the
output

voltage
will be
about








,

w
hich is
much smaller than the voltage sensitivity of
the NI
6008 (
138

mV
)
.


Therefore,

a thermoc
ouple
conditioner
along with an additional
amplifier will
be required.
The digital output of the NI 6008 is 8.5 mA which is not suf
ficient to power the
relay

(40 mA)
, so a current amplifier will be needed.
All of the electronic components will be
placed

on an external
PCB

powered by a wall mount AC to DC converter. The comp
uter will
be connected via
USB

to

the NI 6008
. Below is a
block diagram for design A.




O
O
p
p
t
t
i
i
o
o
n
n


1
1


D
D
e
e
s
s
i
i
g
g
n
n


A
A
:
:


H
H
a
a
r
r
d
d
w
w
a
a
r
r
e
e


S
S
p
p
e
e
c
c
i
i
f
f
i
i
c
c
a
a
t
t
i
i
o
o
n
n
s
s






NI 6008 Specifications:



8 analog inputs



voltage range

-
10
V

to
10V



sensitivity
138 mV



2 a
nalog outputs
:


Figure 2


18




voltage range
-
10
V

to 10V



output current 5 mA




12 digital
I/O

0
-
5V



output current 8.5 mA



Compatible with LabVIEW


Thermocouple Specifications:



Provided by client Bob Steffes:




Make:
OMEGA




Model
: PP
-
T
-
24
-
SLE



Type: T



Insulation: Polyvinyl



Wire Type: Solid Wire



Wire Gage: 24 AWG



Max Temperature
: 221
º
F
, 105ºC


Thermocouple
C
onditioner

Specifications:



Model:
AD595



Supply voltage of 5
V

to 30V



Gain of 262



10

mV/°C sensitivity


A
mplifier Specifications:



Supply voltage of 2.7
V

to 5.25V



Gain of 40



Opterating temperature
-
40
o
C to 100
o
C


Control Relay Specifications:



Model: G5C
-
14
-
DC5



Type: SPST



Contact rating of 15A at 125V



Coil rating at 5VDC at 200mW


Power Supply Specifications:



Model:
WM063
-
1950
-
D5



5V, 12V,
-
12V



.6A, 0.16A, 0.16A



6.3 Watts


Transistor Specifications:



Model:
DTC114GSA



Collector
-
Emitter voltage
max 50V



Emitter
-
Base voltage max 5V



Collector current 100 mA


19




Max temperature 150
o
C


Manual Switch Specifications:



Make: GC



Model:
35
-
110



Type SPDT



Current rating 20A 125V

W
W
i
i
r
r
i
i
n
n
g
g


D
D
i
i
a
a
g
g
r
r
a
a
m
m








Figure 3


20


E
E
x
x
t
t
e
e
r
r
n
n
a
a
l
l


H
H
a
a
r
r
d
d
w
w
a
a
r
r
e
e




Component
Specifications:




Make

Model

Cost

Thermocouple
Conditioner

Analog Devices

AD595

$6.18

A
mplifier

Texas Instruments

LPV321

$
1.04


Relay

Omron Electronics

G5C
-
14
-
DC5

$
3.98


Power Supply

Elpac

WM063
-
1950
-
D5

$41.00

transistor

ROHM

DTC114GSA

$0.46

USB
repeater

Cables to Go

Super Booster

$84.24

Cat 5 Cable

100’


$18.26

PCB and Case

Team Manufactured



$50

Manual Switch

GC

35
-
110

$3.32


Total Cost Approximation:

Computer less than 15ft from freeze
-
thaw machine
$
105.98


Computer less than 150ft from
freeze
-
thaw machine $
208.48


Issues
:

This is a custom design that will need to be supported.



Figure 4


21



O
O
p
p
t
t
i
i
o
o
n
n


1
1
:
:




D
D
e
e
s
s
i
i
g
g
n
n


B
B




Design B:

Using an
IC

temperature probe

instead of a thermocouple.


If we choose to impleme
nt design B

using an IC temperature probe and amplifier, the design
would require a large amount of custom design and build
ing
. The
analog
IC temperature
sensor and an amplifier would be housed inside

of a 6” stainless steel probe.
It would require
using thermal ad
hesive to attach the sensor to the tip of the probe, and silicone ad
hesive to
secure the amplifier.
The rest of the d
esign would be the same as in A;

the only difference
would be the type of temperature sensor used.


A scale drawing of the probe is on the

following page.




22




Figure 5


23


NI 6008 Specifications:



8 analog inputs



voltage range
-
10V to 10V



sensitivity 138 mV



2 analog outputs:



voltage range
-
10V to 10V



output current 5 mA



12 digital I/O 0
-
5V



output current 8.5 mA



Compatible with LabVIEW


Amplifier Specifications:



Supply voltage of 2.7V to 5.25V



Gain of 40



Opterating temperature
-
40
o
C to 100
o
C


Control Relay Specifications:



Model: G5C
-
14
-
DC5



Type: SPST



Contact rating of 15A at 125V



Coil rating at 5VDC at 200mW


LM235a Analog Temperature
Sensor
:



Temp range
-
40
o
C to 100
o
C



1
o
C accuracy



Linear output



10 mV/

o
C



5V supply voltage


Transistor Specifications:



Model:
DTC114GSA



Collector
-
Emitter voltage max 50V



Emitter
-
Base voltage max 5V



Collector current 100 mA



Max temperature 150
o
C


Manual
Switch Specifications:



Make: GC



Model:
35
-
110



Type SPDT



Current rating 20A 125V





24


Component Specifications:



Make

Model

Cost

Temp sensor

National Semiconductor

LM235a

$0.89

Relay

Omron Electronics

G5C
-
14
-
DC5

$3.98

transistor

ROHM

DTC114GSA

$0.46

USB

repeater

Cables to Go

Super Booster

$84.24

Amplifier

Texas Instruments

LPV321

$1.04

Steel Probe

Omega

SS
-
38

$
8.50

Pressure fitting

Omega

SSLK
-
38
-
38

$18.00

Thermal Adhesive

Arctic Silver

AATA
-
5G

$5.99

Silicone Adhesive

GE

GE284

$3.44

Cat
-
5 cable

100’


$18.26

Cap

Anderson Barrows

PB61CP

$1.28

Manual Switch

GC

35
-
110

$3.32


Total Cost Approximation:

Computer less than 15ft from freeze
-
thaw machine $
46.90


Computer less than 150ft from freeze
-
thaw machine $
14
9.40

Issues:

Custom design will be required to build the sensor and its case.
We aren’t sure how long it
would take to make the probe, and that
isn’t our area of expertise.


O
O
p
p
t
t
i
i
o
o
n
n


2
2
:
:


D
D
e
e
s
s
i
i
g
g
n
n


A
A



Design
A
:

Using the DELTA
temperatur
e controller for control.
Temperature data
will be
sent to the computer using a
RS 485

to
RS

232

converter.


If

we choose to implement design
2A

the controller will use
PID

control to switch the relay
output which will be connected to the existing system.

The controller will be
able to
automatically cycle from 0 to 40 degrees F. Temperature data will be logged using LabVIEW.



25





DELTA Temperature Controller Specifications
:



Dual outputs



PID, ON/OFF, Manual, and PID programmable control



PID and Auto
-
Tuning



Two

built
-
in control output

(for heating/cooling control), and alarm output



Output options: Relay (250VAC, 5A max), DC Current (4
-
20mA), or Linear Voltage (0
-
5V, 0
-
10V)



RS
-
485 (MODBUS ASCII/RTU) communication



One Thermocouple sensor input (all types)



DIN

rail

mounting



Interface programming



100
-
240V supply, 50
-
60Hz



Thermocouple Specifications:



Provided by client Bob Steffes:




Make:
OMEGA




Model
: PP
-
T
-
24
-
SLE



Type: T



Insulation: Polyvinyl



Wire Type: Solid Wire

Figure 6


26




Wire Gage: 24 AWG



Wire Accuracy: Special Limits of
Error



Max Temp
: 221
o
F, 105
o
C


RS232/484 Converter Specifications:



CommFront Technologies



Port
-
powered, no external power required



Data direction auto
-
turnaround, no flow control is required



Dimensions (H x W x D): 0.63 x 1.3 x 3.4 in


Manual Switch
Specifications:



Make: GC



Model:
35
-
110



Type SPDT



Current rating 20A 125V


Component
Specifications:



Make

Model

Cost

Temperature Controller

DELTA

DTB4848
-

$90

Cat
-
5 cable

100’


$18.26

Thermocouple

Omega

PP
-
T
-
24
-
SLE

Provided

RS232/484 Converter

CommFront Technologies

CVT
-
485
-
1

$60.90

Manual Switch

GC

35
-
110

$3.32



Total Cost Approximation:

$
172.48


O
O
p
p
t
t
i
i
o
o
n
n


2
2
:
:




D
D
e
e
s
s
i
i
g
g
n
n


B
B



Design B:


This w
ould be a worst case scenario

for the Delta temp controller.
This design
would just use the linear voltage
output of the temp
erature

controller like the thermocouple
conditioner and amplifier.

We are considering this possibility because having just a single order
PID controller might not be enough to provide adequate control
of the system. This design
would
use the temp
erature

controller to sense the temperature and use the NI 6008 for all of
the control decisions.

Below is a wiring diagram for design
2
B.


27





NI 6008 Specifications:



8 analog inputs



voltage range
-
10V to 10V



sensitivity 138 mV



2 analog outputs:



voltage range
-
10V to 10V



output current 5 mA



12 digital I/O 0
-
5V



output current 8.5 mA



Compatible with LabVIEW


Thermocouple Specifications:



Provided by client Bob Steffes:




Make:
OMEGA




Model
: PP
-
T
-
24
-
SLE



Type: T



Insulation:
Polyvinyl

Figure 7


28




Wire Type: Solid Wire



Wire Gage: 24 AWG



Max Temperature
: 221
º
F
, 105ºC


Control Relay Specifications:



Model: G5C
-
14
-
DC5



Type: SPST



Contact rating of 15A at 125V



Coil rating at 5VDC at 200mW


Transistor Specifications:



Model:
DTC114GSA



Collector
-
Emitter voltage max 50V



Emitter
-
Base voltage max 5V



Collector current 100 mA



Max temperature 150
o
C


DELTA Temperature Controller Specifications
:



Dual outputs



PID, ON/OFF, Manual, and PID programmable control



PID and Auto
-
Tuning



Two

built
-
in control output

(for heating/cooling control), and alarm output



Output options: Relay (250VAC, 5A max), DC Current (4
-
20mA), or Linear Voltage (0
-
5V, 0
-
10V)



RS
-
485 (MODBUS ASCII/RTU) communication



One Thermocouple sensor input (all types)



DIN

rail mounting



Interface programming



100
-
240V supply, 50
-
60Hz


Manual Switch Specifications:



Make: GC



Model:
35
-
110



Type SPDT



Current rating 20A 125V



Make

Model

Cost

Temperature Controller

DELTA

DTB4848
-

$90

Cat
-
5 cable

100’


$18.26

transistor

ROHM

DTC114GSA

$0.46

USB repeater

Cables to Go

Super
Booster

$84.24

Thermocouple

Omega

PP
-
T
-
24
-
SLE

Provided


29


Manual Switch

GC

35
-
110

$3.32

Relay

Omron Electronics

G5C
-
14
-
DC5

$
3.98



Total Cost Approximation:

Computer less than 15ft from freeze
-
thaw
machine $
97.76


Computer less than 150ft from freeze
-
thaw machine $
200.26



C
C
o
o
n
n
n
n
e
e
c
c
t
t
i
i
o
o
n
n


t
t
o
o


t
t
h
h
e
e


e
e
x
x
i
i
s
s
t
t
i
i
n
n
g
g


s
s
y
y
s
s
t
t
e
e
m
m







Figure 8


30


W
W
i
i
r
r
i
i
n
n
g
g


d
d
i
i
a
a
g
g
r
r
a
a
m
m






S
S
o
o
f
f
t
t
w
w
a
a
r
r
e
e


S
S
p
p
e
e
c
c
i
i
f
f
i
i
c
c
a
a
t
t
i
i
o
o
n
n



The PC operating system will run on Microsoft version XP and the LabVIEW
will run on a
version of no less than 8.0.


U
U
s
s
e
e
r
r


I
I
n
n
t
t
e
e
r
r
f
f
a
a
c
c
e
e


S
S
p
p
e
e
c
c
i
i
f
f
i
i
c
c
a
a
t
t
i
i
o
o
n
n



The user interface will be controlled through a PC computer using LabVIEW software that will
collect the temperature data and record it into an Excel spreadsheet.


The following
image shows an example of the LabVIEW user interface.


Figure 9


31




A
A
d
d
v
v
a
a
n
n
t
t
a
a
g
g
e
e
s
s


a
a
n
n
d
d


D
D
i
i
s
s
a
a
d
d
v
v
a
a
n
n
t
t
a
a
g
g
e
e
s
s





Advantages

Disadvantages

Cost

Option 1 Design A:
Thermocouple

Design and fabrication
within our scope.

Easy to
write the software.

We would have to make
custom circuits and PCBs.
External power supply.


Computer

< 15ft
$
105.98


Computer

< 150ft $
208.48


Option 1 Design B:

Analog Temperature
IC

If we make multiple probes
they would be easy to
replace. No external power
supply or
PCB.

Easy to write
the software.

Fabrication would be
difficult. Little support for
probe.

Computer

< 15ft $
46.90

Computer

< 150ft $
149.40


Option 2 Design A:


RS 485 to RS 232 to
Computer

No custom circuits. Delta
would provide customer
support. Same
cost for the
computer close or far.

Only first order PID
control.

$
172.48

Option 2 Design B:

Analog Voltage to NI
6008 to computer

No custom circuits or PCB.
Varit
y of possible
combinations.
Easy to write
the software.


Computer

< 15ft $
97.76

Computer

< 150ft $
200.26







Figure 10


32


T
T
e
e
a
a
m
m


R
R
e
e
c
c
o
o
m
m
m
m
e
e
n
n
d
d
a
a
t
t
i
i
o
o
n
n



Based on the above three design choices, the team recommendation is for
Option 2 Design A
,
using the DELTA temperature controller.
Based on the advantages, it appears that it will be the
most cost effective
design with minimal custom build therefore requiring minimal support.

Also
if the controller is unable to perform it would only take an additional $5.00 to change to Design
B using the NI 6008.

Using the Delta temperature controller has the highest succes
s rate and
the most flexibility.