1. Power Control System for a Concrete Durability Test Cabinet
May08-34
Matt Griffith
Lindsay Spring
Laron Evans

2. Concrete Freeze-Thaw Machine

3. Temperature Gauge
Concrete Samples
Before and After

4. Problem Statement
The current control and data recording systems are not able to perform accurately or consistently.

5. Problem Statement
If the cycle isn’t consistent then the samples can’t be compared to each other therefore making the test invalid.

6. Customer Need Statement
A completely new system must be implemented to control the heat-cool cycle.
The heat-cool cycle must be automatically recorded by a computer with the use of National Instrument’s LabVIEW.
The user interface will be digitally controlled via an on-site computer.
The heat-cool cycle must be constant for days at a time without adjustment.

7. Functional Requirements
The freezing-thawing apparatus shall have automatic controls which are able to continuously reproduce cycles from 0±3°F to 40±3°F.
If the control fails it will fail in a frozen condition.
The temperature sensor must be able to sample various points within cabinet.
The heat-cool cycle shall take between 2-5 hours.
The time between freezing and thawing phases cannot exceed 10 minutes.
The new system shall operate completely separate from the old system.

8. Requirements to Specifications
The freezing-thawing apparatus shall have automatic controls which are able to continuously reproduce cycles from 0±3°F to 40±3°F.
The system will be computer based.
LabVIEW will be used to program the control system, and to record the temperature data.

9. Requirements to Specifications
FR2
If the control fails it shall fail in a frozen condition.
The program will have error handling, which will be able to make sure the compressor is on.
FR3
The temperature sensor shall be able to sample various points within cabinet.
The thermocouple will have to be long enough to reach the farthest sample in the machine.
FR4
The heat-cool cycle shall take between 2-5 hours.
The system must be heating or cooling at all times.
FR5
The time between freezing and thawing phases shall not exceed 10 minutes.
Our control system must have a time delay of less than 10 min.
FR6
The new system shall operate completely separate from the old system.
There will be a SPDT manual switch Placed after the old control relay.
FR7
All of the temperature data shall be recorded to an excel spreadsheet.
We will have to add code into the LabVIEW program that sends the data to an excel file.

10. Requirements to Specifications
NFR1
The system shall be water resistant.
All of electrical components will be inside a 4x4x2 in. metal junction box.
NFR2
The system shall not cause any fire hazards.
Every thing must be connected after the 15A breaker.
NFR3
The system shall not cause any electrical shocks.
The junction box will have to be grounded to the machine frame, and all wires will have to insulated from the frame.
NFR4
The user interface shall show a temperature vs. time graph that is open at all times during testing.
The temp time graph will have to be large enough to show at least two cycles, and the instantaneous temp will be prominently displayed.

11. Our Approach
Design a new system to take over the control of the heat-cool cycle.
Record the data onto a computer.
LabVIEW will be used to program the control system and record the temperature data.
New system will be user-defined and all recording and storing of data will be automatic.
If new system fails, old system continues to run and collect data.

12. System Block Diagram

13. Functional Block Diagram
Temp
Input
Temp
Sensor
Conditioning Module
Analog to
Digital
Communication module
Computer
With LabVIEW
Relay
Amplifier
Relay
Output To Control Relay

14. User Interface
NI labVIEWTM
Sample Screen Shot
Example User Interface with temp graph, set point, and channel selection

15. Example LabVIEW VI

16. Example LabVIEW VI

17. Design Options Option 1: NI 6008 Option 2: Delta Temp Controller
Design A: Thermocouple and thermocouple amplifier
Design B: Analog temperature IC
Option 2: Delta Temp Controller
Design A: RS 485 to RS 232 to computer
Design B: Analog Voltage to NI 6008 to computer

18. System Block Diagram 1A New Old Computer User Interface NI 6008
Amplifier
New
Module Output 0-5V
Thermocouple
conditioner
Old
Relay
Amplifier
Thermocouple
Relay
Heating
Elements
120V AC
Cycle Control
Manual Switch
Output
Temp
Old Temp
Recorder
120V AC
Refrigerator
Old Temp
Sensor

19. Control System 1A Wall Outlet Specifications G5C-14-DC5 Type SPST
Contact Rating
15A at 125V
Coil Rating
5VDC at 200mW
Power Supply
WM D5
+12V
GND
-12V
+5V
Computer
External
Hardware NI
USB-6008
GND
AI0
AI4
AI1
AI5
AI2
AI6
AI3
AI7
AO0
AO1
P0.0
P0.1
P0.2
P0.3
P0.4
P0.5
P0.6
P0.7
P1.0
P1.1
P1.2
P1.3
PFIO
+2.5V
+5V
USB
Thermocouple
G5C-14-DC5
21µV/°F
NR1
Relay
NR3
NR2
NR4

20. External Hardware Specifications AD595 LPV321 Supply Voltage 5 to 30 V
AI0
+5V
40K
+12V T- 1K
LPV321 T+
P1.3
-12V
GND
GND
Specifications
AD595
LPV321
Supply Voltage
5 to 30 V
2.7V to 5.5V
Gain
262 40
125
NR1

21. Limiting Specifications 1A
Relay 15A contact rating
40mA coil rating
USB-6008
Input voltage -10 to +10V
Output current 8.5mA
Voltage sensitivity 138mV
Thermocouple output
21microV/°F
Temperature sensor must be accurate to ±2°F
Problems
Solutions
Output current is too small to power the relay.
Add a current amplifier. (transistor)
Thermocouple output is much smaller than the sensitivity.
Add a two stage voltage amplifier.
Voltage amp requires an external power supply.
Put the voltage and current amp on an external PCB powered by a wall mount AC to DC converter.

22. Cost Specifications 1A Make Model Cost Thermocouple Conditioner
Make
Model
Cost
Thermocouple Conditioner
Analog Devices
AD595
$6.18
Amplifier
Texas Instruments
LPV321
$1.04
Relay
Omron Electronics
G5C-14-DC5
$3.98
Power Supply
Elpac
WM 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

23. System Block Diagram 1B New Old Computer User Interface NI 6008
Amplifier
New
Module Output 0-5V
Old
Relay
Amplifier
Analog Temp sensor
Relay
Heating
Elements
120V AC
Cycle Control
Manual Switch
Output
Temp
Old Temp
Recorder
120V AC
Refrigerator
Old Temp
Sensor

24. Control System 1B
Thermal Adhesive
LM235A
LPV321 n

25. Limiting Specifications 1B
Relay 15A contact rating
40mA coil rating
USB-6008
Input voltage -10 to +10V
Output current 8.5mA
Voltage sensitivity 138mV
LM235A output
10 mV/°C
Temperature sensor must be accurate to ±2°F
Problems
Solutions
Output current is too small to power the relay.
Add a current amplifier. (transistor)
LM235A output is much smaller than the sensitivity.
Add a voltage amplifier.

26. Cost Specifications 1B Total Cost Approximation:
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
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 $149.40

27. System Block Diagram 2A New Old Computer User Interface
RS232/485 Converter
Delta Temperature Controller
New
RS485
Old
Delta Temperature Controller
Thermocouple
Heating
Elements
120V AC
Cycle Control
Manual Switch
Output
Temp
Old Temp
Recorder
120V AC
Refrigerator
Old Temp
Sensor

28. Control System 2A Delta Temperature Controller DTB4848LR 1 6 11 2 7 12
AO- 6 L 11
Power Supply
120V 15A 2
AO+ 7
OUT2
14VDC N 12 3
RTD 8
COM
ALM2 13 4
TC+ 9
DATA-
ALM1 NO 14
Thermocouple
From Cycle Thermostat 5
TC- 10
DATA+
COM 15 3 1
GC Elec. Switches
SPDT
35-110
RS RS GND
TX RX GND 1 3 5
CommFront
RS232/485 Converter
CVT-485-1 2 2 3 5
To Cycle Relay
Computer

29. Cost Specifications 2A Make Model Cost Temperature Controller DELTA
DTB4848LR
$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

30. Delta Temperature Controller
System Block Diagram 2B
Computer
User
Interface
Delta Temperature Controller
LabVIEW
Module
New
Old
LabVIEW
Module
Module Output 0-5V
Thermocouple
Relay
Heating
Elements
120V AC
Cycle Control
Manual Switch
Output
Temp
Old Temp
Recorder
120V AC
Refrigerator
Old Temp
Sensor

31. Control System 2B

32. Limiting Specifications 2B
Issues
Max USB cable length: 15ft
Solution
Use USB repeater for more distance
Max USB repeater length: 150ft

33. Cost Specifications 2B Total Cost Approximation:
Make
Model
Cost
Temperature Controller
DELTA
DTB4848LR
$90
Cat-5 cable
100 ft
$18.26
transistor
ROHM
DTC114GSA
$0.46
USB repeater
Cables to Go
Super Booster
$84.24
Thermocouple
Omega
PP-T-24-SLE
Provided
Relay
Omron Electronics
G5C-14-DC5
$3.98
Manual Switch GC
35-110
$3.32
Total Cost Approximation:
Computer less than 15ft from freeze-thaw machine $97.76
Computer less than 150ft from freeze-thaw machine $200.26

34. Control Schematic (Existing)
115V
30A
CKT Breaker
1 phase
15A
CKT Breaker
Fan & Controls N
Recorder Outlets H H
Legend
HLR: High Limit Relay
CR: Cycle Relay
: Relay pin number
N.O.: Normally Open
N.C.: Normally Closed
H: Positive Wire
N: Neutral Wire
Fan Switch
Fan Motor
High Limit Thermostat
HLR
Coil
Cycle Thermostat CR
Coil
Heating Switch
Heater Outlets CR
HLR 3 6 5 3
N.C.
N.O.
Cooling Switch
Cond. Unit CR 3 5
N.O.

35. Control Schematic (New)
115V
30A
CKT Breaker
1 phase
15A
CKT Breaker
Fan & Controls N
Recorder Outlets H H
Legend
HLR: High Limit Relay
CR: Cycle Relay
NR: New Relay
: Relay pin number
N.O.: Normally Open
N.C.: Normally Closed
H: Positive Wire
N: Neutral Wire
Fan Switch
Fan Motor
High Limit Thermostat
HLR
Coil
Cycle Thermostat
Manual Switch CR
Coil NR 3 4
N.O.
Heating Switch
Heater Outlets 3 CR
HLR 6 5 3
N.C.
N.O.
Cooling Switch
Cond. Unit CR 3 5
N.O.

36. Wiring Diagram (Existing)
Power Supply
Breaker Box
Cooling
Switch
Neutral Bus
H(15A) H(30A) Bl
Wire Color Code
Bl: Black
R: Red
Bu: Blue
O: Orange
W: White
Br: Brown Bl W
Cond.
Unit
Legend
HLR: High Limit Relay
CR: Cycle Relay R W
Heating
Outlets R
Heating
Switch R CR R W
Fan Motor O W W
HLR W R Bu Br
Recorder
Outlets Bu
Heat Limit
Switch Bu
Cycle Control
Fan On/Off
Switch

37. Wiring Diagram (New System)
Wire Color Code
Bl: Black
R: Red
Bu: Blue
O: Orange
W: White
Br: Brown
Power Supply
Breaker Box
Cooling
Switch
Neutral Bus
H(15A) H(30A) Bl Bl
Legend
HLR: High Limit Relay
CR: Cycle Relay
NR: New Relay
CD: Control Device W
Cond.
Unit R W
Heating
Outlets R
Heating
Switch R CR W R
Fan Motor Br O W W
HLR
Manual
Switch Br W 4
NR 2 3 R Br CD Bu
Recorder
Outlets Bu
Heat Limit
Switch Bu
Cycle Control Bu
Fan On/Off
Switch

38. Team Recommendation 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
< 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.
< 15ft $46.90
< 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 PCB. Varity of possible combinations. Easy to write the software.
Some custom design.
< 15ft $97.76
< 150ft $200.26

39. NI USB-6008 LabVIEW Hardware
Provides basic data acquisition for data logging, portable measurements, and lab experiments.
We will use the inputs to send the control signals to the heating and cooling relays.

40. System Block Diagram Heat Heat Limit Data Log LabView Cycle Control
Temp
Sensor
LabView
Freeze
Compressor
LabView

41. Operating environment
Indoor Laboratory
Heavy concrete blocks
Dust and dirt
Water

42. Market Research The dedicated computer allows the user to:
The professional option models are controlled with an emergency stop button, a local lid switch, and dedicated computer which provides a much larger user interface.
The dedicated computer allows the user to:
Program time and temperature profiles
Select operating modes
View status of equipment and logic
functions
View status of alarms and network
connectivity
Log data to the dedicated computer that is independent from your server-insuring continuous data collection through network failures and upgrades
Professional 20 Block Freeze with
Touch Screen Control and Data Logging to Server

43. Questions?