Transcript P12441: Thermoelectric Power Pack

DETAILED DESIGN REVIEW
MSD Project #12441:
Thermoelectric Power Pack
Lead Software Engineer: Colin McCune (EE)
Project Manager: Andrew Phillips (EE)
Test Engineer: Lauren Cummings (EE)
Cost Engineer: Xiaolong Zhang (EE)
Goals of Detailed Design Review
1.Communicate detailed design to P12442 and project
guides.
2.Catch mistakes and overlooked details of the design.
3.Display feasibility of the design.
Customer Needs
Needs Importance
Description
Comments/Status
1
3*
Fan runs the entire duration of cooking
2
3*
Plan to couple to team 12442’s stove.
3
3
Cheap cost of system
Component cost including PCB if
applicable
4
3
User-friendly operation
Minimal user interaction
5
3
Safe to operate
6
2
Fan runs at start-up
Multiple start/restart cycles
7
2
Rugged design
Survive crush and drop test
8
2
Operational in Harsh Environments
Exposure to Rain, Moisture, Heat
and Salinity
9
2
Ability to charge USB device
10
1
System must be transportable
11
1
5 year life span (3x use per day)
Importance Scale: 1 - Low Importance, 2 - Moderate Importance, 3 - High Importance
Engineering Specifications 1-10
Spec
Customer
Need
Description
Importance
Units
Marginal
Target
Comments/Status
1
1
Component Cost
3
$
15
10
Including any PCB, for
quantities of 1-10K.
2
2, 6, 8
Power supplied to
fan
3
W
.7
1.2
3
2, 6, 8
Voltage supplied to
the fan
3
V
11
12
Converter needs to be
adjustable.
4
8
Amount of startups
that can be
performed on
battery power.
3
Start up
1
3
A system startup is the 20
minute period in which the fan is
powered by the battery only.
5
3
User interaction to
maintain proper
system operation
3
Actions
1
0
The user shouldn’t
need to perform adjustments to
properly operate electronics.
6
2
Electrical
connections
provided to the
stove.
3
Connections
6
4
2 input wires, 2 output wires
7
4, 7, 11
Survive drop test
2
Drops
2
20
Survive 20, 2 meter drops.
8
4, 7, 11
Survive crush test
2
PSI
2
5
Enclosure must survive being
stepped on
10
4, 7, 11
Survive a rain test
2
hours
1
2
Put it in the shower.
Importance Scale: 1 - Low Importance, 2 - Moderate Importance, 3 - High Importance
Engineering Specifications 11-22
Spec
Customer
Need
Description
Importance
Units
Marginal
Target
11
4, 7, 11
Survive a humidity test
2
hours
1
5
12
5, 10
Enclosure surface
temperature
2
°C
10
55
13
3, 5
User interaction to
protect system
2
Actions
1
0
14
9
USB output power
2
W
2.375
2.5
15
16
9
9
2
2
V
A
4.75
.475
5
.5
17
9
USB output voltage
USB output current
Number of charges
from battery
2
Charges
1
2
18
11
Product Life Span
2
Hours
1500
11,000
19
20
10
10
1
1
lbs
In
6
5x5x5
3
3x3x1.5
21
3
1
#
2
0
22
3
System Weight
Enclosure Volume
User actions during
operation cycle
Fuse high cost
components
1
Dollars
1
3
Comments/Status
Place the unit in an above 90%
enclosed area.
Surface of enclosure may not exceed
55 °C during operation.
The user should not need to perform
an action to protect the system
Margin derived from specs 15, and
16
From USB spec
From USB spec
Assume 3 hours/use, 2 uses/day, for
5 years
Include battery packs
Include battery packs
Put fuses on lines that supply high
cost components.
Functional Decomposition: Maximum Power Point Tracker (MPPT)
Function Decomposition: Enclosure System
System Architecture
Picking the Battery
Grade
Lead-Acid
Description
Nickle-Metal Hydride
Grade
Description
Lithium-Ion
Grade
Description
Cost ($ per pack)
Discharge Capacity
(mAh)
+
7.5 - 10
0
9.65 -11.88
+
1300 - 4500
0
1500 - 2500
+
2000 - 3000
Charging Complexity
0
Trickle or multi-stage
0
Trickle or multi-stage
-
Constant current,
constant voltage
Robust
Mass (Kg)
Life span (Cycles)
Charge Time (Hours)
Charge/Discharge
Efficiency
Volume (Cubic
Inches)
Voltage per Cell
0
0
waiting on quote
0
-
.3 - 2
0
.026 - .029
0
.0435 - .0465
-
500 - 800
0
500 - 1000
+
400 - 1200
-
2 - 20
0
1.5 - 4
0
1.75 - 4.25
+
50% - 92%
0
66%
+
80% - 90%
-
~21
0
~2
+
~1
+
6 - 12
0
1.2
0
3.6 - 4.2
Special Requirement
0
Must be kept vertical to
function
0
0
Must be bought in
prebuilt packs
Internal Resistance
(mΩ)
0
~20
0
~25
-
~2000 - 6000
Change in Charge
Voltage (V)
-
~2V
0
~.4V
-
~1.5V
Battery
System
Power (W) Time (H) Efficiency
Fan
1.2
3
0.9
Microcontroller
0.005
3
0.9
USB
2.5
3
0.9
Analog Controls
0.3
3
0.9
Total
13.22
Required Power (Wh)
3.96
0.02
8.25
0.99
• Battery Selection
• Given the high storage requirements, relatively high current
draw (about 700mA), and low cost requirements the
Panasonic LC-R064R5P Lead Acid battery was selected.
• The recommended trickle charge current for the battery to
achieve a 5 hour charge is 720mA. This is slightly higher
than the predicted maximum output current of the MPPT of
670mA. Because of this no current control or disconnect
system is needed.
Battery Selections Effect on the System
• From the figure below it can be seen that at a
discharge rate of 1.125 A the terminal voltage ranges
from 5.1V to 6.5V. The power systems will need to
be designed to operate across this voltage range.
MPPT Pugh Chart
MPPT Reference Material*
Maximum Power Equations
MPPT Schematic
Results
*A maximum power point tracking circuit of thermoelectric generators without digital controllers – Shiho Kim, Sungkyu Cho, Namjae Kim, and Jungyong Park
MPPT Sawtooth Wave Generator
Sawtooth generator simulation.
Sawtooth generator simulation
schematic.
MPPT Simulation Schematic
MPPT TEG Simulation Results
12V Fan Converter
Fan converter schematic
Fan Converter BOM
Ref Manufacturer
CCOMP
CIN
COUT
Yageo
Murata
Manufacturer PN
Description
Distributer
Distributer PN
Quantity
Price per
1k
CC0805KRX7R9BB472
CAP CER 4700PF 50V 10% X7R
0805
Digikey
311-1133-2-ND
1
0.010
Mouser
81GRM188R61A335KE5
D
1
0.050
CAP ALUM 100UF 16V 20%
SMD
Digikey
565-2446-2-ND
1
0.093
MLCC SMD/SMT 3.3uF 10Volts
GRM188R61A335KE15D
X5R 10%
United ChemiEMVY160ADA101MF55G
Con
CSS
Murata
GRM2195C1H912JA01D
MLCC SMD/SMT 0.0091uF
50Volts C0G 0.05
Mouser
81GRM2195C1H912JA1D
1
0.082
D1
Toshiba
CMS06(TE12L,Q,M)
RECT SCHOTTKY 30V 2A 34E1A
Digikey
CMS06QMTR-ND
1
0.186
L1
Bourns Inc.
SDR0503-101KL
INDUCTOR POWER 100UH 10%
SMD
Digikey
SDR0503-101KLTR-ND
1
0.210
CRCW080520K0FKEA
RES 20.0K OHM 1/8W 1% 0805
SMD
Digikey
541-20.0KCTR-ND
1
0.008
RCOMP Vishay/Dale
RFB1
Vishay/Dale
CRCW080510K2FKEA
RES 10.2K OHM 1/8W 1% 0805
SMD
Digikey
541-10.2KCTR-ND
1
0.008
RFB2
Vishay/Dale
CRCW080586K6FKEA
RES 86.6K OHM 1/8W 1% 0805
SMD
Digikey
541-86.6KCTR-ND
1
0.008
U1
Texas
Instruments
LM3224MM-ADJ
IC BOOST/FLYBCK ADJ 2.45A
8MSOP
Digikey
LM3224MM-ADJTR-ND
1
1.470
Microcontroller Converter
Ref
Manufacturer
Manufacturer PN
Description
Distributer
Distributer PN
Quantity
Price per
1k
L1
Taiyo Yuden
BRC2012T2R2MD
INDUCTOR 2.2UH 1.0A
20% SMD
Digikey
587-2905-2-ND
1
0.100
R1
Vishay-Dale
CRCW1206100KJNEA
RES 100K OHM 1/4W
5% 1206 SMD
Digikey
541-100KECT-ND
1
0.019
R2
Stackpole Electronics
Inc
RMCF2512FT16R5
RES TF 1W 16.5 OHM
1% 2512
Digikey
RMCF2512FT16R5TR-ND
1
0.041
C1
Taiyo Yuden
LMK212BJ106KD-T
CAP CER 10UF 10V
10% X5R 0805
Digikey
587-1299-2-ND
1
0.038
C2
Taiyo Yuden
JMK212BJ226MG-T
CAP CER 22UF 6.3V
20% X5R 0805
Digikey
587-1305-2-ND
1
0.056
U1
Texas Instruments
TPS62172
BUCK CONVERTER 317V 0.5A 2.5MHZ
Mouser
595-TPS62172DSGT
1
1.410
System Converter simulation
Steady Input
Current(A)
Steady Output
Current(A)
Steady Output
Voltage(V)
0.352662
0.200006
3.3001
Both input / output current and output voltage become stable after 300 µs.
Vary input voltages to 5V, 6V and 7V, output voltages stay the same at 3.3V.
USB Converter
Input: 5V to 7V, to account for and voltage fluctuations from the MPPT and the full discharge level of the
battery.
Output: 5V +/- 5% per USB specifications, the output current will be 700mA max to allow for a maximum
draw of 500ma for the USB, and an additional 200mA draw for the analog circuitry.
Ref Manufacturer
Manufacturer PN
Description
Distributer Distributer PN Quantity Price per 1k
C1
TDK
CGJ4J2X7R1C104K CAP CER 0.1UF 16V 10% X7R 0805 Digikey 445-8183-1-ND
1
0.044
C6,7
Kemet
C0805C105K4RACTU CAP CER 1UF 16V 10% X7R 0805
Digikey 399-1284-1-ND
2
0.024
C3,4,5
TDK
C3216X5R1C106M CAP CER 10UF 16V 20% X5R 1206
Digikey 445-1426-1-ND
3
0.078
IHLP1212BZER1R0M1
L1
Vishay-Dale
INDUCTOR POWER 1.0UH 5A SMD Digikey 541-1319-1-ND
1
0.648
1
541-100KECTR1
Vishay-Dale CRCW1206100KJNEA RES 100K OHM 1/4W 5% 1206 SMD Digikey
1
0.019
ND
296-29937-1U1
TI
TPS62133
IC BUCK SYNC 5V 3A 16QFN
Digikey
1
2.85
ND
USB Operation at Nominal Input and 1A Output
The input current (above) and output voltage and current (below) with a 6V input
and a load current of 1A.
Output Behavior With A Varying Input
The output voltage and current with an input voltage of 5V, 6V, and 7V.
Enclosure Concept
Enclosure Concept
Top View
Side View
Electrical Test Plans
System
Test
Ideal Value
Tolerance
Test Method
MPPT
Output Voltage
6.5V
.1V
Use multimeter to test output pins of the MPPT circuitry
Charged Voltage
6.5V
0.1V
Use multimeter to test the positive and negative terminal
Discharged Voltage
5.1V
0.1V
Use multimeter to test the positive and negative terminal
Output Voltage
12V
0.5V
Use multimeter to test output terminals of the fan
Output Current With a
100Ω Load
0.07A
0.01A
Connect multimeter in series with fan to test current
Output Voltage
3.3V
0.01V
Use multimeter to test output pins of the system converter
circuitry
0.2A
0.03A
Connect multimeter in series with system load to test current
Output Voltage
5V
0.1V
Use multimeter to test output terminals of the USB
Output Current With a 10Ω
Load
0.7A
0.05A
Connect multimeter in series with USB to test current
Battery
Fan
System
Converter Output Current With a 10Ω
Load
USB
Mechanical Test Plans
Test
Description
Drop
Completed system will be dropped 20
times from a height of 2 meters onto a
hard surface (pavement)
20 drops
Crush
Completed system will be stepped on
by a member of the design team,
placing a force of approximately 5 psi
on the system. System will be located
on hard surface for this test.
Rain
Completed system will be placed in a
shower for 2 hours
Completed system will be placed in an
Humidity enclosure with above 90% humidity for
5 hours
Ideal Value Marginal Value
Equipment
Test Method
2 drops
Completed system, pavement,
meter stick
Pass/Fail
5 psi
2 psi
Completed system, pavement,
member of design team
Pass/Fail
2 hours
1 hour
Completed system, shower,
stopwatch
Pass/Fail
1 hour
Completed system, enclosed
area, humidifier, humidity
measurement system,
stopwatch
Pass/Fail
5 hours
Sample Test Document
1.What is being tested and why
2.Equipment
1. List of required equipment
2. The settings of the required equipment
3.Procedure
1. What is being measured?
2. How is it being measured?
4.Result table
1. Step number
2. What is being measured?
3. What is the expected value?
4. What is the measured value?
5.Pass/Fail and why
1. Did the device pass the test?
2. Defend the decision.
ID
1
2
3
4
5
6
Risk Item
Effect
Cause
Likelihood Severity Importance Action to Minimize Risk Owner
Minimize the amount of
Other features Component
components.
Exceeding
of the end
cost.
3
3
9
Increase the
Xiaolong
target cost per product may be Manufacturing
functionality of existing
unit.
not included.
cost.
components
P12442 does
Not enough
Insufficient
3
3
9
Effectively communicate Colin
not provide power, features communication
with P12442 over
sufficient
must be
between teams
generated temperature
temperature sacrificed, poor
difference.
difference
functionality
Unable to
The MPPT will Inexperience,
2
3
6
Community support,
Lauren
program
not be able to
difficulty,
professor and professional and Colin
microcontroller
provide
hardware
assistance
maximum power complications.
Unit will not
have full
Device requires
Poor design and
functionality.
too much
component
Unstable
power.
selection.
behavior when
operated.
The project will
Poor design
Device fails to
not be
Poor project
operate.
completed.
planning,
Poor planning,
Less time for dePrototype
complex
bugging, failure
construction
system. Unfore
to deliver on
time
seen
time
circumstances
2
3
6
2
3
6
2
3
6
Design to be as power
efficient as possible.
Utilize MPPT functions.
Using the uC as much as
possible.
Have at least weekly
design meetings. Choose
high efficiency parts.
Strict scheduling
milestones, effective and
reachable deadlines,
component delivery time,
ordering parts early
enough
Importance Scale: 1 - Low, 2 - Moderate, 3 - High
Andrew
Lauren
Colin
Risks 7-11
ID
7
8
9
10
11
Risk Item
Effect
Cause
Likelihood Severity Importance Action to Minimize Risk
Owner
Stove will take
Component
System cannot longer to heat up
Design the unit to
failure. Bug in
power fan
and longer for
operate on battery
the uC
2
3
6
Andrew
during "warm
the TEG to
power. Ensure the uC
code. Poor
up"
provide full
operates correctly
design.
power.
Difficult to be
Going over
Track spending
able to fund
development
Poor planning
1
3
3
Ordering correct parts
Xiaolong
further
budget.
Proper testing.
development.
Decreased
Battery
Inexperience in
battery lifetime,
Professor and
Xiaolong and
charging
the area, poor
2
3
6
system does not
professional assistance
Andrew
difficulties
design
operate properly
Sell less units
Complexity of
Improper use
Minimize user interaction.
Poor Design
1
3
3
Colin
operation
Reduce system
Make simple to operate.
lifetime
Fewer sales.
Poor part
Design the unit to be as
Decreased
Unit will get
selection.
robust as possible.
1
3
3
Lauren
reliability
damaged more Poor fabrication.
Choose high-lifetime
often.
Poor design.
components.
Project Plan
Questions or Comments?