Transcript EE595_Team2_P3_Fall07

TEAM 2
Project
• DC servo motor controller applied to a
trolling motor application.
– Features include a high efficiency motor
control, water temperature sensor, and a
battery charge level indicator.
1
Expertise & Experience
•
Dan Drews
•
Expertise: Microprocessors, Power Electronics
Experience: None
•
Wayne Stollenwerk
•
Expertise: Electronics, Power Supply
Experience: Co-op, Test Engineering,
Documentation
•
Bhavi Mistry
•
Expertise: Signals & Systems, Analog Circuits
Experience: None
•
Anthony Camomilli
•
Expertise: Solid-state Electronics, Short Circuit
Protection, Documentation/Schematics,
Component Selection/Cost Analysis
Experience: Engineering Intern, Electrical
Designer
2
Project Team Roles
•
•
•
•
•
LPI :
LSD:
LPM:
LRM:
LMM:
Dan Drews
Wayne Stollenwerk
Anthony Camomilli
Anthony Camomilli
Bhavi Mistry
3
Decision Making
• Project decisions shall be made in
consensus
• Majority vote with due compromise will
be used to decide disagreements.
4
Total Resources
17.5 hrs/week
Lab meetings
17.5 hrs/week
Team meetings
30.0 hrs/week
Individual contribution
Total number of hours contributed by the team is 65hrs/week
• Estimated cost for the proposed Project is $ 300
• However the design cost may vary towards the completion of the project.
5
Gantt Chart
SEPT
OCT
NOV
DEC
4 11 18 25 2 9 16 23 30 6 13 20 27 4 11 13
Planning
Prod. Design
Proc. Design
Validation
Feedback
6
Proposed Product Summary
•
DC Servo Motor Controller
– 2hp variable speed brushless
servo motor
with 12VDC supply
– Safe design, with intuitive user
inputs
– Applied as a trolling motor
– Economical
– Secondary motor for use in
shallow areas or where quite
operation is preferred
– Environmentally friendly
– Similar to other products on the
market
– Designed for the Consumer
Market
7
Project Selection
• Overall Selection Process
– This project is supported best by the abilities of all
team members
– Risks include low margins, competitive market
– Other projects fell outside the scope of this class
as well as requirements for special parts requiring
long lead time
– Unanimously supported by all team members
8
System Level Requirements
• Performance Requirements:
• High efficiency (>85%)
• Extended lifetime (5+ years)
• Power Modes will be ON/OFF,
Forward/Reverse
• Basic Mechanical capabilities will be
speed control.
9
System Level Requirements
Standard Requirements
•
•
•
•
•
•
Energy source will be 12V Battery Operating
Temperature range: 5 – 45 °C
Storage Temperature range: -55 – 125 °C
Operating voltage range: 10.2 – 14.0V
U.S. Market (Low Budget Consumer)
Max Power Consumption: 740 Watts
10
Business case
(estimated values)
• Average selling price
 $225
• Annual sales volume
 150,000 Units
• Per unit cost of parts
 $125
• Per unit cost of assembly, test & manufacturing
 $50
• Total development cost
 $100,000
11
Usable Battery Life
Usable Battery Voltage Range
120
100
% Charge
80
60
40
20
0
12.73
12.62
12.5
12.37
12.24
12.1
11.96
11.81
11.66
11.51
Nominal Voltage
Operating Voltage Range Based on (+/- 10%)
12
Block Diagram
12V Battery
User Input/Display
PWM 3
(Dan)
2
Battery Sensor
(Bhavi)
4
H-Bridge
Temp Sensor
w/ display
1
(Anthony)
(Wayne)
Motor
13
Block Diagram Descriptions
Block
#
Block Name
Owner
2
Battery sensor
Bhavi
3
PWM
4
5
Brief Description
Of Block Function
Power
Interfac
es
Digital
Interfaces
Analog
Interface
s
Control, charge and
sense the battery.
Other details not yet
decided.
In:
12VDC
Out: LED
Array
None
Dan
Supplies H-Bridge with
adjustable duty cycle
square wave
In:
12VDC
In: Pot.
Out: square
wave
None
H-Bridge
Wayne
H-Bridge will boost
power of PWM signal
and deliver to the
motor, includes shootthrough protection
In:
12VDC
In: PWM
signal
Out: Motor
Driver
None
Temp. Sensor
w/ display
Anthony
Measures and displays
accurate temp
In:
12VDC
Out: LCD
Display for
Temp
None
14
Ethics Considerations
– Quality and Safety
• We will design our trolling motor out of RoHS
compliant materials and provide documentation
as to safe operation of the device
– Ensuring legal compliance
• We will conform to national safety standards
that govern the electrical safety for aquatic
machinery
15
Ethics Considerations
– Quality and Safety
• We will use UL listed components
– Adequate Verification and Validation
• We will have our data independently verified by another team member
– Ensuring legal compliance
• We will research prior patents and compliance with current safety
standards
– Conflict of interest
• Not applicable
– Treatment of confidential or proprietary information
• Not applicable
– Environmental Damage
• We will use ROHS compliant devices
– Outside employment/business activities
• We will complete all work internally
16
Ethics & Intellectual Property
•
United States Patent 6,276,975
– Trolling motor battery gauge
– August 21, 2001
•
United States Patent 5,254,932
– Charging voltage control circuit for battery chargers
– October 19, 1993
•
United States Patent 6,377,012
– Servo system controller
– April 23, 2002
•
Mitigation Strategy
– It will be necessary to carefully examine the patent’s asserted claims, and
specifically target the language and structure of those claims.
17
Safety Hazards and
Mitigations
18
Safety Test Standards Used in DC
Motor Controlers
• UL 1004
(Safety Standard Electric Motors)
• EN 60204-1
(Safety of machinery –Electrical equipment of
machines)
• EN 60529
(Degree of protection provided by enclosures
(IP-Code)
19
Unsafe Single Point/Device
Failures
• Mitigation Design/Devices/Materials/Packaging
– Logic control
– Fusing the devices
• Affected Blocks
– H-Bridge
• Tests Required to Verify Protection
– Logic Testing
– Torture Test
20
Burns from Hot, Touchable
Surfaces
• Mitigation
Design/Devices/Materials/Packaging
– Insulated electrical enclosure
• Affected Blocks
– None
• Tests Required to Verify Protection
– Simple Heat Measurements during lab
21
Electric Shock
• Mitigation
Design/Devices/Materials/Packaging
– Insulated water-proof materials, fusing
• Affected Blocks
– Battery charger, Motor
• Tests Required to Verify Protection
– Ground Fault Test
22
Fire, Explosion or Shattering
• Mitigation
Design/Devices/Materials/Packaging
- Reverse voltage protection and fusing
• Affected Blocks
– All the blocks
• Tests Required to Verify Protection
– Short circuit Test
23
Abusive Or Unknowing Users
• Mitigation
Design/Devices/Materials/Packaging
– Warning Labels
• Affected Blocks
– Battery Charger, Battery, Motor
• Tests Required to Verify Protection
– Precautionary Test
24
EMC Hazards and Mitigation
25
EMC Standard Tests Used in DC
Motor Controllers
• IEC:6100-4-2: ESD Immunity
• IEC:6100-4-3: Radiated Radio Frequency Immunity
• CISPR-11: Limits and Methods of Measurement of
Electromagnetic Disturbance Characteristics of
Industrial, Equipment
• IEC:6100-4-6: Conducted Radio Frequency Immunity
• IEC:6100-4-9: Pulsed Magnetic Field Immunity
26
Electro-Static Discharge
• Mitigation
Design/Devices/Materials/Packaging
– Shielding. Insulation and Passive Line Protection
• Affected Blocks
– All
• Tests Required to Verify Protection
– ESD testing at touch points
27
Magnetic Field Energy
• Mitigation
Design/Devices/Materials/Packaging
– Shielded Wire
• Affected Blocks
– H-Bridge, Servomotor
• Tests Required to Verify Protection
– Test for Radio-active and conductive Noise
28
RF Electric Field Energy
• Mitigation
Design/Devices/Materials/Packaging
– Component selection
• Affected Blocks
– The temperature displayer
• Tests Required to Verify Protection
– Verifying component certification like UL listings
29
Interference with Other
Electronic Systems
• Mitigation
Design/Devices/Materials/Packaging
– Minimize circuit paths to prevent loops
– Proper Shielding
• Affected Blocks
– H-Bridge, PWM and Battery charger circuit
• Tests Required to Verify Protection
– Secured lab testing
30
Product Level Design
31
Block Prototyping Plan
Block
Name
Block
Area
(cm2)
Located
on Board
#
(1, 2, ..
etc)
Board
Substrate
Type
Comp
Attachment
Type
Board
Types of
Dimensio Connect
ns
ors
(cm x cm)
Battery
Indicator
3.5 cm2
1
PC Board
Through Hole
10 cm2
Soldered
Wires
PWM
6.3 cm2
2
PC Board
Through Hole
7.8 x 7.0
88.98 cm2
Soldered
Wires
H-Bridge
29.3 cm2
2
PC Board
Through Hole
7.8 x 7.0
88.98 cm2
Soldered
Wires
Temp
Sensor
55 cm2
3
PC Board
Through Hole
7.62x5.08
38.7 cm2
Soldered
Wires
32
Individual Block Detail
33
Temp sensor and display
34
Block 1 Description and Purpose
• Block 5 consists of a temperature sensing
circuit and a user display.
• It is intended that this should allow the user to
choose a more ideal location for fishing.
• Operates independent of other blocks
35
Block 1 Performance
Requirements
• Low power consumption (<5 watts)
• Limited power available
• Heat dissipation
• Temperature sensing accuracy (+/- 1°)
• 12VDC Input
• Small Footprint
• User Display
36
Block 1 Standards Requirements
Standard Requirements
•
•
•
•
•
Energy source will be 12V Battery
Operating Temperature range: 5 – 45 °C
Storage Temperature range: -55 – 125 °C
Minimum operating voltage range: 10.2 – 14.0V
U.S. Market (Low Budget Consumer)
37
Block 1 Diagram Breakdown
12V Battery
User Input/Display
PWM 3
(Dan)
2
Battery Sensor
(Bhavi)
4
H-Bridge
Temp Sensor
w/ display
1
(Anthony)
(Wayne)
Motor
38
Block 1 Diagram Breakdown
12V Battery
Voltage Regulator
Regulated 9VDC
Full Scale Reference
Dual Slope Converter Scaling
LCD Driver
Sensor
Oscillator
User Input/Display
LCD
Auto-Zero Cycle
39
Block 1 Preliminary Schematic
40
Block 1 Theory of Operation
• The basic theory of operation for block 5 is simple
– The LM34 outputs a analog signal that varies by 10mV / °F
– That signal is captured by the 7106
– The 7106 measures the input, stores the input, and sends this
value out to the LCD display
– It will then repeat this process based on the internal clock
– As an option you can have the 7106 zero the inputs before each
measurement
41
Block 1 Component Selection:
The 7106
42
Block 1 Component Selection Cont.
• The 7106 is a direct drive LCD driver with integrated
differential inputs
–
–
–
–
No current limiting required for LCD to function
Allows for direct sensor input
Reduced IC count and wide operating range
Requires External Oscillator for Clock
• A 48kHz clock can be created using a 100K resistor and a 100pF Cap
• LCD backplane Is driven at 1/800 clock or ~60Hz
– Requires Range Specific components for Dual Slope Conversion
– Auto Zero Cycle allows for offset voltage error correction on inputs
• Works similar to a sample and hold circuit
– Voltage scaling accommodated by reference voltage input
• 100mV => 199.9 (200 mV full scale)
• 1V
=> 1.999 (2V full scale)
43
Block 1 Component Selection Cont.
• The temperature sensing is accomplished by
collecting the output of a LM34 Fahrenheit
sensor
– Easily Measured 10 mV/°F
– Sensitive (+/- 1°F) Can be compensated for greater
Accuracy
– Expensive $5-$12
• All resistors and capacitors that are task important
will require 5% tolerance or better
44
Block 1 Preliminary Bill of
Materials
Cost
BOM ITEM
Item
Qty
ITEM DESCRIPTION
1
TC7106
1
IC ADC 3 1/2DGT LCD DVR 40-DIP
2
LCD 3.5 DIGIT
1
LCD 3.5 DIGIT .50" REFLECTIVE TN
3
.1uF CAP
1
CAP .1uF 50V 5% CER RADIAL
4
.47 uF CAP
1
CAP .47uF 50V 5% CER RADIAL
5
.22uF CAP
1
CAP .22 uF 50V 5% CER RADIAL
6
Temp Sensor
1
LM34 temp Sensor
7
Voltage Regulator
1
LM2940 Voltage Regulator
8
100pF Cap
1
CAP 100pF 50V 5% CER RADIAL
$0.08
9
.02 uF CAP
1
CAP .02 uF 50V 10% CER RADIAL
$0.05
10
24k Resistor
1
RES METAL FILM 160K OHM 1/4W 5%
$0.11
11
47k Resistor
1
RES METAL FILM 160K OHM 1/4W 5%
$0.09
12
100k Resistor
1
RES METAL FILM 160K OHM 1/4W 5%
$0.07
13
1k Resistor
1
RES METAL FILM 160K OHM 1/4W 5%
$0.11
14
1M Resistor
1
RES METAL FILM 160K OHM 1/4W 5%
$0.18
$4.50
$3.78
$0.14
$0.12
$0.13
$5.92
$1.82
Total:
$17.10
45
Block 1 Prototype PCB Layout
46
Block 1 Prototype PCB Cost
47
Block 1 Prototype (Actual)
Bread Board Prototype
PCB Prototype
48
Block 1
Detailed Package Selection
• Device Package Type Rationale
• Package for LM2940 (T0-220) was determined by cost, ease of
prototype, heat disipation, and availability
• Package for LM34 (T0-92) was determined by size since it needs to be
compact enough to be fitted to a small metal cap for production
• Package for 7106 (DIP 40 Pin), was selected for pure ease of use, easy
to solder with fair room to work
• Nominal Resistance, Capacitance, Inductance
Values & % Tolerance Calculations
• Capacitor values chosen at 5% to reduce error in 7106 timing
• Resistors chosen at 5% to reduce part count between blocks
• 1% resistor values would decrease error in critical applications
49
Block 1 Proposed Production BOM
Generic Part Name
PCB Attach
# of Pins
Placement-Solder
Area mm2 PCB
$Cost Each
TC7106
SMT
44
Fully Automatic
200
$4.50
LCD 3.5 DIGIT
SMT
40
Fully Automatic
350
$3.78
.1uF CAP
SMT
2
Fully Automatic
0.08
$0.16
.47 uF CAP
SMT
2
Fully Automatic
0.08
$0.18
.22uF CAP
SMT
2
Fully Automatic
0.08
$0.16
Temp Sensor
Wire Leads
3
Man Insert - Man Solder
0
$5.92
Voltage Regulator
SMT
3
Fully Automatic
16
$1.82
100pF Cap
SMT
2
Fully Automatic
0.08
$0.12
.02 uF CAP
SMT
2
Fully Automatic
0.08
$0.05
24k Resistor
SMT
2
Fully Automatic
0.08
$0.11
47k Resistor
SMT
2
Fully Automatic
0.08
$0.18
100k Resistor
SMT
2
Fully Automatic
0.08
$0.38
1k Resistor
SMT
2
Fully Automatic
0.08
$0.25
1M Resistor
SMT
2
Fully Automatic
0.08
$0.85
566.8
$18.46
Totals
50
Block 1 Production Component
Package and Rational
• 44 pin square style surface mount leaves more room for
signal routing
• T0-92 for the LM34 is off the board and would be more
difficult to work with if it was surface mount
• T0-263 works fine for me with out additional cooling
because of the low current requirements of my block
• Capacitors
– 0603(1U) 0805(.1U) size & cost
• Resistors
– Thick Film Surface mount Resistors chosen for their high
resistance ranges and fair accuracy
51
Battery Charge Indicator
52
Block 2 Description and Purpose
•
Block 2 is a Battery Sensor circuit which consists of a Voltage Detector circuit
and Temperature sensor
•
It is connected to Battery charger circuit and Battery
•
It is an important block because it senses when the battery should begin
charging at different voltage levels.
•
The block also has a temperature sensor which senses the overheating of the
battery while its operation.
•
The block uses 4 Opamps and the combination of resistors and Led’s circuitry
for efficient operation
53
Block 2 Performance Requirements
•
•
•
•
•
Battery chemistry: Lead acid
Battery capacity: 12V, 70A
Switch Type: Push, On/Off
Sensory: Temperature sensor LM35 (+/- 1°C)
Modified circuit uses Zener diode to fix the voltage at
reference level voltage.
54
Block 2 Standard Requirements
• Energy source: 12V Battery
• Minimum Operating temperature Range: -30 to +150
degree Celsius
• Operating Voltage Range 10.2v to 14V
• Manufacturing Cost $ 5.00/unit
• US Market (Low Budget Customer)
55
Block 2 Standard Requirements
• The discrete steps for the voltage operation is as shown
below in the table:
Battery
voltage
Red Led
Green
Led
Yellow
Led
Orange
Led
Comment
<9.8 V
OFF
OFF
OFF
OFF
Buzzer off
>9.8 V
ON
OFF
OFF
OFF
Danger
level
11.5 V
ON
ON
OFF
OFF
Low level
12.0 V
ON
ON
ON
OFF
Normal
level
12.5 V
ON
ON
ON
ON
High level
56
Block 2 Diagram Breakdown
12V Battery
User Input/Display
PWM 3
(Dan)
2
Battery Sensor
(Bhavi)
4
H-Bridge
Temp Sensor
w/ display
1
(Anthony)
(Wayne)
Motor
57
Block 2 Diagram Breakdown
12V Battery
Voltage
reference
Switch
4 Comparators
Voltage
dividers
User Input/Display
(4 LED’s representing percent charge 100, 75, 50, 25)
58
Block 2 Theory Of Operation
• Battery sensor circuit consists of Voltage detector circuit which
uses 4 Op-amps combined in a package of IC 324
• The non-inverting terminals are connected to the potential
divider chain consisting of resistors
• A reference voltage is set at 5V using Zener diode
• When the circuit is connected to the battery, the battery voltage
will be sampled by the detector circuit and depending on the
voltage levels at the output Led’s will be on
59
Block 3 Preliminary Schematic
60
Preliminary Bill of Materials
61
Block 2 Bill of Materials
•
•
•
•
IC 324 - $0.33/unit
Led’s- $1.00/4 units for 3mm
Zener diode-$ 0.19/unit
Total cost $ 5.00
62
Block 2 Theory Of Operation
• Battery sensor circuit consists of Voltage detector circuit which
uses 4 Op-amps combined in a package of IC LM324
• The non-inverting terminals are connected to the potential
divider chain consisting of resistors
• A reference voltage is set at 5V using Zener diode
• When the circuit is connected to the battery, the battery voltage
will be sampled by the detector circuit and depending on the
voltage levels at the output Led’s will be on
63
Block 2 Proposed Production BOM
Generic Part
Name
Resistors
QTY
PCB
Attach
10 TH
# of
Pins
Packag
e
20 Axial
Area mm2
PCB
$Cost
Each
Man-Insert Man
solder
25
$0.15
Man-insert Auto
solder
20
$1.86
PlacementSolder
Led
4 TH
On/Off
Switch
1 SMT
Fully Automatic
15
$1.36
Push Switch
1 SMT
Fully Automatic
20
$6.59
Peizo Buzzer
1 SMT
Fully Automatic
10
$1.02
1 TH
Man-insert auto
solder
10
$0.04
100
$17.95
Zener diode
8 Radial
2 Axial
Total
64
Block 2 PCB Layout
65
Block 2 Prototype Cost
66
PWM
67
Block 3 Description and Purpose
• Block 3 contains the PWM (pulse width modulation) control for the
motor. Using op-amps a triangle wave generator and a
comparator can be designed to a specific frequency, in this case
24kHz, and a 12V pulse width modulated signal can be produced.
The requirements for this output as set by Block 4. Block 4
requires an absolute minimum current of 10 A and the low
voltage needs to be below 0.8V.
• Texas Instruments produces a PWM solenoid driver that will
accomplish the task of this block while meeting the standard and
performance requirements.
68
Block 3 Performance
Requirements
• PWM signal is designed for:
•
•
•
•
Supply Voltage between 10-14.7V
24kHz so no audible noise is generated during switching.
Output low is below 0.8V and output high is above 5V.
Must supply at least |10A| of current to the FET drivers.
69
Block 3 Standards Requirements
Standard Requirements
•
•
•
•
•
Energy source will be 12V Battery Operating
Operating Temperature range: 5 – 45 °C
Storage Temperature range: -55 – 125 °C
Minimum operating voltage range: 10 – 14.7V
U.S. Market (Low Budget Consumer)
70
Block 3 Diagram Breakdown
12V Battery
User Input/Display
PWM 3
(Dan)
2
Battery Sensor
(Bhavi)
4
H-Bridge
Temp Sensor
w/ display
1
(Anthony)
(Wayne)
Motor
71
Block 3 Diagram Breakdown
4
User Input/Display
12V Battery
H-Bridge
(Wayne)
PWM Signal
Potentiometer
Voltage Divider
Comparator
Square Wave
Oscillator
Integrator
72
Block 3 Preliminary schematic
73
Block 3 Simulation
74
Block 3 Preliminary Bill of
Materials
•
•
•
•
1
1
9
4
• 1
• 1
• 1
LM324 OP-Amp
Potentiometer
Resistors
Capacitors
$0.45 (block of 4)
$4.50 per unit
$0.15 per unit
$0.20 per unit (avg)
Texas Instrument DRV103U
Potentiometer
Capacitor
$3.60 per unit
$4.50 per unit
$0.13 per unit
• Totals:
$9.98 Discrete Design
$8.32 IC Design
75
Block 3 Prototype PCB Layout
76
Block 3 Proposed Production BOM
Generic Part Name
QTY
PCB Attach
# of Pins
Package
Area mm2 PCB
Placement-Solder
$Cost Each
Op-Amp
3
SMT
8
SOIC
Fully Automatic
151.94
$2.15
Resistor
3
SMT
2
TO-220
Fully Automatic
5.12
0.00855
Resistor
1
SMT
2
TO-220
Fully Automatic
5.12
0.00855
Resistor
1
SMT
2
TO-220
Fully Automatic
5.12
0.00855
Resistor
2
SMT
2
TO-220
Fully Automatic
5.12
0.00855
Resistor
1
SMT
2
TO-220
Fully Automatic
5.12
0.00855
Potentiometer
1
SMT
3
Mate-N-Lock
Man Insert - Man Solder
1110.21
$1.84
Capacitor
2
SMT
2
Radial
Man Insert - Auto Solder
73.44
$0.21
Zener Diode
2
SMT
2
SOD-323
Fully Automatic
2.43
0.07
1361
8.78
Total
77
H-Bridge
78
Block 4 Description and Purpose
• Power supply for the DC servo motor (trolling motor)
• Capability to to spin the motor in forward or reverse
direction
• Utilize PWM on the power return
• Two n-channel mosfets are used to control the PWM
• One mosfet for forward one for reverse
• PWM signal supplied by block 3
• Three way switch turns on the fet drivers and power
relays.
79
Block 4 Performance
Requirements
• Original design requirement to supply 0 - 40 amps to the
to the trolling motor by PWM at 20KHZ
• Modified design After testing for locked rotor current 0 –
53 amps.
• Original configuration was h-bridge with 2 p-channel
mosfets and 2 n-channel mosfets
• Modified design replaces p-channel mosfets with power
relays and shunt diodes to reduce power loss and
generate less heat
• Design required to accept input at 5V logic or battery
level logic for PWM input signal
80
Block 4 Standards Requirements
Standard Requirements
•
•
•
•
•
Energy source will be 12V Battery Operating
Operating Temperature range: 5 – 45 °C
Storage Temperature range: -55 – 125 °C
Minimum operating voltage range: 10.2 – 14.0V
U.S. Market (Low Budget Consumer)
81
Presentation P2
Block 4 Diagram Breakdown
12V Battery
User Input/Display
PWM 3
(Dan)
2
Battery Sensor
(Bhavi)
4
H-Bridge
Temp Sensor
w/ display
1
(Anthony)
(Wayne)
Motor
82
Presentation P2
Block 4 Diagram Breakdown
12V Battery
Forward position
Three way switch
On
off
On
Forward power relay
Reverse position
Reverse power relay
Motor
Forward n mosfet
Reverse n mosfet
Forward mosfet driver
3
Reverse n-channel mosfet
PWM
(Dan)
83
Block 4 Theory of Operation
• The basic theory of operation for block 5 is as follows
– The three way switch controls forward, reverse, or off
– In the forward position the switch turns on the forward relay and
forward n-channel fet driver, turns off the reverse relay and reverse
n-channel fet driver
– The forward fet driver now accepts a pwm from block 3 while the
the reverse fet driver is off
– The forward fet driver drives the motor forward by applying a pwm
signal to the forward n-channel fet (power return line)
– The larger the duty cycle the more power is applied to the motor
– The same operation applies to reverse
– When the switch is off no power is applied
84
Block 4 Preliminary schematic
85
Block 4 Preliminary current
simulation PWM at 1% duty cycle
86
Block 4 Preliminary current simulation
PWM at 50% duty cycle
87
Block 4 Preliminary current simulation
PWM at 99% duty cycle
88
Block 4 PWM Simulation
waveforms
89
Block 4 PWM Simulation
waveforms
90
Block 4 PWM Simulation
waveforms
91
Block 4 Preliminary schematic
with back emf
92
Block 4 Preliminary current simulation
PWM at 99% duty cycle, back emf added to simulate
normal operating max current conditions
93
Block 4 Preliminary Bill of
Materials
•
•
•
•
•
•
•
•
•
•
1
3-way 15VDC 1Amp switch $1 per unit
2
shunt diodes 200V 10Amp
(t0-220) $0.78 per unit
2
Power relays 12V 70Amp
$5.34 per unit
2
n-channel mosfets 55V 80Amp
(T0-220) $1.52 per unit
2
Fet drivers (6A low side)
(SOIC) $1.24 per unit
2
1UF ceramic monolithic capacitors for fet drivers $0.10 per unit
2
.1UF ceramic monolithic capacitors for fet drivers $0.10 per unit
1
pcb $5.00 per unit
1
heat sink for fets
$1 per unit
Total cost $25.50
94
Block 4 Prototype PCB Layout
95
Block 4 Prototype PCB Cost
96
Block 4 Prototype (Actual)
97
Block 4 Additional Detail
Detailed Design Calculations & Component Selections
• Device Package Type Rationale
• Package for n-mosfet (T0-220) was determined by cost, ease of prototype,
heat sinkability, and availability
• Package for power relays was determined by size, cost, and availability
• Package for fet drivers was determined by cost and availability
• Package for Diodes was determined by cost and availability
• Nominal Resistance, Capacitance, Inductance Values & % Tolerance Calculations
• All values determined by component data
• Resistor Compositions, Capacitor Dielectric, Inductor Winding; Selection Rationale
• Capacitors choosen by low esr category
98
Block 4 Additional Detail
(cont)
• Resistor, Capacitor, Inductor, Diode, Transistor & IC Max Voltage Calculations
• Max voltages based on component data and assigned max battery voltage of
14.0V
• Resistor, Inductor, Transistor, Diode, Xfmr, & IC Max Power Calculations
• Max power based on measured current and Max Battery voltage
(53A*14.0V)=740W
• Max power of n-channel fets based on rdson .0065*53*53 = 18.25W
• Power Electronics Heat Sink qj Calculations and Max Die Temp Rise Above Ambient
• Calculations based on data sheet
•
Wire Gauges, Interconnect Contact, & Trace Width Ratings
• 8AWG based on 53Arms for operated
99
Block 4 Proposed Production BOM
Generic Part Name
Three way Switch
p-channel mosfet
n-channel mosfet
Fet Drivers
Capacitor
Capacitor
Thermal clad board
PCB Attach # of Pins
Wire Leads
3
SMT
3
SMT
3
SMT
8
SMT
2
SMT
2
Area mm 2 PCB $Cost Each $Cost Total
Placement-Solder
Man Insert - Man Solder
$1.00
$1.00
D2 Pak
Fully Automatic
166
$1.53
$3.06
D2 Pak
Fully Automatic
166
$1.07
$2.14
SOP
Fully Automatic
31
$0.07
$0.29
0603
Fully Automatic
1.53
$0.01
$0.06
0805 (2012) Fully Automatic
2.835
$0.05
$0.20
Total
367.365
Total
$6.75
Package
100
Block 4 Production Component
Package and Rational
• N-channel and P-channel mosfet
– D2 PAK power rating, size, cost, smt. availability
• Mosfet Driver
– SOP size, cost, smt availability
• Capacitors
– 0603(1U) 0805(.1U) size, cost, availability
• Thermal Clad Board
– heat transfer ratings lower than .5degrees C per
watt
101
Product Mfg. Process Design
102
Block Consolidation for
Production Boards
• For production
– Blocks 2 & 5 on one board
– Blocks 3 & 4 on one board
• This will give us a separation of heat
and a separation of High Power and
Low power Circuitry
103
PCB Assembly Process
PCB and Thermoclad
Fabrication
Etch PCB design
To board
Drill mounting holes
Screen print
Visual inspection
Clean and prepare
board for assembly
Automatic
Component
Placement
Apply Solder paste
Visual inspection
Oven
Reflow Solder
X-ray inspection
Stress screen
Functional test
Wash
In Circuit test
Pack and ship Product
104
Overall Master BOM
Generic Part Name
Resistors
QTY
PCB Attach
# of Pins
10
TH
20
Light Emitting Diode
4
TH
8
ON/OFF Switch
1
Push Switch
Package
Placement-Solder
Area mm2 PCB
$Cost Each
Axial
Man Insert - Man Solder
$0.15
Radial
Man Insert - Auto Solder
$1.86
SMT
Fully Automatic
$1.36
1
SMT
Fully Automatic
$6.59
Piezo Buzzer
1
SMT
Fully Automatic
$1.02
Zener Diode
1
TH
$0.04
Op-Amp
1
Resistor
2
Axial
Man Insert - Auto Solder
SMT
14
SOP
Fully Automatic
151.94
$2.19
2
SMT
2
TO-220
Fully Automatic
5.12
0.00855
Resistor
1
SMT
2
TO-220
Fully Automatic
5.12
0.00855
Resistor
2
SMT
2
TO-220
Fully Automatic
5.12
0.00855
105
Overall Master BOM cont.
Generic Part Name
QTY
PCB Attach
# of Pins
Package
Placement-Solder
Area mm2 PCB
$Cost Each
Resistor
1
SMT
2
TO-220
Fully Automatic
5.12
0.00855
Potentiometer
1
SMT
2
TO-220
Fully Automatic
1110.21
$21.00
Capacitor
1
SMT
2
Fully Automatic
73.44
$0.43
Three way Switch
1
Wire Leads
3
Man Insert - Man Solder
p-channel mosfet
2
SMT
3
D2 Pak
Fully Automatic
166
$1.53
n-channel mosfet
2
SMT
3
D2 Pak
Fully Automatic
166
$1.07
Fet Drivers
4
SMT
8
SOP
Fully Automatic
31
$0.07
Capacitor
4
SMT
2
0603
Fully Automatic
1.53
$0.01
$1.00
shunt diode
Power relay
106
Overall Master BOM cont.
Generic Part Name
Capacitor
QTY
PCB Attach
4
PCB
Thermal clad board
SMT
# of Pins
2
Package
0805 (2012)
SMT
Placement-Solder
Fully Automatic
Area mm2 PCB
$Cost Each
2.835
$0.05
Fully Automatic
1
Heat sink
TC7106
1
SMT
44
QFP
Fully Automatic
200
$4.50
LCD 3.5 DIGIT
1
SMT
40
QFP
Fully Automatic
350
$3.78
.1uF CAP
1
SMT
2
Fully Automatic
0.08
$0.16
.47 uF CAP
1
SMT
2
Fully Automatic
0.08
$0.18
22uF CAP
1
SMT
2
Fully Automatic
0.08
$0.16
Temp Sensor
1
Wire Leads
3
Man Insert - Man Solder
0
$5.92
Voltage Regulator
1
SMT
3
Fully Automatic
16
$1.82
2290
$64.88
Totals
107
Thank You for Your Time
108