Transcript Battery Charging Circuit Options

Wireless Test Instrumentation for
Rotating Parts
ECE 193 Advisor: Rajeev Bansal
Olivia Bonner
David Vold
Brendon Rusch
Michael Grogan
ME 32 Advisor: Robert Gao
Kyle Lindell
Andrew Potrepka
Outline
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Problem Statement
Solution
Parts Ordered
Parts To Be Ordered
Improvements To Electronics
Energy Harvesting Options
Battery Options
Future Tasks
Budget
Timeline
Problem Statement
● Sikorsky has asked the team to come up with a proof of
concept for a wireless sensing system.
● Benefits of a Wireless System:
○ No long, heavy wires
○ No slip rings
○ Overall weight of system reduced
● Challenges of a Wireless System:
○ Powering the system
○ Large temperature range
■ -65 F to 400 F
System Requirements
Electronics Compartment:
● Size: 1.5” diameter x 5.1” long
● Temperature Range: -65ºF to 300ºF
Sensor(s):
● Minimum of 2 sensor types
● Temperature Range: -65ºF to 400ºF
Rotating Speed of Tail Rotor Shaft:
● 1200 RPM
System Block Diagram
Figure 1. System Block Diagram
Power Circuitry
Figure 2. Power Circuitry Block Diagram
Ordered Parts
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Sensor(s):
○ Infrared thermometer
○ Ambient thermometer
○ Accelerometer
○ Microphone
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Microcontroller:
○ Arduino Nano v3.0
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Transceiver:
○ WiFly Module
Parts To Be Ordered
● Energy Harvesting Method
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Brushless Generator
● Power Circuitry
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Rectifier
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Switching Regulator
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Charging Circuit
● Battery
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Lithium cells (Li-Ion, Li-Poly)
Improvements to Electronics
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Previous Design:
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Custom built,
expensive to
replace/modify
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Our Design:
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Greater
connectivity
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Small size
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No documentation
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Affordable
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Limited connectivity
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Missing components
Greater available
documentation
Electronics Options
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New Custom Design:
○ Get only what we need in the size we want
○ Prohibitively expensive (cost > $1300)
○ Only can afford one
○ Little documentation
Off the shelf options (Arduino, Teensy):
○ Excellent connectivity
○ Available in our size
○ Open sourced, excellent documentation
○ Affordable (cost < $40)
Arduino Nano V3.0
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Small, low power
evaluation board
Plenty of documented
projects and code
on website
Many compatible
sensors/add ons
for sale
Sensor/Add-on Choices
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Triple axis accelerometer
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Electret microphone
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Ambient thermometer
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Infrared thermometer
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Low-power wifi module
Energy Harvesting Options
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Thermoelectric
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Piezoelectric
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Insufficient power from available
temperature gradient
Too large
Insufficient power
Needs vibrations within a narrow
range of frequencies
Magnetic
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Sufficient power
Requires low KV motor, gearing,
or a step-up regulator
Necessitates use of gravitational
torque
Battery Options
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NiCd and NiMH
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Quick and simple charging
Durable
Poor energy density
1.2V per cell
Smaller temperature range
Memory (NiCd only)
Lithium cells (Li-Ion, Li-Poly)
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High energy density
3.7V per cell
Various shapes available (Li-Poly)
Wider temperature range
More complex charging
Less durable
Battery Charging Circuit Options
Create our own:
∙ Uses transistor, variable regulator, 2 capacitors, potentiometer, 1 Ohm/1 Watt
resistor, 3 normal resistors
Battery Charging Circuit Options
Using Power Management IC Chips:
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Chip Features:
Charger Plus Pack Protection in One IC
Low Operating Current (550nA)
Near Zero Current (<0.1nA) Low Battery Disconnect Function to Protect Batteries
from Over-Discharge
Pin Selectable Float Voltage Options: 4.0V, 4.1V, 4.2V
Ultralow Power Pulsed NTC Float Conditioning for Li-Ion/Polymer Protection
Suitable for Intermittent, Continuous and Very Low Power Charging Sources
High Battery Status Output
Battery Charging Circuit Options
Using Power Management IC Chips:
∙ Chip Features: combines high-accuracy current and voltage
regulation,battery conditioning, temperature monitoring, charge
termination, charge-status indication, and AutoComp charge-rate
compensation in a single 8-pin IC.
Test Rig: Potential Modifications
∙ Different circuit – different layout inside capsule
∙ Mount the rig to change pitch angle
∙ Second set of wired sensors for data comparison
Tasks for Next 45 Days
∙ Assemble and test Arduino Nano with sensors
∙ Assemble and test Wi-Fi module
∙ Order: motors, batteries, charging circuit equipment
∙ Make modifications to test rig as necessary
Budget
Purchase Breakdown
Arduino Nano
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Budget: $2,000
Spent to Date: $159
Additional Estimated Costs:
$350
Estimated Surplus: $1,491
Mini B USB Cable
$35
$4.50
Xbee Add-on Board
$25
Wifi module
$35
Nano Protoshield
$15
Triple Axis Accelerometer
$15
Infared Thermometer
$20
Thermometer
Electret Microphone
$1.50
$8
DC Generator (Estimated)
$20
Power Management Circuitry (Estimated)
$30
Battery (Estimated)
$100
Printed Circuit Board (Estimated)
$200
Total
$509
Timeline
Questions
Student Assessment
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Presentation Style
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Readability of Material
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Team results and deliverables are clear?
Grade A, B, or C with clicker