Transcript presentation

WIRELESS CONTROLLED
POWERSTRIP
Shubham Pahadia
Austin Chu
Doni Tampubolon
Team 4
Goals and Benefits
Figure 1: Overall Project
■ Provide user with the ability to manage power
status of outlets through a central hub
■ Modernize the ability of power tracking and
consumption
■ Very low power consumption means low
electricity cost: 0.12c per day cost
■ User Friendly installation method
Features
■ Smartphone application to allow hub control for easy manipulation and observation
■ Compact Design
■ Internal Switch Relay to control power to end load
■ Power Sensor Suite for all outlets to record power consumption
■ Low Power Usage
■ Large Memory Storage
System Overview
Figure 2: High Level Block Diagram
System Overview
1. Power Unit
2. Outlet Unit + Sensor Suite
3. Control Unit
Figure 3: High Level Block Diagram
(Detailed)
Smartphone Application
Design
■
Power Status Radio Buttons to turn outlets on and off
■
PickerView to decide which set of data you wish to see
■
Textbox to illustrate data being sent and receive data
■
TabView Controller for controlling individual Outlets
Figure 4: Smartphone Interface
Bluetooth Connection
Figure 5: Smartphone-Bluetooth Interface
■ Module: AdaFruit Bluefruit LE SPI Friend (BLE)
– Low Power Consumption: runs on 3.3V and
12.5mA (max) => 41.5 mW
– Distance up to 5 meters
■ Transmits character data from Smartphone to MCU
■ Lower Power Usage compared to Wi-Fi Unit
MCU Control
■
Reads and sends SPI data from and to SD Card and Bluetooth
■
Sends Digital Signal to Relays
■
Receives Analog Signals from Sensor Suite
■
Low Power Consumption: runs on 3.3V and 4.16mA (max) =>
13.7 mW
Figure 6: MCU Control Flowchart
Sensor Suite
Voltage Sensor: ZMPT101B
■ Low Power Consumption: runs on 5V and 2mA (max) => 10 mW
■ Senses up to 120V AC
Current Sensor: ACS726
■ Low Power Consumption: runs on 3.3V and 14mA (max) => 46.5 mW
■ Senses up to 20A
Relay System
Figure 7: Relay Design
■ Power Supply from Regulator
■ Controlled through Digital High and Low from
MCU
■ Outlet Connection was through the Normally
Closed Connection
Rectifier Design
■ Used Variac to send AC Voltage
■ High Capacitors yielded a smaller ripple
■ Successfully outputted a constant DC output
using Rectifier Design through connection with
an Outlet
Figure 8: Rectifier Design
Flyback Design
■ Initially planned on using PWM to control
switching frequency
■ Moved to DC-DC controller due to isolation
issues
■ Converted from 160Vdc to 5Vdc with plusminus .8V
■ Bootstrap circuit provided initial power
■ Small design and cost effective vs other
converters
Figure 9: Flyback Design
Linear Regulator
■ Needed a 3.3V DC Supply to various components while flyback only
provided 5V output
■ Regulated an output for safety in order to not break our sensitive
units
Figure 10: Regulator Design
Conclusion
■ Completed each individual component
■ Had difficulties integrating the power supply to the entire project
■ Completed our initial goal of a wirelessly controlled relay extension cord for smart
home purposes
Learning Experience
■ Challenging but rewarding experience when we had individual components work
■ Managed to get a better understanding of the design process, teamwork and
communication skills
■ Developed new skills in programming, circuit design, power systems, and
engineering practices
Future Hardware Development
■ Integrate Power Supply System with Device Components
■ Increase number of outlet outputs
■ Improve on Flyback Design to utilize a PWM instead of controller for lower power
usage
■ Improve Soldering and Manufacturing
Future Software Development
■ Implement a log-in feature for smartphone application for security purposes
■ Implement encryption on data for security purposes
■ Improve GUI for creating a more polished product
■ Implement a greater variety in the data stored and displayed
SWOT Analysis
Strengths:
Weakness:
Cost effective
Space Efficient
Low Power Consumption
Inherent Safety Issues
AC-DC Converter implementation
Threats:
Opportunities:
Prior Integration in new homes
Niche Market
Susceptible to Security Breakthroughs
Power Management
Software Expansion
Need for smartHome purposes
Thank You and Acknowledgements
■ Special Thanks to Jackson Lenz for assisting us throughout the entire process
■ Thanks to Machine Shop for PCB and Housing construction
■ Thanks to Peers for their reviews and assistance throughout the project
■ Thanks to TAs for their guidance on various questions and safety
■ Thanks to professors for teaching proper engineering practices and the learning
opportunity
■ Thanks to our audience for letting us share our experience and journey through our
capstone project as undergraduate students at U of I