In sharing this portfolio I hope that it showcases excellence in the practical aspects of Electrical & Electronics Engineering, accompanied by an interest and inclination for Music.
|Hardware||Electronics, Power Electronics, Altera FPGA Board, Altera ATMEL AVR Micro-controller|
|Software||Java, C, MATLAB|
|Music||Piano (ABRSM Grade 5)|
Development & Test of a Quadrature Power Pickup for Inductive Power Transfer Systems
Part IV Project (Final-year research project)
Power electronics components, quadrature power pickup
2-person team – role involved creating computer simulation, running testing regime and producing exhibition poster
To computer model, design, build and test 2 different circuit topologies for quadrature power pickup controllers (for power regulation). Furthermore, to study circuit behaviour and investigate power flow with respect to lateral displacement of pickup on power track.
- Specified a controller for 300V, 500W output across displacement range of 70mm, investigating LC and LCL compensation circuits.
- Development stages consisted of: computer simulation, circuit design, build, and experimental verification.
- Voltage and current waveforms observed at key points in circuit to examine power flow.
- Power link loss budgets were prepared.
- Achieving an even, flat-top power profile for the pickup system with respect to lateral displacement.
- Understanding power flow experimental results against theoretical predictions.
- Developed 2 fully-functional prototypes of commercial interest.
- Department of Electrical & Computer Engineering Year IV Research Project Award – First Place in ‘Power Electronics’ Category.
- Department of Electrical & Computer Engineering Year IV Research Project Award – Best Poster.
- Findings published – Raabe S., Covic G.A., Boys J.T., Pennalligen C., Shekar P. ‘Practical considerations in the design of multi-phase pick-ups for contactless power transfer systems’ in 35th Annual Conference of the IEEE Industrial Electronics Society, IECON, 2009, pp. 753 – 758.
Final report – IEEE conference-style
Electrical Engineering Design Course
4-person team – role involved preparing design specification, paper designing and signal testing
To conceptualise and construct a prototype function generator which may be used for audio system testing or logic circuit verification. It should output low to medium frequency triangle, square and sine waveforms.
- Specified a solution for up to 3V amplitude, 2Hz – 200kHz frequency, with a total harmonic distortion/non-linearity under 3%
- Functional blocks were implemented in a staged approach – variable frequency control, analogue switch, frequency band selection (capacitor bank), triangle waveform buffer, comparator (for square wave), filter (for sine wave).
- Variable amplitude and duty cycle controls added as extra features.
- Signal testing with oscilloscope on breadboard (mock-up) and PCB circuits.
- Testing parameters included: frequency, voltage amplitude, DC shift, maximum output power/current, THD, linearity
- Achieving un-distorted waveforms at extremes of frequency bands
- Minimising distortion spikes caused by analogue switch
Function Generator Prototype
Triangle Wave Output
Square Wave Output
Sine Wave Output
Engineering Design Course
2-person team – role involved paper designing, breadboard concept designing/testing and signal testing
To design and implement a prototype radio which will receive standard commercial AM transmissions.
- Functional blocks were implemented in a staged approach – tuned circuit (including loop antenna), RF amplifier, envelope detector and power amplifier driving a speaker.
- Volume control feature added.
- Signal testing with oscilloscope and function generator on breadboard and PCB circuits.
- Ensuring functional electronic blocks work in harmony, with intended transformation on input signal.
- Obtaining a clean, undistorted sound at output.
AM Radio Prototype
Motor Control Unit
Standard consumer-grade electronic components, ATMEL ATMega8 micro-controller, C language
2-person team – role involved implementing motor speed regulation algorithm on micro-controller
To design and develop a prototype motor control unit using sensorless feedback, to drive the drum door DC motor on a ‘Fisher & Paykel’ clothes dryer, and undertake a comprehensive feasibility study.
- Specified a motor control unit to drive the motor at constant speed of 180deg cycle in 3 seconds, largely independent of load, with supply voltage of 14-24V to account for mains voltage fluctuation.
- Implemented an H-bridge block for bi-directional movement of motor (open/close door).
- Programmed an ATMEL ATMega8 micro-controller for sensorless feedback control of motor speed through back-EMF and motor-current sensing inputs, varying a Pulse Width Modulated signal output to the motor.
- Performance analysis employed the following tests: motor speed regulation with varying supply voltage and load, time to detect motor stall and sensitivity to jam events.
- Achieving audible smoothness of operation, in line with high-end appliances (motor speed must remain constant).
- Difficulty in detecting some jam events, due to slight variations in motor speed.
Motor Control Unit Block Schematic
Motor Speed Regulation Algorithm Flowchart
Predictive Text Messaging
Software Design Course
To implement an algorithm with functionality similar to predictive text messaging on numerical input mobile phones. The user enters numerical keyboard input and the program must match and output a list of all possible intended words from a supplied dictionary.
- Read given dictionary file into dynamic memory allocation due to unknown size
- Converted user’s numeric string input into an integer to match with word list
- Extended this function to allow user input of a sentence (multiple words), ignoring illegal characters
- Added measurement operations to estimate run time of program
- None! Found it easy so worked on keeping code efficient and run time down.
Principles of Programming Course
To implement your own version of the popular arcade game Pac-Man.
- Development stages involved creating Maze, Pac-Man, Pellets and Ghosts
- Maze object – array of ‘corridor’ lines along which Pac-Man motion is constrained
- Pac-Man object – animated object, stores user keyboard input for direction change at next opportunity
- Pellets object -array of points, deleted as Pac-Man moves over them
- Ghost object – animated object, random 90deg direction changes, collision event with Pac-Man ends game
- Extra features (sound effects, simple graphics) added to enter Pac-Man competition
- Dealing with new events
Scattered Data Interpolation
Engineering Computing Course
To implement a scattered data interpolation algorithm on a 3D data set, in this case to determine the structure of a hypothetical oil reservoir.
- Divided the oil reservoir area into a 2D grid cell array
- Interpolated the upper and lower surfaces of the oil well at the centre of each cell
- Applied inverse distance squared weighting algorithm to interpolate data from experimentally measured wells
- Extracted data to create a 3D graphical map of oil reservoir
- Constructing looping through all grid cells and wells