Electrical Engineering · Virginia Tech

Youssef
Abdelhafez

01. About

Youssef Abdelhafez

Building systems
that fly, think, and move.

I'm an Electrical Engineering student at Virginia Tech with a focus on Controls, Robotics, and Autonomy. My academic and project work spans analog circuit design, digital systems, and embedded engineering — all pointing toward a career in avionics and guidance, navigation & control (GNC).

I build things end-to-end: from hand-drawn schematics and Bode plot analysis to breadboarded prototypes and documented failure logs. I'm drawn to systems that demand precision — the kind where getting the math wrong has real consequences.

Currently seeking co-op and internship opportunities in aerospace, defense, or embedded systems engineering.

Technical Arsenal

MATLAB LTspice Proteus Falstad Verilog Arduino Oscilloscopes Multimeters WaveForms Analog Discovery 2 Active Filters Op-Amp Design State Machines Circuit Simulation

02. Projects

Selected Engineering Work

Featured Build

Audio-Responsive Color Organ

A 3-channel analog audio filter circuit that splits a music signal into low, mid, and high frequency bands — each driving a dedicated LED and buzzer output via NPN transistor switches. Designed from scratch, characterized with MATLAB Bode plots, and iterated through five documented failure cycles before reaching final form.

Core ICsLM324 Op-Amps
Filter TopologyActive RC (Sallen-Key)
Output StagesNPN Transistors
RectifierDiode Envelope Det.
CharacterizationAnalog Discovery 2
SimulationFalstad + MATLAB

Signal Architecture Path

🎙 Audio In
→
Pre-Amp
LM324
→
Low-Pass
<500 Hz
→
Rectifier
→
NPN Q
→
🔴 LED
Band-Pass
500–4k Hz
→
Rectifier
→
NPN Q
→
🟢 LED
High-Pass
>4k Hz
→
Rectifier
→
NPN Q
→
🔵 LED

Documentation & Build Photos

⚠️ Design Failures & Fixes

FAILURE 01

Pre-amp output too weak to drive filter stages — LEDs didn't respond to music input.

→ Increased gain stage, re-biased LM324 input

FAILURE 02

Filter cutoff frequencies shifted significantly from calculated values on physical breadboard.

→ Measured actual R/C values, revised MATLAB model

FAILURE 03

Band-pass filter had excessive rolloff — mid-band was nearly invisible in LED response.

→ Redesigned Q factor, tuned center frequency

FAILURE 04

Rectifier stage leaked into adjacent channel — cross-talk between LED outputs.

→ Added buffer op-amp stage between rectifier and transistor base

⚡

Automatic Power Factor Correction Unit

Designed and simulated a power factor correction circuit in Proteus. Analyzed load compensation strategies and wrote a full technical report documenting reactive power reduction and switching control logic.

ProteusPFCPower ElectronicsSimulation
🌱

Arduino Soil Moisture Monitor

Embedded sensor system using Arduino that reads analog soil moisture levels, applies threshold-based logic for dry/wet classification, and displays real-time output via serial monitor and LED indicators.

ArduinoEmbedded CSensorsADC

03. Contact

Let's build something together.

I'm actively seeking co-op and internship opportunities in aerospace, avionics, embedded systems, and GNC engineering. My resume is available on request.