Ignition System Redesign: Redesigned and improved the ZVS-based high-voltage flight ignition system for hypersonic vehicles, with the goal of enhancing the reliability of the design, replacing components with market-stable alternatives, implementing protection mechanisms, and optimizing the board size and total cost.
Component Sourcing & Selection:
Researched, sourced, and tested FET ICs that would be implemented into the design as the main switching FETs rated for 600V operation with a high repetitive avalanche energy capability
Sourced high-current inductors for the ZVS topology, replacing a 6-inductor configuration with a 4-inductor configuration by finding components with higher inductance and still above threshold saturation current. This reduced the board size by 20% and resolved end-of-life (EOL) concerns associated with previous inductors.
System Testing:
Performed maximum power testing to validate consistent inductor and FET performance
Conducted plasma ignition tests, capturing high-voltage waveforms and gate signals using an oscilloscope
Protection Circuit Design:
Developed robust analog overcurrent and overvoltage protection circuits using comparators and RS latches to prevent oscillatory failure loops
Designed a latched fault mechanism: faults persist until manually reset, preventing rapid toggling that had previously caused the electrical power system to fail
Added TVS diodes across the FETs (source to drain) to handle high-energy switching transients and protect against voltage spikes, with a focus on repetitive avalanche handling thereby protecting the main switching FETs
Integrated thermocouples, a sensing circuit board, and an Arduino with the internal circuitry of the oven to turn it on and off as needed to reach desired temperatures
Implemented a PID loop control
Wrote mealy state machine code that transitioned through the different reflow states, such as preheat, soak, and reflow
Designed (using SolidWorks) a 3D printed container to hold peripheral equipment (LCD touchscreen display, Arduino, thermocouple driver boards, etc.)