Core idea
Generate repeatable high-voltage pulses (nanosecond-scale targeted) and couple them into a defined gas path. We prioritize controllability and measurement so results are defensible and reproducible.
Overview
What we’re building
This capstone deliverable is a controllable high-voltage pulsed-discharge platform: pulse-generation electronics, HV conversion, pulse conditioning/protection, a reaction chamber, and basic instrumentation (including mass flow measurement and logging).
What “Car Filter” means here
“Car Filter” is the long-term application framing: a compact module that could be integrated into vehicles to reduce CO₂ emissions. In the capstone timeframe, we are building and validating the prototype platform and test methodology.
Project overview video
Short video update showing the current state of the build and direction.
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Engineering Update
Why we pivoted to nanosecond pulsed discharge
We originally explored a low-frequency, high-voltage spark approach using a Van de Graaff generator. We are now pursuing a nanosecond pulsed-discharge architecture because it supports better controllability, repetition-rate tuning, and measurement-driven iteration.
Original concept: low-frequency, open-air sparks
The first direction used a Van de Graaff generator to create a high-voltage discharge with a more thermal interpretation of CO₂ dissociation. That concept helped shape the early project idea, but it was difficult to control and not well matched to repeatable prototype testing.
- Discharge behavior was harder to regulate and measure consistently
- Energy delivery was not practical for a controlled bench-scale platform
- Safety and repeatability concerns pushed the team toward a different architecture
Original Van de Graaff concept
Current direction: fast pulsed discharge
Nanosecond pulsed discharge emphasizes fast voltage transitions and repeatable pulse delivery into the chamber. The goal is a controllable electrical drive that supports systematic testing with logged operating conditions.
Phase 2.1 · Bring-up
StormFlask 2.0 platform
Establish a baseline chamber and pulser electronics that can be safely brought up and measured.
- Chamber assembly + electrode iteration
- Pulse-generation electronics integration
- Baseline measurements and repeatable behavior checks
Phase 2.2 · Pulse shaping & iteration
Refine the discharge regime
Improve pulse delivery and discharge stability through electrical and mechanical iteration.
- Pulse conditioning/protection network revisions
- Electrode geometry adjustments and spacing sweeps
- Repeatability mapping versus flow and repetition rate
Targets · Initial Operating Window
Voltage, repetition, control
Early testing uses bounded ranges suitable for safe staged bring-up and instrumentation.
- HV output target: 10–15 kV (load dependent)
- Repetition rate: kHz range (tunable)
- Gas-path hardware integrated with ESP32-S DevKit control
Long-term goal: improve efficiency and packaging so the concept could evolve into a compact module compatible with new or existing vehicles. In the near term, we prioritize a safe, repeatable platform and defensible measurements.
System Architecture
Prototype architecture at a glance
Control → pulse generation → HV conversion → pulse conditioning/protection → chamber. Instrumentation includes gas-path hardware and electrical measurements, while accurate flow sensing is still under revision.
High Voltage
- Transformer-based HV stage (pulsed output)
- Pulse delivery is load dependent and instrumented
- Designed for controlled pulsed operation
Electronics
- MCU control (ESP32-S DevKit)
- Isolated control path + switching/pulser stage
- Support hardware includes buck converters for the LED “work light” and MFC control
Chamber
- StormFlask 2.0 test article (Phase 2.1)
- Interchangeable electrode configurations
- Defined gas path through the discharge region
Instrumentation
- Mass flow sensor in-line on the gas path
- Electrical measurements (waveforms, stability trends)
- Structured test procedure and logging
Tap / hover a block
Control → Pulses → HV → Conditioning → Chamber → Measurements
Documentation
Current build highlights
The homepage stays visual and high-level. Detailed theory, equations, and deeper hardware notes are on the Progress page.
Current chamber
HV system PCB
Full prototype setup
- Transformer power is supplied at 6 V and 2.5 A for the current bench setup
- One buck converter powers the internal LED “work light” at 10 V
- One adjustable buck converter sets the MFC control voltage to about 1.6 V
- The ESP32-S DevKit is used to control PWM, adjust gas-flow hardware, and receive MFC data when available
- That control-and-logging path did not end up working fully reliably in the current build
- Gas flows from the cylinder, across the spark region, through the handheld analyzer, with flow rate intended to be controlled by the MFC
Preliminary analyzer reading
What the build has achieved
The team has built the chamber, demonstrated spark-gap generation, assembled the full bench prototype, and run CO₂ through the chamber into a handheld analyzer during preliminary testing.
What still needs validation
During preliminary testing, the analyzer produced CO readings after the transformer had been running for about 30 seconds to 1 minute, peaking at around 50 ppm. Stronger diagnostics such as gas chromatography or mass spectrometry are still needed to confirm repeatability and rule out confounding factors. The MFC control-and-logging path also still needs revision for reliable flow data.
Project Status
Plain-language project status
This project is in the prototype and testing stage. A real bench-scale system now exists, and the next step is improving validation rather than making bigger claims.
What has been built
The chamber, HV electronics, gas path, and overall bench setup have all been assembled and brought into early testing.
What has been observed
After letting the transformer run for roughly 30 seconds to 1 minute during CO₂ testing, the handheld analyzer showed CO readings that peaked at about 50 ppm. The result is encouraging, but it still requires stronger validation.
What comes next
Future work will focus on tighter pulse control, better gas diagnostics, and more repeatable testing under controlled conditions.
For detailed build phases, roadblocks, and test plans, see the Progress page.
Optional
Short context quiz (non-technical)
This is for visitors who want a quick “why it matters” checkpoint before diving into the technical pages.