How to Falsify TNA with $200 Hardware — and Why It Matters for Education

This educational technical note describes a low-cost ($100–200) DIY analog computer built with basic electronic components to physically demonstrate the core dynamics of Throughput-Based Analysis (TNA): the differential equation dN/dt = G(t) − Ψ(t). By mapping inflow (G), discharge capacity (Ψ), and accumulation (N) to voltages, resistances, and capacitors, the setup allows real-time experimentation with threshold systems and collapse conditions without requiring prior knowledge of differential equations. Designed for secondary-school classrooms, it enables hands-on exploration of accumulation, saturation, and failure across multiple disciplines—including biology (toxin buildup), ecology (population overshoot), economics (inflation), demography (reproductive constraints), and environmental science (resource depletion). The device emphasizes falsifiability, reproducibility, and systems thinking, providing a tangible introduction to open-system constraints and entropy principles through simple knob adjustments and visible alarms.