A trackside energy harvester that converts tiny rail/sleeper deflection under train wheels into electricity. Build it as a safe demo module under a test sleeper or on a lab rig. The harvested power can run LED beacons, IoT sensors (axle counter, temperature, vibration), LoRa/GSM nodes, or trickle-charge a battery—best used hybrid with solar.

Parts Used:

1. Load Interface: Steel load shoe + elastomer pad to pick ~0.5–2 mm deflection without harming track geometry.
2. Energy Harvester Module: PZT stack/plate or micro-piston or linear generator cartridge.
3. Power Electronics: Full-bridge rectifier, synchronous boost/MPPT (piezo needs high-V, high-Z front end), buck to 5/12/24 V.
4. Storage: Supercapacitor bank (e.g., 10–50 F at 5–16 V) and/or small LiFePO₄ battery with BMS.
5. Sensors (use case): Axle counter (reed/hall), temperature, vibration (MEMS), current/voltage monitor.
6. Enclosure & Mounts: IP67 enclosure, strain-relieved cables, anti-vibration mounts; no modification to rail.
7. Output Load: LED beacon, LoRa/NRF/GSM node, data logger; optional hybrid solar input.
8. Safety & Service: Mechanical stops (limit compression), fuses/TVS, connectors, gasketed covers.