Thamstat

A transformer that runs hot or out of balance fails with little warning, and checking one meant someone standing next to it with a meter.

We wrote ESP32 firmware that measures input and output every 15 seconds, switches test loads and shows readings on the device, then built a live dashboard with health states, trend charts and alerts. Alerts reach engineers on Telegram and by email, only under load and only after repeated bad readings, so they are worth reading.