---
title: "Engineering notes | Ehsan Mazaheri Tehrani"
description: "Notes on the systems behind the work: what was tried, what held up, and what it cost."
url: "https://emazaheri.com/notes"
---

# Engineering notes

Notes on the systems behind the work: what was tried, what held up, and what it cost. Each note states its assumptions and shows how to reproduce the result.

RSS: https://emazaheri.com/notes/feed.xml

## [Reading a motor spectrum without overreading it](https://emazaheri.com/notes/reading-a-motor-spectrum)

Field note · Sep 8, 2026 · 5 min · Signal processing, Fault diagnosis, Evaluation

What each fault in the Lab does to a machine, why it lands where it does in the spectrum, and where the simulation is kinder than a real drive.