Source: https://mokxi.com/learn/path/electrical-safety Updated: 2026-11-11 All paths # Electrical safety for every bench How shock harms, voltage classes, fuses, lockout and tagout, testing before you touch and battery fire, on low-voltage stand-ins you can break safely, then a guarded press to inspect. Free 7 lessons 5 h 4 chapters 1,720 XP Electrical ยท Beginner +100 XP 0 of 7 done Start the course free How a shock harms Lesson plan for teachers What you will build ## 3 projects, built step by step 7 lessons in 4 chapters, about 5 hours on a simulated breadboard. Free, in your browser, every step checked by the simulator. Chapter 1 project ### Voltage classes Mains, safely on a screen: a 230 V signal through a transformer to a low-voltage supply, what extra-low voltage means, the US 120 V version, and what the wrong transformer does. Open it in the simulator Chapter 2 project ### Lockout and tagout Why a STOP button is not off: a disconnect that really isolates, a capacitor that keeps the line live after it opens, bleeding the stored energy, and the lockout steps in general terms. Open it in the simulator Chapter 3 project ### Battery fire One 18650 lithium cell on a dead short: over 20 A, the heat inside the cell, a smaller fault, storage charge, and what to do when a cell goes wrong. Open it in the simulator The map ## Chapter by chapter Each lesson opens when the one before it is done, and each chapter ends in a project. Chapter 1 ## Current and your body Why current harms, and what the voltage classes mean. Open 150 XP ### How a shock harms Your body as a resistor on the bench supply: why current, not voltage, does the harm, how wet skin changes everything, and why mains is never a bench experiment. 0 of 5 steps Start What is in it Project Locked 320 XP ### Voltage classes Mains, safely on a screen: a 230 V signal through a transformer to a low-voltage supply, what extra-low voltage means, the US 120 V version, and what the wrong transformer does. 0 of 6 steps Chapter 2 ## Fuses and lockout What a fuse protects, and how to make a machine truly dead. Locked 150 XP ### Fuses protect the wire A small lamp plays a fuse: loads add current, a fault makes the fuse go white hot while the lamps go dark, a current limit trips instead, and why a fuse is sized to the wire, not the gadget. 0 of 5 steps Project Locked 350 XP ### Lockout and tagout Why a STOP button is not off: a disconnect that really isolates, a capacitor that keeps the line live after it opens, bleeding the stored energy, and the lockout steps in general terms. 0 of 6 steps Chapter 3 ## Meters and batteries Test before you touch, and keep lithium cells calm. Locked 175 XP ### Test before you touch One meter on a divider: a live reading, proving a circuit dead, why ohms lies on a live circuit, what the meter categories mean, and the live-dead-live habit. 0 of 6 steps Project Locked 350 XP ### Battery fire One 18650 lithium cell on a dead short: over 20 A, the heat inside the cell, a smaller fault, storage charge, and what to do when a cell goes wrong. 0 of 6 steps Chapter 4 ## Boss project Inspect a guarded press for every way it could hurt someone. Locked 225 XP ### Boss: a safety walk-through Walk a guarded press like a safety inspector: a safe stroke, a refused start, a hand through the light curtain, a reset that waits, a wider guard you set yourself, and the e-stop. 0 of 8 steps Syllabus ## Every lesson in the course All 7 lessons, in order, each with what it covers. Any of them opens in the editor right away. Chapter 1 ### Current and your body - How a shock harms Your body as a resistor on the bench supply: why current, not voltage, does the harm, how wet skin changes everything, and why mains is never a bench experiment. - Voltage classes Mains, safely on a screen: a 230 V signal through a transformer to a low-voltage supply, what extra-low voltage means, the US 120 V version, and what the wrong transformer does. Chapter 2 ### Fuses and lockout - Fuses protect the wire A small lamp plays a fuse: loads add current, a fault makes the fuse go white hot while the lamps go dark, a current limit trips instead, and why a fuse is sized to the wire, not the gadget. - Lockout and tagout Why a STOP button is not off: a disconnect that really isolates, a capacitor that keeps the line live after it opens, bleeding the stored energy, and the lockout steps in general terms. Chapter 3 ### Meters and batteries - Test before you touch One meter on a divider: a live reading, proving a circuit dead, why ohms lies on a live circuit, what the meter categories mean, and the live-dead-live habit. - Battery fire One 18650 lithium cell on a dead short: over 20 A, the heat inside the cell, a smaller fault, storage charge, and what to do when a cell goes wrong. Chapter 4 ### Boss project - Boss: a safety walk-through Walk a guarded press like a safety inspector: a safe stroke, a refused start, a hand through the light curtain, a reset that waits, a wider guard you set yourself, and the e-stop. Kits ## Build it on your bench too Every lesson runs in the simulator with nothing to buy. When you want the real thing, these kits have the parts. Have a kit already? ### Find your kit Pick the starter kit you own and run every lesson in its manual with the same parts on the same pins. See every kit Questions ## About Electrical safety for every bench Is Electrical safety for every bench free? Yes. All 7 lessons of Electrical safety for every bench are free and run in your browser, with nothing to install and no parts to buy before you start. Do I need any parts? No. Every circuit is built on a simulated breadboard, and the simulator checks each step as you go. When you want to build it for real, the same parts and wiring work on a real bench. How long does Electrical safety for every bench take? About 5 hours: 7 lessons in 4 chapters, each one a few short steps. Your progress is kept, so you can stop after any lesson and pick up where you left off. What will I build? Each chapter ends in a project that puts it together: Voltage classes, Lockout and tagout and Battery fire. Where do I start? With "How a shock harms", and each lesson builds on the one before it. New to circuits? Electronics basics is the course that starts from zero.