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 simulatorAll 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.
0 of 7 done
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.
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 simulatorBattery 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 simulatorThe 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.
- Open150 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
- ProjectLocked320 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.
- Locked150 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
- ProjectLocked350 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.
- Locked175 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
- ProjectLocked350 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.
- Locked225 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.
Current and your body
- How a shock harmsYour 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 classesMains, 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.
Fuses and lockout
- Fuses protect the wireA 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 tagoutWhy 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.
Meters and batteries
- Test before you touchOne 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 fireOne 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.
Boss project
- Boss: a safety walk-throughWalk 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.
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 kitQuestions
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.