The spark you never felt
You walk across a carpet. You touch a door handle. Zap, a tiny spark.
You only feel a spark when the charge is big, about 3000 volts. A computer chip can be hurt by a charge you cannot feel at all.
A technician picks up a new memory card. It looks fine. It never works. Why?
Key words
| Word | What it means |
|---|---|
| Static electricity | an electric charge that builds up on a person or an object |
| ESD | electrostatic discharge: the sudden jump of static charge from one thing to another |
| Electrostatic sensitive | easily damaged by static, like chips and memory cards |
| Humidity | how much water is in the air |
| Earthing | a safe path that lets a charge flow away to the ground |
| Wrist strap | a band worn on the wrist, joined by a lead to earth |
| Anti-static mat | a work mat that lets charge drain away safely |
| Anti-static bag | a special bag that keeps a part safe from static |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can say how static damages hardware and name the checks and equipment that stop it.
Starter
Have a go
Starter
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
What ESD does
ESD is a sudden jump of static charge. It happens when a charged person touches a part.
Chips are made of tiny pathways. A small jump can burn one. The damage can be total. It can also be hidden: the part works for a while, then fails weeks later.
That is why a part that "looks fine" may still be broken.
Mobility awareness: move less
Movement makes charge. Shoes rubbing on a carpet and clothes rubbing on a chair both build static.
Mobility awareness means you know how your own movement makes charge, and you limit it. Do not walk about with parts in your hand. Do not shuffle your feet. Stay in one place at the bench.
Keep parts in their bags until you need them.
Quick check
Have a go
Quick check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.