You're going to run into a few questions that might require you to know the difference between electromagnetic
interference versus radio frequency interference versus electrostatic discharge that are known as EMI
RFI and ESD So let's just take a moment and make sure we're comfortable with all three of these.
Let's start with electromagnetic interference.
Just about every electronic device out there emits some form of radiation.
Now this radiation can be in the radio range it could possibly be in the infrared.
Who knows.
But the problem is is that they emit radiation and this can cause problems.
Generically we call all this electromagnetic interference when it's interfering with somebody else.
Now if it's only in the radio range like it with this wireless access point in that case we call it
radio frequency interference.
The bottom line is is that we need to be able to do something about it.
Number one we isolate.
We try to move the stuff away from the things that it's causing the interference from.
The second thing we're going to do is we're going to shield our devices.
So for example here's a piece of shielded ethernet cable that's designed to protect us from EMI and
RFI.
Equally we can do separate circuits and a lot of situations will actually see for example this electric
motor which has its own separate electric current which helps to protect everybody else from EMI.
Now EMI and RFI are based on radiation.
However I want to talk about one more thing that's based on good ole electricity and that's electrostatic
discharge.
Everything on earth has some amount of electrical charge.
Now we've all felt this.
Anybody who's walked up to a door knob on a dry day wearing a pair so pajamas while petting their cat
has definitely felt a little bit of electrostatic discharge.
Now while this is an inconvenience for humans if we do the exact same thing to a piece of electronics
it can absolutely destroy it.
So what we need to do is protect ourselves from ESD.
Number one we try to keep everything at the same potential.
Here's a typical ESD wrist strap.
The whole idea behind using this device is we stamp one end into the workpiece and then we keep the
other part on our wrist.
That way we stay at the same potential.
Also just about any form of electronic device for example this USP thumb drive has built in anti ESD
circuitry to protect it in case we do get a little bit of a charge.
The important thing is that you recognize the difference between EMI versus RFI versus ESD and also
make sure you understand the security features we can do to keep our availability of our electronic
equipment really high.