You can't see it or hear it, but it sure can effect your electronics! Adabot and Minerva set out to solve the mystery of electrical noise … and maybe even watch a movie together.
Adabot: Hello Minerva - do you read me? Over.
Minerva: Hello Ada [static] It’s difficult to hear [static]
Adabot: Hello Minerva [static] - your signal is unclear please re-[static] , over.
Minerva: I can’t quite hear you Adabot. There’s too much noise!
Minerva: Sorry Adabot - there’s too much noise in the signal. I couldn’t hear you :(
Adabot: I know - I couldn’t hear you either.
Adabot: Plus - I was going to watch a movie, but it won’t play. Any idea why?
Minerva: Something around here might be creating noise and interfering with the wifi signal.
Adabot: Noise? I don’t hear any noise.
Minerva: Well, Adabot - sometimes there’s noise that we can’t hear. It’s not audio noise, it’s electrical noise and it can cause problems for wireless circuits like your laptop’s wifi …
Minerva: … or even our walkie talkies.
Adabot: Noise you can’t hear? Interesting. Where could it be coming from?
Minerva: Lots of things can create electrical noise, but the most common are device with motors in them..
Minerva: like say … this fan!
Adabot: Hmm - but the video still isn’t loading.
Minerva: Or … devices that use a lot of power and send out radio waves … or microwaves, did I just hear the microwave oven?
Adabot: Oh good - my popcorn’s done!
Minerva: And look - now that the microwave stopped, the video is loading just fine :)
Adabot: Excellent - we are now noise free!
Adabot: But why does electrical noise cause problems like that?
Minerva: Too much electrical noise can confuse or overwhelm a circuit. Engineers often have to work on reducing electrical noise in their circuitry because less electrical noise makes a circuit work better.
Adabot: Oh - just like how it’s hard for someone to do work when there’s lots of regular noise around.
Minerva: Exactly! OK - now that the wifi is working, let’s try the Walkie Talkies again.
Adabot: Hello Minerva Can you read me? Over.
Minerva: Loud and clear! So what was it you wanted to ask me?
Adabot: Oh right! Would you like to come over here and watch a movie with me?
In electronics, noise is an unwanted disturbance in an electrical signal. Noise generated by electronic devices varies greatly as it is produced by several different effects.
In communication systems, noise is an error or undesired random disturbance of a useful information signal. The noise is a summation of unwanted or disturbing energy from natural and sometimes man-made sources.
- via wikipedia
Lots of things can generate electrical noise. Some common sources are:
- DC Motors
- Fluorescent Lighting
- Radio Equipment (including WiFi & Bluetooth)
- Power Lines
- Welding Equipment
Electrical noise can be kept out of a circuit by using conductive shielding which is connected to ground. This electromagnetic shielding can absorb electrical noise and prevent it from escaping or entering a circuit. When a digital or audio cable breaks or wears out, you can usually see the shielding show through the cable's outer layer.
Electromagnetic shielding can also take the form of metal enclosures or 'cages' mounted directly on a device's circuit board as seen above.
Learn more about electrical noise by checking out these links: