What's the purpose of that magnetic ring that the Reset/Power switches and LED wires go through?

[propellerhead]

What's the purpose of that magnetic ring that the Reset/Power switches and LED wires go through?

What does it do?

 

[SWScorch]

Its supposed to reduce electromagnetic interference, but I dont think it really matters since I've only seen a few with them.

 

[lenjack]

I've never seen a case without the ring.

 

[Corporate Thug]

pics?

 

[lenjack]

I don't have a pic, but if you look at the bottom of the case, you should see the case wires to the motherboard running through a metal "donut".

 

[Cogman]

I've seen them And woundered the same thing myself. They arnt very strong magnents though.

 

[beatle]

I think it's supposed to cure computer cancer and also align all of the electrons so they're flowing in the same direction.

 

[NuclearFusi0n]

oh the ferrite peice. it reduces interference iirc

 

[Nevin]

It is a ferrite (iron) ring. With the wire(s) running through it, it forms a choke and blocks ultra high frequencies. (RF)

Those lumps at the end(s) of your monitor cable are the same thing.

Nevin House
Arctic Silver, Inc.

 

[Mday]

it is NOT a magnet. it is a ferrite choke. it's basically a piece of iron and does the job as other ppl have said. for that specific application with the reset switch, and LEDs, you can remove it if you wish.

 

[deerslayer]

I always wondered what they were for too! I always take mine out, glad it isn't important

 

[JohnPaul]

Really cheap cases don't even have them. I'm looking at one without one right now.

 

[chr6]

good question i always wondered what that thing was for. i always took it off and wore it on my pinky. i always got them in enlight cases. i usually took it off and just zip tied the wires for cleanliness.

 

[jetmech96]

Unless you guys are EMI engineers, I don't recomend screwing with them. They are there for a reason. EMI engineering is a black art. The manufacture wouldn't put things on cased unless it was for a good reason becaue it would just add to the cost of production. As an electronics engineer, I try to get the most you can, because it can never hurt to have more protection.
If you do take them off don't blame us engineers for desinging a crappy case beacuse you hear noise through you speakers or you can't tune a local radio station near your computer.

 

[nebula]

jetmech: Possibly the reason for this choke is 'cause several of these wires are for switches, the thinking being EMI may trip the switch and turn your computer on, but then again if your computer is off, then no EMI? Well, external devices I 'spose. Secondly, to reduce/eliminate high frequency noise heard from the PC speaker?

Just my engineering mind acting up again...

 

[Mark R]

The reason for the choke is because the switches are outside the metal core of the case. The high-speed electronics in a PC radiate large amounts of EMI.

A good case will have very few gaps in the metal allowing good shielding. However, the wires inside the case act as antennae and will pick up the EMI, and conduct it along their length to the switches. The switches are usually in a plastic front panel outside of the metal screening enclosure. Potentially EMI could leak out from the wires outside the enclosure.

The choke blocks the EMI before the wires leave the screened enclosure.

And yes, the cases are designed to protect external devices (e.g. radios) from the PC - not so much the otherway round.