Many cables for computers have a small, hard, round filter near one end. What are these for?
2007-05-23 05:36:15 · 6 answers · asked by Dan C 3 in Computers & Internet ➔ Hardware ➔ Other - Hardware
Those are ferrite rings or cores (ferrite is a powder pressed into a shape). They filter out high-frequency radio signals that travel along the wire. If these signals are not absorbed, they may cause interference in radios, tv's or other wireless devices that are on the same frequency.
When a video signal travels from the PC to the monitor, is is a 20-60 KHz signal (or more). WHile the monitor cable is shielded, there may still be residual signal emissions that may cause interference if not absorbed by the ferrite core.
2007-05-23 05:43:31 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Those filters (EMI Filters, bypass or "decoupling" capacitors ) are designed to minimize the EM (Electro Magentic) signal interference (EMI) with surrounding electronics. Stray EMI signals can cause distortion in electrical components.
2007-05-23 12:47:13 · answer #2 · answered by acb29 4 · 0⤊ 0⤋
If the "filter" is connected between the machine and the cable it's a keylogger. A keylogger is a nefarious little piece of spyware.
2007-05-23 12:45:01 · answer #3 · answered by pm 5 · 0⤊ 0⤋
They reduce the amount of high frequency signals that can get onto the cable. This reduces the EMI radiation from the system and helps it pass the FCC requirements.
2007-05-23 12:41:27 · answer #4 · answered by Simon T 6 · 0⤊ 0⤋
They are not filters - they are cylinders of iron that reduce electro-magnetic interference.
2007-05-23 12:39:47 · answer #5 · answered by Anonymous · 0⤊ 0⤋
They remove, or almost remove, all electrical magnetic interference that there is in the connection.
2007-05-23 12:43:56 · answer #6 · answered by carl j 3 · 0⤊ 0⤋