About USB cables.

Hello Everybody!!!

I have 2 USB cables with something fatter closer to the mini USB plug.
One is fatter than the other. This cable is way thicker too.

What are this things in the middle, resistors, regulators?.

I busted my best computer charging an eCig from the USB port.
Little did I know this could be a problem.
It started crashing with the regular(no bulge) USB cable,
and kept on crashing with the bulged ones too.
Until it finally went blank, as in white.
The info is there, but I can’t see it.
But that’s off topic now I guess.

What I wish to know is what’s that
fat thing in the line of the cable.

Thank you very much for your help. Carlos.

If it looks like this:

It is a ferrite core:

Purpose is to block high frequency noise.


It looks like that, yes. Round.

Which bring another question. Is this better, worse? for charging
USB devices or it’s just for audio.
Please, reply at you leisure. I know you must be busy.

Thank you for your prompt reply. Carlos.

The ferrite cores are helpful if you have a lot of EMI flying around, and you have long cables. They are typically used on data transfer and audio cables, to help block some of the interference, because a long cable acts like an antenna. Having one on a charging only cable is not always necessary, since there is only DC voltage going through.

Feel free to correct me if I am wrong.

It does not affect charging. It very seldom affects anything*, but some equipment requires it to follow regulations.

*A (very) few times it is vital for correct function.

Hi musicmagic, If someone is going to correct you, rest assured it won’t be me.
A Higher Authority saw your reply and made no corrections. So you’re All right!!.
Thank you for your reply!!.

HKJ, I could have PM you with the questions.
I’m totally convinced that you knew the answers.
But maybe someone else will benefit from this knowledge.
I know I have. I keep indebted to you.

Thank you very very much. Carlos

P.S. I can’t blame the cables for my computer loss. DAYUM!!!.

I bet a lot of us are enjoying learning what that mysterious little thing is.

Also known as a “RF (radiated frequencies) Choke”, Common-Mode Choke and AF and Power Supply Filter Chokes.

RF Choke - Chokes for higher frequencies often have iron powder or ferrite cores. They are often wound in complex patterns (basket winding) to reduce self-capacitance and proximity effect losses. Chokes for even higher frequencies have non-magnetic cores and low inductance. A modern form of choke used for eliminating digital RF noise from lines is the ferrite bead, a cylindrical or torus-shaped core of ferrite slipped over a wire. These are often seen on computer cables. A typical RF Choke (RFC) value could be 2 millihenries.

Common-Mode Choke - Common-mode chokes, where two coils are wound on a single core, are useful for prevention of electromagnetic interference (EMI) and radio frequency interference (RFI) from power supply lines and for prevention of malfunctioning of electronic equipment. They pass differential currents (equal but opposite), while blocking common-mode currents.

AF and Power Supply Filter Choke - Audio frequency chokes usually have ferromagnetic cores to increase their inductance. They are often constructed similarly to transformers, with laminated iron cores. A major use in the past was in power supplies to produce DC current, where they were used in conjunction with large electrolytic capacitors as filters to remove the AC ripple at the output of rectifiers. A rectifier circuit designed for a choke-input filter may produce too much DC output voltage and subject the rectifier and filter capacitors to excessive in-rush and ripple currents if the inductor is removed. However, modern electrolytic capacitors with high ripple current ratings, and voltage regulators that remove more power supply ripple than chokes could, have eliminated heavy, bulky chokes from mains frequency power supplies. Smaller chokes are used in switching power supplies to remove the higher frequency switching transients from the output (and sometimes from feeding back into the mains input); these often have toroidal ferrite cores. A typical inductance value might be 10 Henries (or much more).

Chokes are VERY common and generally used on low power (amps or watts or both) equipment that transmit or receive data or signals that might be in an area exposed to high voltage devices or exceptionally noisy (non-sine wave) devices.

It is a common mode choke, or at least "would be" choke, it only has 1/4 turn.

I bet I’m enjoying having more cables than you.
With and without that mysterious little thing.
How’s that for sarcasm and stupidity.
I bet I beat you at that too.
Only I never speak for a group.
If I would, i’ll respect the group more than you.

Arte soy entre las artes, y en el monte, monte soy. —— Jose Marti.