Ferrite: Those magic thingies at the end of your cables

You've probably noticed those strange cylinders at the end of your puter cables.
It looks a bit like the cable was a bit overzealous at dinnertime and swallowed something a bit too large...
As it happens, those strange meals are actually ferrite cores.
Ferrite is a totally magical material!
While there are many different types of ferrite used for things such as transformers, inductors, magnets in motors, and all kinds of other stuff, one of the most common uses is for ferrite chokes.
A choke is basically a filter - in this case a low-pass filter - that prevents high-frequency noise from passing along your data cable (or its shielding).
So there you have it!
More techie tips: scottiestech.info

[@BrokebackBob]

Your channel is becoming one of my favorites!

[@vulcan4d]

All cables used to have this but they started to cheap out. For those who don't fully understand physics, the energy transmitted actually travels outside the wire. This fact usually blows people's minds.

[@nicolaecampan2385]

Your clip is not useless for me, it just confirmed that the AC spindle on my CNC router was f-ing the data signal passing thru the USB cable and messing the movement of the stepper motors! Thanks for your vid, i subscribed for sure, cheers from Transylvania, Romania, Europe! :)

[@nicolaecampan2385]

@H Higgins Thank You for the reply! 😎🙏

[@deborahfischer5708]

I find your videos very interesting. With each one, I never know what new thing I will learn. I enjoy your sense of humor, too!

[@tylerjewell1040]

Spent a while looking for a video with this explanation and finally found it. Thank you. Looking to optimize a filter for fixed wing FPV.

[@kerriemills1310]

Wow! You are Amazing Scottie thank you. A brilliantly timed video, it actually helped me work on a conundrum. Brilliant thank you again.👍💫

[@felimartz]

Great video, simple, easy to digest, accurate.

[@johnnybuoy9551]

No bull crap. No Time wasting. Just To the point explanation. Very useful video

[@IceManLikeGervin]

Very interesting...great upload!

[@glenmartin2437]

Thank you. Used the clamp on ferrite beads on a very noisy switching power supply and they reduced the the hash on my speakers.

[@SteveStoltz]

Ive always kind of wondered exactly how those ferrite cores actually worked.

[@user-gk3rb3zi5i]

Thanks 4 such an easily understandable yet so informative presentation.

[@CJWarlock]

Good video. I knew that stuff already but sometimes I like to relax while watching things I know explained in someone else's way. Who has a similar habit? :) Thanks for the video. Cheers!

[@KeithCopeland778]

Thank you for a fantastic explanation!!!

[@hamedkhan5692]

thank you really appreciate someone teaching us what we never take into consideration in our daily lives... :)

[@philippedoucet3301]

Cool info. Thanks 😃

[@candrasniper3404]

I found it on my bluetooth receiver amp system. While the ground loop is existed, i hear radio signal out from the speakers. Thanks, I've known that bulky things on my cable is used for what now.

[@massoud999]

Thanks, I learned something new.

[@LosoIAm]

Great video - many thanks!

[@davidadame1313]

a video on how to wire a meter or the difference between a contactor and a relay would be cool.

[@dragan3290]

Excellent tutorial.

[@truetodo]

Always chill informative videos. Question, has ferrite been used to protect from other types of frequencies, like a Faraday box in a way? I'm not smart.

[@ProtonOne11]

Testing rooms for radio emission and immunity are usually completely covered on the inside with ferrite tiles, to keep the outside radio signals away from your measuring devices, or to keep the generated fields in the test room inside. On top of the ferrite tiles there are normally some more absorbant cones inside the room to eliminate most of the reflections of radiowaves from the walls and ceiling.

[@meulula]

Great explanation. Bugged me the lower frequency free pass through though. Do we need bigger ferrite chokers then?

[@jpsalis]

two year old comment but inductors work better at higher frequencies, I'd imagine you'd need some other solution to block lower frequency emissions

[@tyronebigsby2169]

Hell yeah thanks dude!

[@mayuresh1704]

Wonderful information, nice presented! 👍

[@corey8704]

Today Dr.Strange pulls a Big Clive and teaches us about ferrite beads with the white board. /S Good video! New subscriber.

[@ljsablad04]

This things can be use on spark plug cable on motorcycles?

[@gmtv9928]

Enjoyed your video. Would you happen to know how I can reduce the interference from tv cable and electrical cable running side by side? Whoever installed the TV cable at my home installed it next to the electrical cables/wires. I'm always getting TV screen freeze or my sound fades on my TV.

[@ScottiesTech]

If the TV cable is coax, it should be relatively immune to interference from power lines. I would check all connections first, and then perhaps any amplifiers on the line.

[@gmtv9928]

@@ScottiesTech Thank you for getting back to me.

[@songznel]

thank you i got exactly the answer i was looking for

[@spidusp]

I have couple of these ferites should i trash it or keep it?

[@chauhan-pb1oy]

what if we cover the whole wire with aluminium foil?

[@bigbob3409]

Good info 👍

[@thechinaboy]

Is mouse encoder(mouse roll) 's output high frequency ? encoder > 3 way cable > board

[@jeep970]

Hey beam me up Scotty,...that was fun .../thanks for the lesson

[@matrixmodulator]

Would it benefit to use multiple of them on the same dc brick cable? Like 5-10 on 1 cable...? What about using them on guitar cables?

[@ScottiesTech]

It might, although usually it works better to loop the cable several times through a larger core.

[@navisb8345]

Thanks brother

[@lauratiso]

I had a printer which would stop and fails if in the middle of printing someone turns on a car, microwave oven, or even lamps nearby. I solved it completely by using an USB cable with ferrite core in both sides. The one which came with the printer hasn't it.

[@davidbolha]

I have a bunch of those yoke ferrite cores from old CRT TVs/computer monitors. 😎

[@bsimpson6204]

I had a real problem with interference on the audio out from my PC to my speakers. I'll admit, it took a while for me to wake up and snap a ferrite over the cable but the affect was magic, all interference gone!

[@wally8075]

There is ferrite inside of some circuit boards. Some ferrite is coated. But what is coated onto the ferrite? I recently broke a core like this, but I saw dust come up from the break. I want to know is this stuff is poisonous.

[@davidbolha]

Definitely never scratch a magnetron's ceramic coating. 😲

[@QoraxAudio]

Why are those ferrite chokes mostly found on older cables? With the modern, higher frequencies, I would expect them to be more significant instead. Especially high bandwidth digital stuff like USB 3.1 generates a ton of noise.

[@ScottiesTech]

I suspect it's a combination of cost savings, higher frequencies (at which the ideal antenna length becomes much shorter than, say, a USB cable, and thus the cable doesn't act so much like an antenna that picks up the noise), and better overall design.

[@QoraxAudio]

@@ScottiesTech Well, the costs savings make sense. But when it comes to, for example USB noise, I was mostly referring to emission of the noise. Especially the ~2.4GHz bands, like WiFi and Bluetooth communication is are known to be susceptible to the USB 3.0 noise. Even with good shielding the noise still gets radiated, because of the capacitive coupling between the shield and datalines. But TBH, I don't know how well ferrite chokes work to prevent RF emission, since most sources only mention the filtering of incoming noise.

[@ScottiesTech]

@@QoraxAudio As far as I know, ferrites don't really do a very good job of preventing radiated noise at high frequencies. But then, I'm no EMI specialist by any stretch. That's an entire science in and of itself!

[@bionicmalice]

This is weird , my audio interface had ferrite and it was picking up signals from mouse and keyboard ,but as soon as i changed the cable of audio interface , the noise was gone...im so totally confused now lol

[@thomashardin911]

You said they cannot restrict lower frequencies like AC hum, but could it restrict 59 kHz frequency? which in deed fried an iPad recently!

[@ScottiesTech]

Maybe, depending on the ferrite used... Most of those available to snap over cables start around 150-300kHz and suppress up into the multi-MHz range... But their frequency response is pretty much a bell curve, so you would get only a little bit of attenuation at 59 kHz... AFAIK, anyway!

[@bayanicruz7311]

I have that allready in my rg8 coax cable for my 2m ham radio..good work bro..frm DX 419 philipphines

[@coondogtheman]

I have a drill charger that causes noise on an FM radio. I put one of these on the power cord of the charger on the charger end. It cut down on the noise but not all the way, Should I put another on the plug end?

[@ScottiesTech]

Or use a bigger one, and wrap the cord through the ferrite core several times.

[@viarez12]

Hello i want to ask some question. I have speaker for my computer, but i can hear radio sound clearly. Where do you think its the best to put ferrit on? Speaker power cable/ speaker jack 3.5 audio cable to my monitor or else? Im completely green, hope you can enlighten me. Thank You

[@ScottiesTech]

Try the audio cable right before it goes into the speakers. That might help.

[@surendersingal2192]

Very through explanation with diagram of wire pair n choke. Wonder of little peeson? Thank you sir.

[@robertsims6136]

NICE VIDEO

[@gabtv2754]

What is the ferrite's size for motorcycle?

[@BrokebackBob]

Hi Scottie! Are you in the age range where you built or knew about Heathkits?

[@ScottiesTech]

I know of them. We had a Heathkit color TV when I was a wee little thing.

[@kirstinstrand6292]

Thanks. Got any idea as to how we can lower your EMF'S from 5G?

[@sheamaddy9893]

Faraday cage

[@leonardoalcantara3693]

What is the size of the ferrit

[@generalawareness101]

Question: My PC is an RF hot box and anything within 6 inches becomes hot as well. Take for instance my microphone next to the pc it picks up hum and get it over six inches it goes away. I noticed on the VST (EQ) I was using that when I hooked up a DBX286s the frequencies were all over the place but the peaks were 60/120/180/etc... so 60hz mains hum with a lot of harmonics. What do I do for that?

[@ScottiesTech]

Alas, no. Ferrite blocks high frequency noise, not low-frequency. If there's a lot of 60Hz + harmonics, you may want to check your ground as well as any and all power supplies (puter, power bricks, etc). One bad supply can create lots of problems like that.

[@vientodepaz]

Scotties, please can you help me ! Rfi Emi ferrite ring suppressor with clip can i use it on my smart tv? I have a problem. when I turn on the switch on my closet (which has light savings) My smart tv blinks. thank you.

[@ScottiesTech]

What exactly is this closet switch? A timed switch or something?

[@elmoreglidingclub3030]

Great stuff!! I’m working to understand ham radio stuff; so glad I found your videos.

[@solarsynapse]

I need to block 120KHz on a 120VAC cable. Is that too low for these?

[@rexgeorg7324]

so it would have no effect on an electric cable to a lamp or kettle etc. or would it ?

[@ProtonOne11]

It would have an effect, but for 50/60 Hz AC, the impedance is so low that there is not much happening in the ferrite. Usually ferrite cores for filtering have theyr impedance specified at 100 MHz, as that is around the frequency where they present the highest impedance. And if you put both the neutral and phase wire thru the same core, you have a differential mode current flowing to your load and back, and not a common mode current. So it really depends on what you would want to filter out on that electric cable...

[@rexgeorg7324]

@@ProtonOne11Thanx ..Could it increase the efficiency of an electric kettle ? ..saving time and money

[@senzayyzone]

New sub what mic do you use for your video?

[@ScottiesTech]

Rode SmartLav!

[@96binghong]

so if I add those ferrite choke at the output cable of a sound system, it will eliminate those humming noise, is that correct?

[@ScottiesTech]

Audio hum can come from a lot of different things, but it's certainly worth a shot!

[@96binghong]

@@ScottiesTech thx for the reply,and great content,keep it up

[@josron6088]

Thanks. You explained it in such a way that even an idiot like me can understand it.

[@davidbolha]

What about yoke ferrite cores (CRT TVs) ? 🤔

[@davidbolha]

@H Higgins Aaah... thanks ! 🤔😏🖒

[@EricNorcross]

Is your co-host a tribble?

[@rogerlarson8040]

So I have an 75 watt Led light on an airplane and it creates noise on my aviation radio, any way of getting rid of this noise/ the Aviation radio is 122.976 MHZ.

[@ScottiesTech]

Hmm, that can be tricky. You seem to have figured out that when the LED light is on, the driver circuit for the LED is generating noise. Most likely, that noise is audio-frequency, and that's being coupled somehow to the radio. It could be a loose ground connection for the light, or coupling between two wires in a harness somewhere. You might try an 'audio noise filter' on the power leads for the radio (which is not just a ferrite core, but usually a capacitor and sometimes another component or two).

[@yxndis555]

What happens if a wire doesn't have a ferrite core?

[@samza9622]

Depending what wire you have and where it's at it might be vulnerable to interference or rfi/emi.

[@davidjones1393]

THKS

[@thedocnextdoor2364]

Is it really necessary to have these if I use such s cable just for charging my redmi smartphone and datacable? I'm asking this because my sony cable has broken at the base of this bead and thus I need to remove this bead to make my cable working again and wind back the cut wires...please do respond at the earliest

[@ScottiesTech]

No, they're not absolutely essential. You should be fine if you remove it.

[@thedocnextdoor2364]

@@ScottiesTechyeah I did it it gives little trouble no problem infact

[@kan815k]

Can these use on spark plug leads to improve spark?

[@ScottiesTech]

I don't think so.

[@worstalentscout]

is it safe to put a ferrite core on my 2.5 inch SATA SSD's data cable and power cable ?

[@worstalentscout]

@@randgrithr7387 many thanks for the reply............so do i need to put the ferrite a certain distance from the SSD since the ferrite's magnetic properties might harm the SSD ?

[@BabaGhanoushMusic]

I just bought a variety pack of the ferrite clips, I’m really hoping it’ll stop adding noise to my focusrite Scarlett 2i2 audio interface. I’m going to clamp every single thing I can think of. Wish me luck!

[@AZNFLACO]

I'm having the same issue now. Did it work?!?

[@BabaGhanoushMusic]

@@AZNFLACO unfortunately, not really. By now, I’ve determined the issue to be RF noise coming from my computer, but don’t know how to eliminate it (dirty air)

[@AZNFLACO]

@@BabaGhanoushMusic such a bummer. I will continue to research on how to fix it. Thanks for your reply!

[@BabaGhanoushMusic]

@@AZNFLACO of course, let me know in how it goes

[@MykEviiL]

@@BabaGhanoushMusic how did it go?

[@chachee15]

there is a radio station playing through my computer speaker and i didnt do that. will this thing stop that?

[@johnrhodes3350]

I think it will

[@chachee15]

@@johnrhodes3350 it didn't

[@johnrhodes3350]

@@chachee15 I'm Sorry, Bad Luck

[@Hi.M_Anshu]

What happens if you use two ferrite beads on the same cable?

[@ScottiesTech]

You get more noise filtering - usually.

[@Hi.M_Anshu]

@@ScottiesTech My laptop charger went bust thanks to a surge and I had an old charger with a broken tip lying around, so I tried a very crude work around of attaching one cable with another without cutting off the Ferrite bead. So from what you say, I'm guessing there shouldn't be a problem?

[@ScottiesTech]

@@Hi.M_Anshu Nope, that shouldn't be a problem.

[@Hi.M_Anshu]

@@ScottiesTech Thanks mate ✌️

[@mahrufurrahman9759]

Nice.

[@tayler2396]

Can ferrite cores be moved to a more convenient location on a cable and still be effective, as in...kzbin.info/www/bejne/a4WkoI1qlNeeZ6s ?

[@ScottiesTech]

Yes, but ideally they should remain as close to the gizmo as possible.

[@tayler2396]

@@ScottiesTech Thanks. I learned a lot from your video.

[@heaveninhell6904]

Electronics engineers knows best

[@carloslealdiaz]

Chokes on a DC wire ?

[@ScottiesTech]

Yup, that's common on things like DC power bricks for gizmos... because the switching power supply can produce 'high-frequency' noise, OR more likely because the power cable (for things like PC speakers) can act as an antenna and pick up noise from the puter, which then gets passed into the speakers and amplified.

[@carloslealdiaz]

@@ScottiesTech Please , in spanish .

[@carloslealdiaz]

Ésos cilindros están colocados en los cables sólo para causar daños .

[@davidbolha]

14 Pythons with a "swallowing problem" disliked. 😉😂😆

[@idealynx]

Hey Scottie, thanks for the video. I appreciate you taking the time to make it. A few of my dashcamtalk.com forum members and myself are having a problem with high-pitched noise coming from our Viofo A129 dashcams, but only when they are connected to the car's fusebox using a Viofo 3-wire hardwire kit. I was hoping you may be able to help. Here is the dashcam we're all using: www.amazon.com/gp/product/B07DL8MS1T/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 and here is the hardwire kit, that seems to be the root of the problem: www.amazon.com/gp/product/B07K83R5W1/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 And finally, here is the forum where this is being discussed: dashcamtalk.com/forum/threads/a129-duo-high-pitched-noise.38653/ I know I'm asking a lot, but if you have some time any advice you could give us would be very much appreciated. Thanks!

[@ScottiesTech]

Well, lessee... According to the various posts on the forum, the whine seems to come and go and it's hard to narrow it down to the hardwire kit or the camera itself. It's powered by a USB plug, and it looks like the 3-wire cable already has a big honkin' ferrite core on the cable. One thing to try is if you have a USB battery bank (like for recharging smartphones) that was a 2.1A output, try powering the cam from that battery bank with a USB cable. That should be a relatively clean +5V supply over the USB cable. If that makes the whine disappear, then it's essentially a problem with the 3-wire kit. In that case, you could try adding another ferrite to the cable (loop the cable through a bigger ferrite twice if you can), but that seems like a stretch since there's already one present. I would actually lean more towards some issue with the cam itself. The cam seems to have both WiFi and GPS, both of which could cause noise. And if it's a prob with the design of the cam, that could also explain why something seemingly goofy like changing the SD card could change the whine. That might slightly change power requirements or something, thereby modifying or stopping the whine. But in the end, if powering with a clean 5V supply (like from a Li-ion battery bank) doesn't work, and another ferrite doesn't work to block noise introduced by the 3-wire cable kit, then I'd lean towards inadequate EMI shielding/isolation inside the unit itself.

[@RevDrTCBlalock]

Bee Groovy! Much Hak5g for US ALL!

[@truck9094]

Good information

[@DarktekG]

Thx u!

[@alexbaeantenna374]

Mantap

[@TH-xo4zx]

Honestly they could fit a whole lot of shit in there if they can fit chips and beacons and shit into the cable itself seamlessly

[@dee1380]

It seems these usb cables are normally not recognized.. I have 2 of these long cables, but they are not recognizeable. Is there anythang I can do?

[@ScottiesTech]

It might be length, or it might be that they don't have the data lines connected internally and were only intended for use as power cables. Or something I didn't think of!

[@matildayuncken5174]

What would a ferrite bead do to a 5g tower?

[@ScottiesTech]

Not much. It depends on the type of ferrite itself and the frequency of the 5G system. 5G can be low frequency (i.e. 600 Mhz) all the way up to tens of GHz (millimeter wave). Ferrite is usually used to block 'high-frequency' noise that is much lower than, say, millimeter wave 5G.

[@wojomojo]

You lost me at "DC and lower frequency noise" @5:26. DC has zero frequency, so technically it can't be lower frequency.

[@ruksanaparveen6342]

Bla bla bla

[@EvoPortal]

He didn't even state what frequencies the choke works on. What a waste of a video.