Eliminating radio interference from Apple charger

&gt; This radio interference was also present on the aviation frequencies (around 124 MHz)<p>How did this thing get FCC approval? What&#x27;s it&#x27;s FCC approval number? Who tested this thing? Want to look that up.<p>If RF got outside the charger and into the USB cable, it&#x27;s very badly designed. The power in the USB cable is DC. There shouldn&#x27;t be any significant RF component. There should be ferrite beads and capacitors in the power supply to deal with this. When the filtering is close to the switcher, it&#x27;s much easier to deal with the noise, and very small ferrite beads, available in surface mount, can usually do the job. Once it gets out on an external wire, it&#x27;s hard to filter.<p>This is an old problem for Apple. A report from 2013, from a pilot charging an Ipad in an aircraft.[1]<p>[1] <a href="https:&#x2F;&#x2F;pointsforpilots.blogspot.com&#x2F;2013&#x2F;06&#x2F;radio-interference-of-12v-ipad-charger.html" rel="nofollow noreferrer">https:&#x2F;&#x2F;pointsforpilots.blogspot.com&#x2F;2013&#x2F;06&#x2F;radio-interfere...</a>

I&#x27;m quite frankly amazed that this is the first time this guy has had to put a choke on something as a radio amateur. I guess he doesn&#x27;t use HF that much otherwise he&#x27;d probably have opted to buy an entire bag of ferrites.<p>Maybe his magsafe charger really is bad, but if it&#x27;s plugged into a computer or a crap charger it&#x27;s also likely that it&#x27;s just RFI riding the cable straight out of the computer. USB stuff is the worst offender in my shack -- the majority of USB cables are just a complete joke.

I see something that <i>looks</i> like a MagSafe puck with a black plastic piece snapped on for some reason.<p>Are we sure it’s a <i>real</i> MagSafe puck? The article didn’t check that.<p>Sadly copies of Apple stuff are so rampant, especially on Amazon, if you didn’t buy it yourself from a reputable retailer. It’s quite possible it’s a fake. The little white charger bricks were copied rampantly. With Apple’s prices the fakers stand to make a lot.<p>Given Apple’s normal engineering quality that would be my first guess. Or Bloggie’s guess it’s the PSU that’s the issue.<p>It’s interesting they found the problem, and that a simple ferrite bead fixed it.<p>But I have no doubt there are fakes out there for something g like the MagSafe puck. Without ruling that out simply declaring it a “piece of crap” seems unwarranted.

OP appears to be Finnish judging by the OH callsign - perhaps his regulator cares about all the interference to the amateur bands from cheap electronic devices. As a fellow ham I can assure you that the FCC does not care about interference from these devices if they are only causing issues for amateurs. If all the cheap switching power supplies and other devices were actually tested, almost none of them would be RF quiet (or even compliant). However the large majority of the public is not impacted by these things and so there is no real constituency to get something done.

That&#x27;s... not a magsafe charger? That&#x27;s a USB-C NFC charger. By all means show it&#x27;s shit in every possible way but let&#x27;s not grace them by acknowledging it has <i>anything</i> to do with magsafe. That&#x27;s a Applified Qi charger.

This thread looks like a relevant one to mention an issue with the Mac Studio that causes large inrush currents when you plug it in. The power connector arcs badly enough to trip a domestic 30mA RCD, it&#x27;s reproducable with several units and on different electrical circuits at both home and office.

Tangent- I had a similar problem in my undergrad EE capstone class where our serial connection to our microcontroller kept being filled with random garbage. I moved my laptop at one point - and it stopped! The charging cable had been lying across the wires for the serial bus, and apple chargers talk to their laptops over a serial protocol as it turned out. We were picking up crosstalk!

I heard years ago, Steve Jobs wouldn&#x27;t allow a choke on a cable because they looked bad. A chronic problem as long as Apple has existed?

Once upon a time, when I was working at Broadcom, I put on a nice demo for some colleagues.<p>I had a long serial line strung across my desk from a USB-Serial dongle to an embedded board. It ran under the LCD monitor. Weird banding and noise was showing on the monitor.<p>The demo was: &quot;watch the artifacts on the monitor go away, as I clamp this ferrite bead around the serial cable&quot;.

The poster&#x27;s assumption that this is caused by the Apple product could be incorrect. The emissions could be caused by the supply equipment noise propagating down the cable. The load presented by the Apple product could induce the supply equipment to emit noise at that frequency.

&gt; Eliminating Radio Interference from Apple Charger<p>Why not notify the FCC ?

My problem with literally every wireless charger I ever used is awful coil whine or ticking noise, really disturbing if you have the charger next to your bed. I&#x27;ve tried official Apple one, Samsung one, Anker, Auckley, few other random chinese brands, and they are all so loud when charging(Samsung&#x27;s is probably the worst for it, as it has a fan inside - yes it charges my S23 pretty quickly but I wouldn&#x27;t use it anywhere other than a loud office environment). I don&#x27;t know if this is a problem of insulation or is it just inevitable given the technology used.

There was an audible digital clock noise (of the phone) &quot;ground loop&quot; when charging an iPhone 6S on the same ground potential as wireless headphones Bose QC 35 (v1) while also charging the headphones AND connected via the analog headphone jack to the phone. (The noise was very loud in the headphones while operating in a passive analog input (powered off) while charging.)<p>Moving either charger to a different ground potential removed the issue. There was probably a missing backfeed filter diode on a ground track or decoupling capacitor somewhere in the headphones&#x27; charging circuit.

Apple have form for some very odd stray vibrations around their macbook and being on charge. It&#x27;s a not-electric-but-you-think-it-is thing around soft-touching their brushed aluminium case, sometimes.<p>The &quot;gosh, this is hot&quot; thing when its on charge has been an issue from time to time, as the magsafe ages out, or some component on the mac board. Apparently its caused by HF on top of the desired DC, leaking out the componentry somehow as mechanical vibration.

Pretty detailed and creative write-up, but my first thought was “how would it have worked with a 20000mAh battery ?” - admittedly a cludge, but could be much simpler..

From a marketing standpoint, Apple managed to turn &quot;The Notch&quot; into a feature. Whether they could do the same with &quot;The Lump&quot; is asking a lot IMHO.<p>Perhaps (as the author says), the engineers could come up with something more elegant.

The other day I used one of those ultrasonic eyeglasses cleaning machines while I had my AirPods Pro in and they went crazy with static as long as I had the machine on.

&gt; The final product showing the ferrite bead with three wraps of the interference causing USB cable around it.<p>Isn’t that just two wraps? Or two and a half at best?

I wonder if someone suggested this at apple and was overruled because a bulky ferrite would &quot;look bad&quot;

Did the ferrite on the power cord , reduce the charge efficiency ?

so does this make charging more efficient? does it help preserve hardware in the long-run?<p>is there a guarantee that these frequencies weren&#x27;t added in for some engineered purpose?

Seems like an FCC complaint is in order

&gt;But it really bothers me to buy 40€ product and I still need to fix it with component costing over 2€<p>Honestly doesn&#x27;t surprise me. I hold the same kind of sentiment after spending $1200~ on a brand new iphone 14 pro max just to find that I had to buy the charger brick so I could plug it into a wall. Come on Apple. Eliminating QOL things doesn&#x27;t just automatically equal improvement.