Eliminating radio interference from Apple charger • Hacker News Board

Re: Eliminating radio interference from Apple charger

#41

Post by lxgr » Wed, Oct 04, 2023, 7:48 PM UTC

bdav2418 wrote: post #27

90-00-09 wrote: post #23

Earlier quoted context omitted.

That's not analogous. Not including the charger in newer iPhones actually reduced e-waste for me personally. I have collected many charges over the years and don't need more. When a device fails or I trade it in - I keep the charger (as most people I would think). Perhaps they should have made the charger optional... but completely agree overall with the decision not to include it.

I would agree that its fine to not include it, had they not switched to usb-c right when they stopped including bricks so all my new devices came with usb-c chargers but I only have usb-a bricks

To be fair, they did include a USB-C charger with the iPhone 11 for one year. But yeah, people on a two-year upgrade (or longer) cadence will likely not have had an Apple USB-C power adapter included with any of their devices.

Re: Eliminating radio interference from Apple charger

#42

Post by lxgr » Wed, Oct 04, 2023, 7:51 PM UTC

tails4e wrote: post #26

wyager wrote: post #22

Earlier quoted context omitted.

Probably like 98% of customers already have a USB power source of some kind, so that seems like a reasonable cut corner.

Not really, modern phones have fast charge capability that's been improving generation over generetion, so what happens is new chargers are bought to take advantage of that. The older gen chargers are E-waste either way, and apple gets to charge us for something they should have included.

USB Power Delivery has been pretty stable; even my oldest charger, bought in 2017, is capable of fast charging the latest iPhone and Android devices – except for those exclusively using some proprietary "fast charge" crap (which is strongly discouraged by the USB-C specification).

Re: Eliminating radio interference from Apple charger

#43

Post by pnpnp » Wed, Oct 04, 2023, 7:52 PM UTC

stetrain wrote: post #15

oherrala wrote: post #8

Earlier quoted context omitted.

You can be using a device and it might not harm you personally, but it could harm anyone around you using these frequencies. This includes airplanes and ground control, and boats. Your device's interference could cause problems or even life threatening dangerous situations. That's why it's illegal in many countries to cause too much radio interference (there's always some).

There's a big difference between causing interference in a receiver a few inches away versus an airplane 1000ft above you. It may be that this charger passes the legal requirements while still causing small amounts of interference when placed near a receiver.

There’s also a big difference between one charger emitting some noise, and a couple million in a big city raising the noise floor for the frequency.

Re: Eliminating radio interference from Apple charger

#44

Post by Bud » Wed, Oct 04, 2023, 7:53 PM UTC

tails4e wrote: post #26

wyager wrote: post #22

Earlier quoted context omitted.

Probably like 98% of customers already have a USB power source of some kind, so that seems like a reasonable cut corner.

Not really, modern phones have fast charge capability that's been improving generation over generetion, so what happens is new chargers are bought to take advantage of that. The older gen chargers are E-waste either way, and apple gets to charge us for something they should have included.

[dead]

Re: Eliminating radio interference from Apple charger

#45

Post by gorkish » Wed, Oct 04, 2023, 7:54 PM UTC

I'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't use HF that much otherwise he'd probably have opted to buy an entire bag of ferrites.

Maybe his magsafe charger really is bad, but if it's plugged into a computer or a crap charger it's also likely that it'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.

Re: Eliminating radio interference from Apple charger

#46

Post by CamperBob2 » Wed, Oct 04, 2023, 7:54 PM UTC

yftsui wrote: post #11

NegativeLatency wrote: post #2

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

Just contrary, cheap products / poor engineering team use them on devices such as low end laptop chargers, usually on the DC power cord to pass EMC compliance tests. A good designed product fix them in the electronic circuits.

An underrated observation. For example, the worst USB cables in my experience aren't the ones with no ferrites, they're the ones with the ferrites.

Re: Eliminating radio interference from Apple charger

#47

Post by oldbbsnickname » Wed, Oct 04, 2023, 7:58 PM UTC

There was an audible digital clock noise (of the phone) "ground loop" 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.)

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' charging circuit.

Re: Eliminating radio interference from Apple charger

#48

Post by [deleted] » Wed, Oct 04, 2023, 8:01 PM UTC

js2 wrote: post #17

Animats wrote: post #10

> This radio interference was also present on the aviation frequencies (around 124 MHz) How did this thing get FCC approval? What's it's FCC approval number? Who tested this thing? Want to look that up. If RF got outside the charger and into the USB cable, it's very badly designed. The power in the USB cable is DC. There shouldn't be any significant RF component. There should be ferrite beads and capacitors in the po…

I can't be sure this is the exact model as OP, but the FCC testing doesn't seem to indicate any issues from my brief skim: https://fccid.io/BCGA2548 (I have not read the entire report and I have no expertise in RF.)

[deleted]

Re: Eliminating radio interference from Apple charger

#49

Post by MilaM » Wed, Oct 04, 2023, 8:04 PM UTC

sdflhasjd wrote: post #28

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's reproducable with several units and on different electrical circuits at both home and office.

I noticed exactly the same thing on a new Mac mini M2 base model when I conncted the power cord. Now I'm relieved that it seems to be a common problem.

I don't know anything about electronics. Do you think this is some kind of defect or bad design of the power supply?

Re: Eliminating radio interference from Apple charger

#50

Post by [deleted] » Wed, Oct 04, 2023, 8:06 PM UTC

SV_BubbleTime wrote: post #38

Animats wrote: post #10

> This radio interference was also present on the aviation frequencies (around 124 MHz) How did this thing get FCC approval? What's it's FCC approval number? Who tested this thing? Want to look that up. If RF got outside the charger and into the USB cable, it's very badly designed. The power in the USB cable is DC. There shouldn't be any significant RF component. There should be ferrite beads and capacitors in the po…

>The power in the USB cable is DC. There shouldn't be any significant RF component. Well that isn't even remotely correct. Any time you have switching, which this does, in DC you have VERY high frequency components in every rise and fall time. Much faster than your period or switching frequency, it's all about how fast you rise/fall. You switch, rapidly, through anything that has inductance, and you have RF.

[deleted]