51
Condor
6y

Woohoo! 32k achieved!!! Finally I can post some new rant without risking some sudden overshoot 😁

So putting celebrations aside for a minute, a while ago I've noticed a tingle when I stroke my finger across metal areas of my tablet, or the sides of my phone (which probably has metal near it too) while it's charging. And it's been bugging me ever since.

Now, some things to note are that it only happens when my feet are touching the ground though slippers, and that the frequency is so low that I can actually feel the tingle when I slide my finger across the material. This to me at least seems like electricity flows through me into ground, and touching the ground directly provides a path so easy for the electrons to run away that I don't feel it at all. But if I lift my feet off the ground entirely, I just get charged up and after that, nothing else happens.

So those are my ideas. The answers on the subject on the other hand.. absolute cancer. Unsurprisingly, most of them came from Apple users. Here's some of them.

https://discussions.apple.com/threa...
- I've not noticed it, but if you're concerned bring the phone to Apple for evaluation.
- Me too facing same problem.. did u visit apple care?
And one good answer at least...
- google emf sensitivity, its real. You are right, there is a small current flowing through your body, try to limit your usage. The problem with this issue is those who aren't affected (lucky ones for now) will tell you these products are 100% safe. To a degree they are, i used my ipod touch for about 2 years straight vwith virtually no symptoms. then the tingling started and it gets worse.You will get more sensitive to progressively less powerful things. I dont want to scare you but just limit your usage like i didnt do 🙂

Overall that discussion was pretty good actually, aside from "bring it to the Genius Bar, they'll know for sure and not just sell you another unit". But then there's Reddit.
https://reddit.com/r/iphone/...
- Ok, real reason is probably that the extension cord and/or outlet is probably not grounded correctly. Either that or you are using a cheap knockoff charger.
Either use a surge protector and/or use the authentic Apple Charger.
- It's not the volts that hurt you, it's the amps
- I think you are in deep love with your phone. That tingling sensation is usually referred to as "love" in human language.
- Do less acid, I would advise.

Okay, so that's the real cancer. Grounding issue sounds reasonable despite it being wrong. Grounding is actually not needed when your charging appliance doesn't have any exposed metal parts. And isolation from high voltage to low voltage side actually happens through things like routering holes into the PCB, creating spark gaps, and using galvanic isolation through things like optocouplers. As for a surge protector? I'm using them to protect my PC and my servers, but the only purpose they serve is to protect from.. you guessed it.. voltage surges, like lightning bolts hitting the grid. They don't do shit for grounding or reducing this tingle! What a fucking tool.

It's not the volts that kill, it's the amps.. yeah I'm sure that the debunking of that is easy to find. Not gonna explain that here. And the rest of it.. yeah it's just fucking cancer.

Now what's the real issue with this tingle? It's actually a Class-Y rated (i.e. kV rated) capacitor that's on the transformer of any switch-mode power supply, including phone chargers. If memory serves me right, it helps with decoupling the switching noise and so on. But as it's connected to the primary side of the transformer, if the cap is sufficiently large and you are sufficiently sensitive, it can actually cause that tingle by passing a fraction of the mains electricity into your body. It's totally safe though, as the power that these caps pass is very small. But to some, it's noticeable.

Hope you found this interesting! And thanks a lot for bringing me to 2^15. I really appreciate it ♥️

Comments
  • 5
    FFS, I should post more :P
  • 5
    @Haxk20 My actual rants never get a lot of ++ but my memes always do.

    Baffles me because of how many people here complain about them lol
  • 3
    @Haxk20 @irene Technically… more like a diode or a battery, but yeah.. electrifying!! Bzzt!
  • 2
    @Observable But why?
  • 1
    @olback @Observable Weird flex but okay
  • 1
    My GF's Surface Pro does this, and it's been bugging the both of us since it first happened. Thanks for clearing up!

    And, of course, congratulations 😁🎉
  • 1
    Chargers are usually not grounded. Certainly not Apple ones (Unless you're in the UK). That's BS. Some laptop chargers are grounded but not all of them. The amount of power going through you is nowhere near enough to hurt you. If it were, that would mean that holding on to the end of the charger would kill you.
  • 2
    @Observable Was this for fun or a bet?
  • 1
    That was interesting to read.
    Here is a ++
  • 3
    @Nanos now that fridge might be a case of bad grounding actually. Be sure to unplug the fridge at some point and see whether the screws short to the ground pin. If not, open up the fridge and connect ground manually (it'll probably be left floating) or replace the fridge, depending on what's easiest in your case. In a worryingly large amount of countries, proper grounding is still not a thing.

    As for the floor I have, it looks like carpet but it's actually a stone floor with heating elements in it for floor warming. I've checked it before and it's a reasonably good grounding path, to the point where I feel like I have sufficiently eliminated ESD when I service boards barefoot.

    My best guess at my slippers giving this tingle could be capacitive coupling between my body's parasitic capacitance and ground. That'd also explain why it goes away when I directly touch the ground, because then my body is shorted directly to ground, hence why the electron path becomes so easy and the voltage collapses to the point where I can't feel it anymore. It's just my theory though, and I'd really appreciate discussion on it.
  • 3
    @Stuxnet I for one am always here for a good meme. Rants are 50/50: I find them good or I don't even understand what they are about 😁
  • 3
    Oh and congrats @Condor 🎉 quite a milestone, however probably not hard to reach when you're in all the threads 😂
  • 2
    @Elyz thanks 😁 and yeah I probably am.. I should definitely try to manage my time on devRant a little bit better, haha. Pretty sure that it'd easily be several hours a day at this point 😅
  • 1
    Even double-insulated devices can have ground faults, it's just very unusual. I had the same problem with a laptop 20 years ago.

    After many years as a electronics hobbyist, I now know that the solutions to this problem are: (1) get a new charger, or (2) add an isolation transformer between the wall socket and your charger.

    Pro tip: A new device charger is cheaper and lighter than a transformer.
  • 1
    @Nanos without a circuit diagram of that WiFi switch, it could be anything really ¯\_(ツ)_/¯
    Personally I've had some issues with some cheap powerbank controllers, of which the voltage would collapse intermittently. Probably it can be fixed by adding a capacitor on the output. Or I could get myself some different ones and only use those things for inductive loads like motors, where the effects aren't as noticeable.
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