Socket outlet with USB ports

Interesting. I have just fitted one of these as well. On my multimeter I get the same reading on the back of a metal cased ipod - 90V ac between the case and earth. Checking with 3 other plug-in USB chargers I see between 30-90v. A quality USB charger from here http://www.allreli.com/products/power/charger.html shows the same 90v. I can't feel anything on my fingers at all - not even wet, but with a "tongue test" I can detect a very very very small voltage - much, much less than a standard 9v battery. (I presume everybody checks these to see if there is any juice left on their tongue??)

If I touch the ipod body to earth I can see a microscopically small spark.

But if I plug into the front of my computer I see 0v.

I suspect it is symptomatic of the small switch-mode power supplies they use in these chargers.

I can't explain it electronically, but obviously not knocking out the RCD so guess it is OK. Still - not what you would expect!

 

Been round the house with a genuine apple iphone charger and get 62v between ipod case and earth on every socket. I think this is normal.

 

That said, it should NOT be normal to get a tingle whilst it is on charge, therefore, if static has definitely been ruled out, then I would suspect a bad earth or connection

 

Check earthing on all systems....with correct ELI tester.
Check Main bonding.
Use an analogue meter if poss....on iphone.
You can sometimes get induced voltage on aerial leads due to local Mobile telephone transmitters etc.
RS

 

Been doing a little research on this as it's interesting. My electronics knowledge is rudimentary, but not non-existent. Found this reply elsewhere:-

"the fact that your power supply is double isolated does not mean anything.

there is most likely still at least one ceramic cap connected from the primary (mains voltage) side to the output. the purpose of this capacitor is to reduce the conducted electromagnetic interference (EMI) so that the power supply can legally be sold and meet the legal requirements that involve the leakage current being low enough not to cause a hazard to a person that touches the output connector of the power supply. the leakage current can legally be high enough to give you a real shock if your hands are wet. but not high enough to stop your heart.

the unfortunate thing is that these power supplies that do not have any ground connection on the primary side will leak some current through this EMI capacitor, so if you measure the voltage between the output and earth ground with a high impedance voltmeter you will see a significant ac voltage. that is just normal"

So, as far as my limited electronics knowledge goes, where you have a DC power supply supplied from AC mains, and the output is not grounded (i.e. just about all of them used for ipods, phones, and just about every other small appliance), the output can float at up to half mains voltage through leakage of the filter capacitors in the power supply, and this is normal. However, the leakage from the capacitors can never provide enough current to be harmful, and the amount of current is limited by regulation

I think we are seeing a problem where none exists. This article is relevant http://www.marcspages.co.uk/pq/3333.htm

 

Hmm interesting,

That said, the sparkies will be on later & will be able to shed more light on the subject

 

Well I'm NICEIC ......wear marigolds whilst using your phone.

 

I wonder what model of iPhone it is, as it may be the iPhone 4 with the dodgy aerial that needs insulating

 

Having been reading up on earth leakage, filtration, EMI, etc in consumer devices (yes I'm not so busy this afternoon ) I am now absolutely convinced this is totally normal. The standard that defines this seems to be IEC60950 which as far as I can discover specifies a (earth leakage) limit of 250µA for IT equipment. From what I am reading, the more efficient the EMI filter is the more leakage there is, so there is a play off when choosing the capacitors for the filter between better noise filtering and earth leakage. The filter capacitors in the power supply will leak current depending on their rating.

This phenomena shows up because these small power supplies don't have an earth pin (it's usually just a solid plastic guide), therefore the leakage through the filter capacitors shows up on the output side as a voltage, if the output side is earthed this leakage can be felt/measured. Safe as long as within standards. No need for marigolds My interpretation anyway!!

 

As apple themselves sell non-apple USB power supplies in their store I think this is dubious. My SF socket says it is rated 5V 2.4A just like this one http://store.apple.com/uk/product/HF059ZM/A/belkin-10-port-usb-charger. Useful article here
http://plugable.com/2014/10/02/usb-...hargers-or-charge-sync-hubs-whats-best-for-me.

 

Wouldn't surprise me if Apple started selling the new Apple iPower socket (a wall socket with integrated usb supply) How novel..... (just wait till they patent it)

 

The electrons in sockets vary dependent on where in this great country you live, lol, surely 5v at 1A is pretty damn universal.......isn't it?, or do we, as suggested, need to purchase Apple electrons and a vastly inflated cost.

 

" I can't feel anything on my fingers at all - not even wet, but with a "tongue test" I can detect a very very very small voltage - much, much less than a standard 9v battery. (I presume everybody checks these to see if there is any juice left on their tongue??)"
A 1.5volt battery maybe, Definitely nothing else!

 

Been testing 9v batteries for 50 years on my tongue. Hasn't done me any harm yet.......... tongue slightly more sensitive than wet fingers...........

 

You must have a long tongue