14 Replies Latest reply: Feb 20, 2013 1:56 AM by Meisuna
Kena1921 Level 1 Level 1 (0 points)

Hi

 

I've noticed that when my iPad is charging in it's dock that the back of the iPad gently vibrates and there is a tingling feeling when touched.  I have found a lot of similar posts across the web but none give a definitive answer.  Does anyone know if this is normal behaviour or is there a problem?

 

Many thanks


MacBook Air
  • carl wolf Level 6 Level 6 (14,295 points)

    It's normal.  The "vibration" is an electrical sensation, with a frequency that is equal to the AC imput line frequency (50 or 50 Hz).  In order to meet the international radiated emissions requirements, the power adapter places one-half of the line voltage on the iPad chassis.  Although it can be annoying, the current is very low - well within the international safety standards.  This sensation may be alleviated by turning the AC plu 180 degrees.  The sensation can be eliminated completely by grounding the power adapter or iPad, while it is charging.

  • Kena1921 Level 1 Level 1 (0 points)

    Many thanks for the reply.

     

    Could you expand on the following...

     

    This sensation may be alleviated by turning the AC plu 180 degrees. 

     

    and

     

    The sensation can be eliminated completely by grounding the power adapter or iPad, while it is charging.

     

    many thanks

  • Apfelwurm Level 4 Level 4 (1,700 points)

    carl wolf wrote:

     

    In order to meet the international radiated emissions requirements, the power adapter places one-half of the line voltage on the iPad chassis.

    I hope that you are joking!

    In my country we have a line voltage of 230 Volts. According to you, there would be a whopping 115 Volts on the chassis of my iPad when I recharge it!

     

    carl wolf wrote:

     

    This sensation may be alleviated by turning the AC plu 180 degrees. 

    Huh?

     

    carl wolf wrote:


    The sensation can be eliminated completely by grounding the power adapter or iPad, while it is charging.

    If that were true, don't you think that Apple would have to issue a very serious health and safety warning when an iPad user recharges his/her iPad?

  • blitzteh Level 2 Level 2 (175 points)

    Uhm, this is abnormal

     

    The iPad should never vibrate, I highly suggest that you bring your iPad to an apple store or certefied apple reseller. It may be caused by a part that is not functionally very well.

  • Apfelwurm Level 4 Level 4 (1,700 points)

    Why are you replying to me instead of to the OP?

  • blitzteh Level 2 Level 2 (175 points)

    to carl, im with the same argument as you

     

    the vibrating sign should be a red flag that something is wrong with the ipad, it may be at higher risk of fire

  • smscca Level 1 Level 1 (0 points)

    I am experiencing the same vibrating issue.  I checked my outlet and it is properly grounded.

     

    Has anyone been able to confirm that this is normal?  Has Apple resolved this for anyone?

  • Kilgore-Trout Level 7 Level 7 (27,750 points)

    I would have to vote NO, not normal. Two years of using iPads, including the new iPad since the 17th, and I have NEVER experienced that. And although I do have quite a bit of respect for Carl wolf's opinion, I'm not quite drinking the Kool aid on this one.

     

    Personally, I'd return it.

  • Edsj Level 1 Level 1 (5 points)

    I haven't come across this problem with my new I pad but maybe you could :

     

    1-Make sure that the charger plug is fully plugged in to the I pad

    2-if your lead has me damaged maybe get a new one as it may just be trying to warn you with the current passing through it.

     

    Hope this help

     

    Kind regards the sj's

  • Kena1921 Level 1 Level 1 (0 points)

    Thanks for all the replies but I have now got a definitive answer to this. 

     

    I have just been to the Apple Store at Cribbs Causeway in Bristol and spoken to two people including one on the Genius Bar.  The sensation/vibration is perfectly normal and the iPad is in fact designed to behave like this.  The reason that some iPads do this and some don't is to do with how the charger is earthed.  However the charged released is tiny and is of no danger whatsoever.  So there is nothing wrong with the iPad and it has behaved like this in these circumstanes since day 1.

     

    So thanks Carl Wolf you were spot on and everyone else can sleep safely.  Hopefully others in this situation will pick up on this thread.

  • Kena1921 Level 1 Level 1 (0 points)

    Thanks for all the replies but I have now got a definitive answer to this. 

     

    I have just been to the Apple Store at Cribbs Causeway in Bristol and spoken to two people including one on the Genius Bar.  The sensation/vibration is perfectly normal and the iPad is in fact designed to behave like this.  The reason that some iPads do this and some don't is to do with how the charger is earthed.  However the charged released is tiny and is of no danger whatsoever.  So there is nothing wrong with the iPad and it has behaved like this in these circumstanes since day 1.

     

    So thanks Carl Wolf you were spot on and everyone else can sleep safely.  Hopefully others in this situation will pick up on this thread.

  • Philly_Phan Level 6 Level 6 (12,350 points)

    Kena1921 wrote:

     

    Could you expand on the following...

     

    This sensation may be alleviated by turning the AC plu 180 degrees.

    That is certainly true in the U.S. and other countries with 110VAC.  I have two 110VAC lines coming from the power company.  Each one is 110VAC relate to earth ground.  They're phased 180 degrees apart and there is 220V between them.  In my house, earth ground is obtained by a connection to the cold water pipe on the feed side of the meter.  Also, a "Neutral" is created by a connection to ground.  Although they are carried on separate physical wires, Ground and Neutral are electrically identical.

     

    "Normal" appliances and receptacles utilize the 110VAC line and the Neutral line.  The ground wire is carried as a safety mechanism in case the Neutral breaks.  (Otherwise, the human might provide a path to ground, which is unpleasant, at best.)  Heavy duty appliances (such as electrical clothes dryers) utilize both 110VAC lines and no Neutral and operate at 220VAC.  The Ground is still present for safety.

     

    SOME 110VAC devices have plugs that include a third prong for Ground.  These plugs can not be reversed 180 degrees.  SOME 110VAC devices have plugs that do not have the third prong but are mechanically polarized (one prong is wider than the other).  These plugs also can not be reversed.  The Apple charger does not have a Ground prong and does not have a polarized plug and therefore can be reversed.

     

    Turning the plug 180 degrees changes which wire inside the charger is connected to Neutral and therefore to Ground and that frequently eliminates what we refer to as "60 cycle hum" (in the old days, Hz was known as cycles/second).

     

    By the way, my reference to "110V/220V" is the result of common usage where I grew up.  Others call it 115V/230V or even 120V/240V.  The actual values could be anything in that range.

     

    Now, can anyone educate me regarding the wiring Europe?

  • smscca Level 1 Level 1 (0 points)

    This is certainly good news.  I am very glad this vibration when charging is normal.

  • Meisuna Level 1 Level 1 (0 points)

    My iPod does this too, and so does my Macbook. I am still not entirely sure what it's about exactly despite all the replies but it seems that it's normal for pretty much all Apple products to do this when charging. At least all of mine have. It doesn't seem to be of any harm though--haven't had any problems because of it.