Does your laptop give you tiny electric shocks when you use it? Do you feel a strange buzzing sound when you touch the metal case?
If the answer is yes, your next logical questions will probably be “what is the cause?” and “is it dangerous?”.
I’ve been getting these little dumps from metal-cased laptops for years. When I first felt them, I was understandably upset, but if they’re uncomfortable, they’re not dangerous, and there are things you can do to reduce the problem.
Where does the problem come from ?
Simply put, what you experience is a slight electric shock coming from the power supply, traveling along the cable and grounding itself through the case. This is a tiny amount of current – on the order of microamperes – which is in no way harmful or dangerous.
It’s just something switching power supplies do.
To add other variables to the mix, first of all, not all loaders do this. Oddly, Apple has built a radio frequency noise cancellation feature into its chargers, which seems to make them more likely to deliver small shocks.
The shocks can also vary. Sometimes you don’t feel them, sometimes it’s tingling, other times it’s quite unpleasant.
Many factors must be taken into account
And there are a lot of other variables. For example, the surface the laptop is on, what you are standing on, where on your body the laptop contacts (the skin is thin on the undersides of the arms and wrists, as well than on the backs of your hands, so you feel the shocks here more than, say, on your hands), and the part of your body that comes in contact with the metal body (the small areas of contact concentrate the small shocks ).
Different laptops are also a factor. Personally, I find the MacBooks and MacBook Pros to be the worst. Another factor is the different chargers.
Weather conditions also play a role, with hot, dry air compounding the problem as the load cannot dissipate as easily and your skin perspires more, which promotes conduction. Plus, if you’re using a laptop in a T-shirt, you’re more likely to experience the tingles and pops of juice than someone who wears long sleeves.
And there are people who don’t feel anything at all.
What solutions exist?
I have seen all kinds of solutions to this problem. In the US, UK, and EU, you can use a grounding plug adapter for MacBooks. For other chargers and other countries, it becomes more complicated, and you may need to seek help from an electrician.
I have also seen people put thin plastic film on the metal parts of their laptops to insulate them.
You can also simply not use the computer when it is plugged in. It’s not the best solution, but it works.