Electricity in the United States
110/120 Volt AC, 60 Hz
Line voltage in the USA is 110/120 Volt AC, 60Hz.
If you intend to bring your own devices / appliances you may
be need two things:
1) An adapter plug
2) your device must be prepared to be switched to 110/120 V,
otherwise you either can't use it or you have to buy a
(relatively heavy and expensive) voltage converter, which is not
advised. Better consider to buy devices especially designed for
travel purposes - they're mostly small, light-weighted and of
course switchable to 110/120V.
These small helpers are really usefull, because they just have
one single purpose: to adapt your type of device plug to fit
into American sockets. Usually you can buy them as a 'worldwide
variety pack' in shops which sell electronic devices, luggage or
you even get them in some larger supermarkets. In this package
you find an adapter for many countries around the world. But you
should buy it in your home country, because you need all the
adapters to fit on your original plug. Costs are low, approx.
10-20 Dollars/Euro, depending on quality and brand.
Is your device switchable?
You can easy find out whether you can switch them when you turn
the device and look at each side and the bottom. There should be
this little switch labeled '110/120V'. If you can't find it,
your device is probably not switchable.
Notebooks, cell-phone charger etc.
This kind of travel proofed gear is always capable to adapt to
110/120 V and vice versa to 220/240 V. They come with an voltage
converter by nature, all what you will need is a adapter for the
plug. A note regarding cell phones: only if your cell phone standard
is capable of working on a American frequency it makes sense to
bring it to the US. If not, it also might not have the capability to
manage 110/120V !
Always check all devices before traveling and decide whether it
makes sense to take them with you.