One of the problem with moving between countries is that there is no universal standard for AC power. Voltages (110V to 220V) are different. Plug shapes are different. If you are traveling for a short time, often you get away somewhat if your hotel supplies the necessary adapters or wall sockets. For example, many good hotels in Hong Kong and China provide American type of sockets for power cords. Although the voltage level is different: US is 110V, China and Hong Kong is 220V, at least if your gadget chargers can take "universal voltage of 110V-22V", you can just plug your gadget chargers directly into the sockets.
For long term living in an apartment or home in Shanghai, you should plan a little ahead:
The normal three pins socket in China has three blade type holds at an angle, very different from the US sockets. However, luckily many sockets also have the two prong blade+circular holds that will accept US style two prong plugs.
Even if you can plug your American style two prong plug into one of these two prong sockets, remember that the voltage is different. If your appliance, or you power supply, is not designed to accept universal voltage, it will likely burn up. However most modern power supplies, like iPhone chargers, are universal and they will just work.
A classic mistake is when you try to plug an American power strip into these sockets. The power strip often has electronics in them for spike protection, but they are rated only for the American 110V. Plugging in one of these power strip will likely result in a small bang and smokes.
- This wiki page list all the voltages around the world,
- and here is all you need to know about different plug/socket types