If you're going to China or Tibet, don't forget to pack your plug adapters and voltage converters along with your hair dryer and alarm clock. Because of various engineering influences, China has several types of electrical sockets, but with a good adapter set you should be fine.
Voltage in China is 220V/50HZ. In Mainland China, Tibet, Hong Kong, and Macau, the common power voltage is 220 Volt 50 Hz AC.
Before you use an American appliance in China, you'll need a voltage converter or transformer. Most North American countries use 110V electricity, while China uses 220V electricity, and if you try to plug an an appliance in using just a plug adapter, you'll ruin your appliance and might destroy the socket and cause an electrical short. Voltage converters and voltage transformers "step down" electricity to 110V, so your appliances will run properly. You'll want to check how many watts your converter or transformer can handle: It's best to buy a converter or transformer that can handle at least 25 percent more wattage than the appliances you plan to use. Not all appliances will need a voltage converter
The Accepting Wall Sockets in China
Now to the actual wall sockets, the photo below is what most wall sockets look like these days in China. The top socket takes a two-prong plug. The prongs must be the same size ("Type A"), although many modern devices with Type A plugs have one wider prong. This type won't fit into a Chinese wall socket and will require an adapter. This socket will also take a "Type C" or "Type F" plug that is standard in Germany.
Adapters to Bring or Buy
You can buy adapters before you leave at travel-supply stores and electronic stores. Airports also sell universal adapters, especially in the international departure gate area. But if you don't get one before you go, you'll be able to pick them up easily in China (and they'll be a whole lot cheaper). Your hotel should also be able to supply you one for free during your stay.
Converter or Transformer
Most travelers to China will probably need only a voltage converter, a small box that uses a plug adapter to plug into the socket. A voltage converter is useful for small appliances like a hair dryer, electric toothbrush or an alarm clock. A dual-wattage voltage converter can switch from 50 watts (for non-heat producing appliances, like a clock) to 1,600 watts (for hair dryers or irons). It's not a good idea to use complex electronics on the 1,600 watt setting, though, as this will eventually burn out both the appliance and the converter. If you're planning to bring a large appliance that will use electricity for long periods, such as a television, you'll need a voltage transformer.
China has three types of plug. The most common type of plug is similar to an American two-pronged plug, but the Chinese plug has shorter prongs without the holes found in American plugs, so you'll still need to use an adapter because the American plugs will be too large for the sockets. Australian engineers brought the Australian three-pin plug to China; this "Type I" plug has three flat prongs, with the top two diagonally slanted toward each other. British "Type G" plugs, with three rectangular prongs, are also found, especially in the former British colony of Hong Kong.
You might want the security of knowing you have everything you need before you leave, but it will be cheaper to buy plug adapters in China. Your hotel also might provide plug adapters. If you're bringing your laptop to China, you might not need to use a voltage converter because many laptops are designed to handle 220V electricity. Check your power pack, which should state the amount of voltage your laptop can handle. If you're staying in a mid-level or luxury hotel, your room already might have 110V converter plugs built in.