ttt ((b))

To be absolutely sure what voltage your appliances take, look on the bottom (usually near the power cord) and if it says something like "100-240V AC 50/60Hz", then it is multi-voltage, and can be plugged straight into the wall outlet through an inexpensive converter plug. My digital camera chargers are all of this type.

A dual-voltage appliance will have a switch which must be changed before you can use it on 240V electricity. It will say something like "100-120/220-240V AC 50/60Hz". Travel hairdryers are usually dual-voltage. Plug it into 240V when it is set on 120V and it will burn out very quickly.

If the appliance is "120V AC 60Hz", then it must be used with a transformer. Robespierre give a good discription, but let me reiterate: 120V electronic devices should only be used with a transformer, never with a solid-state or switching converter. A converter is meant only for short term use with heating devices such as travel irons, etc.

BTW, don't worry too much about using a 60Hz appliance with 50Hz current, unless it has a built-in clock or timer. A 60Hz clock will lose 10 min every hour when operated with 50Hz electricity, even through a transformer.