What element is changed to use the same appliance in US and in Europe ?

Hi,





We can often see the same household appliances in Europe, Asia or America even though the voltage is different.


They don't use a heavy voltage converter, so what element is changed in the appliance in order to use it anywhere ?





Thanks|||As the supply voltage differ at thes places the the voltage has to be stepped up or down depending on the supply voltage.





It is done by a step up or down transformer or by smps (switch mode power supply)





In some appliances it is built inside and the selection of voltages is done by a switch.