Look at the plug for your electronic device. Determine if the device contains any language about dual voltage.
Look for a notation about input. When you find that line, determine the voltage the device will accept. If the input is 110V to 240V, your device is dual voltage. You can use a plug adapter, but do not need to use a power converter.
Purchase a power converter if the device says 110V but does not mention 240V. Your device is not dual voltage.
Contact your travel agent or a representative at your travel destination before you travel. Plug holes, shapes and sizes vary from country to country.