There are relatively inexpensive DC to AC converters that you can get for a vehicle that connect into your cigarette lighter. THis is probably the safest way to do this.
For AC it is relatively simple from an electrical point of view. All that is required is a transformer. Even if there are other electronic solutions, unless there is good reason. Stick with the idea...
An AC adapter adapts the device that one wants to power up to the AC line. That means it converts the AC line voltage to something that can be used by the device in question. An AC adapter converts...