We have a 22 inch Samsung we got at Costco several years ago. The swivel mount is one we bought at Camping World. It's one of the few things I would ever recommend from that source, but it is very strong, and locks in place so the TV stays put for travel.
Ours is mounted using the corner "stud" above the drawer stack at the foot of the bed. It can swivel fully to be seen at the dinette. It uses a transformer/brick to convert to 13 or 14 volts, and uses very little power, so I can use a small 12volt to 120 volt plug-in inverter if I don't want to power up the 1500 watt one for the whole house.