For example, I have an antique portable television made by the Singer manufacturing company that plugs into US mains. However, it also has a 12v DC input and can run off of that. I also have a retro CCTV monitor that uses the same 120v mains plug and has a placard on the back that says it can use a 12V 12W battery. How is this possible? If an electronic device is designed to take 12v, wouldn’t 120v destroy the device? On the other hand, if a device is designed to accept 120v, shouldn’t 12v not be enough to operate it?
Edit: added a clarifying question
In: Physics
The TV internals probably actually only run off 12 V. The TV just has an additional component to turn 120 V AC into 12 V DC, but can also take the DC directly from other sources.
Latest Answers