Comment

In the US, telephone land lines actually carry their own DC electrical charge which is provided by the telephone central office and travels through copper wires to each phone.

This is why, during a power outage in the US, a land line phone will typically continue to work. The exception being if the outage is large enough to also take out the central phone office.

source

Sort:hotnew top

spankmonkey@lemmy.world ⁨1⁩ ⁨month⁩ ago
The central phone office frequently has its own backup generators or independent power supplies which is what I was referring to.

source
- LilB0kChoy@lemm.ee ⁨1⁩ ⁨month⁩ ago
  Gotcha. That makes sense why the phones always seemed to work in every power outage. I wanted to mention the 48 volts DC setup because I’m not sure if that’s common or standard outside of the US.
  
  source
  - spankmonkey@lemmy.world ⁨1⁩ ⁨month⁩ ago
    Oh yeah, your comment was a great addition!
    
    source