The honest answer is in the US all doorbells are powered by simple 24VAC transformers that burn 6–7 watts just being powered up, forever, for decades. This annoyed me plus I wanted a fun bell so I wired up a pi to use a modern, efficient 24VDC power supy to ring the bell and it gets turned on by the pi only when its needed so now my idle wattage is more like 0.25W.
Oh that’s a silly question. Why not?
The honest answer is in the US all doorbells are powered by simple 24VAC transformers that burn 6–7 watts just being powered up, forever, for decades. This annoyed me plus I wanted a fun bell so I wired up a pi to use a modern, efficient 24VDC power supy to ring the bell and it gets turned on by the pi only when its needed so now my idle wattage is more like 0.25W.