why do TV remotes get “weak” when the batteries start running low?

Question

I’d instinctively expect it to be more of a binary thing: they work, then when the batteries get to a certain level they completely stop working.

Instead you get this in between phase when the batteries start getting low, where you have to get closer to the TV for them to work. Why?

In: 5

Answer 1

Remotes work by flashing an Infra-red LED at a receiver on the TV, as the batteries weaken this light gets dimmer so you have to be closer to the receiver for it to be able to detected it. You can see the IR lights flashing of you look at your remote through a video camera like one your phone.