The smoke detectors in our house are connected to AC house power so that they continue to work even if the battery is removed. This is obvious because the green light on the battery detector stays on even after the battery is removed.
But where does the smoke detector get its power when the battery is still installed? It would make sense to me for the smoke alarm to always get its power from the AC house power, only using the battery when AC house power fails or is interrupted.
But the smoke alarm batteries typically have to be replaced once a year, even though AC house power has been available for almost all of this time.
So my question is: why does a smoke alarm apparently use battery power even when AC house power is almost always available?
Thanks for any response.
But where does the smoke detector get its power when the battery is still installed? It would make sense to me for the smoke alarm to always get its power from the AC house power, only using the battery when AC house power fails or is interrupted.
But the smoke alarm batteries typically have to be replaced once a year, even though AC house power has been available for almost all of this time.
So my question is: why does a smoke alarm apparently use battery power even when AC house power is almost always available?
Thanks for any response.