There is a small box on the ceiling of the hotel room. What is the flashing red light?

Smoke alarm realizes fire prevention by monitoring the concentration of smoke. Usually divided into ion smoke alarm and photoelectric smoke alarm, the former is that when smoke enters the ionization chamber in the alarm, it will destroy the electric field balance and give an alarm;

The latter is that when the smoke enters the optical maze, the receiving tube receives refracted and reflected infrared light, causing an alarm. No matter what kind of alarm, when the smoke generated by the fire reaches a certain concentration, it will automatically give an alarm (the speaker will give an alarm sound and automatically send an alarm signal to the remote receiving host).

Extended data

principle of operation

From the internal principle, the smoke alarm realizes fire prevention by monitoring the concentration of smoke. The smoke alarm adopts ionic smoke sensor, which has advanced technology and stable and reliable work. It is widely used in various fire alarm systems, and its performance is far superior to that of gas-sensitive resistance fire alarm. ?

It has radioactive source americium 24 1 in the inner and outer ionization chambers, and the positive and negative ions generated by ionization move to the positive and negative electrodes respectively under the action of electric field. Under normal circumstances, the current and voltage of the inner and outer ionization chambers are stable. Once there is smoke, the ionization chamber outside will disappear quickly. If the normal motion of charged particles is disturbed, the current and voltage will change, which will destroy the balance between the inner and outer ionization chambers. So the wireless transmitter sends out a wireless alarm signal to inform the remote receiving host and send alarm information.

Baidu encyclopedia-smoke alarm