The air defense alarm uses the current communication means and information technology, and the alarm control center issues instructions, and all alarms sound simultaneously under the control of unified instructions. The present alarm is called electroacoustic alarm, which is different from the traditional mechanical way. It is a power amplifier composed of electronic components. In addition to sending out alarm signals, it can also be used as a loudspeaker.
Extended data:
Air defense alarms are divided into three categories, namely, early warning alarm, air raid alarm and disarming alarm:
1. The warning sound is an alarm signal when you know that the enemy is about to attack the city. Ring for 36 seconds, stop for 24 seconds, and repeat for 3 minutes. After hearing this sound, you will know that enemy planes may come to attack the city, so prepare in advance;
2. The air raid alarm means that the plane will attack as soon as it comes, so it must be guarded against. It is a short time, sounding for 6 seconds, stopping for 6 seconds, and repeating for 3 minutes;
The alarm clock will ring for 3 minutes. Hearing this sound, you will think that the air raid alarm is over.
People's Network-"916" National Defense Education Day air defense warning will be outside the Fifth Ring Road in Beijing.