The hand-crank horn is a power-free alarm device that delivers an effective warning in any location without access to electricity. To operate it, simply turn the handle clockwise. Once the speed reaches 50-80 revolutions per minute, the alarm will produce a sharp, powerful, and penetrating sound. The volume of the alarm directly depends on how fast you turn the handle. The newer models feature a shutter mechanism in the sound window, allowing users to quickly close the opening and block the sound, enabling different signal patterns. This advanced feature is not found in older versions.
**Hand Series**
The hand alarm is compact, lightweight, and highly portable. It requires no tools for installation and can be operated with just 0.15 square meters of space and one person standing. Its ease of use makes it ideal for quick deployment in emergency situations.
It is widely used in civil defense, detention centers, prisons, mines, airports, pastures, oil depots, warehouses, hotels, and other commercial facilities as a reliable alarm system during critical events.
**Use of Hand Alarm**
Primarily designed for emergency warnings, this alarm is easy to carry and commonly used in flood control, disaster prevention, forest firefighting, military operations, and public or industrial settings where immediate alert is essential.
**Traditional Alarm Principle**
Traditional alarms rely on vibration sensors. When these sensors detect movement or vibrations, they automatically trigger an alarm. However, this can lead to false alarms from natural events like thunderstorms, animals, or even vehicles nearby.
**Hand Siren Principle**
The hand-cranked siren works by manually rotating the handle, which drives a gear system to increase the speed. This high-speed rotation then moves a sound wheel, generating loud and powerful sound waves. The initial speed of the handle directly affects the alarm's effectiveness—higher speed means louder sound. Factors such as the user’s height, strength, and shaking speed all influence the sound quality. Therefore, we recommend a minimum cranking speed of 90 revolutions per minute to ensure optimal performance.
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