Also known as a wristwatch, it refers to an instrument worn on the wrist to time/display time. In English, watch is derived from the word wacche in the Middle Ages. The watch strap is usually made of leather, rubber, nylon cloth, stainless steel and other materials, and the "watch head" that displays the time is tied around the wrist.

 How does a watch work?

 The manufacture and production of watches are based on a simple and ingenious invention, the "spring". It tightens and stores energy and releases it slowly. In order to push the running device and pointer in the watch to achieve the function of displaying the time. This spring arrangement in the watch is called the main spring. Watch structure A watch consists of a watch head and a watch strap. The parts of the watch head include: movement, case, bottom cover, mirror, literal (often called dial), pointer, handle (time-adjusting, also called pressing), order (required for some watch types). How a watch works, a watch is a precision instrument used to indicate time. The principle of the instrument is to use a vibrating system with a constant period, continuously vibrating as a standard. If you know the time (vibration period) required by the vibration system to complete the full vibration of a watch, and calculate the number of vibrations, then the time elapsed after so many vibrations is equal to the vibration period multiplied by the number of vibrations. That is, time=vibration period×vibration times.

 What kinds of watches are there?

1. Mechanical watch. Timing instruments with mechanical vibration systems, such as pendulum clocks, balance wheel clocks, etc. Its working principle is to use a constant period, continuous vibration of the vibration system.

2. Electronic watch. The basic part consists of electronic components. The working principle of electronic clocks is designed according to the physical phenomenon of "electricity generates magnetism and magnetism generates electricity". That is, the electrical energy is converted into magnetic energy, and then the magnetic energy is converted into mechanical energy, which drives the hour and minute hands to run to achieve the purpose of timing.

3. Transistor balance wheel watch. It is to use dry batteries as energy, transistors as switches, and balance springs as oscillation systems.

4. Quartz watch. The "quartz crystal" is used as the oscillator, and the motor is controlled by electronic frequency division to drive the pointer, and the travel time is very precise. Electronic line watch.

5. Light wave table. Through the built-in radio wave receiver and antenna of the watch, the solar-powered radio-controlled watch receives the "standard time" radio waves sent by the transmitting tower, obtains data such as time and calendar, and automatically corrects the time and date of the watch.