In the last episode, we mentioned that a ‘quartz revolution’ that almost destroyed the world’s watch industry in the 1970s changed the watch from a luxury product to a cheap microelectronic product. Although the Swiss traditional watchmaking industry can be said to hate quartz watches, but from the perspective of timing and practicality, this is indeed a great revolution. In the above episode, I mainly talked about some common knowledge issues about quartz watches that netizens are more concerned about. In this episode, we will analyze quartz watches in depth from a technical perspective.
We first need to talk about the development of electronic clocks and their respective characteristics. I think that the development of quartz clocks should be divided into five generations. The first generation was a balance spring type electronic clock, which mainly appeared in the form of semiconductor clocks. It was more common in the 1970s and 1980s, and such watches were relatively rare. It has the following characteristics: the use of battery power instead of clockwork; The triode switch circuit is used for electromagnetic conversion. The balance spring is still used, with the same frequency as the mechanical watch, 2.5 Hz, 18,000 times per hour. The timer has many parts, and the accuracy of the travel time is not significantly improved.
The second generation is a tuning fork-type electronic timepiece, which has been produced by Omega and Hamilton, and has been trial-produced by Tianjin Watch Factory and Beijing Watch Factory, but the process of its development has been short-lived and has a very small amount in the world. It is characterized by high travel time accuracy (+/- 2 seconds / day); it uses a metal tuning fork oscillator with a frequency of 300-720 Hz; the number of parts is relatively small, but its detent wear is large and its life is short.
The third generation is the current analog quartz clock, which is also a watch with a very large market share at present, which is characterized by high travel time accuracy (15 seconds / month, 0.5 seconds / day, and advanced annual difference within 10 seconds); Quartz crystal oscillator, commonly used frequency of 32,768 Hz; relatively few parts of the movement, about 50 to 60 pieces, about 130 ordinary mechanical watches, more than 150 automatic watches, about 200 with calendar function; Quartz watches have fewer man-hours and lower costs, only about 300 processes, while mechanical watches require at least 1,300 processes; this watch is easy to use, a battery can run for 2 to 3 years, good stability, and no position difference ; More importantly, the movement is thin and the diameter is small, the appearance and shape can be changed at will.
The fourth generation is a digital display quartz timepiece. This type is a digital display of time. It uses large-scale integrated circuits with almost no mechanical parts to achieve diversified functions. It also uses a quartz crystal oscillator with a frequency of 32,768 Hz. Large-scale production, high efficiency of automated assembly, and low cost; but the life is not high, mainly because the life of the LCD panel is short, about 7-10 years.
The fifth generation is the radio wave watch that Citizen is now pushing. The radio wave watch has extremely high travel time accuracy. Under the condition of receiving a signal, the error is 100,000 years for 1 second. Because the traditional clocks are ‘soldier combat’, one watch is one sample, one hundred watches are 100 samples; and the radio wave watch is ‘group battle’, all the clocks are exactly the same time!
Because the radio wave watch combines traditional clock technology with modern time-frequency technology, microelectronics technology, communication technology, computer technology and many other technologies, it receives the standard time signal transmitted by the national time service center by radio long wave and is decoded by the built-in microprocessor. After that, the auto-calibration timer goes off, so that the time displayed by all radio timepieces and the national standard time are automatically maintained in precise synchronization. Moreover, China has become the fifth country in the world after Germany, the United States, the United Kingdom, and Japan to implement the long-wave time service technology for civilian use. In addition, the radio wave watch can also be used as an ordinary quartz clock in the dead zone of the signal, and the time can be automatically corrected when entering the signal coverage area.
Let me talk about the composition of the quartz oscillator. The quartz oscillator is composed of a quartz oscillator and an oscillation circuit. The oscillation frequency is generally 32,768 Hz per second. The analog quartz watch passes through a 16-level two-frequency division, and finally outputs a narrow pulse signal with a positive and negative alternating of 0.5 Hz per second. The liquid crystal display meter is divided into 15 levels of two, and outputs a pulse signal of 1 Hz per second. (Frequency division means that the same clock signal is used to convert clock signals of different frequencies through a certain circuit structure. Two frequency division means that the circuit structure has a frequency division effect. When the clock triggers every two cycles, the circuit outputs a periodic signal. For example, a pulse clock is used to trigger a counter, and the counter is cleared once every 2 counts and a pulse is output, then this circuit achieves the function of dividing by two. From Baidu Encyclopedia).
I believe that when you see the physical description above, most people will be confused. Below, I will describe the working principle in Chinese. The quartz oscillator is composed of a highly stable quartz oscillator and a part of a CMOS integrated circuit. The high-frequency oscillation frequency of 32,768 Hz is generated through the technical processing of the CMOS circuit. Finally, positive and negative alternating pulse signals are generated. The input coil and current generate a variable magnetic field in the stator and interact with the permanent magnet field of the magnetized rotor. Rotate the rotor component in a directional direction, the gear of the rotor drives the transmission gear train to indicate the second, and the hour and minute are indicated by the moving needle system. The energy consumed during the entire working process is supplemented by batteries. The drift of the quartz oscillation frequency can be adjusted by fine-tuning the capacitor, or by using a logic frequency modulation circuit in the integrated circuit.
Next I will talk about the advantages and disadvantages of the performance of mechanical watch movements and analog quartz movements. In terms of power system, the clockwork of the mechanical watch will inevitably have a torque drop, which will affect the time difference and have a great impact on the travel time accuracy. The quartz watch only needs to discharge the battery smoothly, which has little effect on the travel time. As for the transmission gear train, the mechanical watch transmits both torque and time, and it is a speed-increasing transmission, which has a great impact on travel time. The quartz watch only transmits time and does not transmit torque, and it is a deceleration transmission, which has a small impact on travel time.
In terms of speed regulating mechanism, the processing and assembly of balance springs of mechanical watches are complicated, and there are many factors affecting the vibration cycle. Generally, there will be position errors. The vibration frequency is 3 to 4 Hz, and the day difference is generally 20 to 30 seconds. Precision mechanical watch in about 10 seconds. Quartz watch has high precision, no position difference, vibration frequency of 32768 Hz, and the day difference is completely guaranteed within 0.5 seconds. The movement of the hands is basically the same, but the second hand moment of the mechanical watch is large, the second hand moment of the quartz watch is small, the difference between the two is 40 ~ 60 times. In terms of adjustment, the mechanical watch needs to move the position of the fast and slow hands, change the length of the balance spring, or change the moment of inertia of the balance wheel. Manual operation is very difficult. The quartz watch only needs to adjust the speed with the logic frequency modulation method, and has a high degree of industrialization. In addition, the mechanical watch will be affected by temperature. The high temperature meter will slow down and the low temperature meter will move faster (temperature coefficient standard: 1 second / day / degree), while the quartz watch will go up and down except for the inflection point temperature of 25 ℃ Slow (temperature coefficient standard: 0.1 second / day / degree).
The automatic mechanism of the mechanical watch can collect the kinetic energy of the human body, eliminating the trouble of winding the bar by hand every day; although the advantage of the quartz watch is that the time is accurate, less than 0.5 seconds per day, the disadvantage is that the battery needs to be replaced every two or three years. The design idea of the human power watch is to combine the advantages of the two. Japan has registered a patent for ‘Human Power’, and Switzerland calls such a structure ‘automatic quartz.’ Its working principle guides the flying tourbillon in the watch through the natural movement of the human arm, drives the micro-generator to generate current, and stores electrical energy in the capacitor storage device to provide electrical energy for the quartz movement. When the electric capacity is sufficient, the watch can be transported away continuously for more than 3 months, and the theoretical service life of the capacitor can be up to 10 years. This type of watch is called electric energy in Japan; automatic quartz in Switzerland.
I believe that after reading the above text, you will definitely have the idea of winning a quartz watch. I think that a mechanical watch is really useless, but I want to say that if you buy it to see the time, it must be a quartz watch, but if you pursue superb craftsmanship , Polished and cultural value, then mechanical watches are always irreplaceable.