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英語聽力文摘592 石英計時!

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Keeping Time With Quartz

Most people know that wrist watches commonly contain quartz. In fact, if you wear a watch, chances are it’s a quartz watch, since most watches is made today use quartz. But, you may not know what quartz has to do with keeping time.

Quartz is a mineral, otherwise known as silicon dioxide, which is common in the earth’s crust, and the main ingredient of sand. This mineral is popular with watch manufacturers because it vibrates quickly when electrically stimulated, and loses little energy when vibrating.

The steady vibrations are what allow a watch to keep time. The quartz used in watches is actually synthetic, because it vibrates more steadily than natural quartz.

Here’s how a quartz watch works. A small, paper-thin piece of synthetic quartz acts as the watch’s oscillator. Think of the oscillator like the pendulum in a grandfather clock, that by its continuous motion tells the watch how much time has passed. The oscillator is a sort of counter which ticks off the seconds, minutes and hours, and the watch displays the time counted.

When the quartz oscillator receives an electrical charge from a battery or some other power source, it vibrates at over 32,000 times per second. As it vibrates, an integrated circuit in the watch programmed to know the oscillator’s frequency regulates the vibrations so that a certain number of them equals one second.

If the watch has a minute and second hand, the regulated electrical pulses are changed into mechanical pulses that move gears and set the watch hands in motion. If the watch is digital, the quartz’s electrical impulses add up to minutes, hours, and days.

  石英計時

  大多數(shù)人都知道通常腕表內(nèi)含有石英。事實上,只要你帶表,那基本上都是石英表,因為當今通用的多數(shù)表都由石英制造。但是,你可能不知道石英與計時之間有何關聯(lián)。

  石英是一種礦物質(zhì),也就是二氧化硅,通常存在于地殼中,同時也是沙子的主要成分。石英常被用于制作鐘表是因為這種礦物質(zhì)在受到電刺激后會快速擺動,而擺動過程中的能量損耗很小。

  這種平穩(wěn)的擺動就是手表計時的奧妙所在。手表所用的石英實際上是合成的,合成石英比自然石英擺動得更為穩(wěn)定。

  現(xiàn)在讓我們來探尋石英手表的工作原理。微小如紙薄的合成石英相當于手表的振蕩器。這種振蕩器如同座鐘的鐘擺,通過它不間斷的擺動反饋到手表來提示時間。振蕩器是一種標記秒、分及小時的計算器,而手表則顯示出所記時間。

  當石英振蕩器接收到來自電池或其他電源的電荷時,它將以超過32,000次/秒的頻率擺動。擺動過程中,通過編程手表中的集成電路來測定振動器的頻率,進而調(diào)整擺動,以達到固定擺動次數(shù)為一秒。

  如果手表有分針和時針,設置好的電脈沖可轉換成機械脈沖,推動齒輪轉動進而帶動指針運動。若是電子手表,石英的電脈沖可累計成分鐘、小時及天數(shù)。

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