Basic Electronics Fnal

Basic Electronics Fnal - Basic Electronics Final Exam Chose...

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Basic Electronics Final Exam Chose any 5 questions: 13. How does a quartz watch work? The quartz watch was introduced in the 1970’s and it was a very popular and expensive commodity. Originally, they were only available with a red LED display but today they are available with both a LED display and a traditional dial display. Before quartz watches, the only kind of watches that were available were called wind-up watches. Wind-up watches are made up of: a spring to provide the power, some sort of oscillating mass to provide a time base, two or more hands (to tell the time), an enumerated dial on the face of the watch, and gears to slow down from the ticking rate of the oscillating mass and connect the mass and spring to the hands on the dial. These watches proved to be large and cumbersome, however the technology was relatively un- changed for hundreds of years. As the technology advanced in the 1960’s, watch makers found alternatives to the oscillating mass called the transistor oscillator, which was essentially a tuning fork. In addition to the transistor oscillator, integrated circuits were being used in watch production as well as batteries instead of the wind-up spring. The biggest advance came with the use of the Quartz Crystal. According to Howstuffworks.com, the quartz crystal is a thousand times better for timing than the tuning fork. Quartz crystals give a very accurate frequency, they have been in use for radio transmitters and receivers for years. The fact that the Quartz crystal remains crystalline to hundreds of degrees Fahrenheit makes it an electronic miracle. It generates a sufficient electrical charge as well. Usually, the quartz crystal is shaped into a disk or a
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bar. A quartz bar can oscillate at relatively low frequency (about 32 KHz). Modern quartz watches use a low frequency bar or tuning fork shaped crystal. The precision of the angle that these crystals are cut determines how accurate the time keeping will be. (source- www.howstuffworks.com) 14. What is the difference between an LCD and a LED and what are the advantages of each? LCD- Liquid Crystal Display. You can find LCD’s everywhere today, they are in computers, clocks, televisions, etc. Liquid crystal displays are a thin, flat device made up of both color and monochrome pixels arrayed in front of a light source and they draw
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Basic Electronics Fnal - Basic Electronics Final Exam Chose...

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