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Showing posts with label I DONT KNOW IT BEFORE. Show all posts
Showing posts with label I DONT KNOW IT BEFORE. Show all posts

LCD













About Color Liquid Crystal Display (LCD)

The LCD that can show colors must have three subpixels with
1.red
2. green
3.blue color filters to create each color pixel.

Through the careful control and variation of the voltage applied, the intensity of each subpixel can range over 256 shades. Combining the subpixels produces a possible palette of 16.8 million colors (256 shades of red x 256 shades of green x 256 shades of blue). These color displays take an enormous number of transistors. For example, a typical laptop computer supports resolutions up to 1,024x768. If we multiply 1,024 columns by 768 rows by 3 subpixels, we get 2,359,296 transistors etched onto the glass! If there is a problem with any of these transistors, it make a "bad pixel" on the display. Most active matrix displays have a few bad pixels scattered across the screen.
LCD technology is constantly evolving. LCDs today employ several variations of liquid crystal technferroelectric liquid crystal (FLC) and surface stabilized ferroelectric liquid crystal (SSFLC).

Display size is limited by the quality-control problems faced by manufacturers. Simply put, to increase display size, manufacturers must add more pixels and transistors. As they increase the number of pixels and transistors, they also increase the chance of including a bad transistor in a display. Manufacturers of existing large LCDs often reject about 40 percent of the panels that come off the assembly line. The level of rejection directly affects LCD price since the sales of the good LCDs must cover the cost of manufacturing both the good and bad ones. Only advances in manufacturing can lead to affordable displays in bigger sizes.

Posted by Kami Sunday, May 18, 2008 0 comments


The basic circuit breaker consists of a simple switch, connected to either a bimetallic strip or an electromagnet. The diagram above shows a typical electromagnet design.


The electricity magnetizes the electromagnet. Increasing current boosts the electromagnet's magnetic force, and decreasing current lowers the magnetism. When the current jumps to unsafe levels, the electromagnet is strong enough to pull down a metal lever connected to the switch linkage. The entire linkage shifts, tilting the moving contact away from the stationary contact to break the circuit. The electricity shuts off.

A bimetallic strip design works on the same principle, except that instead of energizing an electromagnet, the high current bends a thin strip to move the linkage. Some circuit breakers use an explosive charge to throw the switch. When current rises above a certain level, it ignites explosive material, which drives a piston to open the switch

Posted by Kami Monday, April 21, 2008 0 comments

The Basics
A typical analog camcorder contains two basic parts:
A camera section, consisting of a CCD, lens and motors to handle the zoom, focus and aperture
A VCR section, in which a typical TV VCR is shrunk down to fit in a much smaller space.
The camera component's function is to receive visual information and interpret it as an electronic video signal. The VCR component is exactly like the VCR connected to your television: It receives an electronic video signal and records it on video tape as magnetic patterns (see How VCRs Work for details).
These two sections are easily seen in the following photos.

Posted by Kami Monday, April 14, 2008 0 comments

In most of the world, camcorders, or video camera-recorders, have been a familiar sight for nearly 20 years. People take them everywhere: to school plays, sports events, family reunions and even births! When you go to a popular tourist spot, you are surrounded by them. Camcorders have really taken hold in the United States, Japan and many other countries around the world because they are an extremely useful piece of technology that you can own for under $300 (or more than $100,000).
How can such a small device do so much? Particularly for anyone born before the 1980s, it's simply amazing that quality video cameras are now readily available as consumer items, and that they're so easy to use. In this article, we'll look inside these extremely popular devices to find out what exactly is going on. We'll explore traditional analog camcorders and also look at the technology used in digital camcorders.

Posted by Kami 0 comments


Oscillators are important in many different types of electronic equipment. For example, a quartz watch uses a quartz oscillator to keep track of what time it is. An AM radio transmitter uses an oscillator to create the carrier wave for the station, and an AM radio receiver uses a special form of oscillator called a resonator to tune in a station. There are oscillators in computers, metal detectors and even stun guns.
To understand how electronic oscillators work, it is helpful to look at examples from the physical world. In this article, you'll learn the basic idea behind oscillators and how they're used in electronics

Posted by Kami 0 comments

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