Magnetic Card Reader

MAGNETIC CARD READER

What is it?

A magnetic card reader contains either a magnetic object embedded within the card or a magnetic stripe on the exterior of the card. According to existing standards, a magnetic card stores information in three separate tracks. All three tracks possess different bit densities and encoded character sets. The average bit density of the first track is 210 bits per inch (bpi). A 64-bit character dataset is used to store information in track 1. The characters are made up of six data bits and an odd parity bit. The encoding format grants the least-significant bit to come first and the parity bit, last. So, track one can hold around 79 characters.

What is it for?

This electronic device is designed to read stored information from a magnetic card by means of swiping the card through a slot in the reading device or holding the card next to a magnetic card reader.

What does it look like?

It is a rectangular plastic object that looks like a credit/debit card

What is the technology behind it?

"Two-Frequency, Coherent Phase Recording" is used for encoding magnetic cards. It is also called as F/2F sampling-encoding. By using combined data and clock bits self-clocking is achieved. The reader also contains an oscillator section which is used to provide the clocks for the recovery section and for the enable/disable timers. The enable/disable counters provide initialization for the recovery section. The recovery section locks onto the data rate and recovers the individual data bits from the data stream.

The magnetic card reader is a microcontroller-based device and has been programmed for a specific application. That program simply reads the card in a forward direction in a simple data format or it can be complex enough to read the card in any direction with a corresponding encoding format.

Sources:

http://www.epos-store.co.uk/images/powermag.jpg

http://www.tech-faq.com/magnetic-card-reader.shtml

Audio Devices (Microphone, Sound Card, Special Software)

by Jasmine Denise Calalang Santos

Microphone

1. What is it? What is it for?

A microphone is an audio-input device that translates acoustical energy (sound waves) into electric energy (audio signal) that the computer can read and process. Essentially, the microphone has one use: TO TRANSFER SOUND. Now, this sound that is transferred can either be recorded, amplified, or literally transferred to a receiver in another location. It is most commonly used in computers, recording studios, radio, concerts, telephones, and PA systems.

2. What does it look like?

3. What is the technology behind it?

“Microphones are a type of transducer - a device which converts energy from one form to another.” What all microphones have in common is the diaphragm, which is the first part of the microphone that is affected by the sound waves. Once it vibrates, all other parts of the microphone also vibrate. These simultaneous vibrations create a collective vibration which is then converted to an electric current that becomes the audio signal that is then sent to a sound card to be processed.

Sound Card

1. What is it? What is it for?

A sound card is a kind of expansion card that facilitates the input and output of sounds to and from a computer. It sends audio information to a particular output or compatible audio device. Some of the most common uses of a sound card are “to provide the audio components from the multimedia applications like music, video, presentation, games, etc.

2. What does it look like?

Soundcards have a line of connectors that read the electric signals sent by the microphone or another audio input device and digitalizes these signals for the computer to understand. These digitalized signals are then stored in the computer’s hard disk for further processing to be done by special software.

Special Software

1. What is it? What is it for?

Special software for voice recognition, in general, is a software that interprets the digitalized signals from the sound card into text-style documents or into commands for the computer to fulfill. “Simply put, it substitutes voice entry for keyboard entry.”

2. What does it look like?

3. What is the technology behind it?

Sound waves, being waves, come in frequencies that vary from low to high. Each sound is supposed to have a corresponding frequency that is unique to it. What the special software has is a collection of these frequencies. It analyzes the sound waves of the input and matches it with its own library, by comparing their “voiceprints”. In a nutshell, "it’s pattern matching.”

References

http://www.mediacollege.com/audio/microphones/how-microphones-work.html (Accessed August 6, 2009)

http://www.tech-faq.com/microphone.shtml (Accessed August 6, 2009

http://blogs.menupages.com/southflorida/category/nightlife_bars/ (Accessed August 6, 2009

http://www.mediacollege.com/audio/microphones/how-microphones-work.html (Accessed August 6, 2009)

http://www.pc.speakers.ie/ (Accessed August 7, 2009)

http://ezinearticles.com/?How-Does-A-Sound-Card-Work&id=847430 (Accessed August 7, 2009)

http://www.winrag.com/season2issue1.htm (Accessed August 7, 2009)

http://www.foxdelta.com/products/sc1-old.htm (Accessed August 7, 2009)

http://electronics.howstuffworks.com/speech-recognition.htm (Accessed August 7, 2009)

http://www.wisegeek.com/what-is-speech-recognition-software.htm (Accessed August 7, 2009)

http://askbobrankin.com/voice_recognition.html (Accessed August 7, 2009)

Field Emission Display (FED) Monitors

Field Emission Display monitors

1. What it is?

A field emission display (FED) is a new type of flat-panel display in which electron emitters, arranged in a grid, are individually controlled by "cold" cathodes to generate colored light. Field emission display technology makes possible the thin panel of today's liquid crystal displays (LCD), offers a wider field-of-view, provides the high image quality of today's cathode ray tube (CRT) displays, and requires less power than today's CRT displays.

http://searchcio-midmarket.techtarget.com/sDefinition/0,,sid183_gci213960,00.html, August 7, 2009

2. What is it for?

Field emission display (FED) technology has been proposed as a display technology that enjoys the advantages of allowing for wide viewing angles as well as being thin and light weight. The field emission display has the advantage of high image quality found with the conventional cathode ray tube display.

Other advantages: high yield, fast reacting time, good performance in displaying coordination, having high brightness, light and thin structure, wide range of color temperature, high mobile efficiency, excellent distinguishability of tilted direction, etc.

In addition to the better brightness, the viewing angle is broader, power consumption is lower, response speed is faster, and the operation temperature range is larger. Through the construction of a high efficiency fluorescent film, the field emission display provides outstanding brightness performance even outdoors so it is thought as a quite competitive display panel and is even likely to replace the liquid crystal display. Field emission devices are used in a number of different applications, including displays, e-beam lithography, chemical analysis and space propulsion.

http://www.electronics-manufacturers.com/info/monitors-and-displays/fed-display.html, August 7, 2009

3. What does it look like?

http://www.gizmag.com/pictures/relevant/9635_14070883805.jpg , August 7, 2009

4. What is the technology behind it?

FEDs capitalize on the well-established cathode-anode-phosphor technology built into full-sized CRTs using this in combination with the dot matrix cellular construction of LCDs. Instead of using a single bulky tube, FEDs use tiny "mini tubes" for each pixel, and the display can be built in approximately the same size as an LCD screen.

Each red, green and blue sub-pixel is effectively a miniature vacuum tube. A FED pixel cell has thousands of sharp cathode points, or nanocones, at its rear. These are made from material such as molybdenum, from which electrons can be pulled very easily by a voltage difference, to strike red, green and blue phosphors at the front of the cell. Colour is displayed by "field sequential colour". The display will show all the green information first, then redraw the screen with red followed by blue.

http://www.pctechguide.com/43FlatPanels_FEDs.htm, August 7, 2009

Digital Handheld Camera

by Crystal Manillet Go Callano

The digital handheld camera or commonly known as the "camcorder", have become compact and lightweight. It is used to record videos and allows you to transfer these footage to you computer. Most also let you take digital still shots, essentially giving you a digital camera as a bonus. Newer camcorders offer a wide set of features such as the capacity to capture widescreen videos to match the aspect of widescreen HDTVs. The main advantage of having a digital handheld camera is that it allows the user to transfer the video footage to a compatible computer without loss of quality. Transfers are usually made through Firewire or using the USB.

Digital Camcorders come in a variety of formats options. Despite the growth of new non-tape formats, the MiniDV is still the most popular video camera format.The reason for this is because the MiniDV lets these camcorders be very compact, and extra MiniDV tapes are easy to find. Also, it has excellent sound quality but is reasonably priced.

Other digital handheld cameras are the DVD camcorders and the HDD camcorders. DVD camcorders record directly to compact DVD-R/RW, DVD+R/RW or DVD-RAM, and these discs can in most cases be watched directly on a home DVD player or computer. the HDD camcorders on the otherhand, have video data directly to an internal hard disk.these makes them more compact and sturdy (since there are not much movable parts).

Some terms used in camcorders:

CCD (charged-coupled device )-A CCD is a charge-coupled device, a light-sensitive chip that acts like film for capturing video.

Character generators - These allow you to add the time and date, titles, and other written information to the images that you are recording.

Fade In/Fade Out - Automatically fades the image from or to a black (or white) screen.

Pixel - One of the tiny points (or dots) that make up a video image.

Resolution - The ability to produce fine detail in a video picture. It is usually measured in horizontal lines.

References

http://products.howstuffworks.com/digital-camcorders-buying-guide.htm ; Accessed on 06 August 2009

http://techhook.com/img/canon_HG21_digital_camcorder.jpg; Accessed on 06 august 2009

Web Camera

by Krystle Danielle Wong Lim

1. What is it?/ What is it for?

The term webcam is a combination of "Web" and "video camera." Webcams are typically small cameras that are either attached to a user's monitor or sit on a desk. Webcams can also be used for video chat sessions with other people. Instead of broadcasting the video on the Web, users can set up a video chat session with one or more friends and have a conversation with live audio and video. The maximum resolution of a webcam is also lower than most handheld video cameras. For this reason, webcams are relatively inexpensive compared to most video cameras. And while they may not be ideal for filming a movie, webcams are great for video chat sessions with friends. It is a misconception that using a webcam is just to record yourself doing something beneficial or entertaining. A webcam can also be used a security surveillance system. (ex. , if you want to see what your children or employees are doing while you are away)

2. What does it look like?

3. What is the technology behind it?

The technology behind using a webcam is very simple. You basically needs three things in order for it to work; a webcam, software to record and capture video and a medium to broadcast the recorded images and video. The first thing that needs to be done is the buying and setting up of the webcam. Some webcams are very simple to connect to your computer; all you have to do is connect it to the USB port on the computer. There is software that comes with the webcam that allows you to captures the images and videos. Depending on what you need the webcam for, the proper settings need to be in place. Once the camera and software is installed, you now need a way to broadcast the images and videos. Your computer is now able to capture video and photos then upload it to a web server. Your software will continue to capture and upload the images while you have it in capture or record mode. For recording streaming video, you will need a constant connection to the internet. This way you will be sure to receive up-to-date images captured from your webcam. A reliable and fast connection is also needed on both computers when communicating between two webcams.

References

http://www.sharpened.net/glossary/definition.php?webcam; Accessed on 05 August 2009

http://www.messenger.yahoo.com/superwebcam.php; Accessed on 05 August 2009

http://www.ehow.com/how-does_4564068_a-webcam-work.html; Accessed on 05 August 2009