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Input Devices

Scanning passports at airports

Biometric passport has an embedded electronic microprocessor chip which contains information that can confirm the identity of the passport holder. It uses contactless smart card technology, including a microprocessor chip embedded in the front or back cover, or centre page, of the passport. The passport's important information is printed on the data page of the passport and stored in the chip.

Passports have two lines, each line is 44 characters long. The following information must include: name, passport number, nationality, date of birth, gender, and passport expiration date. Many countries began to issue machine-readable travel documents in the 1980s. It is also machine readable which will be in a standard layout, size and font. On passports you have a photo of yourself printed onto your passport. This is so they can identify you by face recognition.


Barcode readers at supermarket checkouts

Barcode readers are used as there are no visible price tags on the products. Also, the prices can change on the products, without barcode readers they cannot keep up with the price checking. The barcode readers are linked to the head office central computers who can follow market trends and adjust prices electronically. It also acts as a tool for buyers to accurately restock products in accurate quantities. Barcode readers also tracks the amount of fresh produce sold in each store and therefore minimise any waste for overstocking, especially for products such as strawberries and fresh vegetables that go past their best very quickly. In addition it can track what is not as popular to buyers so they can put promotions on those products to attract customers e.g. buy one get on half price.


Touch screens on mobile devices

Touch screens in mobile devices are between users and devices that enables easy interaction and visual experience. Having touch screens allows the user to interact freely with the device without any problems.

There are 4 different types of touch screen technologies used for a mobile device; capacitive touch screen, resistive touch screen, surface acoustic wave and infrared touch screens.


Biometric scanners – eg retina or finger print scanner

Biometric scanners are automated methods of recognizing a person based on a physical or behavioural characteristic. The features measured are face, fingerprints, hand geometry, handwriting, iris, retinal, vein, and voice. Biometric data are separate and distinct from personal information. Biometric templates cannot be reverse-engineered to recreate personal information and they cannot be stolen and used to access personal information. Biometrics technology has been around for many years, making life easier for the user to access a device. This is a great security feature as to unlock your device you may need your finger print or your retina to log in to your phone, computer etc.


Digital video

Digital video is an electronic representation of moving visual images, known as video in the form of encoded digital data. This is in contrast to analogue video, which represents moving visual images with analogue signals. Digital video comprises a series of digital images displayed in rapid succession. Digital video was first introduced commercially in 1986 with the Sony D1 format, which recorded an uncompressed standard definition component video signal in digital form. As well as uncompressed formats, popular compressed digital video formats today include H.264 and MPEG-4. Modern interconnect standards for digital video include HDMI, DisplayPort, Digital Visual Interface (DVI) and serial digital interface (SDI).



Sound recording

Sound recording and reproduction is an electrical, mechanical, electronic, or digital inscription and re-creation of sound waves, such as spoken voice, singing, instrumental music, or sound effects. The two main classes of sound recording technology are analogue recording and digital recording.

Digital recording and reproduction converts the analogue sound signal picked up by the microphone to a digital form by the process of sampling. This lets the audio data be stored and transmitted by a wider variety of media. Digital recording stores audio as a series of binary numbers representing samples of the amplitude of the audio signal at equal time intervals, at a sample rate high enough to convey all sounds capable of being heard. A digital audio signal must be reconverted to analogue form during playback before it is amplified and connected to a loudspeaker to produce sound.


Input Sensors


Street lights

A Street light is a raised source of light on the edge of a road or path. Many lamps have light-sensitive photocells that activate automatically when light is or is not needed: dusk, dawn, or the onset of dark weather. Many street light systems are being connected underground instead of wiring from one utility post to another. When light hits an object it has high resistance. It conducts electricity poorly. They also have pressure, heat and motion sensors.


Security devices

Security devices stop someone stealing something and alerts staff, manufacture, shop owner etc. If someone tries to steal an item, there is a sensor that senses that item that wasn’t scanned and that causes an alarm to go off.


Pollution control

Pollution control senses the quality of the air. It does this so it can detect any impurities so it can switch on air filters. pH sensors in the ocean, air particle sensor, carbon monoxide sensors -  surface reacts to the presence of it.



Games are played by using a console, controller, joystick etc that can detect the movement to perform the game action. Games will also have motion sensors to play the game.


Household machines – eg washing machines

Washing machines measure the weight of washing depending on the amount of water needed. The water is measured by pressure- the more water, the higher the pressure. Temperature sensor detects the given temperature for the wash and the detection on the rotation of the drum during the wash. Rotational detection is detected by the light flickering.


Industrial applications – manufacturing

CNC Machining is a process used in the manufacturing sector that involves the use of computers to control machinery. Tools that can be controlled in this manner include lathes, mills, routers and grinders. CNC stands for Computer Numerical Control.

Under CNC Machining, machine tools function through numerical control. A computer program is customized for an object and the machines are programmed with the machining language (G-code) that essentially controls all features like feed rate, coordination, location and speed. With CNC machining, the computer can control exact positioning and velocity. CNC machining is used in manufacturing both metal and plastic parts.

First a CAD drawing is created (2D or 3D), and then a code is created that the CNC machine will understand. The program is loaded and finally an operator runs a test of the program to ensure there are no problems. This test run is known as "cutting air" and it is an important step because any mistake with speed and tool position could result in a scraped part or a damaged machine.

There are many advantages to using CNC Machining. The process is more precise than manual machining and can be repeated in the same way over and over again. Because of the precision possible with CNC machining, this process can produce complex shapes that would be almost impossible to achieve with manual machining. CNC machining is used in the production of many complex three-dimensional shapes. It is because of these qualities that CNC Machining is used in jobs that need a high level of precision or very repetitive tasks. For example – to create the shell of a car it would be designed electronically by a laser to press the body panel of the car. Paint machines uses CNC machinery, so they can apply right amount of paint to an object e.g. vehicles

Also, for chocolate production – there is a computer with keyboard and lenses programmed in to score the amount of milk or chocolate needed for a bar of chocolate.





1.            Computer Model 1



1.            Inputs worksheet