Transistors Microprocessors And Its Impact On Society example essay topic

A transistor is a special device that is used in almost every electronic device that has a circuit. A transistor is a solid state device that replaced the thermionic device, which was used for the purposes of communication. However, the development of transistors allowed for many more developments and inventions that have helped shape the way we live and the world that we live in. The following essay will focus on what exactly the transistor is and how it was developed. It will explore the differences of solid state devices and thermionic devices, and why solid state devices replaced thermionic devices. The final part of this essay will assess the impact that transistors, microchips and microprocessors have had on society.

A transistor is a device made of semiconductors that can conduct and insulate They have three layers of silicon. They can be classed as either NPN or PNP transistors, depending on which two types of semiconductors are used. These types are p- type semiconductors or n-type semiconductors. P-type semiconductors are silicon that is doped with an ion, which has a valence of 3. This results in positive holes, which are the majority carriers, and the electrons, the minority carriers.

The holes allow for the electrons to jump and the movement of these electrons produces a current. N-type semiconductors are silicon, which is doped with an ion that has a valence of 5. This creates an excess of negative electrons in the lattice, which are the majority carriers. The holes are the minority carriers. The movement of these electrons creates the current. The n- type semiconductor is the base and the p-type semiconductors are the emitter and the collector.

They can act as either amplifiers or switches. A transistor amplifier produces a large current alteration between the emitter and the collector when a small AC current is applied to the base. When a transistor acts as a switch, a small current is applied to a middle layer. This lets a much larger current flow through the whole device. Transistors act as both transmitters and resistors because they convert sound waves into electrical waves and they also control the electronic current. There are four types of transistors.

They include: - The point contact transistor- works by the effect obtained through the contact of points. - Bi-polar junction transistor (BUT) - it consists of oppositely charged regions (p- or n- regions) joined pole to pole - Junction FET includes the oppositely charged regions - Metal oxide semiconductor FET uses the oxides of the semiconductor to administer the second voltage. The Junction FET and the Metal oxide semiconductor FET both make use of the second voltage to control a current- the field effect theory. The transistor was developed in an attempt to create a device for communications. Devices that needed to amplify signals originally used a vacuum tube (also called diodes). Vacuum tubes were used in radios and the early computers.

A vacuum tube is a vacuum that has been covered in glass. Current flows through the vacuum when electrical contacts were put on the ends of the tube. It forced current to travel in one direction only because this was important for radios that needed direct current. However, the vacuum tube had many disadvantages, which included: - Very expensive - Unreliable - Size was large and bulky - Heated up quickly - Slow to operate Although vacuum tubes made amplification possible, these factors created a need for a new device to improve communications.

In order to overcome these difficulties, a team of scientists at Bell Laboratories came up with the? SS point- contact transistor?? This device was made from germanium, which was put into contact with two thin metal wires. This point contact transistor amplified current and it replaced vacuum tubes.

The device worked but there were some disadvantages to this as well. It was hard to make and germanium transistors did not work at high temperatures. This was when the silicon transistor was invented. Silicon was harder to refine because of its higher melting point, but it offered some advantages over the germanium transistor.

It was more efficient and better able to handle power. The first transistor was invented by John Bardeen, Walter Brattain, and William Shockley Thermionic devices are devices that use thermionic emission, which is when electrons are emitted from solids when heated to high temperatures. A thermionic device consists of a sealed glass at low pressure. Two or more electrodes are inserted into the glass.

The cathode becomes the heated electrode. It requires a separate heating circuit to heat that takes a long time to heat up. Once it is heated enough, the cathode emits free electrons, which are attracted to the anode. This attraction forms an electric current, which flows in one direction only. The current is controlled by the voltage, which is applied at another electrode called a grid. Thermionic devices include the electron guns of cathode ray tubes and other devices, such as diodes, valves, triodes and pentodes.

Thermionic devices used conducting material a glass covering. Solid state devices are electronic devices that are made with solid semiconductor components (silicon crystals). They are totally solid and do not need glass covering. They produce current by doping silicon (semiconductor) which makes holes. The electrons can then move from one hole to the next to create current. They do not require a lot of heat to operate, and they work immediately.

Solid state devices for a number of reasons replaced thermionic devices. Solid state devices are much smaller than thermionic devices. This allows the electron equipment to be reduced in size and produced in masses... A thermionic device requires a vacuum to allow electrons to flow between the electrodes. Solid state devices operate at normal air pressures. Thermionic devices are packaged in an evacuated glass tube, whereas solid state devices are packaged in thermosetting plastic.

Solid state devices consume less energy and do not require a start- up time. Thermionic valves consume a lot more energy and produce much more heat. Thermionic devices are much bigger than solid state devices. This limits the minimum size of an electronic device.

Thermionic devices do not operate as fast as solid state devices as they require a start-up time. However, the main two reasons why solid state devices replaced thermionic devices were because of the size and the energy requirements. A solid state device such as a silicon chip can contain thousands of transistors on a tiny chip and a thermionic device requires vacuum tubes. Thermionic devices require much greater energy to operate. They are less efficient than solid state devices. Transistors changed the course of history for computers and electronics.

They were used in many devices such as telephones, hearing aids, radios, portable radios, radar? |s, satellites, car engines, cameras, clocks and computers. They have had an impact upon society in so many ways. Transistors have enhanced space travel, microsurgery, mobile phones, modems, GPS and the stock market. They have revolutionized the world and made almost everything much more convenient and pleasant. Transistors have affected our way of life in so many ways, for example, we use the car ever day to go places and do things. If there were no transistors, we would have to walk every time we needed to travel.

We use the computer to surf the net and to do our schoolwork on. If there were no transistors, there wouldn? |t be any computers and hence, we would have to write every single assignment. Our society has very much been dependant on mobile phones. If transistors were not invented it would be very hard to communicate as frequently and as conveniently as we do now.

Transistors are used in a very wide range of devices which society today depends greatly upon. If transistors were non-existent the world would be a very different place and life would be much herder and difficult. We would have to hunt our own food and make our own clothes. We would not be able to store food in the refrigerator as things such as milk would go off and food would become rotten. The transistor was the device that made the development of almost every invention in the information age possible.

For example, modern day computers that which use microchips and microprocessors. Microchips are also called integrated circuits (IC). They are small electronic devices made from semiconductors. They are used to make microprocessors, audio and video equipment, and cars. A microchip is classified into categories depending on the number of transistors it has on it.

- SSI - (small-scale integration): Up to 100 electronic components per chip - MSI - (medium-scale integration): From 100 to 3,000 electronic components per chip - LSI - (large-scale integration): From 3,000 to 100,000 electronic components per chip - VLSI - (very large-scale integration): From 100,000 to 1,000,000 electronic components per chip - ULS I - (ultra large-scale integration): More than 1 million electronic components per chip A microprocessor is an Intel chip, which consists of 7 million transistors. It is a group of transistors, which are arranged in a certain way on a silicon chip, along with other electronic parts. Microprocessors are the central processing unit of a computer. They control nearly every electronic device. The main characteristics of a microprocessor are: - Instruction set: The set of instructions that it can perform - Bandwidth: The number of bits processed in a single instruction.

- Clock speed: how many instructions it can perform per second If a microprocessor has a higher value then the CPU will be more powerful. Microprocessors are categorised into two main categories: - RISC (reduced instruction set computer) - CISC (complex instruction set computer) Microprocessors have made personal computers possible and cheap, which has allowed people to use them to communicate to different parts of the world without having to travel the world. They have also made electronic games possible and cheap. Along with the positive impact on society, transistors have also had a negative impact. There are health problems that are associated with transistors.

For example, overuse of the computer causes strain on the eyes and hand injury (carpal tunnel syndrome). Radiation and the high-pitched noise emitted from a monitor cause migraines and cluster headaches. These issues are also the same for television sets as they also emit radiation. Television and computer monitors can trigger epileptic fits. Another main problem associated with technology is the increasing rate of obesity. The convenience that is provided by technology has taken the place of physical activity and daily exercise.

For example, physicals recreational activities are being replaced by video games and play stations, and shopping is being done over the Internet. People, especially teenagers, are spending too much time on mobile phones, which also carry some problems and health hazards. The radiation emitted from mobile phones may be dangerous, and the costs of these phone bills are increasing. This means that people and students have to work extra hours to pay off the bills and this interferes with their other commitments. Transistors have greatly impacted out lives today and they have provides us with many conveniences and a better way of life. Although there are some negative issues and concerns regarding the transistor, the positives out weigh the negatives.

The transistor, especially the microchip and microprocessor has had a positive impact on society and life. Without these things the world to be a very different and difficult place. In conclusion, the transistor has revolutionized the world. It was developed in a time where communication methods were in need of improvement and better equipment for amplification possibilities.

This development lead to the silicon transistor, which in turn replaced thermionic devices. The silicon transistor made all the new technologies that we are now enjoying, to be possible. It has had a great impact on society and enhanced our lifestyles in a positive way. The transistor has truly changed the world of electronics and computers in an amazing way. Reference: web web web web web web web web web web web Warren, N. (2001)., Excel HSC Physics. Step by step guide to HSC success.

NSW: Pascal Press The World Book (2000). Encyclopedia of Science and Physics. USA: World Book Inc. Millar, G., et al, (1996). Physics 12 3&4 units.

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