The final step in the development process, starting in the 1980s and continuing on, was "Very Large-Scale Integration" (VLSI), with hundreds of thousands of transistors, and beyond (well past several million in the latest stages).
For the first time it became possible to fabricate a CPU on a single integrated circuit, to create a microprocessor. In 1986 the first one megabit RAM chips were introduced, which contained more than one million transistors. Microprocessor chips produced in 1994 contained more than three million transistors.
This step was largely made possible by the codification of "design rules" for the CMOS technology used in VLSI chips, which made production of working devices much more of a systematic endeavour. (See the 1980 landmark text by Carver Mead and Lynn Conway referenced below.)
Among the most advanced integrated circuits are the microprocessors or "cores", which control everything from computers to cellular phones to digital microwave ovens. Digital memory chips and ASICs are examples of other families of integrated circuits that are important to the modern information society. While cost of designing and developing a complex integrated circuit is quite high, when spread across typically millions of production units the individual IC cost is minimized. The performance of ICs is high because the small size allows short traces which in turn allows low power logic (such as CMOS) to be used at fast switching speeds.
ICs have consistently migrated to smaller feature sizes over the years, allowing more circuitry to be packed on each chip. This increased capacity per unit area can be used to decrease cost and/or increase functionality—see Moore's law which, in its modern interpretation, states that the number of transistors in an integrated circuit doubles every two years. In general, as the feature size shrinks, almost everything improves—the cost per unit and the switching power consumption go down, and the speed goes up. However, ICs with nanometer-scale devices are not without their problems, principal among which is leakage current (see subthreshold leakage and MOSFET for a discussion of this), although these problems are not insurmountable and will likely be solved or at least ameliorated by the introduction of high-k dielectrics. Since these speed and power consumption gains are apparent to the end user, there is fierce competition among the manufacturers to use finer geometries. This process, and the expected progress over the next few years, is well described by the International Technology Roadmap for Semiconductors (ITRS).
A monolithic integrated circuit (also known as IC, microcircuit, microchip, silicon chip, or chip) is a miniaturized electronic circuit (consisting mainly of semiconductor devices, as well as passive components) that has been manufactured in the surface of a thin substrate of semiconductor material.
A hybrid integrated circuit is a miniaturized electronic circuit constructed of individual semiconductor devices, as well as passive components, bonded to a substrate or circuit board
An electronic circuit is an electrical circuit that also contains active electronic devices such as transistors or vacuum tubes.
Electronic circuits can display highly complex behaviors, even though they are governed by the same laws as simple electrical circuits.
Electronic circuits can usually be categorized as analog, digital, or mixed-signal (a combination of analog and digital) electronic circuits
Semiconductor devices are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium, and gallium arsenide. Semiconductor devices have replaced thermionic devices (vacuum tubes) in most applications. They use electronic conduction in the solid state as opposed to the gaseous state or thermionic emission in a high vacuum.
Semiconductor devices are manufactured both as single discrete devices and as integrated circuits (ICs), which consist of a number—from a few to millions—of devices manufactured and interconnected on a single semiconductor substrate
The main reason semiconductor materials are so useful is that the behaviour of a semiconductor can be easily manipulated by the addition of impurities, known as doping. Semiconductor conductivity can be controlled by introduction of an electric field, by exposure to light, and even pressure and heat; thus, semiconductors can make excellent sensors. Current conduction in a semiconductor occurs via mobile or "free" electrons and holes (collectively known as charge carriers).
The diesel internal combustion engine differs from the gasoline powered Otto cycle by using a higher compression of the fuel to ignite the fuel rather than using a spark plug ("compression ignition" rather than "spark ignition").
In the diesel engine, air is compressed adiabatically with a compression ratio typically between 15 and 20. This compression raises the temperature to the ignition temperature of the fuel mixture which is formed by injecting fuel once the air is compressed.
The ideal air-standard cycle is modeled as a reversible adiabatic compression followed by a constant pressure combustion process, then an adiabatic expansion as a power stroke and an isovolumetric exhaust. A new air charge is taken in at the end of the exhaust, as indicated by the processes a-e-a on the diagram.
Since the compression and power strokes of this idealized cycle are adiabatic, the efficiency can be calculated from the constant pressure and constant volume processes. The input and output energies and the efficiency can be calculated from the temperatures and specific heats:
Two basic methods of converting photons to electricity have been studied, solar dynamic (SD) and photovoltaic (PV).
SD uses a heat engine to drive a piston or a turbine which connects to a generator or dynamo. Two heat cycles for solar dynamic are thought to be reasonable for this: the Brayton cycle or the Stirling cycle. Terrestrial solar dynamic systems typically use a large reflector to focus sunlight to a high concentration to achieve a high temperature so the heat engine can operate at high thermodynamic efficiencies; an SPS implementation will be similar. A major advantage of space solar is the efficiency with which huge mirrors can be supported and pointed in zero gravity and vacuum conditions of space. They can be constructed with very thin aluminum or other metal sheets and very light frames, easily constructed from materials available in space (eg, on the Moon's surface).
PV uses semiconductor cells (e.g., silicon or gallium arsenide) to directly convert sunlight photons into voltage via a quantum mechanical mechanism. These are commonly known as “solar cells”, and will likely be rather different from the glass panel protected solar cell panels familiar to many and in current terrestrial use. They will, for reasons of weight, probably be built in a membrane form not suitable to terrestrial use which is subject to considerable gravitational loading.
It is also possible to use Concentrating Photovoltaic (CPV) systems, which like SD are a form of existing terrestrial Concentrating Solar Energy approaches which convert concentrated light into electricity by PV, thus avoiding thermodynamic constraints which apply to heat engines. On Earth, they also use tracking systems, mirrors, and lenses to achieve high concentration ratios and are able to reach efficiencies above 40% Concentrating Photovoltaic Technology. Because their PV area is rather smaller than for conventional PV, the majority of the deployed collecting area in CPV systems is mirrors, as with SD systems; so they share the advantages of building and pointing large (simple) mirror arrays in space as opposed to (complex) PV panels.
A solar power satellite, or SPS or Powersat, as originally proposed would be a satellite built in high Earth orbit that uses microwave power transmission to beam solar power to a very large antenna on Earth. Advantages of placing the solar collectors in space include the unobstructed view of the Sun, unaffected by the day/night cycle, weather, or seasons. It is a renewable energy source, zero emission, and only generates waste as a product of manufacture and maintenance. However, the costs of construction are very high, and SPS will not be able to compete with conventional sources (at current energy prices) unless at least one of the following conditions is met:[citation needed]
Sufficiently low launch costs can be achieved
A determination (by governments, industry, ...) is made that the disadvantages of fossil fuel use are so large they must be substantially replaced.
Conventional energy costs increase sufficiently to provoke serious search for alternative energy
In common with other types of renewable energy such a system could have advantages to the world in terms of energy security via reduction in levels of conflict, military spending, loss of life, and avoiding future conflict over dwindling energy sources.
With the ever increasing price of oil and the knock on effect of huge rises of the cost of gas at the pumps, everybody is looking for either alternative fuels or ways to make gas mileage improvements to their own vehicles. Something that has received a lot of hype lately is Water Power Cars and Hydrogen Generator Kits to allow you to run your car on water.
Well you will be pleased to know that it is possible to run your car on water. Apparently the technology has been around for quite a few years but the big oil companies have done their best to hide it, and even to make people think that it is not possible, after all the more you save on gas the less profit they make. So one way or another this technology has been suppressed UNTIL NOW.
If you think that you will be able to run your car on water alone then think again, as that really would be impossible. The secret of these water power cars is a clever little device called a Hydrogen Generator. These Hydrogen Generators use a tiny amount of water as a supplement to the regular gasoline in your fuel tank, which can then give you gas mileage improvements of up to 50%.
Basically this Hydrogen Generator system works by electrolyzing a small container of water under the hood of your car. In this way it is turned into Hydrogen and Oxygen gas or HHO. This gas is then taken into the airflow of the intake manifold of your car where it is mixed with regular gas from your cars fuel tank. As this mixture burns a lot better as well as smoother than just regular gasoline you get the gas mileage improvements that you have been looking for.
So just how easy it is for you to turn your own car into one of these water fuelled cars? Well in fact it is VERY EASY and also VERY AFFORDABLE. With most of these Hydrogen Generator kits on the market available for less than $200 you could re-coup your initial outlay in just a few weeks on gas savings. And as they come with easy to follow step-by-step guides to show you how, they are also very easy to fit.
With these water fuelled cars you not only get great gas mileage improvements, but as this fuel burns cleaner and smoother you also get more power, prolonged engine life as there is less wear and tear, less harmful emissions from your exhaust, so cutting down on the amount of green house gases being pumped into the atmosphere. So it would seem that everyone is a winner (well almost everyone, the big oil companies will not be so pleased).
So with the technology of water power cars, and the simplicity and low cost of installation you too could run your car on water. Why not do yourself a favour and check it out for yourself right now, after all you have got nothing to lose and everything to gain.
Article Source: http://www.articlesbase.com/automotive-articles/water-power-cars-can-you-run-your-car-on-water-472593.html