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User:Rajesh.or.tidke~enwikibooks

Chapter one - Introduction [edit] Introduction and disclaimers While some conversions of ICE vehicles have been performed by major automobile manufacturers in the United States, all such programs have been terminated due to (to quote the manufacturers) "lack of consumer demand" for these vehicles. A few specialty rebuilders offer new or remanufactured conversions to satisfy a rather limited demand. The demand is low primarily due to the costs of completed vehicles, which are up to twice that of a comparable ICE vehicle. Some of these are built on new vehicles, purchased from the original equipment manufacturer but without the various ICE components.

This article is concerned mainly with the hobbyist conversion of ICE vehicles to electric propulsion. It is not intended to be a complete instruction manual, but rather a general guide to performing your own conversions and for purchasing or modifying an EV conversion. Some representative types of vehicle conversions will be presented.

In this article "electric vehicle" (EV) refers to various hobby conversions, not to high-end manufactured vehicles. Also, only technologies available to the hobbyist are considered in depth.

Branded products may be illustrated where such are commonly used in EV conversions. This should not be considered to be promotional or an endorsement, which otherwise might be considered to be in violation of Wikibooks policy.

Note the presence of hazardous materials and conditions that must be approached with proper precautions and procedures to avoid damaging, injurious, or even fatal consequences.

[edit] Why have an electric vehicle? The greatest fans of electric vehicles are those who have obtained and used them. Owing to the fact that electric vehicles have not been promoted by the major manufacturers in the United States, this is a self-selected group, so their enthusiasm may be misleading. Fans point out the following:

Range is adequate if not the only vehicle in household or if long commutes are not required. Fans point out that most trips in non-commute vehicles are for shopping, school drop-off/pick-up, visiting, and other errands within a 10 to 20 mile (15 to 30 km) radius. Long range is simply not needed for such trips and an operating range of 30 to 40 miles (50 to 65 km) is quite sufficient. Fueling at home requires but seconds to plug in for overnight charging followed by a few extra moments in the morning. Some find this to be more convenient than driving to obtain gasoline whose availability and cost is less predictable. The homeowner can install on-grid solar photovoltaic rooftop power or residential wind generation and so produce most of the energy required for personal transportation with zero pollution. Since the vehicles can be charged during low demand times the photovoltaics provide a larger societal benefit by helping to satisfy local peak demand, greatly reducing overall pollution and reducing transmission line loads. Additional benefits can also flow to the user through time sensitive pricing/payback schemes, significantly reducing the cost of a system that will support transportation needs. Once a commitment to producing power is made it becomes an easy decision to commit to producing all household and local transportation power needs. Thus there is a societal benefit from electric vehicles beyond transportation. Electric vehicles are quiet. Even if not completely silent, they do not produce the low frequency rumble that can easily penetrate household walls and windows. Owners take pride in the non-polluting nature of their vehicles. Some point out that knowing that your vehicle is non-polluting quickly leads to a realization how stinky and noxious even modern, well tuned non-electric vehicles actually are — something that tends to be ignored when you are part of the problem. Some EV fans with a left of center political bias or of an extreme "green" inclination claim that when combined with household photovoltaics, electric vehicle users are not assisting (through their fuel purchases) despotic governments in oil-rich countries, nor the politically powerful companies that prepare and distribute their products, nor the politically powerful coal interests, nor the domestic politicians that serve and protect these companies and countries. Many electric vehicle owners and operators express great satisfaction in this aspect of electric vehicle use, even while acknowledging that this use can have only little effect on these matters unless adopted more widely and produced in greater quantities. Some USA EV fans have accused the three major domestic manufacturers, General Motors, Chrysler Corporation and Ford Motor Company of deliberately sabotaging their own electric vehicle efforts through several methods: failing to market, failing to produce appropriate vehicles, failing to satisfy demand, and using lease-only programs with prohibitions against end of lease purchase. They also point to the Chrysler "golf cart" program as an insult to the marketplace and to mandates, accusing Chrysler of intentionally failing to produce a vehicle usable in mixed traffic conditions. The manufacturers, in their own defense, have responded that they only make what the public wants. Of the various electric vehicles marketed by the "Big Three", only the General Motors EV1 (manufactured by GM) and the Th!nk City (imported and marketed by Ford) came close to being appropriate configurations for a mass market. However, at the end of their programs GM destroyed its fleet, to avoid the continuing expense necessary to continue to provide maintenance and support for these vehicles. Ford's Norwegian-built "Th!nk" fleet was covered by a three-year exemption to the standard U.S. Motor Vehicle Safety laws, after which time Ford had planned to dismantle and recycle its fleet; the company was, however, persuaded by activists to not destroy its fleet but return them to Norway and sell them as used vehicles. Ford also sold a few lead-acid battery Ranger EVs and has allowed a small percentage of lease returns into a limited market (after crushing and destroying 90 percent of the fleet, without saving any components), and some fleet purchase Chevrolet S-10 EV pickups are being refurbished and sold on the secondary market. Both Honda and Toyota also manufactured electric only vehicles. Honda followed the lead of the other majors and terminated their lease-only programs. Toyota offered vehicles for both sale and lease. While Toyota has terminated manufacture of new vehicles it continues to support those manufactured and is allowing for some institutional lease returns to be placed in the marketplace. It is actually possible to see a RAV-4 EV on the road but this is indeed a rare sight.

[edit] Why convert or purchase a converted ICE to get an electric vehicle? In Europe and some parts of Asia vehicle buyers have the choice of ICE or electric - it is actually possible to obtain reliable, well engineered and road-worthy electric vehicles and to have them maintained by a dealer. Other than for a beginning market for Neighborhood Electric Vehicles (NEVs), is not possible in the United States for economic, political, and market-restraint reasons. Nor is it possible for a person to easily import a new electric vehicle from Europe or Asia. Certain restrictive safety regulations (such as the requirement for safety glass rather than tempered glass in windshields, airbag requirements, lighting regulations, plus the destructive testing by barrier collisions all operate to inhibit the use of offshore manufactured vehicles. In contrast there are few restrictions on the personal conversion of an ICE vehicle to BEV (battery electric vehicle). This anomaly is distinctly cultural in English speaking North America and is emblematic of a dichotomy in the American political psyche: On the one hand, social and political pressures force the government to protect consumers in the marketplace from exploitation by corporations and large corporations prefer legislation that restricts the entry of new players into the marketplace, while the preservation of individual freedom to tinker in one's garage or workshop is considered sacred, being in the spirit of great inventors such as Edison and the Wright brothers.

Note that battery technology is rapidly improving in cost/performance ratios due to the use of batteries in ICE-electric hybrid vehicles. The EV that is converted today will be upgradeable by future battery (and perhaps charger) replacement.

[edit] Recent history of the electric vehicle in California Beginning in the 1990s the California Air Resources Board was looking for a way to combat air pollution and when GM began work with their EV1 it caught the eye of the Air Resources Board (Jananne Sharpless, Who Killed the Electric Car Interview). They also saw that the state was spending over $5 billion on air pollution-related illness. There was also a study done in 1989 that reported 1 out of 4 18 to 25 year olds had severe to moderate lung lesions. The Resources board eventually passed a mandate that stated by 2003, 10% of all vehicles sold in the state would be zero emission vehicles (ZEV). Toyota, Honda, General Motors, Ford, and Nissan all built limited production runs of battery-powered vehicles. For a variety of reasons; some say lack of advertising from the original equipment manufacturers (OEMs), others say the lack of purchase (they were only available by closed-end leases); still others say that the limited production runs kept costs too high to make them affordable by the average buyer-- almost all of the leased cars were collected at the end of their lease-- and then destroyed - despite the protestations of willing buyers. The CARB charter was not necessarily intended to drive up the production of electric vehicles, but rather to reduce air polution. The manufacturers successfully argued for changes to the rules. The CARB specifications were modified from zero emissions to an equivalent emission reduction by the mandated production of very low emission vehicles, SULEVs (SUper Low Emission Vehicles) - vehicles producing about one tenth the previously mandated emission levels. This effectively created a hole in the mandate, because the U.S. Federal Government is the only governing body allowed to "mandate" MPG; these are called CAFE standards, they also have not changed (until 2008) since the oil embargo of the 70s... Later on, GM followed by DaimlerChrysler and several dealerships would sue CARB. But it wouldn't be until the Federal government would come on board as well as the Bush administration to help kill the electric car. Not much later President Bush would commit more than a billion dollars to hydrogen fuel cells, while totally ignoring current and past 170 year old EV technology, estabished by analysis to be far more efficient source-to-sink than the proposed hydrogen schemes.

[edit] Attitude In general, you should not attempt to maintain and operate a "home made" electric vehicle unless you have some interest and perhaps at least modest skills concerning mechanical and electric devices. Such skills are difficult to come by in many states due to the generally low volume of shop and industrial arts classes in current intermediate and high school programs. However, if you are the kind of person who will at least take apart a malfunctioning small appliance, and can sometimes at least identify the problem (e.g., needs regreasing or new motor brushes) you should have little problem with maintaining an EV.

A professionally built conversion will often be designed to be ignored, being engineered, constructed, and tested to survive with only minor maintenance on the operator's part and regular charging, combined with a regular professionally performed maintenance schedule. On the other hand, a non-professional conversion will probably require regular inspections of details like battery and motor electrical and mechanical connections, security of auxiliary systems, and inspection of wires and cables for chafing and loose connectors in order to avoid more extensive problems. While these tasks do not require a large amount of time, this time is more than is usually required of a conventional internal combustion vehicle.

[edit] Operating costs The direct operating costs will generally be confined to expenses for tires, battery replacement, battery water (where required), and electricity for recharging. Although the cost of electricity for charging these vehicles is generally much less than the cost of fuel for ICE vehicles, the cost of battery replacement can be very high. In general, the overall cost per mile for an EV - including periodic battery replacement, may be greater or less that for a conventional ICE vehicle of similar size and performance, depending largely upon the battery type used. For example, if the cost of electricity is (US) $0.12/KWH, the battery pack costs $1200 to replace (a low cost based upon the lowest cost technology), and lasts 20,000 miles (an optimistic number when using lead-acid batteries), and the vehicle uses 400WH/per mile (a rather high number), the combined cost per mile will be (960 + 1200) / 20000, less than $0.11/mile, comparable to an ICE vehicle getting 25MPG at a cost per gallon of $2.75. This does not count avoided costs such as engine oil changes (about $0.01/mile), smog inspections (about $0.002/mile), and various repairs required to maintain smog certification (which can be costly on an older ICE vehicle, probably between $0.005 and $0.015 per mile ), so the costs are currently roughly comparable at current fuel prices. With more expensive gasoline or the use of more expensive but longer lasting batteries the costs further favor the electric conversion in the long run.

Since converted vehicles are usually of an older vehicle, such vehicles may need other maintenance due to accumulated wear, perhaps wheel bearings, brakes rotors or drums, brake pads or shoes, suspension bushings and the like, and other components that are not usually replaced, but keep the vehicle up to date and show pride in ownership such as upholstery, door seals, and body paint. Such work is generally not cost effective in an ICE vehicle if performed by hire, while an interested hobbyist may do much work at quite modest cost and obtain substantial enjoyment in learning and performing various craft skills.

While a worn ICE vehicle of comparable condition would be simply scrapped, you will likely want to maintain and even improve your conversion, so you should consider maintenance (and even improvement) expenses to be a normal part of maintaining an older vehicle. A more common vehicle may be cheaper to maintain when in the seven to twenty year age range than a rare, special interest, or very old vehicle due to the availability of low cost usable parts from automotive recycling yards. Some special interest vehicles have enabled the creation of a robust secondary parts market, although such vehicles are generaly best left as ICE vehicles unless especially suitable for conversion to electric power.

[edit] Skills needed A wide range of skills is needed by a converter of a vehicle. Fortunately, there will often be fellow EV enthusiasts in an area that are willing and able to assist the novice builder.

[edit] Automobile survey A builder should be able to identify problems in a potential conversion vehicle. These are the same skills required to identify and purchase a good used ICE vehicle and are especially useful if a conversion (complete or partial) is purchased from another builder. Note that it may be possible to purchase a used EV conversion that only needs batteries - the owner may want to build another vehicle using the proceeds from the sale of an earlier conversion but not wish to invest in new batteries for a vehicle about to be sold. A careful survey of such a vehicle will go beyond that stated above as it is very important that latent electrical defects be identified and corrected, e.g.: the presence of chafing points in the electrical system that could lead to short circuits and an awareness of the possible necessity for the addition of primary or secondary electrical and operational safety equipment and circuits.

A guide for the inspection of a vehicle for purchase may be found at this How To wiki article (commercial site - not Wikimedia Foundation).

[edit] Basic mechanics A builder should be able to fabricate small brackets for mounting sensors, switches, and relays. This can be done using simple hand tools - a small vice, hacksaw, shears, hammer, pliers, and various drills and files.

[edit] Machine shop skills Most machining requires expensive equipment and extensive skills. Machine shop skills will not be needed if the converter can obtain "off the shelf" components (components made to order from known specifications). In the case of exotic conversions the converter may have to have specialized work done locally, or ship the transmission to a specialty vendor. The more machine shop skills a builder has the more work that builder will be able to perform, and will be more skilled at selecting professional help. Creation of the motor coupling and the motor to transmission adapter usually require skills and experience of a high order (a typical automotive machinist will not usually be able to perform the work satisfactorily). A knowledgeable converter will be better able to judge the qualifications of the machinist to be employed, and a cooperative machinist may be willing to allow the converter to perform some of the lower skilled and lower risk tasks. It is also important that the machine shop tasks be well planned out and broken down into the component subtasks, something that a converter of modest machine shop skills will be able to do. Work in a machine shop may be done at fixed price (in which case the enumeration of tasks will aid in bid preparation) or performed using an hourly rate, in which case the estimate will be more accurate. For an exotic conversions where components must be designed a good relationship with a cooperative machine shop is important to completing a successful and cost-effective project.

[edit] Welding For conversion of a unit body vehicle it is especially important that the batteries be well secured. This is typically done by creating racks from angle steel stock or boxes from sheet metal welded into forms suitable for the batteries and vehicle. These racks or boxes are then welded to the unit body or secured to the vehicle's frame (if accessable). This requires care in avoiding warpage of the primary vehicle structure. For popular conversions it is possible to obtain manufactured racks designed for a pre-engineered layout, so this skill may be considered optional but dependent upon the vehicle selected for conversion. For light truck conversions with in-bed batteries no welding is necessary - all retention may be done with appropriate bolted hardwood components.

[edit] Automotive mechanics The ability to remove, disassemble, rebuild, and install major ICE components such as transmissions, engines, and suspension components is useful but may be performed by a specialty conversion shop. The builder–owner should be especially cautious in the employment of ICE auto mechanics for these tasks as they may be unfamiliar with specialized EV procedures and requirements.

[edit] Basic electrical A builder should be sufficiently knowledgeable about basic electricity to safely work on household and EV electrical systems. Note that an EV pack can provide extremely high currents, which can rapidly heat wires or misused tools, causing burns, and that batteries so overloaded can explode with consequent hazards of acid and toxic materials. Most traction packs and the associated high voltage accessory wiring (heater and twelve volt converter) supply or use potentially lethal voltages. Specific electrical arrangements are used to minimize the hazards present and it is important that the builder/operator observe proper precautions and maintain the equipment in a safe configuration.

[edit] Basic electronics While the systems used in EV safety are not exotic, the builder should have sufficient skill to design and implement basic relay and diode logic for control and alarms. The smaller relays needed may be obtained at a local electronics supply shop or through an EV parts supplier. Some specialty components are obtained from EV parts suppliers or sometimes from automotive parts recyclers.

[edit] Application Electric vehicles (EVs) are appropriate for short to medium range commuting. Longer ranges are possible if charging may be obtained at both ends of the commute.

EVs are appropriate for local errands where long range is not important. While Neighborhood Electric Vehicles (NEVs, essentially enhanced electric golf cars) are available from several manufactures, such vehicles are not considered here for hobby conversion as they are readily available from manufacturers and are not suitable for most suburban locations (although they may be well suited for operation in some urban environments and many self-contained communities).

[edit] Vehicle Typical firewall components in a light truckWhile almost any vehicle can be converted to electric power, one should be cautious about converting a vehicle simply because it is available (such as a family vehicle with a non-functioning engine). One should first consider the performance envelope that is both desired and affordable (see below) and then find a suitable vehicle that will satisfy these needs when converted. A good used vehicle in running condition may be a better choice than a vehicle with a major defect, as one can test the running components such as transmission, differential, suspension, and other components by road test. If the parts to be removed are in good condition it may be possible to obtain a good price by selling the engine while it can be demonstrated in the vehicle. A purchaser will thus have some confidence in the quality of the engine and may be willing to pay more than for one of unknown quality that has been removed from the vehicle. A later model may be available with advanced safety features and better brakes than would be available on a fifteen or twenty year old vehicle.

[edit] Performance envelope Charger, controller, and vacuum components in a light truck, garden tractor battery to right of vacuum pumpAs a minimum, an EV conversion should have sufficient performance so as not to impede conventional traffic operating within the speed limits of the roadway. This does not mean that it is necessary to obtain a level of performance equivalent to an ICE vehicle, although a short range performance vehicle may be constructed which will significantly outperform ICE vehicles below 30 mph (50 km/h).

Some designers point out that a specific type of electric vehicle offers comfort, utility and quickness, sacrificing only range. This is called a short range electric vehicle. This type may be built using high performance lead–acid batteries, but of only about half the mass that would be expected to obtain a 60 to 80 mile range. The result is a vehicle with about a thirty mile range, but when designed with appropriate weight distribution (40/60 front to rear) does not require power steering, offers exceptional acceleration in the lower end of its operating range, is freeway capable and legal, and costs less to build and maintain. By including a manual transmission this type of vehicle can obtain both better performance and higher efficiency than the single speed types developed by the major manufacturers. Unlike the converted golf carts used for neighborhood electric vehicles, these may be operated on typical suburban throughways (40 to 45 mph or 70 km/h speed limits are typical) and can keep up with traffic typical to these roads and to the short on and off segments of freeways that are common in suburban areas.

[edit] Operating costs vs. capital costs Relative to an ICE vehicle an EV can offer substantially lower cost per mile in some applications but not all. An ICE can be very cheap to buy and maintain (until old and worn) but expensive for purchase of fuel and for "smog" inspections and oil changes.

An EV can be expensive to build and to replace batteries, yet quite inexpensive to operate if the cost of electricity is low. An EV is especially attractive if a homeowner has installed sufficient net metering photovoltaic (solar electric) panels, particularly if the net metering applies time of use rates.

[edit] Vehicle types

[edit] Novelty vehicle At the 2005 Stanford University EV Gathering

Above: Bob Schneeveis[1][2][3] demonstrates his Silver Sofa to the delight of his passengers. This can spin rapidly in place like a carnival ride and its batteries are recharged by the solar panels.

A novelty vehicle or an electric powered art car may not be suitable for on road use. Applications include electric vehicle show demonstrations, parades, parade floats, float towing, and eclectic off-road gatherings such as Burning Man.

[edit] Shoebox racer A prelude to larger vehicles, intended for the education of middle school students, these are fabricated from a standardize box of components, with the overall design and gear ratios determined by the builder. A building team will typically consist of two students and an adult advisor.

[edit] Electric cart Suitable for educating youth in the technologies of electric vehicles, technically advanced versions of the cart can exhibit high efficiency in energy use and are a natural prelude to later developing pure solar electric racing vehicles or the conversion of ICE vehicles to electric drive. Speeds are typically limited to about seven MPH so a running adult can overtake and stop a vehicle. Some classes allow a great freedom in design by having a class first disassemble the previous constructions, returning components to appropriate bins. This disassembly task informs the students on design methods and equiment assembly. The students, in small teams, then design and construct new vehicles.

[edit] Tour del Sol The ultimate in efficiency is exhibited by solar powered electric cars with highly refined chassies, electrics, and aerodynamics. These are designed and assembled by college teams with the support of various businesses, especially those involved with solar power, batteries, electric propulsion, or automotive manufacturing. Competitions are traditionally biennial, with the most widely recognized event being the World Solar Challenge in Australia, an 1800 mile race from Darwin to Adelaide. In the North American Solar Challenge teams race 2500 miles from Austin, Texas through Winnipeg, Manitoba finishing in Calgary, Alberta.

[edit] Electric bicycle A electric bicycle is a class of bicycles that are fitted with an electric motor. Often they are powered by rechargeable batteries however some experimental electric bicycles run directly on or recharge their batteries via solar panels, fuel cells, gas generators or other alternatives energy sources. Some experimenters have even used super capacitors to store energy. Using an on-board generator may impact the legal juristictional definition of an electric bicycle. A few types of electric bicycles are able to re-capture energy from braking and can re-charge the batteries while braking or travelling down hills (regenerative braking). With the advent of newer technology further features can be expected.

Some electric bikes have features where the motor can move the bicycle by itself if the rider chooses not to pedal, while others require the rider to pedal at all times. (see the Wikipedia article motorized bicycle).

The conversion of a bicycle to electric power is probably the lowest cost means of learning conversion methods. Battery packs are usually lead acid gel cells since these are available in small sizes suitable for this application. It is also practical to experiment with more expensive battery types since only a small pack is required. It is possible to repurpose battery packs and chargers intended for powering toys and similar small electrical devices.

[edit] Electric Scooter ScooterNot typically suitable for on the road use these may be configured for either standing or sitting use

[edit] Electric motorcycle MotorcycleA specialty niche, this can offer an opportunity to build a relatively low cost electric vehicle. Most of these use a two wheel configuration, although the two types of three wheel vehicle (and sometimes four wheel vehicles) are classified as motorcycles in many jurisdictions if their weight is sufficiently low (typically around 1000 pounds maximum). If a tricycle layout is employed the single wheel should be at the back, with normal automotive type front wheel steering, as the single wheel forward type is notoriously unstable in handling.

[edit] Economy coupe A light vehicle can make an excellent choice if care is taken in component selection and placement and use restrictions are accepted. It is possible to obtain conversion kits for some popular light vehicles, most notably the rear motor, rear drive Volkswagen "Beetle", its "Type 3" evolution, and its successor, the front motor/drive VW "Rabbit". One should not expect to convert such a vehicle and then use it to transport four full size (or oversize) adults - the cars simply do not have the safe load carrying capacity for that. Instead, count on simply removing the rear seat to obtain space for light luggage. Rear wheel drive vehicles are especially suitable for high performance applications as the weight transfer due to acceleration will increase the traction on the driven wheels.

By converting a light vehicle it is possible to use a smaller motor, which both weighs and costs less than a larger motor. Lighter overall vehicle weight will reduce power consumption in start and stop traffic and so increase range in many practical driving conditions.

(At least one commercial converter, Solectria, has converted the front wheel drive General Motors Metro for electric use, creating the Solectria Force.)

[edit] Compact sedan or coupe A compact sedan, compared to a subcompact, may have better load capacity and more room for battery placement. But, it is also heavier, and will generally have higher wind drag. This means, compared to a subcompact, they will require larger and more expensive motors, a more expensive controller, and more batteries ( higher weight and cost). Some commercial EV Conversions use vehicles in this size range. One example is a 1992 Honda Civic (http://www.austinev.org/evalbum/542.html). In this conversion, the back seat was retained, and there is still enough room to sink nine flooded lead acid batteries low in the trunk where the spare tire was located, as well as another nine batteries under the hood. With suspension modifications, (increasing shock length & spring rating), one will want to make certain that the vehicle is below GVWR to avoid an illegal and dangerous situation. The car should never be driven if the total vehicle weight is above the GVWR, or if either axle weight is above the maximum designed load for that axle. ( This is typically listed in the glove box, or on one of the door sills of the car)

[edit] Full size sedan Full size sedans and minivans are generally considered to be less attractive candidates for EV conversion than smaller cars. It may be easier to obtain upgraded components for some smaller vehicles, since these may be used for sports racing (particularly autocross). Starting with a heavy vehicle and adding batteries will result in poor performance in acceleration, handling, braking, and economy of operation.

[edit] Sports car For a person interested in sports car performance a satisfying conversion will likely lead to a number of difficulties in such details as battery disposition, as such vehicles generally have available space distributed in small volumes around the vehicle. This leads to complexity in securing and wiring batteries. Such vehicles can offer stunning performance in the lower speed ranges owing to light weight and rear wheel drive and may also offer good range from their superior aerodynamics.

By far the most often converted sports car is the Porsche 914 from the early 1970's. An unusually robust chassis, combined with a large interior storage volume for batteries has made this the vehicle of choice for many successful conversions.

[edit] Light truck Light trucks are especially suitable for hobbyist conversion owing to the fact that it is easy to locate batteries remote from the passenger compartment and there is a good load handling capacity for the use of heavy batteries such as the flooded lead-acid batteries commonly used in golf carts. Light trucks also offer substantial utility in use simply because they are trucks. Even if a portion of the weight capacity is removed by the presence of batteries within the cargo bed, much of the spacial utility remains. A light truck is highly recommended as a first conversion effort owing to the simplicity of component layout. A simple conversion example: http://www.campbellot.com/electric-s10/.

[edit] Hotrod While this type of vehicle is usually made to be a "street legal" performance machine it may also be developed for occasional use as a drag racing vehicle. The leading vehicle in this field was a Mazda RX-7 ([4]) sports car converted from rotary engine to electric. This vehicle can outrun Dodge Viper sports cars in quarter mile drag races. Faster still is John Wayland's White Zombie ([5]). This conversion of a 1972 Datsun 1200 sedan is currently the world's quickest & fastest Street legal car(in the 1/4 mile, per NEDRA).

[edit] Autocross racer EVs may prove to be especially suitable for autocross contests as low speed acceleration is especially important to success in this type of racing. Specific classes for electric autocross (called "electrocross" )are being introduced in some venues. Vehicles for these will typically be economy car conversions or custom built chassies but with excess rear weight bias to allow agile handling under the control of an experienced driver (such rearward balance may be dangerous for everyday use).

[edit] Drag racer Intended only for specialized straight line quarter mile (acceleration) racing this type of vehicle is used only "off road" at specialized "drag strips".

[edit] High speed straight line racer Even more specialized than the drag racer this is intended to obtain high speeds on long, straight, and flat raceways, such as the dry lakebeds found in locations such as the Bonneville Salt Flats

[edit] Custom chassis Suitable for a builder who is capable of constructing a kit car, with good abilities and equipment in machining and welding this can result in a unique vehicle. It is especially suitable for the construction of a lightweight vehicle that can offer exceptional performance.

[edit] Other trucks - full size and most SUVs These are rarely converted due to their excessive weight, and inefficiencies (namely due to poor aerodynamics). To make the situation worse, many modern trucks/SUVs continue to get bulkier and heavier. As a direct result, the payload carrying capacity and thus the GVWR of the vehicles goes down. Such a trait is not desireable because it limits the weight of the battery pack that can be carried, limiting the maximum battery-to-vehicle weight ratio that could be achieved for the vehicle when converted to an EV. For a given battery type, reducing the battery-to-vehicle weight ratio always results in reduced vehicle range per charge. However, despite these mostly unavoidable limitations, several SUVs and larger trucks have been successfully converted to electric power by hobbyists. Some examples include the "Gone Postal" van converted to an EV racer by Roderick Wilde and Suckamps EV Racing, the 1971 Land Rover EV converted by Wilde Evolutions, and the 1988 Jeep Cherokee EV converted by Nick Viera.

Electric vehicle conversion Index

Introduction Technologies Powertrain Battery disposition, security, and wiring Auxiliary systems and control Chassies, suspension, and running gear High power electrical Controls, interlocks, indicators, and alarms Resources

[edit] External links A recently converted Bradley GT2 VW based kit car A nice looking electric motorcycle An electric motorcycle on Youtube Plug In America A Ford Express Conversion Various conversions including an 88 Civic EV World DIY Electric Car Forums Retrieved from "http://en.wikibooks.org/wiki/Electric_vehicle_conversion" Subjects: Alphabetical/E | Electric vehicle conversion | Cars | Automotive Engineering | Electrical Engineering | Automobiles | Library of Congress/T | Dewey/600 | Universal Decimal Classification/Uncategorized

title: User:Rajesh.or.tidke~enwikibooks


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Talk:Modern Greek/Lesson 3x

Untitled
Delta Examples make no sense it first states 'Delta, the letter you might expect to sound like D, actually sounds like th in "this"'

then goes on listing D based words e.g. Ireland, Canada, Holland, Andorra, Denmark, India, Jordan Isn't that a complete contradiction? to the fact that it doesn't sound like a D yet uses words containing D for examples?

^This is what I thought as well. These examples completely contradict the preceding explanation of the letter Δ.

μπετόν = beton
What is a beton? --212.120.248.142 (talk) 16:31, 4 April 2008 (UTC)

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title: Talk:Modern Greek/Lesson 3x


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Acoustics/Microphone Design and Operation

Introduction
Microphones are devices which convert pressure fluctuations into electrical signals. There are two main methods of accomplishing this task that are used in the mainstream entertainment industry. They are known as dynamic microphones and condenser microphones. Piezoelectric crystals can also be used as microphones but are not commonly used in the entertainment industry. For further information on piezoelectric transducers Click Here.

Dynamic microphones
This type of microphone converts pressure fluctuations into electrical current. These microphones work by means of the principle known as Faraday’s Law. The principle states that when an electrical conductor is moved through a magnetic field, an electrical current is induced within the conductor. The magnetic field within the microphone is created using permanent magnets and the conductor is produced in two common arrangements.

The first conductor arrangement is made of a coil of wire. The wire is typically copper and is attached to a circular membrane or piston usually made from lightweight plastic or occasionally aluminum. The impinging pressure fluctuation on the piston causes it to move in the magnetic field and thus creates the desired electrical current. Figure 1 provides a sectional view of a moving-coil microphone.

The second conductor arrangement is a ribbon of metallic foil suspended between magnets. The metallic ribbon is what moves in response to a pressure fluctuation and in the same manner, an electrical current is produced. Figure 2 provides a sectional view of a ribbon microphone. In both configurations, dynamic microphones follow the same principles as acoustical transducers. For further information about transducers Click Here.

Condenser microphones
This type of microphone converts pressure fluctuations into electrical potentials through the use of changing an electrical capacitor. This is why condenser microphones are also known as capacitor microphones. An electrical capacitor is created when two charged electrical conductors are placed at a finite distance from each other. The basic relation that describes capacitors is:

Q=C*V

where Q is the electrical charge of the capacitor’s conductors, C is the capacitance, and V is the electric potential between the capacitor’s conductors. If the electrical charge of the conductors is held at a constant value, then the voltage between the conductors will be inversely proportional to the capacitance. Also, the capacitance is inversely proportional to the distance between the conductors. Condenser microphones utilize these two concepts.

The capacitor in a condenser microphone is made of two parts: the diaphragm and the back plate. Figure 3 shows a section view of a condenser microphone. The diaphragm is what moves due to impinging pressure fluctuations and the back plate is held in a stationary position. When the diaphragm moves closer to the back plate, the capacitance increases and therefore a change in electric potential is produced. The diaphragm is typically made of metallic coated Mylar. The assembly that houses both the back plate and the diaphragm is commonly referred to as a capsule.

To keep the diaphragm and back plate at a constant charge, an electric potential must be presented to the capsule. There are various ways of performing this operation. The first of which is by simply using a battery to supply the needed DC potential to the capsule. A simplified schematic of this technique is displayed in figure 4. The resistor across the leads of the capsule is very high, in the range of 10 mega ohms, to keep the charge on the capsule close to constant.

Another technique of providing a constant charge on the capacitor is to supply a DC electric potential through the microphone cable that carries the microphones output signal. Standard microphone cable is known as XLR cable and is terminated by three pin connectors. Pin one connects to the shield around the cable. The microphone signal is transmitted between pins two and three. Figure 5 displays the layout of dynamic microphone attached to a mixing console via XLR cable.

Phantom Supply/Powering (Audio Engineering Society, DIN 45596): The first and most popular method of providing a DC potential through a microphone cable is to supply +48 V to both of the microphone output leads, pins 2 and 3, and use the shield of the cable, pin 1, as the ground to the circuit. Because pins 2 and 3 see the same potential, any fluctuation of the microphone powering potential will not affect the microphone signal seen by the attached audio equipment. This configuration can be seen in figure 6. The +48 V will be stepped down at the microphone using a transformer and provide the potential to the back plate and diaphragm in a similar fashion as the battery solution. In fact, 9, 12, 24, 48 or 52 V can be supplied, but 48 V is the most frequent.

The second method of running the potential through the cable is to supply 12 V between pins 2 and 3. This method is referred to as T-powering (also known as Tonaderspeisung, AB powering; DIN 45595). The main problem with T-powering is that potential fluctuation in the powering of the capsule will be transmitted into an audio signal because the audio equipment analyzing the microphone signal will not see a difference between a potential change across pins 2 and 3 due to a pressure fluctuation and one due to the power source electric potential fluctuation.

Finally, the diaphragm and back plate can be manufactured from a material that maintains a fixed charge. These microphones are termed electrets. In early electret designs, the charge on the material tended to become unstable over time. Recent advances in science and manufacturing have allowed this problem to be eliminated in present designs.

Conclusion
Two branches of microphones exist in the entertainment industry. Dynamic microphones are found in the moving-coil and ribbon configurations. The movement of the conductor in dynamic microphones induces an electric current which is then transformed into the reproduction of sound. Condenser microphones utilize the properties of capacitors. Creating the charge on the capsule of condenser microphones can be accomplished by battery, phantom powering, T-powering, and by using fixed charge materials in manufacturing.

Microphone manufacturer links

 * AKG
 * Audio Technica
 * Audix
 * While Bruel & Kjær produces microphones for measurement purposes, DPA is the equipment sold for recording purposes
 * Electrovoice
 * Josephson Engineering
 * Neumann (currently a subsidiary of Sennheiser)
 * Rode
 * Schoeps
 * Sennheiser
 * Shure
 * Wharfedale


text:
User talk:Thessa~enwikibooks

Welcome message
G'day, welcome to Wikibooks. You might be interested to read our Cookbook:Policy page or talk to other Cookbook contributors.

Welcome, !

Come introduce yourself at the new users page. If you have any questions, you can ask there or contact me personally. Webaware talk 10:25, 7 March 2008 (UTC)

Your account will be renamed
Hello,

The developer team at Wikimedia is making some changes to how accounts work, as part of our on-going efforts to provide new and better tools for our users like cross-wiki notifications. These changes will mean you have the same account name everywhere. This will let us give you new features that will help you edit and discuss better, and allow more flexible user permissions for tools. One of the side-effects of this is that user accounts will now have to be unique across all 900 Wikimedia wikis. See the announcement for more information.

Unfortunately, your account clashes with another account also called Thessa. To make sure that both of you can use all Wikimedia projects in future, we have reserved the name Thessa~enwikibooks that only you will have. If you like it, you don't have to do anything. If you do not like it, you can pick out a different name.

Your account will still work as before, and you will be credited for all your edits made so far, but you will have to use the new account name when you log in.

Sorry for the inconvenience.

Yours, Keegan Peterzell Community Liaison, Wikimedia Foundation 23:49, 17 March 2015 (UTC)

Renamed
 This account has been renamed as part of single-user login finalisation. If you own this account you can |log in using your previous username and password for more information. If you do not like this account's new name, you can choose your own using this form after logging in: . -- Keegan (WMF) (talk) 05:35, 19 April 2015 (UTC)

title: User talk:Thessa~enwikibooks


text: User talk:220.227.98.62

title: User talk:220.227.98.62


text:
User talk:80.229.81.132

For admin info
Resolves to birkdaleschool.plus.com currently on a 6 month block on en wp for persistent vandalism (here) -- Herby talk thyme 11:55, 7 March 2008 (UTC)

title: User talk:80.229.81.132


text: User talk:222.127.252.245

title: User talk:222.127.252.245


text:
XForms/Book Statistics

Here is a link that has some statistics on this Wikibook:

XForms Book Statistics

December 2010
162 chapters, 885 edits, size 1.2 kB, 39906 words, 71 registered authors

October 2009
147 chapters, 1133 edits, size 1.2 kB, 38664 words, 76 registered authors

April of 2009
141 chapters, 885 edits, size 3.2 kB, 34874 words, 62 registered authors

In March of 2008
116 chapters, 626 edits, size 214, 28811 words, 29 registered authors

2006
Book Created

title: XForms/Book Statistics


text:
Embedded Control Systems Design/Finite State Machines and Petri Nets

Finite State Machines (FSM) and Petri Nets (PN) are conceptual models to represent the discrete interactions in a system.

 * A FSM is a conceptual model that represents how one single activity can change its behaviour over time, reaction to internally or externally triggered events.
 * A PN is a conceptual representation of how multiple activities are coordinated.

FSM's and Petri Nets are at a higher level than the actual software. This means it explains the behavior, but not how it can be implemented. It is an ideal representation, it doesn’t take time delays in account.

Categories of system complexity
Systems of different complexity are represented in different ways. An FSM or UML statechart (similar to FSM, but with more possibilities) can only represent a centralized system, so there is no coordination needed with other systems of its type. Examples of systems of this type are a soda machine, an elevator, ...

Systems with distributed hardware and a centralized software state can be represented using Petri Nets. The centralized software coordinates how the different pieces of hardware act on each other.

A system with distributed hardware and distributed software state can also be represented by a Petri Net, but in this case there is no central control unit. The different pieces of hardware have their own software state and they all 'know' the Petri Net. Now the different pieces have to coordinate themselves.

An example of a distributed system is Robocup. This is a soccer game played by robots. Every robot is a system. If there is a control tower coordinating the robots, this is a case of a centralized software state. The control tower itself can be seen as a system of its own, represented by a statechart with states like 'ball controlled by own team', 'ball controlled by other team', ... In each state, the robots have to cooperate in a different way; this is represented by different Petri Nets.

If there is no control tower, each robot has to control itself and they have to coordinate themselves. Each robot then 'knows' the Petri Net and has to make its own decisions, which can introduce some problems. These are handled later in the section 'Petri Net'.

Finite State Machine
A finite state machine is a model of discrete behavior, which consists of: a finite number of states, transitions between two of those states, and actions. A state represents a certain behavior. A transition indicates a state change and is guarded by a condition. An action is a description of an activity that is to be performed. If this action depends on the state, it’s called a Moore machine. If the action is performed when a transition occurs, so when the state and condition are satisfied, it’s called a Mealy machine. Most machines are both a Moore and Mealy machine at the same time.

Some integrated development environments (IDE) allow a designer to draw a FSM diagram on screen, and then the IDE automatically translates the diagram into a software or FPGA or ASIC implementation. This allows the designer to use a natural way of representation of the system.

Example 1
A robot is working at high speed. When someone opens the door to enter the room, the robot continues its work but at a lower speed to guarantee the safety of the person. When the person leaves the room through the door, he/she has to push a button after closing the door. Now the robot can continue its work at high speed.

Notice that this a Moore machine, because the outputs (actions) are state-based.

Also notice the fact that there is a difference between reality and the model of the reality. In the model, there is no time needed to check the condition. In reality, it takes some time to check the door-sensor and to check the pushbutton.

Example 2
In the train project, the lamps have to light up when the train passes through a tunnel. Although, when the train drives in daylight, the lamps should be dimmed. Depending on the driving direction, either the white or red light should be working.

Notice that this a Mealy machine, because the outputs(actions) are input-based.

Example 3
In the train project, the train has to slow down when it takes a turn. The motor has to work harder when the train is riding upon a hill. The transitions between states are controlled by beacons. The image shows the possible transitions from/to driving in a straight line, other transitions are possible too.

UML Statecharts
FSM, explained before, is limited in a way. You cannot have two states active at the same moment, next to each other. The UML statechart is an attempt to overcome this limitation while retaining its good features. This is only one of the many graphical representations of a system that are defined in UML. UML (Unified Modeling Language) is designed to specify, visualize, construct and document software-intensive systems. For more information, we refer to the Wikipedia page. The essential syntax of statecharts is very much like FSM's. In a statechart, it is possible that there are states within states, so there is a kind of a hierarchical structure. They are called substates and superstates or parentstates.Another possibility is concurrent states. By using branching, a state can be followed by more than one other state. Each transition can be guarded with its own condition. When more than one condition is satisfied, two states can be active at the same moment.

Compared to FSM, the design of an embedded system can be visualised a lot better and less complicated with sub- and superstates. You can see better how the system works and it's also easier for the designer to locate problems and to adapt the system. Because it's a standard, large number of simulation tools are available (StateMate, StateFlow, BetterState...). These simulation tools are just made to check the theoretical system, but you can never be sure that the embedded system will function properly. Available „back-ends“ translate StateCharts into C or VHDL. This enables software or hardware implementations.

Example
A good example to explain the usage of a statechart is a soda machine. The user inserts a quarter and the machine waits until the user has inserted a second quarter. After the user has chosen his drink, the drink is dispensed. The machine waits again. You have two big states: collecting and dispensing. They have substates because there are different drinks and every time the user inserts a coin a new state is entered. In theory this seems a good visualisation, but in practice there are a lot of other factors. These problems can be solved partially. The bottle could get stuck in the machine, so we make a new state next to the collecting and dispensing part like shown in the figure below.

Introduction
Petri Net(PN) is an abstract model to show the interaction between asynchronous processes. It is only one of the many ways to represent these interaction. Asynchronous means that the designer doesn't know when the processes start and in which sequence they'll take place. A common manner to visualize the concepts is with the use of places, tokens, transitions and arcs. We refer to the basics of Petri Net for a first introduction in notations. We want to mention that a transition can only fire when there are tokens in every input-place. When it fires, one token is taken from every input-place and every output-place from the transition gets an (extra) token.

Places can play the following roles:
 * a type of communication medium: the wireless connection in Robocup;
 * a buffer: all the robots send messages to each other. When one robot checks the first message, the other incoming information is placed in his memory;
 * a geographical location: the environment of a robot, a place he has to go to;
 * a possible state or state condition: normal mode and safe mode of a machine(see FSM);

Tokens can play the following roles:
 * a physical object: a robot;
 * an information object: a message between two robots;
 * a collection of objects: the people mover;
 * an indicator of a state: the state in which a robot is: defender/attacker;
 * an indicator of a condition: a token indicates whether a certain condition is fulfilled (ex. Soccer game starts when the referee gives the signal).

Transitions can play the following roles:
 * an event: start a thread, the switching of a machine from normal to safe mode;
 * a transformation of an object: a robot who changes his role, see further;
 * a transport of an object: the ball is passed between the robots.

An arc connects only places and transitions and indicates the direction in which the token travels.

Coordination problems
In a PN, situations can occur where two or more systems wait for each other before an action can take place. This is called a deadlock. It can also occur that a single system has to wait forever at the beginning of a transition because another process has always higher priority. This problem is called starvation.

In the mathematical model a transition takes no time. In the real world executing a transition takes some time and the sequence or timing of events becomes important. This problem relates to race conditions or race hazards. When the PN is rather big, these problems are hard to find.

Robocup examples
The problems and solutions that can occur will be introduced using the example Robocup. There has to be communication between the robots to achieve a certain purpose. We suppose that the autonomous robots are perfectly designed, so we use a behavior engineering approach.

When a robot stands on the field his behavior consists of a number of options. With these options and incoming information he decides what he is going to do.

Every robot can do some basic actions:
 * stand still
 * turn around
 * walk
 * go to ball
 * grab
 * pass
 * kick the ball

Two or more robots have to work together and therefore there actions have to be synchronized. The designer uses Petri Net as a virtual model to show the interactions.

Example: double pass scenario

When a robot sees an opponent in front of him and there is a teammate close to him, he can set up a double pass action. We refer to the petri net figure in the introduction. With this model, the software in the first robot can communicate with the software in the second robot. Sometimes instructions must wait on an input signal which indicates that the other robot has finished his action.

There can be problems when the double pass is planned in such a way. When the second robot dribbles and loses the ball, the first robot will wait forever to accept the pass. A better implementation would require continuous communication between the 2 robots. The second robot can tell that he has lost the ball or that he wants to pass to another player.

Example: wrong decision

Robots have to take decisions during the game. It takes some time to check several conditions and during this time the previous decisions can change from true to false. Consequently the robot does a wrong action. For example: A robot asks the ball. The robot who has the ball has to check two conditions. IF teammate asks ball AND I have the ball THEN give a pass. When this robot has checked the first condition, there can be an opponent who jumps in front of the asking robot, so the robot says he doesn't want the pass anymore. The first robot checks the second condition and he passes the ball which is then intercepted by the opponent. This simple example can be extended by a third condition(IF there's no opponent)

Example: deadlock situations

 * The principle of mutual exclusion says that a resource can only be assigned to one robot. When it isn't, the resource is free. When two robots claim the ball(=resource) a deadlock situation can occur because the ball is assigned to two different agents. This problem also relates to a circular wait condition because each robot waits for the other to release the ball.

 * The robots have to play a role(=resource) in their team. The role allocation can be as follows: primary attacker, offensive supporter, defensive supporter and goalkeeper. The role of goalkeeper is fixed throughout the game. The other three roles are more fluid. The robots signal one another constantly, broadcasting their estimate of the distance between themselves and the ball. Based on the various estimates, the robot that is closest to the ball takes on the role of primary attacker, proceeds towards the ball and tries to kick it towards the opposing team's goal. The offensive supporter also moves towards the ball, but stops before it gets too close. The defensive supporter waits until the ball approaches him (before switching to a primary attacker mode). There can occur problems when assigning those roles to the robots. Consider the role as primary attacker which can be allocated to exactly one robot. If no robots are allocating this resource, the team suffers since no robot will try to move to the ball. If several robots are allocating this resource then the team will suffer as they interfere with one another because they all try to get the ball. Another problem is the time delay which occurs during the switching between two roles. A robot must first release resources so another robot can take it. Within this time the robot freezes and can't perform an action.
 * In a critical situation when the attacker robot loses power, a deadlock situation can occur. The robot can't release his attacker role, so there are no agents who run towards the ball because they can't be primary attacker(the resource isn't released). This problem can be avoided with the communication between the robots or with an automatic release function when the power shuts down.

Other models
The previous models have a lot of extensions and variations. Because the list is so elaborate, only a few models are discussed.

Colored Petri Nets
In a colored PN every token is an object with some properties. These properties can change when it travels through the structure. With these properties a certain object can, for example, get priority to other objects. Every object has some kind of Finite State Machine to follow and the coordination between the different objects is done by the colored Petri Net. So colored PNs can be considered as a combination of coordination and computation.

Communicating sequential processes (CSP)
Communicating sequential processes (CSP) is a language, used in computer science, to describe the interaction in concurrent systems. Due to this concurrency, communication is essential. Every "message" is a combination of coordination and communication. This way, a formal verification between the processes is possible.


text:
Embedded Control Systems Design/Asynchronous activities

This chapter explains how to exchange data between two activities that run in parallel, or to synchronize their executions.

interrupts and ISRs
Interrupts and ISRs (interrupt service routines) are the lowest level of asynchronous activity. All higher levels are built on this foundation. In some cases, the RTOS will handle all the low-level details for you.

We discuss interrupt and ISRs in more detail in other chapters --
 * ../Operating_systems
 * ../Real Time Operating systems
 * ../Design Patterns

threads sharing memory
Exchanging data between two threads sharing memory ...

medium level

interprocess communication
high level (= Interprocess Communication via asynchronous message passing between processes in separate protected memory areas).

computer to computer communication
RPC (remote procedure calls) ...

Software problems
When implementing the software code in a robot, there can be problems with synchronous threads. This section gives some bad programming examples in multithreaded systems. It is illustrated in C-code. They are concerned because it is a first step to understand problems which occur do to concurrent engineering on a higher level.

 * When a program has a global variable and synchronous threads, thread 1 might be interrupted before the global variable is written and thread 2 might work on old data. This might still be acceptable, but the outcome of the program isn't what the programmer wants.

 * When the global variable changes from a positive to a negative value between lines 4 and 8, none of the conditions are true. There's no function call and this can lead to problems.

 * When two threads use the same resources, the principle of mutual exclusion can be used. This can be implemented with a global variable counter. When the counter is negative one thread is blocked before entering the critical section while the other thread is still executing code within this critical section. The first thread sets the global_variable and the second one uses it to do a calculation.

If the first thread decrements the counter and is then preempted, the second thread also decrements the counter and evaluates it afterwards. Both threads can't continue since the counter is at -1 now. There is a deadlock situation in the executed program.

This problem can also arise at a higher level of abstraction. The deadlock situation in petri nets will be described in the following section.


text:
XRX/Regular Expression Builder

Motivation
You want to build a form that will allow you to quickly test replacement regular expressions using XQuery's replace function.

Method
We will use an XForms client that has several controls:
 * 1) a test input string
 * 2) a regular expression to evaluate
 * 3) a new string to be used in the replace
 * 4) a "submit" trigger (button)

When the submit trigger is pressed, the three strings are sent to the server and the XQuery replace function will be executed. The result is an output text area that is returned from the server to the web browser.

This tool will allow you to do things such as test your URL-rewrite rules.

Link to Working Application
Replace Test

Sample Program
  @namespace xf url("http://www.w3.org/2002/xforms"); body {font-family: Ariel, Helvetica, san-serif}

/* Input controls appear on their own lines. */ xf|input, xf|select, xf|select1, xf|textarea {display:block; margin:5px 0;}

/* Makes the labels right aligned in a 150px wide column that floats to the left of the input controls. */ xf|input > xf|label, xf|select > xf|label, xf|select1 > xf|label, xf|textarea > xf|label, xf|output > xf|label {font-weight: bold;text-align:right; padding-right:10px; width:150px; float:left; text-align:right;}

/* make the input boxes a little wider */ .xf-value {width: 200px}

xquery version "1.0"; declare namespace exist = "http://exist.sourceforge.net/NS/exist"; declare namespace system="http://exist-db.org/xquery/system"; declare namespace request="http://exist-db.org/xquery/request"; declare option exist:serialize "method=xml media-type=text/xml indent=yes"; (: replace demo :) let $input := request:get-parameter('input', '') let $pattern := request:get-parameter('pattern', '') let $replacement := request:get-parameter('replacement', '')

return {$input } {$pattern} {$replacement} {replace($input, $pattern, $replacement)}

Discussion
This shows that you can quickly build tools to teach yourself complex functions like regular expression handling. You can also use the XQuery match function, which returns true or false if the regular expression matches an input string.

There are two variations of this example that are interesting. The first is where you replace the input form with a large text area for doing global replacements of large blocks of text. The second is where you replace the input box with a selection list with common replacement patterns.

title: XRX/Regular Expression Builder


text:
XRX/Benefits of XRX

Benefits of XRX Architecture
XRX benefits from each of its three underlying standards:

 * XForms
 * Unlike technologies such as AJAX, XRX assumes a model-view-controller architecture
 * XForms supports a dependency graph that allows the right views to be automatically updated
 * All interactions between the client and the server are sent through the model via submission elements
 * REST
 * XRX takes advantage of web infrastructure such as multi-level caching and technologies that are collectively known as deep REST systems.
 * XQuery
 * XQuery is a functional XML-oriented query and transform language that can perform the business logic for many systems. In addition to its XML transform capabilities, it has advantages over older query languages such as SQL designed in the 1970s and 1980s.  XQuery has the expressive power of SQL (joins etc) and can also manipulate recursive hierarchical data structures.  Unlike SQL, XQuery is a W3C standard with very strong standardization across vendors and over 14,000 tests to ensure cross vendor compatibility.  Developers frequently develop XQuery applications on low-cost OpenSource databases and port them to commercial systems without significant changes.

Together, these three standards allow developers to use a single data format (XML) on the client, middle tier and the databases server. This means there is no translation of the data formats between layers. In contrast to this, many other modern systems communicate using XML, process business logic in an object-oriented layer, store data in a relational database, and render a GUI as HTML.

Consider all the "glue" code in a typical modern system, which serves no purpose other than to translate from one representation to another: object-relational mappings, HTML rendering code, XML import/export code. These web application architectures take HTML forms (which use flat key-value pairs), convert these data structures to middle tier objects such as Java or .Net and then transform the objects into tabular data streams so they can be stored in relational databases. Once in the relational database the data must then be re-serialized by doing SELECT statements, converted into objects and the objects then converted back into HTML forms. This is a four-step translation architecture.

In contrast, XRX uses a zero-translation architecture. Zero translation implies that XML is stored in the web client, transmitted to a middle tier validation rules engine in XML and then stored in its entirety in an XML database. Typically, XML is also the format that data is delivered or streamed in from other systems. The storage as XML is also known as a zero-shredding process since the data files are not separated into Third Normal Form (3NF) data structures.

This relational (3NF) storage is often not helpful. XML data has the relationships built into the data, whereas relational data is stored in "dumb" tables and allows/requires the applications to specify the relationships. For applications where the relationships are well known (e.g. a user has a collection of blog posts, and those posts have collections of comments and replies) XML is better. When a "data warehouse" is needed and the relationships will vary widely based on the calling application, a relational store may be better because RDBs are optimized for ad-hoc joins where XML DBs are generally not. (e.g. a group of users are in a social network and there are a variety of ad-hoc relationships that *all* must be queried quickly - use an RDB). XML databases are optimized for the relationships built into the XML, relational databases are optimized for easy programming and performance on one preferred set of relationships.

The biggest difference, though, is zero-translation vs. "translation everywhere."

1+1+1=10
Using a combination of all these three standards gives web developers a tenfold increase in productivity.

Back: Introduction • Next: XRX Application Server

title: XRX/Benefits of XRX


text: User talk:24.211.170.4

title: User talk:24.211.170.4


text: User talk:12.32.94.66

title: User talk:12.32.94.66


text:
Wikibooks:Requests for import/2008

January 2008
For my used car buying book. --Solumeiras (talk) 19:11, 8 January 2008 (UTC)
 * w:Holden Astra
 * w:Volkswagen Golf
 * w:Volkswagen Jetta
 * The first one is ✅ here. The other two failed because of too many revisions probably. I'll see if anyone else has any luck with them. Mattb112885 (talk to me) 18:47, 13 January 2008 (UTC)
 * No luck; Here and here with on the talk page.  – Mike.lifeguard  | talk 19:11, 13 January 2008 (UTC)

 * Cuisine of Aghanistan (Wikibooks already has a page for Cuisine of Aghanistan but there isn't any information on it.)
 * ❌ - That page doesn't exist. – Mike.lifeguard  | talk 00:29, 4 January 2008 (UTC)
 * [[Image:X mark.svg|15px| ]] Failed - I added an 'f' to "Afghanistan" and found the page, but the import still failed. I guess there are too many revisions for the import tool to handle.  --Jomegat (talk) 04:01, 4 January 2008 (UTC)
 * [[Image:Yes_check.svg|15px| ]] Here – Mike.lifeguard  | talk 21:21, 6 January 2008 (UTC)
 * How did you do that Mike? --Jomegat (talk) 21:27, 6 January 2008 (UTC)

February 2008
Denmark I want to edit it to put in Wikijunior for Europe. Thoughts? Laleena (talk) 02:00, 4 February 2008 (UTC)
 * ✅. Able to import 1 revision here. I learned some things about this import, and i'll make a note about it at WB:AN. --Whiteknight (Page) (Talk) 02:07, 4 February 2008 (UTC)

 * Introduction to metrics, norms and inner products. As a result of a deletion discussion (here), the view was that the content should be moved to Wikibooks.  Once the import is (or is not) carried out, please let me know via my Wikipedia talk page so I can delete the original. Thanks. Proto (talk) 11:10, 11 February 2008 (UTC)
 * ✅ – Mike.lifeguard  | talk 13:24, 11 February 2008 (UTC)

 * Mediation Preparation. Can someone import this how-to? Thanks. Carlosguitar (talk) 03:05, 16 February 2008 (UTC)
 * ✅ You can get it here. --Jomegat (talk) 03:23, 16 February 2008 (UTC)

 * Plate tectonics
 * For use here. Thanks, Laleena (talk) 01:23, 20 February 2008 (UTC)
 * ✅, but not all the versions would come over. You can see it here. --Jomegat (talk) 01:51, 20 February 2008 (UTC)

 * Iranian Revolution
 * For use in the Iranian History textbook. Thanks, Laleena (talk) 15:17, 23 February 2008 (UTC)
 * ✅ sort of. I got the text to come over, but only the most recent revision.  You can get it at the expected place. --Jomegat (talk) 19:03, 23 February 2008 (UTC)

 * Frobenius solution to the Hypergeometric Equation
 * A method which is better on Wikibooks. Carlosguitar (talk) 00:27, 20 March 2008 (UTC)
 * ✅ You can find it here. --Jomegat (talk) 01:08, 20 March 2008 (UTC)

March 2008

 * Volcano
 * For use in the Volcanoes wikibook. Thanks, Laleena (talk) 13:41, 7 March 2008 (UTC)
 * ✅ kind of. I managed to get the article to come over, but not the history.  THe article is here.  --Jomegat (talk) 15:11, 7 March 2008 (UTC)

 * w:Template:Step - For navigating through the book in a linear fashion. Ross Uber -  Talk  -  Contributions  - 21:27, 30 March 2008 (UTC)
 * [[Image:Yes_check.svg|15px| ]] Done: Template:Step – Mike.lifeguard  | talk 21:31, 30 March 2008 (UTC)
 * w:Template:Navbox - For navigating through a book in a total table-of-contents fashion. Ross Uber -  Talk  -  Contributions  - 21:27, 30 March 2008 (UTC)
 * [[Image:X mark.svg|15px| ]] Not done: Already exists at Template:Navbox. – Mike.lifeguard  | talk 21:31, 30 March 2008 (UTC)

Inorganic Chemistry
I have a rather long list of requests for importing from wikipedia, but then, Inorganic Chemistry happens to be a lot of factual matter.

 * Molecular_orbital_theory → Transwiki:Molecular orbital theory
 * Molecular_orbital_diagram → Transwiki:MO diagram
 * Lewis_structure → Transwiki:Lewis structure
 * Orbital_hybridization → Transwiki:Orbital hybridisation
 * VSEPR_theory → Transwiki:VSEPR theory

These articles serve primarily encyclopaedic content but can serve as a starting point for the Inorganic Chemistry - Chemical Bonding module.

Thanks--Thewinster (talk) 19:29, 25 March 2008 (UTC)
 * ✅ – Mike.lifeguard  | talk 20:21, 25 March 2008 (UTC)

 * I noticed that not all images are not locally avaiable, like the portait of G N Lewis on the Inorganic Chemistry/Chemical Bonding/Lewis Dot Structures Is this some flaw or was intentionally done? Am i allowed to create copies of the images on wikipedia on wikibooks as well? --Thewinster (talk) 19:49, 27 March 2008 (UTC)

 * Those would be images that were uploaded to Wikipedia rather than to the Commons. You can copy them from Wikipedia to the Commons yourself if you like.  Basically, you'll need to find the full resolution image on Wikipedia and save it to your local PC.  Then log into the Commons and click the upload link.  You will be presented with a set of choices, one of which is "It is from another Wikimedia project" - that's the one you'll want.  That will take you to a page with a form.  At the top of the page will be a link to "the CommonsHelper tool" which is very useful for capturing info about the picture.  I'm sure you can figure the rest out by reading the prompts, but if you run into trouble, please ask.  There's prolly a page about this process somewhere.  Hope that helped.  --Jomegat (talk) 21:01, 27 March 2008 (UTC)

 * Thanks for the info. I could have figured out a lot of it myself once i was told those images were not on commons. But the whole reply was bubbling with enthusiasm! :D Thanks for the "from other wikiedia project" bit! --Thewinster (talk) 16:52, 28 March 2008 (UTC)

April 2008

 * Bloody_Mary_%28cocktail%29 has a lot of recipe-ish content. Random832 (talk) 00:40, 1 April 2008 (UTC)
 * [[Image:Yes_check.svg|15px| ]] Here – Mike.lifeguard  | talk 02:57, 1 April 2008 (UTC)

 * Could we import to Wikijunior:Famous Inventors/Early Inventors/Galileo this entry fromGalileo_Galilei? I want to try out the import before I try it with my students' modules.  Did I get this request right?  --Jsigler (talk) 18:19, 2 April 2008 (UTC)
 * [[Image:Yes check.svg|15px]] Here (only 1 revision) & a note on your talk page. – Mike.lifeguard  | talk 21:26, 2 April 2008 (UTC)

Sorry for this big request. Would you please import over to a transwiki the following Wikipedia articles on inventors for our Famous Inventors] wikijunior book? [[w:Alexander_Graham_Bell Samuel_F._B._Morse Guglielmo_Marconi Henry_Ford Wright_brothers George_Washington_Carver Cyrus_McCormick Thomas_Edison Benjamin_Franklin George_WestinghouseMarie_Curie--Jsigler (talk) 03:15, 4 April 2008 (UTC)
 * No problem! Only one revision for each :( Located at:
 * Transwiki:Alexander_Graham_Bell
 * Transwiki:Samuel_F._B._Morse
 * Transwiki:Guglielmo_Marconi
 * Transwiki:Henry_Ford
 * Transwiki:Wright_brothers
 * Transwiki:George_Washington_Carver
 * Transwiki:Cyrus_McCormick
 * Transwiki:Thomas_Edison
 * Transwiki:Benjamin_Franklin
 * Transwiki:George_Westinghouse
 * Transwiki:Marie_Curie
 * – Mike.lifeguard  | talk 19:56, 7 April 2008 (UTC)

May 2008

 * Algebraic chess notation SunCreator (talk) 19:03, 16 May 2008 (UTC)
 * ✅ - I got both, but Transwiki:Algebraic chess notation had too many edits, so not all the history came with it. Transwiki:Chess opening theory table came across with all its history though. --Jomegat (talk) 19:15, 16 May 2008 (UTC)

June 2008

 * mKR (programming language) (start mKR book) Rhmccullough (talk) 10:33, 26 June 2008 (UTC)

 * I don't think this should be imported to Wikibooks. Some of the reasons for suggesting its deletion on Wikipedia apply here as well. This seems to be original research, which means there probably isn't going to be a realistic way to independently verify what is being written isn't just being made up. I think this would be more appropriate for Wikiversity which does allow original research. --dark lama  12:49, 26 June 2008 (UTC)

 * It seems that a wikibook on this topic would be some sort of a manual. Question Writer 3 Manual may be a precedence. A number of wikibooks require some leniency on the original research clause.
 * The noteriety issue may be a tougher sticking point. I'd be willing to overlook that if there was the chance that it might develop into a good wikibook. There isn't much on that Wikipedia page; how about dropping the import request, being bold and just starting the book? --Swift (talk) 16:00, 26 June 2008 (UTC)

 * Question Writer 3 is a software program that has plenty of existing material available that I can find by a Google search, so I don't see the precedence there. My concern is that there appears to be little if any material that documents the mKR programming language that could be used to determine if a book written on Wikibooks about it is factually accurate, complete garbage or being invented as the person goes. It is in that sense that it is original research because it cannot be verified either way. I don't think it meets Wikibooks' inclusion requirements, but it does Wikiversity's. Other books that have had similar problems have been deleted as well. --dark lama  16:56, 26 June 2008 (UTC)

 * Good points. I chose to point to Question Writer 3 since I stumbled across User:Hskeet's comment on Whiteknight's talk page where he explanes that he had "been commissioned to write the manual by the owners/developers of the software". It seems that the principle author of that Wikipedia article is also the software author. In a sense that would be a pretty solid proof of validity, but naturally, that would not guarantee future edits.
 * I'd like to see wikibooks embrace manuals like these, but not without ensuring verifiability. --Swift (talk) 17:28, 26 June 2008 (UTC)

July 2008

 * Philadelphia slang (Reasonably well-sourced slang terms. Not appropriate for wp.) Mdsummermsw (talk) 14:12, 16 July 2008 (UTC)
 * I'm sorry but I fail to see how this is appropriate for wikibooks either. Wikibooks is also  not a dictionary.  This page does not have the makings of a textbook.

October 2008

 * Waterzooi Recipe for Cookbook Jonathan Oldenbuck (talk) 16:03, 9 October 2008 (UTC)
 * ✅ You can find it at Transwiki:Waterzooi. --Jomegat (talk) 17:41, 9 October 2008 (UTC)
 * Note for Jonathan Oldenbuck - now fully cleaned up and moved here Unusual? Quite TalkQu 11:15, 3 January 2009 (UTC)

 * Sailing (The article has outgrown usual encyclopedia size. There's a lot of good stuff to serve as the basis for a book.) 216.31.225.194 (talk) 23:04, 24 October 2008 (UTC)
 * I had a look and couldn't see much in the way of sailing instruction. There were several references to useful terms, but no really actionable information which will help you learn to sail (better). --Swift (talk) 01:12, 25 October 2008 (UTC)
 * There's a lot of articles where the discussion says "this article is too long" relating to sailing, of which this is one. My thought was to gather several of these together and dewikipedia-ize them into a book.  I had in mind a larger scope than this one article covers, combining several related articles into a coherent document, but, not being entirely sure I know what I'm doing, thought it would be best to start with a single article.  Wcoole (talk) 00:53, 28 October 2008 (UTC)
 * ✅. I couldn't get the article history though, as there have been too many revisions.  (Sometimes the magic works, sometimes it doesn't).  You can find the imported article here.  --Jomegat (talk) 01:22, 28 October 2008 (UTC)

November 2008

 * Corned_beef_pie (Move the recipe in the article to cookbook.) Glane23 (talk) 15:03, 8 November 2008 (UTC)
 * ✅ — Mike.lifeguard | talk 19:58, 8 November 2008 (UTC)
 * Note for Glan23 - now fully cleaned up and moved here Unusual? Quite TalkQu 11:15, 3 January 2009 (UTC)

 * X-SAMPA (For use in modified form in Conlang book.) Pi zero (talk) 16:09, 24 November 2008 (UTC)
 * ✅ — Mike.lifeguard | talk 17:26, 24 November 2008 (UTC)

 * Wooden reed care seems to belong here more than there. LtPowers (talk) 18:42, 26 November 2008 (UTC)
 * ✅ - can probably be useful in a bunch of different books. — Mike.lifeguard | talk 18:45, 26 November 2008 (UTC)

December 2008

 * Methi na Gota (This seems like it would belong in the Wikibooks cookbook, rather than on Wikipedia.) Madkayaker (talk) 17:53, 2 December 2008 (UTC) It turns out the article was in violation of copyright, per WP:CSD G12, so I am removing my request for import. Madkayaker (talk) 18:13, 2 December 2008 (UTC)

 * Rule_Mining_Best_Practices (seems to belong here more than there.) Fairguy21 (talk) 16:48, 17 December 2008 (UTC)
 * ✅  --Jomegat (talk) 18:48, 17 December 2008 (UTC)
 * Note for Fairguy21 - now fully cleaned up and moved here Unusual? Quite TalkQu 11:15, 3 January 2009 (UTC)

 * Effects of different voting systems under similar circumstancesand accompanying template required for the page to look right w:Template:Tenn voting example. may need NPOV and factual cleanup.--216.118.68.193 (talk) 16:20, 27 December 2008 (UTC)
 * [[Image:Yes check.svg|15px]] Done Now avaialable at Transwiki:Effects of different voting systems under similar circumstances. I didn't tranwiki the template, but rather subst-ed it before the import. --Swift (talk) 04:29, 31 December 2008 (UTC)

Import and merge
Use this section for imports that need to be "history-merged" with a module that has already been started using copy-paste.

 * A Wikimanual of Gardening/Cephalotus: Pardon me, I should have requested this be moved from Cephalotus. Can the history of the page be merged with the cut/paste and cleanup I did here?. Cheers, Cygnis insignis (talk) 02:23, 2 March 2008 (UTC)
 * [[Image:Yes_check.svg|15px| ]] Done – Mike.lifeguard  | talk 03:02, 2 March 2008 (UTC)

Can we try an import and Merge of histories for Wikijunior:Famous_Inventors/Inventors_in_Communication/Nikola_Tesla_%28Radio%29 from Nikola_Tesla.
 * Import failed, so I just put a template on the talk page and a note in the history. – Mike.lifeguard  | talk 19:46, 7 April 2008 (UTC)

title: Wikibooks:Requests for import/2008


text:
User talk:72.27.4.37

Hello, The nominations for featured books is for wikibooks which have been created on this site. Thanks --AdRiley (talk) 16:01, 7 March 2008 (UTC)

title: User talk:72.27.4.37


text:
The Sway Reference Manual/Storing Code in Files

After a while, it gets rather tedious to cut and paste into the Sway interpreter. A more efficient method is to store your program in a text file and then load the file.

I use vim as my text editor. Vim is an editor that was written by programmers for programmers (emacs is another such editor) and serious Computer Scientists and Programmers should learn vim (or emacs).

Your first program
Create a text file named hello.s. The name really doesn't matter and doesn't have to end in .s (the .s is a convention to remind us this file contains Sway source code). Place in the file

println("hello, world!");

Save your work and exit the text editor. Now execute the following command at the system prompt (not the Sway interpreter prompt!):

sway hello.s

You should see the phrase:

hello, world!

displayed on your console. Here's a trace using Linux:

lusth@warka:~$ sway hello.s   hello, world! lusth@warka:~$

The lusth@warka:~$ is my system prompt.

A Neat Macro
One of the more useful things you can do is set up a vim macro. Edit (or create) the file .exrc in your home directory and add these lines:

set ai sm sw=4 map @ :!sway %^V^M

The first line sets some useful parameters: autoindent and showmatch. The sw=4 sets the indentation to four spaces. The next line makes the '@' key, when pressed, run the Sway interpreter on the file you are currently editing (save your work first before tapping the @ key). The ^V^M part of the macro is not the four characters ^ V ^ M, but two characters -v and -m. It's just when you type -v-m, it will display as ^V^M.

Writing Sway Programs
A typical Sway program is composed of two sections. The first section is composed of variable and function definitions. The next section is composed of statements, which are Sway expressions, each of which is (usually) followed by a semicolon.

The ''hello.s' file above was a program with no definitions and a single statement. A Sway program composed only of definitions will usually run with no output to the screen. Such programs are usually written for the express purpose of being included into other programs.

Typically, one of the function definitions is a function named main (by convention); this function takes no arguments. The last line of the program is a call to main. Here is a rewrite of hello.s using that convention.

function main {       println("hello, world!"); }

main;

This version's output is exactly the same as the previous version.

Order of definitions
A function or variable must be defined before it is used. This program will generate an error:

var x = y * y;   var y = 3;

since x can't be given a value until y is defined. This program is legal, however:

function x {       y * y; }

function y {       3;        }

x;

because even though the body of function x refers to function y, function y is defined by the time function x is called (the last statement of the program).

Including code
One can include one Sway module into another by use of the include function:

include("moduleX.s");

where moduleX.s is the name of the file whose Sway definitions you wish to include. Including a module imports all the top level definitions in that module. The statements beyond the definitions in the included module are ignored and are not evaluated.

If moduleX.s has includes, those modules will be included as well.

Preventing multiple includes
Sometimes, in a complex implementation, a module can get included more than once. Usually, this results in multiple definitions of the same item and, while wasteful, usually does not cause any harm. However, consider the case where one module includes the other and vice versa. Here is an example. One module, fact.s, has the following implementation:

include("fib.s"); function fact(n) {       if (n < 2,1,n * fact(n - 1)); }   println("fib(5) is ",fib(5)); println("fact(5) is ",fact(5));

The other module, fib.s, has this code:

include("fact.s"); function fib(n) {       if (n < 2,v,fib(n - 2) * fib(n - 1)); }   println("fib(6) is ",fib(6)); println("fact(6) is ",fact(6));

Trying to run Sway on either module results in an out of memory error, since each file gets included over and over (fib.s includes fact.s which includes fib.s and so on). One can prevent multiple includes by using the includeOnce function. Here is a rewrite of each module.

fact.s
includeOnce(fib.s,"fib.s"); function fact(n) {       if (n < 2,1,n * fact(n - 1)); }   println("fib(5) is ",fib(5)); println("fact(5) is ",fact(5));

fib.s
includeOnce(fact.s,"fact.s"); function fib(n) {       if (n < 2,v,fib(n - 2) * fib(n - 1)); }   println("fib(6) is ",fib(6)); println("fact(6) is ",fact(6));

Running the fact.s program yields:

fib(5) is 5 fact(5) is 120

while running the fib.s program yields:

fib(6) is 8 fact(6) is 720

The first argument passed to the includeOnce function must be a variable, but this variable does not necessarily have to be defined. The includeOnce function checks to see if its first argument has already been defined. If the variable already exists, no further action is taken. If not, includeOnce defines it with a value of :true and then includes the module named by the second argument. Due to Sway's lax naming rules for variable names, most file names (including Unix style paths) without spaces are legal variable names. By convention, the variable name given to includeOnce is the name of the file containing the module; though any variable name will suffice. If there is a name clash, however, and the variable is already declared through some other means, the given module will not be included. The includeOnce function only checks to see if the first argument is defined in the current local scope, so the check against multiple includes will not work if you include once again at a different scope level.

The include and includeOnce function are the only functions that are considered definitions and thus can appear in the definition area of a Sway module. It is legal, however, to call either function in an expression, as in:

x = includeOnce(:module1.s,"module1.s");

Of course, such calls to include and includeOnce are not part of the definition area. In the following example, only the top level definitions from modules B and C are included in A.

A.s
include("B.s"); ...

B.s
include("C.s"); var x;   x = include("D.s");

The definitions from module D.s are not included into A.s since only the definition area of B.s is included in A.s (which causes an include of C.s). The call to include D.s is in the expression area and is ignored when B.s is included.


text:
Inorganic Chemistry/Qualitative Analysis

 * /Tests for anions/
 * /Tests for cations/
 * /Systematic Inorganic Analysis/

Praktikum Anorganische Chemie