Thermal paper

December 23rd, 2009 | himrflei

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ticket printed on thermal paper. A heat source near the paper will color the paper.

Paper roll for thermal transfer printer

Thermal paper is paper that is impregnated with a chemical that changes color when exposed to heat. It is used in thermal printers and particularly in cheap, lightweight devices such as adding machines, cash registers, and credit card terminals.

The surface of the paper is impregnated with a solid-state mixture of a dye and a suitable matrix; a combination of a fluoran leuco dye, octadecylphosphonic acids as an example. When the matrix is heated above its melting point, the dye reacts with the acid, shifts to its colored form, and the changed form is then conserved in metastable state when the matrix solidifies back quickly enough.

Typically the coating will turn black when heated. But coatings that turn blue or red are sometimes used.

Most direct thermal papers require a protective topcoating to:

reduce fading of the thermal image caused by exposure to UV light, water, oils, grease, lard, fats, plasticizers, and similar causes

provide improved printhead wear

reduce or eliminate residue from the thermal coating on the thermal printheads

provide better anchorage of flexographic printing inks applied to the thermal pape , heat press machine .

focus the heat from the thermal printhead on the active coating , t shirt heat transfer .

History

The earliest direct thermal papers were developed by NCR Corporation (using dye chemistry) and 3M (using metallic salts). The NCR technology, although the image would fade rather rapidly compared with the much more expensive, but durable 3M technology, became the market leader over time.

Texas Instruments invented thermal print head in 1965, and the Silent 700, a computer terminal with a thermal printer, was put on market in 1969. The Silent 700 was the first thermal print system that printed on thermal paper.

In the 1970s and early 1980s, Japanese producers (such as Ricoh, Jujo, and Kanzaki) using similar dye-based chemistry formed partnerships with barcode printer manufacturers (such as TEC, Sato, and others) and entered the emerging global bar code industry, primarily in supermarkets. U.S. producers such as Appleton (NCR’s licensee), Nashua Corporation, Graphic Controls, and others fought to gain market share. Leading pressure-sensitive label producers such as Avery Dennison became major consumers of direct thermal paper for label applications.

In the late 1980s and early 1990s, thermal transfer, laser printing, electrophotography, and, to a lesser extent, ink jet printing began to take away industrial and warehouse barcode applications due to better durability. Direct thermal made a strong comeback with point of sale receipts (gasoline pumps, cash registers, rental car receipts, etc.).

In 2006, NCR Corporation’s Systemedia division introduced two-sided thermal printing technology, called “2ST”

The market size of thermal papers is not large.

See also

Thermochromism

External links

Texas Instruments-Computers & Software and Industrial Controls

Silent 700 Electronic Data Terminals, 1976(PDF)

This technology-related article is a stub. You can help Wikipedia by expanding it.

Categories: Paper | Technology stubs

Transfer paper

December 23rd, 2009 | himrflei

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www.tshirttransferpaper.com/ Inkjet Transfer Paper For most, the answer is going to be inkjet transfer paper. It comes in 2 varieties… For light colored fabric, or dark colored fabric. The light colored fabric variety cannot be used on dark fabrics because the paper is essentially transparent. An inkjet printer is not capable of printing white. So, anywhere that the image would have white, you will see straight through to the color of the garment. Inkjet transfer paper for dark colored garments is NOT transparent. It is white. So unlike the process with transfer paper for light fabric, you do not print the image horizontally mirrored. You print it just the way it is, right on the paper with the white background. Now your image will be white where it is supposed to be. The washability for inkjet transfer paper is not as good as a screen printed shirt, but if you follow the washing instructions included with the paper, they will usually last plenty of washes.

Sublimation Transfer Paper Dye sublimation transfer paper is another good process for putting your image on a garment. Fabrics must be white or light in color. 100% polyester, poly/cotton mix (the garment should be at least 50% poly) microfibre & nylon can all be used. This process uses a special dye sublimation printer and ink. It actually switches the solid ink into a gas, never going through a liquid stage. So you never have to worry about waiting for your transfer sheet to dry. The dye sub process can also be used on ceramic, wood, glass, or metal as long as they have a polymer coating. There are a couple products out there now that will allow you to print onto a white sheet and then place that onto a dark garment. However, you would probably be better off just sticking with inkjet transfer paper if that is the route you are going to take.

Color Laser Printer Transfer Paper After trying a few different types of laser printer transfer paper myself, I do not think it is where it should be yet. Admittedly, I was using a home color laser printer that was rather basic. I tried a few different types, and none of them printed properly. I have heard of success with these on some higher end laser printers, and I only tried a few different types of transfer paper from a couple different brands. If you have any real success stories, I would love to hear about them so this can be updated with some positive information , heat transfer products .

This printmaking-related article is a stub. You can help Wikipedia by expanding it , plastisol transfer .

Categories: Printmaking stubsHidden categories: Articles lacking sources from June 2007 | All articles lacking sources

Dye

December 23rd, 2009 | himrflei

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Organic dyes

The first human-made (synthetic) organic dye, mauveine, was discovered by William Henry Perkin in 1856. Many thousands of synthetic dyes have since been prepared.

Synthetic dyes quickly replaced the traditional natural dyes. They cost less, they offered a vast range of new colors, and they imparted better properties upon the dyed materials. Dyes are now classified according to how they are used in the dyeing process.

Acid dyes are water-soluble anionic dyes that are applied to fibers such as silk, wool, nylon and modified acrylic fibers using neutral to acid dyebaths. Attachment to the fiber is attributed, at least partly, to salt formation between anionic groups in the dyes and cationic groups in the fiber. Acid dyes are not substantive to cellulosic fibers. Most synthetic food colors fall in this category.

Basic dyes are water-soluble cationic dyes that are mainly applied to acrylic fibers, but find some use for wool and silk. Usually acetic acid is added to the dyebath to help the uptake of the dye onto the fiber. Basic dyes are also used in the coloration of paper , computer data transfer .

Direct or substantive dyeing is normally carried out in a neutral or slightly alkaline dyebath, at or near boiling point, with the addition of either sodium chloride (NaCl) or sodium sulfate (Na2SO4). Direct dyes are used on cotton, paper, leather, wool, silk and nylon. They are also used as pH indicators and as biological stains , pc video transfer .

Mordant dyes require a mordant, which improves the fastness of the dye against water, light and perspiration. The choice of mordant is very important as different mordants can change the final color significantly. Most natural dyes are mordant dyes and there is therefore a large literature base describing dyeing techniques. The most important mordant dyes are the synthetic mordant dyes, or chrome dyes, used for wool; these comprise some 30% of dyes used for wool, and are especially useful for black and navy shades. The mordant, potassium dichromate, is applied as an after-treatment. It is important to note that many mordants, particularly those in the heavy metal category, can be hazardous to health and extreme care must be taken in using them.

Look up leuco form in Wiktionary, the free dictionary.

Vat dyes are essentially insoluble in water and incapable of dyeing fibres directly. However, reduction in alkaline liquor produces the water soluble alkali metal salt of the dye, which, in this leuco form, has an affinity for the textile fibre. Subsequent oxidation reforms the original insoluble dye. The color of denim is due to indigo, the original vat dye.

Reactive dyes utilize a chromophore attached to a substituent that is capable of directly reacting with the fibre substrate. The covalent bonds that attach reactive dye to natural fibers make them among the most permanent of dyes. “Cold” reactive dyes, such as Procion MX, Cibacron F, and Drimarene K, are very easy to use because the dye can be applied at room temperature. Reactive dyes are by far the best choice for dyeing cotton and other cellulose fibers at home or in the art studio.

Disperse dyes were originally developed for the dyeing of cellulose acetate, and are substantially water insoluble. The dyes are finely ground in the presence of a dispersing agent and then sold as a paste, or spray-dried and sold as a powder. Their main use is to dye polyester but they can also be used to dye nylon, cellulose triacetate, and acrylic fibres. In some cases, a dyeing temperature of 130 C is required, and a pressurised dyebath is used. The very fine particle size gives a large surface area that aids dissolution to allow uptake by the fibre. The dyeing rate can be significantly influenced by the choice of dispersing agent used during the grinding.

Azo dyeing is a technique in which an insoluble azoic dye is produced directly onto or within the fibre. This is achieved by treating a fibre with both diazoic and coupling components. With suitable adjustment of dyebath conditions the two components react to produce the required insoluble azo dye. This technique of dyeing is unique, in that the final color is controlled by the choice of the diazoic and coupling components.

Sulfur dyes are two part “developed” dyes used to dye cotton with dark colors. The initial bath imparts a yellow or pale chartreuse color, This is aftertreated with a sulfur compound in place to produce the dark black we are familiar with in socks for instance. Sulfur Black 1 is the largest selling dye by volume.

Food dyes

One other class which describes the role of dyes, rather than their mode of use, is the food dye. Because food dyes are classed as food additives, they are manufactured to a higher standard than some industrial dyes. Food dyes can be direct, mordant and vat dyes, and their use is strictly controlled by legislation. Many are azoic dyes, although anthraquinone and triphenylmethane compounds are used for colors such as green and blue. Some naturally-occurring dyes are also used.

Other important dyes

A number of other classes have also been established, including:

Oxidation bases, for mainly hair and fur

Laser dyes

Leather dyes, for leather

Fluorescent brighteners, for textile fibres and paper

Solvent dyes, for wood staining and producing colored lacquers, solvent inks, coloring oils, waxes.

Carbene dyes, a recently developed method for coloring multiple substrates

Chemical classification

By the nature of their chromophore, dyes are divided into:

Category:Acridine dyes, derivates of acridine

Category:Anthraquinone dyes, derivates of anthraquinone

Arylmethane dyes

Category:Diarylmethane dyes, based on diphenyl methane

Category:Triarylmethane dyes, derivates of triphenyl methane

Category:Azo dyes, based on -N=N- azo structure

Cyanine dyes, derivates of phthalocyanine

Diazonium dyes, based on diazonium salts

Nitro dyes, based on a -NO2 nitro functional group

Nitroso dyes, based on a -N=O nitroso functional group

Phthalocyanine dyes, derivates of phthalocyanine

Quinone-imine dyes, derivates of quinone

Category:Azin dyes

Category:Eurhodin dyes

Category:Safranin dyes, derivates of safranin

Indamins

Category:Indophenol dyes, derivates of indophenol

Category:Oxazin dyes, derivates of oxazin

Oxazone dyes, derivates of oxazone

Category:Thiazin dyes, derivates of thiazin

Category:Thiazole dyes, derivates of thiazole

Xanthene dyes, derived from xanthene

Fluorene dyes, derivates of fluorene

Pyronin dyes

Category:Fluorone dyes, based on fluorone

Category:Rhodamine dyes, derivates of rhodamine

See also

Hair coloring

Blue Wool Scale

Phototendering

Stain

Biological pigment, any colored substance in organisms

Category:Natural dyes

Category:Pigments

Category:Inorganic pigments

Notes

^ Simon Garfield (2000). Mauve: How One Man Invented a Color That Changed the World. Faber and Faber. ISBN 0-393-02005-3.

External links

Growing and using Natural Dyes

About Dyes

Dyers and Dyes in Oriental Rugs

v d e

Dyeing

Techniques:

Batik Dyeing Kalamkari Katazome Leheria Mordant Resist Shibori Tie-dye Tsutsugaki

Types of dyes:

Dyes Natural Acid Reactive Solvent Substantive Sulfur Vat

Traditional textile dyes:

Brazilin Cochineal Cudbear Dyewoods Fustic Henna Indigo Kermes Logwood Madder Polish cochineal Saffron Tyrian purple Weld Woad

History:

Trade and use of saffron Traditional dyes of the Scottish Highlands

Craft dyes:

Dylon Procion

Categories: Dyes

Thermal printer

December 23rd, 2009 | himrflei

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Essential mechanisms

A thermal printer comprises these key components:

Thermal head generates heat; prints on paper

Platen a rubber roller that feeds paper

Spring applies pressure to the thermal head, causing it to contact the thermo-sensitive paper

Controller boards for controlling the mechanism

In order to print, one inserts thermo-sensitive paper between the thermal head and the platen. The printer sends an electrical current to the heating resistor of the thermal head, which in turn generates heat in a prescribed pattern. The heat activates the thermo-sensitive coloring layer of the thermo-sensitive paper, which manifests a pattern of color change in response. Such a printing mechanism is known as a thermal system or direct system.

The paper is impregnated with a solid-state mixture of a dye and a suitable matrix; a combination of a fluoran leuco dye and an octadecylphosphonic acid is an example. When the matrix is heated above its melting point, the dye reacts with the acid, shifts to its colored form, and the changed form is then conserved in metastable state when the matrix solidifies back quickly enough. See thermochromism.

Controller boards are embedded with firmware to manage the thermal printer mechanisms. The Firmware can manage multiple bar code types, graphics and logos. They enable the user to choose between different resident fonts (also including Asian fonts) and character sizes.

Controller boards can drive various sensors like paper low, paper out, door open, top of form etc., and they are available with the most commonly used interfaces, such as RS-232, parallel, USB or wireless. For point of sale application some boards can also control the cash drawer.

Applications

Thermal printers print faster and quieter than dot matrix printers. They are also more economical since their only consumable is the paper itself. Even though the paper is more expensive, printers can be rapidly refilled, leading to almost zero downtime. Commercial applications of thermal printers include filling station pumps, information kiosks, point of sale systems, voucher printers in slot machines, and for recording live rhythm strips on hospital cardiac monitors , foil transfer .

Through the 1990s, many fax machines used thermal printing technology. Toward the beginning of the 21st century, however, thermal wax transfer, laser, and inkjet printing technology largely supplanted thermal printing technology in fax machines in order to allow plain-paper printouts , inkjet transfer .

The Game Boy Printer, made in 1998, was a small thermal printer used to print out certain elements from some Game Boy games.

Early formulations of the thermo-sensitive coating used in thermal paper were sensitive to incidental heat, abrasion, friction (which can cause heat, thus darkening the paper), light (which can fade printed images), and water. However, more modern thermal coating formulations have resulted in exceptional image stability; theoretically, thermally-printed text should remain legible at least 50 years.

Hospitals commonly record fetal ultrasound scan images on thermal paper. This can cause problems if the parents wish to preserve the image by laminating it using a traditional laminator, as the heat will cause the entire page to darken. It is advisable to test the laminator using thermal fax paper, or an unwanted thermal POS receipt to see if this happens. As before, an option is to make a permanent ink duplicate of the image, and laminate that, testing first to ensure that the copying process won’t darken the image either.

References

^ What Are Direct Thermal and Thermal Transfer RFID Printers?, RFID Radio

^ http://www.zebra.com/id/zebra/na/en/index/resource_library/faqs/thermal.html

See also

Barcode printer

Thermal transfer printer

Computer printer

Daisy wheel printer

Dot matrix printer

Dye-sublimation printer

Line matrix printer

Line printer

Inkjet printer

Label printer

Label printer applicator

Laser printer

Categories: Computer printers | Non-impact printers | Thermochromism

Electric guitar

December 9th, 2009 | himrflei

Gum Rosin ,
Gum Rosin


History

The need for an amplified guitar became apparent to during the big band era, as jazz orchestras of the 1930s and 1940s increased in size, with larger brass sections. Initially, electric guitars used in jazz consisted primarily of hollow archtop acoustic guitar bodies to which electromagnetic transducers had been attached.

Early years

Sketch of Rickenbacker “frying pan” lap steel from 1934 patent application.

Electric guitars were originally designed by an assortment of luthiers, guitar makers, electronics enthusiasts, and instrument manufacturers. Guitar innovator Les Paul experimented with microphones attached to guitars. Some of the earliest electric guitars adapted hollow bodied acoustic instruments and used tungsten pickups. This type of guitar was manufactured beginning in 1932 by Electro String Instrument Corporation in Los Santos under the direction of Adolph Rickenbacher and George Beauchamp. Their first design was built by Harry Watson, a craftsman who worked for the Electro String Company. This new guitar which the company called “Rickenbacker” would be the first of its kind , jazz drum set .

The earliest documented performance with an electrically amplified guitar was in 1932, by guitarist and bandleader Gage Brewer. The Wichita, Kansas-based musician had obtained two guitars, an Electric Hawaiian A-25 (Fry-pan, lap-steel) and a standard Electric Spanish from his friend George Beauchamp of Los Angeles, California. Brewer publicized his new instruments in an article in the Wichita Beacon, October 2, 1932 and through performances that month , stage special effects .

The first recordings using the electric guitar were made by Hawaiian Style players such as Andy Iona as early as 1933. Bob Dunn of Milton Brown’s Musical Brownies introduced the electric Hawaiian guitar to Western Swing with his January 1935 Decca recordings, departing almost entirely from Hawaiian musical influence and heading towards Jazz and Blues. Alvino Rey was an artist who took this instrument to a wide audience in a large orchestral setting and later developed the pedal steel guitar for Gibson. An early proponent of the electric Spanish guitar was jazz guitarist George Barnes who used the instrument in two songs recorded in Chicago on March 1, 1938, Sweetheart Land and It’s a Low-Down Dirty Shame. Some historians incorrectly attribute the first recording to Eddie Durham, but his recording with the Kansas City Five was not until 15 days later. Durham introduced the instrument to a young Charlie Christian, who made the instrument famous in his brief life and is generally known as the first electric guitarist and a major influence on jazz guitarists for decades thereafter.

The first recording of an electric Spanish guitar, west of the Mississippi was in Dallas, in September 1935, during a session with Roy Newman and His Boys, an early Western swing dance band. Their guitarist, Jim Boyd, used his electrically amplified guitar during the recording of three songs, “Hot Dog Stomp” (DAL 178-Vo 03371), “Shine On, Harvest Moon” (DAL 180-Vo 03272), and “Corrine, Corrina” (DAL 181-Vo/OK 03117). An even earlier Chicago recording of an electrically amplified guitarlbeit an amplified lap steel guitaras during a series of session by Milton Brown and His Brownies (another early Western swing band) that took place January 27-28, 1935, wherein Bob Dunn played his amplified Hawaiian guitar.

Early proponents of the electric guitar on record include: Jack Miller (Orville Knapp Orch.), Alvino Rey (Phil Spitalney Orch.), Les Paul (Fred Warring Orch.), Danny Stewart (Andy Iona Orchestra), George Barnes (under many alias), Floyd Smith, Bill Broonzy, T-Bone Walker, George Van Eps, Charlie Christian (Benny Goodman Orch.) Tampa Red, Memphis Minnie, and Arthur Cruddup.

Early electric guitar manufacturers include: Rickenbacker (first called Ro-Pat-In) in 1932, Dobro in 1933, National, AudioVox and Volu-tone in 1934,Vega, Epiphone (Electrophone and Electar), and Gibson in 1935 and many others by 1936.

The version of the instrument that is best known today is the solid body electric guitar, a guitar made of solid wood, without resonating air spaces within it. Rickenbacher, later spelled Rickenbacker, did, however, offer a cast aluminum electric steel guitar, nicknamed The Frying Pan or The Pancake Guitar, developed in 1931 with production beginning in the summer of 1932. This guitar sounds quite modern and aggressive as tested by vintage guitar researcher John Teagle. The company Audiovox built and may have offered an electric solid-body as early as the mid-1930s.

Another early solid body electric guitar was designed and built by musician and inventor Les Paul in the early 1940s, working after hours in the Epiphone Guitar factory. His log guitar (so called because it consisted of a simple 4×4 wood post with a neck attached to it and homemade pickups and hardware, with two detachable Swedish hollow body halves attached to the sides for appearance only) was patented and is often considered to be the first of its kind, although it shares nothing in design or hardware with the solid body “Les Paul” model sold by Gibson. In 1945, Richard D. Bourgerie made an electric guitar pickup and amplifier for professional guitar player George Barnes. Bourgerie worked through World War II at Howard Radio Company making electronic equipment for the American military. Mr. Barnes showed the result to Les Paul, who then arranged for Mr. Bourgerie to have one made for him.

Fender

Main article: Fender Musical Instruments Corporation

Stratocaster by Nermin

Sketch of Fender lap steel guitar from 1944 patent application.

In 1946, radio repairman and instrument amplifier maker Clarence Leonidas Fenderetter known as Leo Fenderhrough his eponymous company, designed the first commercially successful solid-body electric guitar with a single magnetic pickup, which was initially named the “Esquire”. This was a departure from the typically hollow-bodied Jazz-oriented instruments of the time and immediately found favor with Country-Western artists in California. The two-pickup version of the Esquire was called the “Broadcaster”. However, Gretsch had a drumset marketed with a similar name (Broadkaster), so Fender changed the name to “Telecaster”.

Features of the Telecaster included: an ash body; a maple 25″ scale, 21-fret or 22-fret neck attached to the body with four-bolts reinforced by a steel neckplate; two single-coil, 6-pole pickups (bridge and neck positions) with tone and volume knobs, pickup selector switch; and an output jack mounted on the side of the body. A black bakelite pickguard concealed body routings for pickups and wiring. The bolt-on neck was consistent with Leo Fender’s belief that the instrument design should be modular to allow cost-effective and consistent manufacture and assembly, as well as simple repair or replacement. Due to the earlier mentioned trademark issue, some of the first production Telecasters were delivered with headstock decals with the Fender logo but no model identification. These are today very much sought after, and commonly referred to by collectors as “Nocasters”.

In 1954, Fender introduced the Fender Stratocaster, or “Strat.” The Stratocaster was seen as a deluxe model and offered various product improvements and innovations over the Telecaster. These innovations included a well dried ash or alder double-cutaway body design for bridge assembly with an integrated spring vibrato mechanism (called a synchronized tremolo by Fender, thus beginning a confusion of the terms that still continues), three single-coil pickups, and body comfort contours. Leo Fender is also credited with developing the first commercially successful electric bass guitar called the Fender Precision Bass, introduced in 1951.

Vox

In 1962 Vox introduced the pentagonal Phantom guitar, originally made in England but soon after made by Alter EKO of Italy. It was followed a year later by the teardrop-shaped Mark VI, the prototype of which was used by Brian Jones of The Rolling Stones, and later Johnny Thunders of the New York Dolls. Vox guitars also experimented with onboard effects and electronics. In the mid 1960s, as the sound of electric 12-string guitars became popular, Vox introduced the Phantom XII and Mark XII electric 12-string guitars as well as the Tempest XII which employed a more conventional Fender style body and thus is often overlooked as a Vox classic from the Sixties. The few that were manufactured also came from Italy. Vox also produced other traditional styles of 6- and 12-string electric guitars in both England and Italy, The 12-string electric guitars had a much larger neck and body and averaged at the weight of 26.4 pounds(11.9 kg), they were also played on tables such as a piano or other sit down instrument.

Construction

Legend: 1. Headstock: 1.1 machine heads; 1.2 truss rod cover; 1.3 string guide; 1.4 nut.

2. Neck: 2.1 fretboard; 2.2 inlay fret markers; 2.3 frets; 2.4 neck joint.

3. Body; 3.1 “neck” pickup; 3.2 “bridge” pickup; 3.3 saddles; 3.4 bridge; 3.5 fine tuners; 3.6 tremolo arm; 3.7 pickup selector switch; 3.8 volume and tone control knobs; 3.9 output connector; 3.10 strap buttons.

4. Strings: 4.1 bass strings 4.2 treble strings.

While guitar construction has many variations, in terms of the materials used for the body, the shape of the body, and the configuration of the neck, bridge, and pickups, there are features which are found in almost every guitar. The photo below shows the different parts of an electric guitar. The headstock (1) contains the metal machine heads, which are used for tuning ; the nut (1.4), a thin fret-like strip of metal or plastic which…

Electric acoustic guitar

December 9th, 2009 | himrflei

USB Drumming Santa ,
USB Drumming Santa
electric acoustic guitar (or elecoustic for short) is by design an acoustic guitar fitted with pickups, a microphone, or transducers. In Electric-Acoustic Classical Guitars, the transducers and microphones are always used because conventional pickups are not capable of picking up vibrations of non-magnetic materials. The term is not synonymous with that of a semi-acoustic guitar, which is conceptually an electric guitar but with the addition of sound chambers within the guitar body. Usually, electric acoustic guitars are fitted with piezoelectric pickups, and hence require a preamplifier incorporated into the guitar body to amplify the signal before it travels to the main guitar amplifier. These preamps may also come with tone controls of varying types, but usually equalizers with up to six frequency bands are used. They are also referred to it as a “plug-in acoustic guitar”, due to their ability to simply “plug in” to a speaker system without the need for microphones. They are commonly used in folk and sometimes classical music as they possess the sound of an acoustic guitar but more volume if plugged into a speaker system. They are also commonly found in worship music along with other types of christian music. Artists such as Chris Tomlin, Matt Baker and Tim Hughes use these guitars along with bands such as Hillsong and R.E.M..

v d e

Guitars

Guitars by String Number

Four String (Tenor) Six String Seven String Eight String Nine String Ten String Eleven String Twelve String

Guitars by Typ , children electric guitars .

Archtop Classical Multi String Classical Steel String Acoustic Baroque Russian Resonator (Dobro) Semi Acoustic Electric Electric acoustic Tailed bridge guita , toner drum .

Alternate Versions

Bass guitar Baritone guitar Harp guitar Double neck guitar Pikasso guitar Chitarra battente Bajo sexto

Other related topics

Luthier Vintage guitar Jazz guitar Guitar chord Guitar harmonics Prepared guitar Electric Guitar Design Guitar amplifier History of the classical guitar



Categories: Guitars | Guitar stubs

Acoustic guitar

December 9th, 2009 | himrflei

Guitar Backing Tracks ,
Guitar Backing Tracks


Sound production

In all types of guitars the sound is produced by the vibration of the strings. However, because the string can only displace a small amount of air, the volume of the sound needs to be increased in order to be heard. In an acoustic guitar, this is accomplished by using a soundboard and a resonant cavity, the sound box. The body of the guitar is hollow. The vibrating strings drive the soundboard through the bridge, making it vibrate. The soundboard has a larger surface area and thus displaces a larger volume of air, producing a much louder sound than the strings alone.

As the soundboard vibrates, sound waves are produced from both the front and back faces. The sound box provides both a support for the sound board and a resonant cavity and reflector for the sound waves produced on the back face of the soundboard. The air in this cavity resonates with the vibrational modes of the string (see Helmholtz resonance), increasing the volume of the sound again. The back of the guitar will also vibrate to a lesser extent, driven by the air in the cavity. Some sound is ultimately projected through the sound hole (some variants of the acoustic guitar omit this hole, or have f holes, like a violin family instrument). This sound mixes with the sound produced by the front face of the soundboard. The resultant sound is a complex mixture of harmonics that give the guitar its distinctive sound.

Acoustic Guitar Sample

An example of the sounds which an Acoustic Guitar can create through vibration of its strings. This guitar uses steel strings.

Problems listening to this file? See media help.

No amplification actually occurs in this process, in the sense that no energy is externally added to increase the loudness of the sound (as would be the case with an electronic amplifier). All the energy is provided by the plucking of the string. The function of the entire acoustic system is to maximize intensity of sound, but since total energy remains constant, this comes at the expense of decay time. An unamplified guitar (one with no soundboard at all) would have a low volume, but the strings would vibrate much longer, like a tuning fork. This is because a damped harmonic oscillator decays exponentially, with a mean life inversely proportional to the damping, i.e. the more the volume is increased by the soundboard, the shorter the resulting sound will last.

Amplification

Many acoustic guitars incorporate rosettes around the sound hole.

An acoustic guitar can be amplified by using various types of pickups or microphones. The most common type of pickups used for acoustic guitar amplification are piezo and magnetic pickups. Piezo pickups are generally mounted under the bridge saddle of the acoustic guitar and can be plugged into a mixer or amplifier. Magnetic pickups are generally mounted in the sound hole of the acoustic guitar and are very similar to those found in electric guitars.

Instruments with larger areas for the guitar top were introduced by Martin in an attempt to create louder volume levels. The popularity of the larger “dreadnought” body size amongst acoustic performers is related to the greater sound volume produced.

Types

Historical and modern acoustic guitars are extremely varied in their design and construction, far more so than electric guitars. Some of the most important varieties are the classical guitar (nylon-stringed), steel-string acoustic guitar and lap steel guitar. A more complete list is given below, refer to the individual articles for more specific detail.

Nylon/gut stringed guitars:

Renaissance guita , stainless steel drum .

Baroque guita , carbon fiber violin .

Romantic guitar

Classical guitar, the modern version of the original guitar, with nylon strings

Flamenco guitar

Extended-range classical guitar

Steel stringed guitars:

Steel-string acoustic guitar, also known as western, folk or country guitar

Twelve string guitar

Resonator guitar (such as the Dobro)

Archtop guitar

Battente guitar

Lap steel guitar

Lyre guitar

Manouche guitar

Acoustic bass guitar

Russian guitar

Novelty instruments:

Pikasso guitar

Harp guitar

Banjo guitar

Guitar lute

Wikimedia Commons has media related to: Acoustic guitars

References

^ How a guitar works

See also

Types of guitar

Categories: Acoustic guitars

Electromagnetic induction

December 9th, 2009 | himrflei

Small Inductor ,
Small Inductor


Technical Details

Faraday found that the electromotive force (EMF) produced around a closed path is proportional to the rate of change of the magnetic flux through any surface bounded by that path.

In practice, this means that an electrical current will be induced in any closed circuit when the magnetic flux through a surface bounded by the conductor changes. This applies whether the field itself changes in strength or the conductor is moved through it.

Electromagnetic induction underlies the operation of generators, all electric motors, transformers, induction motors, synchronous motors, solenoids, and most other electrical machines.

Faraday’s law of electromagnetic induction states that , pulse transformers .

, dc power transformer .

Thus:

is the electromotive force (emf) in volts

B is the magnetic flux in webers

For the common but special case of a coil of wire, composed of N loops with the same area, Faraday’s law of electromagnetic induction states that

where

is the electromotive force (emf) in volts

N is the number of turns of wire

B is the magnetic flux in webers through a single loop.

A corollary of Faraday’s Law, together with Ampere’s and Ohm’s laws is Lenz’s law:

The emf induced in an electric circuit always acts in such a direction that the current it drives around the circuit opposes the change in magnetic flux which produces the emf.

The direction mentioned in Lenz’s law can be thought of as the result of the minus sign in the above equation.

Practical Demonstration

Two videos demonstrating Faraday’s and Lenz’s laws can be watched at EduMation

Applications

The principles of electromagnetic induction are applied in many devices and systems, including:

Induction Sealing

Induction motors

Electrical generators

Transformers

Contactless charging of rechargeable batteries

The 6.6 kW Magne Charge system for Battery electric vehicles

Induction cookers

Induction welding

Inductors

Electromagnetic forming

Magnetic flow meters

Transcranial magnetic stimulation

Faraday Flashlight

Graphics tablet

Wireless energy transfer

Electric Guitar Pickups

Hall effect meters

Current transformer meters

Clamp meter

Discovery

Michael Faraday is generally credited with having discovered the induction phenomenon in 1831 though it may have been anticipated by the work of Francesco Zantedeschi in 1829[citation needed]. Around 1830 to 1832 Joseph Henry made a similar discovery, but did not publish his findings until later.

See also

Maxwell’s equations for further mathematical treatment.

Faraday’s law of induction

Inductance

Eddy current

Lenz’s law

Moving magnet and conductor problem

External links

BIGS animation The induction

A free java simulation on motional EMF

References

David J. Griffiths (1998). Introduction to Electrodynamics (3rd ed.). Prentice Hall. ISBN 0-13-805326-X.

Paul Tipler (2004). Physics for Scientists and Engineers: Electricity, Magnetism, Light, and Elementary Modern Physics (5th ed.). W. H. Freeman. ISBN 0-7167-0810-8.

J.S. Kovacs and P. Signell, Magnetic induction (2001), Project PHYSNET document MISN-0-145.

Categories: ElectrodynamicsHidden categories: All articles with unsourced statements | Articles with unsourced statements from April 2007

Transformer oil

December 9th, 2009 | himrflei

Bead Inductor, EMI Core Wide Band Choke ,
Bead Inductor, EMI Core Wide Band Choke
ansformer oil, or insulating oil, is usually a highly-refined mineral oil that is stable at high temperatures and has excellent electrical insulating properties. It is used in oil-filled transformers, some types of high voltage capacitors, fluorescent lamp ballasts, and some types of high voltage switches and circuit breakers. Its functions are to insulate, suppress corona and arcing, and to serve as a coolant.

Explanation

The oil helps cool the transformer. Because it also provides part of the electrical insulation between internal live parts, transformer oil must remain stable at high temperatures for an extended period. To improve cooling of large power transformers, the oil-filled tank may have external radiators through which the oil circulates by natural convection. Very large or high-power transformers (with capacities of thousands of KVA) may also have cooling fans, oil pumps, and even oil-to-water heat exchangers.

Large, high voltage transformers undergo prolonged drying processes, using electrical self-heating, the application of a vacuum, or both to ensure that the transformer is completely free of water vapor before the cooling oil is introduced. This helps prevent corona formation and subsequent electrical breakdown under load.

Oil filled transformers with a conservator (an oil tank above the transformer) tend to be equipped with Buchholz relays. These are safety devices that detect the build up of gases (such as acetylene) inside the transformer (a side effect of corona or an electric arc in the windings) and switch off the transformer. Transformers without conservators are usually equipped with sudden pressure relays, which perform a similar function as the Buchholz relay.

The flash point (min) and pour point (max) are 140 C and 6 C respectively. The dielectric strength of new untreated oil is 12 MV/m (RMS) and after treatment it should be >24 MV/m (RMS).

Oil transforme , dry type transformer .

Large transformers for indoor use must either be of the dry type, that is, containing no liquid, or use a less-flammable liquid , single phase transformer .

Well into the 1970s, polychlorinated biphenyls (PCB)s were often used as a dielectric fluid since they are not flammable. They are toxic, and under incomplete combustion, can form highly toxic products such as furan. Starting in the early 1970s, concerns about the toxicity of PCBs have led to their banning in many countries.

Today, non-toxic, stable silicone-based or fluorinated hydrocarbons are used, where the added expense of a fire-resistant liquid offsets additional building cost for a transformer vault. Combustion-resistant vegetable oil-based dielectric coolants and synthetic pentaerythritol tetra fatty acid (C7, C8) esters are also becoming increasingly common as alternatives to naphthenic mineral oil. Esters are non-toxic to aquatic life, readily biodegradable, and have a lower volatility and a higher flash points than mineral oil.

References

Less and nonflammable liquid-insulated transformers, approval standard class Number 3990, Factory Mutual Research Corporation, 1997.

McShane C.P. (2001) Relative properties of the new combustion-resistant vegetable oil-based dielectric coolants for distribution and power transformers. IEEE Trans. on Industry Applications, Vol.37, No.4, July/August 2001, pp.1132-1139, No. 0093-9994/01, 2001 IEEE.

he Environmental technology verification program, U.S. Environmental Protection Agency, Washington, DC, VS-R-02-02, June 2002.

IEEE Guide for loading mineral-oil-immersed transformers, IEEE Standard C57.91-1995, 1996.

Transformer Maintenance.

Patent for a high temperature transformer

Categories: Oils | Transformers (electrical) | Coolants | DielectricsHidden categories: Articles with unsourced statements from January 2009 | All articles with unsourced statements

1900s in fashion

December 2nd, 2009 | himrflei

Skin Cleaning Beauty Machine ,
Skin Cleaning Beauty Machine


Women’s fashions

Overview

Young women adopted the tall, stiff collars and narrow neckties worn by men. Advertisement for Arrow shirt collars, 1907.

John Singer Sargent’s portrait of Miss Eden shows the fashionable full bosom, low neckline, and masses of hair associated with the Gibson Girl, 1905.

Paul Poiret’s new silhouette of 1908 was a radical departure , halloween wig .

With the decline of the bustle, sleeves began to increase in size and the 1830s silhouette of an hourglass shape became popular again. The fashionable silhouette in the early 1900s was that of a mature woman, with full low bust and curvy hips. The “health corset” of this period removed pressure from the abdomen and created an S-curve silhouette , edge card reader .

In 1897, the silhouette slimmed and elongated by a considerable amount. Blouses and dresses were full in front and puffed into a “pigeon breast” shape of the early 20th century that looked over the narrow waist, which sloped from back to front and was often accented with a sash or belt. Necklines were supported by very high boned collars.

Skirts brushed the floor, often with a train, even for day dresses, in mid-decade.

Around 1908, the fashion houses of Paris began to show a new silhouette, with a thicker waist, flatter bust, and narrower hips. By the end of the decade the most fashionable skirts cleared the floor and approached the ankle. The overall silhouette narrowed and straightened, beginning a trend that would continue into the years leading up to the Great War.

Lingerie dresses

Frothy washable day dresses of translucent linen or cotton, called lingerie dresses, were worn in warm climates. These were trimmed lavishly with tiny pintucks, lace insertions, embroidery, and passementerie. Their origins lie in the artistic or aesthetic dress and the adoption of the uncorseted tea gown for wear outside the home.

Sportswear and tailored fashions

Unfussy, tailored clothes were worn for outdoor activities and traveling. The shirtwaist, a costume with a bodice or waist tailored like a man’s shirt with a high collar, was adopted for informal daywear and became the uniform of working women. Wool or tweed suits called tailor-mades or (in French) tailleurs featured ankle-length skirts with matching jackets; ladies of fashion wore them with fox furs and huge hats. Two new styles of hats that became popular at the turn of the century is the automobile bonnet for riding and sailor’s hat worn for tennis matches, bicycling and croquet.

Rise of haute couture

See also main article History of fashion design (1900s)

This decade marked the full flowering of Parisian haute couture as the arbiter of styles and silhouettes for women of all classes. Designers sent fashion models or mannequins to the Longchamp races wearing the latest styles, and fashion photographs identified the creators of individual gowns. In 1908, a new silhouette emerged from Callot Soeurs, Vionnet at the house of Doucet, and most importantly, Paul Poiret. The styles were variously called Merveilleuse, Dirctoire, and Empire after the fashions of the turn of the nineteenth century, which they resembled in their narrow skirts and raised waistlines.

The new styles featured form-fitting gowns with high or indefined waists, or ankle-length skirts and long tunic-like jackets, and required a different “straight line” corset. The Paris correspondent for Vogue described this new look as “straighter and straighter … less bust, less hips, and more waist…how slim, how graceful, how elegant…!”

Hairstyles and hats

Huge, broadbrimmed hats were worn in mid-decade, trimmed with masses of feathers and occasionally complete stuffed birds (male hummingbirds for those who could afford them), or decorated with ribbons and artificial flowers. Masses of wavy hair were fashionable, swept up to the top of the head (over horsehair pads called “rats” if necessary) and gathered into a knot. Large hats were worn with evening wear.

By the end of the decade, hats had smaller drooping brims that shaded the face and deep crowns, and the overall top-heavy effect remained.

Evelyn Nesbit, in this photograph taken in 1901, has some of her wavy hair swept up to the top of her head, with the rest of her hair flowing past her shoulders in curling tendrils.

Style Gallery 1900-1906

1 – 1900

2 – 1901

3 – 1902

4 – 1903-04

5 – 1904

6 – 1905

7 – 1906

8 – 1906

Mrs. Charles Russell wears a sheer patterned gown with fullness at the front waist over a soft sash. This dress might have been called a tea gown at this time (1900).

Fashion illustraion for Summer 1901 shows sloped waistline, “pouter pigeon” front bodices, high necklines and large hats with ribbons.

Photograph of three sisters c. 1902 illustrates the “pouter pidgeon” blouse or shirtwaist and trumpet-skirt that was a mainstay of middle-class clothing.

Underwear (camisole (or, more likely, top half of combinations), corset, and trumpet-shaped petticoat) of 1903-04.

Fashion plate shows the frothy trained day-dress descended from the tea gown, worn with an oversized hat and gloves, 1904.

Elizabeth Wharton Drexel wears an off-the-shoulder orange evening gown with long gloves, 1905.

French gown of 1906 is trimmed with embroidery or passementarie. The wide-brimmed hat is cocked up on one side. Elbow-length sleeves are worn with gloves.

Summer evening fashions of 1906 have short or three-quarter-length sleeves. Some ladies wear hats, and the gentlemen wear dinner jackets.

Style Gallery 1907-1909

1 – 1907

2 – 1907

3 – 1908

4 – 1908

5 – 1908

6 – 1909

7 – 1909

8 – 1909

Golfing costume of 1907 features a tailored jacket and matching ankle-length skirt with patch pockets.

Motoring required voluminous coats or dusters to keep clothes clean and wearers warm in open automobiles. They were worn with fashionable hats wrapped in veils, gloves, and often goggles, 1907.

1908 portait captures the fashionable combination of masses of wavy hair beneath a broad-brimmed hat.

Gowns by Paul Poiret point the way to a new silhouette, with a high waist and narrow, ankle-length skirts, 1908.

Newspaper insert of fashions for 1908 shows dresses of a more conservative cut than the latest Paris modes, but waists are higher and the figure slimmer and more erect than in the first half of the decade.

Bib-front apron with pouter-pigeon cut, 1909.

High-fashion costume of 1909 has a narrower silhouette. The bodice fits closer to the body, although the waist still slopes, and the hat has a deep crown.

Evening gowns of 1909 show the new fitted, higher-waisted silhouette and are worn with huge hats.

Men’s fashion

Hugo Resinger wears a dark suit with a white waistcoat and dotted necktie. He carries the fashionable Homburg hat, 1907.

The long, lean, and athletic silhouette of the 1890s persisted. Hair was generally worn short. Beards were less pointed than before and moustaches were often curled.

Coats, waistcoats, and trousers

The sack coat or lounge coat continued to replace the frock coat for most informal and semi-formal occasions. Three-piece suits consisting of a sack coat with matching waistcoat (U.S. vest) and trousers were worn, as were matching coat and waistcoat with contrasting trousers, or matching coat and trousers with contrasting waistcoat. Trousers were shorter than before, often had turn-ups or cuffs, and were creased front and back using the new trouser press.

Waistcoats fastened high on the chest. The usual style was single-breasted.

The blazer, a navy blue or brightly-colored or striped flannel coat cut like a sack coat with patch pockets and brass buttons, was worn for sports, sailing, and other casual activities.

The Norfolk jacket remained fashionable for shooting and rugged outdoor pursuits. It was made of sturdy tweed or similar fabric and featured paired box pleats over the chest and back, with a fabric belt. Worn with matching breeches or (U.S. knickerbockers), it became the Norfolk suit, suitable for bicycling or golf with knee-length stockings and low shoes, or for hunting with sturdy boots or shoes with leather gaiters.

The cutaway morning coat was still worn for formal day occasions in Europe and major cities elsewhere, with striped trousers.

The most formal evening dress remained a dark tail coat and trousers with a dark or light waistcoat. Evening wear was worn with a white bow tie and a shirt with a winged collar. The less formal dinner jacket or tuxedo, which featured a shawl collar with silk or satin facings, now generally had a single button. Dinner jackets were appropriate formal wear when “dressing for dinner” at home or at a men’s club. The dinner jacket was worn with a white shirt and a dark tie.

Knee-length topcoats and calf-length overcoats were worn in winter.

Shirts and neckties

Formal dress shirt collars were turned over or pressed into “wings”. Collars were overall very tall and stiffened. Dress shirts had stiff fronts, sometimes decorated with shirt studs and buttoned up the back. Striped shirts were popular for informal occasions.

The usual necktie was a narrow four-in-hand. Ascot ties were worn with formal day dress and white bow ties with evening dress.

Accessories

Top hats remained a requirement for upper class formal wear; soft felt Homburgs or stiff bowler hats were worn with lounge or sack suits, and flat straw boaters were worn for casual occasions.

Style gallery

1 – 1900

2 – 1900

3 – 1903

4 – 1904

5-1904