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| Articles about Tubes |
| Conolounge Recycled Paper Tubes Chair | | 2008-08-21 13:51:55 | | This Chair prototype has been made cardboard tubes from the La Tercera newspaper printer paper rolls which makes it an immediate winner in our books. A brainchild of the Chilean design studio Onceneto, the studio had to incorporate steel to prevent it from collapsing.
Via Cool Hunting
Brought to you by: BED Online Magazine - The [...]... | | By: BEDzine - We are crazy about BEDs!!! | | |
| | New Limited Edition Lancome Juicy Tubes | | 2008-08-08 06:48:00 | | Exclusive Limited Edition! Available only at Sephora and Lancome-usa.com
Juicy Tubes transport you to Paris, where can-can dancers light up the stage at the Moulin Rouge. Capture the essence of boudoir-chic with a gloss dressed in thigh-high fishnets and finished with a wide band of french lace, a sexy seam and the Lancome Rose woven throughout.
Available in one perfect rosy-nude shade
... | | By: The Makeup Divas Beauty Blog | | |
| | Les tubes de l'été | | 2008-07-30 13:55:00 | | Voici une liste de chansons que je considère comme insupportables, pourtant dans certaines conditions extrêmes, ces chansons peuvent devenir écoutables. Pour chaque morceau, je vous propose mes conditions idéales d'écoute. Si jamais vous vous retrouvez dans l'une de ces situations, j'ai placé la majorité des titres en écoute grâce au lecteur Deezer. Girlfriend (TTC) A écouter travesti dans un...... | | By: Pron0x-TV | | |
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| Introduction ELECTRON TUBES | | 2008-05-08 06:32:42 | | An often neglected area of study in modern electronics is that of tubes, more precisely known as vacuum tubes or electron tubes. Almost completely overshadowed by semiconductor, or "solid-state" components in most modern applications, tube technology once dominated electronic circuit design. In fact, the historical transition from "electric" to "electronic" circuits really began with tubes, for it was with tubes that we entered into a whole new realm of circuit function: a way of controlling the flow of electrons (current) in a circuit by means of another electric signal (in the case of most tubes, the controlling signal is a small voltage). The semiconductor counterpart to the tube, of course, is the transistor. Transistors perform much the same function as tubes: controlling the flow of electrons in a circuit by means of another flow of electrons in the case of the bipolar transistor, and controlling the flow of electrons by means of a voltage in the case of the field-effect trans... | | By: Electronics Circuits And VLSI Engineering | | |
| | Early tube history ELECTRON TUBES | | 2008-05-08 06:32:07 | | Thomas Edison, that prolific American inventor, is often credited with the invention of the incandescent lamp. More accurately, it could be said that Edison was the man who perfected the incandescent lamp. Edison's successful design of 1879 was actually preceded by 77 years by the British scientist Sir Humphry Davy, who first demonstrated the principle of using electric current to heat a thin strip of metal (called a "filament") to the point of incandescence (glowing white hot). Edison was able to achieve his success by placing his filament (made of carbonized sewing thread) inside of a clear glass bulb from which the air had been forcibly removed. In this vacuum, the filament could glow at white-hot temperatures without being consumed by combustion: In the course of his experimentation (sometime around 1883), Edison placed a strip of metal inside of an evacuated (vacuum) glass bulb along with the filament. Between this metal strip and one of the filament connections he attac... | | By: Electronics Circuits And VLSI Engineering | | |
| | The triode ELECTRON TUBES | | 2008-05-08 06:31:32 | | De Forest's Audion tube came to be known as the triode tube, because it had three elements: filament, grid, and plate (just as the "di" in the name diode refers to two elements, filament and plate). Later developments in diode tube technology led to the refinement of the electron emitter: instead of using the filament directly as the emissive element, another metal strip called the cathode could be heated by the filament. This refinement was necessary in order to avoid some undesired effects of an incandescent filament as an electron emitter. First, a filament experiences a voltage drop along its length, as current overcomes the resistance of the filament material and dissipates heat energy. This meant that the voltage potential between different points along the length of the filament wire and other elements in the tube would not be constant. For this and similar reasons, alternating current used as a power source for heating the filament wire would tend to introduce unwanted AC... | | By: Electronics Circuits And VLSI Engineering | | |
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| The tetrode ELECTRON TUBES | | 2008-05-08 06:31:03 | | As the name suggests, the tetrode tube contained four elements: cathode (with the implicit filament, or "heater"), grid, plate, and a new element called the screen. Similar in construction to the grid, the screen was a wire mesh or coil positioned between the grid and plate, connected to a source of positive DC potential (with respect to the cathode, as usual) equal to a fraction of the plate voltage. When connected to ground through an external capacitor, the screen had the effect of electrostatically shielding the grid from the plate. Without the screen, the capacitive linking between the plate and the grid could cause significant signal feedback at high frequencies, resulting in unwanted oscillations. The screen, being of less surface area and lower positive potential than the plate, didn't attract many of the electrons passing through the grid from the cathode, so the vast majority of electrons in the tube still flew by the screen to be collected by the plate: With a cons... | | By: Electronics Circuits And VLSI Engineering | | |
| | Beam power tubes ELECTRON TUBES | | 2008-05-08 06:30:31 | | In the beam power tube, the basic four-element structure of the tetrode was maintained, but the grid and screen wires were carefully arranged along with a pair of auxiliary plates to create an interesting effect: focused beams or "sheets" of electrons traveling from cathode to plate. These electron beams formed a stationary "cloud" of electrons between the screen and plate (called a "space charge") which acted to repel secondary electrons emitted from the plate back to the plate. A set of "beam-forming" plates, each connected to the cathode, were added to help maintain proper electron beam focus. Grid and screen wire coils were arranged in such a way that each turn or wrap of the screen fell directly behind a wrap of the grid, which placed the screen wires in the "shadow" formed by the grid. This precise alignment enabled the screen to still perform its shielding function with minimal interference to the passage of electrons from cathode to plate. This resulted in lower screen ... | | By: Electronics Circuits And VLSI Engineering | | |
| | The pentode ELECTRON TUBES | | 2008-05-08 06:29:59 | | Another strategy for addressing the problem of secondary electrons being attracted by the screen was the addition of a fifth wire element to the tube structure: a suppressor. These five-element tubes were naturally called pentodes. The suppressor was another wire coil or mesh situated between the screen and the plate, usually connected directly to ground potential. In some pentode tube designs, the suppressor was internally connected to the cathode so as to minimize the number of connection pins having to penetrate the tube envelope: The suppressor's job was to repel any secondarily emitted electrons back to the plate: a structural equivalent of the beam power tube's space charge. This, of course, increased plate current and decreased screen current, resulting in better gain and overall performance. In some instances it allowed for greater operating plate voltage as well. ... | | By: Electronics Circuits And VLSI Engineering | | |
| | Combination tubes ELECTRON TUBES | | 2008-05-08 06:29:26 | | Similar in thought to the idea of the integrated circuit, tube designers tried integrating different tube functions into single tube envelopes to reduce space requirements in more modern tube-type electronic equipment. A common combination seen within a single glass shell was two either diodes or two triodes. The idea of fitting pairs of diodes inside a single envelope makes a lot of sense in light of power supply full-wave rectifier designs, always requiring multiple diodes. Of course, it would have been quite impossible to combine thousands of tube elements into a single tube envelope the way that thousands of transistors can be etched onto a single piece of silicon, but engineers still did their best to push the limits of tube miniaturization and consolidation. Some of these tubes, whimsically called compactrons, held four or more complete tube elements within a single envelope. Sometimes the functions of two different tubes could be integrated into a single, combination tu... | | By: Electronics Circuits And VLSI Engineering | | |
| | Tube parameters ELECTRON TUBES | | 2008-05-08 06:28:54 | | For bipolar junction transistors, the fundamental measure of amplification is the Beta ratio (β), defined as the ratio of collector current to base current (IC/IB). Other transistor characteristics such as junction resistance, which in some amplifier circuits may impact performance as much as β, are quantified for the benefit of circuit analysis. Electron tubes are no different, their performance characteristics having been explored and quantified long ago by electrical engineers. Before we can speak meaningfully on these characteristics, we must define several mathematical variables used for expressing common voltage, current, and resistance measurements as well as some of the more complex quantities: The two most basic measures of an amplifying tube's characteristics are its amplification factor (µ) and its mutual conductance (gm), also known as transconductance. Transconductance is defined here just the same as it is for field-effect transistors, another category of vol... | | By: Electronics Circuits And VLSI Engineering | | |
| | Ionization (gas-filled) tubes ELECTRON TUBES | | 2008-05-08 06:28:19 | | So far, we've explored tubes which are totally "evacuated" of all gas and vapor inside their glass envelopes, properly known as vacuum tubes. With the addition of certain gases or vapors, however, tubes take on significantly different characteristics, and are able to fulfill certain special roles in electronic circuits. When a high enough voltage is applied across a distance occupied by a gas or vapor, or when that gas or vapor is heated sufficiently, the electrons of those gas molecules will be stripped away from their respective nuclei, creating a condition of ionization. Having freed the electrons from their electrostatic bonds to the atoms' nuclei, they are free to migrate in the form of a current, making the ionized gas a relatively good conductor of electricity. In this state, the gas is more properly referred to as a plasma. Ionized gas is not a perfect conductor. As such, the flow of electrons through ionized gas will tend to dissipate energy in the form of heat, there... | | By: Electronics Circuits And VLSI Engineering | | |
| | Display tubes ELECTRON TUBES | | 2008-05-08 06:27:41 | | In addition to performing tasks of amplification and switching, tubes can be designed to serve as display devices. Perhaps the best-known display tube is the cathode ray tube, or CRT. Originally invented as an instrument to study the behavior of "cathode rays" (electrons) in a vacuum, these tubes developed into instruments useful in detecting voltage, then later as video projection devices with the advent of television. The main difference between CRTs used in oscilloscopes and CRTs used in televisions is that the oscilloscope variety exclusively use electrostatic (plate) deflection, while televisions use electromagnetic (coil) deflection. Plates function much better than coils over a wider range of signal frequencies, which is great for oscilloscopes but irrelevant for televisions, since a television electron beam sweeps vertically and horizontally at fixed frequencies. Electromagnetic deflection coils are much preferred in television CRT construction because they do not have t... | | By: Electronics Circuits And VLSI Engineering | | |
| | Microwave tubes ELECTRON TUBES | | 2008-05-08 06:27:02 | | For extremely high-frequency applications (above 1 GHz), the interelectrode capacitances and transit-time delays of standard electron tube construction become prohibitive. However, there seems to be no end to the creative ways in which tubes may be constructed, and several high-frequency electron tube designs have been made to overcome these challenges. It was discovered in 1939 that a toroidal cavity made of conductive material called a cavity resonator surrounding an electron beam of oscillating intensity could extract power from the beam without actually intercepting the beam itself. The oscillating electric and magnetic fields associated with the beam "echoed" inside the cavity, in a manner similar to the sounds of traveling automobiles echoing in a roadside canyon, allowing radio-frequency energy to be transferred from the beam to a waveguide or coaxial cable connected to the resonator with a coupling loop. The tube was called an inductive output tube, or IOT: Two... | | By: Electronics Circuits And VLSI Engineering | | |
| | Tubes versus Semiconductors ELECTRON TUBES | | 2008-05-08 06:26:10 | | Devoting a whole chapter in a modern electronics text to the design and function of electron tubes may seem a bit strange, seeing as how semiconductor technology has all but obsoleted tubes in almost every application. However, there is merit in exploring tubes not just for historical purposes, but also for those niche applications that necessitate the qualifying phrase "almost every application" in regard to semiconductor supremacy. In some applications, electron tubes not only continue to see practical use, but perform their respective tasks better than any solid-state device yet invented. In some cases the performance and reliability of electron tube technology is far superior. In the fields of high-power, high-speed circuit switching, specialized tubes such as hydrogen thyratrons and krytrons are able to switch far larger amounts of current, far faster than any semiconductor device designed to date. The thermal and temporal limits of semiconductor physics place limitations ... | | By: Electronics Circuits And VLSI Engineering | | |
| | Making Millions of Tubes | | 2008-02-25 07:25:00 | | We squeeze millions of them every day, but where do they come from? This video shows how high speed machinery takes a piece of metal the size of a large coin and shapes it into a thin-walled tube to carry toothpaste and hand cream. Slow motion reveals all the details!
The preceding article is a "s... | | By: CR4: The Engineer's Place for Discussion & New | | |
| | Bihar Tubes drops despite of new order win | | 2008-02-13 21:52:00 | | The company made this announcement during trading hours today, 13 February 2008.Meanwhile, BSE Sensex was up 284.81 points or 1.71% to 16,892.82.On BSE, 22,591 shares were traded in the counter. The scrip had an average daily volume of 1.50 lakh shares in the past one quarter.The stock hit a high of Rs 131.75 and a low of Rs 121.10 so far during the day. The stock had a 52-week high of Rs 222.50 on 8 January 2008 and a 52-week low of Rs 43.50 on 7 March 2007.The small-cap scrip had underperformed the market over the past one month till 12 February 2008, declining 37.46% compared to the Sensex`s decline of 19.88%. It had outperformed the market in the past one quarter, declining 11.36% compared to Sensex`s decline of 16.66%.The company`s current equity is Rs 11.46 crore. Face value per share is Rs 10.The current price of Rs 124.55 discounts its Q3 December 2007 annualized EPS of Rs 25.88, by a PE multiple of 4.81.Bihar Tubes` net profit rose 107% to Rs 4.14 crore on 33.9% growth in net ... | | By: Indian stock markets | | |
| | Glowing LED tubes and signs for parties | | 2008-01-03 04:40:46 | | Have you missed a New Year party? Dont worry you can make it UP with these fun projects made of LEDs andother cheap materials. Joe Langevin has compiled several LED and fiber optic projects the average Joe can create easily and get ready for the party. One of them is simple LED sign made of [...]... | | By: Scienceprog - Embedded Related Info | | |
| | Centrifuge Tubes Max Length | | 2007-12-14 07:51:27 | | a standard off the shelf 15 ml centrifuge tube is 120 mm in length, I would like to know if a device based on this tube but 126 mm in length could be used in common bench top centrifuges. It fits in my Durafuge 200 but am wondering if anyone out there knows of any clearance issues , industry standar... | | By: CR4: The Engineer's Place for Discussion & New | | |
| | | Damn, looks like they might really tax the tubes | | 2007-05-24 18:40:02 | | From CNet News
Net taxes could arrive by this fall
By Declan McCullagh
Staff Writer, CNET News.com
Published: May 23, 2007, 10:10 PM PDT
The era of tax-free e-mail, Internet shopping and broadband connections could end this fall, if recent proposals in the U.S. Congress prove successful.
State and local governments this week resumed a push to lobby Congress for far-reaching changes on two different fronts: gaining the ability to impose sales taxes on Net shopping, and being able to levy new monthly taxes on DSL and other connections. One senator is even predicting taxes on e-mail.
At the moment, states and municipalities are frequently barred by federal law from collecting both access and sales taxes. But they’re hoping that their new lobbying effort, coordinated by groups including the National Governors Association, will pay off by permitting them to collect billions of dollars in new revenue by next year.
If that doesn’t happen, other taxes may zoom upward instead... | | By: Ramblings of a Mad Cow | | |
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