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Pneumatics are systems made purely from air controlled components. ElectroPneumatics are those that are aided by electric, which can alternateve 3/2 and 5/2 valves, among other things Pneumatics is a method to transfer energy from one point to another using actuators which which are driven by fluids under pressure. Pneumatics restricts itself to gaseous fluids while hyraulics uses liquids to transfer the energy. The transferring of energy in pneumatics such as pumping air into a pneumatic cylinder must be controlled. You can control the pressure by manually opening a valve, automaticall by detecting its pressure, or by sending an electrical signal. The cotrol of pneumatic components by elecrical impulses is known as electropneumatics. This science is fast expanding as it can make use of all electronic developments such as PLCs and PCs. However electropneumatics has restrictions as it cannot be used in places where electricity cannot be used such as gas factories,etc. jacob m

In the earliest days of the motorcycle frame, welding was not used to assemble the various sections. Most manufacturers used the same methods employed in bicycle manufacture. This was the lug method of construction. The lug from one piece such as the neck was inserted into the frame and silver soldered in place. This was followed by brazing the pieces together and finally by welding motorcycle frame pieces together as they became more powerful than mere bicycles with engines. The Need to Reduce Weight Brought Several Changes There were other reasons why welding the motorcycle frame became the most common form of assembly such as new technologies and metals. The one main reason for this major change in the way they were built was the need to reduce weight. The old methods resulted in a structure which was incredibly heavy. By switching to welded joints, manufacturers no longer needed the lugs (stubs or pegs made to be inserted into the tubular sections). This led to significant weight reduction; allow bikes to be faster and more fuel efficient. Welded Joints Allow for More Accuracy When the lug and brazing method was in use, frames were generally considered to be relatively accurately assembled. However, this accuracy came at the expense of excessive weigh. As motorcycles became more powerful, the need for a better method of assembly developed. At first manufacturers switched over to using carbon steel and holding jigs to weld the framework together. This was followed by the use of ultra-lightweight materials such as aluminum and magnesium. Currently there are three different methods of welding in use. Arc Welding or Shielded Metal Welding Shielded metal arc welding is the first form of electric welding developed for commercial use. It involves the use of electricity to generate the heat necessary to melt the metals to be joined. The heat is also used to melt the filler rod being used. When the rod is placed close to the metals to be joined, an arc is formed which generates the required heat. The rod is wrapped in a chemical flux. When the arc is formed, the heat generated vaporizes the flux, which in turn provides a shield around the weld. This prevents air from getting into the area and compromising the weld. Metal Inert gas or MIG Welding This form of welding still uses electricity to generate the required heat. However the metal filler is supplied from a spool of wire inside the welding machine. The wire is feed through a tube, into the handle and into the weld. The arc is formed where the wire comes into contact with the metals to be joined. The integrity of the weld is protected by carbon dioxide, which is an inert gas. This form of welding is very fast and produces an extremely durable weld. Tungsten Inert Gas or TIG Welding The latest form of motorcycle frame welding is TIG or tungsten inert gas. TIG welding involves the use of a tungsten filler rod, AC or DC current and an inert gas. The choice of gasses is of no particular importance as it is used to keep air out of the joint. Because TIG uses highly localized, intense heat, it is perfect for use with metals where distortion can be a critical factor. These include aluminum and magnesium, to metals which have been gaining in prominence for many purposes in motorcycles as they are extremely lightweight and durable. The methods of welding motorcycle frames have changed dramatically over the years. Manufacturers have learned how to use lighter metals to build their motorcycles. Along with this came the need for even lighter, but stronger welds. However, even today you will find a number of mass produced bikes which still use mild steel tubing which is shielded arc welded together. Each of the different types of welding has its advantages and is used in different areas of the various bikes on the road.

A welding power supply is a device that provides an electric current to perform welding. Welding usually requires high current (over 80 amperes) and it can need above 12,000 amperes in spot welding. Low current can also be used; welding two razor blades together at 5 amps with gas tungsten arc welding is a good example. A welding power supply can be as simple as a car battery and as sophisticated as a high-frequency inverter using IGBT technology, with computer control to assist in the welding process. Contents 1 Classification 2 Power supply designs 2.1 Transformer 2.2 Generator and alternator 2.3 Inverter 2.4 Other types 3 References Classification Welding machines are usually classified as constant current (CC) or constant voltage (CV); a constant current machine varies its output voltage to maintain a steady current while a constant voltage machine will fluctuate its output current to maintain a set voltage. Shielded metal arc welding and gas tungsten arc welding will use a constant current source and gas metal arc welding and flux-cored arc welding typically use constant voltage sources but constant current is also possible with a voltage sensing wire feeder. The nature of the CV machine is required by gas metal arc welding and flux-cored arc welding because the welder is not able to control the arc length manually. If a welder attempted to use a CV machine to weld with shielded metal arc welding the small fluctuations in the arc distance would cause wide fluctuations in the machine's output. With a CC machine the welder can count on a fixed number of amps reaching the material to be welded regardless of the arc distance but too much distance will cause poor welding. Power supply designs The welding power supplies most commonly seen can be categorized within the following types: Transformer A transformer-style welding power supply converts the moderate voltage and moderate current electricity from the utility mains (typically 230 or 115 VAC) into a high current and low voltage supply, typically between 17 to 45 (open-circuit) volts and 55 to 590 amperes. A rectifier converts the AC into DC on more expensive machines. This design typically allows the welder to select the output current by variously moving a primary winding closer or farther from a secondary winding, moving a magnetic shunt in and out of the core of the transformer, using a series saturating reactor with a variable saturating technique in series with the secondary current output, or by simply permitting the welder to select the output voltage from a set of taps on the transformer's secondary winding. These transformer style machines are typically the least expensive. The trade off for the reduced expense is that pure transformer designs are often bulky and massive because they operate at the utility mains frequency of 50 or 60 Hz. Such low frequency transformers must have a high magnetizing inductance to avoid wasteful shunt currents. The transformer may also have significant leakage inductance for short circuit protection in the event of a welding rod becoming stuck to the workpiece. The leakage inductance may be variable so the operator can set the output current.[1] Generator and alternator Welding power supplies may also use generators or alternators to convert mechanical energy into electrical energy. Modern designs are usually driven by an internal combustion engine but older machines may use an electric motor to drive an alternator or generator. In this configuration the utility power is converted first into mechanical energy then back into electrical energy to achieve the step-down effect similar to a transformer. Because the output of the generator can be direct current, or even a higher frequency ac current, these older machines can produce DC from AC without any need for rectifiers of any type, or can also be used for implementing formerly-used variations on so-called heliarc (most often now called TIG) welders, where the need for a higher frequency add-on module box is avoided by the alternator simply producing higher frequency ac current directly. Inverter Since the advent of high-power semiconductors such as the insulated gate bipolar transistor (IGBT), it is now possible to build a switched-mode power supply capable of coping with the high loads of arc welding. These designs are known as inverter welding units. They generally first rectify the utility AC power to DC; then they switch (invert) the DC power into a stepdown transformer to produce the desired welding voltage or current. The switching frequency is typically 10 kHz or higher. Although the high switching frequency requires sophisticated components and circuits, it drastically reduces the bulk of the step down transformer, as the mass of magnetic components (transformers and inductors) that is required for achieving a given power level goes down rapidly as the operating (switching) frequency is increased. The inverter circuitry can also provide features such as power control and overload protection. The high frequency inverter-based welding machines are typically more efficient and provide better control of variable functional parameters than non-inverter welding machines. The IGBTs in an inverter based machine are controlled by a microcontroller, so the electrical characteristics of the welding power can be changed by software in real time, even on a cycle by cycle basis, rather than making changes slowly over hundreds if not thousands of cycles. Typically, the controller software will implement features such as pulsing the welding current, providing variable ratios and current densities through a welding cycle, enabling swept or stepped variable frequencies, and providing timing as needed for implementing automatic spot-welding; all of these features would be prohibitively expensive to design into a transformer-based machine, but require only program memory space in a software-controlled inverter machine. Similarly, it is possible to add new features to a software-controlled inverter machine if needed, through a software update, rather than through having to buy a more modern welder. Other types Additional types of welders also exist, besides the types using transformers, motor/generator, and inverters. For example, laser welders also exist, and they require an entirely different type of welding power supply design that does not fall into any of the types of welding power supplies discussed previously. Likewise, spot welders require a different type of welding power supply, typically containing elaborate timing circuits and large capacitor banks that are not commonly found with any other types of welding power supplies. https://en.wikipedia.org/wiki/Welding_power_supply

Shandong eed with intelligent machinery co., LTD is a China north car co jinan railway transportation equipment co., LTD. (formerly China north group jinan locomotive overlook) wholly-owned subsidiary. Company was founded in 1910, is one of the earliest modern big industry in shandong province, shandong province the first union was born on this. Shandong with eed intelligent machinery co., LTD., has been committed to research and development and manufacturing excellent pneumatic tools, thread screw machine products, our company developed industrial pneumatic tools, thread screw machine product technology, quality and market share in a leading position in the whole country.