be AC or DC powered. The generator is a DC generator, with field windings and Armature electrical engineering armature windings . The input to the amplifier is applied to the field windings, and the output comes from the armature windings. The amplifier output is usually connected to a second motor ... speed control. Armature voltage control only controls the motor speed from zero to motor base speed ... torque at the motor armature will be reduced. Another advantage for this method is that the speed ... the voltage of the motor, since they are connected directly through the armature. Consequently ... generator and motor. The superscripts f , r ,and a , correspond to field, rotor, and armature ... The equation of electrical equilibrium in the armature circuit math G g fa I g f W g r R g a R m a I ... more details
File D Arsonval ammeter movement.jpg thumb 100px Moving coil meter movement with the nearer pole piece partly cut away A pole piece is a structure composed of material of high magnetic permeability that serves to direct the magnetic field produced by a magnet . A pole piece attaches to and in a sense extends a Magnetic pole pole of the magnet, hence the name. Pole pieces are used with both permanent magnet s and electromagnet s. In the case of an electromagnet, the pole piece or pieces simply extend the magnetic core and can even be regarded as part of it, particularly if they are made of the same material. In the case of a permanent magnet, the distinction between the magnet itself and the pole piece or pieces is more clear cut. Materials The traditional material for pole pieces was soft iron . While still often used with permanent magnets, soft iron suffers from eddy current s which make it less suitable for use with electromagnets, and particularly inefficient when the magnet is excited by alternating current . Shapes and forms File Lautsprecher Schema.svg thumb 100px Cross section of a dynamic loudspeaker showing the pole pieces in blue Pole pieces take many shapes and forms depending on the application. A traditional dynamic loudspeaker has a distinctive annular magnet and pole piece structure which serves to concentrate the magnetic flux on the voice coil . The central, cylindrical pole piece surrounded by the voice coil is normally referred to as the pole piece . A second pole piece in turn surrounds the voice coil. A moving coil meter has a different and equally distinctive structure. File MagnetEZ.jpg thumb 100px A horseshoe magnet with a keeper in use A magnet keeper is a specialised pole piece used to temporarily connect the poles of a permanent magnet, to help to preserve the magnetism, and for safety in the case of large and powerful magnets. Another specialised pole piece is the armature electrical engineering armature of an electromechanical solenoid ... more details
Unipolar may refer to Unipolar depression or unipolar disorder a state of intense sadness, melancholia or despair that has advanced to the point of being disruptive to an individual s social functioning and or activities of daily living Unipolar encoding , a line code Unipolar generator , a DC electrical generator in which the magnetic field has the same polarity at every point, so that the armature passes through the magnetic field lines of force continually in the same direction Unipolar induction, also known as homopolar generator Unipolar motor , a type of small DC electric motor commonly found in small, portable cassette players Unipolar neuron , a neuron with a single neurite, round body and with different segments that serve as superficial receptors or terminals Unipolar transistor, alternate name for a field effect transistor , which differs from a bipolar transistor in that only one type of charge carrier is involved in its operation Unipolarity, one form of polarity in international relations disambig ... more details
Orphan date April 2010 mergeto Excitation magnetic date September 2011 More footnotes date January 2010 Critical field resistance is a term that is associated with a shunt generator shunt DC generator . In a DC Shunt Generator, the voltage induced across the Armature V sub a sub is directly proportional to the Flux acting across it, The Flux in a DC Generator is directly proportional to the field current I sub f sub . By Ohm s Law V IR . The critical field resistance is defined as The maximum field circuit resistance for a given speed with which the shunt generator would excite. The shunt generator will build up voltage only if field circuit resistance is less than critical field resistance. It is a Tangent to the Open Circuit Characteristics of the Generator at a given speed . References ref Electrical Technology II by B.L.Thereja ref ref Electrical Machines I by U.A.Bakshi, V.U Bakshi ref Reflist External links http www.vocw.edu.vn content m10682 latest DC Machines DEFAULTSORT Critical Field Resistance Category Electric motors Category Electrical generators ... more details
. The almost constant force exerted by an iso elastic system is employed in the armature of a steadicam ... vertical position due to inertia , but remain balanced, just with the armature at a different angle ... more details
other uses A Metadyne is an electrical machine with three, or more, Brush electric brushes . It can be used as an amplifier or rotary transformer . It is similar to a third brush dynamo but much more complex, having additional regulator or variator windings. It is also similar to an amplidyne except that the latter has a compensating winding. The technical description is a cross field direct current machine designed to utilize Armature electrical engineering armature reaction . A metadyne can convert a constant voltage input into a constant Electric current current , variable voltage, output. Uses Metadynes have been used to control the aiming of Artillery large guns and for speed control in electric train s, e.g. London Underground O Stock . The equipment in the latter case weighed three tons. They have been superseded by Solid state electronics solid state devices. The concept and original patents were issued to the Macfarlane engineering company of Cathcart, Scotland. They were licensed to Met Vick Metropolitan Vickers and there was a cross licence or some form of agreement with GE USA who patented almost to the day the Amplidyne which works the same way the difference is simply in the amount of compensation that is made for armature reaction . Macfarlane used the concept in two main applications constant current for electric welders and, in Amplidyne form, for alternator voltage and current control. I am a former employee as an apprentice. My details are sketchy. There is nothing wrong with the original form. I am just adding two other and actually more important players in the development. History The history of the metadyne is very complex. The name is believed to have been coined by Pestarini in a paper which he submitted to the Montefiore International Contest at Li ge city Li ge , Belgium in 1928. However, machines similar to the metadyne had been experimented with much earlier, e.g. by Rosenberg in 1904. British patent number 26,607 of 1907 by Felton and G ... more details
the armature. These fields were usually horseshoe shaped, with either permanent horseshoe magnet ... be provided through the same armature. The two coils were now separated and placed at the sides of the motor, with their iron core as a sideways figure 8 circuit and the armature in a central pole ... of field flux around the entire circumference of the armature, this give a motor of almost twice the power, for the same armature current. ref name Electrical Machinery, 1917 Armature current, and the associated ... armature itself. This obviously simple system had been used before, but only for low powered locomotives ... its use for these extremely powerful new locomotives, the motor was split in two. The armature was formed ... frame of the locomotive. This gave an acceptable ride. The complexity of this system was that the armature ... to the extent that the armature hit the pole pieces suspension travel being far larger than typical ... at the side of the armature and giving them flat vertical faces, the armature was free to move up ... more details
two magnetic field s. Consider a 2 pole salient pole motor with a vertical magnetic axis. The armature ... force emf in the armature. The direction of alternating current is such that it creates a north ... induces current in the armature conductors and the direction of the induced current depends on the position ... axis is along the direction of the magnetic field, the armature behaves like an electromagnet ... is induced at the brush terminals which will produce current in the armature. The current in the armature ... above the South Pole of the magnetic axis. The poles of the armature are slightly displaced ... more details
td A simple DC electric motor. When the coil is powered, a magnetic field is generated around the armature. The left side of the armature is pushed away from the left magnet and drawn toward the right, causing rotation. td td The armature continues to rotate. td td When the armature becomes horizontally ... drop, and the parasitic voltage drop resulting from the internal resistance of the armature s windings. The current through a motor is given by the following equation math I frac V applied V cemf R armature ... in driving the armature against its own friction at the speed of 195 revolutions per minute. ref name ... of brushes touch the commutator and parallel to the axis of rotation of the armature is referred to as the commutating ... electrically in series with the armature coils via the brushes . In a shunt wound motor, the field coils are connected in parallel, or shunted to the armature coils. In a separately excited sepex ... current is unaffected by changes in the armature current. The sepex system was sometimes used in DC .... The direction of a wound field DC motor can be changed by reversing either the field or armature ... voltage at the motor will be 25 V. During the off time, the armature s inductance causes ..., the armature and hence field current reduces. The reduction in field causes the motor to speed up until ... the armature is directly connected to the armature of the DC motor sometimes but not always of identical ... of horsepower remain in service. The field currents are much lower than the armature currents ... s armature. A locked rotor condition prevents a motor from accelerating after its starting sequence ... from contaminants. DC motor starters The counter emf aids the armature resistance to limit the current through the armature. When power is first applied to a motor, the armature does not rotate. At that instant the counter emf is zero and the only factor limiting the armature current is the armature resistance. Usually the armature resistance of a motor is less than 1 therefore the current ... more details
About a component of electromotive devices the component of a compressor Axial compressor Description Axial compressor Unreferenced date December 2009 File Stator and rotor by Zureks.JPG thumb left Rotor and stator of electric motor File Stator machine triphas e.jpg thumb Stator of a 3 phase AC motor File DSC 9808.jpg thumb Stator of a brushless DC motor from computer cooler fan. The stator is the stationary part of a rotor electric rotor system or a Civil defense siren siren , found in an electric generator , electric motor , siren noisemaker siren , or Flagellum biological rotors . In Motors Depending on the configuration of a spinning electromotive device the stator may act as the field magnet , interacting with the armature electrical engineering armature to create motion, or it may act as the armature , receiving its influence from moving field coils on the Rotor electric rotor . The first direct current DC generators known as dynamo s and Electric motor Wound field DC motor DC motors put the field coils on the stator, and the power generation or motive reaction coils on the rotor. This was necessary because a continuously moving power switch known as the Commutator electric commutator is needed to keep the field correctly aligned across the spinning rotor. The commutator must become larger and more robust as the current increases. The stator of these devices may be either a permanent magnet or an electromagnet . Where the stator is an electromagnet, the coil which energizes it is known as the field coil or field winding . An alternating current AC alternator is able to produce power across multiple high current power generation coils connected in parallel, eliminating the need for the commutator. Placing the field coils on the rotor allows for an inexpensive slip ring mechanism to transfer high voltage, low current power to the rotating field coil. It consists of a steel frame enclosing a hollow cylindrical core made up of laminations of Electrical steel silic ... more details
Unreferenced date December 2009 Chatterton s compound was an adhesive waterproof Electrical insulation insulating compound that was used in early submarine telegraph cable s. Its constitution is as follows 3 parts gutta percha 1 part rosin 1 part pine tar Stockholm tar Chatterton s Compound was also used to stick insulating paper to armatures, for example those on Shortt Synchronome clock Synchronome clocks the most accurate clocks made in the early part of the 20th century. If the paper looked in a bad condition it could be removed by warming up the armature near a flame and replacing it. Chatterton s Compound was used in the manufacture of pneumatic pipe organs to seal lead tubing into wooden blocks for the pneumatic action. It is still used in historical restoration jobs for this purpose but has been replaced with modern materials on more recent builds. It was much used by submarine Cable Technicians for various purposes around oversea telegraph offices prior to the 1960s for general adhesive purposes and was available in round black sticks of about 3 4 inch diameter which responded to heat from a spirit lamp. It was used in jointing gutta percha insulated submarine telegraph cables. It was known to telegraph technicians as chats . In France, the normal black PVC Electrical tape electrical insulating tape is often referred to as Chatterton . DEFAULTSORT Chatterton s Compound Category Materials Material stub ... more details
Refimprove date December 2009 Image Cassette motor.jpg thumb Mergeto Homopolar motor discuss Talk Unipolar motor date March 2009 Image with unknown copyright status removed Image Unipolar.GIF A unipolar motor is a type of small DC electric motor commonly found in small, portable cassette player s. It is also used in stepper motors ref http books.google.com books?id 6JRcqhVUszEC&pg PA260&pgnum 260 v onepage&q&f false Physical computing sensing and controlling the physical world with computers , Dan O sullivan & Dan Igoe. Thomson 2004 ref . Its name is derived from its construction, which employs a magnetic strip wrapped around the inner wall of the housing such that one of its poles faces the inside, while the other faces outward. Although a true Magnetic monopole unipolar magnet magnet with only one pole exists only in theory, the name is appropriate for its function. The motor behaves as if the magnet were unipolar Citation needed date May 2011 , since only one of its poles is influencing the armature. References references Electric motor DEFAULTSORT Unipolar Motor Category Electric motors ... more details
sorts of companies, Oliff has written two comic books, Armature and Armature Darkpark and Lightworld , and is currently writing the third in his series. The Armature character first appeared in ads in Spawn ..., Armature has been a weekly comic strip in Oliff s local newspaper, the Independent Coast Observer ... more details
Taxobox name Oncholaimida regnum Animal ia phylum Nematoda classis Adenophorea subclassis Enoplia superordo Marenoplica ordo Oncholaimida Oncholaimida is an order of nematodes made up of a single superfamily, Oncholaimoidea. They are mainly marine and brackish water forms. They supposedly have predaceous and carnivorous feeding habits. Their amphids are pocket like with oval apertures. The stoma is vase like with walls that are heavily cuticularized. The stomatal armature contains one dorsal tooth and two subventral teeth, while the wall may additionally contain rows of small denticles. The stoma is divided into a cheilostome and an esophastome. In some species the male stoma is indistinct or collapsed. The cephalic sensilla are in the typical two whorl pattern one circumoral and composed of six papilliform sensilla, while the second is a single whorl of ten setiform sensory organs which combines the ancestral two whorls of six and four. In some species the sensilla are all papilliform. The esophagus is generally conoid to cylindrical, and in some species in the posterior position is a series of muscular bulbs. The cuticle is generally smooth, and there are sensory setae or papillae scattered over the length of the body. ref Maggenti, Armand R 2003 . http www.accessscience.com Encyclopedia 4 46 Est 468850 frameset.html?doi Oncholaimida . McGraw Hill Encyclopedia of Science & Technology Online. Retrieved on July 22, 2006. ref ref Nickle, W R May 1, 1991 . Manual of Agricultural Nematology . Marcel Dekker. ISBN 0 8247 8397 2. p. 154. ref Notes div class references small references div Category Nematodes ... more details
Refimprove date August 2011 Image DionisioGate.jpg thumb Torii Gate by Dionicio Rodriguez at Brackenridge Park , San Antonio , Texas. Image DioGateDetail.jpg thumb Torii Gate by Dionicio Rodriguez at Brackenridge Park, San Antonio, Texas Faux bois from the French for false wood refers to the artistic imitation of wood or wood grains in various media. The craft has roots in the Renaissance with trompe l il . It was probably first crafted with concrete using a steel armature by the inventor of ferrocement , Joseph Monier . In 1875, Monier created the first bridge of reinforced concrete at Chazelet, France. It was sculpted to resemble timbers and logs. ref name light Light, Patsy Pittman 2005 . Capturing Nature the Cement Sculpture of Dionicio Rodriguez . Texas A&M University Press. ref Ferrocement faux bois uses a combination of concrete, mortar masonry mortar and grout applied to a steel frame or armature to sculpt life like representations of wooden objects. Final sculpting can be done while the mixture is wet, in a putty state, or slightly stiff. Techniques vary among artisans. Most popular in the late 19th century through the 1940s, ferrocement faux bois has largely disappeared with the passing of those most expert in its practice. What few objects remain from that peak period mostly in the form of garden art, such as planters and birdbaths are now highly prized by collectors. In Mexico, this style was known as El Trabajo R stico The Rustic Work . One highly regarded artist who worked in this style was Dionicio Rodriguez , a Mexican who relocated to Texas in the early 1920s. Although not widely known, his large scale faux bois installations have been listed on the National Register of Historic Places . ref name light Dionicio s great nephew is one of the handful of artists still creating Faux Bois today. See also http fauxboisclasses.blogspot.com Faux Bois in Concrete Dionicio Rodriguez Faux painting Graining Trompe l il Joseph Monier Ferrocement Reinforced conc ... more details
file M.L. Snowden At Work.jpg thumb M.L. Snowden file M.L. Snowden Sculpting.jpg thumb M.L. Snowden Working On Clay Over Armature sculpture Armature M. L. Snowden is an United States American sculptor . Her works, largely in lost wax cast bronze , explore the monumental forces and energies of geological phenomena and human figuration. ref Seamark, Sarah. Masterpiece Weekend of Opulence & Art. Art World News. June 2008. 14 . ref They are intended to convey power and movement through abstraction abstract and Representation arts representational elements. She has created nine chapters composed of more than 50 bronze sculptures, including Terrestrial Forum, The Hydrosphere, The Atmosphere, Foundations of Synergy, Ascension of Elements, Celestial Array, Creation s Gate, Creation, and The Brilliance Trilogy. ref http www.mlsnowden.com Compendium.htm ref She uses the working methods of Auguste Rodin and the Mercie studios of Paris. Her father, sculptor George Holburn Snowden , was mentored by Swiss sculptor Robert Eberhardt , a contemporary of Daniel Chester French and Saint Gaudens, Haute Garonne Saint Gaudens and a professional in the Rodin studios at the turn of the 19th century. ref name legacyDVD M.L. Snowden, The Legacy of Rodin. by Masterpiece Publishing. DVD. 2009 ref M.L. Snowden spent 17 years as an apprentice to her father, ref name history http www.mlsnowden.com History.htm ref who in 1990 bequeathed to her his collection of Auguste Rodin s sculpting tools. ref name legacyDVD Snowden s awards include the Alex J. Ettl Grant ref Legacy of Rodin Society, The First Alex Ettl Grant Lifetime Achievement Awarded to ML Snowden. The Legacy of Rodin Society Newsletter. Mar. 2007 2 3 ref and Japan s 4th International Rodin Competition. ref Legacy of Rodin Society. M.L. Snowden is Named Winner, International Rodin Competition. The Legacy of Rodin Society Newsletter. Jan. 2007 3 . ref Her notable commissions include the Altar Angels in the Cathedral of Our Lady of the Angel ... more details
PML Flightlink were a Hampshire based firm specialising in the design and manufacture of pancake flat electric motor s. The company operated for over 30 years in a number of markets including defense, aerospace, mobility, motion control, processing and printing. ref http www.pmlflightlink.com about.html PML Flightlink company website . ref In 2006, they demonstrated an in wheel electric motor for hybrid electric vehicles cars called the Hi Pa Drive at the British Motor Show in London, using a Mini BMW Mini dubbed the Mini QED as a demonstration object. ref http www.channel4.com 4car news news story.jsp?news id 14903&ref archive British Motor Show Modified hybrid Mini promises 640bhp performance , Channel 4, July 19, 2006. ref Two other car manufacturers have also presented concept cars using this technology Volvo in its Volvo ReCharge , and Ford with a Ford F150 Pickup truck pick up prototype presented at the 2008 Specialty Equipment Market Association trade show in Las Vegas metropolitan area Las Vegas . ref http www.sema.org Main ArticleDetail.aspx?fc c 1209857x2654523x62448720&contentID 60751 Ford s Electric F 150 A Radical Rethink of an American Icon , SEMA eNews, Vol. 11, No. 44, Oct 30, 2008. ref Administration and split On 28 November 2008 by UK court order PML was put into Administration law administration ref cite web title Oak Investment Partners XII, Ltd. Partnership v Boughtwood & Ors, Court of Appeal Chancery Division, EWHC 176 Ch url http vlex.co.uk vid 52635570 date 6 February 2009 publisher http vlex.co.uk vLex accessdate 15 September 2009 ref insolvency handling in the UK similar to Chapter 11 . After the court case, PML was split in two in 2009 http proteanelectric.com Protean Electric continue to develop automotive in wheel motor applications of the Hi Pa Drive and http www.printedmotorworks.com Printed Motor Works design and manufacture Electric motor Printed Armature or Pancake DC Motors Printed Armature Pancake electric motors, Joystick joystic ... more details
multiple issues notable March 2011 original research March 2011 primarysources March 2011 The Single Axially Rotating Flux generator system SARF uses fewer parts, and has a significantly less weight, when compared to convention dual magnet electrical generator s. With the use of super strong neodymium rare earth magnet s, there is no need to waste energy electrifying the Stator field . With fewer moving parts and less weight the generator produces more power with a smaller investment. Applications For wind turbine applications this particular design allows for the possibility of multiple generators to be coupled inline. This offers the possibility of harnessing the power from various size blades to meet various power needs. Controlled experiments have shown that, for its size, the generator can produce roughly double the output of the common home built generator of comparable size at less cost. Construction see talk page Conventional axial generators have two sets of magnets that are set opposite to each other and revolve around an Armature electrical engineering armature to produce electricity . The SARF system allows for the removal of a complete set, or one rotor, of magnets while producing more power. The SARF generator produces more power than dual rotor generators with fewer parts and less weight. Advantages When the SARF system is used for wind turbine applications, off the shelf Alternator Automotive alternators automobile rotors and hubs, it eliminates the need for costly machining . The SARF system is more efficient, has less weight and fewer moving parts, and has a higher power density than dual magnet systems. History The new style of generator was invented Dubious date April 2011 in 2008 at Bowling Green State University by Mr. Charles L. Codding Jr., a past instructor in the Department of Technology Systems Engineering and currently a Process Engineer at BGSU, along with Mr. Jared Voldness, a Technology Education Student. Patent The SARF Single Axially ... more details
a single face armature. When the brake is engaged, the permanent magnets create magnetic lines of flux, which can turn attract the armature to the brake housing. To disengage the brake, power is applied ... flux attracts the armature to the face of the brake. As it does so, it squeezes the inner ... from the brake, the armature is free to turn with the shaft. Springs keep the friction disk and armature ... more details
is much less than power transferred into the armature circuit, AC generators nearly always have the field winding on the rotor and the armature winding on the stator. AC generators are classified into several ... which convert the alternating current produced by the armature to direct current. Motor main Electric ... more details
the operator s broad movements, the Steadicam s armature absorbs any jerks, bumps, and shakes. The Steadicam ... armature which has the camera mounted at one end and a counterbalance weight at the other. The counterbalance ... makes the camera s own viewfinder unusable. In the film industry the armature and weight are traditionally ... weight of the counterbalance and camera means that the armature bears a relatively high inertia ... to quickly shake a bowling ball . The freely pivoting armature adds additional stabilization to the photographed ... maximum isolation from it. When the armature is correctly adjusted, the operator is able to remove ... armature can be rotated vertically, putting the camera on the bottom, and the sled on the top. This is referred ... more details
and compound. These types of connections configure how the motor s field and armature windings ... Learning, 2010. Page 251. ref Series connection A series DC motor connects the Armature electrical engineering armature and Field coil field windings in series with a common D.C. power source. This motor ... is low, the magnetic field produced by the field winding is weak, and so the armature must turn faster ... load. Series motors called universal motors can be used on alternating current. Since the armature ... motor connects the armature and field windings in parallel or shunt with a common D.C. power source ... connection A compound DC motor connects the armature and fields windings in a shunt and a series combination ... more details
Encyclopedia
top
