| 单词 | electromagnet |
| 例句 | Meanwhile, he worked out a design for a large-scale calutron plant employing an array of vacuum tanks arranged in large ovals between the poles of huge electromagnets. Big Science 2015-07-07T00:00:00Z Even before Livingston’s results had been validated properly, Ernest was mapping out a campaign to acquire a more powerful electromagnet to drive protons beyond the million-volt threshold. Big Science 2015-07-07T00:00:00Z The original magnet design called for using copper for the electromagnet coils and the massive transmission bus that carried electricity to the racetracks. Big Science 2015-07-07T00:00:00Z The backs of the chairs were outfitted with small boxes filled with prop garbage; electromagnets controlled by the stage manager released the contents onto the floor during blackouts. How Long Is ‘The Flick’? It Depends on the Seats 2016-05-26T04:00:00Z You can probably guess the trick’s secret: The box contained a plate of steel and located just under the flooring was an exceptionally powerful electromagnet that could be secretly turned off or on. Review | How do they do that? ‘The Secret History of Magic’ is a study of deception as art 2018-07-17T04:00:00Z As part of the sequence, Dom, driving a Dodge Charger fitted with electromagnets, is caught between a pair of trucks. For ‘F9,’ Making Stunts That Stick 2021-05-28T04:00:00Z A second grad student proved handier, establishing proof of concept with a palm-size brass device, on the strength of which Lawrence started fundraising to buy a bigger electromagnet. The man who invented 'Big Science,' Ernest Lawrence 2015-07-16T04:00:00Z In a sequence that plays out on the streets of Edinburgh, the electromagnet pulls an entire car onto its side, then through a shop and into the bed of a delivery truck. For ‘F9,’ Making Stunts That Stick 2021-05-28T04:00:00Z To ascend, Piccard simply jettisoned the pellets by cutting the power to an electromagnet that held them in place. Dive for Avatar 2011-01-18T07:59:02Z A favorite is radioing in for a helicopter with a giant, dangling electromagnet. Perspective | I am a fugitive from the thought police 2018-09-28T04:00:00Z There are very few Bloland recordings out there, but here’s a live take on “Of Dust and Sand,” a piece on “Chamber Industrial” for alto saxophone and a piano whose strings are vibrated by electromagnets: Classical Music This Week: Schubert, Bloland and Lip-Synching ‘Salome’ 2015-05-27T04:00:00Z That coiled diagram, which emerged from a mathematical ratio, now adorns the flat wooden surface of a shieldlike structure that conceals 24 strings made to vibrate by electromagnets. Listen to Five of the World’s Newest, Wildest Instruments 2021-03-12T05:00:00Z But if amped to the highest settings, the electromagnet can, say, be attached to the bottom of a plane and catch a car midair as it drives off a cliff. For ‘F9,’ Making Stunts That Stick 2021-05-28T04:00:00Z Happily, there is induction, which uses electromagnets to efficiently heat cookware without the inherent pollution of fossil fuels like natural gas. The Case for Induction Cooking 2022-03-11T05:00:00Z It turns the neutron star into an extremely strong electromagnet. Pulsars may make dark matter glow 2023-10-06T04:00:00Z She steals an electromagnet from the junkyard in order to snag a meteor out of the sky during a shower, for vaguely nefarious power-mad reasons. Review: In 'PAW Patrol: The Mighty Movie,' a well-funded dog army saves the day 2023-09-29T04:00:00Z To generate the field, a standard scanner employs a large, powerful superconducting electromagnet that pushes a machine’s cost to $1.5 million or more, pricing MRI out of reach of 70% of the world’s population. MRI for all: Cheap portable scanners aim to revolutionize medical imaging 2023-02-22T05:00:00Z Once the carriage reaches the midpoint of its track, the electromagnet is programmed to release the knife — letting it hit a target up to 15 feet away. Watch this laser-guided knife throwing machine nail 10 in a row 2022-08-22T04:00:00Z Figure 22.12 An electromagnet with a ferromagnetic core can produce very strong magnetic effects. College Physics for AP Courses 2015-08-12T00:00:00Z Sometimes, the motion is clear, as in the coils of heavy wire that make an industrial electromagnet. Astronomy 2016-10-13T00:00:00Z The MRI scanner subjects the patient to such powerful electromagnets that the scan room must be shielded. Anatomy and Physiology 2013-06-19T00:00:00Z As the beam shot horizontally, it squeezed through a narrow gap, with one pole of an electromagnet bracketed above and the other below. It Has Been 100 Years Since a Quantum Experiment Showed Why We Don’ Fall Through Our Chairs 2022-02-08T05:00:00Z But perhaps no surprise will be bigger than this, hinted at in the trailer, which shows cars outfitted with powerful electromagnets: a car in space — or at least the outer reaches of Earth’s atmosphere. 12 summer movies that just might get you off the couch and into the theater 2021-06-02T04:00:00Z Alignment of domains in the core produces a magnet, the poles of which are aligned with the electromagnet. College Physics for AP Courses 2015-08-12T00:00:00Z One such technique is plasma wakefield acceleration, a cheaper, more efficient method of accelerating particles using plasmas in comparison with the sprawling and expensive electromagnets employed in present-day colliders. Would New Physics Colliders Make Big Discoveries or Wander a Particle Desert? 2019-03-13T04:00:00Z The protons circulate inside vacuum pipes – one running clockwise, the other counterclockwise – and these are surrounded by superconducting electromagnets strung together around the tunnel like sausages. It’s Intermission for the Large Hadron Collider 2018-12-21T05:00:00Z In Seattle’s 53,000-square-foot building, four treatment rooms with specialized equipment for different circumstances are fed beams of protons shaped and steered by powerful electromagnets. High-tech Seattle cancer center gets new life as lenders get $135M ‘haircut’ 2018-11-30T05:00:00Z The pull of the electromagnet, the force it exerts, is directly related to the amount of electrical current going through its coils. Definition of kilogram set to change 2018-11-15T05:00:00Z In fact, electromagnets and ferromagnets have the same basic characteristics—for example, they have north and south poles that cannot be separated and for which like poles repel and unlike poles attract. College Physics for AP Courses 2015-08-12T00:00:00Z The fridges are currently locked by an electromagnet, which will be turned off wirelessly when the Browns officially claim their first victory of the season, allowing fans to celebrate with free beer. NFL notebook: Roethlisberger in concussion protocol 2018-08-14T04:00:00Z These are sped up by a series of increasingly larger and more energetic electromagnets, until they are ready to enter the main ring of the collider. It’s Intermission for the Large Hadron Collider 2018-12-21T05:00:00Z The power brick also seems to hum when the electromagnets activate, which is not comforting — and surprisingly not an issue unique to this floating product, either. Levitating gadgets will disappoint you 2018-04-12T04:00:00Z The electrical current going through the electromagnet is increased until the two sides are perfectly balanced. Definition of kilogram set to change 2018-11-15T05:00:00Z Combining a ferromagnet with an electromagnet can produce particularly strong magnetic effects. College Physics for AP Courses 2015-08-12T00:00:00Z Then it was a collection of self-winding springs or an “enchanted loom,” then a clock, an electromagnet, a telephone switchboard, a hologram and, most recently, a biological supercomputer. To Unlock the Brain’s Mysteries, Purée It 2017-12-14T05:00:00Z Typically, a breaker contains an electromagnet through which the current flows. Smart circuit-breakers for energy-efficient homes 2017-11-23T05:00:00Z Scientists would show how it could break down water into its constituent gases, make wires glow, or work an electromagnet. How a Victorian Lawyer from Wales Invented the Hydrogen Fuel Cell 2017-10-29T04:00:00Z By measuring the current running through the electromagnet to incredible precision, the researchers were able to calculate h to an accuracy of 0.000001%. Definition of kilogram set to change 2018-11-15T05:00:00Z Whenever strong magnetic effects are needed, such as lifting scrap metal, or in particle accelerators, electromagnets are enhanced by ferromagnetic materials. College Physics for AP Courses 2015-08-12T00:00:00Z That turns them into an electromagnet, generating a magnetic field which pushes against an existing field generated by a second set of permanent magnets inside the stator. As electric motors improve, more things are being electrified 2017-09-14T04:00:00Z If that flow exceeds a set level, the electromagnet becomes sufficiently energised to throw a mechanical switch, which breaks the circuit. Smart circuit-breakers for energy-efficient homes 2017-11-23T05:00:00Z The lathe requires limited electricity, which is needed for an electromagnet that operates the cutting head, as well as to power a strobe that allows the engineer to monitor the turntable’s speed. Reinventing the machine that let America hear itself on the PBS-BBC doc 'American Epic' 2017-07-21T04:00:00Z "We had to demagnetize the building," she says, a painstaking process that required passing an electromagnet over every square meter of the walls. Weighing the universe's most elusive particle 2017-06-29T04:00:00Z Figure 22.13 An electromagnet induces regions of permanent magnetism on a floppy disk coated with a ferromagnetic material. College Physics for AP Courses 2015-08-12T00:00:00Z Meanwhile, Bo is devoted to improving his magic skills, which are secretly aided by an electromagnet he’s built into his arm. Review: Clunky ‘Sleight’ showcases new lead Jacob Latimore 2017-04-27T04:00:00Z A commitment to basic research, led by the federal government, has long made the United States an electromagnet for the smartest people on Earth. Editorials from around New York 2017-03-29T04:00:00Z Just a few feet away, on the other hand, the windings of the superconducting electromagnets need to be cooled to a few degrees above absolute zero. A Dream of Clean Energy at a Very High Price 2017-03-27T04:00:00Z The non-surgical treatment involves holding an electromagnet on the surface of a person’s scalp over a region of the brain called the frontal cortex to produce a change in brain activity. Non-Surgical Brain Stimulation Shows Promise, but Unknowns Remain 2016-08-30T04:00:00Z The strongest permanent magnets have fields near 2 T; superconducting electromagnets may attain 10 T or more. College Physics for AP Courses 2015-08-12T00:00:00Z There are also a few maglev trains that use conventional electromagnets, including one in Shanghai. Gordon T. Danby, Who Helped Invent Magnetic-Levitation Trains, Dies at 86 2016-08-11T04:00:00Z The Magspoof uses an electromagnet to reproduce the same pattern a reader would get from a swiped card, basically making the reader believe that a card has just been swiped through. The Mr. Robot Hack Report: Cantennas and dirty USB drives 2016-08-10T04:00:00Z The sled began on a train track and then was rocketed to 105 miles per hour by electromagnets as electricity was shot into copper coils. 'Hyperloop' sled speeds through U.S. desert via electromagnets 2016-05-11T04:00:00Z Roper said his office is also testing use of projectiles developed for a futuristic electromagnet railgun in conventional U.S. Pentagon's innovation office reaching out to industry for ideas 2016-03-28T04:00:00Z Maglev technology generally lifts train cars using powerful electromagnets—electrically charged coils that create strong magnetic fields—requiring lots of energy and sometimes pricey cooling systems. Hyperloop Race Picks Up Speed 2016-01-22T05:00:00Z "Behind the scenes, powerful electromagnets enable Ferollic to influence the fluid’s shape, to pick it up and move it around," reads the description on the site. This display uses magnetic ferrofluid to tell time, and it's utterly mesmerizing 2015-08-17T04:00:00Z A complex set of electromagnets encircle the doughnut-shaped vessel, some horizontal and some vertical, while one tightly wound coil of wire, called a solenoid, runs down the doughnut hole. Feature: The new shape of fusion 2015-05-21T04:00:00Z The short circuit was caused by a tiny piece of metal debris, which got into the electronics surrounding one of the LHC's powerful electromagnets. LHC fixes glitch, prepares for beams 2015-03-31T04:00:00Z But instead of an actual button that gets clicked, there's a set of electromagnets that move enough to feel like there's a click happening. The MacBook Pro's new Force Touch Trackpad is great. Pity about the name 2015-03-13T04:00:00Z In mid-March two beams of protons, driven and steered by super-cooled electromagnets, will do full circuits of the LHC in both directions - for the first time in two years. LHC restart: 'We want to break physics' 2015-03-04T05:00:00Z While the pianist plays the piano in the conventional way, using the keys, the biocomputer excites notes through small electromagnets hovering millimetres above the metal strings, imbuing the music with an ethereal tone. Fungus plays 'biomusic' duet 2015-02-27T05:00:00Z Lacking electrical resistance, superconductors can be wound into electromagnets that produce much stronger fields than conventional copper magnets. Feature: The new shape of fusion 2015-05-21T04:00:00Z But not all of us have a PhD in electrical and computer engineering, experience with hardware design, and friends who are experts in electromagnets. This is Swyp, the latest card that wants to store all your other credit cards 2015-01-27T05:00:00Z Until Andre Geim, a physics professor at the University of Manchester, discovered an unusual new material called graphene, he was best known for an experiment in which he used electromagnets to levitate a frog. Graphene: Fast, Strong, Cheap, and Impossible to Use | The New Yorker 2014-12-15T05:00:00Z When electrical impulses are sent to the mould, its response is measured in current and translated back to a piano using electromagnets. The computer circuits made of slime 2014-11-25T05:00:00Z That began to change in 1932, with the invention by the American scientist Ernest Lawrence of the cyclotron - a device for accelerating particles around a circular chamber using electromagnets. The scary element that saved the crew of Apollo 13 2014-09-19T04:00:00Z This means it uses a set of electromagnets that pulse on and off to coax an axle to spin. With DC59 Motorhead, Dyson Looks to Create the iPad of Vacuums 2014-07-16T04:00:00Z That metal element is forced in different directions when the device is placed into a moving field, produced by the coils of an electromagnet. 'Robot sperm' controlled by magnets 2014-06-02T04:00:00Z There's a new use in town for helium besides supercooling electromagnets at the Large Hadron Collider and making your voice sound freakishly high-pitched: improving the capacity and efficiency of hard drives. Western Digital Enlists Helium for 6TB Energy-Efficient Drives 2013-11-05T15:45:05.003Z They combine the launch, drive wheels and brake mechanisms all in one, allowing for blistering acceleration and equally effective braking by reversing the polarity of the electromagnets. Roller coasters set to get scarier 2013-10-22T23:00:53Z Popular Science said the electromagnet “will float from New York Harbor in June, down the East Coast, around Florida, up the Gulf Coast and up the Mississippi River by July.” The Week: Kepler Telescope’s Troubles, a Maya Pyramid in Ruins and More 2013-05-20T21:18:08Z To fold itself into a new shape, the device uses an "electro-permanent" motor - similar to the electromagnets used in scrapyards to lift cars. 'Transformer' robot made at MIT 2012-12-04T13:25:16Z The rotor, which turns inside that casing, is surrounded by copper windings that act as electromagnets. Electric motors: Reluctant heroes 2012-11-15T16:05:22Z If nothing else, he says, the superconducting electromagnet that powered the system's pulse generator required a cooling system too big and cumbersome to be used in the field. Microwave weapons: Wasted energy 2012-09-12T17:21:24.203Z The current favored technique is to use a reactor called a tokamak, which employs powerful electromagnets to confine the plasma inside a doughnut-shaped reactor vessel. How to Line a Thermonuclear Reactor 2012-08-16T20:51:00Z Physics An Arduous Business Trip Not everyone has a 50-foot-wide electromagnet to spare. The Week: Kepler Telescope’s Troubles, a Maya Pyramid in Ruins and More 2013-05-20T21:18:08Z It closed by gravity, and was held in the open position by a clutch which could be released by means of a powerful electromagnet controlled from the captain's bridge. Loss of the Steamship 'Titanic' 2012-04-17T02:00:14.973Z That reverses the polarity of the electromagnets and causes the rotor to be pulled around by attraction and repulsion between the electromagnets and the permanent magnets. Electric motors: Reluctant heroes 2012-11-15T16:05:22Z Constable Depatie said that a crane with a large electromagnet would be used to collect the coins. | The Americas: Canada: Coins Pour Onto Highway 2012-03-29T04:48:42Z Wurden blames ITER’s delays and ballooning costs on a premature commitment to a technology known as a tokamak, a doughnut-shaped cage within which powerful electromagnets confine a fusion plasma. Laser fusion nears crucial milestone 2012-03-07T18:20:22.413Z Afterward, they would use electromagnets three meters in diameter to clean the seafloor of debris. Raise It or Raze It?: How Will the Stranded Italian Cruise Ship Be Salvaged? 2012-03-06T10:15:00.390Z "Writing bits this way is potentially much more energy efficient, because there is no longer a need for energy-consuming electromagnets," Kimel says. Hot Idea for a Faster Hard Drive 2012-02-07T17:29:10Z It’s only possible because of induction technology, which means it uses electromagnets to heat cookware. The World's Sexiest Stove 2012-01-09T11:32:06Z He places a strong electromagnet so that its lines of magnetic flux pass transversely between the spark balls. Hertzian Wave Wireless Telegraphy 2012-01-09T03:00:20.570Z The Make Up of a Field Magnet.—In construction, the electromagnet, used for creating a field in which the armature of a dynamo revolves, consists of four parts: 1. Hawkins Electrical Guide, Number One Questions, Answers, & Illustrations, A Progressive Course of Study for Engineers, Electricians, Students and Those Desiring to acquire a Working Knowledge of Electricity and its Applications 2011-12-24T03:07:54.823Z We can't reverse the poles on simple bar magnets, but we can on electromagnets. Electricity for the 4-H Scientist Idaho Agricultural Extension Service Bulletin 396, June, 1962 2011-11-18T03:00:30.487Z Sturgeon's electromagnet might have been used for telegraphy through very short distances, but Henry's magnet, with its coils of many turns of insulated wire, was needed for long-distance signalling. The Story of Great Inventions 2011-10-05T02:00:16.353Z This pen is deflected through the agency of an electromagnet every second, and thus the seconds of the clock are recorded on the chronograph by offsets from the spiral curve. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 6 "Geodesy" to "Geometry" 2011-09-19T02:00:10.473Z This coherer is connected in between the aerial and the earth, and is also in circuit with a battery and the electromagnet of a telegraphic relay. Hertzian Wave Wireless Telegraphy 2012-01-09T03:00:20.570Z These are known as permanent magnets in distinction from electromagnets. Hawkins Electrical Guide, Number One Questions, Answers, & Illustrations, A Progressive Course of Study for Engineers, Electricians, Students and Those Desiring to acquire a Working Knowledge of Electricity and its Applications 2011-12-24T03:07:54.823Z The rotating electromagnet will have to be connected to the 2 wires through which we pass the current. Electricity for the 4-H Scientist Idaho Agricultural Extension Service Bulletin 396, June, 1962 2011-11-18T03:00:30.487Z In one of the rooms of the Albany Academy, Professor Henry caused an electromagnet to sound a bell when the current was transmitted through more than a mile of wire. The Story of Great Inventions 2011-10-05T02:00:16.353Z The science of electricity and magnetism could only advance by getting regular supplies of electricity from the common electric machine or the galvanic battery and by making powerful electromagnets. How We Think 2011-09-16T02:00:18.973Z This movement may be effected by the attraction of an iron armature by an electromagnet, or by the varying magnetism of the core of the coil, or it may be effected more slowly by hand. Hertzian Wave Wireless Telegraphy 2012-01-09T03:00:20.570Z The printing of the characters is effected in various ways; sometimes by clockwork mechanism and sometimes by the direct action of an electromagnet. Inventions in the Century 2011-07-20T02:00:14.643Z A rotating electromagnet changes poles as contacts are made first one way, then the other. Electricity for the 4-H Scientist Idaho Agricultural Extension Service Bulletin 396, June, 1962 2011-11-18T03:00:30.487Z The telephone, like the telegraph, depends on the electromagnet. The Story of Great Inventions 2011-10-05T02:00:16.353Z The arc is made as large as possible by the action of a small electromagnet placed just above the gap. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z The mercury interrupter may be worked by a separate electromagnet or by the magnetism of the core of the induction coil. Hertzian Wave Wireless Telegraphy 2012-01-09T03:00:20.570Z The tables are also explanatory of the fact that mild steel has gradually replaced iron in the manufacture of dynamo electromagnets and transformer-cores. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z This is a simple way to reverse the current in the coil of the electromagnet. Electricity for the 4-H Scientist Idaho Agricultural Extension Service Bulletin 396, June, 1962 2011-11-18T03:00:30.487Z The electromagnet was needed to solve the problem. The Story of Great Inventions 2011-10-05T02:00:16.353Z The electromagnet takes the place of the crane-hook in an ordinary crane. The New Gresham Encyclopedia Volume 4, Part 2: Ebert to Estremadura 2011-04-14T02:00:56.200Z The decoherence is effected by giving the stool a tilt by means of an electromagnet. Hertzian Wave Wireless Telegraphy 2012-01-09T03:00:20.570Z Broadly speaking, the materials which are now employed in the manufacture of the cores of electromagnets for technical purposes of various kinds may be said to fall into three classes, namely, forgings, castings and stampings. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z This is done by shaping the stationary magnet around the path of the rotating electromagnet. Electricity for the 4-H Scientist Idaho Agricultural Extension Service Bulletin 396, June, 1962 2011-11-18T03:00:30.487Z Two things are needed, then, to make a dynamo: an electromagnet and a coil to turn between the poles of that magnet. The Story of Great Inventions 2011-10-05T02:00:16.353Z The other arm carries a wire coil attached to an electric circuit—in other words, an electromagnet. Weighing a kilogram: The constant gardeners 2011-01-27T10:58:13Z The collider is designed so that protons travel down the centers of powerful electromagnets that are the size of redwood trunks, which bend the particles’ paths into circles, creating a collision. A Primer on the Large Hadron Collider and Particle Physics 2010-04-04T04:10:00Z This is generally the case in the electromagnets which are employed as the field magnets in dynamo machines. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z We can also wrap wires around this circular iron and make an electromagnet of it. Electricity for the 4-H Scientist Idaho Agricultural Extension Service Bulletin 396, June, 1962 2011-11-18T03:00:30.487Z In England a coil turning between the poles of an electromagnet had been used, but the electromagnet received its current from another machine in which a steel magnet was used. The Story of Great Inventions 2011-10-05T02:00:16.353Z Only so recently as 1861 Siemens patented the device of fastening a mass of iron to one end of an electromagnet in order to increase the power of the other end. On the magnet, magnetick bodies also, and on the great magnet the earth a new physiology, demonstrated by many arguments & experiments The selector consists of two electromagnets which are bridged in series across the telephone circuit and are of very high impedance. Cyclopedia of Telephony and Telegraphy, Vol. 2 A General Reference Work on Telephony, etc. etc. Forms of Electromagnet.—The form which an electromagnet must take will greatly depend upon the purposes for which it is to be used. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z Figure 2 You have made what we call an electromagnet. Electricity for the 4-H Scientist Idaho Agricultural Extension Service Bulletin 396, June, 1962 2011-11-18T03:00:30.487Z In the differential system the current from the home battery divides into two branches passing around the coils of the electromagnet in opposite directions. The Story of Great Inventions 2011-10-05T02:00:16.353Z The vacuum tank is placed between the poles of an electromagnet, whose field bends the ion beam into a circular orbit. LRL Accelerators The 184-Inch Synchrocyclotron In this 1 is an electromagnet supplied by a constant-current battery 2 to keep the vibratory system continually in motion. Cyclopedia of Telephony and Telegraphy, Vol. 2 A General Reference Work on Telephony, etc. etc. The Magnetic Circuit.—The phenomena presented by the electromagnet are interpreted by the aid of the notion of the magnetic circuit. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z This is one of the advantages of an electromagnet. Electricity for the 4-H Scientist Idaho Agricultural Extension Service Bulletin 396, June, 1962 2011-11-18T03:00:30.487Z An electromagnet is also shown over each membrane. The Story of Great Inventions 2011-10-05T02:00:16.353Z He went without further talk to a stack of the multicolored slabs and dowels, which lay beside a neat array of what looked like conduit pipes, electromagnets, and coiled cable. The Enormous Room Instead of being driven by an electromagnet, the register brushes are placed under tension of a spring which tends at all times to draw them forward. Cyclopedia of Telephony and Telegraphy, Vol. 2 A General Reference Work on Telephony, etc. etc. A design or form of electromagnet which will be very suitable for some purposes will be useless for others. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z His practice of arming a loadstone was to be of considerable importance in the period before the invention of the electromagnet. The Natural Philosophy of William Gilbert and His Predecessors With Professor Henry's invention the electromagnet was ready for use in the dynamo. The Story of Great Inventions 2011-10-05T02:00:16.353Z On the third of them is placed an iron armature, 550 which works between the poles of an electromagnet fixed to the case, and by which the pendulum is actuated. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 5 "Clervaux" to "Cockade" The wire of the first forms part of the circuit of an electromagnet which, so long as it is energized, supports Le Bouleng�. a vertical rod called the “chronometer.” Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 3 "Chitral" to "Cincinnati" Inventors were then incited to construct powerful electromagnets as tested by the weight they could carry from their armatures. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z You slap a powerful electromagnet on her, pour on the juice, and off you go. Thin Edge In this telegraph he was using an electromagnet in the transmitter and another electromagnet in the receiver. The Story of Great Inventions 2011-10-05T02:00:16.353Z The anchor escapement of a common grandfather’s clock can be made to drive the works by means of an electromagnet, the pendulum being removed. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 5 "Clervaux" to "Cockade" In the Bashforth chronograph a platform, arranged to descend slowly alongside of a vertical rotating cylinder, carries two markers, controlled by electromagnets, which describe a double spiral on the prepared surface of the cylinder. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 3 "Chitral" to "Cincinnati" Joule, ever memorable for his investigations on the mechanical equivalent of heat, gave much attention about 1838-1840 to the construction of electromagnets and succeeded in devising some forms remarkable for their lifting power. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z It is formed by an armature carrying coils and by strong electromagnets. Letters of a Radio-Engineer to His Son In the telephone we see another use of the electromagnet. The Story of Great Inventions 2011-10-05T02:00:16.353Z All then that is necessary is to fix a piece of iron on the anchor so that its weight pulls the anchor over one way, while an electromagnet pulls the iron the other. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 5 "Clervaux" to "Cockade" The wire of the second screen conveys a current through another electromagnet which supports a much shorter rod. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 3 "Chitral" to "Cincinnati" ELECTROMAGNETISM, that branch of physical science which is concerned with the interconnexion of electricity and magnetism, and with the production of magnetism by means of electric currents by devices called electromagnets. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z Charlie fell to work at once, mounting another electromagnet beside the one he had set up, and rigging up two more X-ray bulbs beside the packing box which held the meteor. Astounding Stories, March, 1931 Dynamo, armature coil rotates in the field of an electromagnet, armature supplies current for the electromagnet as well as for the external circuit—William Siemens, Germany, 1866. The Story of Great Inventions 2011-10-05T02:00:16.353Z Impulses sent through the electromagnet will then drive the clock. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 5 "Clervaux" to "Cockade" A pillar also mounted geometrically, placed vertically in front of the carriage, carries the electromagnet style or signals and tuning-fork which can be brought into contact with the glass by means of a lever. Encyclopaedia Britannica, 11th Edition, Volume 6, Slice 3 "Chitral" to "Cincinnati" Further progress was made in 1867 when H. Wilde introduced the use of electromagnets for the field magnets. Encyclopaedia Britannica, 11th Edition, Volume 9, Slice 2 "Ehud" to "Electroscope" 2011-01-29T03:00:23.777Z He mounted a powerful electromagnet just below the meteorite, and set up an X-ray tube to bombard it with rays. ight came, and the fire of the white sun faded from the sky. Astounding Stories, March, 1931 For charging storage batteries and making electromagnets, separating water into two gases, and for running certain kinds of motors, however, the direct current is necessary. Common Science The desired action is secured by a combination of a permanent magnet and an electromagnet which is connected to the alternating current supply. The Automobile Storage Battery Its Care And Repair The current surged through the powerful electromagnet behind the plaster flattening his metal body helplessly against the wall. The Velvet Glove Under the influence of the battery, the wire-wrapped knife had become a small electromagnet. The Great Drought He manipulated the rheostat that controlled the current through the electromagnet, and continued to read his instruments. Astounding Stories, March, 1931 Notice that the circuit is completed through a little metal attachment on the base of the clapper, and that when the clapper is pulled toward the electromagnet the circuit is broken. Common Science As the current decreases, the pull of the electromagnet on the regulator armature weakens and the spring overcomes the pull of the electromagnet and closes the regulator points. The Automobile Storage Battery Its Care And Repair A powerful electromagnet, with a thin, strong wire fastened to it, to be hurled from a helix-gun. Salvage in Space Have you ever seen a small bar magnet placed within the field of attraction of a large electromagnet? Astounding Stories of Super-Science February 1930 Instead of a simple horseshoe-shaped bar, two shorter bars riveted into a plate are generally used for electromagnets of this type. How it Works Dealing in simple language with steam, electricity, light, heat, sound, hydraulics, optics, etc., and with their applications to apparatus in common use Examine the motor and see that it is made of several electromagnets which keep attracting each other around and around. Common Science As far as I'm concerned you could have your suit lined with aces and electromagnets in your boots. Deathworld In the toes, knees, and hands, were powerful electromagnets controlled by switches in the fingers of the gloves and powered by the current in the long line. The Penal Cluster Of course you have, and you have noticed that, when the north pole of the bar magnet was pointed toward the electromagnet, the bar was attracted. Astounding Stories of Super-Science February 1930 He built himself a Tesla coil, and a table with hidden AC electromagnets in it that would make a metal plate float in the air. By Proxy The making of various kinds of electromagnets and putting currents of electricity to work is becoming one of the great industries of mankind. Common Science The wheel is caused to rotate between the opposite poles of powerful electromagnets. Fragments of science, V. 1-2 To do this he placed the receiver against his ear and called to Watson, who was in the adjoining room, to start the current through the electromagnet of the corresponding transmitter. Ted and the Telephone "But in that case the magnetism of the electromagnet was so large that the polarity of the small magnet was reversed!" Astounding Stories of Super-Science February 1930 A minute later, it reappeared with a large electromagnet and a relux plate, to which were attached a huge pair of silver busbars. Islands of Space On the roof of the building they slowed with startling rapidity, held back by electromagnets under the top dressing of the roof landing, as Arcot learned later. The Black Star Passes The field strength of the electromagnets, controlled by rheostats, instantly shaped the charge into a glowing ball of fire! Tom Swift and The Visitor from Planet X "Were these transmitters and receivers made from electromagnets and strips of flat steel, as you told us the other day?" asked Ted. Ted and the Telephone However, when the bar was reversed and the south pole pointed toward the electromagnet, the bar was still attracted. Astounding Stories of Super-Science February 1930 The relux plate was set in a stand directly in front of the projector, and the big electromagnet was set up directly behind the relux plate. Islands of Space The mechanisms of modern arc-lamps perform these functions automatically by the ingenious use of electromagnets. Artificial Light Its Influence upon Civilization He found Tom setting up an experiment with a glass sphere to which were affixed six powerful electromagnets. Tom Swift and The Visitor from Planet X There is a second "graduating" electromagnet, E1, of 500 ohms resistance introduced between the sending battery, B, and the key. Scientific American Supplement, No. 443, June 28, 1884 The strongest known magnets are electromagnets, which, as we have seen, are merely coils of wire wound on an iron core. General Science The lever was returned to its original position by a spring as soon as the current through the electromagnet ceased. Harvard Psychological Studies, Volume 1 Containing Sixteen Experimental Investigations from the Harvard Psychological Laboratory. Gas-valves for remote control are actuated by gas pressure and by electromagnets. Artificial Light Its Influence upon Civilization The diaphragms were connected to a transistorized circuit designed to modulate the field current to the electromagnets. Tom Swift and The Visitor from Planet X Mr. Pritchett proposes that his apparatus shall give external evidence outside the house by ringing a gong, and by dropping a semaphore arm released by an electromagnet. Scientific American Supplement, No. 441, June 14, 1884. When one talks into a receiver, L, the voice throws into vibration a sensitive iron plate standing before an electromagnet. General Science If, now, such an electromagnet, a permanent magnet, and a pivoted armature be related to a pair of gongs as shown in Fig. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. The heater is cut out by an electromagnet when the glower goes into operation. Artificial Light Its Influence upon Civilization This almost direct consequence was perceived by Lorentz, and it led him to the new idea that radiations emitted by a body ought to be modified by the action of a strong electromagnet. The New Physics and Its Evolution On heating the bulb the duration of the glow was greatly diminished, and it could be instantly extinguished by the presence of an electromagnet. Scientific American Supplement, No. 810, July 11, 1891 As soon as the current ceases to flow, the electromagnet loses its magnetic power and becomes merely iron and wire without magnetic attraction. General Science During those experiments, he observed an iron reed to vibrate before an electromagnet as a result of another iron reed vibrating before a distant electromagnet connected to the nearer one by wires. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Suppose the line and electromagnet have together a resistance of 6 ohms, and that we have 24 small Daniell cells, each of electromotive force say 1 volt, and of internal resistance 4 ohms. Scientific American Supplement, No. 787, January 31, 1891 This is so arranged that the instant of touching of the point of screw, a, completes the electric circuit, in which an electromagnet of short thick wire is placed. Scientific American Supplement, No. 484, April 11, 1885 Anything novel in the way of science attracted their bright, active minds as an electromagnet attracts steel. The Boy Inventors' Radio Telephone The strength of any electromagnet depends upon the number of coils wound on the iron core and upon the strength of the current which is sent through the coils. General Science The diaphragms became thin iron disks, instead of membranes carrying iron; the electromagnet cores were made of permanently magnetized steel instead of temporarily magnetized soft iron, and the battery was omitted from the line. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Several times it has been proposed to increase the power of electromagnets by constructing them with intermediate masses of iron between the central core and the outside, between the layers of windings. Scientific American Supplement, No. 787, January 31, 1891 To unlock, push the button D, which act will cause the electromagnet to raise the latch C, when the bolt may be drawn and the door opened. The Boy Mechanic: Volume 1 700 Things for Boys to Do This dial carries two insulated studs, p, each electrically connected with one terminal of the coils of an electromagnet, K, whose other terminal is connected to the other pole of the battery. Scientific American Supplement, No. 481, March 21, 1885 In such an arrangement there is practically the strength of two separate electromagnets. General Science This device consists of an electromagnet having two cores, with a permanent polarizing magnet therebetween, the arrangement in this respect being the same as in an ordinary polarized bell. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Indeed, this form of electromagnet is often designed very badly, the yoke being too thin, both mechanically and magnetically, for the purpose which it has to fulfill. Scientific American Supplement, No. 787, January 31, 1891 The pendulum bob at the lower end is adjusted to swing just clear of the electromagnets. The Boy Mechanic: Volume 1 700 Things for Boys to Do Every telephone receiver and transmitter has a mouth-and ear-piece to receive or throw out the sound, a thin round sheet of lacquered metal—called a diaphragm, and an electromagnet; together they reproduce human speech. Stories of Inventors The Adventures of Inventors and Engineers The ringing of the electric bell is due to the attractive power of an electromagnet. General Science Sneak currents though small, may, when allowed to flow for a long time through the winding of an electromagnet for instance, develop enough heat to char or injure the insulation. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. I have already mentioned Hughes' researches on the form of electromagnet best adapted for rapid signaling. Scientific American Supplement, No. 787, January 31, 1891 If you are able to secure the electromagnets from a discarded electric bell they will work fine for the magnets M1 and M2. The Boy Mechanic: Volume 1 700 Things for Boys to Do In 1832, he conceived the idea of a true electric telegraph—a writing at a distance by means of the electromagnet. Samuel F. B. Morse, His Letters and Journals In Two Volumes, Volume II So long as we press the button this process continues producing what sounds like a continuous jingle; in reality the clapper strikes the bell every time a current passes through the electromagnet. General Science The sphere forming the target is out of balance, and when the latch is withdrawn from it by the action of the electromagnet it falls into the position shown in the middle cut of Fig. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Now I want particularly to ask you to guard against the idea that all these results obtained from electromagnets are equally applicable to permanent magnets of steel; they are not, for this simple reason. Scientific American Supplement, No. 787, January 31, 1891 The decomposition of water by electrolytic action was recognized and made the basis of communicating at a distance even before the days of the electromagnet. Edison, His Life and Inventions He had constructed powerful electromagnets consisting of coils of wire. The Dawn of Amateur Radio in the U.K. and Greece: a personal view This is usually done by installing at each station a local battery and a very delicate and sensitive electromagnet called the relay. General Science State how it differs from an electromagnet coil. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. For example, a copper disk or copper ring placed over the pole of a straight electromagnet so excited is violently repelled. Scientific American Supplement, No. 787, January 31, 1891 The electromagnets and other actuating mechanism cannot be seen plainly in this figure, but are produced diagrammatically in Fig. Edison, His Life and Inventions Its buzzing steel soundplate, pumped up by powerful electromagnets, was loud enough to fill an auditorium. The Hacker Crackdown, law and disorder on the electronic frontier For this reason, the field magnet is usually an electromagnet. General Science Describe an electromagnet and its function in telephony. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. He observed the throw of the galvanometer when the circuit which contained the battery and the electromagnet was opened by a key which at the same moment connected the electromagnet wires to the galvanometer. Scientific American Supplement, No. 787, January 31, 1891 A is a bar of soft iron, bent as shown, and wound around with insulated copper wire, the ends of which are connected with a battery, B, thus forming an electromagnet. Edison, His Life and Inventions Hence this portion is attracted first, the armature assumes an inclined position, maintained by a brass button, t, which prevents any adhesion between the armature and the core of the electromagnet. Scientific American Supplement, No. 360, November 25, 1882 The back and forth motion of the iron plate induces current in the electromagnet c. General Science So does an electromagnet composed of windings and Page 42 iron cores. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. His object was to find out the best form of electromagnet, the best distance between the poles, and the best form of armature for the rapid work required in Hughes' printing telegraphs. Scientific American Supplement, No. 787, January 31, 1891 In a shunt circuit with the receiving instrument he introduced electromagnets. Edison, His Life and Inventions In using a magnet for testing, it will be most satisfactory if it is an electromagnet and not of the permanent type. Oxy-Acetylene Welding and Cutting Electric, Forge and Thermit Welding together with related methods and materials used in metal working and the oxygen process for removal of carbon The sum of the information so far may be stated in other words to be how to make an electromagnet, and how to produce an induced current. Steam, Steel and Electricity The qualities of electromagnets and lamps in these respects are used to advantage by the lamp signal arrangement shown in Fig. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. It clearly is an ordinary electromagnet in that respect. Scientific American Supplement, No. 787, January 31, 1891 He had studied and experimented with electromagnets in enormous variety, and knew their peculiarities in charge and discharge, lag, self-induction, static effects, condenser effects, and the various other phenomena connected therewith. Edison, His Life and Inventions Thus Henry produced the electromagnet which was the beginning of the mastery by man of the subtle fluid. The Great Events by Famous Historians, Volume 17 An electromagnet is used instead of a permanent magnet and this is energized by a 6-volt storage battery as shown in the wiring diagram at A in Fig. The Radio Amateur's Hand Book In the case of a simple bar electromagnet, such as is shown in Fig. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Now let us apply these most important though rather intricate considerations to the practical problems of the quick working of the electromagnet. Scientific American Supplement, No. 787, January 31, 1891 Each car axle had a large iron disk mounted on and revolving with it between the poles of a powerful horseshoe electromagnet. Edison, His Life and Inventions Instead there is a deposit of magnetic impulse on the wire, which is made by connecting up an ordinary telephone transmitter with the electromagnets and talking through the coil. The Dream Doctor When the core gains the interior of the coil it becomes a veritable electromagnet, as found by Arago, having a north pole at one end and a south pole at the other. The Story of Electricity The wire used in winding magnets is, of course, an important part of the electromagnet. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Exciting this electromagnet with a certain battery, it was found that the attraction was greatest when the shoes were pushed to about 15 millimeters, or about one-quarter of the interpolar distance, apart. Scientific American Supplement, No. 787, January 31, 1891 It may be observed, parenthetically, for the benefit of the lay reader, that in telegraphy the device known as the relay is a receiving instrument containing an electromagnet adapted to respond to the weak line-current. Edison, His Life and Inventions All wires which are wound into coils, such as electromagnets, possess inductance in a greatly increased degree. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Of these by far the most important are based on its property of developing light and heat as in the electric spark, chemical action as m the voltameter, and magnetism as in the electromagnet. The Story of Electricity The principle of the differential electromagnet may be illustrated in connection with Fig. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. There must be a wider width between the poles than is desirable in electromagnets for traction. Scientific American Supplement, No. 787, January 31, 1891 Almost midway between the hopper and the bin is placed an electromagnet whose polar extension is so arranged as to be a little to one side of a stream of material falling from the hopper. Edison, His Life and Inventions Let inductive coils such as electromagnets be inserted serially in the wires of the line one by one, while conversation goes on. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. The poker has become the core of the electromagnet. The Story of Electricity For this reason it is usual in this type to so adjust the armature that its ends will actually strike against the pole pieces of the electromagnet when thrown into vibration. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. I feel almost ashamed to say those words "well known," because on the Continent everybody knows what you mean by a Hughes' electromagnet. Scientific American Supplement, No. 787, January 31, 1891 This device is known as an electromagnet, and the charging and discharging of such a magnet may, of course, be repeated indefinitely. Edison, His Life and Inventions In it, 1 is an electromagnet energized by voice currents; its varying field varies an arc between the electrodes 2-2 and 3 in a vacuum tube. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Such an electromagnet is a more powerful device than a swinging needle, and better able to actuate a mechanism. The Story of Electricity The electromagnet is of the two-coil type, and is supported on the brackets 2 and 3. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. We have already laid down the principle which will enable us to design electromagnets to act at a distance. Scientific American Supplement, No. 787, January 31, 1891 It is thus attracted toward an adjacent electromagnet when cold and is uninfluenced when hot, and as the result motion is produced. Edison, His Life and Inventions External binding posts mounted on the tail cap, as shown, were connected by heavy leading-in wires to the terminals of the electromagnet. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. In this apparatus the electromagnet, on attracting its armature, presses the paper against a revolving type wheel and receives the print of a type, so that the message can be read by a novice. The Story of Electricity These relays and other adaptations of the electromagnet will be discussed more fully later on. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Englishmen do not even know that Professor Hughes has invented a special form of electromagnet. Scientific American Supplement, No. 787, January 31, 1891 Edison's previous discovery of differential friction of surfaces through electrochemical decomposition was now adapted by him to produce motion at the end of a circuit without the intervention of an electromagnet. Edison, His Life and Inventions The matter of bringing out the terminal ends of the winding is one that has received a great deal of attention in the construction of electromagnets and coils for various purposes. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. The electromagnet attracts the armature A, and the hammer H strikes the gong; but in the act the spring S is drawn from the contact T, and the circuit is broken. The Story of Electricity In this yoke 4 is pivoted, by means of trunnion screws, the armature 5, this extending on each side of the pivot so that its ends lie opposite the free poles of the electromagnets. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. From these experimental results I pass to the special design of electromagnets for special purposes. Scientific American Supplement, No. 787, January 31, 1891 This brings us to the gist of the ingenious way in which Edison substituted the action of electrochemical decomposition for that of the electromagnet to operate a relay. Edison, His Life and Inventions The two things principally affecting the manufacture of electromagnets for telephone purposes are the number of turns in a winding and the resistance of the wound wire. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Consequently the electromagnet, no longer excited, lets the armature go, and the spring leaps back against the contact T, withdrawing the hammer from the gong. The Story of Electricity We will now consider the actual mechanical construction of the electromagnet. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. The alternate rapid reversals of the magnetism in the magnetic field of an electromagnet, when excited by alternating electric currents, sets up eddy currents in every piece of undivided metal within range. Scientific American Supplement, No. 787, January 31, 1891 This consists of an electromagnet, T, operated by a key, K, and separate battery. Edison, His Life and Inventions In performing the ordinary functions of an electromagnet it translates the energy of an electrical current into the energy of mechanical motion. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. This can readily be done by adjusting an electromagnet to drop a screen of red glass before the flame of the lamp. The Story of Electricity In telephony electromagnets frequently serve, as already stated, to perform other functions than the producing of motion by attracting or releasing their armatures. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. I may here refer to some determinations made by M. Vaschy,4 respecting the coefficients of self-induction of the electromagnets of a number of pieces of telegraphic apparatus. Scientific American Supplement, No. 787, January 31, 1891 It consisted of two dials mounted separately, each revolved by an electromagnet, so that the desired figures were brought to an aperture in the case enclosing the apparatus, as in the Laws system. Edison, His Life and Inventions Where it is desired that an electromagnet coil shall possess high impedance, it is usual to employ a laminated instead of a solid core. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. When the rate is too slow the key is closed, and a current passing through the electromagnet pulls on the pendulum, thus correcting the clock. The Story of Electricity Instead of developing the necessary magnetic field by means of electromagnets, as in the case of the ordinary dynamo, the field of the magneto generator is developed by permanent magnets, usually of the horseshoe form. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. The electromagnet, a horseshoe, lies horizontally; its poles are provided with protruding curved pins of brass. Scientific American Supplement, No. 787, January 31, 1891 The poles of the electromagnet in the local circuit are hollowed out and filled up with carbon disks or powdered plumbago. Edison, His Life and Inventions One of the easiest and most common ways of reducing reluctance in a circuit is to bend the ordinary bar electromagnet Page 148 into horseshoe form. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Behind local dials are electromagnets which, by means of an armature working a frame and ratchet wheel, move the hands forward every minute or half-minute as the current is sent from the standard clock. The Story of Electricity The two electromagnets are mounted side by side, as shown, by attaching their cores to a yoke piece 1 of soft iron. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Also let the coefficient of self-induction of the electromagnet and circuit be 6 quadrants. Scientific American Supplement, No. 787, January 31, 1891 The armature and the carbon-tipped poles of the electromagnet form part of the local circuit; and if the relay is actuated by a weak current the armature will be attracted but feebly. Edison, His Life and Inventions If the armature of the electromagnet shown in Fig. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. The current, by exciting an electromagnet, jerks the stylus, and the interval between two jerks is found from the length of the trace between them and the speed of the paper or smoked surface. The Story of Electricity This bends around back of the electromagnets and comes into close proximity to the armature 5. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Many electricians, unacquainted with Helmholtz's law, have been in the habit of accounting for this by saying that there is a lag in the iron of the electromagnet cores. Scientific American Supplement, No. 787, January 31, 1891 It will be understood that electromagnets were the ticker's actuating agency. Edison, His Life and Inventions This is a very important form of electromagnet and is largely used in telephony. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Frequently in telephony, the electromagnets are provided with more than one winding. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. By this means one end of each of the electromagnet cores is given one polarity—say north—while the armature Page 129 is given the other polarity—say south. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. Take the case of an electromagnet forming some part of the receiving apparatus of a telegraph system in which it is desired to secure very rapid working. Scientific American Supplement, No. 787, January 31, 1891 It consisted, generally speaking, of an electromagnet with relays connecting with a red and a blue lamp. Edison, His Life and Inventions Great use is made in the design of telephone circuits of the fact that the electromagnets, which accomplish the useful mechanical results in causing the movement of parts, possess the quality of impedance. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. This construction results in what is known as the tubular or iron-clad electromagnet, which is shown in section and in end view in Fig. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. The early forms of telephone receivers were of the single-pole type; that is, the type wherein but one pole of the electromagnet was presented to the diaphragm. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. It relates to the electromagnet of a Morse receiver of the pattern habitually used on the French telegraph lines. Scientific American Supplement, No. 787, January 31, 1891 Take from an ordinary relay a coil, with its iron core, half the electromagnet, so to speak, without any yoke or armature. Scientific American Supplement, No. 787, January 31, 1891 Hence the cause of the commonly received opinion among telegraph engineers that for rapid work electromagnets must have short cores. Scientific American Supplement, No. 787, January 31, 1891 The electromagnets in American patterns of telegraphic apparatus usually have shorter cores, and a relatively greater thickness of winding upon them, than those of European patterns. Scientific American Supplement, No. 787, January 31, 1891 The receiver of the Automatic Electric Page 87 Company just discussed employs but a single electromagnet by which the initial magnetization of the cores and also the variable magnetization necessary for speech reproduction is secured. Cyclopedia of Telephony & Telegraphy Vol. 1 A General Reference Work on Telephony, etc. etc. |
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