The de Méritens magneto generator illustrated shows the 'ring wound' armature. As there is now only a single rotor disk, each horseshoe magnet comprises a stack of individual magnets, but acts through a pair of pole pieces.
|
|
These phonographs featured a large counterbalanced tone arm with horseshoe magnet pick-up. These types of pick- ups could also be "driven" to actually move the needle and RCA took advantage of that by designing a system of home recording that used "pre-grooved" records.
|
|
In 1840, American Charles Grafton Page passed an electric current through a coil of wire placed between the poles of a horseshoe magnet. He observed that connecting and disconnecting the current caused a ringing sound in the magnet. He called this effect "galvanic music".
|
|
183, p. 37 In a subsequent experiment with a spiral conductor, Page mounted it rigidly between the poles of a suspended horseshoe magnet. When current stopped flowing in the spiral, a tone could be heard from the magnet, which Page termed 'galvanic music'.Page, 1837c.
|
|
Taycol began with simple horseshoe magnet motors, but their real speciality was with wound fields. Most of these used a single transverse field coil mounted above the rotor. Their larger 'Marine' and 'Double Special' ranges used a dual-coil layout, with two vertical field coils mounted at the sides. A similar, although smaller and far less powerful motor, was the Meccano E15R motor.
|
|
The guitar's pickup includes individual string magnets as well as a large horseshoe magnet. Slingerland ceased making electric instruments in 1940 in order to exclusively focus on producing percussion instruments. The company remained in the Slingerland family until 1970, but continued to be a prominent drum manufacturer throughout the 1970s. After introducing the Magnum series in the late 1970s, Slingerland lost its footing, and the company folded.
|
|
A rusty-looking horseshoe magnet which causes everyone to love its owner. It is closely associated with the Shaggy Man. In The Road to Oz, he finds that being loved by everyone can be inconvenient. In Tik-Tok of Oz he reveals that Ozma has modified its powers so that it only works when it is displayed and affects only the feelings of those who see it.
|
|
The Stooges are crooked gamblers in the Old Western town of Lobo City. Eventually, they are caught cheating the residents (including an evil, tough, muscular woodcutter named Pierre) of a frontier town when Larry hid a horseshoe magnet inside his shoe. They are discovered and must escape into the woods. Now as fugitives, the Stooges have to elude the sheriff, the Stooges hunt, fish, and disguise themselves as Indians.
|
|
Joseph died in 1929 and his son Roy took over the business, and around this time adopted the (horseshoe) Magnet trade mark. In early 1948 the family business was restructured as a limited liability company, and in June 1950 a new entity called J. L. Aerated Waters Ltd. was founded to take over the assets of J. Ladd Ltd. A month later the new company was renamed "Ladds Limited".
|
|
The operating principle of electromagnetic generators was discovered in the years of 1831–1832 by Michael Faraday. The principle, later called Faraday's law, is that an electromotive force is generated in an electrical conductor which encircles a varying magnetic flux. He also built the first electromagnetic generator, called the Faraday disk; a type of homopolar generator, using a copper disc rotating between the poles of a horseshoe magnet. It produced a small DC voltage.
|
|
The operating principle of electromagnetic generators was discovered in the years 1831–1832 by Michael Faraday. The principle, later called Faraday's law, is that an electromotive force is generated in an electrical conductor which encircles a varying magnetic flux. He also built the first electromagnetic generator, called the Faraday disk, a type of homopolar generator, using a copper disc rotating between the poles of a horseshoe magnet. It produced a small DC voltage.
|
|
A "horseshoe magnet" made of alnico, an iron alloy. The magnet, made in the shape of a horseshoe, has the two magnetic poles close together. This shape creates a strong magnetic field between the poles, allowing the magnet to pick up a heavy piece of iron. Magnetic field lines of a solenoid electromagnet, which are similar to a bar magnet as illustrated below with the iron filings A magnet is a material or object that produces a magnetic field.
|
|
Dagupan previously used a seal design from 1948 to 2012 which was designed by Archbishop Mariano Madriaga. The elements of the seal includes a horseshoe magnet, a railway, a road, and a ribbon bearing the words "Sigue Dagupan". It was submitted and approved by the Philippine Heraldry Committee. Railroad and highway were added to emphasize the city's geographic location and to stress the strategic role it played to establish Dagupan as the trading post of the North.
|
|
11 year old Johnny Brent (Fox), home from school during a scarlet fever outbreak, but not making much attempt to stay isolated. He goes to the coast in Liverpool to watch his father board a ship and then spends the rest of the morning wandering around the beach. He manages to con a younger boy out of a large horseshoe magnet by trading it for an "invisible watch". The other boy's nanny is not happy with the swap.
|
|
In the years 1831–1832, Michael Faraday discovered the operating principle of electromagnetic generators. The principle, later called Faraday's law, is that an electromotive force is generated in an electrical conductor that is subjected to a varying magnetic flux, as for example, a wire moving through a magnetic field. He also built the first electromagnetic generator, called the Faraday disk, a type of homopolar generator, using a copper disc rotating between the poles of a horseshoe magnet. It produced a small DC voltage.
|
|
Bell's original box telephone: 1877 "Butterstamp" telephone handset of 1877 The first telephones consisted of a wooden box which resembled a camera. The mouthpiece was a two-inch tube that had an opening into a cavern air chamber that had in the back a 4.5 inch round plate of sheet iron. This box telephone consisted a large "U" shaped, horseshoe magnet with an iron core attached to each pole. The soft iron core attachments were wound with a spool of small gauge insulated wire.
|
|
Replica of Barkhausen's original apparatus, consisting of an iron bar with a coil of wire around it (center) with the coil connected through a vacuum tube amplifier (left) to an earphone (not shown). When the horseshoe magnet (right) is rotated, the magnetic field through the iron changes from one direction to the other, and the crackling Barkhausen noise is heard in the earphone. Magnetization (J) or flux density (B) curve as a function of magnetic field intensity (H) in ferromagnetic material. The inset shows Barkhausen jumps.
|
|
It is widely used in many other alloys, including nickel brasses and bronzes and alloys with copper, chromium, aluminium, lead, cobalt, silver, and gold (Inconel, Incoloy, Monel, Nimonic). A "horseshoe magnet" made of alnico nickel alloy. Because it is resistant to corrosion, nickel was occasionally used as a substitute for decorative silver. Nickel was also occasionally used in some countries after 1859 as a cheap coinage metal (see above), but in the later years of the 20th century, it was replaced by cheaper stainless steel (i.e.
|
|
Telegraphy pre-dated telephony and magnetos were used to drive some of the early printing telegraph instruments. Manual telegraphy with keys and reception by either a needle instrument or a syphon recorder could be powered by batteries. The later automatic and printing instruments, such as the Wheatstone ABC telegraph, required greater currents that could be delivered by a hand-cranked magneto. A hand-crank was used to rotate a belt drive that increases the rotational speed of an armature with a pair of coils between the poles of a stationary horseshoe magnet.
|
|
A "horseshoe magnet" made of Alnico 5, about 1 in high. The metal bar (bottom) is a keeper. A magnet keeper, also known historically as an armature, is a bar made from magnetically soft iron or steel, which is placed across the poles of a permanent magnet to help preserve the strength of the magnet by completing the magnetic circuit; it is important for magnets that have low magnetic coercivity, such as alnico magnets (0.07T). Keepers also have a useful safety function, as they stop external metal being attracted to the magnet.
|
|
When placed between the poles of a powerful horseshoe magnet, this simple copper block produced many kilowatts of microwave signals, revolutionizing radar. After the early 1940 invention of the cavity magnetron, which produced microwaves at around 10 cm, all of the British forces began development of radars using these devices. Among these were the Air Ministry teams who had developed AI and ASV turned their attention to AIS, the S standing for "senitmetric". Tests in April 1941 with early lash-up devices against showed they could detect semi-submerged submarines at several miles range.
|
|
This was made of two blocks of wood, one of which had a hole in it for the two inch round converging mouthpiece designed by Peirce. The other block of wood supported a horseshoe magnet made of two toy magnets. It had a sheet metal plate on top that was just touching an iron rod with a spool of small gauge insulated wire to pick up voice sounds. The pattern of electrical currents generated by the spool of wire related to a person's voice spoken into the mouthpiece.
|
|
The first commercially successful type of electrical phonograph pickup was introduced in 1925. Although electromagnetic, its resemblance to later magnetic cartridges is remote: it contained a bulky horseshoe magnet and employed the same imprecisely mass- produced single-use steel needles which had been standard since the first crude disc record players appeared in the 1890s. Its tracking weight was specified in ounces, not grams. This early type of magnetic pickup completely dominated the market well into the 1930s, but by the end of that decade it had been superseded by a comparatively lightweight piezoelectric crystal pickup type.
|
|
The only practical limits were based on the required frequency and desired physical size of the tube. Developed using common lab equipment, the first magnetron consisted of a copper block with six holes drilled through it to produce the resonant loops, which was then placed in a bell jar and vacuum pumped, which was itself placed between the poles of the largest horseshoe magnet they could find. A test of their new cavity magnetron design in February 1940 produced 400 watts, and within a week it had been pushed over 1.000 watts. The design was then demonstrated to engineers from GEC, who were asked to try to improve it.
|
|
A coronal cloud is released when a solar flare becomes a coronal mass ejection; the coronal cloud often contains more radioactive particles than the mass ejection itself. A coronal mass ejection occurs when a solar flare becomes so hot that it snaps and breaks in two, becoming a "rope" of heat and magnetism that stretches between two sunspots. The resulting coronal mass ejection can be compared to a horseshoe magnet, the sunspots being the poles and the oscillating magnetic connector the handle. Coronal mass ejections typically do not last very long, because they cool down as the coronal cloud of gas is released and begins to hurtle away from the Sun.
|
|
The idea of using a grid for control was patented by Lee de Forest, resulting in considerable research into alternate tube designs that would avoid his patents. One concept used a magnetic field instead of an electrical charge to control current flow, leading to the development of the magnetron tube. In this design, the tube was made with two electrodes, typically with the cathode in the form of a metal rod in the center, and the anode as a cylinder around it. The tube was placed between the poles of a horseshoe magnet arranged such that the magnetic field was aligned parallel to the axis of the electrodes.
|
|
The Charlie Christian pickup, as the bar-style pickup of the early ES-150 models came to be known, was a departure from previous pickups. Earlier pickups featured either a horseshoe magnet that arched over the strings (as found on the Rickenbacker A-22 "Frying Pan"), or a static coil through which a magnet passed, the magnet being vibrated by the guitar's bridge (a design used by former Gibson employee Lloyd Loar on his Vivi-Tone guitar). The Charlie Christian pickup consists of a coil of copper wire wound around a black plastic bobbin. The coil has a rectangular hole in its center, and the coil and bobbin fit around a chrome-plated steel blade polepiece.
|
|
Follow-up studies had noted the ability of the magnetron to create small levels of microwaves under certain conditions, but only halting development had taken place along these lines. By combining the magnetron concept with resonator loops created by drilling holes in solid copper, an idea from W. W. Hansen's work on klystrons, the two constructed a model version of what they called the resonant cavity magnetron. They placed it inside a glass enclosure evacuated with an external vacuum pump, and placed the entire assembly between the poles of a powerful horseshoe magnet, which caused the electrons to bend around into a circular path. Trying it out for the first time on 21 February 1940, it immediately began producing 400 W of 10 cm (3 GHz) microwaves.
|
|
The first AC motor in the world of Italian physicist Galileo Ferraris Drawing from U.S. Patent 381968, illustrating principle of Tesla's alternating current motor Alternating current technology was rooted in Michael Faraday's and Joseph Henry's 1830–31 discovery that a changing magnetic field can induce an electric current in a circuit. Faraday is usually given credit for this discovery since he published his findings first. In 1832, French instrument maker Hippolyte Pixii generated a crude form of alternating current when he designed and built the first alternator. It consisted of a revolving horseshoe magnet passing over two wound-wire coils. Because of AC's advantages in long- distance high voltage transmission, there were many inventors in the United States and Europe during the late 19th century trying to develop workable AC motors.
|
|
An 1842 diagram of Barlow's wheel Model with two wheels in series, manufactured in 1845 for educational use Barlow's wheel was an early demonstration of a homopolar motor, designed and built by English mathematician and physicist, Peter Barlow in 1822.on Peter Barlow in the Encyclopedia of geomagnetism and Paleomagnetism By David Gubbins, Emilio Herrero-Bervera , (pp 44) It consists of a star-shaped wheel free to turn suspended over a trough of the liquid metal mercury, with the points dipping into the mercury, between the poles of a horseshoe magnet. A DC electric current passes from the hub of the wheel, through the wheel into the mercury and out through an electrical contact dipping into the mercury. The Lorentz force of the magnetic field on the moving charges in the wheel causes the wheel to rotate.
|
|
In 1824, the French physicist François Arago formulated the existence of rotating magnetic fields using a rotating copper disk and a needle, termed Arago's rotations. English experimenters Charles Babbage and John Herschel found they could induce rotation in Arago's copper disk by spinning a horseshoe magnet under it with English scientist Michael Faraday later attributing the effect to electromagnetic induction.W. Bernard Carlson, Tesla: Inventor of the Electrical Age, Princeton University Press - 2013, pages 52-54 In 1879 English physicist Walter Baily replaced the horseshoe magnets with four electromagnets and, by manually turning switches on and off, demonstrated a primitive induction motor.W. Bernard Carlson, Tesla: Inventor of the Electrical Age, Princeton University Press - 2013, page 55 Practical application of a rotating magnetic field in an AC motor is generally attributed to two inventors, the Italian physicist and electrical engineer Galileo Ferraris, and the Serbian-American inventor and electrical engineer Nikola Tesla.
|
|