Ferrite core
Encyclopedia
A ferrite
core is a structure on which the windings of electric transformer
s and other wound components such as inductor
s are formed. It is used for its properties of high magnetic permeability
coupled with low electrical conductivity (which helps prevent eddy current
s).
There are two broad applications for ferrite cores which differ in size and frequency of operation: signal transformers are of small size and higher frequencies, power transformers are of large size and lower frequencies. Cores can also be classified by shape: there are toroidal
cores, shell cores, cylindrical cores, and so on.http://www.mag-inc.com/products/ferrite-cores
The ferrite cores used for power transformers are working in the range of low frequencies (1 to 200 kHz usually) and are quite big in size, can be toroidal, or shell or C shape and are useful in all kinds of switching
electronic devices (especially power supplies from 1 watt to 1000 watts maximum, since more powerful applications are usually out of range of ferritic single core and required grain oriented laminations cores).
The ferrite cores used for signals have a range of applications from 1 kHz to many MHz, perhaps as much as 300 MHz, and have found their main application in electronics.
, a simple form of non-volatile random access memory, which was at one time the dominant form of computer random access memory. The name "core" was derived from the term for the magnetic core of a transformer
. Each memory core can be thought of as a special-purpose tiny transformer with the two address lines as the primary and the sense winding (wire) as the secondary; however it differs from an ordinary transformer in that the output depends on the magnetic state of the core.
Although computer memory long ago moved to silicon chip
s, memory is still occasionally called "core." This is most obvious in the naming of the core dump
, which refers to the contents of memory recorded at the time of a program error.
Ferrite (magnet)
Ferrites are chemical compounds consisting of ceramic materials with iron oxide as their principal component. Many of them are magnetic materials and they are used to make permanent magnets, ferrite cores for transformers, and in various other applications.Many ferrites are spinels with the...
core is a structure on which the windings of electric transformer
Transformer
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
s and other wound components such as inductor
Inductor
An inductor is a passive two-terminal electrical component used to store energy in a magnetic field. An inductor's ability to store magnetic energy is measured by its inductance, in units of henries...
s are formed. It is used for its properties of high magnetic permeability
Permeability (electromagnetism)
In electromagnetism, permeability is the measure of the ability of a material to support the formation of a magnetic field within itself. In other words, it is the degree of magnetization that a material obtains in response to an applied magnetic field. Magnetic permeability is typically...
coupled with low electrical conductivity (which helps prevent eddy current
Eddy current
Eddy currents are electric currents induced in conductors when a conductor is exposed to a changing magnetic field; due to relative motion of the field source and conductor or due to variations of the field with time. This can cause a circulating flow of electrons, or current, within the body of...
s).
There are two broad applications for ferrite cores which differ in size and frequency of operation: signal transformers are of small size and higher frequencies, power transformers are of large size and lower frequencies. Cores can also be classified by shape: there are toroidal
Toroidal inductors and transformers
Toroidal inductors and transformers are electronic components, typically consisting of a circular ring-shaped magnetic core of iron powder, ferrite, or other material around which wire is coiled to make an inductor. Toroidal coils are used in a broad range of applications, such as high-frequency...
cores, shell cores, cylindrical cores, and so on.http://www.mag-inc.com/products/ferrite-cores
The ferrite cores used for power transformers are working in the range of low frequencies (1 to 200 kHz usually) and are quite big in size, can be toroidal, or shell or C shape and are useful in all kinds of switching
Switching
LAN switching is a form of packet switching used in local area networks. Switching technologies are crucial to network design, as they allow traffic to be sent only where it is needed in most cases, using fast, hardware-based methods.- Layer 2 switching :...
electronic devices (especially power supplies from 1 watt to 1000 watts maximum, since more powerful applications are usually out of range of ferritic single core and required grain oriented laminations cores).
The ferrite cores used for signals have a range of applications from 1 kHz to many MHz, perhaps as much as 300 MHz, and have found their main application in electronics.
Magnetic core memory
Ferrite rings, or "cores", were used in the 1950s, 60s and early 70s as the individual storage elements of magnetic core memoryMagnetic core memory
Magnetic-core memory was the predominant form of random-access computer memory for 20 years . It uses tiny magnetic toroids , the cores, through which wires are threaded to write and read information. Each core represents one bit of information...
, a simple form of non-volatile random access memory, which was at one time the dominant form of computer random access memory. The name "core" was derived from the term for the magnetic core of a transformer
Transformer
A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
. Each memory core can be thought of as a special-purpose tiny transformer with the two address lines as the primary and the sense winding (wire) as the secondary; however it differs from an ordinary transformer in that the output depends on the magnetic state of the core.
Although computer memory long ago moved to silicon chip
Silicon Chip
Silicon Chip is an Australian electronics magazine. It was started in November, 1987 by Leo Simpson. Following the demise of Electronics Australia, it is the only hobbyist-related electronics magazine remaining in Australia.- Magazine :...
s, memory is still occasionally called "core." This is most obvious in the naming of the core dump
Core dump
In computing, a core dump consists of the recorded state of the working memory of a computer program at a specific time, generally when the program has terminated abnormally...
, which refers to the contents of memory recorded at the time of a program error.
See also
- BalunBalunA balun is a type of electrical transformer that can convert electrical signals that are balanced about ground to signals that are unbalanced , and the reverse. They are also often used to connect lines of differing impedance...
- Ferrite beadFerrite beadA ferrite bead is a passive electric component used to suppress high frequency noise in electronic circuits. It is a specific type of electronic choke. Ferrite beads employ the mechanism of high dissipation of high frequency currents in a ferrite to build high frequency noise suppression devices...
- Ferrite (magnet)Ferrite (magnet)Ferrites are chemical compounds consisting of ceramic materials with iron oxide as their principal component. Many of them are magnetic materials and they are used to make permanent magnets, ferrite cores for transformers, and in various other applications.Many ferrites are spinels with the...
- Ferrite (iron)Ferrite (iron)Ferrite or alpha iron is a materials science term for iron, or a solid solution with iron as the main constituent, with a body centred cubic crystal structure. It is the component which gives steel and cast iron their magnetic properties, and is the classic example of a ferromagnetic material...
- Magnetic coreMagnetic coreA magnetic core is a piece of magnetic material with a high permeability used to confine and guide magnetic fields in electrical, electromechanical and magnetic devices such as electromagnets, transformers, electric motors, inductors and magnetic assemblies. It is made of ferromagnetic metal such...
- Toroidal inductors and transformersToroidal inductors and transformersToroidal inductors and transformers are electronic components, typically consisting of a circular ring-shaped magnetic core of iron powder, ferrite, or other material around which wire is coiled to make an inductor. Toroidal coils are used in a broad range of applications, such as high-frequency...
- Zinc ferriteZinc ferriteZinc ferrites are a series of synthetic inorganic compounds of zinc and iron with the general formula of ZnxFe3-xO4. Zinc ferrite compounds can be prepared by aging solutions of Zn2, Fe3, and triethanolamine in the presence and in the absence of hydrazine, or reacting iron oxides and zinc oxide...