Сымының оралмалы түрінен жасалған электромагнит - Соленоид

Type of electromagnet formed by a coil of wire
the electromagnet

A solenoid ('/s//oʊ//l//ə//n//ɔɪ//d/) is a type of electromagnet formed by a helical coil of wire whose length is substantially greater than its diameter, which generates a controlled magnetic field. The coil can produce a uniform magnetic field in a volume of space when an electric current is passed through it. André Marie Ampère coined the term solenoid in 1823, having conceived of the device in 1820. The helical coil of a solenoid does not necessarily need to revolve around a straight line axis; for example, William Sturgeon's electromagnet of 1824 consisted of a solenoid bent into a horseshoe shape (similarly to an arc spring). Solenoids provide magnetic focusing of electrons in vacuums, notably in television camera tubes such as vidicons and image orthicons. Electrons take helical paths within the magnetic field. These solenoids, focus coils, surround nearly the whole length of the tube.

Within the category of finite solenoids, there are those that are sparsely wound with a single pitch, those that are sparsely wound with varying pitches (varied pitch solenoid), and those with varying radii for different loops (non cylindrical solenoids). They are called irregular solenoids. They have found applications in different areas, such as sparsely wound solenoids for wireless power transfer, varied pitch solenoids for magnetic resonance imaging (MRI), and non cylindrical solenoids for other medical devices. The calculation of the intrinsic inductance and capacitance cannot be done using those for the conventional solenoids, i. e. the tightly wound ones. New calculation methods were proposed for the calculation of intrinsic inductance(codes available at ) and capacitance. (codes available at )