Inductors, Physics

Inductors:

Coils which are used for their opposition to current change in a circuit are known as inductors or chokes.

CONSTRUCTION

Inductors with an air core have small inductance values and are used at high frequencies within radio tuning circuits, or as r.f. chokes to stop radio frequency currents taking certain paths in circuits. Coils for use at high frequency are made of Litz wire which consists of several thin copper wires insulated from each other.

Materials based on iron are used where a large inductance is required. Iron increases the strength of the magnetic field several hundred times. Silicon steel and nickel iron are used at frequencies up to 20kHz.

Iron cores are laminated. The laminations reduce the conversion of electrical energy to heat by making it difficult for currents in the coil to induce currents in the core. These induced currents are called ‘eddy currents' because they flow in circles through the iron core. If the laminations are at right angles to the plane of the coil windings, the core offers a large resistance to the eddy currents.

Iron based cores can be used at high frequencies if the material is in the form of a powder which has been coated with an insulator and pressed together.

Ferrite cores consist of ferric oxide combined with other oxides such as nickel oxide and may also be used at high frequencies.

Iron dust and ferrite cores increase the inductance of a coil considerably. For example, an air cored inductor of 1mH could be increased to 400mH by fitting a ferrite core. These cores also have a high resistance, thereby reducing eddy currents.

Posted Date: 9/13/2012 6:21:50 AM | Location : United States







Related Discussions:- Inductors, Assignment Help, Ask Question on Inductors, Get Answer, Expert's Help, Inductors Discussions

Write discussion on Inductors
Your posts are moderated
Related Questions
High temperatures and pressures are given for the following power plants. ISU co-generation:   400 psi, 750F City of Ames with RDF:   700 psi, 850F Super-critical power pl

What are the safety terms to be inspected on Rotary Junction Box? Ans: Safety terms to be checked on rotary junction box are full tightness of all terminal connections, main

HOW CAN A PURE SPECRUM BE PRODUCED IN THE LABOLATORY

Core type Transformers:   in this type of transformer the windings enclose the core (fig .given below).  Both the windings are separated and half of every winding is placed on ever

1 OHM: If a potential difference of 1 volt is applied across the ends of a conductor and the resulting current flowing by the conductor is 1 ampere, the resistance of the condu

With the help of a neat and labelled diagram, describe the underlying principle and working of a moving coil galvanometer. What is the function of? (i) Uniform radial field

Gravitational Field inside a Spherical Shell In this problem we prove that the gravitational field inside a thin spherical shell of finitemass is zero. By extension, the field

Suppose the sides of a closed polygam represent vector arrangend head to tail rule , what is sum of these vectors ?

(i) It having of district bright bands. (ii)It is given by an excited source in molecular state. (iii) E.g. Spectra of molecular NH 3 , CO, H 2 etc.

Can a contour map explain a cause and effect relationship among three variables?