Winding of inductor coils, Physics

Formers used for winding coils are ceramic or glass, because they are stable. Copper wire with silver plating is used up to 50 M Hz. Lit wire produces lower RF resistance than solid copper but it is effective below 2MHz. Above this frequency , RF currents flow through outside conductors of stranded wire. At these frequencies, universal winding is used to reduce self capacitance. In this winding, the wire is oscillated from side to side as the coil is wound.

HONEY COMB COILS: These windings are relatively widely spaced and turns per layer give honey comb appearance.


It is similar to universal winding except this instead of spilling back and forth in same area, the spiralling also progresses along the former. With this type of winding, it is possible TO HAVE HIGH PERMEABILITY in tuned inductors.


It is figure of merit of coil.

Q = XL/R = tanφ

 Q is dependent upon frequency. If Q is high, then the sensitivity of circuit is good.

Choice of size of wire: For audio frequencies, standard wire gives good response. At higher frequencies, it is desirable to use many standards to have high Q. Cost increases with more standards.

CHOICE OF WIRE INSULATION: The insulators control the spacing between wires and winding size. It is necessary to select insulators with low dielectric losses. Enamel coated multi stand wires insulated with flannel of silk, cotton, glass, etc.

Choice of formers: The size of former is decided by space limitation, winding size, etc. The material used for the former should be strong, dimensionally stable with temperature changes and electrically good but fragile and costly. Peonies are less costly but vary widely in their electrical properties. In transmitter coils, ceramic formers are used.

Choice of finish: Wax varnishes or lacquers are used for final finish to make them mechanically and electrically stable.

Choice of shielding: To prevent undesirable coupling between inductors, it is necessary to use a shield on it. Shield is a conducting material, copper or aluminium. Aluminium is less costly. As the shield is not a perfect conductor, losses add to the losses in inductor.

Coupling of coils: To obtain close coupling, second winding is wound is continuation with first winding, separated by a layer of tape. For loose coupling, winding are placed apart on the same former or placed side by side with ferrite rods.

Posted Date: 7/9/2012 6:59:12 AM | Location : United States

Related Discussions:- Winding of inductor coils, Assignment Help, Ask Question on Winding of inductor coils, Get Answer, Expert's Help, Winding of inductor coils Discussions

Write discussion on Winding of inductor coils
Your posts are moderated
Related Questions

A 2400-kg satellite is in a circular orbit around a planet. The satellite travels with a constant speed of 6.67x10 3 m/s. What is the acceleration of the satellite? Determine the m

An approximate equation for the velocity distribution in a rectangular channel with turbulent flow is where umax is the velocity at the surface, y is the distance from the

Does a piece of glass reflect more light than a piece of paper?

Q. An X-ray diffraction of a crystal gave a closest line at an angle of 6o27'. If the wavelength of X-ray is 0.58Ao, find the distance between the two cleavage planes. 2d Sinθ

8. System is shown in the figure. Assume that cylinder remain is contact with the two wedges. Find the speed of cylinder at the given instant cylinder

Explain the Lenz Law An induced current always flows in a direction so that its electromagnetic field opposes the change in magnetic flux producing it. This is embodied in the

Question: A person is doing effort to locate the image of an object of a plane mirror by means of a ray-tracing diagram. The person draws a ray by the object which strikes the

Bone cancer -  A portion of the skeleton being destroyed by cancer will be trying to rebuild itself and will take up more or many elements than normal bone. - The blood is injecte

Electric Current: Electric current may be described as the rate of flow of charge. I=q/T Where, I = electric current q = charge T = time The unit of current i