Winding of inductor coils, Physics

Assignment Help:

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.

PROGRESSIVE UNIVERSAL WINDINGS:

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.

QUALITY FACTORS OF COILS

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.


Related Discussions:- Winding of inductor coils

Evaluate the lowest possible temperature of the water, One way to keep the ...

One way to keep the contents of a garage from becoming too cold on a night when severe subfreezing temperature is forecast is to put a tub of watering the garage. Assume the mass o

Find total radiance emittance for the blackbody?, For a blackbody, the freq...

For a blackbody, the frequency at which maximum energy is emitted is 3 x 10 13 Hz:   A.  Give a wavenumber for the wavelength of the infrared emission? B.  What is the tempe

How several pounds does one gallon of water weigh, Q. How several pounds do...

Q. How several pounds does one gallon of water weigh? Answer:- One wine measure or else US gallon of water weighs 8.34 pounds. An imposing Gallon is ten pounds of water at

Electromagnetic induction, what is construction,,, principle...and working ...

what is construction,,, principle...and working of AC generator

Rotational kinematics.., A wheel is mounted on a stationary axle starts at ...

A wheel is mounted on a stationary axle starts at rest and is given the following angular acceleration a =(9-12t) (SI units)where t is the time after the wheel begins to rotate.Fin

Evaluate the height to which the center of the baton travels, A baton twirl...

A baton twirler throws a spinning baton directly upward. As it goes up and returns to the twirler's hand, the baton turns through four revolutions. Ignoring air resistance and assu

Motion in one dimension, a car with an initial speed of 24.5 km/hr accelera...

a car with an initial speed of 24.5 km/hr accelerates at a uniform rate of 0.98 m/s^2 for 5.6sec. find the final speed and displacement of the car during this time.

Explain electric potential inside hollow conducting shell, Five coulombs of...

Five coulombs of charge are placed on a thin-walled conducting shell. Once the charge has come to rest, the electric potential inside the hollow conducting shell is found to be:

Calculate the number of compton interactions per second, Suppose that we ha...

Suppose that we have a monochromatic non-diverging beam of x rays    that are incident on a slab of Pb. Inside the Pb plate there are three apertures (openings) that allow the beam

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd