
	Where results make sense

Topic: Skin effect

Related Topics

Current (electricity)

RF shielding

Ground loop (electricity)

Ground (electricity)

Faraday cage

Transformer

Frequency

Electrostatic shielding

Conductor (material)

Super low frequency

Resistor

Ground constants

Electromagnetic radiation

Skin

Virtual ground

In the News (Wed 11 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Compact Skin Effect Circuit
		The skin effect has been extensively studied, although many methods treat the skin effect at high frequencies only, failing to predict the properties of transmission lines at low frequencies.
		Skin effect lumped circuit models in which the elements are frequency independent have been used [1-3], but tend to produce very large ladder circuits.
		The equivalent circuit accurately models the skin effect in circular cross section conductors up to a frequency corresponding to a 100 skin depth radius conductor.
	weewave.mer.utexas.edu /MED_files/MED_research/Intrcncts/Skin_Effect_Ldr/MTT_96_skn_ldr.html (0 words)

	Skin Effect
		Skin effect is the tendency for high-frequency currents to flow on the surface of a conductor.
		Proximity effect is the tendency for current to flow in other undesirable patterns---loops or concentrated distributions---due to the presence of magnetic fields generated by nearby conductors.
		Where skin effect would also be a problem, more complex litz constructions can be used to ensure equal strand currents.
	www.dartmouth.edu /~sullivan/litzwire/skin.html (580 words)

	Method of making a heating device for utilizing the skin effect of alternating current - Patent 4436565
		In a typical skin effect heating system, however, the insulated power cable normally lies on the bottom of the heat tube and is therefore, in reality, eccentrically positioned with respect to the outer conductor (the heat tube).
		In fabricating a skin effect heating system, the heat tube is generally fastened or welded, to the pipeline as it is assembled.
		In relatively long skin effect heating systems (in the order of 5 miles or more), if the shield layer is not periodically grounded to the heat tube, the potential between the shield 36 and the heat tube 14 can be significant due to the impedance in the cable and the tube.
	www.freepatentsonline.com /4436565.html (6308 words)

	skin effect - a definition from Whatis.com
		Skin effect is a tendency for alternating current (AC) to flow mostly near the outer surface of a solid electrical conductor, such as metal wire, at frequencies above the audio range.
		The main problem with skin effect is that it increases the effective resistance of a wire for AC at moderate to high frequencies, compared with the resistance of the same wire at direct current (DC) and low AC frequencies.
		The skin effect causes virtually all of the current to flow on the outside of the vehicle as it passes from cloud to ground.
	whatis.techtarget.com /definition/0,,sid9_gci541369,00.html (420 words)

	Some Skin Effect Notes
		The skin effect is the description given to the phenomenon where electromagnetic fields (and therefore the current) decay rapidly with depth inside a good conductor.
		The skin depth in copper is about.005 centimeters for the 160 meter band,.002 centimeters for the 20 meter band,.001 centimeters for the 6 meter band, and.0003 centimers for the 70 centimeter band.
		The main effect on the form of the fields inside the conductor is governed by the shape of the conductor.
	fermi.la.asu.edu /w9cf/skin/index.html (977 words)

	Spartanburg SC \| GoUpstate.com \| Spartanburg Herald-Journal (Site not responding. Last check: )
		The skin effect is the tendency of an alternating electric current (AC) to distribute itself within a conductor so that the current density near the surface of the conductor is greater than that at its core.
		The skin effect causes the effective resistance of the conductor to increase with the frequency of the current.
		The effect was first described in a paper by Horace Lamb in 1883 for the case of spherical conductors, and was generalized to conductors of any shape by Oliver Heaviside in 1885.
	www.goupstate.com /apps/pbcs.dll/section?category=NEWS&template=wiki&text=skin_effect (582 words)

	Skin Depth - Microwave Encyclopedia - Microwaves101.com (Site not responding. Last check: )
		Skin depth is one of the most fundamental issues in microwave engineering, but it also affects lower frequencies, even 60 cycle AC power.
		Skin depth is a measure of how far electrical conduction takes place in a conductor, and is a function of frequency.
		At RF frequencies, the effect that conductor thickness has on its conductance is nonlinear (actually, a negative exponential!) There is a limitation on the conductance that you can achieve, and increasing the thickness of precious metals to reduce losses RF can be a waste of money if you don't know what you are doing.
	www.microwaves101.com /encyclopedia/skindepth.cfm (1190 words)

	Oilfield Glossary: Term 'skin effect'
		In an induction log, the skin effect causes a reduction of the R-signal (in-phase) and an increase in the X-signal (out-of-phase) at the receiver.
		The skin effect is termed positive if there is an increase in pressure drop, and negative when there is a decrease, as compared with the predicted Darcy pressure drop.
		A positive skin effect indicates extra flow resistance near the wellbore, and a negative skin effect indicates flow enhancement near the wellbore.
	www.glossary.oilfield.slb.com /Display.cfm?Term=skin%20effect (233 words)

	Skin Aging
		Skin biopsy specimens were taken from 29 postmenopausal women who had not been given hormone replacement therapy and from 26 women who had been treated with oestrogen and testosterone implants for two to 10 years.
		The protective effect of glycolic acid was a 20% reduction of skin tumor incidence, a 55% reduction of tumor multiplicity (average number of tumors/mouse), and a 47% decrease in the number of large tumors (larger than 2 mm).
		Photoaged skin displays prominent alterations in the cellular component and the extracellular matrix of the connective tissue with an accumulation of disorganized elastin and its microfibrillar component fibrillin in the deep dermis and a severe loss of interstitial collagens, the major structural proteins of the dermal connective tissue.
	www.lef.org /protocols/abstracts/abstr-099.html (9862 words)

	Re: Litz wire and the skin effect (Site not responding. Last check: )
		Skin effect arises out of the electrodynamic forces in the conductor that drive current flow to the conductor surface.
		Proximity effect arises out of the EM forces on one turn of a coil caused by the current flow in all the other turns of a coil.
		Proximity effect acts to drive the current from the whole surface of the conductor to a small region of the surface of the conductor.
	www.midnightscience.com /_web/000017ba.htm (146 words)

	Science Fair Projects - Skin effect
		The skin effect is the tendency of an alternating electric current to distribute itself within a conductor so that the current density near the surface of the conductor is greater than that at its core.
		The skin effect has practical consequences in the design of electrical power transmission and distribution, and in radio-frequency and microwave circuits.
		A type of cable called litz wire (from the German Litzendraht, woven wire) is used to mitigate the skin effect for frequencies of a few kilohertz to about one megahertz.
	www.all-science-fair-projects.com /science_fair_projects_encyclopedia/Skin_effect (580 words)

	Skin effect (Site not responding. Last check: )
		Taser officials say there are two different skin effects and Faraday Shield concepts: one that applies to electrical engineering and one that applies to biomedicine.
		The skin effect is calculated by a mathematical equation that applies to the way alternating current flows on the surface of an electrical conductor.
		Taser officials acknowledge that there is room for scientific debate on the skin effect and how it applies to Taser, saying it is "not critical" to the overall safety of the stun gun.
	www.azcentral.com /specials/special43/articles/0304taserissue2-ON.html (373 words)

	Modeling Skin Effect - Fall 1997
		Skin effect is the phenomenon where the apparent resistance of a wire increases as the frequency increases.
		where e is the skin depth, res is the resistivity, f is the frequency, and km is the relative permeability.
		DCres is the DC resistance, res is the resistivity of the material, km is the relative permeability, and rad is the radius of the wire.
	www.spectrum-soft.com /news/fall97/skin.shtm (1357 words)

	Mike Holt's Code Forum: ampacity
		Skin effect is a function of diameter, spacing, and frequency.
		So skin effect may be negligible, but most of the 60hz current still travels on the outter surface of the wire.
		Skin effect is caused by the unequal inductance in a conductor, that is why spacing (proximity to it's return conductor) and frequency are factors.
	www.mikeholt.com /cgi-bin/codeforum/ultimatebb.cgi?ubb=print_topic;f=3;t=001906 (2588 words)

	Skin Effect
		Skin effect is a physical phenomenon that relates to the limited penetration into a conductor of an RadioFrequent signal according to its frequency.
		A serious effect of the skin effect is the virtually decreasing cross-section area of the cable which is conducting the current: assume a cable with a diameter of 1 square inch.
		The skin effect is totally negligible at frequencies lower then 50Khz and a car system is powered with DC, so in a car you don’t have to fear the skin effect.
	diyaudiocorner.tripod.com /skin.htm (1378 words)

	Skin, Eddy, and Proximity…All Summed Up
		Skin, Eddy, and Proximity…All Summed Up The simple case of a conductor carrying current can be used to demonstrate and compute the adverse effects that all circuits are exposed to known as skin, eddy, and proximity effects.
		Skin depth is defined as the distance from the surface to where the current density is1/e times the surface current density.
		In circuit components such as circuit boards and magnetic devices, special attention has to be given to these effects minimizing their high frequency adverse effects.
	www.gbint.com /Files/Apps/Skin/skin.htm (508 words)

	Model Gallery : Skin Effect in Wire
		This example demonstrates the skin effect in electromagnetic applications.
		The model is solved twice at a frequency of 50 Hz, once with a copper wire and once with an aluminum core leaving with a thin copper shell.
		The skin effect is clearly seen in this plot of current density in the z-direction.
	www.comsol.com /showroom/gallery/79.php (95 words)

	Skin Care: Acne
		Rosacea is a long lasting, non-scarring skin condition of the face that is often misdiagnosed as adult acne.
		Different gentle skin cleansers are available for acne, there are several types of mild cleansers that you may use if your skin is irritated or aggravated...
		Skin Camouflage is a useful cosmetic for covering skin defects.
	www.skincareguide.com /acne.html (0 words)

	Skin Effect Relevance in Speaker Cables — Audioholics Home Theater Reviews and News
		While Skin Effect is a real world problem in high frequency applications such as RF Power and Transmission, it is negligible at audio frequencies as I will demonstrate in this article based on fundamental engineering and scientific principles.
		It is the tendency of alternating current to flow near the surface of a conductor, thereby restricting the current to a small part of the total cross-sectional area and increasing the resistance to the flow of current.
		Note: The skin effect is caused by the self-inductance of the conductor, which causes an increase in the inductive reactance at high frequencies, thus forcing the carriers, i.e., electrons, toward the surface of the conductor.
	www.audioholics.com /education/cables/skin-effect-relevance-in-speaker-cables (0 words)

	Skin Effect and cable impedance
		This term is probably more useful that ‘skin effect’ as it acts as a reminder that the effects arise due to the fields internal to the conductor.
		Hence when the strands are thin but in electrical contact with their neighbours we can expect the effect of internal impedance to be similar to that of a solid wire of a diameter similar to the bundle of strands.
		Thus the main electronic effect of using a bundle of strands is to dilute the effective conductivity and lower its apparent value.
	www.st-andrews.ac.uk /~jcgl/Scots_Guide/audio/skineffect/page1.html (1496 words)

	Modeling skin effect in Spice - 9/28/2006 - EDN (Site not responding. Last check: )
		Skin effect involves the interplay between flux linkages and currents in and on conductors.
		This situation results in an apparent increase in resistance of the conductor because more of the current is concentrated near the surface and edges of the conductor, and it also causes the effective inductance of the conductor to decrease as frequency increases.
		Both the skin effect's attenuation and the time of arrival of the high-frequency components can dramatically corrupt the signal and lead to a nearly closed eye pattern.
	www.edn.com /article/CA6372836.html (1670 words)

	The basics of 400-Hz power systems.
		For example, the skin effect of a 4/0 AWG aluminum conductor is less than that of a same sized copper conductor.
		Proximity effect is the distortion of current distribution caused by the induction between the currents in conductors.
		In general, proximity effect is directly proportional to the magnitude of current and inversely proportional to the distance between conductors.
	bg.ecmweb.com /ar/electric_basics_hz_power (745 words)

	Caffeine May Prevent Skin Cancer
		The effect on mice exposed to ultraviolet radiation was dramatic.
		These common skin cancers often appear in older people who spent too much time in the sun in their youth.
		I think the point of this study is that caffeine may work against a kind of skin cancer that is not as deadly as melanoma.
	www.webmd.com /content/article/50/40296.htm (647 words)

	Skin effect - Glasgledius (Site not responding. Last check: )
		The skin effect is the tendency of a high-frequency electric current to distribute itself in a conductor so that the current density near the surface of the conductor is greater than that at its core.
		The change in resistance due to the skin effect is quantified by calculating the skin depth σ.
		A type of cable called litz wire (from the German Litzendraht, woven wire) is used to mitigate the skin effect.
	www.glasglow.com /E2/sk/Skin_effect.html (198 words)

	Marc's Technical Pages: Power Quality Symptoms and Solutions - Skin effect
		There are two types of skin effect and they are easily confused until the "mechanics" of each are clearly understood.
		This skin effect is when, during high current draw, the outside of the conductor remains cool while the inner heats up.
		It is generally accepted that skin effect is not considered on conductors with diameter from less than and up to 3 times the skin effect depth at the frequency concerned.
	www.marcspages.co.uk /pq/3250.htm (1111 words)

Try your search on: Qwika (all wikis)