LED energy saving lamp to teach you what is the skin effect?
Release time2012-12-14 15:12:45     Browsing times1018
We tested the LED application, should be found using high frequency current drive is often burnt black phenomenon, eventually leading to death lamp lights. Specific performance in colloidal gold due to continuous high temperature on silicon carbide black, this is because of the high frequency impedance is much higher than the DC impedance, the impedance increases made of gold colloid black heat is more serious, the reason for this is the skin effect.
One, what is the skin effect
Skin effect is called the skin effect, when the alternating current through a conductor, the current will focus on the conductor surface flow, this phenomenon is called the skin effect. Skin effect in electromagnetics, eddy current ( vortex ) scientific terms. This phenomenon is energized by a ferromagnetic material, in unpowered ferromagnetic material, in a powered-off ferromagnetic material surface is opposite to the direction of the magnetic field, the magnetic field will produce a cutting magnetic induction line current, the current known as the eddy current, this phenomenon is the skin effect.
In two, the skin effect principle
Skin effect current or voltage high frequency electronic conduction, will focus on the general surface of conductor, rather than the average distribution in the cross-sectional area of the conductor. Skin effect so that the conductor resistance increases effective. The higher the frequency, the more significant effect. When a high frequency current through the current in a conductor, the conductor surface can be considered only in a thin layer, which is equivalent to the conductor cross section decreases, increasing resistance. The line of the central part, almost no current through, can make the center portion is removed so as to save the materials. Therefore, in the high frequency circuit adopts a hollow conductor instead of the solid conductor. In addition,
In order to weaken the skin effect, in the high frequency circuit also tend to use a plurality of mutually insulated fine wires woven into bundles, replacement of the same cross-sectional area of the thick filament strands of wire harness, this is called the defense line.
In three, the skin effect of the application
Alternating electromagnetic field strength of the conductor, and depth decreased exponentially, so in sunscreens in mixed conductor particles (usually zinc oxide and titanium dioxide ), can make the sun's ultraviolet light ( electromagnetic wave ) of the strength reduction. This is a principle, physical sunscreen agent. In addition, the skin effect and the electromagnetic shielding method, utilizing the skin effect can prevent the high frequency electromagnetic wave penetrating the conductor, the electromagnetic shielding device, which is an elevator, a mobile phone signal receiving no good reason. In industrial application, the skin effect of metal surface hardening.