regulator, impedance, and skin effect

[zhi_yi]

skin effect resistance

hi there, please tell me how to distinguish the differences between shunt regulator circuits and series regulator circuits

can we say the total resistance of a circuit that contains only resistors as the impedance?

high frequency commonly cause inductors to behave strangely due to the "skin effect" & electromagnetics core losses, please tell me what is skin effect? and please tell me something about electromagnetic interferences

thank you very much

 

[master_slave]

difference between shunt and series regulator

The main difference between SHUNT and SERIES regulators is that in series regulators, the regulator circuit is in series with the load and is between the load and the source voltage. It regulates load voltage and therefore has a dropout voltage across it. The shunt regulator circuit is in parallel with the load and the source and regulates load current. That is their most apparent difference.

Skin effect is a phenomenon in which in high frequency applications, the flow of electrons tends to be at the "surface" or the outer layer of the conductor, thereby increasing the conductor's resistance and dissipation. At high frequencies, significant skin-effect losses degrade signal-waveform amplitudes. It was found out that skin effect is proportional to the square root of frequency.

More about skin effect can be found at https://en.wikipedia.org/wiki/Skin_effect

And lastly, can you rephrase your question about the total resistance?

 

[Kral]

A series regulator has a pass element (Transistor) that is in series with the load. A shunt regulator has a regulating element (Zener diode or transistor) in parallel with the load.
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The series regulator is much more efficient at load currents less than maximum, because its dissipation is zero when the load current is zero. The shunt regulator, on the other hand simply distributes a constant power between the shunt regulator element and the load. If the load current is zero, the shunt regulator power is high. As the load current is increased mor power is dissipated by the load, and less pwer is dissipate by the shunt element. At full load, the efficiencies are about the same.
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I don't understand your question about total resistance.
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Skin effect is the tendency for current to be "crowded" toward the outside of a conductor at high frequencies. This increases the effective resistance of the conductor. Skin effect is negligible for frequencies below about 100 KHz.
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There are 2 types of core loss:
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Hysteresis loss is caused by the coercivity of the core material. As current is decreased to zero, the magnetic field does not go to zero. It therefore requires some energy to restore the field to zero as the current is reversed. Hysteresis losses vary As B^n, where B is the flux density, and n is a constant that varies with the core material. For silicon steel, n is apporoximately 1.6.
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Eddy Current losses arise because the core material is a conductor, and therefore has induced current flow due to the magnetic field. Eddy current losses are reduced by using insulated laminations in the core, rather than solid core material. Other materials, such as ferrites are inherently insulators, so laminations are not necessary. Eddy current losses vary as the square of B (flux density) and the square of V (Voltage).

 

[zhi_yi]

oo.. thank you

sorry for the grammer error, hope you can understand this rephrased sentences

impedance is the total resistance of a circuit, and that circuit might be contain capasitive resistance (Xc), inductive resistance(XL), and also resistance of resistor (R). is it right? so, my question is, from a circuit that is only contain R, can we say the total resistance (Rtotal) of that circuit as impedance?

thank you

 

[Humungus]

Impedance represents the ratio between the voltage applied to a net to the total current flowing through that voltage source, or more precisely, the ratio between incremental changes of the mentioned quantities. Notice that in general cases, the impedance of a net is a complex number. So, the real part of the impedance is called resistance, while the imaginary part reactance.

Then it deosn't make sense to talk about capacitive resistance. It is capacitive reactance, and this concep has associated particular relationships between voltage and current.

If the impedance of a net is purely real, then the net has a resistive behavior, which means that the voltage applied and the total current flowing are in phase.

In general, as there are real and imaginary components to the impedance, voltage and current are not in phase.

Which level are you? Haven't you seen linear systems in your courses?