Eddy currents
- (also called Foucault's currents)
- are loops of electrical current induced within conductors
- by a changing magnetic field in the conductor
- according to Faraday's law of induction.
- Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field.
What is eddy current principle?
The eddy current method is based on the principle of generating circular electrical currents (eddy currents) in a conductive material. This is achieved by the use of a coil connected to an alternating current generator driving an alternating magnetic field (primary field).
Why is it called eddy current?
Eddy currents are named so because the current looks like eddies or whirlpools. When a conductor is placed in the changing magnetic field, the induced current in the conductor is termed as Eddy currents
What is eddy current and its application?
Strong eddy currents are set up in the metal produce so much heat that the metal melts. This
process is used in extracting a metal from its ore.The arrangement of heating the metal by means of strong induced current is called the induction furnace. (2)-Induction motor, the eddy currents may be used to rotate the rotor.
Are eddy currents AC or DC?
In a DC circuit, the current always flows in the same direction. There is no oscillation whatsoever. Eddy currents, however, have no direction. They just circulate whenever a conducting material of large enough cross section is available.
What is the advantage of eddy current?
The advantages of eddy current testing are: Sensitivity to surface defects. Able to detect defects of 0.5mm in length under favourable conditions. Can detect through several layers.
What are the two uses of eddy current?
- Eddy currents in conductors (having some resistance) generate heat as well as electromagnetic forces.
- 1.The heat can be used for induction heating.
- 2.The electromagnetic forces can be used for levitation i.e. in maglev trains.
Are eddy currents useful or harmful?
Because of the tendency of eddy currents to oppose, eddy currents cause a loss of energy. Eddy currents transform more useful forms of energy, such as kinetic energy, into heat, which isn't generally useful.
Disadvantages of Eddy Currents:
There is a major heat loss during cycling eddy currents due to friction in the magnetic circuit, especially where the core is saturated. Thus there is the loss of useful electrical energy in the form of heat. There is magnetic flux leakage.
There is a major heat loss during cycling eddy currents due to friction in the magnetic circuit, especially where the core is saturated. Thus there is the loss of useful electrical energy in the form of heat. There is magnetic flux leakage.
Are eddy currents AC or DC?
In a DC circuit, the current always flows in the same direction. There is no oscillation whatsoever. Eddy currents, however, have no direction. They just circulate whenever a conducting material of large enough cross section is available.