where coil store energy??

[ahmed osama]

dear all

well many times when we speaks about coils , they say that coil store energy like cap. stors charges on its plates , the coil store the magentic energy inside its core

so in case of air coil where the energy is stored !!!!!!!

thanks all
bye

 

[IanP]

Coil is not an energy storage, it is an energy transformer ..
Electromagnetic field => current =>electromagnetic field ..

Don’t compare storage properties of a coil with storage properties of a cap ..
Cap is more like a battery whereas a coli is more like a kicking horse ..

If you need more details, see this:
How the Parallel-LC Circuit Stores Energy

IanP
:wink:

 

[ahmed osama]

Coil is not an energy storage, it is an energy transformer ..
Electromagnetic field => current =>electromagnetic field ..

Don’t compare storage properties of a coil with storage properties of a cap ..
Cap is more like a battery whereas a coli is more like a kicking horse ..

If you need more details, see this:
How the Parallel-LC Circuit Stores Energy

IanP
:wink:

well did u read ur link well ???

in the beging he is saying "........ store this energy alternately in the inductor and capacitor ...."
then
in explain of Figure 1-8A

"......The energy which was first stored by the electrostatic field of the capacitor is now stored in the electromagnetic field of the inductor............"

he saying what i asking about it ??

bye

 

[FvM]

The explanation in the link is somewhat cursory, but ýour question has been exactly anwered. The energy is stored in the magnetic field, not particularly in the core. If you have a core with an air gap, most of the energy is stored in the field part in the air gap!

 

[Archerman]

No, the coil doesn’t store the energy itself. If the magnetic field collapses the energy will be recreated in the coil in an opposite direction, because the magnetic field is in a different direction. Remember energy can not be destroyed; you can only convert the state or form of it at the most. This is also known as the back EMF in motors or relays. You then need to protect your driving transistor with a diode otherwise you will damage the transistor.

 

[MANILKA]

You have to keep in mind that we are dealing with the rate of change of flux or rate of change of current. So you need to keep the fluxuation going on or else you will lose it.

 

[ahmed osama]

well assume coil with zero Resis. and u applied a current pulse to it then u have short it . i guess the current will circulate forever ummmmmmm is it right??

 

[albbg]

Yes, you are right. That ideally perpetual current is the so called persistent current. Such a phenomenon is produced in superconductors even if for long but finite time due to non-idealities

 

[encoder]

I think as a electrical engineer i know little bit energy is not stored in core it is stored in magnetic field (i can give you an example of inductor when electric current flows through the inductor the inductor stores the energy in it)

 

[FvM]

As a supplement to the previous discussion, here's an energy density plot from a Quickfield example, a simple moving iron electromagnetical actor. It shows graphically, where the energy of the magnetic circuit is concentrated. The energy distribution can be also used to explain the generated mechanical force, it's equivalent to "gained" energy dE/dx by reducing the gap.