induced currents (1 Viewer)

[del pietro]

Are Eddy Currents and Back emf, all refering to Induced Currents?

In other words are they pretty much the same thing?

Pls help clarify

 

[Riviet]

Are Eddy Currents and Back emf, all refering to Induced Currents?

In other words are they pretty much the same thing?

Pls help clarify

When a solid conductor, such as a copper sheet is placed in a region of changing magnetic flux, circular eddy currents are induced in the conductor. By Lenz's Law, these eddy currents oppose the motion of the conductor and can therefore be used for electromagnetic current purposes.

In an electric motor, a current supplied to a coil sitting in a magnetic field causes it to turn. However, while the coil of the motor is rotating, it experiences a change of magnetic flux with time and by Faraday's Law an emf is induced in the coil. By Lenz's Law, this induced emf must oppose the supplied emf driving the coil. This induced emf is the back emf.
I hope that clarifies things.

 

[speedie]

wow thanks, i was confused about that too.

ps. riviet ur a tank, can i pls have ur msn?

 

[Riviet]

wow thanks, i was confused about that too.

ps. riviet ur a tank, can i pls have ur msn?

Hehe, glad to help, PM your msn e-mail to me and I'll add you.

 

[Libbster]

Back emf is definitely not a current. Back emf is a voltage (or potential difference) that opposes the forward emf (voltage).
Back emf causes a "back current" that opposes the "forward current." However there can only be current if there is a complete circuit.

 

[Mountain.Dew]

one small thing: back emf and supply emf apply to motors ONLY. electromagnetic braking doesnt use 'back emf' as such...well, at least not the term.

 

[del pietro]

ok now i capish.. that has made things much clearer.
thanx heaps guys!

 

[helper]

Back emf is definitely not a current. Back emf is a voltage (or potential difference) that opposes the forward emf (voltage).
Back emf causes a "back current" that opposes the "forward current." However there can only be current if there is a complete circuit.

Just clarrifying, there is no such thing as a back and forward current, there is one current.
The back EMF opposes the Supplied voltage, resulting in a smaller net voltage for the circuit, reducing the current because of Ohm's Law.