How Do You Calculate Current from a Faraday Disc?

AI Thread Summary
Calculating current from a Faraday disc involves considering factors like back electromotive force (emf) and the specific motor's torque. While voltage calculations are more straightforward, determining current requires additional complexity. Using a flat coil instead of a solid disk can enhance efficiency if the coil's magnetic field aligns with the stator magnets. Resources like the linked article provide further insights into the topic. Understanding these principles is crucial for effective generator design and performance.
charlie r
Messages
2
Reaction score
0
Hi,

How do you calculate the current from a faraday disc? I have found calculations for the voltage, but what about the current?
I think it is a bit more complicated due to back emf, but if you know what motor you are using (the torque it can generate), then can you work it out?
Thanks for any help,

Charlie
 
Physics news on Phys.org
Thanks Drakkith, great link.
It seems that this isn't as simple as i first hoped it was!

Charlie
 
If you use a flat coil instead of solid disk and coil is wind in such direction, that its magnetic field adds to the field of stator magnets, the generator will be more efficient.
 
This is from Griffiths' Electrodynamics, 3rd edition, page 352. I am trying to calculate the divergence of the Maxwell stress tensor. The tensor is given as ##T_{ij} =\epsilon_0 (E_iE_j-\frac 1 2 \delta_{ij} E^2)+\frac 1 {\mu_0}(B_iB_j-\frac 1 2 \delta_{ij} B^2)##. To make things easier, I just want to focus on the part with the electrical field, i.e. I want to find the divergence of ##E_{ij}=E_iE_j-\frac 1 2 \delta_{ij}E^2##. In matrix form, this tensor should look like this...
Thread 'Applying the Gauss (1835) formula for force between 2 parallel DC currents'
Please can anyone either:- (1) point me to a derivation of the perpendicular force (Fy) between two very long parallel wires carrying steady currents utilising the formula of Gauss for the force F along the line r between 2 charges? Or alternatively (2) point out where I have gone wrong in my method? I am having problems with calculating the direction and magnitude of the force as expected from modern (Biot-Savart-Maxwell-Lorentz) formula. Here is my method and results so far:- This...
Back
Top