I see this formula destroyed all over the net. I am building a generator, and I have found that some error has been made in the manipulation of Faradays Law. If my derivation is correct, then I need somebody to tell me how to more accurately calculate the area of my coils. (This is the only variable I can think of that I will keep this from working) I have made a prototype, and my expected results should be slightly lower than my calculations due to losses. Here is the manipulation I have made. This is in refrence to an axial flux design. A rotor of magnets in alternating pole configuration is spun past a stator of coils. The rotor has 12 magnets total. I am saying this because it effects the rate of change of flux for one revolution. The magnets are circular, and the coils are in the shape of a trapezoid.(adsbygoogle = window.adsbygoogle || []).push({});

EMF= N* (Rate of change of flux/rate of change in time)

I justified the following per my own derivation.

N = Number of turns per coil

P = number of poles. (2 poles make one cycle of AC EMF)

A =area of the coil in [square meters]EFFECTIVE

Bm = flux density at the coil [Teslas]

n = revolutions per second

The flux changes 12 times for every revolution.

the frequency of the flux change is 2*PI*f = 2*PI*((P/2)*n)

Since this incorporates the rate of change in time...

(P/2) is one complete AC cycle on a coil

EMF = 2*PI*((P/2)*n)*A*Bm

I have made a prototype of the generator and the EMF produced is way higher than the calculated values. The closest equation that matches the resulted output is:

EMF = Bm*l*v (multiplying this by N)

l= 2*PI*r (of the single strand of wire)

I multiply this by the number of turns, and the answer is slightly higher than the result.

Please verify my work. I am ready to spend a lot of money to complete this, and I would like to have my calculations match, or come close to by logical analysis, of my results.

**Physics Forums - The Fusion of Science and Community**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Faradays Law, The correct version

Can you offer guidance or do you also need help?

Draft saved
Draft deleted

Loading...

Similar Threads for Faradays correct version | Date |
---|---|

Simulating a Faraday Cage | Feb 27, 2018 |

Magnetic flux in tap changing transformers | Nov 23, 2017 |

DSP Tuner - Is this correct for freq offset? | Oct 9, 2017 |

Faraday Cage: Thickness of the conductor | Mar 3, 2017 |

Why is EMF (ElectroMotive Force) equal to a voltage? | Feb 27, 2017 |

**Physics Forums - The Fusion of Science and Community**