Understanding EMF of a Coil and Formulas Used
Electromotive Force (EMF) induced in an electrical coil is governed fundamentally by Faraday's Law of Electromagnetic Induction. The law states that the magnitude of induced EMF is directly proportional to the rate of change of magnetic flux linkage. For sinusoidal alternating magnetic fields, the Root Mean Square (RMS) induced EMF value is calculated using the standard transformer and alternator equation:
Where $E_{rms}$ represents the root mean square voltage, $f$ is the frequency in Hertz, $N$ is the total number of turns in the coil, and $\Phi_m$ is the maximum magnetic flux measured in Webers. When dealing with rotational machinery like generators, the maximum flux can also be derived from the product of magnetic flux density ($B$) and effective cross-sectional area ($A$). Peak and average values are similarly computed using fundamental waveform form factors.
How to Use This Calculator
- Select Calculation Mode: Choose between Faraday's direct flux mode or the rotational generator RPM mode.
- Enter Coil Parameters: Input your number of turns, magnetic flux values, and frequency or rotational speed.
- Configure Preferences: Choose your desired output voltage units and power factor settings.
- Submit and Analyze: Click the calculate button to review RMS, peak, and average voltage outputs instantly.