03-08-2011, 09:26 AM
The voltage induced across the secondary coil may be calculated from Faraday's law of induction, which states that:
![JPG Image .jpg](https://seminarproject.net/images/attachtypes/image.gif)
where VS is the instantaneous voltage, NS is the number of turns in the secondary coil and Φ equals the magnetic flux through one turn of the coil.
The voltage induced across the primary coil:
![JPG Image .jpg](https://seminarproject.net/images/attachtypes/image.gif)
where VP is the instantaneous voltage, NP is the number of turns in the primary coil and Φ equals the magnetic flux through one turn of the coil.
Taking the ratio of the two equations for VS and VP gives the basic equation for stepping up or stepping down the voltage
![JPG Image .jpg](https://seminarproject.net/images/attachtypes/image.gif)