V is the instantaneous voltage. N is the number of turns in the winding. dɸ / dt is the change in magnetic flux (ɸ) through the windings over time. P and S refer to the Primary and Secondary windings respectively. The V/N ratio for an ideal transformer is given by: V1/N1 = V2/N2 This equation states that, for an ideal transformer, the primary voltage divided by the number of turns in its winding equals the secondary voltage divided by the number of turns in its winding. From this equation we can see that, as long as there are no losses in either winding, all of the power supplied to the primary will be transferred to the secondary. However, because real-world transformers are not 100% efficient due to resistive losses in their windings, some power will be dissipated as heat that needs to be fixed correctly so all equations are accounted for.
