The battery charger for an mp3 player contains a step-down transformer with a turns ratio of 1:29, so that the voltage of 120 v available at a wall socket can be used to charge the battery pack or operate the player. what voltage does the secondary coil of the transformer provide?
Transformer contains two coils: primary and secondary. They allow change of voltage to lower or higher value. In first case we have step-down and in second case we have step-up transformer.
Formula used for transformer is: [tex]\frac{ N_{1} }{N_{2} } = \frac{ V_{1} }{V_{2} } [/tex]
Where: N1 = number of turns on primary coil N2 = number of turns on secondary coil V1 = voltage on primary coil V2 = voltage on secondary coil
In a step-down transformer primary coil has more turns than secondary coil. So the ratio 1:29 means that for each turn on secondary coil we have 29 turns on primary coil.
We can solve the equation for V2: [tex] {V_{2}}=\frac{ V_{1}{N_{2} } }{N_{1} } \\ {V_{2}}=\frac{ 120*{x } }{29x } \\ {V_{2}}=4.14V[/tex]
