It is known that the transmission power of both sides in the ideal trnsformer are equivalent, that’s to say, the primary input power is equal to the secondary output power;
Let’s suppose that the primary input voltage is V1, primary input current is I1; While the secondary output voltage is V2, secondary output current is I2, then V1*I1=V2*I2;
Likewise, in step down transformer, V1>V2, so I2>I1.(The secondary current is higher than primary current.)
