Transformers, what is the relationship between the voltage and current at the primary and secondary coil?

Sorry im really stuck. Does the current change from primary to secondary? I know the voltage changes in a step-up/ step-down, but what about the current. God im really stuck. Many thanks.Transformers, what is the relationship between the voltage and current at the primary and secondary coil?we know that for power, P=IV. we also know that whatever power goes into the transformer comes out of the transformer(conservation of energy). this means that V is inversely proportional to I. or I is inversely proportional to V.



if you already know how much V was stepped up, then just step down the I by the same ratio. for eg, if 110V 10A was transformed to 220V, then the step up ratio is 2. therefore current is stepped down by 2. so current will be 5. try equating 110x10 with 220x5, it is constant.



all of this assumes that the transformer is 100% efficient. if there are losses due to heat, then you multiply the exit current by the efficiency factor. eg, if the trans is said to be 80% effiecient, then the actual exit current would not be 5A but 4A. voltage is not affected by effiency issues.



by the way transformers only work with AC, the guy who mentioned direct currents is thinking of current rectifer not transformer.Transformers, what is the relationship between the voltage and current at the primary and secondary coil?
Power on both sides are equal. Let N1 be the number of turns on the primary side and N2 be the number of turns on the seconday side. Then V2 = (N1/N2)V1 and I2 = (N2/N1)I1.Transformers, what is the relationship between the voltage and current at the primary and secondary coil?V1*V2 = I1*I2



where 1 and 2 refer to primary and secondary



If you have values substitute and find out.Transformers, what is the relationship between the voltage and current at the primary and secondary coil?
it would depend on whether or not the input was ac or dc, but usualy transformed current would become dc.Transformers, what is the relationship between the voltage and current at the primary and secondary coil?Totally has to do with the ratio of the loops of those coils. Such as 2:1 would cut the voltage in half but double the amperage where as 1:2 the voltage would double but the amperage would be cut in half.Transformers, what is the relationship between the voltage and current at the primary and secondary coil?
It's worth pointing out that this applies only to alternating current - transformers don't transform DC. For AC, voltage is proportional to turns and current is inversely proportional to turns.