Transformers - Conservation of Energy help?

[weasleyisourking]

Why do transformers not break the Conservation of Energy rule?

Obviously, they are able to change the voltage of the secondary circuit, and thus as V and I are proportional, they also change the current.

If you are using a step-up transformer, where does the 'extra' current come from?

Its probably a silly question but I just don't quite understand how this in keeping with this fundamental principle.

Thanks.

Don't judge me!

[luffy]

What you pretty much have to understand is that power is conserved in a transformer (assuming it is ideal). Power = energy/time. Thus, energy is also conserved.

In a step-up transformer, the voltage increases and the current DECREASES proportionally (as P = VI). Hence, it is quite the opposite of "extra" current - the current is smaller. Thus, as power remains the same, energy is conserved.

In a step-down transformer, voltage is decreased and current increases proportionally. Hence, as power remains the same, energy is conserved.

I think you are under the conception that energy is associated ONLY with current. In simple terms, it is both current and voltage that must be considered in the "conservation of energy" rule in this scenario.

Hope I explained it well enough....

[weasleyisourking]

What you pretty much have to understand is that power is conserved in a transformer (assuming it is ideal). Power = energy/time. Thus, energy is also conserved.

In a step-up transformer, the voltage increases and the current DECREASES proportionally (as P = VI). Hence, it is quite the opposite of "extra" current - the current is smaller. Thus, as power remains the same, energy is conserved.

In a step-down transformer, voltage is decreased and current increases proportionally. Hence, as power remains the same, energy is conserved.

I think you are under the conception that energy is associated ONLY with current. In simple terms, it is both current and voltage that must be considered in the "conservation of energy" rule in this scenario.

Hope I explained it well enough....

Well now I feel like a dumb ass. 

Thanks for your help! I get it now I forgot about how V and I are inversely proportional in transformers.

I was thinking of V = IR not P=VI.

Thankyou thankyou thankyou