How does a transformer step down voltage while increasing current?

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SUMMARY

The discussion clarifies how transformers operate by stepping down voltage while increasing current, adhering to the principle of power conservation (P=IV). It emphasizes that transformers function only with alternating current (AC), as direct current (DC) results in a dead short. The turns ratio of the transformer is crucial; for example, a transformer with 1000 primary windings and 100 secondary windings can convert 120 volts to 12 volts while adjusting the current accordingly. Understanding these principles is essential for grasping transformer functionality.

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  • Understanding of AC and DC electrical systems
  • Knowledge of transformer turns ratio
  • Familiarity with the power equation P=IV
  • Basic concepts of magnetic fields and inductance
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Taylor_1989
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Here is my problem I am having: I am having trouble seeing how current is step down in a transformer when the voltage increase. This is how I see it. In a battery ( I know d.c just using as example. ) The voltage is basically an electric field created by the internal circuit in the battery, so the work done on the electrons to give them the energy to move from a low to a high potential is done by the battery, so a 12V energy is given to each Colombo of charge so the current would flow at X amount, but if you wanted to increase current flow you would increase the voltage so more energy is given to each Colombo of charge mean they move fast so to speak, I do realize that electrons don't move that quick, it the effect of the electric field throughout the conductor (hope I am right saying that). But when I look at a A.C transformer e.g step up the voltage has increased but the current has decreased, why is this? could someone please explain.

I do apologize if some of the information I put is incorrect, I am self taught, so I can only quote what I have read so far.
 
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Forget about the stuff you just said...

Simple as this...power in = power out. (minus some minor losses)

P=IV

Change the voltage...the current changes proportionally to make the same power...or watts.

Also, a trasformer will not work in DC. A transformer in DC is just a dead short. Reactance of a inductor is JWL. W=0 in DC. Therefore zero resistance...dead short.

To add a little more...there is a turns ratio in the transformer. To go from 120 volts to say 12 volts...you could have 1000 windings of coil on the primary side and 100 windings of coil on the secondary side. The primary coil creates a rotating magnetic field that induces a current into the secondary side also creating a rotating magnetic field. Some of the other gurus on here will have to give the the details down to the electrons and coloumbs and so forth.
 
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