Step up the voltage and the current drops by the same ratio — a transformer changes the balance between volts and amps, never the total power available (minus small real-world losses).
V₁/V₂ = N₁/N₂ = I₂/I₁ is a direct consequence of energy conservation, not a design choice — it’s exactly why long-distance power transmission uses very high voltage: the same power at higher voltage means proportionally lower current, and resistive losses scale with current squared.
Estimate with the rule, then check it against the calculator that models it properly.
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