step-up-trades-current-for-voltage - Electronic Circuits XV & XVI: Transformers and Switched-Capacitor Conversion Step by Step

A step-up-trades-current-for-voltage scan holds the primary power fixed and varies the secondary turns across three rows, checking that the higher secondary voltage pairs with lower secondary current through V_s * I_s = V_p * I_p row by row. The arithmetic is exact only for the stated turns counts, voltages, currents, power, and rows in the ideal lossless, perfectly coupled transformer model. Real transformers add winding resistance, leakage flux, core losses, magnetizing current, frequency rolloff, probe/calibration limits, finite precision, and measurement uncertainty.

A step-up case shows the same power ledger from the other direction. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Voltage can rise while ideal power stays fixed

The scan keeps primary voltage and primary current fixed. More secondary turns raise voltage and lower secondary current.

P=V_pI_p=V_sI_s

Higher secondary voltage carries lower secondary current

Every row keeps the primary side at the same exact power.

\begin{array}{c|c|c|c|c}N_s&V_s&I_s&I_p&P\\2&5\ \text{V}&3\ \text{A}&3\ \text{A}&15\ \text{W}\\4&10\ \text{V}&\tfrac{3}{2}\ \text{A}&3\ \text{A}&15\ \text{W}\\6&15\ \text{V}&1\ \text{A}&3\ \text{A}&15\ \text{W}\\\end{array}

A step-up transformer trades current for voltage

The larger secondary voltage is paired with smaller secondary current for the same ideal power.

5\ \text{V}\rightarrow15\ \text{V}\quad;\quad3\ \text{A}\rightarrow1\ \text{A}