larger-capacitor-cuts-ripple - Electronic Circuits XIII & XIV: Power Supplies and Switching Energy Step by Step

A larger-capacitor-cuts-ripple scan holds the load current and recharge interval fixed and varies the capacitance across three rows, checking that ripple delta-V = I * delta-t / C falls as capacitance grows row by row. The arithmetic is exact only for the stated load currents, recharge intervals, capacitances, ripple voltages, and rows in the ideal capacitor and ideal load model. Real reservoirs add ESR, capacitance tolerance, diode drops, load transients, ripple waveform shape, meter/probe calibration limits, finite precision, and measurement uncertainty.

A capacitance contrast isolates the ripple denominator. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Capacitance sits in the ripple denominator

The same load current and recharge interval are kept. Only the capacitance is changed.

\Delta V={I\Delta t\over C}

Larger capacitance lowers the same charge droop

The rows scan capacitance upward while the numerator stays fixed, so the voltage ripple steps downward.

\begin{array}{c|c|c|c}I&\Delta t&C&\Delta V\\2\ \text{A}&3\ \text{s}&1\ \text{F}&6\ \text{V}\\2\ \text{A}&3\ \text{s}&2\ \text{F}&3\ \text{V}\\2\ \text{A}&3\ \text{s}&4\ \text{F}&\tfrac{3}{2}\ \text{V}\\\end{array}

Doubling capacitance halves this ripple ledger

The load current and interval stay fixed. Only capacitance changes, so the checked ripple is smaller.

2\ \text{A}\cdot3\ \text{s}/4\ \text{F}=\tfrac{3}{2}\ \text{V}