Bridge Diode Drop Loss Cross-Scan - Electronic Circuits XIII & XIV: Power Supplies and Switching Energy Step by Step

A bridge rectifier path spends two diode drops before the reservoir sees the remaining peak voltage. The subtraction is exact for the stated idealized diode drops; real diode voltage changes with current and temperature, while transformer sag, ripple, switching recovery, load variation, and meter uncertainty also move the peak.

A bridge rectifier spends the diode drop once per conducting diode. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

A bridge output peak is source peak minus two diode drops

The checked source starts from a twelve-volt peak and spends two one-volt diode drops, leaving ten volts for the reservoir.

12\ \text{V}\mathbin{-}2\cdot1\ \text{V}=10\ \text{V}

The diode-drop knob subtracts twice per bridge path

With the same source peak and two conducting diodes, each extra volt of diode drop removes two volts from the output peak.

\begin{array}{c|c|c|c}V_{\text{source}}&V_D&n&V_{\text{out}}\\12\ \text{V}&0\ \text{V}&2&12\ \text{V}\\12\ \text{V}&1\ \text{V}&2&10\ \text{V}\\12\ \text{V}&2\ \text{V}&2&8\ \text{V}\\\end{array}