Conducting Diode Count Boundary Three-Row Scan - Electronic Circuits XIII & XIV: Power Supplies and Switching Energy Step by Step

Each conducting diode subtracts its drop from the rectified peak, so more conducting diodes can move the reservoir valley from pass to boundary to fail. With a 12 V source peak and 1 V diode drop, diode counts 1, 2, and 3 leave margins 1, 0, and -1 V exactly for the ideal rectifier model; real supplies add diode-drop variation, transformer regulation, ripple, ESR, load variation, heating, and voltage measurement uncertainty.

A changed diode path count moves the reservoir valley gate. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

1 conducting diode sets the valley gate

Source peak stays 12 V and diode drop stays 1 V. Conducting diode count 1 leaves rectified peak 11 V and valley margin 1 V.

11\ \text{V}\mathbin{-}2\ \text{V}\mathbin{-}8\ \text{V}=1\ \text{V}\Rightarrow\text{pass}

2 conducting diodes set the valley gate

Source peak stays 12 V and diode drop stays 1 V. Conducting diode count 2 leaves rectified peak 10 V and valley margin 0 V.

10\ \text{V}\mathbin{-}2\ \text{V}\mathbin{-}8\ \text{V}=0\ \text{V}\Rightarrow\text{pass}

3 conducting diodes set the valley gate

Source peak stays 12 V and diode drop stays 1 V. Conducting diode count 3 leaves rectified peak 9 V and valley margin negative 1 V.

9\ \text{V}\mathbin{-}2\ \text{V}\mathbin{-}8\ \text{V}=-1\ \text{V}\Rightarrow\text{fail}