8.1 Half wave rectifier

  Semi-conductor Devices and Electronics

A half wave rectifier is a single $p-n$ junction diode connected in series to the load resistor.
Alternating input voltage is given to a step-down transformer and the resulting reduced output voltage of a transformer is given to the diode $D$ and load resistance $R_L$.
The DC output voltage is measured across the load resistor $R_L$.

The half wave rectifier converts only one-half cycle of the input alternating current (AC) to a direct current (DC).

• Peak value of current is, $${I_m} = \frac{{{V_m}}}{{{r_f} + {R_L}}}$$
  where,
  $r_f$: Forward diode resistance
  $R_L$: Load resistance
  $V_m$: Peak value of the alternating voltage

• $rms$ value of current is, $${I_{rms}} = \frac{{{I_m}}}{2}$$
• DC value of current is, $${I_{DC}} = \frac{{{I_m}}}{\pi }$$
• Peak inverse voltage is, $$PIV = {V_m}$$
• DC value of voltage is, $$\begin{equation} \begin{aligned}
  {V_{DC}} = {I_{DC}}{R_L} \\
  {V_{DC}} = \frac{{{I_m}}}{\pi }{R_L} \\\end{aligned} \end{equation} $$