Average Rectified Voltage

Formula

Description

The average value of a full-wave rectified sine wave is 2/π (approximately 0.637) times the peak value. This is the DC component of the rectified waveform before filtering. It is important for calculating the DC output of unfiltered rectifiers, calibrating average-responding AC meters, and understanding the relationship between peak, RMS, and average values. Many inexpensive multimeters actually measure the average rectified value and apply a correction factor of 1.11 (π/(2√2)) to display the RMS value, which is only accurate for pure sine waves.

Variables

• V_avg — Average rectified voltage (V)
• V_peak — Peak voltage of the sine wave (V)

Practical Notes

For a half-wave rectifier, V_avg = V_peak/π ≈ 0.318 × V_peak (half the full-wave value). The form factor of a sine wave is V_rms/V_avg = π/(2√2) ≈ 1.111. Average-responding meters reading non-sinusoidal waveforms (square waves, PWM, distorted signals) will give incorrect RMS readings.