The ripple factor (α) is defined as the ratio between the rms value of the output voltage and the DC value of the output voltage times 100. The next formula expresses this definition and is used to calculate the ripple factor:
Formula 1
Ripple factor:
α = (Vrms / Vdc) x 100
Where:
α is the ripple factor
Vrms is the rms value of the output voltage in volts (V)
Vdc is the average value of the output voltage in volts (V)
Ripple factors:
(Resistive load)
a) Half-wave rectifier = 120%
b) Full wave rectifier = 48%
TABLE - Rectifier's Characteristics (using resistive loads)
| Parameter | Half Wave | Full Wave (Center tap Transformer | Full Wave (Bridge) |
| Vdc in the load | Vmax / ? | 2 x Vmax / ? | 2 x Vmax / ? |
| Vrms in the load | Vmax / 2 | Vmax / ?2 | Vmax / ?2 |
| Reverse voltage across the diodes Vr = (Max.) | Vmax | 2 x Vmax | Vmax |
| Ripple Factor (?) | 120% | 48% | 48% |
| Storage Factor referred to the output Power in the load | 3.49 x Pdc (primary and secondary) | 1.75 x Pdc (secondary) - 1.23 x Pdc (primary) | 1.23 x Pdc (primary and secondary) |
Pdc = output power in watts (W)
