Current and voltage in a full-wave rectifier can be calculated by the next formulas. The formulas are valid both to 2-diodes systems and the bridge rectifier using 4 diodes.
Formula 1:
Average voltage:
Where:
Vavg is the medium voltage across the load in volts (V)
Vmax is the peak voltage or maximum voltage in volts (V)
π is 3.1416
Formula 2
Average current:
Where:
Iavg is the average current through the load measured in amperes (A)
Imax is the peak current or maximum current in amperes (A)
π is 3.1416
Derivated formula:
Formula 3
Maximum current:
Where:
Imax is the maximum current in amperes (A)
Iavg is the average current in amperes (A)
π is 3.1416
Note: The voltage fall in the diodes is not considered by this calculation.
Application example:
Calculate the peak voltage in a full-wave rectifier where the average output voltage in a load is 9 V.
Data:
Vavg = 9 V
π = 3.14
Vmax = ?
Applying formula:
Vmax = 9 x 3.14 / 2 = 14.13 volts
