## Ripple Factor of bridge rectifier

The pulsating output of a rectifier can be considered to contain a dc component and ac component called the ripples. The ripple current is undesirable and its value should be the smallest possible in order to make the rectifier effective.

The ripple voltage or current is measured in turn of the ripple factor which is defined as the ratio of the effective value of the ac components of voltage (or current) present in the output from the rectified to the direct or average value of the output voltage (or current)

The effective value of the load current is given as

**I ^{2} = I_{dc}^{2} + I_{1}^{2} + I_{2}^{2} + I_{4}^{2} + ……=I_{dc}^{2} + I_{ac}^{2}**

Where I_{1}, I_{2}, I_{4} etc. are the rms values of fundamental, second, fourth etc. harmonics and I_{ac}^{2} is the sum of the square of the rms Value of the ac components.

So ripple factor, **γ = I _{ac} /I_{dc} = √{(I^{2} + I_{dc}^{2})/I_{dc}} = √[{I_{rms}/I_{dc}}^{2} – 1] = √(K_{f}^{2} – 1)**

Where K_{f} is the form factor of the input voltage. For half-wave rectifier, from factor is given as

**K _{f} = I_{rms} / I_{av} = (I_{max}/√2)/(2I_{max} / π) = π/2√2 = 1.11**

Now, Ripple factor is given as

** γ = √(K _{f}^{2} – 1) = √(1.11^{2} – 1) = 0.482**

### Related Topic

**Full-wave bridge rectifier****Average and RMS Value of bridge rectifier****Efficiency of bridge rectifier****Peak Inverse Voltage (PIV) of bridge rectifier****Peak Current of bridge rectifier****Transformer Utilization Factor of bridge rectifier****Advantage of bridge rectifier****Disadvantage of bridge rectifier**

Hi, just wondering, is there an error in the post? The rms value you are talking about, is of the full wave rectifier, not half wave rectifier? because the formula for the half wave rectifier is /2.

thanks.

denys

No it is correct , The Rms for full wave rectifier is : /root{2}