What is Crest factor or Peak factor? – Crest factor Formula

Crest factor is defined as the ratio of the peak value (or maximum value) to the RMS value of a waveform. It is denoted by the capital letter ‘C’. It is also known as peak factor. The waveform can be any quantity like current, voltage, etc.

Crest factor Formula

\text{Crest factor}=\frac{{A_{peak}}}{{A_{rms}}}

where,

Apeak is the peak or maximum value of the waveform

Arms is the rms value of the waveform

Crest factor of Half wave rectifier

Let the peak value of the rectified output be Vm.

The RMS value of output voltage of single-phase half-wave rectifier is given by

V_{rms}=\frac{V_{m}}{2}

As we know the crest factor is given by

\text{Crest factor}=\frac{{V_{peak}}}{{V_{rms}}}

Therefore, we get

\text{Crest factor}=\frac{{V_{m}}}{{\frac{V_{m}}{2}}}

∴ Crest factor = 2

The crest factor of half wave rectifier is 2

Crest factor of Full wave rectifier

Let the peak value of the rectified output be Vm.

The RMS value of output voltage of single-phase full-wave rectifier is given by

V_{rms}=\frac{V_{m}}{\sqrt{2}}

As we know the crest factor is given by

\text{Crest factor}=\frac{{V_{peak}}}{{V_{rms}}}

Therefore, we get

\text{Crest factor}=\frac{{V_{m}}}{{\frac{V_{m}}{\sqrt{2}}}}

∴ Crest factor = √2 = 1.414213

The crest factor of full wave rectifier is √2

Crest factor of Bridge rectifier

Let the peak value of the rectified output be Vm.

The RMS value of output voltage of bridge rectifier is given by

V_{rms}=\frac{V_{m}}{\sqrt{2}}

As we know the crest factor is given by

\text{Crest factor}=\frac{{V_{peak}}}{{V_{rms}}}

Therefore, we get

\text{Crest factor}=\frac{{V_{m}}}{{\frac{V_{m}}{\sqrt{2}}}}

∴ Crest factor = √2 = 1.414213

The crest factor of full wave rectifier is √2

Leave a Comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

error: Content is protected !!