Form factor (electronics)

The form factor is a term used in electrical metrology and refers to the ratio of rms to rectified value of a periodic signal. It can take on, depending on the waveform values ​​from one to infinity.

General

For the form factor F of a size, in this case, the electrical voltage selected as the size of U, T applies to the period:

The form factor is particularly important for the measurement of AC voltages and currents of importance because, although usually the effective value is to be displayed, but with simpler instruments only the rectified value is detected. These devices show the 1.11 times the standard value equal to, that is, they are adjusted to the form factor of a sinusoidal signal

For other waveforms (triangle, rectangle, etc.) with different form factors so the measurement is distorted.

For mixed sizes, it is useful in some situations, only specify the form factor rather than the entire signal for its alternating component.

The ratio of peak value to effective value is called a crest factor, or crest factor.

Form factors

The following table shows the form factors and related variables for various simple waveforms. They are all independent of the peak value.

A DC voltage represents a special case of a change of size with an infinitely long period