Difference between revisions of "Phase"

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(What is it?)
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As a sinoidal signal in the time domain can be defined as  
 
As a sinoidal signal in the time domain can be defined as  
  
''s(time)=amplitude * sin(2Pi*frequency * time + phase)''
+
[[Image:Phase3.jpg|mathematical description of signal with phase]]
  
the phase describes an 'offset' of the signal along the time axis and defines the 'zero crossing' of the signal. An sinoid signal is periodic, therefore usually only phase values from +/-180deg are used.
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The signal phase describes an 'offset' of the signal along the time axis and defines the 'zero crossing' of the signal. An sinoid signal is periodic, therefore usually only phase values from +/-180deg (or +/-Pi) are used.
  
 
==An Example==
 
==An Example==

Revision as of 20:16, 28 September 2004

What is it?

As a sinoidal signal in the time domain can be defined as

mathematical description of signal with phase

The signal phase describes an 'offset' of the signal along the time axis and defines the 'zero crossing' of the signal. An sinoid signal is periodic, therefore usually only phase values from +/-180deg (or +/-Pi) are used.

An Example

You see here an sinoidal signal with a frequency of 1kHz and an amplitude of 2 Volts. Time scale is -1msec..+1msec. The signal is shown with 3 different phases, from left to right:

  • -60 degree
  • 0 degree
  • +60 degree
signal with different phases

Please have a look at the zero crossings!

Note: the phase can be either expressed as +/-Pi or +/-180deg. The signal itself can be described as cosine or sine, both is equivalent and up to you depending where you define time = 0.


should/can we type TeX? is this supported by our wiki setup?