03-14-2009 07:17 AM - edited 03-14-2009 07:20 AM
How to get the wave profile of the attached vi.
The waveform is made of oscillition of AC waveform. Only the wave profile is useful.
May I know how to get it out.
03-14-2009 12:31 PM
If I understand you correctly, you want the enveloping curve of the signal or the amplitudes of each period?
Some ideas, you posted too little info on the signal:
* chop the signal with a trigger close to zero, then just take the max for each chunk
* Filter out the carrier signal, use a bandstop filter of the frequency
* Do an AM demodulation by multiplying the signal with a square or sine wave of the amplitude and phase of the carrier signal, afterwards do some lowpass filtering (40 Hz).
Felix
03-15-2009 09:25 AM
Please see the screenshot for the signal, the lower chat shows the zoom in.
I want to get the red curve envelope in the upper figure. And also get the parameter of i1 and i2.
* chop the signal with a trigger close to zero, then just take the max for each chunk
does it mean chop it into pieces, and get the max of each piece, just like a sliding window.
* Filter out the carrier signal, use a bandstop filter of the frequency
May you give some details, since the envelope signal still contain sharp component at start and slow signal at end.
* Do an AM demodulation by multiplying the signal with a square or sine wave of the amplitude and phase of the carrier signal, afterwards do some lowpass filtering (40 Hz).
Sounds great, may you give the details, thanks.
03-15-2009 09:25 AM
03-15-2009 10:13 PM
Its different for another one. It need to get the redline envelope and the i1,2.
Please see the attached screenshot. the lower chart is zoom in.