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Re: [Help-gnucap] howto use different phase and frequency in sources for
Rubén Gómez Antolí
Re: [Help-gnucap] howto use different phase and frequency in sources for transient analysis?
Tue, 27 Oct 2009 23:00:04 +0100
Mozilla-Thunderbird 18.104.22.168 (X11/20090701)
al davis escribió:
Quick answer .. I will get back with more details in a few
Ok, We wait for these details.
What is the Pspice syntax for specifying phase on a "sin"
source? It's not in Berkeley spice.
There is the usual custom for propietary apps: deform the standard to
complicate the competence (like HTML's IE tags, for example):
Here are the 90% of my problems: exercises thought for Pspice with
incompatible syntax for free engines like Gnucap or Ngspice; or model,
macromodel for Pspice (like thyristor, UJT...) with a difficult -or
imposible for a newbie, like me- way to translate to Berkeley spice.
It would be just another way to specify the delay ... the phase
at time = 0.
I just did find a bug in the way the Fourier command computes
But that is not the problem you saw.
The absolute phase you see in a Fourier analysis is referenced
to the start of the interval, so it will be different on
different runs depending on the starting time. It does appear
to be correct, from that perspective.
That really doesn't matter. It is just a time shift.
I think the reason your waveform built from the sum of sources
doesn't match the signal you took the Fourier transform of is
that you are only using up to the fifth harmonic, so there is a
Perhaps I should explain a bit more:
Start with a Diode brigde rectifier and do a Fourier analysis:
# i(LS) --------- actual --------- -------- relative --------
#freq value dB phase value dB phase
0. 0.0063273 -43.98 90.000 405.58E-6 -67.84 100.271
60. 15.601 23.86 -10.271 1. 0.00 -0.000
120. 0.011073 -39.11 -92.415 709.79E-6 -62.98 -82.144
180. 11.821 21.45 148.226 0.75772 -2.41 158.497
240. 0.0071613 -42.90 85.933 459.04E-6 -66.76 96.205
300. 6.3621 16.07 -57.484 0.40781 -7.79 -47.213
360. 0.0028582 -50.88 -93.075 183.21E-6 -74.74 -82.804
420. 2.009 6.06 77.596 0.12877 -17.80 87.867
480. 189.74E-6 -74.44 -162.004 12.162E-6 -98.30 -151.732
540. 0.94716 -0.47 143.495 0.060713 -24.33 153.766
and transient analysis for view i(VS).
Next exercise: check grafically source current i(VS) how sum of
fundamental and two first harmonics (3 and 5).
I obtain the three currents well, something "displaced" compare with
But i(VS) is not the wave expected.
Also, the circuit doesn't look correct, but that could be due to
partial cut and paste errors.
There are no errors in paste circuit, I'm sure now that circuit is not
correct; this is my fault: I should work on it a bit more.
Thanks so much for your fast answer.
Salud y Revolución.
Libertad es poder elegir en cualquier momento. Ahora yo elijo GNU/Linux,
para no atar mis manos con las cadenas del soft propietario.
Desde El Ejido, en Almería, usuario registrado Linux #294013