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Active Inductor simulation (Read 268 times)
blue111
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Active Inductor simulation
Aug 09th, 2017, 8:27pm
 
I am using ngspice to simulate active inductor in https://github.com/promach/frequency_trap

why Vtest = -2 ?

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Geoffrey_Coram
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Re: Active Inductor simulation
Reply #1 - Aug 11th, 2017, 7:53am
 
Perhaps because of the "ac 2" in the source description for the source Vtest? I can't tell the polarity of the source in the schematic.
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Ken Kundert
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Re: Active Inductor simulation
Reply #2 - Aug 11th, 2017, 11:53am
 
It is very strange that AC results would be negative. By the default the magnitude should be shown. Did you ask for the real part to be plotted?

-Ken
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mhx
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Re: Active Inductor simulation
Reply #3 - Aug 11th, 2017, 10:02pm
 
> why Vtest = -2 ?

(I wonder: Cs=100uF, Cl=1F?)

In case you are doing this with NGSPICE:
the NGSPICE plot command "plot V(test)"
displays -2. (The real part of V(test)).
This is because the positive terminal of
the AC source is grounded.
Try plot abs(V(test)) instead.

-marcel
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« Last Edit: Aug 12th, 2017, 12:30am by mhx »  
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blue111
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Re: Active Inductor simulation
Reply #4 - Sep 7th, 2017, 9:23pm
 
@mhx

is there a way to put 'plot v_ip_out#branch' inside spice-epilog control directive without any syntax error ?

Note: this only works in ngspice interactive terminal, but not in gschem spice-epilog control directive.

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