Hi, I found the time to go back to my past and revisit spice (used older Berkeley spice then) so I tried a simple RLC circuit from the following link and using ngspice: http://www.allaboutcircuits.com/vol_2/chpt_6/3.html Unfortunately, I was not able to duplicate the plots as shown in the above link. I am assuming that the author is using something other than ngspice or I am doing something wrong? Attached is the rlc.sch file with the same circuit sans the circuit netlist but it can be easily generated: > gnetlist -o rlc.cir -g spice-sdb rlc.sch The contents of rlc.cir is: ********************************************************* * Spice file generated by gnetlist * * spice-sdb version 4.28.2007 by SDB -- * * provides advanced spice netlisting capability. * * Documentation at http://www.brorson.com/gEDA/SPICE/ * ********************************************************* *============== Begin SPICE netlist of main design ============ L1 0 3 10mH C1 3 2 10uF R1 1 2 1 V1 1 0 dc 0 ac 1 sin .end Since the following was probably added manually: .ac lin 20 100 200 .plot ac i(v1) so, I added this in manually and ngspice seems to have ignored it when started, so at this point I left it out. I restarted ngspice: > ngspice rlc.cir ****** ** ngspice-21plus : Circuit level simulation program ** The U. C. Berkeley CAD Group ** Copyright 1985-1994, Regents of the University of California. ** Please submit bug-reports to: ngspice-bugs@xxxxxxxxxxxxxxxxxxxxx ** Creation Date: Thu Jul 22 17:58:52 UTC 2010 ****** Circuit: * gnetlist -o rlc.cir -g spice-sdb rlc.sch ngspice 1 -> ac lin 20 100 200 <-- manually typed in Doing analysis at TEMP = 27.000000 and TNOM = 27.000000 No. of Data Rows : 20 ngspice 2 -> plot i(v1) v(2,3) v(3) <-- manually typed in I noted that I had to leave out 'ac' in plot command line as ngspice did not recognize this vector... Anyway, the plot results did not match what was given in the link. What I was looking for was a peak as shown in the link but it looked more like a lowpass filter.... what am I doing wrong? Thanks-
Attachment:
rlc.sch
Description: application/kicad-schematic
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