I am moving from LTspice to NgSpice. In the former the inductance has a default value of a series resistance of 1milli oHms (that could be set to zero by adding 'Rser=0' in the line command defining the value and nodes of the inductor), whereas for the latter no information seems to be given in the documentation. Does anyone have an idea if the NgSpice inductors have a series resistance or not. If yes, what is the command to use in order to set its value to 0?

Thanks in advance

  • \$\begingroup\$ Any simulator that hides the fact that it has an added internal series resistor (even though that value may be easy to change as per LTSpice) is, in my humble opinion, a disservice to designers. An inductor is an inductor and should never be merged with a resistor. That fact that LTSpice and others have done so is more a marketing ploy than a sensible engineering decision. So, if NgSpice doesn't naturally include a series resistor then rejoice and sing this from the hilltops. \$\endgroup\$
    – Andy aka
    Jan 21, 2022 at 10:44
  • \$\begingroup\$ @Andyaka I agree, I had some problems at first to understand why I had an added resistance in DC, but gotten to correct it later. Do you have any idea about NgSpice, if it eventually does the same? \$\endgroup\$
    – Wallflower
    Jan 21, 2022 at 10:47
  • \$\begingroup\$ I don't use NgSpice. \$\endgroup\$
    – Andy aka
    Jan 21, 2022 at 11:23
  • \$\begingroup\$ @Andyaka It's not hidden, it's both in the help and in the properties dialog. \$\endgroup\$ Jan 21, 2022 at 12:25

1 Answer 1


Just set up a current source of 1 A with a parallel inductor and read the DC voltage. Even better, use the same current source but in an .AC analysis (of several decades). It should be more than sufficient to determine whether there are poles or zeroes.


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