[Qucs-help] Mosfets strange behaviour...

[<ct...@li...>]

Hi, i am a beginner in electronic and i try to simulate the attached project file.

First thing :
I don't know why, but i can't put directly the mosfet to the project, i had to use "manage library" instead
and i'm not sure if it's the right way to do...

Second things
With a source of 5V, no warning appear, perhaps the value a correct.
If i change the voltage to 9v, some warnings occurs, and the values of the probes are quite strange.
If i put a voltage of 24v, i have no values, sometime the simulation never end...

If i replace the mosfet by a 2n2222 transistor, everything work fine...

I can't understand what i am doing wrong...
Please help and excuse my poor english.

Many thanks, Chris

below the file mosfet.sch




<Qucs Schematic 0.0.18>
<Properties>
  <View=0,0,1348,800,1,0,0>
  <Grid=10,10,1>
  <DataSet=mosfet.dat>
  <DataDisplay=mosfet.dpl>
  <OpenDisplay=1>
  <Script=mosfet.m>
  <RunScript=0>
  <showFrame=0>
  <FrameText0=Titre>
  <FrameText1=Auteur :>
  <FrameText2=Date :>
  <FrameText3=Version :>
</Properties>
<Symbol>
</Symbol>
<Components>
  <.DC DC1 1 60 60 0 63 0 0 "26.85" 0 "0.001" 0 "1 pA" 0 "1 uV" 0 "no" 0 "150" 0 "no" 0 "none" 0 "CroutLU" 0>
  <GND * 1 320 620 0 0 0 0>
  <R R3 1 420 530 15 -26 0 1 "4700000 Ohm" 1 "26.85" 0 "0.0" 0 "0.0" 0 "26.85" 0 "european" 0>
  <R R2 1 760 370 15 -26 0 1 "680 Ohm" 1 "26.85" 0 "0.0" 0 "0.0" 0 "26.85" 0 "european" 0>
  <Lib T1 1 760 450 8 -26 0 0 "NMOSFETs" 0 "BS170" 0>
  <IProbe Ic 1 650 280 -26 16 0 0>
  <IProbe Ib 1 650 450 -26 16 0 0>
  <R R1 1 420 370 15 -26 0 1 "RSensor" 1 "26.85" 0 "0.0" 0 "0.0" 0 "26.85" 0 "european" 0>
  <.SW SW1 1 1190 120 0 63 0 0 "DC1" 1 "lin" 1 "RSensor" 1 "100000 Ohm" 1 "500000 Ohm" 1 "20" 1>
  <Vdc V1 1 320 450 18 -26 0 1 "9 V" 1>
</Components>
<Wires>
  <320 480 320 620 "" 0 0 0 "">
  <320 280 320 420 "" 0 0 0 "">
  <420 400 420 450 "" 0 0 0 "">
  <420 450 420 500 "" 0 0 0 "">
  <420 450 620 450 "" 0 0 0 "">
  <760 400 760 420 "" 0 0 0 "">
  <760 280 760 340 "" 0 0 0 "">
  <320 280 420 280 "" 0 0 0 "">
  <420 280 620 280 "" 0 0 0 "">
  <420 280 420 340 "" 0 0 0 "">
  <320 620 420 620 "" 0 0 0 "">
  <760 480 760 620 "" 0 0 0 "">
  <420 620 760 620 "" 0 0 0 "">
  <420 560 420 620 "" 0 0 0 "">
  <680 280 760 280 "" 0 0 0 "">
  <680 450 730 450 "" 0 0 0 "">
</Wires>
<Diagrams>
</Diagrams>
<Paintings>
</Paintings>