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I am running the following Tesla coil circuit in Open Modelica:

enter image description here

I have implemented the circuit with Open Modelica like this:

enter image description here

But the problem is that the R9 register is not having any voltage or current. I have tested connecting the R9 port to ground, and it gains voltage and current. But when it is connected to an N-MOSFET it gets no voltage or current. Is this related to the threshhold voltage of the N-MOSFET?

And R3's voltage is fine like this:

enter image description here

This is my code:

model SSTC
  Modelica.Electrical.Analog.Semiconductors.NPN Q1_NPN annotation(
    Placement(visible = true, transformation(origin = {-46, -38}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Analog.Semiconductors.NPN Q2_npn annotation(
    Placement(visible = true, transformation(origin = {12, -32}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Analog.Basic.Resistor R3(R = 10)  annotation(
    Placement(visible = true, transformation(origin = {-16, -32}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Analog.Basic.Ground ground annotation(
    Placement(visible = true, transformation(origin = {22, -94}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Analog.Basic.Resistor R1(R = 7500)  annotation(
    Placement(visible = true, transformation(origin = {-78, -38}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Analog.Sources.PulseVoltage pulseVoltage(V = 12, period = 1)  annotation(
    Placement(visible = true, transformation(origin = {-124, -48}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
  Modelica.Electrical.Analog.Basic.Resistor R8(R = 150)  annotation(
    Placement(visible = true, transformation(origin = {22, 60}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
  Modelica.Electrical.Analog.Sources.ConstantVoltage constantVoltage(V = 18)  annotation(
    Placement(visible = true, transformation(origin = {-30, 60}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
  Modelica.Electrical.Analog.Basic.Resistor R9(R = 10) annotation(
    Placement(visible = true, transformation(origin = {60, -26}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Analog.Basic.Resistor R10(R = 10) annotation(
    Placement(visible = true, transformation(origin = {56, 70}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Analog.Semiconductors.NMOS nMOS annotation(
    Placement(visible = true, transformation(origin = {108, -20}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Analog.Basic.Capacitor capacitor(C = 0.00000001)  annotation(
    Placement(visible = true, transformation(origin = {76, 34}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
  Modelica.Electrical.Analog.Basic.Transformer transformer(L1 = 50, L2 = 5000, M = 10)  annotation(
    Placement(visible = true, transformation(origin = {128, 40}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Electrical.Analog.Basic.Ground ground1 annotation(
    Placement(visible = true, transformation(origin = {142, -94}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
  Modelica.Blocks.Sources.BooleanPulse booleanPulse(period = 0.1, width = 50) annotation(
    Placement(visible = true, transformation(extent = {{84, 82}, {104, 102}}, rotation = 0)));
  Modelica.Electrical.Analog.Ideal.CloserWithArc switch2(V0 = 100, Vmax = 1000, dVdt = 10000, off(fixed = true)) annotation(
    Placement(visible = true, transformation(extent = {{164, 40}, {184, 60}}, rotation = 0)));
  Modelica.Electrical.Analog.Sources.ConstantVoltage constantVoltage1(V = 12)  annotation(
    Placement(visible = true, transformation(origin = {-156, -16}, extent = {{-10, -10}, {10, 10}}, rotation = -90)));
  Modelica.Electrical.Analog.Basic.Resistor R7(R = 180)  annotation(
    Placement(visible = true, transformation(origin = {-86, 0}, extent = {{-10, -10}, {10, 10}}, rotation = 0)));
equation
  connect(pulseVoltage.p, R1.p) annotation(
    Line(points = {{-124, -38}, {-88, -38}}, color = {0, 0, 255}));
  connect(R1.n, Q1_NPN.B) annotation(
    Line(points = {{-68, -38}, {-56, -38}}, color = {0, 0, 255}));
  connect(Q1_NPN.C, R3.p) annotation(
    Line(points = {{-36, -32}, {-26, -32}}, color = {0, 0, 255}));
  connect(R3.n, Q2_npn.B) annotation(
    Line(points = {{-6, -32}, {2, -32}}, color = {0, 0, 255}));
  connect(Q1_NPN.E, ground.p) annotation(
    Line(points = {{-36, -44}, {-32, -44}, {-32, -84}, {22, -84}}, color = {0, 0, 255}));
  connect(pulseVoltage.n, ground.p) annotation(
    Line(points = {{-124, -58}, {-124, -84}, {22, -84}}, color = {0, 0, 255}));
  connect(Q2_npn.C, R8.n) annotation(
    Line(points = {{22, -26}, {22, 50}}, color = {0, 0, 255}));
  connect(constantVoltage.p, R8.p) annotation(
    Line(points = {{-30, 70}, {22, 70}}, color = {0, 0, 255}));
  connect(constantVoltage.n, ground.p) annotation(
    Line(points = {{-30, 50}, {-140, 50}, {-140, -84}, {22, -84}}, color = {0, 0, 255}));
  connect(Q2_npn.C, R9.p) annotation(
    Line(points = {{22, -26}, {50, -26}}, color = {0, 0, 255}));
  connect(R8.p, R10.p) annotation(
    Line(points = {{22, 70}, {46, 70}}, color = {0, 0, 255}));
  connect(nMOS.B, ground.p) annotation(
    Line(points = {{118, -20}, {118, -84}, {22, -84}}, color = {0, 0, 255}));
  connect(nMOS.S, ground.p) annotation(
    Line(points = {{118, -26}, {118, -84}, {22, -84}}, color = {0, 0, 255}));
  connect(R10.n, capacitor.p) annotation(
    Line(points = {{66, 70}, {76, 70}, {76, 44}}, color = {0, 0, 255}));
  connect(capacitor.n, nMOS.D) annotation(
    Line(points = {{76, 24}, {76, 2}, {118, 2}, {118, -14}}, color = {0, 0, 255}));
  connect(transformer.n1, nMOS.D) annotation(
    Line(points = {{118, 30}, {118, -14}}, color = {0, 0, 255}));
  connect(R10.n, transformer.p1) annotation(
    Line(points = {{66, 70}, {118, 70}, {118, 50}}, color = {0, 0, 255}));
  connect(transformer.n2, ground1.p) annotation(
    Line(points = {{138, 30}, {142, 30}, {142, -84}}, color = {0, 0, 255}));
  connect(transformer.p2, switch2.p) annotation(
    Line(points = {{138, 50}, {164, 50}}, color = {0, 0, 255}));
  connect(switch2.n, ground1.p) annotation(
    Line(points = {{184, 50}, {178, 50}, {178, -84}, {142, -84}}, color = {0, 0, 255}));
  connect(booleanPulse.y, switch2.control) annotation(
    Line(points = {{105, 92}, {174, 92}, {174, 62}}, color = {255, 0, 255}));
  connect(constantVoltage1.n, ground.p) annotation(
    Line(points = {{-156, -26}, {-156, -84}, {22, -84}}, color = {0, 0, 255}));
  connect(constantVoltage1.p, R7.p) annotation(
    Line(points = {{-156, -6}, {-156, 0}, {-96, 0}}, color = {0, 0, 255}));
  connect(R7.n, Q1_NPN.C) annotation(
    Line(points = {{-76, 0}, {-36, 0}, {-36, -32}}, color = {0, 0, 255}));
  connect(Q2_npn.E, ground.p) annotation(
    Line(points = {{22, -38}, {22, -84}}, color = {0, 0, 255}));
  connect(R9.n, nMOS.G) annotation(
    Line(points = {{70, -26}, {98, -26}}, color = {0, 0, 255}));
  annotation(
    uses(Modelica(version = "4.0.0")));
end SSTC;
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1 Answer 1

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As i understand, by "resistor not having voltage or current" you mean that there is no significant voltage drop on it. This is caused by its small resistance (10 Ohm) and low current, because there is no direct current flow through MOSFET gate electrode. And in series with R3 there is R7 with bigger value which limits current through both of them. Both effects are normal, this is just Ohm's law.

You likely will not be able to simulate Tesla coil in such way because it works due to distributed resonance in the secondary coil of transformer, which, likely is not taken in account in this model.

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