Measuring mu' and mu'' of ferrite cores

NanoVNASaver/Charts/RI.py

@@ -72,33 +72,7 @@ def __init__(self, name=""):
         mode_group.addAction(self.y_action_fixed_span)
         self.y_menu.addAction(self.y_action_automatic)
         self.y_menu.addAction(self.y_action_fixed_span)
-        self.y_menu.addSeparator()
 
-        self.action_set_fixed_maximum_real = QtWidgets.QAction(
-            f"Maximum R ({self.maxDisplayReal})")
-        self.action_set_fixed_maximum_real.triggered.connect(
-            self.setMaximumRealValue)
-
-        self.action_set_fixed_minimum_real = QtWidgets.QAction(
-            f"Minimum R ({self.minDisplayReal})")
-        self.action_set_fixed_minimum_real.triggered.connect(
-            self.setMinimumRealValue)
-
-        self.action_set_fixed_maximum_imag = QtWidgets.QAction(
-            f"Maximum jX ({self.maxDisplayImag})")
-        self.action_set_fixed_maximum_imag.triggered.connect(
-            self.setMaximumImagValue)
-
-        self.action_set_fixed_minimum_imag = QtWidgets.QAction(
-            f"Minimum jX ({self.minDisplayImag})")
-        self.action_set_fixed_minimum_imag.triggered.connect(
-            self.setMinimumImagValue)
-
-        self.y_menu.addAction(self.action_set_fixed_maximum_real)
-        self.y_menu.addAction(self.action_set_fixed_minimum_real)
-        self.y_menu.addSeparator()
-        self.y_menu.addAction(self.action_set_fixed_maximum_imag)
-        self.y_menu.addAction(self.action_set_fixed_minimum_imag)
 
     def copy(self):
         new_chart: RealImaginaryChart = super().copy()
@@ -109,23 +83,6 @@ def copy(self):
         new_chart.minDisplayImag = self.minDisplayImag
         return new_chart
 
-    def drawChart(self, qp: QtGui.QPainter):
-        qp.setPen(QtGui.QPen(Chart.color.text))
-        qp.drawText(self.leftMargin + 5, 15,
-                    f"{self.name} (\N{OHM SIGN})")
-        qp.drawText(10, 15, "R")
-        qp.drawText(self.leftMargin + self.dim.width + 10, 15, "X")
-        qp.setPen(QtGui.QPen(Chart.color.foreground))
-        qp.drawLine(self.leftMargin,
-                    self.topMargin - 5,
-                    self.leftMargin,
-                    self.topMargin + self.dim.height + 5)
-        qp.drawLine(self.leftMargin - 5,
-                    self.topMargin + self.dim.height,
-                    self.leftMargin + self.dim.width + 5,
-                    self.topMargin + self.dim.height)
-        self.drawTitle(qp)
-
     def drawValues(self, qp: QtGui.QPainter):
         if not self.data and not self.reference:
             return
@@ -333,7 +290,7 @@ def find_scaling(self):
         max_real = 0
         max_imag = -1000
         for d in self.data:
-            imp = self.impedance(d)
+            imp = self.value(d)
             re, im = imp.real, imp.imag
             if math.isinf(re):  # Avoid infinite scales
                 continue
@@ -345,7 +302,7 @@ def find_scaling(self):
         for d in self.reference:
             if d.freq < self.fstart or d.freq > self.fstop:
                 continue
-            imp = self.impedance(d)
+            imp = self.value(d)
             re, im = imp.real, imp.imag
             if math.isinf(re):  # Avoid infinite scales
                 continue
@@ -393,12 +350,12 @@ def imag_scaling_constraints(self, min_imag, max_imag):
         return min_imag, max_imag
 
     def getImYPosition(self, d: Datapoint) -> int:
-        im = self.impedance(d).imag
+        im = self.value(d).imag
         return int(self.topMargin + (self.max_imag - im) / self.span_imag
                    * self.dim.height)
 
     def getReYPosition(self, d: Datapoint) -> int:
-        re = self.impedance(d).real
+        re = self.value(d).real
         return int(self.topMargin + (self.max_real - re) / self.span_real
                    * self.dim.height if math.isfinite(re) else self.topMargin)
 
@@ -521,5 +478,5 @@ def contextMenuEvent(self, event):
             f"Maximum jX ({self.maxDisplayImag})")
         self.menu.exec_(event.globalPos())
 
-    def impedance(self, p: Datapoint) -> complex:
-        return p.impedance()
+    def value(self, p: Datapoint) -> complex:
+        raise NotImplementedError()

NanoVNASaver/Charts/RIMu.py

@@ -0,0 +1,178 @@
+#  NanoVNASaver
+#
+#  A python program to view and export Touchstone data from a NanoVNA
+#  Copyright (C) 2019, 2020  Rune B. Broberg
+#  Copyright (C) 2020,2021 NanoVNA-Saver Authors
+#
+#  This program is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+import math
+import numpy as np
+import logging
+from scipy.constants import mu_0
+
+from PyQt5 import QtWidgets, QtGui
+
+from NanoVNASaver.Formatting import format_frequency_chart
+from NanoVNASaver.RFTools import Datapoint
+from NanoVNASaver.Charts.Chart import Chart
+
+from .RI import RealImaginaryChart
+
+logger = logging.getLogger(__name__)
+
+MU = "\N{GREEK SMALL LETTER MU}"
+
+class RealImaginaryMuChart(RealImaginaryChart):
+
+    def __init__(self, name=""):
+        super().__init__(name)
+        self.y_menu.addSeparator()
+
+        self.action_set_fixed_maximum_real = QtWidgets.QAction(
+            f"Maximum {MU}' ({self.maxDisplayReal})")
+        self.action_set_fixed_maximum_real.triggered.connect(
+            self.setMaximumRealValue)
+
+        self.action_set_fixed_minimum_real = QtWidgets.QAction(
+            f"Minimum {MU}' ({self.minDisplayReal})")
+        self.action_set_fixed_minimum_real.triggered.connect(
+            self.setMinimumRealValue)
+
+        self.action_set_fixed_maximum_imag = QtWidgets.QAction(
+            f"Maximum {MU}'' ({self.maxDisplayImag})")
+        self.action_set_fixed_maximum_imag.triggered.connect(
+            self.setMaximumImagValue)
+
+        self.action_set_fixed_minimum_imag = QtWidgets.QAction(
+            f"Minimum {MU}'' ({self.minDisplayImag})")
+        self.action_set_fixed_minimum_imag.triggered.connect(
+            self.setMinimumImagValue)
+
+        self.y_menu.addAction(self.action_set_fixed_maximum_real)
+        self.y_menu.addAction(self.action_set_fixed_minimum_real)
+        self.y_menu.addSeparator()
+        self.y_menu.addAction(self.action_set_fixed_maximum_imag)
+        self.y_menu.addAction(self.action_set_fixed_minimum_imag)
+
+        # Manage core parameters 
+        # TODO pick some sane default values?
+        self.coreLength = 1.
+        self.coreArea = 1.
+        self.coreWindings = 1
+
+        self.menu.addSeparator()
+        self.action_set_core_length = QtWidgets.QAction(
+            "Core effective length")
+        self.action_set_core_length.triggered.connect(
+            self.setCoreLength)
+
+        self.action_set_core_area = QtWidgets.QAction(
+            "Core area")
+        self.action_set_core_area.triggered.connect(
+            self.setCoreArea)
+
+        self.action_set_core_windings = QtWidgets.QAction(
+            "Core number of windings")
+        self.action_set_core_windings.triggered.connect(
+            self.setCoreWindings)
+
+        self.menu.addAction(self.action_set_core_length)
+        self.menu.addAction(self.action_set_core_area)
+        self.menu.addAction(self.action_set_core_windings)
+
+    def copy(self):
+        new_chart: RealImaginaryMuChart = super().copy()
+
+        new_chart.coreLength = self.coreLength
+        new_chart.coreArea = self.coreArea
+        new_chart.coreWindings = self.coreWindings
+
+        return new_chart
+
+    def drawChart(self, qp: QtGui.QPainter):
+        qp.setPen(QtGui.QPen(Chart.color.text))
+        qp.drawText(self.leftMargin + 5, 15,
+                    f"{self.name}")
+        qp.drawText(5, 15, f"{MU}'")
+        qp.drawText(self.leftMargin + self.dim.width + 10, 15, f"{MU}''")
+        qp.setPen(QtGui.QPen(Chart.color.foreground))
+        qp.drawLine(self.leftMargin,
+                    self.topMargin - 5,
+                    self.leftMargin,
+                    self.topMargin + self.dim.height + 5)
+        qp.drawLine(self.leftMargin-5,
+                    self.topMargin + self.dim.height,
+                    self.leftMargin + self.dim.width + 5,
+                    self.topMargin + self.dim.height)
+        self.drawTitle(qp)
+
+    def contextMenuEvent(self, event):
+        self.action_set_fixed_start.setText(
+            f"Start ({format_frequency_chart(self.minFrequency)})")
+        self.action_set_fixed_stop.setText(
+            f"Stop ({format_frequency_chart(self.maxFrequency)})")
+        self.action_set_fixed_minimum_real.setText(
+            f"Minimum {MU}' ({self.minDisplayReal})")
+        self.action_set_fixed_maximum_real.setText(
+            f"Maximum {MU}' ({self.maxDisplayReal})")
+        self.action_set_fixed_minimum_imag.setText(
+            f"Minimum {MU}'' ({self.minDisplayImag})")
+        self.action_set_fixed_maximum_imag.setText(
+            f"Maximum {MU}'' ({self.maxDisplayImag})")
+        self.menu.exec_(event.globalPos())
+
+    def setCoreLength(self):
+        val, selected = QtWidgets.QInputDialog.getDouble(
+            self, "Core effective length",
+            "Set core effective length in mm", value=self.coreLength,
+            decimals=2)
+        if not selected:
+            return
+        if not (self.fixedValues and val >= 0):
+            self.coreLength = val
+        if self.fixedValues:
+            self.update()
+
+    def setCoreArea(self):
+        val, selected = QtWidgets.QInputDialog.getDouble(
+            self, "Core effective area",
+            "Set core cross section area length in mm\N{SUPERSCRIPT TWO}", value=self.coreArea,
+            decimals=2)
+        if not selected:
+            return
+        if not (self.fixedValues and val >= 0):
+            self.coreArea = val
+        if self.fixedValues:
+            self.update()
+
+    def setCoreWindings(self):
+        val, selected = QtWidgets.QInputDialog.getInt(
+            self, "Core number of windings",
+            "Set core number of windings", value=self.coreWindings)
+        if not selected:
+            return
+        if not (self.fixedValues and val >= 0):
+            self.coreWindings = val
+        if self.fixedValues:
+            self.update()
+
+    def value(self, p: Datapoint) -> complex:
+        return self.mu_r(p)
+
+    def mu_r(self, p: Datapoint) -> complex:
+        inductance = p.impedance()/(2j*math.pi*p.freq)
+
+        # Core length and core area are in mm and mm2 respectively
+        # note: mu_r = mu' - j * mu ''
+        return np.conj(inductance * (self.coreLength/1e3) / (mu_0 * self.coreWindings**2 * (self.coreArea/1e6)))

NanoVNASaver/Charts/RIZ.py

@@ -0,0 +1,98 @@
+#  NanoVNASaver
+#
+#  A python program to view and export Touchstone data from a NanoVNA
+#  Copyright (C) 2019, 2020  Rune B. Broberg
+#  Copyright (C) 2020,2021 NanoVNA-Saver Authors
+#
+#  This program is free software: you can redistribute it and/or modify
+#  it under the terms of the GNU General Public License as published by
+#  the Free Software Foundation, either version 3 of the License, or
+#  (at your option) any later version.
+#
+#  This program is distributed in the hope that it will be useful,
+#  but WITHOUT ANY WARRANTY; without even the implied warranty of
+#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#  GNU General Public License for more details.
+#
+#  You should have received a copy of the GNU General Public License
+#  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+import logging
+
+from PyQt5 import QtWidgets, QtGui
+
+from NanoVNASaver.Formatting import format_frequency_chart
+from NanoVNASaver.RFTools import Datapoint
+from NanoVNASaver.Charts.Chart import Chart
+
+from .RI import RealImaginaryChart
+
+logger = logging.getLogger(__name__)
+
+class RealImaginaryZChart(RealImaginaryChart):
+    def __init__(self, name=""):
+        super().__init__(name)
+        self.y_menu.addSeparator()
+
+        self.action_set_fixed_maximum_real = QtWidgets.QAction(
+            f"Maximum R ({self.maxDisplayReal})")
+        self.action_set_fixed_maximum_real.triggered.connect(
+            self.setMaximumRealValue)
+
+        self.action_set_fixed_minimum_real = QtWidgets.QAction(
+            f"Minimum R ({self.minDisplayReal})")
+        self.action_set_fixed_minimum_real.triggered.connect(
+            self.setMinimumRealValue)
+
+        self.action_set_fixed_maximum_imag = QtWidgets.QAction(
+            f"Maximum jX ({self.maxDisplayImag})")
+        self.action_set_fixed_maximum_imag.triggered.connect(
+            self.setMaximumImagValue)
+
+        self.action_set_fixed_minimum_imag = QtWidgets.QAction(
+            f"Minimum jX ({self.minDisplayImag})")
+        self.action_set_fixed_minimum_imag.triggered.connect(
+            self.setMinimumImagValue)
+
+        self.y_menu.addAction(self.action_set_fixed_maximum_real)
+        self.y_menu.addAction(self.action_set_fixed_minimum_real)
+        self.y_menu.addSeparator()
+        self.y_menu.addAction(self.action_set_fixed_maximum_imag)
+        self.y_menu.addAction(self.action_set_fixed_minimum_imag)
+
+    def drawChart(self, qp: QtGui.QPainter):
+        qp.setPen(QtGui.QPen(Chart.color.text))
+        qp.drawText(self.leftMargin + 5, 15,
+                    f"{self.name} (\N{OHM SIGN})")
+        qp.drawText(10, 15, "R")
+        qp.drawText(self.leftMargin + self.dim.width + 10, 15, "X")
+        qp.setPen(QtGui.QPen(Chart.color.foreground))
+        qp.drawLine(self.leftMargin,
+                    self.topMargin - 5,
+                    self.leftMargin,
+                    self.topMargin + self.dim.height + 5)
+        qp.drawLine(self.leftMargin-5,
+                    self.topMargin + self.dim.height,
+                    self.leftMargin + self.dim.width + 5,
+                    self.topMargin + self.dim.height)
+        self.drawTitle(qp)
+
+    def contextMenuEvent(self, event):
+        self.action_set_fixed_start.setText(
+            f"Start ({format_frequency_chart(self.minFrequency)})")
+        self.action_set_fixed_stop.setText(
+            f"Stop ({format_frequency_chart(self.maxFrequency)})")
+        self.action_set_fixed_minimum_real.setText(
+            f"Minimum R ({self.minDisplayReal})")
+        self.action_set_fixed_maximum_real.setText(
+            f"Maximum R ({self.maxDisplayReal})")
+        self.action_set_fixed_minimum_imag.setText(
+            f"Minimum jX ({self.minDisplayImag})")
+        self.action_set_fixed_maximum_imag.setText(
+            f"Maximum jX ({self.maxDisplayImag})")
+        self.menu.exec_(event.globalPos())
+
+    def value(self, p: Datapoint) -> complex:
+        return self.impedance(p)
+
+    def impedance(self, p: Datapoint) -> complex:
+        return p.impedance()

NanoVNASaver/Charts/RISeries.py → NanoVNASaver/Charts/RIZSeries.py

@@ -19,12 +19,12 @@
 import logging
 
 from NanoVNASaver.RFTools import Datapoint
-from .RI import RealImaginaryChart
+from .RIZ import RealImaginaryZChart
 
 logger = logging.getLogger(__name__)
 
 
-class RealImaginarySeriesChart(RealImaginaryChart):
+class RealImaginaryZSeriesChart(RealImaginaryZChart):
 
     def impedance(self, p: Datapoint) -> complex:
         return p.seriesImpedance()