From 2d42445ee8f8d3eeb2e9e327c44b1ef014e69273 Mon Sep 17 00:00:00 2001 From: miguel Date: Tue, 24 Nov 2020 19:24:41 +1100 Subject: [PATCH] New versions - imperial and large metric --- inductor.css | 29 +++ inductor.html | 239 ++++++----------------- inductor.js | 127 +++++++++++++ inductor_imp.html | 437 ++++++++++++++++++++++++++++++++++++++++++ inductor_lrg.html | 476 ++++++++++++++++++++++++++++++++++++++++++++++ 5 files changed, 1129 insertions(+), 179 deletions(-) create mode 100644 inductor.js create mode 100644 inductor_imp.html create mode 100644 inductor_lrg.html diff --git a/inductor.css b/inductor.css index 7afcca7..78ffc11 100644 --- a/inductor.css +++ b/inductor.css @@ -114,6 +114,35 @@ div input { } } +@media screen and (min-width: 800px) { + section.gridLayoutClass { + display: grid; + grid-template-columns: 1fr 1fr; + grid-template-rows: 1fr 1fr; + grid-template-areas: + "inductor-container" "slider-container" + "inductor-container" "notes"; + justify-items: stretch; + } + + section div.inductor-container { + height: 100vh; + width: 50vw; + box-sizing: border-box; + } + + section div.slider_container { + width: 100%; + height: 20%; + } + + section div.notes { + width: 100%; + height: 50%; + } +} + + /* @media (orientation: landscape) { section.gridLayoutClass { diff --git a/inductor.html b/inductor.html index b3c912c..fb2d8c2 100644 --- a/inductor.html +++ b/inductor.html @@ -7,7 +7,7 @@ -
Miguel VK3CPU - RF Inductor Calculator v1.0
+
VK3CPU - RF Inductor Calculator v1.0
[Imperial] [Large Metric]
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Notes:
RF Inductor Calculator was developed to help users predict the RF characteristics of a single-layer solenoid-style air-core inductor.

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  • Rac : AC resistance is calculated using the skin effect and proximity resistance from empirical data collected by Medhurst using the spacing ratio, and length-to-diameter ratio.
  • Q : Quality factor of device, based on reactance (X) ÷ resistance (Rac) at the given frequency.
    • +
    + \ No newline at end of file diff --git a/inductor.js b/inductor.js new file mode 100644 index 0000000..71a0717 --- /dev/null +++ b/inductor.js @@ -0,0 +1,127 @@ +// Global constants: +const mu0 = Math.PI * 4e-7; +const cu_sigma = 58e6; // Copper conductance value + +function dcResistance(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns) { + const cond_radius_meters = 0.5 * cond_diameter_meters; + const c_spacing = spacing_ratio * cond_diameter_meters; + const corr_factor = Math.sqrt(1.0 + (c_spacing**2 / loop_diameter_meters**2)); + const conductor_length = Math.PI * loop_diameter_meters * loop_turns * corr_factor; + const conductor_area = Math.PI * (cond_radius_meters**2.0); + return 1.68e-8 * conductor_length / conductor_area; +} + +function skinDepth(frequency_hz) { + return Math.sqrt(1.0 / (Math.PI * frequency_hz * mu0 * cu_sigma)); +} + +// From Knight "Solenoid Impedance and Q" +function dc2acFactor(cond_diameter_meters, skin_depth) { + return cond_diameter_meters**2 / (4.0 * (cond_diameter_meters * skin_depth - skin_depth**2)); +} + +function getInductance(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns) { + const a_coil_radius = loop_diameter_meters * 0.5; + //const b_conductor_radius = cond_diameter_meters * 0.5; + const coil_length = cond_diameter_meters * spacing_ratio * loop_turns; + var retval = (loop_turns**2.0) * mu0 * Math.PI * (a_coil_radius**2.0) * nagaokaCoefficient(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns) / coil_length; + return retval; // In Henries +} + +function inductiveReactance(frequency, inductance) { + return 2.0 * Math.PI * frequency * inductance; // In Ohms +} + +function nagaokaCoefficient(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns) { + // From Knight's 2016 paper on coil self-resonance, attributed to Wheeler's 1982 eqn as modified by Bob Weaver + const c_spacing = spacing_ratio * cond_diameter_meters; + const x = loop_diameter_meters / (c_spacing * loop_turns); + const zk = 2.0 / (Math.PI * x); + const k0 = 1.0 / (Math.log(8.0 / Math.PI) - 0.5); + const k2 = 24.0 / (3.0 * Math.PI**2 - 16.0); + const w = -0.47 / (0.755 + x)**1.44; + const p = k0 + 3.437/x + k2/x**2 + w; + var retval = zk * (Math.log(1 + 1/zk) + 1/p); + return retval; +} + +function ctdw(ff, ei, ex, kL) { + // From Knight's 2016 paper + //const kL = nagaokaCoefficient(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns); + const kct = 1.0/kL - 1.0; + return 11.27350207 * ex * ff * (1.0 + kct * (1.0 + ei/ex) / 2.0); +} + +function ciae(ff, ei, ex) { + // From Knight's 2016 paper + return 17.70837564 * (ei+ex) / Math.log(1.0 + Math.PI**2 * ff); +} + +function multiloopCapacitance(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns) { + const e0 = 8.854187e-12; + const h = spacing_ratio * cond_diameter_meters; + const ei = 1.0; // Assume internal epsilon is air (or free-space) + const ex = 1.0; // Assume external epsilon is air (or free-space) + const solenoid_length = 1.0 * loop_turns * h; + const ff = solenoid_length / loop_diameter_meters; + const kL = nagaokaCoefficient(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns); + var multiloop_capacitance = 1e-12 * (ctdw(ff, ei, ex, kL) / Math.sqrt(1 - h**2 / loop_diameter_meters**2) + ciae(ff, ei, ex)) * loop_diameter_meters; + return multiloop_capacitance; // in Farads +} + +const proximityResistance = [ + // From R.G. Medhurst H.F. Resistance and Self-Capacitance of Single-Layer Solenoids (Feb, 1947) + [ 0.0, 1.0, 1.111, 1.25, 1.429, 1.667, 2.0, 2.5, 3.333, 5.00, 10.0 ], + [ 0.0, 5.31, 3.73, 2.74, 2.12, 1.74, 1.44, 1.20, 1.16, 1.07, 1.02 ], + [ 0.2, 5.45, 3.84, 2.83, 2.20, 1.77, 1.48, 1.29, 1.19, 1.08, 1.02 ], + [ 0.4, 5.65, 3.99, 2.97, 2.28, 1.83, 1.54, 1.33, 1.21, 1.08, 1.03 ], + [ 0.6, 5.80, 4.11, 3.10, 2.38, 1.89, 1.60, 1.38, 1.22, 1.10, 1.03 ], + [ 0.8, 5.80, 4.17, 3.20, 2.44, 1.92, 1.64, 1.42, 1.23, 1.10, 1.03 ], + [ 1.0, 5.55, 4.10, 3.17, 2.47, 1.94, 1.67, 1.45, 1.24, 1.10, 1.03 ], + [ 2.0, 4.10, 3.36, 2.74, 2.32, 1.98, 1.74, 1.50, 1.28, 1.13, 1.04 ], + [ 4.0, 3.54, 3.05, 2.60, 2.27, 2.01, 1.78, 1.54, 1.32, 1.15, 1.04 ], + [ 6.0, 3.31, 2.92, 2.60, 2.29, 2.03, 1.80, 1.56, 1.34, 1.16, 1.04 ], + [ 8.0, 3.20, 2.90, 2.62, 2.34, 2.08, 1.81, 1.57, 1.34, 1.165, 1.04], + [ 10.0, 3.23, 2.93, 2.65, 2.37, 2.10, 1.83, 1.58, 1.35, 1.17, 1.04 ], + [999.0, 3.41, 3.11, 2.815, 2.51, 2.22, 1.93, 1.65, 1.395, 1.19, 1.05] +]; + +function getProximityResFromSpacing(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns) { + // Use the proximityResistance look-up table and interpolate values depending on the spacing ratio and the number of turns. + var retval = 0.0; + const length_diameter_ratio = loop_turns * spacing_ratio * cond_diameter_meters / loop_diameter_meters; + var i = 0; // Going to the right, which is the spacing ratio + var j = 0; // Going down the page, which is the solenoid length to diameter ratio + for (i = 1; i < (proximityResistance[0].length); i++) { + if(spacing_ratio < proximityResistance[0][i]) { + i--; + break; + } + } + for (j = 1; j < (proximityResistance.length); j++) { + if(length_diameter_ratio < proximityResistance[j][0]) { + j--; + break; + } + } + var t1 = ((spacing_ratio - proximityResistance[0][i]) / (proximityResistance[0][i+1] - proximityResistance[0][i])) * (proximityResistance[j][i+1] - proximityResistance[j][i]) + proximityResistance[j][i]; + var t2 = ((spacing_ratio - proximityResistance[0][i]) / (proximityResistance[0][i+1] - proximityResistance[0][i])) * (proximityResistance[j+1][i+1] - proximityResistance[j+1][i]) + proximityResistance[j+1][i]; + retval = ((length_diameter_ratio - proximityResistance[j][0])/(proximityResistance[j+1][0] - proximityResistance[j][0])) * (t2 - t1) + t1; + return retval; +} + +function acResistance(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns, frequency_hz) { + const Rdc = dcResistance(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns); + const dc2ac = dc2acFactor(cond_diameter_meters, skinDepth(frequency_hz)); + const prox = getProximityResFromSpacing(loop_diameter_meters, cond_diameter_meters, spacing_ratio, loop_turns); + return Rdc * dc2ac * prox; +} + +function qualityFactor(reactance, resistance) { + return reactance/resistance; +} + +function selfResonantFrequency(inductance, capacitance) { + var freq = 1.0 / (2.0 * Math.PI * Math.sqrt(inductance * capacitance)); + return freq; +} diff --git a/inductor_imp.html b/inductor_imp.html new file mode 100644 index 0000000..a5b5d44 --- /dev/null +++ b/inductor_imp.html @@ -0,0 +1,437 @@ + + + + + + VK3CPU RF Inductor Calculator + + + +
    VK3CPU - RF Inductor Calculator v1.0
    [Metric] [Large Metric]
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    + Notes:
    + RF Inductor Calculator was developed to help users predict the RF characteristics of a single-layer solenoid-style air-core inductor.

    + Inputs via the slider widgets: +
      +
    • ⌀a : Conductor diameter in millimeters (mm). Estimated equivalent AWG wire size is also displayed where appropriate.
      • +
    • ⌀b : Loop diameter in millimeters (mm).
      • +
    • c/a : 'c' is the inter-winding spacing, and 'a' is the conductor diameter, so 'c/a' is the spacing ratio. (Must be >= 1.1) + A low-value will increase the resistance due to the proximity effect.
      • +
    • N : Number of turns or windings.
      • +
    • f : The frequency of interest (MHz) for some of the calculations.
      • +
    +

    Characteristics on the left are independent of frequency, while the characteristics on the right are dependent on the selected frequency.

    + Each of the graphic representations attempt to keep the relative geometry correct, without exceeding the drawing boundary. The coil diameter + relative to the conductor diameter are representative.

    + Calculated dimensions: +
      +
    • ⌀o : Outer loop diameter (mm)
      • +
    • ⌀i : Inner loop diameter (mm) - corresponds to the diameter of the winding former.
      • +
    • c : Distance between windings, measured from the conductor centers (mm).
      • +
    • ℓ : Length of the coil (mm). Equal to c x N.
      • +
    + Calculated parameters: +
      +
    • L : Inductance is calculated using an equation incorporating the Nagaoka coefficient.
      • +
    • C : Capacitance is calculated using Knight's 2016 paper on self-resonance and self-capacitance of solenoid coils.
      • +
    • Rdc : DC resistance is calculated using conductor length divided by the conductor cross-sectional area, assuming a copper conductor.
      • +
    • SRF : Self-resonant frequency (MHz) for the unloaded coil. Currently using a lumped reactances model. (Looking into modifying the model to + use the conductor length and velocity factor as described by Knight (2016).
      • +
    • Xl : Inductive reactance at the given frequency. (Ω)
      • +
    • δ : Skin depth due to skin effect (μm)
      • +
    • Rac : AC resistance is calculated using the skin effect and proximity resistance from empirical data collected by Medhurst using the spacing ratio, and length-to-diameter ratio.
      • +
    • Q : Quality factor of device, based on reactance (X) ÷ resistance (Rac) at the given frequency.
      • +
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    + + + + + + \ No newline at end of file diff --git a/inductor_lrg.html b/inductor_lrg.html new file mode 100644 index 0000000..d990913 --- /dev/null +++ b/inductor_lrg.html @@ -0,0 +1,476 @@ + + + + + + VK3CPU RF Inductor Calculator + + + +
    VK3CPU - RF Inductor Calculator v1.0
    [Imperial] [Small Metric]
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    + Notes:
    + RF Inductor Calculator was developed to help users predict the RF characteristics of a single-layer solenoid-style air-core inductor.

    + Inputs via the slider widgets: +
      +
    • ⌀a : Conductor diameter in millimeters (mm). Estimated equivalent AWG wire size is also displayed where appropriate.
      • +
    • ⌀b : Loop diameter in millimeters (mm).
      • +
    • c/a : 'c' is the inter-winding spacing, and 'a' is the conductor diameter, so 'c/a' is the spacing ratio. (Must be >= 1.1) + A low-value will increase the resistance due to the proximity effect.
      • +
    • N : Number of turns or windings.
      • +
    • f : The frequency of interest (MHz) for some of the calculations.
      • +
    +

    Characteristics on the left are independent of frequency, while the characteristics on the right are dependent on the selected frequency.

    + Each of the graphic representations attempt to keep the relative geometry correct, without exceeding the drawing boundary. The coil diameter + relative to the conductor diameter are representative.

    + Calculated dimensions: +
      +
    • ⌀o : Outer loop diameter (mm)
      • +
    • ⌀i : Inner loop diameter (mm) - corresponds to the diameter of the winding former.
      • +
    • c : Distance between windings, measured from the conductor centers (mm).
      • +
    • ℓ : Length of the coil (mm). Equal to c x N.
      • +
    + Calculated parameters: +
      +
    • L : Inductance is calculated using an equation incorporating the Nagaoka coefficient.
      • +
    • C : Capacitance is calculated using Knight's 2016 paper on self-resonance and self-capacitance of solenoid coils.
      • +
    • Rdc : DC resistance is calculated using conductor length divided by the conductor cross-sectional area, assuming a copper conductor.
      • +
    • SRF : Self-resonant frequency (MHz) for the unloaded coil. Currently using a lumped reactances model. (Looking into modifying the model to + use the conductor length and velocity factor as described by Knight (2016).
      • +
    • Xl : Inductive reactance at the given frequency. (Ω)
      • +
    • δ : Skin depth due to skin effect (μm)
      • +
    • Rac : AC resistance is calculated using the skin effect and proximity resistance from empirical data collected by Medhurst using the spacing ratio, and length-to-diameter ratio.
      • +
    • Q : Quality factor of device, based on reactance (X) ÷ resistance (Rac) at the given frequency.
      • +
    +
    +
    + + + + + + \ No newline at end of file