/* * This program source code file is part of KICAD, a free EDA CAD application. * * Copyright (C) 2011 jean-pierre.charras * Copyright (C) 1992-2015 Kicad Developers, see AUTHORS.txt for contributors. * * 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 . */ /* see * http://www.desmith.net/NMdS/Electronics/TraceWidth.html * http://www.ultracad.com/articles/pcbtemp.pdf * for more info */ #include #include #include #include #include "class_regulator_data.h" #include "pcb_calculator_frame.h" #include "pcb_calculator_settings.h" #include "units_scales.h" wxString tracks_width_versus_current_formula = #include "tracks_width_versus_current_formula.h" extern double DoubleFromString( const wxString& TextValue ); // The IPC2221 formula used to calculate track width is valid only for copper material const double copper_resistivity = 1.72e-8; void PCB_CALCULATOR_FRAME::writeTrackWidthConfig() { // Save current parameters values in config. auto cfg = static_cast( Kiface().KifaceSettings() ); cfg->m_TrackWidth.current = m_TrackCurrentValue->GetValue(); cfg->m_TrackWidth.delta_tc = m_TrackDeltaTValue->GetValue(); cfg->m_TrackWidth.track_len = m_TrackLengthValue->GetValue(); cfg->m_TrackWidth.track_len_units = m_TW_CuLength_choiceUnit->GetSelection(); cfg->m_TrackWidth.resistivity = m_TWResistivity->GetValue(); cfg->m_TrackWidth.ext_track_width = m_ExtTrackWidthValue->GetValue(); cfg->m_TrackWidth.ext_track_width_units = m_TW_ExtTrackWidth_choiceUnit->GetSelection(); cfg->m_TrackWidth.ext_track_thickness = m_ExtTrackThicknessValue->GetValue(); cfg->m_TrackWidth.ext_track_thickness_units = m_ExtTrackThicknessUnit->GetSelection(); cfg->m_TrackWidth.int_track_width = m_IntTrackWidthValue->GetValue(); cfg->m_TrackWidth.int_track_width_units = m_TW_IntTrackWidth_choiceUnit->GetSelection(); cfg->m_TrackWidth.int_track_thickness = m_IntTrackThicknessValue->GetValue(); cfg->m_TrackWidth.int_track_thickness_units = m_IntTrackThicknessUnit->GetSelection(); } void PCB_CALCULATOR_FRAME::OnTWParametersChanged( wxCommandEvent& event ) { switch(m_TWMode) { case TW_MASTER_CURRENT: OnTWCalculateFromCurrent( event ); break; case TW_MASTER_EXT_WIDTH: OnTWCalculateFromExtWidth( event ); break; case TW_MASTER_INT_WIDTH: OnTWCalculateFromIntWidth( event ); break; } } void PCB_CALCULATOR_FRAME::OnTWCalculateFromCurrent( wxCommandEvent& event ) { // Setting the calculated values generates further events. Stop them. if( m_TWNested ) { event.StopPropagation(); return; } m_TWNested = true; // Update state. if( m_TWMode != TW_MASTER_CURRENT ) { m_TWMode = TW_MASTER_CURRENT; TWUpdateModeDisplay(); } // Prepare parameters: double current = std::abs( DoubleFromString( m_TrackCurrentValue->GetValue() ) ); double extThickness = std::abs( DoubleFromString( m_ExtTrackThicknessValue->GetValue() ) ); double intThickness = std::abs( DoubleFromString( m_IntTrackThicknessValue->GetValue() ) ); double deltaT_C = std::abs( DoubleFromString( m_TrackDeltaTValue->GetValue() ) ); // Normalize by units. extThickness *= m_ExtTrackThicknessUnit->GetUnitScale(); intThickness *= m_IntTrackThicknessUnit->GetUnitScale(); // Calculate the widths. double extTrackWidth = TWCalculateWidth( current, extThickness, deltaT_C, false ); double intTrackWidth = TWCalculateWidth( current, intThickness, deltaT_C, true ); // Update the display. TWDisplayValues( current, extTrackWidth, intTrackWidth, extThickness, intThickness ); // Re-enable the events. m_TWNested = false; } void PCB_CALCULATOR_FRAME::OnTWCalculateFromExtWidth( wxCommandEvent& event ) { // Setting the calculated values generates further events. Stop them. if( m_TWNested ) { event.StopPropagation(); return; } m_TWNested = true; // Update state. if( m_TWMode != TW_MASTER_EXT_WIDTH ) { m_TWMode = TW_MASTER_EXT_WIDTH; TWUpdateModeDisplay(); } // Load parameters. double current; double extThickness = std::abs( DoubleFromString( m_ExtTrackThicknessValue->GetValue() ) ); double intThickness = std::abs( DoubleFromString( m_IntTrackThicknessValue->GetValue() ) ); double deltaT_C = std::abs( DoubleFromString( m_TrackDeltaTValue->GetValue() ) ); double extTrackWidth = std::abs( DoubleFromString( m_ExtTrackWidthValue->GetValue() ) ); double intTrackWidth; // Normalize units. extThickness *= m_ExtTrackThicknessUnit->GetUnitScale(); intThickness *= m_IntTrackThicknessUnit->GetUnitScale(); extTrackWidth *= m_TW_ExtTrackWidth_choiceUnit->GetUnitScale(); // Calculate the maximum current. current = TWCalculateCurrent( extTrackWidth, extThickness, deltaT_C, false ); // And now calculate the corresponding internal width. intTrackWidth = TWCalculateWidth( current, intThickness, deltaT_C, true ); // Update the display. TWDisplayValues( current, extTrackWidth, intTrackWidth, extThickness, intThickness ); // Re-enable the events. m_TWNested = false; } void PCB_CALCULATOR_FRAME::OnTWCalculateFromIntWidth( wxCommandEvent& event ) { // Setting the calculated values generates further events. Stop them. if( m_TWNested ) { event.StopPropagation(); return; } m_TWNested = true; // Update state. if( m_TWMode != TW_MASTER_INT_WIDTH ) { m_TWMode = TW_MASTER_INT_WIDTH; TWUpdateModeDisplay(); } // Load parameters. double current; double extThickness = std::abs( DoubleFromString( m_ExtTrackThicknessValue->GetValue() ) ); double intThickness = std::abs( DoubleFromString( m_IntTrackThicknessValue->GetValue() ) ); double deltaT_C = std::abs( DoubleFromString( m_TrackDeltaTValue->GetValue() ) ); double extTrackWidth; double intTrackWidth = std::abs( DoubleFromString( m_IntTrackWidthValue->GetValue() ) ); // Normalize units. extThickness *= m_ExtTrackThicknessUnit->GetUnitScale(); intThickness *= m_IntTrackThicknessUnit->GetUnitScale(); intTrackWidth *= m_TW_IntTrackWidth_choiceUnit->GetUnitScale(); // Calculate the maximum current. current = TWCalculateCurrent( intTrackWidth, intThickness, deltaT_C, true ); // And now calculate the corresponding external width. extTrackWidth = TWCalculateWidth( current, extThickness, deltaT_C, false ); // Update the display. TWDisplayValues( current, extTrackWidth, intTrackWidth, extThickness, intThickness ); // Re-enable the events. m_TWNested = false; } void PCB_CALCULATOR_FRAME::OnTWResetButtonClick( wxCommandEvent& event ) { // a wxString:Format( "%g", xx) is used to use local separator in floats m_TrackCurrentValue->SetValue( wxString::Format( "%g", 1.0 ) ); m_TrackDeltaTValue->SetValue( wxString::Format( "%g", 10.0 ) ); m_TrackLengthValue->SetValue( wxString::Format( "%g", 20.0 ) ); m_TW_CuLength_choiceUnit->SetSelection( 0 ); m_TWResistivity->SetValue( wxString::Format( "%g", copper_resistivity ) ); m_ExtTrackWidthValue->SetValue( wxString::Format( "%g", 0.2 ) ); m_TW_ExtTrackWidth_choiceUnit->SetSelection( 0 ); m_ExtTrackThicknessValue->SetValue( wxString::Format( "%g", 0.035 ) ); m_ExtTrackThicknessUnit->SetSelection( 0 ); m_IntTrackWidthValue->SetValue( wxString::Format( "%g", 0.2 ) ); m_TW_IntTrackWidth_choiceUnit->SetSelection( 0 ); m_IntTrackThicknessValue->SetValue( wxString::Format( "%g", 0.035 ) ); m_IntTrackThicknessUnit->SetSelection( 0 ); } void PCB_CALCULATOR_FRAME::TWDisplayValues( double aCurrent, double aExtWidth, double aIntWidth, double aExtThickness, double aIntThickness ) { wxString msg; // Show the current. if( m_TWMode != TW_MASTER_CURRENT ) { msg.Printf( wxT( "%g" ), aCurrent ); m_TrackCurrentValue->SetValue( msg ); } // Load scale factors to convert into output units. double extScale = m_TW_ExtTrackWidth_choiceUnit->GetUnitScale(); double intScale = m_TW_IntTrackWidth_choiceUnit->GetUnitScale(); // Display the widths. if( m_TWMode != TW_MASTER_EXT_WIDTH ) { msg.Printf( wxT( "%g" ), aExtWidth / extScale ); m_ExtTrackWidthValue->SetValue( msg ); } if( m_TWMode != TW_MASTER_INT_WIDTH ) { msg.Printf( wxT( "%g" ), aIntWidth / intScale ); m_IntTrackWidthValue->SetValue( msg ); } // Display cross-sectional areas. msg.Printf( wxT( "%g" ), (aExtWidth * aExtThickness) / (extScale * extScale) ); m_ExtTrackAreaValue->SetLabel( msg ); msg.Printf( wxT( "%g" ), (aIntWidth * aIntThickness) / (intScale * intScale) ); m_IntTrackAreaValue->SetLabel( msg ); // Show area units. wxString strunit = m_TW_ExtTrackWidth_choiceUnit->GetUnitName(); msg = strunit + wxT( "²" ); m_extTrackAreaUnitLabel->SetLabel( msg ); strunit = m_TW_IntTrackWidth_choiceUnit->GetUnitName(); msg = strunit + wxT( "²" ); m_intTrackAreaUnitLabel->SetLabel( msg ); // Load resistivity and length of traces. double rho = std::abs( DoubleFromString( m_TWResistivity->GetValue() ) ); double trackLen = std::abs( DoubleFromString( m_TrackLengthValue->GetValue() ) ); trackLen *= m_TW_CuLength_choiceUnit->GetUnitScale(); // Calculate resistance. double extResistance = ( rho * trackLen ) / ( aExtWidth * aExtThickness ); double intResistance = ( rho * trackLen ) / ( aIntWidth * aIntThickness ); // Display resistance. msg.Printf( wxT( "%g" ), extResistance ); m_ExtTrackResistValue->SetLabel( msg ); msg.Printf( wxT( "%g" ), intResistance ); m_IntTrackResistValue->SetLabel( msg ); // Display voltage drop along trace. double extV = extResistance * aCurrent; msg.Printf( wxT( "%g" ), extV ); m_ExtTrackVDropValue->SetLabel( msg ); double intV = intResistance * aCurrent; msg.Printf( wxT( "%g" ), intV ); m_IntTrackVDropValue->SetLabel( msg ); // And power loss. msg.Printf( wxT( "%g" ), extV * aCurrent ); m_ExtTrackLossValue->SetLabel( msg ); msg.Printf( wxT( "%g" ), intV * aCurrent ); m_IntTrackLossValue->SetLabel( msg ); } void PCB_CALCULATOR_FRAME::TWUpdateModeDisplay() { wxFont labelfont; wxFont controlfont; // Set the font weight of the current. labelfont = m_staticTextCurrent->GetFont(); controlfont = m_TrackCurrentValue->GetFont(); if( m_TWMode == TW_MASTER_CURRENT ) { labelfont.SetWeight( wxFONTWEIGHT_BOLD ); controlfont.SetWeight( wxFONTWEIGHT_BOLD ); } else { labelfont.SetWeight( wxFONTWEIGHT_NORMAL ); controlfont.SetWeight( wxFONTWEIGHT_NORMAL ); } m_staticTextCurrent->SetFont( labelfont ); m_TrackCurrentValue->SetFont( controlfont ); // Set the font weight of the external track width. labelfont = m_staticTextExtWidth->GetFont(); controlfont = m_ExtTrackWidthValue->GetFont(); if( m_TWMode == TW_MASTER_EXT_WIDTH ) { labelfont.SetWeight( wxFONTWEIGHT_BOLD ); controlfont.SetWeight( wxFONTWEIGHT_BOLD ); } else { labelfont.SetWeight( wxFONTWEIGHT_NORMAL ); controlfont.SetWeight( wxFONTWEIGHT_NORMAL ); } m_staticTextExtWidth->SetFont( labelfont ); m_ExtTrackWidthValue->SetFont( controlfont ); // Set the font weight of the internal track width. labelfont = m_staticTextIntWidth->GetFont(); controlfont = m_IntTrackWidthValue->GetFont(); if( m_TWMode == TW_MASTER_INT_WIDTH ) { labelfont.SetWeight( wxFONTWEIGHT_BOLD ); controlfont.SetWeight( wxFONTWEIGHT_BOLD ); } else { labelfont.SetWeight( wxFONTWEIGHT_NORMAL ); controlfont.SetWeight( wxFONTWEIGHT_NORMAL ); } m_staticTextIntWidth->SetFont( labelfont ); m_IntTrackWidthValue->SetFont( controlfont ); // Text sizes have changed when the font weight was changes // So, run the page layout to reflect the changes wxWindow* page = m_Notebook->GetPage ( 1 ); page->GetSizer()->Layout(); } /* calculate track width for external or internal layers * * Imax = 0.048 * dT^0.44 * A^0.725 for external layer * Imax = 0.024 * dT^0.44 * A^0.725 for internal layer * with A = area = aThickness * trackWidth ( in mils ) * and dT = temperature rise in degree C * Of course we want to know trackWidth */ double PCB_CALCULATOR_FRAME::TWCalculateWidth( double aCurrent, double aThickness, double aDeltaT_C, bool aUseInternalLayer ) { // Appropriate scale for requested layer. double scale = aUseInternalLayer ? 0.024 : 0.048; // aThickness is given in normalize units (in meters) and we need mil aThickness /= UNIT_MIL; /* formula is Imax = scale * dT^0.44 * A^0.725 * or * log(Imax) = log(scale) + 0.44*log(dT) * +(0.725*(log(aThickness) + log(trackWidth)) * log(trackWidth) * 0.725 = log(Imax) - log(scale) - 0.44*log(dT) - 0.725*log(aThickness) */ double dtmp = log( aCurrent ) - log( scale ) - 0.44 * log( aDeltaT_C ) - 0.725 * log( aThickness ); dtmp /= 0.725; double trackWidth = exp( dtmp ); trackWidth *= UNIT_MIL; // We are using normalize units (sizes in meters) and we have mil return trackWidth; // in meters } double PCB_CALCULATOR_FRAME::TWCalculateCurrent( double aWidth, double aThickness, double aDeltaT_C, bool aUseInternalLayer ) { // Appropriate scale for requested layer. double scale = aUseInternalLayer ? 0.024 : 0.048; // Convert thickness and width to mils. aThickness /= UNIT_MIL; aWidth /= UNIT_MIL; double area = aThickness * aWidth; double current = scale * pow( aDeltaT_C, 0.44 ) * pow( area, 0.725 ); return current; } void PCB_CALCULATOR_FRAME::initTrackWidthPanel() { wxString msg; // Disable calculations while we initialise. m_TWNested = true; // Read parameter values. auto cfg = static_cast( Kiface().KifaceSettings() ); m_TrackCurrentValue->SetValue( cfg->m_TrackWidth.current ); m_TrackDeltaTValue->SetValue( cfg->m_TrackWidth.delta_tc ); m_TrackLengthValue->SetValue( cfg->m_TrackWidth.track_len ); m_TW_CuLength_choiceUnit->SetSelection( cfg->m_TrackWidth.track_len_units ); #if 0 // the IPC formula is valid for copper traces, so we do not currently adjust the resistivity m_TWResistivity->SetValue( cfg->m_TrackWidth.resistivity ); #else m_TWResistivity->SetValue( wxString::Format( "%g", copper_resistivity ) ); #endif m_ExtTrackWidthValue->SetValue( cfg->m_TrackWidth.ext_track_width ); m_TW_ExtTrackWidth_choiceUnit->SetSelection( cfg->m_TrackWidth.ext_track_width_units ); m_ExtTrackThicknessValue->SetValue( cfg->m_TrackWidth.ext_track_thickness ); m_ExtTrackThicknessUnit->SetSelection( cfg->m_TrackWidth.ext_track_thickness_units ); m_IntTrackWidthValue->SetValue( cfg->m_TrackWidth.int_track_width ); m_TW_IntTrackWidth_choiceUnit->SetSelection( cfg->m_TrackWidth.int_track_width_units ); m_IntTrackThicknessValue->SetValue( cfg->m_TrackWidth.int_track_thickness ); m_IntTrackThicknessUnit->SetSelection( cfg->m_TrackWidth.int_track_thickness_units ); if( tracks_width_versus_current_formula.StartsWith( "SetPage( tracks_width_versus_current_formula ); else { wxString html_txt; ConvertMarkdown2Html( wxGetTranslation( tracks_width_versus_current_formula ), html_txt ); m_htmlWinFormulas->SetPage( html_txt ); } // Make sure the correct master mode is displayed. TWUpdateModeDisplay(); // Enable calculations and perform the initial one. m_TWNested = false; wxCommandEvent dummy; OnTWParametersChanged( dummy ); }