kicad/pcb_calculator/tracks_width_versus_current...

464 lines
17 KiB
C++

/*
* 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 <http://www.gnu.org/licenses/>.
*/
/* see
* http://www.desmith.net/NMdS/Electronics/TraceWidth.html
* http://www.ultracad.com/articles/pcbtemp.pdf
* for more info
*/
#include <cassert>
#include <cmath>
#include <wx/wx.h>
#include <wx/config.h>
#include <dialog_helpers.h>
#include <pcb_calculator_frame_base.h>
#include <pcb_calculator.h>
#include <UnitSelector.h>
#include <units_scales.h>
wxString tracks_width_versus_current_formula =
#include <tracks_width_versus_current_formula.h>
extern double DoubleFromString( const wxString& TextValue );
// Key words to read/write some parameters in config:
#define KEYWORD_TW_CURRENT wxT( "TW_Track_Current" )
#define KEYWORD_TW_DELTA_TC wxT( "TW_Delta_TC" )
#define KEYWORD_TW_TRACK_LEN wxT( "TW_Track_Len" )
#define KEYWORD_TW_TRACK_LEN_UNIT wxT( "TW_Track_Len_Unit" )
#define KEYWORD_TW_RESISTIVITY wxT( "TW_Resistivity" )
#define KEYWORD_TW_EXTTRACK_WIDTH wxT( "TW_ExtTrack_Width" )
#define KEYWORD_TW_EXTTRACK_WIDTH_UNIT wxT( "TW_ExtTrack_Width_Unit" )
#define KEYWORD_TW_EXTTRACK_THICKNESS wxT( "TW_ExtTrack_Thickness" )
#define KEYWORD_TW_EXTTRACK_THICKNESS_UNIT wxT( "TW_ExtTrack_Thickness_Unit" )
#define KEYWORD_TW_INTTRACK_WIDTH wxT( "TW_IntTrack_Width" )
#define KEYWORD_TW_INTTRACK_WIDTH_UNIT wxT( "TW_IntTrack_Width_Unit" )
#define KEYWORD_TW_INTTRACK_THICKNESS wxT( "TW_IntTrack_Thickness" )
#define KEYWORD_TW_INTTRACK_THICKNESS_UNIT wxT( "TW_IntTrack_Thickness_Unit" )
void PCB_CALCULATOR_FRAME::TW_WriteConfig( wxConfigBase* aCfg )
{
// Save current parameters values in config.
aCfg->Write( KEYWORD_TW_CURRENT, m_TrackCurrentValue->GetValue() );
aCfg->Write( KEYWORD_TW_DELTA_TC, m_TrackDeltaTValue->GetValue() );
aCfg->Write( KEYWORD_TW_TRACK_LEN, m_TrackLengthValue->GetValue() );
aCfg->Write( KEYWORD_TW_TRACK_LEN_UNIT, m_TW_CuLength_choiceUnit->GetSelection() );
aCfg->Write( KEYWORD_TW_RESISTIVITY, m_TWResistivity->GetValue() );
aCfg->Write( KEYWORD_TW_EXTTRACK_WIDTH, m_ExtTrackWidthValue->GetValue() );
aCfg->Write( KEYWORD_TW_EXTTRACK_WIDTH_UNIT, m_TW_ExtTrackWidth_choiceUnit->GetSelection() );
aCfg->Write( KEYWORD_TW_EXTTRACK_THICKNESS, m_ExtTrackThicknessValue->GetValue() );
aCfg->Write( KEYWORD_TW_EXTTRACK_THICKNESS_UNIT, m_ExtTrackThicknessUnit->GetSelection() );
aCfg->Write( KEYWORD_TW_INTTRACK_WIDTH, m_IntTrackWidthValue->GetValue() );
aCfg->Write( KEYWORD_TW_INTTRACK_WIDTH_UNIT, m_TW_IntTrackWidth_choiceUnit->GetSelection() );
aCfg->Write( KEYWORD_TW_INTTRACK_THICKNESS, m_IntTrackThicknessValue->GetValue() );
aCfg->Write( KEYWORD_TW_INTTRACK_THICKNESS_UNIT, 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::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( " x " ) + strunit;
m_ExtTrackAreaUnitLabel->SetLabel( msg );
strunit = m_TW_IntTrackWidth_choiceUnit->GetUnitName();
msg = strunit + wxT( " x " ) + strunit;
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::TW_Init( wxConfigBase* aCfg )
{
int tmp;
wxString msg;
// Disable calculations while we initialise.
m_TWNested = true;
// Read parameter values.
aCfg->Read( KEYWORD_TW_CURRENT, &msg, wxT( "1.0" ) );
m_TrackCurrentValue->SetValue( msg );
aCfg->Read( KEYWORD_TW_DELTA_TC, &msg, wxT( "10.0" ) );
m_TrackDeltaTValue->SetValue( msg );
aCfg->Read( KEYWORD_TW_TRACK_LEN, &msg, wxT( "20" ) );
m_TrackLengthValue->SetValue( msg );
aCfg->Read( KEYWORD_TW_TRACK_LEN_UNIT, &tmp, 0 );
m_TW_CuLength_choiceUnit->SetSelection( tmp );
aCfg->Read( KEYWORD_TW_RESISTIVITY, &msg, wxT( "1.72e-8" ) );
m_TWResistivity->SetValue( msg );
aCfg->Read( KEYWORD_TW_EXTTRACK_WIDTH, &msg, wxT( "0.2" ) );
m_ExtTrackWidthValue->SetValue( msg );
aCfg->Read( KEYWORD_TW_EXTTRACK_WIDTH_UNIT, &tmp, 0 );
m_TW_ExtTrackWidth_choiceUnit->SetSelection( tmp );
aCfg->Read( KEYWORD_TW_EXTTRACK_THICKNESS, &msg, wxT( "0.035" ) );
m_ExtTrackThicknessValue->SetValue( msg );
aCfg->Read( KEYWORD_TW_EXTTRACK_THICKNESS_UNIT, &tmp, 0 );
m_ExtTrackThicknessUnit->SetSelection( tmp );
aCfg->Read( KEYWORD_TW_INTTRACK_WIDTH, &msg, wxT( "0.2" ) );
m_IntTrackWidthValue->SetValue( msg );
aCfg->Read( KEYWORD_TW_INTTRACK_WIDTH_UNIT, &tmp, 0 );
m_TW_IntTrackWidth_choiceUnit->SetSelection( tmp );
aCfg->Read( KEYWORD_TW_INTTRACK_THICKNESS, &msg, wxT( "0.035" ) );
m_IntTrackThicknessValue->SetValue( msg );
aCfg->Read( KEYWORD_TW_INTTRACK_THICKNESS_UNIT, &tmp, 0 );
m_IntTrackThicknessUnit->SetSelection( tmp );
if( tracks_width_versus_current_formula.StartsWith( "<!" ) )
m_htmlWinFormulas->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 );
}