//**************************************************************************
// Javascript for the Coil Design program, coildsgn.html
//**************************************************************************


//var Unit_Mult, Unit_Dim, PtoL_Inductance;
//var LtoP_Inductance, Wire_Num, Wire_Dia, Form_Dia, Turn_Space, TPI;
//var IO_Dim, Wire_Dim, Wire_Type;
//var Ini_Coil_Turns, Ini_Form_Dia, Ini_Coil_Len, Ini_Len_Dia_Ratio, Ini_TPI;
//var Alt_Coil_Turns, Alt_Form_Dia, Alt_Coil_Len, Alt_Len_Dia_Ratio, Alt_TPI;
//var Final_Coil_Turns;


//var AWG_Array = new Array(40);


//**************************************************************************
// Given a coils physical dimensions and number of turns, calculate the
// inductance.
//**************************************************************************


function Coil_Ind_Calc() {


   //***********************************************************************
   // Get the coil diameter. If the diameter is in milimeters, convert it
   // to inches for calculating.
   //***********************************************************************


   if (document.Coil_Ind.Coil_Dia_Dim.options[0].selected) {
      Coil_Dia = parseFloat(document.Coil_Ind.Coil_Dia.value); }
   else {
      Coil_Dia = parseFloat(document.Coil_Ind.Coil_Dia.value)/25.4;}


   //***********************************************************************
   // Get the coil length. If the length is in milimeters, convert it
   // to inches for calculating.
   //***********************************************************************


   if (document.Coil_Ind.Coil_Len_Dim.options[0].selected) {
      Coil_Len = parseFloat(document.Coil_Ind.Coil_Len.value); }
   else {
      Coil_Len = parseFloat(document.Coil_Ind.Coil_Len.value)/25.4;}


   Coil_Turns = parseFloat(document.Coil_Ind.Coil_Turns.value);


   Numer = Math.pow(Coil_Dia,2)*Math.pow(Coil_Turns,2);
   Denom = 18 * Coil_Dia + 40 * Coil_Len;
   PtoL_Inductance = Numer / Denom;
   document.Coil_Ind.Inductance.value = Rnd(PtoL_Inductance,3) + " uH";


   Turn_Space = Coil_Len/Coil_Turns;


   document.Coil_Ind.Turn_Space.value = DIN2FIN(Turn_Space,64)+ " (" + Rnd(Turn_Space*25.4,1) + " mm)";
}