'John Fields
                          '20 May 2005



top:      SCREEN 0
          COLOR 0, 7
         
init:     CLS
          INPUT "Enter maximum coil length in inches: ", winw
          INPUT "Enter bobbin shaft diameter in inches: ", bdia
          INPUT "Enter wire size in AWG: ", awg
          INPUT "Enter switch sensitivity in Ampere-Turns : ", sens
          INPUT "Enter minimum coil voltage in volts ", vcoil
          INPUT "Enter desired coil current in milliamperes : ", icoil

          rflag = 0
recal:    pi = 3.14159                             'duh...
          tper = 0
          dia = 0
          cir = 0
          wlen = 0
          res = 0
          ntot = 0
          nlay = 0
          layr = 1
         
          IF awg = 20 THEN wdia = .0334: wres = 10.13
          IF awg = 21 THEN wdia = .0298: wres = 12.77
          IF awg = 22 THEN wdia = .0266: wres = 16.2
          IF awg = 23 THEN wdia = .0239: wres = 20.31
          IF awg = 24 THEN wdia = .0213: wres = 25.67
          IF awg = 25 THEN wdia = .019: wres = 32.37
          IF awg = 26 THEN wdia = .017: wres = 41.02
          IF awg = 27 THEN wdia = .0153: wres = 51.43
          IF awg = 28 THEN wdia = .0137: wres = 65.33
          IF awg = 29 THEN wdia = .0123: wres = 81.22
          IF awg = 30 THEN wdia = .0109: wres = 103.7
          IF awg = 31 THEN wdia = .0097: wres = 130.9
          IF awg = 32 THEN wdia = .0088: wres = 162
          IF awg = 33 THEN wdia = .0078: wres = 205.7
          IF awg = 34 THEN wdia = .007: wres = 261.3
          IF awg = 35 THEN wdia = .0062: wres = 330.7
          IF awg = 36 THEN wdia = .0056: wres = 414.8
          IF awg = 37 THEN wdia = .005: wres = 512.1
          IF awg = 38 THEN wdia = .0045: wres = 648.2
          IF awg = 39 THEN wdia = .0039: wres = 846.6
          IF awg = 40 THEN wdia = .0035: wres = 1079
          IF awg = 41 THEN wdia = .0028: wres = 1323
          IF awg = 42 THEN wdia = .0025: wres = 1659
          IF awg = 43 THEN wdia = .0022: wres = 2143
          IF awg = 44 THEN wdia = .002: wres = 2593

          IF awg < 20 THEN GOTO err1     'out of range error
          IF awg > 44 THEN GOTO err1     'out of range

          wdia = 1.2 * wdia              'add some slop for winding
          wres = wres / 12000            'convert ohms/kft to ohms/inch
          rcoil = 1000 * (vcoil / icoil) 'target coil resistance
          tper = INT(winw / wdia)        'number of turns per layer
          dia = bdia + wdia              'diameter of barrel and wire
          cir = pi * dia                 'length of turn on layer 1
          wlen = cir * tper              'length of wire on layer 1
          res = wlen * wres              'resistance of layer 1               
          ntot = sens / (icoil * .001)   'total turns on coil
          nlay = INT(ntot / tper)        'total layers on coil
         
          DO WHILE layr < nlay
          layr = layr + 1                'increment layer counter
          dia = dia + (2 * wdia) 'increment diameter and add 20% slop
          cir = pi * dia                 'new length of turn
          wlen = wlen + (cir * tper)     'new accumulated length of wire
          res = (wlen * wres)            'new accumulated resistance
          LOOP
         
          IF rflag = 0 AND res > rcoil THEN GOTO err2
          rflag = 1
          IF res < rcoil THEN winw = winw - .03125: GOTO recal

          dia$ = LEFT$(STR$(dia), 5)
         
          CLS
          PRINT ""
          PRINT "Target coil resistance ="; rcoil; "ohms"
          PRINT "Wire size = #"; awg; "AWG"
          PRINT "Length of wire ="; INT(wlen / 12); "feet"
          PRINT "Length of coil ="; winw; "inch"
          PRINT "Diameter of coil =" + dia$ + " inches"
          PRINT "Resistance of coil ="; INT(res); "ohms"
          PRINT "Number of turns "; ntot
          PRINT "Number of layers "; layr
          PRINT ""
          PRINT "Another run? <Y>N"
          
loopa:    a$ = INKEY$
          IF a$ = "Y" THEN GOTO init
          IF a$ = "y" THEN GOTO init
          IF a$ = CHR$(13) THEN GOTO init
          IF a$ = "" THEN GOTO loopa
          END

err1:     CLS
          PRINT "Sorry, that wire size is out of range."
          PRINT "Choose from 20 to 44 AWG."
          PRINT "Want to try again? <Y>N"
          GOTO loopa

err2:     CLS
          PRINT "Sorry, the coil's resistance is too high. "
          PRINT "Use a larger wire size or a longer bobbin."
          PRINT "Want to try again? <Y>N"
          GOTO loopa