[Init]
MAINWIN 80 43:ON ERROR GOTO [Init]:CLS:PI=asn(1)*2:PRINT
PRINT TAB(15);"Passive Filter Design  1968 - 2005  Bill Yotter"
PRINT TAB(12);"Books to ZX81 BASIC to GWBASIC to APBASIC to JustBASIC"
PRINT
PRINT TAB(8);"This program makes the assumption that the user has at minimum"
PRINT TAB(8);"a rudimentary knowledge of electronics; experienced users may "
PRINT TAB(8);"understand and benefit the most from this suite of design tools."
PRINT TAB(8);"Note: Selecting configurations or values outside the bounds of"
PRINT TAB(8);"reality will produce program errors which run automatic restart."
PRINT
PRINT tab(8);"Most of the abbreviations used are listed in RCL Calculator."
PRINT
PRINT TAB(14);"Example filter description:  C1s - L1p,C2s - C3s,L2p"
PRINT
PRINT TAB(14);"Equates to:  o---(C1s)---+---+--(C3s)--+---o"
PRINT TAB(14);"                         |   |         |"
PRINT TAB(14);"                      (L1p)  +--(L2p)--+"
PRINT TAB(14);"                         |"
PRINT TAB(14);"                      (C2s)"
PRINT TAB(14);"                         |"
PRINT TAB(14);"             o-----------+-----------------o"
PRINT:PRINT
PRINT TAB(30);"1) Bandpass K"
PRINT TAB(30);"2) Bandstop K"
PRINT TAB(30);"3) Lowpass  K"
PRINT TAB(30);"4) Highpass K"
PRINT TAB(30);"5) Lowpass  M"
PRINT TAB(30);"6) Highpass M"
PRINT TAB(30);"7) Air Capacitor"
PRINT TAB(30);"8) Air Inductor"
PRINT TAB(30);"9) RCL Calculator"
PRINT TAB(30);"0) Exit"
PRINT:PRINT TAB(30);"Selection ? ";:X$=INPUT$(1)
IF X$="1" THEN [BandpassK]
IF X$="2" THEN [BandstopK]
IF X$="3" THEN [LowpassK]
IF X$="4" THEN [HighpassK]
IF X$="5" THEN [LowpassM]
IF X$="6" THEN [HighpassM]
IF X$="7" THEN [AirCap]
IF X$="8" THEN [AirInd]
IF X$="9" THEN [RCL]
IF X$="0" THEN END
GOTO [Init]
[BandpassK]
CLS:PRINT
PRINT" Bandpass K :":PRINT
PRINT" L1s,C1s - C2p,L2p":PRINT
PRINT" C6p,L4p - L1s,C1s - C6p,L4p":PRINT
PRINT" L5s,C3s - C2p,L2p - L5s,C3s":PRINT
INPUT" Impedance      ? ";Z
INPUT" Low  frequency ? ";F1
INPUT" High frequency ? ";F2:PRINT
L1=Z/(PI*(F2-F1))
C1=(F2-F1)/(4*PI*F1*F2*Z)
L2=((F2-F1)*Z)/(4*PI*F1*F2)
C2=1/(PI*(F2-F1)*Z)
PRINT" L1 = ";L1;TAB(30);"C1 = ";C1
PRINT" L2 = ";L2;TAB(30);"C2 = ";C2
PRINT" L3 = ";L1*2;TAB(30);"C3 = ";C1*2
PRINT" L4 = ";L2*2;TAB(30);"C4 = ";C2*2
PRINT" L5 = ";L1/2;TAB(30);"C5 = ";C1/2
PRINT" L6 = ";L2/2;TAB(30);"C6 = ";C2/2
PRINT:X$=INPUT$(2):GOTO [Init]
[BandstopK]
CLS:PRINT
PRINT" Bandstop K :":PRINT
PRINT" L1s,C1p - L2p,C2s":PRINT
PRINT" L4p,C6s - L1s,C1p - L4p,C6s":PRINT
PRINT" L5s,C3p - L2p,C2s - L5s,C3p":PRINT
INPUT" Impedance      ? ";Z
INPUT" Low  frequency ? ";F1
INPUT" High frequency ? ";F2:PRINT
L1=((F2-F1)*Z)/(PI*F1*F2)
C1=1/(4*PI*Z*(F2-F1))
L2=Z/(4*PI*(F2-F1))
C2=(F2-F1)/(PI*Z*F1*F2)
PRINT" L1 = ";L1;TAB(30);"C1 = ";C1
PRINT" L2 = ";L2;TAB(30);"C2 = ";C2
PRINT" L3 = ";L1*2;TAB(30);"C3 = ";C1*2
PRINT" L4 = ";L2*2;TAB(30);"C4 = ";C2*2
PRINT" L5 = ";L1/2;TAB(30);"C5 = ";C1/2
PRINT" L6 = ";L2/2;TAB(30);"C6 = ";C2/2
PRINT:X$=INPUT$(1):GOTO [Init]
[LowpassK]
CLS:PRINT
PRINT" Lowpass  K :":PRINT
PRINT" Ls - Cp":PRINT
INPUT" Impedance   ? ";Z
INPUT" Cutoff freq ? ";F:PRINT
L=Z/(PI*F)
C=1/(PI*F*Z)
PRINT" L1 = ";L
PRINT" C1 = ";C
PRINT:X$=INPUT$(1):GOTO [Init]
[HighpassK]
CLS:PRINT
PRINT" Highpass K :":PRINT
PRINT" Cs - Lp":PRINT
INPUT" Impedance   ? ";Z
INPUT" Cutoff freq ? ";F:PRINT
L=Z/(4*PI*F)
C=1/(4*PI*F*Z)
PRINT" L1 = ";L
PRINT" C1 = ";C
PRINT:X$=INPUT$(1):GOTO [Init]
[LowpassM]
CLS:PRINT
PRINT" Lowpass M :":PRINT
PRINT" L3s - L2p,C1s - L3s":PRINT
PRINT" L1s  - L2p,C1s":PRINT
PRINT" C3p - L1s,C2p - C3p":PRINT
INPUT" Impedance     ";Z
INPUT" Cutoff   freq ? ";FC
INPUT" Infinite freq ? ";FI:PRINT
M=SQR(1-(FC/FI)^2)
L1=(M*Z)/(PI*FC)
L2=((1-M^2)*Z)/(4*PI*M*FC)
C1=M/(PI*FC*Z)
C2=(1-M^2)/(4*PI*FC*Z)
PRINT" L1 = ";L1;TAB(30);"C1 = ";C1
PRINT" L2 = ";L2;TAB(30);"C2 = ";C2
PRINT" L3 = ";L1/2;TAB(30);"C3 = ";C1/2
PRINT:X$=INPUT$(1):GOTO [Init]
[HighpassM]
CLS:PRINT
PRINT" Highpass M :":PRINT
PRINT" C1s - L1p,C2s":PRINT
PRINT" C3s - L1p,C2s - C3s":PRINT
PRINT" L3p - L2s,C1p - L3p":PRINT
INPUT" Impedance     ? ";Z
INPUT" Cutoff   freq ? ";FC
INPUT" Infinite freq ? ";FI:PRINT
M=(SQR(1-(FI/FC)^2))
L1=Z/(4*PI*M*FC)
L2=ABS((M*Z)/((1-M^2)*PI*FC))
C1=1/(4*PI*M*FC*Z)
C2=ABS(M/((1-M^2)*PI*FC*Z))
PRINT" L1 = ";L1;TAB(30);"C1 = ";C1
PRINT" L2 = ";L2;TAB(30);"C2 = ";C2
PRINT" L3 = ";L1*2;TAB(30);"C3 = ";C1*2
PRINT:X$=INPUT$(1):GOTO [Init]
[AirCap]
CLS:PRINT
PRINT TAB(15);" Enter a 0 for the unknown parameters :":PRINT
PRINT TAB(10);" Dialectric for:  air=1.00059  paper=2.25  glass=7  water=77":PRINT
PRINT TAB(20);:INPUT"Area in inches      ? ";A
PRINT TAB(20);:INPUT"Distance in inches  ? ";D
PRINT TAB(20);:INPUT"Capacitance in pf   ? ";C
PRINT TAB(20);:INPUT"Dialectric (er')    ? ";ER
PRINT:IF ER<=0 THEN ER=1.00059
IF (A<>0 AND C<>0 AND D<>0) THEN PRINT TAB(20);"er' = ";((C*D)/.222091193)/A:GOTO [LOOP]
IF (A<>0 AND D<>0) THEN PRINT TAB(20);"Capacitance in pf = ";.222091193*((ER*A)/D)
IF (A<>0 AND C<>0) THEN PRINT TAB(20);"Distance in inchs = ";(.222091193*ER*A)/C;"   (";SQR(A);CHR$(34);" per side)"
IF (C<>0 AND D<>0) THEN PRINT TAB(20);"Area in inches    = ";((C*D)/.222091193)/ER;"  ";
IF (C<>0 AND D<>0) THEN PRINT"(";SQR(((C*D)/.222091193)/ER);CHR$(34);" per side)"
[LOOP]
PRINT:X$=INPUT$(1):GOTO [Init]
[AirInd]
CLS:PRINT
PRINT TAB(15);"Enter 0 for the number of turns and/or inductance :":PRINT
PRINT TAB(20);:INPUT"Inductance       ? ";H
PRINT TAB(20);:INPUT"Number of Turns  ? ";N
PRINT TAB(20);:INPUT"Length in inchs  ? ";L
PRINT TAB(20);:INPUT"Wire Diameter    ? ";D
PRINT:R=D/2
IF H=0 AND N=0 THEN [SWIND]
IF H<>0 THEN [TURNS]
PRINT TAB(20);"The inductance = ";(R^2*N^2)/(9*R+10*L)/1000000
PRINT:X$=INPUT$(1):GOTO [Init]
[TURNS]
PRINT TAB(20);"The number needed = ";((SQR(H*(9*R+(10*L))))/R)*1000
PRINT:X$=INPUT$(1):GOTO [Init]
[SWIND]
X=((4*(L*2.54)/(D*2.54)-1)+1.00059)/4
LS=.002*(L*2.54)*LOG(X)/1000000
PRINT TAB(20);"Straight wire Ind = ";LS
PRINT:X$=INPUT$(1):GOTO [Init]
[RCL]
CLS:PRINT:PI=asn(1)*2
PRINT TAB(3);"RCL  Passive Component Value Calculations   1968 - 2005   Bill Yotter"
PRINT TAB(5);"Books to Z80 ASM to ZX81 BASIC to GWBASIC to APBASIC to JustBASIC"
PRINT " "
PRINT " c = capacitance  l = inductance    p = parallel      R = resistance"
PRINT " s = series       t = total         v = voltage       X = reactance"
PRINT " I = amperage     Q = selectivity   z = impedance     V = your value"
PRINT " BW= bandwidth    Fr= resonat freq  PI= asn(1)*2      N = repeating.."
PRINT:PRINT:PRINT TAB(5);"Menu follows, select 0 to 9:":PRINT
PRINT " 1) Fr =       1/((2*PI*SQR(C*L))"
PRINT " 2) Cr or Lr = 1/((2*PI*Fr)^2*V)            Frs <Z <v >I    Qs = X/R"
PRINT " 3) Xl =       2*PI*F*L                     Frp >Z >v <I    Qp = R/X"
PRINT " 4) L =        Xl/(2*PI*F)                                  Q  = Fr/BW"
PRINT " 5) Xc or C =  1/(2*PI*F*V)"
PRINT " 6) Series <-> Parallel Conversions"
PRINT " 7) Rt = Rp    1/((1/N1)+(1/N2)..)"
PRINT "    Ct = Cs"
PRINT "    Lt = Lp"
PRINT "    Xt = Xp"
PRINT " 8) Rt = Rs    1N+2N+.."
PRINT "    Ct = Cp"
PRINT "    Lt = Ls"
PRINT "    Vt = Vs"
PRINT "    It = Ip"
PRINT "    Xt = Xs"
PRINT " 9) Zt = Rs  Xcs Xls     SQR(A^2+(B-C)^2)"
PRINT "    Vt = Vrs Vxcs Vxls"
PRINT "    It = Irp Ixcp Ixlp"
PRINT " 0) Return to Passive Filter Design"
PRINT:PRINT TAB(25);"Selection ? ";:X$=INPUT$(1):PRINT
T=0:PRINT:PRINT TAB(25);"# ";X$;")"
IF X$="1" THEN [RCLa]
IF X$="2" THEN [RCLb]
IF X$="3" THEN [RCLc]
IF X$="4" THEN [RCLd]
IF X$="5" THEN [RCLe]
IF X$="6" THEN [RCLf]
IF X$="7" THEN [RCLg]
IF X$="8" THEN [RCLh]
IF X$="9" THEN [RCLi]
IF X$="0" THEN [Init]
GOTO [RCL]
[RCLa] ' Resonant Freq
PRINT TAB(25);:INPUT"Cap ? ";C
PRINT TAB(25);:INPUT"Ind ? ";L
PRINT:PRINT TAB(25);"Fr  =  ";1/(2*PI*SQR(C*L)):X$=INPUT$(1):GOTO [RCL]
[RCLb] ' resonant component
PRINT TAB(25);:INPUT"Cr/Lr ? ";X
PRINT TAB(25);:INPUT"Fr    ? ";F
PRINT:PRINT TAB(25);"Part  =  ";1/((2*PI*F)^2*X):X$=INPUT$(1):GOTO [RCL]
[RCLc] ' ind reactance
PRINT TAB(25);:INPUT"Ind   ? ";L
PRINT TAB(25);:INPUT"Freq  ? ";F
PRINT:PRINT TAB(25);"XL    =  ";2*PI*F*L:X$=INPUT$(1):GOTO [RCL]
[RCLe] ' cap reactance
PRINT TAB(25);:INPUT"Xc/C  ? ";X
PRINT TAB(25);:INPUT"Freq  ? ";F
IF X>1 THEN X$="Cap " ELSE X$="Xc  "
PRINT:PRINT TAB(25);X$;"  = ";1/(2*PI*F*X):X$=INPUT$(1):GOTO [RCL]
[RCLg] ' parallel
PRINT TAB(25);:INPUT "Value ? ";X
T=1/(1/X):GOTO [RCLga]
[RCLgb] PRINT TAB(25);:INPUT "Value ? ";X
IF X=0 THEN [RCL]
T=1/((1/T)+(1/X))
[RCLga]
PRINT TAB(25);:PRINT"Total = ";T:GOTO [RCLgb]
[RCLh] ' series
PRINT TAB(25);:INPUT "Value ? ";X
IF X=0 THEN [RCL]
T=T+X
PRINT TAB(25);"Total = ";T:GOTO [RCLh]
[RCLi] ' vector equation
PRINT TAB(25);:INPUT"Value ? ";A
PRINT TAB(25);:INPUT"Value ? ";B
PRINT TAB(25);:INPUT"Value ? ";C
PRINT:PRINT TAB(25);"Total =  ";SQR(A^2+(B-C)^2):X$=INPUT$(1):GOTO [RCL]
[RCLd] ' l from Xl
PRINT TAB(25);:INPUT"Xl   ? ";XL
PRINT TAB(25);:INPUT"Freq ? ";F
PRINT:PRINT TAB(25);"Ind  =  ";XL/(2*PI*F):X$=INPUT$(1):GOTO [RCL]
[RCLf] ' rs - rp conversion
PRINT TAB(25);"1) S > P"
PRINT TAB(25);"2) P > S ";:X$=INPUT$(1)
IF X$="1" THEN PRINT:GOTO [RCLfa]
IF X$="2" THEN PRINT:GOTO [RCLfb]
GOTO [RCL]
[RCLfa]
PRINT:PRINT TAB(25);:INPUT"Rs   ? ";RS
PRINT TAB(25);:INPUT"Xs   ? ";XS
PRINT:PRINT TAB(25);"Rp   = ";RS*(1+(XS/RS)^2)
PRINT TAB(25);:PRINT"Xp   = ";(RS*(1+(XS/RS)^2))/(XS/RS):X$=INPUT$(1):GOTO [RCL]
[RCLfb]
PRINT:PRINT TAB(25);:INPUT"Rp   ? ";RP
PRINT TAB(25);:INPUT"Xp   ? ";XP
PRINT:PRINT TAB(25);"Rs   = ";RP/(1+(RP/XP)^2)
PRINT TAB(25);"Xs   =  ";(RP/(1+(RP/XP)^2))*(RP/XP):X$=INPUT$(1):GOTO [RCL]