Version 4 SHEET 1 1768 964 WIRE 32 -176 -256 -176 WIRE 208 -176 32 -176 WIRE 208 -144 208 -176 WIRE 336 -96 272 -96 WIRE 416 -96 336 -96 WIRE 416 -80 416 -96 WIRE -256 -32 -256 -176 WIRE -80 -32 -112 -32 WIRE 16 -32 0 -32 WIRE 64 -32 16 -32 WIRE 112 -32 64 -32 WIRE 208 -32 208 -48 WIRE 208 -32 112 -32 WIRE 16 -16 16 -32 WIRE 208 -16 208 -32 WIRE 112 16 112 -32 WIRE 208 80 208 64 WIRE 320 80 208 80 WIRE -256 96 -256 48 WIRE -112 96 -112 -32 WIRE -112 96 -256 96 WIRE 416 96 416 0 WIRE 416 96 384 96 WIRE 544 96 416 96 WIRE 576 96 544 96 WIRE -256 112 -256 96 WIRE 16 112 16 64 WIRE 112 112 112 80 WIRE 112 112 16 112 WIRE 320 112 112 112 WIRE 352 144 352 128 WIRE 448 144 352 144 WIRE 464 144 448 144 WIRE 352 160 352 144 WIRE 16 176 16 112 WIRE 208 176 208 80 WIRE 16 304 16 256 WIRE 144 304 16 304 WIRE 208 304 208 256 WIRE 208 304 144 304 WIRE -256 320 -256 192 WIRE 0 320 -256 320 WIRE 144 320 144 304 WIRE 144 320 0 320 WIRE 0 352 0 320 FLAG 352 64 0 FLAG 352 240 0 FLAG 0 352 0 FLAG 448 144 +v FLAG 32 -176 +v FLAG -112 -32 vh FLAG 544 96 va FLAG 336 -96 vb FLAG 64 -32 ve SYMBOL npn 272 -144 M0 SYMATTR InstName Q1 SYMATTR Value BC547B SYMBOL res 192 -32 R0 SYMATTR InstName R1 SYMATTR Value 270R SYMBOL res 0 -32 R0 SYMATTR InstName R3 SYMATTR Value 10k SYMBOL Misc\\battery 352 144 R0 SYMATTR InstName V1 SYMATTR Value 10v SYMBOL res 400 -96 R0 SYMATTR InstName R5 SYMATTR Value 2k2 SYMBOL res -272 96 R0 SYMATTR InstName R6 SYMATTR Value 2k SYMBOL res 16 -48 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R8 SYMATTR Value 18k SYMBOL ntc_resistor 192 160 R0 WINDOW 123 33 181 Left 0 WINDOW 3 28 145 Left 0 WINDOW 38 24 108 Left 0 SYMATTR Value2 RTH=667 TAU=15 SYMATTR Value R0=2k B=3988 SYMATTR SpiceModel NTC_BTH SYMATTR InstName R4 SYMBOL cap 96 16 R0 SYMATTR InstName C1 SYMATTR Value 10µ SYMBOL res -272 -48 R0 SYMATTR InstName R7 SYMATTR Value 2k5 SYMBOL ntc_resistor 0 160 R0 WINDOW 3 10 181 Left 0 SYMATTR Value R0=50K B=3988 SYMATTR InstName R10 SYMATTR SpiceModel NTC_B SYMBOL Opamps\\LM741 352 160 M180 WINDOW 3 -64 149 Left 0 SYMATTR InstName U2 TEXT -232 360 Left 0 !.op TEXT -1032 -120 Left 0 !.SUBCKT NTC_BTH 1 2 R0={R0} B={B} RTH={RTH} TAU={TAU} \n* R0 resistance at 25degree\n* B material constant\n* Rth thermal resistance in degree/Watt\n* TAU time constant \n*.PARAM R0=10000\n*.PARAM B=3988\n.PARAM TK=273.15\n.PARAM T0=25\n* Resistor model\nRP 1 2 1G\nB1 1 2 I=V(1,2)/{R0*exp(B*(1/(V(3)+TEMP+TK)-1/(T0+TK)))}\n* Thermal model\n*V(3) is dT = Tntc-TEMP\nRTH 3 0 {RTH}\nCTH 3 0 {TAU/RTH}\nBTH 0 3 I=V(1,2)*V(1,2)/{R0*exp(B*(1/(V(3)+TEMP+TK)-1/(T0+TK)))}\n.ENDS TEXT 192 376 Left 0 ;NTC 2k, B=3988 with self heating TEXT 480 272 Left 0 !.step temp 0 30 1 TEXT 512 312 Left 0 !.temp =25 TEXT 720 160 Left 0 !.SUBCKT NTC_B 1 2 R0={R0} B={B}\n*.PARAM R0=10000\n*.PARAM B=3988\n.PARAM TK=273.15\n.PARAM T0=25\nRP 1 2 1G\nB1 1 2 I=V(1,2)/{R0*exp(B*(1/(TEMP+TK)-1/(T0+TK)))}\n.ENDS TEXT -200 400 Left 0 ;NTC 50k, B=3988 with no selfheating TEXT -240 208 Left 0 ;zero TEXT -96 16 Left 0 ;cal