Version 4 SHEET 1 1764 900 WIRE -336 -64 -688 -64 WIRE 144 -64 -336 -64 WIRE 160 -64 144 -64 WIRE 288 -64 160 -64 WIRE 160 -48 160 -64 WIRE -688 -32 -688 -64 WIRE -336 -32 -336 -64 WIRE 768 -16 688 -16 WIRE 832 -16 768 -16 WIRE 288 16 288 -64 WIRE 544 16 400 16 WIRE 832 32 832 -16 WIRE 160 64 160 32 WIRE 224 64 160 64 WIRE -688 80 -688 48 WIRE -624 80 -688 80 WIRE -576 80 -624 80 WIRE -288 80 -576 80 WIRE -128 80 -208 80 WIRE 0 96 -64 96 WIRE 16 96 0 96 WIRE 48 96 16 96 WIRE 160 96 160 64 WIRE 160 96 128 96 WIRE 560 96 496 96 WIRE -688 112 -688 80 WIRE -128 112 -160 112 WIRE 400 128 400 16 WIRE 432 128 400 128 WIRE 560 144 496 144 WIRE 688 144 688 -16 WIRE 688 144 560 144 WIRE -336 192 -336 48 WIRE -288 192 -336 192 WIRE -160 192 -160 112 WIRE -160 192 -208 192 WIRE -128 192 -160 192 WIRE 0 192 0 96 WIRE 0 192 -48 192 WIRE 288 192 288 112 WIRE 336 192 288 192 WIRE 432 192 336 192 WIRE 640 208 576 208 WIRE 736 208 736 176 WIRE 736 208 640 208 WIRE -576 224 -576 80 WIRE 336 224 336 192 WIRE 432 224 400 224 WIRE -688 240 -688 192 WIRE 736 240 736 208 WIRE 576 256 576 208 WIRE 640 256 640 208 WIRE -336 288 -336 192 WIRE 576 352 576 320 WIRE 640 352 640 320 WIRE 640 352 576 352 WIRE 736 352 736 320 WIRE 736 352 640 352 WIRE 832 352 832 112 WIRE 832 352 736 352 WIRE 736 368 736 352 WIRE -688 432 -688 320 WIRE -576 432 -576 288 WIRE -576 432 -688 432 WIRE -336 432 -336 368 WIRE -336 432 -576 432 WIRE 288 432 -336 432 WIRE 336 432 336 288 WIRE 336 432 288 432 WIRE 400 432 400 224 WIRE 400 432 336 432 WIRE -336 448 -336 432 WIRE 288 448 288 432 FLAG -96 128 0 FLAG -96 64 +V FLAG 144 -64 +V IOPIN 144 -64 In FLAG 288 448 0 FLAG 336 192 Vrel FLAG 16 96 Vo FLAG -624 80 Vset FLAG 736 368 0 FLAG 736 176 +v FLAG 560 96 RLA_n/c FLAG 560 144 RLA_n/o FLAG 544 16 +v FLAG 768 -16 Htr FLAG -336 448 0 SYMBOL res -32 176 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R8 SYMATTR Value 1meg SYMBOL pnp 224 112 M180 SYMATTR InstName Q1 SYMATTR Value 2N3906 SYMBOL res 144 80 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R4 SYMATTR Value 2k2 SYMBOL res -704 -48 R0 SYMATTR InstName R6 SYMATTR Value 22k SYMBOL res -704 96 R0 SYMATTR InstName R9 SYMATTR Value 9k SYMBOL res -704 224 R0 SYMATTR InstName R10 SYMATTR Value 1k SYMBOL res -192 176 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 30 13 VTop 0 SYMATTR InstName R3 SYMATTR Value 10k SYMBOL res -192 64 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R7 SYMATTR Value 10k SYMBOL cap -592 224 R0 SYMATTR InstName C1 SYMATTR Value 1µ SYMBOL XOPAMP -96 32 R0 WINDOW 38 -47 223 Left 0 SYMATTR SpiceModel LM393A SYMATTR InstName U1 SYMBOL Misc\\battery 736 224 R0 SYMATTR InstName V1 SYMATTR Value 12v SYMBOL cap 624 256 R0 SYMATTR InstName C2 SYMATTR Value 22µ SYMBOL cap 560 256 R0 SYMATTR InstName C3 SYMATTR Value 100n SYMBOL rly_spdt 464 144 R0 SYMATTR SpiceModel RLY_POW1 SYMATTR InstName U2 SYMATTR Value RCOIL=500 TON=5m VNOM=12 SYMBOL diode 352 288 R180 WINDOW 0 24 72 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName D1 SYMATTR Value 1N4006 SYMBOL res 144 -64 R0 SYMATTR InstName R1 SYMATTR Value 22k SYMBOL res 816 16 R0 SYMATTR InstName R5 SYMATTR Value 100 SYMBOL res -352 -48 R0 SYMATTR InstName R2 SYMATTR Value 22k SYMBOL res -352 272 R0 SYMATTR InstName R11 SYMATTR Value {R} TEXT 104 456 Left 0 !.tran 0 5 0 10m TEXT -680 464 Left 0 !.INCLUDE LM393A.5_1_ti.mod TEXT 408 328 Left 0 ;Power Relay TEXT 440 384 Left 0 !.include relay.lib TEXT 424 304 Left 0 ;12V_500R TEXT -784 152 Left 0 ;20Kpot TEXT -776 288 Left 0 ;2Kpot TEXT 736 80 Left 0 ;Heater TEXT 752 56 Left 0 ;Sim TEXT 920 -56 Left 0 ;.STEP TEMP LIST 0 10 5 TEXT 928 -96 Left 0 ;.OP TEXT 912 -160 Left 0 ;.STEP TEMP 0 50 10 TEXT 960 56 Left 0 !.OPTIONS TNOM={T0} TEXT 952 96 Left 0 !.PARAM R0=10000\n*.PARAM B=3988\n.PARAM TK=273.15\n.PARAM T0=25 TEXT 920 -128 Left 0 !;TRAN 200 TEXT 920 -192 Left 0 !.options TEMP=5 TEXT 944 224 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 -312 464 Left 0 ;NTC 10k, B=3988 with no selfheating TEXT -1712 -360 Left 0 ;Dynamic Model for the NTC Thermistor in LTSPICE \n-------------------------------------------------------------------------------\n 7/30/2004 Helmut Sennewald\nHint: The unit Ohm can be achieved on the y-axis if V(node)/1A is plotted.\n \ndT=TEMP-T0\nTEMP = T0 + dT\nT = TEMP+TK\nT0 is 27 degree for SPICE. It can be overwritten with e.g. ".OPTIONS TNOM=25".\nTK is 273.15 degree.\nR0 is resistance at a defined temperature, mostly 25 degree for NTC-thermistors.\n \n \nExponential temperature dependence\n-----------------------------------------------------------\nThis is a very common formula used for NTC thermistors.\nB is a material constant, e.g. B=3988\nB = T1*T2/(T2-T1)*ln(R1/R2) R1, R2 is resistance at T1, T2\nR0 is resistance at T1 .\n \nFormula: R = R0*exp(B*( 1/(TEMP+TK) - 1/(T0+TK) ))\nT = B/( ln(R/R0)+B/(T0+TK) )\nExample: NTC with B=3988\n.PARAM R0=10000\n.PARAM B=3988\n.PARAM TK=273.15\n.PARAM T0=25\n*R1 n1 n2 {R0*exp(B*( 1/(TEMP+TK) - 1/(TNOM+TK) ))}\nReplace resistor R1 by a voltage controlled current source B1(Bi-source)\nB1 n1 n2 I=V(n1,n2)/{R0*exp(3988*(1/(TEMP+TK)-1/(T0+TK)))}\n \nThermal model for self heating\n------------------------------------------------\nThe current through the thermistor rises the thermistor's temperature.\ndTth = P * Rth\nRth is the thermal resistance in degree/Watt \nRth = 1/delta_th in the EPCOS datasheet\nCth = TAU/Rth is the time constant\nPtherm = V*V/Rtherm \nV is the voltage acroos the thermistor. TEXT -480 520 Left 0 !.step R={R0*exp(B*(1/(TEMP+TK)-1/(T0+TK)))}