Version 4 SHEET 1 1172 680 WIRE -336 -64 -592 -64 WIRE 240 -64 -16 -64 WIRE 816 -64 560 -64 WIRE -592 -32 -592 -64 WIRE -16 -32 -16 -64 WIRE 560 -32 560 -64 WIRE -592 80 -592 48 WIRE -16 80 -16 48 WIRE 560 80 560 48 WIRE -336 96 -336 -64 WIRE 240 96 240 -64 WIRE 816 96 816 -64 WIRE -464 144 -592 144 WIRE -400 144 -464 144 WIRE 112 144 -16 144 WIRE 176 144 112 144 WIRE 688 144 560 144 WIRE 752 144 688 144 WIRE -592 176 -592 144 WIRE -16 176 -16 144 WIRE 560 176 560 144 WIRE -336 208 -336 192 WIRE 240 208 240 192 WIRE 816 208 816 192 WIRE -592 288 -592 256 WIRE -16 288 -16 256 WIRE 560 288 560 256 FLAG 240 208 0 FLAG -16 288 0 FLAG -16 80 0 FLAG 112 144 b1 FLAG 816 208 0 FLAG 560 288 0 FLAG 560 80 0 FLAG 688 144 b2 FLAG -336 208 0 FLAG -592 288 0 FLAG -592 80 0 FLAG -464 144 b3 SYMBOL npn 176 96 R0 SYMATTR InstName Q1 SYMATTR Value 2N3904_0v65 SYMBOL current -16 256 M180 WINDOW 0 24 88 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName I1 SYMATTR Value 3.333µ SYMBOL voltage -16 -48 R0 SYMATTR InstName V1 SYMATTR Value 5 SYMBOL npn 752 96 R0 SYMATTR InstName Q2 SYMATTR Value 2N3904_0v70 SYMBOL current 560 256 M180 WINDOW 0 24 88 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName I2 SYMATTR Value 3.333µ SYMBOL voltage 560 -48 R0 SYMATTR InstName V2 SYMATTR Value 5 SYMBOL npn -400 96 R0 SYMATTR InstName Q3 SYMATTR Value 2N3904_0v60 SYMBOL current -592 256 M180 WINDOW 0 24 88 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName I3 SYMATTR Value 3.333µ SYMBOL voltage -592 -48 R0 SYMATTR InstName V3 SYMATTR Value 5 TEXT 520 360 Left 0 !.model 2N3904_0v70 NPN(IS=1.6E-15 VAF=100\n+ Bf=300 IKF=0.4 XTB=1.5 BR=4\n+ CJC=4E-12 CJE=8E-12 RB=20 RC=0.1 RE=0.1\n+ TR=250E-9 TF=350E-12 ITF=1 VTF=2 XTF=3 \n+ Vceo=40 Icrating=200m mfg=Philips) TEXT -584 -128 Left 0 !.op TEXT -64 360 Left 0 !.model 2N3904_0v65 NPN(IS=1.2E-14 VAF=100\n+ Bf=300 IKF=0.4 XTB=1.5 BR=4\n+ CJC=4E-12 CJE=8E-12 RB=20 RC=0.1 RE=0.1\n+ TR=250E-9 TF=350E-12 ITF=1 VTF=2 XTF=3 \n+ Vceo=40 Icrating=200m mfg=Philips) TEXT -640 360 Left 0 !.model 2N3904_0v60 NPN(IS=7.0E-14 VAF=100\n+ Bf=300 IKF=0.4 XTB=1.5 BR=4\n+ CJC=4E-12 CJE=8E-12 RB=20 RC=0.1 RE=0.1\n+ TR=250E-9 TF=350E-12 ITF=1 VTF=2 XTF=3 \n+ Vceo=40 Icrating=200m mfg=Philips) TEXT -464 -120 Left 0 ;Only the parameter "Is" has been adjusted to get a Vbe of 0.6V, 0.65V and 0.7V