* SPICE netlist
Q1 N004 vi1 N009 0 TR1
Q2 N009 N013 N017 0 BC547B
Q3 N013 N013 N016 0 BC547B
R1 Vref N013 100
R2 Vreg N003 0.1k
R3 Vreg N002 0.1k
Q4 N006 N004 N003 0 BC557B
Q5 N004 N004 N002 0 BC557B
Q6 N006 N008 N009 0 TR1
R4 N016 0 10
R5 N017 0 10
R6 N001 Vf 3.3k
R7 Vf N011 2.2k
R8 Vf N011 2.4k
M1 N011 N014 0 0 BSZ0901NSI
R9 N015 N014 1k
V1 N015 0 6.5
R10 N011 N018 1.1k
R11 N018 0 20
Q7 N005 N006 N001 0 2N2222
Q8 N001 N005 Vreg 0 tip42C
R12 N001 0 100
V3 Vreg 0 {VINDC}
V4 Vref 0 1.2
V5 5v 0 5
R13 N008 vi2 2.2k
R14 N008 vi2 2.4k
R15 vi2 N012 1.1k
R16 N012 vi2 20
R17 N008 vi2 3.3k
V7 N010 0 1.2 AC 1
E1 vi1 N010 N007 0 0.5
E2 vi2 N010 N007 0 -0.5
V2 N007 0 AC 1
.include librerias/bd140.lib
.inc opamp.sub
.include librerias/complex_discretes.lib
.ac lin 1000 10 10Meg
.param VINDC 6.25

* LTspice schematic (.asc)
Version 4
SHEET 1 3312 1328
WIRE -8 -664 -296 -664
WIRE 200 -664 -8 -664
WIRE 376 -664 200 -664
WIRE 616 -664 472 -664
WIRE 1112 -664 616 -664
WIRE 1656 -664 1112 -664
WIRE -8 -616 -8 -664
WIRE 200 -600 200 -664
WIRE 1112 -568 1112 -664
WIRE -8 -504 -8 -536
WIRE 200 -504 200 -520
WIRE 88 -456 56 -456
WIRE 136 -456 88 -456
WIRE 424 -456 424 -600
WIRE 456 -456 424 -456
WIRE 616 -456 616 -664
WIRE 616 -456 552 -456
WIRE -8 -376 -8 -408
WIRE 88 -376 88 -456
WIRE 88 -376 -8 -376
WIRE 200 -376 200 -408
WIRE 504 -376 504 -392
WIRE 504 -376 200 -376
WIRE -1464 -328 -1656 -328
WIRE -1224 -328 -1464 -328
WIRE -664 -248 -664 -280
WIRE -8 -216 -8 -376
WIRE 200 -216 200 -376
WIRE -1656 -200 -1656 -328
WIRE -1416 -200 -1416 -264
WIRE -1176 -200 -1176 -280
WIRE 1656 -200 1656 -664
WIRE -1464 -184 -1464 -328
WIRE -1224 -184 -1224 -328
WIRE -72 -168 -88 -168
WIRE 360 -168 264 -168
WIRE 520 -168 360 -168
WIRE 664 -168 520 -168
WIRE 760 -168 664 -168
WIRE -664 -136 -664 -168
WIRE 360 -136 360 -168
WIRE 520 -136 520 -168
WIRE 664 -136 664 -168
WIRE -1224 -104 -1224 -136
WIRE -1464 -88 -1464 -136
WIRE -8 -88 -8 -120
WIRE 104 -88 -8 -88
WIRE 200 -88 200 -120
WIRE 200 -88 104 -88
WIRE -1656 -72 -1656 -120
WIRE -1416 -72 -1416 -120
WIRE -1272 -72 -1416 -72
WIRE -1176 -72 -1176 -120
WIRE -1176 -72 -1272 -72
WIRE 1112 -56 1112 -488
WIRE 1112 -56 936 -56
WIRE 1256 -56 1112 -56
WIRE -1272 -24 -1272 -72
WIRE 360 -8 360 -56
WIRE 376 -8 360 -8
WIRE 520 -8 520 -56
WIRE 520 -8 376 -8
WIRE 1112 8 1112 -56
WIRE 1256 8 1256 -56
WIRE -664 56 -664 24
WIRE 376 56 376 -8
WIRE -296 88 -296 -200
WIRE -1272 136 -1272 56
WIRE 1112 152 1112 88
WIRE 1256 152 1256 88
WIRE 1256 152 1112 152
WIRE -664 168 -664 136
WIRE 376 200 376 136
WIRE -296 232 -296 168
WIRE -184 232 -296 232
WIRE 1112 248 1112 152
WIRE 1112 248 984 248
WIRE -296 280 -296 232
WIRE 104 280 104 -88
WIRE 1112 296 1112 248
WIRE -184 328 -184 232
WIRE -184 328 -232 328
WIRE 40 328 -184 328
WIRE 376 344 376 280
WIRE 520 344 520 -8
WIRE 520 344 376 344
WIRE 664 344 664 -56
WIRE 664 344 520 344
WIRE -664 376 -664 296
WIRE 520 376 520 344
WIRE 984 376 984 248
WIRE 1272 376 1160 376
WIRE 1448 376 1352 376
WIRE 520 408 520 376
WIRE -296 440 -296 376
WIRE 104 440 104 376
WIRE 1448 456 1448 376
WIRE -664 488 -664 456
WIRE 984 536 984 456
WIRE -296 584 -296 520
WIRE 104 584 104 520
WIRE 104 584 -296 584
WIRE 104 664 104 584
WIRE 424 664 104 664
WIRE 984 664 984 616
WIRE 984 664 424 664
WIRE 1112 664 1112 392
WIRE 1112 664 984 664
WIRE 1448 664 1448 536
WIRE 1448 664 1112 664
WIRE 1656 664 1656 -120
WIRE 1656 664 1448 664
FLAG 936 -56 Vf
FLAG 424 664 0
FLAG -664 -136 0
FLAG -664 168 0
FLAG -664 -280 Vreg
FLAG -664 24 Vref
FLAG -664 488 0
FLAG -664 296 5v
FLAG -296 -664 Vreg
FLAG -1272 136 0
FLAG -1416 -264 vi1
FLAG -1176 -280 vi2
FLAG -88 -168 vi1
FLAG 520 376 vi2
FLAG -1224 -104 0
FLAG -1464 -88 0
FLAG -1656 -72 0
FLAG -296 -200 Vref
DATAFLAG -784 -528 ""
DATAFLAG -496 -704 ""
DATAFLAG -704 -656 ""
SYMBOL npn -72 -216 R0
SYMATTR InstName Q1
SYMATTR Value TR1
SYMBOL npn 40 280 R0
SYMATTR InstName Q2
SYMATTR Value BC547B
SYMBOL npn -232 280 M0
SYMATTR InstName Q3
SYMATTR Value BC547B
SYMBOL res -312 72 R0
SYMATTR InstName R1
SYMATTR Value 100
SYMBOL res 184 -616 R0
SYMATTR InstName R2
SYMATTR Value 0.1k
SYMBOL res -24 -632 R0
SYMATTR InstName R3
SYMATTR Value 0.1k
SYMBOL pnp 136 -408 M180
SYMATTR InstName Q4
SYMATTR Value BC557B
SYMBOL pnp 56 -408 R180
SYMATTR InstName Q5
SYMATTR Value BC557B
SYMBOL npn 264 -216 M0
SYMATTR InstName Q6
SYMATTR Value TR1
SYMBOL res -312 424 R0
SYMATTR InstName R4
SYMATTR Value 10
SYMBOL res 88 424 R0
SYMATTR InstName R5
SYMATTR Value 10
SYMBOL res 1096 -584 R0
SYMATTR InstName R6
SYMATTR Value 3.3k
SYMBOL res 1096 -8 R0
SYMATTR InstName R7
SYMATTR Value 2.2k
SYMBOL res 1240 -8 R0
SYMATTR InstName R8
SYMATTR Value 2.4k
SYMBOL nmos 1160 296 M0
SYMATTR Value BSZ0901NSI
SYMATTR InstName M1
SYMBOL res 1368 360 R90
SYMATTR InstName R9
SYMATTR Value 1k
SYMBOL voltage 1448 440 R0
SYMATTR InstName V1
SYMATTR Value 6.5
SYMBOL res 968 360 R0
SYMATTR InstName R10
SYMATTR Value 1.1k
SYMBOL res 968 520 R0
SYMATTR InstName R11
SYMATTR Value 20
SYMBOL npn 456 -392 R270
SYMATTR InstName Q7
SYMATTR Value 2N2222
SYMBOL pnp 472 -600 M270
SYMATTR InstName Q8
SYMATTR Value tip42C
SYMBOL res 1640 -216 R0
SYMATTR InstName R12
SYMATTR Value 100
SYMBOL voltage -664 -264 R0
SYMATTR InstName V3
SYMATTR Value {VINDC}
SYMBOL voltage -664 40 R0
SYMATTR InstName V4
SYMATTR Value 1.2
SYMBOL voltage -664 360 R0
SYMATTR InstName V5
SYMATTR Value 5
SYMBOL res 344 -152 R0
SYMATTR InstName R13
SYMATTR Value 2.2k
SYMBOL res 504 -152 R0
SYMATTR InstName R14
SYMATTR Value 2.4k
SYMBOL res 360 40 R0
SYMATTR InstName R15
SYMATTR Value 1.1k
SYMBOL res 360 184 R0
SYMATTR InstName R16
SYMATTR Value 20
SYMBOL res 648 -152 R0
SYMATTR InstName R17
SYMATTR Value 3.3k
SYMBOL voltage -1272 -40 R0
SYMATTR Value 1.2
SYMATTR Value2 AC 1
SYMATTR InstName V7
SYMBOL e -1416 -216 R0
SYMATTR InstName E1
SYMATTR Value 0.5
SYMBOL e -1176 -216 R0
SYMATTR InstName E2
SYMATTR Value -0.5
SYMBOL voltage -1656 -216 R0
SYMATTR Value2 AC 1
SYMATTR InstName V2
SYMATTR Value ""