* SPICE netlist
V1 +15V 0 15v
V2 0 -15V 15v
XU5 N004 N005 +15V -15V N007 LM741 ;pnba In+)In-)V+)V-)OUT
C1 Vcap 0 100n
R1 N001 N005 1k
Q1 Vcap N007 N005 0 PNP
XU3 N002 N001 +15V -15V N001 LM741 ;pnba In+)In-)V+)V-)OUT
V4 N002 0 13
D2 N007 N005 1N4148
V3 N006 0 PULSE(-15 15 0 10m 0 0 10m)
XU1 N008 N003 +15V -15V N004 LM741 ;pnba In+)In-)V+)V-)OUT
R2 N004 N003 10k
R3 N003 N006 30k
V5 N008 0 9.75
.SUBCKT TL082 1 2 3 4 5
C1 11 12 3.498E-12
C2 6 7 15.00E-12
DC 5 53 DX
DE 54 5 DX
DLP 90 91 DX
DLN 92 90 DX
DP 4 3 DX
EGND 99 0 POLY(2) (3,0) (4,0) 0 .5 .5
FB 7 99 POLY(5) VB VC VE VLP VLN 0 4.715E6 -5E6 5E6 5E6 -5E6
GA 6 0 11 12 282.8E-6
GCM 0 6 10 99 8.942E-9
ISS 3 10 DC 195.0E-6
HLIM 90 0 VLIM 1K
J1 11 2 10 JX
J2 12 1 10 JX
R2 6 9 100.0E3
RD1 4 11 3.536E3
RD2 4 12 3.536E3
RO1 8 5 150
RO2 7 99 150
RP 3 4 2.143E3
RSS 10 99 1.026E6
VB 9 0 DC 0
VC 3 53 DC 2.200
VE 54 4 DC 2.200
VLIM 7 8 DC 0
VLP 91 0 DC 25
VLN 0 92 DC 25
.tran 10m startup
.SUBCKT LM741 1 2 99 50 28
IOS 2 1 20N
R1 1 3 250K
R2 3 2 250K
I1 4 50 100U
R3 5 99 517
R4 6 99 517
Q1 5 2 4 QX
Q2 6 7 4 QX
C4 5 6 60.3614P
I2 99 50 1.6MA
EOS 7 1 POLY(1) 16 49 1E-3 1
R8 99 49 40K
R9 49 50 40K
V2 99 8 1.63
D1 9 8 DX
D2 10 9 DX
V3 10 50 1.63
EH 99 98 99 49 1
G1 98 9 5 6 2.1E-3
R5 98 9 95.493MEG
C3 98 9 333.33P
G3 98 15 9 49 1E-6
R12 98 15 1MEG
C5 98 15 5.3052E-15
G4 98 16 3 49 3.1623E-8
L2 98 17 530.5M
R13 17 16 1K
F6 50 99 POLY(1) V6 450U 1
E1 99 23 99 15 1
R16 24 23 25
D5 26 24 DX
V6 26 22 0.65V
R17 23 25 25
D6 25 27 DX
V7 22 27 0.65V
V5 22 21 0.18V
D4 21 15 DX
V4 20 22 0.18V
D3 15 20 DX
L3 22 28 100P
RL3 22 28 100K
.step param Vref list 13 12.8 10 8

* LTspice schematic (.asc)
Version 4
SHEET 1 1520 608
WIRE 536 -304 344 -304
WIRE 344 -224 344 -304
WIRE 392 -224 344 -224
WIRE 536 -208 536 -304
WIRE 536 -208 456 -208
WIRE 600 -208 536 -208
WIRE 392 -192 344 -192
WIRE 344 -160 344 -192
WIRE 600 -144 600 -208
WIRE -8 -48 -40 -48
WIRE 120 -48 72 -48
WIRE 504 0 280 0
WIRE 600 0 600 -64
WIRE 600 0 504 0
WIRE 504 16 504 0
WIRE 600 48 600 0
WIRE 280 80 280 0
WIRE 328 80 280 80
WIRE -168 96 -360 96
WIRE -40 96 -40 -48
WIRE -40 96 -88 96
WIRE -8 96 -40 96
WIRE 504 96 504 80
WIRE 504 96 392 96
WIRE 536 96 504 96
WIRE 120 112 120 -48
WIRE 120 112 56 112
WIRE 328 112 120 112
WIRE -8 128 -56 128
WIRE 728 144 600 144
WIRE 760 144 728 144
WIRE -696 176 -696 160
WIRE -696 176 -760 176
WIRE -696 192 -696 176
WIRE 760 192 760 144
WIRE -760 208 -760 176
WIRE -360 208 -360 96
WIRE -56 208 -56 128
WIRE 760 304 760 256
FLAG -760 208 0
FLAG -696 80 +15V
FLAG -696 272 -15V
FLAG 360 128 -15V
FLAG 360 64 +15V
FLAG 760 304 0
FLAG 728 144 Vcap
FLAG 424 -176 -15V
FLAG 424 -240 +15V
FLAG 344 -80 0
FLAG -360 288 0
FLAG 24 144 -15V
FLAG 24 80 +15V
FLAG -56 288 0
SYMBOL voltage -696 64 R0
SYMATTR InstName V1
SYMATTR Value 15v
SYMBOL voltage -696 176 R0
SYMATTR InstName V2
SYMATTR Value 15v
SYMBOL Opamps\\opamp2 360 32 R0
SYMATTR Value LM741
SYMATTR InstName U5
SYMBOL cap 744 192 R0
SYMATTR InstName C1
SYMATTR Value 100n
SYMBOL res 584 -160 R0
SYMATTR InstName R1
SYMATTR Value 1k
SYMBOL pnp 536 144 M180
SYMATTR InstName Q1
SYMBOL Opamps\\opamp2 424 -272 R0
SYMATTR Value LM741
SYMATTR InstName U3
SYMBOL voltage 344 -176 R0
SYMATTR InstName V4
SYMATTR Value 13
SYMBOL diode 520 80 R180
SYMATTR InstName D2
SYMATTR Value 1N4148
SYMBOL voltage -360 192 R0
SYMATTR InstName V3
SYMATTR Value PULSE(-15 15 0 10m 0 0 10m)
SYMBOL Opamps\\opamp2 24 48 R0
SYMATTR Value LM741
SYMATTR InstName U1
SYMBOL res 88 -64 R90
SYMATTR InstName R2
SYMATTR Value 10k
SYMBOL res -72 80 R90
SYMATTR InstName R3
SYMATTR Value 30k
SYMBOL voltage -56 192 R0
SYMATTR InstName V5
SYMATTR Value 9.75