* SPICE netlist
V1 N008 0 48V
V2 0 N011 48V
D1 N010 0 BZX84C15L
D2 N010 0 BZX84C15L
D3 N010 0 BZX84C15L
D4 N010 0 BZX84C15L
D5 N010 0 BZX84C15L
D6 N005 N008 BZX84B20VLY
XU1 0 N006 N005 LT1085-5 ;pnba GND)OUT)IN
XU2 N011 N012 N010 LT1086-12 ;pnba ADJ)OUT)IN
R1 N012 N011 40
R2 N009 N008 0.1R
R3 N002 N008 10k
R4 N007 N009 10k
R5 0 N002 1k
R6 0 N007 1k
R7 N001 N002 1k
R8 N004 N007 1k
R9 0 N001 100k
R10 N003 N004 100k
R11 N009 0 10
XU3 N004 N001 N003 opamp Aol=100K GBW=10Meg ;pnba invin)noninvin)out
.tran 0 1 0 0.0001

* LTspice schematic (.asc)
Version 4
SHEET 1 1072 928
WIRE 200 -464 56 -464
WIRE 536 -464 200 -464
WIRE 56 -432 56 -464
WIRE 200 -432 200 -464
WIRE 392 -416 376 -416
WIRE 488 -416 472 -416
WIRE 488 -368 488 -416
WIRE 488 -368 424 -368
WIRE 536 -368 536 -464
WIRE 536 -368 488 -368
WIRE 280 -352 264 -352
WIRE 376 -352 376 -416
WIRE 376 -352 360 -352
WIRE 424 -352 424 -368
WIRE 56 -336 56 -352
WIRE 264 -336 264 -352
WIRE 264 -336 56 -336
WIRE 376 -336 376 -352
WIRE 392 -336 376 -336
WIRE 472 -320 456 -320
WIRE 392 -304 376 -304
WIRE -312 -272 -376 -272
WIRE -8 -272 -56 -272
WIRE 200 -272 200 -352
WIRE 280 -272 200 -272
WIRE 376 -272 376 -304
WIRE 376 -272 360 -272
WIRE 424 -272 424 -288
WIRE 504 -272 424 -272
WIRE 56 -256 56 -336
WIRE 200 -256 200 -272
WIRE -376 -224 -376 -272
WIRE 376 -224 376 -272
WIRE 392 -224 376 -224
WIRE 472 -224 472 -320
WIRE -376 -144 -376 -160
WIRE -376 -144 -504 -144
WIRE 56 -144 56 -176
WIRE 56 -144 -376 -144
WIRE 88 -144 56 -144
WIRE 200 -144 200 -176
WIRE 200 -144 168 -144
WIRE 248 -144 200 -144
WIRE -504 -112 -504 -144
WIRE -8 -80 -8 -272
WIRE 504 -80 504 -272
WIRE 504 -80 -8 -80
WIRE -184 -48 -184 -176
WIRE 536 -48 536 -368
WIRE 536 -48 -184 -48
WIRE -504 0 -504 -32
WIRE -504 0 -536 0
WIRE -376 0 -504 0
WIRE -328 0 -376 0
WIRE -280 0 -328 0
WIRE -232 0 -280 0
WIRE -184 0 -184 -48
WIRE -184 0 -232 0
WIRE -8 0 -184 0
WIRE 248 0 248 -144
WIRE 248 0 72 0
WIRE -536 16 -536 0
WIRE -376 16 -376 0
WIRE -328 16 -328 0
WIRE -280 16 -280 0
WIRE -232 16 -232 0
WIRE -184 16 -184 0
WIRE -504 32 -504 0
WIRE -376 96 -376 80
WIRE -328 96 -328 80
WIRE -328 96 -376 96
WIRE -280 96 -280 80
WIRE -280 96 -328 96
WIRE -232 96 -232 80
WIRE -232 96 -280 96
WIRE -184 96 -184 80
WIRE -184 96 -232 96
WIRE -504 144 -504 112
WIRE -424 144 -504 144
WIRE -120 144 -424 144
WIRE -376 336 -376 96
WIRE -312 336 -376 336
WIRE -8 336 -56 336
WIRE -8 352 -8 336
WIRE -424 464 -424 144
WIRE -184 464 -184 432
WIRE -184 464 -424 464
WIRE -8 464 -8 432
WIRE -8 464 -184 464
FLAG -536 16 0
SYMBOL voltage -504 -128 R0
SYMATTR InstName V1
SYMATTR Value 48V
SYMBOL voltage -504 16 R0
SYMATTR InstName V2
SYMATTR Value 48V
SYMBOL zener -360 80 R180
SYMATTR InstName D1
SYMATTR Value BZX84C15L
SYMBOL zener -312 80 R180
SYMATTR InstName D2
SYMATTR Value BZX84C15L
SYMBOL zener -264 80 R180
SYMATTR InstName D3
SYMATTR Value BZX84C15L
SYMBOL zener -216 80 R180
SYMATTR InstName D4
SYMATTR Value BZX84C15L
SYMBOL zener -168 80 R180
SYMATTR InstName D5
SYMATTR Value BZX84C15L
SYMBOL zener -392 -224 R0
SYMATTR InstName D6
SYMATTR Value BZX84B20VLY
SYMBOL PowerProducts\\LT1085-5 -184 -272 R0
SYMATTR InstName U1
SYMBOL PowerProducts\\LT1086-12 -184 336 R0
SYMATTR InstName U2
SYMBOL res -24 336 R0
SYMATTR InstName R1
SYMATTR Value 40
SYMBOL res 184 -160 R90
SYMATTR InstName R2
SYMATTR Value 0.1R
SYMBOL res 40 -272 R0
SYMATTR InstName R3
SYMATTR Value 10k
SYMBOL res 184 -272 R0
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL res 40 -448 R0
SYMATTR InstName R5
SYMATTR Value 1k
SYMBOL res 184 -448 R0
SYMATTR InstName R6
SYMATTR Value 1k
SYMBOL res 376 -368 R90
SYMATTR InstName R7
SYMATTR Value 1k
SYMBOL res 376 -288 R90
SYMATTR InstName R8
SYMATTR Value 1k
SYMBOL res 488 -432 R90
SYMATTR InstName R9
SYMATTR Value 100k
SYMBOL res 488 -240 R90
SYMATTR InstName R10
SYMATTR Value 100k
SYMBOL res 88 -16 R90
SYMATTR InstName R11
SYMATTR Value 10
SYMBOL OpAmps\\opamp 424 -256 M180
SYMATTR InstName U3