Version 4
SHEET 1 880 680
WIRE -400 176 -400 -64
WIRE -400 368 -400 256
WIRE -224 -64 -400 -64
WIRE -224 -32 -224 -64
WIRE -224 224 -224 48
WIRE -224 272 -224 224
WIRE -224 368 -224 336
WIRE -176 224 -224 224
WIRE -128 224 -176 224
WIRE -128 272 -128 224
WIRE 0 -64 -224 -64
WIRE 0 -32 0 -64
WIRE 0 144 0 48
WIRE 0 176 0 144
WIRE 0 272 -128 272
WIRE 96 -64 0 -64
WIRE 96 -32 96 -64
WIRE 96 160 96 48
WIRE 96 224 64 224
WIRE 96 224 96 160
WIRE 128 224 96 224
WIRE 192 160 96 160
WIRE 192 176 192 160
WIRE 320 144 0 144
WIRE 320 272 192 272
WIRE 352 144 320 144
WIRE 400 -64 96 -64
WIRE 400 -32 400 -64
WIRE 400 64 400 32
WIRE 400 272 320 272
WIRE 400 272 400 160
WIRE 400 288 400 272
FLAG -224 368 0
FLAG -400 368 0
FLAG 400 368 0
FLAG -176 224 ref
FLAG 320 272 shunt
FLAG 320 144 regel
SYMBOL diode -240 272 R0
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL Misc\\EuropeanResistor -240 -48 R0
SYMATTR InstName R1
SYMATTR Value 1k
SYMBOL voltage -400 160 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 8V
SYMBOL npn 128 176 R0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL npn 64 176 M0
SYMATTR InstName Q2
SYMATTR Value 2N3904
SYMBOL Misc\\EuropeanResistor 384 272 R0
SYMATTR InstName R4
SYMATTR Value 1
SYMBOL Misc\\EuropeanResistor -16 -48 R0
SYMATTR InstName R5
SYMATTR Value 1k
SYMBOL Misc\\EuropeanResistor 80 -48 R0
SYMATTR InstName R6
SYMATTR Value 1k
SYMBOL LED 384 -32 R0
SYMATTR InstName D2
SYMBOL nmos 352 64 R0
SYMATTR InstName M1
SYMATTR Value BSS123
TEXT -442 482 Left 0 !.dc V1 0 20 0.2V
TEXT 312 -88 Left 0 ;plot I(D2), V(ref)