Version 4
SHEET 1 1364 1144
WIRE -32 512 -256 512
WIRE 144 512 -32 512
WIRE -400 576 -400 560
WIRE -256 576 -256 512
WIRE -256 576 -400 576
WIRE -224 576 -256 576
WIRE 32 576 -144 576
WIRE 416 576 32 576
WIRE 144 592 144 512
WIRE 32 608 32 576
WIRE 112 608 32 608
WIRE -400 624 -400 576
WIRE 224 624 176 624
WIRE 416 624 416 576
WIRE -256 640 -256 576
WIRE 112 640 -96 640
WIRE -32 672 -32 512
WIRE 416 704 416 688
WIRE -32 752 -32 736
WIRE 144 752 144 656
WIRE 144 752 -32 752
WIRE 352 752 304 752
WIRE -256 768 -256 720
WIRE -208 768 -256 768
WIRE -96 768 -96 640
WIRE -96 768 -128 768
WIRE -32 768 -32 752
WIRE -256 800 -256 768
WIRE 224 800 224 624
WIRE 240 800 224 800
WIRE 416 848 416 800
WIRE 416 848 304 848
WIRE 576 848 576 832
WIRE 576 848 416 848
WIRE 416 864 416 848
WIRE -256 896 -256 880
WIRE -32 896 -32 848
WIRE 112 944 -16 944
WIRE 272 944 112 944
WIRE -16 960 -16 944
WIRE 416 960 416 944
WIRE 112 976 112 944
WIRE 272 976 272 944
WIRE 80 992 64 992
WIRE 240 992 224 992
WIRE 80 1024 64 1024
WIRE 240 1024 224 1024
FLAG -400 704 0
FLAG -400 560 IN
IOPIN -400 560 Out
FLAG 576 832 OUT
IOPIN 576 832 Out
FLAG -256 896 0
FLAG -32 896 0
FLAG 416 960 0
FLAG 112 1040 0
FLAG 64 992 0
FLAG 64 1024 0
FLAG 272 1040 0
FLAG 224 992 0
FLAG 224 1024 0
FLAG -16 1040 0
SYMBOL voltage -400 608 R0
WINDOW 123 -105 74 Left 0
WINDOW 39 0 0 Left 0
WINDOW 0 24 7 Left 0
WINDOW 3 -79 138 Left 0
SYMATTR InstName Vin
SYMATTR Value PULSE(20 28 0 1)
SYMBOL res -272 624 R0
SYMATTR InstName R1
SYMATTR Value 0.1
SYMBOL res -128 560 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL res -112 752 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R4
SYMATTR Value 1k
SYMBOL res -48 752 R0
SYMATTR InstName R5
SYMATTR Value 1k
SYMBOL zener -16 736 R180
WINDOW 0 24 72 Left 0
WINDOW 3 -18 27 Right 0
SYMATTR InstName D3
SYMATTR Value BZX84C12L
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL pnp 240 848 M180
WINDOW 0 44 33 Left 0
WINDOW 3 42 63 Left 0
SYMATTR InstName Q3
SYMATTR Value BC857C
SYMBOL pnp 352 800 M180
WINDOW 0 44 33 Left 0
WINDOW 3 42 63 Left 0
SYMATTR InstName Q4
SYMATTR Value BC857C
SYMBOL res 400 848 R0
SYMATTR InstName R6
SYMATTR Value 5k
SYMBOL current -256 800 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName I1
SYMATTR Value {Iload}
SYMBOL zener 432 688 R180
WINDOW 0 24 72 Left 0
WINDOW 3 -164 33 Left 0
SYMATTR InstName D4
SYMATTR Value BZX84C4V7
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL Misc-OpAmp\\TL072_TI 112 944 R0
SYMATTR InstName U1
SYMBOL Misc-OpAmp\\TL072_STM 272 944 R0
WINDOW 0 26 38 Left 0
WINDOW 3 -79 128 Left 0
SYMATTR InstName U2
SYMBOL voltage -16 944 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL Misc-OpAmp\\TL072_STM 144 560 R0
WINDOW 0 26 38 Left 0
WINDOW 3 -79 128 Left 0
SYMATTR InstName U3
TEXT -424 928 Left 0 !.tran 1
TEXT -504 984 Left 0 !.step param Iload list 10m 100m 1 5