* SPICE netlist
D1 N013 N021 NSCW100
V1 N001 0 PULSE(0 5 0 10u 10u 1 5)
R1 N001 N007 1k
Q1 N013 N012 N007 0 2N4403
V2 N021 0 0.3
D2 N014 N022 NSCW100
V3 N002 0 PULSE(0 5 0 10u 10u 2 5)
R2 N002 N008 1k
Q2 N014 N012 N008 0 2N4403
V4 N022 0 0
D3 N015 N023 NSCW100
V5 N003 0 PULSE(0 5 0 10u 10u 3 5)
R3 N003 N009 1k
Q3 N015 N012 N009 0 2N4403
V6 N023 0 0
D4 N016 N024 NSCW100
V7 N004 0 PULSE(0 5 0 10u 10u 4 5)
R4 N004 N010 1k
Q4 N016 N012 N010 0 2N4403
V8 N024 0 0
R7 N006 N019 470
V9 N006 0 5
I2 N005 N012 SINE(8mA 8mA 30Hz)
V10 N005 0 5V
XU1 N019 N011 N006 0 N017 LT1006 ;pnba In+)In-)V+)V-)OUT
Q5 N020 N018 N012 0 2N4403
R5 N020 0 100
C1 N011 N017 100n
R6 N012 N011 10k
B1 N019 0 I=(sin(time*10)*0.003 + 0.005)*(sin(time*1000)>0)
R8 N018 N017 1k
C2 N006 N019 1n
R9 N006 N012 10k
.tran 5

* LTspice schematic (.asc)
Version 4
SHEET 1 1904 640
WIRE 8 -320 -8 -320
WIRE 232 -320 216 -320
WIRE 456 -320 440 -320
WIRE 680 -320 664 -320
WIRE 8 -176 8 -320
WIRE 232 -176 232 -320
WIRE 456 -176 456 -320
WIRE 680 -176 680 -320
WIRE 952 -176 856 -176
WIRE 952 -144 952 -176
WIRE -824 -96 -952 -96
WIRE -728 -96 -824 -96
WIRE -504 -96 -728 -96
WIRE -168 -96 -504 -96
WIRE -168 -80 -168 -96
WIRE 8 -80 8 -96
WIRE 232 -80 232 -96
WIRE 456 -80 456 -96
WIRE 680 -80 680 -96
WIRE -824 -64 -824 -96
WIRE 856 -64 856 -176
WIRE -728 -48 -728 -96
WIRE 952 -48 952 -64
WIRE -952 32 -952 -96
WIRE -440 32 -568 32
WIRE -296 32 -440 32
WIRE -168 32 -168 0
WIRE -168 32 -216 32
WIRE -56 32 -56 -32
WIRE -56 32 -168 32
WIRE 168 32 168 -32
WIRE 168 32 -56 32
WIRE 392 32 392 -32
WIRE 392 32 168 32
WIRE 616 32 616 -32
WIRE 616 32 392 32
WIRE 856 32 856 16
WIRE 856 32 616 32
WIRE -168 48 -168 32
WIRE -504 64 -504 -96
WIRE 8 64 8 16
WIRE 232 64 232 16
WIRE 456 64 456 16
WIRE 680 64 680 16
WIRE -568 80 -568 32
WIRE -536 80 -568 80
WIRE -440 96 -472 96
WIRE -360 96 -440 96
WIRE -232 96 -280 96
WIRE -824 112 -824 16
WIRE -728 112 -728 16
WIRE -728 112 -824 112
WIRE -536 112 -728 112
WIRE -824 128 -824 112
WIRE -168 160 -168 144
WIRE 8 160 8 128
WIRE 232 160 232 128
WIRE 456 160 456 128
WIRE 680 160 680 128
WIRE -952 256 -952 112
WIRE -824 256 -824 208
WIRE -504 256 -504 128
WIRE -168 256 -168 240
WIRE 8 256 8 240
WIRE 232 256 232 240
WIRE 456 256 456 240
WIRE 680 256 680 240
WIRE -824 320 -824 288
FLAG 8 256 0
FLAG -88 -320 0
FLAG 232 256 0
FLAG 136 -320 0
FLAG 456 256 0
FLAG 360 -320 0
FLAG 680 256 0
FLAG 584 -320 0
FLAG -824 256 0
FLAG -952 256 0
FLAG 952 -48 0
FLAG -504 256 0
FLAG -168 256 0
SYMBOL LED -8 64 R0
SYMATTR InstName D1
SYMATTR Value NSCW100
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL voltage 8 -320 R90
SYMATTR InstName V1
SYMATTR Value PULSE(0 5 0 10u 10u 1 5)
SYMBOL res -8 -192 R0
SYMATTR InstName R1
SYMATTR Value 1k
SYMBOL pnp -56 16 M180
SYMATTR InstName Q1
SYMATTR Value 2N4403
SYMBOL voltage 8 144 R0
SYMATTR InstName V2
SYMATTR Value 0.3
SYMBOL LED 216 64 R0
SYMATTR InstName D2
SYMATTR Value NSCW100
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL voltage 232 -320 R90
SYMATTR InstName V3
SYMATTR Value PULSE(0 5 0 10u 10u 2 5)
SYMBOL res 216 -192 R0
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL pnp 168 16 M180
SYMATTR InstName Q2
SYMATTR Value 2N4403
SYMBOL voltage 232 144 R0
SYMATTR InstName V4
SYMATTR Value 0
SYMBOL LED 440 64 R0
SYMATTR InstName D3
SYMATTR Value NSCW100
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL voltage 456 -320 R90
SYMATTR InstName V5
SYMATTR Value PULSE(0 5 0 10u 10u 3 5)
SYMBOL res 440 -192 R0
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL pnp 392 16 M180
SYMATTR InstName Q3
SYMATTR Value 2N4403
SYMBOL voltage 456 144 R0
SYMATTR InstName V6
SYMATTR Value 0
SYMBOL LED 664 64 R0
SYMATTR InstName D4
SYMATTR Value NSCW100
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL voltage 680 -320 R90
SYMATTR InstName V7
SYMATTR Value PULSE(0 5 0 10u 10u 4 5)
SYMBOL res 664 -192 R0
SYMATTR InstName R4
SYMATTR Value 1k
SYMBOL pnp 616 16 M180
SYMATTR InstName Q4
SYMATTR Value 2N4403
SYMBOL voltage 680 144 R0
SYMATTR InstName V8
SYMATTR Value 0
SYMBOL res -840 -80 R0
SYMATTR InstName R7
SYMATTR Value 470
SYMBOL voltage -952 16 R0
SYMATTR InstName V9
SYMATTR Value 5
SYMBOL current 856 -64 R0
SYMATTR InstName I2
SYMATTR Value SINE(8mA 8mA 30Hz)
SYMBOL voltage 952 -160 R0
SYMATTR InstName V10
SYMATTR Value 5V
SYMBOL Opamps\\LT1006 -504 32 R0
SYMATTR InstName U1
SYMBOL pnp -232 144 M180
SYMATTR InstName Q5
SYMATTR Value 2N4403
SYMBOL res -184 144 R0
SYMATTR InstName R5
SYMATTR Value 100
SYMBOL cap -456 32 R0
SYMATTR InstName C1
SYMATTR Value 100n
SYMBOL res -200 16 R90
SYMATTR InstName R6
SYMATTR Value 10k
SYMBOL bi -824 128 R0
SYMATTR InstName B1
SYMATTR Value I=(sin(time*10)*0.003 + 0.005)*(sin(time*1000)>0)
SYMBOL res -264 80 R90
SYMATTR InstName R8
SYMATTR Value 1k
SYMBOL cap -744 -48 R0
SYMATTR InstName C2
SYMATTR Value 1n
SYMBOL res -184 -96 R0
SYMATTR InstName R9
SYMATTR Value 10k