Version 4
SHEET 1 880 680
WIRE 480 112 160 112
WIRE 592 128 576 128
WIRE 144 144 128 144
WIRE 160 144 160 112
WIRE 160 144 144 144
WIRE 240 144 208 144
WIRE 384 144 320 144
WIRE 480 144 480 112
WIRE 576 144 576 128
WIRE 128 160 128 144
WIRE 384 160 384 144
WIRE 384 176 384 160
WIRE -32 192 -48 192
WIRE 160 192 160 144
WIRE 352 192 160 192
WIRE 64 208 32 208
WIRE 496 208 416 208
WIRE -32 224 -96 224
WIRE 208 224 208 144
WIRE 352 224 208 224
WIRE 160 240 160 192
WIRE 240 240 160 240
WIRE -48 272 -48 192
WIRE 80 272 -48 272
WIRE 128 272 128 256
WIRE 128 272 80 272
WIRE 208 272 208 224
WIRE 400 272 208 272
WIRE 496 272 496 208
WIRE 496 272 480 272
WIRE 528 272 528 208
WIRE 528 272 496 272
WIRE 592 272 592 128
WIRE 592 272 528 272
WIRE -96 288 -96 224
WIRE 80 304 80 272
WIRE 208 304 208 272
WIRE 288 320 256 320
WIRE 400 320 368 320
WIRE 416 320 400 320
WIRE 160 336 160 240
WIRE 400 336 400 320
WIRE 240 352 240 240
WIRE 368 352 240 352
WIRE 0 368 0 352
WIRE 496 368 432 368
WIRE 256 384 256 320
WIRE 352 384 256 384
WIRE 368 384 352 384
WIRE 496 400 496 368
WIRE -96 416 -96 368
WIRE 32 416 -96 416
WIRE 80 416 80 384
WIRE 80 416 32 416
WIRE 160 416 160 400
WIRE 160 416 80 416
WIRE 208 416 208 384
WIRE 208 416 160 416
WIRE 80 448 80 416
WIRE 256 448 80 448
WIRE 352 448 352 384
WIRE 352 448 336 448
WIRE 400 448 352 448
WIRE 496 448 496 400
WIRE 496 448 480 448
WIRE 0 480 0 464
WIRE 80 480 80 448
FLAG 80 480 0
FLAG 0 240 V-
FLAG 0 176 V+
FLAG 384 160 V+
FLAG 384 240 0
FLAG 416 320 V+
FLAG 400 400 0
FLAG 496 400 Cuad
FLAG 144 144 Sie
FLAG 0 352 V+
FLAG 0 480 V-
SYMBOL Robertugo\\OPAMP5 0 144 R0
WINDOW 0 -28 64 Left 0
WINDOW 38 13 11 Left 0
SYMATTR InstName U1
SYMATTR SpiceModel TL082
SYMBOL Robertugo\\OPAMP5 384 144 R0
WINDOW 0 -30 64 Left 0
WINDOW 38 29 48 Left 0
SYMATTR InstName U2a
SYMATTR SpiceModel max991
SYMBOL Robertugo\\OPAMP5 400 304 R0
WINDOW 0 -30 64 Left 0
WINDOW 38 29 49 Left 0
SYMATTR InstName U2
SYMATTR SpiceModel max991
SYMBOL npn2 64 160 R0
WINDOW 0 41 27 Left 0
WINDOW 3 18 51 Left 0
SYMATTR InstName Q1
SYMATTR Value 2N3904
SYMBOL res 64 288 R0
WINDOW 0 1 95 VRight 0
WINDOW 3 -3 -15 VRight 0
SYMATTR InstName R1
SYMATTR Value 1.21K
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL cap 144 336 R0
WINDOW 0 -35 31 Left 0
WINDOW 3 -40 53 Left 0
SYMATTR InstName C2
SYMATTR Value 330p
SYMBOL res 224 160 R270
WINDOW 0 18 -5 VTop 0
WINDOW 3 1 49 VBottom 0
SYMATTR InstName R3
SYMATTR Value 100K
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL res 384 288 R270
WINDOW 0 50 57 VTop 0
WINDOW 3 54 66 VBottom 0
SYMATTR InstName R2
SYMATTR Value 100K
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL res 192 288 R0
WINDOW 0 5 97 VRight 0
WINDOW 3 2 -23 VRight 0
SYMATTR InstName R4
SYMATTR Value 100K
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL res 384 464 R270
WINDOW 0 50 65 VTop 0
WINDOW 3 55 62 VBottom 0
SYMATTR InstName R5
SYMATTR Value 1e6
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL res 272 336 R270
WINDOW 0 30 16 VTop 0
WINDOW 3 59 64 VBottom 0
SYMATTR InstName R7
SYMATTR Value 120K
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL npn2 576 208 M270
WINDOW 0 41 27 Left 0
WINDOW 3 18 51 Left 0
SYMATTR InstName Q2
SYMATTR Value 2N3904
SYMBOL res 240 464 R270
WINDOW 0 32 19 VTop 0
WINDOW 3 59 64 VBottom 0
SYMATTR InstName R6
SYMATTR Value 100K
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL voltage -96 272 R0
WINDOW 0 -15 59 Left 0
WINDOW 3 -6 60 Invisible 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName Vc
SYMATTR Value PWL(0 0 99.9u 0 100u 17m 249.9u 17m 250u 50m 299.9u 50m 300u 100m 349.9u 100m 350u 200m 369.9u 200m 370u 300m 379.9u 300m 380u 400m 389.9u 400m 390u 1 394.9u 1 395u 1.66)
SYMBOL v+&- 0 400 R0
SYMATTR InstName Vcc
SYMATTR Value VNP=5
TEXT -98 124 Left 0 !.tran 400u uic