Version 4
SHEET 1 880 800
WIRE 208 96 64 96
WIRE 272 96 208 96
WIRE 304 96 272 96
WIRE 416 96 384 96
WIRE 432 96 416 96
WIRE 592 96 512 96
WIRE 64 144 64 96
WIRE 208 144 192 144
WIRE 448 144 208 144
WIRE 544 144 496 144
WIRE 64 176 64 144
WIRE 192 176 192 144
WIRE 272 176 272 96
WIRE 416 192 416 96
WIRE 432 192 416 192
WIRE 544 192 544 144
WIRE 544 192 512 192
WIRE 64 288 64 256
WIRE 192 288 192 256
WIRE 272 320 272 256
WIRE 304 320 272 320
WIRE 416 320 384 320
WIRE 432 320 416 320
WIRE 592 320 592 96
WIRE 592 320 512 320
WIRE 208 368 192 368
WIRE 448 368 208 368
WIRE 544 368 544 192
WIRE 544 368 496 368
WIRE 192 400 192 368
WIRE 272 400 272 320
WIRE 416 416 416 320
WIRE 432 416 416 416
WIRE 544 416 544 368
WIRE 544 416 512 416
WIRE 192 512 192 480
WIRE 272 544 272 480
WIRE 304 544 272 544
WIRE 416 544 384 544
WIRE 432 544 416 544
WIRE 592 544 592 320
WIRE 592 544 512 544
WIRE 624 544 592 544
WIRE 736 544 704 544
WIRE 208 592 192 592
WIRE 448 592 208 592
WIRE 544 592 544 416
WIRE 544 592 496 592
WIRE 192 624 192 592
WIRE 272 624 272 544
WIRE 592 624 592 544
WIRE 624 624 592 624
WIRE 416 640 416 544
WIRE 432 640 416 640
WIRE 544 640 544 592
WIRE 544 640 512 640
WIRE 736 640 736 544
WIRE 736 640 688 640
WIRE 768 640 736 640
WIRE 624 656 592 656
WIRE 192 736 192 704
WIRE 272 736 272 704
WIRE 544 736 544 640
WIRE 592 736 592 656
FLAG 192 736 0
FLAG 544 736 0
FLAG 272 736 0
FLAG 208 96 Uref
FLAG 208 592 Ud0
FLAG 208 368 Ud1
FLAG 208 144 Ud2
FLAG 592 736 0
FLAG 768 640 Ua
FLAG 192 512 0
FLAG 192 288 0
FLAG 64 288 0
FLAG 64 144 Uref
SYMBOL sw 528 96 M270
SYMATTR InstName S1
SYMATTR Value SWH
SYMBOL sw 528 192 R90
SYMATTR InstName S2
SYMATTR Value SWL
SYMBOL voltage 192 608 M0
WINDOW 3 56 128 VLeft 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V0
SYMATTR Value PULSE(0 5 1 10n 10n 1 2)
SYMBOL sw 528 320 M270
SYMATTR InstName S3
SYMATTR Value SWH
SYMBOL sw 528 416 R90
SYMATTR InstName S4
SYMATTR Value SWL
SYMBOL sw 528 544 M270
SYMATTR InstName S5
SYMATTR Value SWH
SYMBOL sw 528 640 R90
SYMATTR InstName S6
SYMATTR Value SWL
SYMBOL res 400 80 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 20k
SYMBOL res 256 160 R0
SYMATTR InstName R2
SYMATTR Value 10k
SYMBOL res 400 304 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 20k
SYMBOL res 256 384 R0
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL res 400 528 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R5
SYMATTR Value 20k
SYMBOL res 256 608 R0
SYMATTR InstName R6
SYMATTR Value 20k
SYMBOL Opamps\\opamp 656 576 R0
SYMATTR InstName U1
SYMBOL res 720 528 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName Rf
SYMATTR Value 10k
SYMBOL voltage 192 384 M0
WINDOW 3 56 128 VLeft 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value PULSE(0 5 2 10n 10n 2 4)
SYMBOL voltage 192 160 M0
WINDOW 3 56 128 VLeft 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value PULSE(0 5 4 10n 10n 4 8)
SYMBOL voltage 64 160 M0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName Vref
SYMATTR Value 5V
TEXT 128 32 Left 2 !.model SWH SW(Vt=2.5, Ron=1m, Roff=1G)
TEXT 128 56 Left 2 !.model SWL SW(Vt=2.5, Ron=1G, Roff=1m)
TEXT 16 32 Left 2 !.tran 10s
TEXT 16 56 Left 2 !.lib opamp.sub