Version 4 SHEET 1 992 680 WIRE -672 -160 -688 -160 WIRE -480 -160 -592 -160 WIRE 576 -160 464 -160 WIRE 672 -160 656 -160 WIRE -448 -16 -464 -16 WIRE -320 -16 -368 -16 WIRE -272 -16 -320 -16 WIRE 288 -16 -272 -16 WIRE 352 -16 288 -16 WIRE 448 -16 432 -16 WIRE -624 0 -624 -64 WIRE 608 0 608 -64 WIRE -480 16 -480 -160 WIRE -480 16 -592 16 WIRE -272 16 -272 -16 WIRE 288 16 288 -16 WIRE 464 16 464 -160 WIRE 576 16 464 16 WIRE -688 32 -688 -160 WIRE -688 32 -768 32 WIRE -656 32 -688 32 WIRE 672 32 672 -160 WIRE 672 32 640 32 WIRE 752 32 672 32 WIRE -576 48 -592 48 WIRE -464 48 -464 -16 WIRE -464 48 -576 48 WIRE 448 48 448 -16 WIRE 560 48 448 48 WIRE 576 48 560 48 WIRE -624 80 -624 64 WIRE 608 80 608 64 WIRE -480 112 -480 16 WIRE -448 112 -480 112 WIRE -272 112 -272 96 WIRE -272 112 -368 112 WIRE 288 112 288 96 WIRE 352 112 288 112 WIRE 464 112 464 16 WIRE 464 112 432 112 WIRE -272 128 -272 112 WIRE -272 128 -304 128 WIRE 288 128 288 112 WIRE 288 128 256 128 WIRE -576 144 -576 48 WIRE -480 144 -480 112 WIRE -272 144 -272 128 WIRE 288 144 288 128 WIRE 464 144 464 112 WIRE 560 144 560 48 WIRE -752 160 -752 128 WIRE -752 272 -752 240 WIRE -576 272 -576 224 WIRE -480 272 -480 224 WIRE -272 272 -272 224 WIRE 288 272 288 224 WIRE 464 272 464 224 WIRE 560 272 560 224 FLAG -272 272 0 FLAG -624 80 0 FLAG 288 272 0 FLAG -304 128 TX1 FLAG 256 128 TX2 FLAG -624 -64 vcc FLAG -752 128 vcc FLAG -752 272 0 FLAG -480 272 0 FLAG -320 -16 vc FLAG -768 32 RX1 FLAG -576 272 0 FLAG 608 80 0 FLAG 608 -64 vcc FLAG 464 272 0 FLAG 752 32 RX2 FLAG 560 272 0 SYMBOL OpAmps\\UniversalOpAmp2 -624 32 M0 SYMATTR InstName U2 SYMBOL bv -272 128 R0 WINDOW 3 40 82 Left 2 SYMATTR InstName B1 SYMATTR Value V=(sgn(rand(1e3*time)-0.5)+1)/2 SYMBOL bv 288 128 R0 WINDOW 3 -44 44 Right 2 SYMATTR InstName B2 SYMATTR Value V=(sgn(rand(1e3*time+10000)-0.5)+1)/2 SYMBOL res -288 0 R0 SYMATTR InstName R1 SYMATTR Value 50 SYMBOL res 272 0 R0 SYMATTR InstName R2 SYMATTR Value 50 SYMBOL voltage -752 144 R0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 1 SYMBOL res -352 96 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R3 SYMATTR Value 20k SYMBOL res -352 -32 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R4 SYMATTR Value 10k SYMBOL res -576 -176 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R5 SYMATTR Value 20k SYMBOL res -464 240 R180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R6 SYMATTR Value 20k SYMBOL res -560 240 R180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R7 SYMATTR Value 20k SYMBOL OpAmps\\UniversalOpAmp2 608 32 R0 SYMATTR InstName U1 SYMBOL res 336 96 M90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R8 SYMATTR Value 20k SYMBOL res 336 -32 M90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R9 SYMATTR Value 10k SYMBOL res 560 -176 M90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R10 SYMATTR Value 20k SYMBOL res 448 240 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R11 SYMATTR Value 20k SYMBOL res 544 240 M180 WINDOW 0 36 76 Left 2 WINDOW 3 36 40 Left 2 SYMATTR InstName R12 SYMATTR Value 20k TEXT -314 328 Left 2 !.tran 0 0.1 0 10u