Version 4
SHEET 1 1112 928
WIRE -464 -144 -464 -160
WIRE -336 -144 -336 -160
WIRE 224 -64 80 -64
WIRE 432 -64 304 -64
WIRE -464 -48 -464 -64
WIRE -336 -48 -336 -64
WIRE 256 64 256 48
WIRE 80 80 80 -64
WIRE 240 80 80 80
WIRE 832 80 784 80
WIRE -464 96 -464 80
WIRE -336 96 -336 80
WIRE 432 96 432 -64
WIRE 432 96 304 96
WIRE 528 96 432 96
WIRE 240 112 -160 112
WIRE 528 112 528 96
WIRE 704 112 704 80
WIRE 784 112 784 80
WIRE 256 144 256 128
WIRE -464 192 -464 176
WIRE -336 192 -336 176
WIRE 80 208 80 80
WIRE -160 224 -160 112
WIRE -208 240 -272 240
WIRE -208 288 -224 288
WIRE -432 320 -448 320
WIRE -272 320 -272 240
WIRE -272 320 -352 320
WIRE -160 336 -160 304
WIRE -80 336 -160 336
WIRE 32 336 0 336
WIRE -160 368 -160 336
WIRE -272 384 -272 320
WIRE -208 384 -272 384
WIRE 80 384 80 288
WIRE 240 384 80 384
WIRE 432 384 320 384
WIRE 528 384 528 368
WIRE 528 384 432 384
WIRE 784 400 784 368
WIRE 704 416 704 368
WIRE -208 432 -224 432
WIRE 256 512 256 496
WIRE 80 528 80 384
WIRE 240 528 80 528
WIRE 432 544 432 384
WIRE 432 544 304 544
WIRE -160 560 -160 448
WIRE 240 560 -160 560
WIRE 256 592 256 576
FLAG -336 -48 0
FLAG 256 48 +V
FLAG -336 -160 +V
FLAG 256 144 -V
FLAG -464 -48 0
FLAG -464 -160 -V
FLAG -448 320 0
FLAG 704 80 +VL
FLAG 704 416 -VL
FLAG -336 192 0
FLAG -336 80 +VL
FLAG -464 192 0
FLAG -464 80 -VL
FLAG 784 400 0
FLAG 832 80 OUT
FLAG -224 288 0
FLAG -224 432 0
FLAG 32 336 0
FLAG 256 496 +V
FLAG 256 592 -V
SYMBOL voltage -336 -160 R0
SYMATTR InstName V1
SYMATTR Value 30
SYMBOL voltage -464 -160 R0
SYMATTR InstName V2
SYMATTR Value -30
SYMBOL voltage -336 320 R90
WINDOW 123 74 56 VTop 2
WINDOW 39 53 56 VTop 2
WINDOW 0 -32 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName V3
SYMATTR Value SINE(0 39m 1K)
SYMBOL res 320 -80 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 11.5K
SYMBOL Opamps\\LT1991 704 240 R0
SYMATTR InstName U1
SYMBOL res 336 368 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 11.5K
SYMBOL voltage -336 80 R0
SYMATTR InstName V4
SYMATTR Value 18
SYMBOL voltage -464 80 R0
SYMATTR InstName V5
SYMATTR Value -18
SYMBOL res 64 192 R0
SYMATTR InstName R2
SYMATTR Value 232
SYMBOL e -160 208 R0
SYMATTR InstName E1
SYMATTR Value .5
SYMBOL e -160 352 R0
SYMATTR InstName E2
SYMATTR Value .5
SYMBOL voltage -96 336 R270
WINDOW 123 -74 56 VBottom 2
WINDOW 39 -53 56 VBottom 2
WINDOW 0 32 56 VTop 2
WINDOW 3 -32 56 VBottom 2
SYMATTR InstName Vcm
SYMATTR Value -28
SYMBOL LTC2057 272 544 R0
SYMATTR InstName U2
SYMBOL LTC2057 272 96 R0
SYMATTR InstName U3
TEXT 696 568 Left 2 !.tran 3m