Version 4 SHEET 1 1024 680 WIRE 320 208 144 208 WIRE 16 224 16 208 WIRE 464 224 384 224 WIRE 16 240 16 224 WIRE 320 240 256 240 WIRE 464 272 464 224 WIRE 256 288 256 240 WIRE 16 336 16 320 WIRE 16 336 -64 336 WIRE -64 352 -64 336 WIRE 144 368 144 208 WIRE 464 384 464 352 WIRE 256 400 256 368 WIRE 16 432 16 416 WIRE 144 480 144 448 WIRE 464 496 464 464 FLAG 144 480 0 FLAG -64 352 0 FLAG 256 400 0 FLAG 16 224 V+ FLAG 464 496 0 FLAG 16 432 V- FLAG 352 192 V+ FLAG 352 256 V- SYMBOL voltage 16 224 R0 SYMATTR InstName V1 SYMATTR Value 12 SYMBOL voltage 144 352 R0 SYMATTR InstName V2 SYMATTR Value PULSE(-5 5 0 1m 1m 0 2m) SYMBOL res 448 256 R0 SYMATTR InstName R1 SYMATTR Value 18k SYMBOL voltage 256 272 R0 SYMATTR InstName V3 SYMATTR Value 1.5 SYMBOL voltage 16 320 R0 SYMATTR InstName V4 SYMATTR Value 12 SYMBOL OpAmps/LT1001 352 160 R0 SYMATTR InstName U2 SYMBOL res 448 368 R0 SYMATTR InstName R2 SYMATTR Value 13k TEXT 72 144 Left 2 !.tran 0 10m 1m