Version 4
SHEET 1 1060 680
WIRE -400 -32 -752 -32
WIRE 0 -32 -400 -32
WIRE 160 -32 0 -32
WIRE -176 96 -608 96
WIRE -752 112 -752 -32
WIRE 64 112 -16 112
WIRE 0 160 0 -32
WIRE -96 176 -96 112
WIRE -32 176 -96 176
WIRE 64 192 64 112
WIRE 64 192 32 192
WIRE -176 208 -176 96
WIRE -32 208 -176 208
WIRE -400 224 -400 -32
WIRE -752 240 -752 192
WIRE -432 240 -752 240
WIRE 160 240 160 -32
WIRE -336 256 -368 256
WIRE -608 272 -608 96
WIRE -592 272 -608 272
WIRE -496 272 -512 272
WIRE -432 272 -496 272
WIRE -176 272 -176 208
WIRE -96 272 -96 176
WIRE -752 320 -752 240
WIRE -496 352 -496 272
WIRE -336 352 -336 256
WIRE -336 352 -416 352
WIRE -752 448 -752 384
WIRE -400 448 -400 288
WIRE -400 448 -752 448
WIRE -176 448 -176 352
WIRE -176 448 -400 448
WIRE -96 448 -96 352
WIRE -96 448 -176 448
WIRE 0 448 0 224
WIRE 0 448 -96 448
WIRE 160 448 160 320
WIRE 160 448 0 448
WIRE 0 480 0 448
FLAG 0 480 0
FLAG -80 32 Saturation
FLAG -496 32 Schmitt_Trigger
SYMBOL Opamps\\LT1413 0 128 R0
SYMATTR InstName U3
SYMBOL Misc\\battery 160 224 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 5v
SYMBOL res -112 128 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R1
SYMATTR Value 1k
SYMBOL res -112 256 R0
SYMATTR InstName R2
SYMATTR Value 68
SYMBOL Misc\\signal -176 256 R0
WINDOW 3 -142 153 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value SFFM(0.3 1 1k 1 1)
SYMBOL Opamps\\LT1413 -400 192 R0
WINDOW 3 21 107 Left 2
SYMATTR InstName U4
SYMBOL res -768 96 R0
SYMATTR InstName R10
SYMATTR Value 10k
SYMBOL res -512 368 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R8
SYMATTR Value 56k
SYMBOL res -496 256 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R9
SYMATTR Value 2k2
SYMBOL diode -768 320 R0
SYMATTR InstName D1
SYMATTR Value 1N4148
TEXT -978 420 Left 2 !.tran 0.003