Version 4
SHEET 1 880 680
WIRE 240 80 -208 80
WIRE 240 112 240 80
WIRE 208 128 -112 128
WIRE 320 144 272 144
WIRE 368 144 320 144
WIRE 208 160 160 160
WIRE 240 192 240 176
WIRE 32 256 -16 256
WIRE 160 256 160 160
WIRE 160 256 112 256
WIRE 208 256 160 256
WIRE 320 256 320 144
WIRE 320 256 288 256
WIRE -208 304 -208 80
WIRE -112 304 -112 128
WIRE -16 304 -16 256
WIRE 160 304 160 256
WIRE -208 416 -208 384
WIRE -112 416 -112 384
WIRE -16 416 -16 384
WIRE 160 416 160 384
FLAG 240 192 0
FLAG -112 416 0
FLAG -208 416 0
FLAG -16 416 0
FLAG 160 416 0
FLAG 368 144 OUT
FLAG -208 80 VCC
FLAG -112 128 IN
FLAG -16 256 REF
SYMBOL Opamps\\opamp2 240 80 R0
SYMATTR InstName U1
SYMATTR Value LM393
SYMBOL voltage -208 288 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL voltage -112 288 R0
WINDOW 3 24 96 Invisible 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value PULSE(6.5 7.5 0 1 1 0)
SYMBOL voltage -16 288 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V3
SYMATTR Value 12
SYMBOL res 16 272 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R6
SYMATTR Value 1k2
SYMBOL res 144 288 R0
SYMATTR InstName R8
SYMATTR Value 1k8
SYMBOL res 304 240 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R7
SYMATTR Value 12k
TEXT 240 376 Left 2 !.inc lm393.mod
TEXT 240 352 Left 2 !.tran 2