Version 4
SHEET 1 1100 680
WIRE 432 64 432 48
WIRE 400 80 352 80
WIRE 496 96 464 96
WIRE 592 96 496 96
WIRE 640 96 592 96
WIRE 752 96 704 96
WIRE 800 96 752 96
WIRE 912 96 880 96
WIRE 112 112 48 112
WIRE 240 112 192 112
WIRE 400 112 240 112
WIRE 432 144 432 128
WIRE 592 160 592 96
WIRE 912 160 912 96
WIRE -112 256 -112 208
WIRE 48 256 48 112
WIRE 240 256 240 112
WIRE 352 256 352 80
WIRE 592 256 592 224
WIRE 592 256 352 256
WIRE 912 256 912 240
WIRE 912 256 592 256
WIRE 912 272 912 256
WIRE -112 496 -112 336
WIRE 48 496 48 336
WIRE 48 496 -112 496
WIRE 240 496 240 320
WIRE 240 496 48 496
WIRE 912 496 912 352
WIRE 912 496 240 496
WIRE -112 512 -112 496
FLAG -112 512 0
FLAG 432 48 P5
FLAG -112 208 P5
FLAG 432 144 0
FLAG 240 112 RC
FLAG 752 96 Out
FLAG 496 96 Q
SYMBOL tlc272 432 32 R0
SYMATTR InstName U1
SYMBOL voltage -112 240 R0
SYMATTR InstName V1
SYMATTR Value 5
SYMBOL voltage 48 240 R0
WINDOW 3 14 125 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR Value PULSE(0 5 0 5n 5n {ton} {tper})
SYMATTR InstName V2
SYMBOL cap 224 256 R0
SYMATTR InstName C1
SYMATTR Value 100n
SYMBOL res 208 96 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 1Meg
SYMBOL res 896 144 R0
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL res 896 256 R0
SYMATTR InstName R3
SYMATTR Value 27k
SYMBOL ind 784 112 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName L1
SYMATTR Value 100µ
SYMBOL cap 576 160 R0
SYMATTR InstName C2
SYMATTR Value 100n
SYMBOL diode 640 112 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMATTR Value BAV99
TEXT 992 208 Left 2 ;Meter
TEXT -96 560 Left 2 !.param tper=1/14.4k
TEXT -96 592 Left 2 !.param ton={tper/256*128}
TEXT 256 560 Left 2 !.tran 1
TEXT 1000 312 Left 2 ;Rsense