Version 4
SHEET 1 880 680
WIRE 272 -176 160 -176
WIRE 400 -176 272 -176
WIRE 704 -176 400 -176
WIRE 160 -80 160 -176
WIRE 400 -80 400 -176
WIRE 272 -64 272 -176
WIRE 160 32 160 -16
WIRE 400 32 400 -16
WIRE 704 48 704 -176
WIRE 160 160 160 112
WIRE 192 160 160 160
WIRE 272 160 272 16
WIRE 272 160 256 160
WIRE 400 160 400 112
WIRE -48 208 -144 208
WIRE 96 208 32 208
WIRE 272 208 272 160
WIRE 336 208 272 208
WIRE -144 320 -144 288
WIRE 160 320 160 256
WIRE 160 320 -144 320
WIRE 400 320 400 256
WIRE 400 320 160 320
WIRE 704 320 704 128
WIRE 704 320 400 320
WIRE 160 352 160 320
FLAG 160 352 0
SYMBOL npn 96 160 R0
SYMATTR InstName Q1
SYMBOL npn 336 160 R0
SYMATTR InstName Q2
SYMBOL res 144 16 R0
SYMATTR InstName R1
SYMATTR Value 470R
SYMBOL res 384 16 R0
SYMATTR InstName R2
SYMATTR Value 470R
SYMBOL res 48 192 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL diode 144 -80 R0
SYMATTR InstName D1
SYMBOL voltage 704 32 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 5V
SYMBOL res 256 -80 R0
SYMATTR InstName R5
SYMATTR Value 1k
SYMBOL voltage -144 192 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value PULSE(0 5 0 0 0 1m 2m)
SYMBOL diode 384 -80 R0
SYMATTR InstName D2
SYMBOL schottky 256 144 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D3
SYMATTR Value MBR0520L
SYMATTR Description Diode
SYMATTR Type diode
TEXT -264 200 Left 2 ;PORT PIN
TEXT 88 -176 VRight 2 !.tran 10m