Version 4
SHEET 1 1100 680
WIRE 256 -160 -128 -160
WIRE 640 -160 256 -160
WIRE 928 -160 640 -160
WIRE 1024 -160 928 -160
WIRE 640 -80 640 -160
WIRE 928 -16 928 -160
WIRE 640 32 640 0
WIRE 864 32 640 32
WIRE 256 64 256 -160
WIRE 640 112 640 32
WIRE 928 144 928 80
WIRE 256 160 256 144
WIRE 368 160 256 160
WIRE 496 160 448 160
WIRE 576 160 496 160
WIRE 256 176 256 160
WIRE 496 192 496 160
WIRE -128 224 -128 -160
WIRE 96 224 16 224
WIRE 192 224 176 224
WIRE 928 224 928 208
WIRE 496 288 496 272
WIRE 256 320 256 272
WIRE 640 320 640 208
WIRE 640 320 256 320
WIRE 256 336 256 320
WIRE 928 384 928 304
FLAG -128 304 0
FLAG 256 416 0
FLAG 496 288 0
FLAG 928 384 0
FLAG 16 304 0
SYMBOL res 240 48 R0
SYMATTR InstName R1
SYMATTR Value 13.75k
SYMBOL voltage -128 208 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 9
SYMBOL npn 192 176 R0
SYMATTR InstName Q1
SYMATTR Value BC547B
SYMBOL res 240 320 R0
SYMATTR InstName R2
SYMATTR Value 7.5k
SYMBOL res 464 144 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL res 480 176 R0
SYMATTR InstName R4
SYMATTR Value 15k
SYMBOL npn 576 112 R0
SYMATTR InstName Q2
SYMATTR Value BC547B
SYMBOL res 624 -96 R0
SYMATTR InstName R5
SYMATTR Value 2k
SYMBOL res 912 208 R0
SYMATTR InstName R7
SYMATTR Value 510
SYMBOL voltage 16 208 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value SINE(4.5 4.5 10)
SYMBOL res 192 208 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R8
SYMATTR Value 470k
SYMBOL LED 912 144 R0
SYMATTR InstName D1
SYMATTR Value NSSWS108T
SYMATTR Description Diode
SYMATTR Type diode
SYMBOL pnp 864 80 M180
SYMATTR InstName Q3
SYMATTR Value 2N3906
TEXT -162 440 Left 2 !.tran 1