Version 4 SHEET 1 1144 864 WIRE 304 -128 176 -128 WIRE 1024 -128 304 -128 WIRE 304 0 304 -48 WIRE 736 0 304 0 WIRE 304 64 304 0 WIRE 800 80 800 0 WIRE 176 112 176 -48 WIRE 240 112 176 112 WIRE 176 144 176 112 WIRE 304 176 304 160 WIRE 608 176 304 176 WIRE 704 176 608 176 WIRE 1024 176 1024 -128 WIRE -16 192 -432 192 WIRE 112 192 48 192 WIRE 304 192 304 176 WIRE 608 256 608 176 WIRE 704 256 704 176 WIRE -432 288 -432 192 WIRE 48 304 48 192 WIRE 208 304 48 304 WIRE 304 304 304 272 WIRE 304 304 288 304 WIRE 512 304 304 304 WIRE 304 336 304 304 WIRE 512 368 512 304 WIRE 384 416 304 416 WIRE 448 416 384 416 WIRE 800 448 800 80 WIRE 384 464 384 416 WIRE -432 528 -432 368 WIRE 176 528 176 240 WIRE 176 528 -432 528 WIRE 304 528 304 496 WIRE 304 528 176 528 WIRE 384 528 304 528 WIRE 512 528 512 464 WIRE 512 528 384 528 WIRE 656 528 656 320 WIRE 656 528 512 528 WIRE 800 528 656 528 WIRE 1024 528 1024 256 WIRE 1024 528 800 528 WIRE 800 576 800 528 FLAG 800 80 Out FLAG 800 576 0 SYMBOL npn 112 144 R0 SYMATTR InstName Q1 SYMATTR Value BF199 SYMBOL npn 240 64 R0 SYMATTR InstName Q2 SYMATTR Value 2N3866 SYMBOL npn 448 368 R0 SYMATTR InstName Q3 SYMATTR Value BF199 SYMBOL res 160 -144 R0 SYMATTR InstName R1 SYMATTR Value 5,7k SYMBOL res 288 -144 R0 SYMATTR InstName R2 SYMATTR Value 1,7k SYMATTR SpiceLine tol=1 pwr=0.1 SYMBOL res 288 176 R0 SYMATTR InstName R3 SYMATTR Value 1,1k SYMBOL res 288 320 R0 SYMATTR InstName R4 SYMATTR Value 4k SYMBOL res 304 288 R90 WINDOW 0 0 56 VBottom 2 WINDOW 3 32 56 VTop 2 SYMATTR InstName R5 SYMATTR Value 4k SYMBOL cap 48 176 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C1 SYMATTR Value 100n SYMBOL voltage -432 272 R0 WINDOW 123 24 152 Left 2 WINDOW 39 24 124 Left 2 SYMATTR Value2 AC 1 0 SYMATTR SpiceLine Rser=50 SYMATTR InstName V1 SYMATTR Value SINE(0 10µ 10.7Meg 0 0 0 0) SYMBOL voltage 1024 160 R0 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V2 SYMATTR Value 12 SYMBOL res 784 432 R0 SYMATTR InstName R6 SYMATTR Value 1k SYMBOL cap 800 -16 R90 WINDOW 0 0 32 VBottom 2 WINDOW 3 32 32 VTop 2 SYMATTR InstName C2 SYMATTR Value 100n SYMBOL res 288 400 R0 SYMATTR InstName R7 SYMATTR Value {R} SYMBOL cap 368 464 R0 SYMATTR InstName C3 SYMATTR Value 100n SYMBOL npn 608 320 R270 SYMATTR InstName Q4 SYMATTR Value BC337-40 TEXT -352 328 Left 2 !;ac oct 1000 9000000 11000000 TEXT -328 248 Left 2 !.tran 0 500n 250n 1n TEXT -416 464 Left 2 !.step param R list 15k 20k 25k 40k