Version 4
SHEET 1 880 680
WIRE 672 -144 448 -144
WIRE 448 -128 448 -144
WIRE 672 -16 672 -144
WIRE 448 0 448 -48
WIRE 256 32 -32 32
WIRE 384 48 320 48
WIRE -32 64 -32 32
WIRE 256 64 176 64
WIRE 176 144 176 64
WIRE -32 272 -32 144
WIRE 176 272 176 224
WIRE 448 272 448 96
WIRE 672 272 672 64
FLAG 176 272 0
FLAG -32 272 0
FLAG 448 272 0
FLAG 672 272 0
SYMBOL voltage -32 48 R0
WINDOW 3 -30 269 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value PULSE(0 5 1 1p 1p 5 10 3)
SYMATTR InstName V1
SYMBOL voltage 176 128 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V2
SYMATTR Value 2
SYMBOL Opamps\\opamp 288 112 M180
SYMATTR InstName U1
SYMBOL npn 384 0 R0
SYMATTR InstName Q1
SYMBOL res 432 -144 R0
SYMATTR InstName R1
SYMATTR Value 3.3k
SYMBOL voltage 672 -32 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V3
SYMATTR Value 7
TEXT -64 336 Left 0 !.tran 10
TEXT 48 -24 Left 0 !.include opamp.sub