Version 4
SHEET 1 880 788
WIRE -304 -160 -400 -160
WIRE 208 -160 -304 -160
WIRE 560 -160 208 -160
WIRE 208 -112 208 -160
WIRE 560 -112 560 -160
WIRE -304 -48 -304 -96
WIRE 208 0 208 -32
WIRE 448 0 208 0
WIRE -400 32 -400 -160
WIRE 208 32 208 0
WIRE -176 80 -240 80
WIRE 32 80 -112 80
WIRE 144 80 32 80
WIRE 32 112 32 80
WIRE 208 128 208 96
WIRE 320 128 208 128
WIRE 560 128 560 -32
WIRE 560 128 400 128
WIRE 640 128 560 128
WIRE 448 176 448 0
WIRE 496 176 448 176
WIRE -240 208 -240 80
WIRE 32 224 32 192
WIRE 96 224 32 224
WIRE 560 224 176 224
WIRE 32 256 32 224
WIRE 208 256 208 128
WIRE 560 272 560 224
WIRE -400 384 -400 112
WIRE -240 384 -240 288
WIRE 32 384 32 336
WIRE 208 384 208 336
WIRE 560 384 560 336
FLAG -304 -48 0
FLAG 560 384 0
FLAG -400 384 0
FLAG -240 384 0
FLAG 32 384 0
FLAG 208 384 0
SYMBOL npn 144 32 R0
SYMATTR InstName Q1
SYMATTR Value BC546B
SYMBOL npn 496 128 R0
SYMATTR InstName Q2
SYMATTR Value BC546B
SYMBOL Misc\\EuropeanResistor 192 240 R0
SYMATTR InstName R1
SYMATTR Value 560
SYMBOL Misc\\EuropeanResistor 48 208 R180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R2
SYMATTR Value 160k
SYMBOL Misc\\EuropeanResistor 304 144 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R3
SYMATTR Value {Rver}
SYMBOL Misc\\EuropeanResistor 192 240 M270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R4
SYMATTR Value 560
SYMBOL Misc\\EuropeanResistor 16 240 R0
SYMATTR InstName R5
SYMATTR Value 560
SYMBOL Misc\\EuropeanResistor 192 -128 R0
SYMATTR InstName R6
SYMATTR Value 68k
SYMBOL Misc\\EuropeanResistor 544 -128 R0
SYMATTR InstName R7
SYMATTR Value 2.7k
SYMBOL cap -112 64 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value 1µ
SYMBOL cap 704 112 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C2
SYMATTR Value 1µ
SYMBOL cap -288 -96 R180
WINDOW 0 24 56 Left 2
WINDOW 3 24 8 Left 2
SYMATTR InstName C3
SYMATTR Value 220µ
SYMBOL cap 576 336 R180
WINDOW 0 24 56 Left 2
WINDOW 3 24 8 Left 2
SYMATTR InstName C4
SYMATTR Value 47µ
SYMBOL voltage -400 16 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 18V
SYMBOL voltage -240 192 R0
WINDOW 123 24 124 Left 2
WINDOW 39 0 0 Left 2
SYMATTR Value2 AC 0.001
SYMATTR InstName V2
SYMATTR Value SINE(0 0.001 1000)
TEXT -432 680 Left 2 ;tran 0.05
TEXT -424 752 Left 2 !.ac oct 1000 1 1meg
TEXT -200 64 Left 2 ;IN
TEXT 728 136 Left 2 ;OUT
TEXT -432 616 Left 2 !.step param Rver 5k 50k 5k
TEXT -434 772 Left 2 ;.tran 0 5 0.1u startup