Version 4
SHEET 1 888 680
WIRE -432 -128 -432 -176
WIRE -432 48 -432 -48
WIRE -432 144 -432 48
WIRE -416 -176 -432 -176
WIRE -400 48 -432 48
WIRE -400 80 -400 48
WIRE -336 -80 -336 -96
WIRE -336 144 -432 144
WIRE -336 144 -336 0
WIRE -240 -144 -240 -176
WIRE -240 -32 -240 -80
WIRE -240 32 -240 -32
WIRE -240 128 -240 96
WIRE -208 -32 -240 -32
WIRE -160 -96 -160 -144
WIRE -160 16 -160 0
WIRE -160 48 -160 16
WIRE -160 128 -240 128
WIRE -160 128 -160 112
WIRE -96 -144 -160 -144
WIRE -96 -80 -96 -144
WIRE -96 16 -160 16
WIRE -96 16 -96 0
WIRE -96 32 -96 16
WIRE -96 128 -160 128
WIRE -96 128 -96 112
WIRE -32 -176 -240 -176
WIRE -32 0 -32 -176
WIRE -32 128 -96 128
WIRE -32 128 -32 64
WIRE -32 160 -32 128
WIRE 32 -176 -32 -176
WIRE 96 16 80 16
WIRE 208 -176 112 -176
WIRE 336 -96 288 -96
WIRE 336 -80 336 -96
WIRE 336 16 160 16
WIRE 336 16 336 0
WIRE 336 32 336 16
WIRE 336 128 -32 128
WIRE 336 128 336 112
WIRE 368 -144 -96 -144
WIRE 368 -16 368 -144
WIRE 416 -144 368 -144
WIRE 432 -16 368 -16
WIRE 432 16 336 16
WIRE 464 -96 336 -96
WIRE 464 -32 464 -96
WIRE 464 128 336 128
WIRE 464 128 464 32
WIRE 560 -176 272 -176
WIRE 560 -144 496 -144
WIRE 560 -144 560 -176
WIRE 560 0 496 0
WIRE 560 0 560 -144
WIRE 560 16 560 0
WIRE 560 128 464 128
WIRE 560 128 560 96
WIRE 624 -144 560 -144
FLAG 624 -144 Out
IOPIN 624 -144 Out
FLAG 288 -96 V+
IOPIN 288 -96 In
FLAG -336 -96 Tri
IOPIN -336 -96 Out
FLAG -400 80 0
FLAG -416 -176 V+
IOPIN -416 -176 Out
FLAG 80 16 Tri
IOPIN 80 16 In
FLAG -32 160 0
SYMBOL Robertugo\\OPAMP5 464 -64 R0
WINDOW 0 -24 62 Left 0
WINDOW 38 -113 65 Left 0
SYMATTR InstName U1
SYMATTR SpiceModel LM358
SYMBOL res 512 -160 R90
WINDOW 0 40 93 VRight 0
WINDOW 3 40 -35 VRight 0
SYMATTR InstName R8
SYMATTR Value 470k
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL voltage -432 -144 R0
WINDOW 0 -42 3 Left 0
WINDOW 3 -16 57 Left 0
WINDOW 123 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 5
SYMATTR SpiceLine Rser=.25 Cpar=50n
SYMBOL voltage -336 -96 R0
WINDOW 0 -15 60 Left 0
WINDOW 3 -16 57 Invisible 0
WINDOW 123 0 0 Left 0
WINDOW 39 4 134 Left 0
SYMATTR InstName V3
SYMATTR Value PULSE(0 {Vt} 0 1u 1u 0 2u)
SYMBOL njf -208 -96 R0
WINDOW 0 -23 42 Left 0
WINDOW 3 -32 97 Left 0
SYMATTR InstName J1
SYMATTR Value BF245B
SYMBOL res 128 -192 R90
WINDOW 0 1 100 VRight 0
WINDOW 3 1 -28 VRight 0
SYMATTR InstName R2
SYMATTR Value 10k
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL cap 272 -192 R90
WINDOW 0 14 67 VBottom 0
WINDOW 3 -9 -13 VTop 0
SYMATTR InstName C1
SYMATTR Value 10n
SYMBOL diode -224 -80 R180
WINDOW 0 -25 65 Left 0
WINDOW 3 24 0 Invisible 0
SYMATTR InstName D1
SYMATTR Value 1N914
SYMBOL diode -48 0 R0
WINDOW 0 24 69 Left 0
WINDOW 3 24 72 Invisible 0
SYMATTR InstName D2
SYMATTR Value 1N914
SYMBOL cap -256 32 R0
SYMATTR InstName C2
SYMATTR Value 1n
SYMBOL polcap -176 48 R0
WINDOW 3 24 64 Left 0
SYMATTR InstName C3
SYMATTR Value 100n
SYMATTR Description Capacitor
SYMATTR Type cap
SYMATTR SpiceLine V=16 Irms=35m Rser=2.8 MTBF=1000 Lser=0 mfg="Nichicon" pn="UPR1C100MAH" type="Al electrolytic" ppPkg=1
SYMBOL res -112 16 R0
WINDOW 0 24 49 Left 0
WINDOW 3 20 86 Left 0
SYMATTR InstName R3
SYMATTR Value 1e6
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL res -112 -96 R0
WINDOW 0 24 49 Left 0
WINDOW 3 20 86 Left 0
SYMATTR InstName R4
SYMATTR Value 1e5
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL res 320 16 R0
SYMATTR InstName R5
SYMATTR Value 39K
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL res 320 -96 R0
WINDOW 0 -45 36 Left 0
WINDOW 3 -51 73 Left 0
SYMATTR InstName R6
SYMATTR Value 39K
SYMATTR SpiceLine tol=1 pwr=0.1
SYMBOL cap 160 0 R90
WINDOW 0 0 32 VBottom 0
WINDOW 3 32 32 VTop 0
SYMATTR InstName C4
SYMATTR Value 10n
SYMBOL res 544 0 R0
SYMATTR InstName RL
SYMATTR Value 1K
SYMATTR SpiceLine tol=1 pwr=0.1
TEXT 62 74 Left 0 !.tran 0 3m 2m9
TEXT 40 104 Left 0 !.step param Vt List  1 2
TEXT 56 144 Left 0 !.four 0.5meg V(Out)
TEXT 296 144 Left 0 !.option noopiter
TEXT -24 -112 Left 0 ;Para audio:\nC1; C4: 100n\nC2: 220n; C3: 10u; \nU1: LM324