Version 4
SHEET 1 880 680
WIRE -96 -240 -96 -272
WIRE -96 -128 -96 -176
WIRE -96 -128 -304 -128
WIRE 32 -128 -96 -128
WIRE 80 -128 32 -128
WIRE 336 -112 144 -112
WIRE 384 -112 336 -112
WIRE -96 -96 -96 -128
WIRE 80 -96 32 -96
WIRE -304 -80 -304 -128
WIRE 544 -80 544 -128
WIRE 704 -80 704 -128
WIRE -96 16 -96 -32
WIRE 32 32 32 -96
WIRE 144 32 32 32
WIRE 176 32 144 32
WIRE 288 32 256 32
WIRE 336 32 336 -112
WIRE 336 32 288 32
WIRE 544 32 544 0
WIRE 704 32 704 0
WIRE 32 80 32 32
WIRE 144 144 144 32
WIRE 176 144 144 144
WIRE 288 144 288 32
WIRE 288 144 240 144
WIRE -304 192 -304 -16
WIRE -192 192 -192 0
WIRE 32 192 32 160
FLAG 544 32 0
FLAG 704 32 0
FLAG 544 -128 +UB
FLAG 704 -128 -UB
FLAG 112 -144 -UB
FLAG 112 -80 +UB
FLAG 32 192 0
FLAG -304 192 0
FLAG 32 -128 IN
FLAG 384 -112 OUT
FLAG -96 -272 -UB
FLAG -96 16 +UB
FLAG -192 192 0
SYMBOL voltage 544 -96 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 15
SYMBOL voltage 704 16 R180
WINDOW 0 24 96 Left 2
WINDOW 3 24 16 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value 15
SYMBOL Opamps\\UniversalOpamp2 112 -112 M180
SYMATTR InstName U1
SYMBOL res 16 64 R0
SYMATTR InstName R1
SYMATTR Value 4.7k
SYMBOL res 272 16 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R2
SYMATTR Value 4.7k
SYMBOL Misc\\xtal -320 -80 R0
SYMATTR InstName C1
SYMBOL diode -112 -240 R0
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL diode -112 -96 R0
SYMATTR InstName D2
SYMATTR Value 1N4148
SYMBOL cap 240 128 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C2
SYMBOL res -208 -96 R0
SYMATTR InstName R3
TEXT -416 -152 Left 2 ;PIEZO FILM SENSOR
TEXT 96 -216 Left 2 ;TL071
TEXT 144 216 Left 2 ;fg = 1 / (2 x 3,14 x R2 x C2)
TEXT 144 256 Left 2 ;V = 1 + R2 / R1
TEXT -16 312 Left 2 ;https://www.elektronik-kompendium.de/sites/slt/0210151.htm
TEXT -240 240 Left 2 ;R3 >= 10M
LINE Normal -192 -128 -192 -80 2