Version 4
SHEET 1 880 680
WIRE 736 -160 -160 -160
WIRE 448 -80 304 -80
WIRE 480 -80 448 -80
WIRE 592 -80 560 -80
WIRE 624 -80 592 -80
WIRE 736 -80 736 -160
WIRE 736 -80 704 -80
WIRE 304 -48 304 -80
WIRE 16 16 -16 16
WIRE 112 16 80 16
WIRE 656 16 656 0
WIRE 592 32 592 -80
WIRE 624 32 592 32
WIRE 736 48 736 -80
WIRE 736 48 688 48
WIRE 768 48 736 48
WIRE 304 64 304 32
WIRE 448 64 448 -80
WIRE 480 64 448 64
WIRE 592 64 560 64
WIRE 624 64 592 64
WIRE 656 96 656 80
WIRE 592 112 592 64
WIRE 48 128 48 112
WIRE -160 144 -160 -160
WIRE -128 144 -160 144
WIRE -16 144 -16 16
WIRE -16 144 -48 144
WIRE 16 144 -16 144
WIRE 224 144 224 128
WIRE 112 160 112 16
WIRE 112 160 80 160
WIRE 144 160 112 160
WIRE 192 160 144 160
WIRE 16 176 -16 176
WIRE 304 176 256 176
WIRE 336 176 304 176
WIRE 368 176 336 176
WIRE 496 176 432 176
WIRE 544 176 496 176
WIRE 192 192 160 192
WIRE -16 208 -16 176
WIRE 48 208 48 192
WIRE 304 208 304 176
WIRE 496 208 496 176
WIRE 224 224 224 208
WIRE 592 224 592 208
WIRE 160 304 160 192
WIRE 304 304 304 288
WIRE 304 304 160 304
WIRE -160 320 -160 304
WIRE -48 320 -48 304
WIRE 304 320 304 304
WIRE 496 320 496 288
WIRE -160 416 -160 400
WIRE -48 416 -48 400
WIRE 304 432 304 400
FLAG 48 112 +V
FLAG 224 128 +V
FLAG 48 208 -V
FLAG 224 224 -V
FLAG -16 208 0
FLAG 304 432 0
FLAG 656 0 +V
FLAG 656 96 -V
FLAG 304 64 0
FLAG 592 224 0
FLAG 496 320 0
FLAG -160 416 0
FLAG -48 416 0
FLAG -160 304 +V
FLAG -48 304 -V
FLAG 144 160 Vtr
FLAG 336 176 Vr
FLAG 304 -80 Vst
FLAG 768 48 Vstr
FLAG 496 176 Vg
SYMBOL Opamps\\UniversalOpamp2 48 160 R0
SYMATTR InstName U1
SYMBOL Opamps\\UniversalOpamp2 224 176 R0
SYMATTR InstName U2
SYMBOL Misc\\EuropeanResistor 288 192 R0
SYMATTR InstName Rk
SYMATTR Value 5k
SYMBOL Misc\\EuropeanResistor 288 304 R0
SYMATTR InstName R1
SYMATTR Value 5k
SYMBOL cap 80 0 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C0
SYMATTR Value 10n IC=0
SYMBOL Opamps\\UniversalOpamp2 656 48 R0
SYMATTR InstName U3
SYMBOL Misc\\EuropeanResistor 720 -96 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R5
SYMATTR Value 10k
SYMBOL Misc\\EuropeanResistor 576 -96 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R4
SYMATTR Value 10k
SYMBOL Misc\\EuropeanResistor 576 48 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R6
SYMATTR Value 10k
SYMBOL njf 544 112 R0
SYMATTR InstName J1
SYMATTR Value 2N4393
SYMBOL voltage 304 -64 R0
SYMATTR InstName Vst
SYMATTR Value 2.4
SYMBOL Misc\\EuropeanResistor 480 192 R0
SYMATTR InstName R7
SYMATTR Value 4.7k
SYMBOL diode 432 160 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL Misc\\EuropeanResistor -32 128 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R0
SYMATTR Value 10k
SYMBOL voltage -160 304 R0
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL voltage -48 304 R0
SYMATTR InstName V2
SYMATTR Value -12
TEXT -152 -272 Left 2 !.tran 0 5m 0 1u
TEXT -152 -240 Left 2 !.options plotwinsize=0
TEXT 176 -256 Left 3 ;f = 1/(4*R*C) * (R1+Rk)/R1 * Ust/Ub