Version 4
SHEET 1 880 1112
WIRE 208 144 -80 144
WIRE 336 160 272 160
WIRE 464 160 336 160
WIRE -80 176 -80 144
WIRE 208 176 128 176
WIRE 128 256 128 176
WIRE 240 256 128 256
WIRE 336 256 336 160
WIRE 336 256 320 256
WIRE -80 288 -80 256
WIRE 128 288 128 256
WIRE 128 400 128 368
FLAG 464 160 Ua
FLAG -80 144 U0
FLAG 128 176 U1
FLAG 128 400 0
FLAG -80 288 0
DATAFLAG 48 144 "round($*10k)/10k"
DATAFLAG 192 256 "round($*10k)/10k"
DATAFLAG 400 160 "round($*10k)/10k"
SYMBOL Opamps\\opamp 240 224 M180
WINDOW 0 -16 142 Left 2
WINDOW 3 -16 114 Left 2
SYMATTR InstName U1
SYMBOL Misc\\EuropeanResistor 224 272 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R2
SYMATTR Value 90k
SYMBOL Misc\\EuropeanResistor 112 272 R0
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL voltage -80 160 R0
SYMATTR InstName V1
SYMATTR Value 1
TEXT -96 496 Left 2 !.subckt opamp in- in+ out\nRe in+ in- 100k\nEV out 0 in+ in- 100\n.ends
TEXT -96 456 Left 2 !.op
TEXT -96 648 Left 2 ;R12=R1*R2/(R1+R2)\n R1e=R1*Re/(R1+Re)  \n \n Überlagerung anwenden\n U1 = Ua*R1e/(R2+R1e) +U0*R12/(R12+Re)  (1)\n  \n Ua = V*(U0-U1) (2)  \n U1 = U0 -Ua/V  (3)\n \n U1 in (1) durch (3) ersetzen\n \n U0 -Ua/V = Ua*R1e/(R2+R1e) +U0*R12/(R12+Re) \n Ua*(R1e/(R2+R1e) +1/V) = U0*(1-R12/(R12+Re))\n Ua/U0 =  (1-R12/(R12+Re))/(R1e/(R2+R1e) +1/V)\n Ua/U0 = (Re/(R12+Re)) / ( (R1e+(R2+R1e)/V)/(R2+R1e) )\n Ua/U0 = (R2+R1e)/ ( (R12/Re+1)*(R1e+(R2+R1e)/V))\n Ua/U0 = (R2+R1e)/ ((R1e+(R2+R1e)/V)*(R12/Re+1))