Version 4
SHEET 1 880 680
WIRE -128 176 -320 176
WIRE 224 176 -64 176
WIRE -128 192 -128 176
WIRE -320 208 -320 176
WIRE -64 224 -64 176
WIRE -64 224 -96 224
WIRE -16 224 -64 224
WIRE 224 224 224 176
WIRE 240 224 224 224
WIRE 80 240 48 240
WIRE 96 240 80 240
WIRE 128 240 96 240
WIRE 224 240 208 240
WIRE 336 240 304 240
WIRE 368 240 336 240
WIRE -16 256 -32 256
WIRE 96 256 96 240
WIRE 224 256 224 240
WIRE 240 256 224 256
WIRE -320 304 -320 288
WIRE -128 304 -128 256
WIRE -128 304 -320 304
WIRE 224 304 224 256
WIRE 272 304 224 304
WIRE 368 304 368 240
WIRE 368 304 352 304
WIRE -320 320 -320 304
WIRE -32 336 -32 256
WIRE 96 336 96 320
WIRE 96 336 -32 336
WIRE 128 336 96 336
WIRE 368 336 368 304
WIRE 368 336 208 336
FLAG -320 176 V+
FLAG -320 320 0
FLAG 272 208 V+
FLAG 16 272 V+
FLAG 336 240 Sq
FLAG 80 240 Tr
FLAG 16 208 0
FLAG 272 272 0
SYMBOL Robertugo\\OPAMP5 272 176 R0
WINDOW 0 -22 64 Left 0
WINDOW 38 -167 17 Left 0
SYMATTR InstName U2
SYMATTR SpiceModel LM118/LT
SYMBOL Robertugo\\OPAMP5 16 304 M180
WINDOW 0 -25 62 Left 0
WINDOW 38 -42 -14 Left 0
SYMATTR InstName U1
SYMATTR SpiceModel LM118/LT
SYMBOL Robertugo\\Pote -112 160 M0
WINDOW 123 92 91 Center 0
SYMATTR InstName Simet
SYMATTR Value Rt=1e4
SYMATTR Value2 Set={cur}
SYMBOL cap 112 320 R180
WINDOW 0 -34 63 Left 0
WINDOW 3 -45 42 Left 0
SYMATTR InstName C1
SYMATTR Value 10n
SYMBOL res 224 224 R90
WINDOW 0 17 104 VBottom 0
WINDOW 3 -11 21 VTop 0
SYMATTR InstName R1
SYMATTR Value 47k
SYMBOL res 368 288 R90
WINDOW 0 14 123 VBottom 0
WINDOW 3 -32 49 VTop 0
SYMATTR InstName R2
SYMATTR Value 1e5
SYMBOL res 224 320 R90
WINDOW 0 0 80 VBottom 0
WINDOW 3 -28 42 VTop 0
SYMATTR InstName R3
SYMATTR Value 1e4
SYMBOL voltage -320 192 R0
WINDOW 3 -11 56 Left 0
SYMATTR InstName Vcc
SYMATTR Value 15
TEXT -292 282 Left 0 !.tran 10m
TEXT -296 320 Left 0 !.step param cur .4 .6 .1