Version 4
SHEET 1 908 680
WIRE -208 -112 -336 -112
WIRE 32 -112 -208 -112
WIRE 176 -16 -112 -16
WIRE 272 -16 256 -16
WIRE 288 -16 272 -16
WIRE 368 -16 352 -16
WIRE 384 -16 368 -16
WIRE 272 32 272 -16
WIRE 384 64 384 -16
WIRE 384 64 160 64
WIRE -112 80 -112 -16
WIRE -208 96 -208 -32
WIRE -144 96 -208 96
WIRE 32 112 32 -112
WIRE 32 112 -80 112
WIRE 240 112 32 112
WIRE -336 128 -336 32
WIRE -144 128 -336 128
WIRE 240 128 240 112
WIRE -208 144 -208 96
WIRE -112 160 -112 144
WIRE 160 160 160 64
WIRE 160 160 -112 160
WIRE -208 240 -208 224
WIRE -96 256 -96 240
WIRE 0 256 -16 256
WIRE 16 256 0 256
WIRE 160 256 96 256
WIRE 176 256 160 256
WIRE 240 256 240 192
WIRE 272 256 240 256
WIRE -336 272 -336 128
WIRE -272 272 -336 272
WIRE 160 272 160 256
WIRE 272 272 272 256
WIRE 96 288 96 256
WIRE 96 288 80 288
WIRE -208 336 -208 320
WIRE -160 336 -208 336
WIRE -96 336 -96 256
WIRE -208 368 -208 336
WIRE 0 400 0 256
WIRE 0 400 -160 400
FLAG -336 352 0
FLAG -272 336 0
FLAG -208 464 0
FLAG 160 352 0
FLAG 272 352 0
FLAG 96 352 0
FLAG 272 32 0
SYMBOL res -352 -128 R0
WINDOW 0 -45 35 Left 2
WINDOW 3 -56 70 Left 2
SYMATTR InstName R1
SYMATTR Value 10k
SYMBOL res -352 256 R0
WINDOW 0 -58 38 Left 2
WINDOW 3 -62 81 Left 2
SYMATTR InstName R2
SYMATTR Value 10k
SYMBOL cap -352 -32 R0
WINDOW 0 -20 58 Left 2
SYMATTR InstName C1
SYMATTR Value 1n
SYMBOL cap -288 272 R0
WINDOW 0 -6 -25 Left 2
WINDOW 3 -18 17 Left 2
SYMATTR InstName C2
SYMATTR Value 1n
SYMBOL res -224 -128 R0
WINDOW 3 34 70 Left 2
SYMATTR InstName R3
SYMATTR Value 10k
SYMBOL res -224 128 R0
SYMATTR InstName R4
SYMATTR Value 3300
SYMBOL res -224 224 R0
WINDOW 3 36 68 Left 2
SYMATTR InstName R5
SYMATTR Value {R1}
SYMBOL res -112 272 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R6
SYMATTR Value 100k
SYMBOL res 0 272 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 0 56 VBottom 2
SYMATTR InstName R7
SYMATTR Value 100k
SYMBOL res 144 256 R0
WINDOW 0 33 100 Left 2
WINDOW 3 33 129 Left 2
SYMATTR InstName R8
SYMATTR Value 10k
SYMBOL res 256 256 R0
SYMATTR InstName R9
SYMATTR Value 20k
SYMBOL cap 224 128 R0
SYMATTR InstName C3
SYMATTR Value 10n
SYMBOL diode 176 272 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 -4 40 VBottom 2
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL njf -160 464 R180
SYMATTR InstName J1
SYMATTR Value BF245C
SYMBOL cap 80 288 R0
WINDOW 0 -42 37 Left 2
WINDOW 3 -48 63 Left 2
SYMATTR InstName C4
SYMATTR Value 10n
SYMBOL cap -160 352 R270
WINDOW 0 -24 -8 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName C5
SYMATTR Value 10n
SYMBOL voltage 160 -16 R270
WINDOW 0 42 46 Left 2
WINDOW 3 24 16 Left 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 15
SYMBOL Opamps\\UniversalOpamp2 -112 112 R0
SYMATTR InstName U1
SYMBOL voltage 272 -16 R270
WINDOW 0 32 56 VTop 2
WINDOW 3 -32 56 VBottom 2
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V2
SYMATTR Value 15
TEXT 360 -160 Left 2 !.step param R1 list 5000 3300 1200 750 100
TEXT 368 -112 Left 2 !.tran 5sec