Version 4
SHEET 1 1400 680
WIRE 640 -32 -112 -32
WIRE -16 16 -48 16
WIRE 80 16 48 16
WIRE -112 64 -112 -32
WIRE -48 80 -48 16
WIRE -16 80 -48 80
WIRE 80 80 80 16
WIRE 80 80 48 80
WIRE 272 80 240 80
WIRE 368 80 336 80
WIRE -112 160 -112 144
WIRE -48 160 -48 80
WIRE -48 160 -112 160
WIRE -16 160 -48 160
WIRE 144 160 128 160
WIRE 240 160 240 80
WIRE 240 160 224 160
WIRE 272 160 240 160
WIRE 544 160 496 160
WIRE 80 176 80 80
WIRE 80 176 48 176
WIRE 128 176 128 160
WIRE 128 176 80 176
WIRE 368 176 368 80
WIRE 368 176 336 176
WIRE 496 176 496 160
WIRE 496 176 368 176
WIRE 640 176 640 -32
WIRE 640 176 608 176
WIRE -16 192 -48 192
WIRE 272 192 240 192
WIRE 544 192 512 192
WIRE -48 240 -48 192
WIRE 240 240 240 192
WIRE 512 272 512 192
WIRE 544 272 512 272
WIRE 640 272 640 176
WIRE 640 272 624 272
WIRE 512 352 512 272
WIRE 512 352 496 352
WIRE 528 352 512 352
FLAG -224 64 0
FLAG -224 144 0
FLAG -224 -16 V+
FLAG 304 144 V+
FLAG 304 208 V-
FLAG -224 224 V-
FLAG 240 240 0
FLAG 576 144 V+
FLAG 576 208 V-
FLAG 16 144 V+
FLAG 16 208 V-
FLAG -48 240 0
FLAG 656 352 0
FLAG 368 352 0
SYMBOL Opamps\\LT1001 304 112 R0
SYMATTR InstName U1
SYMBOL voltage -224 128 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 15
SYMBOL voltage -224 -32 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V3
SYMATTR Value 15
SYMBOL cap 336 64 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName C1
SYMATTR Value 4.7µ
SYMBOL res 240 144 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R3
SYMATTR Value 1k
SYMBOL Opamps\\LT1001 576 112 R0
SYMATTR InstName U3
SYMBOL res 640 256 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName R4
SYMATTR Value 1k
SYMBOL Opamps\\LT1001 16 112 R0
SYMATTR InstName U2
SYMBOL diode 48 64 R90
WINDOW 0 0 32 VBottom 2
WINDOW 3 32 32 VTop 2
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL diode -16 32 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D2
SYMATTR Value 1N4148
SYMBOL res -96 160 R180
WINDOW 0 36 76 Left 2
WINDOW 3 36 40 Left 2
SYMATTR InstName R2
SYMATTR Value 1k
SYMBOL zener 496 336 R90
WINDOW 0 -4 32 VBottom 2
WINDOW 3 36 32 VTop 2
SYMATTR InstName D3
SYMATTR Value BZX84C6V2L
SYMBOL zener 592 336 R90
WINDOW 0 -4 32 VBottom 2
WINDOW 3 36 32 VTop 2
SYMATTR InstName D4
SYMATTR Value BZX84C6V2L
SYMBOL diode 592 368 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D5
SYMATTR Value 1N4148
SYMBOL diode 368 368 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D6
SYMATTR Value 1N4148
TEXT -48 304 Left 2 !.tran .5