Version 4 SHEET 1 1556 680 WIRE -480 -352 -480 -400 WIRE -432 -400 -480 -400 WIRE -320 368 -320 -368 WIRE -224 -400 -352 -400 WIRE -224 -400 -224 -608 WIRE -224 -368 -320 -368 WIRE -224 -336 -224 -368 WIRE -224 -224 -224 -256 WIRE -224 -96 -224 -144 WIRE -176 -608 -224 -608 WIRE -160 -400 -224 -400 WIRE -160 -368 -224 -368 WIRE -128 -528 -128 -560 WIRE -128 -416 -128 -448 WIRE -128 -304 -128 -352 WIRE -128 -176 -128 -224 WIRE -64 -560 -128 -560 WIRE -64 -512 -64 -560 WIRE -32 -608 -96 -608 WIRE -32 -384 -96 -384 WIRE -32 -384 -32 -608 WIRE 0 -160 0 -208 WIRE 0 -32 0 -80 WIRE 0 112 0 48 WIRE 0 160 0 112 WIRE 0 288 0 224 WIRE 80 112 0 112 WIRE 80 160 80 112 WIRE 80 288 80 224 WIRE 96 -384 -32 -384 WIRE 96 -16 96 -384 WIRE 128 112 80 112 WIRE 176 -208 0 -208 WIRE 176 -160 176 -208 WIRE 176 -16 96 -16 WIRE 176 -16 176 -80 WIRE 240 -16 176 -16 WIRE 256 112 208 112 WIRE 256 160 256 112 WIRE 256 288 256 240 WIRE 288 -208 176 -208 WIRE 288 -160 288 -208 WIRE 400 -272 400 -368 WIRE 400 16 400 -272 WIRE 400 64 400 16 WIRE 400 192 304 192 WIRE 400 192 400 144 WIRE 496 -16 320 -16 WIRE 496 64 496 -16 WIRE 496 208 496 144 WIRE 528 -368 400 -368 WIRE 528 -272 400 -272 WIRE 560 -16 496 -16 WIRE 560 16 400 16 WIRE 592 -176 592 -208 WIRE 592 -32 592 -96 WIRE 592 80 592 32 WIRE 592 208 592 160 WIRE 656 -208 592 -208 WIRE 656 -176 656 -208 WIRE 736 -368 592 -368 WIRE 736 -272 608 -272 WIRE 736 -272 736 -368 WIRE 736 0 624 0 WIRE 736 0 736 -272 WIRE 768 0 736 0 WIRE 880 0 848 0 WIRE 880 80 880 0 WIRE 880 240 880 144 WIRE 912 0 880 0 WIRE 960 -544 960 -592 WIRE 960 -432 960 -464 WIRE 960 -384 960 -432 WIRE 960 -272 960 -304 WIRE 960 -240 960 -272 WIRE 960 -144 960 -176 WIRE 992 -432 960 -432 WIRE 1008 -272 960 -272 WIRE 1024 0 992 0 WIRE 1040 -592 960 -592 WIRE 1040 -544 1040 -592 WIRE 1088 -432 1056 -432 WIRE 1088 -384 1088 -432 WIRE 1088 -48 1088 -160 WIRE 1088 112 1088 48 WIRE 1088 240 1088 192 WIRE 1136 -272 1088 -272 WIRE 1136 -160 1088 -160 WIRE 1312 -272 1248 -272 WIRE 1312 -256 1312 -272 WIRE 1312 -160 1248 -160 WIRE 1312 -160 1312 -176 WIRE 1312 -128 1312 -160 WIRE 1408 -272 1312 -272 WIRE 1408 368 -320 368 WIRE 1408 368 1408 -272 FLAG 1088 240 0 FLAG 880 240 0 FLAG 656 -176 0 FLAG 592 208 0 FLAG 256 288 0 FLAG 80 288 0 FLAG 0 288 0 FLAG 288 -160 0 FLAG -64 -512 0 FLAG -128 -176 0 FLAG -224 -96 0 FLAG -480 -352 0 FLAG 496 208 0 FLAG 1312 -128 0 FLAG 1040 -544 0 FLAG 960 -144 0 FLAG 1088 -384 0 SYMBOL ld_hl7801e 1184 -224 R0 SYMATTR InstName X1 SYMBOL npn 1024 -48 R0 SYMATTR InstName Q1 SYMATTR Value 2N2222 SYMBOL res 1072 96 R0 SYMATTR InstName R1 SYMATTR Value 8.2 SYMBOL res 1008 -16 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R2 SYMATTR Value 1k SYMBOL cap 864 80 R0 SYMATTR InstName C1 SYMATTR Value 0.022µF SYMBOL res 864 -16 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R3 SYMATTR Value 1k SYMBOL Opamps\\LT1057 592 64 M180 WINDOW 0 33 89 Left 0 WINDOW 3 34 118 Left 0 SYMATTR InstName U1 SYMBOL res 624 -288 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R4 SYMATTR Value 1k SYMBOL cap 592 -384 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName C2 SYMATTR Value 0.10µF SYMBOL voltage 592 -192 R0 WINDOW 0 40 53 Left 0 WINDOW 3 41 81 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V1 SYMATTR Value 12.0 SYMBOL voltage 592 64 R0 WINDOW 0 41 29 Left 0 WINDOW 3 40 53 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V2 SYMATTR Value 12.0 SYMBOL res 336 -32 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R5 SYMATTR Value 1k SYMBOL res 384 48 R0 SYMATTR InstName R6 SYMATTR Value 1k SYMBOL res 224 96 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R7 SYMATTR Value 2.2k SYMBOL cap 64 160 R0 WINDOW 3 53 60 Left 0 SYMATTR Value 10µF SYMATTR InstName C3 SYMBOL zener 16 224 R180 WINDOW 0 24 72 Left 0 WINDOW 3 24 0 Left 0 SYMATTR InstName D1 SYMATTR Value BZX84C6V2L SYMBOL res -16 -48 R0 SYMATTR InstName R8 SYMATTR Value 1k SYMBOL res 160 -176 R0 SYMATTR InstName R9 SYMATTR Value 1MEG SYMBOL voltage 0 -64 R180 WINDOW 0 52 101 Left 0 WINDOW 3 37 69 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V3 SYMATTR Value 12.0 SYMBOL voltage 960 -448 R180 WINDOW 0 57 71 Left 0 WINDOW 3 46 41 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V4 SYMATTR Value 12.0 SYMBOL Opamps\\LT1057 -128 -448 R0 WINDOW 0 33 89 Left 0 WINDOW 3 34 118 Left 0 SYMATTR InstName U3 SYMBOL res -80 -624 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R10 SYMATTR Value 1k SYMBOL voltage -128 -432 R180 WINDOW 0 52 101 Left 0 WINDOW 3 37 69 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V6 SYMATTR Value 12.0 SYMBOL voltage -128 -208 R180 WINDOW 0 -69 92 Left 0 WINDOW 3 -87 63 Left 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V7 SYMATTR Value 12.0 SYMBOL res -240 -240 R0 SYMATTR InstName R11 SYMATTR Value 10k SYMBOL res 480 48 R0 SYMATTR InstName R12 SYMATTR Value 1k SYMBOL potentiometer_standard 240 256 M180 WINDOW 3 82 -14 Left 0 WINDOW 39 61 154 Left 0 WINDOW 38 78 13 Left 0 WINDOW 0 77 36 Left 0 SYMATTR Value Rt=1k set=0.25 SYMATTR SpiceLine "" SYMATTR SpiceModel potentiometer SYMATTR InstName U4 SYMBOL res 1296 -272 R0 SYMATTR InstName R13 SYMATTR Value 1.0 SYMBOL potentiometer -240 -352 R0 WINDOW 0 -125 73 Left 0 WINDOW 3 -303 107 Left 0 SYMATTR InstName U2 SYMATTR Value Rt=50K set={wip} SYMBOL voltage -336 -400 R90 WINDOW 0 -32 56 VBottom 0 WINDOW 3 32 56 VTop 0 WINDOW 123 0 0 Left 0 WINDOW 39 0 0 Left 0 SYMATTR InstName V5 SYMATTR Value 0V SYMBOL res 944 -400 R0 SYMATTR InstName R14 SYMATTR Value 110 SYMBOL zener 976 -176 R180 WINDOW 0 151 70 Left 0 WINDOW 3 45 41 Left 0 SYMATTR InstName D2 SYMATTR Value BZX84C8V2L SYMBOL res 1104 -288 R90 WINDOW 0 0 56 VBottom 0 WINDOW 3 32 56 VTop 0 SYMATTR InstName R15 SYMATTR Value 82 SYMBOL cap 1056 -448 R90 WINDOW 0 0 32 VBottom 0 WINDOW 3 32 32 VTop 0 SYMATTR InstName C4 SYMATTR Value 0.1µF TEXT 32 -448 Left 0 !.op TEXT 32 -496 Left 0 !.temp 25 TEXT 40 -520 Left 0 !.step lin param wip 0 50k 10k