Version 4
SHEET 1 1064 680
WIRE -48 -64 -288 -64
WIRE 128 -64 -48 -64
WIRE 480 -64 128 -64
WIRE 656 -64 480 -64
WIRE 480 -32 480 -64
WIRE -48 48 -48 -64
WIRE -288 80 -288 -64
WIRE 256 80 64 80
WIRE 304 80 256 80
WIRE 480 80 480 48
WIRE 480 80 384 80
WIRE 16 96 0 96
WIRE 256 96 256 80
WIRE 128 144 128 -64
WIRE 64 160 64 80
WIRE 96 160 64 160
WIRE 480 160 480 80
WIRE 656 160 656 -64
WIRE 256 176 256 160
WIRE 256 176 160 176
WIRE 304 176 256 176
WIRE 432 176 384 176
WIRE 16 192 16 96
WIRE 96 192 16 192
WIRE -288 224 -288 144
WIRE -48 224 -48 128
WIRE -48 224 -288 224
WIRE -288 272 -288 224
WIRE 480 288 480 256
WIRE -288 400 -288 352
WIRE 128 400 128 208
WIRE 128 400 -288 400
WIRE 480 400 480 368
WIRE 480 400 128 400
WIRE 656 400 656 240
WIRE 656 400 480 400
WIRE 480 448 480 400
FLAG 480 448 0
SYMBOL res 464 -48 R0
SYMATTR InstName R1
SYMATTR Value 27
SYMBOL res 288 160 M90
WINDOW 0 0 56 VBottom 2
WINDOW 3 29 60 VTop 2
SYMATTR InstName R3
SYMATTR Value 470
SYMBOL voltage 656 144 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 26
SYMBOL res 464 272 R0
SYMATTR InstName RL
SYMATTR Value 100
SYMBOL References\\LT1634-2.5 -288 112 R0
SYMATTR InstName U2
SYMBOL potentiometer -64 32 R0
WINDOW 3 -112 -129 Left 2
SYMATTR InstName U4
SYMATTR Value Rtot=5K wiper={w}
SYMBOL res -304 256 R0
SYMATTR InstName R2
SYMATTR Value 22k
SYMBOL res 288 64 M90
WINDOW 0 0 56 VBottom 2
WINDOW 3 29 60 VTop 2
SYMATTR InstName R5
SYMATTR Value 2200
SYMBOL cap 240 96 R0
SYMATTR InstName C1
SYMATTR Value 1n
SYMBOL Opamps\\LT1366 128 112 R0
SYMATTR InstName U1
SYMBOL pmos 432 256 M180
SYMATTR InstName M1
SYMATTR Value IRF9640
TEXT -304 464 Left 2 !.op
TEXT -304 496 Left 2 !.step param w 0 1 0.1
TEXT -304 552 Left 2 !.lib potentiometer.sub
TEXT 0 496 Left 2 ;.options gminsteps=0
TEXT 408 296 Left 2 ;Last
RECTANGLE Normal 576 384 384 272 2