Version 4
SHEET 1 880 680
WIRE 208 -160 80 -160
WIRE 400 -160 208 -160
WIRE 208 -144 208 -160
WIRE 400 -144 400 -160
WIRE 208 -48 208 -64
WIRE 304 -48 208 -48
WIRE 208 -32 208 -48
WIRE 400 -32 400 -64
WIRE 304 16 304 -48
WIRE 304 16 272 16
WIRE 336 16 304 16
WIRE 80 112 80 -160
WIRE 400 112 400 64
WIRE 208 128 208 64
WIRE 80 208 80 192
WIRE 208 208 208 192
WIRE 208 208 80 208
WIRE 400 208 400 192
WIRE 400 208 208 208
WIRE 208 224 208 208
FLAG 208 224 0
SYMBOL res 192 -160 R0
SYMATTR InstName R1
SYMATTR Value 27k
SYMBOL voltage 80 96 R0
WINDOW 3 14 -287 Left 2
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value PULSE(23 25 0 .95 .95 .05 2 5)
SYMBOL References\\LT1004-1.2 208 160 R0
SYMATTR InstName U2
SYMBOL npn 272 -32 M0
SYMATTR InstName Q1
SYMATTR Value BC847B
SYMBOL npn 336 -32 R0
SYMATTR InstName Q2
SYMATTR Value BC847B
SYMBOL res 384 96 R0
SYMATTR InstName R2
SYMATTR Value 1235.4
SYMBOL res 384 -160 R0
SYMATTR InstName R3
SYMATTR Value 100
TEXT 46 248 Left 2 !.tran 0 10 0
TEXT 264 240 Left 2 !.step temp list 10 20 30 40 50