Version 4
SHEET 1 880 680
WIRE -64 -48 -112 -48
WIRE 48 -48 -64 -48
WIRE 160 -48 48 -48
WIRE 240 -48 160 -48
WIRE 480 -48 240 -48
WIRE 544 -48 480 -48
WIRE -64 16 -64 -48
WIRE 48 16 48 -48
WIRE 160 16 160 -48
WIRE 480 16 480 -48
WIRE 544 16 544 -48
WIRE 160 112 160 96
WIRE 352 112 160 112
WIRE 480 112 480 80
WIRE 480 112 432 112
WIRE 544 112 544 96
WIRE 544 112 480 112
WIRE 544 144 544 112
WIRE 240 160 240 -48
WIRE -64 176 -64 80
WIRE 48 176 48 96
WIRE 48 176 -64 176
WIRE 128 176 48 176
WIRE 208 176 128 176
WIRE 352 192 272 192
WIRE 464 192 432 192
WIRE 480 192 464 192
WIRE -112 208 -112 -48
WIRE 160 208 160 112
WIRE 208 208 160 208
WIRE 48 240 48 176
WIRE 160 240 160 208
WIRE -112 384 -112 288
WIRE 48 384 48 320
WIRE 48 384 -112 384
WIRE 160 384 160 320
WIRE 160 384 48 384
WIRE 240 384 240 224
WIRE 240 384 160 384
WIRE 544 384 544 240
WIRE 544 384 240 384
WIRE -112 464 -112 384
FLAG -112 464 0
FLAG -112 -48 +Ub
FLAG 544 112 e
FLAG 464 192 b
FLAG 160 208 non
FLAG 128 176 inv
SYMBOL Opamps\\LTC6240 240 192 R0
SYMATTR InstName U1
SYMBOL voltage -112 192 R0
WINDOW 123 0 0 Left 2
WINDOW 39 0 0 Left 2
SYMATTR InstName V1
SYMATTR Value 12
SYMBOL Misc\\EuropeanResistor 448 176 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R1
SYMATTR Value 39
SYMBOL pnp 480 240 M180
SYMATTR InstName Q1
SYMATTR Value BCW68F
SYMBOL res 528 0 R0
SYMATTR InstName R2
SYMATTR Value 50
SYMBOL Misc\\EuropeanResistor 176 112 R180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R3
SYMATTR Value 2K7
SYMBOL Misc\\EuropeanResistor 176 336 R180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R4
SYMATTR Value 2K7
SYMBOL Misc\\EuropeanResistor 448 96 R90
WINDOW 0 5 56 VBottom 2
WINDOW 3 27 56 VTop 2
SYMATTR InstName R5
SYMATTR Value 39K
SYMBOL diode 496 80 R180
WINDOW 0 24 64 Left 2
WINDOW 3 24 0 Left 2
SYMATTR InstName D1
SYMBOL Misc\\EuropeanResistor 64 336 R180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R6
SYMATTR Value 15K
SYMBOL Misc\\EuropeanResistor 64 112 R180
WINDOW 0 31 76 Left 2
WINDOW 3 31 40 Left 2
SYMATTR InstName R7
SYMATTR Value {x}
SYMBOL cap -80 16 R0
SYMATTR InstName C1
SYMATTR Value 1n
TEXT 600 40 Left 2 ;Lüfter
TEXT -24 -72 Left 2 ;NTC22K
TEXT -152 488 Left 2 !.tran 1
TEXT 264 64 Left 2 ;0.4V Hysterese
TEXT 280 176 Left 2 ;1
TEXT 184 160 Left 2 ;2
TEXT 184 192 Left 2 ;3
TEXT 224 232 Left 2 ;4
TEXT 224 144 Left 2 ;8
TEXT 256 248 Left 2 ;LM393
TEXT 448 248 Left 2 ;BC327
TEXT 16 488 Left 2 !.step param x 27K 15K