Version 4
SHEET 1 880 680
WIRE 144 16 -32 16
WIRE 224 16 144 16
WIRE 336 16 304 16
WIRE 496 16 432 16
WIRE 608 16 608 -112
WIRE 608 16 576 16
WIRE 640 16 608 16
WIRE 736 16 704 16
WIRE -32 80 -32 16
WIRE 144 160 144 16
WIRE 176 160 144 160
WIRE 272 160 240 160
WIRE 384 160 384 80
WIRE 384 160 336 160
WIRE 448 160 384 160
WIRE 608 160 608 16
WIRE 608 160 528 160
WIRE -32 320 -32 160
FLAG 736 16 0
FLAG 608 -112 out
FLAG -32 320 0
SYMBOL pnp 432 80 M270
SYMATTR InstName Q1
SYMATTR Value 2N2907
SYMBOL Misc\\EuropeanResistor 208 32 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R1
SYMATTR Value 12
SYMBOL Misc\\EuropeanResistor 432 176 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R2
SYMATTR Value 4.7k
SYMBOL diode 272 176 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL diode 176 176 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName D2
SYMATTR Value 1N4148
SYMBOL polcap 640 32 R270
WINDOW 0 32 32 VTop 2
WINDOW 3 0 32 VBottom 2
SYMATTR InstName C1
SYMATTR Value 100µ
SYMBOL voltage -32 64 R0
SYMATTR InstName V1
SYMATTR Value 20
SYMBOL Misc\\EuropeanResistor 480 32 R270
WINDOW 0 27 56 VTop 2
WINDOW 3 5 56 VBottom 2
SYMATTR InstName R3
SYMATTR Value {RV}
TEXT -96 -184 Left 2 !.tran 0.1 startup
TEXT -96 -104 Left 2 !.step param RV= 0.5 100k 1k
TEXT -96 -136 Left 2 ;RV Variabler Widerstand