Version 4
SHEET 1 880 680
WIRE -144 320 -144 128
WIRE -144 624 -144 400
WIRE 80 128 -144 128
WIRE 80 144 80 128
WIRE 80 240 80 208
WIRE 80 336 80 304
WIRE 80 400 80 336
WIRE 80 624 80 480
WIRE 192 336 80 336
WIRE 256 128 80 128
WIRE 256 144 256 128
WIRE 256 288 256 224
WIRE 256 416 256 384
WIRE 256 528 256 480
WIRE 256 624 256 592
FLAG 256 624 0
FLAG -144 624 0
FLAG 80 624 0
SYMBOL diode 64 144 R0
SYMATTR InstName D1
SYMATTR Value 1N4148
SYMBOL diode 64 240 R0
SYMATTR InstName D2
SYMATTR Value 1N4148
SYMBOL pnp 192 384 M180
SYMATTR InstName Q1
SYMATTR Value 2N3906
SYMBOL Misc\\EuropeanResistor 240 128 R0
SYMATTR InstName R1
SYMATTR Value 10
SYMBOL LED 240 416 R0
SYMATTR InstName D3
SYMATTR Value LED
SYMBOL LED 240 528 R0
SYMATTR InstName D4
SYMATTR Value LED
SYMBOL voltage -144 304 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 10V
SYMBOL Misc\\EuropeanResistor 64 384 R0
SYMATTR InstName R2
SYMATTR Value 500
TEXT 382 264 Left 0 !.dc v1 0 20V 0.1
TEXT 360 152 Left 0 ;Konstantstromquelle
TEXT 368 472 Left 0 ;I(D3) plotten lassen