Version 4
SHEET 1 880 680
WIRE 240 48 112 48
WIRE 656 48 320 48
WIRE 112 144 112 48
WIRE 656 144 656 48
WIRE 112 352 112 224
WIRE 656 352 656 224
WIRE 656 352 112 352
WIRE 112 384 112 352
FLAG 112 384 0
FLAG 656 48 VO
SYMBOL voltage 112 128 R0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR InstName V1
SYMATTR Value 600
SYMBOL res 336 32 R90
WINDOW 0 0 56 VBottom 2
WINDOW 3 32 56 VTop 2
SYMATTR InstName Ri
SYMATTR Value 50
SYMBOL res 672 240 R180
WINDOW 0 36 76 Left 2
WINDOW 3 36 40 Left 2
SYMATTR InstName RL
SYMATTR Value {R_L}
TEXT 78 408 Left 2 !.tran 1
TEXT 160 -72 Left 2 !.step param R_L 10 100 10