Version 4
SHEET 1 1044 680
WIRE -176 272 -176 144
WIRE -176 464 -176 352
WIRE -96 320 -96 240
WIRE -96 464 -176 464
WIRE -96 464 -96 384
WIRE -96 480 -96 464
WIRE -80 48 -96 48
WIRE -80 304 -80 48
WIRE -48 464 -96 464
WIRE -48 464 -48 176
WIRE -32 144 -176 144
WIRE -32 368 -32 144
WIRE -16 240 -96 240
WIRE -16 400 -16 240
WIRE 0 48 -80 48
WIRE 0 176 -48 176
WIRE 0 240 -16 240
WIRE 0 304 -80 304
WIRE 0 368 -32 368
WIRE 240 144 -32 144
WIRE 240 176 224 176
WIRE 240 176 240 144
WIRE 240 304 224 304
WIRE 240 304 240 192
WIRE 240 400 -16 400
WIRE 240 400 240 304
WIRE 272 192 240 192
WIRE 272 368 224 368
WIRE 272 384 272 368
WIRE 272 464 -48 464
WIRE 272 464 272 448
WIRE 304 48 64 48
WIRE 304 160 304 48
WIRE 304 240 224 240
WIRE 304 240 304 224
FLAG -96 480 0
FLAG -96 48 Out
IOPIN -96 48 Out
SYMBOL Robertugo\\555_ALL 160 288 R0
WINDOW 38 -75 81 Left 0
WINDOW 0 -62 -81 Left 0
SYMATTR InstName U1
SYMBOL cap -112 320 R0
WINDOW 0 21 8 Left 0
WINDOW 3 19 64 Left 0
SYMATTR InstName Ct
SYMATTR Value 10n
SYMBOL cap 256 384 R0
WINDOW 0 21 8 Left 0
WINDOW 3 19 64 Left 0
SYMATTR InstName Cbp
SYMATTR Value 10n
SYMBOL voltage -176 256 R0
WINDOW 3 -13 59 Left 0
SYMATTR Value 12
SYMATTR InstName Vcc
SYMBOL diode 0 64 R270
WINDOW 0 19 -18 VTop 0
WINDOW 3 45 102 VBottom 0
SYMATTR InstName Don
SYMATTR Value 1N914
SYMBOL Robertugo\\Pote 288 128 R0
WINDOW 123 34 133 Center 0
SYMATTR InstName U2
SYMATTR Value Rt=20K
SYMATTR Value2 Set={Cursor}
TEXT 166 482 Left 0 !.tran 5m
TEXT -872 152 Left 0 !.params: Vdd 12 Ronx=.1 \n.step param Cursor  .01 .99 .2\n.meas tran ta FIND time WHEN V(out)={Vdd/2} td=1m rise=1\n.meas tran tb FIND time WHEN V(out)={Vdd/2} td=1m rise=11\n.meas tran Frec PARAM 10/(tb-ta)\n.Meas tran Tc FIND time WHEN V(Out)={Vdd/2} td=1m fall=1\n.Meas tran Td FIND time WHEN V(Out)={Vdd/2} td=1m fall=2\n.Meas tran T1 Param  (Tc-Ta)\n.Meas tran T2  Param  (Td-Ta)\n.Meas tran Ton Param If (T1>0, T1, T2)\n.Meas tran Duty% Param  Ton*Frec*100
TEXT 248 152 Left 0 ;Rton
TEXT 248 224 Left 0 ;Rtoff