Version 4
SHEET 1 1060 680
WIRE -272 112 -448 112
WIRE 192 128 -192 128
WIRE -448 144 -448 112
WIRE -176 160 -240 160
WIRE 192 160 192 128
WIRE 192 160 48 160
WIRE -400 176 -416 176
WIRE -288 176 -336 176
WIRE -208 176 -288 176
WIRE 80 192 64 192
WIRE -448 224 -448 208
WIRE -272 224 -272 112
WIRE -176 224 -224 224
WIRE 64 224 64 192
WIRE 64 224 48 224
WIRE 80 224 64 224
WIRE 192 224 192 160
WIRE 192 224 160 224
WIRE -368 240 -368 208
WIRE -288 240 -288 176
WIRE -288 240 -368 240
WIRE -208 288 -208 176
WIRE -176 288 -208 288
WIRE 80 288 48 288
WIRE 192 288 192 224
WIRE -448 304 -448 288
WIRE -272 304 -272 288
WIRE -272 304 -448 304
WIRE -224 304 -224 224
WIRE -224 304 -272 304
WIRE -448 320 -448 304
WIRE -272 320 -272 304
WIRE -192 352 -192 128
WIRE -176 352 -192 352
WIRE 112 352 48 352
WIRE -224 384 -224 304
WIRE 80 384 80 288
WIRE 80 384 -224 384
WIRE 192 384 192 368
WIRE 192 384 160 384
WIRE -448 400 -448 384
WIRE -368 400 -448 400
WIRE -272 400 -272 384
WIRE -272 400 -368 400
WIRE 160 400 160 384
WIRE -208 416 -208 288
WIRE -192 416 -208 416
WIRE -368 432 -368 400
WIRE -336 432 -368 432
WIRE -240 432 -240 160
WIRE -240 432 -272 432
WIRE 112 432 112 416
WIRE 112 432 -240 432
WIRE 192 432 192 384
WIRE 192 432 112 432
FLAG 160 400 0
FLAG -192 416 Out
IOPIN -192 416 Out
FLAG 80 192 Od
IOPIN 80 192 Out
SYMBOL cap -272 416 R90
WINDOW 0 14 53 VBottom 0
WINDOW 3 -11 -2 VTop 0
SYMATTR InstName Ct
SYMATTR Value 1n
SYMATTR SpiceLine V=50v
SYMBOL diode -464 224 R0
WINDOW 3 24 72 Invisible 0
WINDOW 0 18 63 Left 0
SYMATTR Value 1N914
SYMATTR InstName D1
SYMBOL diode -464 320 R0
WINDOW 3 24 72 Invisible 0
WINDOW 0 18 64 Left 0
SYMATTR Value 1N914
SYMATTR InstName D2
SYMBOL diode -256 384 R180
WINDOW 0 18 -1 Left 0
WINDOW 3 24 0 Invisible 0
SYMATTR InstName D3
SYMATTR Value 1N914
SYMBOL diode -256 288 R180
WINDOW 0 19 1 Left 0
WINDOW 3 24 0 Invisible 0
SYMATTR InstName D4
SYMATTR Value 1N914
SYMBOL Misc\\battery 192 272 R0
WINDOW 0 -79 34 Left 0
WINDOW 3 -79 58 Left 0
SYMATTR InstName Vcc
SYMATTR Value 12v
SYMATTR Value2 AC 0 0
SYMATTR SpiceLine Rser=1 Cpar=100u
SYMBOL res 176 208 R90
WINDOW 0 57 89 VBottom 0
WINDOW 3 32 35 VTop 0
SYMATTR InstName Rd
SYMATTR Value 100k
SYMBOL Pote -432 112 M0
WINDOW 123 -75 142 Center 0
WINDOW 3 -62 170 Center 0
WINDOW 0 51 41 VRight 0
SYMATTR Value2 set=cursor
SYMATTR Value rt=100k
SYMATTR InstName Duty
SYMBOL Pote -304 192 M270
WINDOW 0 47 33 VRight 0
WINDOW 3 -36 27 VCenter 0
WINDOW 123 -16 20 VCenter 0
SYMATTR InstName Freq
SYMATTR Value rt=100k
SYMATTR Value2 Set=.01
SYMBOL 555_ALL -16 272 R0
WINDOW 38 -83 78 Left 0
SYMATTR InstName U1
SYMBOL cap 128 416 R180
WINDOW 0 72 11 Left 0
WINDOW 3 24 8 Left 0
SYMATTR InstName Cbp
SYMATTR Value 10n
SYMATTR SpiceLine V=50v
TEXT 232 128 Left 0 !.tran 3m
TEXT 232 152 Left 0 !.params: Vdd 12 Ronx=.1 \n.step param cursor 0 1 .5\n.meas tran ta FIND time WHEN V(out)={Vdd/2} td=.2m rise=1\n.meas tran tb FIND time WHEN V(out)={Vdd/2} td=.2m rise=11\n.meas tran Frec PARAM 10/(tb-ta)\n.Meas tran Tc FIND time WHEN V(Out)={Vdd/2} td=.2m fall=1\n.Meas tran Td FIND time WHEN V(Out)={Vdd/2} td=.2m 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