Version 4
SHEET 1 980 680
WIRE -448 -16 -448 -64
WIRE -448 144 -448 48
WIRE -448 224 -448 208
WIRE -448 240 -448 224
WIRE -448 336 -448 304
WIRE -368 336 -448 336
WIRE -368 368 -368 336
WIRE -368 448 -368 432
WIRE -320 96 -320 48
WIRE -320 448 -368 448
WIRE -320 480 -320 448
WIRE -304 96 -320 96
WIRE -272 -64 -448 -64
WIRE -272 48 -320 48
WIRE -272 48 -272 -64
WIRE -272 64 -272 48
WIRE -272 144 -272 128
WIRE -272 224 -448 224
WIRE -272 224 -272 208
WIRE -272 240 -272 224
WIRE -272 336 -368 336
WIRE -272 336 -272 304
WIRE -240 448 -320 448
WIRE -240 448 -240 160
WIRE -224 224 -272 224
WIRE -224 224 -224 80
WIRE -208 16 -416 16
WIRE -208 16 -208 0
WIRE -208 288 -208 16
WIRE -192 400 -192 352
WIRE -176 160 -240 160
WIRE -176 224 -224 224
WIRE -176 288 -208 288
WIRE -176 352 -192 352
WIRE 64 160 48 160
WIRE 64 320 64 160
WIRE 64 400 -192 400
WIRE 64 400 64 320
WIRE 80 80 -224 80
WIRE 80 288 48 288
WIRE 80 288 80 80
WIRE 96 352 48 352
WIRE 96 368 96 352
WIRE 96 448 -240 448
WIRE 96 448 96 432
WIRE 112 224 48 224
WIRE 176 320 64 320
WIRE 176 336 176 320
WIRE 176 448 96 448
WIRE 176 448 176 416
WIRE 208 160 64 160
WIRE 208 224 192 224
WIRE 208 224 208 160
FLAG -320 480 0
FLAG -208 0 Out
IOPIN -208 0 Out
SYMBOL cap -384 368 R0
WINDOW 0 38 6 Left 0
WINDOW 3 36 33 Left 0
SYMATTR InstName C1
SYMATTR Value 68n
SYMATTR SpiceLine V=50v
SYMBOL polcap 80 368 R0
WINDOW 0 -45 46 Left 0
WINDOW 3 -44 69 Left 0
SYMATTR InstName C2
SYMATTR Value 10n
SYMATTR Description Capacitor
SYMATTR Type cap
SYMATTR SpiceLine V=50 Irms=22m Rser=3.9 MTBF=2000 Lser=0 ppPkg=1
SYMBOL diode -464 144 R0
WINDOW 3 24 72 Invisible 0
WINDOW 0 40 35 Left 0
SYMATTR Value 1N914
SYMATTR InstName D1
SYMBOL diode -464 240 R0
WINDOW 3 24 72 Invisible 0
WINDOW 0 38 32 Left 0
SYMATTR Value 1N914
SYMATTR InstName D2
SYMBOL diode -256 304 R180
WINDOW 0 33 31 Left 0
WINDOW 3 24 0 Invisible 0
SYMATTR InstName D3
SYMATTR Value 1N914
SYMBOL diode -256 208 R180
WINDOW 0 38 28 Left 0
WINDOW 3 24 0 Invisible 0
SYMATTR InstName D4
SYMATTR Value 1N914
SYMBOL Misc\\battery 176 320 R0
WINDOW 0 -41 87 Left 0
WINDOW 3 -44 114 Left 0
SYMATTR InstName V1
SYMATTR Value 12v
SYMATTR Value2 AC 0 0
SYMATTR SpiceLine Rser=1 Cpar=100u
SYMBOL res 208 208 R90
WINDOW 0 0 56 VBottom 0
WINDOW 3 32 56 VTop 0
SYMATTR InstName R4
SYMATTR Value 100k
SYMBOL Pote -432 80 R180
WINDOW 123 -63 122 Center 0
WINDOW 3 -39 95 Center 0
WINDOW 0 51 41 VRight 0
SYMATTR Value2 Set=Cursor
SYMATTR Value Rt=20k
SYMATTR InstName Duty
SYMBOL Pote -288 32 R0
WINDOW 0 -112 29 Left 0
WINDOW 3 -73 52 Center 0
WINDOW 123 -79 77 Center 0
SYMATTR InstName Freq
SYMATTR Value Rt=20k
SYMBOL 555_ALL -16 272 R0
WINDOW 38 -83 78 Left 0
SYMATTR InstName U1
TEXT -184 104 Left 0 !.tran 0 25m 5m startup
TEXT 232 88 Left 0 !.params: Vdd 12 Ronx=.1 \n.step param Cursor  0 1 .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