Version 4
SHEET 1 880 680
WIRE 272 -80 96 -80
WIRE 464 -80 272 -80
WIRE 464 -32 464 -80
WIRE 464 128 464 48
WIRE 528 128 464 128
WIRE 560 128 528 128
WIRE 96 144 96 -80
WIRE 464 192 464 128
WIRE 96 304 96 224
WIRE 464 304 464 256
WIRE 464 304 96 304
WIRE 96 336 96 304
FLAG 528 128 Uda
FLAG 272 -80 Upwm
FLAG 96 336 0
SYMBOL voltage 96 128 R0
WINDOW 3 -484 113 Left 0
WINDOW 123 0 0 Left 0
WINDOW 39 0 0 Left 0
SYMATTR Value PULSE(0 255 0 1p 1p {tper*128} {tper*256})
SYMATTR InstName V1
SYMBOL res 448 -48 R0
SYMATTR InstName R1
SYMATTR Value 12k
SYMBOL cap 448 192 R0
SYMATTR InstName C1
SYMATTR Value 1µ
TEXT -320 120 Left 0 !.param tper=1/3.6864meg
TEXT -328 168 Left 0 !.tran .15
TEXT 624 120 Left 0 !.ic v(Uda)=0