1-in-4 sequencer freezes up--a noise problem?

[jasen]

2nd picture shows the combination of CD4013 and CD4001, which ends up
outputting 4 pulses in sequence to points A, B, C & D. These outputs
then go to BOTH four LED's on the board (shown as 3 yellows, and 1
green), AND four Crydom SSR's that control the four Christmas tree
lights: amber, amber, amber, Green.

Oh! _that_ sort of christmas tree!

Bye.
Jasen

 

[[email protected]]

Oh! _that_ sort of christmas tree!

Bye.
Jasen

Dear Ed, Thanks for the "hot tips"--I'll try the diode and 470 uF cap
when I get back to Fresno. Also, Jasen, sorry for the seasonal
confusion. Yes, I do mean THAT sort of Christmas tree. I think you
can now view my Christmas tree (and ALL the "trimmings") at:

http://new.photos.yahoo.com/[email protected]/

Bruce

 

[[email protected]]

Ok! That one is clear.
Add two components to it:
A diode between your + supply and 555 pin 8.
(Banded end connected to pin 8)
A 470 uF cap from pin 8 to ground.

That may fix it. Even if it does, keep working
on posting your circuits. When you can do that,
you can get help more easily.

Ed

Dear Ed,

I GOT IT! I tried your suggestions (diode and 470uF cap) and did not
find success, but when I put 470 uF caps across all three chips (CD4013
& CD4001, as well as the 555) I got some improvement. The new problem
that surfaced was that it would go to the bottom light (green) and
trigger the circuit, but then continue on back to the top amber light.
So the green light would consistently trigger the computer clock to
start timing, but if a racer blinked, they'd not see that the green
light had been ON--since the top amber light light is the one that
stayed on. I figured that the 470 cap on the 555 was holding so much
charge that it allowed the 555 to get one more clock pulse to be
delivered, even after the power to the 555 was shut off. That may not
be a correct analysis, but in any case, when I removed the 470 cap from
the 555 timer, it worked flawlessly (stopping with green light ON) 30
times in a row. I assume that means it works "consistently". Thanks
for inspiring me to fiddle with the circuit. Sorry about never getting
pictures of my circuits posted for people to see--I had two trojan
viruses that attacked last week, and some other frustrations in trying
to get my pictures posted on the net. I know that should be a simple
thing, but I never succeeded in doing it.

Thanks again for your help,
Bruce

 

[ehsjr]

Dear Ed,

I GOT IT! I tried your suggestions (diode and 470uF cap) and did not
find success, but when I put 470 uF caps across all three chips (CD4013
& CD4001, as well as the 555) I got some improvement. The new problem
that surfaced was that it would go to the bottom light (green) and
trigger the circuit, but then continue on back to the top amber light.
So the green light would consistently trigger the computer clock to
start timing, but if a racer blinked, they'd not see that the green
light had been ON--since the top amber light light is the one that
stayed on. I figured that the 470 cap on the 555 was holding so much
charge that it allowed the 555 to get one more clock pulse to be
delivered, even after the power to the 555 was shut off. That may not
be a correct analysis, but in any case, when I removed the 470 cap from
the 555 timer, it worked flawlessly (stopping with green light ON) 30
times in a row. I assume that means it works "consistently". Thanks
for inspiring me to fiddle with the circuit. Sorry about never getting
pictures of my circuits posted for people to see--I had two trojan
viruses that attacked last week, and some other frustrations in trying
to get my pictures posted on the net. I know that should be a simple
thing, but I never succeeded in doing it.

Thanks again for your help,
Bruce

Did you bypass the supply on all the chips with
..01 uf caps from + to ground, physically near each
chip? If not, do so.

Ed

 

[[email protected]]

Did you bypass the supply on all the chips with
.01 uf caps from + to ground, physically near each
chip? If not, do so.

Ed

Dear Ed,
Yes, I did do that, initially, but it didn't do the trick. In any
case, it tis working now : )
Bruce.

 

[[email protected]]

Dear Chris,

You are quite a good-hearted fellow to go to such troble for me! I
see you posted something a few days ago. I have successfully
demonstrated to myself that I can point readers to a photo of the
circuit on the `Net (see my post from today.) So I will be assembling
a series of photos that will show both the schematics as well as the
physical layout of the board (so people could note places where 120 VAC
inductive effecs might be a problem.) I'll try to get the photos up
soon.
Thanks for your patience,
Bruce

Thanks to all you who helped me along the way to my eventual success.
With everything else you know, perhaps you'd know someone who'd like my
extra copy of Rudolph Graf's Encyclopedia of Electronic Circuits,
Volume 6. I'm in Fresno, will ship anywhere in USA.
Bruce