Problem in LCD 16x4 due to NOISE

[kripacharya]

post your result for each case i have given in #9..

sorry sir when i run it without tube then works fine and after connecting tube it works randomely

- - - Updated - - -

without connecting relay - works fine
connecting relay and conecting tube - go randomely
only relay - remain to test

Hello master's
i am doing project in which when i am running project standalone without connecting relay's that time works properly. but when i am connect relays to circuit with isolation of opto-coupler and enable and disable the relays then lcd is out of control.
i have interface 8 relays each having light tube of 230 VAC.
is it due to high frequency in chokes which is used for light tube or any other reason?
controller p89v51rd2
lcd 16x4
compiler keil

LoL !!! i think we need to close this thread now Venkadesh_M. I don't think there's any resolution gonna happen here.

cheers!

 

[sreepss]

Hai,

* Is this problem affecting your LCD's Only??? or it is effecing the whole controller section?

* What is the rating of the power source you are using in your design?

* Is the ULN's Freewheeling diodes are porperly connected to the Supply

 

[wp100]

Hi,

You could try switching just one relay/tube on at a time with a 15 second delay before the next tube.
Tried suppressors as mentioned earlier ?

8 relays coming on together with 8 chokes and 8 tubes creates a massive load on the supply and possibly your ULN2803/psu, depending on the current each relay takes ?

 

[kripacharya]

Hai,

* Is this problem affecting your LCD's Only??? or it is effecing the whole controller section?

* What is the rating of the power source you are using in your design?

* Is the ULN's Freewheeling diodes are porperly connected to the Supply

Hi,

You could try switching just one relay/tube on at a time with a 15 second delay before the next tube.
Tried suppressors as mentioned earlier ?

8 relays coming on together with 8 chokes and 8 tubes creates a massive load on the supply and possibly your ULN2803/psu, depending on the current each relay takes ?

Forget it guys, this is a dead end thread. Or rather, it's a looping thread. Goes round n round n round.... LoL !!

 

[wp100]

Forget it guys, this is a dead end thread. Or rather, it's a looping thread. Goes round n round n round.... LoL !!

Hi,

I have run several chokes and tubes via relays from a micro for years, so it is perfectly possible to do.

However we can only help based on the info he gives us, which so far has only been in general terms.

Given more details of the project / circuit / construction etc it might be a simple answer...

 

[kripacharya]

Hi,

I have run several chokes and tubes via relays from a micro for years, so it is perfectly possible to do.

However we can only help based on the info he gives us, which so far has only been in general terms.

Given more details of the project / circuit / construction etc it might be a simple answer...

exactly my point. It SHOULD be a simple bug/ answer, but the OP doesn't have the wherewithall to provide cogent informations for a meaningful analysis.
Hence a waste of effort on our part.

anyhow.. i'm out.
cheers!

 

[embpic]

sorry for the delay of replying and providing lack of information. i am apologize for that.
and actually i am solving problem of my frnd's project. i have collected circuit diagram from him.
and i am also damn involve in this project to solve prolem

 

[kripacharya]

I would seem from your description that the isolation which you expect is not really there. You should examine your physical circuit again to see where this coupling is taking place. Maybe some problem with earthing/ grounding which is sometimes easy to overlook. What about your power supply ? Is it common to both parts of your system ?

You could also post your circuit, pics, diagrams etc.

yes sir power supply is same to operate relay but is dual not isolated.
how i could give proper isolation?
.

So finally we have a circuit, but my original points still unanswered :

1) Why do you have this long chain of Opto AND relays ?
2) If you go and connect everything at the power supply, then your isolation is ruined anyhow. It doesn't matter how many opto's or relays or whatever you put in the signal path. And theres Still no definitive details on the power supply arrangement?!?

 

[embpic]

sorry sir not getting what you meant to say.
if i think i am getting what you want say, then
1) then i have connect each opto for each relay and i am opearting each relay separately.
2) i have connect 24 volts for this relay circuit and operating controller on 5volts.

 

[kripacharya]

....
2) i have connect 24 volts for this relay circuit and operating controller on 5volts.

That is good.
But are your ground/ earth points connected, or separate ?

Are the supplies floating ??

 

[embpic]

yes sir i have connect ground and earthing.
and tried both seprately and by connecting together also.
sir, i have connect RC network of 10 ohm resister and 0.1/K/1000 of C.
and added after suppressor also which is RDN 275/14.
but still not getting any positive result.


i have tried three of condition given in #9 by Venkadesh_M
and result are

only controller without relay circuit -works fine
controller with relay circuit without tube -works fine
controller with relay circuit and tubes -works Bad

 

[kripacharya]

There are only two solutions for your problem.
1) don't use tubelights
2) don't work on these projects with your 'friend'

 

[embpic]

i think this is not solution and there should be way which is you don't know and even i also don't know.

 

[kripacharya]

i think this is not solution and there should be way which is you don't know and even i also don't know.

Oh all of us here know how to fix it. It's the communication & information provided which are of insufficient quality.

Have you provided any details of your power supplies, and how they are interconnected ?
No.

Have you given us a pic of your actual physical setup ?
No.

Have you done proper decoupling everywhere ?
I doubt it.

...and so on