Previous in Forum: Motor Nameplate Missing: How to Determine Motor kW and rpm by Physical Inspection Only   Next in Forum: Portable Home Charger Earthing - EV
Close
Close
Close
67 comments
Associate

Join Date: Jan 2021
Posts: 38

LED Wings Project

01/05/2021 11:17 PM

Hello, I am new here, I followed google and he point me to this forum for a problem I have. I am discussing this problem in another forum already, so im referring to the guys there in my video explanations.

I built this composite circuit that have a sensing circuit in it which is disturbed by the mains 50Hz in the wall, over the normal switch light location. Here is the circuit diagram: https://www.deviantart.com/q12a/art/Q20201219-SCAN-Image-864540519

Here is the latest video I made, explaining and showing the problem. Its a short 5minute movie. https://www.youtube.com/watch?v=feGfhEhiCsI

When I test it on my table (which is made from mild steel and also grounded) the entire circuit behaves ok. But here on the wall, it's disturbed. I already tried shielding with a piece of metal sheet grounded. It helped but like 5%, which is not good enough.

Thank you and I hope you can give me a solution to my problem.

Login to Reply
Pathfinder Tags: 50Hz mains 220Vac led wings
Interested in this discussion?
You can "subscribe" to this discussion to be notified of new comments.
Click on the Subscribe menu at the top of the page.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#1

Re: LED Wings Project

01/06/2021 9:52 AM

It's all very vague and confusing....let's begin at the beginning....what you are building here is a motion activated light switch( my best guess)...Is that so? And the problem is it doesn't work...? but it looks like it is to control many things, very large and complicated looking....So clarify, what is this device meant to do?

https://nerdtechy.com/best-motion-sensor-light-switch-outlets

__________________
Break a sweat everyday doing something you enjoy
Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#8
In reply to #1

Re: LED Wings Project

01/06/2021 9:36 PM

I made a single answer to all the issues so far.

Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#10
In reply to #1

Re: LED Wings Project

01/06/2021 9:52 PM

I am not permitted to delete my post.

I am not permitted to edit my post.

I wanted to delete this answer here because I made a single answer to all the issues so far.

Login to Reply
Guru

Join Date: Aug 2005
Location: Hemel Hempstead, UK
Posts: 5030
Good Answers: 272
#2

Re: LED Wings Project

01/06/2021 11:32 AM

Is the ~50cm an aerial?

I don't see any decoupling caps on the power supply, like the 2.2µF shown here

Of course they should be scattered all over the circuit.

__________________
We are alone in the universe, or, we are not. Either way it's incredible... Adapted from R. Buckminster Fuller/Arthur C. Clarke
Login to Reply Score 1 for Good Answer
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 8725
Good Answers: 994
#6
In reply to #2

Re: LED Wings Project

01/06/2021 4:20 PM

I don't know what the circuit is supposed to do, but I can imagine a 50 cm piece of wire connected to the insulated gate of the FET can pick up enough noise to turn it on.

Login to Reply Score 1 for Good Answer
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 29931
Good Answers: 808
#33
In reply to #6

Re: LED Wings Project

01/08/2021 4:58 AM

The circuit becomes an electromagnetic field detector.

One should not be surprised if it picks up "mains hum", then...

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#34
In reply to #33

Re: LED Wings Project

01/08/2021 5:32 AM

thats why im using a metal sheet shield grounded to prevent mains interference.

Login to Reply
2
Guru

Join Date: Apr 2010
Location: About 4000 miles from the center of the earth (+/-100 mi)
Posts: 8725
Good Answers: 994
#42
In reply to #34

Re: LED Wings Project

01/09/2021 1:53 PM

thats why im using a metal sheet shield grounded to prevent mains interference

Just a thought...would this sheet metal be ferrous (iron, steel, mu-metal etc)? Current flowing through a wire creates a magnetic field encircling the wire which is not blocked by a non-ferrous shield such as copper or aluminum.

Turn off everything you can that is drawing current and see if it makes a difference.

Login to Reply Good Answer (Score 2)
Associate

Join Date: Jan 2021
Posts: 38
#44
In reply to #42

Re: LED Wings Project

01/09/2021 10:59 PM

Thank you mister Rixter for continuing the discussion.

Your thought may be a salvation thought ! You are very right, copper is way more better conductor than mild steel that im using right now in my shield.

"would this sheet metal be ferrous (iron, steel, mu-metal etc)?"

-Yes the shield im using is mild steel.

"Current flowing through a wire creates a magnetic field encircling the wire which is not blocked by a non-ferrous shield such as copper or aluminum."
- Now that im reading it more carefully, is NOT blocked by copper or aluminium? I was planning to use a copper board instead of this mild steel one. I dont have such big one but i have something large enough.

Login to Reply
2
Guru
Engineering Fields - Electrical Engineering - Been there, done that. Engineering Fields - Control Engineering - New Member

Join Date: Dec 2008
Location: Long Island NY
Posts: 14850
Good Answers: 913
#19
In reply to #2

Re: LED Wings Project

01/07/2021 10:06 AM

I'm late to this game. I'll start my analysis post here since Randall identified what is probably the root of the problem, this sensing circuit and detector. This is not a reliable approach for detecting motion of a person for it will also detect a myriad of other signals.

A MOSFET is a very non-linear device (ideal for ON/OFF digital signals) where transitions start when Vgs exceeds the gate threshold voltage. For this part that threshold is anywhere from 1 to 2.5 V. Since only parasitic loads establish the input impedance of this circuit along with the circuit topology alignment of parasitic sources driving this impedance, Vgs will not be established to any knowable value. The LED driver (LM3914) responds to an analog level to turn ON varying LED.

I am not the least bit surprised that this circuit responds differently depending on where it is placed in respect to many things in its environment. In one location it will work exactly as desired but move it to another location and the LED will be always ON or OFF without any response to a person's movement. A person moving an extension cord in another room or humidity level changes might even change the response levels of this circuit. Depending on the installation, this "spooky" uncertainty in response may be desired.

For a more reliable circuit design to proximity motion making an analog level, I recommend examining a Theremin circuit approach. I realize this is a much more complicated circuit using many more technologies but with the exception of the RF oscillator you won't need to produce any audio oscillators.

__________________
"Don't disturb my circles." translation of Archimedes last words
Login to Reply Good Answer (Score 2)
Associate

Join Date: Jan 2021
Posts: 38
#20
In reply to #19

Re: LED Wings Project

01/07/2021 10:22 AM

Im happy that you come in and give an awesome answer.

I never thought on the theremin circuit. What a great idea !!!

I will definitely check that out.

Thank you !
In the meanwhile, I resolved the problem I had.

Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#22
In reply to #19

Re: LED Wings Project

01/07/2021 10:33 AM

Mister redfred ,please check my latest update in the end of the page #21 . Its a bit longer movie. But you are right, it does change its properties in room location. I did not thought it would. Now I learned a lesson.

Login to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#3

Re: LED Wings Project

01/06/2021 2:23 PM

Looks better when it's working....

https://www.youtube.com/channel/UC_ROxTeqmkHpe0j_mmmelCw

ok you need a test meter to begin with so you can troubleshoot the circuits....

__________________
Break a sweat everyday doing something you enjoy
Login to Reply Score 1 for Good Answer
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#4
In reply to #3

Re: LED Wings Project

01/06/2021 2:51 PM

https://comspacex.wordpress.com/2017/12/31/electric-field-detector/

https://www.eddybergman.com/2019/05/electro-magnetic-field-detector.html

I suspect one of your components has failed...so you need to test them...make sure the components you're using can handle the current involved...

__________________
Break a sweat everyday doing something you enjoy
Login to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#5
In reply to #4

Re: LED Wings Project

01/06/2021 3:29 PM

....or it's possible the sensitivity is set too high....which might also be a component failure...

__________________
Break a sweat everyday doing something you enjoy
Login to Reply Score 1 for Good Answer
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#7
In reply to #5

Re: LED Wings Project

01/06/2021 4:39 PM

It might be the 220v circuit is creating an EM field that is overloading, or saturating the antenna and overloading the sensitivity of the circuit....If you disconnect the 220v will it work? ...Is it supposed to work that if the hand gets close enough to light all of the LED's then the light switch is activated?

__________________
Break a sweat everyday doing something you enjoy
Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#9

Re: LED Wings Project

01/06/2021 9:37 PM

To mister SolarEagle; Thank you for your extensive answer so far ! I was sleeping and I could not respond very quickly to you.

"what you are building here is a motion activated light switch( my best guess)...Is that so?"

- Yes it is. It has a motion sensing circuit module.

"And the problem is it doesn't work...?"

- Yes, it does not function properly, meaning it stays activated , stay ON, all the time. The sensing circuit get interfered with the mains 220Vac 50Hz from the wall, behind the circuit. On the testing table is working as it should, but not on the final and intentional mounting location.

"but it looks like it is to control many things, very large and complicated looking....So clarify, what is this device meant to do?"

-Well, it is looking complicated, I agree, but when we are splitting it into modules, every module doing its thing, then it will look very logical and simple to understand. So, the modules are:

sensing circuit
led wings circuit
signal amplifier module
power module
latching circuit
and relay wiring stage.

All these circuits are basic circuits for each central component they serve. For example, led wings circuit is LM3914 basic circuit but I only added all those leds in a bit more strange configuration, but if you shave all those leds and leave only 10 for each pin, it will look more simple to understand. It is the circuit from its datasheet, nothing more. And the same goes for each other module there. Basically, if you concentrate on modules themselves, it will be very easy to understand.

But I get from all your answers that you already understand this thing already. Correct? If you need any further clarification, I will explain in the greatest detail to you.

"ok you need a test meter to begin with so you can troubleshoot the circuits...."

Yah, I dont have too much test equipment, that is true and they are costing money that I can not produce. SO, we have to figure this out a bit empirical. Sorry for that but it is what it is.

"I suspect one of your components has failed...so you need to test them...make sure the components you're using can handle the current involved...

....or it's possible the sensitivity is set too high....which might also be a component failure...

It might be the 220v circuit is creating an EM field that is overloading, or saturating the antenna and overloading the sensitivity of the circuit....If you disconnect the 220v will it work? ...Is it supposed to work that if the hand gets close enough to light all of the LED's then the light switch is activated?

"

Nothing is failed, nothing is too high.

The circuit is fine and I had the exact same problem like you have right now, when I was building the circuit. My working table is made from mild steel, and the same effect you see happening right now, it was happening back then. Some very good people helped me deal with this issue on another forum and the problem was that the table was ungrounded. I did not had any ground wire in any extension cord (6) in my room, so I had to link the ground wire to any of them until I reach my table that I link it also to ground at the end. The circuit worked flawlessly after that.

- Thank you for digging it deeper !!!! and find out the working circuit. I was planning posting it too for more clarification.

To mister Randall
"Is the ~50cm an aerial?"

and Rixter

" I can imagine a 50 cm piece of wire connected to the insulated gate of the FET can pick up enough noise to turn it on "

- Yes its an antenna (0.25mm diam copper) and is suppose to be in air, but I link it to the board itself, now is "on board". Here is a shot of it and I marked with red its length and its shape:

Now, back to my problem:

What I need to shield this circuit from the mains 220Vac 50Hz from the wall, behind the circuit ? This is the stage I am right now in all this building process.
- Thank you all for all your kind answers so far !

Login to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#11
In reply to #9

Re: LED Wings Project

01/06/2021 10:25 PM

You could try a grounded aluminum plate behind the circuit board, or possibly shortening the antenna...The grounded plate would have to cover the antenna area with possibly a 2" margin all around...It's also possible the antenna is getting feedback from the LED circuit itself...I would experiment with moving the antenna around...

__________________
Break a sweat everyday doing something you enjoy
Login to Reply Score 1 for Good Answer
Associate

Join Date: Jan 2021
Posts: 38
#12

Re: LED Wings Project

01/07/2021 12:08 AM

Why I am getting this error if Im trying to edit my post?

People need to edit stuff ! Especially me that i am not that good with english. Not native, I am doing mistakes that are misleading the idea I want to express.
I get this retarded error if im trying to edit a previous post:

This is not cool !

Login to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#16
In reply to #12

Re: LED Wings Project

01/07/2021 7:24 AM

You only get 15 min to edit your posts...then you're locked in...

__________________
Break a sweat everyday doing something you enjoy
Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#13

Re: LED Wings Project

01/07/2021 12:30 AM

Why does my post gets removed?

Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#14

Re: LED Wings Project

01/07/2021 12:35 AM

I managed to bo back and find the comments I wrote and bring them back here. I hope they will not get deleted this time as well. If so, then is clear.

Excellent drawing SolarEagle ! I'm not kidding, I like that you put interest in it! You are super.
"It's also possible the antenna is getting feedback from the LED circuit itself"
I did all the testings so far possible and push it bit by bit. I started this project some months ago, I worked very slowly at it, since there were some technical problems to resolve and I did what I could do best with the tools I have at my disposal. So, even I did not think on the interference with the leds (too much), I overcome it in testing phase already. Trust me, its not the circuit fault at this point, but its an interference with the wall main live wires. I am very sure of it.
I do like your tester for live wire, that you post earlier. I should definitely build one to more precisely track the wires through cement.
My final plan is to break the wall, expose the live wires and shield them with a metal foil grounded. But that is final solution, that I am not super sure it will totally work, I'll have to test that as well, separately; and i am not that happy to work on that wall at all. It's an extreme idea if nothing else works. Until this extreme stage, I want to give all my best on other modalities of shielding the wall.
I will try it with a larger metal sheet as you both (you and another friend) propose.
Ok, said and done, I did put a new shield, also grounded, behind the board.
With a space between circuit and shield, see the leds are dimmer. (working a bit better now)
Scotched to the shield, the leds are brighter (not working that well)

In a couple of minutes I will put you a video link as well.

Login to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#17
In reply to #14

Re: LED Wings Project

01/07/2021 7:59 AM

Aha! progress!....yes let's see a video...shielding would probably work better with high humidity environment...what is your current relative humidity? Although it might not work as well because the person might become grounded reducing the EM field....sort of a catch-22 situation, but that is just speculation....static electricity thrives in a low humidity environment....more experimentation is called for...

__________________
Break a sweat everyday doing something you enjoy
Login to Reply
Guru
United Kingdom - Member - Indeterminate Engineering Fields - Control Engineering - New Member

Join Date: Jan 2007
Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on.
Posts: 29931
Good Answers: 808
#15

Re: LED Wings Project

01/07/2021 2:25 AM

Proprietary devices, fully tested and locally regulation-compliant, are available from most home DIY stores. It seems a bit pointless to duplicate the design effort when one can readily purchase something that works - unless the exercise is a teaching aid, in which case one might dismantle a proprietary item and study it, perhaps.

__________________
"Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#18

Re: LED Wings Project

01/07/2021 9:16 AM

I am kept outside of this forum for some reason.All my other posts are simply deleted! I can not post when I want on it. I can not edit when I want on it.

So expect less activity from me in this case. It is fine with me.

Here is the proof after I write all the comments and after I click to post, I get this message. That was some hours ago.

It seems someone does not like my posts. Again, it is fine for me, but really, what an attitude! (from this website staff is my best guess).

I did managed to find a solution to the problem I had, Now is working ok on the wall, but still with some trouble from other side of the circuit this time. I am almost done with it.
Thank you anyway, especially to mister SolarEagle here !

Login to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#23
In reply to #18

Re: LED Wings Project

01/07/2021 11:12 AM

The message you are receiving is a software glitch that shows up now and then for everybody....it is not intentional.....if you have violated any rules the administration would have warned you, they do not delete posts unless they are spam, or are offensive...sorry for the inconvenience, but this is the world we live in....

__________________
Break a sweat everyday doing something you enjoy
Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#25
In reply to #23

Re: LED Wings Project

01/07/2021 11:33 AM

Thank you for your answer. I write a long text and put some quite high resolution images inside it. The page was struggling loading those images. It was my clue that the website may not support higher rez. Then It got deleted. It was all on the subject, nothing outside of it.

Then I thought maybe the website is not admitting too much high rez on images, so I made another answer with only the 3 images in it, but at lower rezolution this time. Very manageable, around 300kb per image. Absolutly no text in it, only the images.Then It got deleted. It had no reason to delete it this time.

How I can tell someone delete it and it was not automatic? Because an automatic thing would made it much more faster than my refresh button and after checking it after 10 minutes. It was mean and dark intention behind it.

After I figure out I can "Back" the page to reach the long text, I made another answer and paste the long text in it.

Immediately after, I got that shitty message, while trying to add a reply to someone that just write here. Not mean and dark at all. Very bad attitude ! Shame on you (who did this). Very bad first impression.

Though Im not here to criticize the experience on this website, I got knocked on my ass by it for no reason. And I take it very personally as well. Especially not being able to post or edit when I wish. It's just childish mentality. Very bad website management and implementation. Im sorry to say it, but is true. I really don't like it. If nobody is saying it, nobody will think is a problem. Especially for someone new like me.

Login to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#29
In reply to #25

Re: LED Wings Project

01/07/2021 1:57 PM

Wow you are assuming a lot...nobody is attacking you or deleting your posts or keeping you from posting, you have not broken any rules....make sure your images are in an acceptable format, either jpg or bmp...the size and resolution is adjusted to what fits on the page, you can post any size...Not a good idea to come on here and start accusing people of something and criticizing the site, you are raging against a phantom in your mind that doesn't exist...It takes some time to learn how the format here works...

__________________
Break a sweat everyday doing something you enjoy
Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#31
In reply to #29

Re: LED Wings Project

01/08/2021 12:07 AM

What I had to say, I said it, and is part of my experience and how I perceive it. Believe it or not, is up to you. I got very upset, that's all, and I had to tell about it. Now I am fine since nothing happened since then and I hope nothing will in the future. What you must understand is that i am for the first time here and there are some rules or order of things that are a bit... not normal for me, but is also part of me adapting to them, I admit. Don't take me as I am presuming too much, im only saying out loud exactly what I am thinking, unfortunately upsetting for some people, I admit. :) heh Let's put this conversation behind us, since really is not my intention to criticize or to take on something most probably I am not that familiar enough with yet.

Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#21

Re: LED Wings Project

01/07/2021 10:26 AM

Update: I resolved the original problem but I got into another one.

Watch the movie and say what you think. (The movie is a bit longer)

https://www.youtube.com/watch?v=u5M07m9B63U

Thank you for watching and for your help.

Login to Reply
Guru

Join Date: Mar 2007
Location: at the beach in Florida
Posts: 29823
Good Answers: 1665
#24
In reply to #21

Re: LED Wings Project

01/07/2021 11:33 AM

The antenna cannot be in contact with the cardboard....

__________________
Break a sweat everyday doing something you enjoy
Login to Reply
Associate

Join Date: Jan 2021
Posts: 38
#26
In reply to #24

Re: LED Wings Project

01/07/2021 11:43 AM

"

The antenna cannot be in contact with the cardboard....

"

Why? Because the cardboard presents some weird conductivity? Or because is too close to the metal shield behind the cardboard, maybe?
At this time it is how it is, but I am thinking to make it on a electronic (plexiglass) board... in perspective. For awhile I will keep it like this.
Mister redfred is right, this is waaaaay to sensitive and out of control. And his suggestion with theremin circuit is VERY appealing to me, and I might try it. But that will be an upgrade. I must finish this one as bad as it is right now. It will work !
See if you can think on another [signal amplifier module] that is giving me trouble right now.