How to shield a live wire at 240V ?

[_q12x_]

I have a electronic board with leds (made by me) that is driving a relay. When that relay is closing it’s contacts, is actually switching the 240V for the light bulb switch in my room. This board is quite long, like 50cm (half a meter). The relay is in the left corner, and the live wires from it goes in behind the board to the hole in the wall for the mains switch. I also have a mild steel sheet behind my board that is grounded. It is shielding the interference of the 50Hz from the live wires from the wall to my sensitive circuit. But even If I have this grounded metal shield behind my board, the live wires from the relay are still affecting my entire circuit board, keeping it ON all the time. If I am disconecting the live wires from the relay, the board is functioning very well. Another IF, is if I disconnect the ground from the metal shield, the circuit board goes nuts. So the shield is doing it's job fine, but only for the live wires inside the wall !!! But not for the wires from the relay to the live switch.
- I want a way to shield these wires !
Thank you !

 

[marconi]

Perhaps it is a good time to take a break from the wings project, do something completely different and then return to it a little while later with a fresh mind?

 

[marconi]

I suspect - knowing you a little better after 271 posts (!) - you will carry on

Would you do one test for me in absolutely the way I describe? Make up a 6 Volt battery and use this to power your wings circuitry instead of the 5V power supply. Completely disconnect the 5V mains power supply (top left of your wings board) and unplug it from the socket. I would like to see how the modules behave when powered by a pure continuous direct current not derived from the mains supply. Four AA batteries should do the trick - four Cs or Ds even better.

 

[marconi]

Solving problems is what engineers like you and me and countless others do to have fun. I hope you like the latest motivating poster to go on the wall in your laboratory.

 

[_q12x_]

I suspect - knowing you a little better after 271 posts (!) - you will carry on

Would you do one test for me in absolutely the way I describe? Make up a 6 Volt battery and use this to power your wings circuitry instead of the 5V power supply. Completely disconnect the 5V mains power supply (top left of your wings board) and unplug it from the socket. I would like to see how the modules behave when powered by a pure continuous direct current not derived from the mains supply. Four AA batteries should do the trick - four Cs or Ds even better.

Thank you for your trust and for knowing me !
And indeed I will not give up. Thank you for your trust so far !
I was thinkin on power it up more than 5V myself as well, andI also remember you suggesting me to do it as well, some times before.
I can not do what you ask me, because I'm afraid of damage it. I did a ton of tests so far, on the breadboard, and right at this moment, is working excellent on 5V. It is drawing a very low current of 30mA to 60mA, the entire board ! I'm affraid of damage it or disturb it's normal functionality, irreversibly and I did work for it a ton of time just to experiment so drastically at this point in time. I've already made a test with my american friend, by connecting the pin9 to +5V and indeed all the leds are lit FullY ! , but... the current is way over my expectations, was around 150 to 200mA. So I revert it back to my usual way of functionality which is dimmer but quite visible and it is not blinding me when in use, that's one of my points keeping the leds at a dimmer intensity. Also probably a major modification in the design itself and component count and values- for example: adding a resistor for each led in the wing, who knows. If that will get me the best functionality of it, then I will do it, but this as a possible example, and not in plan to do it now, haha.
I also have that 5V power supply mounted on the wall, though is not a terrible reason for that alone, but it counts as one.
In the future ! (tada-tadaaaa) , I plan to probably make another wing. THis one here is a prototype how I though alone to make it with my own head, and I admit I have mistakes in it. But I plan to make it with an engineer or someone way better than me, who can seriously make it run at it's full potential/randament with full brightness, with brightness variation, with sensing variation perhaps, all the things I could not resolve right now but it is functional as it is so I can't operate it from this point.
I hope you understand my reasons, and not insist on it. Some things I can do, some I can not. Thank you for your support.

 

[marconi]

The final decision on the way ahead is down to you as the chief engineer of this project.

Here are there reasons why I know using a 6V battery will cause no harm to your modules:

1. As soon as current is drawn from the 6V battery it’s terminal voltage will drop because it has internal resistance;

2. For non of your modules or parts of your modules is the supply voltage of exactly 5V critical. An increase to just over 5V but not more than 6V will not damage anything.

3. There is most likely already more voltage variation already from the 5V mains powered dc supply. Is it a regulated or stabilised power supply maintaining 5V? To what tolerance? Is it providing 5V whatever the current? Have you monitored it?

I understand your caution.

The dc from a battery is pure direct current. The dc from the power supply has ripple, some ac mains superimposed and if it is a switched mode power supply then some harmonics of this conversion process. And on top of all these there is the electrical noise conducted between the mains and 5V because of imperfect insulation.

But do not be pressured by me. Do what you feel comfortable with since it is your project.

 

[_q12x_]

- Give me your best IR remote circuit that you can think of/know of, and that is working optimal at least 4meter distance.
It's the next thing I really want to try. My reason and my desire is to use multiple (probably 2)remotes with a IR led.
I suspected the RF boards will be problematic but now I know why ! That is called experience, even if it failed on me.
Can you help me on that?
Oh...and if it helps you in any way. my american friend had build (not like you) only the RF transmission + the 555 circuits for both Tx and Rx. For him it worked perfectly. But for me it did not. My point is that even if its working for you there, is not necessarily to work for me the same. Ive already experienced it and im telling you to know how things are. Another point I want to make with this example i mention, is that we must try it until it works, because if we try enough times, it will work. Im talking about the IR experiment we are about to make.
Im thinking to start making my own design but.... im really new to it, so Ill handle it to you first.
This circuit I found the other days. I want to believe it will behave the best and in my parameters I want it as I enunciate it at the start of this new post here.
If you have your own design, Im happy to see it. I kind of finding this circuit, that is a bit hard because of the double power supply I must insert, and I very much want to avoid that. And also at 5V, and not at 12V as this is offering.
But if no alternatives works, then this is the backup.

 

[marconi]

Do not be upset but I am taking a break from responding to any more posts. It sounds like you have a helpful and knowledgeable American engineer who can assist you.

Honestly, I cannot devote much more time to this interesting challenge. I have to turn my attention to another project to do with solar electricity for my brother-in-law.

When I have time I will/may return to my version of your challenging project.

I repeat we part for now but not for ever so to speak.

Good luck! Please do continue to post your progress because the thread you started now has a few thousand hits so many folk are reading it on the Electricians Forum.

?

 

[_q12x_]

Well, believe me or not (I get the feeling you don't, haha) , I do care about my project to make it as close as I imagine it in the first place. I agree, it is time consuming and hard, especially for me alone. Also slow. Well, not that alone, counting your 2 guys help. But still, I only have 2 hands and I have to keep focused on what is getting me closer to my final objective.
I agree with you. Breaks are good; and Im telling you a secret, breaks are also contributing to the good result as much as the hard work. I am personally take breaks, not so drastic, but more small and often, I kind of managing them. I also have a routine. That's why I'm slow. Also my inexperience in a lot of things, but that is another discussion.
I'll probably open another discussion on IR remote alone, since here is "too much" from what I get it... and I kind of agree, I kind of talked about everything on this way too long thread. We'll see.
I also thought remotes are easy. It looks they are not that easy. Very weird.
Thanks for the help so far. And have fun with that sport play on tv you said you are watching these days.
Cheers mate.

 

[marconi]

Good evening q12x. I am wondering how your project has progressed. I have been busy analysing a 20kW commercial solar electricity project. Have you thought about a career in renewable energy?

regards

marconi

 

[_q12x_]

"I am wondering how your project has progressed"
Oh, hello mister marconi !
I literally didn't check this website for awhile sorry for that, from 2 reasons, and I hope is understandable:
1-I was working slowly and nothing really to update with, and 2- I didn't made too much progress.
Me and my american friend- sorry to mention him but its how reality stands, yes, I get some help and im very grateful I have it to be brutally honest. And you are one of my friend since you got involved into this crazy project of mine.
So... the update so far, is that I am expecting some components to arrive from my friend from america, but in this time while I am waiting for them , I built with my friends help as well, a IR receiver and transmitter only on the breadboard so far. And we got splendid results, especially for the range from the IR to my palm in front of it and back to the receiver. Exactly as you did it, but with new circuit.
The real problem that remains is the interference from the window, that is directly in front of the wall, and in front of that panel and it's IR sensors. So..at any time, any wild IR light, from the sun or somewhere else, might switch this thing. And... hmmm... I am in a bit of depression.
The thing is, with these things, you always get the bad results from them, and if you're very smart or very lucky (or very persistent like I was and still am), you will get some good results as well.
Yes, it is hard as it gets. It's a challenge.
Have you thought about a career in renewable energy?
I wish to be able to work in such fantastic domains like electronics or electrics but I have no paper to certify the validity of my knowledge.... so it's a fantasy to even hope. I know my place very well and Im fine with it, for a long time. What are you thinking about? DO tell me, you made me curious.

 

[marconi]

Hello Mr Inventor. Good to hear from you again. The solar project has been decided on to go ahead but we need permission to connect it to the mains supply: this we have applied for. This means I have time to pick up where I left off with my version of your proximity switch.

l have an idea to control my ruler of lights based on whether the voltage from the sensor is increasing, decreasing or constant. This is to say that the actual voltage from the sensor is not important but rather whether it is going up, down or steady over two samples of it spaced out in time. It is being constructed at the moment. If you like a sensor of hand motion rather than hand proximity.

Are you in good form and making progress?

 

[_q12x_]

I'll probably have to draw the circuit - I didn't draw it yet and a movie to actually show you how things are standing at this point.
I will update soon.

 

[_q12x_]

 

[marconi]

Once again a nice clear video which shows your progress and current challenges. I liked that you have started to prototype circuits on the breadboard before moving them to the larger wings board. I'd like to see a ruler used to confirm your distances as I have done - we don't want any 'fisherman's tales'! ?

I will plough on with my project today and over the weekend.

Regards

Marconi

 

[marconi]

My breadboard so far.