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]

I said already, that I plan to make a separate amplifier for the buzzer and the 10 inputs to it.
My biggest problem is how to wire it. That's it. Doesn't matter then, I will find a solution myself.
This sound thing is a distraction for both at this moment. I only put it in perspective.
At this moment I am playing with the transmitter and receiver boards. Im figure them out.

View attachment 64975
This is what I have.
I am not sure what is that DATA voltage. Im supplying them at 5V both on my breadboard. I put a led and 10k on the receiver DATA and when I touch with my finger the DATA from transmitter, the led turn on. Thats cool so far. Now I need a minimum and a maximum DATA voltages that I cant find anywhere. Hmmm. I assume is 5V. What you think?

Further: I put a 1M,then 100k ,then 10k between +5V and DATA and the led is only lit when the contact is made but it is immediately turned off. That suggest I need a variation on the DATA pin. Hmmm. That sucks a bit. To be able to mentain that led On all the time.

q12x Sorry I have not properly answered or responded to your query but I will try to over the next few days. Ok?

 

[_q12x_]

to mister @marconi

 

[_q12x_]

q12x Sorry I have not properly answered or responded to your query but I will try to over the next few days. Ok?

Dont worry, now i am challenged in making the remote plastic or metal box and is very hard. I hope I can make it.

 

[marconi]

I need to hire a new cameraman.....

 

[_q12x_]

I need to hire a new cameraman.....

Yes now I could see it and thank you for re-uploading it.
Interesting results. Again, I was ON to it before you making the video. Very cool that the calibration worked out (if you indeed re-calibrated). But I think you did.

 

[marconi]

(Yes I did calibrate the comparators)

Attached is a marked up circuit diagram of how to connect the Tick Module to the LM3914.

You will need a circuit which will create a short pulse (0V to 5V to 0V) each time an LED output changes state from 5V to 0V ie when the LED illuminates but not when the LED turns off. And then another circuit to combine these pulses in a logical OR gate. The output of this gate is a short pulse as before each time any one of the 6 LEDs turns on.

The output of the OR gate 'tells' the Tick Module to sound a tick.

This will produce a tick for each LED illumination as the hand approaches the sensor but not as the hand is withdrawn and the LEDs extinguish. You could if you wish have a tick as the LEDs extinguish but I understand this is not what you want to happen.

Is this the level of advice you wanted? I am being careful to leave you the interest and challenge of designing the circuitry - but am ready to help if you wish.

 

[marconi]

Using the 433MHz RF Transmitter and Receiver with Arduino - Electronics-Lab.com - https://www.electronics-lab.com/project/using-433mhz-rf-transmitter-receiver-arduino/


The 433 MHz Tx/Rx is an Amplitude Shift Keyed data link designed to exchange data as 0s and 1s by 'no transmission' and 'transmission' respectively. There are two identical data outputs on the receiver.

Data is represented as 0s and 1s. Or Off = 0 and On = 1. You have demonstrated this already.

The Tx and Tx are meant for two state data signals.

I have found a project in which your Tx and Rx modules have been connected to two Arduino computers. This indicates to me (I have no experience of Arduinos) that the input and output logic levels of the Arduino are compatible with the input and output logic levels/states of the Tx and Rx modules.

If you read this next link you will see a figure showing the voltage ranges for logic states 0 and 1 depending on whether they are for inputs or outputs. The reason that they are not the same for input and output is to ensure 0s are output and interpreted as 0s and similarly 1s are output and interpreted as 1s in the presence of interfering noise and pickup. There is a 'no-man's land' between the voltage regions for 0 and 1 in which it is undecidable whether a 0 or 1 is meant. The width of this no-man's land is different for input and output signals to maximise reliable data communication. The Arduino logic levels are included as a figure.

Logic Levels - learn.sparkfun.com - https://learn.sparkfun.com/tutorials/logic-levels

I would not directly touch the data input to the transmitter because it may be damaged by static electricity. Use a button/switch or have a (sacrificial) buffer transistor circuit whose input has the electrostatic protection afforded by the two reversed biased diodes.

It is also good practice before handling semiconductors and circuit boards to touch something which is earthed to discharge any body/clothing static electricity. Even if static does not immediately damage the semiconductors it can weaken their fragile junctions.

PS: Note the 4mA quiescent current of the Tx module.
PS2: I reckon I am now up-to-date on responding to your earlier posts.

 

[_q12x_]

Yes, you are up-to-date on responding to my earlier posts. Haha.
I am after a more elegant wiring for those 10 pins. Your idea I didnt think on it so its a new way, and I put it in the box of ideas for now. I am imagining to make some holes and wire through the back of it. THats an idea. Another one is to add it on top, next to the scm. This way, all the wires will go straight up and not diagonally like in your case. But your idea is good enough, because now im thinking that up or down on the same side of the 2-10 pins of the IC (it's right side). Thats why I engage people in idea comunications, because sh*t surface more easily. Haha. You like my analogies,right. More ideas ,let's consume all variants first, as stupid they may look at the first look, i dont care. All i care is to be practical and hopefully, easy to assemble. I am also thinking on a wire, like those old PC HDD data cables wires, all in a single cable IDE ATA they were called. I still have some in my boxes.
example here:

Oh, and thank you for the in depth documentation for the remote. I already built a case for the bateries, wait to see my "3d printer" resolve. I have the same problem as before. On the breadboard, is working in a way, but when I assemble everything, is working in completely other way. Lucky me, is not that far away.
I will provide img or movie until tonight. I have already like 7h of constructing that little sh*t and im just taking a break to steam off, by writing here to you guys. Man, is very hard work, I tell you. Especially the cases. Terrible work. But they must be done, because I can and want and know how.
You, think on more ideas to connect those 10 pins outside the IC area, please. I couldn't imagine everything from the start. I imagine from the start until I am right at this moment, with it on the wall, and in perfect working state (which im very impressed, it didnt sh*t itself even after 1 week of routine usage.
Oh, and very good observation about electrostatic defence on the data pins of the transmitter ! I will add those diodes to it as well. Good idea !

 

[marconi]

1/12 Streets Ahead Dolls House 50ft Double Flex Lighting wire DE086 | eBay - https://www.ebay.co.uk/itm/1-12-Streets-Ahead-Dolls-House-50ft-Double-Flex-Lighting-wire-DE086/362653072264?_trkparms=aid%3D1110009%26algo%3DSPLICE.COMPLISTINGS%26ao%3D1%26asc%3D230925%26meid%3Db034dc6f9bb844d482acfca49ae2978f%26pid%3D101196%26rk%3D5%26rkt%3D12%26mehot%3Dpf%26sd%3D193877709939%26itm%3D362653072264%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DItemStripV101HighAdFee&_trksid=p2047675.c101196.m2219

I have used this very thin white twin flex to wire the doll’s houses my wife constructs. Might this be discreet enough to make connections ? It is less than 2mm wide and less than 1mm deep. If you search hard enough you will find there is even thinner wire available from doll’s house electrics suppliers almost like cotton thread. You need to be a vascular surgeon to use it!

Ultra thin insulated connecting wire | Component-Shop - https://www.componentshop.co.uk/cable/ultra-thin-connecting-wire.html

 

[_q12x_]

I have used this very thin white twin flex to wire the doll’s houses my wife constructs. Might this be discreet enough to make connections ? It is less than 2mm wide and less than 1mm deep. If you search hard enough you will find there is even thinner wire available from doll’s house electrics suppliers almost like cotton thread. You need to be a vascular surgeon to use it!

WOW you really did a great job. I have no idea about your type of wire. But I do have some very thin enamailed copper 0.12mm, 0.17mm, and 0.25 that you know it already that i use it extensively. If you have a micrometer or a caliper, measure it for me and give me it's exact diameter. It is interesting what you thought. Again, an idea for the box with ideas. Again, I know is strange how you find me thinking but im gathering ideas like these in my virtual box of ideas for years, and I have many wonderful boxes - it's all in my head ofcourse.

Thinking about your find....its not too much about the thickness. Thickness is important of course but to a point. Im more interested in the [strategical and smart] signal steal from those pins.

 

[_q12x_]

[Remote Control Transmitter and Batteries Built in one day]
Here is 1 day of very hard work and very good results.
I apologize for a very long movie 21min.
But you will see in it how it behaves on the breadboard and how is in my hand. Also some photos of how was built, and also my "3d printing" method I used. I hope I keep you interested in it to actually watch it.

Thank you for your help so far.

 

[marconi]

I will look later. Looks interesting. I cook a meal and then take it to my in-laws every Tuesday evening so cannot pay enough attention right now.

 

[marconi]

Switch - Wikipedia - https://en.wikipedia.org/wiki/Switch

A brief response on something which is probably at play with your remote control battery switch - contact chatter and contact bounce. A mechanical electrical contact especially at low currents rarely establishes contact - and sometimes even when it breaks contact - without a spate of on, off, on, off, on, off... This can be fixed.

I assume you know why the closest led gradually brightens and dims and why the furthest one is either on or off?

Those coin batteries will not have the same ability to deliver power/current and maintain their terminal voltage as your lab power supply. Internal resistance and emf fade/recovery. I have an unreliability problem with a similar technology we use at home to remotely unlock the front door wirelessly using remote control ‘zappers’ More later.
Got to go.

 

[_q12x_]

I think I can add a 555 IC multivibrator circuit to the DATA pin for transmitter. That will create a smooth data for what he needs to react and transmit. Or a simple flip-flop I think will do the trick.
I am suggesting a couple of possible motifs for the smooth operation of the transmiter on the breadboard inside the movie. 1-that i am the antena and it picks up some signal from me. 2- the close circuit everything on the breadboard is powered. 3- the breadboard itself, its construction with all its metalic armature inside, might influence the result. I was partially didnt expect it in hand, to work as on breadboard as I experience it before with the SCM itself.
But I highly desire the same function to have "in hand" as on the breadboard for that led from the receiver!
If I can manage that, it will be great.
It is great so far, that is working, even with bumps, I am extenuated, more psichologically than phisically. And happy in the same time. Its a weird feeling.
Immediate next step I will make, is to integrate that receiver module on the board and see all the thing in action, and I really hope, without any interference of any kind or color.
We will see, soon enough.

 

[marconi]

Well done with producing not only the Tx design but also the interesting video. I admire your dexterity and imagination to use simple materials in both a fine and robust way eg: the matchstick and cardboard enclosure.

Three recommendations on what to test and confirm for the Tx:

1. pressing the button produces a reliable on action to connect 6V to the Tx chip.

2. Touching the data contact wire reliably produces a pulse of radio frequency.

3. When you stop touching the data contact wire the transmission ends Cleanly.

4. Measure the battery terminal voltage when not transmitting and when transmitting and then immediately at the end of a transmission. How does the battery behave? Does it need a little while to recover? The radio transmitters we use need a short time to recover after each transmission which gets longer as the batteries become more and more exhausted.

5. Must you leave the end of Tx uncovered by you hand and does the orientation of the Tx matter eg up and down or level with the floor. Our remotes work best level because the 5 cm wire Rx aerial happens to be horizontal. (polarisation of radio waves)

Do some thinking before constructing a pulse generator circuit on what remote control functionality you want beyond remotely controlled on and off.

got to take my wife to an appointment now.

Basics of Wave Polarization Explained - https://www.rfvenue.com/blog/2014/12/15/wave-polarization-explained