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 !

 

[_q12x_]

Output signal from three level detector passes to leading edge detector whose output is the input to a JK flip flop Toggle switch which operates single red Led to the top left.

Next step is to connect Toggle switch to relay to control mains lamp......

Can you draw me a circuit with what you did until here? Or/and with what you plan to make?
I remember that you said you can't obtain lm3914 and you are using some IC's from your stock. THats why you used so many IC's in the picture? I counted 5 of them.

 

[_q12x_]

Can you draw me a circuit with what you did until here? Or/and with what you plan to make?
and I am not allowed to remove this post lool
This forum is incredible restrictive.

 

[marconi]

The Q output of the toggle switch turns the mosfet power transistor on and off to energise a 5V SPST relay located in the white oblong connector. The SPST contacts switch the mains 230V ac red bulkhead lamp on and off.

The next circuit is a hand proximity sensor which produces a dc output voltage signal in the range 0 - 5V as the hand nears the sensor. The signal will be fed in to the analogue to digital voltmeter circuit.

 

[_q12x_]

The Q output of the toggle switch turns the mosfet power transistor on and off to energise a 5V SPST relay located in the white oblong connector. The SPST contacts switch the mains 230V ac red bulkhead lamp on and off.

The next circuit is a hand proximity sensor which produces a dc output voltage signal in the range 0 - 5V as the hand nears the sensor. The signal will be fed in to the analogue to digital voltmeter circuit.

Can you draw me a circuit with what you did until here? Or/and with what you plan to make?
I remember that you said you can't obtain lm3914 and you are using some IC's from your stock. THats why you used so many IC's in the picture? I counted 5 of them

 

[marconi]

The hand proximity sensors I have in mind are first an active-passive infra-red one because this is relatively easy and reliable.

And then the rather more difficult in terms of performance and reliability a passive- passive sensor which uses the detection of the voltage induced in a human body when it’s in the region of a mains voltage alternating current wiring installation. Electric guitarists will know all about this as a problem during their time on the strings.

Passive vs. Active Sensing - https://www.nrcan.gc.ca/maps-tools-publications/satellite-imagery-air-photos/remote-sensing-tutorials/introduction/passive-vs-active-sensing/14639

 

[_q12x_]

ok... any more progress?
any circuit sketch perhaps?
Im curious what are all those 5 IC's you used.
A better idea is to make a movie !!!

 

[_q12x_]

Passive vs. Active Sensing - https://www.nrcan.gc.ca/maps-tools-publications/satellite-imagery-air-photos/remote-sensing-tutorials/introduction/passive-vs-active-sensing/14639

Nice read. I think radar system might be the best (for 2meter range) , but i dont know exactly its inner workings. All I know it is using RF (radio frequency) and from the same head is the transmitter and receiver connected to a processor to tell the distance,angle and speed of spacial objects. But I've not seen details about its construction. Probably its very complicated.

 

[marconi]

Datasheets for IR LED narrow beam emitter and photodiode(narrow look and unfiltered). I have also bought wider beam ones just in case. Aim is to operate the photodiode reverse biased so that responds linearly to the intensity of IR light falling on it. It will act as a current source with output current proportional to light level - the photo-conductive mode. One can use this current to cause a proportional current to flow through a fixed resistor thereby producing a voltage signal 0-5V........

Aside, one could also operate the photodiode forward biased when it would then operare in the photo-voltaic mode as in a solar panel but the relationship between current/voltage and incident light is not linear.

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

 

[_q12x_]

Thanks for the update ! I want to hear good news.

 

[marconi]

The narrow beam ir detector.

 

[marconi]

final clip in next post.

 

[marconi]

With mains connected to lamp.

next step to use the hand instead of white paper. white paper is a very good ir reflector but the hand in comparison is less reflective. Black paper does not reflect. Initial results with hand suggest I need to work further on the ir sensor active and passive parts. Tomorrow I will try wider look photodiode - 40 degrees. Current one is about 15 degrees.

 

[marconi]

ok... any more progress?
any circuit sketch perhaps?
Im curious what are all those 5 IC's you used.
A better idea is to make a movie !!!

First it is raining in London and has been everyday.
But prompted by the challenge you set yourself with this remote switch I have been most enjoyably occupied in my ’man shed’ experimenting with some circuit ideas along similar lines to you but with some ‘extras’ which I hope will improve performance and functionality.

I do a lot ‘in my head’ these days. The discipline of an engineer’s/scientist’s laboratory journal has lapsed now that only I would ever read it. Instead I have folders of sheets of A4 paper with sketches, doodles, sums, block diagrams and all the data sheets (indispensable if you really want to know all about an electronic component and how to assemble them together well).

I have in mind sending you my prototypes for you to reverse engineer; does that appeal? A challenge to discover the circuits I constructed and then how they work and work together. You can have it for nothing since it will only clutter and gather dust in my man shed. I have had the amusement from any small expenditure I had made and most of the components I already had ’sleeping’ in drawers. You could then develop your own ideas to improve further. One of the greatest gifts in this would be something far far safer than your current set up. I have yet to open up the little oblong connector box with the relay inside and provide details of the relay I used to ensure safety.

You can have most of the surplus components I ordered for just in case items were defective or I made them so. Top tip is to always buy 5 to 10 of each component.

Good night. We will speak again no doubt. ?

 

[_q12x_]

The narrow beam ir detector.

All your 3 videos so far, are showing on the forum page like this:
(-empty- usually there should be an image preview in that white box)

I can see from their name that they have the extension .MOV which is a quicktime file format.
Try to change the extension you are producing these videos. I can be of help in these situations.
Or, upload them into your google drive or any file upload website, like WeTransfer.com for example that I also use, and paste the link to them here in the forum or to me privately, whatever you feel like it. I can also help you with the upload part as well.
When I click on any movie clip, it opens another window, supposedly showing the movie, but it only show the audio format From it. I right click on that progress bar to show you it is only audio and is no video, whatsoever.
Here is what I see:

You must make another video and also speak in it a bit. Do you think I like MY voice in my movies? I have the worse voice but I care more about the content than how i sound.
And many thanks for taking time and continuing this with me here, even if I didn't see it, I could hear it for a bit.

I have in mind sending you my prototypes for you to reverse engineer; does that appeal? A challenge to discover the circuits I constructed and then how they work and work together. You can have it for nothing since it will only clutter and gather dust in my man shed.

Yes, I would like to see what you did. I am always fascinated by other people inventions, and as you said, I am sure I would learn something new from them. I might make something public in my artpages, if i like it enough and I get attracted by it as you did with mine. Who knows, I don't promise anything yet, but is on the table.
Since I couldn't see anything, I can't say anything about your circuit you built so far.

 

[marconi]