How to shield a live wire at 240V ?

[marconi]

Good morning. I have reached a point where the IR hand proximity sensor works smoothly, reliably and without any false switch ons or switch offs. I constructed an IR sensor as in the diagram in my #96; a centre photodiode with an IR LED torch to the left and to the right of it; this arrangement increases the illumination of a small patch of skin on the plam of the hand which the photodiode looks at and increases the intensity of IR light entering the photodiode from diffuse reflection off the skin. The LEDs are angled in slightly towards the photodiode. I will post a picture of it later today. It was not very bright yesterday so the ambient light level in my shed was low; with the shed lights on the first LED of the column of eight sometimes illuminated but this is far too low a Vs signal to turn the lamp on or off.

Now that I am happy with my circuitry I will draw out in later posts some diagrams, each diagram covering one or a number of sub-systems eg: power supply, ADVM, Three level/step detector.....

The electronic components to attempt your original sensor arrived yesterday. I will turn to trying to sense the proximity and closeness of the palm on a hand in a similar way you did - a more difficult way in practice to achieve the same level of smoothness, reliability and low false activation. since it is a passive- passive type sensor there is more variability in the signals the body picks up and the sensor then attempts to pick up.

Regards

Marconi

 

[marconi]

TRIO IR SENSOR:

npn transistor BC547B

850nm IR LEDs ( x 2) with 40 degrees field of view between half power points:

https://static.rapidonline.com/pdf/58-0114_v1.pdf

850nm IR photodiode (Unfiltered) with 15 degrees field of view between half power points:

https://static.rapidonline.com/pdf/58-0470.pdf

I actually used 2 x 22uF in parallel because I did not have a 47uF.

Vs is the signal output which you could feed into your LM3914 pin 5.

I will post a picture of the sensor in the next message.

 

[marconi]

MP4 video later today.

 

[marconi]

Stabilised 5V 2A power supply. ST78SO5CV is T220 type and a finned heat sink attached to it like this:

https://static.rapidonline.com/pdf/36-0250.pdf

 

[marconi]

https://www.ti.com/lit/ds/symlink/lm339.pdf?ts=1612308491496&ref_url=https%3A%2F%2Fwww.google.com%2F

I used two quad comparator chips LM339N. Nine 2.2kOhms resistors across 0 to 5V rails. First comparator connects at point A and the eighth at point B. The signal Vs to drive the eight LEDs is input to all the - inputs of the comparators.

The comparators sink the 8 yellow LEDs to turn them on so the voltage ladder ( the Vref points along the 2.2k potential divider) must feed into the + inputs of the comparators. Then when Vs > Vref the comparator output is 0V and when Vs< Vref the output is 5V.

 

[_q12x_]

Your LM339 is containing 4 comparators in it. But on your breadboard I see 5 IC's.
What's the catch?
Update on my progress: which is a regress. After I mounted that pot, I took it down and put back the sensing circuit module (SCM). And something broke. Relay1 is not commuting anymore. I will debug this problem with some friends on the other forum, who actually helped me to build another SAM (Signal Amplifier Module). So I think I should revert it to my original design that was before , much simpler but more dangerous because it already destroyed 2 transistors, but after considerable functionality, not right away.
We'll see. I couldnt make anything from your suggestions on the relay side, yet. If I resolve this "sh*t" I have now, then I will be able to concentrate on that.
I also got an osciloscope, a very cheap one, for 16$, that is fitting in my palm. But is doing its job, and is quite low on input voltage - up to 50V it can measure. So I have to keep it away from 220.
So my chances of diagnostication are much better now with it. THe problem is that I dont know how to diagnose anything with it yet. THats part of my help I will get from my friends from the other side. Hopefully.
I really have to discover the cause of who or what is burning my transistors in SAM. We'll see.
You are mentioning ADVM. WHat is it?
You can see my updated to day circuit here: Q20201219 Led Wings Projekt Circuit by q12a on DeviantArt - https://www.deviantart.com/q12a/art/Q20201219-Led-Wings-Projekt-Circuit-864540519

 

[marconi]

Your LM339 is containing 4 comparators in it. But on your breadboard I see 5 IC's. I only showed comparators 1-4 and 8; comparators 5-7 are wired in like these to points 5, 6 and 7 counting up the 2.2kOhms ladder.

Update on my progress: which is a regress. After I mounted that pot, I took it down and put back the sensing circuit module (SCM). And something broke. Relay1 is not commuting anymore. I will debug this problem with some friends on the other forum, who actually helped me to build another SAM (Signal Amplifier Module). So I think I should revert it to my original design that was before , much simpler but more dangerous because it already destroyed 2 transistors, but after considerable functionality, not right away. Sorry to hear this. It is always a risk because everything is so fragile. I used up two relays because their fragile pins broke off.

We'll see. I couldnt make anything from your suggestions on the relay side, yet. If I resolve this "sh*t" I have now, then I will be able to concentrate on that. Good plan. One step at a time.

I also got an osciloscope, a very cheap one, for 16$, that is fitting in my palm. But is doing its job, and is quite low on input voltage - up to 50V it can measure. So I have to keep it away from 220.
So my chances of diagnostication are much better now with it. THe problem is that I dont know how to diagnose anything with it yet. THats part of my help I will get from my friends from the other side. That will be interesting and in the long run very useful to you as an electronics engineer.
I really have to discover the cause of who or what is burning my transistors in SAM. I suggest you include a very careful look to see if any wires have shorted together, etcetera...We'll see.
You are mentioning ADVM. WHat is it? Analogue to Digital VoltMeter - what makes your and my arrays of lights light up as the hand becomes closer to the sensor.

 

[marconi]

IR hand proximity switch video.

 

[DPG]

A most excellent result Marconi. It looks to be working in a very linear fashion.

 

[marconi]

I have compared the circuit in your #41 with your latest #106. Maybe it is my eyesight but could you point out any changes you have made to develop your design please? They look the same to me.

 

[_q12x_]

I provided the link to see if anything is changed or not. The only thing I changed more often lately was that SAM. I also provided the link to see what my shortcuts means, like SAM or SCM. It's a fast reference point to go back and check, to avoid getting asked "what is that?". I hope it makes sense, and I should had made myself a bit more clear. I can't be 100% right all the time.
Interesting movie and circuit so far. Thanks for the explanations. But the range is not that good. I personally envision it a bit more different. With more range freedom. And my range is bigger than yours and still I dont like it, still I have to calibrate it to an optimal, user friendly range, if you know what i mean. Not to be careful not to touch it or to avoid the circuit. I want it to be stupid proof. Because when I come home drunk as a skunk, and wave my hand, I literally dont look. But feel. So... thats the point of all this project. A bit high but attainable.
Im not sure how much sense this image can provide to you, but is my guidance in all this project. Its the hearth of it. I hope you can get my point from there.

Actually, that 20cm that I originally plan, now I want it like 40-50cm. It would be nice to easily adjust the range. Only with your IR lights can be adjusted like I want. I have to change the antena size.
Aaah, imagine making money from electronics, just imagine. What a world it would be. It's a pity we, the jobless ones, can make stuff like this only at home. Eh well, life. What can any of us do about it? Excuse me for asking, but how old are you? It's very interesting that you like stuff like this. Very.

 

[DPG]

I provided the link to see if anything is changed or not. The only thing I changed more often lately was that SAM. I also provided the link to see what my shortcuts means, like SAM or SCM. It's a fast reference point to go back and check, to avoid getting asked "what is that?". I hope it makes sense, and I should had made myself a bit more clear. I can't be 100% right all the time.
Interesting movie and circuit so far. Thanks for the explanations. But the range is not that good. I personally envision it a bit more different. With more range freedom. And my range is bigger than yours and still I dont like it, still I have to calibrate it to an optimal, user friendly range, if you know what i mean. Not to be careful not to touch it or to avoid the circuit. I want it to be stupid proof. Because when I come home drunk as a skunk, and wave my hand, I literally dont look. But feel. So... thats the point of all this project. A bit high but attainable.
Im not sure how much sense this image can provide to you, but is my guidance in all this project. Its the hearth of it. I hope you can get my point from there.
View attachment 64389
Actually, that 20cm that I originally plan, now I want it like 40-50cm. It would be nice to easily adjust the range. Only with your IR lights can be adjusted like I want. I have to change the antena size.
Aaah, imagine making money from electronics, just imagine. What a world it would be. It's a pity we, the jobless ones, can make stuff like this only at home. Eh well, life. What can any of us do about it? Excuse me for asking, but how old are you? It's very interesting that you like stuff like this. Very.

We should have a poll on how old we think Marconi is. I reckon 52.

Am I close?

 

[Phil L]

We should have a poll on how old we think Marconi is. I reckon 52.

Am I close?

I’m going for 58

 

[freddo]

We should have a poll on how old we think Marconi is. I reckon 52.

I'm going to go the other way and say 38

 

[marconi]

I provided the link to see if anything is changed or not. The only thing I changed more often lately was that SAM. I also provided the link to see what my shortcuts means, like SAM or SCM. It's a fast reference point to go back and check, to avoid getting asked "what is that?". I hope it makes sense, and I should had made myself a bit more clear. I can't be 100% right all the time. Thank you - very helpful. 'None of us' can be 100% right all the time.
Interesting movie and circuit so far. Thanks for the explanations. But the range is not that good. I personally envision it a bit more different. With more range freedom. And my range is bigger than yours and still I dont like it, still I have to calibrate it to an optimal, user friendly range, if you know what i mean. Not to be careful not to touch it or to avoid the circuit. I want it to be stupid proof. Because when I come home drunk as a skunk, and wave my hand, I literally dont look. But feel. So... thats the point of all this project. A bit high but attainable.
Im not sure how much sense this image can provide to you, but is my guidance in all this project. Its the hearth of it. I hope you can get my point from there. I do get your point. The range of my trio IR sensor is about 0-15cm. The first detection range and peak return range will depend upon the colour, orientation, type (specular or diffuse)and amount of IR reflection and steadiness of the palm of hand; and the false activation on the ambient light noise and clutter. My detection zone is cone-shaped which has some advantages over your desired dome shape. You mentioned 'waving your hand'; for me that is a new requirement because I thought the only motion of the hand you wanted to sense was radial. To be 'stupid proof' or what I called 'reliable' is an interesting part of the project. You might want to right down some of things you do not want to trigger the light turning on or off; if a spider walks over the sensor? If you walk past the sensor within the dome range? If something large is moved in the room which may be sensed from a greater distance? Also what speed of reaction do you want - instantaneous or are you prepared to wait a few seconds(1-3), about a second, half a second?

Actually, that 20cm that I originally plan, now I want it like 40-50cm. It would be nice to easily adjust the range. Only with your IR lights can be adjusted like I want. I have to change the antena size. I look forward to learning how you achieve this requirement.

Aaah, imagine making money from electronics, just imagine. What a world it would be. It's a pity we, the jobless ones, can make stuff like this only at home. Eh well, life. What can any of us do about it? Excuse me for asking, but how old are you? It's very interesting that you like stuff like this. Very. Plenty of folk do make money from electronics and there is no reason from what I can gather of you why you could not also. I am 59, 60 in June. There are plenty of resources on the internet on electronics to suit every level of electronics engineer. There are even on-line recorded lectures you can attend - MIT have some which are free to watch.

I'd like to leave you with one of my favourite quotations which you might want to pin above your workbench:

No problem can withstand the assault of sustained thinking - philosiblog - https://philosiblog.com/2011/12/02/no-problem-can-withstand-the-assault-of-sustained-thinking/

 

[_q12x_]

I really thought you were much younger. You have a young spirit.
Good for you, mister @marconi .
Thanks for your answers. And push forward with your project. You said you got the 2n7000 transistors, right? Then build that sensing module and play with it for now. Then test it to the 220.

 

[marconi]

Attached are diagrams for the three remaining circuits and the integrated circuits I used because I had them already.

https://www.st.com/resource/en/datasheet/hcf40106.pdf

https://www.ti.com/lit/ds/symlink/cd4011b.pdf

https://www.ti.com/lit/ds/symlink/cd74hc73.pdf?ts=1612431648927&ref_url=https%3A%2F%2Fwww.google.co.uk%2F

 

[_q12x_]

More progress, short video of 7min:
(I am refering to some other guy from another forum in this video, following his instructions for a filter inside the sensing circuit). I did a filtering myself for the relay, but that affected very little unfortunately.

 

[marconi]

Good morning. Well done with your progress. May I ask some questions?

 

[_q12x_]

Please. And also good morning.
I also have your filtering I didnt try yet. But I will very soon.