How to shield a live wire at 240V ?

[_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]

 

[_q12x_]

Yes, now is good, I could see the video. It's an .mp4 format, that is what web loves these days.
What are those 2 ? It appear like a photodiode and a IR led ?

I like how is switching.
But please, make me a circuit diagram of what you did here. Exactly. You used some logic there that is very interesting. Draw it on paper, and make it nice and make a good resolution photo of it.
I still wait for my IR leds to come from coronavirus... aaaa, China.
My problem is still my wall interference that im fighting with. In your case and many others, if you dont have strong daylight (like I have) on your wall, you can use your IR leds as you have now. In the end I will try it as well, but first to get them in mail.
You still wait for your 2n7002 transistors? You said you took some. If i remember right.
You said you will duplicate my experiment on the wall near the mains. This is way out of my league.
What i did so far, is not much. I made a simple AC detector, that doesnt work on my wall, but only on my table. I think it's sensing my grounded table. If I lift it in air, its led is lit for a considerable distance from table, from about 20 cm and forward.
Is working somehow, but not really sensing what I need.

Here is in the air(led is on):______________Here is near the table (and led is off):

________________

 

[marconi]

The two silver components you took a picture of are the IR LED and IR photodiode I provided the datasheets for. I am passing about 20mA through the IR LED - the limit is 100mA but I am avoiding operating near the limits to begin with. The forward bias voltage of the IR LED is about 1.5V so a simple estimate of its IR power output is 1.5 x 0.02 = 0.03Watts within its cone of shine (red fan in my attached diagram). The IR LED is my torch to illuminate the hand or whatever else appears in front of the second diode, the IR photodiode. This diode has a 10 to 15 degrees cone 'look' (dark grey fan) which is why the two components - IR LED and IR photodiode are angled towards each other - see my diagram. Today I am going to make another identical IR sensor but using a 40 degrees look photodiode - this will have a larger 'aperture' and thus I hope capture more of the reflected IR beam off the hand but at the risk of other reflected IR energy from nearby objects - so called 'clutter'.

Yes I have some 2N2007 transistors. I plan to work on the type of sensing circuit you have used at first and drawn a circuit diagram. To avoid unwanted pick of mains voltage in anything but the antenna I am going to use some micro-coax to screen the signal between the antenna and the circuitry - but it has yet to arrive - maybe next week sometime.

https://static.rapidonline.com/pdf/51-6094.pdf

This is the 5V SPST 230V ac 5A OMRON relay I selected because it is a good make and the insulation resistance (1000MOhms at 500V ac) and dielectric strength (3000V ac for 1 minute) between the 5V side and the mains side are very high. I will post a picture of how I located it within the oblong white connector block.

https://static.rapidonline.com/pdf/60-2476.pdf

One of the challenges I have set myself it to only use one breadboard. As you can see there is not much room left for the sensing circuit. I have made a wooden post (top right) with an in-line socket glued to it. I can plug in my prototype IR and body voltage sensors to this socket. I will post a close-up of what it looks like later on today. At the moment only 3 of the sockets 10 pins have been used - 0V, 5V and Vs the voltage signal output from the sensor.

 

[marconi]

I was able to use the plastic shields inside the oblong connector to provide some more insulation between the 5V and 230V circuitry.

The IR sensor is reverse biased photodiode connected between the collector and base of a common collector connected npn small signal transistor. The emitter is connected to 0V via a 1kOhm resistor. The Vs sensor signal is developed across this resistor. The IR led is connected across 5V supply via a 220 Ohm resistor.

 

[_q12x_]

Thank you for your explanations ! I understand better now, that the 2 components have diferent cones angles as the red and black as you draw them. Very good. i didnt know that information. It's interesting to have an idea about them. Thank you. I am new to IR in general, so every bit of information is gold to me.
But you still didnt made me your circuit diagram, I still find it intriguing. It works very nice so far, very close to what I did. It will also help you clarify your thoughts, even if you think you know how it works. I know it does to me.
Yes, use coaxial cable. Do anything you can do to diminish the 50Hz interference ! That is this project goal. If we can do it, then it is a successful and finished projekt. If not... then I have to rethink it's usefulness, and keep it away from 50Hs mains. Use every coaxial you can find, every idea you may have, just hammer it until something give signs of properly shielding that thing. And ask your friends as well, my friends suddenly they dont know electronics anymore after my inquiries and they are very busy. Hahaha.
And as always, thank you for your help so far.

 

[marconi]

I will draw my circuits once I am happy with them.

The problem with a circuit like the one in #76 is that it not at all selective in which signal it picks up and amplifies to produce a current to light the led and in my case to produce the sensor output voltage Vs. The antenna and transistor is acting like a radio without any tuning. What I will attempt to do first of all is to restrict the reception of the circuit to 50Hz. So, if one takes the small signal from the antenna and passes it through a low pass filter with a cut off frequency of say 100Hz all those interfering signal beyond 100Hz will be tuned out.

One also has to design the circuit and its construction so that only the antenna is picking up 50Hz signals. As a bare circuit with everything exposed it is unavoidable that all the parts of the circuit will pick up 50Hz. Somehow we have to prevent that.

Anyway, work in progress and interesting too. ?