How to shield a live wire at 240V ?

[_q12x_]

I'm sorry, I kind of understanding what you are saying. But not completely.
I like that the photo is very clear and the movie is ok as well. I really love your osciloscope. Very nice model. I really like it.
So... I understand there is a waveform there, that shape on the osciloscope, and with a spike at the end of it, and that you tell me is some RC waveform. But I dont get the point. I think the point is that rapid fluctuation, will not get interfered by the day light? Or what? I also don't have a propper circuit skematic, so I cant follow what you did there very precisely.
I like that you are trying it but you must be more clear/direct with me. I'm not an electronist, remember? Im an artist and i see things visually and very well pointed. Im Not very abstract thinker.

 

[marconi]

I will do a better job at explanation tomorrow.

 

[_q12x_]

Thank you for your understanding !
In paralel , i have a little question:
I have a custom circuit and I want it printed on a pcb.
Which website can you recommend to me, the cheapest ?
Or alternatives are also desirable !!!

Q20210423 SMD Transistor Pads by q12a on DeviantArt

www.deviantart.com

This is the "TPad" board I want to have it multiplied and it also fits on a A4 size with 1500 Tpads.

 

[marconi]

UK PCB Manufacturer,Low cost UK Printed circuit board Manufacturing,Online quote PCB manufacturing,low cost PCB,Metal core aluminum PCB manufacturer,circuit board manufacturing,PCB assembly,electronics components - https://www.quick-teck.co.uk/

I have never used a company to make pcbs. I googled 'custom pcbs' and one of many sites is at the link above.

 

[marconi]

In words and briefly because I ma being pestered by Maud our 9 weeks old puppy - you remember I showed you some near perfect rectangular pulses on my new scope? They were at the output of the 555 clock running at 25kHz. In the latest post, these pulses switch a MOSFET transistor on and off which in turn turns the 4 infra red LED illuminators on my sensor array on and off - equal time on to time off or a 1 to 1 duty cycle/mark-space ratio.

One might expect that the LEDs will produce perfect pulses of ir light - instantaneously on and instantaneously off. Similarly, when these pulses reflect off something in fron tof them back to the photodiodes, the current which flows in these photodiodes instantly starts to flow at a constant value (dependent on the intensity of the received ir light hitting them) and instantly stops when the light turns off.

The little video of the current waveform (actually shows a the voltage this current develops across a resistor) is not instantaneously flowing or stopping. There is a rise time and a decay time. The rise and the decay look the same shape and duration as one would expect from a 1 to 1 duty cycle. What I wanted to show is the benefit of 'seeing' the waveform actually produced by a sensor on the scope. It dispels any notion that it is a rectangular waveform exactly the same as the driving waveform derived from the 555 clock. So this is the signal which the sensor produces and it is a distorted version of the driving waveform. Why is it distorted? Because in electronics (as in many physical systems) there are lags and delays between stimulus (the driving waveform) and current response by the photodiode. No device can actually respond instantaneously - they can respond very quickly indeed but there is always some time required to respond.

The longer it takes something to respond the slower it clearly responds to changes. The predominant reason why the waveform becomes distorted is the photodiode ( and also the transistors and LEDs) have small amounts of capacitance which I hope you know by now tends to slow down a change in voltage to a change in current. Thus we speak of a CR circuit have a time constant which is related to its frequency response and so-called impulse response. For more look at:

https://www.electronics-tutorials.ws/rc/rc_1.html

https://www.electronics-tutorials.ws/rc/rc_3.html

I have not yet begun to tackle the background light problem. If I have time I will make a video of the sensor voltage waveform changing in amplitude as objects move closer or further away from the sensor.

PS: To understand electronics and thus be able to design circuits one must learn some theory. I hope you find this interesting and gives you some insight as to what is happening.

PS2: Something similar was happening with your radio frequency wireless remote.

PS3: When I was a youngster knowing little I would write down all the technical terms I did not know or understand and then look them up in books or ask my uncle to explain them. All you have to do now is google them so it is hardly any effort to find out and learn. Please look up 'impulse response' and explain it to me

 

[_q12x_]

The predominant reason why the waveform becomes distorted is the photodiode ( and also the transistors and LEDs) have small amounts of capacitance which I hope you know by now tends to slow down a change in voltage to a change in current.
THis part is educative indeed. I didnt make the link in my mind exactly as you explain it here, i tell you sincerely. Though I am aware of the fact that EVERY component has it's own capacitance and resistance in a certain procentage, but usually is very-very low. For example, a capacitor has an internal resistance, and a resistor has an internal capacitance, and the other components for example a diode has a bit of both, a bit of resistance and a bit of capacitance when is working. Basically, nothing is perfect flowing the current through them. THat part I knew it already. But the way you put it is good for me to know "small amounts of capacitance tends to slow down a change in voltage" for each component. The thing is, I am a bit overlooking this little detail because the impact or effect is so small, it is insignificative in the big circuit.
For example, if I was stumble over each of these details in my big wings circuit, I would never had make it, or at least push it until this stage is right now.
I respect the fact that you want to teach me something new ! All the help I want from you is to assist me, as well as you can, and if you can, along the road I am already with this projekt.
When I was a youngster knowing little I would write down all the technical terms I did not know or understand and then look them up in books or ask my uncle to explain them.
That is a very smart thing to do. I do it very rarely, "write down the problem". THough as you mentioned, if I have a problem, with today internet I kind of understanding everything i put my mind to. If not 100% then it will be in a big percentage. It will be better than I knew nothing anyway. Haha.
To respond to your question, which is a bit intriguing but is a part of a bigger problem, from what I can see between the lines: about "impulse response". I just read about it. It is very new concept to me. It refers to frequncies, or oscilations. It is basically a shock or a bang. It is containing all the frequencies at once in the impulse part. Then the response part, from what I understand, is based on the component structure to reflect back. It is like a light red filter for example, when you shine white light over it, but under it, you obtain only the red light. THat is because it absorbs the other frequncies of the light but let pass only the red through it. THat is the response part. But it is applied not for a piece of glass like in my example, but to active components like diodes, or your experimental photodiodes that you measured with that fancy osciloscope which I like very much. Haha

 

[marconi]

Im Not very abstract thinker. Really? You are an artist - second nature I'd have thought. Anyway, have you begun to think about what would be required of a device which followed you around your room: not the technology of its implementation but what would it have to do? How do animals look and see? For a start one might consider the question of 'which part of you'? How would this part be recognised by a device? How would it be followed?

I hope you enjoy the mental stimulation of thinking about it.

 

[_q12x_]

I have some ideas , yes, about the "folowing human" component/circuit.
But I will like to hear your opinions first.
Also I have this another side miniprojekt im working right now:

 

[_q12x_]

I have some ideas , yes, about the "folowing human" component/circuit.
But I will like to hear your opinions first.
Also I have this another side miniprojekt im working right now:

 

[marconi]

Are you making electro-optic jewellery? Just a a thought for a business idea? Or perhaps electro-optic badges?

 

[_q12x_]

"electro-optic jewellery" hahaha yah you may call it like that as well. Good one. Or electric jewellery... at 220V. Hahaha.

 

[marconi]

So you do not think it has the potential to make you some money? It combines your love of art with interest in electronic construction.

 

[_q12x_]

Haha, money from art and from electronics ! Haha. I like your sense of humor. Really.

 

[marconi]

I give up.

 

[DPG]

I give up.

I have admired your patience ?

 

[marconi]

LED Light Up Glasses, Jewellery & Accessories | Glowtopia - https://www.glowtopia.co.uk/product-category/led-light-up-novelties/light-up-glasses/

 

[_q12x_]

In your mind, why do you think I am writing the top text on EACH of my artpages? Really, why do you think? Or any of you. See? And Im doing it like this for 8 years and people like you are saying, aah, pfff that is nothing, that is not true, that is bullsh*t. And I keep continuing writing my warning there, on the next, and the next, and the next. That's how the real world works. With nothings like me. haha.

 

[DPG]

In your mind, why do you think I am writing the top text on EACH of my artpages? Really, why do you think? Or any of you. See? And Im doing it like this for 8 years and people like you are saying, aah, pfff that is nothing, that is not true, that is bullsh*t. And I keep continuing writing my warning there, on the next, and the next, and the next. That's how the real world works. With nothings like me. haha.
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The reason is not capitalism, but your negative attitude in my opinion.

 

[_q12x_]

I think understanding is the real reason as well. Or empathy.

 

[marconi]

I am not getting embroiled in this latest line of discussion. When I have made some more progress on my Version 3 I will post but as I said earlier I am distracted and slowed down by other things at the moment.

Best wishes

Marconi