How Does a neon screwdriver work?

[holmslaw]

Myknobhurts, have you any idea how a sonic screwdriver works?

 

[Grizzly]

In short I am a bit of a ****!

Fixed that for you.

 

[bernardgreen]

I did suggest that all of you should stand on floorboards in your slippers take off a socket front and try putting the back of your finger on a line circuit conductor, in order to prove to you all that this will result in a nasty shock even upstairs in your house.

You are wrong David... you will NOT get a shock if you touch a live wire when no other part of you body is in contact with any other conductive material. Do NOT try this just for the sake of it.

If you doubt this then try to explain how birds can perch on un-insulated 11 Kv over head cables and survive.

Unfortunately nobody seems to have taken up the challenge.

I have when necessary worked on live equipment and have tightened bolts on live 230 volt bus bars in an emergency.

The neon screwdriver also allows current to pass through your body when apparently you are not in contact with earth, so is it a mystery or just the damp in the atmosphere?

That has already been explained to you. The current passing though the neon is 100 times a secod charging and discharging the capacity formed between the body of the person holding the neon screwdriver and any conductive surfaces near by. The current in the neon does give the person "an electric shock" but the current is so small as to be not noticable.

Getting back to the proof. The birds on power lines do have a very minute current in their legs, far too small to have any affect on the nerves and muscle, as the capacity of their body is charged and discharged 100 times a second ( 120 for birds in the USA ). Minute current because there is nothing close to them to form a significant second plate of the capacitor. But when a bird moves along the wire and gets close to a post or other item that forms a significant second plate of the capacitor ( the bird's body being the first plate ) then the capacity increases and the current in the bird's legs increases until it becomes irritating to the bird and it flies away.

 

[Grizzly]

But he shouldn't keep trying to wind me up all the time he should just answer questions and stick to the facts, "oh you think so do you" and "I doubt it" do not constitute a technical debate.

Nor does the utter cobblers you keep trotting out, you deluded individual.

Thank goodness you're making a name for yourself on here and the IET forum. The more rubbish you post, the less likely unsuspecting readers will purchase your pamphlets, except as a comedy item.

 

[matt1e]

he should just answer questions and stick to the facts, "oh you think so do you" and "I doubt it" do not constitute a technical debate.
In short the bloke is a bit of a ****!

With respect Dave you have not answered one question I or others have asked you, in this thread (one of which still on preivious page) or the bondage thread, not one
so how can you expect debate?

To be fair OMS on the IET forums has answered a bucket load of your questions
in this particular thread

Matt

 

[david911cockburn]

What's the question Matt?


Bernard - for god sake just go and try it will you!

 

[sparkticus]

he should just answer questions and stick to the facts, "oh you think so do you" and "I doubt it" do not constitute a technical debate.
In short the bloke is a bit of a ****!

With respect Dave you have not answered one question I or others have asked you, in this thread (still on preivious page) or the bondage thread, not one
so how can you expect debate?

To be fair OMS on the IET forums has answered a bucket load of your questions
in this particular thread

Matt

I'm getting really irritated by Cockburns random ramblings in these threads. He refuses to enter a proper debate despite being given the opportunity and he refuses to accept scientific fact despite it being spoon fed to him. Conclusion: he is a bit thick. You can see that from his pamphlet.

I think it is best for us all to either ignore him or respond with equally ridiculous propositions.

 

[david911cockburn]

Bernard - a bird on a wire is a very long way from the mass of the earth.


Why don't you try putting the back of your finger on an energised line circuit conductor, then you won't have to theorize any more.
Please come back and describe the pain to me so I know that your telling the truth.

 

[david911cockburn]

Hi Spartikus,

Earthing:

If you connect all accesible conductors to the earthing point of the installation, any one of those conductors coming into contact with an energised line circuit conductor will cause the circuit to be automatically disconnected within a specified time.

 

[sparkticus]

Bernard - a bird on a wire is a very long way from the mass of the earth.


Why don't you try putting the back of your finger on an energised line circuit conductor, then you won't have to theorize any more.
Please come back and describe the pain to me so I know that your telling the truth.

Listen you idiot, I have done what you say above and I felt nothing at all.

I used it to demonstrate to a group of students that there is virtually zero potential difference across a human body when one hand grasps a live cable (let alone touch it with the back of the finger) while standing on a wooden floor.

Do you get it now?? If you are right then explain it mathematically and there will be no argument GO ON DO IT!!

 

[bernardgreen]

Bernard - for god sake just go and try it will you!

David. I just told you that I have, in an emergence situation, worked on equipment during which time I was touching with bare hands bus bars carrying 230 volts. I do not get a shock and neither did I feel any significant effect because I ensured that no part of my body could touch or come into contact with any other conducting material.

 

[david911cockburn]

Well I did it recently to prove whether or not an RCD would trip, and it hurt just as much as it always has and the RCD didn't trip and I tested it with a ramp tester.

If you don't think you can hurt yourself, why not try it?

 

[bernardgreen]

Bernard - a bird on a wire is a very long way from the mass of the earth.

But only a few feet away from the other phase wire(s) which although at 11 Kv or more relative to the bird do not form a significant second plate to the small area of the bird's body. But a fat DIYer close to a metal central heating radiator does form a significant capacity.

Why don't you try putting the back of your finger on an energised line circuit conductor, then you won't have to theorize any more. Please come back and describe the pain to me so I know that your telling the truth.

What bit can you not understand. or is a live bus bar somehow different to a energised line circuit conductor in the way that it interfaces to a human finger that touches it.

 

[sparkticus]

Well I did it recently to prove whether or not an RCD would trip, and it hurt just as much as it always has and the RCD didn't trip and I tested it with a ramp tester.

If you don't think you can hurt yourself, why not try it?

"it hurt just as much as it always has" comments like this make you look like a fool. As I have requested, please provide a mathematically accurate model as proof of what you are saying.

 

[david911cockburn]

Mathematically - there is damp in the atmosphere, if you are close enough to the mass of the earth the damp will connect your feet to the mass of the earth.

Why does lightning move across the sky in humid weather?

I can't say for certain I'm an electrician not a scientist, but I know pain when I feel it and you can't touch every circuit conductor during every circumstance.
Just doing it once and not getting hurt is not proof that it can't happen.
Just doing it once and getting hurt, is proof that it can!