Science Project (static charge)

[FlamingoMan]

I am doing a project in science, and I need a device that is able to kill a static charge. I used to have it so the charge would run outside and run into the ground through a copper rod, but my science teacher said that I need to find a way so that I don't need to run it outside. The reason I can't find it myself is that whenever I search up "Device that kills static charges" on bing or google, all I get is websites saying if you can get killed by static discharge or not.

Thanks!

[Strange]

I doubt you have enough charge to need to ground it via a copper rod. A wire connected to anything grounded (a water or gas pipe, the ground pin of an electrical outlet, etc) would do. 

You could also search for "anti-static gun" - these discharge static by generating ionised air that allows the charge to dissipate. They are often used by people who play vinyl records, to remove charge that would accumulate dust. They are quite expensive though.

[swansont]

Even discharging to a large conductive reservoir would go a long way toward mitigating any static buildup.

[FlamingoMan]

4 hours ago, Strange said:

A wire connected to anything grounded (a water or gas pipe, the ground pin of an electrical outlet, etc) would do. 

So I would be able to run a wire into the ground part of part of the outlet without having to use the other two parts?

[swansont]

26 minutes ago, FlamingoMan said:

So I would be able to run a wire into the ground part of part of the outlet without having to use the other two parts?

In a lot of outlets, if it's metal, the screw that holds the faceplate on is grounded, because the box itself is grounded.

[iNow]

8 hours ago, FlamingoMan said:

The reason I can't find it myself is that whenever I search up "Device that kills static charges" on bing or google, all I get is websites saying if you can get killed by static discharge or not.

Try searching instead for “discharging static electricity”

I just touch the light switch. Can even see the spark sometimes in the dark during dry winter months. 

[studiot]

10 hours ago, FlamingoMan said:

The reason I can't find it myself is that whenever I search up "Device that kills static charges" on bing or google, all I get is websites saying if you can get killed by static discharge or not.

Thanks!

 

1 hour ago, iNow said:

Try searching instead for “discharging static electricity”

I just touch the light switch. Can even see the spark sometimes in the dark during dry winter months. 

Answering a qustion like this is more than just answering it is like the old proverb "teach a man to fish..."  +1

 

10 hours ago, FlamingoMan said:

I am doing a project in science, and I need a device that is able to kill a static charge.

FlamingoMan you really ned to provide a good deal more information to obtain detailed hlp.

Where is this static and why do you want to discharge it?
Is this for instance for an electronic workbench as a precaution against damaging sensitive components?

2 hours ago, FlamingoMan said:

So I would be able to run a wire into the ground part of part of the outlet without having to use the other two parts?

Again where is this static? Do yuor local building codes allow you to frig with your school's wiring?

In the UK the codes require 'cross bonding' ( also called equipotential bonding) of services so pipes for water and gas, hot air ducts etc are all bonded (= earthed) to a commn eathing system by separate wiring.
Mostly this earthing is via an earth provided by the electricity supplier.
If you have this system connection to it would be your first port of call.

 

https://www.google.com/search?q=cross+bonding+of+services&ie=utf-8&oe=utf-8&client=firefox-b

 

[FlamingoMan]

7 hours ago, studiot said:

FlamingoMan you really ned to provide a good deal more information to obtain detailed hlp.

Where is this static and why do you want to discharge it?
Is this for instance for an electronic workbench as a precaution against damaging sensitive components?

We are doing a project on static electricity that is being built up from running on a treadmill. We have to build an invention using the idea of a lightning rod to get rid of the static charge (in other words kill the charge). We want to kill the charge because the person is getting shocked.

Edited December 17, 2019 by FlamingoMan

[westom]

12 hours ago, FlamingoMan said:

So I would be able to run a wire into the ground part of part of the outlet without having to use the other two parts?

You are forgetting the concept called electricity.  Earth ground is completely irrelevant to a static electric current.

What is static electricity?  A connection from a positive charge to a negative charge.  Neither are in earth.  Your science teacher has demanded that you first think through the concept.

For example, a human touches a door and discharges.  Why?  Shuffling feet has created changes in the floor (beneath shoes) and in the body (above shoes).  The discharge is a connection from the arm to charges in the floor.  Again, earth ground is irrelevant.

Discharging means connecting two charges.  That is what a wrist strap does.  And it contains a maximum resistance.  Why?  Those charges are easily conducted even through a 1 Megohm resistor.  it takes very little to discharge those static charges.

Remember electricity is only moving charges - completely different from static charges.

Other techniques are relevant.  For example, pink poly is a plastic sheet made with electrically conductive materials. Therefore it does not create charges.  Room humidity at 40% or higher means charges also leak off.  Those things are not said to be electrically conductive to 120 VAC.  But are quite conductive to static electricity.  The difference is found in numbers - current and voltage.

Earth is not where either charge is located.  Connecting to an earth ground rod means that discharge may then enter back into the building to connect to charges in the floor.  Since things you may assume are not electrically conductive (ie linoleum, concrete, wood, paint) can be conductive to static electricity.

[FlamingoMan]

 

1 hour ago, westom said:

What is static electricity?  A connection from a positive charge to a negative charge.  Neither are in earth.  Your science teacher has demanded that you first think through the concept.

For example, a human touches a door and discharges.  Why?  Shuffling feet has created changes in the floor (beneath shoes) and in the body (above shoes).  The discharge is a connection from the arm to charges in the floor.  Again, earth ground is irrelevant.

static electricity is a buildup of negative charges on an object. When it's discharged that means the negative charge is trying to balance itself out. Shuffling feet on carpet is friction which cause negative charges to build up on you (the person). When you touch a metal door knob, the door knob isn't grounded, so instead of running into the ground and dispersing, it balances itself out by creating a spark which is what you are feeling. This is what we have learned. 

[studiot]

10 hours ago, FlamingoMan said:

We are doing a project on static electricity that is being built up from running on a treadmill. We have to build an invention using the idea of a lightning rod to get rid of the static charge (in other words kill the charge). We want to kill the charge because the person is getting shocked.

Thank you for your reply.

I suggest looking at a conductive brush (eg carbon fibre) placed  the extremity of the moving base and rubbing gently against it.
This would collect the static.

You would need to describe the environment in more detail to figure out where to lead the collected charge to.
Simply a trailing lead to a machine holding down bolt may be sufficient, as westom says the charge is not huge, though spectacular.

This technique is common in industrial machines fo instance photocopiers, but normally done internally by the manufacturer.

But westom is definitely wrong to say this:

7 hours ago, westom said:

What is static electricity?  A connection from a positive charge to a negative charge.

 

So plus 1 for sticking to your guns here, you have it correct.

6 hours ago, FlamingoMan said:

 

static electricity is a buildup of negative charges on an object. When it's discharged that means the negative charge is trying to balance itself out. Shuffling feet on carpet is friction which cause negative charges to build up on you (the person). When you touch a metal door knob, the door knob isn't grounded, so instead of running into the ground and dispersing, it balances itself out by creating a spark which is what you are feeling. This is what we have learned. 

 

Edited December 17, 2019 by studiot

[FlamingoMan]

4 hours ago, studiot said:

You would need to describe the environment in more detail to figure out where to lead the collected charge to.

We were not told the environment.

 

4 hours ago, studiot said:

Simply a trailing lead to a machine holding down bolt may be sufficient

Could you rephrase that please? I don't really understand it.

[studiot]

2 hours ago, FlamingoMan said:

 

 

Could you rephrase that please? I don't really understand it.

 

Congratualations.
Simply saying something like this if you do not understand is the best way to get an explanation.

 

The frame of the running machine will be metal and since it almost certainly runs on electricity this should be earthed to mains earth.

The frame will also be bolted to something solid in the floor or wall as it is likely to slowly move about otherwise.

The static will be generated by friction between non metallic parts (the rubber track, shoes, etc)
This is very common in machinery.

If not discharged it will build up but if constantly discharged (eg by my brush) the level will be much lower at any one time.

So simply providing a path from the brush to the metal frame or building structure shuld be adequate for this purpose.
Even if the building structure is non metal it will be a large enough sink to this charge.
I suggested a bolt because it is easy to clamp a wire to something like that, where it is out of the way and not in danger of getting broken.

[Strange]

15 hours ago, westom said:

Earth ground is completely irrelevant to a static electric current.

Not really. This is just an extreme case of swansont's "discharging to a large conductive reservoir would go a long way toward mitigating any static buildup".

 

7 hours ago, studiot said:

Simply a trailing lead to a machine holding down bolt may be sufficient, as westom says the charge is not huge, though spectacular.

Unless this is a purely mechanical treadmill (which it might be) it would be earthed/grounded anyway.

And I'm not sure that grounding the machine would necessarily help. The problem, I assumed, is that human running on the rubber(?) belt of the treadmill builds up a charge. They then get shocked when they touch the metal part of the treadmill (or something else) when they have finished running.

In which case, you want to find a way of preventing them building up a charge in the first place. You could replace the treadmill belt with a more conductive material. Or coat it with a conductive coating. Or you could put a humidifier next to it. Or an array of very fine needles that act like tiny lightning rods to attract the charge - place these just behind the runner's as an incentive not to fall behind.

But maybe you are right, and it is the machine that builds up a static charge so someone gets a shock when they first approach it. More information would be useful...

 

Maybe the first part of the project should be to investigate exactly where (and why) the static charge is built up.

[studiot]

8 minutes ago, Strange said:

And I'm not sure that grounding the machine would necessarily help. The problem, I assume, is that human running on the rubber(?) belt of the treadmill builds up a charge. They then get shocked when they touch the metal part of the treadmill (or something else) when they have finished running.

Didn't I just say that?

[Strange]

2 minutes ago, studiot said:

Didn't I just say that?

Sorry, I missed your previous comment and so misinterpreted what you said. The phrase "a machine holding down bolt" didn't help!

I think your brush idea is a good one.

 

What are those devices called that have the two bits of material that move apart when put near a static charge? Electroscope?? That could be used to find out where the charge is accumulated and then demonstrate that the fix works (without subjecting test runners to painful shocks). 

Yes, electroscope (brains are amazing at dragging up info you didn't think you knew)

Build your own as part of the project: https://study.com/academy/lesson/electroscope-experiment.html

[studiot]

3 minutes ago, Strange said:

Sorry, I missed your previous comment and so misinterpreted what you said. The phrase "a machine holding down bolt" didn't help!

I think your brush idea is a good one.

 

What are those devices called that have the two bits of material that move apart when put near a static charge? Electroscope?? That could be used to find out where the charge is accumulated and then demonstrate that the fix works (without subjecting test runners to painful shocks). 

Yes, electroscope (brains are amazing at dragging up info you didn't think you knew)

Build your own as part of the project: https://study.com/academy/lesson/electroscope-experiment.html

The bits that move apart are metal foil, traditionally gold leaf, but they can be fashioned from kitchen foil.

[MigL]

If Flamingo is interested he can have my grounded wrist strap for working on computer equipment, that I haven't used since the 80s.
These days, even though features on ICs are hundreds of times smaller, I simply touch the faucet ( older house, all copper piping ) to 'discharge' before handling CPUs or RAM. Haven't 'killed' any equipment yet.

Sometimes if I'm feeling lucky, I'll just leave the computer plugged in ( but off ) and touch bare metal before handling components.
You can never trust cheap switching power supplies, though.

[FlamingoMan]

9 hours ago, studiot said:

So simply providing a path from the brush to the metal frame or building structure shuld be adequate for this purpose.
Even if the building structure is non metal it will be a large enough sink to this charge.
I suggested a bolt because it is easy to clamp a wire to something like that, where it is out of the way and not in danger of getting broken.

So all I need to do is place a carbon fiber brush at the extreme (highest point) of the moving platform. Then I provide a connection like a wire from the brush to a clamp which will be clamped onto the metal frame of the treadmill?

[westom]

Read a datasheet.  For example, this interface chip will withstand 15,000 volts without damage:  https://datasheets.maximintegrated.com/en/ds/MAX1487E-MAX491E.pdf

 However, then means it is part of a system.  When not, even 20 volts can damage it.

A wrist strap can be made even with a bare wire.  But that is unsafe.  Wrist straps contain a 1 megohm resistor.  Then any accidental contact to AC electricity does not kill.

Static electric protection is always about how charges in a body connect to charges beneath feet.  Touching a faucet is simply another connection to (discharges) charges in the floor.  On a path that does not flow destructively through a semiconductor.

 

[studiot]

7 hours ago, westom said:

Read a datasheet.  For example, this interface chip will withstand 15,000 volts without damage:  https://datasheets.maximintegrated.com/en/ds/MAX1487E-MAX491E.pdf

 However, then means it is part of a system.  When not, even 20 volts can damage it.

A wrist strap can be made even with a bare wire.  But that is unsafe.  Wrist straps contain a 1 megohm resistor.  Then any accidental contact to AC electricity does not kill.

Static electric protection is always about how charges in a body connect to charges beneath feet.  Touching a faucet is simply another connection to (discharges) charges in the floor.  On a path that does not flow destructively through a semiconductor.

 

 

At least 90% of your tirade is off topic and of little if any help to a youngster wanting to to learn the subject properly.

 

7 hours ago, FlamingoMan said:

So all I need to do is place a carbon fiber brush at the extreme (highest point) of the moving platform. Then I provide a connection like a wire from the brush to a clamp which will be clamped onto the metal frame of the treadmill?

That is certainly an option worth investigating. Talk to your project supervisor about it.

[Carrock]

https://study.com/academy/lesson/electroscope-experiment.html

19 hours ago, studiot said:

The bits that move apart are metal foil, traditionally gold leaf, but they can be fashioned from kitchen foil.

 

The weight per unit area of foil is important as it has to be raised against gravity. Gold is the most malleable element and can be beaten into sheets less than 1000 atoms thick. Good luck trying that with kitchen foil.

You can buy about 1.8ft² of 0.12 micron gold leaf for $8.12 but probably best to find someone who uses it and pay $0.20 for an offcut.

[swansont]

20 minutes ago, Carrock said:

https://study.com/academy/lesson/electroscope-experiment.html

 

The weight per unit area of foil is important as it has to be raised against gravity. Gold is the most malleable element and can be beaten into sheets less than 1000 atoms thick. Good luck trying that with kitchen foil.

You can buy about 1.8ft² of 0.12 micron gold leaf for $8.12 but probably best to find someone who uses it and pay $0.20 for an offcut.

A good point, and a good physics exercise to calculate how much weight you can tolerate for a given amount of charge. But even so, you'll still get a small deflection with heavy foil, because the force you have to overcome varies as sin(theta). (although getting a smaller deflection will inhibit the charge from building up as much). Then it becomes a matter of how small of a deflection you can easily detect.  

[studiot]

43 minutes ago, westom said:

I don't expect to convince you of anything.  You are entrenched in a belief.  Charges that are not moving are somehow electricity.

Which ground? Logic ground is different from chassis ground which is different from floating ground which is different from ground beneath shoes (for static electricity) which is different from  receptacle safety ground which is different from AC utility substation ground which is different from water pipe ground which is different from motherboard ground which is different from analog ground which is different from ground plane for an antenna which is different from virtual ground which is different from automobile ground which is different from earth ground which is different from DC power ground or signal ground.

So connecting a wrist strap to motherboard ground will protect from static discharges?

Only connection that matters is one that connects charges in a body to charges beneath shoes.  Well, connecting to earth ground does eventually make that connection. But the only relevant ground is that where those charges exist.  For static electricity generated by a human, that is charges beneath shoes.

 

 

Quite apart from the logical inconsistencies in this post, I see that you are using the US terminology for ground and earth, as opposed to UK/European termonilogy, which is somewhat different.

I do agree however that all of the 'grounds' you mention arise differently they all conform to a common definition of an electrical ground.

I do not agree that any of this progresses the OP quest for a solution to his problem, however.

Has your alleged 50 years experience nothing to offer?

Edited December 19, 2019 by studiot

[swansont]

!

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