Thread: Sparks!!

Hi

I was just wondering what causes sparks. When i have two wires connected to a battery they jump the gap between as expected but what allows that electrical current to travel though the air and what is the minimum voltage and maximum distance that this can happen? Also, how do bolts of lightening travel?

Thanks for the help in advance.

The spark you can see is electrical current (just like that travelling in the wire) travelling through the air. The physics of what you see there, and what you see with lightning is the same.

The air between the wires is a good electrical insulator (very high resistance), but when the voltage (and hence, electric field) between the wires reaces a high enough level, the air very suddenly becomes a good conductor, and current flows.

The process of a material switching suddenly forom being a good insulator, to a conductor is called 'dilectric breakdown,' and happens when the elctric field throughout the material reaches a certain level (which differs between different materials, and the amount of material).

With lighting the concept is the same, where the (much higher) potential difference is provided by a build up of charge on the clouds from ice particles rubbing together, instead of a battery.

In air, current flows by ionising the air, providing a conductive path.

You can calculate the maximum distance/ minimum voltage for a given lump of material by looking at the dilectric strength of the material. This is usually in MV/m...so as you can see, multiplying by the distance gives the required voltage.

To calculate the dilectric strength of a material might be alot harder, but you can find data on materials that include this property...It's probably determined experimentally, with precise lab equipment.

Originally Posted by mrbean

Hi

I was just wondering what causes sparks. When i have two wires connected to a battery they jump the gap between as expected but what allows that electrical current to travel though the air and what is the minimum voltage and maximum distance that this can happen? Also, how do bolts of lightening travel?

Thanks for the help in advance.

The spark you get is caused, when you break contact or open a loop. Break voltage is easily 30,000 volts. This voltage allowed to charge a capacitor, could hurt you. This is called break voltage, and it sets up a path between the two points as they pull apart. A partial vacuum is formed between the points.

If you look at all the electrical products in your home. Most including electronic equipment have manual or magnetic coil operated switches, that control, AC household current.

You can note that the average gap between those points is 3/32" of an inch. Or .09375 inches apart. That is not much to keep 120 or 240 volt power from jumping the gap. Yet it does. Because it takes thousands of volts to make a connection across an air gap.

What takes place upon make, or, high frequency/high voltage, make voltage, is a partial vacuum is setup, between the points or terminals and this allows electricity to flow through the vacuum or light atmosphere. A vacuum has lower ohms then air.

The designers of the mother ship did not allow for this in deep space.

In factories we are forever causing high frequency and this can cause electricity to jump these small point gaps, as well as cause electricity to go around corners and over many inches of air, to get to another terminal. "U" shaped arcs are common. To connect two terminals on the back of a wall outlet. Either 110 volt or 220 volt outlets.

Sincerely,


William McCormick

mrbean, don't listen to McCormick, he is our pet forum troll.

The spark you get is caused, when you break contact or open a loop. Break voltage is easily 30,000 volts. This voltage allowed to charge a capacitor, could hurt you. This is called break voltage, and it sets up a path between the two points as they pull apart. A partial vacuum is formed between the points.

It's called dielectric breakdown, and has nothing to do with a vacuum. Free electrons ionise air molecules, which constitute more free electrons to the current. In fact sparks cannot travel at all in vacuums since there is nothing to ionise, and provide a low-resistance path. There have been some experiments/instances where current has flown in a vacuum I believe, but thats not what we would consider to be a conventional spark, and it isn't relevant to the mechanism of a conventional spark.

You don't need 30,000 volts to blow a capacitor. I've done it before at 30V. ramp up the voltage, dielectric breakdown occurs, and , POP! It is also not dependent on movement of the effective capacitor 'plates'. Look at Van der Graff generators.

If you look at all the electrical products in your home. Most including electronic equipment have manual or magnetic coil operated switches, that control, AC household current.

Actually most household appliances use D.C. The A.C. supply is rectified, smoothed and stabalised into D.C....which is what most the appliances actually deal with.

You can note that the average gap between those points is 3/32" of an inch. Or .09375 inches apart. That is not much to keep 120 or 240 volt power from jumping the gap. Yet it does. Because it takes thousands of volts to make a connection across an air gap.

As I already said, it depends on the dielectric strength of the medium in MV/m, and the size of the gap. It doesn't take 000's of volts to produce a small spark.

The designers of the mother ship did not allow for this in deep space.

Is this the mothership that brought you to Earth?

In factories we are forever causing high frequency and this can cause electricity to jump these small point gaps, as well as cause electricity to go around corners and over many inches of air, to get to another terminal. "U" shaped arcs are common. To connect two terminals on the back of a wall outlet. Either 110 volt or 220 volt outlets.

Frequency doesn't mattter. It's a matter of dielectric strengh, magnitude of the potential difference, and size of the gap.

I want to use a 10,000 uf capacitor to create a large spark
(for the hell of it)...will connecting the negative and positive end instantly, blow the capacitor?

Â*
No, you will only damage the capacitor if you exceed its rated voltage.

Originally Posted by bit4bit

mrbean, don't listen to McCormick, he is our pet forum troll.

I don't understand why you claim I am a troll?

I was discussing something like this tonight with a doctor, and he did not call me a troll or anything else. We were having an interesting conversation about the nervous system and electricity.
In fact he lost cell service as I turned on the microwave oven.
The same thing happens with my laptop and the wireless network, when I use it near a microwave oven.
I talk to people everyday in every walk of life. With nothing but exchange of knowledge.
However on the Internet as I am explaining very real things that I work with and have worked with since I was a small boy. I get troll?

Originally Posted by bit4bit

It's called dielectric breakdown, and has nothing to do with a vacuum. Free electrons ionise air molecules, which constitute more free electrons to the current. In fact sparks cannot travel at all in vacuums since there is nothing to ionise, and provide a low-resistance path. There have been some experiments/instances where current has flown in a vacuum I believe, but thats not what we would consider to be a conventional spark, and it isn't relevant to the mechanism of a conventional spark.

You don't need 30,000 volts to blow a capacitor. I've done it before at 30V. ramp up the voltage, dielectric breakdown occurs, and , POP! It is also not dependent on movement of the effective capacitor 'plates'. Look at Van der Graff generators.

Dielectrics do not break down. Unless you apply a voltage that overloads them. You can do this many ways. You can create high frequency, to excite a low voltage source to jump a great distance. I have been using such a system to do just that since I was nine.

High frequency causes the air to become abundant with electrons. Enough so that the dielectric air, conducts.
The dielectric becomes exited, and heated by the high frequency.
Much like a vacuum of air, the atoms of air that are left, are in an artificial exited state. Just like steam, is the excited state of water, through application of heat. You can create steam using a vacuum pump.

High frequency does just that. It destroys the insulator/dielectric by breaking down the diode. High frequency creates the gate power through high speed bi polarization. It opens the diode just like a gate opens a diode/triac.

Insulators only work because they raise in voltage to stop, and place an equal or nearly equal electrical force against the source. The only way to stop electricity is to create an equal and opposite EMF electromotive force.

However if you have ARC, (Anode, Rectified, Cathode) and you get arc from a spark, you have 30,000 volts of potential electron pressure. If you can get it stored up you can measure it and get hurt by it.

I do this almost everyday. I must know or die.

Originally Posted by bit4bit

Frequency doesn't mattter. It's a matter of dielectric strengh, magnitude of the potential difference, and size of the gap.

Frequency certainly matters. Frequency can turn that little spark that you claim has no high voltage, into a lethal killing machine. As well as make it jump, around corners and over many inches of air. I have seen this happen many times in many different industries. It is wild to see.

Would you like me to create a demonstration and film it? Or will you just call it a hoax?

How do you think an old car coil worked? Take a standard car coil you can get them from almost any automotive store. And hook up a 12 volt source to them using a transistor to pump power to them. You can even go a little higher on the voltage if you like to offset any transistor voltage loss.
Your output voltage will only be around 175 volts. Wow, yet when they were and still are used in automobiles, they output anywhere from 30,000 to 70,000 volts.

Lets look at what is different in the transistor pulsing about 12 volts through the primary coil of a car coil. And the points pulsing about 12 volts through the primary coil.
ARC is the difference. When those points opened up they created super high voltage., and a spark. And a good portion of that was used to create the even higher secondary output.

You should hit the laboratory before you bad mouth other people. You have a serious lack of experience.

And you have also provided someone with false information that could be life threatening if taken to heart. No pun intended.


Sincerely,


William McCormick

Good.....

I tried it at 16 volts but nothing happened. I do not think I understand it well enough....I never learned how to use anything besides resistors and batteries in school. Everything else I know about circuits is only composed of pieces of knowledge that I have obtained over the years.

So If I wanted to send out the largest impulse of energy possible all at once, how should I go about doing it?

Thanks for the comments.

I would also like to ask what are the sparks which come off two electrodes when the are rubbed together. Often seen in industry and welding.

Originally Posted by Cold Fusion

I tried it at 16 volts but nothing happened.

There is not enough power stored in the capacitor at 16v to generate a spark. The charge flows out quickly with no visible effect. You would need greater voltage to produce a spark of any sort.

Originally Posted by mrbean

I would also like to ask what are the sparks which come off two electrodes when the are rubbed together. Often seen in industry and welding.

There is so much electrical power in your source that it is enough to melt the metal at the points of contact. Examine the contact points and you will see it is pitted and burnt. Those sparks you see are traces of molten metal sent shooting off. This is not the same effect as a discharge arc.


Â*

William McCormick: The information I provided mrbean is correct. You are a famously bad perpetrator of giving false information and wild personal conjecture as fact, so for you to accuse me of that is laugable. I'm not about to get into an argument with you, I've argued with wackos before, and it is a waste of my own time, effort and patience, so I'll choose to ignore your comments instead from now on.

I only suggest you take a look here:

http://en.wikipedia.org/wiki/Electro...scharge#Sparks
http://en.wikipedia.org/wiki/Dielectric_breakdown

You can see that dielectric breakdown is a very real phenomenon, and that my description of the mechanism is accurate.

Cold fusion: The circuit you need is called a voltage multiplier. It consists of an array of diodes and capacitors, that can produce a very high voltage across the terminals (your spark gap), and does so without exceeding the ratings of the components. Here's the wiki article:

http://en.wikipedia.org/wiki/Voltage_multiplier

Originally Posted by bit4bit

William McCormick: The information I provided mrbean is correct. You are a famously bad perpetrator of giving false information and wild personal conjecture as fact, so for you to accuse me of that is laugable. I'm not about to get into an argument with you, I've argued with wackos before, and it is a waste of my own time, effort and patience, so I'll choose to ignore your comments instead from now on.

I only suggest you take a look here:

http://en.wikipedia.org/wiki/Electro...scharge#Sparks
http://en.wikipedia.org/wiki/Dielectric_breakdown

You can see that dielectric breakdown is a very real phenomenon, and that my description of the mechanism is accurate.

Cold fusion: The circuit you need is called a voltage multiplier. It consists of an array of diodes and capacitors, that can produce a very high voltage across the terminals (your spark gap), and does so without exceeding the ratings of the components. Here's the wiki article:

http://en.wikipedia.org/wiki/Voltage_multiplier

Your own link just backed up what I said. It said that it takes about 30,000 volts to break air and create a spark. That is correct. So when you pull that wire off the battery, you have a potential of 30,000 volts.

You can also break down a diode/insulator, with high frequency. Just like disconnecting a battery causes that 30,000 volt spark. When you alternate or pulse at very high frequencies. You can create heat, you can create, a near vacuum. And you can create ARC.

Did you ever try putting transistor controlled 12 volt power through a car coil? No you have not. Have you ever tried powering it with mechanical points? No you have not. Yet you are willing to take a crack at someone, else based on a lack of knowledge. That is the optimally poor scientist at his best.

After you get this spark understanding understood, maybe you will understand just how accurate I am. And how uncaring a world you live in.

A spark is a potential of 30,000 volts. I will bet my life on it. High frequency can make that happen, with lower voltage.

Sincerely,


William McCormick

Originally Posted by William McCormick

Your own link just backed up what I said. It said that it takes about 30,000 volts to break air and create a spark. That is correct. So when you pull that wire off the battery, you have a potential of 30,000 volts.

Where does it say 30,000 V? It says that it depends on the dielectric strenght of the medium (For air: 30kV/m), which naturally depends on the distance also, for a constant voltage. I have a 9V battery in my hand with a wire from each terminal. When I touch the two together I can see very small sparks.

"High voltage" is considered 35,000 volts or more. This does not mean that 35,000 volts or more is required to create a spark.

You can also break down a diode/insulator, with high frequency. Just like disconnecting a battery causes that 30,000 volt spark. When you alternate or pulse at very high frequencies. You can create heat, you can create, a near vacuum. And you can create ARC.

No when you can run whatever frequency signal you want through a capacitor, and the only thing that will change is the capacitive reactance.

You can run whatever frequency you want through a diode, the only thing that happens is a rectification.

Neither component will fail unless you exceed the maximum rated voltage or current....which is irrellevant to frequency.

A spark is a potential of 30,000 volts. I will bet my life on it. High frequency can make that happen, with lower voltage.

Get the nearest 9V battery, turn off the light and touch together the terminal wires. Then video it and upload it, if you want.

Originally Posted by bit4bit

Originally Posted by William McCormick

Your own link just backed up what I said. It said that it takes about 30,000 volts to break air and create a spark. That is correct. So when you pull that wire off the battery, you have a potential of 30,000 volts.

Where does it say 30,000 V? It says that it depends on the dielectric strenght of the medium (For air: 30kV/m), which naturally depends on the distance also, for a constant voltage. I have a 9V battery in my hand with a wire from each terminal. When I touch the two together I can see very small sparks.

"High voltage" is considered 35,000 volts or more. This does not mean that 35,000 volts or more is required to create a spark.

You can also break down a diode/insulator, with high frequency. Just like disconnecting a battery causes that 30,000 volt spark. When you alternate or pulse at very high frequencies. You can create heat, you can create, a near vacuum. And you can create ARC.

No when you can run whatever frequency signal you want through a capacitor, and the only thing that will change is the capacitive reactance.

You can run whatever frequency you want through a diode, the only thing that happens is a rectification.

Neither component will fail unless you exceed the maximum rated voltage or current....which is irrellevant to frequency.

A spark is a potential of 30,000 volts. I will bet my life on it. High frequency can make that happen, with lower voltage.

Get the nearest 9V battery, turn off the light and touch together the terminal wires. Then video it and upload it, if you want.

In air it takes 30,000 volts to create that spark. Look at that spark in the dark. You will see the extent of that tiny spark. You can actually feel the electrical charge in your eyes in the dark, up close.

If you go back and read what I wrote, I wrote it exactly as it occurs in life. I know, I do this everyday. I work with high and low voltage. AC and DC. Anode rays and Cathode rays. Radio, electronics you name it.

I just do not understand why you attack me. You read that to break a very small air gap you need 30,000 volts. When you break a loop, the current continues to flow. Through a partial air vacuum, that disintegrates some atoms. This disintegrating air, causes 30,000 volts of pure fission power. That is why you can feel it in your eyes.

I work with huge, crazy stuff like this all the time. I am sure of it or I would be gone already.

Just happen to have a movie like that already made up. Did this some years back. This introduces another phenomena, it demonstrates the induction device/capacitor well.

The heater is a constant ohm heater. It makes a difference, there is a lack of inductance in this heater.


Blow that up to full screen. Look at the voltage in that arc. I can hold that in my hands. But wow it whacks you. Much worse then 110 volts, 100 times worse. Usually I cannot even feel house current.

http://www.Rockwelder.com/WMV/sparkyhq.wmv

The reason why house current is dangerous. Is that years ago there were more transformer accidents and line shorts.
Often these events would send spikes into the home or business, and through ungrounded equipment. The device you were holding would act as a capacitor plate, and dielectric, and kill the individual, or capacitor plate holding it.

That is why double insulated tools are a bit of a gamble. If you are holding one while a transformer blows, you might not live to tell about it. If the device is grounded you will probably be just fine.

There are other dangers and draw backs to grounded tools as well. Especially when drilling where live voltage may be present.

I have had an ARC jump through a brush cap, into my gut. When someone shorted out the welder in the panel box feeding it. The welder was connected to a spiral stair case we were welding. I had a grinder in my hand, and the brush case jumped to my gut. I was fine. I just thought the strange harmonic coming from the spiral stairs was a bit unnerving.

Never connect your welders work, ground clamp before you hook up the welders power supply, this is a very good rule. Ha-ha.



Sincerely,


William McCormick

Originally Posted by bit4bit

No when you can run whatever frequency signal you want through a capacitor, and the only thing that will change is the capacitive reactance.

That is misinformation. Run capacitors in induction motors are another line of defense against high frequency accidents. They will self destruct upon the introduction of high frequency. Often shutting down the motor. Sometimes not.

High frequency can make a motor turn much faster then it was designed to turn. And it can cause it to draw more amperage. And over heat, because it is no longer in sync with the hertz.

When you charge and discharge a battery in rapid succession what happens? It gets hot. When you charge and discharge a capacitor in rapid succession it gets hot. Solid dielectrics can liquefy and emit arc. Or liquid dielectrics and can emit ARC and breakdown the dielectric.

All because of high frequency.


Which is often accompanied by ARC, 30,000 volts.



Sincerely,


William McCormick

I finally figured out how a voltage multiplier works; it is really an amazing device, even though it is so simple. It uses the the repulsion between positive charges to accelerate the electrons and the negative to draw more energy into each section of the ladder. Ideas like this give me a little more hope in humanity every time.

Originally Posted by Cold Fusion

I finally figured out how a voltage multiplier works; it is really an amazing device, even though it is so simple. It uses the the repulsion between positive charges to accelerate the electrons and the negative to draw more energy into each section of the ladder. Ideas like this give me a little more hope in humanity every time.

They used to call them Jacobs ladder.



Each one of those joints has four connections. Except for the first and last two.



This book was written by Forrest M. Mims III for Radio Shack years ago. I used to bring my laser beams to radio shack to get parts for them years ago. And talk them over with the guys there.

Each time the polarity changes it charges the next tier with that amount of voltage, contained in that half cycle.

Then when you go to drain it you have a series of capacitors, just like putting a couple batteries into a flashlight in series.

I have built a couple of these. They really work well. But I have the schematics for voltage amplifiers that use transformers, they are capable of extreme voltages in just one cycle. Usually what you want for laser beams.

Sincerely,


William McCormick

Isn't Jacob's ladder the phenomenon you get when you have a potenital difference over to conductors that bend away from each other like a hyperbola which causes the plasma, generated between the conductors, to climb?

Just for curiosa, the casacde multiplier is used to create hude potential differences by connecting it to a Faraday's cage.

Originally Posted by thyristor

Isn't Jacob's ladder the phenomenon you get when you have a potenital difference over to conductors that bend away from each other like a hyperbola which causes the plasma, generated between the conductors, to climb?

I always called that "V" escalation. The standard mad scientists apparatus. That is how it was taught to us in school.

This was done with a car coil, and high frequency ARC input.






This cascade device actually requires a certain number of AC cycles to reach voltage. It is very much like a ladder. And I know that many called it a Jacobs ladder, rightly or wrongly.

I call it a voltage converter. It converts AC low voltage to DC high voltage.



Sincerely,


William McCormick

Did yo make that ladder in our house. It must've created quite a lot of ozon.

Yeh, it is sometimes called a Jacobs ladder (which derives from some historical thing I think), or cascade multiplier, because of the way it works. It is a nice circuit, which allows you get high voltages without exceeding the rated voltages of the components.

William, sorry I upset you, but capacitors cannot be blown up from high frequencies...as said before the only property of a capacitor that changes is its capacitive reactance and hence A.C. impeadance. No additional heat is produced. Joule heating from internal reistance is all. Think about it...if capacitors could blow from high frequencies, they would have a frequency rating as well as a voltage rating....they don't. Only the peak voltage matters. Also it does not take 33,000 volts to produce a spark in air:

Originally Posted by Wikipedia

Voltages below about 500-700 volts cannot produce easily visible sparks or glows in air at atmospheric pressure, so by this rule these voltages are 'low'. However, under conditions of low atmospheric pressure (such as in high-altitude aircraft), or in an environment of noble gas such as argon, neon, etc., sparks will appear at much lower voltages. 500 to 700 volts is not a fixed minimum for producing spark breakdown, but it is a rule of thumb. For air at STP, the minimum sparkover voltage is around 380 volts.

http://en.wikipedia.org/wiki/High_voltage#Sparks_in_air

In fact a 'spark' is not really that well defined, but for an ESD in the convential sense we are used to, 'sparks' can be made with a 9V battery and 2 wires (No additional circuitry such as voltage multipliers.) Try it yourself.

I'm guessing the 380 volts classification by wiki is talking about a sustained spark...but momentary sparks can indeed be achieved at much lower voltages, except the holding current can't be made big enough to maintain it.

I start getting sparks at 5.5 volts.

Originally Posted by bit4bit

Yeh, it is sometimes called a Jacobs ladder (which derives from some historical thing I think), or cascade multiplier, because of the way it works. It is a nice circuit, which allows you get high voltages without exceeding the rated voltages of the components.

William, sorry I upset you, but capacitors cannot be blown up from high frequencies...as said before the only property of a capacitor that changes is its capacitive reactance and hence A.C. impeadance. No additional heat is produced. Joule heating from internal reistance is all. Think about it...if capacitors could blow from high frequencies, they would have a frequency rating as well as a voltage rating....they don't. Only the peak voltage matters. Also it does not take 33,000 volts to produce a spark in air:

Originally Posted by Wikipedia

Voltages below about 500-700 volts cannot produce easily visible sparks or glows in air at atmospheric pressure, so by this rule these voltages are 'low'. However, under conditions of low atmospheric pressure (such as in high-altitude aircraft), or in an environment of noble gas such as argon, neon, etc., sparks will appear at much lower voltages. 500 to 700 volts is not a fixed minimum for producing spark breakdown, but it is a rule of thumb. For air at STP, the minimum sparkover voltage is around 380 volts.

http://en.wikipedia.org/wiki/High_voltage#Sparks_in_air

In fact a 'spark' is not really that well defined, but for an ESD in the convential sense we are used to, 'sparks' can be made with a 9V battery and 2 wires (No additional circuitry such as voltage multipliers.) Try it yourself.

I'm guessing the 380 volts classification by wiki is talking about a sustained spark...but momentary sparks can indeed be achieved at much lower voltages, except the holding current can't be made big enough to maintain it.

Liquid run capacitors will overheat and blow apart. That is part of their design. It is like charging and draining a battery at many times its rated output or rated cycling rate. A battery is a capacitor.

It might be hard to blow apart some small, ceramic capacitors that have a lot of surface area to keep them cool. And often these small capacitors are used for high frequency, because of their ability.
But if you charge and drain a larger can capacitor very quickly, it will get hot. And the dielectric will break down.
Remember when you raise the frequency you are going to raise the intensity or watts per second. Input and output.

And they do have a frequency rating as well.

I have sustained sparks with no voltage applied. Ha-ha.



Sincerely,


William McCormick

Originally Posted by thyristor

Did yo make that ladder in our house. It must've created quite a lot of ozon.

Na, nothing compared to welding. When you weld with TIG (Tungsten Electrode Inert Gas) you get a lot of Ozone. And MIG too. MIG was originally (Molten Electrode, Inert Gas) welding. Then they changed it to (Metal electrode, Inert Gas) welding. The molten electrode causing the ARC effect. And very high voltage.

You would not believe the voltages a welder is exposed to.
And "V" escalation. Rusty connections are unbelievable.

A couple bad splice joints in a welding supply cable. And it will stand you up even if you don't want to stand up, especially when you are wet. Just a portion of one finger connected to the electrode, while you are grounded will do it.

I was working with another fellow the day before Christmas, at a church, in queens, welding an iron gate.
It was snowing and raining. My welding gauntlets were soaking wet. We had a few cables strung together. I had just gotten a good shock from the cracked rod holder. I asked the fellow I was with, a really funny Jamaican guy named Greg, to kick me off the rod holder if I got stuck. I only had a few more feet to go.

Well I touched this cracked rod holder. And I swear I jumped up uncontrollably. I was standing straight up. As I touched it I noticed that, there were white sparks coming from the splice joints. It was getting dark and I could see them in the dark for the first time. It was so amazing that I said "Greg I have to do that again. It was just too amazing.

I asked him again if I get stuck just kick me off. I did it again and jumped up again. My back locked up, as if it was a piece of metal.

I went across the street and got a pair of lady playtex gloves and finished it up. With the lady Playtex gloves, against your skin, they can raise in voltage so you don't have to. You just put the wet gauntlets on over the latex gloves. We finished the job just in time.

I do not recommend this behavior or state that it is safe. I just state I behaved in this manner.





Sincerely,


William McCormick