Static Electricity Explained




Click Here for E-Book Details



Click Here for E-Book Details

Static electricity is an electric charge built up on persons or objects through friction. It is most familiar as an occasional annoyance in seasons of low humidity, but can be destructive and harmful in some situations. When working in direct contact with integrated cicuit electronics, or in the presence of flammable gas, care must be taken to avoid accumulating and discharging static electricity.

Static electricity is electricity that does not flow in a current. Static electricity generated by rubbing two nonmagnetic objects together. The friction between the two objects generates attraction because the substance with an excess of electrons transfers them to the positively-charged substance. Usually, substances that don't conduct current electricity (insulators) are good at holding a charge. These substances may include rubber, plastic, glass or pitch. The electrons that are transferred are stored on the surface of an object.

static electricity

Materials Causing Charges 

It is created by putting certain materials together and then pulling them apart causes excess electrical charges to be created on their surfaces. This can be done by pushing them together and pulling them apart or by rubbing the materials together, which is the main way it is created.

Excess Of Charges 

Most matter is electrically neutral. That means its atoms and molecules have the same number of electrons as protons. If a material somehow obtains extra electrons and attaches them to the atom's outer orbits or shells, that material has a negative ( - ) charge. Likewise, if a material loses electrons, it has an excess of positive (+) charges. The electric field from the excess of charges then causes the electric effects of attraction, repulsion or a spark (lightning).

Stealing Electrons 

According to Solar System Model (or Bohr Model) of the atom, electrons are in orbits or shells around the nucleus. A maximum number of electrons are allowed in each orbit. Forces in each atom seek to reach that maximum number, such that if an element is just one electron short of the maximum amount in its outer orbit, it would try to "steal" an electron from another element that may be just starting its outer orbit. This is the basis of chemical reactions.

Adhesive Molecular Force  

An electric charge will also tend to hold two different materials together. In that situation, the force is called the adhesive molecular force. When different materials are pressed together and then pulled apart, the adhesive molecular force pulls electrons from material unto the other. This creates the phenomenon known as "static electricity".

You can see this electric charge effect with a piece of Scotch tape or similar tape. First verify that it is not attracted to your finger. Then stick it to some surface and then pull it off. Put you finger near the tape and it will now be attracted to your finger, showing that there is an excess of charges on the tape.

Despite their small size, protons and electrons carry an electrical charge. Protons carry a "positive" charge, while electrons carry a "negative" energy charge.

Usually, the two different charges balance each other out, and nothing happens. But when two objects with like charges (all positive or all negative) come together, the charges repel and the objects move away from each other. Objects with opposite charges attract each other because the different charges want to enter a state of balance with each other.

Objects can get a negative charge by picking up electrons from other objects. For example, when your shoes scuff against the rug, your shoes are actually picking up electrons from the rug. The electrons fly over your body, giving you a negative charge.

Your new electrons fly over your body because they are looking for a positive charge. If you touch a metal doorknob, the electrons on your body will leap into the metal, attracted by the protons there. The transfer of electrons is actually a small electrical current, and produces the tiny electric shock you feel called Static electricity.

Lightning is similar, except on a much bigger scale. Both lightning and an electric charge happens because of the attraction between the opposite static electricity charges.

Not friction  

Although your can create an electric charge by pressing materials together and pulling them apart, rubbing them together works even better, except in the case of something sticky like tape.

One unfortunate result from saying that rubbing materials creates this electric charge is that most people think that friction causes the charges to build up. It is not friction that causes the spark, rather it is the adhesive forces that pull off electrons.

Dry human skin and rabbit fur have the greatest tendency to give up electrons when rubbed on something and become positively ( + ) charged. Teflon and vinyl have the greatest tendency to become negatively charged ( - ) when rubbed. If you want to create it, rubbing fur on teflon should give the best results.

In conclusion 

It occurs when there are an excess of positive (+) or negative (-) charges on an object's surface. You can create a charge by rubbing certain materials together. It is not caused by friction. The position of the material in the Triboelectric Series determines how effectively the charges will be exchanged.


Subscription

 
Training Courses

Electrical Testing and Troubleshooting Electrical Systems

  • January 22-23, 2015 - Mississauga, ON
  • January 26-27, 2015 - Edmonton, AB
  • January 28-29, 2015 - Richmond, BC

VFDs and Electric Motor Control Training

  • February 3-4, 2015 - Richmond, BC
  • February 5-6, 2015 - Edmonton, AB
  • February 9-10, 2015 - Winnipeg, MB
  • February 11-12, 2015 - Saskatoon, SK
  • February 17-18, 2015 - Mississauga, ON

HV Substation Maintenance Practices

  • February 4-5, 2015 - Mississauga, ON
  • February 11-12, 2015 - Edmonton, AB

2015 Electrical Code Update Training

  • February 12-13, 2015 - Richmond, BC
  • February 17-18, 2015 - Calgary, AB
  • February 19-20, 2015 - Edmonton, AB
  • March 2-3, 2015 - St. Johns, NL
  • March 5-6, 2015 - Moncton, NB
  • March 10-11, 2015 - Ottawa, ON
  • March 12-13, 2015 - Mississauga, ON
  • April 20-21, 2015 - Winnipeg, MB
  • April 22-23, 2015 - Saskatoon, SK

1-Day Arc Flash/Electrical Safety Workshop

  • February 19, 2015 - Winnipeg, MB
  • February 20, 2015 - Saskatoon, SK
  • February 23, 2015 - Richmond, BC
  • February 24, 2015 - Edmonton, AB
  • February 26, 2015 - Mississauga, ON

2-Day LV-MV-HV Electrical Safety Training

  • February 24-25, 2015 - Edmonton, AB
  • February 26-27, 2015 - Mississauga, ON

1-Day HV Electrical Safety Workshop

  • February 25, 2015 - Edmonton, AB
  • February 27, 2015 - Mississauga, ON

Electrical Relay Protection Training

  • March 24-25, 2015 - Mississauga, ON
  • March 26-27, 2015 - Winnipeg, MB
  • April 7-8, 2015 - Richmond, BC
  • April 9-10, 2015 - Edmonton, AB

2-Day Arc Flash/Electrical Safety Workshop

  • May 4-5, 2015 - Richmond, BC
  • May 6-7, 2015 - Edmonton, AB
  • May 11-12, 2015 - Mississauga, ON
  • May 13-14, 2015 - St. Johns, NL

Generators and Standby Emergency Power

  • May 11-12, 2015 - Richmond, BC
  • May 13-14, 2015 - Edmonton, AB
  • May 20-21, 2015 - Mississauga, ON
 
Affiliates
 
Featured Product

S&C IntelliRupter® PulseCloser

S&C Electric Company
S&C's IntelliRupter PulseCloser is a breakthrough in distribution system protection.
more...
 
Advertisement
 
Latest Buyer's Guide Companies
Sign Up Today and Receive Our FREE E- Newsletter

E-newsletter service - Exciting industry trends, technical developments, product information, forums and electrical training courses.