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About RF Cafe
1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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Triboelectricity is the physics of charge generated through friction. The photo to the left shows a girl's hair standing on end while she has her hand on a Van de Graff generator, which transfers electrons to the metal sphere via a rubber belt. Another familiar example is rubbing a balloon on your shirt and sticking it to the wall.
In the table below, rubbing any material in the list with any material below it will cause the upper material to become positively charged. For example rubbing celluloid on nylon will produce a negative charge on the celluloid and a positive charge on the nylon. The farther apart the materials are in the list, the greater the charge will be.
Caveat: Sources for materials in this table of triboelectric charge rankings were collect from what I consider to be reliable sources. Among them are the Electrostatic Discharge Association and Alpha Labs. Charge affinity numbers are not presented here because there is no consistent agreement. Instead, relative positions are given, and even those are debatable.
|Steel (does not charge, affinity = 0)|
|Polyethylene (Scotch tape)|
|Hot Melt Glue|
|Epoxy-based PCB, FR-4|
|Relatively Negative (-)|
Electrostatics is the branch of science that deals with the phenomena arising from stationary or slowly moving electric charges.
Since classical antiquity it was known that some materials such as amber attract light particles after rubbing. The Greek word for amber, ήλεκτρον (electron), was the source of the word 'electricity'. Electrostatic phenomena arise from the forces that electric charges exert on each other. Such forces are described by Coulomb's law. Even though electrostatically induced forces seem to be rather weak, the electrostatic force between e.g. an electron and a proton, that together make up a hydrogen atom, is about 40 orders of magnitude stronger than the gravitational force acting between them.
Electrostatic phenomena include many examples as simple as the attraction of the plastic wrap to your hand after you remove it from a package, to the apparently spontaneous explosion of grain silos, to damage of electronic components during manufacturing, to the operation of photocopiers. Electrostatics involves the buildup of charge on the surface of objects due to contact with other surfaces. Although charge exchange happens whenever any two surfaces contact and separate, the effects of charge exchange are usually only noticed when at least one of the surfaces has a high resistance to electrical flow. This is because the charges that transfer to or from the highly resistive surface are more or less trapped there for a long enough time for their effects to be observed. These charges then remain on the object until they either bleed off to ground or are quickly neutralized by a discharge: e.g., the familiar phenomenon of a static 'shock' is caused by the neutralization of charge built up in the body from contact with nonconductive surfaces. - Wikipedia