Encyclopedia Of Polymer Science And Technology Concise Pdf
- and pdf
- Saturday, May 1, 2021 6:02:34 AM
- 4 comment
File Name: encyclopedia of polymer science and technology concise .zip
- Concise Encyclopedia of the Structure of Materials
- Encyclopedia of Materials: Science and Technology
- Earth, Planetary, and Space Sciences
- Resettable fuse
Concise Encyclopedia of the Structure of Materials
A resettable fuse or polymeric positive temperature coefficient device PPTC is a passive electronic component used to protect against overcurrent faults in electronic circuits. The device is also known as a multifuse or polyfuse or polyswitch. They are similar in function to PTC thermistors in certain situations but operate on mechanical changes instead of charge carrier effects in semiconductors. These devices were first discovered and described by Gerald Pearson at Bell Labs in and described in US patent 2,, A polymeric PTC device is made up of a non-conductive crystalline organic polymer matrix that is loaded with carbon black particles  to make it conductive.
While cool, the polymer is in a crystalline state, with the carbon forced into the regions between crystals, forming many conductive chains. Since it is conductive the "initial resistance" ,  it will pass a current. If too much current is passed through the device the device will begin to heat. As the device heats, the polymer will expand, changing from a crystalline into an amorphous state.
A small leakage current still flows through the device and is sufficient to maintain the temperature at a level which will keep it in the high resistance state. Leakage current can range from less than a hundred mA at rated voltage up to a few hundred mA at lower voltages.
The device can be said to have latching functionality. The trip current is the current at which the device is guaranteed to trip. When power is removed, the heating due to the leakage current will stop and the PPTC device will cool. As the device cools, it regains its original crystalline structure and returns to a low resistance state where it can hold the current as specified for the device. The resetting will often not take place even if the fault alone has been removed with the power still flowing as the operating current may be above the holding current of the PPTC.
The device may not return to its original resistance value; it will most likely stabilize at a significantly higher resistance up to 4 times initial value. It could take hours, days, weeks or even years for the device to return to a resistance value similar to its original value, if at all. A PPTC device has a current rating and a voltage rating. While a fuse could also offer similar protection, if the fuse is blown, the tweeter cannot operate until the fuse is replaced.
These devices are sold by different companies under various trademarks , including Multifuse Bourns ,  PolySwitch TE Connectivity [ citation needed ] , and Polyfuse Littelfuse [ citation needed ].
PolySwitch is the earliest product of this type [ citation needed ] , having been invented at Raychem Corporation now TE Connectivity and introduced in the early s [ citation needed ]. Due to common availability, electronics engineers and technicians [ who?
From Wikipedia, the free encyclopedia. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.
Patent Mark 16 October Encyclopedia of Polymer Science and Technology, Concise. Batteries for Portable Devices. Self-Healing Polymers and Polymer Composites. Wright; P. Newbery January Electric Fuses. San Francisco Bay Area Council Western Electronic Show and Convention. TE Connectivity. Archived from the original PDF on 22 January Retrieved 31 August Retrieved 21 March Electronic components.
Potentiometer digital Variable capacitor Varicap. Capacitor types Ceramic resonator Crystal oscillator Inductor Parametron Relay reed relay mercury relay. Categories : Resistive components. Hidden categories: Articles needing additional references from January All articles needing additional references All articles with unsourced statements Articles with unsourced statements from January Articles with unsourced statements from May All articles with specifically marked weasel-worded phrases Articles with specifically marked weasel-worded phrases from May Namespaces Article Talk.
Views Read Edit View history. Help Learn to edit Community portal Recent changes Upload file. Download as PDF Printable version.
Encyclopedia of Materials: Science and Technology
new and detailed information on a broad range of materials, including fluids, amorphous spectroscopy of late, a research monograph is also welcome. This ambitious text The first chapter by Zanello is a concise comparative analysis.
Earth, Planetary, and Space Sciences
Catherine is married to Prince William , the elder son of Prince Charles and Princess Diana and the second in line to the British throne. Step back from the day-to-day and get a global perspective with the annual Britannica Premium Membership. The world standard in knowledge since Search Britannica Click here to search. Encyclopedia Categories. Today in context, March 7,
Search this site. I PDF. Algorithmics PDF. An attitude of gratitude Journal.
Ask a Librarian. Full list of eBooks in Science and Engineering. At UCLA there are two different library catalogs to search for materials:. The mission of the UCLA Library is to provide access to and delivery of information resources to UCLA students, faculty, and staff in support of the research and instructional mission of the university.
Volume 2 is the most comprehensive and detailed encyclopedia of solar energy and technology available today, containing all essential solar terms in one place. A convenient source for spelling, classifications, and concise definitions of terms encountered in the study, reading, and practice of solar technologies. The scope of the encyclopedia includes all terms of importance and topics of primary significance in the field. As the solar field is one of the fastest growing and changing sectors in the energy industry today, the ambition of this encyclopedia is to cover all key state-of-the-art solar components and technologies, including photovoltaic appliances and systems, solar-thermal systems, nanophotovoltaics, semiconductor materials and technologies, energy storage systems, software applications, solar architecture, measuring devices, units of measurements, mounting systems and components, hybrid power systems, solar occupations, infrastructure, rules and regulations, economics, and much more. Written in a clear, precise, and easy-to-understand style, the encyclopedia is equally accessible to solar specialists and laymen.
This Concise Encyclopedia draws its material from the award-winning Encyclopedia of Materials: Science and Technology , and includes updates and revisions not available in the original set. This customized collection of articles provides a handy reference for materials scientists and engineers with an interest in the structure of metals, polymers, ceramics and glasses, biomaterials, wood, paper, and liquid crystals. Materials science and engineering is concerned with the relationship between the properties and structure of materials. In this context "structure" may be defined on the atomic scale in the case of crystalline materials, on the molecular scale in the case of polymers, for example , or on the microscopic scale. Each of these definitions has been applied in making the present selection of articles. Faculty and postgraduate research students in materials science and technology and related disciplines, especially physics, chemistry, engineering and biomedical science; also researchers and staff in government and industry. Carbon Mesophase.