16 resultados para transistores

em Repositório Institucional UNESP - Universidade Estadual Paulista "Julio de Mesquita Filho"


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

During the twentieth century the inorganic electronics was largely developed being present in various industrial equipment or household use. However, at the end of that century were verified electronic properties in organic compounds, giving rise to the field of organic electronics. Since then, the physical properties of elementary devices such as diodes and organic transistors have been studied. In this work was studied the properties of diode devices fabricated with a semiconductor polymer, the poly-o-methoxyaniline (POMA). Devices containing electrodes of Au and Al were fabricated with semiconductor polymer of different doping levels. We found that the rectifying behavior for the heterojunctions metal/polimer are reached only for high doping level (with conductivity greater than 1,77. 10-9 S / cm), which gives the devices characteristic of a Schottky diode. The rectifying behavior was observed for electric fields of low magnitude, below the operating field (~ 600 V/cm), while for electric field greater than 600 V/cm the a linear behavior I vs.V was obtained. We determined that this Ohmic behavior arises from the charge transport over the volume of the semiconductor material after the lowering of the metal/semiconductor barrier. In devices with weakly doped semiconductor, the electrical resistance of the volume becomes high and the process of charge transportation is dominated by the volume, for any intensity of the applied electric field

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Due to concerns about rational use of energy, several alternative technologies of power generation appeared, including the conversion of solar energy into electrical energy by photovoltaic panels. In low-income households, the refrigerator represents considerable impact on the electric bill, since it requires constant power given its use in food preservation. It is possible to reduce this share, with the use of an alternative energy source. This work presents a timed switching electronic system, which allows commercial equipment that is not affected by short interruptions in the power supply to use a photovoltaic panel as a source of alternative energy, which usually do not provide energy continuously. Switching is made automatically in case of low incidence of sunlight, and without any form of energy storage. Between each switching, there is a dead time without power supply, therefore preventing the use of synchronizers circuits between the photovoltaic panel and the public power grid. A circuit containing a 80C31 microcontroller is used to control the system’s switching. The photovoltaic panel’s voltage inverter is in H bridge configuration, and is also controlled by the microcontroller through Pulse Width Modulation, which makes use of preprogrammed tables to generate the control signals of the power transistors. Through the use of software simulations, the proposed system was tested, which is capable of supplying intermittent single-phase loads. The simulations indicates that the project developed in this paper can be assembled into a prototype and be tested under real operating conditions, as long as the scaling of components, the characteristics of the photovoltaic panel to be used, and the project involved load are taken into account

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Elétrica - FEIS

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Pós-graduação em Engenharia Elétrica - FEIS

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)