Tecnologia 1-wireTM aplicada ao controle em tempo real de sistemas de aeração de grãos

• Autor(a) principal: Monteiro, Paulo Marcos de Barros
• Data de Publicação: 2002
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/633
• topic: Grãos; Aeração; Simulação por computador; Armazenamento; Grain aeration systems; Computer simulation; Storage; Control systems, 1-WireTM System, Automation, DS1820; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA::ENERGIZACAO RURAL

In this work, a real time intelligent control system for stored grain aeration systems was developed, employing the 1- wireTM technology developed by Dallas Semiconductor. The standard thermocouples, commonly used in aeration systems, were replaced by DS1820 digital temperature sensors. This technology allows for a half duplex data transfer and each device connected to the system can be addressed, because each one contains a unique individual identification code. The 1-wireTM system is an open drain master-slave system connected by a single conductor and powered by a 5 V DC, through a pull up resistor, at the master. For testing the control system, a grain bin prototype was built and a software was developed to perform real time temperature data acquisition. The program makes the necessary calculations and, based on psychrometric conditions of the air and of the grain mass, and the aeration strategy used, monitors the control system.