Digital Control Implementation to Reduce the Cost and Improve the Performance of the Control Stage of an Industrial Switched-Mode Power Supply

The main objective of this work is the design and implementation of the digital control stage of a 280W AC/DC industrial power supply in a single low-cost microcontroller to replace the analog control stage. The switch-mode power supply (SMPS) consists of a PFC boost converter with fixed frequency operation and a variable frequency LLC series resonant DC/DC converter. Input voltage range is 85VRMS-550VRMS and the output voltage range is 24V-28V. A digital controller is especially suitable for this kind of SMPS to implement its multiple functionalities and to keep the efficiency and the performance high over the wide range of input voltages. Additional advantages of the digital control are reliability and size. The optimized design and implementation of the digital control stage it is presented. Experimental results show the stable operation of the controlled system and an estimation of the cost reduction achieved with the digital control stage.

Meta-analysis of strategies to control nitrate leaching in irrigated agricultural systems and their effects on crop yield.

Nitrate leaching (NL) is an important N loss process in irrigated agriculture that imposes a cost on the farmer and the environment. A meta-analysis of published experimental results from agricultural irrigated systems was conducted to identify those strategies that have proven effective at reducing NL and to quantify the scale of reduction that can be achieved. Forty-four scientific articles were identified which investigated four main strategies (water and fertilizer management, use of cover crops and fertilizer technology) creating a database with 279 observations on NL and 166 on crop yield. Management practices that adjust water application to crop needs reduced NL by a mean of 80% without a reduction in crop yield. Improved fertilizer management reduced NL by 40%, and the best relationship between yield and NL was obtained when applying the recommended fertilizer rate. Replacing a fallow with a non-legume cover crop reduced NL by 50% while using a legume did not have any effect on NL. Improved fertilizer technology also decreased NL but was the least effective of the selected strategies. The risk of nitrate leaching from irrigated systems is high, but optimum management practices may mitigate this risk and maintain crop yields while enhancing environmental sustainability.

Evaluation of three solar and daylighting control systems based on Calumen II, Ecotect and Radiance simulation programs to obtain an energy efficient and healthy interior in the experimental building prototype SDE10

Evaluation of three solar and daylighting control systems based on Calumen II, Ecotect and Radiance simulation programs to obtain an energy efficient and healthy interior in the experimental building prototype SDE10

Inclusion of immersive virtual learning environments and visual control systems to support the learning of students with Asperger syndrome

This paper presents the use of immersive virtual reality systems in the educational intervention with Asperger students. The starting points of this study are features of these students' cognitive style that requires an explicit teaching style supported by visual aids and highly structured environments. The proposed immersive virtual reality system, not only to assess the student's behavior and progress, but also is able to adapt itself to the student's specific needs. Additionally, the immersive reality system is equipped with sensors that can determine certain behaviors of the students. This paper determines the possible inclusion of immersive virtual reality as a support tool and learning strategy in these particular students' intervention. With this objective two task protocols have been defined with which the behavior and interaction situations performed by participant students are recorded. The conclusions from this study talks in favor of the inclusion of these virtual immersive environments as a support tool in the educational intervention of Asperger syndrome students as their social competences and executive functions have improved.

Modelling and control of refrigeration systems: an account of a pedagogic experiment in a post-secondary technical course

Comunicação apresentada no CYTEF 2016/VIII Congresso Ibérico | VI Congresso Ibero-Americano de Ciências e Técnicas do Frio, 3-6 maio 2016, Coimbra, Portugal

Odor and corrosion control in sanitary sewerage systems and treatment plants : design manual.

Mode of access: Internet.

Planning of automated data acquisition and process control systems (ADACS) /

"January 1980."

Interaction between fixed and vehicular illumination systems. Phase II. Interim report.

Federal Highway Administration, Office of Research, Washington, D.C.

VIPTRAN--a programming language and its compiler for Boolean systems or process control equations.

Thesis (M.A.)--University of Illinois at Urbana-Champaign.

Energy budget procedures and performance criteria for energy conserving building illumination systems /

"April 1980, issued May 1980."

Organizational maintenance manual for cab, armament, sighting, and fire control, elevating and traversing systems and associated components : howitzer, medium, self-propelled, 155mm, M109A2 (2350-01-031-0586), M109A3 (2350-01-031-8851).

"June 1986."

Organizational maintenance manual for cab, armament, sighting, and fire control, elevating and traversing systems and associated components : howitzer, medium, self-propelled, 155mm, M109A2 (2350-01-031-0586), M109A3 (2350-01-031-8851).

"30 June 1986."

Unit maintenance repair parts and special tools list for cab, armament, sighting and fire control, elevating and traversing systems, and associated components, howitzer, medium, self-propelled, 155mm, M109A2 (NSN 2350-01-031-0586), M109A3 (NSN 2350-01-031-8851) ...

"November 1989."

Direct support and general support maintenance repair parts and special tools list ... for cab, armament, sighting and fire control, elevating and traversing systems, and associated components, howitzer, medium, self-propelled, 155mm, M109A2 (NSN 2350-01-031-0586), M109A3 (NSN 2350-01-031-8851) ...

"December 1989."