Análisis de la resistencia de piezas soldadas por el proceso de resistencia eléctrica

A stay has been carried out in a metalworking company located in the Valle de Aguascalientes Industrial Park, in order to carry out a study that can reflect the state of manufacture of various metal parts that involve an electrical resistance welding process. The manufacturing area is called Automotive and has 5 welding machines of various brands and capacities in which different models of automotive parts are manufactured for various clients of the automotive industry in Aguascalientes Mexico. The study focuses on the review of the process based on the regulations that are handled in the company and that are the JIS B 1196 referring to spot welding, from which two main characteristics are extracted to guarantee the quality of the product and that are the resistance to weld stress and torsional strength. The manufacturing standards used determine that every hour a stress test must be carried out on the different manufactured parts according to their classification, welding is tested on 6M, 8M and 10M nuts of the international system applying loads in a brand FORSE DX-2.5 model hydraulic press and one hundred percent tests torque on parts with 6M nuts welded, which are tested in a devise of our own design. The data taken for the evaluation were obtained in the company's metrology laboratory and showed a very marked dispersion, although said data apparently did not exceed the established limits. A review and evaluation of the process was carried out and limits and improvements were proposed that guarantee good quality of the products. Some practices that can affect quality were found, they are described and a solution is proposed to prevent them from being carried out in the process.

Películas de SRO-HFCVD como dieléctrico en estructuras MIS y sus propiedades eléctricas

This paper presents the results obtained by the electrooptical characterization of a MIS structure built by depositing a film of an Indium Tin Oxide (ITO) on a Silicon Rich Oxide (SRO) film using the Chemical Vapor Deposition Hot Filament (HFCVD) system. The SROHFCVD films were deposited considering two hydrogen fluxes levels at 25 and 100 sccm, under these conditions we grow single and double films, both being heat treated at 1100 ° C to improve their optical and structural characteristics. Through of the techniques of Null Spectroscopy, XPS and Photoluminescence, it was possible to determine the thickness of the SRO films, quantify the silicon excess present in them and analyze their spectra. These films are used as the active layer in Metal-Insulating-Semiconductor (MIS) structures, such structures were electrically characterized through the I-V curves. From the result of these characterizations a comparison is made between the MIS structures with films virgin (V) and with ones heat-treated (T-T). Characterizations indicate that SRO-HFCVD films with T-T significantly modify the optical and electrical properties of MIS structures, which is promising for the design of integrated optical sensors.

Diseño e implementación de un sistema de control a lazo cerrado PID para manipular la temperatura en el proceso de termoformado

The purpose of this work lies in the design and implementation of a closed-circuit temperature control system (SCTLC), to control the temperature transfer in the mold of the thermoprepared system, where the blocks are manufactured from multilayer containers. post-consumer. The plant (electrical resistance) was characterized, with the AC voltage levels (30V, 60V, 90V and 120V) in a time of 60 min each of the voltage levels, considering the initial temperature (ambient temperature), in function of the step signal, then, the plant model was determined using Matlab software and the analytical method with the data of the plant characteristic curve at a voltage of 120Vac, obtaining the first-order transfer function, then The PID controller implemented the Ziegler & Nichols method and the Matlab software were tuned and finally the reference input, the control, the power stage, the plant and the feedback were coupled. This project contributes to control and stabilize the resistance temperature, implemented in the thermoforming process, for the production of blocks using multilayer containers.

Desarrollo del algoritmo genético heurístico para la coordinación de protecciones

The coordination of overcurrent relays is an easy task when dealing with a radial distribution line. However, when directional units are in place to protect meshed networks, the problem becomes very complex. This is because the protection device must offer primary and backup operation for the same or multiple lines using the same protection setting. Moreover, considering two parameters namely the time dial setting and the current pickup setting make the coordination problem even more complex to be achieved manually. Therefore, in this article, the protection coordination study is formulated as an optimization problem to be solved using a heuristic Genetic Algorithm. This not only saves time for the protection engineer; it also transfers the burden to a computer using artificial intelligence and guarantee that the results are close to optimal.

Diseño y construcción de un colorímetro para identificar el desgaste de fusibles comerciales usando sensores fotoeléctricos

Color is a property that we are able to observe thanks to our visual perception; however, an instrument is necessary to perform the quantification on the RGB scale. The purpose of this work is to design and build a colorimeter to identify the wear degree of a conventional residential fuse, the fuse has been exposed to normal wear. The study is carried out using the quantification of light reflection on the RGB scale. The developed sensor consists of: - A cylindrical base made on a 3D printer, which allows the external light to be isolated and the upper part of the fuse socket inserted. - An electronic circuit made up of RGB light emitting led and a photoresistor. - An Arduino program that measures the reflection of the fuse on the RGB scale. Implementing the sensor will allow the identification of fuses in poor condition, which can cause failures in the electrical system. Future work will be aimed at quantifying the increase of energy consumption due to the use of fuses in poor condition transferred in RGB space.

Pedaleando por un ahorro

This project presents the design of an electrical power generation system, which takes advantage of a person’s movement when exercising on a static bicycle. This system is implemented in a gym located in Suchiapa, Chiapas. The analysis is carried out of three categories of people: high performance athlete, occasional athlete and sedentary person, to evaluate the calories consumed per day and exercise time on static bicycle. This information provides an estimate of the energy generated in one day, to compare the receipt of power consumption of CFE before and after the system. The static bicycle is mechanically attached to a generator by means of a support, followed by a diode allowing the passage of the electric current with characteristics similar to a switch, which is connected to a voltage regulator that maintains a constant voltage level. The regulator is coupled to the electric accumulator and an inverter. The latter is in charge of converting the direct current input voltage and alternating current output. By implementing the mechanism with nine static electric bicycles, an energy saving of 17.57 % is obtained.

Caracterización térmica y eléctrica de un sistema fotovoltaico de alta concentración de disco parabólico

Este artículo presenta el estudio experimental que consiste en el análisis del desempeño térmico y eléctrico de un sistema HCPV que cuenta con dos discos parabólicos y sus respectivas unidades de conversión de potencia (PCUs) configurados en una óptica especial conocida como XRX-Köhler. Este sistema utiliza celdas multi-unión, que, a pesar de su alta eficiencia, no utilizan entre el 60-70% de la radiación recibida por lo que esta energía debe ser retirada con un sistema de enfriamiento para mantener su temperatura dentro de un intervalo que asegure su integridad y el mejor desempeño de la misma. A diferencia de las celdas de unión sencillas, las MJ pueden operar a más altas temperaturas con eficiencias aceptables de producción eléctrica. Esta característica de operar en un rango amplio de temperaturas (~ 90°C), puede hacer que sistemas térmicos de aplicaciones solares funcionen con el calor residual y así mejorar el desempeño total del sistema. Se ha desarrollado una serie de campañas de pruebas experimentales para la evaluación tanto de las curvas I-V en forma instantánea como las eficiencias instantáneas eléctrica y térmica obteniendo valores de ~24% y de ~53%, respectivamente.

Diseño de un sistema fotovoltaico autónomo para el uso en áreas recreativas en la zona costera

Photovoltaic station created on a frame of metal and wood taking advantage of the conventional umbrella geometry, made of mesh-shadow of those used on beaches or terraces, projecting its shadow in order to avoid sunstroke to users. A multifunctional element was developed; combining ecology and technology, which uses photovoltaic technology to provide charge to gadgets and integrated LED luminaires. The 2 photovoltaic modules located on the structure not only serve to generate electricity but also to provide protection from solar radiation. For the development of this project, electrical, electronics, energy engineers and various experts in the field have collaborated. This station includes 50 Wp and 1 lithium-ion battery that makes possible the production and storage of electrical energy coming from the solar resource. Thanks to this system, the supply of electricity is guaranteed even when there is a low level of solar radiation. The recharge capacity of this installation is up to 12000 mAh at the same time an availability 24 hours a day.

Estudio de las condiciones de iluminación dentro de las instalaciones de la Facultad de Ingeniería Mecánica y Eléctrica región Poza Rica – Tuxpan

Lighting is a fundamental part in the ergonomic conditioning of workstations; Although, the human being has the ability to adapt to different light conditions, the deficiency in it causes visual fatigue, which can be one of the causes for which workers make mistakes in their activities or even to cause accidents. The present work focuses on an analysis of the lighting conditions in the classrooms, laboratories and cubicles of the faculty of Mechanical and Electrical Engineering, and identify yes, the areas where the visual tasks associated with the workstations have poor lighting or excessive that causes glare, to determine what preventive or corrective measures to take, in order to achieve a safe and healthy environment for the university community. With the help of a luxometer measurements are made to calculate the average illumination (EP) and compare it with the Official Mexican Standard "NOM-025-STPS-2008, Conditions of lighting in the workplace" that establishes the maximum permissible limits ( 500 luxes). The results obtained reflect that not all the mentioned areas comply with NOM-025-STPS-2008.

Sistema de control de temperatura on-off implementado en el proceso de termoformado para elaboración de bloque a partir de envases multicapas

In this work, a temperature control system (SCT) was designed and implemented in the thermoforming process for the manufacture of blocks for wall construction (BCM). The control process in the SCT consists in establishing the reference temperature for the thermoforming and send it to the Mega 2560 microcontroller. This component processes the input signal, obtaining six digital signals that control the surface temperature of each of the external faces of the BCM mold that has a rectangular prism geometry. These signals are sent to the electrical isolation stage where the actuators enable six electrical resistances (200 Watts to 120 Volts). The feedback of the temperature in the control system was made through type-k thermocouples, whose analog signals are compared with the reference signal to regulate the temperature. This project contributes to establish and control the temperature of the resistances, implemented for the thermoforming process, for the elaboration of blocks using multilayer containers.