Electric Circuits

The paper inhere presents the implementation of voltage based solutions of transients using the Laplace transformation in the study course of "Basic principles of electrical engineering II". The proposed approach is intended to expand and improve the knowledge, the skills, and the understanding of students regarding finding the solutions of transients in linear electrical circuits in the Laplace domain.

Se presenta una metodología para cuantificar el efecto de la distorsión armónica de tensión sobre la eficiencia, el factor de potencia y la potencia del motor trifásico de inducción. La metodología usa un circuito equivalente modificado del motor de inducción que permite calcular su operación ante frecuencias armónicas. Las ecuaciones del modelo se resuelven usando el principio de superposición y son simuladas mediante el software MATLAB. La metodología fue aplicada a un motor de jaula de ardilla de 3 HP. Se observa que el factor de potencia y la eficiencia del motor disminuyen respecto a la magnitud y el orden del contenido armónico del sistema de alimentación, por lo tanto la metodología permite determinar la desclasificación de la potencia del motor.

Some embodiments of the present invention describe an apparatus that includes an oscillator, a ramp generator, and an inverter. The apparatus includes an oscillator, an inverter, and a ramp generator. The oscillator is configured to generate a waveform comprising a low time and a hightime. The inverter is configured to receive the waveform generated by the oscillator, and invert the waveform. The ramp generator configured to increase a gate control voltage of a transistor connected to a solar cell, and rapidly decrease the gate control voltage of the transistor. During the low time of the waveform, a measurement of a current and a voltage of the solar cell is performed as the current and voltage of the solar cell are transmitted through a first channel and to a second channel. During the high time of the waveform, a measurement of a current of a shorted cell and a voltage reference is performed as the current of the shorted cell and the voltage reference are transmitted through the first channel and the second channel.

This paper develops Imaginary Vector Algebra (IVA), a rigorous mathematical framework for unifying the description of static vector quantities and dynamic oscillatory phenomena. While established formalisms such as Complex Vector Spaces (C n) and Geometric Algebra provide comprehensive tools, IVA offers a pedagogically distinct approach by explicitly separating a vector entity into a real 'state' component and an imaginary 'phase' component. We define an Imaginary Vector as Z = ⃗ a + i ⃗ b, where ⃗ a, ⃗ b ∈ R n. We establish its properties, including a conjugate-symmetric inner product and a formalism for linear operators. The framework's utility is demonstrated through a detailed numerical analysis of an RLC circuit and the visualization of a quantum bit (qubit). By preserving directional vector information while encoding phase, IVA presents an intuitive and powerful tool for analysis and education in engineering and physics.

One of the primary goals of smart cities is to enhance the welfare and comfort of their citizens. In this context, minimizing the time required to detect fault events becomes a crucial factor in improving the reliability of distribution networks. Fault detection presents a notable challenge in the operation of Smart City Distribution Networks (SCDN) due to complex operating conditions, such as changes in the network topology, the connection and disconnection of distributed energy resources (DERs), and varying microgrid operation modes, all of which can impact the reliability of protection systems. To address these challenges, this paper proposes a fault detection system based on Long Short-Term Memory (LSTM), leveraging instantaneous local current measurements. This approach eliminates the need for voltage signals, synchronization processes, and communication systems for fault detection. On the other hand, LSTM methods enable the implicit extraction of features from current signals and classifies normal operation and fault events through a binary classification formulation. The proposed fault detector was validated on several intelligent electronic devices (IED) deployed in the modified IEEE 34-node test system. The obtained results demonstrate that the proposed detector achieves a 90% accuracy in identifying faults using instantaneous current values as short as 1/4 of a cycle. The results obtained and its easy implementation indicate potential for real-life applications.

Sprinkler systems are usually found around both corporate and industrial areas, where they are often used to water lawns. At most times, sprinkler systems operate during working hours. Hence the sprinklers tend to disturb the everyday movement of by-passers (workers and students) by spraying them with water ('water jetting'). This poses a problem to workers' daily activities as they must opt for alternative routes to avoid areas with sprinklers, which is a tedious and inconvenient process. This paper presents the design and simulation of an Automated Motion Sensing Sprinkler System (AMSSS), which automates controlling the spray distance and tilting of water sprinklers upon motion detection to prevent water jetting of workers and students. The presented work is designed to interface between sprinklers and their water supply via water pumps to control the water flow rate and the sprinkler spray distance. Furthermore, it uses a tilt mechanism actuator controlled by a motor to direct water spray area or location. The system is based on Passive Infrared (PIR) sensors, NE 555 timers, and SR latches to detect motion and provide the signals used to control and coordinate the sprinkler spray patterns. The circuit was designed, simulated, and tested in Proteus with positive results.

The benefits of distributed generation (DG) based on renewable energy sources leads to its high integration in the distribution network (DN). Despite its well-known benefits, mainly in improving the distribution system reliability and security, there are challenges encountered from a protection system perspective. Traditionally, the design and operation of the protection system are based on a unidirectional power flow in the distribution network. However, the integration of distributed generation causes multidirectional power flows in the system. Therefore, the existing protection systems require some improvement or modification to address this new feature. Various protection strategies for distribution system have been proposed so that the benefits of distributed generation can be fully utilized. This paper reviews the current progress in protection strategies to mitigate the impact of distributed generation in the distribution network. In general, the reviewed strategies in this paper are divided into: (1) conventional protection systems and (2) modifications of the protection systems. A comparative study is presented in terms of the respective benefits, shortcomings and implementation cost. Future directions for research in this area are also presented.

Teachers are deeply concerned on how to be more effective in our task of teaching. We must organize the contents of our specific area providing them with a logical configuration, for which we must know the mental structure of the students that we have in the classroom. We must shape this mental structure, in a progressive manner, so that they can assimilate the contents that we are trying to transfer, to make the learning as meaningful as possible. In the generative learning model, the links before the stimulus delivered by the teacher and the information stored in the mind of the learner requires an important effort by the student, who should build new conceptual meanings. That effort, which is extremely necessary for a good learning, sometimes is the missing ingredient so that the teaching-learning process can be properly assimilated. In electrical circuits, which we know are perfectly controlled and described by Ohm's law and Kirchhoff's two rules, there are two concepts that correspond to the following physical quantities: voltage and electrical resistance. These two concepts are integrated and linked when the concept of current is presented. This concept is not subordinated to the previous ones; it has the same degree of inclusiveness and gives rise to substantial relations between the three concepts, materializing it into a law: The Ohm, which allows us to relate and to calculate any of the three physical magnitudes, two of them known. The alternate current, in which both the voltage and the current are reversed dozens of times per second, plays an important role in many aspects of our modern life, because it is universally used. Its main feature is that its maximum voltage is easily modifiable through the use of transformers, which greatly facilitates its transfer with very few losses. In this paper, we present a conceptual map so that it is used as a new tool to analyse in a logical manner the underlying structure in the alternate current circuits, with the objective of providing the students from Sciences and Engineering majors with another option to try, amongst all, to achieve a significant learning of this important part of physics.

ABSTRACT: The purpose of this study was to determine 9th grade students' misconceptions about simple electric circuits and to explore the relationship between these misconceptions and some selected variables (students' gender and experience about electric circuits). Review ...

El propósito central de la investigación que se presenta en este artículo fue promover los procesos argumentativos a partir de los modelos explicativos que existen sobre el concepto de circuitos eléctricos e identificar las relaciones que se pueden establecer entre los procesos argumentativos, entendidos a partir de los niveles de argumentación, y los modelos explicativos de dicho concepto en los estudiantes de grado 11.  La investigación es descriptiva-comprensiva, realizada en tres momentos: en el momento 1, de ubicación o diagnóstico, se identificaron los modelos explicativos iniciales de los estudiantes que hicieron parte de este estudio y se determinó su nivel de argumentación; en el momento 2, de desubicación o intervención, se aplicó una unidad didáctica diseñada para intervenir los niveles argumentativos y los modelos explicativos del concepto de circuitos eléctricos de los estudiantes; finalmente  en el tercer momento de reenfoque o cierre, se realizó un análisis de los cam...

The paper inhere presents the implementation of voltage based solutions of transients using the Laplace transformation in the study course of "Basic principles of electrical engineering II". The proposed approach is intended to expand and improve the knowledge, the skills, and the understanding of students regarding finding the solutions of transients in linear electrical circuits in the Laplace domain.

The math model for a mass-spring-damper given here is where the mass is oscillating in a vertical position. This math model is different than the one which is oscillating in a horizontal position provided in Chapter 10 on Ship Dynamics. This may be more suitable for Naval Architecture and Marine (Ship) Engineering. Also, in electrical engineering circuits course on RLC there is a similar math model where this derivation can be helpful. Some textbooks omit the derivation because its lengthy or if it is useful it can be found in another relevant textbook.

The textbook used for this math model is 'Introduction to Numerical and Analytical Methods with Matlab for Engineers and Scientist'. Author/Engineer: William Bober.

The Naval Architecture textbook: Applied Naval Architecture by Robert Zubaly; first edition sixth printing. Both SI and English unit problems. Prerequisite: Completion of high school math or year one college math. The textbook has some of the relevant math required explained very clearly, which is the basic introduction of an integral in calculus, that is the area under a curve. 2nd order differential equation could require further courses in mathematics. Here, the purpose was to provide some exposure on this math's side of things to gain an understanding on what could be involved in ship dynamics. Aotearoa - New Zealand.

Apologies for any errors and omissions.

Regards,
Karl Bogha.

We have designed a remote controlled fan regulator, which can be used to adjust the speed of the fan by using any kind of remote, most commonly, a TV remote. The device would allow a person to control the speed of a fan by simply pointing the remote towards a sensor and then pressing any key. Whereas there have been methods of controlling fan speed using other methods, like using the sound of clapping, our method is by far the cheapest and simplest. In the final stage, we have done the hardware implementation of the controller by fabricating a printed circuit board.

Engineering at the University of Cape Town, who provided continuing encouragement and academic insight, and who was always available to provide constructive assistance. Amanda, my wife, for her infinite patience, kind suggestions and ceaseless encouragement, as well as being an excel.lent advisor concerning the intricacies of the English language. For his skilful ability and input regarding software development, Mr Chrism Kleyn. Mr Henry Brown for the use of his personal Laserjet printer and assistance during printing. My parents, for their tremendous understanding and moral support. Photograph Bl3 : This photograph shows the two resistors that were used during the investigation into the temperature coefficients of metalfilm resisters and carbon film resistors. They are both 1 oon resistors, and the 5% tolerance carbon film resistor is shown on the left, whilst the 1 % tolerance metal-film resistor is shown on the right Notice the difference in the size of the two resistors. Also included in the photograph is the LM35 temperature sensor, which was employed in virtually all the experiments. This 3-legged device provides a voltage output with +10mV/°C slope .... .it has an internal offset such that the output is 0 volts at 0°C. Photograph Bx : The three devices shown are the AD633, the LF351 high speed, JFET-input operational amplifier, and the AD620 high accuracy, instrumentation amplifier. The LF351 is normally used in applications such as high speed integrators, fast DI A converters, sampleand-hold circuits, and many other circuits requiring low input offset voltage, low input bias current, high input impedance, high slew rate and wide bandwidth. The high accuracy AD620, with its low offset voltage, high common-mode rejection and extremely low offset drift of 0.6µ V /°C, is ideally suited for use in precision data acquisition systems such as transducer interfaces.

Harmonics is a power quality problem which represents a steady-state problem. It leads to a number of issues, ranges from equipment mal-function, which result to overheating of rotating machinery and random tripping of relays for protection of devices. Shunt active power filter (SAPF) has been the most popular choice to address harmonic disturbances in power system networks. For efficient compensation, SAPF greatly depends on fast and accurate detection of reference harmonic current. To generate the reference signals, modified synchronous reference frame (MSRF) technique is chosen. Low pass filter (LPF) has always been used to separate fundamental from harmonic components, and it provides adequate and reasonable results in harmonic mitigation. However, there is need for improvement due to presence of unwanted low order harmonics that cannot completely be eliminated by LPF. Meanwhile, generation of compensation current by SAPF is also depending on switching strategy. Sinusoidal PWM i...

The paper presents the design, description and traction research results concerning the prototype transducer of vehicle velocity installed in FIAT CINQUECENTO 1.1i passenger car. Within the confines of paper the original speedometer installed in the vehicle was calibrated in order to obtain the true values of vehicle velocity. The performed measurements of the transducer were compared with the original speedometer readings and the characteristic of the transducer was prepared. The mechanical part of vehicle velocity transducer, the electronic part of vehicle velocity transducer and traction researches are an object of the paper. Fuel consumption signal processing, the transducer design, the view of the vehicle velocity transducer, electric diagram of the vehicle velocity transducer, the results of the transducer calibration among other things are presented in the paper. The performed research of the prototype electronic transducer prove that it can be successfully used to design and built more advanced transducer dedicated to liquid fuel consumption measurement given in dm 3 /100km unit.

La educacion actual requiere de cambios en los procesos de ensenanza y aprendizaje, en especial en el campo de la educacion matematica donde se encuentra una mayor demanda de estudiantes que presentan dificultades en la comprension de conceptos matematicos, por tanto para mejorar este proceso, la finalidad de esta investigacion es presentar la viabilidad de un modelo teorico para el analisis de procesos de aprendizaje y ensenanza de las matematicas, que es el analisis didactico, el cual se usa para planificacion y desarrollo de las clases. Dicho modelo contempla cuatro tipos de analisis: analisis de contenido, analisis cognitivo, analisis de instruccion y analisis de actuacion, los cuales son aplicados en la Institucion Educativa Baudilio Montoya en la clase de decimo A. Este modelo se ha elaborado para describir (?que ha ocurrido aqui?), explicar (?por que ha ocurrido?), desarrollar (?Que se debe hacer?) y valorar (?que se podria mejorar?).

The successful design and operation of any power system is highly dependent on the economic load dispatch problem, therefore it can be considered as a major factor for any power system. Economic load dispatch (ELD) problem is the short-term determination of the best combination of generation while satisfying the demanded load with minimum cost under the system constrains. Generally, the cost function presented as quadratic function and solved by using different methods. For the past ten years, in order to solve (ELD) problems and to get the best possible results, many new methods have been developed such as meta-heuristic algorithms which are classified into two major classes (swarm intelligence and evolutionary) techniques. In this paper, two (swarm intelligence) optimization techniques are used, namely salp swarm algorithm (SSA) and grasshopper optimization algorithm (GOA) which are relatively new techniques. The (ELD) analytical method, simplified version of the analytical method and optimization techniques (SSA, GOA) applied to a microgrid considering the renewable energy sources (solar and wind) for different generation combination scenarios. At last, a comparison presented between the used methods in order to show the best result possible between them, in addition the result will show the effect of the renewable energy on the total generation cost. The proposed methods (analytical method, the simplified version of the analytical method and the salp swarm algorithm (SSA)) the same results for total average cost approximately (7292.64 $/h) but the execution time was better with the simplified version of the analytical method with time of (0.373 seconds), while the grasshopper optimization algorithm (GOA) showed a higher total cost average approximately (7292.94 $/h).

This paper explains the implementation of a small-signal model for a new five-level series resonant inverter structure. The proposed circuit combines the advantages of multilevel inverters and the characteristics of the physical phenomena, resonance. The small-signal model offers the possibility to design a linearized linear time-invariant (LTI) model around an equilibrium point based on the first-order Taylor series. After that, the performance of the proposed five-level series resonant inverter and its small-signal model are evaluated in MATLAB/Simulink environment. Compared with a MATLAB model generated using the system identification toolbox, the developed small-signal model exhibited a good accuracy in frequency and time domains. In addition, a hardware test bench is developed to validate the proposed model. Both simulation and experimental results show that the proposed multilevel resonant inverter is very interesting for high-voltage high-frequency applications. As a perspective, from the results obtained, we suggest the use of small-signal AC analysis for multilevel series resonant inverter modeling. The paper contains rich information on the recently used tools for dynamic systems modeling and analysis of nonlinear processes that can be applied to modeling and analyzing other power electronics inverters. INDEX TERMS AC analysis of dynamic nonlinear system, five-level series resonant inverter, inverter mathematical model, multilevel inverter simulation, model of inverter, small-signal modeling.

Laporan akhir praktikum ini membahas **Hukum Ohm** yang mempelajari hubungan antara tegangan, arus, dan hambatan dalam rangkaian listrik melalui persamaan dasar V = I x R. Tujuan utamanya adalah membuktikan Hukum Ohm dengan mengukur tegangan dan arus sambil mengubah resistansi, serta menentukan hambatan dalam ampermeter dan voltmeter. Percobaan ini menunjukkan bahwa semakin besar resistansi, semakin kecil arus yang mengalir, dan semakin besar tegangan, semakin besar arus yang dihasilkan, sesuai dengan prinsip Hukum Ohm.

Experiments have been at the heart of scientific development and education for centuries. From the outburst of Information and Communication Technologies, virtual and remote labs have added to hands-on labs a new conception of practical experience, especially in Science, Technology, Engineering and Mathematics education. This paper aims at describing the features of a remote lab named Virtual Instruments System in Reality, embedded in a community of practice and forming the spearhead of a federation of remote labs. More particularly, it discusses the advantages and disadvantages of remote labs over virtual labs as regards to scalability constraints and development and maintenance costs. Finally, it describes an actual implementation in an international community of practice of engineering schools forming the embryo of a first world wide federation of Virtual Instruments System in Reality nodes, under the framework of a project funded by the Erasmus+ Program.

Laboratories are a fundamental part of engineering education due to the very nature of the engineering profession. This is a characteristic of all engineering courses, though it may vary from one curriculum to the other and even in the same curriculum. This paper is dedicated to the analysis of different applications of a remote lab in an Electrical Engineering curriculum. If the types of experiments it offers are concerned, it is classified as an Electric and Eletronic Circuits lab; one in a set that also has Digital Electronics, Analog Electronics, Electrical Machines, Control Systems, etc. But it is not a traditional labit is a remote lab, with traditional components remotely accessed over the Internet. This work presents the preliminary results of the deployment of VISIRa remote lab for Electric and Electronic Circuits in some courses. It discusses the different course contexts and how the use of VISIR was adapted to each one. Results of students' opinions are presented and discussed.

The present investigation about the didactic boards of electricity also known as blackboards in the technical area of electricity, are very applied in the educational centers, to reinforce the verbal explanations of the trainer and increase the active participation of the students, favoring better comprehension and memorization of the learning contents, in general terms the electrical panels are spaces where the connection, control, maneuver, protection, measurement, signaling and distribution devices are concentrated, all these devices allow an electrical installation to work properly. The design and construction of a didactic board for the practices of electrical installations in the educational centers is focused to interact in a dynamic way the teaching-learning process so that the students develop their skills in the different electric circuits that are usually applied in residential electrical installations, The purpose is always to improve the academic level of schoolchildren...

This paper comprehensively analyzes the locus comparison of SVPWM and PWM. The comparison involved,. In PWM methods such as sine-triangle PWM, three phase reference modulating signals are compared against a common triangular carrier to generate the PWM signals for the three phases. In SVPWM methods, a revolving reference voltage vector is provided as voltage reference instead of three phase modulating waves. The magnitude and frequency of the fundamental component in the line side are controlled by the magnitude and frequency, respectively, of the reference vector. The highest possible peak phase fundamental is very less in sine triangle PWM when compared with space vector PWM. Space Vector Modulation (SVM) Technique has become the important PWM technique for three phase Voltage Source Inverters for the control of AC Induction, Brushless DC, Switched Reluctance and Permanent Magnet Synchronous Motors.

In an electric power network, from view point of many consumers, power generation, and transmission should become exactly without interruption. Because the distribution system relates directly to consumers so should have high reliability. Overcurrent relays are often used for primary protection of distribution lines and secondary protection of radial transmission lines. The main objective in protection systems is the rapid separation of minimum amount of equipment as much as possible and without operation interference. These should be done after error detection in the system. This paper proposes proper coordination of directional overcurrent relays (DOCR) based on Particle swarm optimization (PSO) algorithm with take into account of fault current direction restriction. The proposed algorithm has been tested in the standard IEEE 30 bus distribution system.

Dalam mempelajari ilmu yang berhubungan dengan elektro tentunya tidak akan lepas dengan suatu perhitungan. Perhitungan-perhitungan yang dilakukan harus berdasarkan kaidah-kaidah, hukum-hukum, dan metode-metode tertentu. Suatu perhitungan dalam ilmu elektro tidak akan diselesaikan dengan menggunakan cara yang sama. Tentunya tiap-tiap permasalahan yang berhubungan dengan keelektroan akan diselesaikan dengan cara yang berbeda, tergantung apa yang di cari. Dalam menghitung nilai arus pada suatu rangkaian ada beberapa teorema atau metode yang digunakan. Teorema-teorema ini dipakai untuk menganalisis suatu perhitungan sesuai dengan jenis rangkaiannya. Teorema-teorema tersebut tidak lepas dari Hukum Kirchooff dan Hukum Ohm. Salah satu teorema tersebut adalah teorema superposisi. Teorema ini digunakan untuk menganalisis suatu rangkaian dengan sumber lebih dari satu.

The RLC circuit is an electrical circuit that is widely used in daily life. Calculations on RLC circuits are not too difficult if complex numbers are well understood. Complex numbers are a number system in mathematics expressed in the notation a + bi, where a and b are real numbers, and i is an imaginary number. All types of mathematical numbers are part of complex numbers. In this paper, we discuss the calculation of resistance and capacitance in RLC circuits using complex numbers, as well as various ways of presenting and transforming complex numbers. This paper also shows that the application of complex numbers is often used in various aspects of daily life, so understanding them can facilitate calculations in RLC circuits.

Each production line is required to comply with occupational health regulations. But in reality many companies do not comply with these regulations because there are no tools available at the market at low prices. This paper presents an investigation of the health monitoring system framework for production lines on IR 4.0, and proposes a cost-based and system-wide framework. The framework of the paper consists of raspberry pi 3 as the main module of IoT processing, and there are 3 sensors such as DHT11, MQ5, and MQ9. The DHT11 sensor is used to detect temperature and humidity, the MQ5 sensor is used to detect Liquified Petroleum Gas (LPG), and the MQ9 Sensor is used to detect carbon monoxide (CO). The method used in this paper is to look for literature studies, then collect component data, then select components based on literature studies. Then form components into several frameworks, which are then selected as the best framework. Finally, arrange, run and test the system.

O circuito RLC (Resistor- R, Indutor- L e Capacitor -C) e um circuito eletrico oscilante por excelencia. Sua forma simples permite controlar facilmente os parametros que caracterizam o seu funcionamento, o que o torna um otimo mecanismo para a simulacao de outros sistemas oscilantes.[...]

Increased downscaling of CMOS circuits with respect to feature size and threshold voltage has a result of dramatically increasing in leakage current. So, leakage power reduction is an important design issue for active and standby modes as long as the technology scaling increased. In this paper, a simultaneous active and standby energy optimization methodology is proposed for 22 nm sub-threshold CMOS circuits. In the first phase, we investigate the dual threshold voltage design for active energy per cycle minimization. A slack based genetic algorithm is proposed to find the optimal reverse body bias assignment to set of noncritical paths gates to ensure low active energy per cycle with the maximum allowable frequency at the optimal supply voltage. The second phase, determine the optimal reverse body bias that can be applied to all gates for standby power optimization at the optimal supply voltage determined from the first phase. Therefore, there exist two sets of gates and two reverse body bias values for each set. The reverse body bias is switched between these two values in response to the mode of operation. Experimental results are obtained for some ISCAS-85 benchmark circuits such as 74L85, 74283, ALU74181, and 16 bit RCA. The optimized circuits show significant energy saving ranged (from 14.5% to 42.28%) and standby power saving ranged (from 62.8% to 67%).

The development of a microcontroller-based electrostatic charge meter is described. The meter is of the non-contact type and provides a reading of surface voltage by integrating the current supplied to the probe head to keep it at earth potential as the instrument is brought to within a specified distance of the target. The use of a microcontroller allows the use of a small number of components and the resetting of the integrator without relays or switches as well as self-calibration and auto-ranging. The minimal use of capacitors and complete lack of inductance facilitates ATEX certification.

With the depletion of natural resources, it has become a topic of great concern to address the unsustainable way of life. In this study, we investigate the use of piezoelectric material-to generate electricity in schools. The use of these piezoelectric materials in floor tiles could enable us to generate energy from the footsteps of the children in school. The goal is to be able to power lights and fans in classrooms and reduce the consumption of conventional electricityproduced through the combustion of coal and other natural resources. The primary method of research is to develop a prototype with different choices of material and configurations of piezoelectric transducers to maximize power generation in a typical school setting. The results showed that the energy generated from one step needs to be improved by a factor of 100 for a typical classroom to generate enough power for a light and a fan. The research found that current technology, although promising, is incapable of producing enough power via piezoelectric tiles in a school setting.

Laboratories are a fundamental part of engineering education due to the very nature of the engineering profession. This is a characteristic of all engineering courses, though it may vary from one curriculum to the other and even in the same curriculum. This paper is dedicated to the analysis of different applications of a remote lab in an Electrical Engineering curriculum. If the types of experiments it offers are concerned, it is classified as an Electric and Eletronic Circuits lab; one in a set that also has Digital Electronics, Analog Electronics, Electrical Machines, Control Systems, etc. But it is not a traditional labit is a remote lab, with traditional components remotely accessed over the Internet. This work presents the preliminary results of the deployment of VISIRa remote lab for Electric and Electronic Circuits in some courses. It discusses the different course contexts and how the use of VISIR was adapted to each one. Results of students' opinions are presented and discussed.

Many students in secondary schools consider the sciences difficult and unattractive. This applies to physics in particular, a subject in which students attempt to learn and understand numerous theoretical concepts, often without much success. A case in point is the understanding of the concepts current, voltage and resistance in simple electric circuits. In response to these problems, reform initiatives in education strive for a change of the classroom culture, putting emphasis on more authentic contexts and student activities containing elements of inquiry. The challenge then becomes choosing and combining these elements in such a manner that they foster an understanding of theoretical concepts. In this article we reflect on data collected and analyzed from a series of 12 grade 9 physics lessons on simple electric circuits. Drawing from a theoretical framework based on individual (conceptual change based) and socio-cultural views on learning, instruction was designed addressing known conceptual problems and attempting to create a physics (research) culture in the classroom. As the success of the lessons was limited, the focus of the study became to understand which inherent characteristics of inquiry based instruction complicate the process of constructing conceptual understanding. From the analysis of the data collected during the enactment of the lessons three tensions emerged: the tension between open inquiry and student guidance, the tension between students developing their own ideas and getting to know accepted scientific theories, and the tension between fostering scientific interest as part of a scientific research culture and the task oriented school culture. An outlook will be given on the implications for science lessons.

Cloaking is typically reciprocal. We introduce here the concept of transmittable nonreciprocal cloaking whereby the cloaking system operates as a standard omnidirectional cloak for external illumination, but can transmit light from its center outwards at will. We demonstrate a specific implementation of such cloaking that consists in a set of concentric bianisotropic metasurfaces whose innermost element is nonreciprocal and designed to simultaneously block inward waves and passeither omnidirectionaly or directionally-outward waves. Such cloaking represents a fundamental diversification of conventional cloaking and may find applications in areas such as stealth, blockage avoidance, illusion and cooling.

The measurement of instantaneous torque in terms of voltage displaying rotating speed in revolution per minute (RPM) of a rotating shaft is known as a digital tachometer. An infrared module is used as the input that senses the interruption in terms of beam of rays caused by rotating shaft, generating a pulse. The usual method of counting pulse coming from the encoder in a fixed period of time produces a high precision velocity estimate in the high-speed range. The encoded signal is latched and further sent to decoder that decodes the latched pulse i.e. speed displayed in 7 segment display. This paper mainly focuses on developing a contact-less digital tachometer of maximum 3digit with the help of integrated circuits (ICs). I.

Experiments have been at the heart of scientific development and education for centuries. From the outburst of Information and Communication Technologies, virtual and remote labs have added to hands-on labs a new conception of practical experience, especially in Science, Technology, Engineering and Mathematics education. This paper aims at describing the features of a remote lab named Virtual Instruments System in Reality, embedded in a community of practice and forming the spearhead of a federation of remote labs. More particularly, it discusses the advantages and disadvantages of remote labs over virtual labs as regards to scalability constraints and development and maintenance costs. Finally, it describes an actual implementation in an international community of practice of engineering schools forming the embryo of a first world wide federation of Virtual Instruments System in Reality nodes, under the framework of a project funded by the Erasmus+ Program.

Teachers are deeply concerned on how to be more effective in our task of teaching. We must organize the contents of our specific area providing them with a logical configuration, for which we must know the mental structure of the students that we have in the classroom. We must shape this mental structure, in a progressive manner, so that they can assimilate the contents that we are trying to transfer, to make the learning as meaningful as possible. In the generative learning model, the links before the stimulus delivered by the teacher and the information stored in the mind of the learner requires an important effort by the student, who should build new conceptual meanings. That effort, which is extremely necessary for a good learning, sometimes is the missing ingredient so that the teaching-learning process can be properly assimilated. In electrical circuits, which we know are perfectly controlled and described by Ohm's law and Kirchhoff's two rules, there are two concepts that correspond to the following physical quantities: voltage and electrical resistance. These two concepts are integrated and linked when the concept of current is presented. This concept is not subordinated to the previous ones; it has the same degree of inclusiveness and gives rise to substantial relations between the three concepts, materializing it into a law: The Ohm, which allows us to relate and to calculate any of the three physical magnitudes, two of them known. The alternate current, in which both the voltage and the current are reversed dozens of times per second, plays an important role in many aspects of our modern life, because it is universally used. Its main feature is that its maximum voltage is easily modifiable through the use of transformers, which greatly facilitates its transfer with very few losses. In this paper, we present a conceptual map so that it is used as a new tool to analyse in a logical manner the underlying structure in the alternate current circuits, with the objective of providing the students from Sciences and Engineering majors with another option to try, amongst all, to achieve a significant learning of this important part of physics.

Laboratories are a fundamental part of engineering education due to the very nature of the engineering profession. This is a characteristic of all engineering courses, though it may vary from one curriculum to the other and even in the same curriculum. This paper is dedicated to the analysis of different applications of a remote lab in an Electrical Engineering curriculum. If the types of experiments it offers are concerned, it is classified as an Electric and Electronic Circuits lab; one in a set that also has Digital Electronics, Analog Electronics, Electrical Machines, Control Systems, etc. But it is not a traditional lab-it is a remote lab, with traditional components remotely accessed over the Internet. This work presents the preliminary results of the deployment of VISIR-a remote lab for Electric and Electronic Circuits in some courses. It discusses the different course contexts and how the use of VISIR was adapted to each one. Results of students' opinions are presented and discussed.

Experiments have been at the heart of scientific development and education for centuries. From the outburst of Information and Communication Technologies, virtual and remote labs have added to hands-on labs a new conception of practical experience, especially in Science, Technology, Engineering and Mathematics education. This paper aims at describing the features of a remote lab named Virtual Instruments System in Reality, embedded in a community of practice and forming the spearhead of a federation of remote labs. More particularly, it discusses the advantages and disadvantages of remote labs over virtual labs as regards to scalability constraints and development and maintenance costs. Finally, it describes an actual implementation in an international community of practice of engineering schools forming the embryo of a first world wide federation of Virtual Instruments System in Reality nodes, under the framework of a project funded by the Erasmus+ Program.

Pulse and Digital Switching Waveforms. Repaso de Tópicos Seleccionados en la Teoría de Circuitos Electrónicos.  Notaciones.  Teoremas de Redes. Modelo del Transistor de Baja Señal a Baja Frecuencia. Modelos (Π) Pi-Híbrido, de Alta Frecuencia, de Pequeña Señal y Emisor Común. Amplificación de Voltaje y Corriente. Teorema de Miller. Amplificador Operacional. Amplificador Realimentado de Corriente.
Impedancia de Entrada y Salida para un Estado
Transistorizado.

Over-current (OC) protection is one of the often-used protections in DC microgrids. Its rapid operation, critical for protecting the system, is a key reason for its widespread use, as it plays a pivotal role in swiftly isolating fault conditions and preventing potential damage to the microgrid components. However, activating OC in DC microgrids comes with several challenges. These challenges range from the DC microgrid's grounding to the extremely rapid rise time of the fault current. This research presents an adaptive directional OC method for DC microgrids utilizing the IEC 61850 communication protocol. The proposed method employs K-means clustering to define setting groups for OC relays. The presented approach enhances the reliability and performance of OC protection in DC microgrids, by combining communication technology and advanced protection algorithms. Notably, it achieves instantaneous protection speed while maintaining protection coordination. The method utilizes a communication network, offering adaptability to different fault scenarios, even with a partially covered communication network. It significantly reduces maloperations during overloads and applies to various grid topologies. The scheme's effectiveness is evaluated in terms of speed and selectivity through extensive simulation and experimental testing using MATLAB, RT-Lab, Python, and OPAL-RT real-time simulator. This article showcases the practical application and advantages of communication-assisted OC protection in DC microgrids.