Master Circuit Research Articles

Electrical circuit modeling for the relaxor response of bismuth magnesium tantalate pyrochlore

The electrical properties of bismuth magnesium tantalate pyrochlore, Bi3.30Mg1.88Ta2.82O13.88 (BMT) were investigated by both inductor-capacitor-resistor (LCR) and impedance spectroscopy techniques covering a broad temperature range of 10–1073 K and a frequency range of 5 Hz - 1 MHz. At below ∼180 K, BMT pyrochlore exhibited interesting relaxor behaviour that showed high dispersion characteristics in its frequency-temperature dependent dielectric constants, ε′ and dielectric losses, tan δ, respectively. The maximum ε′max of ∼77 was obtained at the temperature maximum, Tm of 154 K. The frequency-independent ε′ data above 154 K at a fixed frequency of 1 MHz can be well fitted with the Curie-Weiss law and the relaxation features of Bi3.30Mg1.88Ta2.82O13.88 obeyed the Vogel-Fulcher equation. The dielectric properties of Bi3.30Mg1.88Ta2.82O13.88 relaxor in the low temperature range of 20–320 K could be satisfactorily modeled with different equivalent circuits. In this perspective, a master circuit consisting of a parallel R-C-CPE element in series with a capacitor was required to accurately fit the low temperature data.

Monitoring and control of IoT-based building electrical load limit

The Demand for electrical energy continues to increase. However, excessive electrical energy consumption can lead to tripped circuits and escalated costs. We developed a prioritised sockets system to avoid electrical trips and excessive power consumption. The PZEM-004T sensor in the master circuit can measure electrical power with deficient error, and the ACS712 sensor in the slave circuit can measure electrical current with an accuracy of 99.85%, making these sensors suitable for monitoring. Additionally, the non-priority sockets can interrupt the power flow when the power exceeds the limit while the priority socket remains active. The mobile application can display real-time historical data and control the switching of prioritised sockets. This system consists of 3 subsystems: the master circuit, the slave circuit, and the mobile application. The priority socket’s current cannot be interrupted. In contrast, the non-priority system can be interrupted when the electrical power load reaches 375 Watts. The mobile application controls the switching of prioritised sockets and monitors the incoming electrical power loads. They connected this system to the internet for proper functioning.

Voltage Stabilisation of a Drive System Including a Power Transformer and Asynchronous and Synchronous Motors of Susceptible Motion Transmission

A mathematical model is developed of the master circuit of an electric driver system including a power transformer and susceptible motion transmission of asynchronous and synchronous drives. Electric motors drive water pumps by means of motion transmission that comprises two elastic couplings of lumped mechanical parameters and a long shaft of distributed mechanical parameters. Differential equations for oscillatory processes for the long shaft and the elastic couplings are different. The shaft is described with partial derivative Euler–Poisson equations, which, combined with the boundary conditions, form mixed problems from the mathematical point of view. The elastic couplings, on the other hand, are described with the ordinary second type Lagrange equations. Based on the theory of electromagnetic field, the partial differential equations describe the skin effects across the rotor age bars. Vertical pumps are presented by means of a loading torque waveform as a function of the input shaft’s angular velocity. The complex mathematical model serves to analyse electromechanical transient processes across the integrated drive system. Starting from there, conditions of stabilisation of the drive system voltage are determined. Electromechanical state equations are presented in the normal Cauchy form and integrated using the fourth-order Runge–Kutta method. Results of computer simulations are shown with graphics, which are interpreted and described.

Implementation of a Real Time Analog Secure Image Communication System via a Chaotic Circuit

A new secure image communication system has been designed and implemented based on a synchronized chaotic circuit. The new chaotic circuit, which has recently proposed by one of the authors contains a resistor, two inductors, and two diodes (i.e. R2L2D). The synchronization part operates with a master – slave configuration. In order to achieve the real-time communication, initially the analog master circuit has been implemented to generate chaotic sequences of numbers. Then, that analog tool has been transmitted to a computer via an analog/digital converter and a hidden image has been obtained. Besides, the slave circuit has also received a copy of that chaotic sequences in order to use it in subtraction process of image gray levels. The digital chaotic image has been transmitted to the slave circuit via a digital/analog converter with an efficient method and the decrypted image has been obtained in real-time. The advantage of that technique over the conversional ones is that it does not require any saved copy of the digital data, even for sending them in gray images to the receiver, since it is real-time. The conventional techniques use the stored and processed data and that can cause security problems in today’s advanced web media. Thus to send the encrypted image in a real-time device by using an analog chaotic equipment has certain security superiority. The analyses on the preliminary decrypted images proves that the process is efficient in time and secure.

A Meter-Bus Master Station Interface Circuit Based on Transistor Amplification Characteristics

This paper introduces a new Meter-Bus master station interface circuit based on a single power supply. By utilizing the switching characteristics and amplification characteristics of the triode, the level signal conversion and signal transmission are realized by fully combining the cut-off region of the triode to work, the linear amplification of the amplification region, and the low-voltage differential conduction of the saturation region. The M-bus master circuit of the prior art solution is usually constructed with many separate components, and the whole circuit also needs positive and negative dual power supplies, so the circuit is very complicated, the circuit failure rate is high, and the cost of the circuit is also high. The circuit described in this paper solves the above technical problems of the current Meter-BUS master circuit.

Design of Impulse Current Units for Master Circuit Breakers and Make Switches for use in High Power Application

The high power laboratory at CPRI has a short circuit generator of capacity 2500 MVA for the short circuit testing of power system equipment. The short circuit is initiated by the closing of Make Switch (MS) and is cleared by the Master Circuit Breaker (MCB). The closing operation of MS and tripping operation of MCB is to be completed in a very short duration of time. This requires a high magnitude impulse current to be injected in to the opening and closing coils of MCB and MS for their quick operation. For generating such an impulse current, a special impulse current unit is to be designed and fabricated. This paper presents the development of impulse current units for the fast opening and closing operation of master circuit breaker and make switch using Arduino Uno board.

Research and Analysis of Reliability of Power Grid SVG Master Circuit in Rural Areas

Problems such as low voltage and big line loss have long existing in the power grid in rural areas of China. In recent years, some province and cities have improved voltage and reduced line loss by installing SVG at substations in rural power grids, and the effect is remarkable.With great compensation capacity and a good variety of modes of compensation, SVG is sure to replace old reactive compensation devices in rural power grid in future, which requires evaluation and analysis of SVG reliability so as to guarantee safety and stability of the power grid. However, now no research or analysis has been made in China on SVG reliability in rural power grids, which affects wide promotion of SVG in rural power grids.Under the background of Liaoning Power Grid 10kV/±5Mvar Chain SVG, this paper analyzes the reliability of k/n (G) system model of SVG master circuit structure, improving the accuracy of system reliability estimation. The estimation matches the operation outcome, thus providing data basis for the feasibility of SVG’s wide application in rural power grid in future.

A Digital Controller Assisted Flexible Auto-tuning Method for Continuous-time Filters

A novel auto-tuning method for the integrated continuous-time filter is proposed in this paper. On the one hand, an off-chip digital controller is adopted here to decrease the on-chip hardware as well as to increase the efficiency and the flexibility of the auto-tuning strategy. As a result, both the calibration and the programmability of the cut-off frequency can be realized by software, meanwhile some non-idealities of the circuit can also be compensated by software. On the other hand, the on-chip auto-tuning circuit is designed based on the master-slave architecture, where a novel and simple master circuit is adopted with digital input and output interfaces, thus providing convenient connections for the controller without the ADC or DAC devices. With the PCB technology, a 6th-order active-RC filter with the proposed auto-tuning method is also implemented to verify the validity and the flexibility of this method.

Circuit Implementation of Coronary Artery Chaos Phenomenon and Optimal PID Synchronization Controller Design

This study aimed at the implementation and synchronization control of cardiac circuit. First, the MATLAB‐Simulink was used to simulate the dynamic behavior of cardiac chaotic circuit, and simple electronic modules were used to implement the cardiac system. Then the Particle Swarm Optimization (PSO) was used to seek for the proportional, integral, and derivative gains of optimal PID controller, and the PID controller which could synchronize the slave cardiac circuit and the master cardiac circuit was obtained, in order to synchronize the master/slave chaotic cardiac circuits. This method can be provided for cardiac doctors to diagnose and medicate cardiac abnormality.

A Recently Evolved Transcriptional Network Controls Biofilm Development in Candida albicans

A biofilm is an organized, resilient group of microbes in which individual cells acquire properties, such as drug resistance, that are distinct from those observed in suspension cultures. Here, we describe and analyze the transcriptional network controlling biofilm formation in the pathogenic yeast Candida albicans, whose biofilms are a major source of medical device-associated infections. We have combined genetic screens, genome-wide approaches, and two invivo animal models to describe a master circuit controlling biofilm formation, composed of six transcription regulators that form a tightly woven network with ∼1,000 target genes. Evolutionary analysis indicates that the biofilm network has rapidly evolved: genes in the biofilm circuit are significantly weighted toward genes that arose relatively recently with ancient genes being underrepresented. This circuit provides a framework for understanding many aspects of biofilm formation by C.albicans in a mammalian host. It also provides insights into how complex cell behaviors can arise from the evolution of transcription circuits.

Intrinsic and extrinsic regulation of type III secretion gene expression in Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen that is particularly problematic in the healthcare setting where it is a frequent cause of pneumonia, bloodstream, and urinary tract infections. An important determinant of P. aeruginosa virulence is a type III secretion system (T3SS). T3SS-dependent intoxication is a complex process that minimally requires binding of P. aeruginosa to host cells, injection of the cytotoxic effector proteins through the host cell plasma membrane, and induction of T3SS gene expression. The latter process, referred to as contact-dependent expression, involves a well-characterized regulatory cascade that activates T3SS gene expression in response to host cell contact. Although host cell contact is a primary activating signal for T3SS gene expression, the involvement of multiple membrane-bound regulatory systems indicates that additional environmental signals also play a role in controlling expression of the T3SS. These regulatory systems coordinate T3SS gene expression with many other cellular activities including motility, mucoidy, polysaccharide production, and biofilm formation. The signals to which the organism responds are poorly understood but many seem to be coupled to the metabolic state of the cell and integrated within a master circuit that assimilates informational signals from endogenous and exogenous sources. Herein we review progress toward unraveling this complex circuitry, provide analysis of the current knowledge gaps, and highlight potential areas for future studies. Complete understanding of the regulatory networks that control T3SS gene expression will maximize opportunities for the development of strategies to treat P. aeruginosa infections.

ROBUST SYNCHRONIZATION OF CHAOTIC LUR'E SYSTEMS VIA REPLACING VARIABLES CONTROL

The sufficient conditions for chaos synchronization of two nonidentical systems by replacing variables control have not been proposed until now. In this paper, synchronization of two chaotic Lur'e systems with parameter mismatch by replacing variables control is studied. First of all, we present a master-slave Lur'e systems synchronization scheme with both parameter mismatch and replacing variables control, and derive a responsive error system for the scheme. A new definition of synchronization with finite L 2-gain is then introduced. Based on the definition, the sufficient synchronization criteria which are in the form of linear matrix inequality (LMI) are proved using a quadratic Lyapunov function. By means of MKY lemma the frequency domain criteria are further derived from the obtained LMIs. These frequency domain criteria are illustrated on the master-slave Chua's circuits with parameter mismatch so that the ranges of the parameters of Chua's circuit are analytically solved in the sense of the synchronization with finite L 2-gain by replacing singe-variable control. The illustrative examples verify that within the ranges of the parameters it is possible to synchronize the master-slave Chua's circuits up to a small synchronization error bound, even the qualitative behaviors of the slave circuit are different from that of the master one, such as the trajectory of the master circuit is chaotic and that of the slave divergent. The relation between the synchronization error bound and parameter mismatch is shown.

Frequency tuning technique for Gm-C filters

A frequency tuning technique based on an envelope locked loop is proposed for Gm-C filters. A degenerated integrator is used as the master circuit to eliminate the problems associated with the DC offset of the operational transconductance amplifier (OTA).

Analog circuits simulation of communication with chaotic lasers

Masked signal communication between two chaotic lasers, described by rate equations, was implemented using analog circuits. Digital modulation of the gain parameter in the master circuit generated the messages. It is shown that there is a level of modulation for which the receiver circuit decodes the signal by on-off synchronization while the Poincaré sections, the first return maps and the time of return maps recovered directly from the master signal could not distinguish the bits. The circuits simulate the dynamics of two optically coupled CO2 lasers with intracavity saturable absorber. The signal appears to be unbreakable in such low dimensional systems because they operate at homoclinic chaos which corresponds to multibranched one-dimensional return maps.

Current-injection Josephson latch employing a single-flux quantum. I

A new current-injection Josephson latch employing a single-flux quantum is proposed. It has a master-slave circuit configuration and operates under ac power supply. In the circuit, data are stored as a circulating current in a superconducting loop consisting of a single junction and inductances. A two-junction interferometer gate directly coupled to the loop reads out the stored data. Dual-rail signals are generated from the read-out data by Josephson junctions and resister-coupled Josephson logic gates. The isolation between a master circuit and a slave circuit is realized using high-impedance states in the Josephson junctions. The circuit design and computer-simulation results on the circuit operation are described in this paper.

A modular expandable implantable temperature biotelemeter.

An implantable biotelemetry system is described for multisite temperature measurements with ease of expansion by use of different master circuit boards to accommodate additional channels. Modular construction of the multichannel FM-FM system allows addition or deletion of channels as the experiment requires. The radio frequency carrer osciUlator is tunable to a "quiet" frequency in the 90-105 MHz range prior to implantation. The telemeter may incorporate enclosed or remote temperature probes which allow deep body temperature measurements in the range of 30-42 °C with an available resolution of ±0.015°C. Transmitters have been utilized in monitoring ovarian and subcutaneous temperatures, and also as an aid in detection of ovulation in the Macaca mulatta.

Master circuit matrix

The setting up of a master circuit matrix, whereby all possible circuits of any given graph or network with the same, or a smaller, number of nodes can be obtained as a simple modification of the former, is discussed. With the help of such a master matrix, it is also possible to obtain accurately the number of all possible circuits in the given graph, without actually generating them. Besides the flexibility in the choice of circuits it provides for network studies, the enumeration of all circuits should find useful application in other fields, such as operational research, materials management etc. The method actually exploits the inherent symmetry in a complete graph and is also suited for computer adaptation. In the process, a new method of enumerating all possible circuits of a complete graph, and a formula to determine their number, are given. Finally, some important properties of the master circuit matrix are discussed, which include a formula for the number of circuits in which a given combination of edges occurs, a recurrence relationship for the circuit enumeration of different masters, an expression for the number of circuits in a subgraph of a complete graph and a method for setting up a circuit matrix of an arbitrary graph from master B etc.

Master circuit matrix

Master circuit matrix