Circuit Structure Research Articles

Modeling and analysis of magnetic resonance wireless transmission coil

Wireless transmission technology is a new type of power transmission technology with electric and magnetic fields as the medium. It has more advantages in transmission direction, transmission characteristics, security, and penetration. The model of a magnetically coupled resonant radio energy transmission system is designed. The main parameters such as resonance frequency and mutual inductance are considered comprehensively. The model is designed using the equivalent topological circuit structure of mutual inductance coupling. The equivalent parameters in the circuit topology can be affected by setting the size of the coil, the distance between the coils, the excitation size, and the high frequency. The structure parameters of the whole system are modeled and calculated by the Ansoft Maxwell software. At the same time, the influence on the power and efficiency of wireless power transmission is explored by several factors such as the coil diameter, the distance between the transmitting end and the receiving end, and the resonance frequency of the system, so as to achieve the purpose of verifying the technical characteristics of wireless power transmission. The key factors that may affect the transmission efficiency and power of the system are analyzed in detail by deriving the calculation model of transmission efficiency and power.

Switchable-coupled-inductor input-regulated Class-E converter at fixed 50%-duty-cycle 1-MHz switching signal

To achieve simple topology and easy controllability, this paper presents a Class-E converter adopting the proposed switchable-coupled-inductor input-regulating (SCI-IR) method to achieve a constant output voltage under variable inputs. In comparison to other regulating or control schemes, this method features a simple circuit structure and incurs negligible power losses during the input-regulation process. By analysing the circuits with resonance tank at steady-state operations, we formulate the SCI-IR design parameters and procedures, and demonstrated experimentally with a Class-E at fixed 50%-duty-cycle 1-MHz switch signal. The measurement reveals that the prototype supports input-regulation with voltage range from 12V to 16V, and delivers the targeted constant output voltage/power of 10V/1W. At all input conditions, the converter remains in the zero-voltage-switching operation and obtains a conversion efficiency of better than 76.2 %.

Loss And Temperature Rise Analysis of Permanent Magnet Motor Based on Magneto-thermal Coupling Field

Because of the situation of motor performance degradation caused by permanent magnet demagnetization and increased loss of built-in permanent magnet synchronous motor under high temperature working conditions, this paper optimizes the rotor magnetic circuit structure of the motor and uses amorphous alloys. The material stator core replaces the original ordinary silicon steel stator core to suppress the motor temperature increase and reduce the motor loss. Through simulation, comparative analysis and calculation, the result could show that losses and temperature increase are significantly reduced after optimization. Finally, temperature rise testing was conducted on the prototype, confirming the correctness of the improved model.

Reimagining Cortical Connectivity by Deconstructing Its Molecular Logic into Building Blocks.

Comprehensive maps of neuronal connectivity provide a foundation for understanding the structure of neural circuits. In a circuit, neurons are diverse in morphology, electrophysiology, gene expression, activity, and other neuronal properties. Thus, constructing a comprehensive connectivity map requires associating various properties of neurons, including their connectivity, at cellular resolution. A commonly used approach is to use the gene expression profiles as an anchor to which all other neuronal properties are associated. Recent advances in genomics and anatomical techniques dramatically improved the ability to determine and associate the long-range projections of neurons with their gene expression profiles. These studies revealed unprecedented details of the gene-projection relationship, but also highlighted conceptual challenges in understanding this relationship. In this article, I delve into the findings and the challenges revealed by recent studies using state-of-the-art neuroanatomical and transcriptomic techniques. Building upon these insights, I propose an approach that focuses on understanding the gene-projection relationship through basic features in gene expression profiles and projections, respectively, that associate with underlying cellular processes. I then discuss how the developmental trajectories of projections and gene expression profiles create additional challenges and necessitate interrogating the gene-projection relationship across time. Finally, I explore complementary strategies that, together, can provide a comprehensive view of the gene-projection relationship.

Development of a novel flattened magnetron for household microwave oven

This paper presents a design scheme of a Novel Flattened Magnetron for Household Microwave Oven, which makes a breakthrough in the magnetic circuit of the existing magnetron and adopts the symmetrical enhanced magnetic circuit design scheme. Magnetron width has been successfully reduced from 80 mm to 50 mm. The reduction is up to 37.5%. Based on the size of the flattened magnetic circuit system, the theory of magnetron noise, and the knowledge of LC low-pass filters, a filtering structure for the flattened magnetron is proposed. Electromagnetic simulation shows that the magnetron with the new magnetic circuit structure can still meet the design specifications of the magnetron used in the existing microwave oven. An experiment was conducted to verify the proposed design's performance, and it was found to be similar to the existing conventional magnetron.

Enhancing quantum adversarial robustness by randomized encodings

The interplay between quantum physics and machine learning gives rise to the emergent frontier of quantum machine learning, where advanced quantum learning models may outperform their classical counterparts in solving certain challenging problems. However, quantum learning systems are vulnerable to adversarial attacks: adding tiny carefully crafted perturbations on legitimate input samples can cause misclassifications. To address this problem, we propose an effective approach to protect quantum learning systems from adversarial attacks by randomly encoding the legitimate data samples through unitary or quantum error correction encoders that are unknown to the attackers. In particular, we rigorously prove that both global and local random unitary encoders lead to exponentially vanishing gradients (i.e., barren plateaus) for any variational quantum circuits that aim to add adversarial perturbations, independent of the input data and the inner structures of adversarial circuits and quantum classifiers. In addition, we prove a rigorous bound on the vulnerability of quantum classifiers under local unitary adversarial attacks. We show that random black-box quantum error correction encoders can protect quantum classifiers against local adversarial noises and their robustness increases as we concatenate error correction codes. To quantify the robustness enhancement, we adapt quantum differential privacy as a measure of the prediction stability for quantum classifiers. Our results establish versatile defense strategies for quantum classifiers against adversarial perturbations, which provide valuable guidance to enhance the reliability and security for both near-term and future quantum learning technologies. Published by the American Physical Society 2024

Design of a PWM/PFM hybrid modulation switching circuit for a four-switch buck-boost converter

Based on the application background of fuel cell, the conversion efficiency of the four-switch Buck-Boost converter using PWM (Pulse width modulation) is low at light load, and the conversion efficiency of the four-switch Buck-Boost converter using PFM (Pulse frequency modulation) is low at heavy load. A PWM/PFM hybrid modulation circuit using digital module to detect induced current and feedback voltage is presented. The circuit structure is simple and easy to integrate. It has the effect of fast selection according to inductance current and feedback voltage. The circuit works in PWM mode by default. After soft startup, PWM/PFM mode can be switched according to the load. Finally, simulation is carried out in FSBB converter. The experimental results show that the PWM/PFM hybrid modulation circuit has the function of multi-load lead switching mode and protection mechanism. Simulation in FSBB converter shows that the converter efficiency reaches 91.99% and the maximum load current is 2A. This helps improve the efficiency of Buck-Boost converters.

Analysis of Multi-Objective Optimization Design of Interior Double Radial and Tangential Combined Magnetic Pole Permanent Magnet Drive Motor for Electric Vehicles

A new type of interior combined pole permanent magnet drive motor is proposed in this paper, which aims to improve the power and comfort of electric vehicles. In view of the complex magnetic circuit structure and rich harmonic magnetic field of the motor, the initial magnetic pole parameters of the rotor are determined by the equivalent magnetic circuit method. Then, aiming at the complex magnetic circuit and rich harmonic magnetic field, a multi-objective optimization method based on the Taguchi method and response surface method is proposed to reduce the cogging torque, high harmonic content in air gap magnetic flux density and increase the output torque. Based on the finite element analysis of the electromagnetic performance of the new type interior combined magnetic pole permanent magnet drive motor before and after optimization, it can be seen that the improved rotor structure can effectively reduce the torque ripple and increase the torque density. Finally, a prototype was developed and experiments were conducted, and experimental results verified the correctness of the proposed multi-objective optimization algorithm.

Design, Analysis and Experimental Verification of a Coreless Permanent Magnet Synchronous Motor

The paper presents a new cost-effective magnetic circuit structure of a coreless permanent magnet synchronous motor (PMSM) with 16 poles and 12 coils for a mass production fan drive unit. 2D and 3D numerical models of the coreless PMSM were developed. Optimisation calculations were carried out using the field model of the machine. Multistage calculations were performed using the professional FEM package, ANSYS Maxwell and the author’s proprietary finite element method (FEM) code. On the basis of the conducted tests and analysis of the obtained results, the “optimal” magnetic circuit structure of the PMSM motor was selected. The prototype motor was subjected to measurement to verify the developed models and the proposed design approach that takes advantage of finite element analysis (FEA).

Current status and applications of time-to-digital converters

Time-to-Digital Converter (TDC) is widely used to realize time interval measurement. The high-precision time measurement technique has important applications in the fields of laser ranging, particle identification, and radioactive nuclear medicine engineering. Based on the existing literature research and data, this paper studies the application areas of TDC in the present development and analyzes the future prospects of TDC applications. The research results showed that: TDC, based on signal screening, realizes time interval measurement as the ultimate purpose of building the system and, at the same time, completes the function of multi-pulse time interval measurement, which can meet the needs of more diversified measurements in the experiments. In the circuit structure, it can identify the feedback output in the all-digital phase-locked loop (ADPLL) and the reference clock phase and frequency information between the feedback output and the reference clock in an ADPLL. It is also promising for use in other areas of high-precision time measurement and processing of circuit signals.

Systematic analysis of the principles and application scenarios of Low-Noise Amplifier

As society advances, new ideas and products are increasingly integrated into our daily lives. 5th generation mobile networks tech enables faster, lag-free connectivity, raising performance standards for components like Low-Noise Amplifiers. Summarizing Low-Noise Amplifier tech and applications helps researchers and firms leverage past knowledge and explore innovations. This paper analyzes Low-Noise Amplifier development and application, discussing types, principles, key performance indicators, and circuit structures of basic amplifiers. Five vital Low-Noise Amplifier characteristicsnoise figure, impedance matching, linearity, stability, and gainare examined. The author introduces design and application cases in radio astronomy, navigation systems, and 5th generation mobile networks communications based on Low-Noise Amplifier characteristics and performance requirements. The author concludes that advancing radio frequency tech requires improved Low-Noise Amplifiers, especially for high-frequency signals in 5th generation mobile networks. Promising noise performance enhancements come from technologies like modified high electron mobility transistors on GaAs and InP substrates. Monolithic Microwave Integrated Circuit integration reduces size while maintaining cost-effective performance. Future advancements in these areas could further boost Low-Noise Amplifier performance.

Optimized design of a 4-bits absolute-value detector based on linear programming

Nowadays, neural signal acquisition systems are constantly developing, and spike classification algorithms have been widely studied and concerned. This paper designed a practical spike detection circuit, named as the absolute value detector. Project is committed to adopting only simple gate circuits, by using Morgans theorem to optimize the circuit structure, so that we can ensure that the detector has the following several advantages, simple and beautiful, easy to understand, powerful performance. In addition, this paper also considered the optimization of performance including latency and energy consumption. The increase of Vdd will increase the energy consumption and reduce the delay, while the increase of size will reduce the energy consumption and increase the delay. Using MATLAB software for linear programming, Under the condition of a 1.5-fold increase in the delay, and then adjusting Vdd and size, energy consumption was down by 78 percent.

A zero‐input‐current‐ripple high‐voltage‐gain DC‐DC converter with integrated Y‐source network

SummaryThis paper proposes a zero‐input‐current‐ripple (ZICR) high‐voltage‐gain dc‐dc converter with an integrated Y‐source network. It achieves zero input current ripple by introducing a parallel branch of an extra inductor, a coupled winding, and a capacitor at the input port. The voltage of the added inductor is opposite to that of the coupled winding. By adding the Y‐source coupled inductor, the boost capability of the converter is improved. The unique boost circuit structure makes that one winding in the three‐winding coupling inductance is step‐down type (the turns ratio n2 < 1) while the other winding is step‐up type (the turns ratio n1 > 1). In such a case, high voltage gain can be obtained under a lower turn ratio of the coupled inductor. The inherent passive clamping circuit clamps the spike voltage noises of the main switch to a low level and improves the efficiency. All the diodes have achieved ZCS (zero current switching) turn‐off. By comparing with several new converters, the advantages of this converter are proved. Finally, a 200‐W, 48‐ to 380‐V, 50‐kHz experimental prototype is built based on the theoretical research. At the rated power, the measured efficiencies with and without ZICR are 95.2% and 95.6%, respectively.

A novel design of hard-magnetic soft switch array for planar and curved surface applications

This paper proposes an array structure with multidirectional remanent magnetization based on hard-magnetic soft materials, which can be used as a soft switch array on planar and curved surfaces. We firstly investigate the displacement response of a hard-magnetic soft switch which is excited by a magnetic field, and related to the magnitude and direction of the magnetic field. When the remanent magnetization direction of the soft switch is opposite to the horizontal component of the magnetic field, the displacement response is greater than that of the driving magnetic field in other directions. The maximum displacement of the soft switch can reach 4.5 mm under a 6 V driving voltage applied to the Helmholtz coil. We further design 2 × 2 and 3 × 3 switch arrays and the circuit structures of the switch arrays. The switch arrays are fabricated, and the displacement responses of the switch arrays under different driving magnetic fields on planar and curved surfaces are finally demonstrated. When the Z-axis displacement of the device reaches more than 3 mm, the LED light can be switched on. The hard-magnetic soft switch array structure designed in this paper can enable the application of soft switches in curved environments, verifying the feasibility of the application of hard-magnetic soft switch arrays. It is expected to provide a guidance for the design and manufacturing of multi-functional hard-magnetic soft switches in the future and the application of hard-magnetic soft switch arrays in planar and curved environments.

Generation multi-scroll chaotic attractors using composite sine function and its application in image encryption

In this paper, a composite sine function is proposed and applied in a chaotic system, which is capable of generating definite number of chaotic attractors. The proposed composite sine function possesses infinite breakpoints, but it can produce a fixed number of scrolls by adjusting its parameters. Compared to other chaotic systems with multiple scrolls chaotic attractors, the realization circuit of the chaotic system with compound sine function allows obtaining different numbers of scrolls by adjusting only one resistance value. As a result, the circuit structure remains unchanged despite variations in the number of scrolls. Various analytical methods are applied to study the dynamical behaviors of the proposed chaotic system, including Lyapunov exponent, equilibrium point, bifurcation diagram, phase diagram, spectral entropy and C0-algorithm. Furthermore, based on the analysis of dynamical characteristics, the electronic circuits of the proposed system are given on Multisim circuit simulation software, and the multi-scroll chaotic attractors exhibit consistency with the numerical simulation results. Finally, we incorporated the proposed chaotic system into a Deoxyribonucleic acid coding algorithm for image encryption, and this method exhibits excellent encryption efficiency and high level of security.

Design of Reconfigurable Logic Block Based Sequential Circuits Using Look Up Table Logics

Reconfigurable sequential circuits find applications in various digital systems, including communication networks, data processing units, embedded systems, and FPGA-based designs. Their ability to adapt and reconfigure their functionality onthe-fly allows them to accommodate dynamic requirements and optimize the use of hardware resources. Traditional implementations of sequential circuits involve static configurations, where the logic and functionality are fixed during synthesis. While these methods are straightforward to design and implement, they lack adaptability and cannot be modified without redesigning the entire circuit. The proposed method involves the utilization of a dedicated Reconfigurable Logic Block (RLB) within the sequential circuits, allowing for dynamic configuration changes without altering the overall circuit structure. The RLB can be programmed to provide different logic functions using look up tables, multiplexers, enabling the sequential circuit such as counters and shift registers to change its behaviour.

Incoherent feedforward loop dominates the robustness and tunability of necroptosis biphasic, emergent, and coexistent dynamics

Biphasic dynamics, the variable-dependent ability to enhance or restrain biological function, is prevalent in natural systems. Accompanied by biphasic dynamics, necroptosis signaling also appears emergent and coexistent dynamics. However, it remains elusive how the properties of these dynamics are characterized by specific circuit structures and components. Starting with necroptosis circuit modeling, we systematically analyzed the network topology for achieving RIP1-dependent biphasic, emergent, and coexistent (BEC) dynamics. RIP1-RIP3-Caspase-8 (C8) incoherent feedforward loop embedded with positive feedback of RIP3 to RIP1 is identified as the core topology. The peak value of RIP3 phosphorylation is determined to present a scale-invariant feature, dictating BEC dynamics and the bell-shaped regulation of necroptosis biphasic dynamics. To quantitatively determine the uncertainty of necroptosis coexistent dynamics, potential landscape and Shannon entropy that measure entropy production during cell death are introduced for the first time. Further random necroptosis circuit analysis identifies the bell-shaped regulation of necroptosis biphasic dynamics by RIP3 auto-phosphorylation, which acts as a complementary process for robustly attaining BEC dynamics. Finally, we searched all possible two- and three-node circuit topologies to screen those that could perform BEC dynamics. A complete atlas of three-node circuit BEC dynamics is generated and only three minimal circuits emerge as robust solutions, confirming incoherent feedforward loop is the core topology. Analysis of the association between the minimal circuit structure and robustness proves that the identified optimal functional achievement structure is highly consistent with the experimental observed RIP1-RIP3-C8 topology. Overall, through highlighting a finite set of circuits, this study yields guiding principles that enable the mapping, modulation, and design of circuits for BEC dynamics in diverse synthetic biology applications.

Childhood adversity modulates structural brain changes in borderline personality but not in major depression disorder

Adverse childhood experiences (ACEs) negatively affect the function and structure of emotion brain circuits, increasing the risk of various psychiatric disorders. It is unclear if ACEs show disorder specificity with respect to their effects on brain structure. We aimed to investigate whether the structural brain effects of ACEs differ between patients with major depression (MDD) and borderline personality disorder (BPD). These disorders share many symptoms but likely have different etiologies. To achieve our goal, we obtained structural 3T-MRI images from 20 healthy controls (HC), 19 MDD patients, and 18 BPD patients, and measured cortical thickness and subcortical gray matter volumes. We utilized the Adverse Childhood Experiences (ACE) questionnaire to quantify self-reported exposure to childhood trauma. Our findings suggest that individuals with MDD exhibit a smaller cortical thickness when compared to those with BPD. However, ACEs showed a significantly affected relationship with cortical thickness in BPD but not in MDD. ACEs were found to be associated with thinning in cortical regions involved in emotional behavior in BPD, whereas HC showed an opposite association. Our results suggest a potential mechanism of ACE effects on psychopathology involving changes in brain structure. These findings highlight the importance of early detection and intervention strategies.

High-Voltage Gain Ripple-Free Resonant DC–DC Converter Using Active Voltage-Quadrupler

This paper presents a high-voltage gain ripple-free resonant DC/DC converter using an active voltage-quadrupler. By incorporating an active voltage-quadrupler at the secondary side of the transformer, the circuit achieved a very high-voltage gain. Without using extra input inductors, the inherent dual transformer plus interleaved active-clamped circuit operating with a fixed duty-ratio of 0.5 generate a ripple-free input current, which extends the lifetime of the fuel cell and shrinks the size of the input capacitive filter. This asymmetric structure of the active-clamp circuit requires an extra dead time for one of the secondary-side switches to achieve zero-voltage switching (ZVS) turn-on. After the extra dead time for one of the secondary-side switches is applied, all power components of the active voltage quadrupler cell are turned on and off with soft switching. The resonant capacitor voltages are unbalanced due to the extra dead time, but they are compensated by applying different secondary-side duty ratios. The operating principle and steady-state characteristics of the proposed converter were analyzed in detail. We built a 1-kW/700-V prototype that copes with 48-72 V inputs, and tested to verify the theoretical analysis.

METHODOLOGY FOR ASSESSING THE EFFECTIVENESS OF THE FUNCTIONING OF OPTICAL-ELECTRONIC SYSTEMS WHEN MONITORING REMOTE OBJECTS

The work proposes an approach to improving the scientific and methodological apparatus for processing information about observed distant objects. The potential possibility of increasing the accuracy of measuring the coordinates of remote objects and obtaining spectrophotometric information through a refined mathematical model of the process of functioning of optical-electronic systems, based on the possibility of restoring the original signal from the observed object by solving the Fredholm integral equation of the 1st kind, is shown. Based on a mathematical model that takes into account the structure of the optical circuit, the influence of noise and external observation conditions, the methodology for assessing the effectiveness of optical-electronic systems when observing remote objects has been improved.