Circuit Switching Research Articles

Interleaved Modified SEPIC Converters with Soft Switching and High Power Factor for LED Lighting Appliance

A novel ac/dc LED driver with power factor correction and soft-switching functions is proposed. The circuit topology mainly consists of two modified single-ended primary inductance converters (SEPIC) with interleaved operation. The first half stage of SEPIC operates like a boost converter and the second half stage operates like a buck–boost converter. Each boost converter is designed to operate in discontinuous current mode (DCM) to function as a power factor corrector (PFC). The two buck–boost converters that share a commonly coupled inductor are designed to operate at near boundary conduction mode (BCM). Without using any active clamping circuit, auxiliary switch or snubber circuit, the active switches can achieve zero-voltage switching on, and all diodes achieve zero-current switching off. First, operation modes in steady state are analyzed, and the mathematical equations for design component parameters are derived. Finally, a prototype circuit of 180 W rated power was built and tested. Experimental results show satisfactory performance of the proposed circuit.

An improved pixel circuit with low noise event rate and enhanced bright‐light sensitivity for dynamic vision sensor

AbstractDynamic vision sensor (DVS) imaging quality is significantly affected by pixel noise and temporal contrast (TC), which is inversely proportional to sensitivity. To reduce the noise event rate and improve sensitivity in bright‐light conditions in the DVS pixel circuit, this paper proposes improvements to the conventional DVS pixel circuit. The proposed DVS pixel circuit adopts stacked medium‐threshold transistors instead of a single high‐threshold transistor in the photoreceptor and introduces a threshold switching circuit. Compared with the conventional DVS pixel circuit, this design increases event threshold normalized by root mean square (RMS) noise voltage, reducing the dim‐light noise bandwidth. Additionally, it achieves higher sensitivity in bright‐light conditions compared with dim‐light conditions. The proposed DVS pixel circuit is implemented in a 110‐nm complementary metal‐oxide semiconductor (CMOS) process. Post‐simulation results show that, for photocurrents between 5 fA and 100 pA, the proposed DVS pixel circuit achieves a 35 Hz peak event rate at 15% TC, which is reduced to 3.1% of the conventional structure. For photocurrents exceeding 30 pA, the proposed structure can switch TC from 15% to 5%, maintaining a noise event rate below 0.1 Hz.

Design and Analysis of K-Band Single-Pole Double-Throw Switches Based on GaAs Technology

Two K-band switch circuits, each consisting of a single-pole double-throw (SPDT) switch, have been built using a 0.15 μm GaAs process. One circuit utilizes diode techniques while the other utilizes field effect transistor (FET) techniques. The diode single-pole double-throw switches that have been devised exhibit exceptional linearity and are capable of withstanding high power levels. The switches exhibit a return loss of 10 dB or higher, an insertion loss of 3 dB or lower, and operate within a frequency range of 19 GHz to 25 GHz. They have a compact design with a core size of only 1.05 mm2 and consume a total power of 136.8 mW. The FET SPDT switch circuits are created utilizing a parallel–parallel quarter-wavelength transmission line architecture. This design allows for a higher power output compared to using a diode. The transistorized single-pole double-throw switch circuit is designed using a parallel–parallel quarter-wavelength transmission line architecture. This design ensures a low insertion loss. By adjusting the length of the transmission line, the circuit can operate in both frequency bands; the K-band and Ka-band.

2D Reconfigurable van der Waals Heterojunction for Logic Gate Circuits and Wide-Spectrum Photodetectors via Sulfur Substitution and Band Matching.

The attractive physical properties of two-dimensional (2D) semiconductors in group IVA-VIA have been fully revealed in recent years. Combining them with 2D ambipolar materials to construct van der Waals heterojunctions (vdWHs) can offer tremendous opportunities for designing multifunctional electronic and optoelectronic devices, such as logic switching circuits, half-wave rectifiers, and broad-spectrum photodetectors. Here, an optimized SnSe0.75S0.25 is grown to design a SnSe0.75S0.25/MoTe2 vdWH for logic operation and wide-spectrum photodetection. Benefiting from the excellent gate modulation under the appropriate sulfur substitution and type-II band alignment, the device exhibits reconfigurable antiambipolar and ambipolar transfer behaviors at positive and negative source-drain voltage (Vds), enabling stable XNOR logic operation. It also features a gate-modulated positive and negative rectifying behavior with rectification ratios of 265:1 and 1:196, confirming its potential as half-wave logic rectifiers. Besides, the device can respond from visible to infrared wavelength up to 1400 nm. Under 635 nm illumination, the maximum responsivity of 1.16 A/W and response time of 657/500 μs are achieved at the Vds of -2 V. Furthermore, due to the strong in-plane anisotropic structure of SnSe0.75S0.25-alloyed nanosheet and narrow bandgap of 2H-MoTe2, it shows a broadband polarization-sensitive function with impressive photocurrent anisotropic ratios of 15.6 (635 nm), 7.0 (808 nm), and 3.7 (1310 nm). The direction along the maximum photocurrent can be reconfigurable depending on the wavelengths. These results indicate that our designed alloyed SnSe0.75S0.25/MoTe2 vdWH has reconfigurable logic operation and broadband photodetection capabilities in 2D multifunctional integrated circuits.

Efficient fiber-inspection and certification method for optical-circuit-switched datacenter networks

Datacenter networks (DCNs) consisting of optical circuit switches (OCSs) have been considered as a promising solution to dramatically improve their transmission capacity, energy efficiency, and communication latency. To scale optical-circuit-switched DCNs (OCS DCNs), hierarchical OCSs with tens of thousands of optical fibers need to be installed, and they should be inspected before starting datacenter operations. Since traditional DCNs consist of electrical-packet switches (EPSs), the condition and cabling of fibers can be inspected easily by probing neighboring EPSs. However, OCS networks cannot be inspected in the same manner because OCSs cannot transmit and receive probe signals. Thus, we have had to attach and detach a light source and power meter (LSPM) to every switch for probing all the fibers, which takes weeks. This paper proposes an efficient method for inspecting and certifying fibers in an entire DCN without repeating LSPM reattachment. Our method is based on (1) theories on quickly estimating the fiber condition on the basis of the intensity of received probe signals, (2) the maximum allowable loss of each fiber derived from the transceiver budget used in operations, and (3) an algorithm that reduces the number of probes needed. The results from an extensive numerical evaluation indicate that our method inspected a DCN with 18,432 fibers in at most a day, whereas a baseline method involving repeated LSPM reattachment would take more than a week. We also confirmed that our method never produced false negatives and false positives under practical network conditions.

Multifunctional In-Memory Logics Based on a Dual-Gate Antiambipolar Transistor toward Non-von Neumann Computing Architecture.

In-memory computing may make it possible to realize non-von Neumann computing because the logic circuits are unified in the memory units. We investigated two types of in-memory logic operations, namely, two-input logic circuits and multifunctional artificial synapses. These were realized in a dual-gate antiambipolar transistor (AAT) with a ReS2/WSe2 heterojunction, in which polystyrene with a zinc phthalocyanine core (ZnPc-PS4) was incorporated as a memory layer. Here, reconfigurability is a key concept for both types of device operations and was achieved by merging the Λ-shaped transfer curve of the AAT and the nonvolatile memory effect of ZnPc-PS4. First, we achieved electrically reconfigurable two-input logic circuits. Versatile logic circuits such as AND, OR, NAND, NOR, and XOR circuits were demonstrated by taking advantage of the Λ-shaped transfer curve of the dual-gate AAT. Importantly, the nonvolatile memory function provided the electrical switching of the individual circuits between AND/OR, NAND/NOR, and XOR/NAND circuits with constant input signals. Second, the memory effect was applied to multifunctional artificial synapses. The inhibitory/excitatory and long-term potentiation/depression synaptic operations were electrically reconfigured simply by controlling one parameter (readout voltage), making three distinct responses possible even with the same presynaptic signals. These findings provide hints that may lead to the realization of new in-memory computing architectures beyond the current von Neumann computers.

Factor analysis of the Chinese version of the Autism Spectrum Quotient 10 and its association with schizotypal traits in adolescents and young adults in Hong Kong.

There is evidence suggesting that autistic traits are associated with schizotypal traits. This study examined the factor structure of the Autism Spectrum Quotient 10 (AQ-10) and its associations with schizotypal traits (measured by the Schizotypal Personality Questionnaire-Brief [SPQ-B]) in a cohort of Chinese adolescents and young adults. Invitation letters, stratified by locations and housing types, were randomly sent to individuals aged 15 to 24 years for participation. Assessments were made using face-to-face or online interviews. Autistic traits were assessed using the Chinese version of the AQ-10. Schizotypal personality traits were assessed using the Chinese version of the 22-item SPQ-B. In total, 395 male and 536 female participants (mean age, 19.93 years) were recruited between July 2020 and May 2021. Exploratory factor analysis of the AQ-10 yielded three factors (theory of mind, task switching, and attention deficits) explaining 55.11% of the total variance. Autistic traits were positively correlated with schizotypal traits of disorganised features (r = 0.21, p < 0.001), interpersonal relationship deficits (r = 0.19, p < 0.001), and cognitive-perceptual deficits (r = 0.11, p = 0.001). In Chinese adolescents and young adults, autistic traits, especially task switching and attention deficits (compared with theory of mind) are more closely correlated with schizotypal personality traits. Disentangling the overlapping and diametrical structure of autistic traits and schizotypal traits may help understand their aetiologies, assessment, and interventions.

Software-defined optical networking applications enabled by programmable integrated photonics

Data center networks are experiencing unprecedented exponential growth, mostly driven by the continuous computing demands in machine learning and artificial intelligence algorithms. Within this realm, optical networking offers numerous advantages, including low latency, energy efficiency, and bandwidth transparency, positioning it as a compelling alternative to its electronic counterparts. In this work, we showcase a range of software-defined optical networking applications deployed on a general-purpose programmable integrated photonic processor. Leveraging graph-based theory, we experimentally demonstrate dynamic optical interconnects, circuit switching, and multicasting on the same photonic platform, yielding remarkable results in terms of crosstalk and reconfiguration speed. Our approach harnesses the benefits of reconfigurability and reliability, paving the way for a new generation of high-performance optical devices tailored for data center and computing clusters.

Class-E, active electrically small antenna with enhanced bandwidth-efficiency product and high radiated power at the high-frequency (HF) band

Antennas operating at the high-frequency (HF) band (3–30 MHz) are frequently electrically small due to the large wavelength of electromagnetic waves (10–100 m). However, the bandwidth-efficiency products of passively matched electrically small antennas (ESAs) are fundamentally limited. Wideband HF waveforms using bandwidths of 24 kHz or more have recently received significant attention in military communications applications. Efficiently radiating such signals from conventional passive ESAs is very challenging due to fundamental physical limits on bandwidth-efficiency products of ESAs. However, active antennas are not subject to the same constraints. In this work, we present the design and experimental characterization of a high-power, class-E active ESA with enhanced bandwidth-efficiency product compared to that of passively matched ESAs. Specifically, the proposed class-E active ESA can radiate wideband HF signals with bandwidths of 24 kHz or more at 3 MHz (fractional bandwidths of ≈1%–4%), with total efficiencies ranging from 40% up to 80% depending on the modulation type and radiated power levels approaching 100 W. Our approach uses a highly efficient, integrated class-E switching circuit specifically designed to drive an electrically small, high-Q HF antenna over a bandwidth exceeding 24 kHz at 3 MHz. Using a high-Q RLC antenna model, we have successfully demonstrated wideband binary ASK, PSK, and FSK modulations with the proposed class-E active ESA. Experimental results indicate that the bandwidth-efficiency product of this class-E active ESA is 5.4–9.8 dB higher than that of an equivalent passive design with the same data rate and bit-error-rate.

Simultaneous Manufacture of Magnetic and Locally Conductive Millimeter Scale Bifunctional Devices via Single‐Material Projection‐Based Stereolithography

AbstractThe development of projection‐based stereolithography 3D printing techniques has provided a powerful approach to fabricate millimeter scale functional devices with complex structures. However, the current processes face challenges in frequent switching between multiple materials or processes, resulting in low efficiency and accuracy during the fabrication of bifunctional devices. To address these challenges, chemical deposition is utilized to modify graphene nanoplatelets (GNs) with Fe3O4 magnetic particles and incorporate them into the photosensitive resin, resulting in the development of a novel bifunctional printing material with magnetic and locally conductive properties. Furthermore, the localized conductivity of devices is controlled by an electric‐field‐assisted alignment process of the magnetic GNs (mGNs) during the printing process. Herein, this single‐material projection‐based stereolithography allows for the simultaneous fabrication of magnetic and locally conductive millimeter scale bifunctional devices without switching between multiple materials or processes. A magnetically driven circuit switch and signal coding gear are fabricated as demonstrations. This work significantly improves the efficiency and accuracy of fabricating millimeter scale bifunctional devices, thereby facilitating their application in the fabrication of miniaturized and integrated devices.

Design and Performance Analysis of Photovoltaic Power Generation Light Emitting Diode Device

This research focuses on an independent photovoltaic power generation system with supercapacitor energy storage as the study subject. The model is simplified, and the photovoltaic power generation light emitting diode (LED) device is designed based on the given parameters. This system selects a Boost-type step-up converter for the supercapacitor charging circuit, capable of achieving Maximum Power Point Tracking (MPPT). The supercapacitor discharge circuit employs an LM2596 series regulator to power the rated load LED (12 V, 1 W), providing good linear regulation capability. In designing other hardware components of the device, the characteristics of a photoresistor are utilized to implement an automatic load switch circuit. An efficient single-chip integrated circuit LM2575 series is used as a regulator to convert the voltage across the supercapacitor terminals to +15 V and +5 V. Considering the need to collect the output voltage of the photovoltaic cell array and the voltage across the supercapacitor terminals, a resistor divider method is used to sample these two voltages. The sampling circuit includes a resistor divider circuit and a linear optocoupler isolation circuit. An HNC-25LTS series Hall current sensor is used for current sampling to measure AC, DC, and pulse signals under electrical isolation conditions. The supercapacitor, solar photovoltaic panel, control unit, and the main circuit for supercapacitor charging and discharging have been assembled in the experiment. Connecting the charging and discharging circuit with the photovoltaic panel and LED, the system provides power to the LED during the night. Under varying light intensity and temperature conditions, the photovoltaic output voltage waveform, PWM waveform, and Boost circuit output voltage waveform remain stable when reaching the MPPT point. The output power with added MPPT control at different times is compared. The results indicate that the designed system has effectively achieved the functionality of MPPT for solar energy.

Current ripple optimization design of DC/DC converter

Abstract Renewable energy has the advantages of renewability and high temperature and has great potential for development, but its instability limits its large-scale promotion. Aiming at the stable operation of the new energy power system and ensuring the safe and reliable operation of the power grid, this project defines the basic topology of the variable multiple DC/DC converter according to the idea of switching circuit parallel factor or reducing ripple under each duty cycle. Secondly, the system structure under the boost mode is modeled, and the system is optimized by the combination of a single closed-loop current balance and duty cycle feedforward control. Finally, the model is simulated, and the results show that the method is correct and reasonable.

Adaptive Takagi–Sugeno (T–S) fuzzy observer based fault tolerant control for DC–DC converters with robustness against uncertainties

AbstractThis paper proposes a Takagi–Sugeno fuzzy system model based fault tolerant control scheme for DC–DC converters, which is robust against parameter uncertainties and achieves the output voltage of an ideal converter. The control involves estimating the duty cycle change in the form of a fault parameter required to track the output voltage, in the presence of several uncertain conditions including converter losses, variation in input voltage, and unknown and changing output load. An adaptive law is designed to estimate the fault parameter that guarantees state and parameter error convergence. The adaptive law is derived using the Lyapunov stability theorem and the required parameters are evaluated by solving a linear matrix inequalities optimization problem. The load resistance is estimated in parallel by using a Kalman filter and fed to the fault parameter estimation scheme. Furthermore, a fast and robust method to detect short and open circuit switch faults is also presented. The proposed technique offers a simple, yet effective method to regulate the output voltage under several faulty and uncertain conditions. The proposed technique is tested on a DC–DC boost converter simulation model and the demonstrated MATLAB/Simulink results show the effectiveness of the proposed algorithm.

Code Mixing in the Lyrics of the Song “You Never Know” by Blackpink

This research was a study of language code mixing contained in the lyrics of a song titled “You Never Know” by Blackpink. This study aimed to identify the forms of code mixing contained in the lyrics of the song you never know by black pink, identify the types of code mixing used in the song lyrics, and describe the source language of the code mixing contained in the lyrics of the song. The method used in this study was content analysis, which was a qualitatively oriented technique, usually used to determine the character of documents or to compare them. The conclusion obtained from this study was the forms of code mixing contained in the lyrics of the song You Never Know by Blackpink consisting of inserting words, phrases and clauses. Code mixing in the form of words totaling 8 data, phrases totaling 20 data and clauses totaling 10 data. The type of code mixing used in the lyrics of the song you never know by Blackpink was alternation code mixing. The outer code mixing used was 8 data. The source language contained in the lyrics of the song You Never Know by Blackpink came from English and Korean. The code-mixed from English language was 26 data and Korean was 44 data. Through this research, it can be suggested that further researchers can be developed with the theory of code switching which is closely related to code switching.

The effects of smartphone use during play on performance and enjoyment among recreational golfers

ABSTRACT Smartphone use during play is common feature of recreational golf. It is not known, however, whether this form of behaviour has any impact on golfers’ performance or round enjoyment. The present study is the first to address this question. Based on theories of cognitive switching and psychological detachment, we propose that frequent digital distraction resulting from smartphone use during play would negatively affect both performance and round enjoyment. We surveyed 186 recreational golfers (94% male) with a mean age of 55.7 years (SD=15.8) at five different courses directly after their participation in mid-week club competitions. Participants were asked to report their age, handicap, gross score, level of round enjoyment, and the frequency and nature of their smartphone use during the round. Our results indicate that smartphone use for work-related purposes has a small negative effect on performance (β = 0.11), but that smartphone use for personal purposes has no effect. Additionally, we find no direct relationship between smartphone use and round enjoyment, but propose that it may indirectly impact enjoyment through its impact on performance. Recreational players aiming to improve their concentration during rounds should be mindful of the manner in which digital distractions can disrupt performance routines during play.

Orchid: enhancing HPC interconnection networks through infrequent topology reconfiguration

Interconnection networks are key components of high-performance computing (HPC) systems. As HPC evolves towards the exascale era, providing sufficient bisection bandwidth between computing node pairs through oversubscription in traditional networks becomes prohibitively expensive and impractical. Over the past decade, several architectures leveraging optical circuit switches (OCSs) for dynamic link bandwidth allocation have gained traction. These architectures require frequent network topology reconfiguration to adapt to changing traffic demands. However, practical implementation remains hampered by the long reconfiguration delays inherent in OCS technology. We propose Orchid, an architecture that leverages OCSs to achieve infrequent topology reconfigurations, effectively addressing the problem of long reconfiguration delays. A key innovation of Orchid is its ability to extract stable traffic matrices from historical data. This functionality guides the reconfiguration of the topology without the need for adjustments with each traffic matrix, thereby enabling the sharing of OCS overhead over an extended timeframe. Furthermore, Orchid addresses potential congestion arising from unexpected traffic through the joint design of OCS configuration and routing, ensuring an even distribution of traffic across global links. Extensive experiments using real HPC application traces and synthetic traffic demonstrate that Orchid achieves significant performance improvements compared to existing HPC interconnection networks. Specifically, Orchid reduces packet delay by at least 3× and enhances throughput by up to 60%.

Synchronization of Fractional Delayed Memristive Neural Networks with Jump Mismatches via Event-Based Hybrid Impulsive Controller

This study investigates the asymptotic synchronization in fractional memristive neural networks of the Riemann–Liouville type, considering mixed time delays and jump mismatches. Addressing the challenges associated with discrepancies in the circuit switching speed and the accuracy of the memristor, this paper introduces an enhanced model that effectively navigates these complexities. We propose two novel event-based hybrid impulsive controllers, each characterized by unique triggering conditions. Utilizing advanced techniques in inequality and hybrid impulsive control, we establish the conditions necessary for achieving synchronization through innovative Lyapunov functions. Importantly, the developed controllers are theoretically optimized to minimize control costs, an essential consideration for their practical deployment. Finally, the effectiveness of our proposed approach is demonstrated through two illustrative simulation examples.

The Performance of a Passive Autoranging Method for a Photonic Current Transducer.

This paper reports on the testing and evaluation of a passive autoranging (AR) method designed to dynamically extend the measurement range of a photonic current transducer (PCT) to pave the way toward a realization of a combined metering- and protection-class current sensor. The PCT utilizes a current transformer (CT), a piezoelectric transducer (PZT), and a fiber Bragg grating (FBG) to enable current measurement at multiple points in an electrical power network whereby multiple sensors are deployed and interrogated serially using a single optical fiber. The autoranging technique relies on incorporating static MOSFET switches to instantaneously short individual serially connected CT burdens in response to a measured current magnitude exceeding pre-set thresholds. The AR circuit switching events produce distinctive signal features that are used by the proposed switching algorithm to apply appropriate scaling factors to reconstruct the measured current from the optical signal. It is shown through laboratory experiments that the AR circuit correctly reacts to pre-set burden current thresholds of 130% of the nominal value and 22 times the nominal value, signifying its "metering" and "protection" range boundaries. The circuit reaction time is below 4 ms, rendering it suitable for standard power system protection purposes. Moreover, the operation of the AR circuit is demonstrated for burden currents of up to 100 A for over 1 s, satisfying a test procedure for the secondary CT circuit, as required by some power system operators. It is demonstrated that the proposed switching algorithm allows for a correct reconstruction of the burden currents from the optical signal acquired by the FBG interrogator, offering the potential to realize a dual-class optical current sensor.

Automatic in-situ measurement of thermal resistance for GaN HEMTs

An automatic in-situ technique for thermal resistance measurement based on an electrical method is proposed in this paper. In contrast to the conventional thermal resistance measurement circuits of the electrical method, this method involves direct measurement of the thermal resistance of GaN high-electron-mobility transistor (HEMT) devices in an operating circuit by introducing a well-matched radio-frequency switching circuit into the operating circuit. The advantage of this method is that the thermal resistance can be measured periodically on the in-situ device without changing the electrical characteristics of the device. Based on this result, the cooling curve of the HEMT device in the power amplifier (PA) circuit is collected and the thermal resistance characteristics of the HEMT are determined via the structure function method. The purpose of this paper is to successfully obtain the thermal resistance of in-situ devices through an automatic in-situ measurement circuit of thermal resistance, and to verify the feasibility of periodic detection of thermal resistance of in-situ devices.

A facile DNA coacervate platform for engineering wetting, engulfment, fusion and transient behavior.

Biomolecular coacervates are emerging models to understand biological systems and important building blocks for designer applications. DNA can be used to build up programmable coacervates, but often the processes and building blocks to make those are only available to specialists. Here, we report a simple approach for the formation of dynamic, multivalency-driven coacervates using long single-stranded DNA homopolymer in combination with a series of palindromic binders to serve as a synthetic coacervate droplet. We reveal details on how the length and sequence of the multivalent binders influence coacervate formation, how to introduce switching and autonomous behavior in reaction circuits, as well as how to engineer wetting, engulfment and fusion in multi-coacervate system. Our simple-to-use model DNA coacervates enhance the understanding of coacervate dynamics, fusion, phase transition mechanisms, and wetting behavior between coacervates, forming a solid foundation for the development of innovative synthetic and programmable coacervates for fundamental studies and applications.