Dual Power Supply Research Articles

Enhancing fatigue performance of AA6063-T6 fasteners through novel electromagnetic cold expansion using a double-frequency discharge

Non-contact electromagnetic cold expansion process (EMCE) represents a highly promising way to enhance the fatigue performance of fasteners. However, within the current technological framework, the necessity for dual power supplies and an accurate discharge control system has constrained the development and application of this technique. To address this, a novel EMCE process utilizing a double-frequency discharge is proposed. This process is accompanied by the development of an electromagnetic system with only one set of power supply to generate a current composed of a gradual-ascending and rapid-descending stage. This current induces a significant radially outward Lorentz force, facilitating hole expansion and introducing residual compressive stress around the hole, thus increasing the fatigue life of the fasteners. The experimental results demonstrate a remarkable enhancement in fatigue life for samples treated with the EMCE process when compared to untreated ones, showing an impressive 6.8-fold, 4.9-fold, and 1.6-fold increase at stress loads of 120 MPa, 130 MPa, and 150 MPa, respectively. Microstructural analysis reveals that the processed components exhibit favorable surface integrity, and there is no significant grain refinement near the hole. Moreover, it is found that there existed optimal current waveform to maximize fatigue life. These findings hold significance in understanding the EMCE process and advancing its practical applicability.

Seat to beat: Novel capacitive ECG integration for in-car cardiovascular measurement

Cardiovascular diseases (CVD) are a leading cause of global mortality, responsible for approximately one in five deaths. In response to these concerning statistics, there is a growing need for innovative solutions enabling cardiac monitoring beyond medical facilities. This paper demonstrates the fabrication and development of a novel system designed to be integrated into passenger car seats, facilitating continuous monitoring of passengers’ cardiac activity. The system comprises a capacitive electrode prototype, a custom-designed analog signal processing circuit, and a computing unit. Two ultrathin capacitive electrodes were fabricated with a diameter of 56.42 mm protected by a guard layer to reduce noise. The amplification circuitry was comprised of operational amplifiers tasked with filtering and conditioning the electrocardiogram (ECG) signal. Heart rates calculated from our measurements were comparable with clinical ECG. The experimental setup underwent testing on human subjects while they were in a state of tranquil sitting within passenger cars and also in laboratory conditions. The proposed system offers the flexibility for single and dual power supplies in full capacitive or hybrid mode. Our experimental results confirm the system’s feasibility and its capability to record high-quality signals from weak biopotentials, highlighting its potential for real-world applications.

Analysis of Rail Potential and Stray Current with an Unified Chain Model of Dual Traction Power Supply System

In dual traction power supply systems, the overhead catenary system operates in different power supply modes. It passes across the AC section, DC section, and a neutral part, which influences the features and properties of the feedback current and aggregates its effects on stray current and rail potential. This research paper presents an integrated model of an AC and DC traction power system (TPS), along with a unified chain equivalent circuit model, the ground wire through the AC section, and the insulation joints fixed in the AC–DC neutral section under different operating positions. To make a unified impedance and admittance matrix for traction network, a virtual conductor wire has been added in the DC section to make the balance order of the TPS. The influence of reflex system configuration on rail potential, stray current, and distribution of rail potential at AC and DC stations has also been calculated. The simulation results demonstrate that establishing the insulation joints in the AC–DC section and using ground wires in the AC part can significantly decrease the stray current and rail potential.

Prospects for the use of inductor electric drives of dual power supply with phase control in the support rotary devices of antenna systems

Prospects for the use of inductor electric drives of dual power supply with phase control in the support rotary devices of antenna systems

Bulk Cum QFG-Driven FVF Double Recycling Current Mirror Subthreshold OTA Based CCII+ Cell and Applications

This paper presents a low-voltage low-power second generation CCII+ cell using bulk-driven FVF class AB mode operated double recycling current mirror OTA. The OTA is used in the input core of CCII+ cell utilizes bulkcum Quasi Floating Gate (QFG)-based voltage to current converter and Partial Positive Feedback (PPF) to enhance the performance of the circuit. The circuit permits closely railto- rail input common mode range, high output current drive capability with low dual power supply of ± 0.25 V. This circuit produces low input referred noise of 1.65 μV/sqrt Hz, dissipates ultra-low power of 342 nW and is suitable for lowfrequency applications, such as bio-signal processing. Further, to validate this design, a MISO type voltage mode biquadratic filter and voltage mode two phase quadrature oscillator are currently being implemented using this CCII+ cells. The circuit is simulated in tanner EDA tools using 180 nm n-tub CMOS process technology with low bias current of 18 nA.

Switching Capacitor Filter with Multiple Functions, Adjustable Bandwidth in the Range of 5 Hz–10 kHz

This article proposes a second-order switch-capacitor filter that integrates low-pass, high-pass, band-pass, band-stop, and all-pass, and achieves flexible bandwidth adjustment of the filter through clock rate and capacitance ratio. The final filter design consists of two completely independent second-order switch-capacitor filter channels, and a 4-order Butterworth low-pass filter is designed through two-stage cascades. The two completely independent second-order switch-capacitor filters are integrated on a single chip and manufactured using the Huahong BCD350GE high-voltage 24 V process. The measurement results indicate that the proposed switch-capacitor filter achieves various functional filtering characteristics and achieves a bandwidth of 5 Hz to 10 kHz. The chip area is 5.1 × 3.1 mm2, powered by a dual power supply of ± 5 V, and the power consumption is 80 mW.

Understanding Mold Wear Mechanisms and Optimizing Performance through Nico Coating: An In-Depth Analysis

This research investigates the wear mechanism of molds and examines the worn areas using high power microscopes and SEM (Scanning Electron Microscopy). In addition, EDS (Energy Dispersive Spectroscopy) and XRF (X-ray fluorescence) techniques are used to compare the worn areas with the normal areas. The results indicate that the wear mechanism of the molds is similar to adhesive wear. To address the issue of die wear, the application of Nico coating to the copper substrate surface is investigated. Two sample preparation methods, namely DC power supply and dual pulse power supply, are employed. SEM analysis shows that the sample group prepared using the dual pulse power supply has a relatively dense surface coating. The samples with a 60:40 weight ratio of Nico exhibit the highest average hardness and thickness, with minimal dispersion as indicated by the low standard deviation. The samples also show minimal roughness. Repeat tests under the same conditions confirm that the coating surface remains dense and uniform with a hardness of 467.628 hv, a thickness of 43.0665 μm and a roughness of 4.331 nm. The nanoindenter test results show that the coating has improved wear resistance (−28.7 nm) compared to the original mold (−142.4 nm), an increase of 80%.

Design of Current Equalization Circuit in Dual Ethernet Power Supply System

A current-balancing circuit for a dual-channel Ethernet power supply system is designed in this paper, which can be used to solve the mismatch between the two channels caused by unavoidable factors, such as mismatched resistances, temperatures and voltages. Based on the design, the mismatch of the currents between the two power transmission paths can be controlled to be less than 1% of the original ones. It can be operated under these conditions with the changes of the load current and the PSE output voltage. The maximum output power of the dual-channel power supply can reach up to 96.5 W. When the DC–DC conversion efficiency is less than 75%, it can still provide 72 W for the PD end, meeting the requirements of the PoE power system. The current-balancing circuit designed in the paper has potential application value to improve the dual PoE power supply system.

Effect of opposite phase AC voltage application using dual power supplies on thrust and induced flow of plasma actuator

This study proposes a new driving method using dual power supplies to address a trade-off between power supply miniaturization and the high voltage output driving of a dielectric barrier discharge plasma actuator by simultaneously applying two AC voltages with opposite phases to the exposed and encapsulated electrodes. The performance of the proposed method was compared with that of two conventional driving methods that use a single power supply. The maximum peak-to-peak voltage with the single power supply was 23 kV, whereas that with the dual power supplies using a transformer with a lower output capability was 30 kV. At the same peak-to-peak voltage, the method using dual power supplies had intermediate time-averaged thrust and induced flow velocity among the three methods. This is attributed to the different discharge distributions at the edge of the exposed electrode, which are caused by the different electric field strengths for each method.

Power Flow Optimization and Control Strategy for Energy Router in Dual Mode Traction Power Supply System

Power Flow Optimization and Control Strategy for Energy Router in Dual Mode Traction Power Supply System

Surface charge characteristics in surface dielectric barrier discharge actuators with thin cylindrical exposed electrode

The influence of the cylindrical exposed electrode diameter on distribution and attenuation of the surface charge in surface dielectric barrier discharges is experimentally investigated using the Pockels effect of the Bi12SiO20 crystal. For the actuator with the smaller exposed electrode diameter, more positive charges accumulate closer to the exposed electrode after positive half periodic discharge, while the quantity of positive charges deposited on the surface in a discharge period at the same distance away from the exposed electrode is smaller. At the same time, the smaller the exposed electrode diameter is, the shorter decay time the positive charge filament needs. Combined with thrust generation of actuators, it can be indicated that a positive residual surface charge closer to the exposed electrode may play a more crucial role in the discharge and consequent thrust than one far away from the exposed electrode does. Also, the effect on the discharge of the positive residual surface charge may be greater than that of the negative residual surface charge. More explorations of the residual surface charge have been done by selectively enhancing the discharge of the actuator with a 10 μm exposed electrode using the pulse-AC dual power supply, drawing the same conclusions.

Categorization and evaluation of voltage sag control methods and equipment: A study

Voltage sags have emerged as major problems in power quality in the recent years and the categorization of methods and tools available for reducing voltage sag is becoming increasingly crucial. Modern approaches and tools for minimizing voltage sag are based on an extensive research, aimed at developing effective categorization techniques to assist end users in selecting the most suitable tools and settings. To begin, this research provides a comprehensive assessment of the existing voltage sag control methods and equipment. Furthermore, it presents a classification scheme that divides voltage sag control strategies into three groups: those implemented by the power provider, the customer, and the equipment manufacturer. A classification system for voltage sag control equipment based on the number and type of power supply, taking into account the variations between single and dual power supply voltage sag control devices is also proposed. Additionally, to assist consumers in selecting the optimal device, this research demonstrates how primary voltage sag control equipment utilizes the preventive measures and an integrated software.

Design and Development of Simple and Low-cost Light Source for Laparoscopic Surgery.

The existing medical light source device used in laparoscopy surgery is very costly and is not yet developed in Nepal. This study aimed to build a light source device that is cost-effective and passes all the testing parameters like Light Emitting Diode illumination, color, and heat. A method of constructing a light source comprises the steps of designing, assembling the system, and undergoing device testing. The design of the device was done through Sketchup software. The dual switched-mode power supply of 3-4 Voltage to the Light Emitting Diode and 12 Voltage to the rest of the system with cooling technology were used. The Light emitted from the Light Emitting Diode focuses the light directly at the fiber optic cable through the coupler. Moreover, the testing of the device concludes that the increment temperature of the device for 1 hour is 1 degree Celsius whereas the maximum increment temperature was found to be 3 degrees. Additionally, the fiber optic illumination at the port is found to be >50000. Also, the color of the Light Emitting Diode is cool white light having a color temperature of 5700 Kelvin and a color rending index of 92. The developed device is four times cheaper than a similar device available in the Nepalese market. Also, this device has been developed first of its kind in Nepal.

Perancangan dan Simulasi Power Supply Simetris pada Yenka

This research was conducted to test the accuracy of the symmetric power supply circuit based on the data made in the table. Symmetrical power supply circuit is designed based on bipolar power supply, have wave power supply and full wave power supply. with the circuit test data made in the table. A power supply, also known as a dual output power supply, is a type of adapter in a circuit that produces two output voltages (output) in a balanced but opposite direction to ground (zero). when at the voltage level at the negative and positive terminals to ground (Reference) with a position of 180 ° inverse from each other. The power supply circuit can work from a symmetrical adapter circuit as a voltage reducer, to switch alternating or AC voltages so that they are reversed into direct or DC voltages. The current source of the power supply converts the alternating current from the AC power plant which is then converted into DC. In addition, the result of this output makes +Vcc and –Vcc. The power supply circuit plays an important role in electronic devices such as computers, phone chargers, and televisions. On a computer the power supply can be found on the cable that is connected to the supply. The power supply can also function to protect electronic components from damage that occurs due to electrical damage that occurs. Testing the accuracy of the symmetrical power supply circuit using the yenka simulator to support the research. This simulator has complete features that make it easier for researchers to assemble circuits. In the simulation of symmetrical power supply bipolar output, full wave power supply and have wave power supply.

Switching characteristics analysis and power loss minimization of SiC BJT based on dual power supply RC driving circuit

As a current driven power device, SiC BJT needs effective driving scheme, but the present schemes are either complicated or not parameter optimized. In this paper we give an optimized parameter design method based on dual power supply RC driving circuit. First, the detailed switching process of SiC BJT considering the loop parasitic parameters is presented. Then, the influence of the accelerating capacitor on the switching loss and driving loss of SiC BJT is analyzed. The theoretical and simulation analysis shows that as the accelerating capacitor increases, the driving loss of SiC BJT increases proportionally, while the switching loss decreases less. Finally, the switching process of SiC BJT was investigated experimentally at various accelerating capacitor values from 3.3 nF to 94 nF. It was found that with the increase of the accelerating capacitor, the total loss during the switching process first decreases and then increases. The total loss minimization during the switching process of SiC BJT can be achieved through properly selecting the accelerating capacitor.

The Torque Ripple Optimization of Open-Winding Permanent Magnet Synchronous Motor With Direct Torque Control Strategy Over a Wide Bus Voltage Ratio Range

Due to the battery voltage performance of the dual power supply open-winding permanent magnet synchronous motor (OW-PMSM) system in electric vehicles, the dc bus voltages of the dual power supply varies and the traditional direct torque control (DTC) method will not be suitable and may lead to obvious torque ripples. Thus, in this article, based on the analysis of the effect of voltage vector on torque variation, a bus voltage ratio is employed in the switching table optimization strategy of DTC for OW-PMSM, the voltage vector selection method is also modified according to different voltage ratio, and then, the optimized control scheme for OW-PMSM over a wide bus voltage ratio is achieved to diminish the torque ripples. Finally, simulation models of the proposed method are built to verify the theory, and the corresponding experiments are also conducted to verify the feasibility and effectiveness of the proposed optimized control strategy.

A review of voltage sag control measures and equipment in power systems

In recent years, voltage sags are one of the most critical research issues in the field of power quality. With the all-embracing study of voltage sag mitigation measures and equipment, the classification of voltage sag mitigation measures and equipment is becoming more and more necessary. Reasonable classification methods not only can guide users to choose appropriate control measures and equipment, but also provide basis and research direction for new voltage sag control measures and equipment. Firstly, this study performs a detailed analysis of the current stage of voltage sag control measures and equipment, and proposes a classification method that divides the voltage sag control measures into three categories: the power supply side, the customer side and the equipment manufacturing company. Secondly, due to the difference between single power supply and dual power supply in voltage sag control equipment, this study proposes a classification method for voltage sag control equipment based on the number and type of power supply. Finally, in order to help users to select the voltage sag control equipment suitable for the actual situation, this paper summarizes the prevention and control ability of the main voltage sag control equipment.

Detection Method of Power Saving Mode of Household Photovoltaic-Storage Integrated Power Supply

Nowadays, more importance has been attached to the energy consumption of household energy storage inverters. This paper proposes a design scheme of original-auxiliary dual power supply for household energy storage inverters, so that the inverter uses a large-capacity power supply when it is loaded with medium or large loads, and uses a small-capacity power supply when it is loaded with light loads or no load, and avoids large losses caused by the two-stage inverter when using a large-capacity power supply with a small load with the purpose of energy saving. The solution adopts a peak detection circuit on the AC power supply side, which can accurately detect the tiny current when the 1∼3W-load is connected, so as to accurately judge the access and exit of the load, so that the power supply can enter or exit the power saving mode of the small-capacity power supply in a timely and flexible manner. In this paper, the feasibility and rationality of the scheme are tested by simulation, and it is proved that the power saving effect of the scheme is remarkable.

More is Less: Domain-Specific Speech Recognition Microprocessor Using One-Dimensional Convolutional Recurrent Neural Network

Low-power keywords recognition has been a focus of acoustic signal processing for several decades. This work investigates the domain-specific speech recognition microprocessor based on optimized one-dimensional convolutional recurrent neural network (1D-CRNN). Compared to previous DNN based frameworks, the proposed 1D-CRNN can process both the feature extraction and keywords classification, and achieve high recognition accuracy with reduced computation operations under wide range background noise SNRs. An energy-efficient 1D-CRNN accelerator is implemented to dynamically reconfigure and process the different layers. This accelerator has the characteristics of “More is Less” in three aspects: 1) the hybrid network with more complex layers is much more compact and requires less computation; 2) although the weight width quantized to 8 bits requires more memory size and multiplication energy cost, the required network neurons can be reduced and hardware utilization can be improved; 3) an energy-aware self-compensation tensor multiplication unit with dual power supply based on approximation design method can be utilized for 1D-CRNN computing. Compared to the state-of-the-art architectures, the novel more-is-less architecture can achieve a much lower power consumption of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1.4~\mu \text{W}\sim 2.1~\mu \text{W}$ </tex-math></inline-formula> (over 80% reduced) under an industry 22nm technology, while maintaining higher system adaptability (support SNRs: −5dB~Clean) for 1~5 real-time keywords recognition.

A 14-bit 40-MS/s Split-DAC based SAR ADC in 65 nm CMOS

A 14-bit 40 MS/s successive approximation register (SAR) analog-to-digital converter (ADC) is designed in this paper. The prototype was designed in CMOS 65-nm technology. To reduce the power dissipation, dual power supply has been used. Supply voltage for the analog blocks is 3.3 V, while digital block is powered by a 1.2-V supply. Sizes of capacitors in DAC arrays are decided mainly by the kT/C noise, matching requirement, chip area and consumed power. In this design, the sub-radix-2 redundant structure is employed to achieve compromise among these aspects. An on-chip LDO is also integrated in the proposed ADC to eliminate the incomplete DAC settling. The supply noise can be also suppressed by the adopted LDO due to its excellent PSRR performance. In addition, top-plate sampling is utilized to ensure the common-mode voltage of the DAC outputs is maintained, thus reducing the difficulty in the design of the comparator. The post-layout simulation results show that the ADC draws 20.9 mW with Nyquist input at 40 MS/s. With calibration, the SNDR and SFDR of the ADC achieve 84.9 dB and 95.4 dB. The active area of the ADC is 540 × 500 μm2.