Adjustable Circuit Research Articles

Realizing Multi-Parameter Measurement Using PT-Symmetric LC Sensors.

With the rapid development in sensor network technology, the complexity and diversity of application scenarios have put forward more and more new requirements for inductor-capacitor (LC) sensors, for instance, multi-parameter simultaneous monitoring. Here, the parity-time (PT) symmetry concept in quantum mechanics is applied to LC passive wireless sensing. Two or even three parameters can be monitored simultaneously by observing the frequency response of the reflection coefficient at the end of the readout circuit. In particular, for three-parameter detection, a novel detection method is studied to extract the three resonant frequencies of the system through the phase-frequency characteristics of the reflection coefficient, which has never appeared in the previous literature on PT symmetry. The changes in three resonant frequencies are in response to changes in the three parameters in the environment. We show theoretically and demonstrate experimentally that the PT-symmetric LC sensor can realize multi-parameter measurement using a series LCR circuit as the sensor and a symmetric adjustable LCR circuit as the readout circuit. Our work paves the way for applying PT symmetry in multi-parameter detection.

Load-Independent Class-E Design with Load Adjustment Circuit Inverter Considering External Quality Factor

Load-Independent Class-E Design with Load Adjustment Circuit Inverter Considering External Quality Factor

Designing and fabricating a stationary magnetic particle system for Non-destructive testing

The bench unit, also known as the stationary magnetic particle system or the wet horizontal system, has been designed and fabricated to incorporate both circular and longitudinal magnetization techniques. Its primary purpose is to test machine parts commonly used in various industries, including aviation, automotive, and railway. The system comprises several key components: a transformer, a current control unit, a parameter display and adjustment circuit, a head shot, a coil, and wet magnetic irrigation device. This system is in compliance with international standards and is ready for implementation in companies that require it

Solar and Wind Power Electric Vehicle

This project concerns a vehicle, the “Solar and Wind Power Electrical Vehicle,” whose operation is controlled using IoT. The principal purpose is to use renewable forces for vehicle movement. There is an ESP32 microcontroller that connects to two electric engines and a motor driver enabling precise commands in the structure. Furthermore, the car consists of a solar battery panel and a wind turbine providing sustainable and ecological energy production. Our main objective is to build a car that uses no oil or gas at all since it can run on something more unconventional, such as solar power, wind energy, etc.; thus, the focus of this project is on creating a green car that will not use fuel made from fossil fuels like petrol or diesel while making sure that it works using only sustainable sources of energy available today. The motor driving system integrates the ESP32 module into the motor speed adjustment circuit (MSAC), which acts as an electronic hub for both motor control signals and serial communication codes between the motor and the CPU (central processing unit) on a single chip. Remote car control using just your phone is possible because IoT connects it. When connected, the driver can have control over each motor's direction individually such that they are interconnected with the two motors by default on the driver circuit board (or the relation may occur by default). Consequently, the vehicle gets an increased capacity for navigating various surfaces more effectively this way—The two engines act as an independent supposing of its configuration. If you want it to move off the road or even on hilly ground, this car would do so easily because there is a mechanism that makes it easier for her to move on such surfaces. It is equipped with a solar panel and wind turbine, allowing the car to be powered by renewable energy from its environment. During the day, the sun charging system converts sunlight into electricity, whereas during the night the wind generator creates power from wind when there is some wind. The stored energy can be preserved in accumulators.

A bifunctional superconducting cell as flux qubit and neuron.

Josephson digital or analog ancillary circuits are an essential part of a large number of modern quantum processors. The natural candidate for the basis of tuning, coupling, and neromorphic co-processing elements for processors based on flux qubits is the adiabatic (reversible) superconducting logic cell. Using the simplest implementation of such a cell as an example, we have investigated the conditions under which it can optionally operate as an auxiliary qubit while maintaining its "classical" neural functionality. The performance and temperature regime estimates obtained confirm the possibility of practical use of a single-contact inductively shunted interferometer in a quantum mode in adjustment circuits for q-processors.

An Adjustable deadtime Control Circuit for LLC Resonance Control Circuit

This study introduces the principle of deadtime generation and gives a deadtime control circuit. The deadtime can be adjusted by the current generated by the MOS transistor in the subthreshold region to control the charging and discharging speed of the capacitor dynamically, and the whole circuit is simulated in the cadence simulation environment. The simulation results show that the designed circuit can manually adjust the dead time in the range of 70 ns-1, 650 ns depending on external settings, and greatly reduce the complexity of the circuit.

Pulsed Optoelectronic Rangefinder and Its Measurement Applications in Architectural Design Rationality Assessment

The laser rangefinder is a device that combines various technologies such as optoelectronics, electronics, microcontroller control technology, signal control, processing technology, and precision mechanical technology. This device has wide application value in aerospace, automatic control, industry, military, geodesy, and construction surveying, among other fields. The pulse laser rangefinder designed uses the SPLLL90_3 laser emitting diode for the laser emission circuit and employs the AD500_9 laser receiving diode for the laser reception circuit. The design of the laser emission circuit includes laser diode selection, emission, sample signal’s modulation circuit design, pulse signal generation, and driving circuit. The design of the laser reception circuit includes laser receiving diode selection, laser reception pulse signal’s acquisition circuit, reception signal adjustment circuit, and microcontroller peripheral circuit. After completing the hardware design of the pulse laser rangefinder, performance testing is conducted. The laser emission waveform and reception waveform are tested under an oscilloscope. The results show that the emission pulse generation and reception pulse acquisition circuits work normally. Range tests show that the rangefinder has a high degree of fit between theoretical and actual measurement distances within a certain time interval, meeting the design expectations. The designed optoelectronic rangefinder is adopted to evaluate the rationality of the design of building wall freeform surfaces through measurement. The results suggest that the designed optoelectronic rangefinder achieves higher detection efficiency and accuracy compared to traditional evaluation methods.

High-Misalignment Tolerance and Output Adjustable Wireless Charging System via Detuned Series–Series Compensated Reconfigurable Transmission Channels

This paper proposes a wireless charging system (WCS) with two reconfigurable transmission channels to achieve constant current/voltage (CC/CV) charging, anti-misalignment solid ability, and zero voltage switching (ZVS) operation. First, the structure design and working principle of the orthogonal magnetic coupler (OMC) are given. The OMC's parameters are optimized using the orthogonal experimental design. Then, the coupling performance of OMC is illustrated by Ansys simulations. Second, the topology and principle of the designed WCS are analyzed. The relationship between charging controllability, misalignment performance, and system parameters is presented. The design method and working principle of the magnetic flux controllable inductor (MFCI) used as the power adjustment circuit and auxiliary improvement of anti-misalignment ability are provided. Third, the schematic diagram and hardware of the closed-loop controller are given. The PLECS simulations verify the feasibility of using the MFCI to realize the above design goals. Finally, an experimental prototype of an unmanned aerial vehicle (UAV) is built to validate the method's feasibility. When the maximum charging power is 126 W, the maximum system efficiency is 91.6%. Besides, assuming system efficiency decreases by 5% from the maximum value, the maximum horizontal misalignment ratio is 42%, corresponding to a desired approximately circular charging region.

Design and Optimization of Wheatstone Bridge Adjustment Circuit for Resistive Sensors

A novel Wheatstone bridge adjustment circuit with both rough-tuning and fine-tuning functions is designed for balancing Wheatstone bridge in this paper. Firstly, the parametric circuit structure is constructed to facilitate the design of rough-tuning and fine-tuning sub-circuit parameters; Secondly, the quantitative index of Wheatstone bridge imbalance is defined, and the parameter design flow of the rough-tuning sub-circuit, which consists of two sets of series-parallel-resistor (SPR) structures that are respectively connected in parallel with the two branches of one half-bridge, is given to directly weaken the initial bridge imbalance in the manufacturing stage. Theoretical analysis results show that the SPR structure can effectively approach any expected value and reduce the number of fixed resistor types. Thirdly, parameters of the fine-tuning sub-circuit, which consists of a resistor and a digital-to-analog converter (DAC), are optimized based on any expected adjustable range. By adjusting the DAC input to seek the middle value of an analog-to-digital converter output, indirectly eliminate the additional bridge imbalance caused by mechanical assembly stress, gravity, ambient temperature, and etc. in the application stage. Then the influence of the fine-tuning parameters on linear fitting coefficients of the output vs. input of the Wheatstone bridge is analyzed theoretically. The results show that the DAC output voltage only has a significant linear impact on the intercept coefficient, while its impact on the scale coefficient is negligible. Finally, the effectiveness of the adjustment circuit is verified on a six-axis force/torque sensor that is developed for an Experimental Module Manipulator in the Chinese Space Station.

An intelligent integrated EDI module based on fuzzy PID

Electrodeionization (EDI) is a popular method of water treatment in the current field of water treatment. EDI module mainly absorbs the charged ions in water through the cation exchange resin and realizes the ion removal of water by applying an electric field to make the charged ions move in a directional way and pass through the cation exchange membrane with selective permeability. The existing EDI module has a low integration degree and the working current cannot be adjusted intelligently according to the field environment. In order to solve the problem of low integration degree, this paper designs an EDI module that integrates the EDI module, sensor, controllable constant current source module, and main controller. Meanwhile, in order to solve the problem that the current EDI working current cannot be adjusted in real-time with the environmental water quality, an EDI module output current control method based on fuzzy PID and a main controller hardware circuit based on the adjustable constant current source circuit of a microcontroller digital-to-analog converter (DAC) are designed to adjust the output current of EDI module intelligently. Then the control model of the control system is established by Matlab respectively using the PID control method and fuzzy PID control method, and the simulation is compared. In this paper, the hardware and software of the module are developed based on STM32. The experimental results show that the designed EDI module can realize accurate and fast control of water quality.

Analysis and research of EMI filter based on SiC power device

The new electronic devices represented by SiC have brought new opportunities to improve the efficiency and power density of the drive circuit system. However, the complex circuit drive system using the new electronic devices still faces many challenges to give full play to its advantages. This paper focuses on the electromagnetic interference of drive circuit. Research on Filter Circuit, through in-depth study of the filter circuit, several second-order active circuits are proposed to filter the signal interference of the conduction path. Finally, an adjustable quality factor bandstop circuit is designed. The proposed circuit has good adjustment and feedback functions when filtering interference signals.

All-in-One SPAD Ranging Sensor With Real-Time Xtalk Calibration and Integrated Biasing

This letter presents a novel fully integrated dToF system-on-chip ranging sensor based on a SPADs array. The sensor is made a configurable array of 16 × 16 SPADs, a 940nm VCSEL, a co-design VCSEL driver and embedded DSP core. To suitable different ranging scenarios with high reliability and low cost, the above mentioned are all packaged into one module for ranging. However, the package of coverglass can cause Xtalk, which have a negative impact on ranging. In order to reduce the influence of Xtalk on ranging. This letter proposes a real-time Xtalk calibration circuit system, which can automatically adjust the laser pulse width, when Xtalk and target bins are mixed together. And also to mitigate the effect of SPAD jitter on the Xtalk bins width, an adjustable bias voltage charge pump circuit is adopted to realize the accurate adjustment of pixel SPAD’s bias voltage. The system has been turned out with precision of better than 5mm within 6m in 80% reflectance of target, still with a precision better than 8mm at a distance within 4m in 18% reflectance of target.

Effect of focus ring with external circuit on cathode edge sheath dynamics in a capacitively coupled plasma

Capacitively coupled plasmas are widely used in semiconductor processes. The control of plasma to obtain uniform deposition and etching is an open problem, particularly within a few millimeters of the substrate edge. Complex material stacks commonly referred to as focus rings are placed at the wafer edge to provide uniform processes across the entire substrate but have limitations with regard to process window and eventual material erosion. One approach is to combine a focus ring with a tunable external circuit ground path termination to extend the plasma uniformity to the wafer edge over a wider process space. The external circuit coupling focus ring to the ground influences the ion energy profile and the ion angular profile by changing the impedance between the focus ring and the ground and allows wafer edge tuning over a wide range of operating parameters. In this work, it is found that the adjustable external circuit can control the partitioning of bias and RF voltages between the RF powered and passively coupled plasma facing surfaces. The focus ring with an external circuit assembly can also control the spatial distribution of plasma density and, therefore, improve the sheath edge profile. These results point to possible source designs for engineering the distribution of power dissipation and the electric field of the wafer edge in industrial plasma reactors.

Phase‐shifted full‐bridge converter based on an adjustable current auxiliary circuit with full load range ZVS and small duty cycle loss

AbstractIn this paper, a phase‐shifted full‐bridge converter based on an adjustable current auxiliary circuit is proposed. The converter's switches achieve ZVS with the help of the parallel current provided by the auxiliary circuit. The conduction loss of the parallel current is reduced since the magnitude of the current can be adjusted by the variable inductor. Since there is no additional series inductor, the duty cycle loss of the proposed converter is minimal. Moreover, the oscillating voltage on the secondary side decays quickly, indicating that the energy involved in the oscillation is small, which is beneficial to reduce the loss of the RCD. The experimental platform is built. On this basis, theoretical analysis and experimental verification are carried out in this paper.

Design, Simulation, and Experimental Study on the Hydraulic Drive System of an AUV Docking Device with Multi-Degree Freedom

AUV docking devices have the ability to achieve homing of the AUV, supply the AUV with energy, and exchange data with it, thus improving the endurance and ensuring the continuous long-term and large-scale operation of the AUV. To improve the successful docking rate of the AUV, a funnel-shaped underwater docking device with multi-degree freedom based on a deep-sea platform was designed in this paper. The heading angle, pitch angle, and roller angle of the docking device could be adjusted in a timely manner according to the current flow direction and the position of the AUV. In order to realize the timely adjustment of the heading angle, pitch angle, and roll angle of the docking device, a set of underwater hydraulic systems was developed as the power source to drive the corresponding hydraulic cylinders, hydraulic motors, and other executive components. The model of the heading angle adjustment circuit of the hydraulic system was established and the open-loop transfer function of the heading angle adjustment circuit was derived. The dynamic response performance of the hydraulic circuit was simulated and the optimized PID algorithm was used to improve the dynamic response performance. Finally, the accuracy of the heading angle adjustment circuit model and the effectiveness of the control algorithm were validated by experiment of the docking device in a water pool.

Design and implementation of pixel‐based adjustable ESD protection circuits for capacitive fingerprint biometric sensors

AbstractThe trade‐off design between ESD endurability and polymer thickness on sensor plate for capacitive fingerprint is emerging in these years since the image quality of fingerprint is vital for biometrics authentication. In this paper, we propose a pixel‐based ESD protection circuitry in parallel to GDPMOS and GGNMOS and an adjustable body terminal in proposed pixel‐based ESD circuit to meet and exceed air discharge ±15 kV without thicker polymer. With the proposed pixel‐based adjustable ESD protection circuit, the maximum air discharge achieved by (18 kV, −17 kV), and 10 out of 10 samples passed +15 kV, and 10 out of 10 samples passed −15 kV. Compared to conventional ground wall fingerprint sensor, the maximum air discharge was stopped by (15 kV, −15 kV), and just merely five out 10 samples passed 15 kV, seven out of 10 samples passed −15 kV. Besides the excellent ESD endurability, the proposed pixel‐based ESD protection circuit achieves air‐discharge 15.5 kV and grayscale count 230 at merely 50 μm thickness of polymer. Compared to the conventionally used ground wall sensor types, it passes only 13 kV and a grayscale count of 210 at a polymer thickness of 50 μm, but fails 15 KV Level 4 of IEC‐61000‐4‐2. Even with polymer thickness increased to 250 μm, ground wall sensor types barely passed 15 kV, and the grayscale count dropped to 120, which is far from PIV image standard.

A Multichannel, High-Bandwidth Wirelane Receiver for D2D Interconnects

This paper proposes a multichannel and high-bandwidth (BW) receiver for standard packaging die-to-die (D2D) interconnects. The receiver adopts forward clock (FCK) architecture of the high-density transmission standard, which consists of 16 high-speed data paths and a pair of low-speed differential clocks for 512 Gbps BW. To reduce the chip area and power consumption, a common minimal phase-locked loop (MINI-PLL) and data adjustment (CDA) circuit to replaces the clock data recovery circuit (CDR) in the traditional receiver. A delay-matching circuit is adopted to combat PVT variation and lane skew. In addition, a high linearity phase interpolator (PI) circuit design is used in the minimum phase-locked loop (MINI-PLL) to adjust the clock phase and improve the clock jitter performance. Using 28 nm CMOS technology, the overall link power consumption is 1.56 pJ/b. Bit error rate (BER) is less than 10−15 under the real S-parameters with a channel loss of 10db@16GHz.

A Multi-Source Co-Simulation Method for the Thermal Stability of GaAs Sub-6G Power Amplifier with Adjustable Bias Current

In this paper, the thermal stability of GaAs heterojunction bipolar transistor (HBT) power amplifier (PA) in a sub-6G band has been improved by a multi-source co-simulation method. To reduce the parameter errors caused by the variations of thermal resistances, a co-simulation method for the multiple heat sources of fully-integrated PA is proposed. Specifically, an adjustable bias circuit is applied on the PA for temperature compensation using a zero-to-absolute-temperature (ZTAT) current. To verify the proposed method, a sub-6G PA is realized in the GaAs HBT process. The experimental results show that the variations in power added efficiency and output power is stabilized due to the 3.5% error ZTAT current. The errors between simulation and measurement are reduced from 6% to 1%. According to the thermal factor defined in co-simulation, the working temperature decreases 10 °C, while the area only increases 27%. The above results prove that that thermal stability and the simulation reliability can be co-designed with the minimal area cost.

A Self‐contained Trimmable Low Quiescent Current Overvoltage Detector

This paper presents a low‐power self‐contained overvoltage detector. Compared with conventional detectors that consist of stacked Zener diodes, the proposed structure can trim the threshold with binary codes to accommodate system‐level changes. The proposed structure enables trimming by adding a decoder, a biasing circuit, and switches in parallel with Zener diodes. The newly configured structure forms a standalone detector that can operate independently and be powered from the supply under detection with negligible current addition. The proposed structure is applicable to any high‐voltage process that contains N‐type isolation layer and needs no high‐voltage device. The proposed circuit with three bits adjustment circuit was fabricated in a 0.18 μm Bipolar‐CMOS‐DMOS (BCD) process, the overvoltage threshold can be adjusted from 8 to 38 V with post trim variation of ±2.5 V. The measured quiescent current was around 0 μA at 10 V and 28 μA at 38 V, which was comparable to the current consumption in a conventional structure with 38 V overvoltage threshold. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Adjustable shunt-current intensity circuit and system for current conduction treatment of epilepsy

In this paper, we developed a shunt-current intensity self-adjustable closed-loop control circuit system for current conduction treatment in temporal lobe epilepsy. To examine the dose-response relationship between conductive intensity and therapeutic outcomes of current conduction treatment, the control system consists of neural signal recording module for high-speed data rate acquisition, signal amplification and pre-processing, current shunt module for current conduction, data transmission and control module for real-time data communication with the personal computer and on-off of current conduction. Multithread and queue software architecture was implemented to ensure real-time data transmission, display and analysis by LabVIEW software. Results indicate that the input noise of the system is less than 2 [Formula: see text]Vrms, signal frequency bandwidth range is 1 Hz[Formula: see text]10 kHz, and the shunt-current detection range is 0.1–3000 [Formula: see text]A with the accuracy of above 99.985%, meeting the requirements for the detection of neural electrophysiological signal and the research on the dose-response relationship between conductive intensity and therapeutic outcomes of electronic conduction treatment.