Analog Voltage Signal Research Articles

Chaotic dynamics in a class of generalized memristive maps.

The memory effects of the memristors in nonlinear systems make the systems generate complicated dynamics, which inspires the development of the applications of memristors. In this article, the model of the discrete memristive systems with the generalized Ohm's law is introduced, where the classical Ohm's law is a linear relationship between voltage and current, and a generalized Ohm's law is a nonlinear relationship. To illustrate the rich dynamics of this model, the complicated dynamical behavior of three types of maps with three types of discrete memristances is investigated, where a cubic function representing a kind of generalized Ohm's law is used, and this cubic function is a simplified characteristic of the famous tunnel diode. The existence of attractors with one or two positive Lyapunov exponents (corresponding to chaotic or hyperchaotic dynamics) is obtained, and the coexistence of (infinitely) many attractors is observable. A hardware device is constructed to implement these maps and the analog voltage signals are experimentally acquired.

Scalable Multispecies Ion Transport in a Grid-Based Surface-Electrode Trap

Quantum processors based on linear arrays of trapped ions have achieved exceptional performance, but scaling to large qubit numbers requires realizing two-dimensional ion arrays as envisioned in the quantum charge-coupled device (QCCD) architecture. Here, we present a scalable method for the control of ion crystals in a grid-based surface-electrode Paul trap and characterize it in the context of transport operations that sort and reorder multispecies crystals. By combining cowiring of control electrodes at translationally symmetric locations in each grid site with the sitewise ability to exchange the voltages applied to two special electrodes gated by a binary input, site-dependent operations can be achieved using only a fixed number of analog voltage signals and a single digital input per site. In two separate experimental systems containing nominally identical grid traps, one using Yb+171−Ba+138 crystals and the other Ba+137−Sr+88, we demonstrate this method by characterizing the conditional intrasite crystal reorder and the conditional exchange of ions between adjacent sites on the grid. Averaged across a multisite region of interest, we measure subquanta motional excitation in the axial in-phase and out-of-phase modes of the crystals following these operations at exchange rates of 2.5 kHz. In this initial demonstration, the logic controlling the voltage exchange occurs in software, but the applied signals mimic a proposed hardware implementation using crossover switches. These techniques can be further extended to implement other conditional operations in the QCCD architecture such as gates, initialization, and measurement. Published by the American Physical Society 2024

Open-source synthetic photoplethysmographic signal generator with analog output.

The photoplethysmographic (PPG) signal of the finger is being used to create embedded devices that estimate physiological variables. This project outlines an innovative method for developing a synthetic PPG generator that produces both actual reference digital signals and their equivalent analog signals using open-source technology. A series of PPG profiles is synthesized using three variant Gaussian functions. A low-frequency trend induced by respiratory frequency and background noise are then added. To generate a diverse range of continuously variable PPG profiles within specified boundaries and customizable levels of interference, all parameters undergo random fluctuations on a cycle-by-cycle basis, as per user-defined constraints. The generated signal is then converted into its equivalent analog form through the use of an RC filter that low-frequency filters a Pulse-Width Modulation square wave that is modulated directly by the generated signal. The software returns different PPG profiles and allows the signal comparison before vs after the addition of different-intensity modulated respiratory trends and background noise. The digital signal is faithfully converted into an equivalent analog voltage signal capable of reproducing not only the waveform profile but also the respiratory trend and various levels of noise.

An Automated Easy-To-Fabricate Approach to Characterize Various Diodes Using Arduino UNO

This paper introduces a fully automated Arduino based low-cost data acquisition system for studying I-V characteristics of diodes. For that, a Virtual instrument has been developed using the LabVIEW platform and LabVIEW LINX toolkit. The VI incorporates a 12-bit digital-to-analog converter (DAC) with model number MCP4921, which is connected to an Arduino UNO board to generate analog voltage signals for real-time visualization of the current-voltage (I-V) characteristics of both a silicon diode (1N4007) and a germanium diode (1N34).

Design of High-Precision Infrared Photoelectric Sensor and Its Adoption in Soft Package Counting Management in Workshop

As an imperative part of information technology, photoelectric information technology is widely applied in smart phones, mobile computers, portable electronic products, medical care, and industrial technology. In this research, a high-precision infrared photoelectric sensor is designed, which utilizes XDU3093 chip as a built-in photoelectric sensor. The chip has the characteristics of high-power supply rejection ratio and temperature compensation. Then, the focus is on the design of infrared driving module and infrared detection module. Among them, the pulse current of the infrared drive module is more than 100 mA, and the output current is in the form of square wave. To control noise, an isolation circuit between the infrared drive and other modules is set. Infrared detection involves photoelectric sensor. The nwell diode in CMOS process is utilized as photosensitive diode, and at the same time, the surface of the diode is coated to ensure that only infrared light can generate photocurrent through coating. In the experiment, the infrared driver is simulated, and the results show that the driver module can effectively amplify the collected infrared signals, and the detection accuracy reaches 0.2 V. The simulation of infrared detection suggests that there is a linear relationship between photocurrent and background infrared illumination, and the photocurrent decreases with the increase of distance. The designed infrared photoelectric sensor is applied in the soft package counting link of workshop management. The infrared photoelectric acquisition signal is converted into an analog voltage signal, which is processed by the voltage conversion circuit and then transferred to the single chip microcomputer and software module. After the data is uploaded to the upper computer through the serial port, it shows that the number of soft packages can be accurately identified in the workshop soft package counting link based on the designed infrared photoelectric sensor.

Efficient and Accurate Optical Signal Processing and Digitization System for High Speed Data Acquisition and Analysis

The evolution of optical fiber technology has expanded its utility beyond communication to encompass measurement. Key components include the light source, detection elements, and processing circuits. This paper describes a system for optical signal processing and digitization of light pulses, employing advanced components to enhance data acquisition and analysis performance. The optical signal processing phase employed the LF356N operational amplifier, offering attributes like low bias current, high bandwidth, and rapid settling time. Configured as a transimpedance amplifier, the opamp transformed light signals into corresponding analog voltage signals. Subsequently, the voltage signal underwent digitization using the AD976AN, a 16-bit ADC with advanced features such as high-speed data acquisition and an integrated clock. This ADC was controlled by a Teesny 3.6 board with a fast CPU clock speed of up to 256 MHz, greatly facilitating rapid data analysis and algorithm execution. The hardware circuit underwent meticulous design, simulation, and fabrication, followed by rigorous testing involving various distinct light sources with differing parameters. The digitized and computed parameter values (obtained after subjecting the ADC outputs to the suggested algorithm) exhibited a high degree of similarity in comparison to the observed values on the oscillo-scope.

Influence of temperature on fouling removal for pipeline based on eco-friendly ultrasonic guided wave technology

When industrial pipelines are used to transport production materials, the scale can easily form on the inner wall of a pipeline due to long-term contact with the liquid medium. Scaling in industrial pipelines is a common problem that poses a great threat to the production process and environmental protection. In this paper, the influence of temperature on the fouling removal process in pipes is studied. A finite element simulation model was established for guided wave propagation in pipes with different temperatures to obtain the acoustic pressure distribution along the pipes, showing that when the temperature increases, the acoustic pressure value on the solid–liquid surface of the pipes increases, and the cavitation threshold decreases. The experimental system for pipe descaling at different temperatures was established, when the temperature is from 20 to 60 °C, the descaling rate in the inner wall of the pipe far from the transducer is increased from 77.49 to 93.71%, the descaling rate in the inner wall of the pipe near the transducer is increased from 87.01 to 97.02%. The experimental results showed that the descaling performance is better when the pipeline temperature is higher.Compared with the traditional technology, the pipeline descaling technology based on ultrasonic guided waves is highly efficient, safe and eco-friendly, which can remove the fouling inside pipeline online without affecting the transportation. The above conclusions could provide a reference for further popularizing the application of the descaling technology based on ultrasonic guided wave. Graphical abstractLabVIEW program was written by computer to generate 10Vp-p sinusoidal continuous wave digital signal, and then the digital signal is converted into analog voltage signal by using a data acquisition card (DAQ), and then the analog voltage signal is amplified to 300Vp-p by input power amplifier. The amplified analog voltage signal is applied to the transducer, and the transducer converts the voltage signal into vibration signal to generate ultrasonic guided waves in the pipeline and remove dirt in the pipeline.

A Programmable Multiple Frequencies Clock Generator With Process and Temperature Compensation Circuit for System on Chip Design

This article presents a programmable multiple frequencies clock generator with a process and temperature compensation circuit design. The proposed clock generator can achieve a stable and wide frequency range output for a single input frequency by using digital control codes as well as process and temperature compensation mechanisms. In our approach, the first step is to adjust the duty-cycle of the input clock by using a digitally controlled pulsewidth modulator (DCPWM) to generate an output clock signal with a duty-cycle of 20% to 80%. Second, the various duty-cycle clock outputs of the DCPWM are integrated by the duty-cycle-to-voltage converter to generate analog voltage signals to control the succeeding voltage-controlled ring oscillator (VCO). Through the use of various control voltages, different VCO output frequencies are generated. Finally, by using the process and temperature compensation circuit, the proposed clock generator can provide a stable and wide frequency range. The proposed chip is fabricated in a 180-nm CMOS process and has an output frequency range of 35–138 MHz at a supply voltage of 0.9 V. At 120 MHz, the power dissipation and rms jitter are 224.3 μW and 7.84 ps, respectively. The active area of the chip is 0.62 mm × 0.76 mm.

Automatic control of AC bridge-based capacitive strain sensor interface for wireless structural health monitoring

Thin film-based flexible strain sensors have various advantages for structural health monitoring (SHM) because of their capability to sustain large deformations and cover large area of structural surfaces, making them ideal candidates for applications to complex geometries and structural crack monitoring. The authors previously developed a flexible strain sensor technology based on a soft elastomeric capacitor (SEC) for SHM and investigated an alternating current (AC) bridge-based method to transform the strain-induced dynamic capacitance changes in the SEC into analog voltage signals. Previous experiments have verified the capability of the SEC and the AC bridge-based signal converter for structural strain sensing applications. However, careful manipulation requirement for precise AC-bridge balancing, signal amplification control, and shunt calibration limits its practical use for full-scale SHM in field conditions. This study addressed such limitations with critical updates in both hardware and software with fully automated features for high-sensitive capacitive strain sensing. Newly developed hardware and software are fully controlled with a low-cost microcontroller ATmega328p in an automated way. A series of lab tests validated the prototype's performances in the capacitive strain sensing, outperforming an off-the-shelf wired capacitance measurement system (about 34% lower measurement noise), and confirmed that automatic control features worked as designed.

Analysis of Public Mental Health Status and Exploration of Social Anxiety in the Context of Epidemic

To explore the mental health and social anxiety of the public in the context of the epidemic, this article combines intelligent analysis methods to explore social anxiety. In this article, the digital voltage signal output by the processor chip interface is converted into an analog voltage signal. Moreover, this article changes the changing law of duty cycle with the program designed to achieve the purpose of outputting a variety of mental health waveforms that is composed of the sine wave, triangular wave, and square wave. In addition, this article constructs an intelligent hardware system. The research shows that the system proposed in this article can play an important role in the analysis of mental health and social anxiety in the context of the epidemic and has a certain supporting role in the psychological counseling of the social masses in the context of the epidemic.

Discrete Memristor Hyperchaotic Maps

Regarding as a basic circuit component with special nonlinearity, memristor has been widely applied in chaotic circuits and neuromorphic circuits. However, discrete memristor (DM) has not been received much attention, yet. To this end, this paper reports a general DM model and its unified mapping model. Using the general DM model, four representations of DMs are given and their pinched hysteresis loops are exhibited. Based on the unified DM mapping model, four two-dimensional (2D) DM maps are generated and their parameter-relied and initials-relied behaviors are explored using multiple numerical measures. The results demonstrate that all the four 2D DM maps can generate hyperchaos with coexisting bi-stable or memristor initial-boosted behavior, and their sequences have excellent performance indictors. A hardware device is constructed to implement these maps and the analog voltage signals are experimentally acquired. Moreover, pseudo-random number generators (PRNGs) are designed using these DM maps and the test results show that the generated pseudo-random numbers (PRNs) have high randomness.

Volume Measurement System Based on Hall Effect Sensors Circularly Coupled and Arranged in a Quadrature Shape

In this research work, a compact electronic system for measuring volumes in generic cylindrical containers was designed and developed. The system is based on a circular arrangement composed of four Hall effect sensors A1324 and arranged in the form of a quadrature. The theoretical volume calculations obtained based on the angle of inclination of the float for a cylindrical container were correlated with a polynomial function of order 3 with an R2 = 0.99. The analog voltage signal correlated with the theoretical volume was digitized through a microcontroller and a ZigBee transceiver was used as a data transmission channel and through a ZigBee Xbee ZB24 transceiver was used for information transfer. The experimental and theoretical results obtained corroborate a highly accurate and reliable measurement system, which can be applied to different containers and different types of fluids that are to be monitored remotely. Finally based on the theoretical model, this system could be scaled to cylindrical containers of greater capacity without modifying the conditions of the electronic system with the array of Hall effect sensors.

Electronic Design for a Bleeding Detector to be Used in Intraoperative Radiotherapy Applications

An electronic design for a bleeding detector used with mobile linac during intraoperative radiotherapy (IORT) is presented. It consists on a readout circuit based on a De Sauty Bridge and a wireless power supply using a supercapacitor. The goal is the measurement of the height of fluid present in the applicator in order to avoid a misadministration dose during the irradiation process. A minimum measurement height of 5 mm is required by clinic to be confident with the selected radiation dose. The measurement circuit uses a capacitive sensor which detects variations lower than 0.1 pF. The readout circuit converts dynamic capacitance variation from the bleeding detector into an analog voltage signal. Tests have been performed with a 40 mm diameter polymethyl methacrylate applicator (PMMA) using water. Non-bevelled PMMA 0° and 45° tilted have been considered, being this the worst condition used in the clinic. The actual height of the fluid with respect to that measured by our system shows good linearity and repeatability within acceptable limits. For 0° tilted, a 2 mm height fluid detection is achieved well below the 5 mm height demanded by clinic. For 45° tilted, a 5 mm height fluid detection is achieved.

Clockless, Continuous-Time Analog Correlator Using Time-Encoded Signal Processing Demonstrating Asynchronous CDMA for Wake-Up Receivers

A clockless, continuous-time (CT) analog correlator circuit realization is presented based on time-encoded analog signal processing. Voltage-controlled oscillators (VCOs) transform the analog voltage signals into time-encoded analog signals and, in the process, perform signal integration; CT, digital-style delay cells combined with phase-frequency detectors followed by capacitive summers implement a CT matched filter. The correlator prototype designed in 65-nm CMOS-LP technology consumes 37 nW from 0.54 V and is used in the baseband of a wake-up receiver to despread asynchronous code-division multiple access (CDMA) codes and demonstrate code-domain filtering for an 11-bit Barker code. The wake-up receiver's sensitivity is enhanced by 2 dB to -80.9 dBm for a missed detection ratio of 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> , and its selectivity is improved by 5 dB, thanks to the use of the correlator. Simultaneous wake-up using CDMA is demonstrated with selective responses of the receiver to different desired codes in the presence of an undesired code.

Investigation on Stray-Capacitance Influences of Coaxial Cables in Capacitive Transducers for a Space Inertial Sensor.

Ultra-sensitive inertial sensors are one of the key components in satellite Earth’s gravity field recovery missions and space gravitational wave detection missions. Low-noise capacitive position transducers are crucial to these missions to achieve the scientific goal. However, in actual engineering applications, the sensor head and electronics unit usually place separately in the satellite platform where a connecting cable is needed. In this paper, we focus on the stray-capacitance influences of coaxial cables which are used to connect the mechanical core and the electronics. Specially, for the capacitive transducer with a differential transformer bridge structure usually used in high-precision space inertial sensors, a connecting method of a coaxial cable between the transformer’s secondary winding and front-end circuit’s preamplifier is proposed to transmit the AC modulated analog voltage signal. The measurement and noise models including the stray-capacitance of the coaxial cable under this configuration is analyzed. A prototype system is set up to investigate the influences of the cables experimentally. Three different types and lengths of coaxial cables are chosen in our experiments to compare their performances. The analysis shows that the stray-capacitance will alter the circuit’s resonant frequency which could be adjusted by additional tuning capacitance, then under the optimal resonant condition, the output voltage noises of the preamplifier are measured and the sensitivity coefficients are also calibrated. Meanwhile, the stray-capacitance of the cables is estimated. Finally, the experimental results show that the noise level of this circuit with the selected cables could all achieve 1–2 × 10−7 pF/Hz1/2 at 0.1 Hz.

Development of the Platform-Type Aircraft Weighing System Based on the Internet of Things

For the area for the aircraft weighing is relatively large and the display terminal is placed near the aircraft, the operator can’ not conveniently read the data on the display, so the platform-type aircraft weighing system based on the internet of things is developed. The system consists of three platforms, three digital modules, three 4G wireless modules and one cloud server. Three platforms containing sensors are placed under three wheels to measure the weight of an aircraft. The analog voltage signals of the sensors are converted to digital signals by digital modules and then uploaded to the cloud server by a 4G wireless module. A website with IP address consistent with the public IP address is established on the cloud server. The sensor data uploaded to the server is read by the ASP.NET Web Application program. A computer software is developed to log in to the website at any time to check the weighing data and calculate the position of the gravity center of the aircraft according to the formula for calculating the gravity center. The experimental results show that the weighing system is not limited by distance, has good real-time performance, stable operation and reliable calculation.

A High-Temperature, Low-Noise Readout ASIC for MEMS-Based Accelerometers.

This paper presents the development and measurement results of a complementary metal oxide semiconductor (CMOS) readout application-specific integrated circuit (ASIC) for bulk-silicon microelectromechanical system (MEMS) accelerometers. The proposed ASIC converts the capacitance difference of the MEMS sensor into an analog voltage signal and outputs the analog signal with a buffer. The ASIC includes a switched-capacitor analog front-end (AFE) circuit, a low-noise voltage reference generator, and a multi-phase clock generator. The correlated double sampling technique was used in the AFE circuits to minimize the low-frequency noise of the ASIC. A programmable capacitor array was implemented to compensate for the capacitance offset of the MEMS sensor. The ASIC was developed with a 0.18 μm CMOS process. The test results show that the output noise floor of the low-noise amplifier was −150 dBV/√Hz at 100 Hz and 175 °C, and the sensitivity of the AFE was 750 mV/pF at 175 °C. The output noise floor of the voltage reference at 175 °C was −133 dBV/√Hz at 10 Hz and −152 dBV/√Hz at 100 Hz.

Data Acquisition System Design of Length Gauge

Length gauge is one of measurement standard in the Length Metrology Laboratory, Research Center Metrology – LIPI. Practical use and good accuracy make it a mainstay in calibration. In use, length gauge requires a display unit to display readings of measuring results. The display unit is very susceptible to damage because it is directly connected to an electric power supply. To procure the display unit, requires funds and time. Therefore, the objective of the research is to design a length gauge data acquisition system that is simple and low cost without compromising function. Research was carried out by making a current into a voltage converter, converting an analog voltage signal into a pulse signal, separates the signal when the length gauge moves up and down, counting the generated pulse signal and displays it on the PC. Once the data acquisition system is calibrated, it was found that the readability of the system is 2 μm and with an uncertainty of 2.0 m. With this value of this uncertainty, based on ANSI/NCSL Z540-1-1994, the data acquisition system can be used as standard to calibrate measuring devices with an accuracy of at least 8 m.

Rate of Change of Frequency Estimation for Power Systems Using Interpolated DFT and Kalman Filter

This paper presents a new method for estimating the rate of change of frequency (RoCoF) of voltage or current signals measured using instrument transformers. The method is demonstrably superior to currently available methods in the literature, in terms of estimation latency and estimation error. The estimation is performed in two steps. In the first step, the analog voltage or current signal obtained from an instrument transformer is statistically processed using interpolated discrete Fourier transform (IDFT) in order to obtain the means and variances of the signal parameters. These means and variances are then given as inputs to the second step, in which Kalman filtering (KF) is used to find the final RoCoF estimate. Accurate mathematical expressions for the means and variances of signal parameters have been derived and used in the second step, which is the main reason behind the superior performance of the method. The applicability of the method has been demonstrated on a benchmark power system model.

Update (v1.3) to DLTPulseGenerator: A library for the simulation of lifetime spectra based on detector-output pulses

In the last two updates v1.1 and v1.2 of DLTPulseGenerator library, we provided the simulation of distributed specific lifetimes and the simulation of lifetime spectra consisting of non-Gaussian distributed and linearly combined Instrument Response Functions (IRF). In this update v1.3, the DLTPulseGenerator library was modified to account for additional hardware influences, which significantly modify the ideal shape of a detector output-pulse defined previously by a log-normal distribution function. These influences mainly originate from the electronic parts, which accomplish the conversion of the analog voltage signal into digital numbers, i.e. the A/D converter (ADC). Eventually, this provides the modeling of authentic detector output-pulses, which leads to a spectra simulation under more realistic conditions.