Contactless Switch Research Articles

Ultra‐High DC and Low Impedance Output for Free‐Standing Triboelectric Nanogenerator

AbstractThe free‐standing triboelectric nanogenerator (F‐S TENG) is demonstrated to be an efficient energy conversion device. However, limited by the inherent features of high‐voltage, low alternating current and high output impedance, TENGs suffer from inefficient energy utilization and difficulties in practical applications. Therefore, the efficient harvest of mechanical energy and optimization of output are currently critical issues for TENGs. Here, a strategy is proposed for optimizing the inherent features by coupling F‐S TENG to a capacitor auto‐conversion circuit (CAC). For the first time, a specific idea is proposed explicitly to reduce the output impedance by the management circuit. Eventually, a high current density of 32 A m−2 and a charge density of 1.75 mC m−2 are achieved, which is 8.78 times higher than previous works. The power density and energy density reach to 124 W m−2 and 252 mJ m−2 under 470 and 150 Ω respectively. Then, 5000 LEDs and two lamps rated at 220 V and 50 W are manually illuminated. The resulting pulse output is utilized as a trigger source for the thyristor, enabling DC contactless switching. This work provides a novel approach to realize high‐performance DC output of TENGs and effectively reduce external load impedance.

Contactless Switching System Based on Gesture Recognition

ith the downgrading of COVID-19, the public affairs we contact in our daily life still cause potential indirect transmission risks, so we should pay more Gesture recognition is used to safely and quickly control these objects, so as to avoid them becoming the "hotbed" of virus transmission, reduce the chance of virus infection, and ensure the safety of public health. Gesture recognition is used to safely and quickly control these objects, so as to avoid them becoming the "hotbed " of virus transmission, reduce the chance of virus infection, and ensure the safety of users. Based on this, we propose to develop a contactless switching system using low cost and high reliability infrared gesture recognition.

Application of numerical and graphical methods of analysis in nonlinear resistive circuits of electronic devices

The article discusses the research issues and methods of analysis of semiconductor circuits used in electronic circuits of contactless switching devices, provides analytical, graphic and numerical methods for the analysis of nonlinear semiconductor resistive circuits. The approximations of the Volt-Ampere characteristics (VACh) of semiconductor elements and the solution of the differential equations of state of electrical circuits by a numerical method using a computer are given. Diode, thyristor semiconductor nonlinear resistive circuits with active and inductive loads are considered. In the analysis of steady-state modes and transient processes, numerical methods for solving differential equations of states by the Euler method were used.

Development of contactless switching devices for asynchronous machines in order to save energy and resources

To limit the inrush currents in the stator windings, various schemes for starting an asynchronous electric motor are used. In addition, the existing devices have a complex control system, which creates certain difficulties in installation and operation. But the analysis of scientific literature and materials from certain sources testifies to the insufficient study of this problem. In scientific work, the advantages and disadvantages of a new type of contactless starter are compared with contact and non-contact starters of various types. An original circuit of a new type of thyristor starter with a simplified design has been developed and manufactured, which has the ability to smoothly start and control the power consumption of asynchronous machines. Computer simulation of a new type of contactless starter with pulse-width modulation control in the Matlab Simulink program has been carried out: a pulse current is supplied to the controlled thyristor electrode on the basis of the pulse-width modulation control and the thyristor opens and passes the current, the resistance is set to decrease the input signal level. The design of the proposed starter is based on the combination of a thyristor starter with logical control, which has the ability to smoothly start and remote control of the power consumption of asynchronous electric motors, which has the ability to save energy and resources. Modern methods of implementing a logical control system, a pulse current generator with RLC filters, are proposed, and the task of remote monitoring and control of power consumption of asynchronouselectricmotors is set.

Dispenser Printed Bismuth‐Based Magnetic Field Sensors with Non‐Saturating Large Magnetoresistance for Touchless Interactive Surfaces

AbstractPrinted magnetic field sensors enable a new generation of human‐machine interfaces and contactless switches for resource‐efficient printed interactive electronics. As printed magnetoresistors rely on scarce or hard to manufacture magnetosensitive powders, their scalability and demonstration of printing with industry‐grade technologies are the key material science challenges. Here, the authors report dispenser printing of a commodity scale nonmagnetic bismuth‐based paste processed by large area laser sintering to obtain printed magnetoresistive sensors. The sensors are printed on different substrates including ceramics, paper, and polymer foils. It is validated experimentally that the peculiar quantum large orbital magnetoresistive effect remains effective in printed bismuth sensors, allowing their operation in high magnetic fields. The sensors reveal up to 146% resistance change at 5 T at room temperature with a maximum resolution of 2.8 μT. If printed on flexible foils, these sensors show resilience to bending deformation for more than 2000 bending cycles and withstand even thermal forming, as relevant for smart wearables and in‐mold electronics. The freedom in the substrate choice and sensor design enabled by dispenser printing allows to implement the proposed sensor technology for different applications focused on touchless interactive platforms, such as advertisement materials, interactive wallpapers, and printed security panels.

Two-layer logic elements for classic cryogenic computers

In this paper, for the first time, two-layer logic elements "NOT", "AND", "OR" and "NOR" were manufactured, in which the heating element of a nanowire in one layer is located in the place where the heated element of another superconductive nanowire is located in a nearest NbN layer. The film thickness of NbN (5-7 nm) was used to form of superconducting nanowires in different layers, and the thickness of Al2O3 (25 nm) was used as an interlayer dielectric. The paper shows the design of logic elements, and also demonstrates their operation in pulse mode. The use of multilayer structures without galvanic coupling between nanowires allows the design of multi-level logic devices. Keywords: NbN thin superconducting films, contactless switching of the superconductor state, cryoelectronic devices, integrated cryogenic resistors, logic elements "NOT"/"AND"/"OR"/"NOR", cryogenic computers.

Analysis of dynamic circuits of contactless switching devices

The main content of the study is the analysis of theoretical and virtual-experimental studies and methods of analysis of transients in semiconductor nonlinear dynamic circuits of contactless switching devices, presents transient graphs constructed using a virtual computer model. In addition, presents solutions of differential equations of the state of such circuits by the numerical Euler method.

Control of quality and modes of power supply systems using contactless devices

The article discusses the issues of creating contactless switching devices for automatic quality control and operation modes of power supply systems, using the developed contactless thyristor voltage relays, characterized by high reliability and speed, combining a sensitive system and a powerful final controlling element. Schemes with operating principles and experimental characteristics are given. It is proposed to use it to automatically turn on or off the booster transformer winding when the input voltage changes to maintain the rated voltage of electricity consumers, as well as to create a power regulator for capacitor banks of reactive energy compensating devices.

New solutions for controlled compensating devices

The article presents material, which is based on the results of the analysis of literature sources on automatic devices for regulating reactive power in power supply systems. In addition, this article provides information regarding the operability of the developed circuits of contactless devices and verification of the experimental study of the operation of installations with their use. Also presented is material about an experimental study of a contactless switching device for automatic power control of capacitor banks in various operating modes. A measuring device with programmed control “Fluke” was used to record and process experimental data of non-contact devices for regulating the power of capacitor banks. The results of experimental studies of a new device for automatic power control of capacitor banks, it can be stated that it fully meets the requirements.

Development and experimental study of circuits of contactless device for automation of compensation of reactive power of capacitor batteries

This article presents material based on the results of the analysis of literature sources on automatic devices for regulating reactive power in power supply systems. The operating mode of the compensating devices is determined taking into account the permissible voltage deviations at the terminals of the electric power receivers. Voltage, load current, reactive power directions, power factor, phase angle between the supply voltage and load current, and time can be used as control parameters. In addition, the article provides information regarding the performance of the developed circuits of contactless devices and verification of the experimental study of the operation of installations with their use. Also presented is material on the experimental study of a prototype of a contactless switching device for automatic power control of capacitor banks in various operating modes. Summarizing the results of experimental studies of a new device for automatic power control of capacitor banks, it can be stated that it fully meets the requirements for such devices and can ensure reliable operation of the power supply network with an appropriate power factor.

RESEARCH OF OPTOELECTRONIC VOLTAGE RELAY

Article represents using theoretical analysis and experimental studies of nonlinear resistive circuits and it was developed that it is important to use such circuits as power contactless switching devices to ensure a quality power supply for consumers. The paper deals with the problems of designing lightweight, reliable, high-speed contactless optoelectronic voltage relays with extended service life, combining a responsive device and a strong executive body with a sinusoidal form of the load voltage curve. Theoretical studies of transients in nonlinear dynamic circuits result in the solution of differential condition equations by a computational method built on the basis of optoelectronic pressure relays with time delay. Experimental investigations and the operating theory of this relay are addressed.

Control of Superconducting Transitions in Nanowires Using Galvanically Uncoupled Gates for Designing Superconductor-Based Electronic Devices

A possibility of contactless switching of an NbN nanowire from superconducting to normal state by passing a current through a gate located at a certain distance from the nanowire is demonstrated. The gate, being isolated from the nanowire by an Al2O3 layer, contains an integrated resistance formed by ion irradiation. Dependences of the minimum power released in the gate that is sufficient for nanowire to pass to the normal state on the dc current through the nanowire are experimentally obtained. A signal inverter containing three successive cascades is developed based on this principle. This design shows that the proposed approach can be used to form a logic element base for cryogenic computing.

Theoretical research and development optoelectronic communication devices

Nowadays, with the wide automation of production processes and the introduction of automatic control systems, the requirements for the creation of contactless electric devices have substantially increased. The development of power semiconductor electronics allows the solution of complex technical problems aimed at improving the efficiency of electrical devices. The leading role in this direction is given to optoelectronic devices and thyristor devices, which provide contactless switching processes and galvanic isolation, and have improved transient and frequency characteristics The article deals with the creation of compact, reliable, highspeed optoelectronic contactless voltage relays with an extended service life, combining a sensitive system and a powerful actuator having a sinusoidal shape of the voltage curve at the load. Theoretical, experimental studies and the principle of operation of an optoelectronic contactless voltage relay with time delay are given.

Research of the trigger effect in diode-thyristor circuits of contactless relay devices

The paper investigates the main properties of the trigger effect in diode-thyristor circuits and proposes the creation of small-sized thyristor contactless voltage relays, combining in one device a sensitive system to changes in input voltage and powerful actuators capable of switching large load currents. The article also discusses a non-contact thyristor relay of alternating current voltage, the load mode of which is analyzed, taking into account the voltage of the transition to the open state of the thyristor and the formula for the effective value of the voltage across the load. It is proposed to use the developed such relays as contactless switching and control equipment, which allow to reliably and quickly control the operating modes of electrical equipment, regulate the reactive power of capacitor banks, create ring networks, improve the quality of electricity in distribution networks and reduce capital costs for the construction of a power supply system.

Study of the state of the issue of increasing the quality of electric energy in the power supply systems

This article examines the importance of ensuring the quality of electricity and considers the possibility of using a system for monitoring the quality of electricity in the power supply system. Based on the results of the study, it was found that the use of contactless switching devices as switches of sections of windings of power transformers allows you to abandon current-limiting reactors and resistors. This is achieved by the fact that the switching of the windings occurs at the moment the load current passes through zero.

Analysis of voltage stabilizers and non-contact relays in power supply systems

The article discusses the results of comparison and analysis of voltage stabilizing devices and contactless relays in the power supply system. Based on the analysis, the time variation of the voltage in the capacitive circuit is shown. Based on the results of the study, it was found that the determination of the actual value of the capacitive voltage by controlling the thyristor of the “charge-discharge” process of the capacitance makes it possible to determine the time delay of the contactless switching device when the capacitor reaches the saturation point.

Outdoor photoluminescence imaging of solar panels by contactless switching: Technical considerations and applications

AbstractMonitoring the performance of solar modules in a photovoltaic system is critical in order to understand the health of the system. Existing methods for field inspection have limited capability of detecting various electronic defects that can, however, be identified with luminescence‐based methods. A contactless outdoor photoluminescence‐imaging based measurement method that uses the sun as the excitation source was presented in our earlier work. This paper extends our previous work and presents two unique applications to (a) identify and quantify local areas of high series resistance within the cells and (b) identify bypass diodes that have failed in open‐circuit. The paper also discusses specific technical considerations of this method. The main merit of this method is that it can be used when the module is under normal operation in the field, without requiring changing of the electrical wiring of the photovoltaic array.

Polymeric Transducers: An Inkjet Printed B-Field Sensor with Resistive Readout Strategy.

Magnetic field sensors are successfully used in numerous application contexts such as position sensing, speed detection, current detection, contactless switches, vehicle detection, and electronic compasses. In this paper, an inkjet printed magnetic sensor, based on the magneto-mechanical sensing principle, is presented together with a physical model describing its physical behavior and experimental results. The main novelties of the proposed solution consist of its low cost, rapid prototyping (printing and drying time), disposability, and in the use of a commercial low-cost printer. A measurement survey has been carried out by investigating magnetic fields belonging to the range 0–27 mT and for different values of the excitation current forced in the actuation coil. Experimental results demonstrate the suitability of both the proposed sensing strategy and model developed. In particular, in the case of an excitation current of 100 mA, the device responsivity and resolution are 3700 µε/T and 0.458 mT, respectively.

Snap-through of elastic bistable beam under contactless magnetic actuation

We propose the modeling of contactless switching of a bistable slender beam using Laplace force actuation. The model beam is based on the elastica approach which allows large amplitudes of the cross-section rotation and large elastic transformations. Furthermore, the extensibility of the elastic beam is accounted for and it plays a crucial role in the switching process. The study is devoted particularly to the actuation mechanism of the bistable beam uniformly loaded by a density of lineic force which is permanently perpendicular to the beam deformation. Such actuation can be produced by the Laplace force due to an electric current traveling along the beam placed in a magnetic induction. The mechanism of the bistable switching is analyzed in detail using a variational formulation and stable and unstable equilibria are described. We investigate numerically the post-buckling behavior to capture the exact buckling modes that follow the path in the unstable region. The numerical simulations are also used to obtain the bistable response in terms of actuating force (or electric current amplitude), beam end-shortening and mid-point displacement of the beam. We also perform a finite element computation and provide a validation of the results obtained by solving the set of equations of the boundary value problem.The second part of the work is focussed on the experimental validation of the switching mechanism of the bistable beam presented in the analytical part. We design an experimental set-up for the fine measurement of the mid-point displacement of the bistable beam as a function of the electric current traveling the beam. The region of bistable instability is revealed by experimental adjustment of the bifurcation point associated with the actuating force. All the results extracted from experimental tests are compared to those coming from the modeling investigations, which ascertains with good accuracy the approach of the proposed model for bistable beam.

Non-contact voltage relay for switching windings of a boost transformer

In power supply systems the change in the magnitude of the voltage degrades the operation of electrical appliances right up to their failure. The proposed scheme of a contactless voltage relay based on a contactless voltage relay with switching the windings of a booster step-up transformer with a time delay allows switching the windings of a magnetizing booster transformer with a voltage change at the consumer terminals. Analytical studies of a non-autonomous non-linear dynamic circuit, which is the basis of the proposed device based on the classical method of solving a differential equation, which determines the nature of the voltage change for controlling thruster switches. The change of energy parameters of the proposed stabilizer depending on the voltage is given. The article considers the principle of operation of the proposed scheme of a contactless switching device based on a contactless voltage relay that switches the windings of a booster step-up transformer. An analytical study of a non-autonomous nonlinear dynamic circuit, which is the basis of the proposed device and the characteristics uc = f t required for switching the thruster is presented.