Switching Unit Research Articles

Development of a Real-time Micro-controller Based Watering System

The developed system consists of a solenoid valve and water pump which are directly linked to a microcontroller (ATMEGA-328PU) unit through a transistor -network based relay switching unit. A soil moisture sensor linked to the soil senses the dryness and wetness of the soil. The microcontroller and soil moisture sensor utilizes a 5V power supply unit given through a regulated supply via a regulator called LM7805.A 12V power supply units activates the normally open units of the relay linked to the solenoid valve and the pump. Whenever the dryness of the soil is sensed, the microcontroller decodes and sends an instruction to the solenoid valve to open and the water pump to start driving the water which is sprinkled through the sprinkler. The performance of the system has been evaluated and the response time is fast.

Metering and Reactive Compensation Unit (MRCU) for Improved Energy Efficiency and Management - Supply of Electricity to Agricultural Consumers

In order to meet the growing demands of electricity, it is imperative to increase the efficiency of distribution system and reduce all wastage of energy. In this paper, the data from the distribution companies and regulatory bodies are analysed to identify the inefficiencies existing in the electricity distribution to the agriculture consumers of the state of Gujarat in India. The primary causes for the inefficiencies in the system are absence of effective monitoring and correct and reliable data on the usage of electricity by agricultural consumers, and the technical loses of electricity on account of low Power Factor and poor voltage regulation. The paper proposes a comprehensive solution to address the identified problems by way of installing a Metering Reactive Compensation Unit (MRCU) independent of consumers’ energy meters. MRCU will contain capacitors for reactive compensation, relay and switching unit, metering unit for current, voltage, Kilowatt, KVARH and KWH, and LORA based communication module for 24x7 data capture. The data captured at the cloud level will be analysed by a head end software system for real time reports and corrective actions. The estimated monetary benefits from installing MRCUs for entire Gujarat’s agricultural consumers is estimated to be Rs 1500 Crore in a year, apart from an estimated energy saving of close to 2000 MUs per year.

Analysis of Voltage Sharing of Series-Connected SiC MOSFETs and Body-Diodes

In recent years, SiC MOSFETs have gained strong attention in medium-voltage power conversion applications. To increase the blocking voltage level, series-connection of SiC MOSFETs is an attractive solution but may suffer a severe voltage unbalance issue. To gain insights into the voltage unbalance issue, this article presents a detailed study of the impact of parasitic capacitors on the voltage sharing of series-connected SiC MOSFETs and body-diodes. The parasitic capacitors are categorized into two groups for analysis: 1) parasitic capacitors from gate terminal; 2) parasitic capacitors from drain/source terminals. The study reveals that gate parasitic capacitors affect gate miller-plateau voltage and ultimately the dv/dt during the turn-off. The voltage sharing will be worse under higher turn-off current or larger gate resistor. The drain/source parasitic capacitors will introduce additional capacitance across device drain-source terminals which results in an unbalanced voltage sharing. The position of switching unit and the heatsink connection schemes will affect the distribution of drain/source parasitic capacitors to cause different voltage sharing results. The drain/source parasitic capacitors will also cause voltage unbalance of series-connected body-diodes under different conditions. To verify the analysis, the voltage sharing between two series-connected 10 kV SiC MOSFETs is tested under different parasitic capacitors conditions.

Single-photon switch controlled by a qubit embedded in an engineered electromagnetic environment

A single-photon switch is an important element for the building of scalable quantum networks. In this paper, we propose a feasible scheme for efficient single-photon switching. The proposed switch is controlled by a state of a qubit formed by the pair of the lowest levels of a three-level system (qutrit) coupled to a resonator. This resonator-qutrit system comprises a switching unit of the considered setup. For suppression of the Purcell relaxation of the control qubit, the switching unit is embedded into a coupled-resonator array serving as an engineered electromagnetic environment with a band gap on a qubit transition frequency. We discuss the possible implementation of the considered single-photon switch on the microwave circuit QED architecture. We demonstrate that high switching contrasts can be attained for the parameters achievable for the state-of-the-art superconducting circuit QED setups.

A New Method for Computation the Success Probability of Coverage for Switch Unit in the Switching Systems

Redundancy technique is used to improve performance and achieving to increase the lifetime of a system. Nowadays, the redundancy method is applied in many industries. One of the common methods of redundancy is its utilization in the switching systems. In switching systems, one or more components are considered active mode and the others in the standby state to be used by switch if necessary. In order to be fully utilized all the components in the redundant device, the switch unit must perform its function, such as switching, perfectly. Successful coverage by switch unit is expressed with a probability. In this paper, a new approach to the likelihood of switch success is proposed, and showing that as increases switching in the system, the efficiency and performance of the switch gradually decreases. The analysis of this method was based on the stress-strength method. Finally, a few numerical examples for the validation of results were applied.

Ultracompact and low-power-consumption silicon thermo-optic switch for high-speed data

Abstract Ultracompact and low-power-consumption optical switches are desired for high-performance telecommunication networks and data centers. Here, we demonstrate an on-chip power-efficient 2 × 2 thermo-optic switch unit by using a suspended photonic crystal nanobeam structure. A submilliwatt switching power of 0.15 mW is obtained with a tuning efficiency of 7.71 nm/mW in a compact footprint of 60 μm × 16 μm. The bandwidth of the switch is properly designed for a four-level pulse amplitude modulation signal with a 124 Gb/s raw data rate. To the best of our knowledge, the proposed switch is the most power-efficient resonator-based thermo-optic switch unit with the highest tuning efficiency and data ever reported.

Proximity-Dependent Switchable ATP Aptasensors Utilizing a High-Performance FRET Reporter.

Here, fluorescent molecular rotors are employed to develop a new type of high-performance FRET system with large Stokes shift, high photostability, and pH insensitivity, showing great promise for use in proximity-dependent DNA aptasensors. Two carboxylated benzothiazole-based molecular rotors are synthesized, displaying bright green and red fluorescence once labeled to DNA. In the proximity state, an efficient FRET occurs between the two dyes, comparable to that of the most commonly used Cy3/Cy5 pair. Similar phenomena are also observed if naphthothiazole-based analogues are adopted. Our developed FRET pair is then attached to the two parts of a split ATP aptamer in a dimeric DNA nanoscaffold controlled by a bimolecular i-motif. In this way, a pH-switched proximity-induced fluorescent ATP aptasensor is constructed, with good sensitivity, selectivity, and reconfiguration. Furthermore, by altering the linker length of the switching unit, the proximity effect is investigated systematically, providing new insight into DNA proximity reactions and their roles in some physiological processes.

New hardware redundancy approach for making modules tolerate faults using a new fault detecting voter unit structure

Electronic systems’ growth causes complexity and increases the risk of failure. Fault tolerance structures are one of the useful ideas for resolving this problem. In this paper, a fault tolerant approach to digital electronic modules is introduced, using hardware redundancy to make those modules fault tolerant. The proposed structure of hardware redundancy has a voter unit that can mask and detect faults at the same time. Such a voter unit is achieved by using both majority voter units and minority voter units in its structure. The proposed voter unit has a three-layer structure. One minority voter, three majority voters, and another minority voter are respectively producing these three layers of the proposed voter unit. These layers can mask and correct fault and detect the faulty module by producing a unique fault detecting code simultaneously. The code works properly as long as the majority of the modules work properly. Then, the result of the voter unit (the code) is transmitted to a relevant switching unit in order to switch the faulty module with a spare module. A redundant system based on the proposed redundancy structure with M spare modules can switch M faulty modules and tolerate (M + 1) faults.

An Android Based Home Electrical Appliance Control System

Electric bulbs, television sets, fans and other home appliances are usually controlled largely with human effort using mechanical switches. However, over the past decade, there has been drastic improvement and advancement in consumer electronics and embedded systems. This has ensured a home environment where appliances can be connected and controlled using wireless technology and an Android smart phone. This study demonstrates the design of an automated system to assist and provide support in order to fulfill the needs of the physically disabled and elderly ones in controlling electrical appliances in homes. The heart of the control system is the wireless Bluetooth technology which provide remote access from a smart phone to a Bluetooth module and then to a control and switching unit. Bluetooth wireless connection enables the system to communicate with a Java application on an Android smart phone without cable. The user can easily touch on the phone screen to control the home appliances linked to the system. This method which requires minimal human effort is able to assist the disabled, sick and elderly people who have difficulties with locomotion. Thus, a control system has been designed which offer a low design, installation ease, quick response time and a user friendly interface in controlling home electrical appliances.Keywords - Android Phone, Bluetooth, Microcontroller, Relay and Switching

Multi-Photochromic Molecules Based on Dihydroazulene Units.

Multi-photochromic systems incorporating individually addressable switching units are attractive for development of advanced data storage devices. Here, we present the synthesis and properties of a selection of such molecular systems incorporating the dihydroazulene/vinylheptafulvene (DHA/VHF) photo-/thermoswitch. The influence of the linker (meta-phenylene vs. azulene-1,3-diyl vs. thiophene-2,5-diyl) separating two DHA units on the switching properties was investigated. An azulene-1,3-diyl spacer largely inhibited both the DHA-to-VHF photoisomerizations and the thermal VHF-to-DHA back-reactions; the latter occurred ten times slower than for the related compound with a meta-phenylene spacer. A DHA trimer containing three DHA units around a central benzene ring was found to undergo stepwise DHA-to-VHF photoisomerizations, whereas the thermal back-reactions occurred at similar rates for the three VHF entities. A meta-phenylene-bridged DHA dimer was subjected to further structural modifications at position C-1 of each DHA, having strong implications for the switching events, and synthetic steps for further functionalizations at position C-7 of each DHA were investigated. Finally, the molecular structure (from X-ray crystallographic analysis) between the meta-phenylene-bridged DHA dimer and CuI is presented.

Electrical resistivity survey data for potential aquifer in Banggi Island, Sabah, Malaysia.

The survey data on potential aquifer was collected at two sites located in Banggi Island (i.e. Laksian Primary School [LPS] and Padang Primary School [PPS]), Malaysia on 25 and 26 April 2013. Both locations are geologically surrounded by various types of lithologies, namely, sandstone, mudstone, siltstone, shale, chert, conglomerate, lignite, tuff, limestone, terrace sand, gravel and coral. The resistivity data consisted of six-line pole-dipole short arrays and were recorded in-situ using SAS 4000 ABEM Lund Imaging System, together with a relay switching unit (Electrode Selector ES 464), six multiconductor cables, steel rod electrodes and jumpers. The data, namely electrode spacing, depth of investigation, subsurface resistivity, type of material and horizontal data coverage were used to assess the characteristics of the potential aquifer. The recorded data were then processed using RES2DINV software to obtain 2-D inversion model of the subsurface. The data were also equipped with six models of inverse resistivity section for both areas. The data obtained can be used by the government and stakeholders for groundwater exploration and extraction in order to provide water supplies for local communities, especially since access to these resources from the surrounding water treatment plants on the island is limited.

Damage detection and localisation of CMCs by means of electrical health monitoring

Carbon-based composites such as C/C-SiC are used in thermal protection systems for atmospheric re-entry. The electrical properties of this semiconductor material can be used for health monitoring, as electrical resistivity changes with damage, strain, and temperature. In this work, electrical resistance measurements are used to detect damage in a thermal protection system made of C/C-SiC. This can be done in-situ. Damage experiments with 320,hbox {mm},times ,120,hbox {mm},times ,3hbox { mm} panel shaped samples were conducted with a multiplexer switching unit to determine up to 288 electrical resistance and voltage measurements per cycle time and spatially resolved. The change in resistance is an indicator for damage, and with the use of post-processing algorithms, the location of the damage can be determined. With these data, inhomogeneous temperatures can be accorded for and damage can be detected. This method reacts even to small damages where less than 0.02% of the monitored surface is damaged. A localisation with a deviation from the real defect of less than 8% in sample width and 17% in sample length is presented.

The Construction of High-Performance Optoelectronic Interconnection Network and the Realization of Cloud Computing for Traffic Data Recognition

Due to the problems of congestion, insufficient scalability, and high cost in the network core layer link, the network interconnection architecture needs to be optimized. The photoelectric interconnection technology has attracted the attention of many researchers with its high bandwidth, low latency, and low power consumption. In this study, after fully considering the requirements of optoelectronic switching on network node degree and processing delay and corresponding to different transmission characteristics of circuit switching and optical circuit switching, an optoelectronic interconnection architecture supporting heterogeneous network topology, namely THtop, is proposed. According to the optical circuit switching/circuit switching characteristics of the Internet, the corresponding topology structure is designed respectively in this architecture to enhance the system integration and reduce the cost. At the same time, in order to meet the requirements of wavelength and number of hops of optical circuit switching, distributed control is designed in THtop, and the design method of heterogeneous optical switching unit is introduced in the switching equipment, so that the optical switching node can further reduce the cost while playing its role. The use of high-speed optoelectronic networks will cause a large amount of traffic on the channel. In this study, the traffic identification is analyzed on the proposed THtop architecture. The Map Reduce framework in cloud computing is used as the identification model, and the K-means algorithm is taken as the identification algorithm. According to its characteristics, the W_K-means algorithm is proposed for the type identification of traffic. The results show that under the OpenNet Internet simulation environment, when the traffic is set to a certain level, more than 90% of the non-blocking network switching can be realized under the THtop architecture, and the completion time of the mouse flow and elephant flow can be significantly improved. Therefore, under the Map Reduce model, the proposed W_K -means algorithm can quickly identify different traffic types.

Nonvolatile Electrically Reconfigurable Integrated Photonic Switch Enabled by a Silicon PIN Diode Heater.

Reconfigurability of photonic integrated circuits (PICs) has become increasingly important due to the growing demands for electronic-photonic systems on a chip driven by emerging applications, including neuromorphic computing, quantum information, and microwave photonics. Success in these fields usually requires highly scalable photonic switching units as essential building blocks. Current photonic switches, however, mainly rely on materials with weak, volatile thermo-optic or electro-optic modulation effects, resulting in large footprints and high energy consumption. As a promising alternative, chalcogenide phase-change materials (PCMs) exhibit strong optical modulation in a static, self-holding fashion, but the scalability of present PCM-integrated photonic applications is still limited by the poor optical or electrical actuation approaches. Here, with phase transitions actuated by in situ silicon PIN diode heaters, scalable nonvolatile electrically reconfigurable photonic switches using PCM-clad silicon waveguides and microring resonators are demonstrated. As a result, intrinsically compact and energy-efficient switching units operated with low driving voltages, near-zero additional loss, and reversible switching with high endurance are obtained in a complementary metal-oxide-semiconductor (CMOS)-compatible process. This work can potentially enable very large-scale CMOS-integrated programmable electronic-photonic systems such as optical neural networks and general-purpose integrated photonic processors.

Pumpkin harvesting robotic end-effector

The development of an end-effector with a unique harvesting methodology based on the properties of pumpkin was presented in this paper. The components of the end-effector designed using Solidworks software; it dynamically simulated using SAM software; and after several modifications, the final components manufactured and assembled. This end-effector is a five-fingered anthropomorphic hand with electric drive and internal impactive gripping mode, designed to grasp and harvest heavyweight crops with a radius range of 76.2 to 265 mm by consideration of sustainable force distribution. The controlling unit of the system was a PLC system consists of a computer, a position board, an amplifier, a servo motor, switching units, and emergency switches. The coordinate of pumpkins enter the PC manually and after analysis using a controlling algorithm, the PC sends the related commands to the servo motor and switch unit via position board and optical cables. The controlling algorithm developed using the Denavit-Hartenberg (D-H) method. The maximum stress values of the final design were 6.2×107 and 7.8×107N/m2 in the opened and closed mode, respectively. The accuracy, repeatability, harvest possibility, and harvesting success rate were 8.78 mm, 8.32 mm, 92%, and 79%, respectively. The results proved that the fingers components have enough capability under the maximum payload of the system, and the designed end-effector can harvest the different varieties of pumpkin because the range of radius, volume and mass can cover the extracted physical parameter of pumpkins. The results indicated that the designed controlling unit and developed algorithm could control the system properly and do the desired function appropriately.

Photoinduced Forward and Backward Pedalo-Type Motion of a Molecular Switch.

Photoresponsive molecular switches enable spatial and temporal control of molecular processes and are therefore crucial for the development of smart functional materials. Because the light-induced dynamics of these switching units are at the core of the resulting functionality, a detailed insight into their structural time evolution is fundamental for molecular embedding. Here, we performed a hybrid quantum mechanics (CASPT2 and TDDFT)/molecular mechanics (QM/MM) study to elucidate the photodynamics of an azodicarboxamide-based molecular switch, which is a promising candidate for implementation in highly dense environments such as polymers. In particular, we report a detailed picture of the molecular motion at the atomic level based on a relevant number of excited-state trajectories. We show that the azodicarboxamide-based molecular switch undergoes both a forward and backward pedalo-type motion upon excitation. Trans-cis photoisomerization on the other hand, which is well-known to occur for other azo-based chromophores, is shown to be a negligible pathway. By validating the volume-conserving pedalo-type motion, we provide a rational basis for the design of novel types of photoresponsive functional materials in which the active component must operate in a confined space.

Experimental and numerical investigations of overlapping function in enhancing flow continuity for reciprocating-switcher energy recovery device

For reciprocating-switcher energy recovery device(RS-ERD), there still exists a significant flow discontinuity during the periodical stroke switching of the device, which causes broad fluid pulsations and additional energy dissipation. To enhance the continuity, overlapping function was structurally built in the switcher of RS-ERD, and was experimentally and numerically investigated under three overlapping distances(0 mm, 6 mm and 12 mm). The experimental results showed that, compared to 0 mm overlapping distance, the pulsations in pressure loss and flowrate of high pressure fluid decreased by 62.82% and 26.92% respectively for 6 mm overlapping distance at the operating condition of 6.0 MPa and 30 m3/h. For 12 mm overlapping distance, the corresponding pulsations were further reduced by 98.72% and 90.77%. Thanks to the overlapping function, the power dissipation for each stroke switching unit decreased by 65.23%(in 6 mm) and 99.00%(in 12 mm) in comparison to 0 mm overlapping distance, which significantly declined the self-energy consumption of RS-ERD. The decreases in the pulsation amplitudes and energy dissipation can be attributed to the overlapping of opening degree in valve plates, which achieves the reduction of the local flow velocity and flowrate variation rate in switching. The research results provide a new approach to strengthen the operational stability of RS-ERD.

RF-MEMS Monolithic K and Ka Band Multi-State Phase Shifters as Building Blocks for 5G and Internet of Things (IoT) Applications.

RF-MEMS, i.e., Micro-Electro-Mechanical Systems (MEMS) for Radio Frequency (RF) passive components, exhibit interesting characteristics for the upcoming 5G and Internet of Things (IoT) scenarios, in which reconfigurable broadband and frequency-agile devices, like high-order switching units, tunable filters, multi-state attenuators, and phase shifters will be necessary to enable mm-Wave services, small cells, and advanced beamforming. In particular, satellite communication systems providing high-speed Internet connectivity utilize the K and Ka bands, which offer larger bandwidth compared to lower frequencies. This paper focuses on two design concepts of multi-state phase shifter designed and manufactured in RF-MEMS technology. The networks feature 4 switchable stages (16 states) and are developed for the K and Ka bands. The proposed phase shifters are realized in a surface micromachining RF-MEMS technology and the experimentally measured parameters are compared with Finite Element Method (FEM) multi-physical electromechanical and RF simulations. The simulated phase shifts at both the operating bands fit well the measured value, despite the measured losses (S21) are larger than 5–7 dB if compared to simulations. However, such a non-ideality has a technological motivation that is explained in the paper and that will be fixed in the manufacturing of future devices.

Locomotion Mode Identification and Gait Phase Estimation for Exoskeletons During Continuous Multilocomotion Tasks

Gait phase estimation is important technology in controlling the exoskeleton robot to assist elderly walking. Several kinds of Gait estimation methods have been proposed, however, the previously proposed methods were mainly aiming at one kind of walking task, e.g., level ground walking. There are only a few studies aiming at continuous gait phase estimation during continuous multilocomotion tasks. In this article, we design a continuous gait phase estimator based on adaptive oscillator (AO) network. In order to overcome the problem that the traditional AO does not converge or converges slowly when the gait task is switching, a new structure of gait phase estimator, including a gait tasks classifier, an AO reset, a peak detector, and a model-based (MB) transition gait phase estimator is designed to improve the performance of AOs network. The switching unit is designed to reorganize the output gait phase. Considering the stabilization of the sensors in continuous multilocomotion tasks, the gait tasks classifier only utilizes the angle of hip joints. The results show that the constructed classifier has similar performance to other gait tasks classifiers and requires minimum sensing sources. The continuous gait phase estimation results during continuous multilocomotion tasks show that the proposed method has better performance than the traditional AO and the AO network with self-designed reset.

Design of Piezoelectric Energy Harvester and Power Conditioning

The existing system presents a novel approach called simultaneous wireless strain sensing and energy harvesting from multiple piezo-patches, which is intended for self-powered Structural Health Monitoring applications. The Energy Harvesting subsystem is mainly the self-powered extended synchronous electric charge extraction interface based on double cross-coupled rectifying structure and a single fly back transformer, which is able to harvest energy from multiple piezo-patches. In this proposed work, the DC power is generated using piezoelectric and MEMS. Then the Produced by DC energy is given to Ultra Low Power Converter Using with Micro controller then Ultra capacitor used to Highly Discharging in the DC power bank. The outputs of transducers are also given to micro controller. The obtained energy is boosted up using Booster Ultra Low Power Converter. The output of the Ultralow Power Converter is given to the Relay for the switching unit to store energy in a DC Power Bank and the stored energy is inverted to AC voltage