Constant Current System Research Articles

The Embedded System of Battery Charging with Constant Current System using Microcontroller and IC LM338

The battery has the function of an electrical energy storage system. However, charging the battery is prone to damage. Damage to the battery is often caused by overcharging. The time used during the battery charging process is an important factor that must be considered when charging. thus, efficient battery charging is important and very necessary to avoid damage. An another important aspect of a battery charging method is the current and voltage values supplied during its charging process. The presence of inappropriate values damages and reduce battery life, while the maintenance of a constant current is an important charging process step that extends service life. This research is expected to create a safe and optimal battery charging system with a simple low-cost circuit based on constant current by utilizing the LM388 Integrated Circuit (IC) regulator. This study discusses a 12 V battery charging system with monitored and controlled constant current using an R-Shunt sensor. Voltage monitoring while charging was carried out with voltage sensors using a constant current of 0.1 to 1.3 Ampere. Furthermore, voltages and currents were displayed through a Liquid Crystal Display (LCD) screen controlled with Arduino Uno during battery charging. The measurement results showed that the circuit reached voltages and currents of 14.07 V and 0.19 A respectively for a charge duration of 8 hours.

ANFIS-based control of resonant converters for optimized charging system of electric vehicle (EV) batteries

This paper presents a resonant converter-based Electric Vehicle (EV) battery charging module utilizing Proportional-Integral (PI) and Adaptive Neuro-Fuzzy Inference System (ANFIS) control for an optimized charging system. The EV charging module is integrated with a resonant converter comprising a full bridge, HFTF, and DBR. The module utilizes a Resonant Converter which reduces the switching loss incurred during converter operation at high frequency by offering ZCS or ZVS at the switching time. A standard PI Controller manages the duty ratios of the primary full bridge switches with tuned gains. The CC and CV controllers each have their own PI Controller for current and voltage, respectively. To enhance the performance of the EV System, the standard PI Controllers in both the CC and CV control systems are replaced with ANFIS Controllers which are trained as per the data generated by the CC and CV control using an optimization technique that controls the duty ratio of the switches. The proposed ANFIS-based and PI-based control strategy provides an adaptive and flexible approach to control the battery voltage and current by intelligent adjustment of Constant Current (CC) and Constant Voltage (CV) operation modes and the passive elements switching across specific ranges of State-Of-Charge (SOC) to enhance the performance and safety of the charging system. MATLAB Simulation results demonstrated that the proposed ANFIS-based control reduces current ripple content compared to PI-based control. The ANFIS Controller improves overall battery performance, reliability, and stability, which makes it a better choice for next-generation EV charging systems.

Real-World Outcomes in USA using DBS Systems with Directionality and Multiple Independent Current Control (P5-11.017)

Real-World Outcomes in USA using DBS Systems with Directionality and Multiple Independent Current Control (P5-11.017)

Long-Term Evaluation of Deep Brain Stimulation for Treatment of Parkinson’s Disease Using a Multiple-Source, Constant-Current System: 5-year Follow-Up of a Prospective, Double-Blind RCT (S16.006)

Long-Term Evaluation of Deep Brain Stimulation for Treatment of Parkinson’s Disease Using a Multiple-Source, Constant-Current System: 5-year Follow-Up of a Prospective, Double-Blind RCT (S16.006)

Dielectric-elastomer-enhanced triboelectric nanogenerator with amplified outputs

Dielectric elastomers are effective ambient motion energy harvesters due to their flexibility, high energy density, and their ability to match low frequency unsteady motions. However, the dielectric elastomer generator (DEG) is in reality a charge pump, which requires an external supply of electrical charge to work as an energy harvester. In this work, the DEG is coupled with a contact-mode triboelectric nanogenerator (TENG) to form a hybrid. The TENG autonomously produces charges by contact electrification and the DEG in turn amplifies the electrical output by raising the charges to a higher electrical potential. In addition, dielectric elastomer exhibits dielectric strength two orders of magnitude higher than air, thus enabling delivery of a higher output voltage than that by TENG only. Both the TENG and the DEG converts mechanical motion to electrical energy via capacitance change. This makes them physically compatible for easy integration. We first analyze the coupled system and identify the optimal conditions that maximizes output yield in the shortest amount of time. We found that, the maximum output was realized when the TENG and DEG were excited perfectly out-of-phase for same input frequency. We showed that the DEG is ideally able to amplify the voltage output from TENG that is proportional to the capacitance change ratio of the DEG. By the same token, the maximum power will also be amplified proportionally for a constant current system. Our experiment showed that 260% and 180% DEG capacitance change can produce saturation voltage amplification of 2.7 and 2, respectively. Our work demonstrated dielectric-elastomer-enhanced output of a TENG and presented the optimal conditions for maximal amplification.

Charging equaliser based on wireless power transfer for electric scooters

It is more convenient and safer to employ wireless power transfer (WPT) systems to charge the battery pack of electric scooters (ESs) than conventional plug-in systems. A charging equaliser suitable for ESs is proposed to achieve constant current (CC) output without communication link between the transmitter side and the receiver side. The full-bridge rectifier and select switches utilised at the receiver side are employed to be operated once to change from the balancing mode to charging modes. The characteristics of the load-independent current output in the CC mode are achieved by properly selecting the parameters of the circuit so that no sophisticated control strategies are required to regulate the output as per the charging profile. The experimental results show that when the voltage of battery pack is charged at 32 or 4.2 V, the current is 1.02 or 1.12 A, respectively. Therefore, the proposed system can be considered as a CC system.

Controllable Electrochemical Synthesis of Ag Hierarchical Micro/Nanostructures with High SERS-Activity

We report a one-step electrochemical deposition technique to prepare three-dimensional (3D) Ag hierarchical micro/nanostructured film consisting of well-crystallized Ag nanosheets grown on an indium tin oxide (ITO) conductive substrate. The Ag hierarchical micro/nanostructures were fabricated in the mixed solution of AgNO3 and sodium citrate in a constant current system at room temperature. Through reduction of Ag[Formula: see text] electrodeposited on the surface of ITO substrate, nanoparticles were grown to form nanosheets which further combined into 3D sphere-like microstructures. The 3D Ag micro/nanostructures have many sharp edges and nanoscale gaps which can give rise to good Raman-enhanced effect. Due to localized surface plasmon resonance (LSPR) effects, these special Ag micro/nanostructures exhibited good Raman-enhanced performance. Using Rhodamine 6G (R6G) molecules as probe molecule, we studied the influence of excitation wavelength on Raman enhancement. The results showed that the 532[Formula: see text]nm excitation wavelength is the best to obtain the strongest Raman signal and to reduce the influence of other impurity peaks. Using the as-synthesized Ag hierarchical micro/nanostructures, we can detect the 10[Formula: see text][Formula: see text]mol/L R6G aqueous solution, exhibiting great Raman-enhanced effect.

Study on the gaseous and electrochemical hydrogen storage properties of as-milled Ce[sbnd]Mg[sbnd]Ni-based alloys

For gaining further insight into the involvement of the gaseous and electrochemical hydrogen storage properties of CeMg12-type alloys, partial substitution and ball milling were both used to synthesize the nanocrystalline and amorphous CeMg11Ni + x wt.% Ni (x = 100, 200) samples. This research aims at elucidating the functional roles of Ni content and milling time on samples' structure and hydrogen storage performance. X-Ray diffraction and high-resolution transmission electron microscope were used to reveal the micro constructions of alloys. To determine the gaseous hydrogen storage property, Sievert's apparatus and a thermal gravity analysis bonded with a H2 probe were adopted. The dehydrogenation activation energy was computed in the Kissinger method. The electrochemical performances of the as-milled samples were measured through a constant current system. Further researches showed that the electrochemical performance of as-milled samples had been dramatically improved by increasing Ni content. With milling duration lengthens, the gaseous hydrogen absorption capacity, gaseous hydriding rate and high rate discharge capability of samples reached the maximal values, but electrochemical discharge capacity and gaseous dehydriding rate always increased. The dehydrogenation activation energy decrease resulted by improving Ni percent and milling duration was deemed as the cause of the excellent gaseous kinetics of samples.

Treatment of reverse-osmosis concentrate of printing and dyeing wastewater by electro-oxidation process with controlled oxidation-reduction potential (ORP)

Reverse osmosis concentrate (ROC) of printing and dyeing wastewater remains as a daunting environmental issue, which is characterized by high salinity, chemical oxygen demand (COD), chroma and low biodegradability. In this study electro-oxidation process (PbO2/Ti electrode) coupled with oxidation-reduction potential (ORP) online monitor was applied to treat such a ROC effluent. The results show that with the increase of specific electrical charge (Qsp), the removal efficiencies of COD, TN and chroma increased significantly at the incipience and then reached a gentle stage; the optimal total current efficiency (12.04 kWh m−3) was obtained with the current density of 10 mA cm−2 (Qsp, 3.0 Ah L−1). Meanwhile, some inorganic ions can be simultaneously removed to varying degrees. FTIR analyses indicated that the macromolecular organics were decomposed into smaller molecules. A multi-parameter linear relationship between ORP and Qsp, COD and Cl− concentration was established, which can quantitatively reflect the effect of current density, chloride ion concentration, pollutants and reaction time on the performance of the electro-oxidation system. As compared to a traditional constant-current system, the constant-ORP system developed in this study (through the back-propagation neural network [BPN] model with ORP monitoring) approximately reduced the energy cost by 24–29%. The present work is expected to provide a potential alternative in optimizing the electro-oxidation process.

Long term results of the VANTAGE study: A prospective multicenter trial evaluating deep brain stimulation with a multiple source, constant current system in Parkinson’s disease

Long term results of the VANTAGE study: A prospective multicenter trial evaluating deep brain stimulation with a multiple source, constant current system in Parkinson’s disease

Constant Current vs. Constant Voltage Systems for Temporal Spinal Cord Stimulation for Intractable Pain.

Although spinal cord stimulation (SCS) is a useful treatment for chronic intractable pain, the optimal method of stimulation has not yet been established. In this prospective, crossover study, we compared the efficacy of using a constant current (CC) system with that of a constant voltage (CV) system for temporal SCS. Twenty patients were enrolled and divided into two groups. For 10 patients, a CV system was applied on Days 1-5, followed by the use of a CC system on Days 6-10. For the other 10 patients, a CC system was applied for the first five days, followed by a CV system for the subsequent five days. We evaluated the alteration of pain intensity using a visual analogue scale (VAS), the area of stimulation, the stability of effect, and patient satisfaction regarding treatment. The pain scores decreased significantly after the start of the SCS. There was no significant difference in the change in VAS between the two systems. The stimulation method used for temporal SCS did not affect the reduction of pain intensity. Patients felt a wider stimulation area by the CC system compared to the CV system.

134 VANTAGE Trial

INTRODUCTION: Deep brain stimulation (DBS) has been demonstrated to be effective for Parkinson disease (PD) symptom relief. We sought to characterize the benefit of subthalamic nucleus (STN) DBS for PD patients using a recently CE-marked multiple-source, constant-current system that permits a well-defined distribution of applied current. We report the 3-year results of the first clinical trial using multiple independent current control (MICC) DBS in the management of symptoms of PD. METHODS: VANTAGE is a monitored, prospective, multicenter, nonrandomized, open-label interventional trial sponsored by Boston Scientific Corporation. Forty subjects with idiopathic PD were implanted bilaterally with a DBS system (Vercise) targeting the STN and followed up to 3 years after lead placement. Motor improvement was evaluated using Unified Parkinson's Disease Rating Scale (UPDRS) III scores in stim ON/meds OFF in comparison with preoperative scores. Other assessments such as CAPSIT motor tests, Tremor Rating Scale, Dyskinesia Rating Scale, PDQ-39, SF-36, Schwab and England, and resource utilization were administered. Patient motor diaries were collected over 3 days. Adverse events were also recorded. RESULTS: This study will report the safety and effectiveness outcomes of VANTAGE subjects at 3 years postimplantation as compared with baseline. CONCLUSION: The VANTAGE trial is the first reported trial of a multiple-source, constant-current rechargeable system for use in the management of PD symptoms. Study outcomes will inform clinicians on the use of this system and its flexibility to manage the symptoms of idiopathic PD.

고휘도 LED를 이용한 머신비전용 조명광원 제어기 개발

Abstract This paper is to introduce a lighting source controller using high brightness LED to create a clear and reliable condition for an accurate measurement and testing, which is a core technology in clinical image system and mechanical automation system. This controller is designed to supply a stable power in a constant-current system by installing a high brightness LED driver, and to improve the reproducibility of brightness by using 32-bit ARM processor core, dividing brightness quantity into 256 levels, making the remote control and the external interface possible, and preventing and digitizing the brightness inaccuracy caused by errors of resistance values. This controller enables the lighting range to be wide and possible in a low lighting level compared to analog, adds the RS-485 communication function, and makes it for the users to control the on-off function and the dimming level by receiving date from an external device. Key Words : hbled, lighting, lighting source controller, machine vision, vision system

Patient-Perceived Differences Between Constant Current and Constant Voltage Spinal Cord Stimulation Systems

Spinal cord stimulation (SCS) systems employ implantable pulse generators that use either a constant current (CC) or a constant voltage (CV) power source. CC power sources adjust voltage in response to resistance (impedance) to ensure that consistent current is delivered to the patient. CV power sources do not adjust voltage in response to impedance; therefore, current delivered to the patient will vary in response to changes in impedance. Both systems produce paresthesia and have been shown to treat chronic pain; however, it has been suggested that patients prefer CC stimulation over CV stimulation. This Institutional Review Board-approved, randomized, double-blinded crossover study compared patient preference for the stimulation sensation elicited by a CC or CV neurostimulation system. Thirty patients completed a baseline evaluation prior to implantation of a percutaneous trial system and returned one-day postimplant for randomization and initiation of SCS. Three days later, patients were evaluated and crossed over into the alternate treatment group. Final evaluation of patient well-being, pain relief, satisfaction, quality of life, preference, and stimulation sensation occurred on Day 6. Patient preference was assessed using a one-sample Z-test. Treatment and group differences were explored using paired t-test for continuous and ordinal variables and chi-square of Fisher's exact test for categorical variables. More patients (70%) preferred CC stimulation over CV stimulation (30%), and CC stimulation produced a significantly larger decrease in pain scores than CV stimulation. Interestingly, patients initially exposed to CC stimulation were less likely to be satisfied with CV stimulation. The results from this study indicate that patients preferred and experienced greater satisfaction and pain relief with the CC system during an SCS trial period. Differences between the two systems following long-term use has yet to be compared. However, the benefits of the CC system seen with short-term use should be considered when selecting an SCS system.

Impedance Variations over Time for a Closed-Loop Neurostimulation Device: Early Experience with Chronically Implanted Electrodes

Responsive neurostimulation (RNS®) is an investigational treatment modality for intractable focal epilepsy. We analyzed impedance values over time to gain a better understanding of RNS device stability, potential differences between depth and strip electrodes, and general implications of long-term electrode implantation. Impedance measurements were retrospectively reviewed from seven patients over a 3-year period. Statistical analysis was performed to investigate trends in impedance values over time and to determine if any differences existed between the means and variances of impedance values for the two different electrodes. Intraparenchymal depth electrodes demonstrated lower mean impedances and had less variation over time when compared to subdural strip electrodes. There was no significant change in mean impedance over time for depth electrodes, while that of subdural electrodes increased over time to peak at 16-20 months and returned to baseline by 2 years. The RNS device provides unique long-term data for both depth and subdural electrodes in human subjects. Although changes in impedance were observed with respect to time after implantation and electrode type, these variations were of a clinically insignificant magnitude. As a constant-current system, the device is ultimately able to administer stable therapeutic doses in the setting such minor variability. While further animal research and post mortem investigations in human subjects are necessary to broaden our understanding of the mechanisms occurring at the electrode-neural interface and the biocompatibility of chronically implanted electrodes, the relative stability of impedances seen in this cohort of chronic implants brings promise to future implementations of chronic intracranial neural implants.

GPS기반 동기점멸방식의 해상용 LED등명기의 설계 및 제작

해상용 등명기의 동기 점멸은 해상에서 선박이 운항할 때, 다른 위험 표시기의 점등 패턴과 구분하여 선박의 안전한 운항을 지원한다. 일반적인 해상용 등명기의 점등기법은 낮과 밤을 감지하여 정해진 점등 규약에 따라 점등하는 방식으로 시간이 지남에 따라 등명기들의 시간 오차가 발생하여 등명기 전체의 동기 점멸이 이루어지지 못하고 있다. 이러한 문제를 해결하기 위하여 본 연구에서는 GPS의 위성시간을 기준으로 하여 모든 등명기들이 개별적으로 동기시간을 일정하게 맞추는 동기식 점등기법을 사용한 정전류방식의 해상용 LED 등명기를 설계하였으며, LED등명기 내부의 제한되고 밀폐된 공간에서 효율적인 방열성능을 갖는 방열방법을 제시하였다. The synchronous flash of a marine lantern, differentiated from the flash pattern of other risk indicators, supports the safe sailing of vessels. General marine lanterns flash according to the flash protocol through sensing the day and the night. Thus, there can be time error over time and the marine lantern does not synchronously flash as a whole. To resolve this problem, this study designed LED marine lantern based on constant-current system using synchronous flash technique enabling all marine lanterns to keep its time based on GPS satellite time. Also we suggested a radiation method with an effective heat emission performance in the restricted and closed space of a marine lantern.

Investigation of subauroral ion drifts and related field-aligned currents and ionospheric Pedersen conductivity distribution

Abstract. Based on Astrid-2 satellite data, results are presented from a statistical study on subauroral ion drift (SAID) occurrence. SAID is a subauroral phenomenon characterized by a westward ionospheric ion drift with velocity greater than 1000m/s, or equivalently, by a poleward-directed electric field with intensity greater than 30mV/m. SAID events occur predominantly in the premidnight sector, with a maximum probability located within the 20:00 to 23:00 MLT sector, where the most rapid SAID events are also found. They are substorm related, and show first an increase in intensity and a decrease in latitudinal width during the expansion phase, followed by a weakening and widening of the SAID structures during the recovery phase. The potential drop across a SAID structure is seen to remain roughly constant during the recovery phase. The field-aligned current density and the height-integrated Pedersen conductivity distribution associated with the SAID events were calculated. The results reveal that the strongest SAID electric field peaks are associated with the lowest Pedersen conductivity minimum values. Clear modifications are seen in the ionospheric Pedersen conductivity distribution associated with the SAID structure as time evolves: the SAID peak is located on the poleward side of the corresponding region of reduced Pedersen conductivity; the shape of the regions of reduced conductivity is asymmetric, with a steeper poleward edge and a more rounded equatorward edge; the SAID structure becomes less intense and widens with evolution of the substorm recovery phase. From the analysis of the SAID occurrence relative to the mid-latitude trough position, SAID peaks are seen to occur relatively close to the corresponding mid-latitude trough minimum. Both these features show a similar response to magnetospheric disturbances, but on different time scales - with increasing magnetic activity, the SAID structure shows a faster movement towards lower latitudes than that of the mid-latitude trough. From the combined analysis of these results, we conclude that the SAID generation mechanism cannot be regarded either as a pure voltage generator or as a pure current generator, applied to the ionosphere. While the anti-correlation between the width and the peak intensity of the SAID structures with substorm evolution indicates a magnetospheric source acting as a constant voltage generator, the ionospheric modifications and, in particular the reduction in the conductivity for intense SAID structures, are indicative of a constant current system closing through the ionosphere. The ionospheric feedback mechanisms are seen to be of major importance for sustaining and regulating the SAID structures. Key words. Ionosphere (mid-latitude ionosphere; electric fields and currents; ionosphere-magnetosphere interactions)

Simulations of reactive sputtering with constant voltage power supply

Reactive sputtering in an Al–O2/Ar system equipped with a dc power supply in constant voltage mode was simulated using a kinetics model in this article. This work showed that reactive sputtering under reactive gas flow rate control and with a constant voltage power was much different from that with a constant current power both in time-dependent and parameter-dependent behaviors. Numerical analysis predicted the continuous, N-shaped V–I characteristics curves, which agreed with the experimental curves reported by other researchers in a system which was equipped with a dc constant current power but operated under voltage control [R. McMahon et al., J. Vac. Sci. Technol. 20 376 (1982); K. Steenbeck et al., Thin Solid Films 92, 371 (1982)] and in a system with a modulated power supply [H. Ohsaki et al., Thin Solid Films 281-282, 213 (1996)]. The continuous parameter-dependent functions indicated that there is no hysteresis effect in constant voltage reactive sputtering, which is a well-known feature of dc constant current magnetron sputtering of an Al–O2/Ar system. According to the simulated kinetics curves using the same simulation parameters, the initial values of oxide coverage on the target surface had no influences on the final parameters at steady state in a constant voltage system, whereas different initial coverage may lead to different steady states (hysteresis behaviors) in a constant current system. This article showed that the films of any reactive gas contents, i.e., the M1−θ−(MOx)θ films (M=metal, MOx=compound of metal) with full range of 0⩽θ⩽1, could be produced in constant voltage reactive sputtering which is a system simpler than those under partial pressure control.

Predictive Value of Facial Nerve Electrophysiologic Stimulation Thresholds in Cerebellopontine‐Angle Surgery

The predictive value of intraoperative stimulation thresholds for facial nerve function, using a constant-current system, was examined in 49 patients undergoing resection of cerebellopontine-angle tumors. Immediately after surgery, 75% of the 0.1-mA threshold group, 42% of the 0.2-mA group, and 18% of the 0.3-mA or greater group had good (grade I or II) facial nerve function. One year after surgery, 90% of the 0.1-mA group, 58% of the 0.2-mA group, and 41% of the 0.3-mA or greater group had grade I or II function. A statistically significant breakpoint of 0.2 mA was found to predict good postoperative facial function. Delayed facial paralysis occurred in 22% of patients, but the prognosis for these patients was favorable. Both current stimulation threshold and duration are necessary for a meaningful comparison of data between investigators.

What drives the equatorial electrojet?

There is a controversy over whether the equatorial electrojet is a separate system with its own return currents at low latitudes or it is an integral part of the Sq current system driven by emfs mostly beyond the Sq focus. The arguments of Onwumechili (1989) in support of the first hypothesis are examined, but the second idea is preferred. Ground-based, satellite and rocket data are reviewed together with correlation studies and various computer models. A picture is suggested where there is a relatively constant current system, including both electrojet and Sq, with other superposed current systems mostly driven by semidiurnal tides, which are responsible for both day-to-day and seasonal variations and also for the poor correlation between geomagnetic variations at the electrojet and elsewhere.