Light Circuit Research Articles

A Multisource Collaborative Energy Extraction Circuit for Vibration, Ambient Light, and Thermal Energy With MPPT and Single Inductor

This paper presents a multi-source collaborative energy extraction circuit (MSC-EC) for vibration, ambient light and thermal energy with maximum power point tracking (MPPT) and a single inductor. The MSC-EC can simultaneously extract energy from the piezoelectric transducer (PZT) and Photovoltaic cell (PV) when the peak open-circuit (OC) voltage of the PZT is detected by the peak voltage detector and the voltage of PV is higher than the maximum power point (MPP) voltage of PV (MPP voltage is about 0.7 times the OC voltage of PV), which can also collaboratively extract energy from the thermoelectric generator (TEG) in the extraction of vibration energy or ambient light energy to improve the efficiency of thermal energy extraction. Experimental results indicate that the MPPT efficiency of PV is about 83%, and the maximum energy extraction efficiency of TEG is about 74%. The maximum output power of MSC-EC is 4.2 mW under certain conditions.

A Self-Supplied Power Optimizer for Piezoelectric Energy Harvesters Operating under Non-Sinusoidal Vibrations

A self-supplied circuit that is able to significantly increase the power delivered to a bridge rectifier by a Resonant Piezoelectric Vibration Energy Harvester (RPVEH) is presented and discussed. The proposed circuit, called the Energy Harvester Power Optimizer (EHPO), is implemented by means of a switch-mode converter that emulates a negative capacitance. Unlike switch-mode impedance emulators, based on sophisticated tracking algorithms requiring lossy microcontrollers, EHPO exploits a very light control circuit based on a hysteresis comparator. The EHPO is self-supplied since it does not need an external supply, but it draws the energy for its operation directly from the RPVEH. Moreover, it is developed without the assumption of purely sinusoidal vibrations. Experimental results show that the EHPO can significantly increase the power delivered to a rectifier, both in the case of sinusoidal vibrations (percent gain of the net extracted power up to about 190%) and non-sinusoidal vibrations (percent gain of the net extracted power up to about 245%), regardless of the shape of the forcing acceleration and regardless of the RPVEH resonance frequency.

An Efficient Ambient-Moisture-Driven Wearable Electrical Power Generator.

Existing devices for generating electrical power from water vapor in ambient air require high levels of relative humidity (RH), cannot operate for prolonged periods, and provide insufficient output for most practical applications. Here a heterogeneous moisture-driven electrical power generator (MODEG) is developed in the form of a free-standing bilayer of polyelectrolyte films, one consisting of a hygroscopic matrix of graphene oxide(GO)/polyaniline(PANI) [(GO)PANI] and the other consisting of poly(diallyldimethylammonium chloride)(PDDA)-modified fluorinated Nafion (F-Nafion (PDDA)). One MODEG unit (1 cm2 ) can deliver a stable open-circuit output of 0.9V at 8µA for more than 10h with a matching external load. The device works over a wide range of temperature (-20 to +50 °C) and relative humidity (30% to 95% RH). It is shown that series and parallel combinations of MODEG units can directly supply sufficient power to drive commercial electronic devices such as light bulbs, supercapacitors, circuit boards, and screen displays. The (GO)PANI:F-Nafion (PDDA) hybrid film is embedded in a mask to harvest the energy from exhaled water vapor in human breath under real-life conditions. The device could consistently generate 450-600mV during usual breathing, and provides sufficient power to drive medical devices, wearables, and emergency communication.

Near-zero-index platform in photonics: tutorial

The need for miniaturization and faster communications resulted in the rise of photonics, with the big promise of light circuits with high speed and low heating. Near-zero-index materials have gained attention due to their peculiar electromagnetic properties, such as enhancement of the electric field and extraordinary transmission inside photonic waveguides. Furthermore, in such a medium, light propagates with constant phase, thus holding great promise for the field of quantum photonics, where information is preserved instead of degraded by the environment, causing decoherence. However, its realization still remains challenging, as it requires very specific geometries to fulfill some requirements related to the effective medium theory. In this tutorial, we present a theoretical overview of low-index materials’ most intriguing yet useful characteristics and their prospective applications.

All-optical logic gates using E-shaped silicon waveguides at 1.55 μm

Owing to the advanced fabrication technology of silicon, silicon waveguides are particularly attractive for implementing all-optical signal processing devices and switches. Therefore, in this paper, a silicon-on-silica waveguide that consists of four slots arranged in the shape of letter E is proposed to be employed as the building block for simulating fundamental all-optical logic gates (AOLGs), including XOR, AND, OR, NOT, NOR, NAND, and XNOR, at 1.55 μm telecommunications wavelength. The operation concept of these logic gates relies on the constructive and destructive interference that results from the phase difference induced by optical beams that are incident on the E-shaped waveguide. The performance of the target logic gates is assessed against the contrast ratio (CR) metric. Moreover, the dependence of the spectral transmission on the device's key operating parameters is investigated and assessed. Compared to other reported designs, the results obtained by conducting simulations using the finite-difference-time-domain in lumerical commercial software show that the proposed waveguide can operate at a higher speed of 80 Gb/s and attain higher CRs of 36, 39, 35.5, 28.8, 30, 38, and 36.7 dB for logic XOR, AND, OR, NOT, NOR, NAND, and XNOR, respectively. This suggests that by using the proposed scheme, AOLGs could be realized more feasibly with greater performance and faster operation toward satisfying the present and future needs of light wave circuits and systems.

Research on Energy-saving Calculation of Navigational Lighting System Powered by Low Current in Green Airport

The airport navigation lighting system is an important energy-consuming system in the flight area. The annual energy consumption of large and medium-sized airports can reach millions of kilowatt hours. At present, the airport is replacing traditional halogen lamps with LED navigation lighting for energy conservation. For LED lighting under the traditional 6.6 A power supply system, the circuit loss is high, and the overall energy-saving effect of the system is not good. A low-current power supply energy-saving navigation lighting system is proposed. The primary cable, secondary cable, isolation transformer, and auxiliary lighting system in the navigation lighting circuit are studied by performing the energy-saving calculation of navigation lights under low currents. By building a set of navigation lighting systems to conduct energy consumption experiments and comparing them with theoretical calculations, a calculation model is proposed to provide a basis for energy-saving calculations for the application of a low-current power supply navigation lighting system.

Effect of LED Lighting on Selected Quality Parameters of Electricity.

Recently, various technological light sources have appeared on the market. As a result, it is extremely important to evaluate the characteristics of the available lamps and the impact they may have on the power grid. This article presents regulations and standards for power quality, including higher current and voltage harmonics, and analyzes three selected light-emitting diode lamps. The purpose of the study was to analyze the impact of LED lighting systems on the power quality (PQ) of the electric grid. The results of measurements of parameters determining the power quality of the electricity consumed by modern LED light sources used for room lighting are presented. Commercially available lamps and low-power power supplies (25 to 35 W) with an output current of 350 mA were used for the study. The current waveforms of selected lamps during their connection to the power grid, the results of harmonic emission tests, as well as the effect of increasing the load of selected DC power supplies (drivers) on THD, power factor (PF), and their efficiency are presented. The significant negative impact of power supply circuits in compact LED lamps on the power quality parameters of lighting circuits was demonstrated. The tested lamps significantly exceed the permissible limits of harmonics and THD. Test results have shown that LED lamps show significant savings in electricity consumption, but they behave as nonlinear loads. They generate high-frequency current harmonics, which can lead to degradation of power quality in the distribution network. Therefore, if the primary concern for the user is power quality rather than power savings, traditional incandescent lamps would be a much better choice. When using switched-mode power supplies, attention should be paid to their load rating. You should avoid using power supplies in the lower ranges of permissible load capacity. A more heavily loaded power supply has better performance due to power quality and efficiency.

Emission Gate Driver With Five Low-Temperature Poly-Si Oxide TFTs Without Capacitor for Narrow-Bezel AMOLED Display

We report a highly simplified emission (EM) gate driver circuit for high resolution and narrow bezel active-matrix organic light emitting diode (AMOLED) display using low-temperature poly-Si oxide (LTPO) thin film transistors (TFTs). The proposed circuit consists of five TFTs, three low-temperature poly-Si (LTPS) and two oxide TFTs. The output signal can be controlled with variable pulse width by starting signal of different pulse width. The fabricated circuit operates well with depletion mode oxide TFTs having threshold voltage of -3.5 V. The output swing from 3 V to -7 V and peak to peak voltage of 10 V were used for the output measurement. The output signals with different duty ratio of 10, 50, and 90% are demonstrated. The power consumption is only 41.5 mW when the duty ratio of EM signal is 90% at refresh rate of 120 Hz for 4k (3840 × 2160) AMOLED display.

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.

Polarization-insensitive 90° optical hybrid using silica-based PLC.

A 90° optical hybrid (OH) based on a 4×4 multimode interference (MMI) coupler is characterized and analyzed using the silica-based planar light circuit. The OH is designed to be polarization-insensitive with an extremely low polarization-dependent loss (<0.18d B) and phase error (w i t h i n±1.3∘). The fabricated chip exhibits an excess loss of 3.4dB and 3.8dB for TE and TM polarizations at 1550nm. The measured phase error is w i t h i n±7.2∘ over 50nm in the C+L band with a polarization-dependent error w i t h i n±3.5∘. The fabrication tolerance of the MMI width and waveguide sidewall angle is analyzed, which can well explain the deviation from the theoretical calculation.

Efficient H2 production in a ZnFe2O4/g-C3N4 photo-cathode single-chamber microbial electrolysis cell.

Photo-assisted single-chamber microbial electrolysis cells (MECs) incorporating semiconductor cathodes are attractively promising for exclusive hydrogen without CH4 and CO2. However, the unsustainable, high cost, and unstable metal catalysts on the cathodes along with the intricacies behind the interplay of circuital current, light illumination, and bacterial communities on both electrodes are poorly understood. Herein, photo-assisted single-chamber MECs incorporating ZnFe2O4/g-C3N4 cathodes are demonstrated to achieve efficient production of exclusive hydrogen (0.11 ± 0.01 m3/m2/day; 1.70 ± 0.04 m3/m3/day) with a solar-to-hydrogen conversion efficiency of 4.08 ± 0.17% and an energy efficiency relative to electrical input of 233 ± 5%. The ZnFe2O4/g-C3N4 structured cathodes exhibited appreciable higher photocurrents than the controls (g-C3N4: 4.3-fold; ZnFe2O4: 3.3-fold), and negligible leaking of Fe and Zn after the 4th-cycle operation. Circuital current and light illumination were proven to varying degree shape both electrodes for building up functional bacterial communities with metabolic regulation at the prolonged operation of 12 batch cycles. Energy metabolism and carbohydrate metabolism along with membrane transport, signal transduction, and cell motility based on PICRUSt functional prediction further confirmed the photo-assisted single-chamber MECs for efficient hydrogen production. This study provided a sustainable, cost-effective, and efficient approach for achieving high rates of exclusive hydrogen production and offered new insights for ingenious interplay of circuital current, light illumination, and bacterial communities for efficient hydrogen production in the photo-assisted single-chamber MECs. KEY POINTS: • ZnFe2O4/g-C3N4 cathodes of single-chamber MECs achieve efficient H2 production. • Light irradiation and circuit current shape bacterial communities on both electrodes. • Circuital current contributes to less leaking of Fe and Zn, and thus system stability.

Single Stage Active Power Factor Correction Circuit for Street LED Light with Battery Backup

This paper proposes a single-stage active power factor correction circuit for street LED light with battery back-up. The buck–boost converter and flyback converter are combined to achieve optimal performance. The first part of the integrated LED driver, the buck–boost converter is used to adjust the power while operating in the discontinuous conduction operation. The second part of the driver, the flyback converter provides regulated voltage to the LEDs. The battery backup circuit charges the battery when ac input power is available and provides power to LED lamp when input power supply is not available. The proposed LED driver was designed for 100 W output power and tested by PSpice simulation. The simulation results obtained are given in the paper to demonstrates the functionality of the proposed LED driver system. The result show good operation and performance of proposed LED driver.

A Simple Colorimeter for Measuring the Concentration of Multicomponent Food Coloring

Built-in instruments are commonly employed in physics experiments. In this case, students are usually unaware of the instrument’s fundamental physics. Here we constructed a simple and compact colorimeter. A light-emitting diode (LED) was used as a light source. The light detector circuit consists of a photoresistor, a resistor, and a 9-V battery. During the experiment, we illuminated the solution of food coloring. The transmitted light was measured via the voltage in the resistor of the light detector to obtain the absorbance. The value was then used to determine the concentration of the solution. This instrument has been used to measure a mixture of food coloring’s concentration e.g. 1 ml/l Carmoisine and 1 ml/l Ponceau. For this sample, the measurement gave a concentration of 0.97 ml/l Carmoisine and 0.81 ml/l Ponceau. This instrument is simple and appropriate for teaching.

Build and Implement Radiation Control using IoT in Parabolic Trough Solar Collector (PTSC)

Connecting the devices to the internet based on the internet of things IoT increases the capability of monitoring and measuring, and controlling essential variables. In this study, the radiation intensity was controlled via the internet of things IoT for PTSC to study the collector's behavior. The light control circuit was designed, built, and implemented. The circuit mainly consists of a power supply, Arduino, relay, and potentiometer. Radiation was successfully monitored using a sensor and displayed through a smartphone via Wi-Fi, and the intensity of radiation light controls the PCM status. A data logging system was applied using a micro SD in a smartphone card and Arduino Node-MCU as a microcontroller. The experimental results show the relationship between solar radiation and resistance change. Inversely, the maximum radiation found from this work was 780 W/m2 with 74 k Ω resistance, and the minimum radiation was 300 W/m2 with 170 k Ω resistance. The output power changes directly through solar radiation, which means the power output with maximum solar radiation will be 3018 W. Using IoT Technology reduces efforts of long-time monitoring during the experiment (many hours).

Sorption of 137Cs and 60Co on Titanium Oxide Films in Light Water Reactor Primary Circuit Environment.

This paper discusses the processes of the long-lived 137Cs and 60Co immobilization on titanium surfaces in simulated light water reactor primary circuit environments. This study is prompted by numerous problems in both the maintenance of equipment during reactor operation and the dismantling of the reactor after the completion of the operation, which is associated with contamination of working surfaces with long-lived radionuclides. The composition of the oxide films formed on the surface of commercial titanium alloy ПT-3B has been studied with specimens prepared in autoclave test conditions and surface samples from the pipeline sections to which the primary coolant was applied. These films on the coolant pipeline surface consist of a titanium dioxide layer tightly adhered to the pipeline metal surface and weakly fixed deposits—crystallites comprised of titanium oxides and other corrosion products (oxides and hydrated oxides of iron, nickel, chromium etc.). The radionuclide composition of the samples was studied by gamma-spectrometry. It is shown that the mechanism of titanium-surface contamination with 137Cs is by physisorption, contamination level increases upon the presence of dispersed particles. For 60Co, both sorption and deposition onto surfaces are observed.

Led source of light with high light circuit

THE PURPOSE. Consider the problems of the heat transfer process in the structural elements of the LED light source. Describe the cooling system of an LED light source using an equivalent circuit and thermal resistances. Conduct a comparative analysis of cooling systems for LED lighting devices. Perform thermodynamic calculations of the light device radiator using computer programs of automatic design systems. Suggest a way to improve the heat transfer properties of the radiator of the LED light source.METHODS. When solving the tasks set, the method of retrospective-prospective meta-analysis was used, computer programs of automatic design systems and direct determination of technical parameters using measuring instruments were used.RESULTS. The article describes the relevance of the topic, discusses the features of the heat transfer process in the structural elements of the LED light source. Thermodynamic calculations of the radiator of the lighting device were made using computer programs of automatic design systems KOMPAS and SolidWorks. The article proposes a method for improving the heat transfer properties of the radiator of an LED light source.CONCLUSION. There are many different cooling systems with their own advantages and disadvantages. The most efficient cooling systems are forced cooling systems, however, their use entails an increase in the final cost of the lighting device and a decrease in its light output due to an increase in energy consumption. Passive cooling systems are relatively cheap, but to provide effective cooling of LEDs, they must have a sufficient area of contact with the heat source, have good thermal conductivity and heat dissipation. In this case, the best way to improve the heat transfer properties of the radiator is to apply a special coating with a high heat transfer. This will increase the cooling efficiency with minimal cost without resorting to a significant change in the design features of an existing system.

A Novel Strategy for Smart Building Convergence Based on the SmartLVGrid Metamodel

Smart buildings provide opportunities for technological transformations in building environments to improve resource management, comfort, and efficiency of the systems present in these facilities. For this, Internet of Things (IoT) solutions contribute, with monitoring and remote control features, to automate these environments. However, these solutions can promote the disposal or replacement of outdated but still-needed legacy systems. Thus, a reference model that uses retrofit techniques to update pre-existing systems would be an alternative to enable smart building convergence. The lack of models that advocate this type of strategy provides an opportunity for the emergence of methods capable of filling this gap. Thus, this work presents a strategy for implementing monitoring, control, and communication resources to achieve smart building convergence in legacy building systems. This strategy consists of the use of retrofit techniques based on the adaptation of the SmartLVGrid metamodel. To validate this proposal, we developed hardware platforms and, respectively, their firmware to implement the premises established in a legacy building lighting circuit. The results obtained present a new possibility of implementing smart buildings from the retrofit of legacy infrastructures, as the pre-existing building lighting circuit obtained new functionalities and was preserved as much as possible.

LIGHT RELIANT CIRCUIT AS AN EMERGENCY LIGHTING SYSTEM

One of a person's essential needs is light. This study focuses on the feasibility of using light reliant circuits as an emergency lighting system. The product of the study is an emergency lighting system that substitutes the needed light in times of unexpected power outage. With this, the emergency lighting systems consisting of 12v strip LED lights, light resistor, battery holder, light reliant circuit, alligator clips, heat controller, metal mosfet, and ohm resistor were developed. The process requires assembling, soldering the light-dependent resistor to the gate and source of the IRF740 mosfet to provide connection to the sensor. Following the device’s development, its functionality would be evaluated in terms of its coverage range, activation time, and light intensity. The researchers used a lux meter and a tape measure to determine the range of coverage of the emergency lighting system, resulting in a distance cap of 50 lux at the lowest intensity. Results of the study showed that the emergency lighting system projected the appropriate lux at a distance of 156.3 cm (5 foot 1 inch) on average, indicating the recommended height or distance allowing the intensity to give more than a decent aid to brownout situations. Further examination of the findings reveals that there was only one alteration, which was a 0.02 millisecond difference between trial 1 and trials 2 and 3. Based on the trials, the average time length is 0.107 milliseconds. With this time length, it’s a conclusion that this emergency lighting system is responsive enough at needed times and situations and in unexpected times. The average light intensity of 86,851 lux can be detected by the emergency lighting system. The light intensity would be critical in calculating the emergency lighting system's proper distance of measurement. Therefore, it is duly recommended for the household to install the product as it yields good results based on the tests conducted.

AUTOMATIC STREET LIGHT CONTROL AND MONITORING SYSTEM

Street lighting is one of the important parts of a city’s infrastructure where the main function is to illuminate the city’s streets during dark hours of the day. Previously, the number of streets in the town and city were less. So, the street lamps were relatively simple but with the development of urbanization, the number of streets increased rapidly with high traffic density. There are several factors needed to be considered in order to design a good street lighting system such as night-time safety for community members and road users, provide public lighting at low cost and the reduction of light pollution. Initially, the street lamps were controlled manually where a control switch is set in each of the street lamps. It is called first generation of the original street light. After that, another method that was been used was optical control method. This method uses high pressure sodium lamp in their system. It can be seen that this method is widely used in the country nowadays. This method operates by setting up an optical control circuit. It lights up automatically at dusk and turns off automatically after dawn in the morning. The system utilizes the latest technology for the sources of light as LED Lamps instead of generally used street lamps such as High Pressure Sodium Lamps, etc. The LED technology is preferred as it offers several advantages over other traditional technologies. The application is designed in such a way that we place light sensors in all street light circuits, which is responsible to switch on and off automatically. Once the lights are switched on current sensors placed at every street light circuits are responsible to report problem status to the centralized system with help of GSM module attached with the circuit The system described can effectively save energy by reducing the power consumption as per requirement. Since this is a sensor based system, so it is self-controlled and automated system. The system is also flexible for any modification or further expansion such as interfacing of new sensors, connecting surveillance camera for the security purpose, etc. This project of Smart Street Light System is a cost effective, practical, eco-friendly and the safest way to save energy.

Research on the detection of arc fault in series connection of landscape power supply

Aiming at the series fault arc phenomenon in landscape lighting and the hidden dangers of electrical fires, in this paper, a landscape power supply series fault arc model is constructed and its model is simulated. The simulation results show that when a fault occurs, the arc current becomes smaller (almost zero) due to the increase in the impedance of the lighting circuit; this phenomenon is called the “current zero off” phenomenon of the fault arc current. The current zero off phenomenon of the fault arc current is the main fault feature in the landscape lighting circuit. In this paper, the wavelet algorithm is used to detect the fault current waveform. According to the fault characteristics, by judging whether the modulus maximum value of the wavelet coefficient has periodic characteristics with an interval of 100±15 sampling points, it is analyzed whether a series-type arc fault occurs. The built physical model verifies the feasibility and correctness of the arc detection algorithm. The research results of this paper have certain reference value for the detection and application of fault arc.