scholarly journals Parasitic-Based Active Gate Driver Improving the Turn-On Process of 1.7 kV SiC Power MOSFET

2021 ◽  
Vol 11 (5) ◽  
pp. 2210
Author(s):  
Bartosz Lasek ◽  
Przemysław Trochimiuk ◽  
Rafał Kopacz ◽  
Jacek Rąbkowski
Keyword(s):  
Gate Voltage ◽  
Drain Current ◽  
Theoretical Background ◽  
Dissipated Energy ◽  
Feedback Signal ◽  
Power Losses ◽  
Turn On ◽  
Speed Up ◽  
Gate Driver ◽  
The Right

This article discusses an active gate driver for a 1.7 kV/325 A SiC MOSFET module. The main purpose of the driver is to adjust the gate voltage in specified moments to speed up the turn-on cycle and reduce the amount of dissipated energy. Moreover, an adequate manipulation of the gate voltage is necessary as the gate current should be reduced during the rise of the drain current to avoid overshoots and oscillations. The gate voltage is switched at the right moments on the basis of the feedback signal provided from a measurement of the voltage across the parasitic source inductance of the module. This approach simplifies the circuit and provides no additional power losses in the measuring circuit. The paper contains the theoretical background and detailed description of the active gate driver design. The model of the parasitic-based active gate driver was verified using the double-pulse procedure both in Saber simulations and laboratory experiments. The active gate driver decreases the turn-on energy of a 1.7 kV/325 A SiC MOSFET by 7% comparing to a conventional gate driver (VDS = 900 V, ID = 270 A, RG = 20 Ω). Furthermore, the proposed active gate driver lowered the turn-on cycle time from 478 to 390 ns without any serious oscillations in the main circuit.

Reosquido Desalinasi Metode Evaporasi dengan Ultraviolet Berbasis Mikrokontroller

2018 ◽  
Vol 3 (2) ◽  
pp. 38-47
Author(s):  
Muhammad Abdul Azis ◽  
Nuryake Fajaryati
Keyword(s):  
Temperature Measurement ◽  
Fresh Water ◽  
Sea Water ◽  
Evaporation Process ◽  
Heater Element ◽  
The Third ◽  
Turn On ◽  
Speed Up ◽  
Arduino Uno

This research aims to create a Reosquido desalination tool for evaporation methods using a microcontroller. This tool can control the temperature to speed up the evaporation process in producing fresh water. The method applied to Reosquido desalination uses Evaporation. The first process before evaporation is the detection of temperature in sea water that will be heated using an element heater. The second process of temperature measurement is to turn off and turn on the Arduino Uno controlled heater, when the temperature is less than 80 ° then the heater is on. The third process is evaporation during temperatures between 80 ° to 100 °, evaporation water sticks to the glass roof which is designed by pyramid. Evaporated water that flows into the reservoir is detected by its solubility TDS value. The fourth process is heater off when the temperature is more than 100 °. Based on the results of the testing, the desalination process using a microcontroller controlled heater can speed up the time up to 55% of the previous desalination process tool, namely manual desalination prsoes without using the heater element controlled by the temperature and controlled by a microcontroller which takes 9 hours. Produces fresh water as much as 30ml from 3000ml of sea water, so that it can be compared to 1: 100.

scholarly journals Equivalent Circuit Modeling of a Dual-Gate Graphene FET

Electronics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 63
Author(s):  
Saima Hasan ◽  
Abbas Z. Kouzani ◽  
M A Parvez Mahmud
Keyword(s):  
Equivalent Circuit ◽  
Gate Voltage ◽  
Voltage Dependence ◽  
Drain Current ◽  
Bilayer Graphene ◽  
Circuit Modeling ◽  
Equivalent Circuit Modeling ◽  
Dual Gate ◽  
Source Voltage ◽  
Transit Frequency

This paper presents a simple and comprehensive model of a dual-gate graphene field effect transistor (FET). The quantum capacitance and surface potential dependence on the top-gate-to-source voltage were studied for monolayer and bilayer graphene channel by using equivalent circuit modeling. Additionally, the closed-form analytical equations for the drain current and drain-to-source voltage dependence on the drain current were investigated. The distribution of drain current with voltages in three regions (triode, unipolar saturation, and ambipolar) was plotted. The modeling results exhibited better output characteristics, transfer function, and transconductance behavior for GFET compared to FETs. The transconductance estimation as a function of gate voltage for different drain-to-source voltages depicted a proportional relationship; however, with the increase of gate voltage this value tended to decline. In the case of transit frequency response, a decrease in channel length resulted in an increase in transit frequency. The threshold voltage dependence on back-gate-source voltage for different dielectrics demonstrated an inverse relationship between the two. The analytical expressions and their implementation through graphical representation for a bilayer graphene channel will be extended to a multilayer channel in the future to improve the device performance.

scholarly journals Perceiving numerosity does not cause automatic shifts of spatial attention

2021 ◽  
Author(s):  
Michele Pellegrino ◽  
Mario Pinto ◽  
Fabio Marson ◽  
Stefano Lasaponara ◽  
Fabrizio Doricchi
Keyword(s):  
Spatial Attention ◽  
Colour Change ◽  
Simultaneous Presentation ◽  
Variable Delay ◽  
Large Magnitude ◽  
Small Magnitude ◽  
Spatial Component ◽  
Speed Up ◽  
The Right

AbstractIt is debated whether the representation of numbers is endowed with a directional-spatial component so that perceiving small-magnitude numbers triggers leftward shifts of attention and perceiving large-magnitude numbers rightward shifts. Contrary to initial findings, recent investigations have demonstrated that centrally presented small-magnitude and large-magnitude Arabic numbers do not cause leftward and rightward shifts of attention, respectively. Here we verified whether perceiving small or large non-symbolic numerosities (i.e., clouds of dots) drives attention to the left or the right side of space, respectively. In experiment 1, participants were presented with central small (1, 2) vs large-numerosity (8, 9) clouds of dots followed by an imperative target in the left or right side of space. In experiment 2, a central cloud of dots (i.e., five dots) was followed by the simultaneous presentation of two identical dot-clouds, one on the left and one on the right side of space. Lateral clouds were both lower (1, 2) or higher in numerosity (8, 9) than the central cloud. After a variable delay, one of the two lateral clouds turned red and participants had to signal the colour change through a unimanual response. We found that (a) in Experiment 1, the small vs large numerosity of the central cloud of dots did not speed up the detection of left vs right targets, respectively, (b) in Experiment 2, the detection of colour change was not faster in the left side of space when lateral clouds were smaller in numerosity than the central reference and in the right side when clouds were larger in numerosity. These findings show that perceiving non-symbolic numerosity does not cause automatic shifts of spatial attention and suggests no inherent association between the representation of numerosity and that of directional space.

scholarly journals A Novel Gate Drive Circuit for Suppressing Turn-on Oscillation of Non-Kelvin Packaged SiC MOSFET

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2449
Author(s):  
Hongyan Zhao ◽  
Jiangui Chen ◽  
Yan Li ◽  
Fei Lin
Keyword(s):  
Thermal Conductivity ◽  
Breakdown Voltage ◽  
Basic Principle ◽  
Double Pulse ◽  
Experimental Results ◽  
Switching Frequency ◽  
Turn On ◽  
Proof Testing ◽  
Gate Driver ◽  
Drive Circuit

Compared with a silicon MOSFET device, the SiC MOSFET has many benefits, such as higher breakdown voltage, faster action speed and better thermal conductivity. These advantages enable the SiC MOSFET to operate at higher switching frequencies, while, as the switching frequency increases, the turn-on loss accounts for most of the loss. This characteristic severely limits the applications of the SiC MOSFET at higher switching frequencies. Accordingly, an SRD-type drive circuit for a SiC MOSFET is proposed in this paper. The proposed SRD-type drive circuit can suppress the turn-on oscillation of a non-Kelvin packaged SiC MOSFET to ensure that the SiC MOSFET can work at a faster turn-on speed with a lower turn-on loss. In this paper, the basic principle of the proposed SRD-type drive circuit is analyzed, and a double pulse platform is established. For the purpose of proof-testing the performance of the presented SRD-type drive circuit, comparisons and experimental verifications between the traditional gate driver and the proposed SRD-type drive circuit were conducted. Our experimental results finally demonstrate the feasibility and effectiveness of the proposed SRD-type drive circuit.

scholarly journals Simulation of Drastic Lag Phenomena in GaAs-Based FETs for Large Voltage Swing

VLSI Design ◽  
2001 ◽  
Vol 13 (1-4) ◽  
pp. 245-249
Author(s):  
K. Horio ◽  
Y. Mitani ◽  
A. Wakabayashi ◽  
N. Kurosawa
Keyword(s):  
Surface State ◽  
Gate Voltage ◽  
Current Transient ◽  
Drain Voltage ◽  
Turn On ◽  
Voltage Swing

Turn-on characteristics of GaAs MESFETs and HEMTs are simulated when the gate voltage is changed abruptly. The gate-lag or slow current transient becomes more pronounced when the off-state gate voltage is more negative, because the surface-state effects or substrate-trap effects become more significant. Changes of I–V curves of GaAs MESFETs, when the drain voltage is swept with different speeds, are also simulated. When the swept time is short, the curve shows overshoot-like behavior and the kink disappears, indicating that the I–V characteristics should be quite different between DC and RF conditions.

scholarly journals A nudge in the right direction: the role of food choice architecture in changing populations' diets

2021 ◽  
pp. 1-12
Author(s):  
H. Ensaff
Keyword(s):  
Food Choice ◽  
Empirical Studies ◽  
Food Selection ◽  
Theoretical Background ◽  
Choice Architecture ◽  
Different Populations ◽  
The Right ◽  
Care Costs

Populations' diets typically fall short of recommendations. The implication of this on ill health and quality of life is well established, as are the subsequent health care costs. An area of growing interest within public health nutrition is food choice architecture; how a food choice is framed and its influence on subsequent food selection. In particular, there is an appeal to manipulating the choice architecture in order to nudge individuals' food choice. This review outlines the current understanding of food choice architecture, theoretical background to nudging and the evidence on the effectiveness of nudge strategies, as well as their design and implementation. Interventions emphasising the role of nudge strategies have investigated changes to the accessibility, availability and presentation of food and the use of prompts. Empirical studies have been conducted in laboratories, online and in real-world food settings, and with different populations. Evidence on the effectiveness of nudge strategies in shifting food choice is encouraging. Underpinning mechanisms, not yet fully explicated, are proposed to relate to salience, social norms and the principle of least effort. Emerging evidence points to areas for development including the effectiveness of choice architecture interventions with different and diverse populations, and the combined effect of multiple nudges. This, alongside further examination of theoretical mechanisms and guidance to engage and inspire across the breadth of food provision, is critical. In this way, the potential of choice architecture to effect meaningful change in populations' diets will be realised.

scholarly journals Sensitivity Study of Polysilicon Nanowire Based on Scattering and Quantum Mechanics Models

2018 ◽  
Vol 201 ◽  
pp. 01002
Author(s):  
Aanand ◽  
Gene Sheu ◽  
Syed Sarwar Imam ◽  
Shao Wei Lu ◽  
Shao-Ming Yang ◽  
...  
Keyword(s):  
Quantum Mechanics ◽  
Gate Voltage ◽  
Drain Current ◽  
Sensitivity Study ◽  
Compact Model ◽  
Current Sensitivity ◽  
Back Gate ◽  
Mechanics Model ◽  
Theoretical Predictions ◽  
Current Characteristics

In this paper, we report nanowire drain saturation current sensitivity property to measure femtomol level change in drain current due to different proteins i.e. DNA with numerical simulation and fabricated polysilicon nanowire based on the theoretical predictions. In addition, the drain current will also be affected by the back-gate voltage and will increase as the back-gate voltage increases. A 3-dimensional Synopsis tool is used to investigate the drain current behavior for a polysilicon nanowire. The scattering compact model reported result of detailed numerical calculation shows in good agreement, indicating the usefulness of scattering compact model. Whereas 3D synopsis unable to explain the whole region of the drain current characteristics in linear region which uses quantum mechanics model approach.

The Changing Ethics of Climate Change

2014 ◽  
Vol 28 (3) ◽  
pp. 351-358 ◽  
Author(s):  
Daniel Mittler
Keyword(s):  
Climate Change ◽  
Power Plant ◽  
Moral Obligation ◽  
Environmental Movement ◽  
Health Problems ◽  
Renewable Energies ◽  
Car Use ◽  
The Face ◽  
Speed Up ◽  
The Right

Many in the environmental movement have argued in recent years that in order to speed up climate actions we should take the ethics out of the climate change debate. Focusing on the moral obligation to act or on the effects of climate change on the most vulnerable was often judged to render the discourse too “heavy,” “negative,” or “difficult.” Many also deemed it unnecessary. After all, renewable energies, better designed cities that allow for reduced car use, and power plant regulations that lead to cleaner local air—to take just three examples—all have real and substantial benefits unrelated to the fact that they are “the right thing to do” in the face of climate change. They create jobs, reduce health problems and costs, and make society fitter.

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