scholarly journals Smartphone-Driven Low-Power Light-Emitting Device

2017 ◽  
Vol 2017 ◽  
pp. 1-6
Author(s):  
Hea-Ja An ◽  
Kyung-Won Kim ◽  
Mun-Ho Ryu ◽  
Han-Yeong Oh ◽  
Nam-Gyun Kim ◽  
...  
Keyword(s):  
Low Power ◽  
Alternative Medicine ◽  
Laser Therapy ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Control Unit ◽  
Smartphone Application ◽  
Recent Past ◽  
Light Emitting ◽  
Low Level

Low-level light (laser) therapy (LLLT) has been widely researched in the recent past. Existing LLLT studies were performed based on laser. Recently, studies using LED have increased. This study presents a smartphone-driven low-power light-emitting device for use in colour therapy as an alternative medicine. The device consists of a control unit and a colour probe. The device is powered by and communicates with a smartphone using USB On-The-Go (OTG) technology. The control unit controls emitting time and intensity of illumination with the configuration value of a smartphone application. Intensity is controlled by pulse width modulation (PWM) without feedback. A calibration is performed to resolve a drawback of no feedback. To calibrate, intensity is measured in every 10 percent PWM output. PWM value is linearly calibrated to obtain accurate intensity. The device can control the intensity of illumination, and so, it can find application in varied scenarios.

scholarly journals Novel Intelligent and Sensorless Proportional Valve Control with Self-Learning Ability

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Bayram Akdemir
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Low Voltage ◽  
Control Unit ◽  
Control Signal ◽  
Learning Ability ◽  
Learning Abilities ◽  
Valve Control ◽  
Self Learning

Linear control is widely used for any fluid or air flows in many automobile, robotics, and hydraulics applications. According to signal level, valve can be controlled linearly. But, for many valves, hydraulics or air is not easy to control proportionally because of flows dynamics. As a conventional solution, electronic driver has up and down limits. After manually settling up and down limits, control unit has proportional blind behavior between two points. This study offers a novel valve control method merging pulse width and amplitude modulation in the same structure. Proposed method uses low voltage AC signal to understand the valve position and uses pulse width modulation for power transfer to coil. DC level leads to controlling the valve and AC signal gives feedback related to core moving. Any amplitude demodulator gives core position as voltage. Control unit makes reconstruction using start and end points to obtain linearization at zero control signal and maximum control signal matched to minimum demodulated amplitude level. Proposed method includes self-learning abilities to keep controlling in hard environmental conditions such as dust, temperature, and corrosion. Thus, self-learning helps to provide precision control for hard conditions.

Low level laser therapy efficacy on orthodontic induced pain management: A narrative review

2020 ◽  
Author(s):  
Amir Hossein Mirhashemi ◽  
Leila Jazi ◽  
Aryan Hesamarefi
Keyword(s):  
Pain Relief ◽  
Low Power ◽  
Laser Therapy ◽  
Animal Studies ◽  
New Technologies ◽  
Low Level Laser Therapy ◽  
Power Laser ◽  
Low Level ◽  
Level Laser ◽  
Key Terms

Introduction: Pain control in patients undergoing orthodontic treatment is one of the major challenges of such treatments. The use of new technologies such as Laser offers promising results in this field. The goal of this study is to survey the works on effect of low-power laser on pain relief during orthodontic treatments. Methodology: The key terms including “orthodontics, reduction, pain, low level, power, laser and laser therapy” alone as well as combinations. those key terms were used to search the databases including “Google Scholar, Science Direct, and PubMed”. The review of collected sources was done which led to selection of 557 papers. The validation was done through CONSORT guidelines. Results: After review of selected papers, 34 studies including 32 human studies and 2 animal studies were selected. Conclusion: The positive findings of reviewed studies on use of laser therapy suggest that low power laser could be effective on pain relief. Conducting further studies on this subject will be beneficial.

scholarly journals Modified SVPWM Algorithm for Three Level VSI With Synchronized and Symmetrical Waveforms

2019 ◽  
pp. 246-266
Author(s):  
Jalla Sowndarya ◽  
M. Shekar ◽  
N. V. Vinay Kumar
Keyword(s):  
Electromagnetic Interference ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Control Unit ◽  
Computational Time ◽  
Space Vector ◽  
Multilevel Converters ◽  
Switching Times ◽  
Increasing Demand

To generate the required reference vector than triangle comparison based PWM techniques for three-level inverters the space vector based PWM (SVPWM) strategies contain broader choice of switching sequences. This space vector based PWM technique involves in various steps. These steps are computationally exhaustive. The SVPWM has been used in three phase inverter control system. The center-aligned PWM is the most effective way for the Microprocessor Control Unit implementation of the SVPWM, because it can easily generate the center aligned PWM of the multilevel inverters for generation of the signal of space vector pulse width modulation (SVPWM), this concept brings out the method. The inverter leg switching times are generated by this algorithm and middle vector switching times are centered in a sampled interval. The proposed algorithm does not require any sector identification. And it reduces the computational time as a result. The adjacent voltage space vectors are forming the small triangles it is called sectors. Multilevel converters can meet the increasing demand of power ratings and power quality associated with reduced harmonic distortion and lower electromagnetic interference. Furthermore to optimize switching waveforms, space vector pulse-width modulation algorithms offer great flexibility among them. Finally the results are verified through MATLAB/SIMULINK

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