scholarly journals ANALYSIS OF LOW-FREQUENCY RIPPLE TRANSMISSION TO DCM OPERATING CONVERTERS FOR LED DRIVERS

2020 ◽  
Vol 25 (1) ◽  
pp. 9-18
Author(s):  
Jean Santis Brand ◽  
Maicol Flores de Melo ◽  
José Marcos Alonso Álvarez ◽  
Marco Antônio Dalla Costa
Keyword(s):  
Low Frequency ◽  
Led Drivers

scholarly journals Analysis and Control of Electrolytic Capacitor-Less LED Driver Based on Harmonic Injection Technique

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3030 ◽  
Author(s):  
Mahmoud Nassary ◽  
Mohamed Orabi ◽  
Manuel Arias ◽  
Emad Ahmed ◽  
El-Sayed Hasaneen
Keyword(s):  
Power Factor ◽  
Low Frequency ◽  
Buck Converter ◽  
Electrolytic Capacitor ◽  
Injection Technique ◽  
Led Driver ◽  
Harmonic Injection ◽  
Output Capacitor ◽  
And Control ◽  
Led Drivers

AC-DC LED drivers may have a lifespan shorter than the lifespan of LED chips if electrolytic capacitors are used in their construction. Using film capacitors solves this problem but, as their capacitance is considerably lower, the low-frequency ripple will increase. Solving this problem by limiting the output ripple to safe values is possible by distorting the input current using harmonic injection technique, as long as these harmonics still complies with Power Factor Regulations (Energy Star). This harmonic injection alleviates the requirements imposed to the output capacitor in order to limit the low-frequency ripple in the output. This idea is based on the fact that LEDs can be driven by pulsating current with a limited Peak-To-Average Ratio (PTAR) without affecting their performance. By considering the accurate model of LEDs, instead of the typical equivalent resistance, this paper presents an improved and more reliable calculation of the intended harmonic injection. Wherein, its orders and values can be determined for each input/output voltage to obtain the specified PTAR and Power Factor (PF). Also, this harmonic injection can be simply implemented using a single feedback loop, its control circuit has features of wide bandwidth, simple, single-loop and lower cost. A 21W AC-DC buck converter is built to validate the proposed circuit and the derived mathematical model and it complies with IEC61000 3-2 class D standard.

Analysis of low‐frequency current ripple transmission in series‐resonant LED drivers

2015 ◽  
Vol 51 (9) ◽  
pp. 716-717 ◽  
Author(s):  
M.F. Melo ◽  
W.D. Vizzotto ◽  
L. Chies ◽  
M.A. Dalla Costa ◽  
J.M. Alonso
Keyword(s):  
Low Frequency ◽  
Series Resonant ◽  
In Series ◽  
Led Drivers ◽  
Current Ripple ◽  
Frequency Current

Optimized Design of a Wide-Bandwidth Controller for Low-Frequency Ripple Compensation in Offline LED Drivers

2018 ◽  
Vol 6 (3) ◽  
pp. 1166-1178
Author(s):  
Guilherme Marcio Soares ◽  
Pedro S. Almeida ◽  
Leonardo W. de Oliveira ◽  
J. Marcos Alonso ◽  
Henrique A. C. Braga
Keyword(s):  
Low Frequency ◽  
Optimized Design ◽  
Wide Bandwidth ◽  
Led Drivers

scholarly journals HYBRID DUAL-LOOP CONTROL FOR CURRENT REGULATION AND LOW-FREQUENCY RIPPLE REJECTION IN LED DRIVERS

2021 ◽  
Vol 26 (03) ◽  
pp. 1-13
Author(s):  
Maikel Fernando Menke ◽  
José Marcos Alonso Álvarez ◽  
Rodrigo V. Tambara ◽  
Álysson Raniere Seidel
Keyword(s):  
Low Frequency ◽  
Current Regulation ◽  
Loop Control ◽  
Led Drivers

Analysis of Low Frequency Ripple Transmission in LED Drivers

2018 ◽  
Author(s):  
Maicol F. de Melo ◽  
Jean S. Brand ◽  
Renan R. Duarte ◽  
Marco A. Dalla Costa ◽  
J. Marcos Alonso ◽  
...  
Keyword(s):  
Low Frequency ◽  
Led Drivers

A Study on the Fine Structure of the Lateral Line Organ of the Sea Eel

1973 ◽  
Vol 31 ◽  
pp. 648-649
Author(s):  
K. Hama
Keyword(s):  
Fine Structure ◽  
Electron Microscope ◽  
Lateral Line ◽  
Low Frequency ◽  
Sensory Cells ◽  
Apical Surface ◽  
Voltage Electron ◽  
Sensory Epithelia ◽  
Low Frequency Vibration ◽  
Transmission Electron

The lateral line organs of the sea eel consist of canal and pit organs which are different in function. The former is a low frequency vibration detector whereas the latter functions as an ion receptor as well as a mechano receptor.The fine structure of the sensory epithelia of both organs were studied by means of ordinary transmission electron microscope, high voltage electron microscope and of surface scanning electron microscope.The sensory cells of the canal organ are polarized in front-caudal direction and those of the pit organ are polarized in dorso-ventral direction. The sensory epithelia of both organs have thinner surface coats compared to the surrounding ordinary epithelial cells, which have very thick fuzzy coatings on the apical surface.

Lectin Binding to Human Breast Tumor Cells

1976 ◽  
Vol 34 ◽  
pp. 34-35
Author(s):  
Robert E. Nordquist ◽  
J. Hill Anglin ◽  
Michael P. Lerner
Keyword(s):  
Carcinoma Cell ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Low Frequency ◽  
Breast Carcinoma Cell Line ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Duct Carcinoma ◽  
Specific Antigens ◽  
Ricin Agglutinin

A human breast carcinoma cell line (BOT-2) was derived from an infiltrating duct carcinoma (1). These cells were shown to have antigens that selectively bound antibodies from breast cancer patient sera (2). Furthermore, these tumor specific antigens could be removed from the living cells by low frequency sonication and have been partially characterized (3). These proteins have been shown to be around 100,000 MW and contain approximately 6% hexose and hexosamines. However, only the hexosamines appear to be available for lectin binding. This study was designed to use Concanavalin A (Con A) and Ricinus Communis (Ricin) agglutinin for the topagraphical localization of D-mannopyranosyl or glucopyranosyl and D-galactopyranosyl or DN- acetyl glactopyranosyl configurations on BOT-2 cell surfaces.

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