Search for: linear-regulators
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    A low loss linear voltage regulator for high voltage dc power supplies based on adjustable inductors

    , Article 11th Power Electronics, Drive Systems, and Technologies Conference, PEDSTC 2020, 4 February 2020 through 6 February 2020 ; 2020 Osanlo, M ; Pouresmaeil, K ; Kaboli, S ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    High voltage power supplies are widely used in telecommunication systems. To better utilize these power supplies, voltage should be stabilized at a certain level. In this application, in case of changing voltage, the desired output parameters will change, such as RF output power quality. Various methods have been proposed to stabilize the voltage at acceptable levels. One of the most commonly used methods is use of switching regulators that are considered for high efficiency in comparison with linear regulators. But the use of these regulators also has problems. One of these problems is electromagnetic interference which is very important in telecommunication systems. Therefore, the need for... 

    Design and Construction of High-voltage Linear Regulator with Minimal Losses for Power Supply of Microwave Tube Cathode

    , M.Sc. Thesis Sharif University of Technology Osanloo, Mohsen (Author) ; Kaboli, Shahriyar (Supervisor)
    Microwave tubes are widely used in the telecommunications transmitters. high voltage power supplies are used to feed them. According to the specifications that arises for microwave tubes, To take advantage of these tubes need to maintain and stabilize voltage in a certain amount to be felt. If the tube supply voltage changes, the desired output parameters such as RF output power quality will change. To stabilize the voltage is within acceptable limits provided in different ways. One common method is the use of switching regulators due to the high efficiency compared to linear regulators considered. But it also will bring problems. Some of these problems can be pointed to electromagnetic... 

    Design and Fabrication of DC-DC Buck Converter and LDO with Tunable Voltage Conversion Ratio in a wide Range in 0.18µm-HV BCD Process

    , M.Sc. Thesis Sharif University of Technology Tafaghodi Jami, Sadra (Author) ; Medi, Ali (Supervisor) ; Zolghadri, Mohammad Reza (Co-Supervisor)
    By reducing the size of the transistor, it is possible to implement systems on a chip. For this puspose, these chips require different supply voltage levels. Therefore, two types of linear and switching converters are used to convert DC voltage level. At high convertion ratios, linear regulators have lower efficiencies than switching converters. However, in switching converters, due to their nature of functionality, very high efficiencies (near 100 percent) can be achieved. The advantages of linear regulators include low output voltage ripple, no need for off-chip elements, low noise, and simplicity. For this reason, a linear regulator is usually used in the output of the switching... 

    An Extremely low ripple high voltage power supply for pulsed current applications

    , Article IEEE Transactions on Power Electronics ; Volume 35, Issue 8 , 2020 , Pages 7991-8001 Zarghani, M ; Mohsenzade, S ; Hadizade, A ; Kaboli, S ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    This article describes the development of an 18 kV, 30 kW power supply for a pulsed current load with the maximum current of 20 A and a di/dt equal to 100 A/μs. The achieved output ripple is less than 0.01%. In such a high level of precision, the most important issues are considerable difference between the instantaneous and average output powers, as well as insufficient reaction speed of the converter to the fast load change. Very low level of the voltage feedback and its sensitivity to the noise. The first issue necessitates a notable overdesign of the converter switches if the output voltage precision is dedicated to the converter. The second issue raises the problems relevant to... 

    Design and Fabrication of Buck-Boost DC-DC Converter and Linear Regulator With Digitally-Tunable Output Voltage in 0.18µm-HV BCD CMOS Process

    , M.Sc. Thesis Sharif University of Technology Kargaran, Masoud (Author) ; Medi, Ali (Supervisor)
    In this project, an inverting Buck-Boost converter with two negative linear regulator is designed, implemented and measured in CMOS 0.18μm-HV BCD technology. Input voltage of Buck-Boost converter can vary from +15V to +28 and output voltage is digitally adjustable from -1V to -10V. Maximum output current of the converter is 300mA. A current mode controller and a lag compensator is used to control the converter. A high speed highside current sensor is designed and used in current mode controller. Sampled current of the current sensor is also used in a current limit circuitary to limit the maximum current of highside switch. Two negative linear regulators are placed at the output of the... 

    Optimal robust control of drug delivery in cancer chemotherapy: A comparison between three control approaches

    , Article Computer Methods and Programs in Biomedicine ; Volume 112, Issue 1 , 2013 , Pages 69-83 ; 01692607 (ISSN) Moradi, H ; Vossoughi, G ; Salarieh, H ; Sharif University of Technology
    During the drug delivery process in chemotherapy, both of the cancer cells and normal healthy cells may be killed. In this paper, three mathematical cell-kill models including log-kill hypothesis, Norton-Simon hypothesis and Emax hypothesis are considered. Three control approaches including optimal linear regulation, nonlinear optimal control based on variation of extremals and H∞-robust control based on μ-synthesis are developed. An appropriate cost function is defined such that the amount of required drug is minimized while the tumor volume is reduced. For the first time, performance of the system is investigated and compared for three control strategies; applied on three nonlinear models...