Huang-Lin Error Correcting Code and the circuit

Bingshan Lin,Yuanshan Huang,Zhongquan Ren 대한전자공학회 1995 International Conference on Electronics, Informati Vol.1995 No.8

A retrospective analysis of 20-year data of the surgical management of ulcerative colitis patients in Taiwan: a study of Taiwan Society of Inflammatory Bowel Disease

( Chun-chi Lin ),( Shu-chen Wei ),( Been-ren Lin ),( Wen-sy-tsai ),( Jinn-shiun Chen ),( Tzu-chi Hsu ),( Wei-chen Lin ),( Tien-yu Huang ),( Te-hsin Chao ),( Hung-hsin Lin ),( Jau-min Wong ),( Jen-kou 대한장연구학회 2016 Intestinal Research Vol.14 No.3

Background/Aims: With the recent progress in medical treatment, surgery still plays a necessary and important role in treating ulcerative colitis (UC) patients. In this study, we analyzed the surgical results and outcomes of UC in Taiwan in the recent 20 years, via a multi-center study through the collaboration of Taiwan Society of IBD. Methods: A retrospective analysis of surgery data of UC patients from January 1, 1995, through December 31, 2014, in 6 Taiwan major medical centers was conducted. The patients’ demographic data, indications for surgery, and outcome details were recorded and analyzed. Results: The data of 87 UC patients who received surgical treatment were recorded. The median post-operative follow-up duration was 51.1 months and ranged from 0.4 to 300 months. The mean age at UC diagnosis was 45.3±16.0 years and that at operation was 48.5±15.2 years. The 3 leading indications for surgical intervention were uncontrolled bleeding (16.1%), perforation (13.8%), and intractability (12.6%). In total, 27.6% of surgeries were performed in an emergency setting. Total or subtotal colectomy with rectal preservation (41.4%) was the most common operation. There were 6 mortalities, all due to sepsis. Emergency operation and low pre-operative albumin level were significantly associated with poor survival (P =0.013 and 0.034, respectively). Conclusions: In the past 20 years, there was no significant change in the indications for surgery in UC patients. Emergency surgeries and low pre-operative albumin level were associated with poor survival. Therefore, an optimal timing of elective surgery for people with poorly controlled UC is paramount.

New Three-Level PWM DC/DC Converter - Analysis, Design and Experiments

Lin, Bor-Ren,Chen, Chih-Chieh The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.1

This paper studies a new three-level pulse-width modulation (PWM) resonant converter for high input voltage and high load current applications. In order to use high frequency power MOSFETs for high input voltage applications, a three-level DC converter with two clamped diodes and a flying capacitor is adopted in the proposed circuit. For high load current applications, the secondary sides of the proposed converter are connected in parallel to reduce the size of the magnetic core and copper windings and to decrease the current rating of the rectifier diodes. In order to share the load current and reduce the switch counts, three resonant converters with the same active switches are adopted in the proposed circuit. Two transformers with a series connection in the primary side and a parallel connection in the secondary side are adopted in each converter to balance the secondary side currents. To overcome the drawback of a wide range of switching frequencies in conventional series resonant converters, the duty cycle control is adopted in the proposed circuit to achieve zero current switching (ZCS) turn-off for the rectifier diodes and zero voltage switching (ZVS) turn-on for the active switches. Finally, experimental results are provided to verify the effectiveness of the proposed converter.

Hybrid ZVS Converter with a Wide ZVS Range and a Low Circulating Current

Lin, Bor-Ren,Chen, Jia-Sheng The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.3

This paper presents a new hybrid soft switching dc-dc converter with a low circulating current and high circuit efficiency. The proposed hybrid converter includes two sub-converters sharing two power switches. One is a three-level PWM converter and the other is a LLC converter. The LLC converter and the three-level converter share the lagging-leg switches and extend the zero-voltage switching (ZVS) range of the lagging-leg switches from nearly zero to full load since the LLC converter can be operated at f_sw (switching frequency) $\approx$ f_r (series resonant frequency). A passive snubber is used on the secondary side of the three-level converter to decrease the circulating current on the primary side, especially at high input voltage and full load conditions. Thus, the conduction losses due to the circulating current are reduced. The output sides of the two converters are connected in series. Energy can be transferred from the input voltage to the output load within the whole switching period. Finally, the effectiveness of the proposed converter is verified by experiments with a 1.44kW prototype circuit.

Implementation of a ZVS Three-Level Converter with Series-Connected Transformers

Lin, Bor-Ren The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.2

This paper studies a soft switching DC/DC converter to achieve zero voltage switching (ZVS) for all switches under a wide range of load condition and input voltage. Two three-level PWM circuits with the same power switches are adopted to reduce the voltage stress of MOSFETs at $V_{in}/2$ and achieve load current sharing. Thus, the current stress and power rating of power semiconductors at the secondary side are reduced. The series-connected transformers are adopted in each three-level circuit. Each transformer can be operated as an inductor to smooth the output current or a transformer to achieve the electric isolation and power transfer from the input side to the output side. Therefore, no output inductor is needed at the secondary side. Two center-tapped rectifiers connected in parallel are used at the secondary side to achieve load current sharing. Due to the resonant behavior by the resonant inductance and resonant capacitance at the transition interval, all switches are turned on at ZVS. Experiments based on a 1kW prototype are provided to verify the performance of proposed converter.

Half-Bridge Zero Voltage Switching Converter with Three Resonant Tanks

Lin, Bor-Ren,Lin, Wei-Jie The Korean Institute of Power Electronics 2014 JOURNAL OF POWER ELECTRONICS Vol.14 No.5

This paper presents a zero voltage switching (ZVS) converter with three resonant tanks. The main advantages of the proposed converter are its ability to reduce the switching losses on the power semiconductors, decrease the current stress of the passive components at the primary side, and reduce the transformer secondary windings. Three resonant converters with the same power switches are adopted at the low voltage side to reduce the current rating on the transformer windings. Using a series-connection of the transformer secondary windings, the primary side currents of the three resonant circuits are balanced to share the load power. As a result, the size of both the transformer core and the bobbin are reduced. Based on the circuit characteristics of the resonant converter, the power switches are turned on at ZVS. The rectifier diodes can be turned off at zero current switching (ZCS) if the switching frequency is less than the series resonant frequency. Therefore, the reverse recovery losses on the rectifier diodes are overcome. Experiments with a 1.6kW prototype are presented to verify the effectiveness of the proposed converter.

Interleaved ZVS Resonant Converter with a Parallel-Series Connection

Lin, Bor-Ren,Shen, Sin-Jhih The Korean Institute of Power Electronics 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.4

This paper presents an interleaved resonant converter with a parallel-series transformer connection in order to achieve ripple current reduction at the output capacitor, zero voltage turn-on for the active switches, zero current turn-off for the rectifier diodes, less voltage stress on the rectifier diodes, and less current stress on the transformer primary windings. The primary windings of the two transformers are connected in parallel in order to share the input current and to reduce the root-mean-square (rms) current on the primary windings. The secondary windings of the two transformers are connected in series in order to ensure that the transformer primary currents are balanced. A full-wave diode rectifier is used at the output side to clamp the voltage stress of the rectifier diode at the output voltage. Two circuit modules are operated with the interleaved PWM scheme so that the input and output ripple currents are reduced. Based on the resonant behavior, all of the active switches are turned on under zero voltage switching (ZVS), and the rectifier diodes are turned off under zero current switching (ZCS) if the operating switching frequency is less than the series resonant frequency. Finally, experiments with a 1kW prototype are described to verify the effectiveness of the proposed converter.

Implementation of an Interleaved AC/DC Converter with a High Power Factor

Lin, Bor-Ren,Lin, Li-An The Korean Institute of Power Electronics 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.3

An interleaved bridgeless buck-boost AC/DC converter is presented in this paper to achieve the characteristics of low conduction loss, a high power factor and low harmonic and ripple currents. There are only two power semiconductors in the line current path instead of the three power semiconductors in a conventional boost AC/DC converter. A buck-boost converter operated in the boundary conduction mode (BCM) is adopted to control the active switches to achieve the following characteristics: no diode reverse recovery problem, zero current switching (ZCS) turn-off of the rectifier diodes, ZCS turn-on of the power switches, and a low DC bus voltage to reduce the voltage stress of the MOSFETs in the second DC/DC converter. Interleaved pulse-width modulation (PWM) is used to control the switches such that the input and output ripple currents are reduced such that the output capacitance can be reduced. The voltage doubler topology is adopted to double the output voltage in order to extend the useable energy of the capacitor when the line voltage is off. The circuit configuration, principle operation, system analysis, and a design example are discussed and presented in detail. Finally, experiments on a 500W prototype are provided to demonstrate the performance of the proposed converter.

Analysis and Implementation of a DC-DC Converter with an Active Snubber

Lin, Bor-Ren,Lin, Li-An The Korean Institute of Power Electronics 2011 JOURNAL OF POWER ELECTRONICS Vol.11 No.6

This paper presents a soft switching converter to achieve the functions of zero voltage switching (ZVS) turn-on for the power switches and dc voltage step-up. Two circuit modules are connected in parallel in order to achieve load current sharing and to reduce the size of the transformer core. An active snubber is connected between two transformers in order to absorb the energy stored in the leakage and magnetizing inductances and to limit the voltage stresses across the switches. During the commutation stage of the two complementary switches, the output capacitance of the two switches and the leakage inductance of the transformers are resonant. Thus, the power switches can be turned on under ZVS. No output filter inductor is used in the proposed converter and the voltage stresses of the output diodes is clamped to the output voltage. The circuit configuration, the operation principles and the design considerations are presented. Finally, laboratory experiments with a 340W prototype, verifying the effectiveness of the proposed converter, are described.

DC-DC converter implementation with wide output voltage operation

Lin, Bor-Ren The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.2

A direct current (DC) to DC converter with soft switching and high efficiency is developed for industry power units with a wide range of output voltage applications. A series resonant converter is the main circuit on the primary side to accomplish the soft switching characteristics for the active devices and rectifier diodes without switching loss or reverse recovery current loss. To overcome the drawback of the limited operation input or output voltage range in conventional LLC converters, a hybrid resonant converter including a half-bridge circuit and a full-bridge circuit with auxiliary windings is developed to achieve 8:1 (V_o,max=8V_o,min) output voltage characteristics for a wide range of output voltage applications. To achieve this function, two AC power switches are used in the developed circuit. Since a single-stage hybrid resonant converter is presented instead of a two-stage converter to realize wide voltage range operation, the developed circuit has better efficiency when compared to conventional LLC converters and two-stage DC-DC converters. To confirm the circuit analysis and effectiveness, a prototype with a 400 W rated power was built and tested.