alyson essay by lisa w abortion is wrong persuasive essay satirical college essay essay format for dummies why democracy is the best form of government essay

Published papers

Below you can find a list of papers written by our team

You can also use the jump menu below for quick jumping.

(1) Title Constant Frequency, Forward Converter With Resonant Transition
On page(s) 282-292
Location Toronto, Ontario, Canada
Meeting date 06/09/1991 – 06/14/1991
Conference/Proceedings High Frequency Power Conversion, June 1991. HFPC ’91. Conference Proceedings 1991, Sixth International
Abstract
A single ended forward converter, operating at constant frequency and switching at zero voltage is presented. By using a secondary switch, the main transformer’s core is symmetrically reset and a part of magnetizing energy is used to discharge the parasitic capacitance of the primary switch to zero. Zero voltage switching conditions are achieved over a broad input voltage and output current range. An experimental 500 KHz converter, which delivers an output power of 200W at 5V, is presented. Operating from an input voltage of 180 to 400 Vdc, the converter exhibits efficiency greater than 88% at full load.

(2) Title A New High Frequency, Zero Voltage Switched, PWM Converter
On page(s) 657-664
Location Boston, MA, USA
Meeting date 02/23/1992 – 02/27/1992
Conference/Proceedings Applied Power Electronics Conference and Exposition, February 1992. APEC ’92. Conference Proceedings 1992, Seventh Annual
Abstract
A high efficiency, high power density converter, operating at constant frequency and switching at zero voltage is presented. Zero voltage switching conditions are achieved over a broad input voltage and output current range. Continuous power transfer from the input to the output minimizes the output filter requirements and by using integrated magnetic technique, high power density can be achieved. By employing the same configuration to classical PWM topologies, a new family of ZVS-PWM converters can be derived. An experimental 5V, 100A converter was designed and built. The converter operates from an input voltage of 200Vdc to 400Vdc, at 400 KHz switching frequency.

(3) Title Constant Frequency Zero Voltage PWM Converters
On page(s) 428-439
Location Nuremberg, Germany
Meeting date 04/28/1992 – 04/30/1992
Conference/Proceedings International Power Conversion & Intelligent Motion, April 1992. PCIM ’92. Conference Proceedings 1992, Twenty-Fourth International
Abstract
By utilizing a supplementary control switch, which steers the primary current back to the input source to achieve zero voltage switching conditions, a new family of ZVS-PWM converters is derived. The forward ZVS-PWM in single ended configuration is analyzed. High frequency, zero voltage switched, PWM technique is combined with continuous transfer of energy to the secondary, for double ended secondary, for double ended configuration, offering very high power density capability. Experimental results are presented for 300W converter, operating from a large input voltage range of 200V to 400V at 400 KHz switching frequency.

(4) Title High Frequency, Soft Transitions Converter
On page(s) 880-887
Location San Diego, California, USA
Meeting date 03/07/1993 – 03/11/1993
Conference/Proceedings Applied Power Electronics Conference and Exposition, March 1993. APEC ’93. Conference Proceedings 1993, Eighth Annual
Abstract A high efficiency, high power density power conversion technology is presented. This topology is compatible with high output voltage applications such as 24V and 48V, where Schottky rectifiers cannot be used. The converter combines zero voltage switching across the primary switches, continuous energy transfer from the primary to the secondary and soft commutations of the output rectifiers. The soft switching of the output rectifiers minimizes the reverse recovery losses associated with ultra fast rectifiers operating at high frequency. An experimental converter using this concept is evaluated. The converter operates from an input voltage of 200V to 430V at 300 KHz, providing 400W (50V@8A) with efficiency of 95% at full load.

(5) Title Soft Transitions Power Factor Correction Circuit
On page(s) 144-150
Location Nuremberg, Germany
Meeting date 06/22/1993 – 06/24/1993
Conference/Proceedings High Frequency Power Conversion, June 1993. HFPC ’93. Conference Proceedings 1993, Twenty-Sixth International
Abstract Reverse recovery of the diode rectifier has a negative effect on power converters’ performance when operating at high frequency. Due to the low impedance across the voltage source when the diode commutes this negative effect becomes worse in non-isolated converters using buck and boost topologies. Today’s industry requests for better power diodes rectifier regarding switching speed and low conduction losses seems to touch the technology limits. Thus the paper presents circuit techniques that minimize the negative effects of silicon power rectifiers’ reverse recovery. Two “soft” switching techniques applied to buck and boost topology are presented together with experimental results in a power factor correction application.

(6) Title Soft Transitions Power Factor Correction Circuit
On page(s) 202-208
Location Vienna, Virginia, USA
Meeting date 05/23/1993 – 05/27/1993
Conference/Proceedings High Frequency Power Conversion, May 1993. HFPC ’93. Conference Proceedings 1993, Eighth International
Abstract The losses due to the reverse recovery of rectifiers impact significantly the performances of power converters especially at high frequency. The effect of reverse recovery time it is more severe in non isolated converters such as buck and boost topologies, due to the low impedance across the voltage source during the commutation of the diode. The current industry demand for rectifiers with high switching speed and low conduction losses has pushed the silicon based technology for power semiconductor to its performance limit. This is driving the quest for a new material such as, gallium arsine, diamond and silicon carbide, which are potential candidates for future power semiconductor devices. This paper is focused on circuit techniques, which minimize the negative effects of silicon rectifiers’ reverse recovery. There are presented two “soft” switching techniques applied to buck and boost topology, together with experimental results in a power factor correction application.

(7) Title High Efficiency DC-DC Converter
On page(s) 638-644
Location Orlando, Florida, USA
Meeting date 02/13/1994 – 02/17/1994
Conference/Proceedings Applied Power Electronics Conference and Exposition, February 1994. APEC ’94. Conference Proceedings 1994, Ninth Annual
Abstract
The paper presents a family of topologies used in DC-DC power converters employing two complementary switches in the primary and two MOSFET synchronous rectifiers in the secondary. This technique leads to soft transitions across switching devices and to a simple complementary square waveform for the driving signal of the MOSFET synchronous rectifiers. Using one topology from the family a high-efficient very dense 100W converter was built. Operating from an input voltage of 35Vdc to 72Vdc and providing 20A under 5V more than 90% efficiency at full load was obtained. Combining full-integrated multilayer PCB magnetic technology with the high efficiency target has lead to a power density of 52W/inch3

(8) Title High Efficiency DC-DC Converter
On page(s) 109-116
Location Nuremberg, Germany
Meeting date 06/28/1994 – 06/30/1994
Conference/Proceedings International Power Conversion & Intelligent Motion, June 1994. PCIM ’94. Conference Proceedings 1994, Twenty-Eighth International
Abstract The paper presents a whole family of converters using two complementary switches in the primary side and two MOSFET synchronous rectifiers in the secondary side. These devices together with the main transformer and the filtering choke are coupled in large number of topologies. Using complementary switches one can obtain soft transitions across switching elements. Also the complementary square waveforms reflected in the secondary side offers a simple and efficient driving signal command for the synchronous rectifiers. Starting from one topology from the specified range a very efficient high-density 100W power converter was built. The converter operates from an input voltage of 35Vdc to 72Vdc, providing 5V at 20A, with efficiency above 90% at full load. High efficiency combined with the use of a full-integrated multilayer PCB magnetic technology has allowed a power density of 52W/inch3

(9) Title High Efficiency DC-DC Converter
On page(s) 120-127
Location San Jose, California, USA
Meeting date 04/17/1994 – 04/21/1994
Conference/Proceedings High Frequency Power Conversion, April 1994. HFPC ’94. Conference Proceedings 1994, Ninth International
Abstract
A family of converter topologies employing two complementary switches in the primary and two MOSFET synchronous rectifiers in the secondary is presented. The use of two complementary switches in the primary leads to soft transitions across the switching elements, and the complementary square waveforms reflected in the secondary offers a simple and efficient driving waveform for the synchronous rectifiers. Employing one of these topological configurations, a very high efficiency and high power density 150W converter was implemented. The converter operates from an input voltage of 35Vdc to 72Vdc, providing 5V at 30A, with efficiency above 90% at full load. High efficiency combined with the use of a full-integrated multilayer PCB magnetic technology has allowed a power density of 51W/inch3

(10) Title The Impact Of Low Output Voltage Requirements On Power Converters
On page(s) 1-10
Location San Jose, California, USA
Meeting date 05/06/1995 – 05/12/1995
Conference/Proceedings High Frequency Power Conversion, May 1995. HFPC ’95. Conference Proceedings 1995, Tenth International
Abstract
The trend to lower output voltage sets new challenges for the power conversion industry. The paper will present circuit techniques designed to employ low voltage Schottky rectifiers and will elaborate about the advantages and limitation associated with synchronized rectification. Based on the components available today a direct comparison between the Schottky rectifiers and synchronized rectifiers is made substantiated by experimental results. This paper further presents the impact of leakage inductance and circuit parasitic inductance on the low output voltage converter’ performance. A special chapter is dedicated to minimization of copper losses in the secondary winding of the transformer and the output inductor. Using circuit topologies doing this one arrives to a better copper utilization especially for low output voltage applications. The paper concludes with experimental results of Rompower’s 75W 3.3V output DC-DC converter operating from an input voltage of 36V to 60V.

(11) Title The Impact Of Low Output Voltage Requirements On Power Converters
On page(s) 59-68
Location Nuremberg, Germany
Meeting date 06/20/1995 – 06/22/1995
Conference/Proceedings International Power Conversion & Intelligent Motion, June 1995. PCIM ’95. Conference Proceedings 1995, Thirtieth International
Abstract Today’s power conversion trend is to use lower output voltages. This avenue sets new challenges that must be faced. The paper presents several techniques applied in power converter circuits when using low voltage Schottky rectifiers. Also it will discuss the advantages and limitations associated with synchronized rectification. A comparison between Schottky rectifiers and synchronized rectifiers made by experimental results is presented. Further the negative impact of the leakage inductance and circuit parasitic inductance on the performance is analyzed. Special care is dedicated to the copper loss minimization in the secondary winding of the transformer and the output choke. Using circuit topologies doing this one arrives to a better copper utilization especially for low output voltage applications. The paper concludes with experimental results of Rompower’s 75W 3.3V output DC-DC converter operating from an input voltage of 36V to 60V.

(12) Title Increasing the Utilization Of The Transformer’s Magnetic Core By Using Quasi-integrated Magnetics
On page(s) 238-252
Location Las Vegas, Nevada, USA
Meeting date 09/07/1996 – 09/13/1996
Conference/Proceedings High Frequency Power Conversion & Advanced Power Electronics Technology, September 1996. HFPC ’96. Conference Proceedings 1996, Eleventh International
Abstract
This paper will present several topologies that lead to a better utilization of transformer’s magnetic core. In these topologies the main transformer becomes a magnetic storage element, reducing the size of the output filter. Quasi-integrated magnetic will be presented as an intermediate step between conventional and fully integrated magnetic underlying its advantages and limitations. There will be presented quasi-integrated magnetic topologies with and without secondary winding tap. Two methods of eliminating the secondary winding tap will be suggested, one by using current-doubler and the second by employing two symmetrical transformers. Two 100W 5V@20A experimental converters were built and evaluated using quasi-integrated magnetic under two different implementations.

(13) Title Increasing the Utilization Of The Transformer’s Magnetic Core By Using Quasi-integrated Magnetics
On page(s) 299-313
Location Hong Kong
Meeting date 10/14/1997 – 10/17/1997
Conference/Proceedings Power Conversion & Intelligent Motion, October 1997. PCIM ’97. Conference Proceedings 1997
Abstract Several topologies leading to a better utilization of transformer’s magnetic core are investigated. To reduce the size of the output filter these topologies uses the main transformer as a storage element too. Thus a quasi-integrated magnetic is established as an intermediate step between conventional and fully integrated magnetic underlying its advantages and limitations. A quasi-integrated magnetic topology using a tap or not in the secondary side is analyzed. Two methods of eliminating the secondary winding tap will be suggested, one by using current-doubler and the second by employing two symmetrical transformers. Two 100W 5V@20A experimental converters were built and evaluated using quasi-integrated magnetic under two different implementations.

(14) Title Quasi-Integrated Magnetic an Avenue For High Power density and Efficiency In Power Converters
On page(s) 395-402
Location Atlanta, Georgia, USA
Meeting date 02/23/1997 – 02/27/1997
Conference/Proceedings Applied Power Electronics Conference and Exposition, February 1997. APEC ’97. Conference Proceedings 1997, Twelfth Annual
Abstract In order to utilize better the magnetic core of the transformer in DC-DC converters there are investigated some topologies that could fulfill this aim. The main idea is to use the transformer, usually an isolation component in a DC-DC converter, as a storage element too thus reducing the size of the choke from the filtering stage. In this way a quasi-integrated magnetic approach is set that can be seen as an intermediate step between conventional and fully integrated magnetic. Advantages and limitations are underlined. A topology using quasi-integrated magnetic was investigated with and without tap in the secondary side. As a result two methods that could eliminate the secondary winding tap are presented, one using a current doubler and the other one using two symmetrical transformers. Two experimental 100W converters providing 20A under 5V were built and evaluated using quasi-integrated magnetic approach under two different implementations.

(15) Title Power Conversion Technology For Power Levels Under 3kW
On page(s) 255-263
Location Nuremberg, Germany
Meeting date 05/26/1998 – 05/28/1998
Conference/Proceedings International Power Conversion & Intelligent Motion, May 1998. PCIM ’98. Conference Proceedings 1998, Thirty-Eighth International
Abstract We have witnessed in the last several years a transition from a technological driven to a price driven market. The power technology development was de-emphasized unless it targeted cost reduction. Though the cost is still one of the first priorities, quality and reliability made strong headway being named number one and two priority. The paper will present several technological advances, which can offer better performance in respect of reliability and quality, at a lower total cost. Different standardization techniques will be also presented. Standardization becomes the main avenue to improve the design and product quality, the reliability, to lower NRE and to reduce time-to-market.

(16) Title Small-signal Characterization Of The Forward-Flyback Converters With Active Clamp
On page(s) 626-632
Location Anaheim, California, USA
Meeting date 02/15/1998 – 02/19/1998
Conference/Proceedings Applied Power Electronics Conference and Exposition, February 1998. APEC ’98. Conference Proceedings 1998, Thirteenth Annual
Abstract Linear equivalent models of the forward-flyback converters with active clamp are deduced, using the Vorperian model of the PWM switch. Control-to-output transfer functions are plotted against frequency, for a 36-72V to 5V converter, for different load resistances, thus allowing the design of error amplifier as to ensure circuit stability. Experimental results confirm model validity.

(17) Title Very High Power Density Flyback Converter
On page(s) 97-103
Location Nuremberg, Germany
Meeting date 05/26/1998 – 05/28/1998
Conference/Proceedings International Power Conversion & Intelligent Motion, May 1998. PCIM ’98. Conference Proceedings 1998, Thirty-Eighth International
Abstract The paper states the concept of a very high power density flyback converter. Due to its less complex schematic flyback converters are recommended for power supplies providing low output power with inputs from low level DC voltages to high DC voltages (off-line SMPS). Main innovations are used: planar magnetics-PCB transformer and proprietary special packaging. As a result the parasitic are highly reduced and the almost ideal DC-DC converter, of 25 W, 12 V input to 48 V output reaches a power density of 100 W/inch3

(18) Title Distributed Magnetics In High Power Converters
Location Santa Clara, California, USA
Conference/Proceedings High Frequency Magnetic Material, May 1999
Abstract This paper presents an actual avenue in magnetics topic, especially planar technology, related with DC-DC Power Converters. Starting from basic electric laws simple ideas could be derived and applied to practice. This leads to final interesting results that fulfill most of the initial technical requirements.

(19) Title A 3kW Soft Switching DC-DC Converter
On page(s) 86-92
Location New Orleans, Louisiana, USA
Meeting date 02/06/2000 – 02/10/2000
Conference/Proceedings Applied Power Electronics Conference and Exposition, February 2000. APEC ’00. Conference Proceedings 2000, Fifteenth Annual
Abstract
This paper will present a circuit technique designed to reduce the negative impact of reverse recovery in the rectifiers for high output voltage converters. This technique works by combining reduced amplitude of the reverse recovery current and a lower voltage across the rectifier during the turn off commutation. Another major advantage of the proposed circuit is the fact that the current reflected in the primary is shaped to a triangular form with a low dI/dt during the turn on of the main switch. This will allow the completion of the resonant transition to zero voltage across the primary switchers. In the secondary section the reverse recovery current is reduced due to low dI/dt current slope at turn off and the reverse voltage is clamped to the output voltage. The maximum reverse recovery voltage does not exceed the output voltage. The soft commutation in the primary section and the secondary allows a higher frequency of operation without penalty in efficiency. A 3kW converter for on board battery charger in electric vehicles provides an output voltage between 170V to 380V. Efficiency above 96% is obtained at a switching frequency of 250 kHz while the power density of the converter exceeds 100W/inch3

(20) Title A 3kW Soft Switching DC-DC Converter
On page(s) 427-435
Location Nuremberg, Germany
Meeting date 06/19/2001 – 06/21/2001
Conference/Proceedings International Power Conversion & Intelligent Motion, June 2001. PCIM ‘01. Conference Proceedings 2001, Forty-Third International
Abstract
This paper will present a circuit technique designed to reduce the negative impact of reverse recovery in the rectifiers for high output voltage converters. This technique works by combining reduced amplitude of the reverse recovery current and a lower voltage across the rectifier during the turn off commutation. Another major advantage of the proposed circuit is the fact that the current reflected in the primary is shaped to a triangular form with a low dI/dt during the turn on of the main switch. This will allow the completion of the resonant transition to zero voltage across the primary switchers. In the secondary section the reverse recovery current is reduced due to low dI/dt current slope at turn off and the reverse voltage is clamped to the output voltage. The maximum reverse recovery voltage does not exceed the output voltage. The soft commutation in the primary section and the secondary allows a higher frequency of operation without penalty in efficiency. A 3kW converter for on board battery charger in electric vehicles provides an output voltage between 170V to 380V. Efficiency above 96% is obtained at a switching frequency of 250 kHz while the power density of the converter exceeds 100W/inch3

(21) Title Signal Transfer Through Power Magnetics
Location Bloomington, Minnesota, USA
Meeting date 09/17/2002 – 09/18/2002
Conference/Proceedings IBM Power Technology And Qualifications, 2002 Power Technology Symposium; Theme: Future Technology, September 2002
Abstract
This paper presents a method of signal transfer through a power magnetic without interference with the main power train. There will be described two implementations of this concept. In the first application the concept is applied in a 15W DC-DC Converter using flyback topology. The main transformer of the flyback converter is used to store and transfer energy to the secondary and at the same time to transfer the gate signal from the primary side to the secondary side with minimum delay. Incorporating the signal winding and the power winding on the same magnetic core decrease the cost and increases the power density, which is a very important feature for the latest generation of DC-DC Converters. In the second application of this technology is implemented in a quarter brick DC-DC Converter, using a half bridge topology. In this implementation the gate signal for the primary switchers is transferred from the secondary to the primary side through the output chokes. The output chokes are used to store energy and in the same time to transfer signal from the secondary to the primary. The technology is implemented in a DC-DC Converter 132W, 3.3V @ 40A DC-DC Converter, with an efficiency of 91.5% at full load and reaching a power density of 146W/inch3

(22) Title High Efficiency Flyback Converter Using Synchronous Rectification
On page(s) 867-871 vol. 2
Location Dallas, Texas, USA
Meeting date 03/10/2002 – 03/14/2002
Conference/Proceedings Applied Power Electronics Conference and Exposition, March 2002. APEC ’02. Conference Proceedings 2002, Seventeenth Annual
Abstract
This paper presents a method of driving a synchronous rectifier in a flyback topology. For optimum driving of the synchronous rectifier in a flyback converter, the primary side gate signal has to be transferred to the secondary with minimum delay. This paper presents a method of signal transfer through a power transformer without interference with the main power train. In this concept, the main transformer of the flyback converter is used to store and transfer energy to the secondary and, at the same time, to transfer the gate signal from the primary side to the secondary side with minimum delay. Both the power winding and the signal transfer winding are incorporated in a multilayer PCB, reducing the labor cost. Incorporating the signal winding and the power winding on the same magnetic core decreases the cost and increases the power density, which is a very important feature for the latest generation of DC-DC power converters. This technology is implemented in a 15 W 3.3 V@ 4.5A DC-DC converter, with an efficiency reaching 90% at full load. The power density of the converter reaches 40 W/inch3

(23) Title High Efficiency Flyback Converter Using Synchronous Rectification
On page(s) 89-94
Location Nuremberg, Germany
Meeting date 05/14/2002 – 05/16/2002
Conference/Proceedings International Power Conversion & Intelligent Motion, May 2002. PCIM ’02. Conference Proceedings 2002., Forty-Fifth International
Abstract
This paper presents a method of driving a synchronous rectifier in a flyback topology. For optimum driving of the synchronous rectifier in a flyback converter, the primary side gate signal has to be transferred to the secondary with minimum delay. This paper presents a method of signal transfer through a power transformer without interference with the main power train. In this concept, the main transformer of the flyback converter is used to store and transfer energy to the secondary and, at the same time, to transfer the gate signal from the primary side to the secondary side with minimum delay. Both the power winding and the signal transfer winding are incorporated in a multilayer PCB, reducing the labor cost. Incorporating the signal winding and the power winding on the same magnetic core decreases the cost and increases the power density, which is a very important feature for the latest generation of DC-DC power converters. This technology is implemented in a 15 W 3.3 V@ 4.5A DC-DC converter, with an efficiency reaching 90% at full load. The power density of the converter reaches 40 W/inch3

(24) Title Self-driven Constant Voltage Reset Circuit
On page(s) 893-897 vol. 2
Location Miami Beach, Florida, USA
Meeting date 02/09/2002 – 02/13/2003
Conference/Proceedings Applied Power Electronics Conference and Exposition, February 2003. APEC ’03. Conference Proceedings 2002, Eighteenth Annual
Abstract
This paper presents a reset mechanism, which combines the advantages of the active clamp reset and the traditional third wire reset technique. In this concept the reset voltage is constant similar to the third wire reset, wherein a constant voltage is applied to the transformer during the reset cycle. The technology has several key advantages from the active clamp reset mechanism. The energy contained in the leakage and magnetizing inductance is recycled, and the voltage across the main switch is clamped. In addition to this, the flux trough the transformer is symmetrical to zero and the duty cycle can be higher than 50%, similar to the active clamp circuit. Though this circuit contains most of the active clamp circuit’ key features it does not exhibit its limitations. One of the drawbacks of the active clamp circuit is its behavior during transients wherein the duty cycle changes. During transients, until the reset capacitor charges to its optimum level, the voltage across the switch may reach uncontrollable levels. In this reset technique the voltage across the switch is constant regardless of the duty cycle and reacts to transients without any limitations. In addition to this the implementation is very simple; it does not require any additional driving and timing circuits for the reset switch. The reset switch is driven directly form the transformer by a driving winding and the reset voltage can be easily adjusted by a resistor divider. Using this technology a DC-DC converter was implemented, providing 1.2 V @ 20A, from an input voltage range of 36 V to 60 reaching an efficiency of 86% at full load.

(25) Title Constant Voltage Reset Circuit
On page(s) 119-125
Location Nuremberg, Germany
Meeting date 05/20/2003 – 05/22/2003
Conference/Proceedings International Power Conversion & Intelligent Motion, May 2003. PCIM ‘03. Conference Proceedings 2003, Fourty-Seventh International
Abstract
This paper presents a reset mechanism, which combines the advantages of the active clamp reset and the traditional third wire reset technique. In this concept the reset voltage is constant similar to the third wire reset, wherein a constant voltage is applied to the transformer during the reset cycle. The technology has several key advantages from the active clamp reset mechanism. The energy contained in the leakage and magnetizing inductance is recycled, and the voltage across the main switch is clamped. In addition to this, the flux through the transformer is symmetrical to zero and the duty cycle can be higher than 50%, similar to the active clamp circuit. Though this circuit contains most of the active clamp circuit’s key features it does not exhibit its limitations. One of the drawbacks of the active clamp circuit is its behavior during transients wherein the duty cycle changes. During transients, until the reset capacitor charges to its optimum level, the voltage across the switch may reach uncontrollable levels. In this reset technique the voltage across the switch is constant regardless of the duty cycle and reacts to transients without any limitations. In addition to this the implementation is very simple; it does not require any additional driving and timing circuits for the reset switch. The reset switch is driven directly form the transformer by a driving winding and the reset voltage can be easily adjusted by a resistor divider. Using this technology a DC-DC converter was implemented, providing 1.2 V @ 20A, from an input voltage range of 36 V to 60 reaching an efficiency of 86% at full load. Another application of this technology in a 1/8 brick DC-DC Converter is also presented.

(26) Title Magnetic Integration Through Multiple Functions In The Magnetic Cores
On page(s) 225-230
Location Tongli, Wujiang
Meeting date 01/18/2005 – 01/19/2005
Conference/Proceedings Delta Power Electronics Center, January 2005, DPEC Seminar Proceedings
Abstract The paper presents a method of employing a magnetic core for multiple functions. For some magnetic cores shapes such EE and EI, we can implement two independent functions. These functions can be two independent power processing, can be a signal processing and power processing, or can be a power transfer and energy storage. In the continuous quest for miniaturization and cost reduction, these technologies offer a significant advantage. Several example of such implementation in high density DC-DC Converters will be presented.

(27) Title Increasing The Efficiency In High Current And Low Voltage Application
On page(s) 231-234
Location Tongli, Wujiang
Meeting date 01/18/2005 – 01/19/2005
Conference/Proceedings Delta Power Electronics Center, January 2005, DPEC Seminar Proceedings
Abstract The continuous quest for lower voltage and higher current has created some challenges for the power designers especially if the high efficiency and high power density is pursued. This paper will underline the challenges associated with very low voltage and high current application. It will focus mostly on the reduction of effective duty cycle due to the leakage and stray inductance. It will present a magnetic structure which actually minimizes not only the leakage inductance but also the stray inductance which plays a crucial role in this application. In addition to that the magnetic structure reduces by a factor of two the footprint of the magnetic core, using a special layout structure which leads to cancellation of the magnetic filed created by the flowing current outside of the transformer the stray inductance is practically eliminated. These concepts were implemented in a 1.2V @100A quarter brick isolated DC-DC Converter which has an efficiency 2% higher than the competition at full load and reached 90% for 1.2V @ 60A, higher than many VRMs.

(28) Title Magnetic Integration For High Density And High Efficiency Applications
Location Dresden, Germany
Meeting date 09/15/2005 – 09/16/2005
Conference/Proceedings European Center for Power Electronics e. V., September 2005. ECPE ‘05. Seminar: “Power Supplies”
Abstract
The tutorial will present a comprehensive overview of the integrated and quasi-integrated magnetic concepts and implementations. In the quest for higher power densities and higher efficiency integrated magnetic structures have become more popular. There will be presented many forms of integrated magnetic in close correlation with converter topologies. Included are several structures wherein the transformer and the storage elements are placed on the same magnetic core, forming the traditional integrated magnetic with emphasis on the latest trends. In addition to this will be presented structures wherein two independent power trains are placed on the same standard magnetic core and structures wherein the main transformer and a signal transformer are sharing the same magnetic core without interference. The focus for the integrated magnetic will be for low profile and or planar magnetic structures. Ripple steering in new applications will also be presented. There will be presented the advantages of different forms of magnetic integration in very high current and low voltage application. The seminar will also show present and future trends in magnetic integration and new forms of planar magnetic.

(29) Title Increasing The Efficiency In High Current And Low Voltage Application
On page(s) 231-234
Location Pudong, Shanghai, China
Meeting date 01/10/2006 – 01/11/2006
Conference/Proceedings Delta Power Electronics Center, January 2005, DPEC Seminar Proceedings
Abstract The paper will present a converter design targeted to push the performance in respect of efficiency and power density while reducing the cost. The innovation will come from the topology, magnetic structure, drive circuit and the control method. It will present a group of innovation which together lead to a design with outstanding performance.These technologies will be implemented in a 12V output voltage bus converter for HP , delivering 450W with limited airflow.

(30) Title ZVS and ZCS High Efficiency Low Profile Adapter
Location Pudong, Shanghai, China
Meeting date 03/21/2007 – 03/23/2007
Conference/Proceedings International Conference for Power Conversion, Intelligent Motion & Power Quality, March 2007. PCIM China. Conference Proceedings 2007, March 2007
Abstract The paper presents an innovative design that delivers 65W of power at more than 91% efficiency in a footprint of a business card using a high frequency quasi-resonant fly-back topology with synchronous rectification, while maintaining a reasonable low cost of the AC/DC adapter. Topology and techniques for obtaining ZVS and ZCS for high frequency and high voltage switching are described. The goal of the design is maintaining a reasonable temperature rise of the case while delivering 65W power in a reduced volume. The resulting product increases more than twice the power density compared to the standard notebook adapters.

(31) Title High Efficiency 100W Quasi-Resonant Multi-Phases Interleaved PFC Using Planar Magnetic Components
Location Austin, Texas, USA
Meeting date 02/23/2008 – 02/28/2008
Conference/Proceedings Applied Power Electronics Conference and Exposition, February 2008. APEC ’08. Conference Proceedings 2008, Twenty-third Annual
Abstract The paper presents an innovative PFC design that delivers 100 W of power at 96%-97% efficiency for nominal input range, in low profile using a high frequency quasi-resonant interleaved boost topology, while maintaining a reasonable low cost of the ac-dc adapter. Theoretical considerations and practical results for high frequency interleaved boost converters are described. The goal of the design is maintaining a reasonable temperature rise of the case while delivering 100W power in a reduced volume. The resulting product increases more than twice the power density compared to the standard notebook universal adapters.

(32) Title High Efficiency Adapter Using Dual Switch PFC-Flyback Single Stage
Location Nuremberg, Germany
Meeting date 05/27/2008 – 05/29/2008
Conference/Proceedings International Conference for Power Conversion, Intelligent Motion & Power Quality, May 2008. PCIM Europe ‘08. Conference Proceedings 2008
Abstract The paper presents an innovative design that delivers 85W of power at more than 91% efficiency in a low profile using a high frequency quasi-resonant fly-back topology with synchronous rectification, and improved power factor based on dual switch method. A closed to 0.9 power factor is achieved employing only one magnetic element and two primary side switchers. A significant power density increase is obtained due to a combination of smaller bulk capacitor and a smaller magnetic element.

(33) Title 750W High Efficiency and Soft-Switching Off-Line 12 V Converter
Location Washington, DC, USA
Meeting date 02/15/2009 – 02/19/2009
Conference/Proceedings Applied Power Electronics Conference and Exposition, February 2009. APEC ’09. Conference Proceedings 2009, Twenty-fourth Annual
Abstract The paper presents an innovative off-line low profile converter design that delivers 750 W of power at 95%-96% efficiency for nominal input range, using variable frequency topology with high frequency zero voltage switching (ZVS) and zero current switching (ZCS) for primary switchers. Theoretical considerations and practical results are presented for high frequency and high voltage soft-switching. The goal of the design is to maintain a reasonable temperature rise of the multi-layer PCB board while delivering 750 W power in a reduced volume and low cost. The resulting product increases more than twice the power density compared to the standard two stages 400V to 12V power converters and outperforms other one stage solutions in a 125 x 70 mm2 footprint with only a 18 mm profile.

(34) Title A Family of High Efficiency Variable Frequency Soft-Switching Off-line DC-DC Converters
Location Nuremberg, Germany
Meeting date 05/12/2009 – 05/14/2009
Conference/Proceedings International Conference for Power Conversion, Intelligent Motion & Power Quality, May 2009. PCIM Europe ‘09. Conference Proceedings 2009
Abstract The paper presents a family of off-line DC-DC converters for medium to high power delivering more than 95% efficiency for output levels of 12 to 48 V. The multi-layer PCB solution allows for low profile converters with multiple applications, from AC-DC adapters to TELECOM and computing. The main gain of this new design approach consist in using variable frequency topology with high frequency zero voltage switching (ZVS) and zero current switching (ZCS) for primary switchers. Theoretical considerations and practical results are presented for high frequency and high voltage soft-switching. The goal of the designs is to maintain a reasonable temperature rise of the multi-layer PCB board while delivering up to 90 W and respective 750 W power in a reduced volume and low cost.

Back to top »