EDUCATION
Doctor of Philosophy in Electrical Engineering, November, 1990.
Virginia Polytechnic Institute and State University, Blacksburg, Virginia.
Dissertation: A New Small-Signal Model for Current-Mode Control.Master of Science in Electrical Engineering, January 1986.
Virginia Polytechnic Institute and State University, Blacksburg, Virginia.
Thesis: Investigation of Parallel Switching Power Supply Modules.Bachelor of Science in Electrical Engineering, Summa Cum Laude, May 1981.Boston University, Boston, Massachusetts.
Senior project: Investigation of Ferro-Resonant Power Supplies.

EXPERIENCE
President, Ridley Engineering, Inc. April 1991 - present.

Assistant Director, Virginia Power Electronics Center,
Virginia Polytechnic Institute and State University, 1987 - April 1991.
VPEC is the largest university power electronics group in the world,
with seven full-time faculty, thirty graduate students,
and approximate funding of $2 million per year. It has recently been appointed an NSF research center.

Position responsibilities included:

• Management of four power electronics research laboratories and
  supervision of three research engineers
• Performance of research on contracts
• Design and teaching of power electronics courses for industry partners of VPEC
• Generation of proposals for research contracts
• Guidance of graduate students on research contracts for industry and government
• Promotions, public relations, and interfacing with industry members of
  VPEC's 40-member industry partnership program. This is the most successful program of its kind in this field with each member paying $10,000 per year to belong to the partnership
  

Specific research projects:

• Design and analysis of power factor correction circuits for single-phase and three phase ac inputs, at up to 16 kW; Development of new small-signal models for single-phase units
• Design and analysis of parallel power converters for computer mainframes
• Development of new control systems and small-signal models for multiple converter power systems
• Development of high-speed simulation and analysis software for piecewise-linear switched circuits
• Development of computer-aided design tools for control-loop design for power converter circuits, and optimization for power circuits and magnetic components
• Design of high-frequency, zero-voltage switching full-bridge converter, and design of zero-current-switched quasi-resonant converter for computer systems
• Multi-loop control design of high-frequency multi-resonant power converters for on-board computer applications

PROFESSIONAL ACTIVITIES
Designed and taught power electronics courses and tutorials at conferences in the US and overseas:

Four-Day Design Workshop, Munich, Germany, September 2007
Four-Day Design Workshop, Bordeaux, France, June 2007
Four-Day Design Workshop, Munich, Germany, June 2007
Four-Day Design Workshop, Atlanta, GA, April 2007
Four-Day Design Workshop, Atlanta, GA, February 2007
Four-Day Design Workshop, Atlanta, GA, December 2006
Four-Day Design Workshop, Atlanta, GA, November 2006
Four-Day Design Workshop, Atlanta, GA, September 2006
Four-Day Design Workshop, Atlanta, GA, August 2006
Four-Day Design Workshop, Atlanta, GA, May 2006
Four-Day Design Workshop, Atlanta, GA, February 2006
Four-Day Design Workshop, Atlanta, GA, January 2006
Four-Day Design Workshop, Atlanta, GA, September 2005
Four-Day Design Workshop, Atlanta, GA, November 2005
Four-Day Design Workshop, Atlanta, GA, June 2005
Four-Day Design Workshop, Atlanta, GA, April 2005
Four-Day Design Workshop, Atlanta, GA, January 2005

Power Systems Design and Modeling, Powersystems World Conference, Chicago, IL, October 2004

Four-Day Design Workshop, Atlanta, GA, August 2004

PWM Swich Modeling Historical Review and New Developments, Applied Power Electronics Conference in Anaheim, CA, February 2004

Four-Day Design Workshop, Atlanta, GA, February 2004

Four-Day Design Workshop, Atlanta, GA, October 2003

Four-Day Design Workshop, Atlanta, GA, July 2003

Four-Day Design Workshop, Atlanta, GA, April 2003

Four-Day Design Workshop, Atlanta, GA, January 2003

Four-Day Design Workshop, Atlanta, GA, ON Semiconductor, October 2002

Four-Day Design Workshop, Atlanta, GA, August 2002

Four-Day Design Workshop, Atlanta, GA, Intersil Corp. - June 2002

Four-Day Design Workshop, Atlanta, GA, February 2002

Four-Day Design Workshop, Atlanta, GA, October 2001

Control and Magnetics Design Course, Chicago, IL, May 2001

Control and Magnetics Design Course, Dallas, TX, April 2001

Control and Magnetics Design Course, Woburn, MA, March 2001

Control and Magnetics Design Course, Anaheim, CA, February 2001

Control and Magnetics Design Course, Atlanta, GA, January 2001

Control and Magnetics Design Course, San Jose, CA, December 2000

Three-Day Design Course, Boston, MA, April 2000

Three-Day Design Course, Laguna Beach, CA, February 2000

Three-Day Design Course, Chicago, IL, September 1999

Three-Day Design Course, Santa Clara, CA, July 1999

Powersystems World '98, October, 1999

Powersystems World '98, October, 1998

Powersystems World '97, September, 1997

Powersystems World, High-Frequency Power Conversion (HFPC) Conference in Las Vegas, Nevada, September, 1996

High-Frequency Power Conversion (HFPC) Conference in San Jose, California, May 1995

Power Conversion and Intelligent Motion (PCIM) Conference in Long Beach, California, September 1995

High-Frequency Magnetics Design seminar taught at the HFPC conference in San Jose and at PCIM conference in Long Beach, California, September 1995

Three-Phase Power Factor Correction seminar taught at the IEEE
Applied Power Electronics Conference May 1995 in Florida, February 1994, and at the HFPC conference in San Jose, April 1994

The Fundamentals of Power Supply Stability seminar taught at the
High-Frequency Power Conversion Conference in Washington, May 1993

Distributed Power Systems seminar taught at the High-Frequency Power Conversion Conference in San Diego, May 1992

Active Power Factor Correction seminar taught at the IEEE Applied Power Electronics Conference in Boston, February 1992

New Modeling Tools for PWM Converters and Current-Mode Control Workshop and Computer Workshop on PWM Converter Modeling and Design,taught at the High-Frequency Power Conversion Conference, Santa Clara, California, May 1990 and at the Power Conversion and Intelligent Motion Conference in Munich, Germany, June 1990

Designing Control Loops for Power Electronics Circuits taught at the
Applied Power Electronics Conference, Los Angeles, California, March 1990

Design of High-Frequency Quasi-Resonant and Multi-Resonant Converters taught at the Applied Power Electronics Conference, Baltimore, Maryland, March 1989

Institute of Electrical and Electronic Engineers

• Chairman of the IEEE PELS Atlanta, Georgia Chapter, 2004
• Session Chairman at IEEE Power Electronics Specialists Conference, June 1990, and IEEE Applied Power Electronics Conference, 1988-1994
• Panelist at IEEE rap session on computers in power electronics, Applied Power Electronics Conference, 1990
• Panelist at IEEE rap session high-frequency power conversion, Power Electronics Specialists Conference, 1988
• Reviewer for IEEE Transactions on Power Electronics and IEEE Transactions on Aerospace, 1988 to present
• Program committee member for IEEE Power Electronics Specialists Conference, 1990 and 1991 and Applied Power Electronics Conference, 1991-1993
  

HONORS AND AWARDS
Best paper award winner at Power Conversion and Intelligent Motion Conference, 1989, for A New Continuous-Time Model for Current-Mode Control.Best paper award winner at High-Frequency Power Conversion Conference, 1988, for Multi-loop Control for High-Frequency Quasi-Resonant Converters.Best paper award winner at High-Frequency Power Conversion Conference, 1987, for Multi-loop Control for Quasi-Resonant Converters.US patent awarded for multi-loop control for quasi-resonant converters.US and Swiss patents awarded for three-phase power factor correction circuit for line-failure redundancy.US and Swiss patents awarded for new control scheme for wide-range power factor correction circuits.Presidential Award from Virginia Polytechnic Institute and State University, 1986.Scarlet Key Award from Boston University, 1981.Best senior project award from Boston University, 1981.Member of Tau Beta Pi engineering honor society.

 

PUBLICATIONS
Refereed Journal PapersChoi, Byungcho, Bo H. Cho, Fred C. Lee, and Raymond B. Ridley, The Stacked Power System: A New Power Conditioning Architecture for Mainframe Computer Systems, IEEE Transactions on Power Electronics, Vol. 9, No. 6, November, 1994, pp. 616-623.Vlatkovic, Vlatko, Juan A. Sabate, Raymond B. Ridley, and Fred C. Lee, Small Signal Analysis of the Phase-Shifted PWM Converter, IEEE Transactions on Power Electronics, Vol. 7, No. 1, January, 1992, pp. 128-135.Sable, Dan M., Raymond B. Ridley, and Bo H. Cho, Comparison of Performance of Single-Loop and Current-Injection Control for PWM Converters that Operate in Both Continuous and Discontinuous Modes of Operation, IEEE Transactions on Power Electronics, Vol. 7, No. 1, January, 1992, pp. 136-142.R. B. Ridley, A New Continuous-Time Model for Current-Mode Control, Special Issue of the IEEE Transactions on Power Electronics on Modeling for Power Electronic Circuits and Systems, April, 1991.R. B. Ridley, W. A. Tabisz, F. C.. Lee, and V. Vorperian, Multi-Loop Control for Quasi-Resonant Converters, High Frequency Power Conversion Conference, Washington, D.C., IEEE Transactions on Power Electronics, Vol. 6, No. 1, January 1991.R. B. Ridley, C. Zhou, and F. C.. Lee, Practical Nonlinear Design Optimization for Power Converter Components, IEEE Transactions on Power Electronics, Vol. 5, No. 1, January 1990.V. Vorperian and R. B. Ridley, A Simple Scheme for Unity Power Factor Rectification for High-Frequency AC Buses, IEEE Transactions on Power Electronics, Vol. 5, No. 1, January 1990.R. B. Ridley, B. H. Cho and F. C.. Lee, Analysis and Interpretation of Loop Gains of Multi-Loop-Controlled Switching Regulators, IEEE Transactions on Power Electronics, Vol. 3, No. 4, October 1988.R. B. Ridley, Secondary LC-Filter Analysis and Design Techniques for Current-Mode Controlled Converters, IEEE Transactions on Power Electronics, Vol. 3, No. 4, October 1988.D. M. Sable, B. H. Cho and R. B. Ridley, Elimination of the Positive Zero in Fixed Frequency Boost and Flyback Converters, accepted for publication in IEEE Transactions on Power Electronics. Also presented at the Applied Power Electronics Conference, Los Angeles, California, March 1990.J. A. Sabate, V. Vlatkovic, R. B. Ridley, F. C.. Lee and B. H. Cho, Small-Signal Analysis of the Zero-Voltage-Switched Full-Bridge PWM Converter, accepted for publication in IEEE Transactions on Power Electronics. Also presented at the High-Frequency Power Conversion International Conference, Santa Clara, California, May 1990.IEEE Conference Papers:R. B. Ridley, New Simulation Techniques for PWM Converters, IEEE Applied Power Electronics Conference, San Diego, 1993.R. B. Ridley, M. J. Reynell, S. Kern, Thermal Considerations for Distributed Power Converter Systems, Applied Power Electronics Conference, San Diego, 1993.R. B. Ridley, S. Kern, B. Fuld, Analysis and Design of a Wide Input Range Power Factor Correction Circuit for Three-Phase Applications, IEEE Applied Power Electronics Conference, San Diego, 1993.W. Tang, F. C. Lee, R. B. Ridley, I. Cohen, Charge Control: Modeling, Analysis and Design, proceedings of the IEEE Power Electronics Specialists Conference, Spain, 1992.W. Tang, F. C. Lee, R. B. Ridley, Small-signal Modeling of Average Current-Mode Control, proceedings of the IEEE Applied Power Electronics Conference, Boston, 1992.J. A. Sabate, V. Vlatkovic, R. B. Ridley and F. C. Lee, High-Voltage, High-Power, ZVS Full-Bridge PWM Converter Employing an Active Snubber, proceeding of the Applied Power Electronics Conference, 1991.R. B. Ridley, A New Continuous-Time Model for Current-Mode Control with Constant On-Time, Constant Off-Time, and Discontinuous Conduction Mode, Power Electronics Specialists Conference, San Antonio, Texas, June 1990.B. Choi, B. H. Cho, R. B. Ridley and F. C.. Lee, Control Strategy for Multi-Module Parallel Converter System, Power Electronics Specialists Conference, San Antonio, Texas, June 1990.C. Zhou, R. B. Ridley and F. C.. Lee, Design and Analysis of a Hysteretic Boost Power Factor Correction Circuit, Power Electronics Specialists Conference, San Antonio, Texas, June 1990.D. M. Sable, R. B. Ridley and B. H. Cho, Comparison of Performance of Single-Loop and Current-Injection Control for PWM Converters which Operate in Both Continuous and Discontinuous Modes of Operation, Power Electronics Specialists Conference, San Antonio, Texas, June 1990.J. A. Sabate, V. Vlatkovic, R. B. Ridley, F. C.. Lee and B. H. Cho, Design Considerations for High-Voltage, High-Power Full-Bridge Zero-Voltage-Switched Converters, Applied Power Electronics Conference, Los Angeles, California, March 1990.S. A. Chin, J. Tero, M. M. Jovanovic, R. B. Ridley and F. C. Lee, A New IC Controller for Resonant-Mode Power Supplies, Applied Power Electronics Conference, Los Angeles, California, March 1990.R. B. Ridley, A. Lotfi, V. Vorperian and F. C.. Lee, Design and Control of a Full-Wave, Quasi-Resonant Flyback Converter, Applied Power Electronics Conference, New Orleans, 1988.C.J. Hsiao, R. B. Ridley, H. Naitoh and F. C.. Lee, Circuit-Oriented Discrete-Time Modeling and Simulation for Switching Converters, Power Electronics Specialists Conference, Blacksburg, Virginia, June 1987.S. S. Kelkar, R. B. Ridley, C.J. Hsiao, R. Ramkumar and F. C. Lee, A Computer-Aided Design and Simulation Tool for Switching Converters, Power Electronics Specialists Conference, Blacksburg, Virginia, June 1987.Non-IEEE Conference Papers:D. M. Sable and R. B. Ridley, A High Frequency Multi-Module Spacecraft Boost Regulator, INTELEC Conference 1988.S. A. Chin, J. Tero, M. M. Jovanovic, R. B. Ridley and F. C. Lee, A 10 MHz Universal Control IC for Resonant-Mode Power Supplies, High-Frequency Power Conversion Conference, Santa Clara, California, May 1990.To view comments on the published papers described above, click here.