Publications

Publications

“The Invisible Circuit:  Non-Idealities in Circuit Elements and System Components”, APEC 16 Seminar Manual

In this seminar we discuss the material characteristics, behavioral characteristics, and electronic sub-elements that are part of circuit elements and system components that cause the elements or components to perform differently than an ideal, pure, or perfect element or component would be expected to perform.

https://powelinno.com/products-2/

“Optimal Switch Timing, Parts 1 and 2” January and February 2016 Issues of How2Power.com online magazine

These articles describe the issues and solutions related to achieving optimal switch timing for reducing conduction and switching losses in soft switching power converters.

http://www.how2power.com/pdf_view.php?url=/newsletters/1601/articles/H2PToday1601_design_TechnicalWitts.pdf

http://www.how2power.com/pdf_view.php?url=/newsletters/1602/articles/H2PToday1602_design_TechnicalWitts.pdf

This figure illustrates the drain source voltage of a main switch during the turn on transition of a zero voltage switching converter having a gate timing circuit that senses the zero voltage condition. This figure illustrates the problem related to the insufficient energy condition.

 

This figure illustrates the drain source voltage of a main switch during the turn on transition of a zero voltage switching converter having an adaptive gate drive timing circuit that accommodates both the zero voltage condition and the minimum voltage condition to obtain optimal switch timing for both the sufficient and insufficient energy conditions.

A block diagram of an optimal timing circuit for a main switch in a zero voltage switching converter that accommodates all energy conditions including the start up zero energy condition.

 

“Leakage Inductance: Friend or Foe, Parts 1, 2, and 3”  October, November, and December 2015 issues of How2Power.com online magazine

These articles help the reader to better understand what leakage inductance is, what the problems caused by leakage inductance are and how to avoid them, and how leakage inductance can be used to great benefit.

 http://www.how2power.com/pdf_view.php?url=/newsletters/1510/articles/H2PToday1510_design_TechnicalWitts.pdf

This figure illustrates how magnetic flux in a transformer relates to magnetizing inductance and leakage inductance.

 

 http://www.how2power.com/pdf_view.php?url=/newsletters/1511/articles/H2PToday1511_design_TechnicalWitts.pdf

An unclamped flyback converter illustrating circuit intrinsic parasitic elements that contribute to ringing during the on time of the main switch. Here the ringing appears at the cathode of the rectifier switch, DOUT. Leakage inductance is a main cause of this ringing.

 

http://www.how2power.com/pdf_view.php?url=/newsletters/1512/articles/H2PToday1512_design_TechnicalWitts.pdf

A balanced EMI filter with leakage inductances is illustrated. For a CM choke the leakage inductance typically provides a significant useful amount of DM inductance enabling a high level of DM attenuation when coupled with DM capacitors. In some cases, such AC off line converters, the DM attenuation achieved by the leakage inductance of the CM choke is sufficient to obviate the DM choke altogether.

 

Illustrated is a fully active clamped zero voltage switching flyback converter having bi-directional power flow ability. The leakage inductance contributes to the energy required to achieve zero voltage switching. The active clamps prevent ringing that would otherwise occur in the absence of the active clamps. See the article for a detailed operational description of this circuit.

 

“From Control to Gate:  Gate Drive Circuits and Techniques”, APEC 13 Seminar Manual

 https://powelinno.com/products-2/

In this seminar we discuss gate interface issues, gate drive circuits for isolated, non-isolated, and high side gate drive circuits, advanced gate drive circuits for optimal timing of soft switching converters, powering gate drivers, and the unique problems of gate drives for synchronous rectifiers and both enhancement mode and depletion mode wide bandgap semiconductors.

 

“Soft Switching Circuits and Techniques”,  APEC 11 Seminar Manual

https://powelinno.com/products-2/

Operational principles of circuits used to reduce and eliminate switching losses are revealed with detailed descriptions of the most compelling soft switching circuits.

 

“Solid State Lighting for Residential Applications”, APEC 10

 

“Practical Soft Switching Power Converters”, APEC 08 Seminar Manual

 https://powelinno.com/products-2/

 

“High Efficiency Power Supply Design” Professional Advancement Course Manual, Power Systems World, October 2006, Long Beach, CA

 https://powelinno.com/products-2/

Topology selection and design decisions that effect efficiency are discussed as well as the loss mechanisms that contribute to inefficiency.

 

“Topology Selection by the Numbers, Parts 1, 2, and 3”, Power Electronics Technology Magazine, March 2006 through May 2006.

 https://www.electronicdesign.com/technologies/power/power-supply/dc-dc-converters/article/21188731/topology-selection-by-the-numbers-part-one

https://www.researchgate.net/publication/294144788_Topology_selection_by_the_numbers_-_Part_one

 https://www.yumpu.com/en/document/read/19291881/topology-selection-by-the-numbers-part-two-power-electronics

https://www.yumpu.com/en/document/read/19291846/topology-selection-by-the-numbers-part-three-power-electronics

https://www.researchgate.net/publication/335101556_Automated_Selection_and_Design_of_DC-DC_Switch_Mode_Power_Supplies_with_MatLab

ieeexplore.ieee.org/document/7038001

https://ieeexplore.ieee.org/document/8507937

 

“High Efficiency Power Supply Design”, APEC 06 Seminar Manual.

 https://powelinno.com/products-2/

 

“Power Conversion Synthesis, Parts 1 through 4: Near Zero Emissions”, Power Electronics Technology, March 2003 through June 2003

 

“EMC Enhanced Power Supply Design”, APEC 2003 Seminar Manual, February 2003, Power Systems World 2003, and APEC 2005 and 2010 Seminar Manuals.

https://powelinno.com/products-2/

 

“Zero Voltage Switching Converter”, Design Idea, Electronic Design Magazine, April 1997

 

“New Simple Resonant Transition Topologies for High Frequency Multi-Phase Parallel PWM Converters”, Proceedings of High Frequency Power Conversion Conference, May 1993

New simple soft switching circuit topologies that lend themselves to multi-phase parallel operation are revealed.

 

“A Simple Clamped ZVS PWM Converter”, Proceedings of IEEE APEC, March 1993

 https://ieeexplore.ieee.org/document/290749

 Practical soft switching flyback and flybuck power converters are revealed.

 

“Improved Multi-Phase Coupled Inductor Topologies”, “Negative Output Impedance Converters for Improved Load Regulation”, and “Active Inrush Current and Current Slope Limiting”, Proceedings of High Frequency Power Conversion Conference, May 1992

 Negative output impedance converters that generate increased output voltage with increasing load to compensate for resistance losses in post filters and down stream cables are revealed.  A new inrush current limiting circuit that requires no current sensing resistor is revealed.

“A Duty Cycle Extension Technique For Single-Ended Forward Converters”, Proceedings of IEEE Applied Power Electronics Conference, February 1992

 https://ieeexplore.ieee.org/document/228431

The use of a non-dissipative LCD clamp is used to achieve duty cycles well above 50% in single ended forward converters to reduce conduction losses is revealed.

 

“An Active Resonant Snubber for High Frequency PWM Converters”, Proceedings of IEEE Power Electronics Specialists Conference, June 1990