The Power Electronics Resource List

Power electronics engineers are often looking for good ways to expand their knowledge of the field. In our conversations we start with reminding ourselves that the best learning comes from doing—experiments and simulation. Yet adding a dimension of learning from others' experiences definitely helps. Here I present a collected list of works that I have come to admire over the years (arranged in alphabetical order of author surname). As with most technical books, I have not read each one of them cover-to-cover, but have often referred parts of them and come back to the bench with lesser ignorance and some aha moments.  

Update: This list now incorporates additions based on suggestions from James Green, Iain Mosely, and Janamejaya Channegowda. Thank you!

Books

 

1. Basso 2008: 'Switch-Mode Power Supplies: SPICE Simulations and Practical Designs' by Christophe P. Basso  

 

2. Billings 2011: 'Switchmode Power Supply Handbook' by Keith Billings and Taylor Morey

 

3. Bossche 2005: 'Inductors and Transformers for Power Electronics' by Alex Van den Bossche and Vencislav Cekov Valchev

 

4. Brown 1990: 'Practical Switching Power Supply Design' by Marty Brown 

 

5. Brown 2001: 'Power Supply Cookbook' by Marty Brown 

 

6. Brown 2007: 'Power Sources and Supplies' by Marty Brown 

 

7. Dixon 2001: 'Unitrode Magnetics Design Handbook' by Lloyd Dixon 

 

8. Erickson 2001: 'Fundamentals of Power Electronics' by Robert Erickson  

 

9. Hart 2010: 'Power Electronics' by Daniel Hart  

 

10. Kazimierczuk 2008: 'Pulse-width Modulated DC–DC Power Converters' by Marian K. Kazimierczuk

 

11. Kazimierczuk 2014: 'High-Frequency Magnetic Components' by Marian K. Kazimierczuk 

 

12. Lenk 2005: 'Practical Design of Power Supplies' by Ron Lenk 

 

13. Maniktala 2006: 'Switching Power Supplies A to Z' by Sanjay Maniktala 

 

14. Mammano 2017: 'Fundamentals of Power Supply Design' by Robert Mammano 

 

15. McLyman 2004: 'Transformer and Inductor Design Handbook' by Colonel Wm. T. McLyman

 

16. Mohan 2007: 'Power Electronics: Converters, Applications, and Design' by Ned Mohan, Tore M. Undeland, and William P. Robbins 

 

17. Pressman 2009: 'Switching Power Supply Design' by Abraham Pressman, Keith Billings, and Taylor Morey 

 

18. Ramanarayanan 2008: 'Course Material on Switched Mode Power Conversion' by V Ramanarayanan 

 

19. Roberts 2017: 'DC/DC Book of Knowledge: Practical tips for the User' by Steve Roberts 

 

20. Roberts 2019: 'AC/DC Book of Knowledge: Practical tips for the User' by Steve Roberts 

 

21. Ruan 2014: 'Soft-Switching PWM Full-Bridge Converters: Topologies, Control, and Design' by Xinbo Ruan

 

22. Sandler 2014: 'Power Integrity: Measuring, Optimizing, and Troubleshooting Power Related Parameters in Electronics Systems' by Steve Sandler 

 

23. Sandler 2018: 'Switched-Mode Power Supply Simulation with SPICE' by Steve Sandler   

 

24. Umanand 1992: 'Design Of Magnetic Components For Switched Mode Power Converters' by L Umanand and S.P. Bhat

25. Umanand 2009: 'Power Electronics: Essentials & Applications' by L Umanand

 

 

Online resources

 

1. Bodo's Power Systems: https://www.bodospower.com/

 

2. How2Power: www.How2Power.com (Editor: David Morrison)

 

3. Iain Mosely Webinars: https://vimeo.com/powerguru

 

4. Monolithic Power Systems YouTube Channel: https://www.youtube.com/channel/UCqOx8jWRKEq4TpfcjCz0Isw

 

5. Ray Ridley Webinars: https://ridleyengineering.com/videos-e/
 

6. Texas Instruments 'Power Supply Design Seminar' (PSDS) archives (1983-present): https://ti.com/psds
 

7. Texas Instruments 'Power Tips' video series: https://training.ti.com/power-tips (Robert Kollman et al.)

 

8. Wurth Elektronik YouTube Channel: https://www.youtube.com/c/wuerthelektronik/videos

 

Ratings are overrated: From Goodhart to good heart

The above word cloud was generated using this online tool:
https://www.jasondavies.com/wordcloud/

Goodhart's law states, "When a metric becomes a target, it ceases to be a good metric." The moment one single parameter gains undue importance, many other equally (if not more) important aspects are ignored or side-lined. Any reasonably complex system is bound to have a dashboard of quantitative specifications and qualitative features which together ascertain proper functioning. To a lazy or overwhelmed observer, metrics provide a poor shortcut to circumvent the tedious process of judging the efficacy of a system. 

Once the players know that the observer has this parochial approach, they can choose to game their proposition to optimize for the single metric under the microscope, at the cost of everything else that matters. In many cases, this single metric is not just maximized, but also bloated beyond its true value to make it look larger-than-life, to make it stand out in the crowd. Once a sufficient number of players get into this habit, everybody else is pulled in just to stay afloat. We thus end up in a mad and meaningless rat race, caught in a vicious circle of megalomaniacal portrayals of ourselves, our work, and our creations. This is what I refer to as CV-lie-zation: The act of bloating up our CV to make us look much better than we are.

The overarching phenomenon of metric fever corrupts a multitude of processes, from marketing and buying of products to screening and selection of candidates in job interviews. A lot of our current systems are about running after these metrics, typically one in each domain. Grades in school, rankings of universities, citations of researchers, impact factor of academic journals, GDP or growth rate of an economy, profits of a business, TRP ratings of a television channel, followers on social media, customer ratings on online business platforms. 

All of these metrics have their place in informing assessments, but are extremely limited when each of them becomes the prima donna in their own domain. Let's resist the urge to oversimplify and embrace putting in the time and effort required to make important decisions. Ask for and evaluate much more than the metric.

Every once in a while...
- Ask a student with "poor grades" what excites them at school,
- Explore the tenth page of your Google online search results,
- Study that old paper with one citation,
- Read that unknown book that's rated one star on Amazon,
- Go to a hidden restaurant that's rated one star,
- Watch a forgotten movie that's rated one star on IMDb,

Valuable discoveries are made at places that no one is looking at. There are pearls hidden in the 'one star'. 

"If you only read the books that everyone else is reading, you can only think what everyone else is thinking." ~Haruki Murakami

The Struggling Nobility

You've noble intentions
And yet you struggle
When you're on your own
With no one to impress
You're perhaps unsure
If your actions matter
If you matter
Is there a point?
Then it hits you
That this is precisely
The state of the human
In front of you
And all around you
We're all making things up
As we go along
Struggling nobility
Posturing as popes

Breaching the wall when stuck in a project

Image source: https://commons.wikimedia.org/wiki/File:Red_brick_wall_texture.JPG

Often we find ourselves stuck in our projects. You put in the time and effort, yet there is no perceptible progress. You've hit a wall and you crouch beside it in defeat. Through experience, each of us comes up with our own tools to breach or circumvent the wall. Here is my getting-unstuck toolkit that seems to work reasonably well in projects ranging from lab research and writing articles/theses to designing and developing prototypes and products, largely in engineering contexts. Some of these tools are just repackaged clichés and others that I can pretend to be a pioneer in until someone corrects my illusion. If you have some tools that you do not see in my kit yet, I would be happy to hear from you.

1. Look at the wall from afar
Constantly looking at the same problem from the same vantage point tends to produce similar thought processes. You can break the thinking loop by changing your perspective which is essentially comprised of two aspects: proximity and angle of approach. By proximity I mean the distance between you and the problem. Are you looking at it at a very microscopic scale, considering only local features? Take a step back, see the bigger picture. Zoom out, observe your subject, and then zoom in again. The key is the time you spend afar. If you do not spend enough time observing from the farther distance, you might find yourself falling back into familiar thinking loops.

2. Change your angle of approach
The other way to change your perspective is to change the angle of approach. If you were previously going head on into the wall, try going at a slant. For example, if you were trying a hands-on experimental approach, may be it is time to look at the theory again, or try a computer simulation instead. If you were tackling a phenomenon in your lab prototype, may be it is worth looking for similar problems in some industrial products. If your approach is too technical, may be it is time to try a more layman approach, agnostic of many of the details.

3. Go around
With all due respect to walls, some of them just do not need breaching. Do you really need to solve that problem? Sometimes, going to the other side is a mere matter of going around the wall, trying a different route, or even locating the door. Ask yourself if you are being that fly banging against the same glass window when the adjacent one is open?

4. Take a break
This one is much too trite, yet seldom not right. You know you are utterly stuck, and it is not the time to push harder. Changing your physiology and your surroundings can change the way you think. Get out of the desk and walk, run, bike, play, shower (colds ones can really kick you out of your brains)—whatever activity suits your taste. During my PhD days, playing cricket a couple of hours a day was my preferred release. I remember Professor Arindam Ghosh, an accomplished condensed matter physicist, being one of the few faculty members at the Indian Institute of Science who would 'play and break the thinking loop.'

5. You are not alone
As much as the wall might seem personal, it is probably not. People have been there before you. So you google your problem and despite your best keyword game and your clicks on the forty-second search page, this devious specific wall has somehow avoided mention in any forum. Thankfully, there are people other than strangers on the internet. Ask someone you know, discuss with a colleague or friend with relevant or related experience. Even if they do not have an direct solution, they might point you towards an alley you did not know about. In the words of Rolf-Dieter Heuer, former director general of CERN, "You just have to look around. Then you will see all the others who have the same difficulties." Sometimes, the very act of trying to articulate your problem triggers a possible solution. As astrophysicist James Guillochon says, "If you are stuck on a problem, write a long email/message to someone who can help (as detailed as possible) but don’t send it. Very often you’ll figure it out in the process of writing that message." A similar method used in the software engineering world is called rubber duck debugging, and we all need our rubber ducks.

6. Ping-pong between walls
It is good to have two (or more) brick walls (e.g. research problems for a graduate student) to bang your head against, so that you can ping-pong between them, all the while making some progress without losing your sanity. The core idea of ping-ponging is to hit different walls which is possible only when there are more than one of them. From this perspective, it is probably not a good idea to have only one problem to hit your head against. Diversity in the nature of problems you handle can help in honing your problem solving skills even while it seems that you are continuously failing at various altars. Author Stephen Birmingham underlines this approach in his practice, "I always work on two things at a time. When one goes flat, I turn to the other."

7. Skip step three
If a task has 10 steps and you are stuck in step-3 for a long time, jump ahead to get started on any of steps 4-10. Many a time, they don't necessarily need the earlier step to be completed and you make some headway while you're still stuck on step-3. Sometimes doing steps 4-10 can facilitate getting unstuck from step-3. Turkish writer Orhan Pamuk seems to endorse this approach: "When I’m blocked, which is not a grave thing for me, I continue writing whatever takes my fancy. I may write from the first to the fifth chapter, then if I’m not enjoying it I skip to number fifteen and continue from there."

8. Small is big
It could be unfair on yourself to directly target a big hurdle when you haven't had experience tackling smaller ones. Mathematician George Polya said it better than I can, "If you can't solve a problem, then there is an easier problem you can solve: find it." Sometimes, there are smaller walls hidden inside the big one. The largest of walls is made up of bricks. Chip away at the smallest scale, one splinter at a time. This is the opposite of zooming out. You have zoomed in so much that you can see individual grains of sand that you are capable of tackling. "Do the good that’s in front of you, even if it feels very small," says American author Sharon Salzberg. 

Sometimes it is not that the wall is insurmountable, but that you do not seem to find time enough to address the wall. English author Fay Weldon furnishes the required inspiration here, "I write in short paragraphs because when I began there were always children around, and it was the most I could do to get three lines out between crises." Professor Richard Felder provides further clarification on this idea, "Don't wait for that 'block of time' to get things done. Do the task in short bursts with whatever time slots are available."

9. When stuck in a sinkhole, write
I was once visiting the Dead Sea when the tour guide took us past some large sinkholes and brought up an intriguing story of an Israeli geologist Eli Raz who fell into one of these ditches. While he was stuck there for fourteen hours, waiting for the rescue team, he wrote a diary entry on his observations and experience of being inside a sinkhole. Lesson: When stuck in a sinkhole, write about your experience. Someone will later find solace, if not solutions, in reading it.

5 Takeaways from a Symposium on Effective Teaching

As a postdoc with keen interest in teaching, I attended the Symposium for Effective Teaching and Learning in the Sciences, 1 September 2016, at University of Ontario Institute of Technology (UOIT). The speakers were experienced educators in various sciences -- physics, chemistry, biology, mathematics, forensic science, computer science, among others. Added to my inexperience as a teacher, I was perhaps the only engineer in a room of scientists. However, with plans to offer some courses in coming terms, I brushed aside any concerns and went on to glean some handy tips from the seasoned teachers.


1. Apply your research skills to teaching

Keynote speaker, Dr. Simon Bates points out that collaboration and experimentation is something we do as researchers, not so much as educators. That needs to change if you want to become a better educator. You need not create all the course content on your own. There is plenty of good quality, open, free content created by others available on the internet. You can save a lot of hours, for yourself and for your students, by curating and separating the good content from the not-so-good.

Traditionally, teachers have despised gadgets in class. However, experimenting with use of new technology in teaching is worth a try because the next generation is most at ease with tech. E.g. It is possible to get instantaneous feedback from students at mid-course stage, not merely at end-of-course. In one of his courses, Dr. Bates garnered 8000 words of feedback in 3 minutes via smartphones. On similar lines, senior lecturer Kimberley Nugent demonstrated live polling for multiple-choice questions in class using Socrative. Other approaches to explore are - encouraging students to come up with test questions, gamification of learning, various other active learning techniques. But how do we accommodate all these new methods in the limited lecture hours? Therein comes your own judgment on how to ration time. In extenuating circumstances, it may be required to cut some content. As Walter Lewin would say, “What counts is not what you cover, but what you uncover.”

2. Don't settle merely at being a good lecturer

Dr. Rupinder Brar, a TVO Best Lecturer awardee, identifies that a good lecturer isn't necessarily a good educator. Making use of results from educational research and even conducting educational research take a lecturer closer to being a effective educator. There are specific grants available for carrying out such research. E.g. Teaching Innovation Fund at UOIT. Several good lecturing practices, live demonstrations for instance, are great for capturing students' attention. However, engagement happens to be only a necessary, not sufficient, condition for learning. Dr. Joseph MacMillan explains, “In-class demos work if done using predict-observe-discuss (POD) method. Else only entertainment, no learning.”
 
3. Get off the podium

Dr. Yuri Bolshan asserts it's important to make students solve problems in classroom, individually and in groups. While they're at it, get off the podium, move around in the class, interact with students, help them out. Talk to about 2-5 students per problem. Any more, and you're left with little time to lecture. Counter-intuitively, this method can actually reduce Professor Fear as the students notice you're only trying to help.

4. Try Slack

Dr. Jeremy Bradbury proposes that Slack, a team-messaging app popular in the industry, can be put to good use in classrooms. Compared to conventional learning management systems like Blackboard (Bb), Slack can offer orders of magnitude higher student engagement. E.g. 130 messages on Bb versus 10,000 messages on Slack over a completed course involving 70 students. It is faster than email, and students like it when personal (Facebook, Twitter) and professional (Slack) stuff are kept separate.

5. Create training videos

Master lecturer in mathematics, Ilona Kletskin advocates creating training videos of any procedural stuff such as worked out examples. This also resonates with the engineering ethos to automate the repetitive stuff. I should probably start with some training videos of how to use and configure lab equipment for the grad students in our research group. 

Do you use any of these methods in your teaching? May be you have some tried and tested techniques of your own. Please do share. I'm all ears.

Why I constructed a timeline of physicists

Timeline of people who contributed to basic & applied physics: 500 Years of Physics @thephysicsgirl @cartoon_physics pic.twitter.com/v50ikKWiLO

— Lalit Patnaik (@lalitpatnaik) August 25, 2015

In a TED interview, notable inventor and entrepreneur Elon Musk was asked about his secret behind being able to address diverse technological problems, from sustainable energy to space exploration. His answer can be paraphrased in two words, "Study physics." That's how important physics is. Even sciences like chemistry and biology, and most of engineering, are higher abstractions of underlying physics. It is the foundation on which all of science and technology, and hence all of society rests.   

Isaac Newton once said, "If I have seen further it is by standing on the shoulders of giants." He wasn't just being humble, he was being frank. In physics, as it is with all fields of human thought, the birth of every great idea happened in an environment of ideas that preceded it. At times, one scientist proposed a revolutionary idea that was completely at odds with the prevailing thought. At other times, a particular set of ideas facilitated a natural progression towards another set of ideas irrespective of the individuals involved so long as people were working on it.

To get a panoramic picture of the evolution of ideas in physics, I constructed a visual timeline titled '500 Years of Physics' (see tweet above). I hope teachers, students and enthusiasts of physics find it useful. Updated PNG and PDF versions of the file are now available and I intend to keep updating and enhancing the list.

The timeline consists of people who made key contributions in fundamental and applied physics. Each one on the chronological list is associated with certain key ideas, theories, and/or experiments. Not everyone on the list was a physicist, but all of them made significant contributions to the collective enterprise called physics. Each horizontal bar starts at the birth year of the corresponding personality, and ends at his/her year of demise. The list gives an idea of contemporaries and forerunners -- who came before or after whom, who worked with whom.

Reading physics from a textbook creates an illusion of a level field; everything -- all the laws, the equations, the theories -- comes on a platter. All the struggle behind, the times elapsed and the environment within which the ideas sprang up are hidden from the students. Superimposing other historical timelines on top of this timeline puts those struggles in perspective and will hopefully help reveal some of the stories behind the science. If you love physics, take a printout of the timeline and pin it near your work desk!

13 Online Shops for Buying Electronic Components in India

 Image courtesy: www.techieinfocenter.com

Are you a newbie or student who wants to explore the world of electronics? Are you a hobbyist or maker who loves to tinker with electronics? Are you a practicing electronics engineer or a hands-on researcher? If your answer to any of the above questions is yes, you need to buy different types of electronics components and printed circuit boards for your projects. They may range from the most basic resistors and capacitors to highly specialized integrated circuits, sensors and development boards. 

Unless you stay in one of the metro cities of India, you will find it hard to get many of these components. Even if you stay in a metro, some components are hard to find. But thanks to the internet, we have many online shops to buy electronic parts from. I've listed 13 options here. Although I've bought from some of them, I haven't bought from all of them. I've included websites that I know people get stuff from. 

1. Free samples

Who does not like freebies? Some companies are generous enough to provide samples of their components either through their websites or if you politely request them stating your purpose and requirement. E.g. TI, Cypress, Allegro. There might be many more. If you're a student, many companies have designated personnel for university relations who can be approached.  

The rest of the list is about online destinations where you BUY the components and boards. 

[Pay in Indian Rupees]

2. Element14 www.element14.com
Formerly Farnell electronics, Element14 is one of the biggest online stores for electronic components. They charge pretty high particularly for small numbers. However, they are sometimes the only option for hard-to-find components and are highly reliable. You might need to have TIN number to buy from them. I was able to get around that problem when I bought from them a few years back.

3. Kits 'n' Spares www.kitsnspares.com
Kits 'n' Spares is a subsidiary of Element14 catering to non-industrial costumers. They sell a wide variety of Do-It-Yourself electronics projects and hobby kits.

4. Nex Robotics www.nex-robotics.com
Nex Robotix is a spin-off from IIT Bombay that intends to cater to the robotics and embedded systems community. However, many of their products are useful for any electronics enthusiast. I've bought some nice stepper motors and breakout boards from them.

5. Explore Labs www.explorelabs.com 
This Jodhpur based startup calls itself "an opensource playground" and stocks a diverse range of DIY electronics kits. They are an authorized distributor for Sparkfun Electronics in India. 

6. ProtoCentral www.protocentral.com
This Bangalore based company sells DIY electronics kits and is another authorized distributor for Sparkfun Electronics in India. They ship worldwide.

7. Tenet Technetronics www.tenettech.com
Tenet Technetronics is yet another Bangalore based online store for electronics hobbysists and engineers.

8. NSK Electronics www.nskelectronics.com
NSK is the third Bangalore based entry on the list. Their SP road shop is hugely popular with localites and also has an online store.

9. OnlineTPS www.onlinetps.com
OnlineTPS is a Bhopal based online provider of electronics components and boards.

10. Ventor Technologies www.ventor.co.in
Ventor Technologies is a Kolkata based online shop for electronics components and boards.

11. rhydoLABZ www.rhydolabz.com
This Kochi based online store is known as the Sparkfun of India and ships worldwide.

DangerousPrototypes visited and blogged about ProtoCentral, Tenet Technetronics, NSK Electronics, and rhydoLABZ during their India Global Geek Tour 2012.

[Pay in US Dollars]

If you can afford to pay in dollars for something that isn't available anywhere else, try the following two international biggies.

12. DigiKey www.digikey.com

13. Mouser www.mouser.com

I hope this was useful. Let me know of your personal experiences with them and also if you know of other reliable online stores. I expect the list to grow with time. Happy soldering!

_____________________________________________________________________________

Reader suggestions

14. Aliexpress www.aliexpress.com [Suggested by Syam Krishnan]
While Element14 requires TIN number, Aliexpress is better suited for personal orders. Go to the "Electronic components and supplies" category on their website. 

15. Digibay www.digibay.in [Suggested by John F Xavier]
John found some affordable modules at their site.

16. Robokits www.robokits.co.in [Suggested by John F Xavier]
John bought servo and stepper motors from them.

17. DNA Technology www.dnatechindia.com [Suggested by Anonymous]

18. Hacktronics India www.hacktronics.co.in [Suggested by Abhijit Kshirsagar]

19. eNTesla India www.entesla.com [Suggested by Sudish Menon]

_____________________________________________________________________________ 

Discovered later

20. Project Point www.projectpoint.in