Hi. This is my story, not Rudy Severns'. I've known Rudy Severns most of his professional life and through his seminars, papers, books, and personal conversations, his mentoring has shaped my engineering career. Those who know Rudy know he never blows his own horn. My efforts in bringing his ebook to your attention have driven him to and beyond his comfort zone, so be aware, he is not writing this, one of his many fans is. But first, a disclaimer. I'm an affiliate for Rudy Severns ebook, Snubber Circuits for Power Electronics, which means, if you buy the ebook through this website, I profit from the sale. This wouldn't change my enthusiastic recommendation for the book, but it is something you should know. Jerrold Foutz, Owner, SMPS Technology.

The Failure of Text Books

If you are like me you found that text books worked fine for what they were intended to do -- to systematically provide the fundamentals you need to lay the foundation for your career in electronics.

And like me, many of you kept your text books, I know I did.

After all, you invested considerable time and effort in mastering their content and it was comfortable to think that when you got in the real design world, you would just have to flip through familiar content to refresh your memory and move on with your design.

It didn't work that way, did it?

The Pain of Real World Circuit Design

When you look up any real-world design problem in a text book, you find that, at best, it is left as a homework assignment. The professor has the answer book, but you probably don't.

You slowly grow more and more frustrated with text books.

The reason?

Schooling rewards you for KNOWING a body of material, not what you do with it. In contrast, industry rewards you for WHAT YOU DO, not what you know. No one cares what you know, only what you can do -- and what you are required to do is meet the design specification, especially field reliability, on-schedule and within budget.

In industry you find that how-to books are more useful than text books because they show step-by-step how to accomplish a design. You probably have one for such basics as magnetic design, operational amplifier design, etc. However, good ones for power electronics are few and far between and often not available when you need them. Application notes go a long way to fill the void that text books leave, but they have their own problems.

So this is the situation in which you often find yourself.

Midnight -- and One More Night Without Sleeping

Your circuit design is due for release for layout in the morning. You have worked hard at all the basics ... magnetics, filters, control circuitry, stability. But the power switches and diodes are close to or hitting the limits of their safe operating area and EMI is excessive. You have left the snubber design to the last minute and the circuit will not meet EMI specifications or field reliability if you don't get this done, and done right. If not done by morning, you've missed schedule.

You might have a friend who is an expert in snubber design who is willing to come to work at midnight to help you. Maybe, -- but I've never had that luxury.

You might be able to get what you need from text books or application notes. But it is unlikely, even if you have a week to do it. You know this won't get you where you need to be by morning.

Wouldn't it be great to get on the Internet and download a how-to ebook on snubbers in minutes, where a world-class snubber expert would guide you through the design to a near-optimum snubber for all the power switches and diodes in your circuit -- before morning?

You bet it would. And that was the driving concept of the ebook, Snubber Circuits for Power Electronics.

Now I admit that I suggested to my long-time friend Rudy Severns that he should write such a book, because he knows more about snubber design than any person I know. He accepted the suggestion and he wrote the ebook I had visualized ... and much, much more. What I had visualized was the 41 page Chapter 7 of the ebook that eventually grew to many chapters and 346 pages.

Chapter 7, Bare Bones Snubber Design is the original concept. It has six design examples walking you through several RC snubbers, then RC-Diode snubbers, and finally an energy recovery snubber. It uses rules-of-thumb, SPICE simulation, lab measurements, and almost no math to create a near-optimum snubber design. And you don't need to read the other chapters to get the job done. Those chapters let you better understand and master the subject after you have met schedule. You just might make that morning deadline if you could only get the ebook -- right now.

You can. That is the reason Snubber Circuits for Power Electronics is in PDF format, hosted in the world-class Kagi store on a secure digital-delivery server. The goal is to have the ebook on your computer within several minutes after ordering it so you can get on with your design -- and that speed-of-delivery usually happens when you buy the ebook with a credit card or verified PayPal purchase.

Payment Options

Some readers of the Snubber Design Newsletter were worried about not being able to buy the ebook with US dollars. This should be no problem.

You can pay for the ebook using all major credit cards: Visa, MasterCard, American Express, Optima, Discover (Novus), Diner's Club, Carte Blanche, Carte Bleue, JCB, and Eurocard -- any of these cards, if they are tied to a financial institution. Pre-paid and gift cards will not work for instant delivery because they are too easy to use for fraudulent purposes. Also, some financial institutions block certain purchases, Internet purchases being one of those. So far, this is happening in less than 1% of attempted purchases.

You can choose to pay by credit card in the following currencies: United States Dollars (USD), Australia Dollars (AUD), Canada Dollars (CAD), Euros (EUR), British Pounds (GBP), Japanese Yen (JPY), Danish Krone (DKK), New Zealand Dollar (NZD), Norwegian Krone (NOK), Swedish Krone (SEK), Swiss Franc (CHF), or verified PayPal accounts. If you do, you should have your ebook in PDF format in minutes.

You may also pay by check, cash, money order or purchase order in approximately 23 currencies -- but you have to wait until funds clear before the ebook is delivered. VAT and some other taxes required by local governments are also collected and paid.

But I Only Want Chapter 7, Bare Bones Snubber Design

Sorry about that. As I said before, Rudy knows more about snubber design than anyone I know, probably more than anyone around. Once he got into the ebook, it grew beyond its original concept to incorporate a fair portion of that knowledge.

Which is a benefit to you. In medieval times, before the printing press, when books where meticulously hand copied, professors were professors because they owned the book, often the only book in the country on the subject. With this ebook, you also own the book, and when you finish reading it, you should be the go-to person on snubber design. It is always good for your career to be the go-to person in as many areas as you can in your organization.

Still haven't decided?

Then learn more about the author, Rudy Severns

Rudy Severns is a Fellow of the Institute of Electrical and Electronic Engineers, elected to this high honor by his peers for his contributions to the understanding and development of high-frequency power converters. Rudy was also selected as the winner of the 2008 Lifetime Achievement Award by Power Technology Magazine, the leading trade magazine in the power electronics field. The six page interview with Rudy Severns in the September 2008 online issue makes interesting reading. Rudy received his bachelor's degree in engineering from the University of California, Los Angeles. He is a consultant in the design of power electronics, magnetic components, and power conversion equipment. His 40+ years of experience include both commercial and military designs with TRW, Lockheed, Hughes Aircraft, Magnavox, Intersil, Siliconix, and the University of California. Since 1978, Rudy has lectured extensively in the U.S., Asia, and Europe on power conversion, magnetic design, and power semiconductor topics. He is also an expert in the theory and construction of antennas (N6LF). He has written over 87 technical articles and he is the author/co-author of two books, Modern DC-DC Switchmode Power Conversion Circuits and MOSPOWER Applications.

For years, Rudy has given in-house training courses on 18 different power electronics subjects. Two of his one-day courses include:

Snubber Circuits for Power Electronics
Snubbers are basic to maximizing semiconductor performance. This course presents the principles and practical design of snubber circuits for use in converters, inverters and motor drives. This course is highly recommended before taking the more complex course on soft switching techniques.
Soft Switching Techniques
In many circuits it is possible to dispense with snubbers by selecting operating modes which provide low stress switching. This course reviews the present art of soft switching.

Rudy has also written one of the most widely read application notes on snubber design, Design of Snubbers For Power Circuits by Rudy Severns, Cornell Dubilier Engineering Technical Paper, a 29-page PDF.

You could not ask for a better guide to introduce you to snubber design.

Convinced that this is the book for you? Then you can buy it now.

Buy Now

What Do You Get?

The eBook in PDF Format

You get a 346-page ebook in 8 1/2 x 11 inch PDF format that is read on a computer using the free Adobe PDF reader. It has a literature bibliography of 504 technical papers and references, and a patent bibliography listing over 75 snubber patents. It contains a chapter on Bare Bones Snubber Design that lets you produce a design -- fast -- without reading the rest of the ebook. The other six chapters provide a deep understanding of snubber circuit design.

A surprising fall-out from our pricing survey was that many engineers prefer PDF ebooks to hard copy. That is because they can carry dozens of ebooks on their laptop computer and electronically search the text and rapidly find information they want. Several were willing to pay more for a PDF than a hard copy. It seems logical, but this one caught us by surprise. The world is changing.

This is NOT a hard-copy book, and there are no plans to make a hard copy, but if you buy the PDF, you can print one copy for your use only.

Table of Contents

  • Preface
  • Acknowledgement
  • Chapter 1 - An overview of snubbers
  • Chapter 2 - Things you need to know about switches
  • Chapter 3 - RC snubbers
  • Chapter 4 - Dissipative RLC+diode snubbers
  • Chapter 5 - Energy recovery snubbers
  • Chapter 6 - Component selection and circuit layout
  • Chapter 7 - Bare bones snubber design
  • Literature bibliography
  • Patent bibliography
  • Index

A Supporting Website

Along with the ebook, goes a supporting website, www.snubberdesign.com. Devoted to snubber design whether or not you buy the ebook, the website will support the ebook as well.

A Money Back Guarantee

First the Kagi Refund/Return Policy

"Refunds are available within 30 days of product purchase by submitting a Refund Request Form to refund@kagi.com. Whenever we receive a refund request, we notify the product suppliers to give them an opportunity to resolve the dispute. Refund requests that have not been resolved within two (2) weeks are processed; and, for credit card purchases, the refund appears on the buyer's next credit card statement."

"For digital goods to be refunded the buyer must acknowledge that any continued use of digital goods constitutes a willful violation of copyright law, for which the buyer may be liable for substantial civil damages."

"The Refund Request Form may be used either by buyers requesting a refund or by product suppliers requesting a refund for their customers."

Now the Guarantee

As noted in the Kagi Refund policy, the supplier has two weeks to resolve any disputes. Well, the dispute is already resolved. As soon as Kagi receives the refund request, it will be approved unless fraud is involved. We would like to know the reason, because we want to sell the ebook to those that understand what they are buying and want the ebook. It is our responsibility to explain the ebook well enough so that happens. Your reason for requesting a refund will help us to do that.

The 30-day guarantee eliminates your risk in buying the ebook, but there is also a risk on the author's part in publishing a book as a PDF ebook rather than a hard-copy book. Fortunately, this ebook is intended for those in the engineering profession and those training for it. As Rudy says so well in his copyright notice: "Preparing a book like this takes well over 1000 hours of effort and a substantial investment by the author and publisher. Hopefully, this book will prove to be a useful contribution to the power electronics art. When such books are successful and provide some reasonable return to their authors, there is motivation to write more such books on other important subjects. The result is of benefit to all in our profession. Honesty is a fundamental requirement for any professional engineer and is expected of those in the profession or training for it. Your help is requested in not making copies of this work and distributing it to others or in accepting any such copy."

This ebook is an experiment in writing and distributing a substantial engineering book. If successful, you can expect more of the same, a benefit to you and your co-workers.

What Does It Cost?

You would expect to pay between $89.95 and $139.85 for a hard copy of a similar power electronics book. Some books, with less content, top out at $179.00.

But you won't have to pay that much because of the economies of electronic production. The cost of this ebook is $20.00 less than the lowest price you would pay for comparable hard copy book. At $69.97 the cost of this ebook is a bargain.


This is called a long sales letter or landing page, and its purpose is to invite you to buy the ebook. Not many read through to the end. You have, and I hope by now you know if you need or want this ebook.

But of course you do!

Here is the link to buy Snubber Circuits for Power Electronics by Rudy Severns.

Buy Now.

Jerrold Foutz, Owner, SMPS Technology

P.S. Do you have questions not yet answered? Send me an email at email

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