I was fortunate recently to win the Experimenting with Polymer Capacitors competition here on element14 and have also been successful in several RoadTests and Project14 contests.  Other successful element14 members have published their entries and I have benefitted from reading them.  For example, find links on entries from the following persons below:

• Jan Cumps
• Donald Lane
• Douglas Wong

Although I have an engineering degree and lots of experience it is not primarily in electronics or programming which might be deemed a disadvantage.  Nonetheless it is possible to contribute and participate successfully in the many opportunities offered here on element14.  This blog outlines how I go about it and I also give my successful entry for the Experimenting with Polymer Capacitors contest.

My considerations before making an entry are these:

• Is it worthwhile to me and to the element14 community?  I don't enter to win prizes and stuff (although I like prizes and stuff ). I enter for the learning opportunity, the interaction with other element14 members and the personal satisfaction of possibly helping others.  It would be much more efficient for me to work a day job and use the money earned to buy stuff.  Good RoadTests and interesting projects worth publishing take time.
• Is the item in the RoadTest something I can use or can it provide a good learning opportunity?  I have a lot of stuff making my little work space difficult to work in already.
• Do I have a unique idea, or at least something new to me?  I want to contribute something new or at least put my spin on things.

My considerations when writing a contest entry are these:

• First, read the contest rules and requirements.  Follow them.  Seems obvious and like it would be unnecessary to state this but apparently there are a number of persons who don't do it.
• Second, write applications that highlight your strengths relative to the contest.  I state competencies tailored to the RoadTest which support my entry without exaggeration. 
• Third, propose unique tests and projects where possible.  You want your entry to stand out.
• Fourth, consider the audience for the RoadTest.  A supplier of educational boards is probably looking for something different than the manufacturer of lab equipment.  And the members of element14 will be looking for something different as well.
• Fifth, read the datasheet / marketing information, etc. for the item.  This will often give ideas as well as provide material that can strengthen your entry.
• Sixth, give a detailed plan for the entry.  This makes getting started on a RoadTest much easier and is the usual basis for my first blog.  Show the person making the selection you know what you are doing.
• Seventh, make sure you have the time and equipment to execute your proposal.

With that behind us, here is my entry for the Experimenting with Polymer Capacitors contest which hopefully follows my "rules" for entry:

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Experimenting with Polymer Capacitors - Deep Dive into ESR

Design Challenge:

Full Name: Frank Milburn

Email:

Address:

Phone:

Reason for the Design Challenge:

Introduction

I am a retired engineer with a broad background and experience in the design, performance testing, and operation of electrical and mechanical systems stretching over more than 40 years.  My first job out of school was in Research and Development followed by Production and Project Management for a major global corporation.  After retirement I became involved in STEM education and have worked on several microcontroller based products.  I have an electronics lab with all the resources required to perform the proposed tests.

I am particularly interested in this design challenge as I have been methodically going back through basic concepts and components for my own benefit and also to better help others in their STEM education.  I do not own an ESR meter and the ESR70 would be useful for the projects that I do.  There are some polymer capacitors in the kit that I have not used before and look forward to investigating further.

I have taken the Polymer Capacitor Quiz and watched the recent Polymer Capacitor Videos.

RoadTest Objectives

• Describe what ESR is and how it can be measured
• Describe what capacitance is and how it can be measured
• Obtain experimental ESR values for various capacitor types and values
• Obtain experimental capacitance values at room temperature for various capacitor types and values

RoadTest Experiment

Two different methods / lab instruments will be used for each measurement.  The experimental apparatus used will include:

• ESR70 ESR meter
• 40,000 count bench multimeter
• 100 MHz oscilloscope
• Function generator

In addition to the measurements taken with the ESR70, the arrangement shown below will be used to evaluate and assess ESR.

The theory and derivation of the equations shown on the block diagram will be detailed in the design challenge report.  In summary, if the frequency of the square wave generated by the function generator is in the 100 kHz range an ideal capacitor would approximate a short circuit.  However, in a real capacitor there is an equivalent series resistance (ESR) that will cause a voltage drop across the capacitor which can be measured with an oscilloscope.  ESR can be calculated with the equation shown since the voltage and internal resistance of the function generator are known and the voltage drop across the capacitor measured.  The method is instructive in that the comparison between ideal and real capacitor behavior can be intuitively grasped from the oscilloscope display.

The ESR70 will be used to confirm the results from the oscilloscope / function generator experiments.  It will also be used to confirm capacitance measurements from a good quality bench multimeter.  Ceramic and aluminum electrolytic capacitors will also be investigated.

Report Summary Format

In addition to the derivations and written summary with observations and photos of the test setup the results will be placed in a spread sheet style table with data similar to that listed below for each capacitor evaluated:

• Datasheet capacitance
• Datasheet ESR
• Experimental capacitance from ESR70 and multimeter
• Experimental ESR from ESR70 and oscilloscope / function generator apparatus

This will allow quick comparison between different capacitor types.  Conclusions and links to cited material will be placed at the end of the write-up.

Sample Work and Commitment

< A list of self serving sample work readily available to those who want to search on element14 has been deleted > 

Having such a list is very helpful however.  I was not successful on a RoadTest entry until after I had made several personal blogs that were well received.  If compared to my first blog in the contest it can be seen that the entry was used as the outline with additional data. Thanks for reading and I hope this helps others with their entries.