Hello everyone, and welcome back to another weekly design challenge summary. It’s the fifth week of the Experimenting with Polymer Capacitors Design Challenge. And lots of progress has been made over the past seven days, but before we get to the good stuff, let’s take a few moments to learn more about this challenge, and what hardware is being featured.
Experimenting with Polymer Capacitors Design Challenge
About The Challenge
The Experimenting with Polymer Capacitors Design Challenge is a new type of challenge for 2019, this challenge is a hands-on competition that everyone in the community can participate in. Instead of requiring a participant to produce a full prototype, project, or original circuit design, we decided that we'd give our members the opportunity in this competition to experiment, test, breadboard, or just play around with Polymer Capacitors, and then tell us about their experiments, and what they learned about Polymers Capacitors in some blog postings.
While only nine sponsored challengers were chosen to receive a free polymer capacitor kit, entering the challenge is not limited to just those nine community members. Anyone can join the competition by including at least one of the kit's polymer capacitors in his/her experiments
The Official Kit
Nine Challengers received a discrete component kit that included several different types of capacitors that can be used to experiment with. As the list is quite long, I am not going to post it here. If you are interested in purchasing the kit for yourself, please visit this link.
- Grand Prize:Keysight Digital Oscilloscope, InfiniiVision 1000 X-Series
- Finisher Prize:Tenma Pen Type Digital Multimeter - To be eligible, a challenger has to complete their project, use products from the challenger kit, and post at least 2 updates in the Experimenting with Polymer Capacitors workspace.
To learn more about the prizes, head over to the this page. (https://www.element14.com/community/docs/DOC-92091/l/experimenting-with-polymer-capacitors-about-the-competition)
The Past Week In Review
Over the past several days, June 2nd - June 8th, we have had a total of six updates posted across five projects. This week I will feature three of my favorite updates from this time period, but before I get to that, let's take a look at which projects were updated.
- Project:Performance in Medical Instrumentation Amplifier - by F. Yao (fyaocn)
- Project:Using Polymer Capacitors for Supply De-coupling in the Current Amplifier - by Donald Lane (three-phase)
- Project:Deep Dive into ESR - by Frank Milburn (fmilburn)
- Project:How Low Can You Go - by Rod (14rhb)
- Project:Vintage Computer Designs - by Very Compact (COMPACT)
This Week’s Top Updates
Donald Lane - Experimenting with Polymer Capacitors Blog #2 -Using Polymer Capacitors for Supply De-coupling in the Current Amplifier
When we last left Donald Lane’s experiment with polymer capacitors he had just finished testing polymer capacitors as supply decouplers in a current amplifier, and this week he is back with the test results. Unfortunately, before Donald could get any solid test results, he had to solve a small problem with the amplifier with electrolytic capacitors. When he would energize the amp, the decoupling caps would bulge and then explode. Fortunately, this issue was not caused by a flaw in the amplifiers design, but rather a bit of human error when soldering in the capacitors resulting in one of the capacitors having its polarity reversed. “At the time of the video a 47uF had failed, but the other board with the polymer capacitors installed had been energized without any issue. I wondered, if I had overheated, the capacitor and damaged it soldering it in,” he wrote. “I just could not figure out the failure reason, I have seen plenty of capacitor failures and knew from the video that the device was over pressurizing, but it took me a good while before I realized that it was a polarity issue.”
With the exploding capacitor issues sorted out Donald was able to move onto the testing phase, and he thoroughly detailed the results of the comparison of the 10uF, 47uF, and 100uF variants of each type of capacitor. “The findings are likely only to be relevant for the set-up of the current amplifier I have built. The main supply for this is totally unregulated, relying upon large smoothing capacitors, and this can clearly be seen in the waveform plots collected,” he continued. “The test results are somewhat chaotic, with very little consistency seen across them. Whilst in some instances, improvements were seen when installing a specific polymer capacitor. That improvement was then not replicated across the complete range of polymer capacitors.” To read the results, and Donald’s final conclusion, head over to the full post by clicking the link above.
Frank Milburn - Experimenting with Polymer Capacitors Blog #3 -Deep Dive into ESR, Application
In his first two challenge updates, Frank Milburn covered the basics of what ESR is and how to test it, he is back with another update that dives into a practical application of using polymer capacitors to add bulk capacitance to reduce output switching ripple reduction on a TI SWIFT Power Module. To do this, he will solder in additional capacitors to the TI SWIFT he previously road-tested. Luckily for him, TI has provided solder pads that match up with some of the Panasonic capacitors that arrived with the official challenger kit. “It recommends a Panasonic aluminum polymer capacitor for C13 with similar value and footprint to one in the kit provided by element14. In this case, a single aluminum polymer capacitor will replace what would otherwise be a number of ceramic capacitors. In the tests that follow, a limited number of conditions were evaluated at relatively low output power conditions,” Frank Wrote. “The setup used for measurement was similar to the original TPSM84A21 RoadTest as shown schematically below, differing only in that the current was read from the bench power supply.” I don’t want to spoil things too much, so head over to the full post at the link above to find out if the polymer capacitors were able to successfully reduce ripple on the TI SWIFT’s output.
F.Yao - Experimenting with Polymer Capacitors Blog #2 -As much as Polymer Capacitors can go in Instrumentation Amplifier
F. Yao is known for his well-written Design Challenge Projects and his documentation of his experiments with polymer capacitors is no exception. In his second update, he chooses to forgo the usual method of having a custom PCB manufactured at a Chinese fab house and etch the PCB himself. This is mostly due to time constraints, and by etching the board himself, F.Yao will save both time and money. “Best choice is sending the Design Gerber files to manufacture, normally they charge little for pilot design and deliver the PCB board within one week in China,” he wrote. “One week is too long, why not make it one hour, do it by myself, I can make it one hour. Luckily, I happen to have all the DIY material.” Once the PCB has been designed he moves on to testing if the amplifier will work correctly with the polymer capacitors. Like many of the other post in this challenge, there is more than I can cover here, so I highly suggest heading over to the full post by clicking the link at the top of this paragraph.
That is going to wrap up this weeks coverage of the Experimenting with Polymer Capacitors Design Challenge. If you have not yet done so, please take a moment and check out all of this weeks updates, and show our challengers some love in the comments section of each update post. Check back next week for another weekly design challenge summary.