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more than you expect!

Posted by COMPACT Top Member Jun 11, 2019
Würth the effort! This challenge is an investigation about the viability of polymer capacitors and their use with vintage electronics. With the Panasonic SMT capacitor portion completed I was still looking for viable Polymer capacitors in through hole sizes and packaging.   Würth Elektronik so kindly obliged and provided me with a nice box set of samples that were all nicely bubble wrapped. Because of their form factors, these capacitors can be used as direct replacements for ...
LM3940-3.3 Linear Voltage Regulator With Polymer Capacitors  The LM3940-3.3 is a linear voltage regulator that whittles down 5V to 3.3V.  This part was introduced for the proliferation of 3.3V parts and logic in the early 1990's. At first glance of the data sheet the minimum output capacitance for this part is 33uF. Unusually large for a linear voltage regulator but National Semiconductor must of had its reasons. Using Capacitor #8 (33uF @ 10V) with an LM3940-3.3 did not work. With ...
Further Improvements  The photo shows the modifications I applied but this would not normally be done as a standard repair. It was purely an experiment applying first principles to improve system stability and reduce EMI.   The modifications include the removal on unnecessary capacitors, the addition of links, PCB breaks and localised Coulomb bucket capacitors. Here is the final result. As you can see the noise has gone and the picture is stable as a mountain.     Co ...
Can we remove this noise using polymer capacitors or by other means?  As a random hack without applying any science I inserted some polymer capacitors at random into the PDN to observe any effects. I chose the capacitors with the most convenient packaging. The ones that allows direct soldering replacement without the need for any adapter boards. No perceptible difference was noticed on the video output or oscilloscope traces.   Applying some science into it shows that there would b ...
I was most surprised to see my name in the Road Testers list. Totally unexpected! Many thanks to the sponsors and element14!   I have encountered a lot of vintage electronic devices that make loud noises or produce smoke and glowing fireballs when powered up due to aging. I'd like to test the claims that polymer capacitors can be used as superior capacitor replacements to extend these devices' longevity and improve their operational stability and safety, whilst using fewer capacitors. & ...