Projects/TransistArduino: Difference between revisions

An ideal capacitor doesn't allow current to flow through it but in reality that's not the case and depending on various parameters there's a small resistive component in the total impedance (or capacitance). This is usually represented as a series resistance ([https://en.wikipedia.org/wiki/Equivalent_series_resistance ESR on wikipedia]). In the case of electrolytic capacitors, my understanding is tatthat it's most likely due to the free electrons in the electrolyte and the reaction that takes place in the electrodes when the voltage is applied ([https://youtu.be/ZAbOHFYRFGg more info in this video from James Lewis at Kemet Capacitors]). When the electrolyte dries out or there's a perforation in the electrodes this ESR increases and that usually has adverse consequences in the rest of the circuit.

I realised that this was very tedious and I was probably going to find myself usingtroubleshooting itcapacitors in the future both as a hobby and most likely at work. A quick search on Google came back with some results and one of them was a review on Hackaday [http://hackaday.com/2015/04/24/review-transistor-tester/ http://hackaday.com/2015/04/24/review-transistor-tester/] regarding some cheap Chinese electronic components tester that I had also seen on Dave Jones' desk at some point. With a bit of research I realised that these boards are clones of a project called TransistorTester [https://www.mikrocontroller.net/articles/AVR-Transistortester https://www.mikrocontroller.net/articles/AVR-Transistortester] which in turn was also based on someone else's work.

One of the things I noticed straight away with the new firmware was the test leads capacitance compensation and initial calibration that can be performed which in turn gave very accurate readings on various capacitors when compared withto my multimeter.