More Mailbag! 00:00 – DrPD UBC-C Open Source PD Protocol Analyser https://www.crowdsupply.com/t76-org/dr-pd https://t76.org/drpd/docs/ https://github.com/T76-org/drpd/tree/main 24:34 – Sabrent USB-C and USB-A 8 power 252W Charger https://link.amazon/B03E4bswK 35:03 – The Audio Circuits Cookbook: Building Blocks and Tools to Design Professional Audio Devices https://link.amazon/B0auUWq4f Forum: https://www.eevblog.com/forum/blog/eevblog-1775-mailbag/ Podcast (podcast2): Download

Part 2 of the PayPal Here teardown, because everyone wanted to know what was under the anti-tamper security mesh, so lets take a look. Datasheet: https://www.nxp.com/docs/en/data-sheet/IMX25CEC.pdf 00:00 – We return to the PayPal Here POS terminal teardown 04:11 – They want to stop Skimming hacks, it’s not just the keys …

Teardown of the now obsoleted PayPal Here POS Payment terminal. 00:00 – PayPal Here POS payment terminal 03:56 – Teardown 05:10 – Case security clips 06:31 – Battery 08:02 – Security tamper mesh 10:43 – POS Terminal companies and my job at KeyCorp 12:14 – Bye Bye secure keys 14:24 …

A follow-up to the previous video showing the complex AC impedance answer to the OpAmp exam question. Part 1: https://www.youtube.com/watch?v=nDEGqme5Z4g https://www.eevblog.com/forum/beginners/how-to-analyze-the-opamp-circuit/ OpAmp playlist: https://www.youtube.com/playlist?list=PLvOlSehNtuHu2FviAaZaiyXwN41G4b1Lf Podcast: Download

Dave answers an exam question on OpAmps that’s interestingly tricky. Bonus opamp tutorial on biasing. Part 2: https://www.youtube.com/watch?v=33rS0oLULqw https://www.eevblog.com/forum/beginners/how-to-analyze-the-opamp-circuit/ OpAmp playlist: https://www.youtube.com/playlist?list=PLvOlSehNtuHu2FviAaZaiyXwN41G4b1Lf 00:00 – A tricky exam question 01:45 – What’s missing? 03:11 – The two most important Opamp rules 04:44 – THINK about what sort of exam you are …