Switching with transistors PNP and NPN (the basics) HD

Old video from my former channel Radioam232, approx 2008. How to use PNP and NPN transistors as a switch. Switch mode = saturating the base from the switch transistor or Darlington with enough voltage/current, so the issue is not difficult.Only problem: a too high base current immediately (!) damages the transistor (Ts 1 and/or TS 2) and there is no (...) indication from that damage. Only that ""it"" does not work. All the videos hat I have published on You Tube can be found via my Channel Trailer: Link is https://youtu.be/xbgQ8T3oqh4 In thematical order you can find these video’s under the “comments” section. My books about electronics are available via the website from “Lulu”, search for author “Ko Tilman” there. My books are also available via Barnes and Noble and via Amazon. Regarding all my video’s: I constantly keep them actual, so the original video’s with the most recent information are always on YouTube. That is the source, and search there. When my video’s are reproduced or re-edited on other websites/channels you cannot be sure about the original content (=really working electronics) and important adaptations to the circuits.