Transistors 101 ep4: Followers and Switches

We look at a few more transistor circuits: the emitter follower, the push-pull amplifier, and the saturated switch.

We learn what they do and how to calculate their voltage transfer functions.

We learn the danger of switching an inductive load with a transistor, and pull 127 volts off a AA flashlight battery.

Schematics are on the project GitHub: https://github.com/kennykb/kevins-cav...

TIMELINE

00:00 Intro
00:50 The emitter follower
03:04 Emitter follower with split supplies
04:00 Kevin can be bit absent-minded.
07:06 Emitter follower under load
08:55 Push-pull amplifier
10:23 Fixing crossover distortion
12:15 Saturated switch
13:39 127 volts from a flashlight battery?
14:38 Taming flyback
16:09 Outro

CREDITS

Music:

“Light Sting” Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
http://creativecommons.org/licenses/b...

“MJS Stings” Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
http://creativecommons.org/licenses/b...

Graphics:

"Transistor Girl"
  / cvbgyterrxk  
© 2021 Samuele Caldini
Used by permission.

“Caïn venant de tuer son frère Abel, by Henri Vidal”,
Alex E. Proimos.
https://commons.wikimedia.org/wiki/Fi...
Creative Commons Attribution 2.0 Generic

“Mandrills Facepalming” Mark Laidre
https://www.flickr.com/photos/dullhun...
Creative Commons Attribution 2.0 Generic

"face palm" 'dancerher'
https://www.deviantart.com/dancerher/...
CC BY-NC-ND 3.0

"Facepalm. Photo by Katie"
https://commons.wikimedia.org/wiki/Fi...
CC BY 2.0 https://creativecommons.org/licenses/...,
via Wikimedia Commons

"Facepalms? Stained Glass Windows at All Saints Church (Ripley, North Yorkshire)"
Tim Green from Bradford
https://commons.wikimedia.org/wiki/Fi...
CC BY 2.0 https://creativecommons.org/licenses/...,
via Wikimedia Commons