Transistor as a Switch - Using Transistor Switching
PNP TRANSISTOR AS A SWITCH | Transistors, Turn ons, Led lights
Switching the high side using NPN and PNP - Project Guidance - Arduino Forum
Help] Should I use an NPN or PNP transistor to switch positive side of a bunch of common anode seven segment displays? Why is one better than the other? Thx! : r/arduino