Recommended · for beginners
PNP Transistor Tutorial (with the Raspberry Pi)
Why people recommend it
Recommended as a basic introduction to switching a load with a PNP transistor, listed alongside guides on LED resistors and optocouplers.
Watch for: Covers PNP specifically, so polarity differs from the more common NPN examples
In their words
From this youtube at about 3 min in, it looks like the PNP has a .7v drop from B to E, but do I need a resistor between the optocoupler and B as the video would suggest?
bhoward on electronics.stackexchange.com, Aug 2015. CC BY-SA.
A Raspberry Pi specific video states that the base resistor must be calculated using the β value of the resistor and the current of the circuit after the collector (R2+R5 and R6+R7).
John P. on electronics.stackexchange.com, Jun 2016. CC BY-SA.
