This is similar to how I select a transistor along with calculating the value of the Base Resistor required to place the transistor in saturation mode; ie a transistor in switching On/OFF mode. There is no point is creating my own video when this explains quite clearly the process.
A project is currently under way where I use this process, soon to be posted. Just a small heads up, the following small switching Transistor is my all time favorite, the S8050 NPN transistor :-)
Datasheet: S8050 Wing Shing Computer Components.
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