In this video I’ll tell you what is darlington transistors, how to use them to switch medium current loads with microcontroller and what downsides they have.
Also you’ll find out about darlington arrays. Of course there would be small demonstration of controlling different loads at the end of this video.
In case if you don’t know how to use an ordinary bipolar transistors, check out this two videos:
How to design a transistor circuit that controls low-power devices from Ben Krasnow
SparkFun According to Pete 7-5-11: Diodes and Transistors
Schematics & datasheets:
All photos are clicable!