Choosing Transistors

Other Hardware General Electronics
1

I'm hoping someone can point me in the right direction on how to choose transistors for a various uses in a project.

I know the difference between PNP and NPN and can choose that part of it appropriately, but there are so many types of transistors to choose from that I feel overwhelmed.

At this point I want to use 1 arduino pin to control multiple leds (all = ON, or all = OFF at the same time) without using too much power from the arduino. I don't have the exact specifications handy and I know it varies, but how would I decide on a transistor once I know the voltage and how many max mA i'll be using?

Is there anywhere in particular on the web, or books/articles, where I could learn about choosing transistors?

2

have a look here :
http://www.mouser.com/catalog/supplier/library/pdf/FairchildBipolarPower.pdf

you'll see the VceSat @Ic =xx info and other characteristics
page 8 for switching transistors

there are other selection guides ..... :wink:

3

You might consider using logic-level Enhance Channel MOSFETs over bipolar transistors. :wink: