Today, I started playing with transistors. I have here some teeny tiny 2n2222-108 transistors.
Actually, it didn't take long before I burned my finger against that transistor… It was really hot. I guess my mistake was to assume that a 680ohm resistance would be enough for the base.
Obviously I can't keep working like an idiot, otherwise it won't be long before something really bad happens.
But I have a problem here: I purchased these components from eBay, and except from the 2n2222-108, I have no way of identifying them to find a datasheet. Turns out that looking for "2n2222-108" on google yield me way too many results.
So, given that I only have "2n2222-108" as identifier, how can I know for sure the limits of the component?
Of course this question does not apply specifically to this component. I may be in the same case with any other.
Best Answer
2n2222 is all you need to know. It is a standard kind of transistor made by many manufacturers. (In fact it is the single most common kind of transistor.) Go to one of the websites that does retail sales of electronic components (e.g., Jameco, Digikey, Mouser). Type "2n2222" into the search box. Click on the first transistor that comes up. Somewhere on that page will be a link that is labeled "data sheet". Click on it. You will get a pdf file (from some random manufacter) that lists the specs.
Here is the one (from ON Semi) that I got when I did this at Digikey just now.