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Where can I find NPN (2N3904)Transistors in scrap/unused electronics, in what devices can they be found in? Answered

I would like to know where I can find an NPN (2N3904)Transistor inside of something I may already have. 



3 years ago

Except Radio Shack just declared bankruptcy, and they don't even have enough money to get the paperwork and legal stuff taken care of :( It's so sad, but unfortunately it is no surprise either. Oh well. Maybe my local shack will have a closeout sale of all the electronic parts! A friend of mone got a whole shelf of stuff for $6!!!!!

Erm... LIKE radio shack. They're not the only game, and they're plentiful online at very low cost

Still not as good as the prices as jameco or digikey or mouser. Even at a loss, (with negative revenue, not just negative profits) and they still could not manage to compete. Radioshack should have moved into the realm of component distribution online, and become something more like best buy or staples as a location store. Not sure how those other component distro's are able to sell brand name components for pennies though!

Sad indeed. Lots of good deals going on now. I visited three of them last week.

That's pretty basic and I know that. Many others would too, I hope. Thank you though, I appreciate it.

Sorry, but your "need" to harvest dubious 3904s from refuse instead of purchasing a forty cent part just seems way too humorous to waste time with any further conversation.

I used to do the same thing lol

Like max said the 2N3904 is an odd one to find. May I suggest....www.ebay.com/itm/30-x-2N3904-NPN-General-Propose-T...

100 Pcs @ 99c including shipping (maybe a month to ship unless you request something faster)

Sure you could pull apart some old gear kicking around your shop; You may just get lucky!

But will it work right? and what is your time worth to you?

Anytime :D

Btw punch "arduino" into the instructables search, if you havn't allready >.> You might have some fun pokeing around :P

My first Arduino was an Arduino Duemilanove purchased a year after it's release date. I have been at it ever since.

Right on; you are a generation ahead of me (Uno) lol

Good luck! Feel free to bounce any Ideas off me :P


3 years ago

I have taken many things apart, but have generally never found jelly-bean parts inside of one. (with the exception of my lithium battery charger, which uses readily available SMD and through-hole parts, like LM324s, a IRFZ44N, ATmega8, 7805, etc.) Just see what devices you can salvage easily, then research the part numbers on them. You will find everything from voltage regulators and references, to active filters and stuff! You might learn a bit as you reverse-engineer the device under destruction!

Most likely you will come across plenty of NPN, PNP and FET transistors, but not specifically the 2N3904. The reason is that the 2N3904 is not really a good transistor. I often prefer 2N2222's or 2N4401's.

I have been learning a lot over time by salvaging components and by doing just that. One of the critical aspects of my endeavor in tinkering and electrical engineering is that I have to learn to determine alternatives and efficiency in terms of electronic components. Anytime I salvage a part I go onto googling it and hunting down it's database, if I'm not familiar with it. So much to learn still. I appreciate your feedback. I wasn't expecting such a speedy reply. Thank you. I'll be looking into those transistors shortly. I went ahead and got a no contact voltage detector, but would still love to build it just for the sake of educating myself and for personal entertainment.