PART FINDER FRIDAY – Small signal BJT! We’re continuing our tradition of showcasing the useful basics that everyone needs to have in their shop. Today we’ll be talking about the PN2222 (NOT to be confused with the P2N2222) NPN transistor. This is our ‘go to’ every-day NPN transistor. Its pin compatible with the the also-popular 2n3904 but with more current capability. It’s been great in the TV-B-Gone kit for pulsing the IR LEDs. You can use it to drive small motors, relays, or solenoids, audio amplification, level shifting, etc etc.
As far as small-signal transistors go, this is a good one to keep stocked up on so we suggest buying 25 or so.