Your source for daily hacks

Published on: August 29, 2013 / Comments: 4

How to figure out the pinout of a NPN or PNP transistor

Well you could always get a multimeter that checks transistors too...

Ever pick up a transistor without being able to read the part number to look up ?  Or can’t find it when you look it up ?  Well grab a multimeter and with a little know-how you might be able to figure it out.

First thing is to find the base, this can be done by measuring the resistance.  Once you have the base figured out, then with the tip of your finger touching the base (acting like a switch) you can determine which one is the collector, and which one is the emitter.  Sounds cool right ?

Check out the full instructions here. (fixed link)


  1. […] tool that can quickly identify both the transistor type, and the correct pin out.  We posted a method earlier on how to determine these characteristics manually, but where’s the fun in that ?  Part of […]

Leave a Reply to Tim Kramer Cancel reply

Some HTML is OK