Hello and Welcome to a simple beginners electronic project. Today I am going to show a transistor tester that is used to determine whether a transistor is NPN or a PNP. If its a NPN then the circuit should light up. This also an easy way to tell if your NPN transistors are working and will save you tons of time in the long run.
NPN transistors use the format of EBC which stands for Emitter Base Collector.
PNP transistors use the format of ECB which stands for Emitter Collector Base.