PNP and NPN Transistors

1577

1d 14:35:51

A simple working examples of a PNP (left) and a NPN (right) transistor circuit. With independent circuit layouts. Controlled by a SPST switch which allows a low controlling current ("base current") through the BASE of the transistor. The controlled current through the EMITTER/COLLECTOR then drives a LED. 

The controlled current always flows in the opposite direction of the emitter arrow symbols for proper junction biasing (polarity between emitter/collector). The sum of the emitter current is equal to the base and collector currents. 

I recommend turning OFF the "conventional current" setting to observe "electron flow."  It's best to observe electron flow when working with semiconductors. 

published 10 years ago

lenzrulz

10 years ago

Nice...

Gregster

10 years ago

really cool exactly what i wanted to do :-) THX

Freddis

4 years ago

The main task of a transistor is to amplify the signal, and it's not possible to observe it in neither of the curcuits. If you remove both transistors from the circuits the outcome will remain the same. The example is bad and you should feel bad.

yereon

9 months ago

He said it's a simple example.. just to show how applying a signal to the base lets the current flow.. AKA turning the transistor into a switch. Why do you think there are so many in CPUs.. to create 0 and 1.. ON and OFF. A switch. Of course they're amplifiers as well, but you're going to confuse people and you're talking s*** for no reason. Instead of saying "bad example", correctly point out what you think he should have done and post your own circuit.

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