Circuit Lake

Electronic Project and Circuit Collection

Simple Transistor Tester

08/04/2012 Category: Analog, Miscellaneous, Tools

The aim of the project is to build a simple NPN and PNP transistors tester and to identify their pin layouts, i.e. EBC, ECB. When you place transistor in correct position, the LED will light up. This circuit requires few parts and it easy to obtain many of the required parts from your local store.

Transistor pin layout tester

The transistor type NPN/PNP determines the polarity of the connections. The orientation of the transistor is the pin layout. Leumas, the designer, define the pin layout when looking at the top of the transistor with the flat side facing toward you. That is probably not the official way to classify them but it makes more sense to me when he is placing them in a circuit.

– EBC stands for Emitter Base Collector. The left is the emitter, the middle pin is the base, and the right pin is the collector.
– ECB stands for Emitter Collector Base. The left is the emitter, the middle pin is the collector, and the right pin is the base.

Transistro tester schematic