Transistors are the backbone of modern electronics. In a circuit, they function as either amplifiers or switches. It’s hard to imagine that simple knowledge could help you build a functional gadget, but today the HackMakeMod team is helping you start down that path. We’ll help you understand how an NPN transistor functions as a switch and show you how it can create a light-sensitive or temperature-sensitive warning device. It is easy to be overwhelmed and discouraged by advanced aspirational project builds when starting your journey in DIY electronics. While your goal may be building a computer or radio, starting with a few smaller DIY projects like this increases the chances you can successfully achieve those goals. Tackling an aspirational build is much easier when you understand how each component works together and have confidence you can get those components integrated into the smaller systems needed to build the project.

We sell a basic electronics kit with many extra parts here...