SparkFun Breadboard Power Supply Stick - 5V/3.3V

Jargon buster

Plain-language definitions for the technical terms used above.

DC barrel jack

A round power connector commonly used for low-voltage DC power supplies, often described by its outer and inner diameters such as 5.5 x 2.1 mm. Matching the barrel size and polarity is important so the plug physically fits and powers the device correctly.

Headers

Rows of connector contacts on a fixed pitch (commonly 2.54 mm) used to link a board to a breadboard, jumper wires, or another board. They come as male pin headers and female socket headers; when a module ships with pre-soldered headers it can be used straight away, whereas bare pads require soldering the pins yourself.

LED

A light-emitting diode (LED) is a small electronic component that emits light when current flows through it in the correct direction. Because it only conducts one way, its polarity matters, and a through-hole LED must be soldered the correct way around to light up.

PTC fuse

A resettable fuse that increases its resistance when too much current flows, helping protect the board from short circuits or overloads. It matters because it can recover after a fault instead of needing replacement like a traditional fuse.