Power sockets help to test small parts of circuits, or empower you to start and stop your experiments easily, without soldering. Some power sockets come with a tiny internal switch. This can serve as a power selector between battery power and grid power. When a plug is inserted correctly the power through the plug will be used, otherwise the battery power connection.

For Arduino, the dimensions of the power socket are 5.5 mm barrel x 2.1 mm pin. The internal pin is the + or plus, usually connected to a terminal on the back side, where the sleeve is the – or minus connected to the middle of the bottom side. The switching connector is usually on the side.

Be aware that a pin diameter of 2.5 mm also exists, so if your plug does not fit you may need either another socket or plug.

Other common names: Barrel jack, DC power connector.

Most important specifications

  • Maximum voltage: 12 V
  • Maximum current: 1 A