DC Barrel Power Jack (5.5x2.1mm)
Standard coaxial DC power jack (5.5mm outer / 2.1mm inner diameter, center-positive) used to supply external power to boards and adapters. Common breadboard-mount versions add a third normally-closed switch contact for power-source detection.
Aliase:DC Jack, Barrel Jack, DC Power Connector, 5.5x2.1mm, Coaxial Power Plug, PJ-002A
DC Barrel Jack (3-Pin, Center-Positive)
3 Pins
Pinout Table3
| Pin | Signal / Name | Type | Alternative Functions |
|---|---|---|---|
| 1 | VCC (+) | Power | Positive DC Voltage Input (Center Pin, typically 5V–24V) |
| 2 | GND (-) | Ground | Negative DC Return / Outer Sleeve Ground |
| 3 | SW | Digital | Normally-Closed Detection Switch (Opens when Plug is Inserted, used to auto-disconnect battery power) |