Coaxial power connector

Barrel plug connectors are commonly used to interface the secondary side of a power supply with the device.

The second, inside contact is a hollow metallic cylinder constructed to accept insertion of the pin in the corresponding socket.

The inner and outer barrels are separated by an insulating layer, which is flared at the tip to prevent a short circuit when the plug is inserted or removed.

There is typically a single spring-loaded contact at the side of the socket and a pin in the center in order to connect the female type plug.

The sizes and shapes of connectors do not consistently correspond to the same power specifications across manufacturers and models.

Typically, this feature is a conical cut-back section of the tip, just behind the insulator that separates the inner from outer contact surfaces.

A "lock-ring DC coaxial connector" uses a captive threaded ring or collar to secure the connection between the plug and jack.

A "lock-tab DC coaxial connector" (also called "bayonet lock") offers a compromise that resists unplugging, but which will disengage when pulled hard enough.

There are several standards in existence, provided by bodies such as the IEC, EIAJ in Japan and DIN in Germany.

Note that the example part numbers given may have different connector barrel (sleeve) lengths, and are not necessarily exact equivalents.

(0.48×2.1 mm on socket side) Used for Sony PSP Charger (Input: 100-240VAC, Output: 5VDC @ 1500mA for PSP 1000, 2000, 3000)used in Miniware TS100 soldering iron by e-DesignIEC 60130-10 Type A (second of two with same type and same OD, the other has ID of 2.1mm and no center PIN) RadioShack sold a line of adapter plugs for universal AC adapters.

Each "Adaptaplug" had a single-letter code, but did not provide any other official designation, nor did RadioShack publish the complete specifications and tolerances on barrel and pin dimensions.

RadioShack's Web site listed the diameters to the nearest 0.1 mm, and sometimes differs slightly from the official EIAJ RC-5320A standard dimensions.

A common coaxial power connector, male (left) and female (right), 5.5 × 2.5 mm. Connector gender is determined by the center contact. Note: connectors depicted do not connect with each other.
Common DC power connectors
Male version of the coaxial connector plug
Some common DC power connectors
Lock-ring DC coaxial connectors. The knurled barrel allows the plug to be secured to jacks that have mating male threads.
Close-up of a yellow-tipped EIAJ connector . Note two round adapter pins on the opposite end.