This UL-certified AC-to-DC converter gives you an easy way to power your DC electronics project from a US-style AC electrical socket. It uses a switching regulator to efficiently output up to 1 A at a near-constant regulated 12 VDC, even when no load is applied. The DC power cable is 4 ft (1.2 m) long and terminated with a center-positive, 5.5 × 2.1 mm barrel connector that works with the DC power adapter barrel jack as well as the barrel jack on many Arduinos