Uxcell 5.5 Mm X 2.1 Mm Female Dc Power Jack 3-pin Wiring Results 1 - 48 of 5Pairs × Male/ Female DC Connector For Led Strip. DC12V UK AC/DC 12V/9V /6V/5V - 1A/2A Power Supply Adapter Plug 3 Pin Mains AC V . It is Centre Positive and has a mm x mm jack. adapter wire length: About cm. . Connection diagram of the adapter - for the B8 wall panel. Wiring a DC socket - why three pins? - Electrical This diagram might help you understand better. Here pin 3 will got to the battery, pin 2 & 1 to the circuit. When you plug in the socket pin 1 & 2 would provide the power to the circuit and battery will be disconnected. when unplugged the battery would be connected back to the circuit.This might be something similar to the female single channel audio connector where two of the 3 pins will be shorted when unplugged and when its pl..Best answer · 36The other possibility is that a 3 pin design is simply to provide a more robust and secure mechanical mounting. Connectors are subjected to mech..6It's difficult to tell from this image, and the Maplins website is very poor when it comes to datasheets and specs, so my answer is just a guess...5 Wiring the track In plain English, with diagrams! PDF fileD concepts Pty Ltd, 3/13 Lionel St., Naval ase WA 6165 Australia. *wwwoncepts * +61 8 9437 2470 * sales@dccconcepts DCC Advice #11 Page 1 Wiring Point-work & Special track conditions for DC or DCC Wiring the track In plain English, with diagrams!