AC Adapter Connector Type - Page 1
Forum section: electronics / beginners

author: David-DIY
author_rank: Newbie
timestamp: January 23, 2013, 06:48:02 pm
content: Hi guys! I need to buy a 12v 3A AC adapter but the problem is that I don't know what type it is, I want to know the name or ID of the connector.Take a look at the pictures and you will know what I am talking about.I want to buy this adapter on eBay thats why I am asking for the connector type (name/id).Best regards,David

author: mariush
author_rank: Super Contributor
timestamp: January 23, 2013, 06:52:45 pm
content: Measure the internal and external diameter with a ruler, then search for universal adapter/ charger on eBay that comes with several jacks and see if one of the jacks fits your parameters.Worst case, get any adapter (but try to use Amazon or some store that should have more quality adapters instead of ebay) , cut the existing jack and put it on the new adapter.

author: UPI
author_rank: Regular Contributor
timestamp: January 23, 2013, 07:20:47 pm
content: Here is one made by a reputable company. It is stable and relatively low noise with a 5.5mm x 2.5mm plug with the inner part of the barrel connector being the positive terminal.http://www.ebay.com/itm/230855859362?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

author: 6502nop
author_rank: Regular Contributor
timestamp: January 24, 2013, 11:02:30 am
content: What you have there is called a "Barrel" connector. Since you have provided nothing to allow us to see the scale, there are three things you'll need to measure:Inside Diameter(ID)A simple way of doing this is to grab your set of drill bits, and carefully insert them, smallest to largest, until the size you chose doesn't fit. This then means that the size of the inside is somewhere between the one that fit and the one that doesn't. For example, if my 5/64" (1.98mm) bit fits, but my 3/32" (2.38mm) is too big, then I'd guess I've got a 2.1mm ID. Be sure to use the dull end of the bits.Outside Diameter(OD)The most common size is 5.5mm (~7/32"), or about the diameter of a NATO 5.56mm round, if you happen to have any lying around. This is easy to check if you have calipers, but if you don't, then just use a Crescent (R) wrench, adjust the jaws to fit the outside of the barrel, then measure the span of the jaws.I happen to have a simple drill bit index guide that has all these holes. I just line up the right one(s), and read the numbers. Most any hardware store should have them.Barrel Length(L)Most people forget this one. Just measure the usable length of the barrel from tip to where the insulation starts. This is important, as some jacks are deeper than others, and too short a barrel either won't make contact, or wind up falling out due to lack of friction/torsion. A minor quibble is whether it's a straight lead or right angle type. I prefer straight leads, as they don't tend to rip out the guts of your project if you forget to unplug it before moving (provided the plug is in the back - if it's on either side, it really doesn't matter much).You didn't set your location, but if you're in theYew Ess uv 'merica, Jameco has a very comprehensive section where they will match up the adaptor to whatever plug you need (if it's non-standard). Although, since you mentioned that it's a 12VAC@3A, I'd go out on a limb and say you're got a 2.5mmID- 5.5mmOD- 10mmL. Now, if you meant "AC to DC adaptor" in your post, it still wouldn't matter too much, as the rule-of-thumb for barrel plugs is to use the 2.1mmID for anything up to about 1.5A. Use 2.5mm for anything more.If you just need a good one-off adaptor, Radio Shack should still stock their "Adapt-a-plug" series. You should find an "octopus" mess of cables nearby to match the plug/socket (they use letter designations), then buy the adaptor and matching plug (if it's not already included). I've got a few of those tips, too.nop

author: David-DIY
author_rank: Newbie
timestamp: January 24, 2013, 04:33:54 pm
content: Thanks for your answers. Problem solved!