DC Power Plug - Page 1
Forum section: electronics / beginners

author: admiralk
author_rank: Regular Contributor
timestamp: February 04, 2019, 12:01:46 am
content: Basically, how important is length? I am making a cable for a battery and the two plugs I have to choose from have different length barrels than the plugs that come with the battery. They are both the same difference, shorter or longer, .09". I really do not want the bare metal exposed, or have a weak connection either. I am limited in choice by the cable diameter, so it is not as simple as just finding one with the right length. Is it safe to assume that the shorter plug will work fine?

author: timelessbeing
author_rank: Frequent Contributor
timestamp: February 04, 2019, 12:12:32 am
content: How should we know?Does it make electrical contact? Does the plug fall out?

author: admiralk
author_rank: Regular Contributor
timestamp: February 04, 2019, 01:32:33 am
content: Well, if I had the plug on hand I would know that, and not be asking. The ring and tip diameters are equivalent, so I doubt it will fall out. I also doubt that Digikey will send me an assortment to try out. All I have is the plug that came with the battery to know what the length is.

author: timelessbeing
author_rank: Frequent Contributor
timestamp: February 04, 2019, 01:40:47 am
content: You didn't say if you had it or not.You're asking for help on a forum. We might be able to help you, if you could tell us what on earth you're talking about.Even a hint, like is it a barrel plug? Better yet provide some images or links.Are they expensive? Can you just order both and see what works best.

author: james_s
author_rank: Super Contributor
timestamp: February 04, 2019, 04:20:15 am
content: The length is important if the socket is recessed and needs a longer barrel. I've dealt with a few devices that had deep set sockets.

author: IanMacdonald
author_rank: Frequent Contributor
timestamp: February 04, 2019, 05:04:11 pm
content: More importantly there are two very similar sizes, 2.1mm and 2.5mm. Use the wrong one and you will have a bad connection.

author: ender4171
author_rank: Contributor
timestamp: February 04, 2019, 05:36:45 pm
content: Take a toothpick, stick it in the barrel receptacle/socket until it bottoms out. Mark the toothpick with a fine point marker/pencil/whatever where the body of the receptacle ends. Use the measure from your mark to the tip of the toothpick to determine the depth of the socket and get whichever will fit it as deep as possible without showing bare metal. You can also use the same method and a flashlight to get the depth of the outer barrel contact. Just make sure that the plug you pick will go in past that contact.

author: admiralk
author_rank: Regular Contributor
timestamp: February 04, 2019, 09:50:18 pm
content: I should have thought of the toothpick trick, worked perfect. Interestingly enough, the shorter plug is near enough to the same length, and the stock ones are long. I guess it does not matter that much if the barrel is exposed.timelessbeing, A DC power plug is a barrel plug, I thought it was pretty standard terminology since Digikey, Mouser, and every other store I looked at used it. And no, they are not expensive, at least not compared to the shipping or the Hirose connector that the device uses.Thanks all!