AC adapter / wall wart barrel plug sizes

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mdf

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#197860 15-Jun-2016 17:00

Is there a standard for the barrel plug sizes for AC adapters/wall warts?

I have a surplus-to-requirements car reversing camera that I've decided will make a pretty cool in-wall laparoscope when attached to a coat hanger. I've got an AC adaptor in my collection that is the right voltage and has the right barrel size to drive either the camera or monitor but not both, so I need to get another one. I can measure the outside of the barrel with calipers, but I'll be jiggered if I can measure the inside. Is there a standard or reference for these so I make sure I get the right thing?

ubergeeknz

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Vocus

#1574563 15-Jun-2016 17:02

can you measure the pin inside the socket?

mdf

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#1574565 15-Jun-2016 17:05

Not accurately. My calipers have reasonably big jaws and won't get inside the socket. I've been google fu-ing and "standard" sizes for pins include 2mm, 2.1mm and 2.5mm.

Dynamic

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#1574569 15-Jun-2016 17:12

I picked up a multi-voltage multi-adapter thingee from Tricky Dick's final sale just as a spare. Would owe me about $12 by the time I posted it to Welly if you felt it worthwhile. 1.5A at 3V through to 0.7A at 12V is the rating. It does not mention the tip sizes on the packaging.

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ubergeeknz

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Vocus

#1574908 16-Jun-2016 10:43

AFAIK the most common is 2.1mm so if you have to take a stab, try that. Or take the device into eg. Jaycar and try each plug in turn.

Fred99

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#1574996 16-Jun-2016 12:49

One other thing to be aware of with those plugs, they're usually set up with the pin as positive (+), but it's not uncommon for them to be the other way around with the pin negative and sleeve positive. It's usually marked somewhere on the device, but sometimes isn't. It's usual that there might be reverse-polarity protection diode in the device, but Murphy/Sod's law says that it won't just when you needed it.

linw

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#1575149 16-Jun-2016 16:41

To size the 'hole', try inserting drills e.g. if a 2mm drill is a trifle sloppy, then it would be a good guess for 2.1mm.

mdf

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#1575172 16-Jun-2016 17:06

ubergeeknz:

Or take the device into eg. Jaycar and try each plug in turn.

Meatspace! Of course! How did I forget that you can actually go into a store and _try_!? The internet is ruining me...

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ubergeeknz

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#1575525 17-Jun-2016 09:51

mdf:

ubergeeknz:

Or take the device into eg. Jaycar and try each plug in turn.

<facepalm>

Meatspace! Of course! How did I forget that you can actually go into a store and _try_!? The internet is ruining me...

Yep, Meatspace is still a thing :D easy to forget I know...