Help identifying this power plug?

[liquidzoo]

So, I've been designing some projects, and in one of them it was suggested that I put a wall wart (wort?) instead of a battery, which is a good idea (in my mind).
 
Saying that, I went to my box-o-electronics and found an old laptop charger (I probably have more somewhere), but I'm not sure what size of a jack I should get (looking at Radio Shack, they have several though I am aware of their huge mark-up) for this plug.
 
I will look and get the appropriate resistors for what I'm powering this with (though since it's only a single LED, this might be way too much overkill and it might just be better to use the battery in this case), but I'm wondering about the jack itself.  Even if I do decide to just use a battery, it will be helpful to know.  I can always add a trickle charger to my CMOY when I build it.
 
Anyway, on to the images:
 

 
Specs are 18.5V, 3.5A output (doubt that matters to the plug, though)
 
Here are the jacks I've been looking at:  http://www.radioshack.com/family/index.jsp?categoryId=2032284

 

[Avro_Arrow]

That laptop power supply is way over the the top if your going to use
it to power the LED in your switch project...
 
For that project you only need something like 6 volts and less than 100mA.
 
That laptop power supply would power a pretty good sized headphone amp though...
 
It might be easier to find a matching plug and jack to buy than trying to find
the right jack for that plug.

 

[liquidzoo]

 
Quote:

That laptop power supply is way over the the top if your going to use
it to power the LED in your switch project...
 
For that project you only need something like 6 volts and less than 100mA.
 
That laptop power supply would power a pretty good sized headphone amp though...
 
It might be easier to find a matching plug and jack to buy than trying to find
the right jack for that plug.

 

Fair enough.  Thanks again for the help.

 

[kevin gilmore]

In addition, those yellow jacks are usually a completely non-standard
size, and you have to find something with both the right outside
and inside diameters.

 

[wdahm519]

Measure the outside and inside diameters, and shaft length.  Then, look up the values and see what matches in a classification table.  Its the only way to know.

 

[Hudson]

Or just buy a matching plug and socket and chop that one off.