Power Adapter Tester for Male Barrels - Page 1
Forum section: electronics / beginners

author: aptraum
author_rank: Newbie
timestamp: June 07, 2014, 05:57:01 pm
content: Has anyone seen a power adapter tester for power bricks? I have about 2000 power adapters to test and was hoping to find or build something that could easily & safely be used by anyone. There are tons of different ATX power testers up on Amazon and was hoping to find something like this but geared towards two different barrel sizes. One of the adapters is 19v and the other is 19.5v, I don't necessarily see the need for a current test just voltage. I'm also considering making a breakout cable with the the female barrels that can hook up to an ATX tester but ideally I would like to find something specifically made for this test. Really surprised I'm having such a hard time finding one in a search.Maybe I'm over thinking this. The more I search for this product on Google, Amazon, eBay etc the more I wonder if I should just purchase 2 sets of multimeter probe cables cut the probes off, solder a barrel connector to the end and plug it directly into a multimeter. Another possibility if I can find the parts is a Y splitter with 2 different size female barrels at the end (pre-made or soldered) that go to a female socket in which I can plug my probes into. Unfortunately I'm not even sure what the multimeter socket is called, seems to be a bannana socket but it's hard to tell in some of the pictures if the probe will be fully insulated. Seems like these options would work fine but not as flashy as a standalone unit.Any ideas or suggestions?Thanks,Andy

author: fcb
author_rank: Super Contributor
timestamp: June 07, 2014, 07:09:51 pm
content: What parameters are you trying to test for? If it's fairly basic, then a voltmeter and a couple of resistors would work fine. - some multimeters can be setup with pass-fail limits I think.If you need more data, then some an active load (Dave did a test on a Mayuno I recall) might be a good choice.2.1mm & 2.5mm Barrel jacks (see Switchcraft), 4mm banana sockets, ohms law are key phrases you need..

author: aptraum
author_rank: Newbie
timestamp: June 07, 2014, 08:15:09 pm
content: Thanks for the reply! Not really doing thorough testing on these adapters just trying to see if the adapter is actually delivering a measurable voltage to see if they can still be used with a large lot of laptops or if they should be correctly recycled. I didn't even think resistors would be necessary since I wasn't building any type of circuit and believed (maybe incorrectly) that creating this type of cable would be similar to using the probes directly on the barrel. Turns out that I don't need 2 different barrel sizes after all since we will only be testing one type of adapter.Adapter in case it helps:Model EXA1206UH for Asus laptops19Vdc, 1.75AMain multimeter to be used in testing = Extech EX330It is wrong to assume, especially when power is concerned, but wouldn't this type of cable basically mirror the function of placing the probes on/in the barrel?Thanks again for any guidance you can give to make this huge task easier!

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: June 07, 2014, 09:47:21 pm
content: The barrel size on those adapters is 4.0mm x 1.35mm .You could buy a power jack and aligator clips,or solder some cheap leads to the jack .http://www.ebay.co.uk/itm/ASUS-ViviBook-ZENBOOK-Parts-X201E-X-201E-DC-Jack-Port-Power-Socket-Connector-/271191467489?pt=UK_Computing_CablesConnectors_RL&hash=item3f244565e1http://www.ebay.co.uk/itm/1M-Long-Alligator-Clip-to-Male-Banana-Plug-Testing-Cable-2-Pair-for-Multimeter-/191195334456?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item2c84214738

author: nerdyHippy
author_rank: Contributor
timestamp: June 08, 2014, 02:50:23 pm
content: You will get more accurate results if you add a load resistor. Many SMPSs significantly change their output voltage in response to different loads, so you'll want your tester to "look like" a laptop as far as the power brick is concerned.

author: aptraum
author_rank: Newbie
timestamp: June 08, 2014, 04:54:39 pm
content: @nerdyHippy - Thanks for the tip on the load resistors, not sure why I didn't think of that...still somewhat of a newbie when it comes to this. I think I found the perfect item over here, works well since I was going to buy some other items for a different project and it doesn't increase the shipping charge:https://www.adafruit.com/products/575Now off to find a self contained socket that will support the plug. Worse case scenario I will remove one from a bad board and make an enclosure for everything. Thanks again for the guidance!

author: theatrus
author_rank: Frequent Contributor
timestamp: June 08, 2014, 06:01:16 pm
content: I would get a large load resistor for this, you probably want to load at least 2-5 watts from the adapter as a sanity check. Going full range (50-120W) is even better if you can get rid of the heat.

author: codeboy2k
author_rank: Super Contributor
timestamp: June 09, 2014, 02:47:56 am
content: I recently tested a Dell laptop adapter at load like this. It's rated at 18.5V / 3.8A and I tested it at 2A load or about 36W. It actually turned out to be not a bad adapter at all, just 0.3% ripple at 2A load. It's a keeper for some future projectI used a scope to check the DC voltage, ripple and switching spikes at no load and at a 2A load.Switching frequency was about 60 KHz and ac-coupled noise was about 50mV unloaded and 55mV loaded @ 2A. That's the 0.3% ripple. DC level was 18.7V unloaded and 18.3V loaded at 2A.I did not have a proper differential probe nor even a second probe available to use on a second channel with math mode, so I had to use the AC-coupled setting on a single channel with the shortest leads possible (and not using the flying ground lead) so as to minimize stray noise pickup. I also turned off the lights, computers and other equipment too, to get the best possible signal.