What is a good-quality universal AC adapter? - Page 1
Forum section: electronics / projects

author: reddish
author_rank: Newbie
timestamp: December 16, 2020, 11:03:13 am
content: Hi all,I am looking to buy a few decent universal AC adapters for some electronics experiments I am doing.For best performance, I do have a decent lab supply, but I'm looking for something portable to feed some PCBs that could benefit from a clean power source.For my application, I am more interested in the robustness, quality, and stability of the voltage and power delivered than in finding the lowest price.Can anyone perhaps recommend brands/models that they have good experience with?Is there perhaps a review/comparison to be found online for stuff like this?Any info would be greatly appreciated!Sidney

author: madires
author_rank: Super Contributor
timestamp: December 16, 2020, 12:08:55 pm
content: What are you exactly looking for? Input voltage? Output voltage? How much power? SMPSU? Linear?

author: NiHaoMike
author_rank: Super Contributor
timestamp: December 16, 2020, 12:54:53 pm
content: Smartphone chargers from reputable brands like Anker are quite well built, go for one with more current capacity than you need and it will handle the load continuously no problem. The fast charge ones will even support voltages above 5V although you'll need a circuit to switch the output voltage.

author: Gyro
author_rank: Super Contributor
timestamp: December 16, 2020, 01:08:06 pm
content: If you need even more power, a second handgenuinelaptop brick from ebay is a good bet. Go for a decent brand like Dell, IBM/Lenovo, HP etc. Make sure the listing has a decent photo of the lable and don't get trapped into the"for xxx" cheapie replacement ones.This approach can get you a 'better than new' adaptor at very modest cost.

author: algorithm
author_rank: Regular Contributor
timestamp: December 16, 2020, 02:08:34 pm
content: I recall seeing 12voltvids repair a pretty handy looking wall wart that was adjustable.But apparently they dont make em like they used ta.While 12voltvids might get hate from some, might not do the cleanest work in somes eyes, but he is 1 of the most efficient Ive ever seen.No matter who you are I imagine there is something worth learning from 12voltvids.I wish I had a friend like 12voltvids to bounce ideas off of and get insight. But anyway.I recently have gone through my hoard of vintage AC adapters, and almost every single 1 has gone 3 times over spec. Even name brand stuff like Nokia 3v. I expect it to be a bit over rating in consideration to voltage drop. But 3x could be damaging I bet.1 thing I noticed in my testing was all the medical device wall warts were still exact spot on. Also a 2wire dsl modem adapter still was exactly on spec. Although I guess not as old as others.I doubt this is applicable since quality seems to be main priority but Ill mention it. I recently bought a 4$ buck boost converter off ebay that can do between 0.5v to 30v with 5v input. So that is a handy way to have a good range with just a usb. Although I havent put it through the ringer to see how much it can handle. It wouldnt surprise me if the quality would be on par with a more expensive alternative.I hope anything I said was helpful. Best of luck in finding the perfect candidate.

author: reddish
author_rank: Newbie
timestamp: December 16, 2020, 10:26:04 pm
content: > What are you exactly looking for? Input voltage? Output voltage? How much power? SMPSU? Linear?Input 220V AC (I'm in the Netherlands).Output voltage: preferably switchable (eg 5V, 9V, 12V DC). If not I'd settle for a 12V fixed voltage.Output power: somewhere in the 2--5W range.Type: I'd be interested to check out well-built switched and linear supplies. I'd want to inspect and judge their behavior under reasonable load on a scope. But I'd like to start such an inspection round with models that are at least somewhat well-engineered.Form factor: preferably a regular wall-wart.

author: reddish
author_rank: Newbie
timestamp: December 16, 2020, 10:30:25 pm
content: > I hope anything I said was helpful.Most certainly, thanks. I'll check out the video. And your suggestion to check supplies for medical equipment is a good idea; I suppose they ought to be built to a bit higher standard where not every 1-cent component is counted.

author: Pawelr98
author_rank: Regular Contributor
timestamp: December 17, 2020, 12:39:23 am
content: Friwo is a good brand.I had practice in a factory in Poland which produced these.In fact I have some parts from those.Good PCB quality and excellent safety as the transformers have secondary wired with "safety" wire.That is a good, thick isolation as well as shields (for a ~60W flyback there were two primary/secondary shields) within the transformer.Primary/secondary isolation is also top-notch with multiple layers of isolation between the windings.I have also used several of those, which were leftovers from a closed product line and rejects that I repaired myself.Never failed me, even after modifications which changed the output voltage (431 divider change).IIRC in all cases outputs had LC filters so I guess it's a nice addition, which keeps the voltage fairly ripple free.If you want an adjustable option, then modying the feedback in a flyback topology (which is the most common thing in the low power range) works well.Just add some resistors with a switch.

author: poorchava
author_rank: Super Contributor
timestamp: December 17, 2020, 08:09:20 am
content: I often use Sunny branded power bricks and wall warts available in TME. They generally do what is written on them.In my day job we had some of them tested for EMC and they pass.MeanWell is also an obvious choice. Reasonably priced and does the job too.

author: madires
author_rank: Super Contributor
timestamp: December 17, 2020, 10:20:36 am
content: Meanwell MW3A06GS/FUSB1 or MW3N06GS.