Chinese ac adapters on eBay - Page 1
Forum section: electronics / projects

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 08, 2020, 05:31:43 pm
content: I've been trying to get a reliable 5v/12v AC adapter for my low-current (<1A per rail) vintage drives.So far, every AC adapter is a massive failure. A 5V rated for 2 amp crushes to 4.6V at 500mA.etc.Price seems no indicator of quality either.Oddly, the most rickety-looking thing is more reliable.https://www.ebay.ca/itm/DIY-KITS-HKS014R5-KIS3R33-Step-Down-Power-Module-US92-18V-48V-To-12V-5V-1-5A/183216582490?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649that thing just works, but now I would like to find a 20-30V DC adapter to power *that* thing.What is your experience with random Chinese AC adapters? Any sellers with reliable supplies?

author: Gregg
author_rank: Super Contributor
timestamp: February 08, 2020, 06:45:41 pm
content: I've had very good luck by finding wall-wart and stand alone corded power supplies at thrift stores for next to nothing ($1 to $2). If they are a name brand or have a UL listing it is a good sign of some quality. Many of these power supplies are left after the device they were supposed to power has died, things like modems and old laptops. A quick sniff test for release of magic smoke is prudent before purchase.

author: magic
author_rank: Super Contributor
timestamp: February 08, 2020, 06:52:04 pm
content: This man knowsAnother decent source is electronics recyclers sometimes selling on auction sites. They may have multiple identical supplies if you want, sometimes even hundreds, and you may get some basic warranty.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 08, 2020, 07:02:46 pm
content: Quote from: Gregg on February 08, 2020, 06:45:41 pmHere in Montreal these places are shutting down one by one. Salvation Army down my street just got bought out to be replaced by condos. Other thrift stores are more about clothes, the electronics sections are smaller and smaller.But I'll keep looking.

author: sixtimesseven
author_rank: Frequent Contributor
timestamp: February 08, 2020, 07:45:40 pm
content: My expirience in Shenzehen on the electronics market is the following. First of you have multi story bulidings with 2x2m boxes each a usb supply manufacturer. Almost all of them have a glas cabinet of some kind in the front with several adapters both put together and in pices. They all look the same. Some have even little weights which they proudly display. There might be 5-7 chargers on one of those plates.We asked one lady about the difference, she took the plate in front of her and showed it to us. She pointed to one side: "good qualely" and then to the other side "good plice". The good quality ones pcb looked decent. The cheap one, well they had nothing on there....I would be VERY careful with those adapters. I straight up told everyone I know that they should not plug in anything from a non trustworthy source into a power outlet... You cannot tell from the outside, the Ebay seller might switch it's source or "quality" at any moment. And there might be high voltage which can kill your devices or you.

author: Monkeh
author_rank: Super Contributor
timestamp: February 08, 2020, 07:49:03 pm
content: Why not just go buy some decent ones from Digikey or Mouser?

author: BravoV
author_rank: Super Contributor
timestamp: February 08, 2020, 08:20:41 pm
content: Quote from: Alex Eisenhut on February 08, 2020, 07:02:46 pmNot sure if this applicable in your area, in my case, I love to randomly search local listings (like Craiglist equivalent), as unused wall-wart AC-DC adapters are basically in every households for decades, sometimes, people are selling bunch of these that powered their old unused/broken "quality" gadgets, and some cases they thought they could earn few bucks by selling "a box" full of these household junks.Few years ago I scored a box full of these quality wall warts AC-DC adapters, maybe 30 to 40 pcs for just about $5 , and my lucky score includes lots of big and quality iron core transformer adapters, like used in really-really old HP inkjet printers, Japanese household electronic appliances, quality phone or laptop switching chargers and etc.Ask for photos, or even better close-up zoomed photos if they can provide it, as this is important for identifying and judging if its worth your trouble.

author: ConKbot
author_rank: Super Contributor
timestamp: February 09, 2020, 05:04:33 am
content: Quote from: Monkeh on February 08, 2020, 07:49:03 pm+1 to that. $6 in low quantity, with UL rating so you can be relatively sure it won't kill you or burn the place down.https://www.digikey.com/product-detail/en/tri-mag-llc/L6R12-050/364-1265-ND/7682628If you need something cheaper, downgrade to an ETL only rated unit. No returns/dodgy specs/slow boat through customs roulette.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: February 09, 2020, 05:55:24 am
content: Quote from: edavid on February 09, 2020, 05:36:23 amQuote

author: EEEnthusiast
author_rank: Frequent Contributor
timestamp: February 09, 2020, 06:06:50 am
content: The cheap AC adaptors run a risk of electric shock due to poor components, badly designed PCB etc..Buy from reliable sources like Digikey , Mouser etc...

author: beanflying
author_rank: Super Contributor
timestamp: February 09, 2020, 06:19:27 am
content: Depending on YOUR local regulations and not the advice of others from around the world make sure your ass is covered if YOU are doing the importing of mains anything to sell or for others to use. It only takes one thing to go wrong and you can be in a world of legal hurt.In Oz for example selling a non compliant wallwart/supply of any sort and generally all states require them tested prior to sale. This simply doesn't happen and garbage is being sold online or via $2 shops or even major retailers in some cases.Digikey, Mouser, E14 etc won't in our case have the paperwork and testing done. So technically using supplies from them puts the seller of them at risk in spite of maybe meeting US or EU standards.Find a local company that meets your regulations and do it right. If it is just for yourself then play safe and enjoy and use whatever you want

author: Prehistoricman
author_rank: Regular Contributor
timestamp: February 09, 2020, 12:23:46 pm
content: Quote from: Alex Eisenhut on February 08, 2020, 05:31:43 pmGeneric laptop chargers are 19V and you should be able to get them in various power ratings.As for finding good quality ones... maybe known brands on the second hand market? Apple laptop chargers also work in this voltage range.

author: janoc
author_rank: Super Contributor
timestamp: February 09, 2020, 01:00:26 pm
content: Quote from: beanflying on February 09, 2020, 06:19:27 amDon't Oz authorities recognize e.g. FCC, CE or UL testing when approving stuff for sale? I can't imagine someone like Mouser selling stuff in Oz that isn't legal there or that they don't have the paperwork in order. If nothing else they have to ensure the plugs are correct already, given that they are different from every other major market. Of course, that assumes you are ordering from a local subsidiary (e.g. Mouser Australia, if there is one), not directly from the US. If you couldn't rely on a vendor like that then there is nothing you could do at all, except getting a supply certified yourself (good luck with that ...).That major retailers (not specialists like Mouser or Digikey) sell dangerous crap that they got from some fly-by-night importer somewhere is another matter - that is common even here in France where you can find literal deathtraps being sold in Fnac, Carrefour and similar places, sometimes even without the CE markings (which is flat out illegal, regardless of how meaningless that marking is).The advice to "find a local company that meets your regulations and do it right." is pretty useless, IMO, because I can't imagine he will be ordering custom made power supplies from some local outfit and having them certified, unless he is going to sell hundreds of pieces. Or rely on some local mom & pop vendor - who is importing the same junk from China as the mall down the road, because they don't have anywhere else where to get it from anyway.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 09, 2020, 02:28:58 pm
content: Yeah looks like my little eBay adventures end here. I spent more on buying garbage overall.edit: I think I figured it out. 5V 2A on a Chinese adapter means 5 volts XOR 2 amps.

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: February 09, 2020, 03:06:33 pm
content: I bought in 4 Chinese 12V 2amp supplies.With 500mA load none lasted more than a few days.So bought some from CPC (part of Farnell) and they were great.Old story, buy from a reputable dealer and you will most likely have no problems.Save a penny, lose a pound !

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 09, 2020, 03:48:21 pm
content: This drop in quality must have happened in the last two or three years. I have a 12V 5A adapter for my LiPo charger and it works well.

author: Bud
author_rank: Super Contributor
timestamp: February 09, 2020, 04:38:02 pm
content: Cant trust industrial suppliers either on unknown or little known brands they stock. Bought a 1A adapter from Digikey that blew up (literally exploded inside) at 0.8A load. I since buy only established brands adapters, though they are triple price.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 09, 2020, 05:00:45 pm
content: Lesson learned for sure. I might have to update my sig.

author: janoc
author_rank: Super Contributor
timestamp: February 09, 2020, 05:42:23 pm
content: Quote from: Alex Eisenhut on February 09, 2020, 03:48:21 pmNot really, this has always been like this. You get what you pay for. If you buy something for $2-$3 delivered, what do you expect to find inside when the budget for that thing had to be literally pennies otherwise the seller wouldn't make any profit? Quality and longevity costs money because one can't use the cheapest parts and cut corners everywhere.When it comes to mains, buying cheap from China (whether via eBay, AliExpress or whatever) is a good way to pay a lot more when one's house burns down or when someone gets electrocuted. That doesn't mean that you can't get a decent quality supply from there - but you can't go for the cheapest one!However, by that time you can buy from a reputable local supplier as well - lot of otherwise identical products have a cheaper "Chinese" version where all "non-essential" parts such as filters and protections have been gutted or not populated and a "western" version, where these are installed to make the device comply with the norms and legal to sell. E.g. some Uni-T multimeters are like that and I am certain it is the same with the power supplies as well.

author: beanflying
author_rank: Super Contributor
timestamp: February 09, 2020, 06:57:21 pm
content: Quote from: janoc on February 09, 2020, 01:00:26 pmAnd this is WHY giving potted advice from elsewhere in the world on Mains powered devices is NOT APPROPRIATE. No Australia does NOT recognise CE as 'approved'.https://esv.vic.gov.au/technical-information/electrical-appliances-and-equipment/equipment-classes/Broadly we and New Zealand have and maintain a standard and as I mentioned an approvals process.So it is you who is giving bad and generic advice on what you think and not fact.The OP needs to check their local regulations!

author: janoc
author_rank: Super Contributor
timestamp: February 09, 2020, 10:18:11 pm
content: Quote from: beanflying on February 09, 2020, 06:57:21 pmOf course they do! But you were the one claiming that even major vendors like Digikey or Mouser "wouldn't have paperwork in order" with regards to country standards where they are selling their goods, which I, frankly, find completely ridiculous.

author: beanflying
author_rank: Super Contributor
timestamp: February 09, 2020, 10:42:05 pm
content: Quote from: janoc on February 09, 2020, 10:18:11 pmProvide evidence to back your claims please that Digikey and Mouser submit each of their likely 1000+ power supplies for Australian testing and approval?Digikey, Mouser, Aliexpress, Evilbay etc all sell power supplies some are good and some are bad and if they have not gone through the local approvals process prior to being resold in Australia they are not legally supposed to be sold. If a product that uses mains power in this country uses a brick type supply internally sourced from elsewhere in the world then that product overall needs to be approved not the brick.I doubt that the EU is dissimilar for approvals prior to dropping their mark on a power supply or mains product but I haven't looked and wouldn't make statements claiming that knowledge,Your statements are ridiculous and WRONG and again the OP needs to check locally to make sure his ass is covered.

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: February 10, 2020, 01:09:46 am
content: Quote from: Alex Eisenhut on February 09, 2020, 03:48:21 pmYes, late 2019.One failed so bad it blew out house circuit breaker.They were cheap ebay rubbish so couldnt expect much really.The problem is deciding which ebay seller is selling good stuff and which bad stuff.So I now err on the side of local reputable dealers.

author: benryanau
author_rank: Contributor
timestamp: February 10, 2020, 04:05:18 am
content: ..and throw an old AM radio on next to it (add a nominal dummy load resistor)..You might be suprised how bad most switchers are. The terrible ones often that are supplied with DSL modems.. what could possibly go wrongThere's a cottage industry waiting there - jump on whirlpool and flog em - "OMG this guy sells Instant megabittz d00dz!!1"

author: janoc
author_rank: Super Contributor
timestamp: February 10, 2020, 09:58:14 am
content: Quote from: beanflying on February 09, 2020, 10:42:05 pmProvide evidence that they don't? You are making that claim, not me.Quote from: beanflying on February 09, 2020, 10:42:05 pmIf you are conflating Mouser (which has an Australian subsidiary and operates thus according to the local law) with individual imports from AliExpress and eBay, I think it is you who needs to get some more information on the subject, not me.Quote from: beanflying on February 09, 2020, 10:42:05 pmEU doesn't "drop their mark". CE is self-certified - i.e. you as the manufacturer or importer affix that marking on the gadget you are selling and you are responsible for providing any paperwork that the device is compliant with the relevant norms should anything happen (declaration of conformity + anything needed to back it up - typically results of lab testing). And I can pretty much guarantee you that any of the large vendors or importers have at least the declaration of conformity on file and available on demand (it is not their job to do ensure the certification itself but they have to have the paperwork from the manufacturer), otherwise they would have been fined into oblivion and their products banned from being sold.This is how it looks for a Mouser sold MeanWell charger, for ex:https://www.mouser.com/catalog/additional/MW_PB-300P,360P-CE-dec.pdfOr switching power supplies (also MeanWell):https://www.mouser.com/catalog/additional/MW_GSM40,60A-CE-dec.pdfQuote from: beanflying on February 09, 2020, 10:42:05 pmYou are completely missing my point. Again.Of course they need to check locally.BUTif they buy a brand name supply from areputablevendor (i.e.specifically not eBay or AliExpress) that isoperating in their country, such as Mouser, Digikey or others (not individual import e.g. from the US Mouser!), then they have pretty good chances that the product will be compliant and fine because that vendor would otherwise be unable to sell it there. I can't see a specialist distributor like Mouser or Digikey risking their reputation and business on selling stuff that is not legal to sell in the given market due to lacking certification - they would be exposing themselves to huge liabilities should anything happen.If you want to claim that Mouser is selling stuff that is not legal to sell in the country because it doesn't have the paperwork in order (whether it needs to be retested by a local authority or not is not relevant - that's not the buyer's problem), then you better provide some better evidence than just calling something "ridiculous and WRONG".

author: beanflying
author_rank: Super Contributor
timestamp: February 10, 2020, 10:34:27 am
content: You clearly didn't bother looking at the links and have less than zero idea about importing and reselling in this or likely any other country outside your own so stop making claims to the contrary based on your brain instead of the facts. Cause a house to burn down or electrocute someone with non confirming equipment and see how you go. Importing non conforming/tested power supplies into Oz is NOT illegal reselling them is. Physical testing is part of that so again to be clear you are WRONG re Mouser, E14, Digiokey et al and conformance.Mouser is a web gateway and is a US based retailer with an office in Hong Kong I am not aware of a local presence. Again you seem to be trying to make believe different to prove your non argument.As this is now well OT feel free to keep getting your knickers in a bunch with others who dare cross your lack of knowledge and imagination.

author: thm_w
author_rank: Super Contributor
timestamp: February 11, 2020, 01:40:45 am
content: Please see this thread:https://www.eevblog.com/forum/buysellwanted/acdc-adapters-12v-4-16a-50w-earth-referenced/Although they may be overkill for your purpose (12V 50W output), they are decent quality.

author: SilverSolder
author_rank: Super Contributor
timestamp: February 11, 2020, 04:51:15 pm
content: Buy a used adapter for a quality name brand item on eBay... they are often very little money, and you will get a nice unit.

author: jiarui
author_rank: Contributor
timestamp: February 11, 2020, 06:39:48 pm
content: I have just recently upgraded my under cabinet lighting. For each cabinet, I used a little PIC controller, with a 433Mhz receiver. I used 12V supply for both the LED lights and with a 5v regulator for the digital parts. I have tested quite a bit of supplies, both from Ebay and Amazon. I mostly just buy the 12V power bricks and just remove the cover and use the bare parts. I also bought, on Ebay the power brick parts, with the plastic cover. Most of the problem I had was that they could not supply the claimed current. I bought all 5A, 12V. A couple of them can only supply about 2.5A. One, had a bad filter cap that I had to replace. Aside from that, they all seems to be OK. None of them broke. I'm now running these 24/4 for about two weeks. I'll have to see how long they'll last.

author: jarez95
author_rank: Newbie
timestamp: February 12, 2020, 03:47:58 pm
content: +1, buy from reputable suppliers please...I once brought a spare laptop adapter from ebay (for the first time) and thought it would be ok. Exploded in my hands as soon as I plugged it in (I was at Uni, it tripped half the office)Luckily my laptop also made it out unscathed !!!Emailed Asus about it and reported the suppliers and then brought an official spare adapter from them was quite expensive, but I was just happy I was safe and didnt cause any irreversible damage.

author: GromBeestje
author_rank: Frequent Contributor
timestamp: February 13, 2020, 07:07:32 am
content: I've been using some of thesehttps://www.aliexpress.com/item/32905696401.html(various models at different voltages) for a while and they appear to work stable over months of operation.