Dodgy USB Power supplies... - Page 1
Forum section: electronics / general

author: pinchies
author_rank: Contributor
timestamp: August 16, 2012, 12:10:34 pm
content: Hi All! Thought I would start a general discussion on standard wall usb charges. I can't get enough of them, always using them.I've had a couple over the last few years, and after seeing some scary teardowns on youtube I threw a bunch away.I was looking for some more on ebay... was thinking of getting a genuine apple one, but then I saw the cheaper ones...http://www.ebay.com.au/itm/170807723778WOW! 989 people bought this! Its got to be (sorry dave) the ducks guts!I noticed the model number on the side: "KMS-AC09". On a whim I googled this, only to find:http://www.saferproducts.gov/ViewIncident/1219045http://www.saferproducts.gov/Common/Pages/DisplayDocument.aspx?documentId=187090Maybe I'll look for a different model...

author: PeterG
author_rank: Frequent Contributor
timestamp: August 16, 2012, 12:36:14 pm
content: Thanks for the info.............. i had that tem on my ebay watch list........ not so interested now.Let us know if you find a reputable 4 port charger.Regards

author: pinchies
author_rank: Contributor
timestamp: September 30, 2012, 04:31:05 am
content: Since I couldn't find a good 4 port, I started investigating single port USB chargers. I now have a couple:1x Genuine Apple 5W Charger1x "High quality" ebay charger (10W - 'iPad Charger')eBay auction: #2511277573041x Dirt Cheap hwang low charger ("10W")eBay auction: #280919861384I am really fascinated in their compact size, and what is the absolute minimum you could get away with for a cheap, but safe, charger.I'm tempted to tear them down myself, but I won't be able to add much value to the intellectual discussion and testing. Perhaps I should mail them to dave?The apple one has already been torn down by others online before, so the other two might be more interesting.

author: FenderBender
author_rank: Super Contributor
timestamp: September 30, 2012, 07:00:28 pm
content: You could tear them down and just post pictures. Let other people do the interpreting if you'd like.

author: Jeff1946
author_rank: Regular Contributor
timestamp: October 01, 2012, 02:29:30 am
content: The USB charger that came with my Kindle is quite small, it is rated at 5V .85A and made by Flextronics. An interesting teardown of an Apple phone charger is found athttp://www.arcfn.com/2012/05/apple-iphone-charger-teardown-quality.htmlUse of a flextronics technique for spike damping is mentioned. Amazon sells these Kindle chargers for $10. I assume they are of good quality. I don't think is worth saving a few dollars on a charger for much more expensive electronics which might be damaged by a charger failure for example if AC jumps to the low voltage side.

author: pinchies
author_rank: Contributor
timestamp: October 01, 2012, 02:31:21 am
content: I've seen that teardown, but I was curious as the australian ones are a different shape. I was also wondering about whether there wereanygood chargers on ebay, or if OEM is the only way to go (safely).

author: T4P
author_rank: Super Contributor
timestamp: October 01, 2012, 06:14:02 am
content: Flextronics ... they are good quality, in fact i rarely see their stuff anywhere (I know they have a factory here near where i study) but i'm not sure where it's made.

author: pinchies
author_rank: Contributor
timestamp: October 03, 2012, 08:27:11 am
content: Quick FYI: I pulled apart both ebay power supplies, the cheaper one has a clearance of ~0.8mm at its smallest point, and the more expensive oneno visible clearance at all. Stay far away! Photos will come at a later date, nothing two interesting though, pretty simple circuits.

author: amyk
author_rank: Super Contributor
timestamp: October 03, 2012, 09:15:53 am
content: I think they'd be OK if used on a surge protected power strip...

author: pinchies
author_rank: Contributor
timestamp: October 03, 2012, 09:23:17 am
content: I think not...."Exploded in the power outlet. Cheap Chinese garbage.""the wall charger explode after 1 week of used"http://feedback.ebay.com.au/ws/eBayISAPI.dll?ViewFeedback2&ftab=AllFeedback&userid=wuyouguo2110&iid=251127757304&de=off&items=25&interval=365&which=negative&mPg=3&page=2

author: T4P
author_rank: Super Contributor
timestamp: October 03, 2012, 12:37:16 pm
content: Exploded in the wall, wow.However, i have heard of "genuine" apple chargers blowing up without anything connected to it

author: LaurenceW
author_rank: Frequent Contributor
timestamp: October 03, 2012, 10:57:04 pm
content: T4P, Your picture - that's not an apple, that's a mushroom, that is.

author: Monkeh
author_rank: Super Contributor
timestamp: October 03, 2012, 11:02:59 pm
content: Quote from: LaurenceW on October 03, 2012, 10:57:04 pmAnd there I was thinking it was a Rayleigh–Taylor instability.

author: pinchies
author_rank: Contributor
timestamp: October 04, 2012, 06:06:44 am
content: Quote from: Monkeh on October 03, 2012, 11:02:59 pmI've been told I'm not allowed to have these in the house anymore, has to be outside. I can't quite remember why... something about damaging the parquetry.In other news...The "good quality" charger had a lump of metal inside to make it heavier. Before I bought it I asked if it was really good quality, and was told it was. I messages the seller to get an explanation.QuoteThey mustn't have read their previous feedback.

author: T4P
author_rank: Super Contributor
timestamp: October 04, 2012, 03:30:59 pm
content: Quote from: LaurenceW on October 03, 2012, 10:57:04 pm