Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

USB power supply puts 220 Mains power out on USB jack

youtube.com

Post reply on HN
Print view View original

81–90 of 160 posts

Re: USB power supply puts 220 Mains power out on USB jack

#81

Post by PhantomGremlin »

Animats wrote: post #55
makomk wrote: post #40

Earlier quoted context omitted.

The really scary thing is that as he points out, it actually seems to be designed with an apparently reasonable amount of isolation between the primary and secondary - it's just that something managed to completely abrade the insulation. Not sure if it was UL compliant as designed because their requirements for transformer construction are quite complicated, but it certainly seems plausible. He's reviewed numerous re…

The really scary thing is that as he points out, it actually seems to be designed with an apparently reasonable amount of isolation between the primary and secondary - it's just that something managed to completely abrade the insulation. That's the argument for a split bobbin. With a hard plastic wall between the two coils, in addition to the wire insulation, it's hard to get a short between both side of the transfor…

Split-bobbin seems to add about $0.10 to the price, raising it from $0.89 to $0.99.

So, there it is.

Good luck finding a miscreant to hold accountable if this sort of cost reduction kills someone. And even if you could hold the culprit accountable, that still can't undo the loss of life anyway.

It's all just collateral damage from the race to the bottom.

Re: USB power supply puts 220 Mains power out on USB jack

#82

Post by userbinator »

Animats wrote: post #55
makomk wrote: post #40

Earlier quoted context omitted.

The really scary thing is that as he points out, it actually seems to be designed with an apparently reasonable amount of isolation between the primary and secondary - it's just that something managed to completely abrade the insulation. Not sure if it was UL compliant as designed because their requirements for transformer construction are quite complicated, but it certainly seems plausible. He's reviewed numerous re…

The really scary thing is that as he points out, it actually seems to be designed with an apparently reasonable amount of isolation between the primary and secondary - it's just that something managed to completely abrade the insulation. That's the argument for a split bobbin. With a hard plastic wall between the two coils, in addition to the wire insulation, it's hard to get a short between both side of the transfor…

Price aside, split bobbin construction also leads to lower efficiency since there is less effective coupling between the two sides.

It's always about tradeoffs, sort of like how you can ride a motorcycle or drive an armoured vehicle. What is safer won't necessarily be better in the other dimensions.

Re: USB power supply puts 220 Mains power out on USB jack

#83

Post by timpattinson »

paddy_m wrote: post #61
yoodenvranx wrote: post #38

Earlier quoted context omitted.

If you are into machining then check out Clickspring, oxtoolco, Abom79, Keith Rucker, Keith Fenner, Shadow HKW, ... If this is not enough then go and visit this list: https://www.reddit.com/r/ArtisanVideos/comments/3v264a/meta_... (But be careful, this is the ultimate rabbit hole)

Keith Fenner is astounding. Years ago my girlfriend said "enough Keith Fenner videos, You have to take a welding class", I did and it was amazing. As a side note, I'm starting a blog where I interview heavy equipment operators and write about heavy equipment. Anyone here interested in that?

Yes

Re: USB power supply puts 220 Mains power out on USB jack

#84

Post by stordoff »

yoodenvranx wrote: post #5
aembleton wrote: post #4

Big Clive, who makes these videos does some brilliant tear-downs. I recommend watching his other videos.

Big Clive is _the_ channel for teardowns of everyday electronic stuff. I am actually not that interested in this kind of stuff but somehow I still watch most of his videos. If you are into more... entertaining teardowns you should have a look at AvE. Even if you don't like it you will still learn some useful canadian terms ;) (edit: just to make it clear, AvE is actually very knowledgable. His "boltr" teardown series…

> My third goto channel for electronic stuff is EEVBlog who also does amazing stuff. If you are going to watch one teardown today then please watch his rather famous video about the worlds worst tablet computer: https://www.youtube.com/watch?v=2o8MDCIlOEk

Oh boy, that thing is a MESS. When he first opened it, I thought it looks like the sort of thing I'd knock together - not pretty, probably mildly unstable, but gets the job done. Then he took a closer look, and it's the sort of thing that wouldn't even be acceptable as a secondary school project, never mind a device to be sold.

Re: USB power supply puts 220 Mains power out on USB jack

#85

Post by voltagex_ »

femto wrote: post #77
voltagex_ wrote: post #9

How do I know what I'm buying is safe? I've sworn by the Nexus chargers in their various incarnations and http://www.amazon.com/Charge-Charging-Station-Micro-USB-Sams... (I have a Tronsmart and an Aukey vertsion)

I can answer from an Australian perspective. Here's how it's supposed to work: Suppliers register and prove that their products comply with Australian standards, and are awarded a compliance number. That number is the consumer's indicator that a product is safe. Any interested party can check that the certification is genuine by looking up the compliance number in an online database. Here's how it works in practise:…

I wonder what the hell's gone wrong in that department to not have a replacement after all that time.

Re: USB power supply puts 220 Mains power out on USB jack

#86

Post by csours »

kbenson wrote: post #52
TeMPOraL wrote: post #22

Earlier quoted context omitted.

> If you are going to watch one teardown today then please watch his rather famous video about the worlds worst tablet computer: https://www.youtube.com/watch?v=2o8MDCIlOEk* I'm crying out of laughter right now. This is absolutely brilliant. That is, the teardown - the tablet itself is an abomination. Thanks for posting this. This channel is great and seems to have a lot of educational content besides teardowns too.

> the tablet itself is an abomination Yes, but I find myself strangely impressed. I like to imagine someone walked up to an engineer and said "So, I just told client $foo that we can provide a tablet version of our PC software. They need it by end of week. That's not a problem, right? Because the CEO is fully on board with this..."

And then the engineer went home, got drunk, and talked his niece/nephew through building this on a bad skype call.

Re: USB power supply puts 220 Mains power out on USB jack

#89

Post by DiabloD3 »

Amezarak wrote: post #75
DiabloD3 wrote: post #14

As a reminder, if you're buying a USB charger or battery, or MicroUSB, Type C, or Lightning cable please buy Anker products. They are not expensive, but they are the best products you can get your hands on. I own multiple Anker products, and have never discovered anything better than these. The only non-Anker charger I currently use is the Google Nexus branded Qi charger (plugged into an Anker multiport brick), and t…

I bought five anker USB cables after reading about them on HN, and a wall charger, and I was actually really disappointed. All the cables stopped working within three weeks. Monoprice USB cables didn't fare well either, but the OEM cables that came with my Icons, kindle, and S3 have lasted years. Wall charger still works great, but the cables are what I was really interested in because people are always running off w…

What did Anker say when you contacted them? Anker has a warranty.

Re: USB power supply puts 220 Mains power out on USB jack

#90

Post by akurilin »

marshray wrote: post #51

If you are wondering "How could an isolation transformer ever get past QC with abraded or nicked insulation?", you might find this video interesting: https://www.youtube.com/watch?v=HEJn74Z3wHk

I've had a portable Bluetooth speaker blow up in my bedroom a couple of years ago while charging. Something malfunctioned in the battery section.

The only reason that didn't set the building on fire was that I was right next to the speaker when it burst into flames. My immediate reaction was to assume my SO playing a really unfortunate firecracker prank on me, but half a second later it was obvious it was the speaker's fault. Turns out batteries can make pretty flames and a lot of fairly unpleasant smoke. To this day, still can't believe how lucky I was to be right next to it with a pillow as it blew up.

The company was kind enough to send us their top of the line product for the incident, in exchange for the faulty unit (for them to study) and a written agreement to not take em to court.

Still pretty uncomfortable around charging devices with batteries to this day, but the reality is that it's unavoidable and there's no point in developing a phobia about it.

Post reply on HN