
USB power supply puts 220 Mains power out on USB jack - software_radio
https://www.youtube.com/watch?v=3Hdn0MuCK_0
======
jklp
Not sure if HN knows about Mehdi Sadaghdar's (aka ElectroBOOM's) YouTube
channel, which is somewhat similar - but takes a more lighthearted view on
electronics.

E.g. Compare Big Clive's mention of a full bridge rectifier in the video vs
Mehdi's YouTube video of the same thing :)

[https://youtu.be/sI5Ftm1-jik](https://youtu.be/sI5Ftm1-jik)

~~~
yitchelle
I love this guy. His skids are like slap stick for the makers.

However, on the serious side, I wish that he would publish a complementary
video showing the real story of what he is doing.

My kids would watch his videos, and then run off the find the bits to do
exactly what he did. Hmm..Luckily I was there to let them know of the real
consequences.

------
marshray
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](https://www.youtube.com/watch?v=HEJn74Z3wHk)

~~~
akurilin
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.

~~~
GigabyteCoin
>for them to study

For them to study, or for them to destroy the evidence so that you absolutely
could not take them to court.

~~~
RickHull
> so that you absolutely could not take them to court.

Did he miss an opportunity or an opportunity cost?

~~~
GigabyteCoin
He's the poster child for a potential class action lawsuit. He witnessed their
product explode with his own eyes.

And yes I would imagine that there could have been some cost associated with
cleaning up the smoke smell left in the room and possibly any burned areas.

------
basicplus2
A true isolation transformer has an earthed copper shield wound in between and
physically separating the primary from secondary windings, anything less is
unsafe.

One of the many reasons I detest "double insulated" equipment, as it is
impossible to determine if it has been designed for safety or not without
ripping it apart and destroying it.

This is a real issue in Australia as our regulators do no regulating and most
equipment I have investigated does not comply with Australian Standards even
though manufacturers lie and put standards compliance numbers on them.

Also the Australian Standards should be considered an absolute Minimum not
"super safe".

~~~
mavhc
Does the Australian Standards body require that devices are sent to them for
testing? Then there could be a database you could check as to whether a device
has passed.

~~~
basicplus2
technically yes.. but it is not enforced

~~~
basicplus2
I should also add that if you are an Australian manufacturer, you have to
submit your product for testing for design compliance and you won't last long
if you dont, but importers can import anything with none, yet another
impediment to Australian manufacturing.

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

~~~
yoodenvranx
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 of electronic power tools is most likely the most thorough you
will find on the internet)

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](https://www.youtube.com/watch?v=2o8MDCIlOEk)

~~~
seany
Mikes electronic stuff is also quite good.

~~~
cellularmitosis
See also scanlime [http://youtu.be/UTUYl-2g-r4](http://youtu.be/UTUYl-2g-r4)

------
aembleton
Here, Clive looks at an Ikea USB power supply:
[https://www.youtube.com/watch?v=uRe9w5PKmsE&nohtml5=False](https://www.youtube.com/watch?v=uRe9w5PKmsE&nohtml5=False)

Much better made.

~~~
mulmen
I recently discovered AvE and now bigclive. I'm not sure how I missed this
particular internet rabbit hole but I love it.

~~~
aembleton
If you want another rabbit hole to start down, I can also recommend Techmoan.
He doesn't do teardowns, but instead likes to buy old HiFi gear and reviews
them.

Some of them are incredibly obscure such as the Tefifon:
[https://www.youtube.com/watch?v=nBNTAmLRmUg](https://www.youtube.com/watch?v=nBNTAmLRmUg)

~~~
mulmen
This is great, thank you!

------
voltagex_
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...](http://www.amazon.com/Charge-Charging-Station-Micro-USB-
Samsung/dp/B01BBYJQ5I/) (I have a Tronsmart and an Aukey vertsion)

~~~
yoodenvranx
I play Ingress a lot (a GPS based mobile game where you run around a lot in
the real world so most players use external batteries) and at least 60-70% of
the whole community uses Anker products. I personally know at a dozen people
who use Anker wall plugs and all of them (including me, 1 wallplug and 2
battery packs) are very happy.

~~~
mmanfrin
Anker and recently Aukey. And iOrange for cables. The problem is that smaller
brands hit the Amazon lottery and get a lot of early 5-star reviews, then swap
out their product with one made of cheaper components.

I think for Anker, their brand has become a bit bigger than is gamble-able on
a bait and switch, so I'm continuing to use their products.

~~~
ents
Anker is ex-Google employees.

~~~
Tepix
Interesting! Source?

------
Animats
That's scary. Not enough isolation between the line side and the output side.
Classic cause of electrocution and fires. The standard for this is UL 1310,
Class 2 Power Supplies. Not sure if this design complies.

There's a lot to be said for split-bobbin transformers, where there's a solid
plastic barrier between the two windings. This just has wire insulation and
some tape.

~~~
makomk
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 really questionable power supplies[1] with a gnat's
whisker of separation between the mains and low voltage sides and much more
dubious transformers, but somehow none of those actually managed to put 240
volts on the output...

[1] Such as the cheap shitty pink USB charger from China:
[https://www.youtube.com/watch?v=ioAq7PI1Uwg](https://www.youtube.com/watch?v=ioAq7PI1Uwg)

~~~
Animats
_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 transformer.

Here are some split-bobbin transformers for switching power supplies on
Alibaba.[1] Split-bobbin seems to add about $0.10 to the price, raising it
from $0.89 to $0.99.

[1] [http://wholesaler.alibaba.com/product-detail/EE22-split-
bobb...](http://wholesaler.alibaba.com/product-detail/EE22-split-bobbin-
transformer-for-charger_60428582199.html)

~~~
PhantomGremlin
_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.

------
oxplot
Finally a possible explanation [1] as to why Apple chargers (USB and laptop)
give you tingles when touching the metal casing of the device they're plugged
into.

Would love to know if the mentioned capacitor is indeed the reason and whether
it leads to enough efficiency to justify the scare it causes with first time
customers.

[1]:
[https://youtu.be/3Hdn0MuCK_0?t=2m14s](https://youtu.be/3Hdn0MuCK_0?t=2m14s)

------
DiabloD3
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 the original Chromecast
brick plugged into my Chromecast.

~~~
PhasmaFelis
The one thing that I can't find from Anker or any other reputable, reasonably-
priced supplier (last time I checked, anyway) is a single-port charger that is
small enough, horizontally and vertically, to not sprawl out onto adjacent
outlets in a power strip.

I don't understand why this is so hard. My first smartphone, a Samsung Galaxy
Nexus, came with one, but it failed within a year and Samsung wanted like $50
for a branded replacement.

~~~
pinot
Like an Apple one?

~~~
DiabloD3
The Apple ones do not speak standard USB charging resistor ladders, thus max
out at 500mA when charging non-Apple devices.

On the flip side, Anker chargers speak both, and charge newer iPhones and
iPads faster than that huge iPad charger does.

------
christogreeff
I love the simplicity of and the humor in the Big Clive videos. The methylated
spirits video was quite... hilarious. DO NOT try this!
[https://www.youtube.com/watch?v=ep2I3Gf3Sec](https://www.youtube.com/watch?v=ep2I3Gf3Sec)

------
reiichiroh
Hmm, I've always bought Anker and occasionally bought other brands like Mpow,
Oldshark (haha) and Aukey which seem like yet another rebrand from the same
batch of Shenzhen factories. I know Anker has considerably more Customer
Service backend and better packaging but I wonder if their products are
engineered any better?

~~~
cyounkins
Google engineer Benson Leung tests a bunch of USB 3.0 cables/chargers and has
generally found Anker to be good. Spreadsheet of results:
[https://docs.google.com/spreadsheets/d/1wJwqv3rTNmORXz-
XJsQa...](https://docs.google.com/spreadsheets/d/1wJwqv3rTNmORXz-
XJsQaXK1dl8I91V4-eP_sfNVNzbA/edit#gid=0)

------
simook
He's like the "Bob Ross" of electronics.

------
lips
Apple chargers, USB-C... When will Amazon offer a hardware fault bounty?

------
userbinator
Seeing the wire damage reminded me of this Boeing 787 fire...

[http://asndata.aviation-
safety.net/reports/2013/20130712-0_B...](http://asndata.aviation-
safety.net/reports/2013/20130712-0_B788_ET-AOP.pdf)

...caused by a battery short resulting from the two wires being trapped
against the case and eventually the insulation abrading through when subject
to vibration. Even the highly regulated aviation industry isn't immune to
simple defects like these.

------
0xffff2
Can someone explain why the transformer is on the DC side of the circuit in
the diagram he draws at the beginning of the video?

~~~
sitharus
This is a switch mode power supply. In order to use a smaller transformer it
uses very high frequency AC rather than 50/60Hz mains frequency.

In order to do this it rectifies the mains input to high voltage DC
(330/220Vish, depending on the mains voltage) then using a power transistor
rapidly switches this on and off at around 1-10kHz. Then the transformer
outputs low voltage AC which is re-rectified and filtered to produce low
voltage DC.

The switch mode chip monitors the output voltage and modulates the switching
frequency to maintain a constant output voltage.

If you look closely at the board (and he talks about this in the video)
there's a separation between the high and low voltage sides. Only the
transformer and certain specialized components should cross this (Y-class
capacitor and optoisolators). Cheap power supplies often miss this out which
could allow a small bit of loose solder being able to send mains voltage to
the output. Look at other videos by Big Clive to see the horrors.

The high voltage side is a bit of a misnomer. It's really just the non-
isolated side - the chip runs on 5v or similar, but it's not completely
separated from the high voltage DC so isn't safe for human contact.

~~~
rlpb
> the chip runs on 5v or similar

How does the chip get 5V, out of interest? Given that it's not allowed to be
connected to the non-isolated side?

~~~
sitharus
Normally though an additional winding on the transformer.

Switch mode transformers have three or four sets of windings. The primary
(high voltage), secondary (low voltage) a bootstrap winding (for the chip) and
sometimes a flyback winding.

The bootstrap winding takes off a variable voltage depending on the local
supply and uses a linear regulator to produce the required voltage.

For a better explanation than I can manage in text the EEVBlog channel goes in
to all sorts of regulators and how they work:
[https://www.youtube.com/watch?v=cM7t1Mpu7s4&list=PLn-
ZIFhWxh...](https://www.youtube.com/watch?v=cM7t1Mpu7s4&list=PLn-
ZIFhWxhWpbwaHZNTBWoOmeyeVPCq_i)

------
serf
This happened to me with a cheap reflow heat gun. [1]

Got a nasty bite as soon as I touched it.

Got what I paid for I guess. Made me rethink super-cheap AC equipment from the
internet, that's for sure.

[1]: www.amazon.com/Kohree-Digital-Rework-Station-Solder/dp/B00ITMPQS2

------
dom96
Aren't there legal tests that any appliance which plugs into the mains must
pass? I'm surprised this kind of thing is possible, but I guess not performing
such tests cuts costs.

~~~
alex_hitchins
Sometimes even large well trusted companies get fake products shipped to them.

I think EEVBlog highlighted this with the FTDI case. People were buying what
they thought were authentic FTDI chips (and paying the proper price) but being
delivered fakes that then went on to be bricked by the driver update.

There is so much margin in swapping good stuff with dreadfull stuff there are
several points in the procurement chain where people can try their luck
passing off crap.

------
ratfacemcgee
oh man i don't even need to click, i know its big clive! i spent all of
saturday watching his videos holy shit there are some dangerous products on
the market!

------
cm2187
Never seen a video from this guy but I love the massive beard moving at the
bottom of the video when he speaks!

------
hacker42
Why does he handle the bare wires of the test lamp near the mains? Is there no
risk the way he hooks it up?

~~~
aembleton
The wires are insulated. Yes, there is a risk but this is what he does.

Check out this video for a story of a risky thing he did with a heating
element and a bath (4:30 is where it really gets going):
[https://www.youtube.com/watch?v=uUn17ccR2a4](https://www.youtube.com/watch?v=uUn17ccR2a4)

------
gargravarr
The scary part is most of us would plug our phones into one of these chargers
without thinking there'd be any more than 5 volts at the output. Best case -
destroyed phone. Worst case - fire or electric shock.

------
jhallenworld
Heh, ground fault interrupters should probably be required on every circuit.

~~~
duskwuff
That only works if the device is grounded, and the fault is to ground. Neither
is the case here. :(

~~~
makomk
The most likely danger with this fault is that someone would touch both the
live device and ground, causing a path to ground. This would cause any RCD to
trip. It's obvious that whoever owned this didn't have one installed because
even the cable shorting to a grounded radiator didn't cause a trip.

------
wiml
Question for the knowledgeable: why did one of the insulation layers have some
metal foil in it? He commented on it as he was unwinding it, as if it was a
little odd but not completely bizarre.

------
Houshalter
I get that tingly feeling when I hold my ipod after plugging it into the wall
through a usb adapter. It's given me a minor shock once I think. That's very
interesting.

------
wodenokoto
great video. I don't know a lot about electronics, so I am left wondering two
things:

why did the fault not stop after i pulled out the first two components?
wouldn't that break off the power circuit inside?

why did the fault stop after he removed the transformer?

~~~
cristoperb
The first two components he removed (the filter Y-capacitor and the opto-
isolator) are _supposed_ to be open-circuit to direct current. And since they
were not at fault (ie, they were not shorted), removing them from the circuit
didn't change anything.

The fault probably stopped after he removed the transformer because in the
process of desoldering and yanking it from the board, he caused enough
strain/vibration that whichever wire was shorting the primary and secondary
windings moved and was no longer causing a short. That sort of intermittent
fault is common in hardware, and quite annoying to debug.

------
tn13
I have always buy Amazon Basics chargers.

------
ocdtrekkie
This takes some horrific failure to accomplish, I imagine.

~~~
mmastrac
The problem appears to be the transformer:
[https://youtu.be/3Hdn0MuCK_0?t=20m49s](https://youtu.be/3Hdn0MuCK_0?t=20m49s)
(and specifically a bit of shredded insulation
[https://youtu.be/3Hdn0MuCK_0?t=25m35s](https://youtu.be/3Hdn0MuCK_0?t=25m35s))

------
leoc
Got your Power Delivery right here.﻿

