How dangerous would it be to use a phone or tablet in the bath whilst it
is connected to a mains-powered USB charger?

Obviously it could be dangerous to the device itself if you drop it into
the water!

Obviously a 5 volt low current supply isn't usually life threatening.

Obviously we have rules about sockets in bathrooms. But a long USB cable
to a socket in another room seems a likely way round that.

But if something is wrong somewhere, such as a mis-wired USB charger,
could there be any appreciable danger?

Is there in future likely to be a bathroom-safe USB socket next to the
shaver and toothbrush socket?

--
Rod

On Sunday, 29 May 2016 09:23:27 UTC+1, polygonum wrote:

How dangerous would it be to use a phone or tablet in the bath whilst it
is connected to a mains-powered USB charger?

Obviously it could be dangerous to the device itself if you drop it into
the water!

Obviously a 5 volt low current supply isn't usually life threatening.

Obviously we have rules about sockets in bathrooms. But a long USB cable
to a socket in another room seems a likely way round that.

But if something is wrong somewhere, such as a mis-wired USB charger,
could there be any appreciable danger?

Is there in future likely to be a bathroom-safe USB socket next to the
shaver and toothbrush socket?

There is a very thin barrier between mains and usb output. If it breaks down you're fried. A great number of noncompliant chargers exist that have very inadequate insulation. I would not do it.


NT

On 29/05/2016 09:55, wrote:
There is a very thin barrier between mains and usb output. If it
breaks down you're fried. A great number of noncompliant chargers
exist that have very inadequate insulation. I would not do it.

I assure you it is not my intention to do it! I expect many people do,
though, and it made me wonder. If I did want to, I'd probably think to
use my battery pack USB charger or, preferably, charge before bath, but
I don't want to drown my phone or tablets.

I was also imagining the next generation of shavers and toothbrushes
possibly having USB charging as standard? Or, wireless charging but with
the charging plate being fed by USB.

--
Rod

polygonum wrote

How dangerous would it be to use a phone or tablet in the
bath whilst it is connected to a mains-powered USB charger?

Not dangerous at all if the charger is designed properly so that no
matter what fails you can ever get any mains voltage on the USB.

Quite dangerous with the worst of the chinese **** that can do that.

Obviously it could be dangerous to the device itself if you drop it into
the water!

Not with a properly designed charger than has the USB
electrically isolated from the mains even if the device fails.

Obviously a 5 volt low current supply isn't usually life threatening.

Never is in fact.

Obviously we have rules about sockets in bathrooms. But a long USB
cable to a socket in another room seems a likely way round that.

But if something is wrong somewhere, such as a mis-wired
USB charger, could there be any appreciable danger?

Not miswired so much as if it isnt properly designed
and does fail when you are using it in the bath.

Is there in future likely to be a bathroom-safe USB
socket next to the shaver and toothbrush socket?

Unlikely given that there isnt any real need to charge anything
in the bathroom except shavers and toothbrushes.

polygonum wrote:

How dangerous would it be to use a phone or tablet in the bath whilst it
is connected to a mains-powered USB charger?

If you look at various USB charger and SMPSU teardowns on youtube, they
often have a sizeable fraction of mains voltage (at a minute current) on
the 5V outputs, the sort of "tingle" you can feel with an unearthed
laptop when it contacts bare skin could feel a lot worse with wet skin
in the bath, the leakage current won't directly hurt you, but if it
makes you jump you could lose your footing or bash your head on the
tiles etc

Is there in future likely to be a bathroom-safe USB socket next to the
shaver and toothbrush socket?

Just charge the device up in advance of using it in the bathroom?

On Sunday, 29 May 2016 10:37:25 UTC+1, Rod Speed wrote:
polygonum wrote

How dangerous would it be to use a phone or tablet in the
bath whilst it is connected to a mains-powered USB charger?

Not dangerous at all if the charger is designed properly so that no
matter what fails you can ever get any mains voltage on the USB.

Of course even a well designed charger doesn't meet that naive expectation.
Other crap snipped.


NT

On Sunday, 29 May 2016 10:37:25 UTC+1, Rod Speed wrote:
Obviously a 5 volt low current supply isn't usually life threatening.

Never is in fact.

It could be quite unpleasant if the water has bath salts added
to improve conductivity and you have wet hands.

USB chargers are not low current. However, it is difficult to
think of a scenario where the 5V would be applied across your body.

I once had an unpleasant shock from a 9V battery when standing
in sea water. I was changing the batteries in a hydrophone
preamplifier at the time.

John

On Sunday, 29 May 2016 11:38:22 UTC+1, wrote:
On Sunday, 29 May 2016 10:37:25 UTC+1, Rod Speed wrote:
Obviously a 5 volt low current supply isn't usually life threatening.

Never is in fact.

It could be quite unpleasant if the water has bath salts added
to improve conductivity and you have wet hands.

USB chargers are not low current. However, it is difficult to
think of a scenario where the 5V would be applied across your body.

I once had an unpleasant shock from a 9V battery when standing
in sea water. I was changing the batteries in a hydrophone
preamplifier at the time.

John

Even a 1.5v cell can kill in contrived circumstances.


NT

wrote in message
...
On Sunday, 29 May 2016 10:37:25 UTC+1, Rod Speed wrote:
polygonum wrote

How dangerous would it be to use a phone or tablet in the
bath whilst it is connected to a mains-powered USB charger?

Not dangerous at all if the charger is designed properly so that no
matter what fails you can ever get any mains voltage on the USB.

Of course even a well designed charger doesn't meet that naive
expectation.

Thanks for that completely superfluous proof that you have
never ever had a ****ing clue about anything at all, ever.

wrote
Rod Speed wrote

Obviously a 5 volt low current supply isn't usually life threatening.

Never is in fact.

It could be quite unpleasant if the water has bath salts
added to improve conductivity and you have wet hands.

Nope, even if its salt water.

USB chargers are not low current.

The current is determined by the 5V and the resistance.
What the USB can deliver when charging something is irrelevant.

However, it is difficult to think of a scenario
where the 5V would be applied across your body.

Yes, its not going to happen with someone in a bath.
And even if it does, the current isnt going to be life threatening,
and is DC anyway, which again isnt going to be life threatening.

I once had an unpleasant shock from a 9V battery when standing
in sea water. I was changing the batteries in a hydrophone
preamplifier at the time.

Sure, and some dont like putting one in their mouth/licking
the terminals, but its not life threatening.

wrote in message
...
On Sunday, 29 May 2016 11:38:22 UTC+1, wrote:
On Sunday, 29 May 2016 10:37:25 UTC+1, Rod Speed wrote:
Obviously a 5 volt low current supply isn't usually life threatening.

Never is in fact.

It could be quite unpleasant if the water has bath salts added
to improve conductivity and you have wet hands.

USB chargers are not low current. However, it is difficult to
think of a scenario where the 5V would be applied across your body.

I once had an unpleasant shock from a 9V battery when standing
in sea water. I was changing the batteries in a hydrophone
preamplifier at the time.

John

Even a 1.5v cell can kill in contrived circumstances.

But not with someone in a bath.

On Sunday, May 29, 2016 at 10:38:57 AM UTC+1, Andy Burns wrote:
polygonum wrote:

How dangerous would it be to use a phone or tablet in the bath whilst it
is connected to a mains-powered USB charger?

If you look at various USB charger and SMPSU teardowns on youtube, they
often have a sizeable fraction of mains voltage (at a minute current) on
the 5V outputs, the sort of "tingle" you can feel with an unearthed
laptop when it contacts bare skin could feel a lot worse with wet skin
in the bath, the leakage current won't directly hurt you, but if it
makes you jump you could lose your footing or bash your head on the
tiles etc

Is there in future likely to be a bathroom-safe USB socket next to the
shaver and toothbrush socket?

Just charge the device up in advance of using it in the bathroom?

Or, heaven forbid, do without it for half an hour or so? Fair enough if you're reading a book on your Kindle, but not if it's sheer terror at the thought of being 'off the grid' for any length of time.

Halmyre wrote:

Andy Burns wrote:

Just charge the device up in advance of using it in the bathroom?

Or, heaven forbid, do without it for half an hour or so? Fair enough
if you're reading a book on your Kindle

I know they make a waterproof kobo, but do Amazon make a waterproof
kindle? I gather there are 3rd party kindle waterproofers.

On Sunday, 29 May 2016 12:10:20 UTC+1, Rod Speed wrote:
tabbypurr wrote in message
...
On Sunday, 29 May 2016 10:37:25 UTC+1, Rod Speed wrote:
polygonum wrote

How dangerous would it be to use a phone or tablet in the
bath whilst it is connected to a mains-powered USB charger?

Not dangerous at all if the charger is designed properly so that no
matter what fails you can ever get any mains voltage on the USB.

Of course even a well designed charger doesn't meet that naive
expectation.

Thanks for that completely superfluous proof that you have
never ever had a ****ing clue about anything at all, ever.

lol, the ultimate accolade from Rodtwit


NT

On 29/05/2016 09:23, polygonum wrote:
How dangerous would it be to use a phone or tablet in the bath whilst it
is connected to a mains-powered USB charger?

Obviously it could be dangerous to the device itself if you drop it into
the water!

Obviously a 5 volt low current supply isn't usually life threatening.

Obviously we have rules about sockets in bathrooms. But a long USB cable
to a socket in another room seems a likely way round that.

But if something is wrong somewhere, such as a mis-wired USB charger,
could there be any appreciable danger?

Is there in future likely to be a bathroom-safe USB socket next to the
shaver and toothbrush socket?



https://www.youtube.com/watch?v=3Hdn0MuCK_0

--
Reentrant

On 29/05/2016 12:19, Rod Speed wrote:
e.

Sure, and some dont like putting one in their mouth/licking
the terminals, but its not life threatening.

I don't like it, but it is the easiest way to check to see if it needs
recharging/replacing.

On 29/05/2016 09:55, wrote:


There is a very thin barrier between mains and usb output. If it
breaks down you're fried. A great number of noncompliant chargers
exist that have very inadequate insulation. I would not do it.

And yet some of the really cheap Chinese stuff is done well, like the
relay board for my arduino. They have routed an air gap around the
common pin to separate it from the 5V coil which is at the same end.


It makes you wonder who designs some of the stuff.

On 29/05/2016 11:54, wrote:

Even a 1.5v cell can kill in contrived circumstances.

Choking for instance.

Bill

On 29/05/2016 13:14, Halmyre wrote:

Or, heaven forbid, do without it for half an hour or so?

Yes! Good grief, there's plenty of other things to do in the bath.

Bill

Odd, isn't it. Everything must be cordless these days - even when of
little benefit. But on the *one* occasion where most would agree cordless
is safest - in the bath - someone wants to run a cordless device off mains.

And you wonder why the EU seems to do odd things like labelling salmon as
containing fish? ;-)

--
*We are born naked, wet, and hungry. Then things get worse.

Dave Plowman London SW
To e-mail, change noise into sound.

On 29/05/2016 18:40, Dave Plowman (News) wrote:
Odd, isn't it. Everything must be cordless these days - even when of
little benefit. But on the *one* occasion where most would agree cordless
is safest - in the bath - someone wants to run a cordless device off mains.

And you wonder why the EU seems to do odd things like labelling salmon as
containing fish? ;-)

I don't want to do it. I don't need to do it. I won't do it. But
thoughts arose about charging shavers and toothbrushes, for which USB
might be viable, which then led me to consider the worst-case. Which was
charging a device, using a crap charger, while in the bath.

The start point in my mind was the need to carry specific chargers for
shaver and toothbrush when travelling.

--
Rod

On 29/05/2016 18:25, Bill Wright wrote:
On 29/05/2016 11:54, wrote:

Even a 1.5v cell can kill in contrived circumstances.

Choking for instance.

Bill

Or:

What are the dangers?

Although a child may not choke, if undetected the batteries can do
serious damage to the gastrointestinal system. When combined with
saliva, the electrical current from the battery produces caustic soda
that burns through the throat or stomach and can cause further damage to
other internal organs.

http://www.rospa.com/home-safety/adv...ell-batteries/

--
Rod

On 29/05/16 18:26, Bill Wright wrote:
On 29/05/2016 13:14, Halmyre wrote:

Or, heaven forbid, do without it for half an hour or so?

Yes! Good grief, there's plenty of other things to do in the bath.


You dirty beast!

Bill



--
"It is an established fact to 97% confidence limits that left wing
conspirators see right wing conspiracies everywhere"

"Bill Wright" wrote in message
...
On 29/05/2016 11:54, wrote:

Even a 1.5v cell can kill in contrived circumstances.

Choking for instance.

And being dropped on your head from a great height too.

Halmyre Wrote in message:
On Sunday, May 29, 2016 at 10:38:57 AM UTC+1, Andy Burns wrote:
polygonum wrote:

How dangerous would it be to use a phone or tablet in the bath whilst it
is connected to a mains-powered USB charger?

If you look at various USB charger and SMPSU teardowns on youtube, they
often have a sizeable fraction of mains voltage (at a minute current) on
the 5V outputs, the sort of "tingle" you can feel with an unearthed
laptop when it contacts bare skin could feel a lot worse with wet skin
in the bath, the leakage current won't directly hurt you, but if it
makes you jump you could lose your footing or bash your head on the
tiles etc

Is there in future likely to be a bathroom-safe USB socket next to the
shaver and toothbrush socket?

Just charge the device up in advance of using it in the bathroom?

Or, heaven forbid, do without it for half an hour or so? Fair enough if you're reading a book on your Kindle, but not if it's sheer terror at the thought of being 'off the grid' for any length of time.



I sometimes watch something on my tablet in the bath. I have a
bath to relax really as much as getting clean. We have one of
those across the bath rack things and I rest it on
there
--
--
Chris French

"Rod Speed" wrote in message
...


"Bill Wright" wrote in message
...
On 29/05/2016 11:54, wrote:

Even a 1.5v cell can kill in contrived circumstances.

Choking for instance.

And being dropped on your head from a great height too.

Pity you weren't dropped on your head from a great height.

On 30/05/16 00:28, bm wrote:
"Rod Speed" wrote in message
...


"Bill Wright" wrote in message
...
On 29/05/2016 11:54, wrote:

Even a 1.5v cell can kill in contrived circumstances.

Choking for instance.

And being dropped on your head from a great height too.

Pity you weren't dropped on your head from a great height.


What makes you think he wasn't?



--
"When one man dies it's a tragedy. When thousands die it's statistics."

Josef Stalin

"The Natural Philosopher" wrote in message
...
On 30/05/16 00:28, bm wrote:
"Rod Speed" wrote in message
...


"Bill Wright" wrote in message
...
On 29/05/2016 11:54, wrote:

Even a 1.5v cell can kill in contrived circumstances.

Choking for instance.

And being dropped on your head from a great height too.

Pity you weren't dropped on your head from a great height.


What makes you think he wasn't?

He wouldn't be posting ******** here (if the 'great height' was high
enough).

En el artículo ,
escribió:

Of course even a well designed charger doesn't meet that naive expectation.
Other crap snipped.

And to prove Woddles wrong (again):

https://www.youtube.com/watch?v=3Hdn0MuCK_0

--
(\_/)
(='.'=) Windows 10: less of an OS, more of a drive-by mugging.
(")_(") -- "Esme" on el Reg

On 29/05/2016 19:55, The Natural Philosopher wrote:
On 29/05/16 18:26, Bill Wright wrote:
On 29/05/2016 13:14, Halmyre wrote:

Or, heaven forbid, do without it for half an hour or so?

Yes! Good grief, there's plenty of other things to do in the bath.


You dirty beast!


It's all in your mind. Me and my loofah are just good friends.

Bill

Mike Tomlinson wrote
wrote

Of course even a well designed charger
doesn't meet that naive expectation.

And to prove Woddles wrong (again):

https://www.youtube.com/watch?v=3Hdn0MuCK_0

Doesn't prove me wrong. That transformer clearly wasn't properly
designed. It was never properly designed so that a manufacturing
fault couldn't see full mains voltage on the USB. A much better
bobbin design that keeps the primary and secondary completely
separate so that no manufacturing fault could see it end with a
direct short between the primary and secondary of that transformer
could occur.

On 30/05/16 02:17, bm wrote:
"The Natural Philosopher" wrote in message
...
On 30/05/16 00:28, bm wrote:
"Rod Speed" wrote in message
...


"Bill Wright" wrote in message
...
On 29/05/2016 11:54, wrote:

Even a 1.5v cell can kill in contrived circumstances.

Choking for instance.

And being dropped on your head from a great height too.

Pity you weren't dropped on your head from a great height.


What makes you think he wasn't?

He wouldn't be posting ******** here (if the 'great height' was high
enough).

Well modern surgery can work miracles.

Don't you remember back in the day of the Wilson Govt. the story of a
surgeon who attended a motorway crash 'And all they found was a **** and
a pipe, but I sewed em back together and now its prime minister'.





--
A lie can travel halfway around the world while the truth is putting on
its shoes.

On Sunday, 29 May 2016 11:27:08 UTC+1, wrote:
On Sunday, 29 May 2016 10:37:25 UTC+1, Rod Speed wrote:
polygonum wrote

How dangerous would it be to use a phone or tablet in the
bath whilst it is connected to a mains-powered USB charger?

Not dangerous at all if the charger is designed properly so that no
matter what fails you can ever get any mains voltage on the USB.

Of course even a well designed charger doesn't meet that naive expectation.
Other crap snipped.


NT

It is possible to do it with a properly designed transformer.
But these seem to be none existent these days.
Expense I suppose.

harry wrote
wrote
Rod Speed wrote
polygonum wrote

How dangerous would it be to use a phone or tablet in the
bath whilst it is connected to a mains-powered USB charger?

Not dangerous at all if the charger is designed properly so that no
matter what fails you can ever get any mains voltage on the USB.

Of course even a well designed charger doesn't meet that naive
expectation.

It is possible to do it with a properly designed transformer.

Yep, whatever those pig ignorant fools claim.

Not even hard to do, just a proper bobbin that keeps
the primary and secondary completely separate so
that whatever primary insulation fails, the bobbin
keeps the coils apart with the thick bobbin walls.

But these seem to be none existent these days.

Bull**** they are. Have a look at the Apple USB chargers sometime.

Expense I suppose.

Nope. Doesnt cost much to do it right.

En el artículo , The Natural Philosopher
escribió:

'And all they found was a **** and
a pipe, but I sewed em back together and now its prime minister'.

Lol!

--
(\_/)
(='.'=) Windows 10: less of an OS, more of a drive-by mugging.
(")_(") -- "Esme" on el Reg

On Monday, 30 May 2016 06:22:18 UTC+1, harry wrote:
On Sunday, 29 May 2016 11:27:08 UTC+1, tabbypurr wrote:
On Sunday, 29 May 2016 10:37:25 UTC+1, Rod Speed wrote:
polygonum wrote

How dangerous would it be to use a phone or tablet in the
bath whilst it is connected to a mains-powered USB charger?

Not dangerous at all if the charger is designed properly so that no
matter what fails you can ever get any mains voltage on the USB.

Of course even a well designed charger doesn't meet that naive expectation.
Other crap snipped.

It is possible to do it with a properly designed transformer.
But these seem to be none existent these days.
Expense I suppose.

Harry isn't en electronic engineer.


NT

I would ask you this, Have you ever looked inside of a usb charger. Most
have no fuse and the switch mode supply is driven directly from the mains
via a semiconductor driving the primary of a transformer a very tiny
transformer, at a high frequency, the other side is connected to a very
simple rectifier and voltage stabilising chip.
You are in effect relying on a cheaply made tiny transformer to isolate
you from the full mains voltage.
I'd no chance it knowing what I know about these things. I have had more
than one fail one very spactacularly and trash the device on it. Crap.
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"polygonum" wrote in message
...
How dangerous would it be to use a phone or tablet in the bath whilst it
is connected to a mains-powered USB charger?

Obviously it could be dangerous to the device itself if you drop it into
the water!

Obviously a 5 volt low current supply isn't usually life threatening.

Obviously we have rules about sockets in bathrooms. But a long USB cable
to a socket in another room seems a likely way round that.

But if something is wrong somewhere, such as a mis-wired USB charger,
could there be any appreciable danger?

Is there in future likely to be a bathroom-safe USB socket next to the
shaver and toothbrush socket?

--
Rod

wrote
harry wrote
tabbypurr wrote
Rod Speed wrote
polygonum wrote

How dangerous would it be to use a phone or tablet in the
bath whilst it is connected to a mains-powered USB charger?

Not dangerous at all if the charger is designed properly so that no
matter what fails you can ever get any mains voltage on the USB.

Of course even a well designed charger doesn't meet that naive
expectation.

It is possible to do it with a properly designed transformer.
But these seem to be none existent these days.
Expense I suppose.

Harry isn't en electronic engineer.

You dont have a ****ing clue about how to design a USB
charger so that whatever fails it is never a life threatening
problem, even if it is used in a wet area like a bathroom.

Fortunately operations like Apple dont actually
employ fools like you to design their USB chargers.

Don't know about that, I've always thought that inductive chargers are
pretty inefficient, even if driven at high frequencies.
I suppose you could have a bit battery and a cable to your device which
would be safer than a mains connection of any kind.



Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"polygonum" wrote in message
...
On 29/05/2016 09:55, wrote:
There is a very thin barrier between mains and usb output. If it
breaks down you're fried. A great number of noncompliant chargers
exist that have very inadequate insulation. I would not do it.

I assure you it is not my intention to do it! I expect many people do,
though, and it made me wonder. If I did want to, I'd probably think to use
my battery pack USB charger or, preferably, charge before bath, but I
don't want to drown my phone or tablets.

I was also imagining the next generation of shavers and toothbrushes
possibly having USB charging as standard? Or, wireless charging but with
the charging plate being fed by USB.

--
Rod

Brian Gaff wrote

I would ask you this, Have you ever looked inside of a usb charger.

There are plenty of teardowns on youtube.

Most have no fuse

The best designed ones do.

and the switch mode supply is driven directly from the mains via a
semiconductor driving the primary of a transformer a very tiny
transformer,

Perfectly possible to do those so that whatever
fails you never get mains voltage on the USB.

at a high frequency, the other side is connected to a very simple
rectifier and voltage stabilising chip.
You are in effect relying on a cheaply made tiny transformer to isolate
you from the full mains voltage.

Perfectly possible to do those so that whatever
fails you never get mains voltage on the USB.

I'd no chance it knowing what I know about these things.

I would with a USB charger from operations
that know what they are doing like Apple.

I have had more than one fail one very spactacularly and trash the device
on it. Crap.

So don’t buy the crap, buy well designed USB chargers instead.

polygonum wrote

How dangerous would it be to use a phone or tablet in the bath whilst it
is connected to a mains-powered USB charger?

Obviously it could be dangerous to the device itself if you drop it into
the water!

Obviously a 5 volt low current supply isn't usually life threatening.

Obviously we have rules about sockets in bathrooms. But a long USB cable
to a socket in another room seems a likely way round that.

But if something is wrong somewhere, such as a mis-wired USB charger,
could there be any appreciable danger?

Is there in future likely to be a bathroom-safe USB socket next to the
shaver and toothbrush socket?

--
Rod