I seem to be buying a few bits of kit recently, like a Kindle and a Sony
MP3 player, that come for charging purposes with a 240V mains plug
having a detachable lead. The end that detaches from the plug is a
standard male USB connector so that, if I want to, I can use it to
connect the device directly to a computer rather than the mains.

The question I have is whether these mains plugs are interchangeable or
whether they're device specific, so I can decide how many I need to take
on holiday. Do I risk doing damage to any of the devices just by using
the wrong plug, albeit with the right lead?

On the one hand, I'd have thought all USB connectors and compatible
devices work on standard voltages etc. On the other, maybe there's a
crucial difference in the power output needed to charge the different
batteries.

Anyone know the answer please?

Norman Wells wrote:
: On the one hand, I'd have thought all USB connectors and compatible
: devices work on standard voltages etc. On the other, maybe there's a
: crucial difference in the power output needed to charge the different
: batteries.

: Anyone know the answer please?

I think so!

PC USB sockets supply 5V and are limited to supplying 5W of power max -
thus anything that can also be charged from a PC is interchangeable between
different mains chargers (assuming the connectors match at the phone end!)

Basically any USB socket/charger is OK for charging most devices.

The iPad/Ipad2, however, needs 10W to charge so that, when connected to a
normal PC USB, socket it does not charge - but it works for data and does
not damage the PC or the USB socket.

On 06/12/2011 17:47, Norman Wells wrote:
I seem to be buying a few bits of kit recently, like a Kindle and a Sony
MP3 player, that come for charging purposes with a 240V mains plug
having a detachable lead. The end that detaches from the plug is a
standard male USB connector so that, if I want to, I can use it to
connect the device directly to a computer rather than the mains.

The question I have is whether these mains plugs are interchangeable or
whether they're device specific, so I can decide how many I need to take
on holiday. Do I risk doing damage to any of the devices just by using
the wrong plug, albeit with the right lead?

On the one hand, I'd have thought all USB connectors and compatible
devices work on standard voltages etc. On the other, maybe there's a
crucial difference in the power output needed to charge the different
batteries.

Anyone know the answer please?


In general, yes, they are all compatible.
There are a couple of gotchas, both apple-related.

1) Some apple i-things will not charge from some generic adapters. IIRC,
it may be necessary to add pull-up and / or pull-rown resistors to set
the data lines at some defined voltage before they will accept the charge.

2) iPads require a 2.1A USB supply, way more than a generic device can
supply ( 500mA ) unless it's specifically specced for iPads. Note that
if an iPad is connected to a regular 500mA USB supply, it *will* in fact
charge, even though it will tell you it isn't. It will just take for ever.

Otherwise, it's all generic USB compatable as far as I've discovered.

--
Ron

"Ron Lowe" wrote in message
...
On 06/12/2011 17:47, Norman Wells wrote:
I seem to be buying a few bits of kit recently, like a Kindle
and a Sony
MP3 player, that come for charging purposes with a 240V mains
plug
having a detachable lead. The end that detaches from the plug
is a
standard male USB connector so that, if I want to, I can use
it to
connect the device directly to a computer rather than the
mains.

The question I have is whether these mains plugs are
interchangeable or
whether they're device specific, so I can decide how many I
need to take
on holiday. Do I risk doing damage to any of the devices just
by using
the wrong plug, albeit with the right lead?

On the one hand, I'd have thought all USB connectors and
compatible
devices work on standard voltages etc. On the other, maybe
there's a
crucial difference in the power output needed to charge the
different
batteries.

Anyone know the answer please?


In general, yes, they are all compatible.
There are a couple of gotchas, both apple-related.

1) Some apple i-things will not charge from some generic
adapters. IIRC, it may be necessary to add pull-up and / or
pull-rown resistors to set the data lines at some defined
voltage before they will accept the charge.

2) iPads require a 2.1A USB supply, way more than a generic
device can supply ( 500mA ) unless it's specifically specced
for iPads. Note that if an iPad is connected to a regular
500mA USB supply, it *will* in fact charge, even though it will
tell you it isn't. It will just take for ever.

Otherwise, it's all generic USB compatable as far as I've
discovered.

--
Ron








There is a third. Whilst USB output is nominally 5V some chargers
output a slightly higher level - 5.2 or 5.3V - and if your device
requires one of this variety then when you plug it into a 5V
output type it will object or not charge. Having said that if the
device is designed to be connected to a PC which also outputs 5V
it often will charge; maybe it has some intelligence to know that
it is a computer being used as source and not to object?



--
Woody

harrogate three at ntlworld dot com

"Brian Mc" wrote in message
...
Norman Wells wrote:
: On the one hand, I'd have thought all USB connectors and compatible
: devices work on standard voltages etc. On the other, maybe there's a
: crucial difference in the power output needed to charge the different
: batteries.

: Anyone know the answer please?

I think so!

PC USB sockets supply 5V and are limited to supplying 5W of power max -
thus anything that can also be charged from a PC is interchangeable
between
different mains chargers (assuming the connectors match at the phone end!)

Basically any USB socket/charger is OK for charging most devices.

The iPad/Ipad2, however, needs 10W to charge so that, when connected to a
normal PC USB, socket it does not charge - but it works for data and does
not damage the PC or the USB socket.

although some devices may try to draw more than 1A and some supplies may
provide more than 1A.

In message , Ron Lowe writes
On 06/12/2011 17:47, Norman Wells wrote:
I seem to be buying a few bits of kit recently, like a Kindle and a Sony
MP3 player, that come for charging purposes with a 240V mains plug
having a detachable lead. The end that detaches from the plug is a
standard male USB connector so that, if I want to, I can use it to
connect the device directly to a computer rather than the mains.

The question I have is whether these mains plugs are interchangeable or
whether they're device specific, so I can decide how many I need to take
on holiday. Do I risk doing damage to any of the devices just by using
the wrong plug, albeit with the right lead?

On the one hand, I'd have thought all USB connectors and compatible
devices work on standard voltages etc. On the other, maybe there's a
crucial difference in the power output needed to charge the different
batteries.

Anyone know the answer please?


In general, yes, they are all compatible.
There are a couple of gotchas, both apple-related.

1) Some apple i-things will not charge from some generic adapters.
IIRC, it may be necessary to add pull-up and / or pull-rown resistors
to set the data lines at some defined voltage before they will accept
the charge.

2) iPads require a 2.1A USB supply, way more than a generic device can
supply ( 500mA ) unless it's specifically specced for iPads. Note
that if an iPad is connected to a regular 500mA USB supply, it *will*
in fact charge, even though it will tell you it isn't. It will just
take for ever.

Otherwise, it's all generic USB compatable as far as I've discovered.


I use this wall charger,

http://preview.tinyurl.com/6m4q9dx

I don't have any Apple stuff, but it works with my phone and my camera.

Would this work for the o/p?
--
Ian

On Dec 6, 5:47*pm, "Norman Wells" wrote:
I seem to be buying a few bits of kit recently, like a Kindle and a Sony
MP3 player, that come for charging purposes with a 240V mains plug
having a detachable lead. *The end that detaches from the plug is a
standard male USB connector so that, if I want to, I can use it to
connect the device directly to a computer rather than the mains.

The question I have is whether these mains plugs are interchangeable or
whether they're device specific, so I can decide how many I need to take
on holiday. *Do I risk doing damage to any of the devices just by using
the wrong plug, albeit with the right lead?

On the one hand, I'd have thought all USB connectors and compatible
devices work on standard voltages etc. *On the other, maybe there's a
crucial difference in the power output needed to charge the different
batteries.

Anyone know the answer please?

We have a fair few devices with USB charges at home these days and
swap chargers and leads without any problems. Some devices (like my
HTC phones) sense whether there is a USB bus present on the middle
pins of the USB cable; if there is it trickle charges (many PC USB
ports can only source a couple of hundred mA), if there isn't it
assumes it's connected to a proper mains charger and charges at around
an amp.

airsmoothed wrote:
On Dec 6, 5:47 pm, "Norman Wells" wrote:

Anyone know the answer please?

We have a fair few devices with USB charges at home these days and
swap chargers and leads without any problems. Some devices (like my
HTC phones) sense whether there is a USB bus present on the middle
pins of the USB cable; if there is it trickle charges (many PC USB
ports can only source a couple of hundred mA), if there isn't it
assumes it's connected to a proper mains charger and charges at around
an amp.

Thanks for everyone's advice.

I'll treat the plugs as interchangeable then.

airsmoothed wrote:
: pins of the USB cable; if there is it trickle charges (many PC USB
: ports can only source a couple of hundred mA),

They are out of spec if they do this! 500mA is allowed from *ANY* PC USB
socket. I think the socket often switches off entirely - until something
else is plugged in - (and for charging not data) if you try to draw more
than that.

Brian Mc wrote:

wrote:

: pins of the USB cable; if there is it trickle charges (many PC USB
: ports can only source a couple of hundred mA),

They are out of spec if they do this! 500mA is allowed from *ANY* PC USB
socket. I think the socket often switches off entirely - until something
else is plugged in - (and for charging not data) if you try to draw more
than that.

USB1 devices are only allowed 100mA (150mA for USB2) until they
negotiate higher power with the host (maximum 500mA for USB1 and 750mA
for USB2)

As mentioned by someone else, dedicted charging ports use combinations
of resistors on the data+/- pins to indicate even higher current is
available.