In article ,
Andy Burns writes:
ARWadsworth wrote:

It is about the wall mart type chargers. One came with the digital camera,
another with the sat nav another with the video camera etc.

I just want to laeve the latst one plugged into the wall socket and change
USB leads as and when needed.

Yeah, just pick the beefiest out of the lot (e.g. newer phones can suck
up to 1000mA from a suitable charger, using "signalling" resistors
between the pins to indicate htis) and you should be fine, saves keeping
a whole row of wall warts warm.

Be careful with ones for mobile phones. Before signalling resistors
were introduced to the USB spec, some of these generated 5.5V to signal
to the phone that they had high current availability so the phone knew
it could charge at 1A or more. A standard USB outlet is 100mA/500mA max
and 5.25V max, and if charged from that, the phone reduces its current
draw to standard USB levels. The 5.5V phone adapters are over the max
USB spec and could in theory cause problems if used to power other USB
devices not designed for it.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]