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Old 07-06-2009, 04:47 AM   #19
gwynevans
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Quote:
Originally Posted by djgreedo View Post
I still have no idea WHY they designed it to not charge from a non-PC based USB port (e.g. mains adaptor/car adaptor) into the mini-USB when it charges perfectly from a PC (even a PC that doesn't have the software/drivers installed).
I think that it's down to a particulalry strict interpretation of the USB spec, which can be read to require that there should be a valid communication/negotiation between client & master/hub before current is drawn, in order to ensure that the device doesn't attempt to draw too much current & damage the master/hub. As the adapters don't support this part of the USB spec & just provide the power, the Sony devices don't draw any current. I've posted links to the specs elsewhere here, if anyone wants to dig deeper!
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