On Wed, 2010-03-17 at 12:49 +0200, Kari Somby wrote: > The protocol says that max current for one USB host is 500 mA. Which is not available to plugged in devices by default. The power supply feature is initially only a low current, and can be increased when the device negotiates with the host. The initial "low current" supply was originally 100mA, but later this was changed to 150mA. But, because the original was lower, you can only reasonably expect to get 100mA out of a port, by default. The maximum current available was 500mA (after negotiation), later this was increased. But, again, because the original was lower, you can only reasonably expect to get 500mA from one host. It's expected that the device plugged into the port would be the thing to do the negotiation. Though it could be possible for software on the computer to program the power power. That would be what those special charging programs do. Just like there are devices which ignore the specs, and try to get power that they don't deserve, there will be hosts that ignore the specs, and can always supply more power than the specifications. I still think it's rather dumb to use an expensive computer to replace a cheap charger or power supply. -- [tim@localhost ~]$ uname -r 2.6.27.25-78.2.56.fc9.i686 Don't send private replies to my address, the mailbox is ignored. I read messages from the public lists. -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
