On Mar 13, 2012, at 9:17 AM, Patrick W wrote:
> Most USB Ports on computers are limited to 500mAh.
> The supplied wall wart for an iPhone 4 is 1000mAh or 1Ah.
> The supplied wall wart for an iPad is 2000mAh or 2Ah.
> The iphone should regulate its self to 1000mAh max current draw when
> charging. SO if your using a charger that produces more current then its
> needing the phone will limit its self to prevent it from charging to fast
> and over heating.
Thanks for explaining the mechanics, or I guess the electronics of it.
While you are there, I was wondering if you could give an opinion on another USB power question.
I am trying to space a USB three way away from MacBook Pro. When plugged in directly, I can power my Canon LiDE30 scanner. I have mixed results trying my three 30-inch male/female USB cables.
The Griffin is the smallest diameter, and functions the best, but it apparently providing just enough power. A generic cable is providing just under enough power, where it might work once of twice, but not enough for multiple scans. It is the common diameter. Both of these will light the LED on the Belkins 3-way.
And then I have an Apple male/female USB cable, that came with my MBP. It can not even light the LED in the 3-way, but is the largest diameter, similar to a Firewire cable.
My question is there no standard for power transmission over USB cables? I'm trying to move the cable clutter just a little further back from the MBP.
I think the total distance from MBP to scanner is right about 6 feet. The scanner is the only one that is USB powered, other than LED.
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