[JubyPete]

gsmith....that was an excellent post. i was an engineer in college, but industrial engineering. but i had my share of physics, etc.

so if i'm following correctly, your point about whether or not the hub has a limiter per port still only affects charge time (although at a different factor from how i suggested), right? if there is no limiter, and i only have 1 device plugged into the hub, then all 2000 mA would go to the one device, meaning it would basically be the same as AC power. even at 500 mA, and 3.9 hours (since that's probably the minimum draw at night while i'm sleeping would be fine.

i was also thinking about the a/c adaptor/transformer size when thinking of the hub. heck, i was also thinking maybe that plug could be zip-linqed =)

that makes sense then, why most usb hubs are only 4 port (especially the self-powered). if i can draw on your knowledge for one more tangential triva fact....what do these new 7 port hubs do? if AC current can only supply 2 A (4 port hub, 500 mA each)...does that mean across 7 ports it's only supplying 285.7 mA? maybe it's the kind of thing where 3 are bus-powered (one "reserved" for upstream) and 4 are powered?

[JubyPete]

gsmith....that was an excellent post. i was an engineer in college, but industrial engineering. but i had my share of physics, etc.

so if i'm following correctly, your point about whether or not the hub has a limiter per port still only affects charge time (although at a different factor from how i suggested), right? if there is no limiter, and i only have 1 device plugged into the hub, then all 2000 mA would go to the one device, meaning it would basically be the same as AC power. even at 500 mA, and 3.9 hours (since that's probably the minimum draw at night while i'm sleeping would be fine.

i was also thinking about the a/c adaptor/transformer size when thinking of the hub. heck, i was also thinking maybe that plug could be zip-linqed =)

that makes sense then, why most usb hubs are only 4 port (especially the self-powered). if i can draw on your knowledge for one more tangential triva fact....what do these new 7 port hubs do? if AC current can only supply 2 A (4 port hub, 500 mA each)...does that mean across 7 ports it's only supplying 285.7 mA? maybe it's the kind of thing where 3 are bus-powered (one "reserved" for upstream) and 4 are powered?

[GSmith]

Everything's right except your assumption "if AC current can only supply 2 A (4 port hub, 500 mA each)...". I'm sorry if I implied that. It's coincidence that the iPAQ AC adapter is rated at output 2A and that a 4-port USB hub is rated at 2A. On the 7-port hubs, the power supply would have to be rated at output of 7*500mA = 3.5A for it to meet the specification of "self-powered".

I think you've got it.

[JubyPete]

gsmith...actually, i thought you meant that the outlet provides 2 A =)

thanks again. now if i can only get that outlet in my bathroom to work =)

- plim

[GSmith]

NOW you've opened a can of worms talking about input current! An AC to DC converter (aka AC adapter) "takes in" the same POWER as it outputs (minus the inefficiency of the converter). Power is equal to V*A (not strictly true, but close enough for our purposes here). In the US, input voltage is about 120V. So if it outputs 3.5A at 5V (equals 17.5 Watts of power) then it takes in the same amount of power, and the current equals Amps=Power/Voltage => 17.5/120 = .146 A (which is the same as 146 milliamps)

Summary: Ac input: 146mA @ 120V => DC output 3.5A @ 5v (ignoring inefficiencies in the adaptor). Now you know how to read AC adaptor specifications!

But that's a lesson for another day, I think. You've got the basics.

Congrats!

[dodge_911]

DON'T !!!!

I had one from javoedge (seems like almost every company orders them at the same place )
It fried the serial connection on my 2215 when i used it with the supplied carcharger and it caused very strange things to happen on-screen, like a faulty tv...
I think it's because it charges and synchs at the same time...

Now, with my non-retractable (switchable) Belkin sync/charge cable, no problems whatsoever...
(mind though, haven't used that one for synching yet, at home i sync over BT or just pop it in it's cradle)