Why get usb2 pcmcia with ac power

I'm getting a pcmcia usb 2 card for the lap /ubbthreads/images/graemlins/smile.gif
LO and BEhold.... Some have external power supplies????
AC adapter and also some that you plug into an existing usb1 port.
Why would I need external power?
All the equipment I use is externally powered or a card reader
/ubbthreads/images/graemlins/help.gif
Tom

There are some devices that use power from the USB port on your PC. Your PCMCIA card slot does not supply the same amount of power that a USB port would. I don't know the specifics, but I do know there are a few devices that do fall into the realm of using more power from the USB port than the PCMCIA card can provide. If it's not too much more $, and you have the OPTION to use the external power or not, I'd go for the one with the power supply. If you can't use the card without the wall wart under any circumstances, go for the one without the power supply.

Like Beretta said, it's for high power devices, or indeed devices that need any bus power at all. A PCMCIA card may not be able to deliver enough power to even spin up a portable hard drive without external power. I know this is true for firewire PC cards.

If the devices are externally powered then there is no need to use the adaptor, it's not required (or rather it's not required in any of the cards or similar devices that I know of) you can run without it just fine. But if you need it for something, then that may be the only way you can use the device. I would get it just in case.

I got one of those about a year ago for my old laptop. The adapter for suposedly for "high drain devices", but I could not find one device that would work without the adapter. Self powered or not, even a USB hub would not be recognized. Plug it in and everything worked fine...but the whole point of a laptop is no cords.

Thanks guys, I opted to try one designed for non power. I'll let you know if successful or not.
Zmoz has raised flags for me now /ubbthreads/images/graemlins/smile.gif
Course I saw this after purchase. DUH!!!
Tom

Well I got the usb2 card without power adapter and it FLIES along mightily fast. /ubbthreads/images/graemlins/smile.gif
I'm in luck that all the devices, so far, that I wish to use are fine.
I use 2 external enclosures for HD's that are externally powered. And I use printer and a multi reader card /ubbthreads/images/graemlins/smile.gif
Anyone who hasn't tried usb2 YOU ARE MISSING OUT!!
Transferring gigs of files to 120gig hd's took a LOOOONG time before usb2. Now 40 times faster. Of course 4 gigs of 50 or 100 files are still much faster than 4 gigs of 5000 files /ubbthreads/images/graemlins/smile.gif
Thanks for your advice
Tom

What are they going for nowadays? I recall seeing a price of about $35; is that in the ballpark for those?
I'm in a chicken/egg state, I don't have the USB 2.0 card because I don't have any devices that could utilize it, and I don't have any USB 2.0 devices because my laptop can't handle it.
The dam might just burst if I get just one... like Frito Lays or something- /ubbthreads/images/graemlins/smile.gif

$18 shipped Ebay
Best thing since.....???
My lap had usb1 ports that I have mouse and keyboard in.
Other items I have usb is (are) printers, an officejet, multi card reader for the teeny memory cards (cameras, pda's), 2 external 120g hd's. The external enclosures can take cd, dvd, burners or any internal mount equip zip drives.
Fritos here you come.
ZMOZ had a problem with a card he got not being able to drive his USB stuff. I'd like to see his particulars on his lap and figure why it didn't work (see above somewhere)
You can probably pick up a card with power adapter for ~ the same price. I was in a hurry. Immediate gratification and all that /ubbthreads/images/graemlins/smile.gif
Tom

Well, I guess I'll have to look into it- does sound like a great cost/benefit ratio!

The only difference is where you put in the power. If all your devices are self powered then you won't need the powered hub, although it can be nice to have one p.s. plugged in the hub if you have several devices that can be bus powered and eliminate some wall warts.

Got the Belkin Cardbus USB 2.0 adapter, and it has an input port for external power, which my current one doesn't have. It can work without the AC adapter for the low draw devices, or the 7.5V 1.2A switching supply can be used for high draw devices.
The powered adapter works well with my Archos V2 Jukebox recorder, because even though it's self powered, it draws extra power to charge its battery through the USB port, which is beyond the 5V 500mA maximum current limit defined by the interface specification for USB 2.0 .

Just as an fyi, even if devices at both ends (say, laptop and printer) are self-powered, you may still get usb prob's.

For example, my dad has an HP laptop with an underpowered USB port. Darn thing keeps losing connection to the printer, which ironically enough is also an HP. Tech support on their web pages confirms it's a known problem with the printer's USB-port staying live.

For now, my dad's just power cycling his printer when he wants to print, but I'll be bringing him an AC powered USB hub the next time I get up his way. Belkin's Tetrahub or something like that.

USB busses typically support minute max current - usually around 100mA total @ 12V. I can't imagine that PCMCIA would have trouble supplying that kind of power (1.2W). There used to be Type III harddrives - and those need some juice due to the nature of harddrives.