Concerning USB

[arneson]

I have had inexplicable troubles with USB.
Could this Universal Buse be a little weak on the power side.
My camera, give or take, 250mil, multi card reader, 100mil, wireless pointer,100mil, 802.11 transciever, 150mil.

As you see I'm well over the 500mil limitation of this bus.
I have a hub which I can use unpowered and yes I could drag around another small black brick to get say, four ports and 500 more milliamps of juice.

The situation above is a laptop, but applies to any system as well.
When my USB port is "overloaded" not only do things become unstable but,I may be off base here, I believe my caps get stressed.

[kc8adu]

Re: Concerning USB

iirc there is a polyswitch to protect the usb port.
if it trips you must remove the load to let it reset.

[willawake]

Re: Concerning USB

i was checking an issue on a laptop recently. customer purchased a new unpowered 4 port hub. with optical mouse plugged into the hub, usb flash disk didnt work. using the old 2 port hub both worked. no other devices were plugged in.

what i am saying based on this and also reports i have seen on the net is that usb hubs whether unpowered or powered differ in performance depending on the model. needs some research to find a good one. maybe laptop ports are not so great also for usb power?

i try to limit the number of usb devices though. they do cause issues and more so in win2k than xp. nice to see scsi scanners gone though and their damn adaptec drivers, what a POS that was.

i use usb/ps2 converters on all the mice so that gets rid of one device and eliminates a lot of probs. i read sometime that it loses some functionality though but i never noticed anything......

if you ever need a card reader for desktop some time though, check out the internal teac floppy/reader combo
http://www.techmati.com/reviews/cardfloppy/index.htm
they are just great and zero issues unlike the sandisk 8in1 which occasionally doesnt work on boot but that might be the mobo.

i like also the lexar usb 2.0 jumpdrive flash disks, they are real fast, can work off them like HDD speed if you liked.

[arneson]

Re: Concerning USB

KC8,
I have never heard of a polyswitch?
Could you go into that a little?

[arneson]

Re: Concerning USB

Raycem showed this and other applications.

[kc8adu]

Re: Concerning USB

KC8,
I have never heard of a polyswitch?
Could you go into that a little?

it is a overcurrent protection device that goes high resistance at a specified current.in order to cool down and reset the load must be removed.

[arneson]

Re: Concerning USB

Hmm,, what else can I overload...video? sata? Parallel?