OESF Portables Forum
Model Specific Forums => Sharp Zaurus => Zaurus - pdaXrom => Topic started by: VirtusRex on June 26, 2007, 12:45:56 pm
-
Hey guys,
I've been looking around for a way to power my USB wireless NIC without a powered host when I came across this article. It's a gadget someone created that supplies power to USB devices, which might come in handle if you wanted to power say now a USB keyboard.
What do you guys think???
Here's the link:
http://tabletblog.com/2006/01/usb-power-injector-2.html (http://tabletblog.com/2006/01/usb-power-injector-2.html)
Later,
VirtusRex
-
Hey guys,
I've been looking around for a way to power my USB wireless NIC without a powered host when I came across this article. It's a gadget someone created that supplies power to USB devices, which might come in handle if you wanted to power say now a USB keyboard.
What do you guys think???
Here's the link:
http://tabletblog.com/2006/01/usb-power-injector-2.html (http://tabletblog.com/2006/01/usb-power-injector-2.html)
Later,
VirtusRex
[div align=\"right\"][{POST_SNAPBACK}][/a][/div] (http://index.php?act=findpost&pid=163785\")
whow
looks like little dangerous for our Z, not ? besides i don't like the 9V battery
why not look for battery powered usb hub or battery powered usb device?
see here:
[a href=\"http://jpmatrix.livejournal.com/]http://jpmatrix.livejournal.com/[/url]
-
Well, it's not dangerous, as long you know what you're doing. I have made (thanks to lougi600) 4xAA power supply for my Z, and would prefer to use the same to power the devices that require more power.
Unfortunately, here in Bulgaria I cannot find where I can buy USB mini male/female jacks
Anyone knows an online store to order?
-
Rather a naive implementation, using a 5V linear regulator with a 9V supply, which will be very inefficient (i.e. eating batteries unnecessarily). The advice with 78xx regulators is also to connect a decoupling capacitor close to input and output to avoid oscillation, and this is not done here.
I'd just go with four NiMH rechargeable cells in series, giving 4.8V or so - close enough. It would be wise to wire a fuse into the circuit.
-
Rather a naive implementation, using a 5V linear regulator with a 9V supply, which will be very inefficient (i.e. eating batteries unnecessarily). The advice with 78xx regulators is also to connect a decoupling capacitor close to input and output to avoid oscillation, and this is not done here.
I'd just go with four NiMH rechargeable cells in series, giving 4.8V or so - close enough. It would be wise to wire a fuse into the circuit.
[div align=\"right\"][a href=\"index.php?act=findpost&pid=164121\"][{POST_SNAPBACK}][/a][/div]
A fuse ... hum : if you want a fuse there it better be a fery fast blow one because the ones inside the Z are already fast blow ... so if you want to be sure that it blows before the ones inside the Z it must be faster (and possibly very close to the max rate absorbed by Z).
A normal wire fuse will be pretty useless for this pourpouse ;-)
For anyone intrested in making wierd stuff for their Z: have a look in my home page under the "ZElectronics" section ... there is some material to get ideas from ;-)
I also saw somewhere that it's possible to change a resistor in the USB OTG voltage regulator of the C1000 (and maybe also C3x00) so that it can drive safely 500mA: this would allow you to connect any single USB device that is within the USB power specifications. The firs time I open my C1k I'll probably make that modification (and document it on my home page).