On Tue, 08 Jan, 2008 at 12:39:09 +0100, Carlos E. R. wrote:
The Tuesday 2008-01-08 at 06:47 +0100, Jon Clausen wrote:
On Mon, 07 Jan, 2008 at 16:40:48 +0100, Carlos E. R. wrote:
It would be possible to design one. The device only needs to monitor the presence of power in the usb power line coming from the laptop, and 1mA would be enough to trigger the base of a transistor that would in turn power up the device. It could even be designed around an optocoupler/triac to power up the AC side of the device.
You just pay an engineer, and he'll do appropriate wonders :-)
Too late, it's been done;
http://www.elsparefonden.org/public-and-commerce/products/energy-saving-equi...
Better:
But that doesn't say how this particular piece works. Typically it would use a relays to switch off the rest of the equipment, but a relays draws significant power from the usb bus of a portable running on battery. What I described were methods to do the same as already known to exist, but designed for laptops.
riiiight... I didn't realize what you meant. Elsparefonden is not a vendor of anything, it's a trust that does research on, and gives advice about reducing powerconsumption in general. Hence the above doesn't pertain to any *particular* device. I guess that most of those thingies basically just use the power from the USB to hold open (or closed) a relay, which turns on the mains. And that power would come from the battery of a laptop. http://www.elsparefonden.org/public-and-commerce/products/energy-saving-equi... suggests that the whole concept may become obsolete, if Wake-On-USB ends up being the norm... But I agree that a version designed for laptops would be good. /jon -- YMMV -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org