USB Charging/Docking station
Saturday, September 6th, 2008I’ve been looking for a setup to handle all of the USB devices I have, which also need to be plugged in to charge. I’ve seen a few plans for nice charging stations to make, but nothing that incorporates the computer connectivity. Why would I want to build two things stations when a single one would do?
So I started looking at the USB 2.0 spec about power requirements. As it turns out, externally powered hubs are required to supply 500 mA to all ports. It is also recommended that the hub draw its power from the bus, to allow continued operation in the absence of the external power source. What is not specified is if the hub is required to deliver power to the ports when it is not receiving power from the bus. If the device does power the ports when the bus-supplied power is absent (e.g. – when the computer is off), then it should work as a charging station for USB-connected devices.
The downside to this is that I’m pretty sure the boxes of these hubs aren’t going to advertise whether or not they deliver power to the ports when the bus power is removed, which means trial-and-error. I am going to guess that the cheaper hubs probably wouldn’t go to the trouble to handle switching power to the ports based on the availability of the bus power. So hopefully my trial-and-error won’t cost me too much.
Now I just need to decide what I want this station to look like, and how I’m going to flush-mount access to the unused ports. Maybe the hub also needs to be easily disassembled
