Workbench USB "switch box"

[ameal]

hi everyone,

In my workbench i have the laptop and connected to it is:

- USB External 500GB Hard Drive
- USB DVD Recorder (which i use instead of the laptop)
- USB Printer
- USB Wireless Adapter
- PICKIT 2
- Pendrive (ocasionally)

You guess what is my problem. The Laptop only has 4 USB ports.
So i will buy myself a HUB.

But... i would like a switch for each of the devices connected to it, controling the USB power line and the devices AC power line (simply by a relay).
What i intend to do is to only connect the PC (or the HUB) and everything comes to life and likewise disconnecting everything goes down, including bench light and power suplly. Also it will become handy having a switch to kill the USB conection when testing USB capable PIC´s.

Later it may become a PC aplication controling the connection to the HUB itself and one can connect any needed peripherals after start up. This means all cables out of the bench, except one.

Is this as easy as just controling the USB power line?
Or do i have to switch of the data lines from the HUB?

Also as something like this ever been done?
my googling for "USB switch" only gave me market units to switch one device between two or more stations. Maybe that's not the name for this circuit.

Any help will be much apreciated.

Warm regards,
Ameal

 

[ameal]

Many of you may wonder why don´t i just use the HUB's and disconnect the devices one by one.
That´s what i´ve been doing.

but...
- my hardrive has external power supply with no switch
- my external DVD recorder has a swith but on the rear panel.
it is located in the shelf and has the hardrive on top
its kind of hard to reach.
- the same above regarding the printer.
- all other are USB supplied and none as a switch, so i'm constantly pulling cables out.

for the sake of someone remembering to call me lazy, i will gladdly not bring this subject again.
But a few pointer would be much aprecciated.

warm regards,
Ameal

 

[cowana]

They make devices like this already. However, it would not be hard to make your own - simply power a relay from the computer's 5v connection, and use the relay to switch the mains voltage.

 

[Exo]

Most modern computers keep their usb ports powered up all the time, even when the system is off or in stand by - the only way to have no power on the usb ports is to unplug the system. This in done to enable usb-wakeup techniques. So you'd have to use a 5V connection from inside the PC to power the relay.

 

[cowana]

None of the PCs or laptops I have worked with power their USB ports when active, whith the exception of one Samsung lapton, which has a special program to enable this (for charging of devices). If I plug my phone into my PC when it is shut down, it won't charge.

 

[Exo]

Perhaps laptops play by a diffirent set of rules. Most desktops however always have power on their usb ports.

 

[ameal]

hi.
i use a laptop and know for shure its USB's power down when i disconnect it.

i thought of just controling the power lines, but the USB connector as 4 pins, two of which, the outer ones which i'd guess are the power lines, are advanced relative to the inside ones. i think they meant to connect first power, then data lines.
i could use a relay in the USB power line to control the AC line, but i also would want to use a switch to control that relay, like ON-OFF-AUTO. in that case the data line would remain connected.
Can the USB input have signal in the data lines without power connected?
Since i won't be disconnecting the connectors the data lines will be always on. do i have to switch them off as well? In what way?

Warm regards,
Ameal