Since this is my first post, I'd just like to introduce myself. My name is Mike, and I am from Grand Rapids, MI. Also, I know next to nothing about electronics, which is why I'm here!

To my question: I have an external HDD that I have hooked to my Nintendo Wii, which I use to play backups of my games. The problem with this is, the drive does not have a switch to turn it on/off, and un/plugging it every time I use it is difficult due to where I have it located. What I'd like to do is make it so that my drive will turn on/off when I turn my Wii on/off. From my limited knowledge, I need to use a relay. The only signal going from the Wii to the drive is the USB cable, which sends a 5v current, and I assume this could be used to trigger the relay. The other pins of the relay could be connected to either the internal molex connector which would just turn the drive itself on/off, or somewhere else powering the entire enclosure. Either way would be fine with me, just as long as the drive doesn't spin when I'm not using it.

So, I guess my question is what type of relay should I use, and what would be the best way to wire it up? Thanks for any help you guys/girls may give me.

 

In the UK there are devices made by a company called OneClick, the Intelliplug and Intellipanel.

These look like multi-way mains power adapters, but actually sense power on one specific socket outlet and switch all the others on when the 'master' load is turned on.

eg. http://www.lindy.co.uk/intelliplug-3-way-automatic-power-switch/73079.html

There are clones by other companies here, are there any equivalent devices in the USA?

Alternatively, before these gadgets appeared I was making my own auto-switches, using a small solid-state relay (that works directly from 5V) connected to a USB lead, so the relay switched on when the main PC was powered up. I fitted the relay in the casing of a multi-way power board.

The relay was a Crydom PF240D25, datasheet here:
http://www.crydom.com/en/Products/Catalog/p_f.pdf

 

Thanks for the reply RJenkins. I actually went and bought a relay at Radio Shack, but I got an SPDT relay. I couldn't figure out what the fifth pin connected to, and decided it was the wrong kind. I then decided to go back to RS and get an SPDT relay, wired it up, and it works beautifully.