Simple external hard drive relay modification to power-on and power-off automatically

I made this instructable because I have a PC and a wii that has hard drives connected to them but when I turn off the PC or my Wii with their respective remote controls, I have to get up and flick the switch manually or the hard drive keeps spinning all the time and wastes energy as well as leaving the potential for damage if I knock it over (when its powered off, the reading heads are stuck in place so there is less risk of damage).

This instructable is going to show you how to make it so that when you plug-in your usb cable or unplug it OR when you power-on or power-off your PC, PS3, Xbox, Wii or whatever your hard drive is plugged in will turn your hard drive on or off accordingly.

The Idea is very simple, a Relay will be used to turn on the power supply when it detects that the USB port is getting power.

-appropriate tools (soldering iron, screw drivers to open the casing etc.)
-hot glue gun (helps keep the wires in place so the solder does not break and so the relay stays in place)
-flux (helps make the connection to the USB pads easier, but not necessary)
-a relay with a 5vdc coil that can take at least 2amps on the pins at 12vdc (most normal power supplies are of 2 amps, but some are 2.5 and 4amps). There are many relays that can do the job, here are a few examples so you can find the most available one for yourself.

You only need ONE, these are all different models that can be used. Anything similar to this should do the job, the important part is the 5vdc coil and a minimum of 2amps at 12vdc as you will notice.
1-a digikey example: notice that this one can take 2 amps at 30vdc, meaning it can take more than that at 12vdc
2-this sparkfun example can take 1amp at 24vdc
3- this sparkfun one can take 5amps at 30vdc
4- finally, I used a R48-5D10-6 which was available at my local store for 2.70$ and can take 10amps at 28Vdc. This left me with plenty of headroom to work with or eventually use this in different projects and allows me to save on shipping costs as well as getting it immediately and supporting my local business.

Remove these adsRemove these ads by Signing Up
fla_23 years ago
Nice instructable...

My old IDE enclosure switch could qualify as strange as well. The switch has four pins used for two separate circuits of 12V and 5V. I guess I would need two relays instead of one unless there is such a thing as a relay that allows one control coil to control two power circuits.
fla_2 fla_23 years ago
I need a "double pole" relay so six or eight pins depending on if it's single or double throw. Thanks Wikipedia.
julienrl (author)  fla_22 years ago
sorry for the lack of response, I just realized (like a year and a half late) that instructable was sending me e-mails at an address I no longer use... Sorry!
maw2303 years ago
I use e-sata with my Vantec External enclosure. Could I modify this ible for use on the e-sata port?
julienrl (author)  maw2303 years ago
Unfortunately I do not know the exact specifications and inner workings of e-sata... however esata does have 5v pins!

I don't know which of the 5v's you would have to use. If you want to go through with it, I would recommend opening it up and putting in a drive you don't care about, then use a voltmeter to prod around. While you are probing, experiment (plug in and unplug the e-sata etc.) I am afraid you will have to figure the rest on your own.

Lastly, please note that, as always when you are opening an electronic device, you will be voiding your warranty and I am not responsible if there is any damage. Good luck! :)
maw230 julienrl3 years ago
Wow, but I guess one would have to use such a disclaimer...

Thanks for the advice, but if I do decide to try it I'll use the USB option.
Fushigi4 years ago
 excelente instructable pero si el wii al apagar en stand by mantiene los 5v en el usb.

yo tengo un ventilador encendido todo el tiempo para que no se caliente cuando esta en stand by.

yo lo recomendaría más para  la PC


excellent instructable but if the wii on stand-by to turn keeps the USB 5V

Ihave a fan on all the time not to hot when in stand-by

I would recommend more for the PC

julienrl (author)  Fushigi4 years ago
that is a good point, but I have my wii settings so that it does not remain on standby so it works perfectly for me.