Building a device to power on/off computers

I want to build a device that will interface with a computer via USB or RS232 that will power a different computer on or off.  I'm envisioning the device having  a lead that will connect directly to the power leads on the target computer's motherboard, and a USB/serial cable heading to the "controller" computer's USB/serial port.

I know there are a million retail solultions out there -- I won't bore you with the details, but none of them work for me.  I need to build one.  

My question is simple:  can anyone point me to readily available electronic components that would allow me to build this?  Again, I don't want a packaged retail solution.  I want the actual electronic components.  

Thanks in advance.

Reg Natarajan
regnatarajanAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Gary CaseRetiredCommented:
Without more details (distance involved in particular) it's difficult to say what might work for sure.   But assuming the distance involved does not exceed the length constraints for an RS-232 cable run, all you need is a 12v momentary contact micro-solenoid switch, and you can simply control it with any of the control signals from an RS-232 serial port.  Check with any auto parts store -- there are quite a few 12v solenoid switches used in automotive electronics.  You need one with a very low current draw.

Here's a simple relay already mounted on a PCB that you could use in a kit box (or mount inside of the "target" PC):  http://www.electrokits.com/electronics/relays-remotes-switches-timers/200.htm

If you would prefer to get a pre-built interface board for this project, you can get them here:

(a) for a paralle port:  http://www.electrokits.com/electronics/relays-remotes-switches-timers/24.htm

(b) for a serial port:  http://www.electrokits.com/electronics/relays-remotes-switches-timers/31.htm

(c) for a USB port:  http://www.electrokits.com/kits/usb/port/relay/board.htm

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Gary CaseRetiredCommented:
... just tested the links and the last one doesn't go directly to the USB switch => but it's listed on that page.  (It does a lot more than you need; and is the most expensive of the above options)
regnatarajanAuthor Commented:
Thanks, Gary.  That's exactly what I needed.
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Hardware

From novice to tech pro — start learning today.