View Full Version : [ubuntu] auto boot with timer by shorting power button

December 6th, 2010, 03:40 PM
I have a relatively basic hardware question for auto booting a desktop computer. I know that is possible to start up my pc by shorting the powerbutton by contacting 2 wires connected to the proper pins. What I would like to do is attach these wires to some sort of timer and have them contact for a split second to auto boot the machine at a specified time. Is there any available timer that would allow me to achieve this, with mods or without mods?

December 6th, 2010, 05:43 PM
Probably. I check with your local electronics hobby store or electronics supplier.

Better option is to set Auto On in your BIOS, if available.

If on a network with other computers that stay on all the time, Wake on LAN is also an option.

December 6th, 2010, 06:15 PM
Well, I don't know of any local electronics store except for Radioshack and they usually don't know much about electronics except for hdmi cables. I also don't have an "electronics supplier." I guess the real question is, what do you call a timer that completes a circuit when activated? Is is a relay timer?

December 7th, 2010, 04:52 PM
Sounds like one of my projects from some years ago.

Just explain to your supplier, whomever that may be, that you want a timer that will close a circuit momentarily at a set time. They should be able to help you with something. I think the circuit itself is called a "one shot" or something similar, but don't quote me since there are a lot of cobwebs in that part of my brain.

Does your BIOS not support turning the system on at a certain time ??

If not, does it support turning on after a power failure ?? If that's supported then you could put it on a timer used for lights and such that simply turns on at a certain time and off at a certain time. You'd want to write something in the OS to shut down before the timer turns off though, unless you'll be there to shut it down manually.

December 8th, 2010, 12:30 AM
The bios does not support timed booting. I tried the power failure settings however it did not seem to work.

It seems like a pretty simple project, I just can't figure out what kind of timer I need.

December 8th, 2010, 01:01 AM
You may have to build it yourself.

If I were "frankensteining" this, I'd start with a cheap plug in timer. I'd plug in a power supply that would power a relay which, when energized, would close the circuit for the power switch.

Biggest problem with that is the wall timer having a short enough duration to turn back off quickly.

I'm sure there's a better solution if you know what sort of logic circuits to put together.