ATX auto power on

jumpoint · 01-23-2000, 03:49 PM

Is there any way to get an ATX motherboard to automatically power on when power is applied to it if there isn't such a setting in the BIOS? I know there are MB's that have a setting like the in the BIOS, but mine doesn't, and it's a pain to open the trunk every time and power it on.

Snupha · 01-23-2000, 05:10 PM

Find the motherboard power-on pins (which the power-on switch connects to). You can either lengthen the old switch, or use a totally different switch (single pull single throw) The motherboard just needs a short connection between these two pins. I figured this out by taking a peice of soder and using it to connect the m/b pins.

jumpoint · 01-24-2000, 01:55 AM

This doesn't work. It's the equivalent of holding in the power button. Any other ideas?

Probedude_2000 · 01-24-2000, 01:21 PM

Check back with me in a week. I am working on a modification to my powerup/powerdown board to have a small onboard relay that is momentarily activated for turning on ATX motherboards. See http://www.dschmidt.com/autooff.html for the current version of this powerup/down board.

Dave

spud42 · 01-24-2000, 09:35 PM

how about a relay where the coil is powered from 12 volts but with a resistor/capacitor network powering the coil sothat it takes a little time for the coil to energise and short the relay contacts. time delay is 5 times the r c time constant.
just an idea hope it works...should do...

nevb · 01-25-2000, 02:56 AM

Hi all,

I found a couple of circuits at the websites below that may just do what we want here! Have a look....
http://www.aaroncake.net/circuits/relaytim2.htm or http://ourworld.compuserve.com/homep....htm#delay.gif

Nev.

[This message has been edited by nevb (edited 01-25-2000).]