Computer Keep On Circuit

Discussion in 'General Electronics Chat' started by Kool1zero, Feb 13, 2012.

  1. Kool1zero

    Thread Starter New Member

    Feb 13, 2012
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    I am tired of my home server turning off on me while I am away at work or school.

    What i want to do is design a circuit that will wait a minute (or a couple minutes) and then essentially push my power button to turn it on again. one idea i have is pretty much base it on if i cant sense 5v for a USB port then press the power button for a few seconds, if i could power the circuit off of the standby power for the motherboard then that way whenever the power supply turned on after a power outage, the circuit would press the button and start the compter.

    so, long story short i need to make a circuit powered by +5v Standby from a 24 pin connector that can sense if +5v is on or off and if its off give me a voltage to press the power button.
     
    Last edited: Feb 13, 2012
  2. Brownout

    Well-Known Member

    Jan 10, 2012
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    Why does your server turn off? Use "Power Options" in your control panel ( Windows ) to make sure your server doesn't hybernate or turn off while not in use.
     
  3. Kool1zero

    Thread Starter New Member

    Feb 13, 2012
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    its not shutting down, its the power goes off, or my parents shut it off
     
  4. vpoko

    Member

    Jan 5, 2012
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    Most modern BIOSes have an option to automatically turn on the PC as soon as power is restored after a power failure. If parents are the issue (and they're doing it intentionally), I'm not sure a circuit would help since they'd probably just pull the plug next time (after noticing that the computer came back on after they already shut it off once).
     
  5. Kool1zero

    Thread Starter New Member

    Feb 13, 2012
    24
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    unfortunetly my bios not have the option to auto on after power off or is it does it doesn't work right . that is part of why I am wanting something that will possibly give me a minute or so before and restart the computer is to avoid my parents realizing it just got back on
     
    Last edited: Feb 15, 2012
  6. Ctenom

    Member

    Nov 1, 2010
    59
    1
    Buy a ups. that way it will never go off
     
  7. BillB3857

    Senior Member

    Feb 28, 2009
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    An Uninterpretable Power Supply won't cure the Poke in the Eye shutdown.
     
  8. Brownout

    Well-Known Member

    Jan 10, 2012
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    I once made a system to press the record button on my VCR when an intrusion was detected. It used a small 'pull' type solinios with a lever. The timer was nothing more than a comparator with an R-C time constant on the input pin. A transistor was connected to drive the soliniod. It's a pretty simple thing to do.

    PS, I had to build a custom fixture for the VCR so that the soliniod could be mounted near the record button. It had a wooden bottom, and a piece of metal angle bar mounted so that it faced the VCR. The soliniod was mounted on the metal face, ajacent to the record button.
     
  9. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Wouldn't it be easier to ask your parents why they are turning off your server?

    If they are worried about the electric bill then maybe you should be paying it? Or move out on your own then you won't have to worry about it.
     
  10. Wendy

    Moderator

    Mar 24, 2008
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    You are going to have to learn some electronics for a project like this. This may include some soldering, and definitely reading schematics. What kind of background do you have?

    The circuit itself is simple enough. A simple timer that will toggle a relay on / off after 5 minutes might do it. Radio Shack would probably have every part you would need, though they are a bit more expensive than buying from other parts providers.

    I don't know your age, but I share the concern about bumping heads with your parents over this issue. I suspect you will get the help you need regardless, but this is something better worked out with them first.
     
    Kool1zero likes this.
  11. Kool1zero

    Thread Starter New Member

    Feb 13, 2012
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    Well, I'm in college for computer engineering, networking engineering, and information systems security. So ive had classes on ac circuits, dc circuits, and I'm just starting electronic devices (like transistors and diodes) and digital electronics. But I've had courses in soldering and such. My parents are frustrated because I spend so much.time on the computer. They barely have email and don't see why i would want something to connection to even though I've showed them.
     
  12. zaw

    New Member

    Feb 13, 2012
    3
    0
    How about time delayed relays connected to 12v.
    12 volt connected to coil end, power switch wires to switch end. When it energized it will stay OPEN. Once power is off ~5 to 10 sec later it will closed by it self and trip the power switch, which will kick on the power supply to energized it self and re-open.
     
  13. vpoko

    Member

    Jan 5, 2012
    258
    47
    You could build a decoy server and keep the real one on in a closet somewhere. Put like 5 fans in an empty PC case so it sounds like a vacuum cleaner, your parents will turn it off and think they've won every time. (PS: I know you're looking for a specific solution, I'm just offering alternatives because I don't know how to build the circuit you need.)
     
  14. Kool1zero

    Thread Starter New Member

    Feb 13, 2012
    24
    1
    Both of these sound good. I briefly saw comparators mentioned in my digital book and looking up relays they sound like they would be useful here, but they also seem expensive. especially ones with timers built in. the relay seems ideal to hit the power button because i've done some investigating and all the button does is close contact between two points, i could add the relay and the factory wiring wouldnt be hurt and if i wanted to stop the circuit i could just remove the power to it. I'll see if i can get a basic circuit block diagram up.

    the part i dont understand if the timer circuit. I've seen people make timers with 555 timers and above Brownout suggested a comparator. either way, i'm just not sure how to make the timer portion. I would rather not use a chip because it would make the circuit much larger
     
  15. Brownout

    Well-Known Member

    Jan 10, 2012
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    That's funny. Integrated circuits make products much smaller.
     
  16. Kool1zero

    Thread Starter New Member

    Feb 13, 2012
    24
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    but it also means i need to put it on a circuit board or piece of breadboard or something larger like that, not just solder the leads together
     
  17. Wendy

    Moderator

    Mar 24, 2008
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    Here is how I might do it.

    When there is no power on the USB port the timer will start oscillating. 1 second on / 10 seconds off.

    [​IMG]

    Power supply is from a wall wart. Exact voltage dictated by the relay K1 coil. Call it 5VDC to 15VDC.

    You could build this simpler, but be careful. I don't see a way of doing this without some time delay somewhere.

    You might be able to get by with the relay "pressing" the on switch if the USB port is down.
     
    Last edited: Feb 14, 2012
  18. Wendy

    Moderator

    Mar 24, 2008
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    Something like this maybe...

    [​IMG]

    The relay coil would have to be 5VDC in this case.
     
  19. BillB3857

    Senior Member

    Feb 28, 2009
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    Any thought about improper shutdown, repeat restarts having an effect on data storage on the hard drive?
     
  20. Wendy

    Moderator

    Mar 24, 2008
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    If the power button is pushed it will go through proper shutdown. The very last thing to die will be the USB port. It should go through a complete reboot.

    I suspect a long shutdown time might be beneficial to allow said parental units to leave the room though.
     
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