Thermal Switch

Discussion in 'hardware' started by Rico, Jun 19, 2016.

  1. Rico

    Rico Registered Member

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    My desktop lives in a narrow cabinet, that has 5" cabinet fan exhausting heat. The PC's power cord, goes out of the narrow cabinet & plugs into my UPS.

    I was thinking about perhaps something 'in line' thermal switch, with probe sensor, in narrow cabinet, that would kill the power to the pc, should the exhaust fan fail & it becomes too hot for the pc.

    Any ideas & links?

    Thanks
    Rico
     
  2. Bill_Bright

    Bill_Bright Registered Member

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    I think that is not a good idea. Killing power to a computer should always be avoided as it can result in a corrupt operating system, corrupt drive, and lost data. I mean, one of the primary purposes of having an UPS in first place is to avoid sudden power outages to the computer.

    My desktop lives in a similar space in my desk. I recommend you remove the entire back of the cabinet behind the computer. Hopefully it is made of that stiff cardboard material that you can cut out with a sharp xacto knife, and not wood or metal. If you need that back to keep the cabinet from wobbling, make a cross-member or two out of something ridged to add stability. With the back fully open, you should not need any cabinet fan (or have to put up with any cabinet fan noise either). An open back will provide much better cooling and will also make dealing with cables much easier too.

    If made of wood or metal you cannot remove or cut out completely, I recommend you, at the very least, cut out large holes behind the computer's exhaust fans (don't for the power supply) so heat will be pushed all the way out the cabinet. And cut out several holes or a wide slot as high as possible to allow heat that has risen to the top of the cabinet space to escape, and not accumulate

    Then use a decent HW monitor program to monitor your computer temps in real-time. I use and recommend CoreTemp to monitor CPU temps with it's System Tray applet.

    If you really are stuck on this thermal switch idea, I would use it to kill power to the UPS, not the computer. Then, assuming your computer monitors your UPS via a USB cable to your computer, program the UPS's monitoring/control software to save any open files, close your open programs, then "gracefully" shutdown Windows and power off the computer. Depending on your UPS software, you should be able to set it to "gracefully" shutdown the computer after as little as 1 minute on battery.

    ****

    As a side note, kudos to you for using an UPS. :thumb: I always recommend EVERY computer be on a "good" UPS with AVR - even in regions with a stable power grid.
     
  3. Rico

    Rico Registered Member

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    Thanks Bill,

    You made better sense. What happened was the cabinet fan failed, & when I came back to the machine it was very hot & off. Let it cool 24 hrs, push the button tried to start, then went off, repeat repeat same same. Next day, try one more time if fail, yank it out, find another machine. The lights would momentarily come on, so I thought power supply as still good, but cpu fried. This time held the button in & she came on, working fine.

    My tower in the garage, also in a cabinet, I use an 'indoor/outdoor' the outdoor sensor is in the cabinet, currently 85 F.

    If anything I was thinking the thermal switch would be a fail safe, or kill power just before, it got to hot to cause damage.

    Nevermind!
     
  4. Bill_Bright

    Bill_Bright Registered Member

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    Personal computers are designed to operate in environments were normal humans are comfortable. While I personally like it hot (I grew up in Arizona and New Mexico), 85° ambient (room) temperature for a computer is too warm without some extra cooling. That said, I suspect that is pushing the limits for the UPSs too. Heat may have even speeded up aging for the fan.

    Even if 85°F is not considered "excessive", running electronics for extended periods of time in "very warm" environments will increasing aging - unless they are designed for that.

    Since this is out in the garage, I suspect cutting the back off this cabinet will not upset the better half too much in terms of aesthetics and that will certainly provide better cooling. But a better solution would be to move the computer indoors.

    Your thermal switch as a fail safe is not a bad idea to help prevent hardware "damage". But again, sudden power losses can and often do result in data corruption, and data loss. I would sure make regular backups. And for sure, 85° in Texas is barely a "warm" day in the summer.
     
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