No announcement yet.

voltage based power down

  • Filter
  • Time
  • Show
Clear All
new posts

  • voltage based power down

    I searched the site for an hour so if I missed an archived thread, please guide me.....

    I need to have my computer remain on in my car, even while I'm in the house. But, I don't want to kill the battery below 10.5v. I would love to use pins 4 and 8 on the com port to shut it down, but only send the shutdown signal after the car drops to 10.5v.

    How would I go about doing this? Is there a relay that can switch on with more than 10.5v and when voltages drops is switches off. What kind of electronic device would allow be to have the computer shutdown only once the voltage drops to 10.5 or below.

  • #2
    I have found a power a diagram of on a power the make 12 volt down to 8 volt easy to build


    twy to to look at my site you can find a idea how to control you computer from the radio or master key to power it down
    Plan for project = 100%
    Part the project. = 100%
    Built...................= 99%
    Finish.................= 99%
    Install ...............= 99% -50%
    Ditail at


    • #3
      I think you want an Opus power supply... Search for it.

      Will the supply protect my battery from being drained when the computer is running?
      A. Yes. The Opus Solutions Inc. DC-DC power supplies have a built in low voltage sensor that will shutdown the computer to protect the life of your battery, should it get too low (depending on battery condition).


      • #4
        how does the CNX-P1260 do it

        Getting a PS that monitors voltage like the CNX-P1260 would be just too easy . I need to acquire such voltage information without resorting to another power supply. This information is going to be used for more than one purpose. So receiving a signal (like +/- 3v) on a wire when the power drops below 10.5v is what I really need.

        Thank you everyone for your input, but I'm still searching for a way to

        "Continuously monitors battery voltage. If voltage stays below +10.5V for more than 10 seconds, a "Forced Shutdown" sequence begins"

        without purchasing a power supply.


        • #5
          It has a microprocessor that measures the battery voltage. When it reads below the threshold it triggers the shutdown event.

          You can use pretty much any microprocessor with analog inputs to do the same thing. Assuming you want to get involved with writing code for it and it develop an interface box.

          Or you can buy an OPUS that has it done already.