No announcement yet.

Morex Question

  • Filter
  • Time
  • Show
Clear All
new posts

  • Morex Question

    Ok, here's the setup.
    I have a 1998 Subaru Outback and I want to power my CarPuter from the lighter/accessory outlet which is regulated by the car at 13.8 volts. There is no power to the outlet unless the car is running so I am not worrying about an overvoltage when I crank. I bought a 12v 5a adaptor from my friendly local Radio-Hack and according to the "knowledgeable" sales associate the CarPuter will only draw the volts it needs (which is backwards from the 12 years professional A/V experience I have ) but I thought I'd toss it out there for y'all.

    I have....
    a clean 13.8 volts
    Morex 60w power supply
    EPIA M Eden6000
    3.5inch IDE HDD
    Slimline DVD-ROM

    My main question is will I blow up my PSU or my Mainboard if I plug it in as advised. Have any of you used this configuration without issues?

    I have spent mucho time on this project with the custom case, 2.5 inch integraded TFT LCD, and infrared remote and would hate to see it go up in smoke. Thanks guys and/or gals.

  • #2
    Please don't use the cigarette lighter outlet if you're going to do this.. the contacts within the cigarette lighter will have a high enough resistance to be significant and you'll drop some voltage across them. This could make your cigarette lighter socket get quite warm and if you're unlucky it might melt.

    If you can, take apart the adapter that you bought from radio shack and see if the IC inside is a linear regulator. If it is, you should be safe to use it in your car (I have something similar in my car.. mine looks like car battery -> 12V linear regulator -> Morex 60W PSU -> Computer).

    One of the problems which you might come across is if your car voltage drops below the linear regulator's minimum dropout + 12V (usually 13.4V). Your linear regulator'll start working like two diodes in series, and you'll have less than 12V going to your 12V devices (Morex just passes through the 12V line, there's no regulation on it). This might muck up your hard drive and dvd rom..

    That's why people on these forums have been paying quite a lot for notebook 12V adapters with some sort of switchmode PSU inside that will put out a regulated 12V with a wider range voltage input. These're pretty expensive though...


    • #3
      I agree about the cig lighter not enough amps will come through it ditch the adptor

      when cranking there will be a under voltage not over voltage to fix this use a 40 amp diode to feed power one way to a 1 farad cap connect your morex to the cap for power input this will fix under voltage problems when cranking and when your sub's and amps start hitting feed the cap from the battery not the key use a switch or itps to start and shutdown your pc


      • #4

        I've used the Radio Shack adapter with my Casetronics C-134 case (has an internal PSU similar to Morex). It works fine as long as you don't try to draw more than 3.75 Amps from it. You can see my schematic and some pictures of what I did on my web site ( ).

        Good luck,


        • #5
          More questions

          My main concern is that automotive adaptor I bought at Radioshack is not a true 12v but rather 13.8v. I was just curious if that would cause an issue. I am not concerned about an under/over voltage during crank from the lighter because it is regulated by the car (i.e it provides no power unless the car is actually running) as far as the heat issue in concerned I planned on wiring it in direct by just pulling the spade connections off of the back of the lighter and connecting it direct. If the 13.8v is too much does anyone know how I can drop it by 1.5v or so but still keep the 5a?

          FYI this is the adaptor I bought


          • #6

            What you have appears to only be a +12v regulator! My guess is that they say the cable (wire) is capable of passing 5Amps....and your typical car alternator puts out 13.8V when the engine is running. So, if you use this with your Morex, you're putting the UN-regulated +13.8V directly onto your motherboard (since the Morex doesn't regulate the incoming +12V line). Some people have done this successfully, but it is not recommended. Some motherboards do not like having greater than +12V applied to them. In fact, I believe some people with Morex PSU's have experienced shutdown of their PSU when connected directly to their car batter/alternator. I expect the Morex has some sort of overvoltage detection device that senses the incoming +12V is too high.

            I'd recommend you think about getting a real power regulatore, either laptop adapter (as I did) or something like an opus DC-DC PSU.

            my 2cents