Announcement

Collapse
No announcement yet.

No more wal-warts for me!

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    No more wal-warts for me!

    I finally decided to get a power distribution box. I ordered
    this one for $95 delivered last week and got it today.

    I found various other units, but this one looked really nice and first impressions confirm this. Very well built and neat unit.

    It has 18 Fused 12vDC Outputs (1A each) with individual LEDs, 10A total supply, and UL Listed. Instead of just a transformer like a lot of other units, it has a power supply module which has a fan.

    Gonna' use it to power cameras, servos, relays, and a few local wal-wart items in the wiring closet.

    gk

    #2
    I may be interested is something like this, unfortunately the picture is very small and cannot see the details.

    Could you please tell me the dimensions of the box, and also if the fuse/led/terminal assembly and power supply can be removed from the case, since I want to install it inside a Leviton Structured wiring rack.

    Thank You,

    Rene

    Comment


      #3
      It's roughly 8x10x4", a little smaller. The power supply is about 6x2x4".

      All of the parts appear to be removable. I took the PS loose (4 screws in bottom) to access one of the mounting screws. The fuse module looks to be attached by 6 screws, so it probably comes off as well. These are also only connected via screw terminals.

      The only issue would be the A/C connection which is the standard computer kind of power cord and the front power switch. You may have to do some rigging to get this transferred.

      IMO, unless you are really pressed for space, I'd just leave it in this box and run wires to the other.

      gk

      Comment


        #4
        Pics

        Here's a couple of pics.
        Attached Files

        Comment


          #5
          Greg,

          Thanks a lot your prompt reply and even PICTURES!!!

          It looks very nice, and I think the fuse panel meet my requirements, unfortunately it seems it does not have connection for a backup battery. I will have to think about it, since I am trying to install the alarm, HA, network and Satellite into two 28" structured wiring boxes, to eliminate all of the mess that I had attached to a 4X4 sheet ot plywood in the utility room, trying to improve the WAF.

          Again, thanks Greg,

          Rene

          Comment


            #6
            Careful!

            One thing to watch out when powering multiple devices in this fashion: ground loops.

            Some devices will end up with different ground potentials than other devices. If these are then connected to a common component (say using serial ports to connect to your computer), you can end up with a current on ground that will cause all kinds of hard to diagnose gremlins. It can even cause physical damage if the supply is robust enough.

            Here's a real world example (from my house ) - in my wiring closet I have an Ocelot, a Temp08, a RCS-TX15, and a Davis Weather Monitor III. I've (mostly) consolidated wallwarts using the manual method. But here's how I had to do it. The Temp08 and the Ocelot both can accept AC as well as DC. They both do it by employing a bridge rectifier where the power comes in. If you are feeding it with DC, you end up with a ground voltage that is one diode drop (approx .7V) higher than your power supply's ground. This will be the "ground" voltage on the serial cables.

            The RCS-TX15 just has a polarity reversal diode on the hot lead, so ground is really ground. The Davis is an unknown - it was too expensive to open up and investigate (and it's design somewhat discourages you from doing so).

            Then we look at external connections. Three of these devices have serial connections (all but the RCS) that are going to one Lantronix terminal server. What you end up with is a real potential for releasing the "Magic Smoke" if you just connect all of these to the same power.

            What I did was build a box that incorporates multiple supplies. I have a 12VDC supply that feeds the RCS, an additional circuit that automates switching on the aux heating strips in the winter, and my IR distribution. Then there is a separate 9VAC transformer that feeds both the Ocelot and the Temp08. Finally I kept the original Davis wal-wart - I did not feel like risking a $600 device for it.

            The astute may notice that there is still a possibility for a voltage differential between the Ocelot and the Temp08 - the diodes in the bridge rectifiers can have different voltage drops. Indeed, I think it is (or should say, was) causing me some problems. After a recent storm, the Temp08 would no longer talk to the 1-Wire bus. I had about 100' of cable with 5 sensors on it. I'm assuming I took an inducted surge that took out the data pin on the Temp08's microcontroller, but it's possible that ground loop currents contributed to the failure. I'm using the opportunity to make my own replacement that will have multiple busses with only a couple devices each so I don't have the ugly daisy chain I currently have (it stars out in 3 different directions).

            In summary, the power distribution box can be a great help, but only if you know what you're powering! Just beware of different device ground levels, use your voltmeter frequently while connecting, and you should keep the magic smoke in the chips where it belongs.

            Jerry

            Comment


              #7
              I hadn't thought about the infamous ground loops until you brought it up. I will have to think some of my strategies in consolidating power suplies.

              I will have to think about the camera PS a little bit more, especially since it does not switches to battery if AC is out.

              I think I will try a marine or boat supply house to see what fuse panels they have for boats, and how could they apply to HA, but they will be used to fuse all of the PIR and IR sensors as well as cameras that work with 12V and NOT devices that could possibly have internal diodes with really looking into their circuits.

              Thanks for the feedback.

              Rene

              Comment

              Working...
              X