Technology
Shallow box access panels and digital photo frames…

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MAKE Flickr photo pool member Chrisdigo writes –

Digital Picture Frames are great to display a picture slide show. It can be put on a table, desk etc. but also can be hanged on a wall, just as a regular frame. But in this case, how do you conceal the AC power adapter cord ?

The electric box manufacturer Carlon has in his catalogue a “shallow box with access panel” ref B117RSW. It was designed for old electrical circuits and you can find it at your favorite home improvement store. I used this box (after some Dremel adjustments) to conceal the AC power adapter in a shallow wall, along with some crimp spade to tap on the 110V power outlet.

Some will argue it is a safety hazard since the AC power adapter is concealed and it may overheat. I’d like to have your feedback on this, but c’mon it’s only 9V and it doesn’t heat at all.

Note: For LCD TV and bigger frame, you can use the Leviton REB – Recessed Entertainment Box – for the same type of results.

transfo_conceal – Link.

26 thoughts on “Shallow box access panels and digital photo frames…

  1. Good idea, but yeah, it violates NEC in pretty much all of the US. You can’t conceal a pluggable device like that.

    One option is to use a “clock hanger” outlet box, where the outlet is recessed back into the box (which would not have worked for your A/C adapter). Or, to run some Cat5 through the wall to a standard outlet, and then provide the power from the wiring closet to the outlet on one or more pairs. You could run power on the pair on pins 7/8 and then also provide an ethernet connection to communicate with/update your device on the standard pins. I’ve done with with a lot of low-voltage stuff in my house (IR repeater network devices, security cams, etc). It’s kind of a poor-mans PoE.

  2. BrK

    A couple of questions

    I know that the cat5 specs only use 1/2 of the pairs in the cable, but am worried about the impact of plugging a laptop into a ‘modified’ cat5 outlet. I think that I *should* be able to do it safely, as the pairs aren’t used, but it is a pretty expensive test… 9v to the wrong part of a laptop is likely to be unfortunate. What are your thoughts?

    Also, I am currently trying to make some IR repeaters, but currently cannot get any of the designs I have found on the web to work at a reasonable range/at all. Do you have a design/method you can share? If you need somewhere to host it, I can arrange that.

  3. Another possibility is that maybe you could mount the power supply on the rafters in the attic or floor supports in the basement/crawlspace with an electrical box they provide for doorbell transformers.

  4. You need to be careful about the distinction between voltage and current – in general, current generates heat rather than voltage. “It’s only 9V” is not really relevant, “It’s only 100mA” would be a more important statement.

  5. BrK:

    You’re talking about running 120V AC through CAT5? The wires are a little small for that, I’d think.

    As far as running 9V through it.. you’d still have to plug it in somewhere.

  6. Current generates no heat (with no voltage drop). The power (wattage) consumed by the frame, and to a lesser extent, generated by the wall adapter during it’s 120VAC to 9VDC conversion process, is where the heat comes from.

    To get a true measure of power consumption (and estimated heat generation) of the adapter and frame, you need to multiply the RMS voltage value of the AC supplied by the AC current to get watts (VAC_RMS * mA_AC = Watts). Or you could just feel the box to see if it gets too warm after a couple hours. :) You might be surprised at how a few watts can warm things up in an enclosed space. My gut feeling is that you are fine. People have been hanging 75 watt bulbs from their ceilings and 200 watt plasmas on their walls for years.

    Check out the power over ethernet (802.3af) spec. It calls for 48vac and 350ma current for powering ethernet devices (my VOIP phone at work is powered this way). If your laptop is POE compliant, there “should” be no problems with 9vdc@ a couple hundred ma. If you have concerns about frying something, just break out the extra powered CAT cable wires to the frame’s power plug. Don’t connect them to the RJ45 connector.

    Russ

  7. BrK -> Yeah that’s right, I’ve done PoE before and should have think about this: this is THE solution, thanks !

    borked -> When you work on “modified cat5 outlet”, be it plugged on IP cameras, or laptop or ect., You have to use a multimeter and double, triple, quadruple check your cabling before you plug in any device. It’s scary but should be fine.

    TomParker -: You’re right, I was confused thanks for the information !

    Shadyman -> no with PoE you’re running low voltage current into the cat5 cable. check this website out: http://www.nycwireless.net/tiki-index.php?page=Poe

  8. You might want to check your homeowners insurance with the original mod (I don’t think it applies to POE stuff, but I could be wrong) as it probably violates construction codes and therefore would give the insurance company the out they need to not pay any claims if your house goes up in flames.

  9. (replying to many comments).

    No, not 120V through it, 9V or whatever the DC voltage is. Then you plug the wall wart into an outlet in your wiring closet and crimp/splice an RJ-45 onto the end of it.

    You can run DC through a Cat5 cable without affecting most end devices. *I* haven’t blown anything up yet, but if you’re really paranoid just use a 2pair cable to connect your laptop or whatever to an outlet. I tend to only provide my kludge-PoE to specific Cat5 outlets in my house, so it’s rarely a problem.

    I use the Xantech gear for my IR network. There are schematics to to build your own stuff, but the Xantech gear just works.

    borked: Thanks for the hosting offer, I have a side business doing cheap server colocation ($60/mo for 1u), so I’m all set on hosting :) If you PM me or email your address or something I’ll send you a Xantech starter kit (no, I don’t have enough to go around to everyone, apologies in advance).

  10. mp2526: read your policy, that’s not really true, but is a common misconception. Unless you knowingly do something with the intent of burning your crib down, it’s really not an issue.

    Not that I’ve hung out there in a LONG time, but this has been roundly covered on comp.home.automation many times over the last decade.

  11. I’m working on an instructable for a cheap (under 150) indash carputer that has itunes a web-browser and gps

    BUT i need a cheap (under $120) 7 or 8 inch LCD screen-

    Can i use one of these to play video? DOes it have RCA inputs or does it only play from a memory card?

    Does anyone know of a vendor online where i might find an LCD screen with vga or rca inputs?

    Email me if you do… fivespeedmax@gmail.com

  12. BRUNOJLB:

    Have you thought of getting a broken portable DVD player off ebay. I bet some of them have an RCA in, which should do what you need.

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