LED wall plug setup question


  #1  
Old 11-15-07, 01:49 PM
borak's Avatar
Member
Thread Starter
Join Date: Nov 2007
Posts: 30
Received 0 Votes on 0 Posts
Talking LED wall plug setup question

Kind of a background on what I'm doing. I plan on building a TV entertainment center that plugs into the wall. In otherwords I plan on building an entertainment center that has multiple sockets built in at multiple location. These will then be powered by a dual plug that plugs into the wall to power the entertainment center. That way I can unplug a DVD player without actually crawling behind the entertainment center to do it.

Here is what I am unsure about. I want to build drawers for holding DVD's. In those drawers I would like to add LED lights.

Do i need a transformer or something to drive down the voltage for those LED's? Anything else I would have to keep in mind while doing this?
 
  #2  
Old 11-15-07, 02:21 PM
C
Member
Join Date: Apr 2004
Location: Ontario Canada
Posts: 1,767
Received 0 Votes on 0 Posts
I don't know what you mean "dual plug" but you do not mean a male-male plug, as those are dangerous and illegal. If you want to separate the power cord from your cabinet, you need a recessed power inlet. You would use a 6 ft cord to connect it to the wall outlet.
If you don't know what you are doing you may just want to purchase a couple of pre-manufactured plug strips.

As for the LEDs, they can be ran off of a transformer.
You need to work out current limiting and voltage and things. If that seems above yo, you can get pre-assembled LED illuminators that work off of 12V. Look at the automotive sectino of your big-box store, or auto specialist outlets that cater to the auto customizing crowd.
 
  #3  
Old 11-15-07, 03:12 PM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,941
Received 45 Votes on 43 Posts
You should buy a UL listed low voltage lighting system that is designed for use in cabinets. They sell this sort of thing at specialty lightning shops and I'm sure online somewhere.
 
  #4  
Old 11-15-07, 05:11 PM
mukansamonkey's Avatar
Member
Join Date: Nov 2007
Location: Indianapolis
Posts: 120
Received 0 Votes on 0 Posts
Just google "LED cabinet light" and start reading.

The easiest way would be to buy a pair of surge protector strips and mount say, one of the audio side and one on the video side. If you care enough about your gear to make a center, you definitely want surge protection. Hardwiring could be prettier if you have some technical skill. Depending on how high-powered your audio gear is you might want to run two cords to two different outlets, but otherwise one 12 or 14AWG cord should be enough to power the whole setup. Not to mention max out a single receptacle.
 
  #5  
Old 11-16-07, 03:28 AM
R
Member
Join Date: Apr 2007
Location: Near Buffalo, NY
Posts: 4,233
Received 1 Vote on 1 Post
Audio and video systems like to ground at one and only one point, so it's always better to plug everything in to one power strip/surge protector and plug that into the wall.

You can determine the load by adding the wattage of all of the components. (Make sure you use the audio receiver's AC power load number and not its speaker output power rating.)

The big power hogs would be the audio amplifier (or powered receiver), plasma TV and computer. Depending on makes & models, those three items alone can draw 1000 watts or more. The rest has a small draw. Probably 20 to 30 watts each for the DVD, cable box, and sat box, and 7 watts for each light. One recep can easily handle the load.

Without a computer and using an LCD instead of plasma, you're probably down under 500 watts total. And unless you run your stereo system at full volume, it's probably using only 100 watts at average listening levels.
 
  #6  
Old 11-16-07, 06:39 AM
borak's Avatar
Member
Thread Starter
Join Date: Nov 2007
Posts: 30
Received 0 Votes on 0 Posts
Nope for Male to Male. The dual plug I was refering to is have the bottom wall socket power the right side and the top wall plug power the left side. I'm not sure if that will lower the strain though. It would be the same strain on the Breaker.

Plan would be to run a Plasma TV, DVD player, Surround sound, PS2, possibly 2 small motors, couple limit switches and some LED's. Almost starting to rethink the LED idea. Liked the idea of the LED strips but not a fan of the cost. My favorite part was "Power supply sold seperately."

Why is it that Audio and Video likes to ground at the same place? That might give me problems on my build.

I'm also starting to think the build might not be worth it. Lol.
 
  #7  
Old 11-16-07, 06:54 AM
R
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,970
Received 0 Votes on 0 Posts
Your idea is unsound without modifications, many of them proposed by other posters.

While you can certainly have two separate cord and plug setups, they would need to serve separate portions of the entertainment center. For example, one cord and plug could serve the television and other video items, while the other serves the audio portion. You cannot, under any circumstances have two plugs that connect together.

However, two separate circuits would need to be used for the two separate setups to make a difference. Very few homes that have not been specifically wired would have two circuits available in close proximity for each other.

The idea for you to use a commercially available power strip is a good one. I recommend that you buy one with a good quality built in surge suppressor. I am not talking about the ones given away free after rebate or available at very low cost.

If you think your power needs are, or might, be greater than a single circuit can provide then install a second unit, or at least leave space for one and make that space accessible. If you don't need it right way you can always use a power strip connected to the first unit.

As for the lighting, I recommend that you buy something commercially available and UL (or equivalent) listed.

While you certainly can build in custom wiring and/or custom lighting, safety MUST be a concern.
 
  #8  
Old 11-16-07, 08:05 AM
borak's Avatar
Member
Thread Starter
Join Date: Nov 2007
Posts: 30
Received 0 Votes on 0 Posts
Thumbs up

Thank you for all the responds.

After reading everything I realize that I was over looking a simple thing. Due to using a surge protector (I forgot about this) I would run the surge protector from a single outlet (the 2 plugs on the same outlet use the same breaker, so don't need them both). The surge protector would then be mounted in the entertainment center. The rest would be nothing more then running extension cords from the surge protector to the given place and putting grooves in the entertainment center where I want them run. By buying a commercial LED strip and power supply I wouldn't need to install a transformer because the power supply should carry that.

My electrical knowledge is slowly growing (still small) but safety is always first (hence it still being an idea). My problem is solved and I thank you for that.

One quick question though.
Why do Audio and Video like having the same ground?
 
  #9  
Old 11-16-07, 08:25 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,575
Received 15 Votes on 13 Posts
The rest would be nothing more then running extension cords from the surge protector to the given place and putting grooves in the entertainment center where I want them run.
Extension cords are not intended for permanent use. Installing in grooves could cause a over heating problem.
 
  #10  
Old 11-16-07, 08:47 AM
borak's Avatar
Member
Thread Starter
Join Date: Nov 2007
Posts: 30
Received 0 Votes on 0 Posts
Wow. My knowledge with electrical is worse than I thought. So my only option is to just plug in all the device plugs to the surge protector? I assume setting up grooves for those is a bad idea too.
 
  #11  
Old 11-16-07, 08:51 AM
R
Member
Join Date: Sep 2003
Location: Central New York State
Posts: 13,970
Received 0 Votes on 0 Posts
Plug the devices into the surge protector. If you must use any sort of extension cord for the devices, use a power strip that is made with 14 gage wire.

Do not attempt to hide the cord inside the wood, as it could overheat. Instead run the cord along the wood, and use appropriately spaced clamps to hold it in place. Cutting holes in the wood to run the cord through, or slight grooves is okay, but nothing more.
 
  #12  
Old 11-16-07, 07:03 PM
mukansamonkey's Avatar
Member
Join Date: Nov 2007
Location: Indianapolis
Posts: 120
Received 0 Votes on 0 Posts
Instead of grooves, I'd suggest poking around the Net for tiedowns specifically designed for cable management. I'm particularly fond of the ones that have a serrated mechanism that slides together to lock, but you can pop apart with a screwdriver. Tidy and easy to use.
Originally Posted by borak View Post
One quick question though.
Why do Audio and Video like having the same ground?
Let me first make a more general statement about grounds. It's safest if every metal object built into your house is grounded to the electrical system ground at some point. Water lines, interior gas pipes, whatever... if it's metal it wants to be interconnected. This is to ensure the two classic reasons for grounding, giving current from a faulty hot wire or a lightning strike a good return path/path to ground.

Now audio/video gear, like other electronics, uses the ground as a voltage reference point and through surge protectors as a means of getting rid of electrical noise. For this to work right all electronic gear must be connected to one, solidly built, grounding system. A real-life example of what happens when this principle is ignored...
In the early days of DirecTV-type dishes, the instruction manual for installing the dishes stated that you needed to drive a ground rod near the dish and ground the chassis (lightning protection basically). However, it didn't mention tying this new ground rod to the existing electrical ground system, so people didn't. So they had two ground rods, probably located many feet apart... interconnected solely by the ground braid of the coax cable attached to the dish, and the components inside the satellite receiver box. With the right soil conditions you can easily get a couple volt difference between the two ground rods, a voltage that continuously regenerates as long as the soil isn't bone-dry. If the ground rod at the dish had been solidly attached to the electrical ground, the voltage in the soil would be negated by traveling through the #12 copper wire. Instead, those few volts were continuously being drained through the electronics inside the receiver box that are connected to the coax braid (expecting it to be a fixed voltage reference). The net result: A lot of receiver boxes getting fried fairly rapidly after being installed.

It's true that a lot of audio gear isn't grounded at all, in which case it doesn't matter. The trouble is that it can matter in some relatively obscure situations, particularly where low-voltage electronics are involved. In another nearly identical real-world case, an incompetent electrician messed up the grounding work for a computer center. The resultant voltage was running across the ground shields on the data network, frying dozens of networking cards. Oops.
Coax in particular should always be grounded to the electrical system, therefore you want to ensure that your other A/V components are also well-grounded when possible.
 
  #13  
Old 11-17-07, 03:30 AM
R
Member
Join Date: Apr 2007
Location: Near Buffalo, NY
Posts: 4,233
Received 1 Vote on 1 Post
Adding to the above post ...

Consumer audio and video cables have a center conductor and an outer shield. The outer shield -- the signal ground -- is almost always connected to the chassis of each component. The chassis is also the electrical ground, and that ground is expected to be zero volts.

When you plug your devices in to different circuits (and sometimes into different receps on the same circuit) you create different lengths for the ground path. Add in the length of the audio and video cables, and you've created a ground loop that may carry voltage where voltage shouldn't exist. As little as 1/10th of a volt on a signal ground can affect video pictures and cause hum & buzz in the audio.

A power strip allows all of the devices to ground at that point, and its single ground is then home-run to the service panel through the house wiring.

When A/V devices are connected out of necessity to different circuits in different rooms, interference due to ground loops may be unavoidable. In that case, the audio and video signals are "isolated" with transformers and/or baluns.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: