Picture of Camouflaged Power-Source Liberator
A simple solution for powering up low-voltage DC devices in public spaces. When you plug this in, one of the plugs is powering an outlet on a decoy junction box and the other plug is providing a continual power source to a low-voltage DC device. This is something that I have been fiddling with for ages and it is not quite done, but I put it online due to the urging of some friends who find the information useful. Maybe you can figure out the final step (I will explain later).

PLEASE NOTE: This project uses high-voltages which are inherently dangerous. Additionally, I am not an electrician and can not verify if this project poses a fire-hazard. Lastly, I am pretty sure that the use of this project on other people's property would be illegal.

***Construct and use at your own risk.***

Step 1: Go get stuff.

Picture of Go get stuff.
You're going to need things to do this:

1. A standard wall socket
2. An outdoor socket cover
3. A cell phone charger (preferably 5V 500ma)
4. Two grounded wall plugs (like the one below)
5. A 1" x 2.5" piece of lucite that is of 1/8" thickness
6. Electrical tape
7. Thick stranded wire (the one below is from a strand of Christmas lights)
8. A plastic 1/8" pull-tie (not shown)

to be explained in final step:

9. Casing and paint (not shown)
10. Epoxy (not shown)


1. A Phillips-head screwdriver
2. A pair of pliers
3. A Dremel (or laser cutter)
4. A utility knife
5. Wire strippers
6. Soldering iron

Step 2: Make the plug bracket.

Picture of Make the plug bracket.
Okay, so the first thing you're going need to do is to make a bracket to mount your grounded wall plugs. This will hold them so that they can both plug into both outlet sockets at the same time.

The one you see was cut with a laser cutter that the Graffiti Research Lab was kind enough to let me use. I recommend begging, borrowing or stealing a laser cutter. Otherwise, you can use a Dremel to cut out the mounts. My first mount was done with a Dremel, so I know it's perfectly feasible. It will just take a little more work.

First take apart the plugs. Notice that there are three prongs and a mounting bracket that holds them straight. You will need all of this. However, at this point you need to take it apart completely.

Basically, each prong on the plug has a little notch on the bottom so that it can catch onto something and hold itself in place. So, the goal here is to cut out the holes so that when each of the three prongs are slid into place and the bracket put back on, they will all line up straight. This will take some trial and error.

For measurements I have included an approximate layout I quickly mocked up in Photoshop (unfortunately the file I was laser cutting from is no more). You are going to want to measure your plug for yourself.

Once all of the holes are cut and all three prongs are latched onto the lucite frame, you're then going to want to slide back on the yellow bracket that holds all three prongs in place. Please note that I cut a circle in the middle of the board. This is so that the bracket can press flush against the board (because the bracket has a little round protrusion in the back).

Once both plugs are in place and seem to line up straight, you are then going to want to see if they will fit into an actual socket.


You should have an unused wall socket that is not connected to anything.

PLUG THEM INTO THAT! (as shown in the picture)

If, as shown in the picture below, the mount fits into the socket and lays flush to it, then you are good to go ahead to the next step. If not, break out your Dremel and keep at it until it does.

Step 3: Prepare the socket.

Picture of Prepare the socket.
Alright, you have the plugs done and now you have to prepare the socket. This is easy. Basically, you connect the thick stranded wire on both sides and ground by screwing them flush with the metal plate. Screw in any screw you are not using.

Wrap the exposed connections with electrical tape to insulate them and make this device slightly safer. Do not wrap the tape around the screws used for mounting the socket. You may need them.

Step 4: Connecting the plugs and the socket.

Picture of Connecting the plugs and the socket.
If you have not figured out by now what is happening, let me explain it a bit. Basically, you are making a device that plugs over a live outdoor power box. This device for all intents and purposes looks exactly like the power box you are plugging it into, except it will be slightly bigger so that it can cover up the initial box.

MOST IMPORTANTLY, this new device will ALSO be powering a low-voltage DC device. Basically, one of the plugs connects to both terminals on the new socket and the other plug will run off to a cell phone charger (which is basically a really compact transformer).

So, the first thing you are going to want to do is cover the backside of the plug bracket with electrical tape in order to insulate it. Then, line up the bracket on the back side of the socket and use the plastic pull tie to hold it in place. That way, if you were to plug it into a socket just then (DONT!) it would be powering both plugs, but at the same time look as though a socket were facing you (see pictures).

There should be three wires running off of the socket. Connect all the wires to one of the plugs as follows:

1. The wire on the left side connects to the left prong
2. The wire on the right side connects to the right prong
3. The ground wire connects to the bottom prong

It should look like the picture. Once the two parts are tied together you can then attach the outdoor plate. After this it should look kind of cool.

Step 5: Break the cell phone plug.

Picture of Break the cell phone plug.
First start by breaking it at the bracket that mounts with the cell phone. What do you see? If you see a red and black wire (or in my case red and brown) then you are in business. You should probably double-check to make sure that the red is plus and that the black is ground with a multi-meter or LED.

Once you have established that there are simply two wires under the black covering, cut it so that you only have about 6" of wire left. Strip off the ends of each wire. These are your low-voltage DC connections. They will connect to ANY low-voltage DC circuit that you want to attach to them.

The next step is to prepare the transformer (the large block part) to connect to the unused plug on your bracket. This is easy. Take your pliers and fold each prong sticking out of the transformer back and forth until each prong snaps off.

Now you should have two terminals flush to the transformer. Solder two thick stranded wires that are 4" long and stripped on both ends to each of the terminals. Wrap the transformer box in electrical tape.

Step 6: Connect the modified cell phone plug to the device.

Picture of Connect the modified cell phone plug to the device.
This step is easy. There should be two stranded wires running off of the cell phone plug. Look at them. Now, find the unused wall plug on the thing that you are making. Connect one wire from the cell phone plug to one prong of the wall plug and connect the other wire to the other prong.

For now, tape the cell phone transformer to the side of the thing that you are making.

If you were to plug this device into a socket right now, you should have two fully functional wall sockets and a wire dropping down from the modified cell phone plug that should be 5V at 500ma capable of powering an LED (or whatever your device is rated at). I hooked my 5V to some bling. Hook yours up to your own bling.

Check the pictures for verification.

Do not touch live wires or stick your fingers into the sockets. Even the low voltage wires, if they are over 500ma, should be avoided. You probably should not touch live wires at any rating if you are pregnant or have a heart condition. This is coming from someone who has been electrocuted many, many times.

Step 7: Build a casing.

Picture of Build a casing.
You now have a device that will plug into a socket, function as a socket and, all the while, power whatever small device your heart desires. This device is clearly in desperate need of a case that will camouflage it out in the urban environment.

The case needs to be approximately an inch and a half longer than the power box you intend to cover. It should be large enough to fit over the junction box, but still allow the device inside to be able to plug all the way into the existing socket. As well, when it is plugged in, the case should be relatively flush to the wall. The face plate should be about half an inch longer in all directions to allow for room on the inside of the case to install your own circuitry.

Even with such slight increases, you should still have more than enough room to fit your circuit board inside. However, do not take my word for it. Make sure that you do before you go to plug it in.

Once the box is built, you are going to want to paint it the color of the box you intend to place it over. If it looks more or less the same, most people probably won't even notice the difference or care to check.

I have yet to construct a casing that I am pleased with. I did get this aluminum (see picture) in hopes that maybe once painted, it would look convincing. I have yet to construct it. However, I'm sure someone should be able to figure something out; be it modifying an existing case or constructing a new one. I would be happy to hear suggestions.

Step 8: Install!

Picture of Install!
Once it is done, you should probably install it. I was thinking that the best thing to do would be to coat the edge of the case with epoxy. You may think about coating the front of the initial junction box with epoxy also. That way it will never come off. Well, not really. But it will take some effort for someone to pull it off. Bring a screwdriver because you may need to pry off the weather covering on the socket that is attached to the building.

I wanted to use this to have a constant source of energy for powering a circuit that would take sensor readings from the environment and transmit them to the internet. I was also considering using it to power a massive work of what kids these days are calling "Electro-graf." Although, I'm not really sure how much of a load conductive paint can handle.

Basically, if you want something powered out on the street, this is a possible solution. However, I under no circumstance advocate the construction or use of one of these devices.

***Construct and use this device at your own risk.***
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badams24 years ago
Have you tried an old-work exterior box such as the one found here (Lowe's)?
Myself8 years ago
I've had the same thought, looking at the boxes installed near the bases of downtown sidewalk trees, where they plug in the strings of lights for the holidays. Just on a lark one day, I brought a 3-light tester with me and plugged it in. No love, the boxes are turned off when they're not in use. Now I wonder where the switch/breaker is! Wifi repeaters and network cameras are the obvious choices, and there are some damn small WDS-capable APs out there. Sensor networks could be fun, and any cellphone programmed to auto-answer in speakerphone mode could be used as a simple remote audio bugging device. I'm not sure why you'd want to watch or bug the sidewalk, however. Repeating free wifi into a poor-coverage area would be hilarious. It's a shame the standard is so ill-suited to that.
Most of those outlet boxes you see near trees, walk ways and in light poles are controlled by either a photocell or a timer. That way they are not wasting power during the day. I'm a electrician by trade and a few things. #1 You will not be able use only part of a GFCI outlet due to it having an internal circuit board and solenoid, coil, and contacts that make it work. #2 if you simply half a regular duplex outlet you have internals that are very dangerous and will have to be insulated. #3 In the USA a standard out let is 125VAC at 60HZ, it's very noisy so attempting to put any receiver or transmitting device in the same box will have a issue. #4 Tampering with any outlet in a public place (park, ect) will most likely end you up in jail due to vandalism and theft of city services.

The concept is a kool one but not a wise one. As far as wifi repeaters you would spend major bucks and have to but then all over just to cover a small area. Not to mention that if your ISP catches you giving out free wifi with intent it's very bad news (cancel service, and might end you up in court).

The one statement about the romex wire being able to stab into the back of the receptacle is correct but it only goes up to 14awg solid wire. Most Boxes are of the 18cubic in type and don't have a lot of room in them you would have to have at least a 22-24 cubic inch box. They do make extension rings for the outside ones and it comes with longer screws. From experience no matter how well you seal the cover it will get moisture inside and if your making one that have a PC board in it you;ll have to epoxy dip that board to keep it dry.

To be perfectly honest with all you would have to do to adapt a outlet box and such to achieve what you want isn't really worth it.

Easier just to get a pinhole wireless cam and mount it inside something thats already there (clock, smoke detector, light fixture, ect)
A actuall use for a group of wifi repeaters could be saving money on phone service. This way, you can use a skype phone while you are in certain places in the city You could probably get a group of people together to help out the cause.
With a little effort you can do this "above board" involving local business, parks and rec. Organizations love opportunities to participate in public projects that cost little or no money.
strmrnnr6 years ago
I don't really see a point in this as it is, because they will still see your cords coming out of it. But, if you were to leave the device there and want to conceal an outside connection for your use, I would think about removing the old plug altogether and hardwiring it into their junction box and using their face plate. A small spacer ring could be made to enlarge the depth of the box for your needs, say 1/2 to 1 inch ( longer screws would be needed also). Diable one plugs and take the back half off for more room also, or use a different face plate and take it out altogether. If it is for changeing a phone without a cord like one guy was having trouble with I would just place the phone charger in a thin box that could hold a spare battery for my phone. Make the top of the thin box look like a blank plate so people will think the plug has been removed or blanked off. Remember also that most outdoor plugs (at least here in Canada) have to be Gound Fault Safety plugs and it should look like one of them.
I think wireless would be the best use.  If you could fit something inside that ran on DC that transmitted wirelessly, even over radio, then it could be useful.  A couple thoughts are: spy cam, network repeater/range extender, remote switch(that cuts power to the remaining outlet) to piss off the target, network traffic spammer(if you can connect it to their wireless you could DOS them).  I am not the type of person who would use this sort of thing and it is definitely not legal in most cases but I applaud randofo for the originality.
qwertyboy6 years ago
lol, "bling"
AllanButton8 years ago
You could do this with only using one male outlet jack. The fake outlet you are adding has two sets of screws on each side you could run the power for your device off the other set of screws giving yourself more space. Now for what you can do with this. If you make it so that it detachs easy, or can find a way to hide a slot in the casing, you could put a digital camera inside ( - the camera casing ) and wire the trigger to a 555 timer so that it snaps pictures automatically. then either make it so you have to come and pick it up to get the memory card out, or hide a slot so you can take the card out and put a new one in. Whats the point of this? Well you could launch a bunch of throwies at something, and set this camera up to take a picture every minutes pointing at what you've throwied, then come back when your card is full ( do the math, 60 pictures an hour, 1440 pictures per day, 2 gig sd card in 3mp camera holds about 4000 on medium quality, so you could run this for 4 days aprox, or chagne it to every 5 minutes thats 6 per hour or 144 per day, or same 3mp on medium, that would last you about 3 weeks, give or take. ) Now if you know the battery life or a throwie, you could adjust your 555 timer on your camera control circuit to take just enough pictures to fill your camera card during that time. When I get a chance im going to do all this, minus the thowies of course, they are just a little to expensive to make a batch like the GRL. - Allan.
Sorry, math is off, pictures every 5 minutes would be 12 an hour. Did the math a little to quickly in my head.
randofo (author)  AllanButton8 years ago
I suppose the second plug is redundant, but it provides a little bit of structural stability to the device. And you can't really fit much of anything in the amount of space it takes up. Also, you could maybe hook it up with bluetooth or wifi and never have to open up the case again. Once you install it, going back to the thing periodically would be a bad idea. Yeah... the GRL has a sugar mamma... with a laser cutter... and a budget.... we should all aspire to as much. You could always follow them around and take the throwies that they leave behind.... someone should make a "magnetic throwie remover" for getting all those throwies in hard to reach places (where inevitably the all end up). Then again, I suppose it would be kind of pointless to remove all their throwies and deposit them elsewhere.
I think I finally came up with a final plan for my camera/outlet, although its more then just an outlet now. I found a building near by with a high amount of street traffic that just happens to have an outlet just on the side of the building where all the people pass by, and has metal siding. The outlet is a flushmount outlet. ( with their permission of course, right? ) I am planning on making the Power-Source Liberator in a normal outdoor outlet box with the back cut out, and running a peice of tube up to a fake motion light, thats motion detector will snap pics of all the people going by. Instead of attaching this all to the wall with screws, its going to be all connected with those strong magnets ( whos names escape me right now ). My friend tells me he knows of a small network device that can connect to a sd card, so it would just be a simple circuit to connect that the card slot in the camera and also to some sort of small router or something and mouth a huge antenea down the pipe thats going to connect the two boxes together. Then just sit around the corner with my ppc and run the script to download and wipe the images. Neat stuff.
eyefi SD card?
randofo (author)  AllanButton8 years ago
Yes.... you should be careful about going back to it once it is installed. People are dumb: LED Bomb Scare

This wasn't the first time for something like this to happen and it won't be the last. Be mindful that people are afraid of anything different these days.
randofo (author)  AllanButton8 years ago
That's pretty cool. You should post an instructable of that. The fake motion sensor light is genius.
Sandisk1duo7 years ago
nice fence Oakland? New York? San Francisco?
randofo (author)  Sandisk1duo7 years ago
Bushwik section of Brooklyn....
mctylr7 years ago
Perhaps a plastic retrofit outlet/switch box from a building centre (e.g. Home Depot, Example). An exterior box model may be easier to weatherproof.

I'd also suggest paying attention to weatherproofing the box if it is intended for outdoor use. Water and electricity don't mix.

The wiring of the plug to sockets should be double checked with a 3-prong AC tester (e.g. U.S. model or U.K. style) - they are infinitely handy to have anyhow.

Heat-shrink tubing is more durable than electrical tape for insulating the wiring joints. And I find it easier to make a neat and tidy seal.

robacarp9 years ago
Using something like this http://www.mouser.com/catalog/626/1468.pdf

You might be able to make something like this picture. (Sorry for the lack of detailed schematics.)

Now that I think about it, it might be easier to just put the thumbscrews in the top/bottom so as to allow more room for the circut board. It might be better to use 1/4 turn screws similar to those that they use on race car bodys, to make it less tempting to exploring little boys....then again, I dont know where you would get something like that.
Those can be had at a race car shop, or even a local hardware store...they have ALL KINDS of great fasteners. go visit one and your wheels will definitely begin to turn......Also, those screws don't need to be used. The outlets have very small holes in the back of them to accommodate standard Romex solid copper wiring. Simply strip the wire, and plug it in.
oh boy...I just realized that the picture shows the screws penetrating the inner outlet.
I don't understand why this is needed. I always plug stuff in wherever I am at and have never had anyone ask me to not do it. When it's been in a store, coffee shop whatever I ask and have never been turned down. I've done this in Seattle, NYNY, Detroit, Denver, Boise, Salt Lake etc. Why do you need to hide the fact your charging a phone or laptop etc???
randofo (author)  skonofvulcan7 years ago
It could be used for powering homemade wireless electronic devices, discreetly, for long periods of time.
I still don't see the need. Just plug it in an outlet near the floor or ground in a open public area and most likely no one would even notice it for up to a year. Why even try to conceal it? Leaving things in the open is the easiest way to have it go unnoticed. Even employees will often assume management put it in, etc. I've plugged in a charger with my camcorder battery in it to charge in a food court before and forgot it latter. Didn't come back for over a week to get it and no one touched it. It was right at floor level and you could even see streak marks where someone had moped around it! If it has no labels, is just a little piece of black electronics they have no idea what it is and they often make stupid assumptions. So just be sure and peal off any stickers etc. In high crime areas it's generaly stuff that your trying to keep an eye on that gets stolen, not stuff that you just place in a out of the way spot and ignore...
randofo (author)  skonofvulcan7 years ago
You clearly have never lived in New York City.
bethehammer8 years ago
Seems like with all of the effort and expense of doing this ... you could just get some solar cells or some other power generation (small wind generator??) and a couple of batteries and have the same thing with out messing with someone elses outlets. Especially since we are talking about only trying to power a low voltage DC device.
randofo (author)  bethehammer8 years ago
The problem I was having with that approach was that in New York City (where I came up with this) you never quite got enough sunlight at street level for it to be reliable and windpower devices were too visible for what I was doing.
_soapy_ randofo8 years ago
Is NY so very bad that being seen winding a small handle will get you mugged?!?

You could perhaps go for one of the rotating magnetic charger designs that capture your movement and turn it into electric for your stuff. Or this - Stealth charger
randofo (author)  _soapy_8 years ago
It's not the criminal element you have to worry about. It's the "see something say something policy." People can sometimes get awfully worked up about nothing these days. Also, New York is rather horrible in regards to objects being left in the public space. Anything not chained down and left unattended longer than 30 seconds will walk away. I once saw someone try to runaway with a full-body mirror left in the doorway of a glass shop in broad daylight.
_soapy_ randofo8 years ago
Hopefully they were dumb enough to run into something like a lamppost because they could only see behind them. :-)
Great Instructable. I love the brainstorming that has followed!
Grady8 years ago
Why not just try to get the subways to offer this kind of phone-charging; they could up the fare by a nickel, to pay for it & it would benefit many.
well this has a great use in the uk trains have cleaning sockets at various point including where a bunch of mates may site just beside the bike area and toilet so its handy there as the conductor made me get off the train when he saw me charging my phone outta one of these so it has its merits
hondagofast8 years ago
Theft of services!
Mr.Cire8 years ago
i still dont get what you did here
he made a fake 'cover' for a power receptacle, which you plug in somewhere. It still functions for regular plug-in stuff, but housed within it is a cel-phone charger, which you could use to power things...but covertly.
i still dont get it
davidbacsik8 years ago
Bling indeed! Very Fly Project.
this seems like an awfully long way to go to bleed off alittle power and leave an outlet sticking 1-2 inches off a surface. even if i could think of a real-world use for this on a lamppost or something, can't you just open the existing junctionbox and place your bleed in there?
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