Window-like Lamp From Old Computer Monitors

I wanted to brighten up a dark corner of my workshop/garage so I added a false window, made from 4 old computer flat-screen monitors and some timber and venetian blinds. You could add this lamp to any room or space that could use some extra light and provide the psychological benefit of simulated natural lighting. If the blinds are down, it is difficult to tell it's not a real window letting in outside light. I learned a few lessons along the way and include those below to help you make one of your own. The total cost for materials and supplies was only about €30, and this project can easily be done in a day or two.

Step 1: Get Some Old Flat Screens: TVs or Computer Monitors.

Old computer monitors make great lightboxes for tracing or general purpose shadow-free lighting, because the light source behind the LCD has very clever diffusers.

Old computer monitors that still work are easy to come by at recycling and waste disposal centres. For this project you only need the back panel to be working. The LCD that makes the image will be removed, so it can be dysfunctional or dead. The LED or fluorescent tube backlight and its very high-tech diffusers are what you want. Ideally get several of matching size, for the number of window panes you want in your "window". You could also use old laptop screens. If you have a choice, the LED ones used today (2016) might be brighter and safer than the early-2000s ones with fluorescent lights in them. You could also retrofit a fluorescent diffuser with LEDs if you wanted to. UPDATE: after I published this Instructable, Dannyk6 published his Instructable, "Smart LED Window" which uses a Raspberry Pi to make his LED-strip-based false window remotely controllable.

Step 2: Remove the LCDs From the Monitors

Get in there with the screwdrivers and remove the LCD that blocks most of the light coming from the screen's backlight. Justin has a nice video instructable showing you how to do this:

For another project, you might do something fun with the LCD, its driver circuits, or the polarising filters it is sandwiched in between...

Step 3: Figure Out How to Get the Backlight to Light

It will be nice if all the panes of your window turn on when powered up. Many monitors already do that. Some require you to push a button or plug in a computer. If you have to push one button for every pane of a 6-pane window, it would be a window-pain, pun intended! It will require some electrical detective work to figure out how to enable the lamp of the backlight on power-up. The power supply for a fluorescent tube type monitor has dangerous (potentially deadly) high voltage (HV) (and so does anything you plug into the mains voltage) so be very careful not to get shocked. If you are not comfortable with high voltage, get help from someone who is.

One of my found trash monitors must have had a 24V DC power supply that plugged into it. To power the backlight, an "18.5V" laptop brick power adapter worked fine. But I needed to figure out how to enable the lamp. To do that, I measured the voltages on the lines going to the HV board when it momentarily flashed on on power-up, and found that the brown wire had a 3.6V enable signal on it. When I spoofed this with a 3.5 or 5V power supply, I could make the backlight illuminate and stay on as long as the line was held high. So I used a 10k trimpot as a voltage divider to make this 3.6V signal and fed it to the brown wire any time the brick is plugged in. You can use two resistors once you know what your trimpot needs to be set to to get the right voltage from your power supply. In my case, it was actually:

19.7V ---/\/\/\/\---3.6V---/\/\/\/\---0V

------------7.7k------------1.7k-----

I was able to remove all the circuitry from this monitor except the HV board.

For another monitor, the HV and mains power supplies were one board, and this just required a pull-up resistor tied to a line that happened to have 5V on it. Once you have figured out the bare minimum circuitry you need, it is a good idea to remove unneeded circuits, as well as any excess hardware, to make the whole window apparatus lighter and less cumbersome.

DIY Perks shows how to hack LED-based laptop screens to bypass the PWM signal that would normally control the backlight brightness. This beautifully done video was the inspiration for my garage window project using fluorescent-lamp (CCFL) computer monitors here.

Step 4: Build Your Window Frame

I used planed and sanded 50x50mm pine timbers but you can use whatever material suits your budget and aesthetics. This was V1.0 of the window-like lamp and I am sure I will build more with nicer wood in the future. Of course, you can also get creative with other materials, but I wanted to make something that was pretty easy to screw together in an evening. For safety reasons, I left a lot of metal casing on the monitors which made things very heavy, so having a sturdy frame was important here. If you strip your monitors to the minimum, especially if you are using laptop monitors, your frame could be much lighter, or you could even have no frame at all, like in the DIY Perks video.

Measure up your monitors to determine the size of each pane in your window frame. You want the wood to cover the borders of the lightboxes by a few mm at least, when they are mounted behind the frame. And if you mount them as described below, you will need about 1cm of space between each screen, and around the outer edges of each screen, to anchor them to the frame.

I cut the pieces to size very quickly with a reciprocating saw, but as a result the ends are not very square. Use a chop saw or mitre saw and do it right.

I drilled pilot holes through the top and bottom pieces and screwed long 10cm wood screws through them and into the vertical beams, two screws per joint. It helps to have a right-angle clamp to do this. Using screws (with pilot holes) avoids splitting wood, and is much stronger than using nails. And it can be disassembled if needed for some reason.

Once the outer square was assembled, I used it to mark the timber to cut the centre pieces to the correct lengths. I was not working at a very high level of precision or accuracy, so I did not trust that I could measure and cut all pieces before any assembly and have it actually come together. Using a partially assembled part to measure the next part is a hacker strategy I often use.

The two horizontal pieces were screwed as above with 10cm screws from the outer vertical pieces, and with angled screws hidden in back, to the centre post. As you can see, I made the top longer to accommodate different sized venetian blinds.

Step 5: Apply Finish to the Frame

I created a lot of extra work for myself by attaching the monitors to the frame before finishing it. I had to mask them off with masking tape and paper, which did not work perfectly and was a lot of work to remove. So if you will be painting, staining, varnishing or otherwise applying messy liquids to your window frame, do it before you attach anything to it. Be sure to sand down any sharp edges, blemishes or splinters before applying finish, of course.

Step 6: Attach Monitor Backlights to the Frame

I used galvanised steel strap and wood screws to hold the monitors securely to the wood frame. One monitor had flanges that I could use to put wood screws through directly, so it was not strapped. The other three I strapped with two straps, one horizontal and one diagonal. Wear goggles or a face shield when cutting steel strap with tin snips, as it may spring and cut your face. Straps were tightened using long wood screws at their centre points, and anchored with two or three screws at their ends.

I combined all the power cables into one by soldering them and insulating with heat-shrink tubing. Pay careful attention to which line is live vs. neutral here, or you may get 230V between two monitor casings: shock hazard. I had some American cables and some UK cables to combine. Here is the colour code:

EU/UK:

Neutral is BLUE or BLACK

Live is BROWN or RED

Earth is GREEN or GREEN/YELLOW

USA:

Neutral is WHITE

Live is BLACK

Ground is GREEN

Note how US black should not connect to EU/UK black!

I attached the power brick to the back of one monitor with Sugru.

Add wood spacers that are taller than the thickness of the electronics, so they do not bump the wall. I glued little blocks of wood to the back of the frame near the 4 corners with 5-minute epoxy. These are also good to protect the monitors if you are laying the window flat on the floor, moving or storing it. You might want instead to add flashing or thin plywood to hide the electronics. That is, make the frame go all the way to the wall along all its visible sides, so that it looks more like a window that is actually mounted in the wall.

Step 7: Add Hardware for Blinds and Hanging

I got some inexpensive PVC venetian blinds at B&Q, after trying aluminium blinds and deciding I would rather have more light shining through the slats. I also like the narrower blinds that only just cover the monitors and show some of the vertical sides of the window frame. The PVC slats are a bit translucent, so lit up even when fully closed. I mounted the anchoring hardware that came with the blinds to the top bar of the frame. This is analogue brightness control! You are welcome to get sophisticated and use dimming circuitry, which would be easy if you are using LED-based monitors (pulse-width modulation). The monitors' built-in brightness controllers may still be working, too. I wanted them at max brightness anyway.

Figure out where the centre of gravity of your assembly is, and add strong hooks or eye bolts to the top bar in such a way that it hangs vertically, not with its base tilted toward or away from the wall. I failed to do that, and had to glue the two bottom spacer feet to the wall with Sugru to make it hang properly. My window weighs about 30kg. I used 2mm steel cable running through the two eyebolts and up to two very strong concrete anchors, penetrating about 60mm into the cinder block wall of my garage. Loops were made on the two ends of the steel cable using steel cable clamps. By running the cable through two eyebolts, the whole thing can be levelled easily once hung. Test these cable clamps for being really tight before depending on them to hold up your artwork. Drilling the holes for the anchor bolts required a 16mm masonry bit and some sweat. I hope you have a hammer drill, goggles, and earplugs. And use some improvised "drinking straw" attachment to your shop vac to suck out all the concrete dust from the drilled holes before inserting the anchors. I foolishly used the blower attachment and got a lot of dust everywhere.

If you are mounting the frame on a drywall or plaster wall, it would be a good idea to find the studs behind the wall with a stud finder (or your smartphone with a stud finder app) and anchor them to two studs with long wood screws or lag bolts. If you just mount it to the drywall, you MUST use sturdy toggle bolt anchors and be sure they expand and catch behind the drywall. Plastic anchors will pull out.

Step 8: Hang and Adjust Window

Get some help to hang the window on its anchors. Adjust the length of the cable to get it at the height that suits you and your space, and use a spirit level or a spotter standing back a bit to be sure it is level. There were a million warnings about accidental strangulation of children on the blinds pulls, so be sure to cut off excess string. I actually crocheted mine to make them shorter and give a nice grip to pull them up with.

I am sure you will have ideas about improvements to be made; post them in the comments! And if you made one, please post a photo of it here, or your own Instructable.