Simple Monitor Backlight




Introduction: Simple Monitor Backlight

About: Educator, entrepreneur, photogeek.

Having a backlight to your monitor reduces eyestrain. I used to use my flexible desklamp aimed at the wall behind my monitor, but that meant I couldn't use it on my workspace. While at our local big box hardware store the other day I saw these cool lightbulbs and thought it would be fun to use one as the backlight. A few bucks and a short time later I was set up.

It's bright (clear 40W bulb) and you wouldn't want to look directly at it, but I like the retro look to it. Of course, you can use any lightbulb in it and be greener using a CFL.

Step 1: Parts and Tools

The parts list is pretty short, and under $10 new. You can likely scrounge all of the parts.
    1. Porcelain Lampholder - these are made to attach to a ceiling box, so you can't stand it directly on your desk.
    2. Electrical cord - I bought a 6' extension cord and cut off the outlet end.
    3. Inline rotary switch - this gets added to the extension cord.
    4. Lightbulb - your choice.
    5. 4" square of 3/4" wood (I used MDF, but anything will work).
    6. Paint (for the wood base).
    7. Feet for the base (I used vinyl bumpers that I had extra from another project).
    8. A couple screws to attach the lampholder to the base.

    1. Screwdriver.
    2. Wirecutters.
    3. Drill with 1/4" bit (or a size that the cord can fit through).
    4. Router (or get creative with the drill).

Step 2: Prep the Cord

If you're using an extension cord, cut of the outlet end - you don't need it.

In line rotary switches are simple to install. In this case, the cord was bigger than the switch was designed for, so I used a rattail file to enlarge the hole.

Split the wire for about 3/4" where you want the switch to go (mine is about 18" from the now raw end). Snip one of the wires, insert in the opened switch and screw it back together. The switch has a couple of prongs that poke through the insulation to connect to the wire inside.


Step 3: Wood Base

The lampholder is made to attach to a ceiling box, so it won't stand level on it's own, and the wires are exposed. You need a base!

A piece of 3/4" wood about 4" square works perfectly. I used MDF because I had some sitting around and it's very easy to work with.

Screw the lampholder to the center of the wood, but not too tight. You want to use it to trace a circle that you'll cut out. Also, mark where the screws hit the base - this will need to be routed out.

Cut out a channel for the screws to sit in. I used a router set to cut about 1/2" deep, and cut a large enough channel for the screws while avoiding the holes that are used to screw the lampholder onto the base. 

Do a rough cut of the circle, to remove most of the extra wood. To get a perfect match, attach the lampholder to the base and sand right up to the side of it. I used a rotary table mounted sander and it did the job very easily.

Drill a 1/4" hole from the side of the base into the center - this is where the cord will feed in. To decide where I wanted the hole, I attached the lampholder and screwed in the lightbulb. The bulb I'm using casts a very strong shadow from the rod that holds the long filament. I didn't want that shadow on the wall, so I drilled the cord hole directly opposite where the rod is - that way the shadow is coming towards me and the cord goes out the back.

Next, paint the base. Mine is black to match my desk. If you're using MDF, you need to seal the sides first, otherwise it will just soak in the paint like a sponge and you'll never get a smooth finish. Here's a great article about using drywall compound as filler: I gave it a grey primer coat and two coats of black glossy paint.

Finally, stick some feet on the bottom to protect your desk.

Step 4: Wire It Up. Done!

Feed the cord through the hole, screw the wire ends to the terminals. 

Screw the lampholder onto the base. Install lightbulb (should take only one of you).


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    9 years ago on Introduction

    This is so elegant and simple. Thanks for the instructable.
    I have seen lamp cords with rotary switches built in and bare wires at the end, if this helps anyone thinking about doing a similar project. I know I have been inspired!


    9 years ago on Introduction

    I have an even better solution to this problem, and its free too! I heard about this while on a forum and ever since I have been using it it awesome and it really works. (i do not work for them but this i have to give them credit for)


    Reply 9 years ago on Introduction

    Thanks for the link. That app changes the color balance of your screen depending on time of day. My monitor is calibrated for photography, so that would mess it up. Also, lighting behind your monitor (not the color of the screen) is what reduces eye strain.


    9 years ago on Introduction

    For everyones safety: Are you sure the Inline rotary switch is meant for 110/220V?
    I´ve only seen them for 12V-lamps? Otherwise a cool project! A LED-lamp is a good alternative and new types are cool retro-looking too.


    Reply 9 years ago on Introduction

    I double checked, and the one I used is made for 120v.