Introduction: Retro Fit a Desk Lamp With LEDs

This instructable details the steps I have performed to change a desk lamp I already had to use LEDs instead of a fluoro tube.

This project cost me at this time $49.95 Australian for the strip of 30 LEDs.
I already had the desk lamp. If i had to buy it it would have cost me ~ $40 Australian. As the LED strip is geared for 12V I used a power pack / wall wart I had spare. If I had to buy a wall wart I guess it would have cost me anoth ~ $20 Australian.

So I guess you could argue that this project really cost ~ $110 Australian which is roughly $75 US.

Check out the individual steps to see what I have done to end up with a quite passable LED desklamp.

Step 1: All the Bits

Just a quick list of all the bits I used.

- Ikea desk lamp (worth about $40 Australian)
- Old wall wart providing up to 1.4A at 12V (less amps will probably still work ok)
- Double sided mounting tape.
- Strip of 30 SMD LEDs

Step 2: Disassembling the Desk Lamp

First up I removed the cover on the lamp head to check out what's inside and what can be re-used for this project (or later projects).

Image 1
How the lamp head looks before the surgery.

Image 2
Remove the two screws and the wing nut. This will allow you to remove the bottom cover.

Image 3
The bottom cover is off and the switch and base for the fluoro tube can be clearly seen.

Image 4
As you can see, the switch has not got any srew terminals for the electrical connections. The terminals are of the type where the cable is pushed in and is locked in place automatically.
To release the cables I had to carefully push in with a small screw driver to release the cable lock.

Image 5
View of the switch and a short piece of cable I reused due to the new cable not being fat enough to lock in the switch terminals.

Step 3: Preparring the LED Bits.

The LED strip I bough was way to long to fit into the head of the desk lamp I had. Luckily the strip can be cut into shorter pieces at a number of locations along the strip. I cut my strip into three lengths of very roughly the size and re-soldered the bits back together in series the same as they would have been connected if I hadn't cut the strip into pieces.

Step 4: Threading the New Power Cable Through the Arms

Make sure that you attach a string of some sort to the old power cable before you pull it out of the arms. This string will make it so much easier to thread through the new power cable.

Once the old power cable has been removed and the string is in place, sticky tape the new power cable to the string and gently pull the new cable trough the arms.

Step 5: Connecting and Mounting the LED Strips

I now connected (soldered) the cable carrying the negative pole directly to the negative lead on the LED strips.

The positive lead from the wall wart and the LED strips I connected to the two terminals on the light switch.

Where ever I soldered two cables together I used some shrink tubing to provide insulation.

Lastly I wound the surplus cable neatly around the two posts provided to make for a tidier look.

Step 6: Test Drive

Next up some images of the test drive before final assembly.

Step 7: Final Assembly and Final Test Drive

After the initial test drive I screwed on the bottom cover again which made it all look neat and tidy again.

I have found during many of my projects that you can not have to many test drives. Some projects have worked through all the test drives but failed after the final assembly.

Step 8: Old New Desk Lamp Back on My Desk

And here you go. My desk lamp is now using LEDs It feels as bright as the old fluoro set-up.
The good thing though with the LED set-up is that I made it work... :-)

erm .... and it also uses less power. 2.4W as opposed to 9W.