LED Filament Lamp

LED's come in all shapes and sizes these days and one of my favourites are LED filaments. You might have seen them in those knock off Edison light globes which use a 30mm LED filament instead of actual wire filaments.

Inside the filament is a row of tiny LED's covered with a flexible material. They run off 3V's and are super bright.

The lamp I built in this 'ible utilizes 120mm yellow LED's (you can get them in 300mm lengths and they come in a variety of colours) and runs off a 5V wall adapter. The main body of the lamp is made from brass tubing and copper pipe

I incorporated a dimmer module too which also acts as an on/off switch.

The light given off by the LED's is diffused using some plastic 'opal' coloured tubing and creates a beautiful ambient light.

Hackaday have also done a review on the build which can be found here

Let's get started...

You don't need many supplies for the build and most parts are available on-line.

PARTS:

1. Bass tubing - 5.56mm (7/32") SKU - KS8130 - Amazon Aust, Amazon US
2. White Polystyrene Tube - 4.8mm (3/16") - Available at most hobby shops. Just put into google - Evergreen 226 tube and you'll find it.
3. LED Filaments (2). I used yellow but you could use any colour you want - Ali Express
4. Dimmer Module - Ali Express
5. 10R resistor - Ali Express
6. 1uF capacitor - Ali Express
7. Thin copper wire - Ali Express
8. 50 Copper Tube (for the base) - your local hardware or plumbing store should have some.
9. Small piece if wood. Whatever you have lying around really. I had some wood I found at the beach and used that.

TOOLS:

1. Pipe cutter (to cut the brass tube)
2. Soldering iron
3. Good quality tape (I used fabric tape)
4. Fine Sand (used to bend the tube)

In a build like this it is always to test out how the LED's light up. I powered everything using a 5V wall adapter (the same one your phone uses)

STEPS:

1. The first thing I did was to see how much voltage was put out of the dimmer module. I connected it to 5V and tested with my multimeter. I found that at full power the output was just over 3V. I knew that the LED's worked on 3V so I added a 10 ohm resistor and that brought the power down to about 2.8V which was perfect.
2. Without the resistor, I found that the LED's start to heat up which is not a good thing to happen to any part - especially LED's!
3. I also added a 1uF cap across the power smooth it out.
4. I connected the dimmer module to 5V wall adapter and testing everything to make sure it worked as expected.

Check step 8 out for a wiring diagram

I used the sand method to bend the tube. This is where you add sand inside the tube to enable to bend it.

STEPS:

1. First - cut off a length of tube about 200mm long. I like to use a tube cutter to do this as it give you a nice, straight cut
2. Tape up one of the ends well using some good quality tape. I used fabric tape to do this.
3. Place the brass tube in a vice to hold it vertical.
4. Create a small funnel out of paper so you can pore the sand into the tube. Tape it onto the tube so it doesn't move about.
5. Fill up the tube with fine sand and every now and then give it a good tap on something hard to make sure the sand fills all of the tube.
6. Tape up the other end once full.

STEPS:

1. You need to use something round to bend the tube over. I used a heavy metal weight which made a good tool to bend the tube over.
2. Place the tube across the top of the round shape you are using and start to add pressure to each side of the tube and make a small, initial bend.
3. Move the tube slightly and make another small bend. Then move the tube back to the initial bend and continue to slowly and carefully bend the tube.
4. Don't worry if you do mess it up the first time, I managed to get a kink on my first try and had to redo it. The thing to remember is to go slowly and you should be fine
5. Keep on adding pressure and bending the tube until you have a U bend shape
6. Remove the tape and empty out the sand
7. Do this twice and then cut the U bends so they are the same length at each ends

Once you have made the U bends, you next need to cut the opal tubing and make sure everything fits as it should

STEPS:

1. The LED's are 120mm in length. I decided to cut the opal tubing to 150mm in length which gave me 15mm on either side to secure it into the brass tubing
2. If you use a tube cutter to cut the brass tube then you will need to de-burr the insides of the tube. You can use a file for this or a be-burring tool if you have one.
3. Place the opal tubing inside the brass tube and ensure that the lamp goes together as it should

I used thin copper wire to connect everything up which worked well. Copper wire is threaded through the plastic tubing as well for the ground connection. If the wire is too thick it might affect the light from the LED's.

Refer to the wiring diagram as it explains how to wire up the lamp better than I can!

STEPS:

1. You need to connect the ground on the LED's together. Solder some copper wire to one of the grounds on the LED and add some heat shrink to the end
2. Thread the copper wire through one of the U bends and solder to ground on the other LED. You also need to attach a longer length of wire to the same ground so do this and then add some heat shrink. This longer piece will be connected to ground on the dimmer module.
3. Before wiring up the positive end of the LED's, drill a hole into the bottom of the U bend. This is where the neck of the lamp will be soldered and also where the ground and positive wires from the LED's will come out of.
4. On one of the positive ends of the LED's, solder another piece of copper wire, thread through the copper tubing and connect to the positive end of the other LED. Also solder on another longer piece. This will be connected to positive on the dimmer.
5. Thread both the ground and positive wires through the hole in the bottom of the U bend. It's hard to make any adjustments once this is done so make sure that the LED's are aligned with the opal tubing.
6. Push the brass tube onto the opal tubing.

I was concerned about soldering the neck of the lamp to the main body. My biggest worry was stripping the coating off the copper wire and it was heated up inside the brass tube. However, by carefully applying heat I managed to pull it off!

STEPS:

1. To ensure the the neck fits correctly to the main body of the lamp, you need to make a round groove in the top of the brass tube. I used a small, round file to do this
2. Next, thread the copper wire through the brass tube (neck) and place the lamp on a level surface. I used a couple heat resistant bricks and left a gap where I needed to solder.
3. Add a little flux to the joint.
4. Slowly and carefully start to apply heat around the area that needs to be soldered. Once the area is heated enough, add the solder to the joint.

For the base I was going to use some wood but decided to use some 50mm copper tubing. It was a lot easier then having to hollow out the wood and it worked well with the overall ascetics. I did add a little bit of wood which is used as a surface to attach the neck of the lamp to.

STEPS:

1. First, cut a piece of 50mm copper tube to the desired height. Mine was about 150mm height.
2. Give it a polish if you want to as well.
3. For the wood top section, I used a piece of drift wood I found at the beach! It has a nice grey patina on the surface which I thought worked well with the rest of the look of the lamp. Place the copper tube on top of the wood and trace around it
4. Cut out the circle so you have it roughed out
5. To make it round, I used a belt sander and used the sander wheel to make it round. If you take your time and don't add too much pressure, you should be able to make almost perfectly round.
6. Next, drill a hole into the into the centre of the wood. It should be the size of the brass tube used to build the lamp.
7. Keep checking until you find that the wood starts to go inside the tube. Use a mallet if necessary to get it inside the copper tube.
8. I also added a little superglue to the inside to secure it into place
9. You need to drill 2 holes into the tube, one for the potentiometer and one for the power cord.
10. The last thing to do is to push the neck of the lamp into the wood and secure it into place. I didn't need to use any gue as it was a good, tight fit.

At the home stretch now. The last thing to do is to wire up and attach the dimmer module to the lamp.

STEPS:

1. The first thing to do is to add the resistor and capacitor to the module. The module has 4 connectors, 2 are to connect power to and the other 2 are for connecting the the wires from the LED's.
2. In the 3rd image you can see the module upside down. Let's number each of connectors 1 to 4 starting from left to right.
3. Power is added to connectors 1 & 4 and the LED wires are added to 2 & 3.
4. Back to the cap and resistor. The capacitor should be added to the connectors that the power (1 & 4)
5. Add one leg of the resistor connector 2.
6. Before adding the wires from the LED's, make sure you strip the enamel off the ends by using a small file
7. Place the ground into connector 3 and solder the positive to the end of the resistor
8. Cut one end of the USB cord (the cord I used had 2 USB connectors so I just cut one off), strip and tin the ends of the wire. Thread this through the hole in the copper tube.
9. Connect the positive to connector 1 and ground to connector 4.
10. Secure the potentiometer inside the copper tube and add a knob to the end.
11. Lastly, add a small cable tie to the USB wire inside the copper tube. This will stop it from being pulled out.

Congrats - you're done!