One of the problems I encountered a number of times while traveling is that I couldn't find any socket. For example, hostels tend to have too few sockets to meet the demands of the guests. So I thought about it and got the insight that actually electricity is pretty much everywhere, you just can't use or access it: car batteries, street lights, lamps etc. This little converter turns a lamp socket into a useful power point. I made 2 versions whereby in the second version the size was significantly reduced. That way it'll fit easily in any backpack!
Step 1: Tools and Supplies
- Hand saw
- Heat gun (optional)
- Clamp (optional)
- Super glue
- Light bulb (I used a E27 here) (obviously preferably a dead light bulb)
- Female connector to attach to a extension cord (is there even a name for it in English?? Have been searching for a while, but can't find it :( In dutch it would be 'contrastekker')
- Strong tape
- Small piece of wood (to use with the clamp)
- Inner tire of a bicycle (optional)
Step 2: Demount the Light Bulb
I started this project with by breaking apart a regular E27 LED light bulb, but later I found out that these energy saving lamps are way better for two reasons: It appeared that there were already wires mounted to the contact points of the fitting and the metal parts were glued to a plastic casing (instead of glass in case of the LED light bulb). During the steps it will become clear why this is beneficial. So let's start!
A - Breaking the glass
CAUTION! Be sure that you use a energy saving lamp that uses xenon instead of mercury! Mercury vapor could cause some serious health issues!
That being said, it's glass that you're trying to break, so it's wise to wear glasses to protect your eyes. Don't worry too much, this is the most dangerous thing you'd be doing by building the lamp base socket ;). After this step, it should look something like the added picture.
B - Get rid of the unnecessary stuff
First, cut the ring that's mounted on top. Now the electrical circuit of the energy saving lamp is clearly visible. Remove the electrical circuit, but do it carefully: there are delicate wires between the fitting and the circuit board. If you manage to keep them in one piece, it saves you a lot of trouble since mounting new wires is kind of a pain in the ass due to the small spaces. (Actually, I accidentally pulled one of the wires out, but since it was the wire to the outer contact point of the fitting, it was quite easy to fix as you will see in the next step. But really, just make sure you don't, it just saves work and trouble ;) ).
Step 3: Adjusting the Female Connector
Since the female connector casing was a bit bigger, it needed to be adjusted. I used a hand saw for it. Just make sure that you leave enough so that it would fit into the light bulb's casing and that you don't damage any of the electrical connections.
Step 4: Wiring
Just one thing to keep in mind is the type and thickness of the wire you use. I will mainly use the lamp base socket to charge my phone or bluetooth speaker. Those appliances won't draw a crazy amount of current from the grid, but if you're planning to use it for heavy duty devices, I recommend to use thicker wires than the ones I used, which is 22AWG solid core.
A - Soldering the two wires together
If you're lucky you may actually be able to use the original wires of the light bulb to connect them directly to the female connector. In my case, you can see that it is just out of reach and so I needed to solder just a bit of extra wire to the wire of the light bulb.
B - Isolate the solder joint
Use tape or heat shrink tubing to isolate the solder joint. Safety first.
C - Mounting a new wire
As said, I messed up by pulling the electrical circuit instead of cutting the wires between the fitting and the electrical circuit. So I had to figure out a way of mounting a new wire in that place. Instead of connecting it on the inside of the fitting I decided to make a tiny hole in the plastic and pull the wire through there since the outside is much easier to reach than the inside. Heating up a piece of iron wire and pushing it through the plastic worked just fine. After pulling the new wire through the hole and soldering it to the fitting, it actually didn't look too bad if you'd ask me!
D - Connect the wires to the female connector
Cut a part of the new wires if it's needed and mount them to the female connector. Pushing the female connector into the light bulb part gives an idea of how it will look in the end. This is the moment that you may still want to adjust the length of the female connector. If not, let's finish it up.
Step 5: Finishing the Lamp Base Socket
Actually, the thing should already be working by now. But if you put it in a backpack like this, it will break very quickly so let's finish it up. I'll show two ways here that work quite well. Method 1 is faster, but not so robust as method 2.
Method 1 - Strong tape
Use some force (or a clamp) to push the two pieces together and use strong tape to mount the two pieces together. It will work, but I recommend not to do it this way since it will probably break fast.
Method 2 - Glue
In the picture you can see that there is a gap between the two pieces since they won't fit perfectly into each other. So use a heat gun to soften the plastic and due to the pressure of the clamp it will reshape on the pressure points. Now the gap is pretty much gone and the pieces fit better together, it's time to apply the super glue/ second glue. Don't save on the amount you apply: The gap could still be fairly big at some points. While the glue dries you could cut a piece of inner tire of a bicycle to cover up the seam. Now the Lamp Base Socket is done!